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38f8b050 1/* Target hook definitions.
cbe34bb5 2 Copyright (C) 2001-2017 Free Software Foundation, Inc.
38f8b050
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3
4 This program is free software; you can redistribute it and/or modify it
5 under the terms of the GNU General Public License as published by the
6 Free Software Foundation; either version 3, or (at your option) any
7 later version.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; see the file COPYING3. If not see
16 <http://www.gnu.org/licenses/>.
17
18 In other words, you are welcome to use, share and improve this program.
19 You are forbidden to forbid anyone else to use, share and improve
20 what you give them. Help stamp out software-hoarding! */
21
acce4e77
JM
22/* See target-hooks-macros.h for details of macros that should be
23 provided by the including file, and how to use them here. */
24#include "target-hooks-macros.h"
38f8b050 25
acce4e77
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26#undef HOOK_TYPE
27#define HOOK_TYPE "Target Hook"
38f8b050 28
acce4e77 29HOOK_VECTOR (TARGET_INITIALIZER, gcc_target)
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30
31/* Functions that output assembler for the target. */
32#define HOOK_PREFIX "TARGET_ASM_"
33HOOK_VECTOR (TARGET_ASM_OUT, asm_out)
34
35/* Opening and closing parentheses for asm expression grouping. */
36DEFHOOKPOD
37(open_paren,
673c2f63
JM
38 "These target hooks are C string constants, describing the syntax in the\n\
39assembler for grouping arithmetic expressions. If not overridden, they\n\
40default to normal parentheses, which is correct for most assemblers.",
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41 const char *, "(")
42DEFHOOKPODX (close_paren, const char *, ")")
43
44/* Assembler instructions for creating various kinds of integer object. */
45DEFHOOKPOD
46(byte_op,
673c2f63
JM
47 "@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_HI_OP\n\
48@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_SI_OP\n\
49@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_DI_OP\n\
50@deftypevrx {Target Hook} {const char *} TARGET_ASM_ALIGNED_TI_OP\n\
51@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_HI_OP\n\
52@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_SI_OP\n\
53@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_DI_OP\n\
54@deftypevrx {Target Hook} {const char *} TARGET_ASM_UNALIGNED_TI_OP\n\
55These hooks specify assembly directives for creating certain kinds\n\
56of integer object. The @code{TARGET_ASM_BYTE_OP} directive creates a\n\
57byte-sized object, the @code{TARGET_ASM_ALIGNED_HI_OP} one creates an\n\
58aligned two-byte object, and so on. Any of the hooks may be\n\
59@code{NULL}, indicating that no suitable directive is available.\n\
60\n\
61The compiler will print these strings at the start of a new line,\n\
62followed immediately by the object's initial value. In most cases,\n\
63the string should contain a tab, a pseudo-op, and then another tab.",
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64 const char *, "\t.byte\t")
65DEFHOOKPOD (aligned_op, "*", struct asm_int_op, TARGET_ASM_ALIGNED_INT_OP)
66DEFHOOKPOD (unaligned_op, "*", struct asm_int_op, TARGET_ASM_UNALIGNED_INT_OP)
67
ad0c4c36
DD
68/* The maximum number of bytes to skip when applying
69 LABEL_ALIGN_AFTER_BARRIER. */
70DEFHOOK
71(label_align_after_barrier_max_skip,
673c2f63
JM
72 "The maximum number of bytes to skip before @var{label} when applying\n\
73@code{LABEL_ALIGN_AFTER_BARRIER}. This works only if\n\
74@code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.",
9158a0d8 75 int, (rtx_insn *label),
ad0c4c36
DD
76 default_label_align_after_barrier_max_skip)
77
78/* The maximum number of bytes to skip when applying
79 LOOP_ALIGN. */
80DEFHOOK
81(loop_align_max_skip,
673c2f63
JM
82 "The maximum number of bytes to skip when applying @code{LOOP_ALIGN} to\n\
83@var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN} is\n\
84defined.",
9158a0d8 85 int, (rtx_insn *label),
ad0c4c36
DD
86 default_loop_align_max_skip)
87
88/* The maximum number of bytes to skip when applying
89 LABEL_ALIGN. */
90DEFHOOK
91(label_align_max_skip,
673c2f63
JM
92 "The maximum number of bytes to skip when applying @code{LABEL_ALIGN}\n\
93to @var{label}. This works only if @code{ASM_OUTPUT_MAX_SKIP_ALIGN}\n\
94is defined.",
9158a0d8 95 int, (rtx_insn *label),
ad0c4c36
DD
96 default_label_align_max_skip)
97
98/* The maximum number of bytes to skip when applying
99 JUMP_ALIGN. */
100DEFHOOK
101(jump_align_max_skip,
673c2f63
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102 "The maximum number of bytes to skip before @var{label} when applying\n\
103@code{JUMP_ALIGN}. This works only if\n\
104@code{ASM_OUTPUT_MAX_SKIP_ALIGN} is defined.",
9158a0d8 105 int, (rtx_insn *label),
ad0c4c36
DD
106 default_jump_align_max_skip)
107
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108/* Try to output the assembler code for an integer object whose
109 value is given by X. SIZE is the size of the object in bytes and
110 ALIGNED_P indicates whether it is aligned. Return true if
111 successful. Only handles cases for which BYTE_OP, ALIGNED_OP
112 and UNALIGNED_OP are NULL. */
113DEFHOOK
114(integer,
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115 "The @code{assemble_integer} function uses this hook to output an\n\
116integer object. @var{x} is the object's value, @var{size} is its size\n\
117in bytes and @var{aligned_p} indicates whether it is aligned. The\n\
118function should return @code{true} if it was able to output the\n\
119object. If it returns false, @code{assemble_integer} will try to\n\
120split the object into smaller parts.\n\
121\n\
122The default implementation of this hook will use the\n\
123@code{TARGET_ASM_BYTE_OP} family of strings, returning @code{false}\n\
124when the relevant string is @code{NULL}.",
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125 /* Only handles cases for which BYTE_OP, ALIGNED_OP and UNALIGNED_OP are
126 NULL. */
127 bool, (rtx x, unsigned int size, int aligned_p),
128 default_assemble_integer)
129
dc2af904
BS
130/* Notify the backend that we have completed emitting the data for a
131 decl. */
132DEFHOOK
133(decl_end,
134 "Define this hook if the target assembler requires a special marker to\n\
135terminate an initialized variable declaration.",
136 void, (void),
137 hook_void_void)
138
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139/* Output code that will globalize a label. */
140DEFHOOK
141(globalize_label,
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142 "This target hook is a function to output to the stdio stream\n\
143@var{stream} some commands that will make the label @var{name} global;\n\
144that is, available for reference from other files.\n\
145\n\
146The default implementation relies on a proper definition of\n\
147@code{GLOBAL_ASM_OP}.",
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148 void, (FILE *stream, const char *name),
149 default_globalize_label)
150
151/* Output code that will globalize a declaration. */
152DEFHOOK
153(globalize_decl_name,
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JM
154 "This target hook is a function to output to the stdio stream\n\
155@var{stream} some commands that will make the name associated with @var{decl}\n\
156global; that is, available for reference from other files.\n\
157\n\
158The default implementation uses the TARGET_ASM_GLOBALIZE_LABEL target hook.",
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159 void, (FILE *stream, tree decl), default_globalize_decl_name)
160
0d4b5b86
BS
161/* Output code that will declare an external variable. */
162DEFHOOK
163(assemble_undefined_decl,
164 "This target hook is a function to output to the stdio stream\n\
165@var{stream} some commands that will declare the name associated with\n\
166@var{decl} which is not defined in the current translation unit. Most\n\
167assemblers do not require anything to be output in this case.",
168 void, (FILE *stream, const char *name, const_tree decl),
169 hook_void_FILEptr_constcharptr_const_tree)
170
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171/* Output code that will emit a label for unwind info, if this
172 target requires such labels. Second argument is the decl the
173 unwind info is associated with, third is a boolean: true if
174 this is for exception handling, fourth is a boolean: true if
175 this is only a placeholder for an omitted FDE. */
176DEFHOOK
177(emit_unwind_label,
673c2f63
JM
178 "This target hook emits a label at the beginning of each FDE@. It\n\
179should be defined on targets where FDEs need special labels, and it\n\
180should write the appropriate label, for the FDE associated with the\n\
181function declaration @var{decl}, to the stdio stream @var{stream}.\n\
182The third argument, @var{for_eh}, is a boolean: true if this is for an\n\
183exception table. The fourth argument, @var{empty}, is a boolean:\n\
184true if this is a placeholder label for an omitted FDE@.\n\
185\n\
186The default is that FDEs are not given nonlocal labels.",
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187 void, (FILE *stream, tree decl, int for_eh, int empty),
188 default_emit_unwind_label)
189
190/* Output code that will emit a label to divide up the exception table. */
191DEFHOOK
192(emit_except_table_label,
673c2f63
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193 "This target hook emits a label at the beginning of the exception table.\n\
194It should be defined on targets where it is desirable for the table\n\
195to be broken up according to function.\n\
196\n\
197The default is that no label is emitted.",
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198 void, (FILE *stream),
199 default_emit_except_table_label)
200
a68b5e52
RH
201/* Emit a directive for setting the personality for the function. */
202DEFHOOK
203(emit_except_personality,
204 "If the target implements @code{TARGET_ASM_UNWIND_EMIT}, this hook may be\
205 used to emit a directive to install a personality hook into the unwind\
206 info. This hook should not be used if dwarf2 unwind info is used.",
207 void, (rtx personality),
208 NULL)
209
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210/* Emit any directives required to unwind this instruction. */
211DEFHOOK
212(unwind_emit,
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JM
213 "This target hook emits assembly directives required to unwind the\n\
214given instruction. This is only used when @code{TARGET_EXCEPT_UNWIND_INFO}\n\
215returns @code{UI_TARGET}.",
ac44248e 216 void, (FILE *stream, rtx_insn *insn),
2784ed9c 217 NULL)
38f8b050 218
3bc6b3e6
RH
219DEFHOOKPOD
220(unwind_emit_before_insn,
221 "True if the @code{TARGET_ASM_UNWIND_EMIT} hook should be called before\
222 the assembly for @var{insn} has been emitted, false if the hook should\
223 be called afterward.",
224 bool, true)
225
4ee3b013
JR
226/* Generate an internal label.
227 For now this is just a wrapper for ASM_GENERATE_INTERNAL_LABEL. */
228DEFHOOK_UNDOC
229(generate_internal_label,
230 "",
231 void, (char *buf, const char *prefix, unsigned long labelno),
232 default_generate_internal_label)
233
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234/* Output an internal label. */
235DEFHOOK
236(internal_label,
673c2f63
JM
237 "A function to output to the stdio stream @var{stream} a label whose\n\
238name is made from the string @var{prefix} and the number @var{labelno}.\n\
239\n\
240It is absolutely essential that these labels be distinct from the labels\n\
241used for user-level functions and variables. Otherwise, certain programs\n\
242will have name conflicts with internal labels.\n\
243\n\
244It is desirable to exclude internal labels from the symbol table of the\n\
245object file. Most assemblers have a naming convention for labels that\n\
246should be excluded; on many systems, the letter @samp{L} at the\n\
247beginning of a label has this effect. You should find out what\n\
248convention your system uses, and follow it.\n\
249\n\
250The default version of this function utilizes @code{ASM_GENERATE_INTERNAL_LABEL}.",
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251 void, (FILE *stream, const char *prefix, unsigned long labelno),
252 default_internal_label)
253
254/* Output label for the constant. */
ad78130c 255DEFHOOK
38f8b050 256(declare_constant_name,
673c2f63
JM
257 "A target hook to output to the stdio stream @var{file} any text necessary\n\
258for declaring the name @var{name} of a constant which is being defined. This\n\
259target hook is responsible for outputting the label definition (perhaps using\n\
260@code{assemble_label}). The argument @var{exp} is the value of the constant,\n\
261and @var{size} is the size of the constant in bytes. The @var{name}\n\
262will be an internal label.\n\
263\n\
264The default version of this target hook, define the @var{name} in the\n\
265usual manner as a label (by means of @code{assemble_label}).\n\
266\n\
267You may wish to use @code{ASM_OUTPUT_TYPE_DIRECTIVE} in this target hook.",
ad78130c 268 void, (FILE *file, const char *name, const_tree expr, HOST_WIDE_INT size),
38f8b050
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269 default_asm_declare_constant_name)
270
271/* Emit a ttype table reference to a typeinfo object. */
272DEFHOOK
273(ttype,
673c2f63
JM
274 "This hook is used to output a reference from a frame unwinding table to\n\
275the type_info object identified by @var{sym}. It should return @code{true}\n\
276if the reference was output. Returning @code{false} will cause the\n\
277reference to be output using the normal Dwarf2 routines.",
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278 bool, (rtx sym),
279 hook_bool_rtx_false)
280
281/* Emit an assembler directive to set visibility for the symbol
282 associated with the tree decl. */
283DEFHOOK
284(assemble_visibility,
673c2f63
JM
285 "This target hook is a function to output to @var{asm_out_file} some\n\
286commands that will make the symbol(s) associated with @var{decl} have\n\
287hidden, protected or internal visibility as specified by @var{visibility}.",
38f8b050
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288 void, (tree decl, int visibility),
289 default_assemble_visibility)
290
291/* Output the assembler code for entry to a function. */
292DEFHOOK
293(function_prologue,
673c2f63
JM
294 "If defined, a function that outputs the assembler code for entry to a\n\
295function. The prologue is responsible for setting up the stack frame,\n\
296initializing the frame pointer register, saving registers that must be\n\
297saved, and allocating @var{size} additional bytes of storage for the\n\
298local variables. @var{size} is an integer. @var{file} is a stdio\n\
299stream to which the assembler code should be output.\n\
300\n\
301The label for the beginning of the function need not be output by this\n\
302macro. That has already been done when the macro is run.\n\
303\n\
304@findex regs_ever_live\n\
305To determine which registers to save, the macro can refer to the array\n\
306@code{regs_ever_live}: element @var{r} is nonzero if hard register\n\
307@var{r} is used anywhere within the function. This implies the function\n\
308prologue should save register @var{r}, provided it is not one of the\n\
309call-used registers. (@code{TARGET_ASM_FUNCTION_EPILOGUE} must likewise use\n\
310@code{regs_ever_live}.)\n\
311\n\
312On machines that have ``register windows'', the function entry code does\n\
313not save on the stack the registers that are in the windows, even if\n\
314they are supposed to be preserved by function calls; instead it takes\n\
315appropriate steps to ``push'' the register stack, if any non-call-used\n\
316registers are used in the function.\n\
317\n\
318@findex frame_pointer_needed\n\
319On machines where functions may or may not have frame-pointers, the\n\
320function entry code must vary accordingly; it must set up the frame\n\
321pointer if one is wanted, and not otherwise. To determine whether a\n\
322frame pointer is in wanted, the macro can refer to the variable\n\
323@code{frame_pointer_needed}. The variable's value will be 1 at run\n\
324time in a function that needs a frame pointer. @xref{Elimination}.\n\
325\n\
326The function entry code is responsible for allocating any stack space\n\
327required for the function. This stack space consists of the regions\n\
328listed below. In most cases, these regions are allocated in the\n\
329order listed, with the last listed region closest to the top of the\n\
330stack (the lowest address if @code{STACK_GROWS_DOWNWARD} is defined, and\n\
331the highest address if it is not defined). You can use a different order\n\
332for a machine if doing so is more convenient or required for\n\
333compatibility reasons. Except in cases where required by standard\n\
334or by a debugger, there is no reason why the stack layout used by GCC\n\
335need agree with that used by other compilers for a machine.",
38f8b050
JR
336 void, (FILE *file, HOST_WIDE_INT size),
337 default_function_pro_epilogue)
338
339/* Output the assembler code for end of prologue. */
340DEFHOOK
341(function_end_prologue,
673c2f63
JM
342 "If defined, a function that outputs assembler code at the end of a\n\
343prologue. This should be used when the function prologue is being\n\
344emitted as RTL, and you have some extra assembler that needs to be\n\
345emitted. @xref{prologue instruction pattern}.",
38f8b050
JR
346 void, (FILE *file),
347 no_asm_to_stream)
348
349/* Output the assembler code for start of epilogue. */
350DEFHOOK
351(function_begin_epilogue,
673c2f63
JM
352 "If defined, a function that outputs assembler code at the start of an\n\
353epilogue. This should be used when the function epilogue is being\n\
354emitted as RTL, and you have some extra assembler that needs to be\n\
355emitted. @xref{epilogue instruction pattern}.",
38f8b050
JR
356 void, (FILE *file),
357 no_asm_to_stream)
358
359/* Output the assembler code for function exit. */
360DEFHOOK
361(function_epilogue,
673c2f63
JM
362 "If defined, a function that outputs the assembler code for exit from a\n\
363function. The epilogue is responsible for restoring the saved\n\
364registers and stack pointer to their values when the function was\n\
365called, and returning control to the caller. This macro takes the\n\
366same arguments as the macro @code{TARGET_ASM_FUNCTION_PROLOGUE}, and the\n\
367registers to restore are determined from @code{regs_ever_live} and\n\
368@code{CALL_USED_REGISTERS} in the same way.\n\
369\n\
370On some machines, there is a single instruction that does all the work\n\
371of returning from the function. On these machines, give that\n\
372instruction the name @samp{return} and do not define the macro\n\
373@code{TARGET_ASM_FUNCTION_EPILOGUE} at all.\n\
374\n\
375Do not define a pattern named @samp{return} if you want the\n\
376@code{TARGET_ASM_FUNCTION_EPILOGUE} to be used. If you want the target\n\
377switches to control whether return instructions or epilogues are used,\n\
378define a @samp{return} pattern with a validity condition that tests the\n\
379target switches appropriately. If the @samp{return} pattern's validity\n\
380condition is false, epilogues will be used.\n\
381\n\
382On machines where functions may or may not have frame-pointers, the\n\
383function exit code must vary accordingly. Sometimes the code for these\n\
384two cases is completely different. To determine whether a frame pointer\n\
385is wanted, the macro can refer to the variable\n\
386@code{frame_pointer_needed}. The variable's value will be 1 when compiling\n\
387a function that needs a frame pointer.\n\
388\n\
389Normally, @code{TARGET_ASM_FUNCTION_PROLOGUE} and\n\
390@code{TARGET_ASM_FUNCTION_EPILOGUE} must treat leaf functions specially.\n\
391The C variable @code{current_function_is_leaf} is nonzero for such a\n\
392function. @xref{Leaf Functions}.\n\
393\n\
394On some machines, some functions pop their arguments on exit while\n\
395others leave that for the caller to do. For example, the 68020 when\n\
396given @option{-mrtd} pops arguments in functions that take a fixed\n\
397number of arguments.\n\
398\n\
399@findex pops_args\n\
400@findex crtl->args.pops_args\n\
401Your definition of the macro @code{RETURN_POPS_ARGS} decides which\n\
402functions pop their own arguments. @code{TARGET_ASM_FUNCTION_EPILOGUE}\n\
403needs to know what was decided. The number of bytes of the current\n\
404function's arguments that this function should pop is available in\n\
405@code{crtl->args.pops_args}. @xref{Scalar Return}.",
38f8b050
JR
406 void, (FILE *file, HOST_WIDE_INT size),
407 default_function_pro_epilogue)
408
409/* Initialize target-specific sections. */
410DEFHOOK
411(init_sections,
673c2f63
JM
412 "Define this hook if you need to do something special to set up the\n\
413@file{varasm.c} sections, or if your target has some special sections\n\
414of its own that you need to create.\n\
415\n\
416GCC calls this hook after processing the command line, but before writing\n\
417any assembly code, and before calling any of the section-returning hooks\n\
418described below.",
38f8b050
JR
419 void, (void),
420 hook_void_void)
421
422/* Tell assembler to change to section NAME with attributes FLAGS.
423 If DECL is non-NULL, it is the VAR_DECL or FUNCTION_DECL with
424 which this section is associated. */
425DEFHOOK
426(named_section,
673c2f63
JM
427 "Output assembly directives to switch to section @var{name}. The section\n\
428should have attributes as specified by @var{flags}, which is a bit mask\n\
429of the @code{SECTION_*} flags defined in @file{output.h}. If @var{decl}\n\
430is non-NULL, it is the @code{VAR_DECL} or @code{FUNCTION_DECL} with which\n\
431this section is associated.",
38f8b050
JR
432 void, (const char *name, unsigned int flags, tree decl),
433 default_no_named_section)
434
0ee70cc0
AV
435/* Tell assembler what section attributes to assign this elf section
436 declaration, using their numerical value. */
437DEFHOOK
438(elf_flags_numeric,
439 "This hook can be used to encode ELF section flags for which no letter\n\
440code has been defined in the assembler. It is called by\n\
441@code{default_asm_named_section} whenever the section flags need to be\n\
442emitted in the assembler output. If the hook returns true, then the\n\
443numerical value for ELF section flags should be calculated from\n\
759a6472
AV
444@var{flags} and saved in @var{*num}; the value is printed out instead of the\n\
445normal sequence of letter codes. If the hook is not defined, or if it\n\
446returns false, then @var{num} is ignored and the traditional letter sequence\n\
447is emitted.",
0ee70cc0 448 bool, (unsigned int flags, unsigned int *num),
bf072854 449 hook_bool_uint_uintp_false)
0ee70cc0 450
f16d3f39
JH
451/* Return preferred text (sub)section for function DECL.
452 Main purpose of this function is to separate cold, normal and hot
453 functions. STARTUP is true when function is known to be used only
454 at startup (from static constructors or it is main()).
455 EXIT is true when function is known to be used only at exit
456 (from static destructors).
457 Return NULL if function should go to default text section. */
458DEFHOOK
459(function_section,
673c2f63
JM
460 "Return preferred text (sub)section for function @var{decl}.\n\
461Main purpose of this function is to separate cold, normal and hot\n\
462functions. @var{startup} is true when function is known to be used only\n\
463at startup (from static constructors or it is @code{main()}).\n\
464@var{exit} is true when function is known to be used only at exit\n\
465(from static destructors).\n\
466Return NULL if function should go to default text section.",
f16d3f39
JH
467 section *, (tree decl, enum node_frequency freq, bool startup, bool exit),
468 default_function_section)
469
14d11d40
IS
470/* Output the assembler code for function exit. */
471DEFHOOK
472(function_switched_text_sections,
473 "Used by the target to emit any assembler directives or additional\
474 labels needed when a function is partitioned between different\
475 sections. Output should be written to @var{file}. The function\
476 decl is available as @var{decl} and the new section is `cold' if\
477 @var{new_is_cold} is @code{true}.",
478 void, (FILE *file, tree decl, bool new_is_cold),
479 default_function_switched_text_sections)
480
38f8b050
JR
481/* Return a mask describing how relocations should be treated when
482 selecting sections. Bit 1 should be set if global relocations
483 should be placed in a read-write section; bit 0 should be set if
484 local relocations should be placed in a read-write section. */
485DEFHOOK
486(reloc_rw_mask,
673c2f63
JM
487 "Return a mask describing how relocations should be treated when\n\
488selecting sections. Bit 1 should be set if global relocations\n\
489should be placed in a read-write section; bit 0 should be set if\n\
490local relocations should be placed in a read-write section.\n\
491\n\
492The default version of this function returns 3 when @option{-fpic}\n\
493is in effect, and 0 otherwise. The hook is typically redefined\n\
494when the target cannot support (some kinds of) dynamic relocations\n\
495in read-only sections even in executables.",
38f8b050
JR
496 int, (void),
497 default_reloc_rw_mask)
498
499 /* Return a section for EXP. It may be a DECL or a constant. RELOC
500 is nonzero if runtime relocations must be applied; bit 1 will be
501 set if the runtime relocations require non-local name resolution.
502 ALIGN is the required alignment of the data. */
503DEFHOOK
504(select_section,
673c2f63
JM
505 "Return the section into which @var{exp} should be placed. You can\n\
506assume that @var{exp} is either a @code{VAR_DECL} node or a constant of\n\
507some sort. @var{reloc} indicates whether the initial value of @var{exp}\n\
508requires link-time relocations. Bit 0 is set when variable contains\n\
509local relocations only, while bit 1 is set for global relocations.\n\
510@var{align} is the constant alignment in bits.\n\
511\n\
512The default version of this function takes care of putting read-only\n\
513variables in @code{readonly_data_section}.\n\
514\n\
515See also @var{USE_SELECT_SECTION_FOR_FUNCTIONS}.",
38f8b050
JR
516 section *, (tree exp, int reloc, unsigned HOST_WIDE_INT align),
517 default_select_section)
518
519/* Return a section for X. MODE is X's mode and ALIGN is its
520 alignment in bits. */
521DEFHOOK
522(select_rtx_section,
673c2f63
JM
523 "Return the section into which a constant @var{x}, of mode @var{mode},\n\
524should be placed. You can assume that @var{x} is some kind of\n\
525constant in RTL@. The argument @var{mode} is redundant except in the\n\
526case of a @code{const_int} rtx. @var{align} is the constant alignment\n\
527in bits.\n\
528\n\
529The default version of this function takes care of putting symbolic\n\
530constants in @code{flag_pic} mode in @code{data_section} and everything\n\
531else in @code{readonly_data_section}.",
ef4bddc2 532 section *, (machine_mode mode, rtx x, unsigned HOST_WIDE_INT align),
38f8b050
JR
533 default_select_rtx_section)
534
535/* Select a unique section name for DECL. RELOC is the same as
536 for SELECT_SECTION. */
537DEFHOOK
538(unique_section,
673c2f63
JM
539 "Build up a unique section name, expressed as a @code{STRING_CST} node,\n\
540and assign it to @samp{DECL_SECTION_NAME (@var{decl})}.\n\
541As with @code{TARGET_ASM_SELECT_SECTION}, @var{reloc} indicates whether\n\
542the initial value of @var{exp} requires link-time relocations.\n\
543\n\
544The default version of this function appends the symbol name to the\n\
545ELF section name that would normally be used for the symbol. For\n\
546example, the function @code{foo} would be placed in @code{.text.foo}.\n\
547Whatever the actual target object format, this is often good enough.",
38f8b050
JR
548 void, (tree decl, int reloc),
549 default_unique_section)
550
551/* Return the readonly data section associated with function DECL. */
552DEFHOOK
553(function_rodata_section,
673c2f63
JM
554 "Return the readonly data section associated with\n\
555@samp{DECL_SECTION_NAME (@var{decl})}.\n\
556The default version of this function selects @code{.gnu.linkonce.r.name} if\n\
557the function's section is @code{.gnu.linkonce.t.name}, @code{.rodata.name}\n\
558if function is in @code{.text.name}, and the normal readonly-data section\n\
559otherwise.",
38f8b050
JR
560 section *, (tree decl),
561 default_function_rodata_section)
562
727a65e6
BS
563/* Nonnull if the target wants to override the default ".rodata" prefix
564 for mergeable data sections. */
565DEFHOOKPOD
566(mergeable_rodata_prefix,
567 "Usually, the compiler uses the prefix @code{\".rodata\"} to construct\n\
568section names for mergeable constant data. Define this macro to override\n\
569the string if a different section name should be used.",
570 const char *, ".rodata")
571
50b0b78a
IS
572/* Return the section to be used for transactional memory clone tables. */
573DEFHOOK
574(tm_clone_table_section,
575 "Return the section that should be used for transactional memory clone\
576 tables.",
577 section *, (void), default_clone_table_section)
578
38f8b050
JR
579/* Output a constructor for a symbol with a given priority. */
580DEFHOOK
581(constructor,
673c2f63
JM
582 "If defined, a function that outputs assembler code to arrange to call\n\
583the function referenced by @var{symbol} at initialization time.\n\
584\n\
585Assume that @var{symbol} is a @code{SYMBOL_REF} for a function taking\n\
586no arguments and with no return value. If the target supports initialization\n\
587priorities, @var{priority} is a value between 0 and @code{MAX_INIT_PRIORITY};\n\
588otherwise it must be @code{DEFAULT_INIT_PRIORITY}.\n\
589\n\
590If this macro is not defined by the target, a suitable default will\n\
591be chosen if (1) the target supports arbitrary section names, (2) the\n\
592target defines @code{CTORS_SECTION_ASM_OP}, or (3) @code{USE_COLLECT2}\n\
593is not defined.",
38f8b050
JR
594 void, (rtx symbol, int priority), NULL)
595
596/* Output a destructor for a symbol with a given priority. */
597DEFHOOK
598(destructor,
673c2f63
JM
599 "This is like @code{TARGET_ASM_CONSTRUCTOR} but used for termination\n\
600functions rather than initialization functions.",
38f8b050
JR
601 void, (rtx symbol, int priority), NULL)
602
603/* Output the assembler code for a thunk function. THUNK_DECL is the
604 declaration for the thunk function itself, FUNCTION is the decl for
605 the target function. DELTA is an immediate constant offset to be
606 added to THIS. If VCALL_OFFSET is nonzero, the word at
607 *(*this + vcall_offset) should be added to THIS. */
608DEFHOOK
609(output_mi_thunk,
673c2f63
JM
610 "A function that outputs the assembler code for a thunk\n\
611function, used to implement C++ virtual function calls with multiple\n\
612inheritance. The thunk acts as a wrapper around a virtual function,\n\
613adjusting the implicit object parameter before handing control off to\n\
614the real function.\n\
615\n\
616First, emit code to add the integer @var{delta} to the location that\n\
617contains the incoming first argument. Assume that this argument\n\
618contains a pointer, and is the one used to pass the @code{this} pointer\n\
619in C++. This is the incoming argument @emph{before} the function prologue,\n\
620e.g.@: @samp{%o0} on a sparc. The addition must preserve the values of\n\
621all other incoming arguments.\n\
622\n\
623Then, if @var{vcall_offset} is nonzero, an additional adjustment should be\n\
624made after adding @code{delta}. In particular, if @var{p} is the\n\
625adjusted pointer, the following adjustment should be made:\n\
626\n\
627@smallexample\n\
628p += (*((ptrdiff_t **)p))[vcall_offset/sizeof(ptrdiff_t)]\n\
629@end smallexample\n\
630\n\
631After the additions, emit code to jump to @var{function}, which is a\n\
632@code{FUNCTION_DECL}. This is a direct pure jump, not a call, and does\n\
633not touch the return address. Hence returning from @var{FUNCTION} will\n\
634return to whoever called the current @samp{thunk}.\n\
635\n\
636The effect must be as if @var{function} had been called directly with\n\
637the adjusted first argument. This macro is responsible for emitting all\n\
638of the code for a thunk function; @code{TARGET_ASM_FUNCTION_PROLOGUE}\n\
639and @code{TARGET_ASM_FUNCTION_EPILOGUE} are not invoked.\n\
640\n\
641The @var{thunk_fndecl} is redundant. (@var{delta} and @var{function}\n\
642have already been extracted from it.) It might possibly be useful on\n\
643some targets, but probably not.\n\
644\n\
645If you do not define this macro, the target-independent code in the C++\n\
646front end will generate a less efficient heavyweight thunk that calls\n\
647@var{function} instead of jumping to it. The generic approach does\n\
648not support varargs.",
38f8b050
JR
649 void, (FILE *file, tree thunk_fndecl, HOST_WIDE_INT delta,
650 HOST_WIDE_INT vcall_offset, tree function),
651 NULL)
652
653/* Determine whether output_mi_thunk would succeed. */
654/* ??? Ideally, this hook would not exist, and success or failure
655 would be returned from output_mi_thunk directly. But there's
656 too much undo-able setup involved in invoking output_mi_thunk.
657 Could be fixed by making output_mi_thunk emit rtl instead of
658 text to the output file. */
659DEFHOOK
660(can_output_mi_thunk,
673c2f63
JM
661 "A function that returns true if TARGET_ASM_OUTPUT_MI_THUNK would be able\n\
662to output the assembler code for the thunk function specified by the\n\
663arguments it is passed, and false otherwise. In the latter case, the\n\
664generic approach will be used by the C++ front end, with the limitations\n\
665previously exposed.",
38f8b050
JR
666 bool, (const_tree thunk_fndecl, HOST_WIDE_INT delta,
667 HOST_WIDE_INT vcall_offset, const_tree function),
668 hook_bool_const_tree_hwi_hwi_const_tree_false)
669
670/* Output any boilerplate text needed at the beginning of a
671 translation unit. */
672DEFHOOK
673(file_start,
673c2f63
JM
674 "Output to @code{asm_out_file} any text which the assembler expects to\n\
675find at the beginning of a file. The default behavior is controlled\n\
676by two flags, documented below. Unless your target's assembler is\n\
677quite unusual, if you override the default, you should call\n\
678@code{default_file_start} at some point in your target hook. This\n\
679lets other target files rely on these variables.",
38f8b050
JR
680 void, (void),
681 default_file_start)
682
683/* Output any boilerplate text needed at the end of a translation unit. */
684DEFHOOK
685(file_end,
673c2f63
JM
686 "Output to @code{asm_out_file} any text which the assembler expects\n\
687to find at the end of a file. The default is to output nothing.",
38f8b050
JR
688 void, (void),
689 hook_void_void)
690
691/* Output any boilerplate text needed at the beginning of an
692 LTO output stream. */
693DEFHOOK
694(lto_start,
673c2f63
JM
695 "Output to @code{asm_out_file} any text which the assembler expects\n\
696to find at the start of an LTO section. The default is to output\n\
697nothing.",
38f8b050
JR
698 void, (void),
699 hook_void_void)
700
701/* Output any boilerplate text needed at the end of an
702 LTO output stream. */
703DEFHOOK
704(lto_end,
673c2f63
JM
705 "Output to @code{asm_out_file} any text which the assembler expects\n\
706to find at the end of an LTO section. The default is to output\n\
707nothing.",
38f8b050
JR
708 void, (void),
709 hook_void_void)
710
711/* Output any boilerplace text needed at the end of a
712 translation unit before debug and unwind info is emitted. */
713DEFHOOK
714(code_end,
673c2f63
JM
715 "Output to @code{asm_out_file} any text which is needed before emitting\n\
716unwind info and debug info at the end of a file. Some targets emit\n\
717here PIC setup thunks that cannot be emitted at the end of file,\n\
718because they couldn't have unwind info then. The default is to output\n\
719nothing.",
38f8b050
JR
720 void, (void),
721 hook_void_void)
722
723/* Output an assembler pseudo-op to declare a library function name
724 external. */
725DEFHOOK
726(external_libcall,
673c2f63
JM
727 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
728pseudo-op to declare a library function name external. The name of the\n\
729library function is given by @var{symref}, which is a @code{symbol_ref}.",
38f8b050
JR
730 void, (rtx symref),
731 default_external_libcall)
732
733/* Output an assembler directive to mark decl live. This instructs
734 linker to not dead code strip this symbol. */
735DEFHOOK
736(mark_decl_preserved,
673c2f63
JM
737 "This target hook is a function to output to @var{asm_out_file} an assembler\n\
738directive to annotate @var{symbol} as used. The Darwin target uses the\n\
739.no_dead_code_strip directive.",
38f8b050
JR
740 void, (const char *symbol),
741 hook_void_constcharptr)
742
743/* Output a record of the command line switches that have been passed. */
744DEFHOOK
745(record_gcc_switches,
673c2f63
JM
746 "Provides the target with the ability to record the gcc command line\n\
747switches that have been passed to the compiler, and options that are\n\
748enabled. The @var{type} argument specifies what is being recorded.\n\
749It can take the following values:\n\
750\n\
751@table @gcctabopt\n\
752@item SWITCH_TYPE_PASSED\n\
753@var{text} is a command line switch that has been set by the user.\n\
754\n\
755@item SWITCH_TYPE_ENABLED\n\
756@var{text} is an option which has been enabled. This might be as a\n\
757direct result of a command line switch, or because it is enabled by\n\
758default or because it has been enabled as a side effect of a different\n\
759command line switch. For example, the @option{-O2} switch enables\n\
760various different individual optimization passes.\n\
761\n\
762@item SWITCH_TYPE_DESCRIPTIVE\n\
763@var{text} is either NULL or some descriptive text which should be\n\
764ignored. If @var{text} is NULL then it is being used to warn the\n\
765target hook that either recording is starting or ending. The first\n\
766time @var{type} is SWITCH_TYPE_DESCRIPTIVE and @var{text} is NULL, the\n\
767warning is for start up and the second time the warning is for\n\
768wind down. This feature is to allow the target hook to make any\n\
769necessary preparations before it starts to record switches and to\n\
770perform any necessary tidying up after it has finished recording\n\
771switches.\n\
772\n\
773@item SWITCH_TYPE_LINE_START\n\
774This option can be ignored by this target hook.\n\
775\n\
776@item SWITCH_TYPE_LINE_END\n\
777This option can be ignored by this target hook.\n\
778@end table\n\
779\n\
780The hook's return value must be zero. Other return values may be\n\
781supported in the future.\n\
782\n\
783By default this hook is set to NULL, but an example implementation is\n\
784provided for ELF based targets. Called @var{elf_record_gcc_switches},\n\
785it records the switches as ASCII text inside a new, string mergeable\n\
786section in the assembler output file. The name of the new section is\n\
787provided by the @code{TARGET_ASM_RECORD_GCC_SWITCHES_SECTION} target\n\
788hook.",
38f8b050
JR
789 int, (print_switch_type type, const char *text),
790 NULL)
791
792/* The name of the section that the example ELF implementation of
793 record_gcc_switches will use to store the information. Target
794 specific versions of record_gcc_switches may or may not use
795 this information. */
796DEFHOOKPOD
797(record_gcc_switches_section,
673c2f63
JM
798 "This is the name of the section that will be created by the example\n\
799ELF implementation of the @code{TARGET_ASM_RECORD_GCC_SWITCHES} target\n\
800hook.",
38f8b050
JR
801 const char *, ".GCC.command.line")
802
803/* Output the definition of a section anchor. */
804DEFHOOK
805(output_anchor,
673c2f63
JM
806 "Write the assembly code to define section anchor @var{x}, which is a\n\
807@code{SYMBOL_REF} for which @samp{SYMBOL_REF_ANCHOR_P (@var{x})} is true.\n\
808The hook is called with the assembly output position set to the beginning\n\
809of @code{SYMBOL_REF_BLOCK (@var{x})}.\n\
810\n\
811If @code{ASM_OUTPUT_DEF} is available, the hook's default definition uses\n\
812it to define the symbol as @samp{. + SYMBOL_REF_BLOCK_OFFSET (@var{x})}.\n\
813If @code{ASM_OUTPUT_DEF} is not available, the hook's default definition\n\
814is @code{NULL}, which disables the use of section anchors altogether.",
38f8b050
JR
815 void, (rtx x),
816 default_asm_output_anchor)
817
a8781821
SB
818DEFHOOK
819(output_ident,
820 "Output a string based on @var{name}, suitable for the @samp{#ident} \
821 directive, or the equivalent directive or pragma in non-C-family languages. \
822 If this hook is not defined, nothing is output for the @samp{#ident} \
823 directive.",
824 void, (const char *name),
825 hook_void_constcharptr)
826
38f8b050
JR
827/* Output a DTP-relative reference to a TLS symbol. */
828DEFHOOK
829(output_dwarf_dtprel,
673c2f63
JM
830 "If defined, this target hook is a function which outputs a DTP-relative\n\
831reference to the given TLS symbol of the specified size.",
38f8b050
JR
832 void, (FILE *file, int size, rtx x),
833 NULL)
834
835/* Some target machines need to postscan each insn after it is output. */
836DEFHOOK
837(final_postscan_insn,
673c2f63
JM
838 "If defined, this target hook is a function which is executed just after the\n\
839output of assembler code for @var{insn}, to change the mode of the assembler\n\
840if necessary.\n\
841\n\
842Here the argument @var{opvec} is the vector containing the operands\n\
843extracted from @var{insn}, and @var{noperands} is the number of\n\
844elements of the vector which contain meaningful data for this insn.\n\
845The contents of this vector are what was used to convert the insn\n\
846template into assembler code, so you can change the assembler mode\n\
847by checking the contents of the vector.",
ac44248e 848 void, (FILE *file, rtx_insn *insn, rtx *opvec, int noperands),
38f8b050
JR
849 NULL)
850
851/* Emit the trampoline template. This hook may be NULL. */
852DEFHOOK
853(trampoline_template,
673c2f63
JM
854 "This hook is called by @code{assemble_trampoline_template} to output,\n\
855on the stream @var{f}, assembler code for a block of data that contains\n\
856the constant parts of a trampoline. This code should not include a\n\
857label---the label is taken care of automatically.\n\
858\n\
859If you do not define this hook, it means no template is needed\n\
860for the target. Do not define this hook on systems where the block move\n\
861code to copy the trampoline into place would be larger than the code\n\
862to generate it on the spot.",
38f8b050
JR
863 void, (FILE *f),
864 NULL)
865
b5f5d41d
AS
866DEFHOOK
867(output_source_filename,
868 "Output COFF information or DWARF debugging information which indicates\
869 that filename @var{name} is the current source file to the stdio\
870 stream @var{file}.\n\
871 \n\
872 This target hook need not be defined if the standard form of output\
873 for the file format in use is appropriate.",
874 void ,(FILE *file, const char *name),
875 default_asm_output_source_filename)
876
6cbd8875
AS
877DEFHOOK
878(output_addr_const_extra,
673c2f63
JM
879 "A target hook to recognize @var{rtx} patterns that @code{output_addr_const}\n\
880can't deal with, and output assembly code to @var{file} corresponding to\n\
881the pattern @var{x}. This may be used to allow machine-dependent\n\
882@code{UNSPEC}s to appear within constants.\n\
883\n\
884If target hook fails to recognize a pattern, it must return @code{false},\n\
885so that a standard error message is printed. If it prints an error message\n\
886itself, by calling, for example, @code{output_operand_lossage}, it may just\n\
887return @code{true}.",
6cbd8875 888 bool, (FILE *file, rtx x),
e1267133 889 hook_bool_FILEptr_rtx_false)
6cbd8875 890
38f8b050
JR
891/* ??? The TARGET_PRINT_OPERAND* hooks are part of the asm_out struct,
892 even though that is not reflected in the macro name to override their
893 initializers. */
894#undef HOOK_PREFIX
895#define HOOK_PREFIX "TARGET_"
896
897/* Emit a machine-specific insn operand. */
4d00d5dd
JR
898/* ??? tm.texi only documents the old macro PRINT_OPERAND,
899 not this hook, and uses a different name for the argument FILE. */
38f8b050
JR
900DEFHOOK_UNDOC
901(print_operand,
902 "",
903 void, (FILE *file, rtx x, int code),
904 default_print_operand)
905
906/* Emit a machine-specific memory address. */
4d00d5dd
JR
907/* ??? tm.texi only documents the old macro PRINT_OPERAND_ADDRESS,
908 not this hook, and uses different argument names. */
38f8b050
JR
909DEFHOOK_UNDOC
910(print_operand_address,
911 "",
cc8ca59e 912 void, (FILE *file, machine_mode mode, rtx addr),
38f8b050
JR
913 default_print_operand_address)
914
915/* Determine whether CODE is a valid punctuation character for the
916 `print_operand' hook. */
4d00d5dd
JR
917/* ??? tm.texi only documents the old macro PRINT_OPERAND_PUNCT_VALID_P,
918 not this hook. */
38f8b050
JR
919DEFHOOK_UNDOC
920(print_operand_punct_valid_p,
921 "",
922 bool ,(unsigned char code),
923 default_print_operand_punct_valid_p)
924
77754180
DK
925/* Given a symbol name, perform same mangling as assemble_name and
926 ASM_OUTPUT_LABELREF, returning result as an IDENTIFIER_NODE. */
927DEFHOOK
928(mangle_assembler_name,
929 "Given a symbol @var{name}, perform same mangling as @code{varasm.c}'s\
930 @code{assemble_name}, but in memory rather than to a file stream, returning\
931 result as an @code{IDENTIFIER_NODE}. Required for correct LTO symtabs. The\
932 default implementation calls the @code{TARGET_STRIP_NAME_ENCODING} hook and\
933 then prepends the @code{USER_LABEL_PREFIX}, if any.",
934 tree, (const char *name),
935 default_mangle_assembler_name)
936
38f8b050
JR
937HOOK_VECTOR_END (asm_out)
938
939/* Functions relating to instruction scheduling. All of these
940 default to null pointers, which haifa-sched.c looks for and handles. */
941#undef HOOK_PREFIX
942#define HOOK_PREFIX "TARGET_SCHED_"
943HOOK_VECTOR (TARGET_SCHED, sched)
944
945/* Given the current cost, COST, of an insn, INSN, calculate and
946 return a new cost based on its relationship to DEP_INSN through
947 the dependence LINK. The default is to make no adjustment. */
948DEFHOOK
949(adjust_cost,
673c2f63 950 "This function corrects the value of @var{cost} based on the\n\
b505225b
TS
951relationship between @var{insn} and @var{dep_insn} through a\n\
952dependence of type dep_type, and strength @var{dw}. It should return the new\n\
953value. The default is to make no adjustment to @var{cost}. This can be\n\
954used for example to specify to the scheduler using the traditional pipeline\n\
955description that an output- or anti-dependence does not incur the same cost\n\
956as a data-dependence. If the scheduler using the automaton based pipeline\n\
673c2f63
JM
957description, the cost of anti-dependence is zero and the cost of\n\
958output-dependence is maximum of one and the difference of latency\n\
959times of the first and the second insns. If these values are not\n\
960acceptable, you could use the hook to modify them too. See also\n\
961@pxref{Processor pipeline description}.",
b505225b
TS
962 int, (rtx_insn *insn, int dep_type1, rtx_insn *dep_insn, int cost,
963 unsigned int dw),
964 NULL)
38f8b050
JR
965
966/* Adjust the priority of an insn as you see fit. Returns the new priority. */
967DEFHOOK
968(adjust_priority,
673c2f63
JM
969 "This hook adjusts the integer scheduling priority @var{priority} of\n\
970@var{insn}. It should return the new priority. Increase the priority to\n\
971execute @var{insn} earlier, reduce the priority to execute @var{insn}\n\
972later. Do not define this hook if you do not need to adjust the\n\
973scheduling priorities of insns.",
ac44248e 974 int, (rtx_insn *insn, int priority), NULL)
38f8b050
JR
975
976/* Function which returns the maximum number of insns that can be
977 scheduled in the same machine cycle. This must be constant
978 over an entire compilation. The default is 1. */
979DEFHOOK
980(issue_rate,
673c2f63
JM
981 "This hook returns the maximum number of instructions that can ever\n\
982issue at the same time on the target machine. The default is one.\n\
983Although the insn scheduler can define itself the possibility of issue\n\
984an insn on the same cycle, the value can serve as an additional\n\
985constraint to issue insns on the same simulated processor cycle (see\n\
986hooks @samp{TARGET_SCHED_REORDER} and @samp{TARGET_SCHED_REORDER2}).\n\
987This value must be constant over the entire compilation. If you need\n\
988it to vary depending on what the instructions are, you must use\n\
989@samp{TARGET_SCHED_VARIABLE_ISSUE}.",
38f8b050
JR
990 int, (void), NULL)
991
992/* Calculate how much this insn affects how many more insns we
993 can emit this cycle. Default is they all cost the same. */
994DEFHOOK
995(variable_issue,
673c2f63
JM
996 "This hook is executed by the scheduler after it has scheduled an insn\n\
997from the ready list. It should return the number of insns which can\n\
998still be issued in the current cycle. The default is\n\
999@samp{@w{@var{more} - 1}} for insns other than @code{CLOBBER} and\n\
1000@code{USE}, which normally are not counted against the issue rate.\n\
1001You should define this hook if some insns take more machine resources\n\
1002than others, so that fewer insns can follow them in the same cycle.\n\
1003@var{file} is either a null pointer, or a stdio stream to write any\n\
1004debug output to. @var{verbose} is the verbose level provided by\n\
1005@option{-fsched-verbose-@var{n}}. @var{insn} is the instruction that\n\
1006was scheduled.",
ac44248e 1007 int, (FILE *file, int verbose, rtx_insn *insn, int more), NULL)
38f8b050
JR
1008
1009/* Initialize machine-dependent scheduling code. */
1010DEFHOOK
1011(init,
673c2f63
JM
1012 "This hook is executed by the scheduler at the beginning of each block of\n\
1013instructions that are to be scheduled. @var{file} is either a null\n\
1014pointer, or a stdio stream to write any debug output to. @var{verbose}\n\
1015is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\
1016@var{max_ready} is the maximum number of insns in the current scheduling\n\
1017region that can be live at the same time. This can be used to allocate\n\
1018scratch space if it is needed, e.g.@: by @samp{TARGET_SCHED_REORDER}.",
38f8b050
JR
1019 void, (FILE *file, int verbose, int max_ready), NULL)
1020
1021/* Finalize machine-dependent scheduling code. */
1022DEFHOOK
1023(finish,
673c2f63
JM
1024 "This hook is executed by the scheduler at the end of each block of\n\
1025instructions that are to be scheduled. It can be used to perform\n\
1026cleanup of any actions done by the other scheduling hooks. @var{file}\n\
1027is either a null pointer, or a stdio stream to write any debug output\n\
1028to. @var{verbose} is the verbose level provided by\n\
1029@option{-fsched-verbose-@var{n}}.",
38f8b050
JR
1030 void, (FILE *file, int verbose), NULL)
1031
1032 /* Initialize machine-dependent function wide scheduling code. */
1033DEFHOOK
1034(init_global,
673c2f63
JM
1035 "This hook is executed by the scheduler after function level initializations.\n\
1036@var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\
1037@var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.\n\
1038@var{old_max_uid} is the maximum insn uid when scheduling begins.",
38f8b050
JR
1039 void, (FILE *file, int verbose, int old_max_uid), NULL)
1040
1041/* Finalize machine-dependent function wide scheduling code. */
1042DEFHOOK
1043(finish_global,
673c2f63
JM
1044 "This is the cleanup hook corresponding to @code{TARGET_SCHED_INIT_GLOBAL}.\n\
1045@var{file} is either a null pointer, or a stdio stream to write any debug output to.\n\
1046@var{verbose} is the verbose level provided by @option{-fsched-verbose-@var{n}}.",
38f8b050
JR
1047 void, (FILE *file, int verbose), NULL)
1048
1049/* Reorder insns in a machine-dependent fashion, in two different
1050 places. Default does nothing. */
1051DEFHOOK
1052(reorder,
673c2f63
JM
1053 "This hook is executed by the scheduler after it has scheduled the ready\n\
1054list, to allow the machine description to reorder it (for example to\n\
1055combine two small instructions together on @samp{VLIW} machines).\n\
1056@var{file} is either a null pointer, or a stdio stream to write any\n\
1057debug output to. @var{verbose} is the verbose level provided by\n\
1058@option{-fsched-verbose-@var{n}}. @var{ready} is a pointer to the ready\n\
1059list of instructions that are ready to be scheduled. @var{n_readyp} is\n\
1060a pointer to the number of elements in the ready list. The scheduler\n\
1061reads the ready list in reverse order, starting with\n\
1062@var{ready}[@var{*n_readyp} @minus{} 1] and going to @var{ready}[0]. @var{clock}\n\
1063is the timer tick of the scheduler. You may modify the ready list and\n\
1064the number of ready insns. The return value is the number of insns that\n\
1065can issue this cycle; normally this is just @code{issue_rate}. See also\n\
1066@samp{TARGET_SCHED_REORDER2}.",
ce1ce33a 1067 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL)
38f8b050
JR
1068
1069DEFHOOK
1070(reorder2,
673c2f63
JM
1071 "Like @samp{TARGET_SCHED_REORDER}, but called at a different time. That\n\
1072function is called whenever the scheduler starts a new cycle. This one\n\
1073is called once per iteration over a cycle, immediately after\n\
1074@samp{TARGET_SCHED_VARIABLE_ISSUE}; it can reorder the ready list and\n\
1075return the number of insns to be scheduled in the same cycle. Defining\n\
1076this hook can be useful if there are frequent situations where\n\
1077scheduling one insn causes other insns to become ready in the same\n\
1078cycle. These other insns can then be taken into account properly.",
ce1ce33a 1079 int, (FILE *file, int verbose, rtx_insn **ready, int *n_readyp, int clock), NULL)
38f8b050 1080
0dc41f28
WM
1081DEFHOOK
1082(macro_fusion_p,
1083 "This hook is used to check whether target platform supports macro fusion.",
1084 bool, (void), NULL)
1085
1086DEFHOOK
1087(macro_fusion_pair_p,
892d9879
KT
1088 "This hook is used to check whether two insns should be macro fused for\n\
1089a target microarchitecture. If this hook returns true for the given insn pair\n\
1090(@var{prev} and @var{curr}), the scheduler will put them into a sched\n\
1091group, and they will not be scheduled apart. The two insns will be either\n\
1092two SET insns or a compare and a conditional jump and this hook should\n\
1093validate any dependencies needed to fuse the two insns together.",
1094 bool, (rtx_insn *prev, rtx_insn *curr), NULL)
0dc41f28 1095
38f8b050
JR
1096/* The following member value is a pointer to a function called
1097 after evaluation forward dependencies of insns in chain given
1098 by two parameter values (head and tail correspondingly). */
1099DEFHOOK
1100(dependencies_evaluation_hook,
673c2f63
JM
1101 "This hook is called after evaluation forward dependencies of insns in\n\
1102chain given by two parameter values (@var{head} and @var{tail}\n\
1103correspondingly) but before insns scheduling of the insn chain. For\n\
1104example, it can be used for better insn classification if it requires\n\
1105analysis of dependencies. This hook can use backward and forward\n\
1106dependencies of the insn scheduler because they are already\n\
1107calculated.",
ce1ce33a 1108 void, (rtx_insn *head, rtx_insn *tail), NULL)
38f8b050
JR
1109
1110/* The values of the following four members are pointers to functions
1111 used to simplify the automaton descriptions. dfa_pre_cycle_insn and
1112 dfa_post_cycle_insn give functions returning insns which are used to
1113 change the pipeline hazard recognizer state when the new simulated
1114 processor cycle correspondingly starts and finishes. The function
1115 defined by init_dfa_pre_cycle_insn and init_dfa_post_cycle_insn are
1116 used to initialize the corresponding insns. The default values of
1117 the members result in not changing the automaton state when the
1118 new simulated processor cycle correspondingly starts and finishes. */
1119
1120DEFHOOK
1121(init_dfa_pre_cycle_insn,
673c2f63 1122 "The hook can be used to initialize data used by the previous hook.",
38f8b050
JR
1123 void, (void), NULL)
1124
1125DEFHOOK
1126(dfa_pre_cycle_insn,
673c2f63
JM
1127 "The hook returns an RTL insn. The automaton state used in the\n\
1128pipeline hazard recognizer is changed as if the insn were scheduled\n\
1129when the new simulated processor cycle starts. Usage of the hook may\n\
1130simplify the automaton pipeline description for some @acronym{VLIW}\n\
1131processors. If the hook is defined, it is used only for the automaton\n\
1132based pipeline description. The default is not to change the state\n\
1133when the new simulated processor cycle starts.",
38f8b050
JR
1134 rtx, (void), NULL)
1135
1136DEFHOOK
1137(init_dfa_post_cycle_insn,
673c2f63
JM
1138 "The hook is analogous to @samp{TARGET_SCHED_INIT_DFA_PRE_CYCLE_INSN} but\n\
1139used to initialize data used by the previous hook.",
38f8b050
JR
1140 void, (void), NULL)
1141
1142DEFHOOK
1143(dfa_post_cycle_insn,
673c2f63
JM
1144 "The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\
1145to changed the state as if the insn were scheduled when the new\n\
1146simulated processor cycle finishes.",
ac44248e 1147 rtx_insn *, (void), NULL)
38f8b050
JR
1148
1149/* The values of the following two members are pointers to
1150 functions used to simplify the automaton descriptions.
1151 dfa_pre_advance_cycle and dfa_post_advance_cycle are getting called
1152 immediately before and after cycle is advanced. */
1153
1154DEFHOOK
1155(dfa_pre_advance_cycle,
673c2f63
JM
1156 "The hook to notify target that the current simulated cycle is about to finish.\n\
1157The hook is analogous to @samp{TARGET_SCHED_DFA_PRE_CYCLE_INSN} but used\n\
1158to change the state in more complicated situations - e.g., when advancing\n\
1159state on a single insn is not enough.",
38f8b050
JR
1160 void, (void), NULL)
1161
1162DEFHOOK
1163(dfa_post_advance_cycle,
673c2f63
JM
1164 "The hook to notify target that new simulated cycle has just started.\n\
1165The hook is analogous to @samp{TARGET_SCHED_DFA_POST_CYCLE_INSN} but used\n\
1166to change the state in more complicated situations - e.g., when advancing\n\
1167state on a single insn is not enough.",
38f8b050
JR
1168 void, (void), NULL)
1169
1170/* The following member value is a pointer to a function returning value
1171 which defines how many insns in queue `ready' will we try for
1172 multi-pass scheduling. If the member value is nonzero and the
1173 function returns positive value, the DFA based scheduler will make
1174 multi-pass scheduling for the first cycle. In other words, we will
1175 try to choose ready insn which permits to start maximum number of
1176 insns on the same cycle. */
1177DEFHOOK
1178(first_cycle_multipass_dfa_lookahead,
673c2f63
JM
1179 "This hook controls better choosing an insn from the ready insn queue\n\
1180for the @acronym{DFA}-based insn scheduler. Usually the scheduler\n\
1181chooses the first insn from the queue. If the hook returns a positive\n\
1182value, an additional scheduler code tries all permutations of\n\
1183@samp{TARGET_SCHED_FIRST_CYCLE_MULTIPASS_DFA_LOOKAHEAD ()}\n\
1184subsequent ready insns to choose an insn whose issue will result in\n\
1185maximal number of issued insns on the same cycle. For the\n\
1186@acronym{VLIW} processor, the code could actually solve the problem of\n\
1187packing simple insns into the @acronym{VLIW} insn. Of course, if the\n\
1188rules of @acronym{VLIW} packing are described in the automaton.\n\
1189\n\
1190This code also could be used for superscalar @acronym{RISC}\n\
1191processors. Let us consider a superscalar @acronym{RISC} processor\n\
1192with 3 pipelines. Some insns can be executed in pipelines @var{A} or\n\
1193@var{B}, some insns can be executed only in pipelines @var{B} or\n\
1194@var{C}, and one insn can be executed in pipeline @var{B}. The\n\
1195processor may issue the 1st insn into @var{A} and the 2nd one into\n\
1196@var{B}. In this case, the 3rd insn will wait for freeing @var{B}\n\
1197until the next cycle. If the scheduler issues the 3rd insn the first,\n\
1198the processor could issue all 3 insns per cycle.\n\
1199\n\
1200Actually this code demonstrates advantages of the automaton based\n\
1201pipeline hazard recognizer. We try quickly and easy many insn\n\
1202schedules to choose the best one.\n\
1203\n\
1204The default is no multipass scheduling.",
38f8b050
JR
1205 int, (void), NULL)
1206
1207/* The following member value is pointer to a function controlling
1208 what insns from the ready insn queue will be considered for the
1209 multipass insn scheduling. If the hook returns zero for insn
1210 passed as the parameter, the insn will be not chosen to be issued. */
1211DEFHOOK
1212(first_cycle_multipass_dfa_lookahead_guard,
673c2f63
JM
1213 "\n\
1214This hook controls what insns from the ready insn queue will be\n\
1215considered for the multipass insn scheduling. If the hook returns\n\
4960a0cb
MK
1216zero for @var{insn}, the insn will be considered in multipass scheduling.\n\
1217Positive return values will remove @var{insn} from consideration on\n\
1218the current round of multipass scheduling.\n\
1219Negative return values will remove @var{insn} from consideration for given\n\
1220number of cycles.\n\
1221Backends should be careful about returning non-zero for highest priority\n\
1222instruction at position 0 in the ready list. @var{ready_index} is passed\n\
1223to allow backends make correct judgements.\n\
673c2f63
JM
1224\n\
1225The default is that any ready insns can be chosen to be issued.",
ac44248e 1226 int, (rtx_insn *insn, int ready_index), NULL)
38f8b050 1227
894fd6f2
MK
1228/* This hook prepares the target for a new round of multipass
1229 scheduling.
1230 DATA is a pointer to target-specific data used for multipass scheduling.
1231 READY_TRY and N_READY represent the current state of search in the
1232 optimization space. The target can filter out instructions that
1233 should not be tried during current round by setting corresponding
1234 elements in READY_TRY to non-zero.
1235 FIRST_CYCLE_INSN_P is true if this is the first round of multipass
1236 scheduling on current cycle. */
1237DEFHOOK
1238(first_cycle_multipass_begin,
673c2f63
JM
1239 "This hook prepares the target backend for a new round of multipass\n\
1240scheduling.",
4960a0cb 1241 void, (void *data, signed char *ready_try, int n_ready, bool first_cycle_insn_p),
894fd6f2
MK
1242 NULL)
1243
1244/* This hook is called when multipass scheduling evaluates instruction INSN.
1245 DATA is a pointer to target-specific data that can be used to record effects
1246 of INSN on CPU that are not described in DFA.
1247 READY_TRY and N_READY represent the current state of search in the
1248 optimization space. The target can filter out instructions that
073a8998 1249 should not be tried after issuing INSN by setting corresponding
894fd6f2
MK
1250 elements in READY_TRY to non-zero.
1251 INSN is the instruction being evaluated.
1252 PREV_DATA is a pointer to target-specific data corresponding
073a8998 1253 to a state before issuing INSN. */
894fd6f2
MK
1254DEFHOOK
1255(first_cycle_multipass_issue,
673c2f63 1256 "This hook is called when multipass scheduling evaluates instruction INSN.",
ac44248e 1257 void, (void *data, signed char *ready_try, int n_ready, rtx_insn *insn,
894fd6f2
MK
1258 const void *prev_data), NULL)
1259
1260/* This hook is called when multipass scheduling backtracks from evaluation of
1261 instruction corresponding to DATA.
1262 DATA is a pointer to target-specific data that stores the effects
1263 of instruction from which the algorithm backtracks on CPU that are not
1264 described in DFA.
1265 READY_TRY and N_READY represent the current state of search in the
1266 optimization space. The target can filter out instructions that
073a8998 1267 should not be tried after issuing INSN by setting corresponding
894fd6f2
MK
1268 elements in READY_TRY to non-zero. */
1269DEFHOOK
1270(first_cycle_multipass_backtrack,
673c2f63
JM
1271 "This is called when multipass scheduling backtracks from evaluation of\n\
1272an instruction.",
4960a0cb 1273 void, (const void *data, signed char *ready_try, int n_ready), NULL)
894fd6f2
MK
1274
1275/* This hook notifies the target about the result of the concluded current
1276 round of multipass scheduling.
1277 DATA is a pointer.
1278 If DATA is non-NULL it points to target-specific data used for multipass
1279 scheduling which corresponds to instruction at the start of the chain of
1280 the winning solution. DATA is NULL when multipass scheduling cannot find
1281 a good enough solution on current cycle and decides to retry later,
1282 usually after advancing the cycle count. */
1283DEFHOOK
1284(first_cycle_multipass_end,
673c2f63
JM
1285 "This hook notifies the target about the result of the concluded current\n\
1286round of multipass scheduling.",
894fd6f2
MK
1287 void, (const void *data), NULL)
1288
1289/* This hook is called to initialize target-specific data for multipass
1290 scheduling after it has been allocated.
1291 DATA is a pointer to target-specific data that stores the effects
1292 of instruction from which the algorithm backtracks on CPU that are not
1293 described in DFA. */
1294DEFHOOK
1295(first_cycle_multipass_init,
673c2f63 1296 "This hook initializes target-specific data used in multipass scheduling.",
894fd6f2
MK
1297 void, (void *data), NULL)
1298
1299/* This hook is called to finalize target-specific data for multipass
1300 scheduling before it is deallocated.
1301 DATA is a pointer to target-specific data that stores the effects
1302 of instruction from which the algorithm backtracks on CPU that are not
1303 described in DFA. */
1304DEFHOOK
1305(first_cycle_multipass_fini,
673c2f63 1306 "This hook finalizes target-specific data used in multipass scheduling.",
894fd6f2
MK
1307 void, (void *data), NULL)
1308
38f8b050
JR
1309/* The following member value is pointer to a function called by
1310 the insn scheduler before issuing insn passed as the third
1311 parameter on given cycle. If the hook returns nonzero, the
1312 insn is not issued on given processors cycle. Instead of that,
1313 the processor cycle is advanced. If the value passed through
1314 the last parameter is zero, the insn ready queue is not sorted
1315 on the new cycle start as usually. The first parameter passes
1316 file for debugging output. The second one passes the scheduler
1317 verbose level of the debugging output. The forth and the fifth
1318 parameter values are correspondingly processor cycle on which
1319 the previous insn has been issued and the current processor cycle. */
c06bbdf7 1320DEFHOOK
38f8b050 1321(dfa_new_cycle,
673c2f63
JM
1322 "This hook is called by the insn scheduler before issuing @var{insn}\n\
1323on cycle @var{clock}. If the hook returns nonzero,\n\
1324@var{insn} is not issued on this processor cycle. Instead,\n\
1325the processor cycle is advanced. If *@var{sort_p}\n\
1326is zero, the insn ready queue is not sorted on the new cycle\n\
1327start as usually. @var{dump} and @var{verbose} specify the file and\n\
1328verbosity level to use for debugging output.\n\
1329@var{last_clock} and @var{clock} are, respectively, the\n\
1330processor cycle on which the previous insn has been issued,\n\
1331and the current processor cycle.",
ac44248e 1332 int, (FILE *dump, int verbose, rtx_insn *insn, int last_clock,
c06bbdf7 1333 int clock, int *sort_p),
38f8b050
JR
1334 NULL)
1335
1336/* The following member value is a pointer to a function called by the
1337 insn scheduler. It should return true if there exists a dependence
1338 which is considered costly by the target, between the insn
1339 DEP_PRO (&_DEP), and the insn DEP_CON (&_DEP). The first parameter is
1340 the dep that represents the dependence between the two insns. The
1341 second argument is the cost of the dependence as estimated by
1342 the scheduler. The last argument is the distance in cycles
1343 between the already scheduled insn (first parameter) and the
1344 second insn (second parameter). */
1345DEFHOOK
1346(is_costly_dependence,
673c2f63
JM
1347 "This hook is used to define which dependences are considered costly by\n\
1348the target, so costly that it is not advisable to schedule the insns that\n\
1349are involved in the dependence too close to one another. The parameters\n\
1350to this hook are as follows: The first parameter @var{_dep} is the dependence\n\
1351being evaluated. The second parameter @var{cost} is the cost of the\n\
1352dependence as estimated by the scheduler, and the third\n\
1353parameter @var{distance} is the distance in cycles between the two insns.\n\
1354The hook returns @code{true} if considering the distance between the two\n\
1355insns the dependence between them is considered costly by the target,\n\
1356and @code{false} otherwise.\n\
1357\n\
1358Defining this hook can be useful in multiple-issue out-of-order machines,\n\
1359where (a) it's practically hopeless to predict the actual data/resource\n\
1360delays, however: (b) there's a better chance to predict the actual grouping\n\
1361that will be formed, and (c) correctly emulating the grouping can be very\n\
1362important. In such targets one may want to allow issuing dependent insns\n\
1363closer to one another---i.e., closer than the dependence distance; however,\n\
1364not in cases of ``costly dependences'', which this hooks allows to define.",
38f8b050
JR
1365 bool, (struct _dep *_dep, int cost, int distance), NULL)
1366
38f8b050
JR
1367/* The following member value is a pointer to a function called
1368 by the insn scheduler. This hook is called to notify the backend
1369 that new instructions were emitted. */
1370DEFHOOK
1371(h_i_d_extended,
673c2f63
JM
1372 "This hook is called by the insn scheduler after emitting a new instruction to\n\
1373the instruction stream. The hook notifies a target backend to extend its\n\
1374per instruction data structures.",
38f8b050
JR
1375 void, (void), NULL)
1376
1377/* Next 5 functions are for multi-point scheduling. */
1378
1379/* Allocate memory for scheduler context. */
1380DEFHOOK
1381(alloc_sched_context,
673c2f63 1382 "Return a pointer to a store large enough to hold target scheduling context.",
38f8b050
JR
1383 void *, (void), NULL)
1384
1385/* Fills the context from the local machine scheduler context. */
1386DEFHOOK
1387(init_sched_context,
673c2f63
JM
1388 "Initialize store pointed to by @var{tc} to hold target scheduling context.\n\
1389It @var{clean_p} is true then initialize @var{tc} as if scheduler is at the\n\
1390beginning of the block. Otherwise, copy the current context into @var{tc}.",
38f8b050
JR
1391 void, (void *tc, bool clean_p), NULL)
1392
1393/* Sets local machine scheduler context to a saved value. */
1394DEFHOOK
1395(set_sched_context,
673c2f63 1396 "Copy target scheduling context pointed to by @var{tc} to the current context.",
38f8b050
JR
1397 void, (void *tc), NULL)
1398
1399/* Clears a scheduler context so it becomes like after init. */
1400DEFHOOK
1401(clear_sched_context,
673c2f63 1402 "Deallocate internal data in target scheduling context pointed to by @var{tc}.",
38f8b050
JR
1403 void, (void *tc), NULL)
1404
1405/* Frees the scheduler context. */
1406DEFHOOK
1407(free_sched_context,
673c2f63 1408 "Deallocate a store for target scheduling context pointed to by @var{tc}.",
38f8b050
JR
1409 void, (void *tc), NULL)
1410
1411/* The following member value is a pointer to a function called
1412 by the insn scheduler.
1413 The first parameter is an instruction, the second parameter is the type
1414 of the requested speculation, and the third parameter is a pointer to the
1415 speculative pattern of the corresponding type (set if return value == 1).
1416 It should return
1417 -1, if there is no pattern, that will satisfy the requested speculation type,
1418 0, if current pattern satisfies the requested speculation type,
1419 1, if pattern of the instruction should be changed to the newly
1420 generated one. */
1421DEFHOOK
1422(speculate_insn,
673c2f63
JM
1423 "This hook is called by the insn scheduler when @var{insn} has only\n\
1424speculative dependencies and therefore can be scheduled speculatively.\n\
1425The hook is used to check if the pattern of @var{insn} has a speculative\n\
1426version and, in case of successful check, to generate that speculative\n\
1427pattern. The hook should return 1, if the instruction has a speculative form,\n\
1428or @minus{}1, if it doesn't. @var{request} describes the type of requested\n\
1429speculation. If the return value equals 1 then @var{new_pat} is assigned\n\
1430the generated speculative pattern.",
ac44248e 1431 int, (rtx_insn *insn, unsigned int dep_status, rtx *new_pat), NULL)
38f8b050
JR
1432
1433/* The following member value is a pointer to a function called
1434 by the insn scheduler. It should return true if the check instruction
1435 passed as the parameter needs a recovery block. */
1436DEFHOOK
1437(needs_block_p,
673c2f63
JM
1438 "This hook is called by the insn scheduler during generation of recovery code\n\
1439for @var{insn}. It should return @code{true}, if the corresponding check\n\
1440instruction should branch to recovery code, or @code{false} otherwise.",
8e90de43 1441 bool, (unsigned int dep_status), NULL)
38f8b050
JR
1442
1443/* The following member value is a pointer to a function called
1444 by the insn scheduler. It should return a pattern for the check
1445 instruction.
1446 The first parameter is a speculative instruction, the second parameter
1447 is the label of the corresponding recovery block (or null, if it is a
8e90de43
SB
1448 simple check). The third parameter is the kind of speculation that
1449 is being performed. */
38f8b050
JR
1450DEFHOOK
1451(gen_spec_check,
673c2f63
JM
1452 "This hook is called by the insn scheduler to generate a pattern for recovery\n\
1453check instruction. If @var{mutate_p} is zero, then @var{insn} is a\n\
1454speculative instruction for which the check should be generated.\n\
1455@var{label} is either a label of a basic block, where recovery code should\n\
1456be emitted, or a null pointer, when requested check doesn't branch to\n\
1457recovery code (a simple check). If @var{mutate_p} is nonzero, then\n\
1458a pattern for a branchy check corresponding to a simple check denoted by\n\
1459@var{insn} should be generated. In this case @var{label} can't be null.",
ac44248e 1460 rtx, (rtx_insn *insn, rtx_insn *label, unsigned int ds), NULL)
38f8b050 1461
38f8b050
JR
1462/* The following member value is a pointer to a function that provides
1463 information about the speculation capabilities of the target.
1464 The parameter is a pointer to spec_info variable. */
1465DEFHOOK
1466(set_sched_flags,
673c2f63
JM
1467 "This hook is used by the insn scheduler to find out what features should be\n\
1468enabled/used.\n\
1469The structure *@var{spec_info} should be filled in by the target.\n\
1470The structure describes speculation types that can be used in the scheduler.",
38f8b050
JR
1471 void, (struct spec_info_def *spec_info), NULL)
1472
1473DEFHOOK_UNDOC
1474(get_insn_spec_ds,
1475 "Return speculation types of instruction @var{insn}.",
ac44248e 1476 unsigned int, (rtx_insn *insn), NULL)
38f8b050
JR
1477
1478DEFHOOK_UNDOC
1479(get_insn_checked_ds,
1480 "Return speculation types that are checked for instruction @var{insn}",
ac44248e 1481 unsigned int, (rtx_insn *insn), NULL)
38f8b050
JR
1482
1483DEFHOOK_UNDOC
1484(skip_rtx_p,
1485 "Return bool if rtx scanning should just skip current layer and\
1486 advance to the inner rtxes.",
1487 bool, (const_rtx x), NULL)
1488
1489/* The following member value is a pointer to a function that provides
1490 information about the target resource-based lower bound which is
1491 used by the swing modulo scheduler. The parameter is a pointer
1492 to ddg variable. */
1493DEFHOOK
1494(sms_res_mii,
673c2f63
JM
1495 "This hook is called by the swing modulo scheduler to calculate a\n\
1496resource-based lower bound which is based on the resources available in\n\
1497the machine and the resources required by each instruction. The target\n\
1498backend can use @var{g} to calculate such bound. A very simple lower\n\
1499bound will be used in case this hook is not implemented: the total number\n\
1500of instructions divided by the issue rate.",
38f8b050
JR
1501 int, (struct ddg *g), NULL)
1502
7942e47e
RY
1503/* The following member value is a function that initializes dispatch
1504 schedling and adds instructions to dispatch window according to its
1505 parameters. */
1506DEFHOOK
1507(dispatch_do,
673c2f63
JM
1508"This hook is called by Haifa Scheduler. It performs the operation specified\n\
1509in its second parameter.",
ac44248e
DM
1510void, (rtx_insn *insn, int x),
1511hook_void_rtx_insn_int)
7942e47e
RY
1512
1513/* The following member value is a a function that returns true is
1514 dispatch schedling is supported in hardware and condition passed
1515 as the second parameter is true. */
1516DEFHOOK
1517(dispatch,
673c2f63
JM
1518"This hook is called by Haifa Scheduler. It returns true if dispatch scheduling\n\
1519is supported in hardware and the condition specified in the parameter is true.",
ac44248e
DM
1520bool, (rtx_insn *insn, int x),
1521hook_bool_rtx_insn_int_false)
7942e47e 1522
b0bd15f7
BS
1523DEFHOOKPOD
1524(exposed_pipeline,
1525"True if the processor has an exposed pipeline, which means that not just\n\
1526the order of instructions is important for correctness when scheduling, but\n\
1527also the latencies of operations.",
1528bool, false)
1529
df7b0cc4
EI
1530/* The following member value is a function that returns number
1531 of operations reassociator should try to put in parallel for
1532 statements of the given type. By default 1 is used. */
1533DEFHOOK
1534(reassociation_width,
1535"This hook is called by tree reassociator to determine a level of\n\
1536parallelism required in output calculations chain.",
ef4bddc2 1537int, (unsigned int opc, machine_mode mode),
df7b0cc4
EI
1538hook_int_uint_mode_1)
1539
b16abbcb
BC
1540/* The following member value is a function that returns priority for
1541 fusion of each instruction via pointer parameters. */
1542DEFHOOK
1543(fusion_priority,
1544"This hook is called by scheduling fusion pass. It calculates fusion\n\
1545priorities for each instruction passed in by parameter. The priorities\n\
1546are returned via pointer parameters.\n\
1547\n\
1548@var{insn} is the instruction whose priorities need to be calculated.\n\
1549@var{max_pri} is the maximum priority can be returned in any cases.\n\
1550@var{fusion_pri} is the pointer parameter through which @var{insn}'s\n\
1551fusion priority should be calculated and returned.\n\
1552@var{pri} is the pointer parameter through which @var{insn}'s priority\n\
1553should be calculated and returned.\n\
1554\n\
1555Same @var{fusion_pri} should be returned for instructions which should\n\
1556be scheduled together. Different @var{pri} should be returned for\n\
1557instructions with same @var{fusion_pri}. @var{fusion_pri} is the major\n\
1558sort key, @var{pri} is the minor sort key. All instructions will be\n\
1559scheduled according to the two priorities. All priorities calculated\n\
1560should be between 0 (exclusive) and @var{max_pri} (inclusive). To avoid\n\
1561false dependencies, @var{fusion_pri} of instructions which need to be\n\
1562scheduled together should be smaller than @var{fusion_pri} of irrelevant\n\
1563instructions.\n\
1564\n\
1565Given below example:\n\
1566\n\
51be4977 1567@smallexample\n\
b16abbcb
BC
1568 ldr r10, [r1, 4]\n\
1569 add r4, r4, r10\n\
1570 ldr r15, [r2, 8]\n\
1571 sub r5, r5, r15\n\
1572 ldr r11, [r1, 0]\n\
1573 add r4, r4, r11\n\
1574 ldr r16, [r2, 12]\n\
1575 sub r5, r5, r16\n\
51be4977 1576@end smallexample\n\
b16abbcb
BC
1577\n\
1578On targets like ARM/AArch64, the two pairs of consecutive loads should be\n\
1579merged. Since peephole2 pass can't help in this case unless consecutive\n\
1580loads are actually next to each other in instruction flow. That's where\n\
1581this scheduling fusion pass works. This hook calculates priority for each\n\
1582instruction based on its fustion type, like:\n\
1583\n\
51be4977
BC
1584@smallexample\n\
1585 ldr r10, [r1, 4] ; fusion_pri=99, pri=96\n\
1586 add r4, r4, r10 ; fusion_pri=100, pri=100\n\
1587 ldr r15, [r2, 8] ; fusion_pri=98, pri=92\n\
1588 sub r5, r5, r15 ; fusion_pri=100, pri=100\n\
1589 ldr r11, [r1, 0] ; fusion_pri=99, pri=100\n\
1590 add r4, r4, r11 ; fusion_pri=100, pri=100\n\
1591 ldr r16, [r2, 12] ; fusion_pri=98, pri=88\n\
1592 sub r5, r5, r16 ; fusion_pri=100, pri=100\n\
1593@end smallexample\n\
b16abbcb
BC
1594\n\
1595Scheduling fusion pass then sorts all ready to issue instructions according\n\
1596to the priorities. As a result, instructions of same fusion type will be\n\
1597pushed together in instruction flow, like:\n\
1598\n\
51be4977 1599@smallexample\n\
b16abbcb
BC
1600 ldr r11, [r1, 0]\n\
1601 ldr r10, [r1, 4]\n\
1602 ldr r15, [r2, 8]\n\
1603 ldr r16, [r2, 12]\n\
1604 add r4, r4, r10\n\
1605 sub r5, r5, r15\n\
1606 add r4, r4, r11\n\
1607 sub r5, r5, r16\n\
51be4977 1608@end smallexample\n\
b16abbcb
BC
1609\n\
1610Now peephole2 pass can simply merge the two pairs of loads.\n\
1611\n\
1612Since scheduling fusion pass relies on peephole2 to do real fusion\n\
1613work, it is only enabled by default when peephole2 is in effect.\n\
1614\n\
1615This is firstly introduced on ARM/AArch64 targets, please refer to\n\
1616the hook implementation for how different fusion types are supported.",
1617void, (rtx_insn *insn, int max_pri, int *fusion_pri, int *pri), NULL)
1618
38f8b050
JR
1619HOOK_VECTOR_END (sched)
1620
0136f8f0
AH
1621/* Functions relating to OpenMP and Cilk Plus SIMD clones. */
1622#undef HOOK_PREFIX
1623#define HOOK_PREFIX "TARGET_SIMD_CLONE_"
1624HOOK_VECTOR (TARGET_SIMD_CLONE, simd_clone)
1625
1626DEFHOOK
1627(compute_vecsize_and_simdlen,
1628"This hook should set @var{vecsize_mangle}, @var{vecsize_int}, @var{vecsize_float}\n\
1629fields in @var{simd_clone} structure pointed by @var{clone_info} argument and also\n\
1630@var{simdlen} field if it was previously 0.\n\
1631The hook should return 0 if SIMD clones shouldn't be emitted,\n\
1632or number of @var{vecsize_mangle} variants that should be emitted.",
1633int, (struct cgraph_node *, struct cgraph_simd_clone *, tree, int), NULL)
1634
1635DEFHOOK
1636(adjust,
1637"This hook should add implicit @code{attribute(target(\"...\"))} attribute\n\
1638to SIMD clone @var{node} if needed.",
1639void, (struct cgraph_node *), NULL)
1640
1641DEFHOOK
1642(usable,
1643"This hook should return -1 if SIMD clone @var{node} shouldn't be used\n\
1644in vectorized loops in current function, or non-negative number if it is\n\
1645usable. In that case, the smaller the number is, the more desirable it is\n\
1646to use it.",
1647int, (struct cgraph_node *), NULL)
1648
1649HOOK_VECTOR_END (simd_clone)
1650
5012919d
AM
1651/* Functions relating to OpenMP SIMT vectorization transform. */
1652#undef HOOK_PREFIX
1653#define HOOK_PREFIX "TARGET_SIMT_"
1654HOOK_VECTOR (TARGET_SIMT, simt)
1655
1656DEFHOOK
1657(vf,
1658"Return number of threads in SIMT thread group on the target.",
1659int, (void), NULL)
1660
1661HOOK_VECTOR_END (simt)
1662
94829f87
NS
1663/* Functions relating to openacc. */
1664#undef HOOK_PREFIX
1665#define HOOK_PREFIX "TARGET_GOACC_"
1666HOOK_VECTOR (TARGET_GOACC, goacc)
1667
1668DEFHOOK
1669(validate_dims,
1670"This hook should check the launch dimensions provided for an OpenACC\n\
1671compute region, or routine. Defaulted values are represented as -1\n\
b6adbb9f 1672and non-constant values as 0. The @var{fn_level} is negative for the\n\
94829f87 1673function corresponding to the compute region. For a routine is is the\n\
b6adbb9f
NS
1674outermost level at which partitioned execution may be spawned. The hook\n\
1675should verify non-default values. If DECL is NULL, global defaults\n\
1676are being validated and unspecified defaults should be filled in.\n\
1677Diagnostics should be issued as appropriate. Return\n\
94829f87
NS
1678true, if changes have been made. You must override this hook to\n\
1679provide dimensions larger than 1.",
6e91acf8 1680bool, (tree decl, int *dims, int fn_level),
94829f87
NS
1681default_goacc_validate_dims)
1682
bd751975
NS
1683DEFHOOK
1684(dim_limit,
1685"This hook should return the maximum size of a particular dimension,\n\
1686or zero if unbounded.",
1687int, (int axis),
1688default_goacc_dim_limit)
1689
6e91acf8
NS
1690DEFHOOK
1691(fork_join,
9bd46bc9
NS
1692"This hook can be used to convert IFN_GOACC_FORK and IFN_GOACC_JOIN\n\
1693function calls to target-specific gimple, or indicate whether they\n\
1694should be retained. It is executed during the oacc_device_lower pass.\n\
1695It should return true, if the call should be retained. It should\n\
1696return false, if it is to be deleted (either because target-specific\n\
1697gimple has been inserted before it, or there is no need for it).\n\
1698The default hook returns false, if there are no RTL expanders for them.",
6e91acf8
NS
1699bool, (gcall *call, const int *dims, bool is_fork),
1700default_goacc_fork_join)
1701
e5014671
NS
1702DEFHOOK
1703(reduction,
1704"This hook is used by the oacc_transform pass to expand calls to the\n\
1705@var{GOACC_REDUCTION} internal function, into a sequence of gimple\n\
1706instructions. @var{call} is gimple statement containing the call to\n\
1707the function. This hook removes statement @var{call} after the\n\
1708expanded sequence has been inserted. This hook is also responsible\n\
1709for allocating any storage for reductions when necessary.",
1710void, (gcall *call),
1711default_goacc_reduction)
1712
94829f87
NS
1713HOOK_VECTOR_END (goacc)
1714
38f8b050
JR
1715/* Functions relating to vectorization. */
1716#undef HOOK_PREFIX
1717#define HOOK_PREFIX "TARGET_VECTORIZE_"
1718HOOK_VECTOR (TARGET_VECTORIZE, vectorize)
1719
1720/* The following member value is a pointer to a function called
1721 by the vectorizer, and return the decl of the target builtin
1722 function. */
1723DEFHOOK
1724(builtin_mask_for_load,
673c2f63
JM
1725 "This hook should return the DECL of a function @var{f} that given an\n\
1726address @var{addr} as an argument returns a mask @var{m} that can be\n\
1727used to extract from two vectors the relevant data that resides in\n\
1728@var{addr} in case @var{addr} is not properly aligned.\n\
1729\n\
1730The autovectorizer, when vectorizing a load operation from an address\n\
1731@var{addr} that may be unaligned, will generate two vector loads from\n\
1732the two aligned addresses around @var{addr}. It then generates a\n\
1733@code{REALIGN_LOAD} operation to extract the relevant data from the\n\
1734two loaded vectors. The first two arguments to @code{REALIGN_LOAD},\n\
1735@var{v1} and @var{v2}, are the two vectors, each of size @var{VS}, and\n\
1736the third argument, @var{OFF}, defines how the data will be extracted\n\
1737from these two vectors: if @var{OFF} is 0, then the returned vector is\n\
1738@var{v2}; otherwise, the returned vector is composed from the last\n\
1739@var{VS}-@var{OFF} elements of @var{v1} concatenated to the first\n\
1740@var{OFF} elements of @var{v2}.\n\
1741\n\
1742If this hook is defined, the autovectorizer will generate a call\n\
1743to @var{f} (using the DECL tree that this hook returns) and will\n\
1744use the return value of @var{f} as the argument @var{OFF} to\n\
1745@code{REALIGN_LOAD}. Therefore, the mask @var{m} returned by @var{f}\n\
1746should comply with the semantics expected by @code{REALIGN_LOAD}\n\
1747described above.\n\
1748If this hook is not defined, then @var{addr} will be used as\n\
1749the argument @var{OFF} to @code{REALIGN_LOAD}, in which case the low\n\
1750log2(@var{VS}) @minus{} 1 bits of @var{addr} will be considered.",
38f8b050
JR
1751 tree, (void), NULL)
1752
10766209
RS
1753/* Returns a built-in function that realizes the vectorized version of
1754 a target-independent function, or NULL_TREE if not available. */
38f8b050
JR
1755DEFHOOK
1756(builtin_vectorized_function,
673c2f63 1757 "This hook should return the decl of a function that implements the\n\
10766209 1758vectorized variant of the function with the @code{combined_fn} code\n\
673c2f63 1759@var{code} or @code{NULL_TREE} if such a function is not available.\n\
10766209
RS
1760The return type of the vectorized function shall be of vector type\n\
1761@var{vec_type_out} and the argument types should be @var{vec_type_in}.",
1762 tree, (unsigned code, tree vec_type_out, tree vec_type_in),
1763 default_builtin_vectorized_function)
1764
1765/* Returns a built-in function that realizes the vectorized version of
1766 a target-specific function, or NULL_TREE if not available. */
1767DEFHOOK
1768(builtin_md_vectorized_function,
1769 "This hook should return the decl of a function that implements the\n\
1770vectorized variant of target built-in function @code{fndecl}. The\n\
673c2f63
JM
1771return type of the vectorized function shall be of vector type\n\
1772@var{vec_type_out} and the argument types should be @var{vec_type_in}.",
38f8b050 1773 tree, (tree fndecl, tree vec_type_out, tree vec_type_in),
10766209 1774 default_builtin_md_vectorized_function)
38f8b050
JR
1775
1776/* Returns a function declaration for a builtin that realizes the
1777 vector conversion, or NULL_TREE if not available. */
1778DEFHOOK
1779(builtin_conversion,
673c2f63
JM
1780 "This hook should return the DECL of a function that implements conversion of the\n\
1781input vector of type @var{src_type} to type @var{dest_type}.\n\
1782The value of @var{code} is one of the enumerators in @code{enum tree_code} and\n\
1783specifies how the conversion is to be applied\n\
1784(truncation, rounding, etc.).\n\
1785\n\
1786If this hook is defined, the autovectorizer will use the\n\
1787@code{TARGET_VECTORIZE_BUILTIN_CONVERSION} target hook when vectorizing\n\
1788conversion. Otherwise, it will return @code{NULL_TREE}.",
38f8b050
JR
1789 tree, (unsigned code, tree dest_type, tree src_type),
1790 default_builtin_vectorized_conversion)
1791
720f5239
IR
1792/* Cost of different vector/scalar statements in vectorization cost
1793 model. In case of misaligned vector loads and stores the cost depends
1794 on the data type and misalignment value. */
38f8b050
JR
1795DEFHOOK
1796(builtin_vectorization_cost,
673c2f63
JM
1797 "Returns cost of different scalar or vector statements for vectorization cost model.\n\
1798For vector memory operations the cost may depend on type (@var{vectype}) and\n\
1799misalignment value (@var{misalign}).",
720f5239 1800 int, (enum vect_cost_for_stmt type_of_cost, tree vectype, int misalign),
38f8b050
JR
1801 default_builtin_vectorization_cost)
1802
1803/* Return true if vector alignment is reachable (by peeling N
1804 iterations) for the given type. */
1805DEFHOOK
1806(vector_alignment_reachable,
673c2f63 1807 "Return true if vector alignment is reachable (by peeling N iterations) for the given type.",
38f8b050
JR
1808 bool, (const_tree type, bool is_packed),
1809 default_builtin_vector_alignment_reachable)
1810
22e4dee7
RH
1811/* Return true if a vector created for vec_perm_const is valid.
1812 A NULL indicates that all constants are valid permutations. */
38f8b050 1813DEFHOOK
5a3c0068 1814(vec_perm_const_ok,
673c2f63 1815 "Return true if a vector created for @code{vec_perm_const} is valid.",
ef4bddc2 1816 bool, (machine_mode, const unsigned char *sel),
22e4dee7 1817 NULL)
38f8b050
JR
1818
1819/* Return true if the target supports misaligned store/load of a
1820 specific factor denoted in the third parameter. The last parameter
1821 is true if the access is defined in a packed struct. */
1822DEFHOOK
1823(support_vector_misalignment,
673c2f63
JM
1824 "This hook should return true if the target supports misaligned vector\n\
1825store/load of a specific factor denoted in the @var{misalignment}\n\
1826parameter. The vector store/load should be of machine mode @var{mode} and\n\
1827the elements in the vectors should be of type @var{type}. @var{is_packed}\n\
1828parameter is true if the memory access is defined in a packed struct.",
38f8b050 1829 bool,
ef4bddc2 1830 (machine_mode mode, const_tree type, int misalignment, bool is_packed),
38f8b050
JR
1831 default_builtin_support_vector_misalignment)
1832
cc4b5170
RG
1833/* Returns the preferred mode for SIMD operations for the specified
1834 scalar mode. */
26983c22 1835DEFHOOK
cc4b5170 1836(preferred_simd_mode,
673c2f63
JM
1837 "This hook should return the preferred mode for vectorizing scalar\n\
1838mode @var{mode}. The default is\n\
1839equal to @code{word_mode}, because the vectorizer can do some\n\
1840transformations even in absence of specialized @acronym{SIMD} hardware.",
ef4bddc2
RS
1841 machine_mode,
1842 (machine_mode mode),
cc4b5170 1843 default_preferred_simd_mode)
26983c22 1844
767f865f
RG
1845/* Returns a mask of vector sizes to iterate over when auto-vectorizing
1846 after processing the preferred one derived from preferred_simd_mode. */
1847DEFHOOK
1848(autovectorize_vector_sizes,
673c2f63
JM
1849 "This hook should return a mask of sizes that should be iterated over\n\
1850after trying to autovectorize using the vector size derived from the\n\
1851mode returned by @code{TARGET_VECTORIZE_PREFERRED_SIMD_MODE}.\n\
1852The default is zero which means to not iterate over other vector sizes.",
767f865f
RG
1853 unsigned int,
1854 (void),
1855 default_autovectorize_vector_sizes)
1856
9f47c7e5
IE
1857/* Function to get a target mode for a vector mask. */
1858DEFHOOK
1859(get_mask_mode,
1860 "This hook returns mode to be used for a mask to be used for a vector\n\
1861of specified @var{length} with @var{nunits} elements. By default an integer\n\
1862vector mode of a proper size is returned.",
1863 machine_mode,
1864 (unsigned nunits, unsigned length),
1865 default_get_mask_mode)
1866
aec7ae7d
JJ
1867/* Target builtin that implements vector gather operation. */
1868DEFHOOK
1869(builtin_gather,
673c2f63
JM
1870 "Target builtin that implements vector gather operation. @var{mem_vectype}\n\
1871is the vector type of the load and @var{index_type} is scalar type of\n\
1872the index, scaled by @var{scale}.\n\
1873The default is @code{NULL_TREE} which means to not vectorize gather\n\
1874loads.",
aec7ae7d
JJ
1875 tree,
1876 (const_tree mem_vectype, const_tree index_type, int scale),
1877 NULL)
1878
3bab6342
AT
1879/* Target builtin that implements vector scatter operation. */
1880DEFHOOK
1881(builtin_scatter,
1882"Target builtin that implements vector scatter operation. @var{vectype}\n\
1883is the vector type of the store and @var{index_type} is scalar type of\n\
1884the index, scaled by @var{scale}.\n\
1885The default is @code{NULL_TREE} which means to not vectorize scatter\n\
1886stores.",
1887 tree,
1888 (const_tree vectype, const_tree index_type, int scale),
1889 NULL)
1890
c3e7ee41
BS
1891/* Target function to initialize the cost model for a loop or block. */
1892DEFHOOK
1893(init_cost,
1894 "This hook should initialize target-specific data structures in preparation "
1895 "for modeling the costs of vectorizing a loop or basic block. The default "
92345349
BS
1896 "allocates three unsigned integers for accumulating costs for the prologue, "
1897 "body, and epilogue of the loop or basic block. If @var{loop_info} is "
1898 "non-NULL, it identifies the loop being vectorized; otherwise a single block "
1899 "is being vectorized.",
c3e7ee41
BS
1900 void *,
1901 (struct loop *loop_info),
1902 default_init_cost)
1903
1904/* Target function to record N statements of the given kind using the
92345349
BS
1905 given vector type within the cost model data for the current loop or
1906 block. */
c3e7ee41
BS
1907DEFHOOK
1908(add_stmt_cost,
1909 "This hook should update the target-specific @var{data} in response to "
92345349
BS
1910 "adding @var{count} copies of the given @var{kind} of statement to a "
1911 "loop or basic block. The default adds the builtin vectorizer cost for "
1912 "the copies of the statement to the accumulator specified by @var{where}, "
1913 "(the prologue, body, or epilogue) and returns the amount added. The "
1914 "return value should be viewed as a tentative cost that may later be "
1915 "revised.",
c3e7ee41
BS
1916 unsigned,
1917 (void *data, int count, enum vect_cost_for_stmt kind,
92345349
BS
1918 struct _stmt_vec_info *stmt_info, int misalign,
1919 enum vect_cost_model_location where),
c3e7ee41
BS
1920 default_add_stmt_cost)
1921
1922/* Target function to calculate the total cost of the current vectorized
1923 loop or block. */
1924DEFHOOK
1925(finish_cost,
1926 "This hook should complete calculations of the cost of vectorizing a loop "
92345349
BS
1927 "or basic block based on @var{data}, and return the prologue, body, and "
1928 "epilogue costs as unsigned integers. The default returns the value of "
1929 "the three accumulators.",
1930 void,
1931 (void *data, unsigned *prologue_cost, unsigned *body_cost,
1932 unsigned *epilogue_cost),
c3e7ee41
BS
1933 default_finish_cost)
1934
1935/* Function to delete target-specific cost modeling data. */
1936DEFHOOK
1937(destroy_cost_data,
1938 "This hook should release @var{data} and any related data structures "
1939 "allocated by TARGET_VECTORIZE_INIT_COST. The default releases the "
1940 "accumulator.",
1941 void,
1942 (void *data),
1943 default_destroy_cost_data)
1944
38f8b050
JR
1945HOOK_VECTOR_END (vectorize)
1946
1947#undef HOOK_PREFIX
1948#define HOOK_PREFIX "TARGET_"
1949
ec6fe917
IV
1950DEFHOOK
1951(record_offload_symbol,
1952 "Used when offloaded functions are seen in the compilation unit and no named\n\
1953sections are available. It is called once for each symbol that must be\n\
1954recorded in the offload function and variable table.",
1955 void, (tree),
1956 hook_void_tree)
1957
6d2b7199
BS
1958DEFHOOKPOD
1959(absolute_biggest_alignment,
1960 "If defined, this target hook specifies the absolute biggest alignment\n\
1961that a type or variable can have on this machine, otherwise,\n\
1962@code{BIGGEST_ALIGNMENT} is used.",
1963 HOST_WIDE_INT, BIGGEST_ALIGNMENT)
1964
38f8b050
JR
1965/* Allow target specific overriding of option settings after options have
1966 been changed by an attribute or pragma or when it is reset at the
1967 end of the code affected by an attribute or pragma. */
1968DEFHOOK
1969(override_options_after_change,
673c2f63
JM
1970 "This target function is similar to the hook @code{TARGET_OPTION_OVERRIDE}\n\
1971but is called when the optimize level is changed via an attribute or\n\
1972pragma or when it is reset at the end of the code affected by the\n\
1973attribute or pragma. It is not called at the beginning of compilation\n\
1974when @code{TARGET_OPTION_OVERRIDE} is called so if you want to perform these\n\
1975actions then, you should have @code{TARGET_OPTION_OVERRIDE} call\n\
1976@code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}.",
38f8b050
JR
1977 void, (void),
1978 hook_void_void)
1979
c713ddc0
BS
1980DEFHOOK
1981(offload_options,
1982 "Used when writing out the list of options into an LTO file. It should\n\
1983translate any relevant target-specific options (such as the ABI in use)\n\
1984into one of the @option{-foffload} options that exist as a common interface\n\
1985to express such options. It should return a string containing these options,\n\
1986separated by spaces, which the caller will free.\n",
1987char *, (void), hook_charptr_void_null)
1988
38f8b050
JR
1989DEFHOOK_UNDOC
1990(eh_return_filter_mode,
1991 "Return machine mode for filter value.",
ef4bddc2 1992 machine_mode, (void),
38f8b050
JR
1993 default_eh_return_filter_mode)
1994
1995/* Return machine mode for libgcc expanded cmp instructions. */
1996DEFHOOK
1997(libgcc_cmp_return_mode,
673c2f63
JM
1998 "This target hook should return the mode to be used for the return value\n\
1999of compare instructions expanded to libgcc calls. If not defined\n\
2000@code{word_mode} is returned which is the right choice for a majority of\n\
2001targets.",
ef4bddc2 2002 machine_mode, (void),
38f8b050
JR
2003 default_libgcc_cmp_return_mode)
2004
2005/* Return machine mode for libgcc expanded shift instructions. */
2006DEFHOOK
2007(libgcc_shift_count_mode,
673c2f63
JM
2008 "This target hook should return the mode to be used for the shift count operand\n\
2009of shift instructions expanded to libgcc calls. If not defined\n\
2010@code{word_mode} is returned which is the right choice for a majority of\n\
2011targets.",
ef4bddc2 2012 machine_mode, (void),
38f8b050
JR
2013 default_libgcc_shift_count_mode)
2014
2015/* Return machine mode to be used for _Unwind_Word type. */
2016DEFHOOK
2017(unwind_word_mode,
673c2f63
JM
2018 "Return machine mode to be used for @code{_Unwind_Word} type.\n\
2019The default is to use @code{word_mode}.",
ef4bddc2 2020 machine_mode, (void),
38f8b050
JR
2021 default_unwind_word_mode)
2022
2023/* Given two decls, merge their attributes and return the result. */
2024DEFHOOK
2025(merge_decl_attributes,
673c2f63
JM
2026 "Define this target hook if the merging of decl attributes needs special\n\
2027handling. If defined, the result is a list of the combined\n\
2028@code{DECL_ATTRIBUTES} of @var{olddecl} and @var{newdecl}.\n\
2029@var{newdecl} is a duplicate declaration of @var{olddecl}. Examples of\n\
2030when this is needed are when one attribute overrides another, or when an\n\
2031attribute is nullified by a subsequent definition. This function may\n\
2032call @code{merge_attributes} to handle machine-independent merging.\n\
2033\n\
2034@findex TARGET_DLLIMPORT_DECL_ATTRIBUTES\n\
2035If the only target-specific handling you require is @samp{dllimport}\n\
2036for Microsoft Windows targets, you should define the macro\n\
2037@code{TARGET_DLLIMPORT_DECL_ATTRIBUTES} to @code{1}. The compiler\n\
2038will then define a function called\n\
2039@code{merge_dllimport_decl_attributes} which can then be defined as\n\
2040the expansion of @code{TARGET_MERGE_DECL_ATTRIBUTES}. You can also\n\
2041add @code{handle_dll_attribute} in the attribute table for your port\n\
2042to perform initial processing of the @samp{dllimport} and\n\
2043@samp{dllexport} attributes. This is done in @file{i386/cygwin.h} and\n\
2044@file{i386/i386.c}, for example.",
38f8b050
JR
2045 tree, (tree olddecl, tree newdecl),
2046 merge_decl_attributes)
2047
2048/* Given two types, merge their attributes and return the result. */
2049DEFHOOK
2050(merge_type_attributes,
673c2f63
JM
2051 "Define this target hook if the merging of type attributes needs special\n\
2052handling. If defined, the result is a list of the combined\n\
2053@code{TYPE_ATTRIBUTES} of @var{type1} and @var{type2}. It is assumed\n\
2054that @code{comptypes} has already been called and returned 1. This\n\
2055function may call @code{merge_attributes} to handle machine-independent\n\
2056merging.",
38f8b050
JR
2057 tree, (tree type1, tree type2),
2058 merge_type_attributes)
2059
2060/* Table of machine attributes and functions to handle them.
2061 Ignored if NULL. */
2062DEFHOOKPOD
2063(attribute_table,
673c2f63 2064 "If defined, this target hook points to an array of @samp{struct\n\
15ab4e1e 2065attribute_spec} (defined in @file{tree-core.h}) specifying the machine\n\
673c2f63
JM
2066specific attributes for this target and some of the restrictions on the\n\
2067entities to which these attributes are applied and the arguments they\n\
2068take.",
38f8b050
JR
2069 const struct attribute_spec *, NULL)
2070
2071/* Return true iff attribute NAME expects a plain identifier as its first
2072 argument. */
2073DEFHOOK
2074(attribute_takes_identifier_p,
673c2f63
JM
2075 "If defined, this target hook is a function which returns true if the\n\
2076machine-specific attribute named @var{name} expects an identifier\n\
2077given as its first argument to be passed on as a plain identifier, not\n\
2078subjected to name lookup. If this is not defined, the default is\n\
2079false for all machine-specific attributes.",
38f8b050
JR
2080 bool, (const_tree name),
2081 hook_bool_const_tree_false)
2082
2083/* Return zero if the attributes on TYPE1 and TYPE2 are incompatible,
2084 one if they are compatible and two if they are nearly compatible
2085 (which causes a warning to be generated). */
2086DEFHOOK
2087(comp_type_attributes,
673c2f63
JM
2088 "If defined, this target hook is a function which returns zero if the attributes on\n\
2089@var{type1} and @var{type2} are incompatible, one if they are compatible,\n\
2090and two if they are nearly compatible (which causes a warning to be\n\
2091generated). If this is not defined, machine-specific attributes are\n\
2092supposed always to be compatible.",
38f8b050
JR
2093 int, (const_tree type1, const_tree type2),
2094 hook_int_const_tree_const_tree_1)
2095
2096/* Assign default attributes to the newly defined TYPE. */
2097DEFHOOK
2098(set_default_type_attributes,
673c2f63
JM
2099 "If defined, this target hook is a function which assigns default attributes to\n\
2100the newly defined @var{type}.",
38f8b050
JR
2101 void, (tree type),
2102 hook_void_tree)
2103
2104/* Insert attributes on the newly created DECL. */
2105DEFHOOK
2106(insert_attributes,
673c2f63
JM
2107 "Define this target hook if you want to be able to add attributes to a decl\n\
2108when it is being created. This is normally useful for back ends which\n\
2109wish to implement a pragma by using the attributes which correspond to\n\
2110the pragma's effect. The @var{node} argument is the decl which is being\n\
2111created. The @var{attr_ptr} argument is a pointer to the attribute list\n\
2112for this decl. The list itself should not be modified, since it may be\n\
2113shared with other decls, but attributes may be chained on the head of\n\
2114the list and @code{*@var{attr_ptr}} modified to point to the new\n\
2115attributes, or a copy of the list may be made if further changes are\n\
2116needed.",
38f8b050
JR
2117 void, (tree node, tree *attr_ptr),
2118 hook_void_tree_treeptr)
2119
2120/* Return true if FNDECL (which has at least one machine attribute)
2121 can be inlined despite its machine attributes, false otherwise. */
2122DEFHOOK
2123(function_attribute_inlinable_p,
673c2f63 2124 "@cindex inlining\n\
5bd40ade 2125This target hook returns @code{true} if it is OK to inline @var{fndecl}\n\
673c2f63
JM
2126into the current function, despite its having target-specific\n\
2127attributes, @code{false} otherwise. By default, if a function has a\n\
2128target specific attribute attached to it, it will not be inlined.",
38f8b050
JR
2129 bool, (const_tree fndecl),
2130 hook_bool_const_tree_false)
2131
2132/* Return true if bitfields in RECORD_TYPE should follow the
2133 Microsoft Visual C++ bitfield layout rules. */
2134DEFHOOK
2135(ms_bitfield_layout_p,
673c2f63
JM
2136 "This target hook returns @code{true} if bit-fields in the given\n\
2137@var{record_type} are to be laid out following the rules of Microsoft\n\
2138Visual C/C++, namely: (i) a bit-field won't share the same storage\n\
2139unit with the previous bit-field if their underlying types have\n\
2140different sizes, and the bit-field will be aligned to the highest\n\
2141alignment of the underlying types of itself and of the previous\n\
2142bit-field; (ii) a zero-sized bit-field will affect the alignment of\n\
2143the whole enclosing structure, even if it is unnamed; except that\n\
2144(iii) a zero-sized bit-field will be disregarded unless it follows\n\
2145another bit-field of nonzero size. If this hook returns @code{true},\n\
2146other macros that control bit-field layout are ignored.\n\
2147\n\
2148When a bit-field is inserted into a packed record, the whole size\n\
2149of the underlying type is used by one or more same-size adjacent\n\
2150bit-fields (that is, if its long:3, 32 bits is used in the record,\n\
2151and any additional adjacent long bit-fields are packed into the same\n\
2152chunk of 32 bits. However, if the size changes, a new field of that\n\
2153size is allocated). In an unpacked record, this is the same as using\n\
2154alignment, but not equivalent when packing.\n\
2155\n\
2156If both MS bit-fields and @samp{__attribute__((packed))} are used,\n\
2157the latter will take precedence. If @samp{__attribute__((packed))} is\n\
2158used on a single field when MS bit-fields are in use, it will take\n\
2159precedence for that field, but the alignment of the rest of the structure\n\
2160may affect its placement.",
38f8b050
JR
2161 bool, (const_tree record_type),
2162 hook_bool_const_tree_false)
2163
2e681adf
JR
2164/* For now this is only an interface to WORDS_BIG_ENDIAN for
2165 target-independent code like the front ends, need performance testing
2166 before switching completely to the target hook. */
2167DEFHOOK_UNDOC
2168(words_big_endian,
2169 "",
2170 bool, (void),
2171 targhook_words_big_endian)
2172
2173/* Likewise for FLOAT_WORDS_BIG_ENDIAN. */
2174DEFHOOK_UNDOC
2175(float_words_big_endian,
2176 "",
2177 bool, (void),
2178 targhook_float_words_big_endian)
2179
9193fb05
JM
2180DEFHOOK
2181(float_exceptions_rounding_supported_p,
2182 "Returns true if the target supports IEEE 754 floating-point exceptions\
2183 and rounding modes, false otherwise. This is intended to relate to the\
2184 @code{float} and @code{double} types, but not necessarily @code{long double}.\
2185 By default, returns true if the @code{adddf3} instruction pattern is\
2186 available and false otherwise, on the assumption that hardware floating\
2187 point supports exceptions and rounding modes but software floating point\
2188 does not.",
2189 bool, (void),
2190 default_float_exceptions_rounding_supported_p)
2191
38f8b050
JR
2192/* True if the target supports decimal floating point. */
2193DEFHOOK
2194(decimal_float_supported_p,
673c2f63 2195 "Returns true if the target supports decimal floating point.",
38f8b050
JR
2196 bool, (void),
2197 default_decimal_float_supported_p)
2198
2199/* True if the target supports fixed-point. */
2200DEFHOOK
2201(fixed_point_supported_p,
673c2f63 2202 "Returns true if the target supports fixed-point arithmetic.",
38f8b050
JR
2203 bool, (void),
2204 default_fixed_point_supported_p)
2205
2206/* Return true if anonymous bitfields affect structure alignment. */
2207DEFHOOK
2208(align_anon_bitfield,
673c2f63
JM
2209 "When @code{PCC_BITFIELD_TYPE_MATTERS} is true this hook will determine\n\
2210whether unnamed bitfields affect the alignment of the containing\n\
2211structure. The hook should return true if the structure should inherit\n\
2212the alignment requirements of an unnamed bitfield's type.",
38f8b050
JR
2213 bool, (void),
2214 hook_bool_void_false)
2215
2216/* Return true if volatile bitfields should use the narrowest type possible.
2217 Return false if they should use the container type. */
2218DEFHOOK
2219(narrow_volatile_bitfield,
673c2f63
JM
2220 "This target hook should return @code{true} if accesses to volatile bitfields\n\
2221should use the narrowest mode possible. It should return @code{false} if\n\
2222these accesses should use the bitfield container type.\n\
2223\n\
7d0b9a9c 2224The default is @code{false}.",
38f8b050
JR
2225 bool, (void),
2226 hook_bool_void_false)
2227
2228/* Set up target-specific built-in functions. */
2229DEFHOOK
2230(init_builtins,
673c2f63
JM
2231 "Define this hook if you have any machine-specific built-in functions\n\
2232that need to be defined. It should be a function that performs the\n\
2233necessary setup.\n\
2234\n\
2235Machine specific built-in functions can be useful to expand special machine\n\
2236instructions that would otherwise not normally be generated because\n\
2237they have no equivalent in the source language (for example, SIMD vector\n\
2238instructions or prefetch instructions).\n\
2239\n\
2240To create a built-in function, call the function\n\
2241@code{lang_hooks.builtin_function}\n\
2242which is defined by the language front end. You can use any type nodes set\n\
2243up by @code{build_common_tree_nodes};\n\
2244only language front ends that use those two functions will call\n\
2245@samp{TARGET_INIT_BUILTINS}.",
38f8b050
JR
2246 void, (void),
2247 hook_void_void)
2248
2249/* Initialize (if INITIALIZE_P is true) and return the target-specific
2250 built-in function decl for CODE.
2251 Return NULL if that is not possible. Return error_mark_node if CODE
2252 is outside of the range of valid target builtin function codes. */
2253DEFHOOK
2254(builtin_decl,
673c2f63
JM
2255 "Define this hook if you have any machine-specific built-in functions\n\
2256that need to be defined. It should be a function that returns the\n\
2257builtin function declaration for the builtin function code @var{code}.\n\
2258If there is no such builtin and it cannot be initialized at this time\n\
2259if @var{initialize_p} is true the function should return @code{NULL_TREE}.\n\
2260If @var{code} is out of range the function should return\n\
2261@code{error_mark_node}.",
38f8b050
JR
2262 tree, (unsigned code, bool initialize_p), NULL)
2263
2264/* Expand a target-specific builtin. */
2265DEFHOOK
2266(expand_builtin,
673c2f63
JM
2267 "\n\
2268Expand a call to a machine specific built-in function that was set up by\n\
2269@samp{TARGET_INIT_BUILTINS}. @var{exp} is the expression for the\n\
2270function call; the result should go to @var{target} if that is\n\
2271convenient, and have mode @var{mode} if that is convenient.\n\
2272@var{subtarget} may be used as the target for computing one of\n\
2273@var{exp}'s operands. @var{ignore} is nonzero if the value is to be\n\
2274ignored. This function should return the result of the call to the\n\
2275built-in function.",
38f8b050 2276 rtx,
ef4bddc2 2277 (tree exp, rtx target, rtx subtarget, machine_mode mode, int ignore),
38f8b050
JR
2278 default_expand_builtin)
2279
d5e254e1
IE
2280DEFHOOK
2281(builtin_chkp_function,
2282 "This hook allows target to redefine built-in functions used by\n\
2283Pointer Bounds Checker for code instrumentation. Hook should return\n\
2284fndecl of function implementing generic builtin whose code is\n\
2285passed in @var{fcode}. Currently following built-in functions are\n\
2286obtained using this hook:\n\
2287@deftypefn {Built-in Function} __bounds_type __chkp_bndmk (const void *@var{lb}, size_t @var{size})\n\
2288Function code - BUILT_IN_CHKP_BNDMK. This built-in function is used\n\
2289by Pointer Bounds Checker to create bound values. @var{lb} holds low\n\
2290bound of the resulting bounds. @var{size} holds size of created bounds.\n\
2291@end deftypefn\n\
2292\n\
2293@deftypefn {Built-in Function} void __chkp_bndstx (const void *@var{ptr}, __bounds_type @var{b}, const void **@var{loc})\n\
2294Function code - @code{BUILT_IN_CHKP_BNDSTX}. This built-in function is used\n\
2295by Pointer Bounds Checker to store bounds @var{b} for pointer @var{ptr}\n\
2296when @var{ptr} is stored by address @var{loc}.\n\
2297@end deftypefn\n\
2298\n\
2299@deftypefn {Built-in Function} __bounds_type __chkp_bndldx (const void **@var{loc}, const void *@var{ptr})\n\
2300Function code - @code{BUILT_IN_CHKP_BNDLDX}. This built-in function is used\n\
2301by Pointer Bounds Checker to get bounds of pointer @var{ptr} loaded by\n\
2302address @var{loc}.\n\
2303@end deftypefn\n\
2304\n\
2305@deftypefn {Built-in Function} void __chkp_bndcl (const void *@var{ptr}, __bounds_type @var{b})\n\
2306Function code - @code{BUILT_IN_CHKP_BNDCL}. This built-in function is used\n\
2307by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\
2308lower bound of bounds @var{b}.\n\
2309@end deftypefn\n\
2310\n\
2311@deftypefn {Built-in Function} void __chkp_bndcu (const void *@var{ptr}, __bounds_type @var{b})\n\
2312Function code - @code{BUILT_IN_CHKP_BNDCU}. This built-in function is used\n\
2313by Pointer Bounds Checker to perform check for pointer @var{ptr} against\n\
2314upper bound of bounds @var{b}.\n\
2315@end deftypefn\n\
2316\n\
2317@deftypefn {Built-in Function} __bounds_type __chkp_bndret (void *@var{ptr})\n\
2318Function code - @code{BUILT_IN_CHKP_BNDRET}. This built-in function is used\n\
2319by Pointer Bounds Checker to obtain bounds returned by a call statement.\n\
2320@var{ptr} passed to built-in is @code{SSA_NAME} returned by the call.\n\
2321@end deftypefn\n\
2322\n\
2323@deftypefn {Built-in Function} __bounds_type __chkp_intersect (__bounds_type @var{b1}, __bounds_type @var{b2})\n\
2324Function code - @code{BUILT_IN_CHKP_INTERSECT}. This built-in function\n\
2325returns intersection of bounds @var{b1} and @var{b2}.\n\
2326@end deftypefn\n\
2327\n\
2328@deftypefn {Built-in Function} __bounds_type __chkp_narrow (const void *@var{ptr}, __bounds_type @var{b}, size_t @var{s})\n\
2329Function code - @code{BUILT_IN_CHKP_NARROW}. This built-in function\n\
2330returns intersection of bounds @var{b} and\n\
2331[@var{ptr}, @var{ptr} + @var{s} - @code{1}].\n\
2332@end deftypefn\n\
2333\n\
2334@deftypefn {Built-in Function} size_t __chkp_sizeof (const void *@var{ptr})\n\
2335Function code - @code{BUILT_IN_CHKP_SIZEOF}. This built-in function\n\
2336returns size of object referenced by @var{ptr}. @var{ptr} is always\n\
2337@code{ADDR_EXPR} of @code{VAR_DECL}. This built-in is used by\n\
2338Pointer Bounds Checker when bounds of object cannot be computed statically\n\
2339(e.g. object has incomplete type).\n\
2340@end deftypefn\n\
2341\n\
2342@deftypefn {Built-in Function} const void *__chkp_extract_lower (__bounds_type @var{b})\n\
2343Function code - @code{BUILT_IN_CHKP_EXTRACT_LOWER}. This built-in function\n\
2344returns lower bound of bounds @var{b}.\n\
2345@end deftypefn\n\
2346\n\
2347@deftypefn {Built-in Function} const void *__chkp_extract_upper (__bounds_type @var{b})\n\
2348Function code - @code{BUILT_IN_CHKP_EXTRACT_UPPER}. This built-in function\n\
2349returns upper bound of bounds @var{b}.\n\
2350@end deftypefn",
2351 tree, (unsigned fcode),
2352 default_builtin_chkp_function)
2353
2354DEFHOOK
2355(chkp_bound_type,
2356 "Return type to be used for bounds",
2357 tree, (void),
2358 default_chkp_bound_type)
2359
2360DEFHOOK
2361(chkp_bound_mode,
2362 "Return mode to be used for bounds.",
2363 enum machine_mode, (void),
2364 default_chkp_bound_mode)
2365
2366DEFHOOK
2367(chkp_make_bounds_constant,
2368 "Return constant used to statically initialize constant bounds\n\
2369with specified lower bound @var{lb} and upper bounds @var{ub}.",
2370 tree, (HOST_WIDE_INT lb, HOST_WIDE_INT ub),
2371 default_chkp_make_bounds_constant)
2372
2373DEFHOOK
2374(chkp_initialize_bounds,
2375 "Generate a list of statements @var{stmts} to initialize pointer\n\
2376bounds variable @var{var} with bounds @var{lb} and @var{ub}. Return\n\
2377the number of generated statements.",
2378 int, (tree var, tree lb, tree ub, tree *stmts),
2379 default_chkp_initialize_bounds)
2380
38f8b050
JR
2381/* Select a replacement for a target-specific builtin. This is done
2382 *before* regular type checking, and so allows the target to
2383 implement a crude form of function overloading. The result is a
2384 complete expression that implements the operation. PARAMS really
2385 has type VEC(tree,gc)*, but we don't want to include tree.h here. */
d66f5459 2386DEFHOOK
38f8b050 2387(resolve_overloaded_builtin,
673c2f63
JM
2388 "Select a replacement for a machine specific built-in function that\n\
2389was set up by @samp{TARGET_INIT_BUILTINS}. This is done\n\
2390@emph{before} regular type checking, and so allows the target to\n\
2391implement a crude form of function overloading. @var{fndecl} is the\n\
2392declaration of the built-in function. @var{arglist} is the list of\n\
2393arguments passed to the built-in function. The result is a\n\
2394complete expression that implements the operation, usually\n\
2395another @code{CALL_EXPR}.\n\
2396@var{arglist} really has type @samp{VEC(tree,gc)*}",
d66f5459 2397 tree, (unsigned int /*location_t*/ loc, tree fndecl, void *arglist), NULL)
38f8b050 2398
ea679d55
JG
2399/* Fold a target-specific builtin to a tree valid for both GIMPLE
2400 and GENERIC. */
08914aaa 2401DEFHOOK
38f8b050 2402(fold_builtin,
673c2f63
JM
2403 "Fold a call to a machine specific built-in function that was set up by\n\
2404@samp{TARGET_INIT_BUILTINS}. @var{fndecl} is the declaration of the\n\
2405built-in function. @var{n_args} is the number of arguments passed to\n\
2406the function; the arguments themselves are pointed to by @var{argp}.\n\
2407The result is another tree, valid for both GIMPLE and GENERIC,\n\
2408containing a simplified expression for the call's result. If\n\
2409@var{ignore} is true the value will be ignored.",
08914aaa 2410 tree, (tree fndecl, int n_args, tree *argp, bool ignore),
38f8b050
JR
2411 hook_tree_tree_int_treep_bool_null)
2412
ea679d55
JG
2413/* Fold a target-specific builtin to a valid GIMPLE tree. */
2414DEFHOOK
2415(gimple_fold_builtin,
2416 "Fold a call to a machine specific built-in function that was set up\n\
2417by @samp{TARGET_INIT_BUILTINS}. @var{gsi} points to the gimple\n\
2418statement holding the function call. Returns true if any change\n\
2419was made to the GIMPLE stream.",
2420 bool, (gimple_stmt_iterator *gsi),
2421 hook_bool_gsiptr_false)
2422
3649b9b7
ST
2423/* Target hook is used to compare the target attributes in two functions to
2424 determine which function's features get higher priority. This is used
2425 during function multi-versioning to figure out the order in which two
2426 versions must be dispatched. A function version with a higher priority
2427 is checked for dispatching earlier. DECL1 and DECL2 are
2428 the two function decls that will be compared. It returns positive value
2429 if DECL1 is higher priority, negative value if DECL2 is higher priority
2430 and 0 if they are the same. */
2431DEFHOOK
2432(compare_version_priority,
673c2f63
JM
2433 "This hook is used to compare the target attributes in two functions to\n\
2434determine which function's features get higher priority. This is used\n\
2435during function multi-versioning to figure out the order in which two\n\
2436versions must be dispatched. A function version with a higher priority\n\
2437is checked for dispatching earlier. @var{decl1} and @var{decl2} are\n\
2438 the two function decls that will be compared.",
3649b9b7
ST
2439 int, (tree decl1, tree decl2), NULL)
2440
2441/* Target hook is used to generate the dispatcher logic to invoke the right
2442 function version at run-time for a given set of function versions.
2443 ARG points to the callgraph node of the dispatcher function whose body
2444 must be generated. */
2445DEFHOOK
2446(generate_version_dispatcher_body,
673c2f63
JM
2447 "This hook is used to generate the dispatcher logic to invoke the right\n\
2448function version at run-time for a given set of function versions.\n\
2449@var{arg} points to the callgraph node of the dispatcher function whose\n\
2450body must be generated.",
3649b9b7
ST
2451 tree, (void *arg), NULL)
2452
2453/* Target hook is used to get the dispatcher function for a set of function
2454 versions. The dispatcher function is called to invoke the right function
2455 version at run-time. DECL is one version from a set of semantically
2456 identical versions. */
2457DEFHOOK
2458(get_function_versions_dispatcher,
673c2f63
JM
2459 "This hook is used to get the dispatcher function for a set of function\n\
2460versions. The dispatcher function is called to invoke the right function\n\
2461version at run-time. @var{decl} is one version from a set of semantically\n\
2462identical versions.",
3649b9b7
ST
2463 tree, (void *decl), NULL)
2464
38f8b050 2465/* Returns a code for a target-specific builtin that implements
ee62a5a6 2466 reciprocal of a target-specific function, or NULL_TREE if not available. */
89356d17 2467DEFHOOK
38f8b050 2468(builtin_reciprocal,
ee62a5a6
RS
2469 "This hook should return the DECL of a function that implements the\n\
2470reciprocal of the machine-specific builtin function @var{fndecl}, or\n\
7b90c63a 2471@code{NULL_TREE} if such a function is not available.",
ee62a5a6 2472 tree, (tree fndecl),
38f8b050
JR
2473 default_builtin_reciprocal)
2474
2475/* For a vendor-specific TYPE, return a pointer to a statically-allocated
2476 string containing the C++ mangling for TYPE. In all other cases, return
2477 NULL. */
2478DEFHOOK
2479(mangle_type,
673c2f63
JM
2480 "If your target defines any fundamental types, or any types your target\n\
2481uses should be mangled differently from the default, define this hook\n\
2482to return the appropriate encoding for these types as part of a C++\n\
2483mangled name. The @var{type} argument is the tree structure representing\n\
2484the type to be mangled. The hook may be applied to trees which are\n\
2485not target-specific fundamental types; it should return @code{NULL}\n\
2486for all such types, as well as arguments it does not recognize. If the\n\
2487return value is not @code{NULL}, it must point to a statically-allocated\n\
2488string constant.\n\
2489\n\
2490Target-specific fundamental types might be new fundamental types or\n\
2491qualified versions of ordinary fundamental types. Encode new\n\
2492fundamental types as @samp{@w{u @var{n} @var{name}}}, where @var{name}\n\
2493is the name used for the type in source code, and @var{n} is the\n\
2494length of @var{name} in decimal. Encode qualified versions of\n\
2495ordinary types as @samp{@w{U @var{n} @var{name} @var{code}}}, where\n\
2496@var{name} is the name used for the type qualifier in source code,\n\
2497@var{n} is the length of @var{name} as above, and @var{code} is the\n\
2498code used to represent the unqualified version of this type. (See\n\
2499@code{write_builtin_type} in @file{cp/mangle.c} for the list of\n\
2500codes.) In both cases the spaces are for clarity; do not include any\n\
2501spaces in your string.\n\
2502\n\
2503This hook is applied to types prior to typedef resolution. If the mangled\n\
2504name for a particular type depends only on that type's main variant, you\n\
2505can perform typedef resolution yourself using @code{TYPE_MAIN_VARIANT}\n\
2506before mangling.\n\
2507\n\
2508The default version of this hook always returns @code{NULL}, which is\n\
2509appropriate for a target that does not define any new fundamental\n\
2510types.",
38f8b050
JR
2511 const char *, (const_tree type),
2512 hook_constcharptr_const_tree_null)
2513
2514/* Make any adjustments to libfunc names needed for this target. */
2515DEFHOOK
2516(init_libfuncs,
673c2f63
JM
2517 "This hook should declare additional library routines or rename\n\
2518existing ones, using the functions @code{set_optab_libfunc} and\n\
2519@code{init_one_libfunc} defined in @file{optabs.c}.\n\
2520@code{init_optabs} calls this macro after initializing all the normal\n\
2521library routines.\n\
2522\n\
2523The default is to do nothing. Most ports don't need to define this hook.",
38f8b050
JR
2524 void, (void),
2525 hook_void_void)
2526
cdbf4541
BS
2527 /* Add a __gnu_ prefix to library functions rather than just __. */
2528DEFHOOKPOD
2529(libfunc_gnu_prefix,
2530 "If false (the default), internal library routines start with two\n\
2531underscores. If set to true, these routines start with @code{__gnu_}\n\
2532instead. E.g., @code{__muldi3} changes to @code{__gnu_muldi3}. This\n\
2533currently only affects functions defined in @file{libgcc2.c}. If this\n\
2534is set to true, the @file{tm.h} file must also\n\
2535@code{#define LIBGCC2_GNU_PREFIX}.",
2536 bool, false)
2537
38f8b050
JR
2538/* Given a decl, a section name, and whether the decl initializer
2539 has relocs, choose attributes for the section. */
2540/* ??? Should be merged with SELECT_SECTION and UNIQUE_SECTION. */
2541DEFHOOK
2542(section_type_flags,
673c2f63
JM
2543 "Choose a set of section attributes for use by @code{TARGET_ASM_NAMED_SECTION}\n\
2544based on a variable or function decl, a section name, and whether or not the\n\
2545declaration's initializer may contain runtime relocations. @var{decl} may be\n\
2546null, in which case read-write data should be assumed.\n\
2547\n\
2548The default version of this function handles choosing code vs data,\n\
2549read-only vs read-write data, and @code{flag_pic}. You should only\n\
2550need to override this if your target has special flags that might be\n\
2551set via @code{__attribute__}.",
38f8b050
JR
2552 unsigned int, (tree decl, const char *name, int reloc),
2553 default_section_type_flags)
2554
d33d9e47
AI
2555DEFHOOK
2556(libc_has_function,
2557 "This hook determines whether a function from a class of functions\n\
2558@var{fn_class} is present at the runtime.",
2559 bool, (enum function_class fn_class),
2560 default_libc_has_function)
2561
38f8b050
JR
2562/* True if new jumps cannot be created, to replace existing ones or
2563 not, at the current point in the compilation. */
2564DEFHOOK
2565(cannot_modify_jumps_p,
673c2f63
JM
2566 "This target hook returns @code{true} past the point in which new jump\n\
2567instructions could be created. On machines that require a register for\n\
2568every jump such as the SHmedia ISA of SH5, this point would typically be\n\
2569reload, so this target hook should be defined to a function such as:\n\
2570\n\
2571@smallexample\n\
2572static bool\n\
2573cannot_modify_jumps_past_reload_p ()\n\
2574@{\n\
2575 return (reload_completed || reload_in_progress);\n\
2576@}\n\
2577@end smallexample",
38f8b050
JR
2578 bool, (void),
2579 hook_bool_void_false)
2580
4b4de898
JR
2581/* True if FOLLOWER may be modified to follow FOLLOWEE. */
2582DEFHOOK
2583(can_follow_jump,
2584 "FOLLOWER and FOLLOWEE are JUMP_INSN instructions;\
2585 return true if FOLLOWER may be modified to follow FOLLOWEE;\
2586 false, if it can't.\
2587 For example, on some targets, certain kinds of branches can't be made to\
2588 follow through a hot/cold partitioning.",
c1ce59ab
DM
2589 bool, (const rtx_insn *follower, const rtx_insn *followee),
2590 hook_bool_const_rtx_insn_const_rtx_insn_true)
4b4de898 2591
38f8b050
JR
2592/* Return a register class for which branch target register
2593 optimizations should be applied. */
2594DEFHOOK
2595(branch_target_register_class,
673c2f63
JM
2596 "This target hook returns a register class for which branch target register\n\
2597optimizations should be applied. All registers in this class should be\n\
2598usable interchangeably. After reload, registers in this class will be\n\
2599re-allocated and loads will be hoisted out of loops and be subjected\n\
2600to inter-block scheduling.",
a87cf97e 2601 reg_class_t, (void),
38f8b050
JR
2602 default_branch_target_register_class)
2603
2604/* Return true if branch target register optimizations should include
2605 callee-saved registers that are not already live during the current
2606 function. AFTER_PE_GEN is true if prologues and epilogues have
2607 already been generated. */
2608DEFHOOK
2609(branch_target_register_callee_saved,
673c2f63
JM
2610 "Branch target register optimization will by default exclude callee-saved\n\
2611registers\n\
2612that are not already live during the current function; if this target hook\n\
2613returns true, they will be included. The target code must than make sure\n\
2614that all target registers in the class returned by\n\
2615@samp{TARGET_BRANCH_TARGET_REGISTER_CLASS} that might need saving are\n\
2616saved. @var{after_prologue_epilogue_gen} indicates if prologues and\n\
2617epilogues have already been generated. Note, even if you only return\n\
2618true when @var{after_prologue_epilogue_gen} is false, you still are likely\n\
2619to have to make special provisions in @code{INITIAL_ELIMINATION_OFFSET}\n\
2620to reserve space for caller-saved target registers.",
38f8b050
JR
2621 bool, (bool after_prologue_epilogue_gen),
2622 hook_bool_bool_false)
2623
2624/* Return true if the target supports conditional execution. */
2625DEFHOOK
2626(have_conditional_execution,
673c2f63
JM
2627 "This target hook returns true if the target supports conditional execution.\n\
2628This target hook is required only when the target has several different\n\
2629modes and they have different conditional execution capability, such as ARM.",
38f8b050
JR
2630 bool, (void),
2631 default_have_conditional_execution)
2632
2e0f1341
ZC
2633DEFHOOK
2634(gen_ccmp_first,
5f3bc026 2635 "This function prepares to emit a comparison insn for the first compare in a\n\
c8012fbc
WD
2636 sequence of conditional comparisions. It returns an appropriate comparison\n\
2637 with @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2638 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2639 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2640 compares in the the conditional comparision are generated without error.\n\
2641 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.",
cb4347e8 2642 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, int code, tree op0, tree op1),
2e0f1341
ZC
2643 NULL)
2644
2645DEFHOOK
2646(gen_ccmp_next,
c8012fbc
WD
2647 "This function prepares to emit a conditional comparison within a sequence\n\
2648 of conditional comparisons. It returns an appropriate comparison with\n\
2649 @code{CC} for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2650 The insns to prepare the compare are saved in @var{prep_seq} and the compare\n\
2651 insns are saved in @var{gen_seq}. They will be emitted when all the\n\
2652 compares in the conditional comparision are generated without error. The\n\
2653 @var{prev} expression is the result of a prior call to @code{gen_ccmp_first}\n\
2654 or @code{gen_ccmp_next}. It may return @code{NULL} if the combination of\n\
2655 @var{prev} and this comparison is not supported, otherwise the result must\n\
2656 be appropriate for passing to @code{gen_ccmp_next} or @code{cbranch_optab}.\n\
2657 @var{code} is the @code{rtx_code} of the compare for @var{op0} and @var{op1}.\n\
2658 @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.",
cb4347e8 2659 rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, int cmp_code, tree op0, tree op1, int bit_code),
2e0f1341
ZC
2660 NULL)
2661
38f8b050
JR
2662/* Return a new value for loop unroll size. */
2663DEFHOOK
2664(loop_unroll_adjust,
673c2f63
JM
2665 "This target hook returns a new value for the number of times @var{loop}\n\
2666should be unrolled. The parameter @var{nunroll} is the number of times\n\
2667the loop is to be unrolled. The parameter @var{loop} is a pointer to\n\
2668the loop, which is going to be checked for unrolling. This target hook\n\
2669is required only when the target has special constraints like maximum\n\
2670number of memory accesses.",
38f8b050
JR
2671 unsigned, (unsigned nunroll, struct loop *loop),
2672 NULL)
2673
1a627b35
RS
2674/* True if X is a legitimate MODE-mode immediate operand. */
2675DEFHOOK
2676(legitimate_constant_p,
673c2f63
JM
2677 "This hook returns true if @var{x} is a legitimate constant for a\n\
2678@var{mode}-mode immediate operand on the target machine. You can assume that\n\
2679@var{x} satisfies @code{CONSTANT_P}, so you need not check this.\n\
2680\n\
2681The default definition returns true.",
ef4bddc2 2682 bool, (machine_mode mode, rtx x),
1a627b35
RS
2683 hook_bool_mode_rtx_true)
2684
38f8b050
JR
2685/* True if the constant X cannot be placed in the constant pool. */
2686DEFHOOK
2687(cannot_force_const_mem,
673c2f63
JM
2688 "This hook should return true if @var{x} is of a form that cannot (or\n\
2689should not) be spilled to the constant pool. @var{mode} is the mode\n\
2690of @var{x}.\n\
2691\n\
2692The default version of this hook returns false.\n\
2693\n\
2694The primary reason to define this hook is to prevent reload from\n\
2695deciding that a non-legitimate constant would be better reloaded\n\
2696from the constant pool instead of spilling and reloading a register\n\
2697holding the constant. This restriction is often true of addresses\n\
2698of TLS symbols for various targets.",
ef4bddc2 2699 bool, (machine_mode mode, rtx x),
fbbf66e7 2700 hook_bool_mode_rtx_false)
38f8b050
JR
2701
2702DEFHOOK_UNDOC
2703(cannot_copy_insn_p,
2704 "True if the insn @var{x} cannot be duplicated.",
ac44248e 2705 bool, (rtx_insn *), NULL)
38f8b050
JR
2706
2707/* True if X is considered to be commutative. */
2708DEFHOOK
2709(commutative_p,
673c2f63
JM
2710 "This target hook returns @code{true} if @var{x} is considered to be commutative.\n\
2711Usually, this is just COMMUTATIVE_P (@var{x}), but the HP PA doesn't consider\n\
2712PLUS to be commutative inside a MEM@. @var{outer_code} is the rtx code\n\
2713of the enclosing rtl, if known, otherwise it is UNKNOWN.",
38f8b050
JR
2714 bool, (const_rtx x, int outer_code),
2715 hook_bool_const_rtx_commutative_p)
2716
2717/* True if ADDR is an address-expression whose effect depends
2718 on the mode of the memory reference it is used in. */
2719DEFHOOK
2720(mode_dependent_address_p,
673c2f63
JM
2721 "This hook returns @code{true} if memory address @var{addr} in address\n\
2722space @var{addrspace} can have\n\
2723different meanings depending on the machine mode of the memory\n\
2724reference it is used for or if the address is valid for some modes\n\
2725but not others.\n\
2726\n\
2727Autoincrement and autodecrement addresses typically have mode-dependent\n\
2728effects because the amount of the increment or decrement is the size\n\
2729of the operand being addressed. Some machines have other mode-dependent\n\
2730addresses. Many RISC machines have no mode-dependent addresses.\n\
2731\n\
2732You may assume that @var{addr} is a valid address for the machine.\n\
2733\n\
2734The default version of this hook returns @code{false}.",
5bfed9a9 2735 bool, (const_rtx addr, addr_space_t addrspace),
38f8b050
JR
2736 default_mode_dependent_address_p)
2737
2738/* Given an invalid address X for a given machine mode, try machine-specific
2739 ways to make it legitimate. Return X or an invalid address on failure. */
2740DEFHOOK
2741(legitimize_address,
673c2f63
JM
2742 "This hook is given an invalid memory address @var{x} for an\n\
2743operand of mode @var{mode} and should try to return a valid memory\n\
2744address.\n\
2745\n\
2746@findex break_out_memory_refs\n\
2747@var{x} will always be the result of a call to @code{break_out_memory_refs},\n\
2748and @var{oldx} will be the operand that was given to that function to produce\n\
2749@var{x}.\n\
2750\n\
2751The code of the hook should not alter the substructure of\n\
2752@var{x}. If it transforms @var{x} into a more legitimate form, it\n\
2753should return the new @var{x}.\n\
2754\n\
2755It is not necessary for this hook to come up with a legitimate address,\n\
2756with the exception of native TLS addresses (@pxref{Emulated TLS}).\n\
2757The compiler has standard ways of doing so in all cases. In fact, if\n\
2758the target supports only emulated TLS, it\n\
2759is safe to omit this hook or make it return @var{x} if it cannot find\n\
2760a valid way to legitimize the address. But often a machine-dependent\n\
2761strategy can generate better code.",
ef4bddc2 2762 rtx, (rtx x, rtx oldx, machine_mode mode),
38f8b050
JR
2763 default_legitimize_address)
2764
2765/* Given an address RTX, undo the effects of LEGITIMIZE_ADDRESS. */
2766DEFHOOK
2767(delegitimize_address,
673c2f63
JM
2768 "This hook is used to undo the possibly obfuscating effects of the\n\
2769@code{LEGITIMIZE_ADDRESS} and @code{LEGITIMIZE_RELOAD_ADDRESS} target\n\
2770macros. Some backend implementations of these macros wrap symbol\n\
2771references inside an @code{UNSPEC} rtx to represent PIC or similar\n\
2772addressing modes. This target hook allows GCC's optimizers to understand\n\
2773the semantics of these opaque @code{UNSPEC}s by converting them back\n\
2774into their original form.",
38f8b050
JR
2775 rtx, (rtx x),
2776 delegitimize_mem_from_attrs)
2777
93bcc8c9
JJ
2778/* Given an RTX, return true if it is not ok to emit it into debug info
2779 section. */
2780DEFHOOK
2781(const_not_ok_for_debug_p,
673c2f63
JM
2782 "This hook should return true if @var{x} should not be emitted into\n\
2783debug sections.",
93bcc8c9
JJ
2784 bool, (rtx x),
2785 hook_bool_rtx_false)
2786
38f8b050
JR
2787/* Given an address RTX, say whether it is valid. */
2788DEFHOOK
2789(legitimate_address_p,
673c2f63
JM
2790 "A function that returns whether @var{x} (an RTX) is a legitimate memory\n\
2791address on the target machine for a memory operand of mode @var{mode}.\n\
2792\n\
2793Legitimate addresses are defined in two variants: a strict variant and a\n\
2794non-strict one. The @var{strict} parameter chooses which variant is\n\
2795desired by the caller.\n\
2796\n\
2797The strict variant is used in the reload pass. It must be defined so\n\
2798that any pseudo-register that has not been allocated a hard register is\n\
2799considered a memory reference. This is because in contexts where some\n\
2800kind of register is required, a pseudo-register with no hard register\n\
2801must be rejected. For non-hard registers, the strict variant should look\n\
2802up the @code{reg_renumber} array; it should then proceed using the hard\n\
2803register number in the array, or treat the pseudo as a memory reference\n\
2804if the array holds @code{-1}.\n\
2805\n\
2806The non-strict variant is used in other passes. It must be defined to\n\
2807accept all pseudo-registers in every context where some kind of\n\
2808register is required.\n\
2809\n\
2810Normally, constant addresses which are the sum of a @code{symbol_ref}\n\
2811and an integer are stored inside a @code{const} RTX to mark them as\n\
2812constant. Therefore, there is no need to recognize such sums\n\
2813specifically as legitimate addresses. Normally you would simply\n\
2814recognize any @code{const} as legitimate.\n\
2815\n\
2816Usually @code{PRINT_OPERAND_ADDRESS} is not prepared to handle constant\n\
2817sums that are not marked with @code{const}. It assumes that a naked\n\
2818@code{plus} indicates indexing. If so, then you @emph{must} reject such\n\
2819naked constant sums as illegitimate addresses, so that none of them will\n\
2820be given to @code{PRINT_OPERAND_ADDRESS}.\n\
2821\n\
2822@cindex @code{TARGET_ENCODE_SECTION_INFO} and address validation\n\
2823On some machines, whether a symbolic address is legitimate depends on\n\
2824the section that the address refers to. On these machines, define the\n\
2825target hook @code{TARGET_ENCODE_SECTION_INFO} to store the information\n\
2826into the @code{symbol_ref}, and then check for it here. When you see a\n\
2827@code{const}, you will have to look inside it to find the\n\
2828@code{symbol_ref} in order to determine the section. @xref{Assembler\n\
2829Format}.\n\
2830\n\
2831@cindex @code{GO_IF_LEGITIMATE_ADDRESS}\n\
2832Some ports are still using a deprecated legacy substitute for\n\
2833this hook, the @code{GO_IF_LEGITIMATE_ADDRESS} macro. This macro\n\
2834has this syntax:\n\
2835\n\
2836@example\n\
2837#define GO_IF_LEGITIMATE_ADDRESS (@var{mode}, @var{x}, @var{label})\n\
2838@end example\n\
2839\n\
2840@noindent\n\
2841and should @code{goto @var{label}} if the address @var{x} is a valid\n\
2842address on the target machine for a memory operand of mode @var{mode}.\n\
2843\n\
2844@findex REG_OK_STRICT\n\
2845Compiler source files that want to use the strict variant of this\n\
2846macro define the macro @code{REG_OK_STRICT}. You should use an\n\
2847@code{#ifdef REG_OK_STRICT} conditional to define the strict variant in\n\
2848that case and the non-strict variant otherwise.\n\
2849\n\
2850Using the hook is usually simpler because it limits the number of\n\
2851files that are recompiled when changes are made.",
ef4bddc2 2852 bool, (machine_mode mode, rtx x, bool strict),
38f8b050
JR
2853 default_legitimate_address_p)
2854
2855/* True if the given constant can be put into an object_block. */
2856DEFHOOK
2857(use_blocks_for_constant_p,
673c2f63
JM
2858 "This hook should return true if pool entries for constant @var{x} can\n\
2859be placed in an @code{object_block} structure. @var{mode} is the mode\n\
2860of @var{x}.\n\
2861\n\
2862The default version returns false for all constants.",
ef4bddc2 2863 bool, (machine_mode mode, const_rtx x),
38f8b050
JR
2864 hook_bool_mode_const_rtx_false)
2865
361a58da
DE
2866/* True if the given decl can be put into an object_block. */
2867DEFHOOK
2868(use_blocks_for_decl_p,
673c2f63
JM
2869 "This hook should return true if pool entries for @var{decl} should\n\
2870be placed in an @code{object_block} structure.\n\
2871\n\
2872The default version returns true for all decls.",
361a58da
DE
2873 bool, (const_tree decl),
2874 hook_bool_const_tree_true)
2875
38f8b050
JR
2876/* The minimum and maximum byte offsets for anchored addresses. */
2877DEFHOOKPOD
2878(min_anchor_offset,
673c2f63
JM
2879 "The minimum offset that should be applied to a section anchor.\n\
2880On most targets, it should be the smallest offset that can be\n\
2881applied to a base register while still giving a legitimate address\n\
2882for every mode. The default value is 0.",
38f8b050
JR
2883 HOST_WIDE_INT, 0)
2884
2885DEFHOOKPOD
2886(max_anchor_offset,
673c2f63
JM
2887 "Like @code{TARGET_MIN_ANCHOR_OFFSET}, but the maximum (inclusive)\n\
2888offset that should be applied to section anchors. The default\n\
2889value is 0.",
38f8b050
JR
2890 HOST_WIDE_INT, 0)
2891
2892/* True if section anchors can be used to access the given symbol. */
2893DEFHOOK
2894(use_anchors_for_symbol_p,
673c2f63
JM
2895 "Return true if GCC should attempt to use anchors to access @code{SYMBOL_REF}\n\
2896@var{x}. You can assume @samp{SYMBOL_REF_HAS_BLOCK_INFO_P (@var{x})} and\n\
2897@samp{!SYMBOL_REF_ANCHOR_P (@var{x})}.\n\
2898\n\
2899The default version is correct for most targets, but you might need to\n\
2900intercept this hook to handle things like target-specific attributes\n\
2901or target-specific sections.",
38f8b050
JR
2902 bool, (const_rtx x),
2903 default_use_anchors_for_symbol_p)
2904
2f251a05
AI
2905/* True if target supports indirect functions. */
2906DEFHOOK
2907(has_ifunc_p,
2908 "It returns true if the target supports GNU indirect functions.\n\
2909The support includes the assembler, linker and dynamic linker.\n\
2910The default value of this hook is based on target's libc.",
2911 bool, (void),
2912 default_has_ifunc_p)
2913
38f8b050
JR
2914/* True if it is OK to do sibling call optimization for the specified
2915 call expression EXP. DECL will be the called function, or NULL if
2916 this is an indirect call. */
2917DEFHOOK
2918(function_ok_for_sibcall,
5bd40ade 2919 "True if it is OK to do sibling call optimization for the specified\n\
673c2f63
JM
2920call expression @var{exp}. @var{decl} will be the called function,\n\
2921or @code{NULL} if this is an indirect call.\n\
2922\n\
2923It is not uncommon for limitations of calling conventions to prevent\n\
2924tail calls to functions outside the current unit of translation, or\n\
2925during PIC compilation. The hook is used to enforce these restrictions,\n\
2926as the @code{sibcall} md pattern can not fail, or fall over to a\n\
2927``normal'' call. The criteria for successful sibling call optimization\n\
2928may vary greatly between different architectures.",
38f8b050
JR
2929 bool, (tree decl, tree exp),
2930 hook_bool_tree_tree_false)
2931
2932/* Establish appropriate back-end context for processing the function
2933 FNDECL. The argument might be NULL to indicate processing at top
2934 level, outside of any function scope. */
2935DEFHOOK
2936(set_current_function,
673c2f63
JM
2937 "The compiler invokes this hook whenever it changes its current function\n\
2938context (@code{cfun}). You can define this function if\n\
2939the back end needs to perform any initialization or reset actions on a\n\
2940per-function basis. For example, it may be used to implement function\n\
2941attributes that affect register usage or code generation patterns.\n\
2942The argument @var{decl} is the declaration for the new function context,\n\
2943and may be null to indicate that the compiler has left a function context\n\
2944and is returning to processing at the top level.\n\
2945The default hook function does nothing.\n\
2946\n\
2947GCC sets @code{cfun} to a dummy function context during initialization of\n\
2948some parts of the back end. The hook function is not invoked in this\n\
2949situation; you need not worry about the hook being invoked recursively,\n\
2950or when the back end is in a partially-initialized state.\n\
2951@code{cfun} might be @code{NULL} to indicate processing at top level,\n\
2952outside of any function scope.",
38f8b050
JR
2953 void, (tree decl), hook_void_tree)
2954
2955/* True if EXP should be placed in a "small data" section. */
2956DEFHOOK
2957(in_small_data_p,
673c2f63
JM
2958 "Returns true if @var{exp} should be placed into a ``small data'' section.\n\
2959The default version of this hook always returns false.",
38f8b050
JR
2960 bool, (const_tree exp),
2961 hook_bool_const_tree_false)
2962
2963/* True if EXP names an object for which name resolution must resolve
2964 to the current executable or shared library. */
2965DEFHOOK
2966(binds_local_p,
673c2f63
JM
2967 "Returns true if @var{exp} names an object for which name resolution\n\
2968rules must resolve to the current ``module'' (dynamic shared library\n\
2969or executable image).\n\
2970\n\
2971The default version of this hook implements the name resolution rules\n\
2972for ELF, which has a looser model of global name binding than other\n\
2973currently supported object file formats.",
38f8b050
JR
2974 bool, (const_tree exp),
2975 default_binds_local_p)
2976
3c5273a9
KT
2977/* Check if profiling code is before or after prologue. */
2978DEFHOOK
2979(profile_before_prologue,
2980 "It returns true if target wants profile code emitted before prologue.\n\n\
2981The default version of this hook use the target macro\n\
2982@code{PROFILE_BEFORE_PROLOGUE}.",
2983 bool, (void),
2984 default_profile_before_prologue)
2985
d56a43a0
AK
2986/* Return true if a leaf function should stay leaf even with profiling
2987 enabled. */
2988DEFHOOK
2989(keep_leaf_when_profiled,
2990 "This target hook returns true if the target wants the leaf flag for\
2991 the current function to stay true even if it calls mcount. This might\
2992 make sense for targets using the leaf flag only to determine whether a\
2993 stack frame needs to be generated or not and for which the call to\
2994 mcount is generated before the function prologue.",
2995 bool, (void),
2996 default_keep_leaf_when_profiled)
2997
38f8b050
JR
2998/* Modify and return the identifier of a DECL's external name,
2999 originally identified by ID, as required by the target,
3000 (eg, append @nn to windows32 stdcall function names).
3001 The default is to return ID without modification. */
3002DEFHOOK
3003(mangle_decl_assembler_name,
673c2f63
JM
3004 "Define this hook if you need to postprocess the assembler name generated\n\
3005by target-independent code. The @var{id} provided to this hook will be\n\
3006the computed name (e.g., the macro @code{DECL_NAME} of the @var{decl} in C,\n\
3007or the mangled name of the @var{decl} in C++). The return value of the\n\
3008hook is an @code{IDENTIFIER_NODE} for the appropriate mangled name on\n\
3009your target system. The default implementation of this hook just\n\
3010returns the @var{id} provided.",
38f8b050
JR
3011 tree, (tree decl, tree id),
3012 default_mangle_decl_assembler_name)
3013
3014/* Do something target-specific to record properties of the DECL into
3015 the associated SYMBOL_REF. */
3016DEFHOOK
3017(encode_section_info,
673c2f63
JM
3018 "Define this hook if references to a symbol or a constant must be\n\
3019treated differently depending on something about the variable or\n\
3020function named by the symbol (such as what section it is in).\n\
3021\n\
3022The hook is executed immediately after rtl has been created for\n\
3023@var{decl}, which may be a variable or function declaration or\n\
3024an entry in the constant pool. In either case, @var{rtl} is the\n\
3025rtl in question. Do @emph{not} use @code{DECL_RTL (@var{decl})}\n\
3026in this hook; that field may not have been initialized yet.\n\
3027\n\
3028In the case of a constant, it is safe to assume that the rtl is\n\
3029a @code{mem} whose address is a @code{symbol_ref}. Most decls\n\
3030will also have this form, but that is not guaranteed. Global\n\
3031register variables, for instance, will have a @code{reg} for their\n\
3032rtl. (Normally the right thing to do with such unusual rtl is\n\
3033leave it alone.)\n\
3034\n\
3035The @var{new_decl_p} argument will be true if this is the first time\n\
3036that @code{TARGET_ENCODE_SECTION_INFO} has been invoked on this decl. It will\n\
3037be false for subsequent invocations, which will happen for duplicate\n\
3038declarations. Whether or not anything must be done for the duplicate\n\
3039declaration depends on whether the hook examines @code{DECL_ATTRIBUTES}.\n\
3040@var{new_decl_p} is always true when the hook is called for a constant.\n\
3041\n\
3042@cindex @code{SYMBOL_REF_FLAG}, in @code{TARGET_ENCODE_SECTION_INFO}\n\
3043The usual thing for this hook to do is to record flags in the\n\
3044@code{symbol_ref}, using @code{SYMBOL_REF_FLAG} or @code{SYMBOL_REF_FLAGS}.\n\
3045Historically, the name string was modified if it was necessary to\n\
3046encode more than one bit of information, but this practice is now\n\
3047discouraged; use @code{SYMBOL_REF_FLAGS}.\n\
3048\n\
3049The default definition of this hook, @code{default_encode_section_info}\n\
3050in @file{varasm.c}, sets a number of commonly-useful bits in\n\
3051@code{SYMBOL_REF_FLAGS}. Check whether the default does what you need\n\
3052before overriding it.",
38f8b050
JR
3053 void, (tree decl, rtx rtl, int new_decl_p),
3054 default_encode_section_info)
3055
3056/* Undo the effects of encode_section_info on the symbol string. */
3057DEFHOOK
3058(strip_name_encoding,
673c2f63
JM
3059 "Decode @var{name} and return the real name part, sans\n\
3060the characters that @code{TARGET_ENCODE_SECTION_INFO}\n\
3061may have added.",
38f8b050
JR
3062 const char *, (const char *name),
3063 default_strip_name_encoding)
3064
3065/* If shift optabs for MODE are known to always truncate the shift count,
3066 return the mask that they apply. Return 0 otherwise. */
3067DEFHOOK
3068(shift_truncation_mask,
673c2f63
JM
3069 "This function describes how the standard shift patterns for @var{mode}\n\
3070deal with shifts by negative amounts or by more than the width of the mode.\n\
3071@xref{shift patterns}.\n\
3072\n\
3073On many machines, the shift patterns will apply a mask @var{m} to the\n\
3074shift count, meaning that a fixed-width shift of @var{x} by @var{y} is\n\
3075equivalent to an arbitrary-width shift of @var{x} by @var{y & m}. If\n\
3076this is true for mode @var{mode}, the function should return @var{m},\n\
3077otherwise it should return 0. A return value of 0 indicates that no\n\
3078particular behavior is guaranteed.\n\
3079\n\
3080Note that, unlike @code{SHIFT_COUNT_TRUNCATED}, this function does\n\
3081@emph{not} apply to general shift rtxes; it applies only to instructions\n\
3082that are generated by the named shift patterns.\n\
3083\n\
3084The default implementation of this function returns\n\
3085@code{GET_MODE_BITSIZE (@var{mode}) - 1} if @code{SHIFT_COUNT_TRUNCATED}\n\
3086and 0 otherwise. This definition is always safe, but if\n\
3087@code{SHIFT_COUNT_TRUNCATED} is false, and some shift patterns\n\
3088nevertheless truncate the shift count, you may get better code\n\
3089by overriding it.",
ef4bddc2 3090 unsigned HOST_WIDE_INT, (machine_mode mode),
38f8b050
JR
3091 default_shift_truncation_mask)
3092
3093/* Return the number of divisions in the given MODE that should be present,
3094 so that it is profitable to turn the division into a multiplication by
3095 the reciprocal. */
3096DEFHOOK
3097(min_divisions_for_recip_mul,
673c2f63
JM
3098 "When @option{-ffast-math} is in effect, GCC tries to optimize\n\
3099divisions by the same divisor, by turning them into multiplications by\n\
3100the reciprocal. This target hook specifies the minimum number of divisions\n\
3101that should be there for GCC to perform the optimization for a variable\n\
3102of mode @var{mode}. The default implementation returns 3 if the machine\n\
3103has an instruction for the division, and 2 if it does not.",
ef4bddc2 3104 unsigned int, (machine_mode mode),
38f8b050
JR
3105 default_min_divisions_for_recip_mul)
3106
3107/* If the representation of integral MODE is such that values are
3108 always sign-extended to a wider mode MODE_REP then return
3109 SIGN_EXTEND. Return UNKNOWN otherwise. */
3110/* Note that the return type ought to be RTX_CODE, but that's not
3111 necessarily defined at this point. */
3112DEFHOOK
3113(mode_rep_extended,
673c2f63
JM
3114 "The representation of an integral mode can be such that the values\n\
3115are always extended to a wider integral mode. Return\n\
3116@code{SIGN_EXTEND} if values of @var{mode} are represented in\n\
3117sign-extended form to @var{rep_mode}. Return @code{UNKNOWN}\n\
3118otherwise. (Currently, none of the targets use zero-extended\n\
3119representation this way so unlike @code{LOAD_EXTEND_OP},\n\
3120@code{TARGET_MODE_REP_EXTENDED} is expected to return either\n\
3121@code{SIGN_EXTEND} or @code{UNKNOWN}. Also no target extends\n\
3122@var{mode} to @var{rep_mode} so that @var{rep_mode} is not the next\n\
3123widest integral mode and currently we take advantage of this fact.)\n\
3124\n\
3125Similarly to @code{LOAD_EXTEND_OP} you may return a non-@code{UNKNOWN}\n\
3126value even if the extension is not performed on certain hard registers\n\
3127as long as for the @code{REGNO_REG_CLASS} of these hard registers\n\
3128@code{CANNOT_CHANGE_MODE_CLASS} returns nonzero.\n\
3129\n\
3130Note that @code{TARGET_MODE_REP_EXTENDED} and @code{LOAD_EXTEND_OP}\n\
3131describe two related properties. If you define\n\
3132@code{TARGET_MODE_REP_EXTENDED (mode, word_mode)} you probably also want\n\
3133to define @code{LOAD_EXTEND_OP (mode)} to return the same type of\n\
3134extension.\n\
3135\n\
3136In order to enforce the representation of @code{mode},\n\
3137@code{TRULY_NOOP_TRUNCATION} should return false when truncating to\n\
3138@code{mode}.",
ef4bddc2 3139 int, (machine_mode mode, machine_mode rep_mode),
38f8b050
JR
3140 default_mode_rep_extended)
3141
3142/* True if MODE is valid for a pointer in __attribute__((mode("MODE"))). */
3143DEFHOOK
3144(valid_pointer_mode,
673c2f63
JM
3145 "Define this to return nonzero if the port can handle pointers\n\
3146with machine mode @var{mode}. The default version of this\n\
3147hook returns true for both @code{ptr_mode} and @code{Pmode}.",
ef4bddc2 3148 bool, (machine_mode mode),
38f8b050
JR
3149 default_valid_pointer_mode)
3150
7352c013
RG
3151/* Disambiguate with errno. */
3152DEFHOOK
3153(ref_may_alias_errno,
3154 "Define this to return nonzero if the memory reference @var{ref}\
3155 may alias with the system C library errno location. The default\
3156 version of this hook assumes the system C library errno location\
3157 is either a declaration of type int or accessed by dereferencing\
3158 a pointer to int.",
84562394 3159 bool, (struct ao_ref *ref),
7352c013
RG
3160 default_ref_may_alias_errno)
3161
38f8b050
JR
3162/* Support for named address spaces. */
3163#undef HOOK_PREFIX
3164#define HOOK_PREFIX "TARGET_ADDR_SPACE_"
3165HOOK_VECTOR (TARGET_ADDR_SPACE_HOOKS, addr_space)
3166
3167/* MODE to use for a pointer into another address space. */
3168DEFHOOK
3169(pointer_mode,
673c2f63
JM
3170 "Define this to return the machine mode to use for pointers to\n\
3171@var{address_space} if the target supports named address spaces.\n\
0a798c16 3172The default version of this hook returns @code{ptr_mode}.",
ef4bddc2 3173 machine_mode, (addr_space_t address_space),
38f8b050
JR
3174 default_addr_space_pointer_mode)
3175
3176/* MODE to use for an address in another address space. */
3177DEFHOOK
3178(address_mode,
673c2f63
JM
3179 "Define this to return the machine mode to use for addresses in\n\
3180@var{address_space} if the target supports named address spaces.\n\
0a798c16 3181The default version of this hook returns @code{Pmode}.",
ef4bddc2 3182 machine_mode, (addr_space_t address_space),
38f8b050
JR
3183 default_addr_space_address_mode)
3184
3185/* True if MODE is valid for a pointer in __attribute__((mode("MODE")))
3186 in another address space. */
3187DEFHOOK
3188(valid_pointer_mode,
673c2f63
JM
3189 "Define this to return nonzero if the port can handle pointers\n\
3190with machine mode @var{mode} to address space @var{as}. This target\n\
3191hook is the same as the @code{TARGET_VALID_POINTER_MODE} target hook,\n\
3192except that it includes explicit named address space support. The default\n\
3193version of this hook returns true for the modes returned by either the\n\
3194@code{TARGET_ADDR_SPACE_POINTER_MODE} or @code{TARGET_ADDR_SPACE_ADDRESS_MODE}\n\
3195target hooks for the given address space.",
ef4bddc2 3196 bool, (machine_mode mode, addr_space_t as),
38f8b050
JR
3197 default_addr_space_valid_pointer_mode)
3198
3199/* True if an address is a valid memory address to a given named address
3200 space for a given mode. */
3201DEFHOOK
3202(legitimate_address_p,
673c2f63
JM
3203 "Define this to return true if @var{exp} is a valid address for mode\n\
3204@var{mode} in the named address space @var{as}. The @var{strict}\n\
3205parameter says whether strict addressing is in effect after reload has\n\
3206finished. This target hook is the same as the\n\
3207@code{TARGET_LEGITIMATE_ADDRESS_P} target hook, except that it includes\n\
3208explicit named address space support.",
ef4bddc2 3209 bool, (machine_mode mode, rtx exp, bool strict, addr_space_t as),
38f8b050
JR
3210 default_addr_space_legitimate_address_p)
3211
3212/* Return an updated address to convert an invalid pointer to a named
3213 address space to a valid one. If NULL_RTX is returned use machine
3214 independent methods to make the address valid. */
3215DEFHOOK
3216(legitimize_address,
673c2f63
JM
3217 "Define this to modify an invalid address @var{x} to be a valid address\n\
3218with mode @var{mode} in the named address space @var{as}. This target\n\
3219hook is the same as the @code{TARGET_LEGITIMIZE_ADDRESS} target hook,\n\
3220except that it includes explicit named address space support.",
ef4bddc2 3221 rtx, (rtx x, rtx oldx, machine_mode mode, addr_space_t as),
38f8b050
JR
3222 default_addr_space_legitimize_address)
3223
3224/* True if one named address space is a subset of another named address. */
3225DEFHOOK
3226(subset_p,
673c2f63
JM
3227 "Define this to return whether the @var{subset} named address space is\n\
3228contained within the @var{superset} named address space. Pointers to\n\
3229a named address space that is a subset of another named address space\n\
3230will be converted automatically without a cast if used together in\n\
3231arithmetic operations. Pointers to a superset address space can be\n\
3232converted to pointers to a subset address space via explicit casts.",
b5bcaa4a 3233 bool, (addr_space_t subset, addr_space_t superset),
38f8b050
JR
3234 default_addr_space_subset_p)
3235
6626f970
RH
3236/* True if 0 is a valid address in the address space, or false if
3237 0 is a NULL in the address space. */
3238DEFHOOK
3239(zero_address_valid,
3240 "Define this to modify the default handling of address 0 for the\n\
3241address space. Return true if 0 should be considered a valid address.",
3242 bool, (addr_space_t as),
3243 default_addr_space_zero_address_valid)
3244
38f8b050
JR
3245/* Function to convert an rtl expression from one address space to another. */
3246DEFHOOK
3247(convert,
673c2f63
JM
3248 "Define this to convert the pointer expression represented by the RTL\n\
3249@var{op} with type @var{from_type} that points to a named address\n\
3250space to a new pointer expression with type @var{to_type} that points\n\
3251to a different named address space. When this hook it called, it is\n\
3252guaranteed that one of the two address spaces is a subset of the other,\n\
3253as determined by the @code{TARGET_ADDR_SPACE_SUBSET_P} target hook.",
38f8b050
JR
3254 rtx, (rtx op, tree from_type, tree to_type),
3255 default_addr_space_convert)
3256
f736b911
RH
3257/* Function to encode an address space into dwarf. */
3258DEFHOOK
3259(debug,
3260 "Define this to define how the address space is encoded in dwarf.\n\
3261The result is the value to be used with @code{DW_AT_address_class}.",
3262 int, (addr_space_t as),
3263 default_addr_space_debug)
3264
ffc22840
GJL
3265/* Function to emit custom diagnostic if an address space is used. */
3266DEFHOOK
3267(diagnose_usage,
3268 "Define this hook if the availability of an address space depends on\n\
3269command line options and some diagnostics should be printed when the\n\
3270address space is used. This hook is called during parsing and allows\n\
3271to emit a better diagnostic compared to the case where the address space\n\
3272was not registered with @code{c_register_addr_space}. @var{as} is\n\
3273the address space as registered with @code{c_register_addr_space}.\n\
3274@var{loc} is the location of the address space qualifier token.\n\
3275The default implementation does nothing.",
3276 void, (addr_space_t as, location_t loc),
3277 default_addr_space_diagnose_usage)
3278
38f8b050
JR
3279HOOK_VECTOR_END (addr_space)
3280
3281#undef HOOK_PREFIX
3282#define HOOK_PREFIX "TARGET_"
3283
3284/* True if MODE is valid for the target. By "valid", we mean able to
3285 be manipulated in non-trivial ways. In particular, this means all
3286 the arithmetic is supported. */
3287DEFHOOK
3288(scalar_mode_supported_p,
673c2f63
JM
3289 "Define this to return nonzero if the port is prepared to handle\n\
3290insns involving scalar mode @var{mode}. For a scalar mode to be\n\
3291considered supported, all the basic arithmetic and comparisons\n\
3292must work.\n\
3293\n\
3294The default version of this hook returns true for any mode\n\
3295required to handle the basic C types (as defined by the port).\n\
3296Included here are the double-word arithmetic supported by the\n\
3297code in @file{optabs.c}.",
ef4bddc2 3298 bool, (machine_mode mode),
38f8b050
JR
3299 default_scalar_mode_supported_p)
3300
3301/* Similarly for vector modes. "Supported" here is less strict. At
3302 least some operations are supported; need to check optabs or builtins
3303 for further details. */
3304DEFHOOK
3305(vector_mode_supported_p,
673c2f63
JM
3306 "Define this to return nonzero if the port is prepared to handle\n\
3307insns involving vector mode @var{mode}. At the very least, it\n\
3308must have move patterns for this mode.",
ef4bddc2 3309 bool, (machine_mode mode),
38f8b050
JR
3310 hook_bool_mode_false)
3311
5aea1e76
UW
3312DEFHOOK
3313(vector_alignment,
3314 "This hook can be used to define the alignment for a vector of type\n\
3315@var{type}, in order to comply with a platform ABI. The default is to\n\
3316require natural alignment for vector types. The alignment returned by\n\
3317this hook must be a power-of-two multiple of the default alignment of\n\
3318the vector element type.",
3319 HOST_WIDE_INT, (const_tree type),
3320 default_vector_alignment)
3321
0f6d54f7
RS
3322/* True if we should try to use a scalar mode to represent an array,
3323 overriding the usual MAX_FIXED_MODE limit. */
3324DEFHOOK
3325(array_mode_supported_p,
3326 "Return true if GCC should try to use a scalar mode to store an array\n\
3327of @var{nelems} elements, given that each element has mode @var{mode}.\n\
3328Returning true here overrides the usual @code{MAX_FIXED_MODE} limit\n\
3329and allows GCC to use any defined integer mode.\n\
3330\n\
3331One use of this hook is to support vector load and store operations\n\
3332that operate on several homogeneous vectors. For example, ARM NEON\n\
3333has operations like:\n\
3334\n\
3335@smallexample\n\
3336int8x8x3_t vld3_s8 (const int8_t *)\n\
3337@end smallexample\n\
3338\n\
3339where the return type is defined as:\n\
3340\n\
3341@smallexample\n\
3342typedef struct int8x8x3_t\n\
3343@{\n\
3344 int8x8_t val[3];\n\
3345@} int8x8x3_t;\n\
3346@end smallexample\n\
3347\n\
3348If this hook allows @code{val} to have a scalar mode, then\n\
3349@code{int8x8x3_t} can have the same mode. GCC can then store\n\
3350@code{int8x8x3_t}s in registers rather than forcing them onto the stack.",
ef4bddc2 3351 bool, (machine_mode mode, unsigned HOST_WIDE_INT nelems),
0f6d54f7
RS
3352 hook_bool_mode_uhwi_false)
3353
8cc4b7a2
JM
3354DEFHOOK
3355(libgcc_floating_mode_supported_p,
3356 "Define this to return nonzero if libgcc provides support for the \n\
3357floating-point mode @var{mode}, which is known to pass \n\
3358@code{TARGET_SCALAR_MODE_SUPPORTED_P}. The default version of this \n\
3359hook returns true for all of @code{SFmode}, @code{DFmode}, \n\
3360@code{XFmode} and @code{TFmode}, if such modes exist.",
ef4bddc2 3361 bool, (machine_mode mode),
8cc4b7a2
JM
3362 default_libgcc_floating_mode_supported_p)
3363
c65699ef
JM
3364DEFHOOK
3365(floatn_mode,
3366 "Define this to return the machine mode to use for the type \n\
3367@code{_Float@var{n}}, if @var{extended} is false, or the type \n\
3368@code{_Float@var{n}x}, if @var{extended} is true. If such a type \n\
3369is not supported, return @code{VOIDmode}. The default version of this \n\
3370hook returns @code{SFmode} for @code{_Float32}, @code{DFmode} for \n\
3371@code{_Float64} and @code{_Float32x} and @code{TFmode} for \n\
3372@code{_Float128}, if those modes exist and satisfy the requirements for \n\
3373those types and pass @code{TARGET_SCALAR_MODE_SUPPORTED_P} and \n\
3374@code{TARGET_LIBGCC_FLOATING_MODE_SUPPORTED_P}; for @code{_Float64x}, it \n\
3375returns the first of @code{XFmode} and @code{TFmode} that exists and \n\
3376satisfies the same requirements; for other types, it returns \n\
3377@code{VOIDmode}. The hook is only called for values of @var{n} and \n\
3378@var{extended} that are valid according to ISO/IEC TS 18661-3:2015; that \n\
3379is, @var{n} is one of 32, 64, 128, or, if @var{extended} is false, 16 or \n\
3380greater than 128 and a multiple of 32.",
3381 machine_mode, (int n, bool extended),
3382 default_floatn_mode)
3383
38f8b050
JR
3384/* Compute cost of moving data from a register of class FROM to one of
3385 TO, using MODE. */
3386DEFHOOK
3387(register_move_cost,
673c2f63
JM
3388 "This target hook should return the cost of moving data of mode @var{mode}\n\
3389from a register in class @var{from} to one in class @var{to}. The classes\n\
3390are expressed using the enumeration values such as @code{GENERAL_REGS}.\n\
3391A value of 2 is the default; other values are interpreted relative to\n\
3392that.\n\
3393\n\
3394It is not required that the cost always equal 2 when @var{from} is the\n\
3395same as @var{to}; on some machines it is expensive to move between\n\
3396registers if they are not general registers.\n\
3397\n\
3398If reload sees an insn consisting of a single @code{set} between two\n\
3399hard registers, and if @code{TARGET_REGISTER_MOVE_COST} applied to their\n\
3400classes returns a value of 2, reload does not check to ensure that the\n\
3401constraints of the insn are met. Setting a cost of other than 2 will\n\
3402allow reload to verify that the constraints are met. You should do this\n\
3403if the @samp{mov@var{m}} pattern's constraints do not allow such copying.\n\
3404\n\
3405The default version of this function returns 2.",
ef4bddc2 3406 int, (machine_mode mode, reg_class_t from, reg_class_t to),
38f8b050
JR
3407 default_register_move_cost)
3408
3409/* Compute cost of moving registers to/from memory. */
3410/* ??? Documenting the argument types for this hook requires a GFDL
3411 license grant. Also, the documentation uses a different name for RCLASS. */
911852ff 3412DEFHOOK
38f8b050 3413(memory_move_cost,
673c2f63
JM
3414 "This target hook should return the cost of moving data of mode @var{mode}\n\
3415between a register of class @var{rclass} and memory; @var{in} is @code{false}\n\
3416if the value is to be written to memory, @code{true} if it is to be read in.\n\
3417This cost is relative to those in @code{TARGET_REGISTER_MOVE_COST}.\n\
3418If moving between registers and memory is more expensive than between two\n\
3419registers, you should add this target hook to express the relative cost.\n\
3420\n\
3421If you do not add this target hook, GCC uses a default cost of 4 plus\n\
3422the cost of copying via a secondary reload register, if one is\n\
3423needed. If your machine requires a secondary reload register to copy\n\
3424between memory and a register of @var{rclass} but the reload mechanism is\n\
3425more complex than copying via an intermediate, use this target hook to\n\
3426reflect the actual cost of the move.\n\
3427\n\
3428GCC defines the function @code{memory_move_secondary_cost} if\n\
3429secondary reloads are needed. It computes the costs due to copying via\n\
3430a secondary register. If your machine copies from memory using a\n\
3431secondary register in the conventional way but the default base value of\n\
34324 is not correct for your machine, use this target hook to add some other\n\
3433value to the result of that function. The arguments to that function\n\
3434are the same as to this target hook.",
ef4bddc2 3435 int, (machine_mode mode, reg_class_t rclass, bool in),
38f8b050
JR
3436 default_memory_move_cost)
3437
7cbed008
JG
3438DEFHOOK
3439(use_by_pieces_infrastructure_p,
3440 "GCC will attempt several strategies when asked to copy between\n\
3441two areas of memory, or to set, clear or store to memory, for example\n\
3442when copying a @code{struct}. The @code{by_pieces} infrastructure\n\
3443implements such memory operations as a sequence of load, store or move\n\
3444insns. Alternate strategies are to expand the\n\
3445@code{movmem} or @code{setmem} optabs, to emit a library call, or to emit\n\
3446unit-by-unit, loop-based operations.\n\
3447\n\
3448This target hook should return true if, for a memory operation with a\n\
3449given @var{size} and @var{alignment}, using the @code{by_pieces}\n\
3450infrastructure is expected to result in better code generation.\n\
3451Both @var{size} and @var{alignment} are measured in terms of storage\n\
3452units.\n\
3453\n\
3454The parameter @var{op} is one of: @code{CLEAR_BY_PIECES},\n\
36b85e43
BS
3455@code{MOVE_BY_PIECES}, @code{SET_BY_PIECES}, @code{STORE_BY_PIECES} or\n\
3456@code{COMPARE_BY_PIECES}. These describe the type of memory operation\n\
3457under consideration.\n\
7cbed008
JG
3458\n\
3459The parameter @var{speed_p} is true if the code is currently being\n\
3460optimized for speed rather than size.\n\
3461\n\
3462Returning true for higher values of @var{size} can improve code generation\n\
3463for speed if the target does not provide an implementation of the\n\
3464@code{movmem} or @code{setmem} standard names, if the @code{movmem} or\n\
3465@code{setmem} implementation would be more expensive than a sequence of\n\
3466insns, or if the overhead of a library call would dominate that of\n\
3467the body of the memory operation.\n\
3468\n\
3469Returning true for higher values of @code{size} may also cause an increase\n\
3470in code size, for example where the number of insns emitted to perform a\n\
3471move would be greater than that of a library call.",
445d7826 3472 bool, (unsigned HOST_WIDE_INT size, unsigned int alignment,
7cbed008
JG
3473 enum by_pieces_operation op, bool speed_p),
3474 default_use_by_pieces_infrastructure_p)
3475
36b85e43
BS
3476DEFHOOK
3477(compare_by_pieces_branch_ratio,
3478 "When expanding a block comparison in MODE, gcc can try to reduce the\n\
3479number of branches at the expense of more memory operations. This hook\n\
3480allows the target to override the default choice. It should return the\n\
3481factor by which branches should be reduced over the plain expansion with\n\
3482one comparison per @var{mode}-sized piece. A port can also prevent a\n\
3483particular mode from being used for block comparisons by returning a\n\
3484negative number from this hook.",
3485 int, (machine_mode mode),
3486 default_compare_by_pieces_branch_ratio)
3487
d95ab70a
RS
3488DEFHOOK
3489(optab_supported_p,
3490 "Return true if the optimizers should use optab @var{op} with\n\
3491modes @var{mode1} and @var{mode2} for optimization type @var{opt_type}.\n\
3492The optab is known to have an associated @file{.md} instruction\n\
3493whose C condition is true. @var{mode2} is only meaningful for conversion\n\
3494optabs; for direct optabs it is a copy of @var{mode1}.\n\
3495\n\
3496For example, when called with @var{op} equal to @code{rint_optab} and\n\
3497@var{mode1} equal to @code{DFmode}, the hook should say whether the\n\
3498optimizers should use optab @code{rintdf2}.\n\
3499\n\
3500The default hook returns true for all inputs.",
3501 bool, (int op, machine_mode mode1, machine_mode mode2,
3502 optimization_type opt_type),
3503 default_optab_supported_p)
3504
38f8b050
JR
3505/* True for MODE if the target expects that registers in this mode will
3506 be allocated to registers in a small register class. The compiler is
3507 allowed to use registers explicitly used in the rtl as spill registers
3508 but it should prevent extending the lifetime of these registers. */
3509DEFHOOK
3510(small_register_classes_for_mode_p,
673c2f63
JM
3511 "Define this to return nonzero for machine modes for which the port has\n\
3512small register classes. If this target hook returns nonzero for a given\n\
3513@var{mode}, the compiler will try to minimize the lifetime of registers\n\
3514in @var{mode}. The hook may be called with @code{VOIDmode} as argument.\n\
3515In this case, the hook is expected to return nonzero if it returns nonzero\n\
3516for any mode.\n\
3517\n\
3518On some machines, it is risky to let hard registers live across arbitrary\n\
3519insns. Typically, these machines have instructions that require values\n\
3520to be in specific registers (like an accumulator), and reload will fail\n\
3521if the required hard register is used for another purpose across such an\n\
3522insn.\n\
3523\n\
3524Passes before reload do not know which hard registers will be used\n\
3525in an instruction, but the machine modes of the registers set or used in\n\
3526the instruction are already known. And for some machines, register\n\
3527classes are small for, say, integer registers but not for floating point\n\
3528registers. For example, the AMD x86-64 architecture requires specific\n\
3529registers for the legacy x86 integer instructions, but there are many\n\
3530SSE registers for floating point operations. On such targets, a good\n\
3531strategy may be to return nonzero from this hook for @code{INTEGRAL_MODE_P}\n\
3532machine modes but zero for the SSE register classes.\n\
3533\n\
3534The default version of this hook returns false for any mode. It is always\n\
3535safe to redefine this hook to return with a nonzero value. But if you\n\
3536unnecessarily define it, you will reduce the amount of optimizations\n\
3537that can be performed in some cases. If you do not define this hook\n\
3538to return a nonzero value when it is required, the compiler will run out\n\
3539of spill registers and print a fatal error message.",
ef4bddc2 3540 bool, (machine_mode mode),
38f8b050
JR
3541 hook_bool_mode_false)
3542
e692f276
RH
3543/* Register number for a flags register. Only needs to be defined if the
3544 target is constrainted to use post-reload comparison elimination. */
3545DEFHOOKPOD
3546(flags_regnum,
3547 "If the target has a dedicated flags register, and it needs to use the\
3548 post-reload comparison elimination pass, then this value should be set\
3549 appropriately.",
3550 unsigned int, INVALID_REGNUM)
3551
38f8b050
JR
3552/* Compute a (partial) cost for rtx X. Return true if the complete
3553 cost has been computed, and false if subexpressions should be
3554 scanned. In either case, *TOTAL contains the cost result. */
e548c9df 3555/* Note that OUTER_CODE ought to be RTX_CODE, but that's
38f8b050
JR
3556 not necessarily defined at this point. */
3557DEFHOOK
3558(rtx_costs,
673c2f63
JM
3559 "This target hook describes the relative costs of RTL expressions.\n\
3560\n\
3561The cost may depend on the precise form of the expression, which is\n\
3562available for examination in @var{x}, and the fact that @var{x} appears\n\
3563as operand @var{opno} of an expression with rtx code @var{outer_code}.\n\
3564That is, the hook can assume that there is some rtx @var{y} such\n\
3565that @samp{GET_CODE (@var{y}) == @var{outer_code}} and such that\n\
3566either (a) @samp{XEXP (@var{y}, @var{opno}) == @var{x}} or\n\
3567(b) @samp{XVEC (@var{y}, @var{opno})} contains @var{x}.\n\
3568\n\
e548c9df
AM
3569@var{mode} is @var{x}'s machine mode, or for cases like @code{const_int} that\n\
3570do not have a mode, the mode in which @var{x} is used.\n\
673c2f63
JM
3571\n\
3572In implementing this hook, you can use the construct\n\
3573@code{COSTS_N_INSNS (@var{n})} to specify a cost equal to @var{n} fast\n\
3574instructions.\n\
3575\n\
3576On entry to the hook, @code{*@var{total}} contains a default estimate\n\
3577for the cost of the expression. The hook should modify this value as\n\
3578necessary. Traditionally, the default costs are @code{COSTS_N_INSNS (5)}\n\
3579for multiplications, @code{COSTS_N_INSNS (7)} for division and modulus\n\
3580operations, and @code{COSTS_N_INSNS (1)} for all other operations.\n\
3581\n\
3582When optimizing for code size, i.e.@: when @code{speed} is\n\
3583false, this target hook should be used to estimate the relative\n\
3584size cost of an expression, again relative to @code{COSTS_N_INSNS}.\n\
3585\n\
3586The hook returns true when all subexpressions of @var{x} have been\n\
3587processed, and false when @code{rtx_cost} should recurse.",
e548c9df
AM
3588 bool, (rtx x, machine_mode mode, int outer_code, int opno, int *total, bool speed),
3589 hook_bool_rtx_mode_int_int_intp_bool_false)
38f8b050
JR
3590
3591/* Compute the cost of X, used as an address. Never called with
3592 invalid addresses. */
3593DEFHOOK
3594(address_cost,
673c2f63
JM
3595 "This hook computes the cost of an addressing mode that contains\n\
3596@var{address}. If not defined, the cost is computed from\n\
3597the @var{address} expression and the @code{TARGET_RTX_COST} hook.\n\
3598\n\
3599For most CISC machines, the default cost is a good approximation of the\n\
3600true cost of the addressing mode. However, on RISC machines, all\n\
3601instructions normally have the same length and execution time. Hence\n\
3602all addresses will have equal costs.\n\
3603\n\
3604In cases where more than one form of an address is known, the form with\n\
3605the lowest cost will be used. If multiple forms have the same, lowest,\n\
3606cost, the one that is the most complex will be used.\n\
3607\n\
3608For example, suppose an address that is equal to the sum of a register\n\
3609and a constant is used twice in the same basic block. When this macro\n\
3610is not defined, the address will be computed in a register and memory\n\
3611references will be indirect through that register. On machines where\n\
3612the cost of the addressing mode containing the sum is no higher than\n\
3613that of a simple indirect reference, this will produce an additional\n\
3614instruction and possibly require an additional register. Proper\n\
3615specification of this macro eliminates this overhead for such machines.\n\
3616\n\
3617This hook is never called with an invalid address.\n\
3618\n\
3619On machines where an address involving more than one register is as\n\
3620cheap as an address computation involving only one register, defining\n\
3621@code{TARGET_ADDRESS_COST} to reflect this can cause two registers to\n\
3622be live over a region of code where only one would have been if\n\
3623@code{TARGET_ADDRESS_COST} were not defined in that manner. This effect\n\
3624should be considered in the definition of this macro. Equivalent costs\n\
3625should probably only be given to addresses with different numbers of\n\
3626registers on machines with lots of registers.",
ef4bddc2 3627 int, (rtx address, machine_mode mode, addr_space_t as, bool speed),
38f8b050
JR
3628 default_address_cost)
3629
e914c11a
JG
3630/* Give a cost, in RTX Costs units, for an edge. Like BRANCH_COST, but with
3631 well defined units. */
3632DEFHOOK
3633(max_noce_ifcvt_seq_cost,
3634 "This hook returns a value in the same units as @code{TARGET_RTX_COSTS},\n\
3635giving the maximum acceptable cost for a sequence generated by the RTL\n\
3636if-conversion pass when conditional execution is not available.\n\
3637The RTL if-conversion pass attempts to convert conditional operations\n\
3638that would require a branch to a series of unconditional operations and\n\
3639@code{mov@var{mode}cc} insns. This hook returns the maximum cost of the\n\
3640unconditional instructions and the @code{mov@var{mode}cc} insns.\n\
3641RTL if-conversion is cancelled if the cost of the converted sequence\n\
3642is greater than the value returned by this hook.\n\
3643\n\
3644@code{e} is the edge between the basic block containing the conditional\n\
3645branch to the basic block which would be executed if the condition\n\
3646were true.\n\
3647\n\
3648The default implementation of this hook uses the\n\
3649@code{max-rtl-if-conversion-[un]predictable} parameters if they are set,\n\
3650and uses a multiple of @code{BRANCH_COST} otherwise.",
3651unsigned int, (edge e),
3652default_max_noce_ifcvt_seq_cost)
3653
f52a73a4
SD
3654/* Permit speculative instructions in delay slots during delayed-branch
3655 scheduling. */
3656DEFHOOK
3657(no_speculation_in_delay_slots_p,
3658 "This predicate controls the use of the eager delay slot filler to disallow\n\
3659speculatively executed instructions being placed in delay slots. Targets\n\
3660such as certain MIPS architectures possess both branches with and without\n\
3661delay slots. As the eager delay slot filler can decrease performance,\n\
3662disabling it is beneficial when ordinary branches are available. Use of\n\
3663delay slot branches filled using the basic filler is often still desirable\n\
3664as the delay slot can hide a pipeline bubble.", bool, (void),
3665 hook_bool_void_false)
3666
38f8b050
JR
3667/* Return where to allocate pseudo for a given hard register initial value. */
3668DEFHOOK
3669(allocate_initial_value,
673c2f63
JM
3670 "\n\
3671When the initial value of a hard register has been copied in a pseudo\n\
3672register, it is often not necessary to actually allocate another register\n\
3673to this pseudo register, because the original hard register or a stack slot\n\
3674it has been saved into can be used. @code{TARGET_ALLOCATE_INITIAL_VALUE}\n\
3675is called at the start of register allocation once for each hard register\n\
3676that had its initial value copied by using\n\
3677@code{get_func_hard_reg_initial_val} or @code{get_hard_reg_initial_val}.\n\
3678Possible values are @code{NULL_RTX}, if you don't want\n\
3679to do any special allocation, a @code{REG} rtx---that would typically be\n\
3680the hard register itself, if it is known not to be clobbered---or a\n\
3681@code{MEM}.\n\
3682If you are returning a @code{MEM}, this is only a hint for the allocator;\n\
3683it might decide to use another register anyways.\n\
3684You may use @code{current_function_is_leaf} or \n\
3685@code{REG_N_SETS} in the hook to determine if the hard\n\
3686register in question will not be clobbered.\n\
3687The default value of this hook is @code{NULL}, which disables any special\n\
3688allocation.",
38f8b050
JR
3689 rtx, (rtx hard_reg), NULL)
3690
c84a808e 3691/* Return nonzero if evaluating UNSPEC X might cause a trap.
38f8b050
JR
3692 FLAGS has the same meaning as in rtlanal.c: may_trap_p_1. */
3693DEFHOOK
3694(unspec_may_trap_p,
673c2f63
JM
3695 "This target hook returns nonzero if @var{x}, an @code{unspec} or\n\
3696@code{unspec_volatile} operation, might cause a trap. Targets can use\n\
3697this hook to enhance precision of analysis for @code{unspec} and\n\
3698@code{unspec_volatile} operations. You may call @code{may_trap_p_1}\n\
3699to analyze inner elements of @var{x} in which case @var{flags} should be\n\
3700passed along.",
38f8b050
JR
3701 int, (const_rtx x, unsigned flags),
3702 default_unspec_may_trap_p)
3703
3704/* Given a register, this hook should return a parallel of registers
3705 to represent where to find the register pieces. Define this hook
3706 if the register and its mode are represented in Dwarf in
3707 non-contiguous locations, or if the register should be
3708 represented in more than one register in Dwarf. Otherwise, this
3709 hook should return NULL_RTX. */
3710DEFHOOK
3711(dwarf_register_span,
673c2f63
JM
3712 "Given a register, this hook should return a parallel of registers to\n\
3713represent where to find the register pieces. Define this hook if the\n\
3714register and its mode are represented in Dwarf in non-contiguous\n\
3715locations, or if the register should be represented in more than one\n\
3716register in Dwarf. Otherwise, this hook should return @code{NULL_RTX}.\n\
3717If not defined, the default is to return @code{NULL_RTX}.",
38f8b050
JR
3718 rtx, (rtx reg),
3719 hook_rtx_rtx_null)
3720
ff050c66
MF
3721/* Given a register return the mode of the corresponding DWARF frame
3722 register. */
3723DEFHOOK
3724(dwarf_frame_reg_mode,
3725 "Given a register, this hook should return the mode which the\n\
3726corresponding Dwarf frame register should have. This is normally\n\
3727used to return a smaller mode than the raw mode to prevent call\n\
3728clobbered parts of a register altering the frame register size",
ef4bddc2 3729 machine_mode, (int regno),
ff050c66
MF
3730 default_dwarf_frame_reg_mode)
3731
38f8b050
JR
3732/* If expand_builtin_init_dwarf_reg_sizes needs to fill in table
3733 entries not corresponding directly to registers below
3734 FIRST_PSEUDO_REGISTER, this hook should generate the necessary
3735 code, given the address of the table. */
3736DEFHOOK
3737(init_dwarf_reg_sizes_extra,
673c2f63
JM
3738 "If some registers are represented in Dwarf-2 unwind information in\n\
3739multiple pieces, define this hook to fill in information about the\n\
3740sizes of those pieces in the table used by the unwinder at runtime.\n\
3741It will be called by @code{expand_builtin_init_dwarf_reg_sizes} after\n\
3742filling in a single size corresponding to each hard register;\n\
3743@var{address} is the address of the table.",
38f8b050
JR
3744 void, (tree address),
3745 hook_void_tree)
3746
3747/* Fetch the fixed register(s) which hold condition codes, for
3748 targets where it makes sense to look for duplicate assignments to
3749 the condition codes. This should return true if there is such a
3750 register, false otherwise. The arguments should be set to the
3751 fixed register numbers. Up to two condition code registers are
3752 supported. If there is only one for this target, the int pointed
3753 at by the second argument should be set to -1. */
3754DEFHOOK
3755(fixed_condition_code_regs,
673c2f63
JM
3756 "On targets which do not use @code{(cc0)}, and which use a hard\n\
3757register rather than a pseudo-register to hold condition codes, the\n\
3758regular CSE passes are often not able to identify cases in which the\n\
3759hard register is set to a common value. Use this hook to enable a\n\
3760small pass which optimizes such cases. This hook should return true\n\
3761to enable this pass, and it should set the integers to which its\n\
3762arguments point to the hard register numbers used for condition codes.\n\
3763When there is only one such register, as is true on most systems, the\n\
3764integer pointed to by @var{p2} should be set to\n\
3765@code{INVALID_REGNUM}.\n\
3766\n\
3767The default version of this hook returns false.",
38f8b050
JR
3768 bool, (unsigned int *p1, unsigned int *p2),
3769 hook_bool_uintp_uintp_false)
3770
3771/* If two condition code modes are compatible, return a condition
3772 code mode which is compatible with both, such that a comparison
3773 done in the returned mode will work for both of the original
3774 modes. If the condition code modes are not compatible, return
3775 VOIDmode. */
3776DEFHOOK
3777(cc_modes_compatible,
673c2f63
JM
3778 "On targets which use multiple condition code modes in class\n\
3779@code{MODE_CC}, it is sometimes the case that a comparison can be\n\
3780validly done in more than one mode. On such a system, define this\n\
3781target hook to take two mode arguments and to return a mode in which\n\
3782both comparisons may be validly done. If there is no such mode,\n\
3783return @code{VOIDmode}.\n\
3784\n\
3785The default version of this hook checks whether the modes are the\n\
3786same. If they are, it returns that mode. If they are different, it\n\
3787returns @code{VOIDmode}.",
ef4bddc2 3788 machine_mode, (machine_mode m1, machine_mode m2),
38f8b050
JR
3789 default_cc_modes_compatible)
3790
3791/* Do machine-dependent code transformations. Called just before
3792 delayed-branch scheduling. */
3793DEFHOOK
3794(machine_dependent_reorg,
673c2f63
JM
3795 "If non-null, this hook performs a target-specific pass over the\n\
3796instruction stream. The compiler will run it at all optimization levels,\n\
3797just before the point at which it normally does delayed-branch scheduling.\n\
3798\n\
3799The exact purpose of the hook varies from target to target. Some use\n\
3800it to do transformations that are necessary for correctness, such as\n\
3801laying out in-function constant pools or avoiding hardware hazards.\n\
3802Others use it as an opportunity to do some machine-dependent optimizations.\n\
3803\n\
3804You need not implement the hook if it has nothing to do. The default\n\
3805definition is null.",
38f8b050
JR
3806 void, (void), NULL)
3807
3808/* Create the __builtin_va_list type. */
3809DEFHOOK
3810(build_builtin_va_list,
673c2f63
JM
3811 "This hook returns a type node for @code{va_list} for the target.\n\
3812The default version of the hook returns @code{void*}.",
38f8b050
JR
3813 tree, (void),
3814 std_build_builtin_va_list)
3815
3816/* Enumerate the va list variants. */
07a5b2bc 3817DEFHOOK
38f8b050 3818(enum_va_list_p,
673c2f63
JM
3819 "This target hook is used in function @code{c_common_nodes_and_builtins}\n\
3820to iterate through the target specific builtin types for va_list. The\n\
3821variable @var{idx} is used as iterator. @var{pname} has to be a pointer\n\
3822to a @code{const char *} and @var{ptree} a pointer to a @code{tree} typed\n\
3823variable.\n\
3824The arguments @var{pname} and @var{ptree} are used to store the result of\n\
3825this macro and are set to the name of the va_list builtin type and its\n\
3826internal type.\n\
3827If the return value of this macro is zero, then there is no more element.\n\
3828Otherwise the @var{IDX} should be increased for the next call of this\n\
3829macro to iterate through all types.",
38f8b050
JR
3830 int, (int idx, const char **pname, tree *ptree),
3831 NULL)
3832
3833/* Get the cfun/fndecl calling abi __builtin_va_list type. */
3834DEFHOOK
3835(fn_abi_va_list,
673c2f63
JM
3836 "This hook returns the va_list type of the calling convention specified by\n\
3837@var{fndecl}.\n\
3838The default version of this hook returns @code{va_list_type_node}.",
38f8b050
JR
3839 tree, (tree fndecl),
3840 std_fn_abi_va_list)
3841
3842/* Get the __builtin_va_list type dependent on input type. */
3843DEFHOOK
3844(canonical_va_list_type,
673c2f63
JM
3845 "This hook returns the va_list type of the calling convention specified by the\n\
3846type of @var{type}. If @var{type} is not a valid va_list type, it returns\n\
3847@code{NULL_TREE}.",
38f8b050
JR
3848 tree, (tree type),
3849 std_canonical_va_list_type)
3850
3851/* ??? Documenting this hook requires a GFDL license grant. */
3852DEFHOOK_UNDOC
3853(expand_builtin_va_start,
3854"Expand the @code{__builtin_va_start} builtin.",
3855 void, (tree valist, rtx nextarg), NULL)
3856
3857/* Gimplifies a VA_ARG_EXPR. */
3858DEFHOOK
3859(gimplify_va_arg_expr,
673c2f63
JM
3860 "This hook performs target-specific gimplification of\n\
3861@code{VA_ARG_EXPR}. The first two parameters correspond to the\n\
3862arguments to @code{va_arg}; the latter two are as in\n\
3863@code{gimplify.c:gimplify_expr}.",
38f8b050
JR
3864 tree, (tree valist, tree type, gimple_seq *pre_p, gimple_seq *post_p),
3865 std_gimplify_va_arg_expr)
3866
3867/* Validity-checking routines for PCH files, target-specific.
3868 get_pch_validity returns a pointer to the data to be stored,
3869 and stores the size in its argument. pch_valid_p gets the same
3870 information back and returns NULL if the PCH is valid,
3871 or an error message if not. */
3872DEFHOOK
3873(get_pch_validity,
673c2f63
JM
3874 "This hook returns a pointer to the data needed by\n\
3875@code{TARGET_PCH_VALID_P} and sets\n\
3876@samp{*@var{sz}} to the size of the data in bytes.",
38f8b050
JR
3877 void *, (size_t *sz),
3878 default_get_pch_validity)
3879
3880DEFHOOK
3881(pch_valid_p,
673c2f63
JM
3882 "This hook checks whether the options used to create a PCH file are\n\
3883compatible with the current settings. It returns @code{NULL}\n\
3884if so and a suitable error message if not. Error messages will\n\
3885be presented to the user and must be localized using @samp{_(@var{msg})}.\n\
3886\n\
3887@var{data} is the data that was returned by @code{TARGET_GET_PCH_VALIDITY}\n\
3888when the PCH file was created and @var{sz} is the size of that data in bytes.\n\
3889It's safe to assume that the data was created by the same version of the\n\
3890compiler, so no format checking is needed.\n\
3891\n\
3892The default definition of @code{default_pch_valid_p} should be\n\
3893suitable for most targets.",
38f8b050
JR
3894 const char *, (const void *data, size_t sz),
3895 default_pch_valid_p)
3896
e32ea2d1
RS
3897DEFHOOK
3898(prepare_pch_save,
3899 "Called before writing out a PCH file. If the target has some\n\
3900garbage-collected data that needs to be in a particular state on PCH loads,\n\
3901it can use this hook to enforce that state. Very few targets need\n\
3902to do anything here.",
3903 void, (void),
3904 hook_void_void)
3905
38f8b050
JR
3906/* If nonnull, this function checks whether a PCH file with the
3907 given set of target flags can be used. It returns NULL if so,
3908 otherwise it returns an error message. */
3909DEFHOOK
3910(check_pch_target_flags,
673c2f63
JM
3911 "If this hook is nonnull, the default implementation of\n\
3912@code{TARGET_PCH_VALID_P} will use it to check for compatible values\n\
3913of @code{target_flags}. @var{pch_flags} specifies the value that\n\
3914@code{target_flags} had when the PCH file was created. The return\n\
3915value is the same as for @code{TARGET_PCH_VALID_P}.",
38f8b050
JR
3916 const char *, (int pch_flags), NULL)
3917
3918/* True if the compiler should give an enum type only as many
3919 bytes as it takes to represent the range of possible values of
3920 that type. */
3921DEFHOOK
3922(default_short_enums,
673c2f63
JM
3923 "This target hook should return true if the compiler should give an\n\
3924@code{enum} type only as many bytes as it takes to represent the range\n\
3925of possible values of that type. It should return false if all\n\
3926@code{enum} types should be allocated like @code{int}.\n\
3927\n\
3928The default is to return false.",
38f8b050
JR
3929 bool, (void),
3930 hook_bool_void_false)
3931
3932/* This target hook returns an rtx that is used to store the address
3933 of the current frame into the built-in setjmp buffer. */
3934DEFHOOK
3935(builtin_setjmp_frame_value,
673c2f63
JM
3936 "This target hook should return an rtx that is used to store\n\
3937the address of the current frame into the built in @code{setjmp} buffer.\n\
3938The default value, @code{virtual_stack_vars_rtx}, is correct for most\n\
3939machines. One reason you may need to define this target hook is if\n\
3940@code{hard_frame_pointer_rtx} is the appropriate value on your machine.",
38f8b050
JR
3941 rtx, (void),
3942 default_builtin_setjmp_frame_value)
3943
7ca35180
RH
3944/* This target hook should manipulate the outputs, inputs, constraints,
3945 and clobbers the port wishes for pre-processing the asm. */
3946DEFHOOK
3947(md_asm_adjust,
3948 "This target hook may add @dfn{clobbers} to @var{clobbers} and\n\
3949@var{clobbered_regs} for any hard regs the port wishes to automatically\n\
3950clobber for an asm. The @var{outputs} and @var{inputs} may be inspected\n\
3951to avoid clobbering a register that is already used by the asm.\n\
3952\n\
3953It may modify the @var{outputs}, @var{inputs}, and @var{constraints}\n\
3954as necessary for other pre-processing. In this case the return value is\n\
3955a sequence of insns to emit after the asm.",
3956 rtx_insn *,
3957 (vec<rtx>& outputs, vec<rtx>& inputs, vec<const char *>& constraints,
3958 vec<rtx>& clobbers, HARD_REG_SET& clobbered_regs),
3959 NULL)
38f8b050
JR
3960
3961/* This target hook allows the backend to specify a calling convention
3962 in the debug information. This function actually returns an
3963 enum dwarf_calling_convention, but because of forward declarations
3964 and not wanting to include dwarf2.h everywhere target.h is included
3965 the function is being declared as an int. */
3966DEFHOOK
3967(dwarf_calling_convention,
673c2f63
JM
3968 "Define this to enable the dwarf attribute @code{DW_AT_calling_convention} to\n\
3969be emitted for each function. Instead of an integer return the enum\n\
3970value for the @code{DW_CC_} tag.",
38f8b050
JR
3971 int, (const_tree function),
3972 hook_int_const_tree_0)
3973
3974/* This target hook allows the backend to emit frame-related insns that
3975 contain UNSPECs or UNSPEC_VOLATILEs. The call frame debugging info
3976 engine will invoke it on insns of the form
3977 (set (reg) (unspec [...] UNSPEC_INDEX))
3978 and
3979 (set (reg) (unspec_volatile [...] UNSPECV_INDEX))
3980 to let the backend emit the call frame instructions. */
3981DEFHOOK
3982(dwarf_handle_frame_unspec,
673c2f63
JM
3983 "This target hook allows the backend to emit frame-related insns that\n\
3984contain UNSPECs or UNSPEC_VOLATILEs. The DWARF 2 call frame debugging\n\
3985info engine will invoke it on insns of the form\n\
3986@smallexample\n\
3987(set (reg) (unspec [@dots{}] UNSPEC_INDEX))\n\
3988@end smallexample\n\
3989and\n\
3990@smallexample\n\
3991(set (reg) (unspec_volatile [@dots{}] UNSPECV_INDEX)).\n\
3992@end smallexample\n\
3993to let the backend emit the call frame instructions. @var{label} is\n\
3994the CFI label attached to the insn, @var{pattern} is the pattern of\n\
3995the insn and @var{index} is @code{UNSPEC_INDEX} or @code{UNSPECV_INDEX}.",
38f8b050
JR
3996 void, (const char *label, rtx pattern, int index), NULL)
3997
3998/* ??? Documenting this hook requires a GFDL license grant. */
3999DEFHOOK_UNDOC
4000(stdarg_optimize_hook,
4001"Perform architecture specific checking of statements gimplified\
4002 from @code{VA_ARG_EXPR}. @var{stmt} is the statement. Returns true if\
4003 the statement doesn't need to be checked for @code{va_list} references.",
355fe088 4004 bool, (struct stdarg_info *ai, const gimple *stmt), NULL)
38f8b050
JR
4005
4006/* This target hook allows the operating system to override the DECL
4007 that represents the external variable that contains the stack
4008 protection guard variable. The type of this DECL is ptr_type_node. */
4009DEFHOOK
4010(stack_protect_guard,
673c2f63
JM
4011 "This hook returns a @code{DECL} node for the external variable to use\n\
4012for the stack protection guard. This variable is initialized by the\n\
4013runtime to some random value and is used to initialize the guard value\n\
4014that is placed at the top of the local stack frame. The type of this\n\
4015variable must be @code{ptr_type_node}.\n\
4016\n\
4017The default version of this hook creates a variable called\n\
4018@samp{__stack_chk_guard}, which is normally defined in @file{libgcc2.c}.",
38f8b050
JR
4019 tree, (void),
4020 default_stack_protect_guard)
4021
4022/* This target hook allows the operating system to override the CALL_EXPR
4023 that is invoked when a check vs the guard variable fails. */
4024DEFHOOK
4025(stack_protect_fail,
673c2f63
JM
4026 "This hook returns a @code{CALL_EXPR} that alerts the runtime that the\n\
4027stack protect guard variable has been modified. This expression should\n\
4028involve a call to a @code{noreturn} function.\n\
4029\n\
4030The default version of this hook invokes a function called\n\
4031@samp{__stack_chk_fail}, taking no arguments. This function is\n\
4032normally defined in @file{libgcc2.c}.",
38f8b050
JR
4033 tree, (void),
4034 default_external_stack_protect_fail)
4035
87a5dc2d
JW
4036/* This target hook allows the operating system to disable the default stack
4037 protector runtime support. */
4038DEFHOOK
4039(stack_protect_runtime_enabled_p,
4040 "Returns true if the target wants GCC's default stack protect runtime support,\
4041 otherwise return false. The default implementation always returns true.",
4042 bool, (void),
4043 hook_bool_void_true)
4044
1d0216c8
RS
4045DEFHOOK
4046(can_use_doloop_p,
4047 "Return true if it is possible to use low-overhead loops (@code{doloop_end}\n\
4048and @code{doloop_begin}) for a particular loop. @var{iterations} gives the\n\
4049exact number of iterations, or 0 if not known. @var{iterations_max} gives\n\
4050the maximum number of iterations, or 0 if not known. @var{loop_depth} is\n\
4051the nesting depth of the loop, with 1 for innermost loops, 2 for loops that\n\
4052contain innermost loops, and so on. @var{entered_at_top} is true if the\n\
4053loop is only entered from the top.\n\
4054\n\
4055This hook is only used if @code{doloop_end} is available. The default\n\
4056implementation returns true. You can use @code{can_use_doloop_if_innermost}\n\
4057if the loop must be the innermost, and if there are no other restrictions.",
807e902e 4058 bool, (const widest_int &iterations, const widest_int &iterations_max,
1d0216c8 4059 unsigned int loop_depth, bool entered_at_top),
807e902e 4060 hook_bool_wint_wint_uint_bool_true)
1d0216c8 4061
38f8b050
JR
4062/* Returns NULL if target supports the insn within a doloop block,
4063 otherwise it returns an error message. */
4064DEFHOOK
4065(invalid_within_doloop,
673c2f63
JM
4066 "\n\
4067Take an instruction in @var{insn} and return NULL if it is valid within a\n\
4068low-overhead loop, otherwise return a string explaining why doloop\n\
4069could not be applied.\n\
4070\n\
4071Many targets use special registers for low-overhead looping. For any\n\
4072instruction that clobbers these this function should return a string indicating\n\
4073the reason why the doloop could not be applied.\n\
4074By default, the RTL loop optimizer does not use a present doloop pattern for\n\
4075loops containing function calls or branch on table instructions.",
ac44248e 4076 const char *, (const rtx_insn *insn),
38f8b050
JR
4077 default_invalid_within_doloop)
4078
78e4f1ad
UB
4079/* Returns true for a legitimate combined insn. */
4080DEFHOOK
4081(legitimate_combined_insn,
4082"Take an instruction in @var{insn} and return @code{false} if the instruction\
4083 is not appropriate as a combination of two or more instructions. The\
4084 default is to accept all instructions.",
ac44248e
DM
4085 bool, (rtx_insn *insn),
4086 hook_bool_rtx_insn_true)
78e4f1ad 4087
38f8b050
JR
4088DEFHOOK
4089(valid_dllimport_attribute_p,
4090"@var{decl} is a variable or function with @code{__attribute__((dllimport))}\
4091 specified. Use this hook if the target needs to add extra validation\
4092 checks to @code{handle_dll_attribute}.",
4093 bool, (const_tree decl),
4094 hook_bool_const_tree_true)
4095
4096/* If non-zero, align constant anchors in CSE to a multiple of this
4097 value. */
4098DEFHOOKPOD
4099(const_anchor,
673c2f63
JM
4100 "On some architectures it can take multiple instructions to synthesize\n\
4101a constant. If there is another constant already in a register that\n\
4102is close enough in value then it is preferable that the new constant\n\
4103is computed from this register using immediate addition or\n\
4104subtraction. We accomplish this through CSE. Besides the value of\n\
4105the constant we also add a lower and an upper constant anchor to the\n\
4106available expressions. These are then queried when encountering new\n\
4107constants. The anchors are computed by rounding the constant up and\n\
4108down to a multiple of the value of @code{TARGET_CONST_ANCHOR}.\n\
4109@code{TARGET_CONST_ANCHOR} should be the maximum positive value\n\
4110accepted by immediate-add plus one. We currently assume that the\n\
4111value of @code{TARGET_CONST_ANCHOR} is a power of 2. For example, on\n\
4112MIPS, where add-immediate takes a 16-bit signed value,\n\
4113@code{TARGET_CONST_ANCHOR} is set to @samp{0x8000}. The default value\n\
4114is zero, which disables this optimization.",
38f8b050
JR
4115 unsigned HOST_WIDE_INT, 0)
4116
5dcfdccd
KY
4117/* Defines, which target-dependent bits (upper 16) are used by port */
4118DEFHOOK
4119(memmodel_check,
673c2f63
JM
4120 "Validate target specific memory model mask bits. When NULL no target specific\n\
4121memory model bits are allowed.",
5dcfdccd
KY
4122 unsigned HOST_WIDE_INT, (unsigned HOST_WIDE_INT val), NULL)
4123
dfe06d3e
JJ
4124/* Defines an offset bitwise ored into shifted address to get corresponding
4125 Address Sanitizer shadow address, or -1 if Address Sanitizer is not
4126 supported by the target. */
4127DEFHOOK
4128(asan_shadow_offset,
4129 "Return the offset bitwise ored into shifted address to get corresponding\n\
4130Address Sanitizer shadow memory address. NULL if Address Sanitizer is not\n\
4131supported by the target.",
4132 unsigned HOST_WIDE_INT, (void),
4133 NULL)
4134
38f8b050
JR
4135/* Functions relating to calls - argument passing, returns, etc. */
4136/* Members of struct call have no special macro prefix. */
4137HOOK_VECTOR (TARGET_CALLS, calls)
4138
4139DEFHOOK
4140(promote_function_mode,
673c2f63
JM
4141 "Like @code{PROMOTE_MODE}, but it is applied to outgoing function arguments or\n\
4142function return values. The target hook should return the new mode\n\
4143and possibly change @code{*@var{punsignedp}} if the promotion should\n\
4144change signedness. This function is called only for scalar @emph{or\n\
4145pointer} types.\n\
4146\n\
4147@var{for_return} allows to distinguish the promotion of arguments and\n\
4148return values. If it is @code{1}, a return value is being promoted and\n\
4149@code{TARGET_FUNCTION_VALUE} must perform the same promotions done here.\n\
4150If it is @code{2}, the returned mode should be that of the register in\n\
4151which an incoming parameter is copied, or the outgoing result is computed;\n\
4152then the hook should return the same mode as @code{promote_mode}, though\n\
4153the signedness may be different.\n\
4154\n\
4155@var{type} can be NULL when promoting function arguments of libcalls.\n\
4156\n\
4157The default is to not promote arguments and return values. You can\n\
4158also define the hook to @code{default_promote_function_mode_always_promote}\n\
4159if you would like to apply the same rules given by @code{PROMOTE_MODE}.",
ef4bddc2 4160 machine_mode, (const_tree type, machine_mode mode, int *punsignedp,
38f8b050
JR
4161 const_tree funtype, int for_return),
4162 default_promote_function_mode)
4163
4164DEFHOOK
4165(promote_prototypes,
673c2f63
JM
4166 "This target hook returns @code{true} if an argument declared in a\n\
4167prototype as an integral type smaller than @code{int} should actually be\n\
4168passed as an @code{int}. In addition to avoiding errors in certain\n\
4169cases of mismatch, it also makes for better code on certain machines.\n\
4170The default is to not promote prototypes.",
38f8b050
JR
4171 bool, (const_tree fntype),
4172 hook_bool_const_tree_false)
4173
4174DEFHOOK
4175(struct_value_rtx,
673c2f63
JM
4176 "This target hook should return the location of the structure value\n\
4177address (normally a @code{mem} or @code{reg}), or 0 if the address is\n\
4178passed as an ``invisible'' first argument. Note that @var{fndecl} may\n\
4179be @code{NULL}, for libcalls. You do not need to define this target\n\
4180hook if the address is always passed as an ``invisible'' first\n\
4181argument.\n\
4182\n\
4183On some architectures the place where the structure value address\n\
4184is found by the called function is not the same place that the\n\
4185caller put it. This can be due to register windows, or it could\n\
4186be because the function prologue moves it to a different place.\n\
4187@var{incoming} is @code{1} or @code{2} when the location is needed in\n\
4188the context of the called function, and @code{0} in the context of\n\
4189the caller.\n\
4190\n\
4191If @var{incoming} is nonzero and the address is to be found on the\n\
4192stack, return a @code{mem} which refers to the frame pointer. If\n\
4193@var{incoming} is @code{2}, the result is being used to fetch the\n\
4194structure value address at the beginning of a function. If you need\n\
4195to emit adjusting code, you should do it at this point.",
38f8b050
JR
4196 rtx, (tree fndecl, int incoming),
4197 hook_rtx_tree_int_null)
e0d14c39
BS
4198
4199DEFHOOKPOD
4200(omit_struct_return_reg,
4201 "Normally, when a function returns a structure by memory, the address\n\
4202is passed as an invisible pointer argument, but the compiler also\n\
4203arranges to return the address from the function like it would a normal\n\
9c582551 4204pointer return value. Define this to true if that behavior is\n\
e0d14c39
BS
4205undesirable on your target.",
4206 bool, false)
4207
38f8b050
JR
4208DEFHOOK
4209(return_in_memory,
673c2f63
JM
4210 "This target hook should return a nonzero value to say to return the\n\
4211function value in memory, just as large structures are always returned.\n\
4212Here @var{type} will be the data type of the value, and @var{fntype}\n\
4213will be the type of the function doing the returning, or @code{NULL} for\n\
4214libcalls.\n\
4215\n\
4216Note that values of mode @code{BLKmode} must be explicitly handled\n\
4217by this function. Also, the option @option{-fpcc-struct-return}\n\
4218takes effect regardless of this macro. On most systems, it is\n\
4219possible to leave the hook undefined; this causes a default\n\
4220definition to be used, whose value is the constant 1 for @code{BLKmode}\n\
4221values, and 0 otherwise.\n\
4222\n\
4223Do not use this hook to indicate that structures and unions should always\n\
4224be returned in memory. You should instead use @code{DEFAULT_PCC_STRUCT_RETURN}\n\
4225to indicate this.",
38f8b050
JR
4226 bool, (const_tree type, const_tree fntype),
4227 default_return_in_memory)
4228
4229DEFHOOK
4230(return_in_msb,
673c2f63
JM
4231 "This hook should return true if values of type @var{type} are returned\n\
4232at the most significant end of a register (in other words, if they are\n\
4233padded at the least significant end). You can assume that @var{type}\n\
4234is returned in a register; the caller is required to check this.\n\
4235\n\
4236Note that the register provided by @code{TARGET_FUNCTION_VALUE} must\n\
4237be able to hold the complete return value. For example, if a 1-, 2-\n\
4238or 3-byte structure is returned at the most significant end of a\n\
42394-byte register, @code{TARGET_FUNCTION_VALUE} should provide an\n\
4240@code{SImode} rtx.",
38f8b050
JR
4241 bool, (const_tree type),
4242 hook_bool_const_tree_false)
4243
4244/* Return true if a parameter must be passed by reference. TYPE may
4245 be null if this is a libcall. CA may be null if this query is
4246 from __builtin_va_arg. */
ec9f85e5 4247DEFHOOK
38f8b050 4248(pass_by_reference,
673c2f63
JM
4249 "This target hook should return @code{true} if an argument at the\n\
4250position indicated by @var{cum} should be passed by reference. This\n\
4251predicate is queried after target independent reasons for being\n\
4252passed by reference, such as @code{TREE_ADDRESSABLE (type)}.\n\
4253\n\
4254If the hook returns true, a copy of that argument is made in memory and a\n\
4255pointer to the argument is passed instead of the argument itself.\n\
4256The pointer is passed in whatever way is appropriate for passing a pointer\n\
4257to that type.",
38f8b050 4258 bool,
ef4bddc2 4259 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named),
38f8b050
JR
4260 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false)
4261
4262DEFHOOK
4263(expand_builtin_saveregs,
673c2f63
JM
4264 "If defined, this hook produces the machine-specific code for a call to\n\
4265@code{__builtin_saveregs}. This code will be moved to the very\n\
4266beginning of the function, before any parameter access are made. The\n\
4267return value of this function should be an RTX that contains the value\n\
4268to use as the return of @code{__builtin_saveregs}.",
38f8b050
JR
4269 rtx, (void),
4270 default_expand_builtin_saveregs)
4271
4272/* Returns pretend_argument_size. */
4273DEFHOOK
4274(setup_incoming_varargs,
673c2f63
JM
4275 "This target hook offers an alternative to using\n\
4276@code{__builtin_saveregs} and defining the hook\n\
4277@code{TARGET_EXPAND_BUILTIN_SAVEREGS}. Use it to store the anonymous\n\
4278register arguments into the stack so that all the arguments appear to\n\
4279have been passed consecutively on the stack. Once this is done, you can\n\
4280use the standard implementation of varargs that works for machines that\n\
4281pass all their arguments on the stack.\n\
4282\n\
4283The argument @var{args_so_far} points to the @code{CUMULATIVE_ARGS} data\n\
4284structure, containing the values that are obtained after processing the\n\
4285named arguments. The arguments @var{mode} and @var{type} describe the\n\
4286last named argument---its machine mode and its data type as a tree node.\n\
4287\n\
4288The target hook should do two things: first, push onto the stack all the\n\
4289argument registers @emph{not} used for the named arguments, and second,\n\
4290store the size of the data thus pushed into the @code{int}-valued\n\
4291variable pointed to by @var{pretend_args_size}. The value that you\n\
4292store here will serve as additional offset for setting up the stack\n\
4293frame.\n\
4294\n\
4295Because you must generate code to push the anonymous arguments at\n\
4296compile time without knowing their data types,\n\
4297@code{TARGET_SETUP_INCOMING_VARARGS} is only useful on machines that\n\
4298have just a single category of argument register and use it uniformly\n\
4299for all data types.\n\
4300\n\
4301If the argument @var{second_time} is nonzero, it means that the\n\
4302arguments of the function are being analyzed for the second time. This\n\
4303happens for an inline function, which is not actually compiled until the\n\
4304end of the source file. The hook @code{TARGET_SETUP_INCOMING_VARARGS} should\n\
4305not generate any instructions in this case.",
ef4bddc2 4306 void, (cumulative_args_t args_so_far, machine_mode mode, tree type,
38f8b050
JR
4307 int *pretend_args_size, int second_time),
4308 default_setup_incoming_varargs)
4309
d5e254e1
IE
4310DEFHOOK
4311(load_bounds_for_arg,
4312 "This hook is used by expand pass to emit insn to load bounds of\n\
4313@var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4314bounds of @var{arg} are not passed in register. If @var{slot} is a\n\
4315memory, then bounds are loaded as for regular pointer loaded from\n\
4316memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4317constant holding number of the target dependent special slot which\n\
4318should be used to obtain bounds. Hook returns RTX holding loaded bounds.",
4319 rtx, (rtx slot, rtx arg, rtx slot_no),
4320 default_load_bounds_for_arg)
4321
4322DEFHOOK
4323(store_bounds_for_arg,
4324 "This hook is used by expand pass to emit insns to store @var{bounds} of\n\
4325@var{arg} passed in @var{slot}. Expand pass uses this hook in case\n\
4326@var{bounds} of @var{arg} are not passed in register. If @var{slot} is a\n\
4327memory, then @var{bounds} are stored as for regular pointer stored in\n\
4328memory. If @var{slot} is not a memory then @var{slot_no} is an integer\n\
4329constant holding number of the target dependent special slot which\n\
4330should be used to store @var{bounds}.",
4331 void, (rtx arg, rtx slot, rtx bounds, rtx slot_no),
4332 default_store_bounds_for_arg)
4333
4334DEFHOOK
4335(load_returned_bounds,
4336 "This hook is used by expand pass to emit insn to load bounds\n\
4337returned by function call in @var{slot}. Hook returns RTX holding\n\
4338loaded bounds.",
4339 rtx, (rtx slot),
4340 default_load_returned_bounds)
4341
4342DEFHOOK
4343(store_returned_bounds,
4344 "This hook is used by expand pass to emit insn to store @var{bounds}\n\
4345returned by function call into @var{slot}.",
4346 void, (rtx slot, rtx bounds),
4347 default_store_returned_bounds)
4348
4349DEFHOOK
4350(setup_incoming_vararg_bounds,
4351 "Use it to store bounds for anonymous register arguments stored\n\
4352into the stack. Arguments meaning is similar to\n\
4353@code{TARGET_SETUP_INCOMING_VARARGS}.",
4354 void, (cumulative_args_t args_so_far, enum machine_mode mode, tree type,
4355 int *pretend_args_size, int second_time),
4356 default_setup_incoming_vararg_bounds)
4357
2f21e1ba
BS
4358DEFHOOK
4359(call_args,
4360 "While generating RTL for a function call, this target hook is invoked once\n\
4361for each argument passed to the function, either a register returned by\n\
4362@code{TARGET_FUNCTION_ARG} or a memory location. It is called just\n\
4363before the point where argument registers are stored. The type of the\n\
4364function to be called is also passed as the second argument; it is\n\
4365@code{NULL_TREE} for libcalls. The @code{TARGET_END_CALL_ARGS} hook is\n\
4366invoked just after the code to copy the return reg has been emitted.\n\
4367This functionality can be used to perform special setup of call argument\n\
4368registers if a target needs it.\n\
4369For functions without arguments, the hook is called once with @code{pc_rtx}\n\
4370passed instead of an argument register.\n\
4371Most ports do not need to implement anything for this hook.",
4372 void, (rtx, tree),
4373 hook_void_rtx_tree)
4374
4375DEFHOOK
4376(end_call_args,
4377 "This target hook is invoked while generating RTL for a function call,\n\
4378just after the point where the return reg is copied into a pseudo. It\n\
4379signals that all the call argument and return registers for the just\n\
4380emitted call are now no longer in use.\n\
4381Most ports do not need to implement anything for this hook.",
4382 void, (void),
4383 hook_void_void)
4384
38f8b050
JR
4385DEFHOOK
4386(strict_argument_naming,
673c2f63
JM
4387 "Define this hook to return @code{true} if the location where a function\n\
4388argument is passed depends on whether or not it is a named argument.\n\
4389\n\
4390This hook controls how the @var{named} argument to @code{TARGET_FUNCTION_ARG}\n\
4391is set for varargs and stdarg functions. If this hook returns\n\
4392@code{true}, the @var{named} argument is always true for named\n\
4393arguments, and false for unnamed arguments. If it returns @code{false},\n\
4394but @code{TARGET_PRETEND_OUTGOING_VARARGS_NAMED} returns @code{true},\n\
4395then all arguments are treated as named. Otherwise, all named arguments\n\
4396except the last are treated as named.\n\
4397\n\
4398You need not define this hook if it always returns @code{false}.",
d5cc9181 4399 bool, (cumulative_args_t ca),
38f8b050
JR
4400 hook_bool_CUMULATIVE_ARGS_false)
4401
4402/* Returns true if we should use
4403 targetm.calls.setup_incoming_varargs() and/or
4404 targetm.calls.strict_argument_naming(). */
4405DEFHOOK
4406(pretend_outgoing_varargs_named,
673c2f63
JM
4407 "If you need to conditionally change ABIs so that one works with\n\
4408@code{TARGET_SETUP_INCOMING_VARARGS}, but the other works like neither\n\
4409@code{TARGET_SETUP_INCOMING_VARARGS} nor @code{TARGET_STRICT_ARGUMENT_NAMING} was\n\
4410defined, then define this hook to return @code{true} if\n\
4411@code{TARGET_SETUP_INCOMING_VARARGS} is used, @code{false} otherwise.\n\
4412Otherwise, you should not define this hook.",
d5cc9181 4413 bool, (cumulative_args_t ca),
38f8b050
JR
4414 default_pretend_outgoing_varargs_named)
4415
4416/* Given a complex type T, return true if a parameter of type T
4417 should be passed as two scalars. */
4418DEFHOOK
4419(split_complex_arg,
673c2f63
JM
4420 "This hook should return true if parameter of type @var{type} are passed\n\
4421as two scalar parameters. By default, GCC will attempt to pack complex\n\
4422arguments into the target's word size. Some ABIs require complex arguments\n\
4423to be split and treated as their individual components. For example, on\n\
4424AIX64, complex floats should be passed in a pair of floating point\n\
4425registers, even though a complex float would fit in one 64-bit floating\n\
4426point register.\n\
4427\n\
4428The default value of this hook is @code{NULL}, which is treated as always\n\
4429false.",
38f8b050
JR
4430 bool, (const_tree type), NULL)
4431
4432/* Return true if type T, mode MODE, may not be passed in registers,
4433 but must be passed on the stack. */
4434/* ??? This predicate should be applied strictly after pass-by-reference.
4435 Need audit to verify that this is the case. */
4436DEFHOOK
4437(must_pass_in_stack,
673c2f63
JM
4438 "This target hook should return @code{true} if we should not pass @var{type}\n\
4439solely in registers. The file @file{expr.h} defines a\n\
4440definition that is usually appropriate, refer to @file{expr.h} for additional\n\
4441documentation.",
ef4bddc2 4442 bool, (machine_mode mode, const_tree type),
38f8b050
JR
4443 must_pass_in_stack_var_size_or_pad)
4444
4445/* Return true if type TYPE, mode MODE, which is passed by reference,
4446 should have the object copy generated by the callee rather than
4447 the caller. It is never called for TYPE requiring constructors. */
4448DEFHOOK
4449(callee_copies,
673c2f63
JM
4450 "The function argument described by the parameters to this hook is\n\
4451known to be passed by reference. The hook should return true if the\n\
4452function argument should be copied by the callee instead of copied\n\
4453by the caller.\n\
4454\n\
4455For any argument for which the hook returns true, if it can be\n\
4456determined that the argument is not modified, then a copy need\n\
4457not be generated.\n\
4458\n\
4459The default version of this hook always returns false.",
38f8b050 4460 bool,
ef4bddc2 4461 (cumulative_args_t cum, machine_mode mode, const_tree type, bool named),
38f8b050
JR
4462 hook_bool_CUMULATIVE_ARGS_mode_tree_bool_false)
4463
4464/* Return zero for arguments passed entirely on the stack or entirely
4465 in registers. If passed in both, return the number of bytes passed
4466 in registers; the balance is therefore passed on the stack. */
4467DEFHOOK
4468(arg_partial_bytes,
673c2f63
JM
4469 "This target hook returns the number of bytes at the beginning of an\n\
4470argument that must be put in registers. The value must be zero for\n\
4471arguments that are passed entirely in registers or that are entirely\n\
4472pushed on the stack.\n\
4473\n\
4474On some machines, certain arguments must be passed partially in\n\
4475registers and partially in memory. On these machines, typically the\n\
4476first few words of arguments are passed in registers, and the rest\n\
4477on the stack. If a multi-word argument (a @code{double} or a\n\
4478structure) crosses that boundary, its first few words must be passed\n\
4479in registers and the rest must be pushed. This macro tells the\n\
4480compiler when this occurs, and how many bytes should go in registers.\n\
4481\n\
4482@code{TARGET_FUNCTION_ARG} for these arguments should return the first\n\
4483register to be used by the caller for this argument; likewise\n\
4484@code{TARGET_FUNCTION_INCOMING_ARG}, for the called function.",
ef4bddc2 4485 int, (cumulative_args_t cum, machine_mode mode, tree type, bool named),
38f8b050
JR
4486 hook_int_CUMULATIVE_ARGS_mode_tree_bool_0)
4487
4488/* Update the state in CA to advance past an argument in the
4489 argument list. The values MODE, TYPE, and NAMED describe that
4490 argument. */
b25b9e8f 4491DEFHOOK
38f8b050 4492(function_arg_advance,
673c2f63
JM
4493 "This hook updates the summarizer variable pointed to by @var{ca} to\n\
4494advance past an argument in the argument list. The values @var{mode},\n\
4495@var{type} and @var{named} describe that argument. Once this is done,\n\
4496the variable @var{cum} is suitable for analyzing the @emph{following}\n\
4497argument with @code{TARGET_FUNCTION_ARG}, etc.\n\
4498\n\
4499This hook need not do anything if the argument in question was passed\n\
4500on the stack. The compiler knows how to track the amount of stack space\n\
4501used for arguments without any special help.",
38f8b050 4502 void,
ef4bddc2 4503 (cumulative_args_t ca, machine_mode mode, const_tree type, bool named),
38f8b050
JR
4504 default_function_arg_advance)
4505
4506/* Return zero if the argument described by the state of CA should
4507 be placed on a stack, or a hard register in which to store the
4508 argument. The values MODE, TYPE, and NAMED describe that
4509 argument. */
b25b9e8f 4510DEFHOOK
38f8b050 4511(function_arg,
673c2f63
JM
4512 "Return an RTX indicating whether a function argument is passed in a\n\
4513register and if so, which register.\n\
4514\n\
4515The arguments are @var{ca}, which summarizes all the previous\n\
4516arguments; @var{mode}, the machine mode of the argument; @var{type},\n\
4517the data type of the argument as a tree node or 0 if that is not known\n\
4518(which happens for C support library functions); and @var{named},\n\
4519which is @code{true} for an ordinary argument and @code{false} for\n\
4520nameless arguments that correspond to @samp{@dots{}} in the called\n\
4521function's prototype. @var{type} can be an incomplete type if a\n\
4522syntax error has previously occurred.\n\
4523\n\
4524The return value is usually either a @code{reg} RTX for the hard\n\
4525register in which to pass the argument, or zero to pass the argument\n\
4526on the stack.\n\
4527\n\
d5e254e1
IE
4528The return value can be a @code{const_int} which means argument is\n\
4529passed in a target specific slot with specified number. Target hooks\n\
4530should be used to store or load argument in such case. See\n\
4531@code{TARGET_STORE_BOUNDS_FOR_ARG} and @code{TARGET_LOAD_BOUNDS_FOR_ARG}\n\
4532for more information.\n\
4533\n\
673c2f63
JM
4534The value of the expression can also be a @code{parallel} RTX@. This is\n\
4535used when an argument is passed in multiple locations. The mode of the\n\
4536@code{parallel} should be the mode of the entire argument. The\n\
4537@code{parallel} holds any number of @code{expr_list} pairs; each one\n\
4538describes where part of the argument is passed. In each\n\
4539@code{expr_list} the first operand must be a @code{reg} RTX for the hard\n\
4540register in which to pass this part of the argument, and the mode of the\n\
4541register RTX indicates how large this part of the argument is. The\n\
4542second operand of the @code{expr_list} is a @code{const_int} which gives\n\
4543the offset in bytes into the entire argument of where this part starts.\n\
4544As a special exception the first @code{expr_list} in the @code{parallel}\n\
4545RTX may have a first operand of zero. This indicates that the entire\n\
4546argument is also stored on the stack.\n\
4547\n\
4548The last time this hook is called, it is called with @code{MODE ==\n\
4549VOIDmode}, and its result is passed to the @code{call} or @code{call_value}\n\
4550pattern as operands 2 and 3 respectively.\n\
4551\n\
4552@cindex @file{stdarg.h} and register arguments\n\
4553The usual way to make the ISO library @file{stdarg.h} work on a\n\
4554machine where some arguments are usually passed in registers, is to\n\
4555cause nameless arguments to be passed on the stack instead. This is\n\
4556done by making @code{TARGET_FUNCTION_ARG} return 0 whenever\n\
4557@var{named} is @code{false}.\n\
4558\n\
4559@cindex @code{TARGET_MUST_PASS_IN_STACK}, and @code{TARGET_FUNCTION_ARG}\n\
4560@cindex @code{REG_PARM_STACK_SPACE}, and @code{TARGET_FUNCTION_ARG}\n\
4561You may use the hook @code{targetm.calls.must_pass_in_stack}\n\
4562in the definition of this macro to determine if this argument is of a\n\
4563type that must be passed in the stack. If @code{REG_PARM_STACK_SPACE}\n\
4564is not defined and @code{TARGET_FUNCTION_ARG} returns nonzero for such an\n\
4565argument, the compiler will abort. If @code{REG_PARM_STACK_SPACE} is\n\
4566defined, the argument will be computed in the stack and then loaded into\n\
4567a register.",
ef4bddc2 4568 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type,
38f8b050
JR
4569 bool named),
4570 default_function_arg)
4571
b25b9e8f 4572DEFHOOK
38f8b050 4573(function_incoming_arg,
4a235312
L
4574 "Define this hook if the caller and callee on the target have different\n\
4575views of where arguments are passed. Also define this hook if there are\n\
4576functions that are never directly called, but are invoked by the hardware\n\
4577and which have nonstandard calling conventions.\n\
673c2f63 4578\n\
4a235312 4579In this case @code{TARGET_FUNCTION_ARG} computes the register in\n\
673c2f63
JM
4580which the caller passes the value, and\n\
4581@code{TARGET_FUNCTION_INCOMING_ARG} should be defined in a similar\n\
4582fashion to tell the function being called where the arguments will\n\
4583arrive.\n\
4584\n\
4a235312
L
4585@code{TARGET_FUNCTION_INCOMING_ARG} can also return arbitrary address\n\
4586computation using hard register, which can be forced into a register,\n\
4587so that it can be used to pass special arguments.\n\
4588\n\
673c2f63
JM
4589If @code{TARGET_FUNCTION_INCOMING_ARG} is not defined,\n\
4590@code{TARGET_FUNCTION_ARG} serves both purposes.",
ef4bddc2 4591 rtx, (cumulative_args_t ca, machine_mode mode, const_tree type,
38f8b050
JR
4592 bool named),
4593 default_function_incoming_arg)
4594
c2ed6cf8
NF
4595DEFHOOK
4596(function_arg_boundary,
673c2f63
JM
4597 "This hook returns the alignment boundary, in bits, of an argument\n\
4598with the specified mode and type. The default hook returns\n\
4599@code{PARM_BOUNDARY} for all arguments.",
ef4bddc2 4600 unsigned int, (machine_mode mode, const_tree type),
c2ed6cf8
NF
4601 default_function_arg_boundary)
4602
123148b5
BS
4603DEFHOOK
4604(function_arg_round_boundary,
4605 "Normally, the size of an argument is rounded up to @code{PARM_BOUNDARY},\n\
4606which is the default value for this hook. You can define this hook to\n\
4607return a different value if an argument size must be rounded to a larger\n\
4608value.",
ef4bddc2 4609 unsigned int, (machine_mode mode, const_tree type),
123148b5
BS
4610 default_function_arg_round_boundary)
4611
38f8b050
JR
4612/* Return the diagnostic message string if function without a prototype
4613 is not allowed for this 'val' argument; NULL otherwise. */
4614DEFHOOK
4615(invalid_arg_for_unprototyped_fn,
673c2f63
JM
4616 "If defined, this macro returns the diagnostic message when it is\n\
4617illegal to pass argument @var{val} to function @var{funcdecl}\n\
4618with prototype @var{typelist}.",
38f8b050
JR
4619 const char *, (const_tree typelist, const_tree funcdecl, const_tree val),
4620 hook_invalid_arg_for_unprototyped_fn)
4621
4622/* Return an rtx for the return value location of the function
4623 specified by FN_DECL_OR_TYPE with a return type of RET_TYPE. */
4624DEFHOOK
4625(function_value,
673c2f63
JM
4626 "\n\
4627Define this to return an RTX representing the place where a function\n\
4628returns or receives a value of data type @var{ret_type}, a tree node\n\
4629representing a data type. @var{fn_decl_or_type} is a tree node\n\
4630representing @code{FUNCTION_DECL} or @code{FUNCTION_TYPE} of a\n\
4631function being called. If @var{outgoing} is false, the hook should\n\
4632compute the register in which the caller will see the return value.\n\
4633Otherwise, the hook should return an RTX representing the place where\n\
4634a function returns a value.\n\
4635\n\
4636On many machines, only @code{TYPE_MODE (@var{ret_type})} is relevant.\n\
4637(Actually, on most machines, scalar values are returned in the same\n\
4638place regardless of mode.) The value of the expression is usually a\n\
4639@code{reg} RTX for the hard register where the return value is stored.\n\
4640The value can also be a @code{parallel} RTX, if the return value is in\n\
4641multiple places. See @code{TARGET_FUNCTION_ARG} for an explanation of the\n\
4642@code{parallel} form. Note that the callee will populate every\n\
4643location specified in the @code{parallel}, but if the first element of\n\
4644the @code{parallel} contains the whole return value, callers will use\n\
4645that element as the canonical location and ignore the others. The m68k\n\
4646port uses this type of @code{parallel} to return pointers in both\n\
4647@samp{%a0} (the canonical location) and @samp{%d0}.\n\
4648\n\
4649If @code{TARGET_PROMOTE_FUNCTION_RETURN} returns true, you must apply\n\
4650the same promotion rules specified in @code{PROMOTE_MODE} if\n\
4651@var{valtype} is a scalar type.\n\
4652\n\
4653If the precise function being called is known, @var{func} is a tree\n\
4654node (@code{FUNCTION_DECL}) for it; otherwise, @var{func} is a null\n\
4655pointer. This makes it possible to use a different value-returning\n\
4656convention for specific functions when all their calls are\n\
4657known.\n\
4658\n\
4659Some target machines have ``register windows'' so that the register in\n\
4660which a function returns its value is not the same as the one in which\n\
4661the caller sees the value. For such machines, you should return\n\
4662different RTX depending on @var{outgoing}.\n\
4663\n\
4664@code{TARGET_FUNCTION_VALUE} is not used for return values with\n\
4665aggregate data types, because these are returned in another way. See\n\
4666@code{TARGET_STRUCT_VALUE_RTX} and related macros, below.",
38f8b050
JR
4667 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing),
4668 default_function_value)
4669
d5e254e1
IE
4670/* Return the rtx for bounds of returned pointer. */
4671DEFHOOK
4672(chkp_function_value_bounds,
4673 "Define this to return an RTX representing the place where a function\n\
4674returns bounds for returned pointers. Arguments meaning is similar to\n\
4675@code{TARGET_FUNCTION_VALUE}.",
4676 rtx, (const_tree ret_type, const_tree fn_decl_or_type, bool outgoing),
4677 default_chkp_function_value_bounds)
4678
38f8b050
JR
4679/* Return the rtx for the result of a libcall of mode MODE,
4680 calling the function FN_NAME. */
4681DEFHOOK
4682(libcall_value,
673c2f63
JM
4683 "Define this hook if the back-end needs to know the name of the libcall\n\
4684function in order to determine where the result should be returned.\n\
4685\n\
4686The mode of the result is given by @var{mode} and the name of the called\n\
4687library function is given by @var{fun}. The hook should return an RTX\n\
4688representing the place where the library function result will be returned.\n\
4689\n\
4690If this hook is not defined, then LIBCALL_VALUE will be used.",
ef4bddc2 4691 rtx, (machine_mode mode, const_rtx fun),
38f8b050
JR
4692 default_libcall_value)
4693
4694/* Return true if REGNO is a possible register number for
4695 a function value as seen by the caller. */
4696DEFHOOK
4697(function_value_regno_p,
673c2f63
JM
4698 "A target hook that return @code{true} if @var{regno} is the number of a hard\n\
4699register in which the values of called function may come back.\n\
4700\n\
4701A register whose use for returning values is limited to serving as the\n\
4702second of a pair (for a value of type @code{double}, say) need not be\n\
4703recognized by this target hook.\n\
4704\n\
4705If the machine has register windows, so that the caller and the called\n\
4706function use different registers for the return value, this target hook\n\
4707should recognize only the caller's register numbers.\n\
4708\n\
4709If this hook is not defined, then FUNCTION_VALUE_REGNO_P will be used.",
38f8b050
JR
4710 bool, (const unsigned int regno),
4711 default_function_value_regno_p)
4712
4713/* ??? Documenting this hook requires a GFDL license grant. */
4714DEFHOOK_UNDOC
4715(internal_arg_pointer,
4716"Return an rtx for the argument pointer incoming to the\
4717 current function.",
4718 rtx, (void),
4719 default_internal_arg_pointer)
4720
4721/* Update the current function stack boundary if needed. */
4722DEFHOOK
4723(update_stack_boundary,
673c2f63
JM
4724 "Define this macro to update the current function stack boundary if\n\
4725necessary.",
38f8b050
JR
4726 void, (void), NULL)
4727
4728/* Handle stack alignment and return an rtx for Dynamic Realign
4729 Argument Pointer if necessary. */
4730DEFHOOK
4731(get_drap_rtx,
673c2f63
JM
4732 "This hook should return an rtx for Dynamic Realign Argument Pointer (DRAP) if a\n\
4733different argument pointer register is needed to access the function's\n\
4734argument list due to stack realignment. Return @code{NULL} if no DRAP\n\
4735is needed.",
38f8b050
JR
4736 rtx, (void), NULL)
4737
4738/* Return true if all function parameters should be spilled to the
4739 stack. */
4740DEFHOOK
4741(allocate_stack_slots_for_args,
673c2f63
JM
4742 "When optimization is disabled, this hook indicates whether or not\n\
4743arguments should be allocated to stack slots. Normally, GCC allocates\n\
4744stacks slots for arguments when not optimizing in order to make\n\
4745debugging easier. However, when a function is declared with\n\
4746@code{__attribute__((naked))}, there is no stack frame, and the compiler\n\
4747cannot safely move arguments from the registers in which they are passed\n\
4748to the stack. Therefore, this hook should return true in general, but\n\
4749false for naked functions. The default implementation always returns true.",
38f8b050
JR
4750 bool, (void),
4751 hook_bool_void_true)
4752
c21df29b
RH
4753/* Return an rtx for the static chain for FNDECL_OR_TYPE. If INCOMING_P
4754 is true, then it should be for the callee; otherwise for the caller. */
38f8b050
JR
4755DEFHOOK
4756(static_chain,
673c2f63
JM
4757 "This hook replaces the use of @code{STATIC_CHAIN_REGNUM} et al for\n\
4758targets that may use different static chain locations for different\n\
4759nested functions. This may be required if the target has function\n\
4760attributes that affect the calling conventions of the function and\n\
4761those calling conventions use different static chain locations.\n\
4762\n\
4763The default version of this hook uses @code{STATIC_CHAIN_REGNUM} et al.\n\
4764\n\
4765If the static chain is passed in memory, this hook should be used to\n\
4766provide rtx giving @code{mem} expressions that denote where they are stored.\n\
4767Often the @code{mem} expression as seen by the caller will be at an offset\n\
4768from the stack pointer and the @code{mem} expression as seen by the callee\n\
4769will be at an offset from the frame pointer.\n\
4770@findex stack_pointer_rtx\n\
4771@findex frame_pointer_rtx\n\
4772@findex arg_pointer_rtx\n\
4773The variables @code{stack_pointer_rtx}, @code{frame_pointer_rtx}, and\n\
4774@code{arg_pointer_rtx} will have been initialized and should be used\n\
4775to refer to those items.",
c21df29b 4776 rtx, (const_tree fndecl_or_type, bool incoming_p),
38f8b050
JR
4777 default_static_chain)
4778
4779/* Fill in the trampoline at MEM with a call to FNDECL and a
4780 static chain value of CHAIN. */
4781DEFHOOK
4782(trampoline_init,
673c2f63
JM
4783 "This hook is called to initialize a trampoline.\n\
4784@var{m_tramp} is an RTX for the memory block for the trampoline; @var{fndecl}\n\
4785is the @code{FUNCTION_DECL} for the nested function; @var{static_chain} is an\n\
4786RTX for the static chain value that should be passed to the function\n\
4787when it is called.\n\
4788\n\
4789If the target defines @code{TARGET_ASM_TRAMPOLINE_TEMPLATE}, then the\n\
4790first thing this hook should do is emit a block move into @var{m_tramp}\n\
4791from the memory block returned by @code{assemble_trampoline_template}.\n\
4792Note that the block move need only cover the constant parts of the\n\
4793trampoline. If the target isolates the variable parts of the trampoline\n\
4794to the end, not all @code{TRAMPOLINE_SIZE} bytes need be copied.\n\
4795\n\
4796If the target requires any other actions, such as flushing caches or\n\
4797enabling stack execution, these actions should be performed after\n\
4798initializing the trampoline proper.",
38f8b050
JR
4799 void, (rtx m_tramp, tree fndecl, rtx static_chain),
4800 default_trampoline_init)
4801
4802/* Adjust the address of the trampoline in a target-specific way. */
4803DEFHOOK
4804(trampoline_adjust_address,
673c2f63
JM
4805 "This hook should perform any machine-specific adjustment in\n\
4806the address of the trampoline. Its argument contains the address of the\n\
4807memory block that was passed to @code{TARGET_TRAMPOLINE_INIT}. In case\n\
4808the address to be used for a function call should be different from the\n\
4809address at which the template was stored, the different address should\n\
4810be returned; otherwise @var{addr} should be returned unchanged.\n\
4811If this hook is not defined, @var{addr} will be used for function calls.",
38f8b050
JR
4812 rtx, (rtx addr), NULL)
4813
4c640e26
EB
4814DEFHOOKPOD
4815(custom_function_descriptors,
4816 "This hook should be defined to a power of 2 if the target will benefit\n\
4817from the use of custom descriptors for nested functions instead of the\n\
4818standard trampolines. Such descriptors are created at run time on the\n\
4819stack and made up of data only, but they are non-standard so the generated\n\
4820code must be prepared to deal with them. This hook should be defined to 0\n\
4821if the target uses function descriptors for its standard calling sequence,\n\
4822like for example HP-PA or IA-64. Using descriptors for nested functions\n\
4823eliminates the need for trampolines that reside on the stack and require\n\
4824it to be made executable.\n\
4825\n\
4826The value of the macro is used to parameterize the run-time identification\n\
4827scheme implemented to distinguish descriptors from function addresses: it\n\
4828gives the number of bytes by which their address is misaligned compared\n\
4829with function addresses. The value of 1 will generally work, unless it is\n\
4830already reserved by the target for another purpose, like for example on ARM.",\
4831 int, -1)
4832
38f8b050
JR
4833/* Return the number of bytes of its own arguments that a function
4834 pops on returning, or 0 if the function pops no arguments and the
4835 caller must therefore pop them all after the function returns. */
4836/* ??? tm.texi has no types for the parameters. */
893d13d5 4837DEFHOOK
38f8b050 4838(return_pops_args,
673c2f63
JM
4839 "This target hook returns the number of bytes of its own arguments that\n\
4840a function pops on returning, or 0 if the function pops no arguments\n\
4841and the caller must therefore pop them all after the function returns.\n\
4842\n\
4843@var{fundecl} is a C variable whose value is a tree node that describes\n\
4844the function in question. Normally it is a node of type\n\
4845@code{FUNCTION_DECL} that describes the declaration of the function.\n\
4846From this you can obtain the @code{DECL_ATTRIBUTES} of the function.\n\
4847\n\
4848@var{funtype} is a C variable whose value is a tree node that\n\
4849describes the function in question. Normally it is a node of type\n\
4850@code{FUNCTION_TYPE} that describes the data type of the function.\n\
4851From this it is possible to obtain the data types of the value and\n\
4852arguments (if known).\n\
4853\n\
4854When a call to a library function is being considered, @var{fundecl}\n\
4855will contain an identifier node for the library function. Thus, if\n\
4856you need to distinguish among various library functions, you can do so\n\
4857by their names. Note that ``library function'' in this context means\n\
4858a function used to perform arithmetic, whose name is known specially\n\
4859in the compiler and was not mentioned in the C code being compiled.\n\
4860\n\
4861@var{size} is the number of bytes of arguments passed on the\n\
4862stack. If a variable number of bytes is passed, it is zero, and\n\
4863argument popping will always be the responsibility of the calling function.\n\
4864\n\
4865On the VAX, all functions always pop their arguments, so the definition\n\
4866of this macro is @var{size}. On the 68000, using the standard\n\
4867calling convention, no functions pop their arguments, so the value of\n\
4868the macro is always 0 in this case. But an alternative calling\n\
4869convention is available in which functions that take a fixed number of\n\
4870arguments pop them but other functions (such as @code{printf}) pop\n\
4871nothing (the caller pops all). When this convention is in use,\n\
4872@var{funtype} is examined to determine whether a function takes a fixed\n\
4873number of arguments.",
38f8b050
JR
4874 int, (tree fundecl, tree funtype, int size),
4875 default_return_pops_args)
4876
ffa88471
SE
4877/* Return a mode wide enough to copy any function value that might be
4878 returned. */
4879DEFHOOK
4880(get_raw_result_mode,
4881 "This target hook returns the mode to be used when accessing raw return\
4882 registers in @code{__builtin_return}. Define this macro if the value\
4883 in @var{reg_raw_mode} is not correct.",
ef4bddc2 4884 machine_mode, (int regno),
ffa88471
SE
4885 default_get_reg_raw_mode)
4886
4887/* Return a mode wide enough to copy any argument value that might be
4888 passed. */
4889DEFHOOK
4890(get_raw_arg_mode,
4891 "This target hook returns the mode to be used when accessing raw argument\
4892 registers in @code{__builtin_apply_args}. Define this macro if the value\
4893 in @var{reg_raw_mode} is not correct.",
ef4bddc2 4894 machine_mode, (int regno),
ffa88471
SE
4895 default_get_reg_raw_mode)
4896
38f8b050
JR
4897HOOK_VECTOR_END (calls)
4898
bcb21886
KY
4899DEFHOOK
4900(use_pseudo_pic_reg,
4901 "This hook should return 1 in case pseudo register should be created\n\
4902for pic_offset_table_rtx during function expand.",
4903 bool, (void),
4904 hook_bool_void_false)
4905
4906DEFHOOK
4907(init_pic_reg,
4908 "Perform a target dependent initialization of pic_offset_table_rtx.\n\
4909This hook is called at the start of register allocation.",
4910 void, (void),
4911 hook_void_void)
4912
38f8b050
JR
4913/* Return the diagnostic message string if conversion from FROMTYPE
4914 to TOTYPE is not allowed, NULL otherwise. */
4915DEFHOOK
4916(invalid_conversion,
673c2f63
JM
4917 "If defined, this macro returns the diagnostic message when it is\n\
4918invalid to convert from @var{fromtype} to @var{totype}, or @code{NULL}\n\
4919if validity should be determined by the front end.",
38f8b050
JR
4920 const char *, (const_tree fromtype, const_tree totype),
4921 hook_constcharptr_const_tree_const_tree_null)
4922
4923/* Return the diagnostic message string if the unary operation OP is
4924 not permitted on TYPE, NULL otherwise. */
4925DEFHOOK
4926(invalid_unary_op,
673c2f63
JM
4927 "If defined, this macro returns the diagnostic message when it is\n\
4928invalid to apply operation @var{op} (where unary plus is denoted by\n\
4929@code{CONVERT_EXPR}) to an operand of type @var{type}, or @code{NULL}\n\
4930if validity should be determined by the front end.",
38f8b050
JR
4931 const char *, (int op, const_tree type),
4932 hook_constcharptr_int_const_tree_null)
4933
4934/* Return the diagnostic message string if the binary operation OP
4935 is not permitted on TYPE1 and TYPE2, NULL otherwise. */
4936DEFHOOK
4937(invalid_binary_op,
673c2f63
JM
4938 "If defined, this macro returns the diagnostic message when it is\n\
4939invalid to apply operation @var{op} to operands of types @var{type1}\n\
4940and @var{type2}, or @code{NULL} if validity should be determined by\n\
4941the front end.",
38f8b050
JR
4942 const char *, (int op, const_tree type1, const_tree type2),
4943 hook_constcharptr_int_const_tree_const_tree_null)
4944
38f8b050
JR
4945/* If values of TYPE are promoted to some other type when used in
4946 expressions (analogous to the integer promotions), return that type,
4947 or NULL_TREE otherwise. */
4948DEFHOOK
4949(promoted_type,
673c2f63
JM
4950 "If defined, this target hook returns the type to which values of\n\
4951@var{type} should be promoted when they appear in expressions,\n\
4952analogous to the integer promotions, or @code{NULL_TREE} to use the\n\
4953front end's normal promotion rules. This hook is useful when there are\n\
4954target-specific types with special promotion rules.\n\
4955This is currently used only by the C and C++ front ends.",
38f8b050
JR
4956 tree, (const_tree type),
4957 hook_tree_const_tree_null)
4958
4959/* Convert EXPR to TYPE, if target-specific types with special conversion
4960 rules are involved. Return the converted expression, or NULL to apply
4961 the standard conversion rules. */
4962DEFHOOK
4963(convert_to_type,
673c2f63
JM
4964 "If defined, this hook returns the result of converting @var{expr} to\n\
4965@var{type}. It should return the converted expression,\n\
4966or @code{NULL_TREE} to apply the front end's normal conversion rules.\n\
4967This hook is useful when there are target-specific types with special\n\
4968conversion rules.\n\
4969This is currently used only by the C and C++ front ends.",
38f8b050
JR
4970 tree, (tree type, tree expr),
4971 hook_tree_tree_tree_null)
4972
5074a1f8
VM
4973/* Change pseudo allocno class calculated by IRA. */
4974DEFHOOK
4975(ira_change_pseudo_allocno_class,
4976 "A target hook which can change allocno class for given pseudo from\n\
31e2b5a3 4977 allocno and best class calculated by IRA.\n\
5074a1f8
VM
4978 \n\
4979 The default version of this target hook always returns given class.",
31e2b5a3 4980 reg_class_t, (int, reg_class_t, reg_class_t),
5074a1f8
VM
4981 default_ira_change_pseudo_allocno_class)
4982
55a2c322
VM
4983/* Return true if we use LRA instead of reload. */
4984DEFHOOK
4985(lra_p,
4986 "A target hook which returns true if we use LRA instead of reload pass.\
55a2c322 4987 \
f37cb70b 4988 The default version of this target hook returns true. New ports\
48975b3d 4989 should use LRA, and existing ports are encouraged to convert.",
55a2c322
VM
4990 bool, (void),
4991 default_lra_p)
4992
4993/* Return register priority of given hard regno for the current target. */
4994DEFHOOK
4995(register_priority,
4996 "A target hook which returns the register priority number to which the\
4997 register @var{hard_regno} belongs to. The bigger the number, the\
4998 more preferable the hard register usage (when all other conditions are\
4999 the same). This hook can be used to prefer some hard register over\
5000 others in LRA. For example, some x86-64 register usage needs\
5001 additional prefix which makes instructions longer. The hook can\
5002 return lower priority number for such registers make them less favorable\
5003 and as result making the generated code smaller.\
5004 \
5005 The default version of this target hook returns always zero.",
5006 int, (int),
5007 default_register_priority)
5008
3b9ceb4b
VM
5009/* Return true if we need register usage leveling. */
5010DEFHOOK
5011(register_usage_leveling_p,
5012 "A target hook which returns true if we need register usage leveling.\
5013 That means if a few hard registers are equally good for the\
5014 assignment, we choose the least used hard register. The register\
5015 usage leveling may be profitable for some targets. Don't use the\
5016 usage leveling for targets with conditional execution or targets\
5017 with big register files as it hurts if-conversion and cross-jumping\
5018 optimizations.\
5019 \
5020 The default version of this target hook returns always false.",
5021 bool, (void),
5022 default_register_usage_leveling_p)
5023
55a2c322
VM
5024/* Return true if maximal address displacement can be different. */
5025DEFHOOK
5026(different_addr_displacement_p,
5027 "A target hook which returns true if an address with the same structure\
5028 can have different maximal legitimate displacement. For example, the\
5029 displacement can depend on memory mode or on operand combinations in\
5030 the insn.\
5031 \
5032 The default version of this target hook returns always false.",
5033 bool, (void),
5034 default_different_addr_displacement_p)
5035
5036/* Determine class for spilling pseudos of given mode into registers
5037 instead of memory. */
5038DEFHOOK
5039(spill_class,
5040 "This hook defines a class of registers which could be used for spilling\
5041 pseudos of the given mode and class, or @code{NO_REGS} if only memory\
5042 should be used. Not defining this hook is equivalent to returning\
5043 @code{NO_REGS} for all inputs.",
ef4bddc2 5044 reg_class_t, (reg_class_t, machine_mode),
55a2c322
VM
5045 NULL)
5046
e93f30a6
VM
5047/* Determine an additional allocno class. */
5048DEFHOOK
5049(additional_allocno_class_p,
5050 "This hook should return @code{true} if given class of registers should\
5051 be an allocno class in any way. Usually RA uses only one register\
5052 class from all classes containing the same register set. In some\
5053 complicated cases, you need to have two or more such classes as\
5054 allocno ones for RA correct work. Not defining this hook is\
5055 equivalent to returning @code{false} for all inputs.",
5056 bool, (reg_class_t),
5057 hook_bool_reg_class_t_false)
5058
42e37616
DM
5059DEFHOOK
5060(cstore_mode,
5061 "This hook defines the machine mode to use for the boolean result of\
5062 conditional store patterns. The ICODE argument is the instruction code\
5063 for the cstore being performed. Not definiting this hook is the same\
5064 as accepting the mode encoded into operand 0 of the cstore expander\
5065 patterns.",
ef4bddc2 5066 machine_mode, (enum insn_code icode),
42e37616
DM
5067 default_cstore_mode)
5068
b4ff394c
PH
5069/* This target hook allows the backend to compute the register pressure
5070 classes to use. */
5071DEFHOOK
5072(compute_pressure_classes,
5073 "A target hook which lets a backend compute the set of pressure classes to\
5074 be used by those optimization passes which take register pressure into\
5075 account, as opposed to letting IRA compute them. It returns the number of\
5076 register classes stored in the array @var{pressure_classes}.",
5077 int, (enum reg_class *pressure_classes), NULL)
5078
d9886a9e
L
5079/* True if a structure, union or array with MODE containing FIELD should
5080 be accessed using BLKmode. */
5081DEFHOOK
5082(member_type_forces_blk,
673c2f63
JM
5083 "Return true if a structure, union or array containing @var{field} should\n\
5084be accessed using @code{BLKMODE}.\n\
5085\n\
5086If @var{field} is the only field in the structure, @var{mode} is its\n\
5087mode, otherwise @var{mode} is VOIDmode. @var{mode} is provided in the\n\
5088case where structures of one field would require the structure's mode to\n\
5089retain the field's mode.\n\
5090\n\
5091Normally, this is not needed.",
ef4bddc2 5092 bool, (const_tree field, machine_mode mode),
d9886a9e
L
5093 default_member_type_forces_blk)
5094
e72531b9
PK
5095/* See tree-ssa-math-opts.c:divmod_candidate_p for conditions
5096 that gate the divod transform. */
5097DEFHOOK
5098(expand_divmod_libfunc,
5099 "Define this hook for enabling divmod transform if the port does not have\n\
5100hardware divmod insn but defines target-specific divmod libfuncs.",
5101 void, (rtx libfunc, machine_mode mode, rtx op0, rtx op1, rtx *quot, rtx *rem),
5102 NULL)
5103
38f8b050
JR
5104/* Return the class for a secondary reload, and fill in extra information. */
5105DEFHOOK
5106(secondary_reload,
673c2f63
JM
5107 "Many machines have some registers that cannot be copied directly to or\n\
5108from memory or even from other types of registers. An example is the\n\
5109@samp{MQ} register, which on most machines, can only be copied to or\n\
5110from general registers, but not memory. Below, we shall be using the\n\
5111term 'intermediate register' when a move operation cannot be performed\n\
5112directly, but has to be done by copying the source into the intermediate\n\
5113register first, and then copying the intermediate register to the\n\
5114destination. An intermediate register always has the same mode as\n\
5115source and destination. Since it holds the actual value being copied,\n\
5116reload might apply optimizations to re-use an intermediate register\n\
5117and eliding the copy from the source when it can determine that the\n\
5118intermediate register still holds the required value.\n\
5119\n\
5120Another kind of secondary reload is required on some machines which\n\
5121allow copying all registers to and from memory, but require a scratch\n\
5122register for stores to some memory locations (e.g., those with symbolic\n\
5123address on the RT, and those with certain symbolic address on the SPARC\n\
5124when compiling PIC)@. Scratch registers need not have the same mode\n\
5125as the value being copied, and usually hold a different value than\n\
5126that being copied. Special patterns in the md file are needed to\n\
5127describe how the copy is performed with the help of the scratch register;\n\
5128these patterns also describe the number, register class(es) and mode(s)\n\
5129of the scratch register(s).\n\
5130\n\
5131In some cases, both an intermediate and a scratch register are required.\n\
5132\n\
5133For input reloads, this target hook is called with nonzero @var{in_p},\n\
5134and @var{x} is an rtx that needs to be copied to a register of class\n\
5135@var{reload_class} in @var{reload_mode}. For output reloads, this target\n\
5136hook is called with zero @var{in_p}, and a register of class @var{reload_class}\n\
5137needs to be copied to rtx @var{x} in @var{reload_mode}.\n\
5138\n\
5139If copying a register of @var{reload_class} from/to @var{x} requires\n\
5140an intermediate register, the hook @code{secondary_reload} should\n\
5141return the register class required for this intermediate register.\n\
5142If no intermediate register is required, it should return NO_REGS.\n\
5143If more than one intermediate register is required, describe the one\n\
5144that is closest in the copy chain to the reload register.\n\
5145\n\
5146If scratch registers are needed, you also have to describe how to\n\
5147perform the copy from/to the reload register to/from this\n\
5148closest intermediate register. Or if no intermediate register is\n\
5149required, but still a scratch register is needed, describe the\n\
5150copy from/to the reload register to/from the reload operand @var{x}.\n\
5151\n\
5152You do this by setting @code{sri->icode} to the instruction code of a pattern\n\
5153in the md file which performs the move. Operands 0 and 1 are the output\n\
5154and input of this copy, respectively. Operands from operand 2 onward are\n\
5155for scratch operands. These scratch operands must have a mode, and a\n\
5156single-register-class\n\
5157@c [later: or memory]\n\
5158output constraint.\n\
5159\n\
5160When an intermediate register is used, the @code{secondary_reload}\n\
5161hook will be called again to determine how to copy the intermediate\n\
5162register to/from the reload operand @var{x}, so your hook must also\n\
5163have code to handle the register class of the intermediate operand.\n\
5164\n\
5165@c [For later: maybe we'll allow multi-alternative reload patterns -\n\
5166@c the port maintainer could name a mov<mode> pattern that has clobbers -\n\
5167@c and match the constraints of input and output to determine the required\n\
5168@c alternative. A restriction would be that constraints used to match\n\
5169@c against reloads registers would have to be written as register class\n\
5170@c constraints, or we need a new target macro / hook that tells us if an\n\
5171@c arbitrary constraint can match an unknown register of a given class.\n\
5172@c Such a macro / hook would also be useful in other places.]\n\
5173\n\
5174\n\
5175@var{x} might be a pseudo-register or a @code{subreg} of a\n\
5176pseudo-register, which could either be in a hard register or in memory.\n\
5177Use @code{true_regnum} to find out; it will return @minus{}1 if the pseudo is\n\
5178in memory and the hard register number if it is in a register.\n\
5179\n\
5180Scratch operands in memory (constraint @code{\"=m\"} / @code{\"=&m\"}) are\n\
5181currently not supported. For the time being, you will have to continue\n\
5182to use @code{SECONDARY_MEMORY_NEEDED} for that purpose.\n\
5183\n\
5184@code{copy_cost} also uses this target hook to find out how values are\n\
5185copied. If you want it to include some extra cost for the need to allocate\n\
5186(a) scratch register(s), set @code{sri->extra_cost} to the additional cost.\n\
5187Or if two dependent moves are supposed to have a lower cost than the sum\n\
5188of the individual moves due to expected fortuitous scheduling and/or special\n\
5189forwarding logic, you can set @code{sri->extra_cost} to a negative amount.",
a87cf97e 5190 reg_class_t,
ef4bddc2 5191 (bool in_p, rtx x, reg_class_t reload_class, machine_mode reload_mode,
38f8b050
JR
5192 secondary_reload_info *sri),
5193 default_secondary_reload)
5194
fba42e24
AS
5195/* Given an rtx X being reloaded into a reg required to be in class CLASS,
5196 return the class of reg to actually use. */
5197DEFHOOK
5198(preferred_reload_class,
673c2f63
JM
5199 "A target hook that places additional restrictions on the register class\n\
5200to use when it is necessary to copy value @var{x} into a register in class\n\
5201@var{rclass}. The value is a register class; perhaps @var{rclass}, or perhaps\n\
5202another, smaller class.\n\
5203\n\
5204The default version of this hook always returns value of @code{rclass} argument.\n\
5205\n\
5206Sometimes returning a more restrictive class makes better code. For\n\
5207example, on the 68000, when @var{x} is an integer constant that is in range\n\
5208for a @samp{moveq} instruction, the value of this macro is always\n\
5209@code{DATA_REGS} as long as @var{rclass} includes the data registers.\n\
5210Requiring a data register guarantees that a @samp{moveq} will be used.\n\
5211\n\
5212One case where @code{TARGET_PREFERRED_RELOAD_CLASS} must not return\n\
5213@var{rclass} is if @var{x} is a legitimate constant which cannot be\n\
5214loaded into some register class. By returning @code{NO_REGS} you can\n\
5215force @var{x} into a memory location. For example, rs6000 can load\n\
5216immediate values into general-purpose registers, but does not have an\n\
5217instruction for loading an immediate value into a floating-point\n\
5218register, so @code{TARGET_PREFERRED_RELOAD_CLASS} returns @code{NO_REGS} when\n\
5219@var{x} is a floating-point constant. If the constant can't be loaded\n\
5220into any kind of register, code generation will be better if\n\
5221@code{TARGET_LEGITIMATE_CONSTANT_P} makes the constant illegitimate instead\n\
5222of using @code{TARGET_PREFERRED_RELOAD_CLASS}.\n\
5223\n\
5224If an insn has pseudos in it after register allocation, reload will go\n\
5225through the alternatives and call repeatedly @code{TARGET_PREFERRED_RELOAD_CLASS}\n\
5226to find the best one. Returning @code{NO_REGS}, in this case, makes\n\
5227reload add a @code{!} in front of the constraint: the x86 back-end uses\n\
5228this feature to discourage usage of 387 registers when math is done in\n\
5229the SSE registers (and vice versa).",
fba42e24
AS
5230 reg_class_t,
5231 (rtx x, reg_class_t rclass),
5232 default_preferred_reload_class)
5233
abd26bfb
AS
5234/* Like TARGET_PREFERRED_RELOAD_CLASS, but for output reloads instead of
5235 input reloads. */
5236DEFHOOK
5237(preferred_output_reload_class,
673c2f63
JM
5238 "Like @code{TARGET_PREFERRED_RELOAD_CLASS}, but for output reloads instead of\n\
5239input reloads.\n\
5240\n\
5241The default version of this hook always returns value of @code{rclass}\n\
5242argument.\n\
5243\n\
5244You can also use @code{TARGET_PREFERRED_OUTPUT_RELOAD_CLASS} to discourage\n\
5245reload from using some alternatives, like @code{TARGET_PREFERRED_RELOAD_CLASS}.",
abd26bfb
AS
5246 reg_class_t,
5247 (rtx x, reg_class_t rclass),
5248 default_preferred_output_reload_class)
5249
07b8f0a8
AS
5250DEFHOOK
5251(class_likely_spilled_p,
673c2f63
JM
5252 "A target hook which returns @code{true} if pseudos that have been assigned\n\
5253to registers of class @var{rclass} would likely be spilled because\n\
5254registers of @var{rclass} are needed for spill registers.\n\
5255\n\
5256The default version of this target hook returns @code{true} if @var{rclass}\n\
5257has exactly one register and @code{false} otherwise. On most machines, this\n\
5258default should be used. For generally register-starved machines, such as\n\
5259i386, or machines with right register constraints, such as SH, this hook\n\
5260can be used to avoid excessive spilling.\n\
5261\n\
5262This hook is also used by some of the global intra-procedural code\n\
5263transformations to throtle code motion, to avoid increasing register\n\
5264pressure.",
07b8f0a8
AS
5265 bool, (reg_class_t rclass),
5266 default_class_likely_spilled_p)
5267
a8c44c52
AS
5268/* Return the maximum number of consecutive registers
5269 needed to represent mode MODE in a register of class RCLASS. */
5270DEFHOOK
5271(class_max_nregs,
673c2f63
JM
5272 "A target hook returns the maximum number of consecutive registers\n\
5273of class @var{rclass} needed to hold a value of mode @var{mode}.\n\
5274\n\
5275This is closely related to the macro @code{HARD_REGNO_NREGS}. In fact,\n\
5276the value returned by @code{TARGET_CLASS_MAX_NREGS (@var{rclass},\n\
5277@var{mode})} target hook should be the maximum value of\n\
5278@code{HARD_REGNO_NREGS (@var{regno}, @var{mode})} for all @var{regno}\n\
5279values in the class @var{rclass}.\n\
5280\n\
5281This target hook helps control the handling of multiple-word values\n\
5282in the reload pass.\n\
5283\n\
5284The default version of this target hook returns the size of @var{mode}\n\
5285in words.",
ef4bddc2 5286 unsigned char, (reg_class_t rclass, machine_mode mode),
a8c44c52
AS
5287 default_class_max_nregs)
5288
5f286f4a
YQ
5289DEFHOOK
5290(preferred_rename_class,
5291 "A target hook that places additional preference on the register\
5292 class to use when it is necessary to rename a register in class\
6d3fbe2f
JR
5293 @var{rclass} to another class, or perhaps @var{NO_REGS}, if no\
5294 preferred register class is found or hook @code{preferred_rename_class}\
5f286f4a
YQ
5295 is not implemented.\
5296 Sometimes returning a more restrictive class makes better code. For\
5297 example, on ARM, thumb-2 instructions using @code{LO_REGS} may be\
5298 smaller than instructions using @code{GENERIC_REGS}. By returning\
5299 @code{LO_REGS} from @code{preferred_rename_class}, code size can\
5300 be reduced.",
5301 reg_class_t, (reg_class_t rclass),
5302 default_preferred_rename_class)
5303
d6220b11
KK
5304/* This target hook allows the backend to avoid unsafe substitution
5305 during register allocation. */
5306DEFHOOK
5307(cannot_substitute_mem_equiv_p,
5308 "A target hook which returns @code{true} if @var{subst} can't\n\
5309substitute safely pseudos with equivalent memory values during\n\
5310register allocation.\n\
5311The default version of this target hook returns @code{false}.\n\
5312On most machines, this default should be used. For generally\n\
5313machines with non orthogonal register usage for addressing, such\n\
5314as SH, this hook can be used to avoid excessive spilling.",
5315 bool, (rtx subst),
5316 hook_bool_rtx_false)
5317
14133a4d
KK
5318/* This target hook allows the backend to legitimize base plus
5319 displacement addressing. */
5320DEFHOOK
5321(legitimize_address_displacement,
5322 "A target hook which returns @code{true} if *@var{disp} is\n\
5323legitimezed to valid address displacement with subtracting *@var{offset}\n\
5324at memory mode @var{mode}.\n\
5325The default version of this target hook returns @code{false}.\n\
5326This hook will benefit machines with limited base plus displacement\n\
5327addressing.",
5328 bool, (rtx *disp, rtx *offset, machine_mode mode),
5329 default_legitimize_address_displacement)
5330
38f8b050
JR
5331/* This target hook allows the backend to perform additional
5332 processing while initializing for variable expansion. */
5333DEFHOOK
5334(expand_to_rtl_hook,
673c2f63
JM
5335 "This hook is called just before expansion into rtl, allowing the target\n\
5336to perform additional initializations or analysis before the expansion.\n\
5337For example, the rs6000 port uses it to allocate a scratch stack slot\n\
5338for use in copying SDmode values between memory and floating point\n\
5339registers whenever the function being expanded has any SDmode\n\
5340usage.",
38f8b050
JR
5341 void, (void),
5342 hook_void_void)
5343
5344/* This target hook allows the backend to perform additional
5345 instantiations on rtx that are not actually in insns yet,
5346 but will be later. */
5347DEFHOOK
5348(instantiate_decls,
673c2f63
JM
5349 "This hook allows the backend to perform additional instantiations on rtl\n\
5350that are not actually in any insns yet, but will be later.",
38f8b050
JR
5351 void, (void),
5352 hook_void_void)
5353
5354/* Return true if is OK to use a hard register REGNO as scratch register
5355 in peephole2. */
5356DEFHOOK
5357(hard_regno_scratch_ok,
673c2f63
JM
5358 "This target hook should return @code{true} if it is OK to use a hard register\n\
5359@var{regno} as scratch reg in peephole2.\n\
5360\n\
5361One common use of this macro is to prevent using of a register that\n\
5362is not saved by a prologue in an interrupt handler.\n\
5363\n\
5364The default version of this hook always returns @code{true}.",
38f8b050
JR
5365 bool, (unsigned int regno),
5366 default_hard_regno_scratch_ok)
5367
5368/* Return the smallest number of different values for which it is best to
5369 use a jump-table instead of a tree of conditional branches. */
5370DEFHOOK
5371(case_values_threshold,
673c2f63
JM
5372 "This function return the smallest number of different values for which it\n\
5373is best to use a jump-table instead of a tree of conditional branches.\n\
5374The default is four for machines with a @code{casesi} instruction and\n\
5375five otherwise. This is best for most machines.",
38f8b050
JR
5376 unsigned int, (void),
5377 default_case_values_threshold)
5378
53680238 5379/* Return true if a function must have and use a frame pointer. */
38f8b050
JR
5380DEFHOOK
5381(frame_pointer_required,
673c2f63
JM
5382 "This target hook should return @code{true} if a function must have and use\n\
5383a frame pointer. This target hook is called in the reload pass. If its return\n\
5384value is @code{true} the function will have a frame pointer.\n\
5385\n\
5386This target hook can in principle examine the current function and decide\n\
5387according to the facts, but on most machines the constant @code{false} or the\n\
5388constant @code{true} suffices. Use @code{false} when the machine allows code\n\
5389to be generated with no frame pointer, and doing so saves some time or space.\n\
5390Use @code{true} when there is no possible advantage to avoiding a frame\n\
5391pointer.\n\
5392\n\
5393In certain cases, the compiler does not know how to produce valid code\n\
5394without a frame pointer. The compiler recognizes those cases and\n\
5395automatically gives the function a frame pointer regardless of what\n\
53680238 5396@code{targetm.frame_pointer_required} returns. You don't need to worry about\n\
673c2f63
JM
5397them.\n\
5398\n\
5399In a function that does not require a frame pointer, the frame pointer\n\
5400register can be allocated for ordinary usage, unless you mark it as a\n\
5401fixed register. See @code{FIXED_REGISTERS} for more information.\n\
5402\n\
5403Default return value is @code{false}.",
38f8b050
JR
5404 bool, (void),
5405 hook_bool_void_false)
5406
5407/* Returns true if the compiler is allowed to try to replace register number
5408 from-reg with register number to-reg. */
5409DEFHOOK
5410(can_eliminate,
53680238 5411 "This target hook should return @code{true} if the compiler is allowed to\n\
673c2f63 5412try to replace register number @var{from_reg} with register number\n\
53680238
BE
5413@var{to_reg}. This target hook will usually be @code{true}, since most of the\n\
5414cases preventing register elimination are things that the compiler already\n\
673c2f63
JM
5415knows about.\n\
5416\n\
5417Default return value is @code{true}.",
38f8b050
JR
5418 bool, (const int from_reg, const int to_reg),
5419 hook_bool_const_int_const_int_true)
5420
5efd84c5
NF
5421/* Modify any or all of fixed_regs, call_used_regs, global_regs,
5422 reg_names, and reg_class_contents to account of the vagaries of the
5423 target. */
5424DEFHOOK
5425(conditional_register_usage,
673c2f63
JM
5426 "This hook may conditionally modify five variables\n\
5427@code{fixed_regs}, @code{call_used_regs}, @code{global_regs},\n\
5428@code{reg_names}, and @code{reg_class_contents}, to take into account\n\
5429any dependence of these register sets on target flags. The first three\n\
527a3750 5430of these are of type @code{char []} (interpreted as boolean vectors).\n\
673c2f63
JM
5431@code{global_regs} is a @code{const char *[]}, and\n\
5432@code{reg_class_contents} is a @code{HARD_REG_SET}. Before the macro is\n\
5433called, @code{fixed_regs}, @code{call_used_regs},\n\
5434@code{reg_class_contents}, and @code{reg_names} have been initialized\n\
5435from @code{FIXED_REGISTERS}, @code{CALL_USED_REGISTERS},\n\
5436@code{REG_CLASS_CONTENTS}, and @code{REGISTER_NAMES}, respectively.\n\
5437@code{global_regs} has been cleared, and any @option{-ffixed-@var{reg}},\n\
5438@option{-fcall-used-@var{reg}} and @option{-fcall-saved-@var{reg}}\n\
5439command options have been applied.\n\
5440\n\
5441@cindex disabling certain registers\n\
5442@cindex controlling register usage\n\
5443If the usage of an entire class of registers depends on the target\n\
5444flags, you may indicate this to GCC by using this macro to modify\n\
5445@code{fixed_regs} and @code{call_used_regs} to 1 for each of the\n\
b48e9677
RS
5446registers in the classes which should not be used by GCC@. Also make\n\
5447@code{define_register_constraint}s return @code{NO_REGS} for constraints\n\
5448that shouldn't be used.\n\
673c2f63
JM
5449\n\
5450(However, if this class is not included in @code{GENERAL_REGS} and all\n\
5451of the insn patterns whose constraints permit this class are\n\
5452controlled by target switches, then GCC will automatically avoid using\n\
5453these registers when the target switches are opposed to them.)",
5efd84c5
NF
5454 void, (void),
5455 hook_void_void)
5456
38f8b050
JR
5457/* Functions specific to the C family of frontends. */
5458#undef HOOK_PREFIX
5459#define HOOK_PREFIX "TARGET_C_"
5460HOOK_VECTOR (TARGET_C, c)
5461
5462/* ??? Documenting this hook requires a GFDL license grant. */
5463DEFHOOK_UNDOC
5464(mode_for_suffix,
5465"Return machine mode for non-standard constant literal suffix @var{c},\
5466 or VOIDmode if non-standard suffixes are unsupported.",
ef4bddc2 5467 machine_mode, (char c),
38f8b050
JR
5468 default_mode_for_suffix)
5469
42e02b20
JG
5470DEFHOOK
5471(excess_precision,
2dbe91cf
JG
5472 "Return a value, with the same meaning as the C99 macro\
5473 @code{FLT_EVAL_METHOD} that describes which excess precision should be\
5474 applied. @var{type} is either @code{EXCESS_PRECISION_TYPE_IMPLICIT},\
42e02b20
JG
5475 @code{EXCESS_PRECISION_TYPE_FAST}, or\
5476 @code{EXCESS_PRECISION_TYPE_STANDARD}. For\
5477 @code{EXCESS_PRECISION_TYPE_IMPLICIT}, the target should return which\
5478 precision and range operations will be implictly evaluated in regardless\
5479 of the excess precision explicitly added. For\
5480 @code{EXCESS_PRECISION_TYPE_STANDARD} and\
5481 @code{EXCESS_PRECISION_TYPE_FAST}, the target should return the\
5482 explicit excess precision that should be added depending on the\
2dbe91cf
JG
5483 value set for @option{-fexcess-precision=@r{[}standard@r{|}fast@r{]}}.\
5484 Note that unpredictable explicit excess precision does not make sense,\
5485 so a target should never return @code{FLT_EVAL_METHOD_UNPREDICTABLE}\
5486 when @var{type} is @code{EXCESS_PRECISION_TYPE_STANDARD} or\
5487 @code{EXCESS_PRECISION_TYPE_FAST}.",
42e02b20
JG
5488 enum flt_eval_method, (enum excess_precision_type type),
5489 default_excess_precision)
5490
38f8b050
JR
5491HOOK_VECTOR_END (c)
5492
5493/* Functions specific to the C++ frontend. */
5494#undef HOOK_PREFIX
5495#define HOOK_PREFIX "TARGET_CXX_"
5496HOOK_VECTOR (TARGET_CXX, cxx)
5497
5498/* Return the integer type used for guard variables. */
5499DEFHOOK
5500(guard_type,
673c2f63
JM
5501 "Define this hook to override the integer type used for guard variables.\n\
5502These are used to implement one-time construction of static objects. The\n\
5503default is long_long_integer_type_node.",
38f8b050
JR
5504 tree, (void),
5505 default_cxx_guard_type)
5506
5507/* Return true if only the low bit of the guard should be tested. */
5508DEFHOOK
5509(guard_mask_bit,
673c2f63
JM
5510 "This hook determines how guard variables are used. It should return\n\
5511@code{false} (the default) if the first byte should be used. A return value of\n\
5512@code{true} indicates that only the least significant bit should be used.",
38f8b050
JR
5513 bool, (void),
5514 hook_bool_void_false)
5515
5516/* Returns the size of the array cookie for an array of type. */
5517DEFHOOK
5518(get_cookie_size,
673c2f63
JM
5519 "This hook returns the size of the cookie to use when allocating an array\n\
5520whose elements have the indicated @var{type}. Assumes that it is already\n\
5521known that a cookie is needed. The default is\n\
5522@code{max(sizeof (size_t), alignof(type))}, as defined in section 2.7 of the\n\
5523IA64/Generic C++ ABI@.",
38f8b050
JR
5524 tree, (tree type),
5525 default_cxx_get_cookie_size)
5526
5527/* Returns true if the element size should be stored in the array cookie. */
5528DEFHOOK
5529(cookie_has_size,
673c2f63
JM
5530 "This hook should return @code{true} if the element size should be stored in\n\
5531array cookies. The default is to return @code{false}.",
38f8b050
JR
5532 bool, (void),
5533 hook_bool_void_false)
5534
5535/* Allows backends to perform additional processing when
5536 deciding if a class should be exported or imported. */
5537DEFHOOK
5538(import_export_class,
673c2f63
JM
5539 "If defined by a backend this hook allows the decision made to export\n\
5540class @var{type} to be overruled. Upon entry @var{import_export}\n\
5541will contain 1 if the class is going to be exported, @minus{}1 if it is going\n\
5542to be imported and 0 otherwise. This function should return the\n\
5543modified value and perform any other actions necessary to support the\n\
5544backend's targeted operating system.",
38f8b050
JR
5545 int, (tree type, int import_export), NULL)
5546
5547/* Returns true if constructors and destructors return "this". */
5548DEFHOOK
5549(cdtor_returns_this,
673c2f63
JM
5550 "This hook should return @code{true} if constructors and destructors return\n\
5551the address of the object created/destroyed. The default is to return\n\
5552@code{false}.",
38f8b050
JR
5553 bool, (void),
5554 hook_bool_void_false)
5555
5556/* Returns true if the key method for a class can be an inline
5557 function, so long as it is not declared inline in the class
5558 itself. Returning true is the behavior required by the Itanium C++ ABI. */
5559DEFHOOK
5560(key_method_may_be_inline,
673c2f63
JM
5561 "This hook returns true if the key method for a class (i.e., the method\n\
5562which, if defined in the current translation unit, causes the virtual\n\
5563table to be emitted) may be an inline function. Under the standard\n\
5564Itanium C++ ABI the key method may be an inline function so long as\n\
5565the function is not declared inline in the class definition. Under\n\
5566some variants of the ABI, an inline function can never be the key\n\
5567method. The default is to return @code{true}.",
38f8b050
JR
5568 bool, (void),
5569 hook_bool_void_true)
5570
5571DEFHOOK
5572(determine_class_data_visibility,
5573"@var{decl} is a virtual table, virtual table table, typeinfo object,\
5574 or other similar implicit class data object that will be emitted with\
5575 external linkage in this translation unit. No ELF visibility has been\
5576 explicitly specified. If the target needs to specify a visibility\
5577 other than that of the containing class, use this hook to set\
5578 @code{DECL_VISIBILITY} and @code{DECL_VISIBILITY_SPECIFIED}.",
5579 void, (tree decl),
5580 hook_void_tree)
5581
5582/* Returns true (the default) if virtual tables and other
5583 similar implicit class data objects are always COMDAT if they
5584 have external linkage. If this hook returns false, then
5585 class data for classes whose virtual table will be emitted in
5586 only one translation unit will not be COMDAT. */
5587DEFHOOK
5588(class_data_always_comdat,
673c2f63
JM
5589 "This hook returns true (the default) if virtual tables and other\n\
5590similar implicit class data objects are always COMDAT if they have\n\
5591external linkage. If this hook returns false, then class data for\n\
5592classes whose virtual table will be emitted in only one translation\n\
5593unit will not be COMDAT.",
38f8b050
JR
5594 bool, (void),
5595 hook_bool_void_true)
5596
5597/* Returns true (the default) if the RTTI for the basic types,
5598 which is always defined in the C++ runtime, should be COMDAT;
5599 false if it should not be COMDAT. */
5600DEFHOOK
5601(library_rtti_comdat,
673c2f63
JM
5602 "This hook returns true (the default) if the RTTI information for\n\
5603the basic types which is defined in the C++ runtime should always\n\
5604be COMDAT, false if it should not be COMDAT.",
38f8b050
JR
5605 bool, (void),
5606 hook_bool_void_true)
5607
5608/* Returns true if __aeabi_atexit should be used to register static
5609 destructors. */
5610DEFHOOK
5611(use_aeabi_atexit,
673c2f63
JM
5612 "This hook returns true if @code{__aeabi_atexit} (as defined by the ARM EABI)\n\
5613should be used to register static destructors when @option{-fuse-cxa-atexit}\n\
5614is in effect. The default is to return false to use @code{__cxa_atexit}.",
38f8b050
JR
5615 bool, (void),
5616 hook_bool_void_false)
5617
5618/* Returns true if target may use atexit in the same manner as
5619 __cxa_atexit to register static destructors. */
5620DEFHOOK
5621(use_atexit_for_cxa_atexit,
673c2f63
JM
5622 "This hook returns true if the target @code{atexit} function can be used\n\
5623in the same manner as @code{__cxa_atexit} to register C++ static\n\
5624destructors. This requires that @code{atexit}-registered functions in\n\
5625shared libraries are run in the correct order when the libraries are\n\
5626unloaded. The default is to return false.",
38f8b050
JR
5627 bool, (void),
5628 hook_bool_void_false)
5629
5630DEFHOOK
5631(adjust_class_at_definition,
5632"@var{type} is a C++ class (i.e., RECORD_TYPE or UNION_TYPE) that has just\
5633 been defined. Use this hook to make adjustments to the class (eg, tweak\
5634 visibility or perform any other required target modifications).",
5635 void, (tree type),
5636 hook_void_tree)
5637
5b880ea6
RO
5638DEFHOOK
5639(decl_mangling_context,
5640 "Return target-specific mangling context of @var{decl} or @code{NULL_TREE}.",
5641 tree, (const_tree decl),
5642 hook_tree_const_tree_null)
5643
38f8b050
JR
5644HOOK_VECTOR_END (cxx)
5645
5646/* Functions and data for emulated TLS support. */
5647#undef HOOK_PREFIX
5648#define HOOK_PREFIX "TARGET_EMUTLS_"
5649HOOK_VECTOR (TARGET_EMUTLS, emutls)
5650
5651/* Name of the address and common functions. */
5652DEFHOOKPOD
5653(get_address,
673c2f63
JM
5654 "Contains the name of the helper function that uses a TLS control\n\
5655object to locate a TLS instance. The default causes libgcc's\n\
5656emulated TLS helper function to be used.",
38f8b050
JR
5657 const char *, "__builtin___emutls_get_address")
5658
5659DEFHOOKPOD
5660(register_common,
673c2f63
JM
5661 "Contains the name of the helper function that should be used at\n\
5662program startup to register TLS objects that are implicitly\n\
5663initialized to zero. If this is @code{NULL}, all TLS objects will\n\
5664have explicit initializers. The default causes libgcc's emulated TLS\n\
5665registration function to be used.",
38f8b050
JR
5666 const char *, "__builtin___emutls_register_common")
5667
5668/* Prefixes for proxy variable and template. */
5669DEFHOOKPOD
5670(var_section,
673c2f63
JM
5671 "Contains the name of the section in which TLS control variables should\n\
5672be placed. The default of @code{NULL} allows these to be placed in\n\
5673any section.",
38f8b050
JR
5674 const char *, NULL)
5675
5676DEFHOOKPOD
5677(tmpl_section,
673c2f63
JM
5678 "Contains the name of the section in which TLS initializers should be\n\
5679placed. The default of @code{NULL} allows these to be placed in any\n\
5680section.",
38f8b050
JR
5681 const char *, NULL)
5682
5683/* Prefixes for proxy variable and template. */
5684DEFHOOKPOD
5685(var_prefix,
673c2f63
JM
5686 "Contains the prefix to be prepended to TLS control variable names.\n\
5687The default of @code{NULL} uses a target-specific prefix.",
38f8b050
JR
5688 const char *, NULL)
5689
5690DEFHOOKPOD
5691(tmpl_prefix,
673c2f63
JM
5692 "Contains the prefix to be prepended to TLS initializer objects. The\n\
5693default of @code{NULL} uses a target-specific prefix.",
38f8b050
JR
5694 const char *, NULL)
5695
5696/* Function to generate field definitions of the proxy variable. */
5697DEFHOOK
5698(var_fields,
673c2f63
JM
5699 "Specifies a function that generates the FIELD_DECLs for a TLS control\n\
5700object type. @var{type} is the RECORD_TYPE the fields are for and\n\
5701@var{name} should be filled with the structure tag, if the default of\n\
5702@code{__emutls_object} is unsuitable. The default creates a type suitable\n\
5703for libgcc's emulated TLS function.",
38f8b050
JR
5704 tree, (tree type, tree *name),
5705 default_emutls_var_fields)
5706
5707/* Function to initialize a proxy variable. */
5708DEFHOOK
5709(var_init,
673c2f63
JM
5710 "Specifies a function that generates the CONSTRUCTOR to initialize a\n\
5711TLS control object. @var{var} is the TLS control object, @var{decl}\n\
5712is the TLS object and @var{tmpl_addr} is the address of the\n\
5713initializer. The default initializes libgcc's emulated TLS control object.",
38f8b050
JR
5714 tree, (tree var, tree decl, tree tmpl_addr),
5715 default_emutls_var_init)
5716
5717/* Whether we are allowed to alter the usual alignment of the
5718 proxy variable. */
5719DEFHOOKPOD
5720(var_align_fixed,
673c2f63
JM
5721 "Specifies whether the alignment of TLS control variable objects is\n\
5722fixed and should not be increased as some backends may do to optimize\n\
5723single objects. The default is false.",
38f8b050
JR
5724 bool, false)
5725
5726/* Whether we can emit debug information for TLS vars. */
5727DEFHOOKPOD
5728(debug_form_tls_address,
673c2f63
JM
5729 "Specifies whether a DWARF @code{DW_OP_form_tls_address} location descriptor\n\
5730may be used to describe emulated TLS control objects.",
38f8b050
JR
5731 bool, false)
5732
5733HOOK_VECTOR_END (emutls)
5734
5735#undef HOOK_PREFIX
5736#define HOOK_PREFIX "TARGET_OPTION_"
5737HOOK_VECTOR (TARGET_OPTION_HOOKS, target_option_hooks)
5738
7aa7f2e3
SL
5739/* Function to validate the attribute((target(...))) strings. If
5740 the option is validated, the hook should also fill in
5741 DECL_FUNCTION_SPECIFIC_TARGET in the function decl node. */
38f8b050
JR
5742DEFHOOK
5743(valid_attribute_p,
673c2f63
JM
5744 "This hook is called to parse @code{attribute(target(\"...\"))}, which\n\
5745allows setting target-specific options on individual functions.\n\
5746These function-specific options may differ\n\
5747from the options specified on the command line. The hook should return\n\
5748@code{true} if the options are valid.\n\
5749\n\
5750The hook should set the @code{DECL_FUNCTION_SPECIFIC_TARGET} field in\n\
5751the function declaration to hold a pointer to a target-specific\n\
5752@code{struct cl_target_option} structure.",
38f8b050
JR
5753 bool, (tree fndecl, tree name, tree args, int flags),
5754 default_target_option_valid_attribute_p)
5755
5756/* Function to save any extra target state in the target options structure. */
5757DEFHOOK
5758(save,
673c2f63
JM
5759 "This hook is called to save any additional target-specific information\n\
5760in the @code{struct cl_target_option} structure for function-specific\n\
bf7b5747 5761options from the @code{struct gcc_options} structure.\n\
673c2f63 5762@xref{Option file format}.",
bf7b5747 5763 void, (struct cl_target_option *ptr, struct gcc_options *opts), NULL)
38f8b050
JR
5764
5765/* Function to restore any extra target state from the target options
5766 structure. */
5767DEFHOOK
5768(restore,
673c2f63
JM
5769 "This hook is called to restore any additional target-specific\n\
5770information in the @code{struct cl_target_option} structure for\n\
bf7b5747
ST
5771function-specific options to the @code{struct gcc_options} structure.",
5772 void, (struct gcc_options *opts, struct cl_target_option *ptr), NULL)
38f8b050 5773
59913123
JJ
5774/* Function to update target-specific option information after being
5775 streamed in. */
5776DEFHOOK
5777(post_stream_in,
5778 "This hook is called to update target-specific information in the\n\
5779@code{struct cl_target_option} structure after it is streamed in from\n\
5780LTO bytecode.",
5781 void, (struct cl_target_option *ptr), NULL)
5782
38f8b050
JR
5783/* Function to print any extra target state from the target options
5784 structure. */
5785DEFHOOK
5786(print,
673c2f63
JM
5787 "This hook is called to print any additional target-specific\n\
5788information in the @code{struct cl_target_option} structure for\n\
5789function-specific options.",
38f8b050
JR
5790 void, (FILE *file, int indent, struct cl_target_option *ptr), NULL)
5791
7aa7f2e3 5792/* Function to parse arguments to be validated for #pragma target, and to
38f8b050
JR
5793 change the state if the options are valid. If the first argument is
5794 NULL, the second argument specifies the default options to use. Return
5795 true if the options are valid, and set the current state. */
56cb42ea 5796DEFHOOK
38f8b050 5797(pragma_parse,
673c2f63
JM
5798 "This target hook parses the options for @code{#pragma GCC target}, which\n\
5799sets the target-specific options for functions that occur later in the\n\
5800input stream. The options accepted should be the same as those handled by the\n\
5801@code{TARGET_OPTION_VALID_ATTRIBUTE_P} hook.",
38f8b050
JR
5802 bool, (tree args, tree pop_target),
5803 default_target_option_pragma_parse)
5804
5805/* Do option overrides for the target. */
5806DEFHOOK
5807(override,
673c2f63
JM
5808 "Sometimes certain combinations of command options do not make sense on\n\
5809a particular target machine. You can override the hook\n\
5810@code{TARGET_OPTION_OVERRIDE} to take account of this. This hooks is called\n\
5811once just after all the command options have been parsed.\n\
5812\n\
5813Don't use this hook to turn on various extra optimizations for\n\
5814@option{-O}. That is what @code{TARGET_OPTION_OPTIMIZATION} is for.\n\
5815\n\
5816If you need to do something whenever the optimization level is\n\
5817changed via the optimize attribute or pragma, see\n\
5818@code{TARGET_OVERRIDE_OPTIONS_AFTER_CHANGE}",
38f8b050 5819 void, (void),
c5387660 5820 hook_void_void)
38f8b050 5821
3649b9b7
ST
5822/* This function returns true if DECL1 and DECL2 are versions of the same
5823 function. DECL1 and DECL2 are function versions if and only if they
5824 have the same function signature and different target specific attributes,
5825 that is, they are compiled for different target machines. */
5826DEFHOOK
5827(function_versions,
673c2f63
JM
5828 "This target hook returns @code{true} if @var{DECL1} and @var{DECL2} are\n\
5829versions of the same function. @var{DECL1} and @var{DECL2} are function\n\
5830versions if and only if they have the same function signature and\n\
5831different target specific attributes, that is, they are compiled for\n\
5832different target machines.",
3649b9b7
ST
5833 bool, (tree decl1, tree decl2),
5834 hook_bool_tree_tree_false)
5835
38f8b050
JR
5836/* Function to determine if one function can inline another function. */
5837#undef HOOK_PREFIX
5838#define HOOK_PREFIX "TARGET_"
5839DEFHOOK
5840(can_inline_p,
673c2f63
JM
5841 "This target hook returns @code{false} if the @var{caller} function\n\
5842cannot inline @var{callee}, based on target specific information. By\n\
5843default, inlining is not allowed if the callee function has function\n\
5844specific target options and the caller does not use the same options.",
38f8b050
JR
5845 bool, (tree caller, tree callee),
5846 default_target_can_inline_p)
5847
63b0cb04
CB
5848DEFHOOK
5849(relayout_function,
5850"This target hook fixes function @var{fndecl} after attributes are processed. Default does nothing. On ARM, the default function's alignment is updated with the attribute target.",
5851 void, (tree fndecl),
5852 hook_void_tree)
5853
38f8b050
JR
5854HOOK_VECTOR_END (target_option)
5855
5856/* For targets that need to mark extra registers as live on entry to
5857 the function, they should define this target hook and set their
5858 bits in the bitmap passed in. */
5859DEFHOOK
5860(extra_live_on_entry,
673c2f63
JM
5861 "Add any hard registers to @var{regs} that are live on entry to the\n\
5862function. This hook only needs to be defined to provide registers that\n\
5863cannot be found by examination of FUNCTION_ARG_REGNO_P, the callee saved\n\
5864registers, STATIC_CHAIN_INCOMING_REGNUM, STATIC_CHAIN_REGNUM,\n\
5865TARGET_STRUCT_VALUE_RTX, FRAME_POINTER_REGNUM, EH_USES,\n\
5866FRAME_POINTER_REGNUM, ARG_POINTER_REGNUM, and the PIC_OFFSET_TABLE_REGNUM.",
38f8b050
JR
5867 void, (bitmap regs),
5868 hook_void_bitmap)
5869
aaeaa9a9 5870/* Targets should define this target hook to mark that non-callee clobbers are
73b3e61b
TV
5871 present in CALL_INSN_FUNCTION_USAGE for all the calls that bind to a local
5872 definition. */
aaeaa9a9
RO
5873DEFHOOKPOD
5874(call_fusage_contains_non_callee_clobbers,
73b3e61b
TV
5875 "Set to true if each call that binds to a local definition explicitly\n\
5876clobbers or sets all non-fixed registers modified by performing the call.\n\
5877That is, by the call pattern itself, or by code that might be inserted by the\n\
5878linker (e.g. stubs, veneers, branch islands), but not including those\n\
5879modifiable by the callee. The affected registers may be mentioned explicitly\n\
5880in the call pattern, or included as clobbers in CALL_INSN_FUNCTION_USAGE.\n\
5881The default version of this hook is set to false. The purpose of this hook\n\
1e288103 5882is to enable the fipa-ra optimization.",
aaeaa9a9
RO
5883 bool,
5884 false)
5885
ee3d2ecd
JJ
5886/* Fill in additional registers set up by prologue into a regset. */
5887DEFHOOK
5888(set_up_by_prologue,
5889 "This hook should add additional registers that are computed by the prologue\
5890 to the hard regset for shrink-wrapping optimization purposes.",
5891 void, (struct hard_reg_set_container *),
5892 NULL)
5893
d45eae79
SL
5894/* For targets that have attributes that can affect whether a
5895 function's return statements need checking. For instance a 'naked'
5896 function attribute. */
5897DEFHOOK
5898(warn_func_return,
5899 "True if a function's return statements should be checked for matching the function's return type. This includes checking for falling off the end of a non-void function. Return false if no such check should be made.",
5900 bool, (tree),
5901 hook_bool_tree_true)
5902
20a6ece0
SB
5903#undef HOOK_PREFIX
5904#define HOOK_PREFIX "TARGET_SHRINK_WRAP_"
5905HOOK_VECTOR (TARGET_SHRINK_WRAP_HOOKS, shrink_wrap)
5906
5907DEFHOOK
5908(get_separate_components,
5909 "This hook should return an @code{sbitmap} with the bits set for those\n\
5910components that can be separately shrink-wrapped in the current function.\n\
5911Return @code{NULL} if the current function should not get any separate\n\
5912shrink-wrapping.\n\
5913Don't define this hook if it would always return @code{NULL}.\n\
5914If it is defined, the other hooks in this group have to be defined as well.",
5915 sbitmap, (void),
5916 NULL)
5917
5918DEFHOOK
5919(components_for_bb,
5920 "This hook should return an @code{sbitmap} with the bits set for those\n\
5921components where either the prologue component has to be executed before\n\
5922the @code{basic_block}, or the epilogue component after it, or both.",
5923 sbitmap, (basic_block),
5924 NULL)
5925
5926DEFHOOK
5927(disqualify_components,
5928 "This hook should clear the bits in the @var{components} bitmap for those\n\
5929components in @var{edge_components} that the target cannot handle on edge\n\
5930@var{e}, where @var{is_prologue} says if this is for a prologue or an\n\
5931epilogue instead.",
5932 void, (sbitmap components, edge e, sbitmap edge_components, bool is_prologue),
5933 NULL)
5934
5935DEFHOOK
5936(emit_prologue_components,
5937 "Emit prologue insns for the components indicated by the parameter.",
5938 void, (sbitmap),
5939 NULL)
5940
5941DEFHOOK
5942(emit_epilogue_components,
5943 "Emit epilogue insns for the components indicated by the parameter.",
5944 void, (sbitmap),
5945 NULL)
5946
5947DEFHOOK
5948(set_handled_components,
5949 "Mark the components in the parameter as handled, so that the\n\
5950@code{prologue} and @code{epilogue} named patterns know to ignore those\n\
5951components. The target code should not hang on to the @code{sbitmap}, it\n\
5952will be deleted after this call.",
5953 void, (sbitmap),
5954 NULL)
5955
5956HOOK_VECTOR_END (shrink_wrap)
5957#undef HOOK_PREFIX
5958#define HOOK_PREFIX "TARGET_"
5959
f0a0390e
RH
5960/* Determine the type of unwind info to emit for debugging. */
5961DEFHOOK
5962(debug_unwind_info,
673c2f63
JM
5963 "This hook defines the mechanism that will be used for describing frame\n\
5964unwind information to the debugger. Normally the hook will return\n\
5965@code{UI_DWARF2} if DWARF 2 debug information is enabled, and\n\
5966return @code{UI_NONE} otherwise.\n\
5967\n\
5968A target may return @code{UI_DWARF2} even when DWARF 2 debug information\n\
5969is disabled in order to always output DWARF 2 frame information.\n\
5970\n\
5971A target may return @code{UI_TARGET} if it has ABI specified unwind tables.\n\
5972This will suppress generation of the normal debug frame unwind information.",
f0a0390e
RH
5973 enum unwind_info_type, (void),
5974 default_debug_unwind_info)
5975
c354951b
AK
5976/* The code parameter should be of type enum rtx_code but this is not
5977 defined at this time. */
5978DEFHOOK
5979(canonicalize_comparison,
673c2f63
JM
5980 "On some machines not all possible comparisons are defined, but you can\n\
5981convert an invalid comparison into a valid one. For example, the Alpha\n\
5982does not have a @code{GT} comparison, but you can use an @code{LT}\n\
5983comparison instead and swap the order of the operands.\n\
5984\n\
5985On such machines, implement this hook to do any required conversions.\n\
5986@var{code} is the initial comparison code and @var{op0} and @var{op1}\n\
5987are the left and right operands of the comparison, respectively. If\n\
5988@var{op0_preserve_value} is @code{true} the implementation is not\n\
5989allowed to change the value of @var{op0} since the value might be used\n\
5990in RTXs which aren't comparisons. E.g. the implementation is not\n\
5991allowed to swap operands in that case.\n\
5992\n\
5993GCC will not assume that the comparison resulting from this macro is\n\
5994valid but will see if the resulting insn matches a pattern in the\n\
5995@file{md} file.\n\
5996\n\
5997You need not to implement this hook if it would never change the\n\
5998comparison code or operands.",
c354951b
AK
5999 void, (int *code, rtx *op0, rtx *op1, bool op0_preserve_value),
6000 default_canonicalize_comparison)
6001
894d8b41
EB
6002DEFHOOK
6003(min_arithmetic_precision,
6004 "On some RISC architectures with 64-bit registers, the processor also\n\
6005maintains 32-bit condition codes that make it possible to do real 32-bit\n\
6006arithmetic, although the operations are performed on the full registers.\n\
6007\n\
6008On such architectures, defining this hook to 32 tells the compiler to try\n\
6009using 32-bit arithmetical operations setting the condition codes instead\n\
6010of doing full 64-bit arithmetic.\n\
6011\n\
6012More generally, define this hook on RISC architectures if you want the\n\
6013compiler to try using arithmetical operations setting the condition codes\n\
6014with a precision lower than the word precision.\n\
6015\n\
6016You need not define this hook if @code{WORD_REGISTER_OPERATIONS} is not\n\
6017defined to 1.",
6018 unsigned int, (void), default_min_arithmetic_precision)
6019
57c5ab1b
RH
6020DEFHOOKPOD
6021(atomic_test_and_set_trueval,
6022 "This value should be set if the result written by\
6023 @code{atomic_test_and_set} is not exactly 1, i.e. the\
6024 @code{bool} @code{true}.",
6025 unsigned char, 1)
267bac10 6026
fceec4d3
AM
6027/* Return an unsigned int representing the alignment (in bits) of the atomic
6028 type which maps to machine MODE. This allows alignment to be overridden
6029 as needed. */
6030DEFHOOK
6031(atomic_align_for_mode,
6032"If defined, this function returns an appropriate alignment in bits for an\
6033 atomic object of machine_mode @var{mode}. If 0 is returned then the\
6034 default alignment for the specified mode is used. ",
ef4bddc2 6035 unsigned int, (machine_mode mode),
fceec4d3
AM
6036 hook_uint_mode_0)
6037
267bac10
JM
6038DEFHOOK
6039(atomic_assign_expand_fenv,
6040"ISO C11 requires atomic compound assignments that may raise floating-point\
6041 exceptions to raise exceptions corresponding to the arithmetic operation\
6042 whose result was successfully stored in a compare-and-exchange sequence. \
6043 This requires code equivalent to calls to @code{feholdexcept},\
6044 @code{feclearexcept} and @code{feupdateenv} to be generated at\
6045 appropriate points in the compare-and-exchange sequence. This hook should\
6046 set @code{*@var{hold}} to an expression equivalent to the call to\
6047 @code{feholdexcept}, @code{*@var{clear}} to an expression equivalent to\
6048 the call to @code{feclearexcept} and @code{*@var{update}} to an expression\
6049 equivalent to the call to @code{feupdateenv}. The three expressions are\
6050 @code{NULL_TREE} on entry to the hook and may be left as @code{NULL_TREE}\
6051 if no code is required in a particular place. The default implementation\
6052 leaves all three expressions as @code{NULL_TREE}. The\
6053 @code{__atomic_feraiseexcept} function from @code{libatomic} may be of use\
6054 as part of the code generated in @code{*@var{update}}.",
6055 void, (tree *hold, tree *clear, tree *update),
6056 default_atomic_assign_expand_fenv)
6057
38f8b050
JR
6058/* Leave the boolean fields at the end. */
6059
38f8b050
JR
6060/* True if we can create zeroed data by switching to a BSS section
6061 and then using ASM_OUTPUT_SKIP to allocate the space. */
6062DEFHOOKPOD
6063(have_switchable_bss_sections,
673c2f63
JM
6064 "This flag is true if we can create zeroed data by switching to a BSS\n\
6065section and then using @code{ASM_OUTPUT_SKIP} to allocate the space.\n\
6066This is true on most ELF targets.",
38f8b050
JR
6067 bool, false)
6068
6069/* True if "native" constructors and destructors are supported,
6070 false if we're using collect2 for the job. */
6071DEFHOOKPOD
6072(have_ctors_dtors,
673c2f63
JM
6073 "This value is true if the target supports some ``native'' method of\n\
6074collecting constructors and destructors to be run at startup and exit.\n\
6075It is false if we must use @command{collect2}.",
38f8b050
JR
6076 bool, false)
6077
6078/* True if thread-local storage is supported. */
6079DEFHOOKPOD
6080(have_tls,
673c2f63
JM
6081 "Contains the value true if the target supports thread-local storage.\n\
6082The default value is false.",
38f8b050
JR
6083 bool, false)
6084
6085/* True if a small readonly data section is supported. */
6086DEFHOOKPOD
6087(have_srodata_section,
673c2f63
JM
6088 "Contains the value true if the target places read-only\n\
6089``small data'' into a separate section. The default value is false.",
38f8b050
JR
6090 bool, false)
6091
6092/* True if EH frame info sections should be zero-terminated. */
6093DEFHOOKPOD
6094(terminate_dw2_eh_frame_info,
673c2f63
JM
6095 "Contains the value true if the target should add a zero word onto the\n\
6096end of a Dwarf-2 frame info section when used for exception handling.\n\
6097Default value is false if @code{EH_FRAME_SECTION_NAME} is defined, and\n\
6098true otherwise.",
38f8b050
JR
6099 bool, true)
6100
6101/* True if #NO_APP should be emitted at the beginning of assembly output. */
6102DEFHOOKPOD
6103(asm_file_start_app_off,
673c2f63
JM
6104 "If this flag is true, the text of the macro @code{ASM_APP_OFF} will be\n\
6105printed as the very first line in the assembly file, unless\n\
6106@option{-fverbose-asm} is in effect. (If that macro has been defined\n\
6107to the empty string, this variable has no effect.) With the normal\n\
6108definition of @code{ASM_APP_OFF}, the effect is to notify the GNU\n\
6109assembler that it need not bother stripping comments or extra\n\
6110whitespace from its input. This allows it to work a bit faster.\n\
6111\n\
6112The default is false. You should not set it to true unless you have\n\
6113verified that your port does not generate any extra whitespace or\n\
6114comments that will cause GAS to issue errors in NO_APP mode.",
38f8b050
JR
6115 bool, false)
6116
6117/* True if output_file_directive should be called for main_input_filename
6118 at the beginning of assembly output. */
6119DEFHOOKPOD
6120(asm_file_start_file_directive,
673c2f63
JM
6121 "If this flag is true, @code{output_file_directive} will be called\n\
6122for the primary source file, immediately after printing\n\
6123@code{ASM_APP_OFF} (if that is enabled). Most ELF assemblers expect\n\
6124this to be done. The default is false.",
38f8b050 6125 bool, false)
38f8b050
JR
6126
6127/* Returns true if we should generate exception tables for use with the
6128 ARM EABI. The effects the encoding of function exception specifications. */
6129DEFHOOKPOD
6130(arm_eabi_unwinder,
673c2f63
JM
6131 "This flag should be set to @code{true} on targets that use an ARM EABI\n\
6132based unwinding library, and @code{false} on other targets. This effects\n\
6133the format of unwinding tables, and how the unwinder in entered after\n\
6134running a cleanup. The default is @code{false}.",
38f8b050
JR
6135 bool, false)
6136
9730bc27
TT
6137DEFHOOKPOD
6138(want_debug_pub_sections,
6139 "True if the @code{.debug_pubtypes} and @code{.debug_pubnames} sections\
6140 should be emitted. These sections are not used on most platforms, and\
6141 in particular GDB does not use them.",
6142 bool, false)
6143
2ba42841 6144DEFHOOKPOD
a50fa76a 6145(delay_sched2, "True if sched2 is not to be run at its normal place.\n\
2ba42841
AO
6146This usually means it will be run as part of machine-specific reorg.",
6147bool, false)
6148
6149DEFHOOKPOD
a50fa76a 6150(delay_vartrack, "True if vartrack is not to be run at its normal place.\n\
2ba42841
AO
6151This usually means it will be run as part of machine-specific reorg.",
6152bool, false)
6153
a50fa76a
BS
6154DEFHOOKPOD
6155(no_register_allocation, "True if register allocation and the passes\n\
6156following it should not be run. Usually true only for virtual assembler\n\
6157targets.",
6158bool, false)
6159
38f8b050
JR
6160/* Leave the boolean fields at the end. */
6161
06b90602
CB
6162/* Functions related to mode switching. */
6163#undef HOOK_PREFIX
6164#define HOOK_PREFIX "TARGET_MODE_"
6165HOOK_VECTOR (TARGET_TOGGLE_, mode_switching)
6166
6167DEFHOOK
6168(emit,
cbb1e3d9
CB
6169 "Generate one or more insns to set @var{entity} to @var{mode}. @var{hard_reg_live} is the set of hard registers live at the point where the insn(s) are to be inserted. @var{prev_moxde} indicates the mode to switch from. Sets of a lower numbered entity will be emitted before sets of a higher numbered entity to a mode of the same or lower priority.",
6170 void, (int entity, int mode, int prev_mode, HARD_REG_SET regs_live), NULL)
06b90602
CB
6171
6172DEFHOOK
6173(needed,
cbb1e3d9 6174 "@var{entity} is an integer specifying a mode-switched entity. If @code{OPTIMIZE_MODE_SWITCHING} is defined, you must define this macro to return an integer value not larger than the corresponding element in @code{NUM_MODES_FOR_MODE_SWITCHING}, to denote the mode that @var{entity} must be switched into prior to the execution of @var{insn}.",
ac44248e 6175 int, (int entity, rtx_insn *insn), NULL)
06b90602
CB
6176
6177DEFHOOK
6178(after,
6179 "@var{entity} is an integer specifying a mode-switched entity. If this macro is defined, it is evaluated for every @var{insn} during mode switching. It determines the mode that an insn results in (if different from the incoming mode).",
ac44248e 6180 int, (int entity, int mode, rtx_insn *insn), NULL)
06b90602
CB
6181
6182DEFHOOK
6183(entry,
6184 "If this macro is defined, it is evaluated for every @var{entity} that needs mode switching. It should evaluate to an integer, which is a mode that @var{entity} is assumed to be switched to at function entry. If @code{TARGET_MODE_ENTRY} is defined then @code{TARGET_MODE_EXIT} must be defined.",
6185 int, (int entity), NULL)
6186
6187DEFHOOK
6188(exit,
6189 "If this macro is defined, it is evaluated for every @var{entity} that needs mode switching. It should evaluate to an integer, which is a mode that @var{entity} is assumed to be switched to at function exit. If @code{TARGET_MODE_EXIT} is defined then @code{TARGET_MODE_ENTRY} must be defined.",
6190 int, (int entity), NULL)
6191
6192DEFHOOK
6193(priority,
6194 "This macro specifies the order in which modes for @var{entity} are processed. 0 is the highest priority, @code{NUM_MODES_FOR_MODE_SWITCHING[@var{entity}] - 1} the lowest. The value of the macro should be an integer designating a mode for @var{entity}. For any fixed @var{entity}, @code{mode_priority} (@var{entity}, @var{n}) shall be a bijection in 0 @dots{} @code{num_modes_for_mode_switching[@var{entity}] - 1}.",
6195 int, (int entity, int n), NULL)
6196
6197HOOK_VECTOR_END (mode_switching)
6198
4bccb39e
RS
6199#undef HOOK_PREFIX
6200#define HOOK_PREFIX "TARGET_"
6201
6202#define DEF_TARGET_INSN(NAME, PROTO) \
6203 DEFHOOK_UNDOC (have_##NAME, "", bool, (void), false)
6204#include "target-insns.def"
6205#undef DEF_TARGET_INSN
6206
6207#define DEF_TARGET_INSN(NAME, PROTO) \
6208 DEFHOOK_UNDOC (gen_##NAME, "", rtx_insn *, PROTO, NULL)
6209#include "target-insns.def"
6210#undef DEF_TARGET_INSN
6211
8684d89d
RS
6212#define DEF_TARGET_INSN(NAME, PROTO) \
6213 DEFHOOKPOD (code_for_##NAME, "*", enum insn_code, CODE_FOR_nothing)
6214#include "target-insns.def"
6215#undef DEF_TARGET_INSN
6216
40af5894
DM
6217DEFHOOK
6218(run_target_selftests,
6219 "If selftests are enabled, run any selftests for this target.",
6220 void, (void),
6221 NULL)
6222
38f8b050
JR
6223/* Close the 'struct gcc_target' definition. */
6224HOOK_VECTOR_END (C90_EMPTY_HACK)
06b90602 6225