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Turn HARD_REGNO_MODE_OK into a target hook
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1 /* Definitions of Tensilica's Xtensa target machine for GNU compiler.
2 Copyright (C) 2001-2017 Free Software Foundation, Inc.
3 Contributed by Bob Wilson (bwilson@tensilica.com) at Tensilica.
4
5 This file is part of GCC.
6
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 3, or (at your option) any later
10 version.
11
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15 for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING3. If not see
19 <http://www.gnu.org/licenses/>. */
20
21 /* Get Xtensa configuration settings */
22 #include "xtensa-config.h"
23
24 /* External variables defined in xtensa.c. */
25
26 /* Macros used in the machine description to select various Xtensa
27 configuration options. */
28 #ifndef XCHAL_HAVE_MUL32_HIGH
29 #define XCHAL_HAVE_MUL32_HIGH 0
30 #endif
31 #ifndef XCHAL_HAVE_RELEASE_SYNC
32 #define XCHAL_HAVE_RELEASE_SYNC 0
33 #endif
34 #ifndef XCHAL_HAVE_S32C1I
35 #define XCHAL_HAVE_S32C1I 0
36 #endif
37 #ifndef XCHAL_HAVE_THREADPTR
38 #define XCHAL_HAVE_THREADPTR 0
39 #endif
40 #ifndef XCHAL_HAVE_FP_POSTINC
41 #define XCHAL_HAVE_FP_POSTINC 0
42 #endif
43 #define TARGET_BIG_ENDIAN XCHAL_HAVE_BE
44 #define TARGET_DENSITY XCHAL_HAVE_DENSITY
45 #define TARGET_MAC16 XCHAL_HAVE_MAC16
46 #define TARGET_MUL16 XCHAL_HAVE_MUL16
47 #define TARGET_MUL32 XCHAL_HAVE_MUL32
48 #define TARGET_MUL32_HIGH XCHAL_HAVE_MUL32_HIGH
49 #define TARGET_DIV32 XCHAL_HAVE_DIV32
50 #define TARGET_NSA XCHAL_HAVE_NSA
51 #define TARGET_MINMAX XCHAL_HAVE_MINMAX
52 #define TARGET_SEXT XCHAL_HAVE_SEXT
53 #define TARGET_BOOLEANS XCHAL_HAVE_BOOLEANS
54 #define TARGET_HARD_FLOAT XCHAL_HAVE_FP
55 #define TARGET_HARD_FLOAT_DIV XCHAL_HAVE_FP_DIV
56 #define TARGET_HARD_FLOAT_RECIP XCHAL_HAVE_FP_RECIP
57 #define TARGET_HARD_FLOAT_SQRT XCHAL_HAVE_FP_SQRT
58 #define TARGET_HARD_FLOAT_RSQRT XCHAL_HAVE_FP_RSQRT
59 #define TARGET_HARD_FLOAT_POSTINC XCHAL_HAVE_FP_POSTINC
60 #define TARGET_ABS XCHAL_HAVE_ABS
61 #define TARGET_ADDX XCHAL_HAVE_ADDX
62 #define TARGET_RELEASE_SYNC XCHAL_HAVE_RELEASE_SYNC
63 #define TARGET_S32C1I XCHAL_HAVE_S32C1I
64 #define TARGET_ABSOLUTE_LITERALS XSHAL_USE_ABSOLUTE_LITERALS
65 #define TARGET_THREADPTR XCHAL_HAVE_THREADPTR
66 #define TARGET_LOOPS XCHAL_HAVE_LOOPS
67 #define TARGET_WINDOWED_ABI (XSHAL_ABI == XTHAL_ABI_WINDOWED)
68 #define TARGET_DEBUG XCHAL_HAVE_DEBUG
69 #define TARGET_L32R XCHAL_HAVE_L32R
70
71 #define TARGET_DEFAULT (MASK_SERIALIZE_VOLATILE)
72
73 #ifndef HAVE_AS_TLS
74 #define HAVE_AS_TLS 0
75 #endif
76
77 \f
78 /* Target CPU builtins. */
79 #define TARGET_CPU_CPP_BUILTINS() \
80 do { \
81 builtin_assert ("cpu=xtensa"); \
82 builtin_assert ("machine=xtensa"); \
83 builtin_define ("__xtensa__"); \
84 builtin_define ("__XTENSA__"); \
85 builtin_define (TARGET_WINDOWED_ABI ? \
86 "__XTENSA_WINDOWED_ABI__" : "__XTENSA_CALL0_ABI__");\
87 builtin_define (TARGET_BIG_ENDIAN ? "__XTENSA_EB__" : "__XTENSA_EL__"); \
88 if (!TARGET_HARD_FLOAT) \
89 builtin_define ("__XTENSA_SOFT_FLOAT__"); \
90 } while (0)
91
92 #define CPP_SPEC " %(subtarget_cpp_spec) "
93
94 #ifndef SUBTARGET_CPP_SPEC
95 #define SUBTARGET_CPP_SPEC ""
96 #endif
97
98 #define EXTRA_SPECS \
99 { "subtarget_cpp_spec", SUBTARGET_CPP_SPEC },
100
101 /* Target machine storage layout */
102
103 /* Define this if most significant bit is lowest numbered
104 in instructions that operate on numbered bit-fields. */
105 #define BITS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
106
107 /* Define this if most significant byte of a word is the lowest numbered. */
108 #define BYTES_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
109
110 /* Define this if most significant word of a multiword number is the lowest. */
111 #define WORDS_BIG_ENDIAN (TARGET_BIG_ENDIAN != 0)
112
113 #define MAX_BITS_PER_WORD 32
114
115 /* Width of a word, in units (bytes). */
116 #define UNITS_PER_WORD 4
117 #define MIN_UNITS_PER_WORD 4
118
119 /* Width of a floating point register. */
120 #define UNITS_PER_FPREG 4
121
122 /* Size in bits of various types on the target machine. */
123 #define INT_TYPE_SIZE 32
124 #define SHORT_TYPE_SIZE 16
125 #define LONG_TYPE_SIZE 32
126 #define LONG_LONG_TYPE_SIZE 64
127 #define FLOAT_TYPE_SIZE 32
128 #define DOUBLE_TYPE_SIZE 64
129 #define LONG_DOUBLE_TYPE_SIZE 64
130
131 /* Allocation boundary (in *bits*) for storing pointers in memory. */
132 #define POINTER_BOUNDARY 32
133
134 /* Allocation boundary (in *bits*) for storing arguments in argument list. */
135 #define PARM_BOUNDARY 32
136
137 /* Allocation boundary (in *bits*) for the code of a function. */
138 #define FUNCTION_BOUNDARY 32
139
140 /* Alignment of field after 'int : 0' in a structure. */
141 #define EMPTY_FIELD_BOUNDARY 32
142
143 /* Every structure's size must be a multiple of this. */
144 #define STRUCTURE_SIZE_BOUNDARY 8
145
146 /* There is no point aligning anything to a rounder boundary than this. */
147 #define BIGGEST_ALIGNMENT 128
148
149 /* Set this nonzero if move instructions will actually fail to work
150 when given unaligned data. */
151 #define STRICT_ALIGNMENT 1
152
153 /* Promote integer modes smaller than a word to SImode. Set UNSIGNEDP
154 for QImode, because there is no 8-bit load from memory with sign
155 extension. Otherwise, leave UNSIGNEDP alone, since Xtensa has 16-bit
156 loads both with and without sign extension. */
157 #define PROMOTE_MODE(MODE, UNSIGNEDP, TYPE) \
158 do { \
159 if (GET_MODE_CLASS (MODE) == MODE_INT \
160 && GET_MODE_SIZE (MODE) < UNITS_PER_WORD) \
161 { \
162 if ((MODE) == QImode) \
163 (UNSIGNEDP) = 1; \
164 (MODE) = SImode; \
165 } \
166 } while (0)
167
168 /* Imitate the way many other C compilers handle alignment of
169 bitfields and the structures that contain them. */
170 #define PCC_BITFIELD_TYPE_MATTERS 1
171
172 /* Align string constants and constructors to at least a word boundary.
173 The typical use of this macro is to increase alignment for string
174 constants to be word aligned so that 'strcpy' calls that copy
175 constants can be done inline. */
176 #define CONSTANT_ALIGNMENT(EXP, ALIGN) \
177 (!optimize_size && \
178 (TREE_CODE (EXP) == STRING_CST || TREE_CODE (EXP) == CONSTRUCTOR) \
179 && (ALIGN) < BITS_PER_WORD \
180 ? BITS_PER_WORD \
181 : (ALIGN))
182
183 /* Align arrays, unions and records to at least a word boundary.
184 One use of this macro is to increase alignment of medium-size
185 data to make it all fit in fewer cache lines. Another is to
186 cause character arrays to be word-aligned so that 'strcpy' calls
187 that copy constants to character arrays can be done inline. */
188 #undef DATA_ALIGNMENT
189 #define DATA_ALIGNMENT(TYPE, ALIGN) \
190 (!optimize_size && (((ALIGN) < BITS_PER_WORD) \
191 && (TREE_CODE (TYPE) == ARRAY_TYPE \
192 || TREE_CODE (TYPE) == UNION_TYPE \
193 || TREE_CODE (TYPE) == RECORD_TYPE)) ? BITS_PER_WORD : (ALIGN))
194
195 /* Operations between registers always perform the operation
196 on the full register even if a narrower mode is specified. */
197 #define WORD_REGISTER_OPERATIONS 1
198
199 /* Xtensa loads are zero-extended by default. */
200 #define LOAD_EXTEND_OP(MODE) ZERO_EXTEND
201
202 /* Standard register usage. */
203
204 /* Number of actual hardware registers.
205 The hardware registers are assigned numbers for the compiler
206 from 0 to just below FIRST_PSEUDO_REGISTER.
207 All registers that the compiler knows about must be given numbers,
208 even those that are not normally considered general registers.
209
210 The fake frame pointer and argument pointer will never appear in
211 the generated code, since they will always be eliminated and replaced
212 by either the stack pointer or the hard frame pointer.
213
214 0 - 15 AR[0] - AR[15]
215 16 FRAME_POINTER (fake = initial sp)
216 17 ARG_POINTER (fake = initial sp + framesize)
217 18 BR[0] for floating-point CC
218 19 - 34 FR[0] - FR[15]
219 35 MAC16 accumulator */
220
221 #define FIRST_PSEUDO_REGISTER 36
222
223 /* Return the stabs register number to use for REGNO. */
224 #define DBX_REGISTER_NUMBER(REGNO) xtensa_dbx_register_number (REGNO)
225
226 /* 1 for registers that have pervasive standard uses
227 and are not available for the register allocator. */
228 #define FIXED_REGISTERS \
229 { \
230 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
231 1, 1, 0, \
232 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, \
233 0, \
234 }
235
236 /* 1 for registers not available across function calls.
237 These must include the FIXED_REGISTERS and also any
238 registers that can be used without being saved.
239 The latter must include the registers where values are returned
240 and the register where structure-value addresses are passed.
241 Aside from that, you can include as many other registers as you like.
242
243 The value encoding is the following:
244 1: register is used by all ABIs;
245 bit 1 is set: register is used by windowed ABI;
246 bit 2 is set: register is used by call0 ABI.
247
248 Proper values are computed in TARGET_CONDITIONAL_REGISTER_USAGE. */
249
250 #define CALL_USED_REGISTERS \
251 { \
252 1, 1, 4, 4, 4, 4, 4, 4, 1, 1, 1, 1, 2, 2, 2, 2, \
253 1, 1, 1, \
254 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, \
255 1, \
256 }
257
258 /* For non-leaf procedures on Xtensa processors, the allocation order
259 is as specified below by REG_ALLOC_ORDER. For leaf procedures, we
260 want to use the lowest numbered registers first to minimize
261 register window overflows. However, local-alloc is not smart
262 enough to consider conflicts with incoming arguments. If an
263 incoming argument in a2 is live throughout the function and
264 local-alloc decides to use a2, then the incoming argument must
265 either be spilled or copied to another register. To get around
266 this, we define ADJUST_REG_ALLOC_ORDER to redefine
267 reg_alloc_order for leaf functions such that lowest numbered
268 registers are used first with the exception that the incoming
269 argument registers are not used until after other register choices
270 have been exhausted. */
271
272 #define REG_ALLOC_ORDER \
273 { 8, 9, 10, 11, 12, 13, 14, 15, 7, 6, 5, 4, 3, 2, \
274 18, \
275 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, \
276 0, 1, 16, 17, \
277 35, \
278 }
279
280 #define ADJUST_REG_ALLOC_ORDER order_regs_for_local_alloc ()
281
282 /* For Xtensa, the only point of this is to prevent GCC from otherwise
283 giving preference to call-used registers. To minimize window
284 overflows for the AR registers, we want to give preference to the
285 lower-numbered AR registers. For other register files, which are
286 not windowed, we still prefer call-used registers, if there are any. */
287 extern const char xtensa_leaf_regs[FIRST_PSEUDO_REGISTER];
288 #define LEAF_REGISTERS xtensa_leaf_regs
289
290 /* For Xtensa, no remapping is necessary, but this macro must be
291 defined if LEAF_REGISTERS is defined. */
292 #define LEAF_REG_REMAP(REGNO) (REGNO)
293
294 /* This must be declared if LEAF_REGISTERS is set. */
295 extern int leaf_function;
296
297 /* Internal macros to classify a register number. */
298
299 /* 16 address registers + fake registers */
300 #define GP_REG_FIRST 0
301 #define GP_REG_LAST 17
302 #define GP_REG_NUM (GP_REG_LAST - GP_REG_FIRST + 1)
303
304 /* Coprocessor registers */
305 #define BR_REG_FIRST 18
306 #define BR_REG_LAST 18
307 #define BR_REG_NUM (BR_REG_LAST - BR_REG_FIRST + 1)
308
309 /* 16 floating-point registers */
310 #define FP_REG_FIRST 19
311 #define FP_REG_LAST 34
312 #define FP_REG_NUM (FP_REG_LAST - FP_REG_FIRST + 1)
313
314 /* MAC16 accumulator */
315 #define ACC_REG_FIRST 35
316 #define ACC_REG_LAST 35
317 #define ACC_REG_NUM (ACC_REG_LAST - ACC_REG_FIRST + 1)
318
319 #define GP_REG_P(REGNO) ((unsigned) ((REGNO) - GP_REG_FIRST) < GP_REG_NUM)
320 #define BR_REG_P(REGNO) ((unsigned) ((REGNO) - BR_REG_FIRST) < BR_REG_NUM)
321 #define FP_REG_P(REGNO) ((unsigned) ((REGNO) - FP_REG_FIRST) < FP_REG_NUM)
322 #define ACC_REG_P(REGNO) ((unsigned) ((REGNO) - ACC_REG_FIRST) < ACC_REG_NUM)
323
324 /* Return number of consecutive hard regs needed starting at reg REGNO
325 to hold something of mode MODE. */
326 #define HARD_REGNO_NREGS(REGNO, MODE) \
327 (FP_REG_P (REGNO) ? \
328 ((GET_MODE_SIZE (MODE) + UNITS_PER_FPREG - 1) / UNITS_PER_FPREG) : \
329 ((GET_MODE_SIZE (MODE) + UNITS_PER_WORD - 1) / UNITS_PER_WORD))
330
331 /* Value is 1 if it is a good idea to tie two pseudo registers
332 when one has mode MODE1 and one has mode MODE2.
333 If TARGET_HARD_REGNO_MODE_OK could produce different values for MODE1
334 and MODE2, for any hard reg, then this must be 0 for correct output. */
335 #define MODES_TIEABLE_P(MODE1, MODE2) \
336 ((GET_MODE_CLASS (MODE1) == MODE_FLOAT || \
337 GET_MODE_CLASS (MODE1) == MODE_COMPLEX_FLOAT) \
338 == (GET_MODE_CLASS (MODE2) == MODE_FLOAT || \
339 GET_MODE_CLASS (MODE2) == MODE_COMPLEX_FLOAT))
340
341 /* Register to use for pushing function arguments. */
342 #define STACK_POINTER_REGNUM (GP_REG_FIRST + 1)
343
344 /* Base register for access to local variables of the function. */
345 #define HARD_FRAME_POINTER_REGNUM (GP_REG_FIRST + \
346 (TARGET_WINDOWED_ABI ? 7 : 15))
347
348 /* The register number of the frame pointer register, which is used to
349 access automatic variables in the stack frame. For Xtensa, this
350 register never appears in the output. It is always eliminated to
351 either the stack pointer or the hard frame pointer. */
352 #define FRAME_POINTER_REGNUM (GP_REG_FIRST + 16)
353
354 /* Base register for access to arguments of the function. */
355 #define ARG_POINTER_REGNUM (GP_REG_FIRST + 17)
356
357 /* Hard frame pointer is neither frame nor arg pointer.
358 The definitions are here because actual hard frame pointer register
359 definition is not a preprocessor constant. */
360 #define HARD_FRAME_POINTER_IS_FRAME_POINTER 0
361 #define HARD_FRAME_POINTER_IS_ARG_POINTER 0
362
363 /* For now we don't try to use the full set of boolean registers. Without
364 software pipelining of FP operations, there's not much to gain and it's
365 a real pain to get them reloaded. */
366 #define FPCC_REGNUM (BR_REG_FIRST + 0)
367
368 /* It is as good or better to call a constant function address than to
369 call an address kept in a register. */
370 #define NO_FUNCTION_CSE 1
371
372 /* Xtensa processors have "register windows". GCC does not currently
373 take advantage of the possibility for variable-sized windows; instead,
374 we use a fixed window size of 8. */
375
376 #define INCOMING_REGNO(OUT) \
377 (TARGET_WINDOWED_ABI ? \
378 ((GP_REG_P (OUT) && \
379 ((unsigned) ((OUT) - GP_REG_FIRST) >= WINDOW_SIZE)) ? \
380 (OUT) - WINDOW_SIZE : (OUT)) : (OUT))
381
382 #define OUTGOING_REGNO(IN) \
383 (TARGET_WINDOWED_ABI ? \
384 ((GP_REG_P (IN) && \
385 ((unsigned) ((IN) - GP_REG_FIRST) < WINDOW_SIZE)) ? \
386 (IN) + WINDOW_SIZE : (IN)) : (IN))
387
388
389 /* Define the classes of registers for register constraints in the
390 machine description. */
391 enum reg_class
392 {
393 NO_REGS, /* no registers in set */
394 BR_REGS, /* coprocessor boolean registers */
395 FP_REGS, /* floating point registers */
396 ACC_REG, /* MAC16 accumulator */
397 SP_REG, /* sp register (aka a1) */
398 RL_REGS, /* preferred reload regs (not sp or fp) */
399 GR_REGS, /* integer registers except sp */
400 AR_REGS, /* all integer registers */
401 ALL_REGS, /* all registers */
402 LIM_REG_CLASSES /* max value + 1 */
403 };
404
405 #define N_REG_CLASSES (int) LIM_REG_CLASSES
406
407 #define GENERAL_REGS AR_REGS
408
409 /* An initializer containing the names of the register classes as C
410 string constants. These names are used in writing some of the
411 debugging dumps. */
412 #define REG_CLASS_NAMES \
413 { \
414 "NO_REGS", \
415 "BR_REGS", \
416 "FP_REGS", \
417 "ACC_REG", \
418 "SP_REG", \
419 "RL_REGS", \
420 "GR_REGS", \
421 "AR_REGS", \
422 "ALL_REGS" \
423 }
424
425 /* Contents of the register classes. The Nth integer specifies the
426 contents of class N. The way the integer MASK is interpreted is
427 that register R is in the class if 'MASK & (1 << R)' is 1. */
428 #define REG_CLASS_CONTENTS \
429 { \
430 { 0x00000000, 0x00000000 }, /* no registers */ \
431 { 0x00040000, 0x00000000 }, /* coprocessor boolean registers */ \
432 { 0xfff80000, 0x00000007 }, /* floating-point registers */ \
433 { 0x00000000, 0x00000008 }, /* MAC16 accumulator */ \
434 { 0x00000002, 0x00000000 }, /* stack pointer register */ \
435 { 0x0000fffd, 0x00000000 }, /* preferred reload registers */ \
436 { 0x0000fffd, 0x00000000 }, /* general-purpose registers */ \
437 { 0x0003ffff, 0x00000000 }, /* integer registers */ \
438 { 0xffffffff, 0x0000000f } /* all registers */ \
439 }
440
441 /* A C expression whose value is a register class containing hard
442 register REGNO. In general there is more that one such class;
443 choose a class which is "minimal", meaning that no smaller class
444 also contains the register. */
445 #define REGNO_REG_CLASS(REGNO) xtensa_regno_to_class (REGNO)
446
447 /* Use the Xtensa AR register file for base registers.
448 No index registers. */
449 #define BASE_REG_CLASS AR_REGS
450 #define INDEX_REG_CLASS NO_REGS
451
452 /* The small_register_classes_for_mode_p hook must always return true for
453 Xtrnase, because all of the 16 AR registers may be explicitly used in
454 the RTL, as either incoming or outgoing arguments. */
455 #define TARGET_SMALL_REGISTER_CLASSES_FOR_MODE_P hook_bool_mode_true
456
457 /* Stack layout; function entry, exit and calling. */
458
459 #define STACK_GROWS_DOWNWARD 1
460
461 #define FRAME_GROWS_DOWNWARD flag_stack_protect
462
463 /* Offset within stack frame to start allocating local variables at. */
464 #define STARTING_FRAME_OFFSET \
465 (FRAME_GROWS_DOWNWARD ? 0 : crtl->outgoing_args_size)
466
467 /* The ARG_POINTER and FRAME_POINTER are not real Xtensa registers, so
468 they are eliminated to either the stack pointer or hard frame pointer. */
469 #define ELIMINABLE_REGS \
470 {{ ARG_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
471 { ARG_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}, \
472 { FRAME_POINTER_REGNUM, STACK_POINTER_REGNUM}, \
473 { FRAME_POINTER_REGNUM, HARD_FRAME_POINTER_REGNUM}}
474
475 /* Specify the initial difference between the specified pair of registers. */
476 #define INITIAL_ELIMINATION_OFFSET(FROM, TO, OFFSET) \
477 (OFFSET) = xtensa_initial_elimination_offset ((FROM), (TO))
478
479 /* If defined, the maximum amount of space required for outgoing
480 arguments will be computed and placed into the variable
481 'crtl->outgoing_args_size'. No space will be pushed
482 onto the stack for each call; instead, the function prologue
483 should increase the stack frame size by this amount. */
484 #define ACCUMULATE_OUTGOING_ARGS 1
485
486 /* Offset from the argument pointer register to the first argument's
487 address. On some machines it may depend on the data type of the
488 function. If 'ARGS_GROW_DOWNWARD', this is the offset to the
489 location above the first argument's address. */
490 #define FIRST_PARM_OFFSET(FNDECL) 0
491
492 /* Align stack frames on 128 bits for Xtensa. This is necessary for
493 128-bit datatypes defined in TIE (e.g., for Vectra). */
494 #define STACK_BOUNDARY 128
495
496 /* Use a fixed register window size of 8. */
497 #define WINDOW_SIZE (TARGET_WINDOWED_ABI ? 8 : 0)
498
499 /* Symbolic macros for the registers used to return integer, floating
500 point, and values of coprocessor and user-defined modes. */
501 #define GP_RETURN (GP_REG_FIRST + 2 + WINDOW_SIZE)
502 #define GP_OUTGOING_RETURN (GP_REG_FIRST + 2)
503
504 /* Symbolic macros for the first/last argument registers. */
505 #define GP_ARG_FIRST (GP_REG_FIRST + 2)
506 #define GP_ARG_LAST (GP_REG_FIRST + 7)
507 #define GP_OUTGOING_ARG_FIRST (GP_REG_FIRST + 2 + WINDOW_SIZE)
508 #define GP_OUTGOING_ARG_LAST (GP_REG_FIRST + 7 + WINDOW_SIZE)
509
510 #define MAX_ARGS_IN_REGISTERS 6
511
512 /* Don't worry about compatibility with PCC. */
513 #define DEFAULT_PCC_STRUCT_RETURN 0
514
515 /* A C expression that is nonzero if REGNO is the number of a hard
516 register in which function arguments are sometimes passed. This
517 does *not* include implicit arguments such as the static chain and
518 the structure-value address. On many machines, no registers can be
519 used for this purpose since all function arguments are pushed on
520 the stack. */
521 #define FUNCTION_ARG_REGNO_P(N) \
522 ((N) >= GP_OUTGOING_ARG_FIRST && (N) <= GP_OUTGOING_ARG_LAST)
523
524 /* Record the number of argument words seen so far, along with a flag to
525 indicate whether these are incoming arguments. (FUNCTION_INCOMING_ARG
526 is used for both incoming and outgoing args, so a separate flag is
527 needed. */
528 typedef struct xtensa_args
529 {
530 int arg_words;
531 int incoming;
532 } CUMULATIVE_ARGS;
533
534 #define INIT_CUMULATIVE_ARGS(CUM, FNTYPE, LIBNAME, INDIRECT, N_NAMED_ARGS) \
535 init_cumulative_args (&CUM, 0)
536
537 #define INIT_CUMULATIVE_INCOMING_ARGS(CUM, FNTYPE, LIBNAME) \
538 init_cumulative_args (&CUM, 1)
539
540 /* Profiling Xtensa code is typically done with the built-in profiling
541 feature of Tensilica's instruction set simulator, which does not
542 require any compiler support. Profiling code on a real (i.e.,
543 non-simulated) Xtensa processor is currently only supported by
544 GNU/Linux with glibc. The glibc version of _mcount doesn't require
545 counter variables. The _mcount function needs the current PC and
546 the current return address to identify an arc in the call graph.
547 Pass the current return address as the first argument; the current
548 PC is available as a0 in _mcount's register window. Both of these
549 values contain window size information in the two most significant
550 bits; we assume that _mcount will mask off those bits. The call to
551 _mcount uses a window size of 8 to make sure that it doesn't clobber
552 any incoming argument values. */
553
554 #define NO_PROFILE_COUNTERS 1
555
556 #define FUNCTION_PROFILER(FILE, LABELNO) \
557 do { \
558 fprintf (FILE, "\t%s\ta10, a0\n", TARGET_DENSITY ? "mov.n" : "mov"); \
559 if (flag_pic) \
560 { \
561 fprintf (FILE, "\tmovi\ta%d, _mcount@PLT\n", WINDOW_SIZE); \
562 fprintf (FILE, "\tcallx%d\ta%d\n", WINDOW_SIZE, WINDOW_SIZE); \
563 } \
564 else \
565 fprintf (FILE, "\tcall%d\t_mcount\n", WINDOW_SIZE); \
566 } while (0)
567
568 /* Stack pointer value doesn't matter at exit. */
569 #define EXIT_IGNORE_STACK 1
570
571 /* Size in bytes of the trampoline, as an integer. Make sure this is
572 a multiple of TRAMPOLINE_ALIGNMENT to avoid -Wpadded warnings. */
573 #define TRAMPOLINE_SIZE (TARGET_WINDOWED_ABI ? \
574 (TARGET_CONST16 || TARGET_ABSOLUTE_LITERALS ? \
575 60 : 52) : \
576 (TARGET_CONST16 || TARGET_ABSOLUTE_LITERALS ? \
577 32 : 24))
578
579 /* Alignment required for trampolines, in bits. */
580 #define TRAMPOLINE_ALIGNMENT 32
581
582 /* If defined, a C expression that produces the machine-specific code
583 to setup the stack so that arbitrary frames can be accessed.
584
585 On Xtensa, a stack back-trace must always begin from the stack pointer,
586 so that the register overflow save area can be located. However, the
587 stack-walking code in GCC always begins from the hard_frame_pointer
588 register, not the stack pointer. The frame pointer is usually equal
589 to the stack pointer, but the __builtin_return_address and
590 __builtin_frame_address functions will not work if count > 0 and
591 they are called from a routine that uses alloca. These functions
592 are not guaranteed to work at all if count > 0 so maybe that is OK.
593
594 A nicer solution would be to allow the architecture-specific files to
595 specify whether to start from the stack pointer or frame pointer. That
596 would also allow us to skip the machine->accesses_prev_frame stuff that
597 we currently need to ensure that there is a frame pointer when these
598 builtin functions are used. */
599
600 #define SETUP_FRAME_ADDRESSES xtensa_setup_frame_addresses
601
602 /* A C expression whose value is RTL representing the address in a
603 stack frame where the pointer to the caller's frame is stored.
604 Assume that FRAMEADDR is an RTL expression for the address of the
605 stack frame itself.
606
607 For Xtensa, there is no easy way to get the frame pointer if it is
608 not equivalent to the stack pointer. Moreover, the result of this
609 macro is used for continuing to walk back up the stack, so it must
610 return the stack pointer address. Thus, there is some inconsistency
611 here in that __builtin_frame_address will return the frame pointer
612 when count == 0 and the stack pointer when count > 0. */
613
614 #define DYNAMIC_CHAIN_ADDRESS(frame) \
615 gen_rtx_PLUS (Pmode, frame, GEN_INT (-3 * UNITS_PER_WORD))
616
617 /* Define this if the return address of a particular stack frame is
618 accessed from the frame pointer of the previous stack frame. */
619 #define RETURN_ADDR_IN_PREVIOUS_FRAME TARGET_WINDOWED_ABI
620
621 /* A C expression whose value is RTL representing the value of the
622 return address for the frame COUNT steps up from the current
623 frame, after the prologue. */
624 #define RETURN_ADDR_RTX xtensa_return_addr
625
626 /* Addressing modes, and classification of registers for them. */
627
628 /* C expressions which are nonzero if register number NUM is suitable
629 for use as a base or index register in operand addresses. */
630
631 #define REGNO_OK_FOR_INDEX_P(NUM) 0
632 #define REGNO_OK_FOR_BASE_P(NUM) \
633 (GP_REG_P (NUM) || GP_REG_P ((unsigned) reg_renumber[NUM]))
634
635 /* C expressions that are nonzero if X (assumed to be a `reg' RTX) is
636 valid for use as a base or index register. */
637
638 #ifdef REG_OK_STRICT
639 #define REG_OK_STRICT_FLAG 1
640 #else
641 #define REG_OK_STRICT_FLAG 0
642 #endif
643
644 #define BASE_REG_P(X, STRICT) \
645 ((!(STRICT) && REGNO (X) >= FIRST_PSEUDO_REGISTER) \
646 || REGNO_OK_FOR_BASE_P (REGNO (X)))
647
648 #define REG_OK_FOR_INDEX_P(X) 0
649 #define REG_OK_FOR_BASE_P(X) BASE_REG_P (X, REG_OK_STRICT_FLAG)
650
651 /* Maximum number of registers that can appear in a valid memory address. */
652 #define MAX_REGS_PER_ADDRESS 1
653
654 /* A C expression that is 1 if the RTX X is a constant which is a
655 valid address. This is defined to be the same as 'CONSTANT_P (X)',
656 but rejecting CONST_DOUBLE. */
657 #define CONSTANT_ADDRESS_P(X) \
658 ((GET_CODE (X) == LABEL_REF || GET_CODE (X) == SYMBOL_REF \
659 || GET_CODE (X) == CONST_INT || GET_CODE (X) == HIGH \
660 || (GET_CODE (X) == CONST)))
661
662 /* A C expression that is nonzero if X is a legitimate immediate
663 operand on the target machine when generating position independent
664 code. */
665 #define LEGITIMATE_PIC_OPERAND_P(X) \
666 ((GET_CODE (X) != SYMBOL_REF \
667 || (SYMBOL_REF_LOCAL_P (X) && !SYMBOL_REF_EXTERNAL_P (X))) \
668 && GET_CODE (X) != LABEL_REF \
669 && GET_CODE (X) != CONST)
670
671 /* Specify the machine mode that this machine uses
672 for the index in the tablejump instruction. */
673 #define CASE_VECTOR_MODE (SImode)
674
675 /* Define this as 1 if 'char' should by default be signed; else as 0. */
676 #define DEFAULT_SIGNED_CHAR 0
677
678 /* Max number of bytes we can move from memory to memory
679 in one reasonably fast instruction. */
680 #define MOVE_MAX 4
681 #define MAX_MOVE_MAX 4
682
683 /* Prefer word-sized loads. */
684 #define SLOW_BYTE_ACCESS 1
685
686 /* Shift instructions ignore all but the low-order few bits. */
687 #define SHIFT_COUNT_TRUNCATED 1
688
689 /* Value is 1 if truncating an integer of INPREC bits to OUTPREC bits
690 is done just by pretending it is already truncated. */
691 #define TRULY_NOOP_TRUNCATION(OUTPREC, INPREC) 1
692
693 #define CLZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) ((VALUE) = 32, 1)
694 #define CTZ_DEFINED_VALUE_AT_ZERO(MODE, VALUE) ((VALUE) = -1, 1)
695
696 /* Specify the machine mode that pointers have.
697 After generation of rtl, the compiler makes no further distinction
698 between pointers and any other objects of this machine mode. */
699 #define Pmode SImode
700
701 /* A function address in a call instruction is a word address (for
702 indexing purposes) so give the MEM rtx a words's mode. */
703 #define FUNCTION_MODE SImode
704
705 #define BRANCH_COST(speed_p, predictable_p) 3
706
707 /* How to refer to registers in assembler output.
708 This sequence is indexed by compiler's hard-register-number (see above). */
709 #define REGISTER_NAMES \
710 { \
711 "a0", "sp", "a2", "a3", "a4", "a5", "a6", "a7", \
712 "a8", "a9", "a10", "a11", "a12", "a13", "a14", "a15", \
713 "fp", "argp", "b0", \
714 "f0", "f1", "f2", "f3", "f4", "f5", "f6", "f7", \
715 "f8", "f9", "f10", "f11", "f12", "f13", "f14", "f15", \
716 "acc" \
717 }
718
719 /* If defined, a C initializer for an array of structures containing a
720 name and a register number. This macro defines additional names
721 for hard registers, thus allowing the 'asm' option in declarations
722 to refer to registers using alternate names. */
723 #define ADDITIONAL_REGISTER_NAMES \
724 { \
725 { "a1", 1 + GP_REG_FIRST } \
726 }
727
728 #define PRINT_OPERAND(FILE, X, CODE) print_operand (FILE, X, CODE)
729 #define PRINT_OPERAND_ADDRESS(FILE, ADDR) print_operand_address (FILE, ADDR)
730
731 /* Globalizing directive for a label. */
732 #define GLOBAL_ASM_OP "\t.global\t"
733
734 /* Declare an uninitialized external linkage data object. */
735 #define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \
736 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN)
737
738 /* This is how to output an element of a case-vector that is absolute. */
739 #define ASM_OUTPUT_ADDR_VEC_ELT(STREAM, VALUE) \
740 fprintf (STREAM, "%s%sL%u\n", integer_asm_op (4, TRUE), \
741 LOCAL_LABEL_PREFIX, VALUE)
742
743 /* This is how to output an element of a case-vector that is relative.
744 This is used for pc-relative code. */
745 #define ASM_OUTPUT_ADDR_DIFF_ELT(STREAM, BODY, VALUE, REL) \
746 do { \
747 fprintf (STREAM, "%s%sL%u-%sL%u\n", integer_asm_op (4, TRUE), \
748 LOCAL_LABEL_PREFIX, (VALUE), \
749 LOCAL_LABEL_PREFIX, (REL)); \
750 } while (0)
751
752 /* This is how to output an assembler line that says to advance the
753 location counter to a multiple of 2**LOG bytes. */
754 #define ASM_OUTPUT_ALIGN(STREAM, LOG) \
755 do { \
756 if ((LOG) != 0) \
757 fprintf (STREAM, "\t.align\t%d\n", 1 << (LOG)); \
758 } while (0)
759
760 /* Indicate that jump tables go in the text section. This is
761 necessary when compiling PIC code. */
762 #define JUMP_TABLES_IN_TEXT_SECTION (flag_pic)
763
764
765 /* Define the strings to put out for each section in the object file. */
766 #define TEXT_SECTION_ASM_OP "\t.text"
767 #define DATA_SECTION_ASM_OP "\t.data"
768 #define BSS_SECTION_ASM_OP "\t.section\t.bss"
769
770
771 /* Define output to appear before the constant pool. */
772 #define ASM_OUTPUT_POOL_PROLOGUE(FILE, FUNNAME, FUNDECL, SIZE) \
773 do { \
774 if ((SIZE) > 0 || !TARGET_WINDOWED_ABI) \
775 { \
776 resolve_unique_section ((FUNDECL), 0, flag_function_sections); \
777 switch_to_section (function_section (FUNDECL)); \
778 fprintf (FILE, "\t.literal_position\n"); \
779 } \
780 } while (0)
781
782
783 /* A C statement (with or without semicolon) to output a constant in
784 the constant pool, if it needs special treatment. */
785 #define ASM_OUTPUT_SPECIAL_POOL_ENTRY(FILE, X, MODE, ALIGN, LABELNO, JUMPTO) \
786 do { \
787 xtensa_output_literal (FILE, X, MODE, LABELNO); \
788 goto JUMPTO; \
789 } while (0)
790
791 /* How to start an assembler comment. */
792 #define ASM_COMMENT_START "#"
793
794 /* Exception handling. Xtensa uses much of the standard DWARF2 unwinding
795 machinery, but the variable size register window save areas are too
796 complicated to efficiently describe with CFI entries. The CFA must
797 still be specified in DWARF so that DW_AT_frame_base is set correctly
798 for debugging. */
799 #define INCOMING_RETURN_ADDR_RTX gen_rtx_REG (Pmode, 0)
800 #define DWARF_FRAME_RETURN_COLUMN DWARF_FRAME_REGNUM (0)
801 #define DWARF_ALT_FRAME_RETURN_COLUMN 16
802 #define DWARF_FRAME_REGISTERS (DWARF_ALT_FRAME_RETURN_COLUMN \
803 + (TARGET_WINDOWED_ABI ? 0 : 1))
804 #define EH_RETURN_DATA_REGNO(N) ((N) < 2 ? (N) + 2 : INVALID_REGNUM)
805 #define ASM_PREFERRED_EH_DATA_FORMAT(CODE, GLOBAL) \
806 (flag_pic \
807 ? (((GLOBAL) ? DW_EH_PE_indirect : 0) \
808 | DW_EH_PE_pcrel | DW_EH_PE_sdata4) \
809 : DW_EH_PE_absptr)
810
811 #define EH_RETURN_STACKADJ_RTX gen_rtx_REG (Pmode, GP_REG_FIRST + 10)
812
813 /* Emit a PC-relative relocation. */
814 #define ASM_OUTPUT_DWARF_PCREL(FILE, SIZE, LABEL) \
815 do { \
816 fputs (integer_asm_op (SIZE, FALSE), FILE); \
817 assemble_name (FILE, LABEL); \
818 fputs ("@pcrel", FILE); \
819 } while (0)
820
821 /* Xtensa constant pool breaks the devices in crtstuff.c to control
822 section in where code resides. We have to write it as asm code. Use
823 a MOVI and let the assembler relax it -- for the .init and .fini
824 sections, the assembler knows to put the literal in the right
825 place. */
826 #if defined(__XTENSA_WINDOWED_ABI__)
827 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \
828 asm (SECTION_OP "\n\
829 movi\ta8, " USER_LABEL_PREFIX #FUNC "\n\
830 callx8\ta8\n" \
831 TEXT_SECTION_ASM_OP);
832 #elif defined(__XTENSA_CALL0_ABI__)
833 #define CRT_CALL_STATIC_FUNCTION(SECTION_OP, FUNC) \
834 asm (SECTION_OP "\n\
835 movi\ta0, " USER_LABEL_PREFIX #FUNC "\n\
836 callx0\ta0\n" \
837 TEXT_SECTION_ASM_OP);
838 #endif