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1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
21 02111-1307, USA. */
22
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "rtl.h"
28 #include "tree.h"
29 #include "flags.h"
30 #include "expr.h"
31 #include "optabs.h"
32 #include "libfuncs.h"
33 #include "function.h"
34 #include "regs.h"
35 #include "toplev.h"
36 #include "output.h"
37 #include "tm_p.h"
38 #include "timevar.h"
39 #include "sbitmap.h"
40 #include "langhooks.h"
41 #include "target.h"
42 #include "cgraph.h"
43 #include "except.h"
44
45 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
46 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
47
48 /* Data structure and subroutines used within expand_call. */
49
50 struct arg_data
51 {
52 /* Tree node for this argument. */
53 tree tree_value;
54 /* Mode for value; TYPE_MODE unless promoted. */
55 enum machine_mode mode;
56 /* Current RTL value for argument, or 0 if it isn't precomputed. */
57 rtx value;
58 /* Initially-compute RTL value for argument; only for const functions. */
59 rtx initial_value;
60 /* Register to pass this argument in, 0 if passed on stack, or an
61 PARALLEL if the arg is to be copied into multiple non-contiguous
62 registers. */
63 rtx reg;
64 /* Register to pass this argument in when generating tail call sequence.
65 This is not the same register as for normal calls on machines with
66 register windows. */
67 rtx tail_call_reg;
68 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
69 form for emit_group_move. */
70 rtx parallel_value;
71 /* If REG was promoted from the actual mode of the argument expression,
72 indicates whether the promotion is sign- or zero-extended. */
73 int unsignedp;
74 /* Number of bytes to put in registers. 0 means put the whole arg
75 in registers. Also 0 if not passed in registers. */
76 int partial;
77 /* Nonzero if argument must be passed on stack.
78 Note that some arguments may be passed on the stack
79 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
80 pass_on_stack identifies arguments that *cannot* go in registers. */
81 int pass_on_stack;
82 /* Some fields packaged up for locate_and_pad_parm. */
83 struct locate_and_pad_arg_data locate;
84 /* Location on the stack at which parameter should be stored. The store
85 has already been done if STACK == VALUE. */
86 rtx stack;
87 /* Location on the stack of the start of this argument slot. This can
88 differ from STACK if this arg pads downward. This location is known
89 to be aligned to FUNCTION_ARG_BOUNDARY. */
90 rtx stack_slot;
91 /* Place that this stack area has been saved, if needed. */
92 rtx save_area;
93 /* If an argument's alignment does not permit direct copying into registers,
94 copy in smaller-sized pieces into pseudos. These are stored in a
95 block pointed to by this field. The next field says how many
96 word-sized pseudos we made. */
97 rtx *aligned_regs;
98 int n_aligned_regs;
99 };
100
101 /* A vector of one char per byte of stack space. A byte if nonzero if
102 the corresponding stack location has been used.
103 This vector is used to prevent a function call within an argument from
104 clobbering any stack already set up. */
105 static char *stack_usage_map;
106
107 /* Size of STACK_USAGE_MAP. */
108 static int highest_outgoing_arg_in_use;
109
110 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
111 stack location's tail call argument has been already stored into the stack.
112 This bitmap is used to prevent sibling call optimization if function tries
113 to use parent's incoming argument slots when they have been already
114 overwritten with tail call arguments. */
115 static sbitmap stored_args_map;
116
117 /* stack_arg_under_construction is nonzero when an argument may be
118 initialized with a constructor call (including a C function that
119 returns a BLKmode struct) and expand_call must take special action
120 to make sure the object being constructed does not overlap the
121 argument list for the constructor call. */
122 static int stack_arg_under_construction;
123
124 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
125 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
126 CUMULATIVE_ARGS *);
127 static void precompute_register_parameters (int, struct arg_data *, int *);
128 static int store_one_arg (struct arg_data *, rtx, int, int, int);
129 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
130 static int finalize_must_preallocate (int, int, struct arg_data *,
131 struct args_size *);
132 static void precompute_arguments (int, int, struct arg_data *);
133 static int compute_argument_block_size (int, struct args_size *, int);
134 static void initialize_argument_information (int, struct arg_data *,
135 struct args_size *, int, tree,
136 tree, CUMULATIVE_ARGS *, int,
137 rtx *, int *, int *, int *,
138 bool *, bool);
139 static void compute_argument_addresses (struct arg_data *, rtx, int);
140 static rtx rtx_for_function_call (tree, tree);
141 static void load_register_parameters (struct arg_data *, int, rtx *, int,
142 int, int *);
143 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
144 enum machine_mode, int, va_list);
145 static int special_function_p (tree, int);
146 static int check_sibcall_argument_overlap_1 (rtx);
147 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
148
149 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
150 unsigned int);
151 static tree split_complex_values (tree);
152 static tree split_complex_types (tree);
153
154 #ifdef REG_PARM_STACK_SPACE
155 static rtx save_fixed_argument_area (int, rtx, int *, int *);
156 static void restore_fixed_argument_area (rtx, rtx, int, int);
157 #endif
158 \f
159 /* Force FUNEXP into a form suitable for the address of a CALL,
160 and return that as an rtx. Also load the static chain register
161 if FNDECL is a nested function.
162
163 CALL_FUSAGE points to a variable holding the prospective
164 CALL_INSN_FUNCTION_USAGE information. */
165
166 rtx
167 prepare_call_address (rtx funexp, rtx static_chain_value,
168 rtx *call_fusage, int reg_parm_seen, int sibcallp)
169 {
170 /* Make a valid memory address and copy constants through pseudo-regs,
171 but not for a constant address if -fno-function-cse. */
172 if (GET_CODE (funexp) != SYMBOL_REF)
173 /* If we are using registers for parameters, force the
174 function address into a register now. */
175 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
176 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
177 : memory_address (FUNCTION_MODE, funexp));
178 else if (! sibcallp)
179 {
180 #ifndef NO_FUNCTION_CSE
181 if (optimize && ! flag_no_function_cse)
182 funexp = force_reg (Pmode, funexp);
183 #endif
184 }
185
186 if (static_chain_value != 0)
187 {
188 static_chain_value = convert_memory_address (Pmode, static_chain_value);
189 emit_move_insn (static_chain_rtx, static_chain_value);
190
191 if (REG_P (static_chain_rtx))
192 use_reg (call_fusage, static_chain_rtx);
193 }
194
195 return funexp;
196 }
197
198 /* Generate instructions to call function FUNEXP,
199 and optionally pop the results.
200 The CALL_INSN is the first insn generated.
201
202 FNDECL is the declaration node of the function. This is given to the
203 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
204
205 FUNTYPE is the data type of the function. This is given to the macro
206 RETURN_POPS_ARGS to determine whether this function pops its own args.
207 We used to allow an identifier for library functions, but that doesn't
208 work when the return type is an aggregate type and the calling convention
209 says that the pointer to this aggregate is to be popped by the callee.
210
211 STACK_SIZE is the number of bytes of arguments on the stack,
212 ROUNDED_STACK_SIZE is that number rounded up to
213 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
214 both to put into the call insn and to generate explicit popping
215 code if necessary.
216
217 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
218 It is zero if this call doesn't want a structure value.
219
220 NEXT_ARG_REG is the rtx that results from executing
221 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
222 just after all the args have had their registers assigned.
223 This could be whatever you like, but normally it is the first
224 arg-register beyond those used for args in this call,
225 or 0 if all the arg-registers are used in this call.
226 It is passed on to `gen_call' so you can put this info in the call insn.
227
228 VALREG is a hard register in which a value is returned,
229 or 0 if the call does not return a value.
230
231 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
232 the args to this call were processed.
233 We restore `inhibit_defer_pop' to that value.
234
235 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
236 denote registers used by the called function. */
237
238 static void
239 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
240 tree funtype ATTRIBUTE_UNUSED,
241 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
242 HOST_WIDE_INT rounded_stack_size,
243 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
244 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
245 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
246 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
247 {
248 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
249 rtx call_insn;
250 int already_popped = 0;
251 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
252 #if defined (HAVE_call) && defined (HAVE_call_value)
253 rtx struct_value_size_rtx;
254 struct_value_size_rtx = GEN_INT (struct_value_size);
255 #endif
256
257 #ifdef CALL_POPS_ARGS
258 n_popped += CALL_POPS_ARGS (* args_so_far);
259 #endif
260
261 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
262 and we don't want to load it into a register as an optimization,
263 because prepare_call_address already did it if it should be done. */
264 if (GET_CODE (funexp) != SYMBOL_REF)
265 funexp = memory_address (FUNCTION_MODE, funexp);
266
267 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
268 if ((ecf_flags & ECF_SIBCALL)
269 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
270 && (n_popped > 0 || stack_size == 0))
271 {
272 rtx n_pop = GEN_INT (n_popped);
273 rtx pat;
274
275 /* If this subroutine pops its own args, record that in the call insn
276 if possible, for the sake of frame pointer elimination. */
277
278 if (valreg)
279 pat = GEN_SIBCALL_VALUE_POP (valreg,
280 gen_rtx_MEM (FUNCTION_MODE, funexp),
281 rounded_stack_size_rtx, next_arg_reg,
282 n_pop);
283 else
284 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
285 rounded_stack_size_rtx, next_arg_reg, n_pop);
286
287 emit_call_insn (pat);
288 already_popped = 1;
289 }
290 else
291 #endif
292
293 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
294 /* If the target has "call" or "call_value" insns, then prefer them
295 if no arguments are actually popped. If the target does not have
296 "call" or "call_value" insns, then we must use the popping versions
297 even if the call has no arguments to pop. */
298 #if defined (HAVE_call) && defined (HAVE_call_value)
299 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
300 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
301 #else
302 if (HAVE_call_pop && HAVE_call_value_pop)
303 #endif
304 {
305 rtx n_pop = GEN_INT (n_popped);
306 rtx pat;
307
308 /* If this subroutine pops its own args, record that in the call insn
309 if possible, for the sake of frame pointer elimination. */
310
311 if (valreg)
312 pat = GEN_CALL_VALUE_POP (valreg,
313 gen_rtx_MEM (FUNCTION_MODE, funexp),
314 rounded_stack_size_rtx, next_arg_reg, n_pop);
315 else
316 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
317 rounded_stack_size_rtx, next_arg_reg, n_pop);
318
319 emit_call_insn (pat);
320 already_popped = 1;
321 }
322 else
323 #endif
324
325 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
326 if ((ecf_flags & ECF_SIBCALL)
327 && HAVE_sibcall && HAVE_sibcall_value)
328 {
329 if (valreg)
330 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
331 gen_rtx_MEM (FUNCTION_MODE, funexp),
332 rounded_stack_size_rtx,
333 next_arg_reg, NULL_RTX));
334 else
335 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
336 rounded_stack_size_rtx, next_arg_reg,
337 struct_value_size_rtx));
338 }
339 else
340 #endif
341
342 #if defined (HAVE_call) && defined (HAVE_call_value)
343 if (HAVE_call && HAVE_call_value)
344 {
345 if (valreg)
346 emit_call_insn (GEN_CALL_VALUE (valreg,
347 gen_rtx_MEM (FUNCTION_MODE, funexp),
348 rounded_stack_size_rtx, next_arg_reg,
349 NULL_RTX));
350 else
351 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
352 rounded_stack_size_rtx, next_arg_reg,
353 struct_value_size_rtx));
354 }
355 else
356 #endif
357 gcc_unreachable ();
358
359 /* Find the call we just emitted. */
360 call_insn = last_call_insn ();
361
362 /* Mark memory as used for "pure" function call. */
363 if (ecf_flags & ECF_PURE)
364 call_fusage
365 = gen_rtx_EXPR_LIST
366 (VOIDmode,
367 gen_rtx_USE (VOIDmode,
368 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
369 call_fusage);
370
371 /* Put the register usage information there. */
372 add_function_usage_to (call_insn, call_fusage);
373
374 /* If this is a const call, then set the insn's unchanging bit. */
375 if (ecf_flags & (ECF_CONST | ECF_PURE))
376 CONST_OR_PURE_CALL_P (call_insn) = 1;
377
378 /* If this call can't throw, attach a REG_EH_REGION reg note to that
379 effect. */
380 if (ecf_flags & ECF_NOTHROW)
381 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
382 REG_NOTES (call_insn));
383 else
384 {
385 int rn = lookup_stmt_eh_region (fntree);
386
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
389 if (rn > 0)
390 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn),
391 REG_NOTES (call_insn));
392 note_current_region_may_contain_throw ();
393 }
394
395 if (ecf_flags & ECF_NORETURN)
396 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
397 REG_NOTES (call_insn));
398
399 if (ecf_flags & ECF_RETURNS_TWICE)
400 {
401 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
402 REG_NOTES (call_insn));
403 current_function_calls_setjmp = 1;
404 }
405
406 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
407
408 /* Restore this now, so that we do defer pops for this call's args
409 if the context of the call as a whole permits. */
410 inhibit_defer_pop = old_inhibit_defer_pop;
411
412 if (n_popped > 0)
413 {
414 if (!already_popped)
415 CALL_INSN_FUNCTION_USAGE (call_insn)
416 = gen_rtx_EXPR_LIST (VOIDmode,
417 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
418 CALL_INSN_FUNCTION_USAGE (call_insn));
419 rounded_stack_size -= n_popped;
420 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
421 stack_pointer_delta -= n_popped;
422 }
423
424 if (!ACCUMULATE_OUTGOING_ARGS)
425 {
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
429
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
432
433 if (rounded_stack_size != 0)
434 {
435 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN))
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
441 else
442 adjust_stack (rounded_stack_size_rtx);
443 }
444 }
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
450
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
453
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
455 such machines. */
456 else if (n_popped)
457 anti_adjust_stack (GEN_INT (n_popped));
458 }
459
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
462
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
465
466 Similarly set NORETURN if the function is in the longjmp family.
467
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
470
471 static int
472 special_function_p (tree fndecl, int flags)
473 {
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
478 think they are.
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
482 wish. */
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
486 {
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
489
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
494 && name[0] == 'a'
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
497 && name[0] == '_'
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
500
501 /* Disregard prefix _, __ or __x. */
502 if (name[0] == '_')
503 {
504 if (name[1] == '_' && name[2] == 'x')
505 tname += 3;
506 else if (name[1] == '_')
507 tname += 2;
508 else
509 tname += 1;
510 }
511
512 if (tname[0] == 's')
513 {
514 if ((tname[1] == 'e'
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
517 || (tname[1] == 'i'
518 && ! strcmp (tname, "sigsetjmp"))
519 || (tname[1] == 'a'
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
522
523 if (tname[1] == 'i'
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
526 }
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork")))
531 flags |= ECF_RETURNS_TWICE;
532
533 else if (tname[0] == 'l' && tname[1] == 'o'
534 && ! strcmp (tname, "longjmp"))
535 flags |= ECF_NORETURN;
536 }
537
538 return flags;
539 }
540
541 /* Return nonzero when FNDECL represents a call to setjmp. */
542
543 int
544 setjmp_call_p (tree fndecl)
545 {
546 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
547 }
548
549 /* Return true when exp contains alloca call. */
550 bool
551 alloca_call_p (tree exp)
552 {
553 if (TREE_CODE (exp) == CALL_EXPR
554 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
555 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
556 == FUNCTION_DECL)
557 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
558 0) & ECF_MAY_BE_ALLOCA))
559 return true;
560 return false;
561 }
562
563 /* Detect flags (function attributes) from the function decl or type node. */
564
565 int
566 flags_from_decl_or_type (tree exp)
567 {
568 int flags = 0;
569 tree type = exp;
570
571 if (DECL_P (exp))
572 {
573 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
574 type = TREE_TYPE (exp);
575
576 if (i)
577 {
578 if (i->pure_function)
579 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
580 if (i->const_function)
581 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
582 }
583
584 /* The function exp may have the `malloc' attribute. */
585 if (DECL_IS_MALLOC (exp))
586 flags |= ECF_MALLOC;
587
588 /* The function exp may have the `returns_twice' attribute. */
589 if (DECL_IS_RETURNS_TWICE (exp))
590 flags |= ECF_RETURNS_TWICE;
591
592 /* The function exp may have the `pure' attribute. */
593 if (DECL_IS_PURE (exp))
594 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
595
596 if (DECL_IS_NOVOPS (exp))
597 flags |= ECF_NOVOPS;
598
599 if (TREE_NOTHROW (exp))
600 flags |= ECF_NOTHROW;
601
602 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
603 flags |= ECF_LIBCALL_BLOCK | ECF_CONST;
604
605 flags = special_function_p (exp, flags);
606 }
607 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
608 flags |= ECF_CONST;
609
610 if (TREE_THIS_VOLATILE (exp))
611 flags |= ECF_NORETURN;
612
613 /* Mark if the function returns with the stack pointer depressed. We
614 cannot consider it pure or constant in that case. */
615 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
616 {
617 flags |= ECF_SP_DEPRESSED;
618 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
619 }
620
621 return flags;
622 }
623
624 /* Detect flags from a CALL_EXPR. */
625
626 int
627 call_expr_flags (tree t)
628 {
629 int flags;
630 tree decl = get_callee_fndecl (t);
631
632 if (decl)
633 flags = flags_from_decl_or_type (decl);
634 else
635 {
636 t = TREE_TYPE (TREE_OPERAND (t, 0));
637 if (t && TREE_CODE (t) == POINTER_TYPE)
638 flags = flags_from_decl_or_type (TREE_TYPE (t));
639 else
640 flags = 0;
641 }
642
643 return flags;
644 }
645
646 /* Precompute all register parameters as described by ARGS, storing values
647 into fields within the ARGS array.
648
649 NUM_ACTUALS indicates the total number elements in the ARGS array.
650
651 Set REG_PARM_SEEN if we encounter a register parameter. */
652
653 static void
654 precompute_register_parameters (int num_actuals, struct arg_data *args,
655 int *reg_parm_seen)
656 {
657 int i;
658
659 *reg_parm_seen = 0;
660
661 for (i = 0; i < num_actuals; i++)
662 if (args[i].reg != 0 && ! args[i].pass_on_stack)
663 {
664 *reg_parm_seen = 1;
665
666 if (args[i].value == 0)
667 {
668 push_temp_slots ();
669 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
670 VOIDmode, 0);
671 preserve_temp_slots (args[i].value);
672 pop_temp_slots ();
673 }
674
675 /* If the value is a non-legitimate constant, force it into a
676 pseudo now. TLS symbols sometimes need a call to resolve. */
677 if (CONSTANT_P (args[i].value)
678 && !LEGITIMATE_CONSTANT_P (args[i].value))
679 args[i].value = force_reg (args[i].mode, args[i].value);
680
681 /* If we are to promote the function arg to a wider mode,
682 do it now. */
683
684 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
685 args[i].value
686 = convert_modes (args[i].mode,
687 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
688 args[i].value, args[i].unsignedp);
689
690 /* If we're going to have to load the value by parts, pull the
691 parts into pseudos. The part extraction process can involve
692 non-trivial computation. */
693 if (GET_CODE (args[i].reg) == PARALLEL)
694 {
695 tree type = TREE_TYPE (args[i].tree_value);
696 args[i].parallel_value
697 = emit_group_load_into_temps (args[i].reg, args[i].value,
698 type, int_size_in_bytes (type));
699 }
700
701 /* If the value is expensive, and we are inside an appropriately
702 short loop, put the value into a pseudo and then put the pseudo
703 into the hard reg.
704
705 For small register classes, also do this if this call uses
706 register parameters. This is to avoid reload conflicts while
707 loading the parameters registers. */
708
709 else if ((! (REG_P (args[i].value)
710 || (GET_CODE (args[i].value) == SUBREG
711 && REG_P (SUBREG_REG (args[i].value)))))
712 && args[i].mode != BLKmode
713 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
714 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
715 || optimize))
716 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
717 }
718 }
719
720 #ifdef REG_PARM_STACK_SPACE
721
722 /* The argument list is the property of the called routine and it
723 may clobber it. If the fixed area has been used for previous
724 parameters, we must save and restore it. */
725
726 static rtx
727 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
728 {
729 int low;
730 int high;
731
732 /* Compute the boundary of the area that needs to be saved, if any. */
733 high = reg_parm_stack_space;
734 #ifdef ARGS_GROW_DOWNWARD
735 high += 1;
736 #endif
737 if (high > highest_outgoing_arg_in_use)
738 high = highest_outgoing_arg_in_use;
739
740 for (low = 0; low < high; low++)
741 if (stack_usage_map[low] != 0)
742 {
743 int num_to_save;
744 enum machine_mode save_mode;
745 int delta;
746 rtx stack_area;
747 rtx save_area;
748
749 while (stack_usage_map[--high] == 0)
750 ;
751
752 *low_to_save = low;
753 *high_to_save = high;
754
755 num_to_save = high - low + 1;
756 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
757
758 /* If we don't have the required alignment, must do this
759 in BLKmode. */
760 if ((low & (MIN (GET_MODE_SIZE (save_mode),
761 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
762 save_mode = BLKmode;
763
764 #ifdef ARGS_GROW_DOWNWARD
765 delta = -high;
766 #else
767 delta = low;
768 #endif
769 stack_area = gen_rtx_MEM (save_mode,
770 memory_address (save_mode,
771 plus_constant (argblock,
772 delta)));
773
774 set_mem_align (stack_area, PARM_BOUNDARY);
775 if (save_mode == BLKmode)
776 {
777 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
778 emit_block_move (validize_mem (save_area), stack_area,
779 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
780 }
781 else
782 {
783 save_area = gen_reg_rtx (save_mode);
784 emit_move_insn (save_area, stack_area);
785 }
786
787 return save_area;
788 }
789
790 return NULL_RTX;
791 }
792
793 static void
794 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
795 {
796 enum machine_mode save_mode = GET_MODE (save_area);
797 int delta;
798 rtx stack_area;
799
800 #ifdef ARGS_GROW_DOWNWARD
801 delta = -high_to_save;
802 #else
803 delta = low_to_save;
804 #endif
805 stack_area = gen_rtx_MEM (save_mode,
806 memory_address (save_mode,
807 plus_constant (argblock, delta)));
808 set_mem_align (stack_area, PARM_BOUNDARY);
809
810 if (save_mode != BLKmode)
811 emit_move_insn (stack_area, save_area);
812 else
813 emit_block_move (stack_area, validize_mem (save_area),
814 GEN_INT (high_to_save - low_to_save + 1),
815 BLOCK_OP_CALL_PARM);
816 }
817 #endif /* REG_PARM_STACK_SPACE */
818
819 /* If any elements in ARGS refer to parameters that are to be passed in
820 registers, but not in memory, and whose alignment does not permit a
821 direct copy into registers. Copy the values into a group of pseudos
822 which we will later copy into the appropriate hard registers.
823
824 Pseudos for each unaligned argument will be stored into the array
825 args[argnum].aligned_regs. The caller is responsible for deallocating
826 the aligned_regs array if it is nonzero. */
827
828 static void
829 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
830 {
831 int i, j;
832
833 for (i = 0; i < num_actuals; i++)
834 if (args[i].reg != 0 && ! args[i].pass_on_stack
835 && args[i].mode == BLKmode
836 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
837 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
838 {
839 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
840 int endian_correction = 0;
841
842 if (args[i].partial)
843 {
844 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
845 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
846 }
847 else
848 {
849 args[i].n_aligned_regs
850 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
851 }
852
853 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
854
855 /* Structures smaller than a word are normally aligned to the
856 least significant byte. On a BYTES_BIG_ENDIAN machine,
857 this means we must skip the empty high order bytes when
858 calculating the bit offset. */
859 if (bytes < UNITS_PER_WORD
860 #ifdef BLOCK_REG_PADDING
861 && (BLOCK_REG_PADDING (args[i].mode,
862 TREE_TYPE (args[i].tree_value), 1)
863 == downward)
864 #else
865 && BYTES_BIG_ENDIAN
866 #endif
867 )
868 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
869
870 for (j = 0; j < args[i].n_aligned_regs; j++)
871 {
872 rtx reg = gen_reg_rtx (word_mode);
873 rtx word = operand_subword_force (args[i].value, j, BLKmode);
874 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
875
876 args[i].aligned_regs[j] = reg;
877 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
878 word_mode, word_mode);
879
880 /* There is no need to restrict this code to loading items
881 in TYPE_ALIGN sized hunks. The bitfield instructions can
882 load up entire word sized registers efficiently.
883
884 ??? This may not be needed anymore.
885 We use to emit a clobber here but that doesn't let later
886 passes optimize the instructions we emit. By storing 0 into
887 the register later passes know the first AND to zero out the
888 bitfield being set in the register is unnecessary. The store
889 of 0 will be deleted as will at least the first AND. */
890
891 emit_move_insn (reg, const0_rtx);
892
893 bytes -= bitsize / BITS_PER_UNIT;
894 store_bit_field (reg, bitsize, endian_correction, word_mode,
895 word);
896 }
897 }
898 }
899
900 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
901 ACTPARMS.
902
903 NUM_ACTUALS is the total number of parameters.
904
905 N_NAMED_ARGS is the total number of named arguments.
906
907 FNDECL is the tree code for the target of this call (if known)
908
909 ARGS_SO_FAR holds state needed by the target to know where to place
910 the next argument.
911
912 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
913 for arguments which are passed in registers.
914
915 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
916 and may be modified by this routine.
917
918 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
919 flags which may may be modified by this routine.
920
921 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
922 that requires allocation of stack space.
923
924 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
925 the thunked-to function. */
926
927 static void
928 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
929 struct arg_data *args,
930 struct args_size *args_size,
931 int n_named_args ATTRIBUTE_UNUSED,
932 tree actparms, tree fndecl,
933 CUMULATIVE_ARGS *args_so_far,
934 int reg_parm_stack_space,
935 rtx *old_stack_level, int *old_pending_adj,
936 int *must_preallocate, int *ecf_flags,
937 bool *may_tailcall, bool call_from_thunk_p)
938 {
939 /* 1 if scanning parms front to back, -1 if scanning back to front. */
940 int inc;
941
942 /* Count arg position in order args appear. */
943 int argpos;
944
945 int i;
946 tree p;
947
948 args_size->constant = 0;
949 args_size->var = 0;
950
951 /* In this loop, we consider args in the order they are written.
952 We fill up ARGS from the front or from the back if necessary
953 so that in any case the first arg to be pushed ends up at the front. */
954
955 if (PUSH_ARGS_REVERSED)
956 {
957 i = num_actuals - 1, inc = -1;
958 /* In this case, must reverse order of args
959 so that we compute and push the last arg first. */
960 }
961 else
962 {
963 i = 0, inc = 1;
964 }
965
966 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
967 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
968 {
969 tree type = TREE_TYPE (TREE_VALUE (p));
970 int unsignedp;
971 enum machine_mode mode;
972
973 args[i].tree_value = TREE_VALUE (p);
974
975 /* Replace erroneous argument with constant zero. */
976 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
977 args[i].tree_value = integer_zero_node, type = integer_type_node;
978
979 /* If TYPE is a transparent union, pass things the way we would
980 pass the first field of the union. We have already verified that
981 the modes are the same. */
982 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
983 type = TREE_TYPE (TYPE_FIELDS (type));
984
985 /* Decide where to pass this arg.
986
987 args[i].reg is nonzero if all or part is passed in registers.
988
989 args[i].partial is nonzero if part but not all is passed in registers,
990 and the exact value says how many bytes are passed in registers.
991
992 args[i].pass_on_stack is nonzero if the argument must at least be
993 computed on the stack. It may then be loaded back into registers
994 if args[i].reg is nonzero.
995
996 These decisions are driven by the FUNCTION_... macros and must agree
997 with those made by function.c. */
998
999 /* See if this argument should be passed by invisible reference. */
1000 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1001 type, argpos < n_named_args))
1002 {
1003 bool callee_copies;
1004 tree base;
1005
1006 callee_copies
1007 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1008 type, argpos < n_named_args);
1009
1010 /* If we're compiling a thunk, pass through invisible references
1011 instead of making a copy. */
1012 if (call_from_thunk_p
1013 || (callee_copies
1014 && !TREE_ADDRESSABLE (type)
1015 && (base = get_base_address (args[i].tree_value))
1016 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1017 {
1018 /* We can't use sibcalls if a callee-copied argument is
1019 stored in the current function's frame. */
1020 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1021 *may_tailcall = false;
1022
1023 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1024 type = TREE_TYPE (args[i].tree_value);
1025
1026 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1027 }
1028 else
1029 {
1030 /* We make a copy of the object and pass the address to the
1031 function being called. */
1032 rtx copy;
1033
1034 if (!COMPLETE_TYPE_P (type)
1035 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1036 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1037 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1038 STACK_CHECK_MAX_VAR_SIZE))))
1039 {
1040 /* This is a variable-sized object. Make space on the stack
1041 for it. */
1042 rtx size_rtx = expr_size (TREE_VALUE (p));
1043
1044 if (*old_stack_level == 0)
1045 {
1046 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1047 *old_pending_adj = pending_stack_adjust;
1048 pending_stack_adjust = 0;
1049 }
1050
1051 copy = gen_rtx_MEM (BLKmode,
1052 allocate_dynamic_stack_space
1053 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1054 set_mem_attributes (copy, type, 1);
1055 }
1056 else
1057 copy = assign_temp (type, 0, 1, 0);
1058
1059 store_expr (args[i].tree_value, copy, 0);
1060
1061 if (callee_copies)
1062 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1063 else
1064 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1065
1066 args[i].tree_value
1067 = build_fold_addr_expr (make_tree (type, copy));
1068 type = TREE_TYPE (args[i].tree_value);
1069 *may_tailcall = false;
1070 }
1071 }
1072
1073 mode = TYPE_MODE (type);
1074 unsignedp = TYPE_UNSIGNED (type);
1075
1076 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1077 mode = promote_mode (type, mode, &unsignedp, 1);
1078
1079 args[i].unsignedp = unsignedp;
1080 args[i].mode = mode;
1081
1082 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1083 argpos < n_named_args);
1084 #ifdef FUNCTION_INCOMING_ARG
1085 /* If this is a sibling call and the machine has register windows, the
1086 register window has to be unwinded before calling the routine, so
1087 arguments have to go into the incoming registers. */
1088 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1089 argpos < n_named_args);
1090 #else
1091 args[i].tail_call_reg = args[i].reg;
1092 #endif
1093
1094 if (args[i].reg)
1095 args[i].partial
1096 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1097 argpos < n_named_args);
1098
1099 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1100
1101 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1102 it means that we are to pass this arg in the register(s) designated
1103 by the PARALLEL, but also to pass it in the stack. */
1104 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1105 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1106 args[i].pass_on_stack = 1;
1107
1108 /* If this is an addressable type, we must preallocate the stack
1109 since we must evaluate the object into its final location.
1110
1111 If this is to be passed in both registers and the stack, it is simpler
1112 to preallocate. */
1113 if (TREE_ADDRESSABLE (type)
1114 || (args[i].pass_on_stack && args[i].reg != 0))
1115 *must_preallocate = 1;
1116
1117 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1118 we cannot consider this function call constant. */
1119 if (TREE_ADDRESSABLE (type))
1120 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1121
1122 /* Compute the stack-size of this argument. */
1123 if (args[i].reg == 0 || args[i].partial != 0
1124 || reg_parm_stack_space > 0
1125 || args[i].pass_on_stack)
1126 locate_and_pad_parm (mode, type,
1127 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1128 1,
1129 #else
1130 args[i].reg != 0,
1131 #endif
1132 args[i].pass_on_stack ? 0 : args[i].partial,
1133 fndecl, args_size, &args[i].locate);
1134 #ifdef BLOCK_REG_PADDING
1135 else
1136 /* The argument is passed entirely in registers. See at which
1137 end it should be padded. */
1138 args[i].locate.where_pad =
1139 BLOCK_REG_PADDING (mode, type,
1140 int_size_in_bytes (type) <= UNITS_PER_WORD);
1141 #endif
1142
1143 /* Update ARGS_SIZE, the total stack space for args so far. */
1144
1145 args_size->constant += args[i].locate.size.constant;
1146 if (args[i].locate.size.var)
1147 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1148
1149 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1150 have been used, etc. */
1151
1152 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1153 argpos < n_named_args);
1154 }
1155 }
1156
1157 /* Update ARGS_SIZE to contain the total size for the argument block.
1158 Return the original constant component of the argument block's size.
1159
1160 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1161 for arguments passed in registers. */
1162
1163 static int
1164 compute_argument_block_size (int reg_parm_stack_space,
1165 struct args_size *args_size,
1166 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1167 {
1168 int unadjusted_args_size = args_size->constant;
1169
1170 /* For accumulate outgoing args mode we don't need to align, since the frame
1171 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1172 backends from generating misaligned frame sizes. */
1173 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1174 preferred_stack_boundary = STACK_BOUNDARY;
1175
1176 /* Compute the actual size of the argument block required. The variable
1177 and constant sizes must be combined, the size may have to be rounded,
1178 and there may be a minimum required size. */
1179
1180 if (args_size->var)
1181 {
1182 args_size->var = ARGS_SIZE_TREE (*args_size);
1183 args_size->constant = 0;
1184
1185 preferred_stack_boundary /= BITS_PER_UNIT;
1186 if (preferred_stack_boundary > 1)
1187 {
1188 /* We don't handle this case yet. To handle it correctly we have
1189 to add the delta, round and subtract the delta.
1190 Currently no machine description requires this support. */
1191 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1192 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1193 }
1194
1195 if (reg_parm_stack_space > 0)
1196 {
1197 args_size->var
1198 = size_binop (MAX_EXPR, args_size->var,
1199 ssize_int (reg_parm_stack_space));
1200
1201 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1202 /* The area corresponding to register parameters is not to count in
1203 the size of the block we need. So make the adjustment. */
1204 args_size->var
1205 = size_binop (MINUS_EXPR, args_size->var,
1206 ssize_int (reg_parm_stack_space));
1207 #endif
1208 }
1209 }
1210 else
1211 {
1212 preferred_stack_boundary /= BITS_PER_UNIT;
1213 if (preferred_stack_boundary < 1)
1214 preferred_stack_boundary = 1;
1215 args_size->constant = (((args_size->constant
1216 + stack_pointer_delta
1217 + preferred_stack_boundary - 1)
1218 / preferred_stack_boundary
1219 * preferred_stack_boundary)
1220 - stack_pointer_delta);
1221
1222 args_size->constant = MAX (args_size->constant,
1223 reg_parm_stack_space);
1224
1225 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1226 args_size->constant -= reg_parm_stack_space;
1227 #endif
1228 }
1229 return unadjusted_args_size;
1230 }
1231
1232 /* Precompute parameters as needed for a function call.
1233
1234 FLAGS is mask of ECF_* constants.
1235
1236 NUM_ACTUALS is the number of arguments.
1237
1238 ARGS is an array containing information for each argument; this
1239 routine fills in the INITIAL_VALUE and VALUE fields for each
1240 precomputed argument. */
1241
1242 static void
1243 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1244 {
1245 int i;
1246
1247 /* If this is a libcall, then precompute all arguments so that we do not
1248 get extraneous instructions emitted as part of the libcall sequence. */
1249 if ((flags & ECF_LIBCALL_BLOCK) == 0)
1250 return;
1251
1252 for (i = 0; i < num_actuals; i++)
1253 {
1254 enum machine_mode mode;
1255
1256 /* If this is an addressable type, we cannot pre-evaluate it. */
1257 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1258
1259 args[i].initial_value = args[i].value
1260 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1261
1262 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1263 if (mode != args[i].mode)
1264 {
1265 args[i].value
1266 = convert_modes (args[i].mode, mode,
1267 args[i].value, args[i].unsignedp);
1268 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1269 /* CSE will replace this only if it contains args[i].value
1270 pseudo, so convert it down to the declared mode using
1271 a SUBREG. */
1272 if (REG_P (args[i].value)
1273 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1274 {
1275 args[i].initial_value
1276 = gen_lowpart_SUBREG (mode, args[i].value);
1277 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1278 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1279 args[i].unsignedp);
1280 }
1281 #endif
1282 }
1283 }
1284 }
1285
1286 /* Given the current state of MUST_PREALLOCATE and information about
1287 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1288 compute and return the final value for MUST_PREALLOCATE. */
1289
1290 static int
1291 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1292 {
1293 /* See if we have or want to preallocate stack space.
1294
1295 If we would have to push a partially-in-regs parm
1296 before other stack parms, preallocate stack space instead.
1297
1298 If the size of some parm is not a multiple of the required stack
1299 alignment, we must preallocate.
1300
1301 If the total size of arguments that would otherwise create a copy in
1302 a temporary (such as a CALL) is more than half the total argument list
1303 size, preallocation is faster.
1304
1305 Another reason to preallocate is if we have a machine (like the m88k)
1306 where stack alignment is required to be maintained between every
1307 pair of insns, not just when the call is made. However, we assume here
1308 that such machines either do not have push insns (and hence preallocation
1309 would occur anyway) or the problem is taken care of with
1310 PUSH_ROUNDING. */
1311
1312 if (! must_preallocate)
1313 {
1314 int partial_seen = 0;
1315 int copy_to_evaluate_size = 0;
1316 int i;
1317
1318 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1319 {
1320 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1321 partial_seen = 1;
1322 else if (partial_seen && args[i].reg == 0)
1323 must_preallocate = 1;
1324
1325 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1326 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1327 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1328 || TREE_CODE (args[i].tree_value) == COND_EXPR
1329 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1330 copy_to_evaluate_size
1331 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1332 }
1333
1334 if (copy_to_evaluate_size * 2 >= args_size->constant
1335 && args_size->constant > 0)
1336 must_preallocate = 1;
1337 }
1338 return must_preallocate;
1339 }
1340
1341 /* If we preallocated stack space, compute the address of each argument
1342 and store it into the ARGS array.
1343
1344 We need not ensure it is a valid memory address here; it will be
1345 validized when it is used.
1346
1347 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1348
1349 static void
1350 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1351 {
1352 if (argblock)
1353 {
1354 rtx arg_reg = argblock;
1355 int i, arg_offset = 0;
1356
1357 if (GET_CODE (argblock) == PLUS)
1358 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1359
1360 for (i = 0; i < num_actuals; i++)
1361 {
1362 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1363 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1364 rtx addr;
1365 unsigned int align, boundary;
1366
1367 /* Skip this parm if it will not be passed on the stack. */
1368 if (! args[i].pass_on_stack && args[i].reg != 0)
1369 continue;
1370
1371 if (GET_CODE (offset) == CONST_INT)
1372 addr = plus_constant (arg_reg, INTVAL (offset));
1373 else
1374 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1375
1376 addr = plus_constant (addr, arg_offset);
1377 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1378 set_mem_attributes (args[i].stack,
1379 TREE_TYPE (args[i].tree_value), 1);
1380 align = BITS_PER_UNIT;
1381 boundary = args[i].locate.boundary;
1382 if (args[i].locate.where_pad != downward)
1383 align = boundary;
1384 else if (GET_CODE (offset) == CONST_INT)
1385 {
1386 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1387 align = align & -align;
1388 }
1389 set_mem_align (args[i].stack, align);
1390
1391 if (GET_CODE (slot_offset) == CONST_INT)
1392 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1393 else
1394 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1395
1396 addr = plus_constant (addr, arg_offset);
1397 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1398 set_mem_attributes (args[i].stack_slot,
1399 TREE_TYPE (args[i].tree_value), 1);
1400 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1401
1402 /* Function incoming arguments may overlap with sibling call
1403 outgoing arguments and we cannot allow reordering of reads
1404 from function arguments with stores to outgoing arguments
1405 of sibling calls. */
1406 set_mem_alias_set (args[i].stack, 0);
1407 set_mem_alias_set (args[i].stack_slot, 0);
1408 }
1409 }
1410 }
1411
1412 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1413 in a call instruction.
1414
1415 FNDECL is the tree node for the target function. For an indirect call
1416 FNDECL will be NULL_TREE.
1417
1418 ADDR is the operand 0 of CALL_EXPR for this call. */
1419
1420 static rtx
1421 rtx_for_function_call (tree fndecl, tree addr)
1422 {
1423 rtx funexp;
1424
1425 /* Get the function to call, in the form of RTL. */
1426 if (fndecl)
1427 {
1428 /* If this is the first use of the function, see if we need to
1429 make an external definition for it. */
1430 if (! TREE_USED (fndecl))
1431 {
1432 assemble_external (fndecl);
1433 TREE_USED (fndecl) = 1;
1434 }
1435
1436 /* Get a SYMBOL_REF rtx for the function address. */
1437 funexp = XEXP (DECL_RTL (fndecl), 0);
1438 }
1439 else
1440 /* Generate an rtx (probably a pseudo-register) for the address. */
1441 {
1442 push_temp_slots ();
1443 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1444 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1445 }
1446 return funexp;
1447 }
1448
1449 /* Do the register loads required for any wholly-register parms or any
1450 parms which are passed both on the stack and in a register. Their
1451 expressions were already evaluated.
1452
1453 Mark all register-parms as living through the call, putting these USE
1454 insns in the CALL_INSN_FUNCTION_USAGE field.
1455
1456 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1457 checking, setting *SIBCALL_FAILURE if appropriate. */
1458
1459 static void
1460 load_register_parameters (struct arg_data *args, int num_actuals,
1461 rtx *call_fusage, int flags, int is_sibcall,
1462 int *sibcall_failure)
1463 {
1464 int i, j;
1465
1466 for (i = 0; i < num_actuals; i++)
1467 {
1468 rtx reg = ((flags & ECF_SIBCALL)
1469 ? args[i].tail_call_reg : args[i].reg);
1470 if (reg)
1471 {
1472 int partial = args[i].partial;
1473 int nregs;
1474 int size = 0;
1475 rtx before_arg = get_last_insn ();
1476 /* Set non-negative if we must move a word at a time, even if
1477 just one word (e.g, partial == 4 && mode == DFmode). Set
1478 to -1 if we just use a normal move insn. This value can be
1479 zero if the argument is a zero size structure. */
1480 nregs = -1;
1481 if (GET_CODE (reg) == PARALLEL)
1482 ;
1483 else if (partial)
1484 {
1485 gcc_assert (partial % UNITS_PER_WORD == 0);
1486 nregs = partial / UNITS_PER_WORD;
1487 }
1488 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1489 {
1490 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1491 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1492 }
1493 else
1494 size = GET_MODE_SIZE (args[i].mode);
1495
1496 /* Handle calls that pass values in multiple non-contiguous
1497 locations. The Irix 6 ABI has examples of this. */
1498
1499 if (GET_CODE (reg) == PARALLEL)
1500 emit_group_move (reg, args[i].parallel_value);
1501
1502 /* If simple case, just do move. If normal partial, store_one_arg
1503 has already loaded the register for us. In all other cases,
1504 load the register(s) from memory. */
1505
1506 else if (nregs == -1)
1507 {
1508 emit_move_insn (reg, args[i].value);
1509 #ifdef BLOCK_REG_PADDING
1510 /* Handle case where we have a value that needs shifting
1511 up to the msb. eg. a QImode value and we're padding
1512 upward on a BYTES_BIG_ENDIAN machine. */
1513 if (size < UNITS_PER_WORD
1514 && (args[i].locate.where_pad
1515 == (BYTES_BIG_ENDIAN ? upward : downward)))
1516 {
1517 rtx x;
1518 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1519
1520 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1521 report the whole reg as used. Strictly speaking, the
1522 call only uses SIZE bytes at the msb end, but it doesn't
1523 seem worth generating rtl to say that. */
1524 reg = gen_rtx_REG (word_mode, REGNO (reg));
1525 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1526 build_int_cst (NULL_TREE, shift),
1527 reg, 1);
1528 if (x != reg)
1529 emit_move_insn (reg, x);
1530 }
1531 #endif
1532 }
1533
1534 /* If we have pre-computed the values to put in the registers in
1535 the case of non-aligned structures, copy them in now. */
1536
1537 else if (args[i].n_aligned_regs != 0)
1538 for (j = 0; j < args[i].n_aligned_regs; j++)
1539 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1540 args[i].aligned_regs[j]);
1541
1542 else if (partial == 0 || args[i].pass_on_stack)
1543 {
1544 rtx mem = validize_mem (args[i].value);
1545
1546 /* Handle a BLKmode that needs shifting. */
1547 if (nregs == 1 && size < UNITS_PER_WORD
1548 #ifdef BLOCK_REG_PADDING
1549 && args[i].locate.where_pad == downward
1550 #else
1551 && BYTES_BIG_ENDIAN
1552 #endif
1553 )
1554 {
1555 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1556 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1557 rtx x = gen_reg_rtx (word_mode);
1558 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1559 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1560 : LSHIFT_EXPR;
1561
1562 emit_move_insn (x, tem);
1563 x = expand_shift (dir, word_mode, x,
1564 build_int_cst (NULL_TREE, shift),
1565 ri, 1);
1566 if (x != ri)
1567 emit_move_insn (ri, x);
1568 }
1569 else
1570 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1571 }
1572
1573 /* When a parameter is a block, and perhaps in other cases, it is
1574 possible that it did a load from an argument slot that was
1575 already clobbered. */
1576 if (is_sibcall
1577 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1578 *sibcall_failure = 1;
1579
1580 /* Handle calls that pass values in multiple non-contiguous
1581 locations. The Irix 6 ABI has examples of this. */
1582 if (GET_CODE (reg) == PARALLEL)
1583 use_group_regs (call_fusage, reg);
1584 else if (nregs == -1)
1585 use_reg (call_fusage, reg);
1586 else if (nregs > 0)
1587 use_regs (call_fusage, REGNO (reg), nregs);
1588 }
1589 }
1590 }
1591
1592 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1593 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1594 bytes, then we would need to push some additional bytes to pad the
1595 arguments. So, we compute an adjust to the stack pointer for an
1596 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1597 bytes. Then, when the arguments are pushed the stack will be perfectly
1598 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1599 be popped after the call. Returns the adjustment. */
1600
1601 static int
1602 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1603 struct args_size *args_size,
1604 unsigned int preferred_unit_stack_boundary)
1605 {
1606 /* The number of bytes to pop so that the stack will be
1607 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1608 HOST_WIDE_INT adjustment;
1609 /* The alignment of the stack after the arguments are pushed, if we
1610 just pushed the arguments without adjust the stack here. */
1611 unsigned HOST_WIDE_INT unadjusted_alignment;
1612
1613 unadjusted_alignment
1614 = ((stack_pointer_delta + unadjusted_args_size)
1615 % preferred_unit_stack_boundary);
1616
1617 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1618 as possible -- leaving just enough left to cancel out the
1619 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1620 PENDING_STACK_ADJUST is non-negative, and congruent to
1621 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1622
1623 /* Begin by trying to pop all the bytes. */
1624 unadjusted_alignment
1625 = (unadjusted_alignment
1626 - (pending_stack_adjust % preferred_unit_stack_boundary));
1627 adjustment = pending_stack_adjust;
1628 /* Push enough additional bytes that the stack will be aligned
1629 after the arguments are pushed. */
1630 if (preferred_unit_stack_boundary > 1)
1631 {
1632 if (unadjusted_alignment > 0)
1633 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1634 else
1635 adjustment += unadjusted_alignment;
1636 }
1637
1638 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1639 bytes after the call. The right number is the entire
1640 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1641 by the arguments in the first place. */
1642 args_size->constant
1643 = pending_stack_adjust - adjustment + unadjusted_args_size;
1644
1645 return adjustment;
1646 }
1647
1648 /* Scan X expression if it does not dereference any argument slots
1649 we already clobbered by tail call arguments (as noted in stored_args_map
1650 bitmap).
1651 Return nonzero if X expression dereferences such argument slots,
1652 zero otherwise. */
1653
1654 static int
1655 check_sibcall_argument_overlap_1 (rtx x)
1656 {
1657 RTX_CODE code;
1658 int i, j;
1659 unsigned int k;
1660 const char *fmt;
1661
1662 if (x == NULL_RTX)
1663 return 0;
1664
1665 code = GET_CODE (x);
1666
1667 if (code == MEM)
1668 {
1669 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1670 i = 0;
1671 else if (GET_CODE (XEXP (x, 0)) == PLUS
1672 && XEXP (XEXP (x, 0), 0) ==
1673 current_function_internal_arg_pointer
1674 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1675 i = INTVAL (XEXP (XEXP (x, 0), 1));
1676 else
1677 return 0;
1678
1679 #ifdef ARGS_GROW_DOWNWARD
1680 i = -i - GET_MODE_SIZE (GET_MODE (x));
1681 #endif
1682
1683 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1684 if (i + k < stored_args_map->n_bits
1685 && TEST_BIT (stored_args_map, i + k))
1686 return 1;
1687
1688 return 0;
1689 }
1690
1691 /* Scan all subexpressions. */
1692 fmt = GET_RTX_FORMAT (code);
1693 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1694 {
1695 if (*fmt == 'e')
1696 {
1697 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1698 return 1;
1699 }
1700 else if (*fmt == 'E')
1701 {
1702 for (j = 0; j < XVECLEN (x, i); j++)
1703 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1704 return 1;
1705 }
1706 }
1707 return 0;
1708 }
1709
1710 /* Scan sequence after INSN if it does not dereference any argument slots
1711 we already clobbered by tail call arguments (as noted in stored_args_map
1712 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1713 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1714 should be 0). Return nonzero if sequence after INSN dereferences such argument
1715 slots, zero otherwise. */
1716
1717 static int
1718 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1719 {
1720 int low, high;
1721
1722 if (insn == NULL_RTX)
1723 insn = get_insns ();
1724 else
1725 insn = NEXT_INSN (insn);
1726
1727 for (; insn; insn = NEXT_INSN (insn))
1728 if (INSN_P (insn)
1729 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1730 break;
1731
1732 if (mark_stored_args_map)
1733 {
1734 #ifdef ARGS_GROW_DOWNWARD
1735 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1736 #else
1737 low = arg->locate.slot_offset.constant;
1738 #endif
1739
1740 for (high = low + arg->locate.size.constant; low < high; low++)
1741 SET_BIT (stored_args_map, low);
1742 }
1743 return insn != NULL_RTX;
1744 }
1745
1746 /* Given that a function returns a value of mode MODE at the most
1747 significant end of hard register VALUE, shift VALUE left or right
1748 as specified by LEFT_P. Return true if some action was needed. */
1749
1750 bool
1751 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1752 {
1753 HOST_WIDE_INT shift;
1754
1755 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1756 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1757 if (shift == 0)
1758 return false;
1759
1760 /* Use ashr rather than lshr for right shifts. This is for the benefit
1761 of the MIPS port, which requires SImode values to be sign-extended
1762 when stored in 64-bit registers. */
1763 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1764 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1765 gcc_unreachable ();
1766 return true;
1767 }
1768
1769 /* Generate all the code for a function call
1770 and return an rtx for its value.
1771 Store the value in TARGET (specified as an rtx) if convenient.
1772 If the value is stored in TARGET then TARGET is returned.
1773 If IGNORE is nonzero, then we ignore the value of the function call. */
1774
1775 rtx
1776 expand_call (tree exp, rtx target, int ignore)
1777 {
1778 /* Nonzero if we are currently expanding a call. */
1779 static int currently_expanding_call = 0;
1780
1781 /* List of actual parameters. */
1782 tree actparms = TREE_OPERAND (exp, 1);
1783 /* RTX for the function to be called. */
1784 rtx funexp;
1785 /* Sequence of insns to perform a normal "call". */
1786 rtx normal_call_insns = NULL_RTX;
1787 /* Sequence of insns to perform a tail "call". */
1788 rtx tail_call_insns = NULL_RTX;
1789 /* Data type of the function. */
1790 tree funtype;
1791 tree type_arg_types;
1792 /* Declaration of the function being called,
1793 or 0 if the function is computed (not known by name). */
1794 tree fndecl = 0;
1795 /* The type of the function being called. */
1796 tree fntype;
1797 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1798 int pass;
1799
1800 /* Register in which non-BLKmode value will be returned,
1801 or 0 if no value or if value is BLKmode. */
1802 rtx valreg;
1803 /* Address where we should return a BLKmode value;
1804 0 if value not BLKmode. */
1805 rtx structure_value_addr = 0;
1806 /* Nonzero if that address is being passed by treating it as
1807 an extra, implicit first parameter. Otherwise,
1808 it is passed by being copied directly into struct_value_rtx. */
1809 int structure_value_addr_parm = 0;
1810 /* Size of aggregate value wanted, or zero if none wanted
1811 or if we are using the non-reentrant PCC calling convention
1812 or expecting the value in registers. */
1813 HOST_WIDE_INT struct_value_size = 0;
1814 /* Nonzero if called function returns an aggregate in memory PCC style,
1815 by returning the address of where to find it. */
1816 int pcc_struct_value = 0;
1817 rtx struct_value = 0;
1818
1819 /* Number of actual parameters in this call, including struct value addr. */
1820 int num_actuals;
1821 /* Number of named args. Args after this are anonymous ones
1822 and they must all go on the stack. */
1823 int n_named_args;
1824
1825 /* Vector of information about each argument.
1826 Arguments are numbered in the order they will be pushed,
1827 not the order they are written. */
1828 struct arg_data *args;
1829
1830 /* Total size in bytes of all the stack-parms scanned so far. */
1831 struct args_size args_size;
1832 struct args_size adjusted_args_size;
1833 /* Size of arguments before any adjustments (such as rounding). */
1834 int unadjusted_args_size;
1835 /* Data on reg parms scanned so far. */
1836 CUMULATIVE_ARGS args_so_far;
1837 /* Nonzero if a reg parm has been scanned. */
1838 int reg_parm_seen;
1839 /* Nonzero if this is an indirect function call. */
1840
1841 /* Nonzero if we must avoid push-insns in the args for this call.
1842 If stack space is allocated for register parameters, but not by the
1843 caller, then it is preallocated in the fixed part of the stack frame.
1844 So the entire argument block must then be preallocated (i.e., we
1845 ignore PUSH_ROUNDING in that case). */
1846
1847 int must_preallocate = !PUSH_ARGS;
1848
1849 /* Size of the stack reserved for parameter registers. */
1850 int reg_parm_stack_space = 0;
1851
1852 /* Address of space preallocated for stack parms
1853 (on machines that lack push insns), or 0 if space not preallocated. */
1854 rtx argblock = 0;
1855
1856 /* Mask of ECF_ flags. */
1857 int flags = 0;
1858 #ifdef REG_PARM_STACK_SPACE
1859 /* Define the boundary of the register parm stack space that needs to be
1860 saved, if any. */
1861 int low_to_save, high_to_save;
1862 rtx save_area = 0; /* Place that it is saved */
1863 #endif
1864
1865 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1866 char *initial_stack_usage_map = stack_usage_map;
1867
1868 int old_stack_allocated;
1869
1870 /* State variables to track stack modifications. */
1871 rtx old_stack_level = 0;
1872 int old_stack_arg_under_construction = 0;
1873 int old_pending_adj = 0;
1874 int old_inhibit_defer_pop = inhibit_defer_pop;
1875
1876 /* Some stack pointer alterations we make are performed via
1877 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1878 which we then also need to save/restore along the way. */
1879 int old_stack_pointer_delta = 0;
1880
1881 rtx call_fusage;
1882 tree p = TREE_OPERAND (exp, 0);
1883 tree addr = TREE_OPERAND (exp, 0);
1884 int i;
1885 /* The alignment of the stack, in bits. */
1886 unsigned HOST_WIDE_INT preferred_stack_boundary;
1887 /* The alignment of the stack, in bytes. */
1888 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
1889 /* The static chain value to use for this call. */
1890 rtx static_chain_value;
1891 /* See if this is "nothrow" function call. */
1892 if (TREE_NOTHROW (exp))
1893 flags |= ECF_NOTHROW;
1894
1895 /* See if we can find a DECL-node for the actual function, and get the
1896 function attributes (flags) from the function decl or type node. */
1897 fndecl = get_callee_fndecl (exp);
1898 if (fndecl)
1899 {
1900 fntype = TREE_TYPE (fndecl);
1901 flags |= flags_from_decl_or_type (fndecl);
1902 }
1903 else
1904 {
1905 fntype = TREE_TYPE (TREE_TYPE (p));
1906 flags |= flags_from_decl_or_type (fntype);
1907 }
1908
1909 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
1910
1911 /* Warn if this value is an aggregate type,
1912 regardless of which calling convention we are using for it. */
1913 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
1914 warning (OPT_Waggregate_return, "function call has aggregate value");
1915
1916 /* If the result of a pure or const function call is ignored (or void),
1917 and none of its arguments are volatile, we can avoid expanding the
1918 call and just evaluate the arguments for side-effects. */
1919 if ((flags & (ECF_CONST | ECF_PURE))
1920 && (ignore || target == const0_rtx
1921 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
1922 {
1923 bool volatilep = false;
1924 tree arg;
1925
1926 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1927 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
1928 {
1929 volatilep = true;
1930 break;
1931 }
1932
1933 if (! volatilep)
1934 {
1935 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1936 expand_expr (TREE_VALUE (arg), const0_rtx,
1937 VOIDmode, EXPAND_NORMAL);
1938 return const0_rtx;
1939 }
1940 }
1941
1942 #ifdef REG_PARM_STACK_SPACE
1943 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1944 #endif
1945
1946 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1947 if (reg_parm_stack_space > 0 && PUSH_ARGS)
1948 must_preallocate = 1;
1949 #endif
1950
1951 /* Set up a place to return a structure. */
1952
1953 /* Cater to broken compilers. */
1954 if (aggregate_value_p (exp, fndecl))
1955 {
1956 /* This call returns a big structure. */
1957 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1958
1959 #ifdef PCC_STATIC_STRUCT_RETURN
1960 {
1961 pcc_struct_value = 1;
1962 }
1963 #else /* not PCC_STATIC_STRUCT_RETURN */
1964 {
1965 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
1966
1967 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
1968 {
1969 /* The structure value address arg is already in actparms.
1970 Pull it out. It might be nice to just leave it there, but
1971 we need to set structure_value_addr. */
1972 tree return_arg = TREE_VALUE (actparms);
1973 actparms = TREE_CHAIN (actparms);
1974 structure_value_addr = expand_expr (return_arg, NULL_RTX,
1975 VOIDmode, EXPAND_NORMAL);
1976 }
1977 else if (target && MEM_P (target))
1978 structure_value_addr = XEXP (target, 0);
1979 else
1980 {
1981 /* For variable-sized objects, we must be called with a target
1982 specified. If we were to allocate space on the stack here,
1983 we would have no way of knowing when to free it. */
1984 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
1985
1986 mark_temp_addr_taken (d);
1987 structure_value_addr = XEXP (d, 0);
1988 target = 0;
1989 }
1990 }
1991 #endif /* not PCC_STATIC_STRUCT_RETURN */
1992 }
1993
1994 /* Figure out the amount to which the stack should be aligned. */
1995 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
1996 if (fndecl)
1997 {
1998 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
1999 if (i && i->preferred_incoming_stack_boundary)
2000 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2001 }
2002
2003 /* Operand 0 is a pointer-to-function; get the type of the function. */
2004 funtype = TREE_TYPE (addr);
2005 gcc_assert (POINTER_TYPE_P (funtype));
2006 funtype = TREE_TYPE (funtype);
2007
2008 /* Munge the tree to split complex arguments into their imaginary
2009 and real parts. */
2010 if (targetm.calls.split_complex_arg)
2011 {
2012 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2013 actparms = split_complex_values (actparms);
2014 }
2015 else
2016 type_arg_types = TYPE_ARG_TYPES (funtype);
2017
2018 if (flags & ECF_MAY_BE_ALLOCA)
2019 current_function_calls_alloca = 1;
2020
2021 /* If struct_value_rtx is 0, it means pass the address
2022 as if it were an extra parameter. */
2023 if (structure_value_addr && struct_value == 0)
2024 {
2025 /* If structure_value_addr is a REG other than
2026 virtual_outgoing_args_rtx, we can use always use it. If it
2027 is not a REG, we must always copy it into a register.
2028 If it is virtual_outgoing_args_rtx, we must copy it to another
2029 register in some cases. */
2030 rtx temp = (!REG_P (structure_value_addr)
2031 || (ACCUMULATE_OUTGOING_ARGS
2032 && stack_arg_under_construction
2033 && structure_value_addr == virtual_outgoing_args_rtx)
2034 ? copy_addr_to_reg (convert_memory_address
2035 (Pmode, structure_value_addr))
2036 : structure_value_addr);
2037
2038 actparms
2039 = tree_cons (error_mark_node,
2040 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2041 temp),
2042 actparms);
2043 structure_value_addr_parm = 1;
2044 }
2045
2046 /* Count the arguments and set NUM_ACTUALS. */
2047 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2048 num_actuals++;
2049
2050 /* Compute number of named args.
2051 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2052
2053 if (type_arg_types != 0)
2054 n_named_args
2055 = (list_length (type_arg_types)
2056 /* Count the struct value address, if it is passed as a parm. */
2057 + structure_value_addr_parm);
2058 else
2059 /* If we know nothing, treat all args as named. */
2060 n_named_args = num_actuals;
2061
2062 /* Start updating where the next arg would go.
2063
2064 On some machines (such as the PA) indirect calls have a different
2065 calling convention than normal calls. The fourth argument in
2066 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2067 or not. */
2068 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2069
2070 /* Now possibly adjust the number of named args.
2071 Normally, don't include the last named arg if anonymous args follow.
2072 We do include the last named arg if
2073 targetm.calls.strict_argument_naming() returns nonzero.
2074 (If no anonymous args follow, the result of list_length is actually
2075 one too large. This is harmless.)
2076
2077 If targetm.calls.pretend_outgoing_varargs_named() returns
2078 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2079 this machine will be able to place unnamed args that were passed
2080 in registers into the stack. So treat all args as named. This
2081 allows the insns emitting for a specific argument list to be
2082 independent of the function declaration.
2083
2084 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2085 we do not have any reliable way to pass unnamed args in
2086 registers, so we must force them into memory. */
2087
2088 if (type_arg_types != 0
2089 && targetm.calls.strict_argument_naming (&args_so_far))
2090 ;
2091 else if (type_arg_types != 0
2092 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2093 /* Don't include the last named arg. */
2094 --n_named_args;
2095 else
2096 /* Treat all args as named. */
2097 n_named_args = num_actuals;
2098
2099 /* Make a vector to hold all the information about each arg. */
2100 args = alloca (num_actuals * sizeof (struct arg_data));
2101 memset (args, 0, num_actuals * sizeof (struct arg_data));
2102
2103 /* Build up entries in the ARGS array, compute the size of the
2104 arguments into ARGS_SIZE, etc. */
2105 initialize_argument_information (num_actuals, args, &args_size,
2106 n_named_args, actparms, fndecl,
2107 &args_so_far, reg_parm_stack_space,
2108 &old_stack_level, &old_pending_adj,
2109 &must_preallocate, &flags,
2110 &try_tail_call, CALL_FROM_THUNK_P (exp));
2111
2112 if (args_size.var)
2113 {
2114 /* If this function requires a variable-sized argument list, don't
2115 try to make a cse'able block for this call. We may be able to
2116 do this eventually, but it is too complicated to keep track of
2117 what insns go in the cse'able block and which don't. */
2118
2119 flags &= ~ECF_LIBCALL_BLOCK;
2120 must_preallocate = 1;
2121 }
2122
2123 /* Now make final decision about preallocating stack space. */
2124 must_preallocate = finalize_must_preallocate (must_preallocate,
2125 num_actuals, args,
2126 &args_size);
2127
2128 /* If the structure value address will reference the stack pointer, we
2129 must stabilize it. We don't need to do this if we know that we are
2130 not going to adjust the stack pointer in processing this call. */
2131
2132 if (structure_value_addr
2133 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2134 || reg_mentioned_p (virtual_outgoing_args_rtx,
2135 structure_value_addr))
2136 && (args_size.var
2137 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2138 structure_value_addr = copy_to_reg (structure_value_addr);
2139
2140 /* Tail calls can make things harder to debug, and we've traditionally
2141 pushed these optimizations into -O2. Don't try if we're already
2142 expanding a call, as that means we're an argument. Don't try if
2143 there's cleanups, as we know there's code to follow the call. */
2144
2145 if (currently_expanding_call++ != 0
2146 || !flag_optimize_sibling_calls
2147 || args_size.var
2148 || lookup_stmt_eh_region (exp) >= 0)
2149 try_tail_call = 0;
2150
2151 /* Rest of purposes for tail call optimizations to fail. */
2152 if (
2153 #ifdef HAVE_sibcall_epilogue
2154 !HAVE_sibcall_epilogue
2155 #else
2156 1
2157 #endif
2158 || !try_tail_call
2159 /* Doing sibling call optimization needs some work, since
2160 structure_value_addr can be allocated on the stack.
2161 It does not seem worth the effort since few optimizable
2162 sibling calls will return a structure. */
2163 || structure_value_addr != NULL_RTX
2164 /* Check whether the target is able to optimize the call
2165 into a sibcall. */
2166 || !targetm.function_ok_for_sibcall (fndecl, exp)
2167 /* Functions that do not return exactly once may not be sibcall
2168 optimized. */
2169 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2170 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2171 /* If the called function is nested in the current one, it might access
2172 some of the caller's arguments, but could clobber them beforehand if
2173 the argument areas are shared. */
2174 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2175 /* If this function requires more stack slots than the current
2176 function, we cannot change it into a sibling call.
2177 current_function_pretend_args_size is not part of the
2178 stack allocated by our caller. */
2179 || args_size.constant > (current_function_args_size
2180 - current_function_pretend_args_size)
2181 /* If the callee pops its own arguments, then it must pop exactly
2182 the same number of arguments as the current function. */
2183 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2184 != RETURN_POPS_ARGS (current_function_decl,
2185 TREE_TYPE (current_function_decl),
2186 current_function_args_size))
2187 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2188 try_tail_call = 0;
2189
2190 /* Ensure current function's preferred stack boundary is at least
2191 what we need. We don't have to increase alignment for recursive
2192 functions. */
2193 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2194 && fndecl != current_function_decl)
2195 cfun->preferred_stack_boundary = preferred_stack_boundary;
2196 if (fndecl == current_function_decl)
2197 cfun->recursive_call_emit = true;
2198
2199 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2200
2201 /* We want to make two insn chains; one for a sibling call, the other
2202 for a normal call. We will select one of the two chains after
2203 initial RTL generation is complete. */
2204 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2205 {
2206 int sibcall_failure = 0;
2207 /* We want to emit any pending stack adjustments before the tail
2208 recursion "call". That way we know any adjustment after the tail
2209 recursion call can be ignored if we indeed use the tail
2210 call expansion. */
2211 int save_pending_stack_adjust = 0;
2212 int save_stack_pointer_delta = 0;
2213 rtx insns;
2214 rtx before_call, next_arg_reg;
2215
2216 if (pass == 0)
2217 {
2218 /* State variables we need to save and restore between
2219 iterations. */
2220 save_pending_stack_adjust = pending_stack_adjust;
2221 save_stack_pointer_delta = stack_pointer_delta;
2222 }
2223 if (pass)
2224 flags &= ~ECF_SIBCALL;
2225 else
2226 flags |= ECF_SIBCALL;
2227
2228 /* Other state variables that we must reinitialize each time
2229 through the loop (that are not initialized by the loop itself). */
2230 argblock = 0;
2231 call_fusage = 0;
2232
2233 /* Start a new sequence for the normal call case.
2234
2235 From this point on, if the sibling call fails, we want to set
2236 sibcall_failure instead of continuing the loop. */
2237 start_sequence ();
2238
2239 /* Don't let pending stack adjusts add up to too much.
2240 Also, do all pending adjustments now if there is any chance
2241 this might be a call to alloca or if we are expanding a sibling
2242 call sequence or if we are calling a function that is to return
2243 with stack pointer depressed.
2244 Also do the adjustments before a throwing call, otherwise
2245 exception handling can fail; PR 19225. */
2246 if (pending_stack_adjust >= 32
2247 || (pending_stack_adjust > 0
2248 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2249 || (pending_stack_adjust > 0
2250 && flag_exceptions && !(flags & ECF_NOTHROW))
2251 || pass == 0)
2252 do_pending_stack_adjust ();
2253
2254 /* When calling a const function, we must pop the stack args right away,
2255 so that the pop is deleted or moved with the call. */
2256 if (pass && (flags & ECF_LIBCALL_BLOCK))
2257 NO_DEFER_POP;
2258
2259 /* Precompute any arguments as needed. */
2260 if (pass)
2261 precompute_arguments (flags, num_actuals, args);
2262
2263 /* Now we are about to start emitting insns that can be deleted
2264 if a libcall is deleted. */
2265 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2266 start_sequence ();
2267
2268 adjusted_args_size = args_size;
2269 /* Compute the actual size of the argument block required. The variable
2270 and constant sizes must be combined, the size may have to be rounded,
2271 and there may be a minimum required size. When generating a sibcall
2272 pattern, do not round up, since we'll be re-using whatever space our
2273 caller provided. */
2274 unadjusted_args_size
2275 = compute_argument_block_size (reg_parm_stack_space,
2276 &adjusted_args_size,
2277 (pass == 0 ? 0
2278 : preferred_stack_boundary));
2279
2280 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2281
2282 /* The argument block when performing a sibling call is the
2283 incoming argument block. */
2284 if (pass == 0)
2285 {
2286 argblock = virtual_incoming_args_rtx;
2287 argblock
2288 #ifdef STACK_GROWS_DOWNWARD
2289 = plus_constant (argblock, current_function_pretend_args_size);
2290 #else
2291 = plus_constant (argblock, -current_function_pretend_args_size);
2292 #endif
2293 stored_args_map = sbitmap_alloc (args_size.constant);
2294 sbitmap_zero (stored_args_map);
2295 }
2296
2297 /* If we have no actual push instructions, or shouldn't use them,
2298 make space for all args right now. */
2299 else if (adjusted_args_size.var != 0)
2300 {
2301 if (old_stack_level == 0)
2302 {
2303 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2304 old_stack_pointer_delta = stack_pointer_delta;
2305 old_pending_adj = pending_stack_adjust;
2306 pending_stack_adjust = 0;
2307 /* stack_arg_under_construction says whether a stack arg is
2308 being constructed at the old stack level. Pushing the stack
2309 gets a clean outgoing argument block. */
2310 old_stack_arg_under_construction = stack_arg_under_construction;
2311 stack_arg_under_construction = 0;
2312 }
2313 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2314 }
2315 else
2316 {
2317 /* Note that we must go through the motions of allocating an argument
2318 block even if the size is zero because we may be storing args
2319 in the area reserved for register arguments, which may be part of
2320 the stack frame. */
2321
2322 int needed = adjusted_args_size.constant;
2323
2324 /* Store the maximum argument space used. It will be pushed by
2325 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2326 checking). */
2327
2328 if (needed > current_function_outgoing_args_size)
2329 current_function_outgoing_args_size = needed;
2330
2331 if (must_preallocate)
2332 {
2333 if (ACCUMULATE_OUTGOING_ARGS)
2334 {
2335 /* Since the stack pointer will never be pushed, it is
2336 possible for the evaluation of a parm to clobber
2337 something we have already written to the stack.
2338 Since most function calls on RISC machines do not use
2339 the stack, this is uncommon, but must work correctly.
2340
2341 Therefore, we save any area of the stack that was already
2342 written and that we are using. Here we set up to do this
2343 by making a new stack usage map from the old one. The
2344 actual save will be done by store_one_arg.
2345
2346 Another approach might be to try to reorder the argument
2347 evaluations to avoid this conflicting stack usage. */
2348
2349 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2350 /* Since we will be writing into the entire argument area,
2351 the map must be allocated for its entire size, not just
2352 the part that is the responsibility of the caller. */
2353 needed += reg_parm_stack_space;
2354 #endif
2355
2356 #ifdef ARGS_GROW_DOWNWARD
2357 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2358 needed + 1);
2359 #else
2360 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2361 needed);
2362 #endif
2363 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2364
2365 if (initial_highest_arg_in_use)
2366 memcpy (stack_usage_map, initial_stack_usage_map,
2367 initial_highest_arg_in_use);
2368
2369 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2370 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2371 (highest_outgoing_arg_in_use
2372 - initial_highest_arg_in_use));
2373 needed = 0;
2374
2375 /* The address of the outgoing argument list must not be
2376 copied to a register here, because argblock would be left
2377 pointing to the wrong place after the call to
2378 allocate_dynamic_stack_space below. */
2379
2380 argblock = virtual_outgoing_args_rtx;
2381 }
2382 else
2383 {
2384 if (inhibit_defer_pop == 0)
2385 {
2386 /* Try to reuse some or all of the pending_stack_adjust
2387 to get this space. */
2388 needed
2389 = (combine_pending_stack_adjustment_and_call
2390 (unadjusted_args_size,
2391 &adjusted_args_size,
2392 preferred_unit_stack_boundary));
2393
2394 /* combine_pending_stack_adjustment_and_call computes
2395 an adjustment before the arguments are allocated.
2396 Account for them and see whether or not the stack
2397 needs to go up or down. */
2398 needed = unadjusted_args_size - needed;
2399
2400 if (needed < 0)
2401 {
2402 /* We're releasing stack space. */
2403 /* ??? We can avoid any adjustment at all if we're
2404 already aligned. FIXME. */
2405 pending_stack_adjust = -needed;
2406 do_pending_stack_adjust ();
2407 needed = 0;
2408 }
2409 else
2410 /* We need to allocate space. We'll do that in
2411 push_block below. */
2412 pending_stack_adjust = 0;
2413 }
2414
2415 /* Special case this because overhead of `push_block' in
2416 this case is non-trivial. */
2417 if (needed == 0)
2418 argblock = virtual_outgoing_args_rtx;
2419 else
2420 {
2421 argblock = push_block (GEN_INT (needed), 0, 0);
2422 #ifdef ARGS_GROW_DOWNWARD
2423 argblock = plus_constant (argblock, needed);
2424 #endif
2425 }
2426
2427 /* We only really need to call `copy_to_reg' in the case
2428 where push insns are going to be used to pass ARGBLOCK
2429 to a function call in ARGS. In that case, the stack
2430 pointer changes value from the allocation point to the
2431 call point, and hence the value of
2432 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2433 as well always do it. */
2434 argblock = copy_to_reg (argblock);
2435 }
2436 }
2437 }
2438
2439 if (ACCUMULATE_OUTGOING_ARGS)
2440 {
2441 /* The save/restore code in store_one_arg handles all
2442 cases except one: a constructor call (including a C
2443 function returning a BLKmode struct) to initialize
2444 an argument. */
2445 if (stack_arg_under_construction)
2446 {
2447 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2448 rtx push_size = GEN_INT (reg_parm_stack_space
2449 + adjusted_args_size.constant);
2450 #else
2451 rtx push_size = GEN_INT (adjusted_args_size.constant);
2452 #endif
2453 if (old_stack_level == 0)
2454 {
2455 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2456 NULL_RTX);
2457 old_stack_pointer_delta = stack_pointer_delta;
2458 old_pending_adj = pending_stack_adjust;
2459 pending_stack_adjust = 0;
2460 /* stack_arg_under_construction says whether a stack
2461 arg is being constructed at the old stack level.
2462 Pushing the stack gets a clean outgoing argument
2463 block. */
2464 old_stack_arg_under_construction
2465 = stack_arg_under_construction;
2466 stack_arg_under_construction = 0;
2467 /* Make a new map for the new argument list. */
2468 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2469 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2470 highest_outgoing_arg_in_use = 0;
2471 }
2472 allocate_dynamic_stack_space (push_size, NULL_RTX,
2473 BITS_PER_UNIT);
2474 }
2475
2476 /* If argument evaluation might modify the stack pointer,
2477 copy the address of the argument list to a register. */
2478 for (i = 0; i < num_actuals; i++)
2479 if (args[i].pass_on_stack)
2480 {
2481 argblock = copy_addr_to_reg (argblock);
2482 break;
2483 }
2484 }
2485
2486 compute_argument_addresses (args, argblock, num_actuals);
2487
2488 /* If we push args individually in reverse order, perform stack alignment
2489 before the first push (the last arg). */
2490 if (PUSH_ARGS_REVERSED && argblock == 0
2491 && adjusted_args_size.constant != unadjusted_args_size)
2492 {
2493 /* When the stack adjustment is pending, we get better code
2494 by combining the adjustments. */
2495 if (pending_stack_adjust
2496 && ! (flags & ECF_LIBCALL_BLOCK)
2497 && ! inhibit_defer_pop)
2498 {
2499 pending_stack_adjust
2500 = (combine_pending_stack_adjustment_and_call
2501 (unadjusted_args_size,
2502 &adjusted_args_size,
2503 preferred_unit_stack_boundary));
2504 do_pending_stack_adjust ();
2505 }
2506 else if (argblock == 0)
2507 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2508 - unadjusted_args_size));
2509 }
2510 /* Now that the stack is properly aligned, pops can't safely
2511 be deferred during the evaluation of the arguments. */
2512 NO_DEFER_POP;
2513
2514 funexp = rtx_for_function_call (fndecl, addr);
2515
2516 /* Figure out the register where the value, if any, will come back. */
2517 valreg = 0;
2518 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2519 && ! structure_value_addr)
2520 {
2521 if (pcc_struct_value)
2522 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2523 fndecl, (pass == 0));
2524 else
2525 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2526 }
2527
2528 /* Precompute all register parameters. It isn't safe to compute anything
2529 once we have started filling any specific hard regs. */
2530 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2531
2532 if (TREE_OPERAND (exp, 2))
2533 static_chain_value = expand_expr (TREE_OPERAND (exp, 2),
2534 NULL_RTX, VOIDmode, 0);
2535 else
2536 static_chain_value = 0;
2537
2538 #ifdef REG_PARM_STACK_SPACE
2539 /* Save the fixed argument area if it's part of the caller's frame and
2540 is clobbered by argument setup for this call. */
2541 if (ACCUMULATE_OUTGOING_ARGS && pass)
2542 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2543 &low_to_save, &high_to_save);
2544 #endif
2545
2546 /* Now store (and compute if necessary) all non-register parms.
2547 These come before register parms, since they can require block-moves,
2548 which could clobber the registers used for register parms.
2549 Parms which have partial registers are not stored here,
2550 but we do preallocate space here if they want that. */
2551
2552 for (i = 0; i < num_actuals; i++)
2553 if (args[i].reg == 0 || args[i].pass_on_stack)
2554 {
2555 rtx before_arg = get_last_insn ();
2556
2557 if (store_one_arg (&args[i], argblock, flags,
2558 adjusted_args_size.var != 0,
2559 reg_parm_stack_space)
2560 || (pass == 0
2561 && check_sibcall_argument_overlap (before_arg,
2562 &args[i], 1)))
2563 sibcall_failure = 1;
2564
2565 if (flags & ECF_CONST
2566 && args[i].stack
2567 && args[i].value == args[i].stack)
2568 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2569 gen_rtx_USE (VOIDmode,
2570 args[i].value),
2571 call_fusage);
2572 }
2573
2574 /* If we have a parm that is passed in registers but not in memory
2575 and whose alignment does not permit a direct copy into registers,
2576 make a group of pseudos that correspond to each register that we
2577 will later fill. */
2578 if (STRICT_ALIGNMENT)
2579 store_unaligned_arguments_into_pseudos (args, num_actuals);
2580
2581 /* Now store any partially-in-registers parm.
2582 This is the last place a block-move can happen. */
2583 if (reg_parm_seen)
2584 for (i = 0; i < num_actuals; i++)
2585 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2586 {
2587 rtx before_arg = get_last_insn ();
2588
2589 if (store_one_arg (&args[i], argblock, flags,
2590 adjusted_args_size.var != 0,
2591 reg_parm_stack_space)
2592 || (pass == 0
2593 && check_sibcall_argument_overlap (before_arg,
2594 &args[i], 1)))
2595 sibcall_failure = 1;
2596 }
2597
2598 /* If we pushed args in forward order, perform stack alignment
2599 after pushing the last arg. */
2600 if (!PUSH_ARGS_REVERSED && argblock == 0)
2601 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2602 - unadjusted_args_size));
2603
2604 /* If register arguments require space on the stack and stack space
2605 was not preallocated, allocate stack space here for arguments
2606 passed in registers. */
2607 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2608 if (!ACCUMULATE_OUTGOING_ARGS
2609 && must_preallocate == 0 && reg_parm_stack_space > 0)
2610 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2611 #endif
2612
2613 /* Pass the function the address in which to return a
2614 structure value. */
2615 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2616 {
2617 structure_value_addr
2618 = convert_memory_address (Pmode, structure_value_addr);
2619 emit_move_insn (struct_value,
2620 force_reg (Pmode,
2621 force_operand (structure_value_addr,
2622 NULL_RTX)));
2623
2624 if (REG_P (struct_value))
2625 use_reg (&call_fusage, struct_value);
2626 }
2627
2628 funexp = prepare_call_address (funexp, static_chain_value,
2629 &call_fusage, reg_parm_seen, pass == 0);
2630
2631 load_register_parameters (args, num_actuals, &call_fusage, flags,
2632 pass == 0, &sibcall_failure);
2633
2634 /* Save a pointer to the last insn before the call, so that we can
2635 later safely search backwards to find the CALL_INSN. */
2636 before_call = get_last_insn ();
2637
2638 /* Set up next argument register. For sibling calls on machines
2639 with register windows this should be the incoming register. */
2640 #ifdef FUNCTION_INCOMING_ARG
2641 if (pass == 0)
2642 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2643 void_type_node, 1);
2644 else
2645 #endif
2646 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2647 void_type_node, 1);
2648
2649 /* All arguments and registers used for the call must be set up by
2650 now! */
2651
2652 /* Stack must be properly aligned now. */
2653 gcc_assert (!pass
2654 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2655
2656 /* Generate the actual call instruction. */
2657 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2658 adjusted_args_size.constant, struct_value_size,
2659 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2660 flags, & args_so_far);
2661
2662 /* If a non-BLKmode value is returned at the most significant end
2663 of a register, shift the register right by the appropriate amount
2664 and update VALREG accordingly. BLKmode values are handled by the
2665 group load/store machinery below. */
2666 if (!structure_value_addr
2667 && !pcc_struct_value
2668 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2669 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2670 {
2671 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2672 sibcall_failure = 1;
2673 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2674 }
2675
2676 /* If call is cse'able, make appropriate pair of reg-notes around it.
2677 Test valreg so we don't crash; may safely ignore `const'
2678 if return type is void. Disable for PARALLEL return values, because
2679 we have no way to move such values into a pseudo register. */
2680 if (pass && (flags & ECF_LIBCALL_BLOCK))
2681 {
2682 rtx insns;
2683 rtx insn;
2684 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2685
2686 insns = get_insns ();
2687
2688 /* Expansion of block moves possibly introduced a loop that may
2689 not appear inside libcall block. */
2690 for (insn = insns; insn; insn = NEXT_INSN (insn))
2691 if (JUMP_P (insn))
2692 failed = true;
2693
2694 if (failed)
2695 {
2696 end_sequence ();
2697 emit_insn (insns);
2698 }
2699 else
2700 {
2701 rtx note = 0;
2702 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2703
2704 /* Mark the return value as a pointer if needed. */
2705 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2706 mark_reg_pointer (temp,
2707 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2708
2709 end_sequence ();
2710 if (flag_unsafe_math_optimizations
2711 && fndecl
2712 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2713 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2714 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2715 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2716 note = gen_rtx_fmt_e (SQRT,
2717 GET_MODE (temp),
2718 args[0].initial_value);
2719 else
2720 {
2721 /* Construct an "equal form" for the value which
2722 mentions all the arguments in order as well as
2723 the function name. */
2724 for (i = 0; i < num_actuals; i++)
2725 note = gen_rtx_EXPR_LIST (VOIDmode,
2726 args[i].initial_value, note);
2727 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2728
2729 if (flags & ECF_PURE)
2730 note = gen_rtx_EXPR_LIST (VOIDmode,
2731 gen_rtx_USE (VOIDmode,
2732 gen_rtx_MEM (BLKmode,
2733 gen_rtx_SCRATCH (VOIDmode))),
2734 note);
2735 }
2736 emit_libcall_block (insns, temp, valreg, note);
2737
2738 valreg = temp;
2739 }
2740 }
2741 else if (pass && (flags & ECF_MALLOC))
2742 {
2743 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2744 rtx last, insns;
2745
2746 /* The return value from a malloc-like function is a pointer. */
2747 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2748 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2749
2750 emit_move_insn (temp, valreg);
2751
2752 /* The return value from a malloc-like function can not alias
2753 anything else. */
2754 last = get_last_insn ();
2755 REG_NOTES (last) =
2756 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2757
2758 /* Write out the sequence. */
2759 insns = get_insns ();
2760 end_sequence ();
2761 emit_insn (insns);
2762 valreg = temp;
2763 }
2764
2765 /* For calls to `setjmp', etc., inform flow.c it should complain
2766 if nonvolatile values are live. For functions that cannot return,
2767 inform flow that control does not fall through. */
2768
2769 if ((flags & ECF_NORETURN) || pass == 0)
2770 {
2771 /* The barrier must be emitted
2772 immediately after the CALL_INSN. Some ports emit more
2773 than just a CALL_INSN above, so we must search for it here. */
2774
2775 rtx last = get_last_insn ();
2776 while (!CALL_P (last))
2777 {
2778 last = PREV_INSN (last);
2779 /* There was no CALL_INSN? */
2780 gcc_assert (last != before_call);
2781 }
2782
2783 emit_barrier_after (last);
2784
2785 /* Stack adjustments after a noreturn call are dead code.
2786 However when NO_DEFER_POP is in effect, we must preserve
2787 stack_pointer_delta. */
2788 if (inhibit_defer_pop == 0)
2789 {
2790 stack_pointer_delta = old_stack_allocated;
2791 pending_stack_adjust = 0;
2792 }
2793 }
2794
2795 /* If value type not void, return an rtx for the value. */
2796
2797 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2798 || ignore)
2799 target = const0_rtx;
2800 else if (structure_value_addr)
2801 {
2802 if (target == 0 || !MEM_P (target))
2803 {
2804 target
2805 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2806 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2807 structure_value_addr));
2808 set_mem_attributes (target, exp, 1);
2809 }
2810 }
2811 else if (pcc_struct_value)
2812 {
2813 /* This is the special C++ case where we need to
2814 know what the true target was. We take care to
2815 never use this value more than once in one expression. */
2816 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2817 copy_to_reg (valreg));
2818 set_mem_attributes (target, exp, 1);
2819 }
2820 /* Handle calls that return values in multiple non-contiguous locations.
2821 The Irix 6 ABI has examples of this. */
2822 else if (GET_CODE (valreg) == PARALLEL)
2823 {
2824 if (target == 0)
2825 {
2826 /* This will only be assigned once, so it can be readonly. */
2827 tree nt = build_qualified_type (TREE_TYPE (exp),
2828 (TYPE_QUALS (TREE_TYPE (exp))
2829 | TYPE_QUAL_CONST));
2830
2831 target = assign_temp (nt, 0, 1, 1);
2832 }
2833
2834 if (! rtx_equal_p (target, valreg))
2835 emit_group_store (target, valreg, TREE_TYPE (exp),
2836 int_size_in_bytes (TREE_TYPE (exp)));
2837
2838 /* We can not support sibling calls for this case. */
2839 sibcall_failure = 1;
2840 }
2841 else if (target
2842 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2843 && GET_MODE (target) == GET_MODE (valreg))
2844 {
2845 /* TARGET and VALREG cannot be equal at this point because the
2846 latter would not have REG_FUNCTION_VALUE_P true, while the
2847 former would if it were referring to the same register.
2848
2849 If they refer to the same register, this move will be a no-op,
2850 except when function inlining is being done. */
2851 emit_move_insn (target, valreg);
2852
2853 /* If we are setting a MEM, this code must be executed. Since it is
2854 emitted after the call insn, sibcall optimization cannot be
2855 performed in that case. */
2856 if (MEM_P (target))
2857 sibcall_failure = 1;
2858 }
2859 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2860 {
2861 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2862
2863 /* We can not support sibling calls for this case. */
2864 sibcall_failure = 1;
2865 }
2866 else
2867 target = copy_to_reg (valreg);
2868
2869 if (targetm.calls.promote_function_return(funtype))
2870 {
2871 /* If we promoted this return value, make the proper SUBREG.
2872 TARGET might be const0_rtx here, so be careful. */
2873 if (REG_P (target)
2874 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2875 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2876 {
2877 tree type = TREE_TYPE (exp);
2878 int unsignedp = TYPE_UNSIGNED (type);
2879 int offset = 0;
2880 enum machine_mode pmode;
2881
2882 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2883 /* If we don't promote as expected, something is wrong. */
2884 gcc_assert (GET_MODE (target) == pmode);
2885
2886 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2887 && (GET_MODE_SIZE (GET_MODE (target))
2888 > GET_MODE_SIZE (TYPE_MODE (type))))
2889 {
2890 offset = GET_MODE_SIZE (GET_MODE (target))
2891 - GET_MODE_SIZE (TYPE_MODE (type));
2892 if (! BYTES_BIG_ENDIAN)
2893 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
2894 else if (! WORDS_BIG_ENDIAN)
2895 offset %= UNITS_PER_WORD;
2896 }
2897 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
2898 SUBREG_PROMOTED_VAR_P (target) = 1;
2899 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
2900 }
2901 }
2902
2903 /* If size of args is variable or this was a constructor call for a stack
2904 argument, restore saved stack-pointer value. */
2905
2906 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
2907 {
2908 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2909 stack_pointer_delta = old_stack_pointer_delta;
2910 pending_stack_adjust = old_pending_adj;
2911 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2912 stack_arg_under_construction = old_stack_arg_under_construction;
2913 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2914 stack_usage_map = initial_stack_usage_map;
2915 sibcall_failure = 1;
2916 }
2917 else if (ACCUMULATE_OUTGOING_ARGS && pass)
2918 {
2919 #ifdef REG_PARM_STACK_SPACE
2920 if (save_area)
2921 restore_fixed_argument_area (save_area, argblock,
2922 high_to_save, low_to_save);
2923 #endif
2924
2925 /* If we saved any argument areas, restore them. */
2926 for (i = 0; i < num_actuals; i++)
2927 if (args[i].save_area)
2928 {
2929 enum machine_mode save_mode = GET_MODE (args[i].save_area);
2930 rtx stack_area
2931 = gen_rtx_MEM (save_mode,
2932 memory_address (save_mode,
2933 XEXP (args[i].stack_slot, 0)));
2934
2935 if (save_mode != BLKmode)
2936 emit_move_insn (stack_area, args[i].save_area);
2937 else
2938 emit_block_move (stack_area, args[i].save_area,
2939 GEN_INT (args[i].locate.size.constant),
2940 BLOCK_OP_CALL_PARM);
2941 }
2942
2943 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2944 stack_usage_map = initial_stack_usage_map;
2945 }
2946
2947 /* If this was alloca, record the new stack level for nonlocal gotos.
2948 Check for the handler slots since we might not have a save area
2949 for non-local gotos. */
2950
2951 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
2952 update_nonlocal_goto_save_area ();
2953
2954 /* Free up storage we no longer need. */
2955 for (i = 0; i < num_actuals; ++i)
2956 if (args[i].aligned_regs)
2957 free (args[i].aligned_regs);
2958
2959 insns = get_insns ();
2960 end_sequence ();
2961
2962 if (pass == 0)
2963 {
2964 tail_call_insns = insns;
2965
2966 /* Restore the pending stack adjustment now that we have
2967 finished generating the sibling call sequence. */
2968
2969 pending_stack_adjust = save_pending_stack_adjust;
2970 stack_pointer_delta = save_stack_pointer_delta;
2971
2972 /* Prepare arg structure for next iteration. */
2973 for (i = 0; i < num_actuals; i++)
2974 {
2975 args[i].value = 0;
2976 args[i].aligned_regs = 0;
2977 args[i].stack = 0;
2978 }
2979
2980 sbitmap_free (stored_args_map);
2981 }
2982 else
2983 {
2984 normal_call_insns = insns;
2985
2986 /* Verify that we've deallocated all the stack we used. */
2987 gcc_assert ((flags & ECF_NORETURN)
2988 || (old_stack_allocated
2989 == stack_pointer_delta - pending_stack_adjust));
2990 }
2991
2992 /* If something prevents making this a sibling call,
2993 zero out the sequence. */
2994 if (sibcall_failure)
2995 tail_call_insns = NULL_RTX;
2996 else
2997 break;
2998 }
2999
3000 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3001 arguments too, as argument area is now clobbered by the call. */
3002 if (tail_call_insns)
3003 {
3004 emit_insn (tail_call_insns);
3005 cfun->tail_call_emit = true;
3006 }
3007 else
3008 emit_insn (normal_call_insns);
3009
3010 currently_expanding_call--;
3011
3012 /* If this function returns with the stack pointer depressed, ensure
3013 this block saves and restores the stack pointer, show it was
3014 changed, and adjust for any outgoing arg space. */
3015 if (flags & ECF_SP_DEPRESSED)
3016 {
3017 clear_pending_stack_adjust ();
3018 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3019 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3020 }
3021
3022 return target;
3023 }
3024
3025 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3026 this function's incoming arguments.
3027
3028 At the start of RTL generation we know the only REG_EQUIV notes
3029 in the rtl chain are those for incoming arguments, so we can look
3030 for REG_EQUIV notes between the start of the function and the
3031 NOTE_INSN_FUNCTION_BEG.
3032
3033 This is (slight) overkill. We could keep track of the highest
3034 argument we clobber and be more selective in removing notes, but it
3035 does not seem to be worth the effort. */
3036
3037 void
3038 fixup_tail_calls (void)
3039 {
3040 rtx insn;
3041
3042 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3043 {
3044 /* There are never REG_EQUIV notes for the incoming arguments
3045 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3046 if (NOTE_P (insn)
3047 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
3048 break;
3049
3050 while (1)
3051 {
3052 rtx note = find_reg_note (insn, REG_EQUIV, 0);
3053 if (note)
3054 {
3055 /* Remove the note and keep looking at the notes for
3056 this insn. */
3057 remove_note (insn, note);
3058 continue;
3059 }
3060 break;
3061 }
3062 }
3063 }
3064
3065 /* Traverse an argument list in VALUES and expand all complex
3066 arguments into their components. */
3067 static tree
3068 split_complex_values (tree values)
3069 {
3070 tree p;
3071
3072 /* Before allocating memory, check for the common case of no complex. */
3073 for (p = values; p; p = TREE_CHAIN (p))
3074 {
3075 tree type = TREE_TYPE (TREE_VALUE (p));
3076 if (type && TREE_CODE (type) == COMPLEX_TYPE
3077 && targetm.calls.split_complex_arg (type))
3078 goto found;
3079 }
3080 return values;
3081
3082 found:
3083 values = copy_list (values);
3084
3085 for (p = values; p; p = TREE_CHAIN (p))
3086 {
3087 tree complex_value = TREE_VALUE (p);
3088 tree complex_type;
3089
3090 complex_type = TREE_TYPE (complex_value);
3091 if (!complex_type)
3092 continue;
3093
3094 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3095 && targetm.calls.split_complex_arg (complex_type))
3096 {
3097 tree subtype;
3098 tree real, imag, next;
3099
3100 subtype = TREE_TYPE (complex_type);
3101 complex_value = save_expr (complex_value);
3102 real = build1 (REALPART_EXPR, subtype, complex_value);
3103 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3104
3105 TREE_VALUE (p) = real;
3106 next = TREE_CHAIN (p);
3107 imag = build_tree_list (NULL_TREE, imag);
3108 TREE_CHAIN (p) = imag;
3109 TREE_CHAIN (imag) = next;
3110
3111 /* Skip the newly created node. */
3112 p = TREE_CHAIN (p);
3113 }
3114 }
3115
3116 return values;
3117 }
3118
3119 /* Traverse a list of TYPES and expand all complex types into their
3120 components. */
3121 static tree
3122 split_complex_types (tree types)
3123 {
3124 tree p;
3125
3126 /* Before allocating memory, check for the common case of no complex. */
3127 for (p = types; p; p = TREE_CHAIN (p))
3128 {
3129 tree type = TREE_VALUE (p);
3130 if (TREE_CODE (type) == COMPLEX_TYPE
3131 && targetm.calls.split_complex_arg (type))
3132 goto found;
3133 }
3134 return types;
3135
3136 found:
3137 types = copy_list (types);
3138
3139 for (p = types; p; p = TREE_CHAIN (p))
3140 {
3141 tree complex_type = TREE_VALUE (p);
3142
3143 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3144 && targetm.calls.split_complex_arg (complex_type))
3145 {
3146 tree next, imag;
3147
3148 /* Rewrite complex type with component type. */
3149 TREE_VALUE (p) = TREE_TYPE (complex_type);
3150 next = TREE_CHAIN (p);
3151
3152 /* Add another component type for the imaginary part. */
3153 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3154 TREE_CHAIN (p) = imag;
3155 TREE_CHAIN (imag) = next;
3156
3157 /* Skip the newly created node. */
3158 p = TREE_CHAIN (p);
3159 }
3160 }
3161
3162 return types;
3163 }
3164 \f
3165 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3166 The RETVAL parameter specifies whether return value needs to be saved, other
3167 parameters are documented in the emit_library_call function below. */
3168
3169 static rtx
3170 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3171 enum libcall_type fn_type,
3172 enum machine_mode outmode, int nargs, va_list p)
3173 {
3174 /* Total size in bytes of all the stack-parms scanned so far. */
3175 struct args_size args_size;
3176 /* Size of arguments before any adjustments (such as rounding). */
3177 struct args_size original_args_size;
3178 int argnum;
3179 rtx fun;
3180 int inc;
3181 int count;
3182 rtx argblock = 0;
3183 CUMULATIVE_ARGS args_so_far;
3184 struct arg
3185 {
3186 rtx value;
3187 enum machine_mode mode;
3188 rtx reg;
3189 int partial;
3190 struct locate_and_pad_arg_data locate;
3191 rtx save_area;
3192 };
3193 struct arg *argvec;
3194 int old_inhibit_defer_pop = inhibit_defer_pop;
3195 rtx call_fusage = 0;
3196 rtx mem_value = 0;
3197 rtx valreg;
3198 int pcc_struct_value = 0;
3199 int struct_value_size = 0;
3200 int flags;
3201 int reg_parm_stack_space = 0;
3202 int needed;
3203 rtx before_call;
3204 tree tfom; /* type_for_mode (outmode, 0) */
3205
3206 #ifdef REG_PARM_STACK_SPACE
3207 /* Define the boundary of the register parm stack space that needs to be
3208 save, if any. */
3209 int low_to_save, high_to_save;
3210 rtx save_area = 0; /* Place that it is saved. */
3211 #endif
3212
3213 /* Size of the stack reserved for parameter registers. */
3214 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3215 char *initial_stack_usage_map = stack_usage_map;
3216
3217 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3218
3219 #ifdef REG_PARM_STACK_SPACE
3220 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3221 #endif
3222
3223 /* By default, library functions can not throw. */
3224 flags = ECF_NOTHROW;
3225
3226 switch (fn_type)
3227 {
3228 case LCT_NORMAL:
3229 break;
3230 case LCT_CONST:
3231 flags |= ECF_CONST;
3232 break;
3233 case LCT_PURE:
3234 flags |= ECF_PURE;
3235 break;
3236 case LCT_CONST_MAKE_BLOCK:
3237 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3238 break;
3239 case LCT_PURE_MAKE_BLOCK:
3240 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3241 break;
3242 case LCT_NORETURN:
3243 flags |= ECF_NORETURN;
3244 break;
3245 case LCT_THROW:
3246 flags = ECF_NORETURN;
3247 break;
3248 case LCT_RETURNS_TWICE:
3249 flags = ECF_RETURNS_TWICE;
3250 break;
3251 }
3252 fun = orgfun;
3253
3254 /* Ensure current function's preferred stack boundary is at least
3255 what we need. */
3256 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3257 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3258
3259 /* If this kind of value comes back in memory,
3260 decide where in memory it should come back. */
3261 if (outmode != VOIDmode)
3262 {
3263 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3264 if (aggregate_value_p (tfom, 0))
3265 {
3266 #ifdef PCC_STATIC_STRUCT_RETURN
3267 rtx pointer_reg
3268 = hard_function_value (build_pointer_type (tfom), 0, 0);
3269 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3270 pcc_struct_value = 1;
3271 if (value == 0)
3272 value = gen_reg_rtx (outmode);
3273 #else /* not PCC_STATIC_STRUCT_RETURN */
3274 struct_value_size = GET_MODE_SIZE (outmode);
3275 if (value != 0 && MEM_P (value))
3276 mem_value = value;
3277 else
3278 mem_value = assign_temp (tfom, 0, 1, 1);
3279 #endif
3280 /* This call returns a big structure. */
3281 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3282 }
3283 }
3284 else
3285 tfom = void_type_node;
3286
3287 /* ??? Unfinished: must pass the memory address as an argument. */
3288
3289 /* Copy all the libcall-arguments out of the varargs data
3290 and into a vector ARGVEC.
3291
3292 Compute how to pass each argument. We only support a very small subset
3293 of the full argument passing conventions to limit complexity here since
3294 library functions shouldn't have many args. */
3295
3296 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3297 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3298
3299 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3300 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3301 #else
3302 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3303 #endif
3304
3305 args_size.constant = 0;
3306 args_size.var = 0;
3307
3308 count = 0;
3309
3310 /* Now we are about to start emitting insns that can be deleted
3311 if a libcall is deleted. */
3312 if (flags & ECF_LIBCALL_BLOCK)
3313 start_sequence ();
3314
3315 push_temp_slots ();
3316
3317 /* If there's a structure value address to be passed,
3318 either pass it in the special place, or pass it as an extra argument. */
3319 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3320 {
3321 rtx addr = XEXP (mem_value, 0);
3322
3323 nargs++;
3324
3325 /* Make sure it is a reasonable operand for a move or push insn. */
3326 if (!REG_P (addr) && !MEM_P (addr)
3327 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3328 addr = force_operand (addr, NULL_RTX);
3329
3330 argvec[count].value = addr;
3331 argvec[count].mode = Pmode;
3332 argvec[count].partial = 0;
3333
3334 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3335 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3336 NULL_TREE, 1) == 0);
3337
3338 locate_and_pad_parm (Pmode, NULL_TREE,
3339 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3340 1,
3341 #else
3342 argvec[count].reg != 0,
3343 #endif
3344 0, NULL_TREE, &args_size, &argvec[count].locate);
3345
3346 if (argvec[count].reg == 0 || argvec[count].partial != 0
3347 || reg_parm_stack_space > 0)
3348 args_size.constant += argvec[count].locate.size.constant;
3349
3350 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3351
3352 count++;
3353 }
3354
3355 for (; count < nargs; count++)
3356 {
3357 rtx val = va_arg (p, rtx);
3358 enum machine_mode mode = va_arg (p, enum machine_mode);
3359
3360 /* We cannot convert the arg value to the mode the library wants here;
3361 must do it earlier where we know the signedness of the arg. */
3362 gcc_assert (mode != BLKmode
3363 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3364
3365 /* Make sure it is a reasonable operand for a move or push insn. */
3366 if (!REG_P (val) && !MEM_P (val)
3367 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3368 val = force_operand (val, NULL_RTX);
3369
3370 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3371 {
3372 rtx slot;
3373 int must_copy
3374 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3375
3376 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3377 functions, so we have to pretend this isn't such a function. */
3378 if (flags & ECF_LIBCALL_BLOCK)
3379 {
3380 rtx insns = get_insns ();
3381 end_sequence ();
3382 emit_insn (insns);
3383 }
3384 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3385
3386 /* If this was a CONST function, it is now PURE since
3387 it now reads memory. */
3388 if (flags & ECF_CONST)
3389 {
3390 flags &= ~ECF_CONST;
3391 flags |= ECF_PURE;
3392 }
3393
3394 if (GET_MODE (val) == MEM && !must_copy)
3395 slot = val;
3396 else
3397 {
3398 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3399 0, 1, 1);
3400 emit_move_insn (slot, val);
3401 }
3402
3403 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3404 gen_rtx_USE (VOIDmode, slot),
3405 call_fusage);
3406 if (must_copy)
3407 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3408 gen_rtx_CLOBBER (VOIDmode,
3409 slot),
3410 call_fusage);
3411
3412 mode = Pmode;
3413 val = force_operand (XEXP (slot, 0), NULL_RTX);
3414 }
3415
3416 argvec[count].value = val;
3417 argvec[count].mode = mode;
3418
3419 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3420
3421 argvec[count].partial
3422 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3423
3424 locate_and_pad_parm (mode, NULL_TREE,
3425 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3426 1,
3427 #else
3428 argvec[count].reg != 0,
3429 #endif
3430 argvec[count].partial,
3431 NULL_TREE, &args_size, &argvec[count].locate);
3432
3433 gcc_assert (!argvec[count].locate.size.var);
3434
3435 if (argvec[count].reg == 0 || argvec[count].partial != 0
3436 || reg_parm_stack_space > 0)
3437 args_size.constant += argvec[count].locate.size.constant;
3438
3439 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3440 }
3441
3442 /* If this machine requires an external definition for library
3443 functions, write one out. */
3444 assemble_external_libcall (fun);
3445
3446 original_args_size = args_size;
3447 args_size.constant = (((args_size.constant
3448 + stack_pointer_delta
3449 + STACK_BYTES - 1)
3450 / STACK_BYTES
3451 * STACK_BYTES)
3452 - stack_pointer_delta);
3453
3454 args_size.constant = MAX (args_size.constant,
3455 reg_parm_stack_space);
3456
3457 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3458 args_size.constant -= reg_parm_stack_space;
3459 #endif
3460
3461 if (args_size.constant > current_function_outgoing_args_size)
3462 current_function_outgoing_args_size = args_size.constant;
3463
3464 if (ACCUMULATE_OUTGOING_ARGS)
3465 {
3466 /* Since the stack pointer will never be pushed, it is possible for
3467 the evaluation of a parm to clobber something we have already
3468 written to the stack. Since most function calls on RISC machines
3469 do not use the stack, this is uncommon, but must work correctly.
3470
3471 Therefore, we save any area of the stack that was already written
3472 and that we are using. Here we set up to do this by making a new
3473 stack usage map from the old one.
3474
3475 Another approach might be to try to reorder the argument
3476 evaluations to avoid this conflicting stack usage. */
3477
3478 needed = args_size.constant;
3479
3480 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3481 /* Since we will be writing into the entire argument area, the
3482 map must be allocated for its entire size, not just the part that
3483 is the responsibility of the caller. */
3484 needed += reg_parm_stack_space;
3485 #endif
3486
3487 #ifdef ARGS_GROW_DOWNWARD
3488 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3489 needed + 1);
3490 #else
3491 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3492 needed);
3493 #endif
3494 stack_usage_map = alloca (highest_outgoing_arg_in_use);
3495
3496 if (initial_highest_arg_in_use)
3497 memcpy (stack_usage_map, initial_stack_usage_map,
3498 initial_highest_arg_in_use);
3499
3500 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3501 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3502 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3503 needed = 0;
3504
3505 /* We must be careful to use virtual regs before they're instantiated,
3506 and real regs afterwards. Loop optimization, for example, can create
3507 new libcalls after we've instantiated the virtual regs, and if we
3508 use virtuals anyway, they won't match the rtl patterns. */
3509
3510 if (virtuals_instantiated)
3511 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3512 else
3513 argblock = virtual_outgoing_args_rtx;
3514 }
3515 else
3516 {
3517 if (!PUSH_ARGS)
3518 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3519 }
3520
3521 /* If we push args individually in reverse order, perform stack alignment
3522 before the first push (the last arg). */
3523 if (argblock == 0 && PUSH_ARGS_REVERSED)
3524 anti_adjust_stack (GEN_INT (args_size.constant
3525 - original_args_size.constant));
3526
3527 if (PUSH_ARGS_REVERSED)
3528 {
3529 inc = -1;
3530 argnum = nargs - 1;
3531 }
3532 else
3533 {
3534 inc = 1;
3535 argnum = 0;
3536 }
3537
3538 #ifdef REG_PARM_STACK_SPACE
3539 if (ACCUMULATE_OUTGOING_ARGS)
3540 {
3541 /* The argument list is the property of the called routine and it
3542 may clobber it. If the fixed area has been used for previous
3543 parameters, we must save and restore it. */
3544 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3545 &low_to_save, &high_to_save);
3546 }
3547 #endif
3548
3549 /* Push the args that need to be pushed. */
3550
3551 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3552 are to be pushed. */
3553 for (count = 0; count < nargs; count++, argnum += inc)
3554 {
3555 enum machine_mode mode = argvec[argnum].mode;
3556 rtx val = argvec[argnum].value;
3557 rtx reg = argvec[argnum].reg;
3558 int partial = argvec[argnum].partial;
3559 int lower_bound = 0, upper_bound = 0, i;
3560
3561 if (! (reg != 0 && partial == 0))
3562 {
3563 if (ACCUMULATE_OUTGOING_ARGS)
3564 {
3565 /* If this is being stored into a pre-allocated, fixed-size,
3566 stack area, save any previous data at that location. */
3567
3568 #ifdef ARGS_GROW_DOWNWARD
3569 /* stack_slot is negative, but we want to index stack_usage_map
3570 with positive values. */
3571 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3572 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3573 #else
3574 lower_bound = argvec[argnum].locate.offset.constant;
3575 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3576 #endif
3577
3578 i = lower_bound;
3579 /* Don't worry about things in the fixed argument area;
3580 it has already been saved. */
3581 if (i < reg_parm_stack_space)
3582 i = reg_parm_stack_space;
3583 while (i < upper_bound && stack_usage_map[i] == 0)
3584 i++;
3585
3586 if (i < upper_bound)
3587 {
3588 /* We need to make a save area. */
3589 unsigned int size
3590 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3591 enum machine_mode save_mode
3592 = mode_for_size (size, MODE_INT, 1);
3593 rtx adr
3594 = plus_constant (argblock,
3595 argvec[argnum].locate.offset.constant);
3596 rtx stack_area
3597 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3598
3599 if (save_mode == BLKmode)
3600 {
3601 argvec[argnum].save_area
3602 = assign_stack_temp (BLKmode,
3603 argvec[argnum].locate.size.constant,
3604 0);
3605
3606 emit_block_move (validize_mem (argvec[argnum].save_area),
3607 stack_area,
3608 GEN_INT (argvec[argnum].locate.size.constant),
3609 BLOCK_OP_CALL_PARM);
3610 }
3611 else
3612 {
3613 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3614
3615 emit_move_insn (argvec[argnum].save_area, stack_area);
3616 }
3617 }
3618 }
3619
3620 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3621 partial, reg, 0, argblock,
3622 GEN_INT (argvec[argnum].locate.offset.constant),
3623 reg_parm_stack_space,
3624 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3625
3626 /* Now mark the segment we just used. */
3627 if (ACCUMULATE_OUTGOING_ARGS)
3628 for (i = lower_bound; i < upper_bound; i++)
3629 stack_usage_map[i] = 1;
3630
3631 NO_DEFER_POP;
3632 }
3633 }
3634
3635 /* If we pushed args in forward order, perform stack alignment
3636 after pushing the last arg. */
3637 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3638 anti_adjust_stack (GEN_INT (args_size.constant
3639 - original_args_size.constant));
3640
3641 if (PUSH_ARGS_REVERSED)
3642 argnum = nargs - 1;
3643 else
3644 argnum = 0;
3645
3646 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3647
3648 /* Now load any reg parms into their regs. */
3649
3650 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3651 are to be pushed. */
3652 for (count = 0; count < nargs; count++, argnum += inc)
3653 {
3654 enum machine_mode mode = argvec[argnum].mode;
3655 rtx val = argvec[argnum].value;
3656 rtx reg = argvec[argnum].reg;
3657 int partial = argvec[argnum].partial;
3658
3659 /* Handle calls that pass values in multiple non-contiguous
3660 locations. The PA64 has examples of this for library calls. */
3661 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3662 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3663 else if (reg != 0 && partial == 0)
3664 emit_move_insn (reg, val);
3665
3666 NO_DEFER_POP;
3667 }
3668
3669 /* Any regs containing parms remain in use through the call. */
3670 for (count = 0; count < nargs; count++)
3671 {
3672 rtx reg = argvec[count].reg;
3673 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3674 use_group_regs (&call_fusage, reg);
3675 else if (reg != 0)
3676 use_reg (&call_fusage, reg);
3677 }
3678
3679 /* Pass the function the address in which to return a structure value. */
3680 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3681 {
3682 emit_move_insn (struct_value,
3683 force_reg (Pmode,
3684 force_operand (XEXP (mem_value, 0),
3685 NULL_RTX)));
3686 if (REG_P (struct_value))
3687 use_reg (&call_fusage, struct_value);
3688 }
3689
3690 /* Don't allow popping to be deferred, since then
3691 cse'ing of library calls could delete a call and leave the pop. */
3692 NO_DEFER_POP;
3693 valreg = (mem_value == 0 && outmode != VOIDmode
3694 ? hard_libcall_value (outmode) : NULL_RTX);
3695
3696 /* Stack must be properly aligned now. */
3697 gcc_assert (!(stack_pointer_delta
3698 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3699
3700 before_call = get_last_insn ();
3701
3702 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3703 will set inhibit_defer_pop to that value. */
3704 /* The return type is needed to decide how many bytes the function pops.
3705 Signedness plays no role in that, so for simplicity, we pretend it's
3706 always signed. We also assume that the list of arguments passed has
3707 no impact, so we pretend it is unknown. */
3708
3709 emit_call_1 (fun, NULL,
3710 get_identifier (XSTR (orgfun, 0)),
3711 build_function_type (tfom, NULL_TREE),
3712 original_args_size.constant, args_size.constant,
3713 struct_value_size,
3714 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3715 valreg,
3716 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3717
3718 /* For calls to `setjmp', etc., inform flow.c it should complain
3719 if nonvolatile values are live. For functions that cannot return,
3720 inform flow that control does not fall through. */
3721
3722 if (flags & ECF_NORETURN)
3723 {
3724 /* The barrier note must be emitted
3725 immediately after the CALL_INSN. Some ports emit more than
3726 just a CALL_INSN above, so we must search for it here. */
3727
3728 rtx last = get_last_insn ();
3729 while (!CALL_P (last))
3730 {
3731 last = PREV_INSN (last);
3732 /* There was no CALL_INSN? */
3733 gcc_assert (last != before_call);
3734 }
3735
3736 emit_barrier_after (last);
3737 }
3738
3739 /* Now restore inhibit_defer_pop to its actual original value. */
3740 OK_DEFER_POP;
3741
3742 /* If call is cse'able, make appropriate pair of reg-notes around it.
3743 Test valreg so we don't crash; may safely ignore `const'
3744 if return type is void. Disable for PARALLEL return values, because
3745 we have no way to move such values into a pseudo register. */
3746 if (flags & ECF_LIBCALL_BLOCK)
3747 {
3748 rtx insns;
3749
3750 if (valreg == 0)
3751 {
3752 insns = get_insns ();
3753 end_sequence ();
3754 emit_insn (insns);
3755 }
3756 else
3757 {
3758 rtx note = 0;
3759 rtx temp;
3760 int i;
3761
3762 if (GET_CODE (valreg) == PARALLEL)
3763 {
3764 temp = gen_reg_rtx (outmode);
3765 emit_group_store (temp, valreg, NULL_TREE,
3766 GET_MODE_SIZE (outmode));
3767 valreg = temp;
3768 }
3769
3770 temp = gen_reg_rtx (GET_MODE (valreg));
3771
3772 /* Construct an "equal form" for the value which mentions all the
3773 arguments in order as well as the function name. */
3774 for (i = 0; i < nargs; i++)
3775 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3776 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3777
3778 insns = get_insns ();
3779 end_sequence ();
3780
3781 if (flags & ECF_PURE)
3782 note = gen_rtx_EXPR_LIST (VOIDmode,
3783 gen_rtx_USE (VOIDmode,
3784 gen_rtx_MEM (BLKmode,
3785 gen_rtx_SCRATCH (VOIDmode))),
3786 note);
3787
3788 emit_libcall_block (insns, temp, valreg, note);
3789
3790 valreg = temp;
3791 }
3792 }
3793 pop_temp_slots ();
3794
3795 /* Copy the value to the right place. */
3796 if (outmode != VOIDmode && retval)
3797 {
3798 if (mem_value)
3799 {
3800 if (value == 0)
3801 value = mem_value;
3802 if (value != mem_value)
3803 emit_move_insn (value, mem_value);
3804 }
3805 else if (GET_CODE (valreg) == PARALLEL)
3806 {
3807 if (value == 0)
3808 value = gen_reg_rtx (outmode);
3809 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3810 }
3811 else if (value != 0)
3812 emit_move_insn (value, valreg);
3813 else
3814 value = valreg;
3815 }
3816
3817 if (ACCUMULATE_OUTGOING_ARGS)
3818 {
3819 #ifdef REG_PARM_STACK_SPACE
3820 if (save_area)
3821 restore_fixed_argument_area (save_area, argblock,
3822 high_to_save, low_to_save);
3823 #endif
3824
3825 /* If we saved any argument areas, restore them. */
3826 for (count = 0; count < nargs; count++)
3827 if (argvec[count].save_area)
3828 {
3829 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3830 rtx adr = plus_constant (argblock,
3831 argvec[count].locate.offset.constant);
3832 rtx stack_area = gen_rtx_MEM (save_mode,
3833 memory_address (save_mode, adr));
3834
3835 if (save_mode == BLKmode)
3836 emit_block_move (stack_area,
3837 validize_mem (argvec[count].save_area),
3838 GEN_INT (argvec[count].locate.size.constant),
3839 BLOCK_OP_CALL_PARM);
3840 else
3841 emit_move_insn (stack_area, argvec[count].save_area);
3842 }
3843
3844 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3845 stack_usage_map = initial_stack_usage_map;
3846 }
3847
3848 return value;
3849
3850 }
3851 \f
3852 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3853 (emitting the queue unless NO_QUEUE is nonzero),
3854 for a value of mode OUTMODE,
3855 with NARGS different arguments, passed as alternating rtx values
3856 and machine_modes to convert them to.
3857
3858 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
3859 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
3860 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
3861 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
3862 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
3863 or other LCT_ value for other types of library calls. */
3864
3865 void
3866 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3867 enum machine_mode outmode, int nargs, ...)
3868 {
3869 va_list p;
3870
3871 va_start (p, nargs);
3872 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3873 va_end (p);
3874 }
3875 \f
3876 /* Like emit_library_call except that an extra argument, VALUE,
3877 comes second and says where to store the result.
3878 (If VALUE is zero, this function chooses a convenient way
3879 to return the value.
3880
3881 This function returns an rtx for where the value is to be found.
3882 If VALUE is nonzero, VALUE is returned. */
3883
3884 rtx
3885 emit_library_call_value (rtx orgfun, rtx value,
3886 enum libcall_type fn_type,
3887 enum machine_mode outmode, int nargs, ...)
3888 {
3889 rtx result;
3890 va_list p;
3891
3892 va_start (p, nargs);
3893 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3894 nargs, p);
3895 va_end (p);
3896
3897 return result;
3898 }
3899 \f
3900 /* Store a single argument for a function call
3901 into the register or memory area where it must be passed.
3902 *ARG describes the argument value and where to pass it.
3903
3904 ARGBLOCK is the address of the stack-block for all the arguments,
3905 or 0 on a machine where arguments are pushed individually.
3906
3907 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3908 so must be careful about how the stack is used.
3909
3910 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3911 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3912 that we need not worry about saving and restoring the stack.
3913
3914 FNDECL is the declaration of the function we are calling.
3915
3916 Return nonzero if this arg should cause sibcall failure,
3917 zero otherwise. */
3918
3919 static int
3920 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3921 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3922 {
3923 tree pval = arg->tree_value;
3924 rtx reg = 0;
3925 int partial = 0;
3926 int used = 0;
3927 int i, lower_bound = 0, upper_bound = 0;
3928 int sibcall_failure = 0;
3929
3930 if (TREE_CODE (pval) == ERROR_MARK)
3931 return 1;
3932
3933 /* Push a new temporary level for any temporaries we make for
3934 this argument. */
3935 push_temp_slots ();
3936
3937 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3938 {
3939 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3940 save any previous data at that location. */
3941 if (argblock && ! variable_size && arg->stack)
3942 {
3943 #ifdef ARGS_GROW_DOWNWARD
3944 /* stack_slot is negative, but we want to index stack_usage_map
3945 with positive values. */
3946 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3947 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3948 else
3949 upper_bound = 0;
3950
3951 lower_bound = upper_bound - arg->locate.size.constant;
3952 #else
3953 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3954 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3955 else
3956 lower_bound = 0;
3957
3958 upper_bound = lower_bound + arg->locate.size.constant;
3959 #endif
3960
3961 i = lower_bound;
3962 /* Don't worry about things in the fixed argument area;
3963 it has already been saved. */
3964 if (i < reg_parm_stack_space)
3965 i = reg_parm_stack_space;
3966 while (i < upper_bound && stack_usage_map[i] == 0)
3967 i++;
3968
3969 if (i < upper_bound)
3970 {
3971 /* We need to make a save area. */
3972 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
3973 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
3974 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
3975 rtx stack_area = gen_rtx_MEM (save_mode, adr);
3976
3977 if (save_mode == BLKmode)
3978 {
3979 tree ot = TREE_TYPE (arg->tree_value);
3980 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
3981 | TYPE_QUAL_CONST));
3982
3983 arg->save_area = assign_temp (nt, 0, 1, 1);
3984 preserve_temp_slots (arg->save_area);
3985 emit_block_move (validize_mem (arg->save_area), stack_area,
3986 expr_size (arg->tree_value),
3987 BLOCK_OP_CALL_PARM);
3988 }
3989 else
3990 {
3991 arg->save_area = gen_reg_rtx (save_mode);
3992 emit_move_insn (arg->save_area, stack_area);
3993 }
3994 }
3995 }
3996 }
3997
3998 /* If this isn't going to be placed on both the stack and in registers,
3999 set up the register and number of words. */
4000 if (! arg->pass_on_stack)
4001 {
4002 if (flags & ECF_SIBCALL)
4003 reg = arg->tail_call_reg;
4004 else
4005 reg = arg->reg;
4006 partial = arg->partial;
4007 }
4008
4009 /* Being passed entirely in a register. We shouldn't be called in
4010 this case. */
4011 gcc_assert (reg == 0 || partial != 0);
4012
4013 /* If this arg needs special alignment, don't load the registers
4014 here. */
4015 if (arg->n_aligned_regs != 0)
4016 reg = 0;
4017
4018 /* If this is being passed partially in a register, we can't evaluate
4019 it directly into its stack slot. Otherwise, we can. */
4020 if (arg->value == 0)
4021 {
4022 /* stack_arg_under_construction is nonzero if a function argument is
4023 being evaluated directly into the outgoing argument list and
4024 expand_call must take special action to preserve the argument list
4025 if it is called recursively.
4026
4027 For scalar function arguments stack_usage_map is sufficient to
4028 determine which stack slots must be saved and restored. Scalar
4029 arguments in general have pass_on_stack == 0.
4030
4031 If this argument is initialized by a function which takes the
4032 address of the argument (a C++ constructor or a C function
4033 returning a BLKmode structure), then stack_usage_map is
4034 insufficient and expand_call must push the stack around the
4035 function call. Such arguments have pass_on_stack == 1.
4036
4037 Note that it is always safe to set stack_arg_under_construction,
4038 but this generates suboptimal code if set when not needed. */
4039
4040 if (arg->pass_on_stack)
4041 stack_arg_under_construction++;
4042
4043 arg->value = expand_expr (pval,
4044 (partial
4045 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4046 ? NULL_RTX : arg->stack,
4047 VOIDmode, EXPAND_STACK_PARM);
4048
4049 /* If we are promoting object (or for any other reason) the mode
4050 doesn't agree, convert the mode. */
4051
4052 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4053 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4054 arg->value, arg->unsignedp);
4055
4056 if (arg->pass_on_stack)
4057 stack_arg_under_construction--;
4058 }
4059
4060 /* Don't allow anything left on stack from computation
4061 of argument to alloca. */
4062 if (flags & ECF_MAY_BE_ALLOCA)
4063 do_pending_stack_adjust ();
4064
4065 if (arg->value == arg->stack)
4066 /* If the value is already in the stack slot, we are done. */
4067 ;
4068 else if (arg->mode != BLKmode)
4069 {
4070 int size;
4071
4072 /* Argument is a scalar, not entirely passed in registers.
4073 (If part is passed in registers, arg->partial says how much
4074 and emit_push_insn will take care of putting it there.)
4075
4076 Push it, and if its size is less than the
4077 amount of space allocated to it,
4078 also bump stack pointer by the additional space.
4079 Note that in C the default argument promotions
4080 will prevent such mismatches. */
4081
4082 size = GET_MODE_SIZE (arg->mode);
4083 /* Compute how much space the push instruction will push.
4084 On many machines, pushing a byte will advance the stack
4085 pointer by a halfword. */
4086 #ifdef PUSH_ROUNDING
4087 size = PUSH_ROUNDING (size);
4088 #endif
4089 used = size;
4090
4091 /* Compute how much space the argument should get:
4092 round up to a multiple of the alignment for arguments. */
4093 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4094 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4095 / (PARM_BOUNDARY / BITS_PER_UNIT))
4096 * (PARM_BOUNDARY / BITS_PER_UNIT));
4097
4098 /* This isn't already where we want it on the stack, so put it there.
4099 This can either be done with push or copy insns. */
4100 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4101 PARM_BOUNDARY, partial, reg, used - size, argblock,
4102 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4103 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4104
4105 /* Unless this is a partially-in-register argument, the argument is now
4106 in the stack. */
4107 if (partial == 0)
4108 arg->value = arg->stack;
4109 }
4110 else
4111 {
4112 /* BLKmode, at least partly to be pushed. */
4113
4114 unsigned int parm_align;
4115 int excess;
4116 rtx size_rtx;
4117
4118 /* Pushing a nonscalar.
4119 If part is passed in registers, PARTIAL says how much
4120 and emit_push_insn will take care of putting it there. */
4121
4122 /* Round its size up to a multiple
4123 of the allocation unit for arguments. */
4124
4125 if (arg->locate.size.var != 0)
4126 {
4127 excess = 0;
4128 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4129 }
4130 else
4131 {
4132 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4133 for BLKmode is careful to avoid it. */
4134 excess = (arg->locate.size.constant
4135 - int_size_in_bytes (TREE_TYPE (pval))
4136 + partial);
4137 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4138 NULL_RTX, TYPE_MODE (sizetype), 0);
4139 }
4140
4141 parm_align = arg->locate.boundary;
4142
4143 /* When an argument is padded down, the block is aligned to
4144 PARM_BOUNDARY, but the actual argument isn't. */
4145 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4146 {
4147 if (arg->locate.size.var)
4148 parm_align = BITS_PER_UNIT;
4149 else if (excess)
4150 {
4151 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4152 parm_align = MIN (parm_align, excess_align);
4153 }
4154 }
4155
4156 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4157 {
4158 /* emit_push_insn might not work properly if arg->value and
4159 argblock + arg->locate.offset areas overlap. */
4160 rtx x = arg->value;
4161 int i = 0;
4162
4163 if (XEXP (x, 0) == current_function_internal_arg_pointer
4164 || (GET_CODE (XEXP (x, 0)) == PLUS
4165 && XEXP (XEXP (x, 0), 0) ==
4166 current_function_internal_arg_pointer
4167 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4168 {
4169 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4170 i = INTVAL (XEXP (XEXP (x, 0), 1));
4171
4172 /* expand_call should ensure this. */
4173 gcc_assert (!arg->locate.offset.var
4174 && GET_CODE (size_rtx) == CONST_INT);
4175
4176 if (arg->locate.offset.constant > i)
4177 {
4178 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4179 sibcall_failure = 1;
4180 }
4181 else if (arg->locate.offset.constant < i)
4182 {
4183 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4184 sibcall_failure = 1;
4185 }
4186 }
4187 }
4188
4189 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4190 parm_align, partial, reg, excess, argblock,
4191 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4192 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4193
4194 /* Unless this is a partially-in-register argument, the argument is now
4195 in the stack.
4196
4197 ??? Unlike the case above, in which we want the actual
4198 address of the data, so that we can load it directly into a
4199 register, here we want the address of the stack slot, so that
4200 it's properly aligned for word-by-word copying or something
4201 like that. It's not clear that this is always correct. */
4202 if (partial == 0)
4203 arg->value = arg->stack_slot;
4204 }
4205
4206 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4207 {
4208 tree type = TREE_TYPE (arg->tree_value);
4209 arg->parallel_value
4210 = emit_group_load_into_temps (arg->reg, arg->value, type,
4211 int_size_in_bytes (type));
4212 }
4213
4214 /* Mark all slots this store used. */
4215 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4216 && argblock && ! variable_size && arg->stack)
4217 for (i = lower_bound; i < upper_bound; i++)
4218 stack_usage_map[i] = 1;
4219
4220 /* Once we have pushed something, pops can't safely
4221 be deferred during the rest of the arguments. */
4222 NO_DEFER_POP;
4223
4224 /* Free any temporary slots made in processing this argument. Show
4225 that we might have taken the address of something and pushed that
4226 as an operand. */
4227 preserve_temp_slots (NULL_RTX);
4228 free_temp_slots ();
4229 pop_temp_slots ();
4230
4231 return sibcall_failure;
4232 }
4233
4234 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4235
4236 bool
4237 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4238 tree type)
4239 {
4240 if (!type)
4241 return false;
4242
4243 /* If the type has variable size... */
4244 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4245 return true;
4246
4247 /* If the type is marked as addressable (it is required
4248 to be constructed into the stack)... */
4249 if (TREE_ADDRESSABLE (type))
4250 return true;
4251
4252 return false;
4253 }
4254
4255 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4256 takes trailing padding of a structure into account. */
4257 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4258
4259 bool
4260 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type)
4261 {
4262 if (!type)
4263 return false;
4264
4265 /* If the type has variable size... */
4266 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4267 return true;
4268
4269 /* If the type is marked as addressable (it is required
4270 to be constructed into the stack)... */
4271 if (TREE_ADDRESSABLE (type))
4272 return true;
4273
4274 /* If the padding and mode of the type is such that a copy into
4275 a register would put it into the wrong part of the register. */
4276 if (mode == BLKmode
4277 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4278 && (FUNCTION_ARG_PADDING (mode, type)
4279 == (BYTES_BIG_ENDIAN ? upward : downward)))
4280 return true;
4281
4282 return false;
4283 }