Update preferred_stack_boundary only when expanding function call
[gcc.git] / gcc / calls.c
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2019 Free Software Foundation, Inc.
3
4 This file is part of GCC.
5
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
10
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
15
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
19
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "target.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "predict.h"
29 #include "memmodel.h"
30 #include "tm_p.h"
31 #include "stringpool.h"
32 #include "expmed.h"
33 #include "optabs.h"
34 #include "emit-rtl.h"
35 #include "cgraph.h"
36 #include "diagnostic-core.h"
37 #include "fold-const.h"
38 #include "stor-layout.h"
39 #include "varasm.h"
40 #include "internal-fn.h"
41 #include "dojump.h"
42 #include "explow.h"
43 #include "calls.h"
44 #include "expr.h"
45 #include "output.h"
46 #include "langhooks.h"
47 #include "except.h"
48 #include "dbgcnt.h"
49 #include "rtl-iter.h"
50 #include "tree-vrp.h"
51 #include "tree-ssanames.h"
52 #include "tree-ssa-strlen.h"
53 #include "intl.h"
54 #include "stringpool.h"
55 #include "attribs.h"
56 #include "builtins.h"
57 #include "gimple-fold.h"
58
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
61
62 /* Data structure and subroutines used within expand_call. */
63
64 struct arg_data
65 {
66 /* Tree node for this argument. */
67 tree tree_value;
68 /* Mode for value; TYPE_MODE unless promoted. */
69 machine_mode mode;
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
71 rtx value;
72 /* Initially-compute RTL value for argument; only for const functions. */
73 rtx initial_value;
74 /* Register to pass this argument in, 0 if passed on stack, or an
75 PARALLEL if the arg is to be copied into multiple non-contiguous
76 registers. */
77 rtx reg;
78 /* Register to pass this argument in when generating tail call sequence.
79 This is not the same register as for normal calls on machines with
80 register windows. */
81 rtx tail_call_reg;
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
84 rtx parallel_value;
85 /* If REG was promoted from the actual mode of the argument expression,
86 indicates whether the promotion is sign- or zero-extended. */
87 int unsignedp;
88 /* Number of bytes to put in registers. 0 means put the whole arg
89 in registers. Also 0 if not passed in registers. */
90 int partial;
91 /* Nonzero if argument must be passed on stack.
92 Note that some arguments may be passed on the stack
93 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
94 pass_on_stack identifies arguments that *cannot* go in registers. */
95 int pass_on_stack;
96 /* Some fields packaged up for locate_and_pad_parm. */
97 struct locate_and_pad_arg_data locate;
98 /* Location on the stack at which parameter should be stored. The store
99 has already been done if STACK == VALUE. */
100 rtx stack;
101 /* Location on the stack of the start of this argument slot. This can
102 differ from STACK if this arg pads downward. This location is known
103 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
104 rtx stack_slot;
105 /* Place that this stack area has been saved, if needed. */
106 rtx save_area;
107 /* If an argument's alignment does not permit direct copying into registers,
108 copy in smaller-sized pieces into pseudos. These are stored in a
109 block pointed to by this field. The next field says how many
110 word-sized pseudos we made. */
111 rtx *aligned_regs;
112 int n_aligned_regs;
113 };
114
115 /* A vector of one char per byte of stack space. A byte if nonzero if
116 the corresponding stack location has been used.
117 This vector is used to prevent a function call within an argument from
118 clobbering any stack already set up. */
119 static char *stack_usage_map;
120
121 /* Size of STACK_USAGE_MAP. */
122 static unsigned int highest_outgoing_arg_in_use;
123
124 /* Assume that any stack location at this byte index is used,
125 without checking the contents of stack_usage_map. */
126 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
127
128 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
129 stack location's tail call argument has been already stored into the stack.
130 This bitmap is used to prevent sibling call optimization if function tries
131 to use parent's incoming argument slots when they have been already
132 overwritten with tail call arguments. */
133 static sbitmap stored_args_map;
134
135 /* Assume that any virtual-incoming location at this byte index has been
136 stored, without checking the contents of stored_args_map. */
137 static unsigned HOST_WIDE_INT stored_args_watermark;
138
139 /* stack_arg_under_construction is nonzero when an argument may be
140 initialized with a constructor call (including a C function that
141 returns a BLKmode struct) and expand_call must take special action
142 to make sure the object being constructed does not overlap the
143 argument list for the constructor call. */
144 static int stack_arg_under_construction;
145
146 static void precompute_register_parameters (int, struct arg_data *, int *);
147 static int store_one_arg (struct arg_data *, rtx, int, int, int);
148 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
149 static int finalize_must_preallocate (int, int, struct arg_data *,
150 struct args_size *);
151 static void precompute_arguments (int, struct arg_data *);
152 static void compute_argument_addresses (struct arg_data *, rtx, int);
153 static rtx rtx_for_function_call (tree, tree);
154 static void load_register_parameters (struct arg_data *, int, rtx *, int,
155 int, int *);
156 static int special_function_p (const_tree, int);
157 static int check_sibcall_argument_overlap_1 (rtx);
158 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
159
160 static tree split_complex_types (tree);
161
162 #ifdef REG_PARM_STACK_SPACE
163 static rtx save_fixed_argument_area (int, rtx, int *, int *);
164 static void restore_fixed_argument_area (rtx, rtx, int, int);
165 #endif
166 \f
167 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
168 stack region might already be in use. */
169
170 static bool
171 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
172 unsigned int reg_parm_stack_space)
173 {
174 unsigned HOST_WIDE_INT const_lower, const_upper;
175 const_lower = constant_lower_bound (lower_bound);
176 if (!upper_bound.is_constant (&const_upper))
177 const_upper = HOST_WIDE_INT_M1U;
178
179 if (const_upper > stack_usage_watermark)
180 return true;
181
182 /* Don't worry about things in the fixed argument area;
183 it has already been saved. */
184 const_lower = MAX (const_lower, reg_parm_stack_space);
185 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
186 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
187 if (stack_usage_map[i])
188 return true;
189 return false;
190 }
191
192 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
193 stack region are now in use. */
194
195 static void
196 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
197 {
198 unsigned HOST_WIDE_INT const_lower, const_upper;
199 const_lower = constant_lower_bound (lower_bound);
200 if (upper_bound.is_constant (&const_upper))
201 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
202 stack_usage_map[i] = 1;
203 else
204 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
205 }
206
207 /* Force FUNEXP into a form suitable for the address of a CALL,
208 and return that as an rtx. Also load the static chain register
209 if FNDECL is a nested function.
210
211 CALL_FUSAGE points to a variable holding the prospective
212 CALL_INSN_FUNCTION_USAGE information. */
213
214 rtx
215 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
216 rtx *call_fusage, int reg_parm_seen, int flags)
217 {
218 /* Make a valid memory address and copy constants through pseudo-regs,
219 but not for a constant address if -fno-function-cse. */
220 if (GET_CODE (funexp) != SYMBOL_REF)
221 {
222 /* If it's an indirect call by descriptor, generate code to perform
223 runtime identification of the pointer and load the descriptor. */
224 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
225 {
226 const int bit_val = targetm.calls.custom_function_descriptors;
227 rtx call_lab = gen_label_rtx ();
228
229 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
230 fndecl_or_type
231 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
232 fndecl_or_type);
233 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
234 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
235
236 if (GET_MODE (funexp) != Pmode)
237 funexp = convert_memory_address (Pmode, funexp);
238
239 /* Avoid long live ranges around function calls. */
240 funexp = copy_to_mode_reg (Pmode, funexp);
241
242 if (REG_P (chain))
243 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
244
245 /* Emit the runtime identification pattern. */
246 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
247 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
248 call_lab);
249
250 /* Statically predict the branch to very likely taken. */
251 rtx_insn *insn = get_last_insn ();
252 if (JUMP_P (insn))
253 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
254
255 /* Load the descriptor. */
256 rtx mem = gen_rtx_MEM (ptr_mode,
257 plus_constant (Pmode, funexp, - bit_val));
258 MEM_NOTRAP_P (mem) = 1;
259 mem = convert_memory_address (Pmode, mem);
260 emit_move_insn (chain, mem);
261
262 mem = gen_rtx_MEM (ptr_mode,
263 plus_constant (Pmode, funexp,
264 POINTER_SIZE / BITS_PER_UNIT
265 - bit_val));
266 MEM_NOTRAP_P (mem) = 1;
267 mem = convert_memory_address (Pmode, mem);
268 emit_move_insn (funexp, mem);
269
270 emit_label (call_lab);
271
272 if (REG_P (chain))
273 {
274 use_reg (call_fusage, chain);
275 STATIC_CHAIN_REG_P (chain) = 1;
276 }
277
278 /* Make sure we're not going to be overwritten below. */
279 gcc_assert (!static_chain_value);
280 }
281
282 /* If we are using registers for parameters, force the
283 function address into a register now. */
284 funexp = ((reg_parm_seen
285 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
286 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
287 : memory_address (FUNCTION_MODE, funexp));
288 }
289 else
290 {
291 /* funexp could be a SYMBOL_REF represents a function pointer which is
292 of ptr_mode. In this case, it should be converted into address mode
293 to be a valid address for memory rtx pattern. See PR 64971. */
294 if (GET_MODE (funexp) != Pmode)
295 funexp = convert_memory_address (Pmode, funexp);
296
297 if (!(flags & ECF_SIBCALL))
298 {
299 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
300 funexp = force_reg (Pmode, funexp);
301 }
302 }
303
304 if (static_chain_value != 0
305 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
306 || DECL_STATIC_CHAIN (fndecl_or_type)))
307 {
308 rtx chain;
309
310 chain = targetm.calls.static_chain (fndecl_or_type, false);
311 static_chain_value = convert_memory_address (Pmode, static_chain_value);
312
313 emit_move_insn (chain, static_chain_value);
314 if (REG_P (chain))
315 {
316 use_reg (call_fusage, chain);
317 STATIC_CHAIN_REG_P (chain) = 1;
318 }
319 }
320
321 return funexp;
322 }
323
324 /* Generate instructions to call function FUNEXP,
325 and optionally pop the results.
326 The CALL_INSN is the first insn generated.
327
328 FNDECL is the declaration node of the function. This is given to the
329 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
330 its own args.
331
332 FUNTYPE is the data type of the function. This is given to the hook
333 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
334 own args. We used to allow an identifier for library functions, but
335 that doesn't work when the return type is an aggregate type and the
336 calling convention says that the pointer to this aggregate is to be
337 popped by the callee.
338
339 STACK_SIZE is the number of bytes of arguments on the stack,
340 ROUNDED_STACK_SIZE is that number rounded up to
341 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
342 both to put into the call insn and to generate explicit popping
343 code if necessary.
344
345 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
346 It is zero if this call doesn't want a structure value.
347
348 NEXT_ARG_REG is the rtx that results from executing
349 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
350 just after all the args have had their registers assigned.
351 This could be whatever you like, but normally it is the first
352 arg-register beyond those used for args in this call,
353 or 0 if all the arg-registers are used in this call.
354 It is passed on to `gen_call' so you can put this info in the call insn.
355
356 VALREG is a hard register in which a value is returned,
357 or 0 if the call does not return a value.
358
359 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
360 the args to this call were processed.
361 We restore `inhibit_defer_pop' to that value.
362
363 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
364 denote registers used by the called function. */
365
366 static void
367 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
368 tree funtype ATTRIBUTE_UNUSED,
369 poly_int64 stack_size ATTRIBUTE_UNUSED,
370 poly_int64 rounded_stack_size,
371 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
372 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
373 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
374 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
375 {
376 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
377 rtx call, funmem, pat;
378 int already_popped = 0;
379 poly_int64 n_popped = 0;
380
381 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
382 patterns exist). Any popping that the callee does on return will
383 be from our caller's frame rather than ours. */
384 if (!(ecf_flags & ECF_SIBCALL))
385 {
386 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
387
388 #ifdef CALL_POPS_ARGS
389 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
390 #endif
391 }
392
393 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
394 and we don't want to load it into a register as an optimization,
395 because prepare_call_address already did it if it should be done. */
396 if (GET_CODE (funexp) != SYMBOL_REF)
397 funexp = memory_address (FUNCTION_MODE, funexp);
398
399 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
400 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
401 {
402 tree t = fndecl;
403
404 /* Although a built-in FUNCTION_DECL and its non-__builtin
405 counterpart compare equal and get a shared mem_attrs, they
406 produce different dump output in compare-debug compilations,
407 if an entry gets garbage collected in one compilation, then
408 adds a different (but equivalent) entry, while the other
409 doesn't run the garbage collector at the same spot and then
410 shares the mem_attr with the equivalent entry. */
411 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
412 {
413 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
414 if (t2)
415 t = t2;
416 }
417
418 set_mem_expr (funmem, t);
419 }
420 else if (fntree)
421 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
422
423 if (ecf_flags & ECF_SIBCALL)
424 {
425 if (valreg)
426 pat = targetm.gen_sibcall_value (valreg, funmem,
427 rounded_stack_size_rtx,
428 next_arg_reg, NULL_RTX);
429 else
430 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
431 next_arg_reg,
432 gen_int_mode (struct_value_size, Pmode));
433 }
434 /* If the target has "call" or "call_value" insns, then prefer them
435 if no arguments are actually popped. If the target does not have
436 "call" or "call_value" insns, then we must use the popping versions
437 even if the call has no arguments to pop. */
438 else if (maybe_ne (n_popped, 0)
439 || !(valreg
440 ? targetm.have_call_value ()
441 : targetm.have_call ()))
442 {
443 rtx n_pop = gen_int_mode (n_popped, Pmode);
444
445 /* If this subroutine pops its own args, record that in the call insn
446 if possible, for the sake of frame pointer elimination. */
447
448 if (valreg)
449 pat = targetm.gen_call_value_pop (valreg, funmem,
450 rounded_stack_size_rtx,
451 next_arg_reg, n_pop);
452 else
453 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
454 next_arg_reg, n_pop);
455
456 already_popped = 1;
457 }
458 else
459 {
460 if (valreg)
461 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
462 next_arg_reg, NULL_RTX);
463 else
464 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
465 gen_int_mode (struct_value_size, Pmode));
466 }
467 emit_insn (pat);
468
469 /* Find the call we just emitted. */
470 rtx_call_insn *call_insn = last_call_insn ();
471
472 /* Some target create a fresh MEM instead of reusing the one provided
473 above. Set its MEM_EXPR. */
474 call = get_call_rtx_from (call_insn);
475 if (call
476 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
477 && MEM_EXPR (funmem) != NULL_TREE)
478 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
479
480 /* Put the register usage information there. */
481 add_function_usage_to (call_insn, call_fusage);
482
483 /* If this is a const call, then set the insn's unchanging bit. */
484 if (ecf_flags & ECF_CONST)
485 RTL_CONST_CALL_P (call_insn) = 1;
486
487 /* If this is a pure call, then set the insn's unchanging bit. */
488 if (ecf_flags & ECF_PURE)
489 RTL_PURE_CALL_P (call_insn) = 1;
490
491 /* If this is a const call, then set the insn's unchanging bit. */
492 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
493 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
494
495 /* Create a nothrow REG_EH_REGION note, if needed. */
496 make_reg_eh_region_note (call_insn, ecf_flags, 0);
497
498 if (ecf_flags & ECF_NORETURN)
499 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
500
501 if (ecf_flags & ECF_RETURNS_TWICE)
502 {
503 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
504 cfun->calls_setjmp = 1;
505 }
506
507 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
508
509 /* Restore this now, so that we do defer pops for this call's args
510 if the context of the call as a whole permits. */
511 inhibit_defer_pop = old_inhibit_defer_pop;
512
513 if (maybe_ne (n_popped, 0))
514 {
515 if (!already_popped)
516 CALL_INSN_FUNCTION_USAGE (call_insn)
517 = gen_rtx_EXPR_LIST (VOIDmode,
518 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
519 CALL_INSN_FUNCTION_USAGE (call_insn));
520 rounded_stack_size -= n_popped;
521 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
522 stack_pointer_delta -= n_popped;
523
524 add_args_size_note (call_insn, stack_pointer_delta);
525
526 /* If popup is needed, stack realign must use DRAP */
527 if (SUPPORTS_STACK_ALIGNMENT)
528 crtl->need_drap = true;
529 }
530 /* For noreturn calls when not accumulating outgoing args force
531 REG_ARGS_SIZE note to prevent crossjumping of calls with different
532 args sizes. */
533 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
534 add_args_size_note (call_insn, stack_pointer_delta);
535
536 if (!ACCUMULATE_OUTGOING_ARGS)
537 {
538 /* If returning from the subroutine does not automatically pop the args,
539 we need an instruction to pop them sooner or later.
540 Perhaps do it now; perhaps just record how much space to pop later.
541
542 If returning from the subroutine does pop the args, indicate that the
543 stack pointer will be changed. */
544
545 if (maybe_ne (rounded_stack_size, 0))
546 {
547 if (ecf_flags & ECF_NORETURN)
548 /* Just pretend we did the pop. */
549 stack_pointer_delta -= rounded_stack_size;
550 else if (flag_defer_pop && inhibit_defer_pop == 0
551 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
552 pending_stack_adjust += rounded_stack_size;
553 else
554 adjust_stack (rounded_stack_size_rtx);
555 }
556 }
557 /* When we accumulate outgoing args, we must avoid any stack manipulations.
558 Restore the stack pointer to its original value now. Usually
559 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
560 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
561 popping variants of functions exist as well.
562
563 ??? We may optimize similar to defer_pop above, but it is
564 probably not worthwhile.
565
566 ??? It will be worthwhile to enable combine_stack_adjustments even for
567 such machines. */
568 else if (maybe_ne (n_popped, 0))
569 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
570 }
571
572 /* Determine if the function identified by FNDECL is one with
573 special properties we wish to know about. Modify FLAGS accordingly.
574
575 For example, if the function might return more than one time (setjmp), then
576 set ECF_RETURNS_TWICE.
577
578 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
579 space from the stack such as alloca. */
580
581 static int
582 special_function_p (const_tree fndecl, int flags)
583 {
584 tree name_decl = DECL_NAME (fndecl);
585
586 if (fndecl && name_decl
587 && IDENTIFIER_LENGTH (name_decl) <= 11
588 /* Exclude functions not at the file scope, or not `extern',
589 since they are not the magic functions we would otherwise
590 think they are.
591 FIXME: this should be handled with attributes, not with this
592 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
593 because you can declare fork() inside a function if you
594 wish. */
595 && (DECL_CONTEXT (fndecl) == NULL_TREE
596 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
597 && TREE_PUBLIC (fndecl))
598 {
599 const char *name = IDENTIFIER_POINTER (name_decl);
600 const char *tname = name;
601
602 /* We assume that alloca will always be called by name. It
603 makes no sense to pass it as a pointer-to-function to
604 anything that does not understand its behavior. */
605 if (IDENTIFIER_LENGTH (name_decl) == 6
606 && name[0] == 'a'
607 && ! strcmp (name, "alloca"))
608 flags |= ECF_MAY_BE_ALLOCA;
609
610 /* Disregard prefix _ or __. */
611 if (name[0] == '_')
612 {
613 if (name[1] == '_')
614 tname += 2;
615 else
616 tname += 1;
617 }
618
619 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
620 if (! strcmp (tname, "setjmp")
621 || ! strcmp (tname, "sigsetjmp")
622 || ! strcmp (name, "savectx")
623 || ! strcmp (name, "vfork")
624 || ! strcmp (name, "getcontext"))
625 flags |= ECF_RETURNS_TWICE;
626 }
627
628 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
629 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
630 flags |= ECF_MAY_BE_ALLOCA;
631
632 return flags;
633 }
634
635 /* Similar to special_function_p; return a set of ERF_ flags for the
636 function FNDECL. */
637 static int
638 decl_return_flags (tree fndecl)
639 {
640 tree attr;
641 tree type = TREE_TYPE (fndecl);
642 if (!type)
643 return 0;
644
645 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
646 if (!attr)
647 return 0;
648
649 attr = TREE_VALUE (TREE_VALUE (attr));
650 if (!attr || TREE_STRING_LENGTH (attr) < 1)
651 return 0;
652
653 switch (TREE_STRING_POINTER (attr)[0])
654 {
655 case '1':
656 case '2':
657 case '3':
658 case '4':
659 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
660
661 case 'm':
662 return ERF_NOALIAS;
663
664 case '.':
665 default:
666 return 0;
667 }
668 }
669
670 /* Return nonzero when FNDECL represents a call to setjmp. */
671
672 int
673 setjmp_call_p (const_tree fndecl)
674 {
675 if (DECL_IS_RETURNS_TWICE (fndecl))
676 return ECF_RETURNS_TWICE;
677 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
678 }
679
680
681 /* Return true if STMT may be an alloca call. */
682
683 bool
684 gimple_maybe_alloca_call_p (const gimple *stmt)
685 {
686 tree fndecl;
687
688 if (!is_gimple_call (stmt))
689 return false;
690
691 fndecl = gimple_call_fndecl (stmt);
692 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
693 return true;
694
695 return false;
696 }
697
698 /* Return true if STMT is a builtin alloca call. */
699
700 bool
701 gimple_alloca_call_p (const gimple *stmt)
702 {
703 tree fndecl;
704
705 if (!is_gimple_call (stmt))
706 return false;
707
708 fndecl = gimple_call_fndecl (stmt);
709 if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
710 switch (DECL_FUNCTION_CODE (fndecl))
711 {
712 CASE_BUILT_IN_ALLOCA:
713 return gimple_call_num_args (stmt) > 0;
714 default:
715 break;
716 }
717
718 return false;
719 }
720
721 /* Return true when exp contains a builtin alloca call. */
722
723 bool
724 alloca_call_p (const_tree exp)
725 {
726 tree fndecl;
727 if (TREE_CODE (exp) == CALL_EXPR
728 && (fndecl = get_callee_fndecl (exp))
729 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
730 switch (DECL_FUNCTION_CODE (fndecl))
731 {
732 CASE_BUILT_IN_ALLOCA:
733 return true;
734 default:
735 break;
736 }
737
738 return false;
739 }
740
741 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
742 function. Return FALSE otherwise. */
743
744 static bool
745 is_tm_builtin (const_tree fndecl)
746 {
747 if (fndecl == NULL)
748 return false;
749
750 if (decl_is_tm_clone (fndecl))
751 return true;
752
753 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
754 {
755 switch (DECL_FUNCTION_CODE (fndecl))
756 {
757 case BUILT_IN_TM_COMMIT:
758 case BUILT_IN_TM_COMMIT_EH:
759 case BUILT_IN_TM_ABORT:
760 case BUILT_IN_TM_IRREVOCABLE:
761 case BUILT_IN_TM_GETTMCLONE_IRR:
762 case BUILT_IN_TM_MEMCPY:
763 case BUILT_IN_TM_MEMMOVE:
764 case BUILT_IN_TM_MEMSET:
765 CASE_BUILT_IN_TM_STORE (1):
766 CASE_BUILT_IN_TM_STORE (2):
767 CASE_BUILT_IN_TM_STORE (4):
768 CASE_BUILT_IN_TM_STORE (8):
769 CASE_BUILT_IN_TM_STORE (FLOAT):
770 CASE_BUILT_IN_TM_STORE (DOUBLE):
771 CASE_BUILT_IN_TM_STORE (LDOUBLE):
772 CASE_BUILT_IN_TM_STORE (M64):
773 CASE_BUILT_IN_TM_STORE (M128):
774 CASE_BUILT_IN_TM_STORE (M256):
775 CASE_BUILT_IN_TM_LOAD (1):
776 CASE_BUILT_IN_TM_LOAD (2):
777 CASE_BUILT_IN_TM_LOAD (4):
778 CASE_BUILT_IN_TM_LOAD (8):
779 CASE_BUILT_IN_TM_LOAD (FLOAT):
780 CASE_BUILT_IN_TM_LOAD (DOUBLE):
781 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
782 CASE_BUILT_IN_TM_LOAD (M64):
783 CASE_BUILT_IN_TM_LOAD (M128):
784 CASE_BUILT_IN_TM_LOAD (M256):
785 case BUILT_IN_TM_LOG:
786 case BUILT_IN_TM_LOG_1:
787 case BUILT_IN_TM_LOG_2:
788 case BUILT_IN_TM_LOG_4:
789 case BUILT_IN_TM_LOG_8:
790 case BUILT_IN_TM_LOG_FLOAT:
791 case BUILT_IN_TM_LOG_DOUBLE:
792 case BUILT_IN_TM_LOG_LDOUBLE:
793 case BUILT_IN_TM_LOG_M64:
794 case BUILT_IN_TM_LOG_M128:
795 case BUILT_IN_TM_LOG_M256:
796 return true;
797 default:
798 break;
799 }
800 }
801 return false;
802 }
803
804 /* Detect flags (function attributes) from the function decl or type node. */
805
806 int
807 flags_from_decl_or_type (const_tree exp)
808 {
809 int flags = 0;
810
811 if (DECL_P (exp))
812 {
813 /* The function exp may have the `malloc' attribute. */
814 if (DECL_IS_MALLOC (exp))
815 flags |= ECF_MALLOC;
816
817 /* The function exp may have the `returns_twice' attribute. */
818 if (DECL_IS_RETURNS_TWICE (exp))
819 flags |= ECF_RETURNS_TWICE;
820
821 /* Process the pure and const attributes. */
822 if (TREE_READONLY (exp))
823 flags |= ECF_CONST;
824 if (DECL_PURE_P (exp))
825 flags |= ECF_PURE;
826 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
827 flags |= ECF_LOOPING_CONST_OR_PURE;
828
829 if (DECL_IS_NOVOPS (exp))
830 flags |= ECF_NOVOPS;
831 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
832 flags |= ECF_LEAF;
833 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
834 flags |= ECF_COLD;
835
836 if (TREE_NOTHROW (exp))
837 flags |= ECF_NOTHROW;
838
839 if (flag_tm)
840 {
841 if (is_tm_builtin (exp))
842 flags |= ECF_TM_BUILTIN;
843 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
844 || lookup_attribute ("transaction_pure",
845 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
846 flags |= ECF_TM_PURE;
847 }
848
849 flags = special_function_p (exp, flags);
850 }
851 else if (TYPE_P (exp))
852 {
853 if (TYPE_READONLY (exp))
854 flags |= ECF_CONST;
855
856 if (flag_tm
857 && ((flags & ECF_CONST) != 0
858 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
859 flags |= ECF_TM_PURE;
860 }
861 else
862 gcc_unreachable ();
863
864 if (TREE_THIS_VOLATILE (exp))
865 {
866 flags |= ECF_NORETURN;
867 if (flags & (ECF_CONST|ECF_PURE))
868 flags |= ECF_LOOPING_CONST_OR_PURE;
869 }
870
871 return flags;
872 }
873
874 /* Detect flags from a CALL_EXPR. */
875
876 int
877 call_expr_flags (const_tree t)
878 {
879 int flags;
880 tree decl = get_callee_fndecl (t);
881
882 if (decl)
883 flags = flags_from_decl_or_type (decl);
884 else if (CALL_EXPR_FN (t) == NULL_TREE)
885 flags = internal_fn_flags (CALL_EXPR_IFN (t));
886 else
887 {
888 tree type = TREE_TYPE (CALL_EXPR_FN (t));
889 if (type && TREE_CODE (type) == POINTER_TYPE)
890 flags = flags_from_decl_or_type (TREE_TYPE (type));
891 else
892 flags = 0;
893 if (CALL_EXPR_BY_DESCRIPTOR (t))
894 flags |= ECF_BY_DESCRIPTOR;
895 }
896
897 return flags;
898 }
899
900 /* Return true if TYPE should be passed by invisible reference. */
901
902 bool
903 pass_by_reference (CUMULATIVE_ARGS *ca, machine_mode mode,
904 tree type, bool named_arg)
905 {
906 if (type)
907 {
908 /* If this type contains non-trivial constructors, then it is
909 forbidden for the middle-end to create any new copies. */
910 if (TREE_ADDRESSABLE (type))
911 return true;
912
913 /* GCC post 3.4 passes *all* variable sized types by reference. */
914 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
915 return true;
916
917 /* If a record type should be passed the same as its first (and only)
918 member, use the type and mode of that member. */
919 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
920 {
921 type = TREE_TYPE (first_field (type));
922 mode = TYPE_MODE (type);
923 }
924 }
925
926 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), mode,
927 type, named_arg);
928 }
929
930 /* Return true if TYPE, which is passed by reference, should be callee
931 copied instead of caller copied. */
932
933 bool
934 reference_callee_copied (CUMULATIVE_ARGS *ca, machine_mode mode,
935 tree type, bool named_arg)
936 {
937 if (type && TREE_ADDRESSABLE (type))
938 return false;
939 return targetm.calls.callee_copies (pack_cumulative_args (ca), mode, type,
940 named_arg);
941 }
942
943
944 /* Precompute all register parameters as described by ARGS, storing values
945 into fields within the ARGS array.
946
947 NUM_ACTUALS indicates the total number elements in the ARGS array.
948
949 Set REG_PARM_SEEN if we encounter a register parameter. */
950
951 static void
952 precompute_register_parameters (int num_actuals, struct arg_data *args,
953 int *reg_parm_seen)
954 {
955 int i;
956
957 *reg_parm_seen = 0;
958
959 for (i = 0; i < num_actuals; i++)
960 if (args[i].reg != 0 && ! args[i].pass_on_stack)
961 {
962 *reg_parm_seen = 1;
963
964 if (args[i].value == 0)
965 {
966 push_temp_slots ();
967 args[i].value = expand_normal (args[i].tree_value);
968 preserve_temp_slots (args[i].value);
969 pop_temp_slots ();
970 }
971
972 /* If we are to promote the function arg to a wider mode,
973 do it now. */
974
975 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
976 args[i].value
977 = convert_modes (args[i].mode,
978 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
979 args[i].value, args[i].unsignedp);
980
981 /* If the value is a non-legitimate constant, force it into a
982 pseudo now. TLS symbols sometimes need a call to resolve. */
983 if (CONSTANT_P (args[i].value)
984 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
985 args[i].value = force_reg (args[i].mode, args[i].value);
986
987 /* If we're going to have to load the value by parts, pull the
988 parts into pseudos. The part extraction process can involve
989 non-trivial computation. */
990 if (GET_CODE (args[i].reg) == PARALLEL)
991 {
992 tree type = TREE_TYPE (args[i].tree_value);
993 args[i].parallel_value
994 = emit_group_load_into_temps (args[i].reg, args[i].value,
995 type, int_size_in_bytes (type));
996 }
997
998 /* If the value is expensive, and we are inside an appropriately
999 short loop, put the value into a pseudo and then put the pseudo
1000 into the hard reg.
1001
1002 For small register classes, also do this if this call uses
1003 register parameters. This is to avoid reload conflicts while
1004 loading the parameters registers. */
1005
1006 else if ((! (REG_P (args[i].value)
1007 || (GET_CODE (args[i].value) == SUBREG
1008 && REG_P (SUBREG_REG (args[i].value)))))
1009 && args[i].mode != BLKmode
1010 && (set_src_cost (args[i].value, args[i].mode,
1011 optimize_insn_for_speed_p ())
1012 > COSTS_N_INSNS (1))
1013 && ((*reg_parm_seen
1014 && targetm.small_register_classes_for_mode_p (args[i].mode))
1015 || optimize))
1016 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1017 }
1018 }
1019
1020 #ifdef REG_PARM_STACK_SPACE
1021
1022 /* The argument list is the property of the called routine and it
1023 may clobber it. If the fixed area has been used for previous
1024 parameters, we must save and restore it. */
1025
1026 static rtx
1027 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1028 {
1029 unsigned int low;
1030 unsigned int high;
1031
1032 /* Compute the boundary of the area that needs to be saved, if any. */
1033 high = reg_parm_stack_space;
1034 if (ARGS_GROW_DOWNWARD)
1035 high += 1;
1036
1037 if (high > highest_outgoing_arg_in_use)
1038 high = highest_outgoing_arg_in_use;
1039
1040 for (low = 0; low < high; low++)
1041 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1042 {
1043 int num_to_save;
1044 machine_mode save_mode;
1045 int delta;
1046 rtx addr;
1047 rtx stack_area;
1048 rtx save_area;
1049
1050 while (stack_usage_map[--high] == 0)
1051 ;
1052
1053 *low_to_save = low;
1054 *high_to_save = high;
1055
1056 num_to_save = high - low + 1;
1057
1058 /* If we don't have the required alignment, must do this
1059 in BLKmode. */
1060 scalar_int_mode imode;
1061 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1062 && (low & (MIN (GET_MODE_SIZE (imode),
1063 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1064 save_mode = imode;
1065 else
1066 save_mode = BLKmode;
1067
1068 if (ARGS_GROW_DOWNWARD)
1069 delta = -high;
1070 else
1071 delta = low;
1072
1073 addr = plus_constant (Pmode, argblock, delta);
1074 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1075
1076 set_mem_align (stack_area, PARM_BOUNDARY);
1077 if (save_mode == BLKmode)
1078 {
1079 save_area = assign_stack_temp (BLKmode, num_to_save);
1080 emit_block_move (validize_mem (save_area), stack_area,
1081 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1082 }
1083 else
1084 {
1085 save_area = gen_reg_rtx (save_mode);
1086 emit_move_insn (save_area, stack_area);
1087 }
1088
1089 return save_area;
1090 }
1091
1092 return NULL_RTX;
1093 }
1094
1095 static void
1096 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1097 {
1098 machine_mode save_mode = GET_MODE (save_area);
1099 int delta;
1100 rtx addr, stack_area;
1101
1102 if (ARGS_GROW_DOWNWARD)
1103 delta = -high_to_save;
1104 else
1105 delta = low_to_save;
1106
1107 addr = plus_constant (Pmode, argblock, delta);
1108 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1109 set_mem_align (stack_area, PARM_BOUNDARY);
1110
1111 if (save_mode != BLKmode)
1112 emit_move_insn (stack_area, save_area);
1113 else
1114 emit_block_move (stack_area, validize_mem (save_area),
1115 GEN_INT (high_to_save - low_to_save + 1),
1116 BLOCK_OP_CALL_PARM);
1117 }
1118 #endif /* REG_PARM_STACK_SPACE */
1119
1120 /* If any elements in ARGS refer to parameters that are to be passed in
1121 registers, but not in memory, and whose alignment does not permit a
1122 direct copy into registers. Copy the values into a group of pseudos
1123 which we will later copy into the appropriate hard registers.
1124
1125 Pseudos for each unaligned argument will be stored into the array
1126 args[argnum].aligned_regs. The caller is responsible for deallocating
1127 the aligned_regs array if it is nonzero. */
1128
1129 static void
1130 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1131 {
1132 int i, j;
1133
1134 for (i = 0; i < num_actuals; i++)
1135 if (args[i].reg != 0 && ! args[i].pass_on_stack
1136 && GET_CODE (args[i].reg) != PARALLEL
1137 && args[i].mode == BLKmode
1138 && MEM_P (args[i].value)
1139 && (MEM_ALIGN (args[i].value)
1140 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1141 {
1142 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1143 int endian_correction = 0;
1144
1145 if (args[i].partial)
1146 {
1147 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1148 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1149 }
1150 else
1151 {
1152 args[i].n_aligned_regs
1153 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1154 }
1155
1156 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1157
1158 /* Structures smaller than a word are normally aligned to the
1159 least significant byte. On a BYTES_BIG_ENDIAN machine,
1160 this means we must skip the empty high order bytes when
1161 calculating the bit offset. */
1162 if (bytes < UNITS_PER_WORD
1163 #ifdef BLOCK_REG_PADDING
1164 && (BLOCK_REG_PADDING (args[i].mode,
1165 TREE_TYPE (args[i].tree_value), 1)
1166 == PAD_DOWNWARD)
1167 #else
1168 && BYTES_BIG_ENDIAN
1169 #endif
1170 )
1171 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1172
1173 for (j = 0; j < args[i].n_aligned_regs; j++)
1174 {
1175 rtx reg = gen_reg_rtx (word_mode);
1176 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1177 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1178
1179 args[i].aligned_regs[j] = reg;
1180 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1181 word_mode, word_mode, false, NULL);
1182
1183 /* There is no need to restrict this code to loading items
1184 in TYPE_ALIGN sized hunks. The bitfield instructions can
1185 load up entire word sized registers efficiently.
1186
1187 ??? This may not be needed anymore.
1188 We use to emit a clobber here but that doesn't let later
1189 passes optimize the instructions we emit. By storing 0 into
1190 the register later passes know the first AND to zero out the
1191 bitfield being set in the register is unnecessary. The store
1192 of 0 will be deleted as will at least the first AND. */
1193
1194 emit_move_insn (reg, const0_rtx);
1195
1196 bytes -= bitsize / BITS_PER_UNIT;
1197 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1198 word_mode, word, false);
1199 }
1200 }
1201 }
1202
1203 /* The limit set by -Walloc-larger-than=. */
1204 static GTY(()) tree alloc_object_size_limit;
1205
1206 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1207 setting if the option is specified, or to the maximum object size if it
1208 is not. Return the initialized value. */
1209
1210 static tree
1211 alloc_max_size (void)
1212 {
1213 if (alloc_object_size_limit)
1214 return alloc_object_size_limit;
1215
1216 HOST_WIDE_INT limit = warn_alloc_size_limit;
1217 if (limit == HOST_WIDE_INT_MAX)
1218 limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node));
1219
1220 alloc_object_size_limit = build_int_cst (size_type_node, limit);
1221
1222 return alloc_object_size_limit;
1223 }
1224
1225 /* Return true when EXP's range can be determined and set RANGE[] to it
1226 after adjusting it if necessary to make EXP a represents a valid size
1227 of object, or a valid size argument to an allocation function declared
1228 with attribute alloc_size (whose argument may be signed), or to a string
1229 manipulation function like memset. When ALLOW_ZERO is true, allow
1230 returning a range of [0, 0] for a size in an anti-range [1, N] where
1231 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1232 allocation functions like malloc but it is a valid argument to
1233 functions like memset. */
1234
1235 bool
1236 get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
1237 {
1238 if (tree_fits_uhwi_p (exp))
1239 {
1240 /* EXP is a constant. */
1241 range[0] = range[1] = exp;
1242 return true;
1243 }
1244
1245 tree exptype = TREE_TYPE (exp);
1246 bool integral = INTEGRAL_TYPE_P (exptype);
1247
1248 wide_int min, max;
1249 enum value_range_kind range_type;
1250
1251 if (integral)
1252 range_type = determine_value_range (exp, &min, &max);
1253 else
1254 range_type = VR_VARYING;
1255
1256 if (range_type == VR_VARYING)
1257 {
1258 if (integral)
1259 {
1260 /* Use the full range of the type of the expression when
1261 no value range information is available. */
1262 range[0] = TYPE_MIN_VALUE (exptype);
1263 range[1] = TYPE_MAX_VALUE (exptype);
1264 return true;
1265 }
1266
1267 range[0] = NULL_TREE;
1268 range[1] = NULL_TREE;
1269 return false;
1270 }
1271
1272 unsigned expprec = TYPE_PRECISION (exptype);
1273
1274 bool signed_p = !TYPE_UNSIGNED (exptype);
1275
1276 if (range_type == VR_ANTI_RANGE)
1277 {
1278 if (signed_p)
1279 {
1280 if (wi::les_p (max, 0))
1281 {
1282 /* EXP is not in a strictly negative range. That means
1283 it must be in some (not necessarily strictly) positive
1284 range which includes zero. Since in signed to unsigned
1285 conversions negative values end up converted to large
1286 positive values, and otherwise they are not valid sizes,
1287 the resulting range is in both cases [0, TYPE_MAX]. */
1288 min = wi::zero (expprec);
1289 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1290 }
1291 else if (wi::les_p (min - 1, 0))
1292 {
1293 /* EXP is not in a negative-positive range. That means EXP
1294 is either negative, or greater than max. Since negative
1295 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1296 min = max + 1;
1297 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1298 }
1299 else
1300 {
1301 max = min - 1;
1302 min = wi::zero (expprec);
1303 }
1304 }
1305 else if (wi::eq_p (0, min - 1))
1306 {
1307 /* EXP is unsigned and not in the range [1, MAX]. That means
1308 it's either zero or greater than MAX. Even though 0 would
1309 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1310 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1311 is greater than the limit the whole range is diagnosed. */
1312 if (allow_zero)
1313 min = max = wi::zero (expprec);
1314 else
1315 {
1316 min = max + 1;
1317 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1318 }
1319 }
1320 else
1321 {
1322 max = min - 1;
1323 min = wi::zero (expprec);
1324 }
1325 }
1326
1327 range[0] = wide_int_to_tree (exptype, min);
1328 range[1] = wide_int_to_tree (exptype, max);
1329
1330 return true;
1331 }
1332
1333 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1334 whose argument numbers given by IDX with values given by ARGS exceed
1335 the maximum object size or cause an unsigned oveflow (wrapping) when
1336 multiplied. FN is null when EXP is a call via a function pointer.
1337 When ARGS[0] is null the function does nothing. ARGS[1] may be null
1338 for functions like malloc, and non-null for those like calloc that
1339 are decorated with a two-argument attribute alloc_size. */
1340
1341 void
1342 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1343 {
1344 /* The range each of the (up to) two arguments is known to be in. */
1345 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1346
1347 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1348 tree maxobjsize = alloc_max_size ();
1349
1350 location_t loc = EXPR_LOCATION (exp);
1351
1352 tree fntype = fn ? TREE_TYPE (fn) : TREE_TYPE (TREE_TYPE (exp));
1353 built_in_function fncode = fn ? DECL_FUNCTION_CODE (fn) : BUILT_IN_NONE;
1354 bool warned = false;
1355
1356 /* Validate each argument individually. */
1357 for (unsigned i = 0; i != 2 && args[i]; ++i)
1358 {
1359 if (TREE_CODE (args[i]) == INTEGER_CST)
1360 {
1361 argrange[i][0] = args[i];
1362 argrange[i][1] = args[i];
1363
1364 if (tree_int_cst_lt (args[i], integer_zero_node))
1365 {
1366 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1367 "%Kargument %i value %qE is negative",
1368 exp, idx[i] + 1, args[i]);
1369 }
1370 else if (integer_zerop (args[i]))
1371 {
1372 /* Avoid issuing -Walloc-zero for allocation functions other
1373 than __builtin_alloca that are declared with attribute
1374 returns_nonnull because there's no portability risk. This
1375 avoids warning for such calls to libiberty's xmalloc and
1376 friends.
1377 Also avoid issuing the warning for calls to function named
1378 "alloca". */
1379 if ((fncode == BUILT_IN_ALLOCA
1380 && IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6)
1381 || (fncode != BUILT_IN_ALLOCA
1382 && !lookup_attribute ("returns_nonnull",
1383 TYPE_ATTRIBUTES (fntype))))
1384 warned = warning_at (loc, OPT_Walloc_zero,
1385 "%Kargument %i value is zero",
1386 exp, idx[i] + 1);
1387 }
1388 else if (tree_int_cst_lt (maxobjsize, args[i]))
1389 {
1390 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1391 mode and with -fno-exceptions as a way to indicate array
1392 size overflow. There's no good way to detect C++98 here
1393 so avoid diagnosing these calls for all C++ modes. */
1394 if (i == 0
1395 && fn
1396 && !args[1]
1397 && lang_GNU_CXX ()
1398 && DECL_IS_OPERATOR_NEW (fn)
1399 && integer_all_onesp (args[i]))
1400 continue;
1401
1402 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1403 "%Kargument %i value %qE exceeds "
1404 "maximum object size %E",
1405 exp, idx[i] + 1, args[i], maxobjsize);
1406 }
1407 }
1408 else if (TREE_CODE (args[i]) == SSA_NAME
1409 && get_size_range (args[i], argrange[i]))
1410 {
1411 /* Verify that the argument's range is not negative (including
1412 upper bound of zero). */
1413 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1414 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1415 {
1416 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1417 "%Kargument %i range [%E, %E] is negative",
1418 exp, idx[i] + 1,
1419 argrange[i][0], argrange[i][1]);
1420 }
1421 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1422 {
1423 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1424 "%Kargument %i range [%E, %E] exceeds "
1425 "maximum object size %E",
1426 exp, idx[i] + 1,
1427 argrange[i][0], argrange[i][1],
1428 maxobjsize);
1429 }
1430 }
1431 }
1432
1433 if (!argrange[0])
1434 return;
1435
1436 /* For a two-argument alloc_size, validate the product of the two
1437 arguments if both of their values or ranges are known. */
1438 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1439 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1440 && !integer_onep (argrange[0][0])
1441 && !integer_onep (argrange[1][0]))
1442 {
1443 /* Check for overflow in the product of a function decorated with
1444 attribute alloc_size (X, Y). */
1445 unsigned szprec = TYPE_PRECISION (size_type_node);
1446 wide_int x = wi::to_wide (argrange[0][0], szprec);
1447 wide_int y = wi::to_wide (argrange[1][0], szprec);
1448
1449 wi::overflow_type vflow;
1450 wide_int prod = wi::umul (x, y, &vflow);
1451
1452 if (vflow)
1453 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1454 "%Kproduct %<%E * %E%> of arguments %i and %i "
1455 "exceeds %<SIZE_MAX%>",
1456 exp, argrange[0][0], argrange[1][0],
1457 idx[0] + 1, idx[1] + 1);
1458 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1459 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1460 "%Kproduct %<%E * %E%> of arguments %i and %i "
1461 "exceeds maximum object size %E",
1462 exp, argrange[0][0], argrange[1][0],
1463 idx[0] + 1, idx[1] + 1,
1464 maxobjsize);
1465
1466 if (warned)
1467 {
1468 /* Print the full range of each of the two arguments to make
1469 it clear when it is, in fact, in a range and not constant. */
1470 if (argrange[0][0] != argrange [0][1])
1471 inform (loc, "argument %i in the range [%E, %E]",
1472 idx[0] + 1, argrange[0][0], argrange[0][1]);
1473 if (argrange[1][0] != argrange [1][1])
1474 inform (loc, "argument %i in the range [%E, %E]",
1475 idx[1] + 1, argrange[1][0], argrange[1][1]);
1476 }
1477 }
1478
1479 if (warned && fn)
1480 {
1481 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1482
1483 if (DECL_IS_BUILTIN (fn))
1484 inform (loc,
1485 "in a call to built-in allocation function %qD", fn);
1486 else
1487 inform (fnloc,
1488 "in a call to allocation function %qD declared here", fn);
1489 }
1490 }
1491
1492 /* If EXPR refers to a character array or pointer declared attribute
1493 nonstring return a decl for that array or pointer and set *REF to
1494 the referenced enclosing object or pointer. Otherwise returns
1495 null. */
1496
1497 tree
1498 get_attr_nonstring_decl (tree expr, tree *ref)
1499 {
1500 tree decl = expr;
1501 tree var = NULL_TREE;
1502 if (TREE_CODE (decl) == SSA_NAME)
1503 {
1504 gimple *def = SSA_NAME_DEF_STMT (decl);
1505
1506 if (is_gimple_assign (def))
1507 {
1508 tree_code code = gimple_assign_rhs_code (def);
1509 if (code == ADDR_EXPR
1510 || code == COMPONENT_REF
1511 || code == VAR_DECL)
1512 decl = gimple_assign_rhs1 (def);
1513 }
1514 else
1515 var = SSA_NAME_VAR (decl);
1516 }
1517
1518 if (TREE_CODE (decl) == ADDR_EXPR)
1519 decl = TREE_OPERAND (decl, 0);
1520
1521 /* To simplify calling code, store the referenced DECL regardless of
1522 the attribute determined below, but avoid storing the SSA_NAME_VAR
1523 obtained above (it's not useful for dataflow purposes). */
1524 if (ref)
1525 *ref = decl;
1526
1527 /* Use the SSA_NAME_VAR that was determined above to see if it's
1528 declared nonstring. Otherwise drill down into the referenced
1529 DECL. */
1530 if (var)
1531 decl = var;
1532 else if (TREE_CODE (decl) == ARRAY_REF)
1533 decl = TREE_OPERAND (decl, 0);
1534 else if (TREE_CODE (decl) == COMPONENT_REF)
1535 decl = TREE_OPERAND (decl, 1);
1536 else if (TREE_CODE (decl) == MEM_REF)
1537 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1538
1539 if (DECL_P (decl)
1540 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1541 return decl;
1542
1543 return NULL_TREE;
1544 }
1545
1546 /* Warn about passing a non-string array/pointer to a function that
1547 expects a nul-terminated string argument. */
1548
1549 void
1550 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1551 {
1552 if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
1553 return;
1554
1555 if (TREE_NO_WARNING (exp) || !warn_stringop_overflow)
1556 return;
1557
1558 /* Avoid clearly invalid calls (more checking done below). */
1559 unsigned nargs = call_expr_nargs (exp);
1560 if (!nargs)
1561 return;
1562
1563 /* The bound argument to a bounded string function like strncpy. */
1564 tree bound = NULL_TREE;
1565
1566 /* The longest known or possible string argument to one of the comparison
1567 functions. If the length is less than the bound it is used instead.
1568 Since the length is only used for warning and not for code generation
1569 disable strict mode in the calls to get_range_strlen below. */
1570 tree maxlen = NULL_TREE;
1571
1572 /* It's safe to call "bounded" string functions with a non-string
1573 argument since the functions provide an explicit bound for this
1574 purpose. The exception is strncat where the bound may refer to
1575 either the destination or the source. */
1576 int fncode = DECL_FUNCTION_CODE (fndecl);
1577 switch (fncode)
1578 {
1579 case BUILT_IN_STRCMP:
1580 case BUILT_IN_STRNCMP:
1581 case BUILT_IN_STRNCASECMP:
1582 {
1583 /* For these, if one argument refers to one or more of a set
1584 of string constants or arrays of known size, determine
1585 the range of their known or possible lengths and use it
1586 conservatively as the bound for the unbounded function,
1587 and to adjust the range of the bound of the bounded ones. */
1588 for (unsigned argno = 0;
1589 argno < MIN (nargs, 2)
1590 && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++)
1591 {
1592 tree arg = CALL_EXPR_ARG (exp, argno);
1593 if (!get_attr_nonstring_decl (arg))
1594 {
1595 c_strlen_data lendata = { };
1596 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1597 maxlen = lendata.maxbound;
1598 }
1599 }
1600 }
1601 /* Fall through. */
1602
1603 case BUILT_IN_STRNCAT:
1604 case BUILT_IN_STPNCPY:
1605 case BUILT_IN_STRNCPY:
1606 if (nargs > 2)
1607 bound = CALL_EXPR_ARG (exp, 2);
1608 break;
1609
1610 case BUILT_IN_STRNDUP:
1611 if (nargs > 1)
1612 bound = CALL_EXPR_ARG (exp, 1);
1613 break;
1614
1615 case BUILT_IN_STRNLEN:
1616 {
1617 tree arg = CALL_EXPR_ARG (exp, 0);
1618 if (!get_attr_nonstring_decl (arg))
1619 {
1620 c_strlen_data lendata = { };
1621 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1622 maxlen = lendata.maxbound;
1623 }
1624 if (nargs > 1)
1625 bound = CALL_EXPR_ARG (exp, 1);
1626 break;
1627 }
1628
1629 default:
1630 break;
1631 }
1632
1633 /* Determine the range of the bound argument (if specified). */
1634 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1635 if (bound)
1636 {
1637 STRIP_NOPS (bound);
1638 get_size_range (bound, bndrng);
1639 }
1640
1641 location_t loc = EXPR_LOCATION (exp);
1642
1643 if (bndrng[0])
1644 {
1645 /* Diagnose excessive bound prior the adjustment below and
1646 regardless of attribute nonstring. */
1647 tree maxobjsize = max_object_size ();
1648 if (tree_int_cst_lt (maxobjsize, bndrng[0]))
1649 {
1650 if (tree_int_cst_equal (bndrng[0], bndrng[1]))
1651 warning_at (loc, OPT_Wstringop_overflow_,
1652 "%K%qD specified bound %E "
1653 "exceeds maximum object size %E",
1654 exp, fndecl, bndrng[0], maxobjsize);
1655 else
1656 warning_at (loc, OPT_Wstringop_overflow_,
1657 "%K%qD specified bound [%E, %E] "
1658 "exceeds maximum object size %E",
1659 exp, fndecl, bndrng[0], bndrng[1], maxobjsize);
1660 return;
1661 }
1662 }
1663
1664 if (maxlen && !integer_all_onesp (maxlen))
1665 {
1666 /* Add one for the nul. */
1667 maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen,
1668 size_one_node);
1669
1670 if (!bndrng[0])
1671 {
1672 /* Conservatively use the upper bound of the lengths for
1673 both the lower and the upper bound of the operation. */
1674 bndrng[0] = maxlen;
1675 bndrng[1] = maxlen;
1676 bound = void_type_node;
1677 }
1678 else if (maxlen)
1679 {
1680 /* Replace the bound on the operation with the upper bound
1681 of the length of the string if the latter is smaller. */
1682 if (tree_int_cst_lt (maxlen, bndrng[0]))
1683 bndrng[0] = maxlen;
1684 else if (tree_int_cst_lt (maxlen, bndrng[1]))
1685 bndrng[1] = maxlen;
1686 }
1687 }
1688
1689 /* Iterate over the built-in function's formal arguments and check
1690 each const char* against the actual argument. If the actual
1691 argument is declared attribute non-string issue a warning unless
1692 the argument's maximum length is bounded. */
1693 function_args_iterator it;
1694 function_args_iter_init (&it, TREE_TYPE (fndecl));
1695
1696 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1697 {
1698 /* Avoid iterating past the declared argument in a call
1699 to function declared without a prototype. */
1700 if (argno >= nargs)
1701 break;
1702
1703 tree argtype = function_args_iter_cond (&it);
1704 if (!argtype)
1705 break;
1706
1707 if (TREE_CODE (argtype) != POINTER_TYPE)
1708 continue;
1709
1710 argtype = TREE_TYPE (argtype);
1711
1712 if (TREE_CODE (argtype) != INTEGER_TYPE
1713 || !TYPE_READONLY (argtype))
1714 continue;
1715
1716 argtype = TYPE_MAIN_VARIANT (argtype);
1717 if (argtype != char_type_node)
1718 continue;
1719
1720 tree callarg = CALL_EXPR_ARG (exp, argno);
1721 if (TREE_CODE (callarg) == ADDR_EXPR)
1722 callarg = TREE_OPERAND (callarg, 0);
1723
1724 /* See if the destination is declared with attribute "nonstring". */
1725 tree decl = get_attr_nonstring_decl (callarg);
1726 if (!decl)
1727 continue;
1728
1729 /* The maximum number of array elements accessed. */
1730 offset_int wibnd = 0;
1731
1732 if (argno && fncode == BUILT_IN_STRNCAT)
1733 {
1734 /* See if the bound in strncat is derived from the length
1735 of the strlen of the destination (as it's expected to be).
1736 If so, reset BOUND and FNCODE to trigger a warning. */
1737 tree dstarg = CALL_EXPR_ARG (exp, 0);
1738 if (is_strlen_related_p (dstarg, bound))
1739 {
1740 /* The bound applies to the destination, not to the source,
1741 so reset these to trigger a warning without mentioning
1742 the bound. */
1743 bound = NULL;
1744 fncode = 0;
1745 }
1746 else if (bndrng[1])
1747 /* Use the upper bound of the range for strncat. */
1748 wibnd = wi::to_offset (bndrng[1]);
1749 }
1750 else if (bndrng[0])
1751 /* Use the lower bound of the range for functions other than
1752 strncat. */
1753 wibnd = wi::to_offset (bndrng[0]);
1754
1755 /* Determine the size of the argument array if it is one. */
1756 offset_int asize = wibnd;
1757 bool known_size = false;
1758 tree type = TREE_TYPE (decl);
1759
1760 /* Determine the array size. For arrays of unknown bound and
1761 pointers reset BOUND to trigger the appropriate warning. */
1762 if (TREE_CODE (type) == ARRAY_TYPE)
1763 {
1764 if (tree arrbnd = TYPE_DOMAIN (type))
1765 {
1766 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1767 {
1768 asize = wi::to_offset (arrbnd) + 1;
1769 known_size = true;
1770 }
1771 }
1772 else if (bound == void_type_node)
1773 bound = NULL_TREE;
1774 }
1775 else if (bound == void_type_node)
1776 bound = NULL_TREE;
1777
1778 /* In a call to strncat with a bound in a range whose lower but
1779 not upper bound is less than the array size, reset ASIZE to
1780 be the same as the bound and the other variable to trigger
1781 the apprpriate warning below. */
1782 if (fncode == BUILT_IN_STRNCAT
1783 && bndrng[0] != bndrng[1]
1784 && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
1785 && (!known_size
1786 || wi::ltu_p (asize, wibnd)))
1787 {
1788 asize = wibnd;
1789 bound = NULL_TREE;
1790 fncode = 0;
1791 }
1792
1793 bool warned = false;
1794
1795 auto_diagnostic_group d;
1796 if (wi::ltu_p (asize, wibnd))
1797 {
1798 if (bndrng[0] == bndrng[1])
1799 warned = warning_at (loc, OPT_Wstringop_overflow_,
1800 "%qD argument %i declared attribute "
1801 "%<nonstring%> is smaller than the specified "
1802 "bound %wu",
1803 fndecl, argno + 1, wibnd.to_uhwi ());
1804 else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
1805 warned = warning_at (loc, OPT_Wstringop_overflow_,
1806 "%qD argument %i declared attribute "
1807 "%<nonstring%> is smaller than "
1808 "the specified bound [%E, %E]",
1809 fndecl, argno + 1, bndrng[0], bndrng[1]);
1810 else
1811 warned = warning_at (loc, OPT_Wstringop_overflow_,
1812 "%qD argument %i declared attribute "
1813 "%<nonstring%> may be smaller than "
1814 "the specified bound [%E, %E]",
1815 fndecl, argno + 1, bndrng[0], bndrng[1]);
1816 }
1817 else if (fncode == BUILT_IN_STRNCAT)
1818 ; /* Avoid warning for calls to strncat() when the bound
1819 is equal to the size of the non-string argument. */
1820 else if (!bound)
1821 warned = warning_at (loc, OPT_Wstringop_overflow_,
1822 "%qD argument %i declared attribute %<nonstring%>",
1823 fndecl, argno + 1);
1824
1825 if (warned)
1826 inform (DECL_SOURCE_LOCATION (decl),
1827 "argument %qD declared here", decl);
1828 }
1829 }
1830
1831 /* Issue an error if CALL_EXPR was flagged as requiring
1832 tall-call optimization. */
1833
1834 static void
1835 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1836 {
1837 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1838 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1839 return;
1840
1841 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1842 }
1843
1844 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1845 CALL_EXPR EXP.
1846
1847 NUM_ACTUALS is the total number of parameters.
1848
1849 N_NAMED_ARGS is the total number of named arguments.
1850
1851 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1852 value, or null.
1853
1854 FNDECL is the tree code for the target of this call (if known)
1855
1856 ARGS_SO_FAR holds state needed by the target to know where to place
1857 the next argument.
1858
1859 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1860 for arguments which are passed in registers.
1861
1862 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1863 and may be modified by this routine.
1864
1865 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1866 flags which may be modified by this routine.
1867
1868 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1869 that requires allocation of stack space.
1870
1871 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1872 the thunked-to function. */
1873
1874 static void
1875 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1876 struct arg_data *args,
1877 struct args_size *args_size,
1878 int n_named_args ATTRIBUTE_UNUSED,
1879 tree exp, tree struct_value_addr_value,
1880 tree fndecl, tree fntype,
1881 cumulative_args_t args_so_far,
1882 int reg_parm_stack_space,
1883 rtx *old_stack_level,
1884 poly_int64_pod *old_pending_adj,
1885 int *must_preallocate, int *ecf_flags,
1886 bool *may_tailcall, bool call_from_thunk_p)
1887 {
1888 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1889 location_t loc = EXPR_LOCATION (exp);
1890
1891 /* Count arg position in order args appear. */
1892 int argpos;
1893
1894 int i;
1895
1896 args_size->constant = 0;
1897 args_size->var = 0;
1898
1899 bitmap_obstack_initialize (NULL);
1900
1901 /* In this loop, we consider args in the order they are written.
1902 We fill up ARGS from the back. */
1903
1904 i = num_actuals - 1;
1905 {
1906 int j = i;
1907 call_expr_arg_iterator iter;
1908 tree arg;
1909 bitmap slots = NULL;
1910
1911 if (struct_value_addr_value)
1912 {
1913 args[j].tree_value = struct_value_addr_value;
1914 j--;
1915 }
1916 argpos = 0;
1917 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1918 {
1919 tree argtype = TREE_TYPE (arg);
1920
1921 if (targetm.calls.split_complex_arg
1922 && argtype
1923 && TREE_CODE (argtype) == COMPLEX_TYPE
1924 && targetm.calls.split_complex_arg (argtype))
1925 {
1926 tree subtype = TREE_TYPE (argtype);
1927 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1928 j--;
1929 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1930 }
1931 else
1932 args[j].tree_value = arg;
1933 j--;
1934 argpos++;
1935 }
1936
1937 if (slots)
1938 BITMAP_FREE (slots);
1939 }
1940
1941 bitmap_obstack_release (NULL);
1942
1943 /* Extract attribute alloc_size from the type of the called expression
1944 (which could be a function or a function pointer) and if set, store
1945 the indices of the corresponding arguments in ALLOC_IDX, and then
1946 the actual argument(s) at those indices in ALLOC_ARGS. */
1947 int alloc_idx[2] = { -1, -1 };
1948 if (tree alloc_size = lookup_attribute ("alloc_size",
1949 TYPE_ATTRIBUTES (fntype)))
1950 {
1951 tree args = TREE_VALUE (alloc_size);
1952 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
1953 if (TREE_CHAIN (args))
1954 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
1955 }
1956
1957 /* Array for up to the two attribute alloc_size arguments. */
1958 tree alloc_args[] = { NULL_TREE, NULL_TREE };
1959
1960 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1961 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1962 {
1963 tree type = TREE_TYPE (args[i].tree_value);
1964 int unsignedp;
1965 machine_mode mode;
1966
1967 /* Replace erroneous argument with constant zero. */
1968 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1969 args[i].tree_value = integer_zero_node, type = integer_type_node;
1970
1971 /* If TYPE is a transparent union or record, pass things the way
1972 we would pass the first field of the union or record. We have
1973 already verified that the modes are the same. */
1974 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1975 && TYPE_TRANSPARENT_AGGR (type))
1976 type = TREE_TYPE (first_field (type));
1977
1978 /* Decide where to pass this arg.
1979
1980 args[i].reg is nonzero if all or part is passed in registers.
1981
1982 args[i].partial is nonzero if part but not all is passed in registers,
1983 and the exact value says how many bytes are passed in registers.
1984
1985 args[i].pass_on_stack is nonzero if the argument must at least be
1986 computed on the stack. It may then be loaded back into registers
1987 if args[i].reg is nonzero.
1988
1989 These decisions are driven by the FUNCTION_... macros and must agree
1990 with those made by function.c. */
1991
1992 /* See if this argument should be passed by invisible reference. */
1993 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1994 type, argpos < n_named_args))
1995 {
1996 bool callee_copies;
1997 tree base = NULL_TREE;
1998
1999 callee_copies
2000 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
2001 type, argpos < n_named_args);
2002
2003 /* If we're compiling a thunk, pass through invisible references
2004 instead of making a copy. */
2005 if (call_from_thunk_p
2006 || (callee_copies
2007 && !TREE_ADDRESSABLE (type)
2008 && (base = get_base_address (args[i].tree_value))
2009 && TREE_CODE (base) != SSA_NAME
2010 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
2011 {
2012 /* We may have turned the parameter value into an SSA name.
2013 Go back to the original parameter so we can take the
2014 address. */
2015 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
2016 {
2017 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
2018 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
2019 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
2020 }
2021 /* Argument setup code may have copied the value to register. We
2022 revert that optimization now because the tail call code must
2023 use the original location. */
2024 if (TREE_CODE (args[i].tree_value) == PARM_DECL
2025 && !MEM_P (DECL_RTL (args[i].tree_value))
2026 && DECL_INCOMING_RTL (args[i].tree_value)
2027 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
2028 set_decl_rtl (args[i].tree_value,
2029 DECL_INCOMING_RTL (args[i].tree_value));
2030
2031 mark_addressable (args[i].tree_value);
2032
2033 /* We can't use sibcalls if a callee-copied argument is
2034 stored in the current function's frame. */
2035 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2036 {
2037 *may_tailcall = false;
2038 maybe_complain_about_tail_call (exp,
2039 "a callee-copied argument is"
2040 " stored in the current"
2041 " function's frame");
2042 }
2043
2044 args[i].tree_value = build_fold_addr_expr_loc (loc,
2045 args[i].tree_value);
2046 type = TREE_TYPE (args[i].tree_value);
2047
2048 if (*ecf_flags & ECF_CONST)
2049 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2050 }
2051 else
2052 {
2053 /* We make a copy of the object and pass the address to the
2054 function being called. */
2055 rtx copy;
2056
2057 if (!COMPLETE_TYPE_P (type)
2058 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2059 || (flag_stack_check == GENERIC_STACK_CHECK
2060 && compare_tree_int (TYPE_SIZE_UNIT (type),
2061 STACK_CHECK_MAX_VAR_SIZE) > 0))
2062 {
2063 /* This is a variable-sized object. Make space on the stack
2064 for it. */
2065 rtx size_rtx = expr_size (args[i].tree_value);
2066
2067 if (*old_stack_level == 0)
2068 {
2069 emit_stack_save (SAVE_BLOCK, old_stack_level);
2070 *old_pending_adj = pending_stack_adjust;
2071 pending_stack_adjust = 0;
2072 }
2073
2074 /* We can pass TRUE as the 4th argument because we just
2075 saved the stack pointer and will restore it right after
2076 the call. */
2077 copy = allocate_dynamic_stack_space (size_rtx,
2078 TYPE_ALIGN (type),
2079 TYPE_ALIGN (type),
2080 max_int_size_in_bytes
2081 (type),
2082 true);
2083 copy = gen_rtx_MEM (BLKmode, copy);
2084 set_mem_attributes (copy, type, 1);
2085 }
2086 else
2087 copy = assign_temp (type, 1, 0);
2088
2089 store_expr (args[i].tree_value, copy, 0, false, false);
2090
2091 /* Just change the const function to pure and then let
2092 the next test clear the pure based on
2093 callee_copies. */
2094 if (*ecf_flags & ECF_CONST)
2095 {
2096 *ecf_flags &= ~ECF_CONST;
2097 *ecf_flags |= ECF_PURE;
2098 }
2099
2100 if (!callee_copies && *ecf_flags & ECF_PURE)
2101 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2102
2103 args[i].tree_value
2104 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2105 type = TREE_TYPE (args[i].tree_value);
2106 *may_tailcall = false;
2107 maybe_complain_about_tail_call (exp,
2108 "argument must be passed"
2109 " by copying");
2110 }
2111 }
2112
2113 unsignedp = TYPE_UNSIGNED (type);
2114 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2115 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2116
2117 args[i].unsignedp = unsignedp;
2118 args[i].mode = mode;
2119
2120 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2121
2122 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
2123 argpos < n_named_args);
2124
2125 if (args[i].reg && CONST_INT_P (args[i].reg))
2126 args[i].reg = NULL;
2127
2128 /* If this is a sibling call and the machine has register windows, the
2129 register window has to be unwinded before calling the routine, so
2130 arguments have to go into the incoming registers. */
2131 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2132 args[i].tail_call_reg
2133 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
2134 argpos < n_named_args);
2135 else
2136 args[i].tail_call_reg = args[i].reg;
2137
2138 if (args[i].reg)
2139 args[i].partial
2140 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
2141 argpos < n_named_args);
2142
2143 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
2144
2145 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2146 it means that we are to pass this arg in the register(s) designated
2147 by the PARALLEL, but also to pass it in the stack. */
2148 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2149 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2150 args[i].pass_on_stack = 1;
2151
2152 /* If this is an addressable type, we must preallocate the stack
2153 since we must evaluate the object into its final location.
2154
2155 If this is to be passed in both registers and the stack, it is simpler
2156 to preallocate. */
2157 if (TREE_ADDRESSABLE (type)
2158 || (args[i].pass_on_stack && args[i].reg != 0))
2159 *must_preallocate = 1;
2160
2161 /* Compute the stack-size of this argument. */
2162 if (args[i].reg == 0 || args[i].partial != 0
2163 || reg_parm_stack_space > 0
2164 || args[i].pass_on_stack)
2165 locate_and_pad_parm (mode, type,
2166 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2167 1,
2168 #else
2169 args[i].reg != 0,
2170 #endif
2171 reg_parm_stack_space,
2172 args[i].pass_on_stack ? 0 : args[i].partial,
2173 fndecl, args_size, &args[i].locate);
2174 #ifdef BLOCK_REG_PADDING
2175 else
2176 /* The argument is passed entirely in registers. See at which
2177 end it should be padded. */
2178 args[i].locate.where_pad =
2179 BLOCK_REG_PADDING (mode, type,
2180 int_size_in_bytes (type) <= UNITS_PER_WORD);
2181 #endif
2182
2183 /* Update ARGS_SIZE, the total stack space for args so far. */
2184
2185 args_size->constant += args[i].locate.size.constant;
2186 if (args[i].locate.size.var)
2187 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2188
2189 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2190 have been used, etc. */
2191
2192 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
2193 type, argpos < n_named_args);
2194
2195 /* Store argument values for functions decorated with attribute
2196 alloc_size. */
2197 if (argpos == alloc_idx[0])
2198 alloc_args[0] = args[i].tree_value;
2199 else if (argpos == alloc_idx[1])
2200 alloc_args[1] = args[i].tree_value;
2201 }
2202
2203 if (alloc_args[0])
2204 {
2205 /* Check the arguments of functions decorated with attribute
2206 alloc_size. */
2207 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2208 }
2209
2210 /* Detect passing non-string arguments to functions expecting
2211 nul-terminated strings. */
2212 maybe_warn_nonstring_arg (fndecl, exp);
2213 }
2214
2215 /* Update ARGS_SIZE to contain the total size for the argument block.
2216 Return the original constant component of the argument block's size.
2217
2218 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2219 for arguments passed in registers. */
2220
2221 static poly_int64
2222 compute_argument_block_size (int reg_parm_stack_space,
2223 struct args_size *args_size,
2224 tree fndecl ATTRIBUTE_UNUSED,
2225 tree fntype ATTRIBUTE_UNUSED,
2226 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2227 {
2228 poly_int64 unadjusted_args_size = args_size->constant;
2229
2230 /* For accumulate outgoing args mode we don't need to align, since the frame
2231 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2232 backends from generating misaligned frame sizes. */
2233 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2234 preferred_stack_boundary = STACK_BOUNDARY;
2235
2236 /* Compute the actual size of the argument block required. The variable
2237 and constant sizes must be combined, the size may have to be rounded,
2238 and there may be a minimum required size. */
2239
2240 if (args_size->var)
2241 {
2242 args_size->var = ARGS_SIZE_TREE (*args_size);
2243 args_size->constant = 0;
2244
2245 preferred_stack_boundary /= BITS_PER_UNIT;
2246 if (preferred_stack_boundary > 1)
2247 {
2248 /* We don't handle this case yet. To handle it correctly we have
2249 to add the delta, round and subtract the delta.
2250 Currently no machine description requires this support. */
2251 gcc_assert (multiple_p (stack_pointer_delta,
2252 preferred_stack_boundary));
2253 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2254 }
2255
2256 if (reg_parm_stack_space > 0)
2257 {
2258 args_size->var
2259 = size_binop (MAX_EXPR, args_size->var,
2260 ssize_int (reg_parm_stack_space));
2261
2262 /* The area corresponding to register parameters is not to count in
2263 the size of the block we need. So make the adjustment. */
2264 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2265 args_size->var
2266 = size_binop (MINUS_EXPR, args_size->var,
2267 ssize_int (reg_parm_stack_space));
2268 }
2269 }
2270 else
2271 {
2272 preferred_stack_boundary /= BITS_PER_UNIT;
2273 if (preferred_stack_boundary < 1)
2274 preferred_stack_boundary = 1;
2275 args_size->constant = (aligned_upper_bound (args_size->constant
2276 + stack_pointer_delta,
2277 preferred_stack_boundary)
2278 - stack_pointer_delta);
2279
2280 args_size->constant = upper_bound (args_size->constant,
2281 reg_parm_stack_space);
2282
2283 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2284 args_size->constant -= reg_parm_stack_space;
2285 }
2286 return unadjusted_args_size;
2287 }
2288
2289 /* Precompute parameters as needed for a function call.
2290
2291 FLAGS is mask of ECF_* constants.
2292
2293 NUM_ACTUALS is the number of arguments.
2294
2295 ARGS is an array containing information for each argument; this
2296 routine fills in the INITIAL_VALUE and VALUE fields for each
2297 precomputed argument. */
2298
2299 static void
2300 precompute_arguments (int num_actuals, struct arg_data *args)
2301 {
2302 int i;
2303
2304 /* If this is a libcall, then precompute all arguments so that we do not
2305 get extraneous instructions emitted as part of the libcall sequence. */
2306
2307 /* If we preallocated the stack space, and some arguments must be passed
2308 on the stack, then we must precompute any parameter which contains a
2309 function call which will store arguments on the stack.
2310 Otherwise, evaluating the parameter may clobber previous parameters
2311 which have already been stored into the stack. (we have code to avoid
2312 such case by saving the outgoing stack arguments, but it results in
2313 worse code) */
2314 if (!ACCUMULATE_OUTGOING_ARGS)
2315 return;
2316
2317 for (i = 0; i < num_actuals; i++)
2318 {
2319 tree type;
2320 machine_mode mode;
2321
2322 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2323 continue;
2324
2325 /* If this is an addressable type, we cannot pre-evaluate it. */
2326 type = TREE_TYPE (args[i].tree_value);
2327 gcc_assert (!TREE_ADDRESSABLE (type));
2328
2329 args[i].initial_value = args[i].value
2330 = expand_normal (args[i].tree_value);
2331
2332 mode = TYPE_MODE (type);
2333 if (mode != args[i].mode)
2334 {
2335 int unsignedp = args[i].unsignedp;
2336 args[i].value
2337 = convert_modes (args[i].mode, mode,
2338 args[i].value, args[i].unsignedp);
2339
2340 /* CSE will replace this only if it contains args[i].value
2341 pseudo, so convert it down to the declared mode using
2342 a SUBREG. */
2343 if (REG_P (args[i].value)
2344 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2345 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2346 {
2347 args[i].initial_value
2348 = gen_lowpart_SUBREG (mode, args[i].value);
2349 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2350 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2351 }
2352 }
2353 }
2354 }
2355
2356 /* Given the current state of MUST_PREALLOCATE and information about
2357 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2358 compute and return the final value for MUST_PREALLOCATE. */
2359
2360 static int
2361 finalize_must_preallocate (int must_preallocate, int num_actuals,
2362 struct arg_data *args, struct args_size *args_size)
2363 {
2364 /* See if we have or want to preallocate stack space.
2365
2366 If we would have to push a partially-in-regs parm
2367 before other stack parms, preallocate stack space instead.
2368
2369 If the size of some parm is not a multiple of the required stack
2370 alignment, we must preallocate.
2371
2372 If the total size of arguments that would otherwise create a copy in
2373 a temporary (such as a CALL) is more than half the total argument list
2374 size, preallocation is faster.
2375
2376 Another reason to preallocate is if we have a machine (like the m88k)
2377 where stack alignment is required to be maintained between every
2378 pair of insns, not just when the call is made. However, we assume here
2379 that such machines either do not have push insns (and hence preallocation
2380 would occur anyway) or the problem is taken care of with
2381 PUSH_ROUNDING. */
2382
2383 if (! must_preallocate)
2384 {
2385 int partial_seen = 0;
2386 poly_int64 copy_to_evaluate_size = 0;
2387 int i;
2388
2389 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2390 {
2391 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2392 partial_seen = 1;
2393 else if (partial_seen && args[i].reg == 0)
2394 must_preallocate = 1;
2395
2396 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2397 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2398 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2399 || TREE_CODE (args[i].tree_value) == COND_EXPR
2400 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2401 copy_to_evaluate_size
2402 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2403 }
2404
2405 if (maybe_ne (args_size->constant, 0)
2406 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2407 must_preallocate = 1;
2408 }
2409 return must_preallocate;
2410 }
2411
2412 /* If we preallocated stack space, compute the address of each argument
2413 and store it into the ARGS array.
2414
2415 We need not ensure it is a valid memory address here; it will be
2416 validized when it is used.
2417
2418 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2419
2420 static void
2421 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2422 {
2423 if (argblock)
2424 {
2425 rtx arg_reg = argblock;
2426 int i;
2427 poly_int64 arg_offset = 0;
2428
2429 if (GET_CODE (argblock) == PLUS)
2430 {
2431 arg_reg = XEXP (argblock, 0);
2432 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2433 }
2434
2435 for (i = 0; i < num_actuals; i++)
2436 {
2437 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2438 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2439 rtx addr;
2440 unsigned int align, boundary;
2441 poly_uint64 units_on_stack = 0;
2442 machine_mode partial_mode = VOIDmode;
2443
2444 /* Skip this parm if it will not be passed on the stack. */
2445 if (! args[i].pass_on_stack
2446 && args[i].reg != 0
2447 && args[i].partial == 0)
2448 continue;
2449
2450 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2451 continue;
2452
2453 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2454 addr = plus_constant (Pmode, addr, arg_offset);
2455
2456 if (args[i].partial != 0)
2457 {
2458 /* Only part of the parameter is being passed on the stack.
2459 Generate a simple memory reference of the correct size. */
2460 units_on_stack = args[i].locate.size.constant;
2461 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2462 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2463 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2464 set_mem_size (args[i].stack, units_on_stack);
2465 }
2466 else
2467 {
2468 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2469 set_mem_attributes (args[i].stack,
2470 TREE_TYPE (args[i].tree_value), 1);
2471 }
2472 align = BITS_PER_UNIT;
2473 boundary = args[i].locate.boundary;
2474 poly_int64 offset_val;
2475 if (args[i].locate.where_pad != PAD_DOWNWARD)
2476 align = boundary;
2477 else if (poly_int_rtx_p (offset, &offset_val))
2478 {
2479 align = least_bit_hwi (boundary);
2480 unsigned int offset_align
2481 = known_alignment (offset_val) * BITS_PER_UNIT;
2482 if (offset_align != 0)
2483 align = MIN (align, offset_align);
2484 }
2485 set_mem_align (args[i].stack, align);
2486
2487 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2488 addr = plus_constant (Pmode, addr, arg_offset);
2489
2490 if (args[i].partial != 0)
2491 {
2492 /* Only part of the parameter is being passed on the stack.
2493 Generate a simple memory reference of the correct size.
2494 */
2495 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2496 set_mem_size (args[i].stack_slot, units_on_stack);
2497 }
2498 else
2499 {
2500 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2501 set_mem_attributes (args[i].stack_slot,
2502 TREE_TYPE (args[i].tree_value), 1);
2503 }
2504 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2505
2506 /* Function incoming arguments may overlap with sibling call
2507 outgoing arguments and we cannot allow reordering of reads
2508 from function arguments with stores to outgoing arguments
2509 of sibling calls. */
2510 set_mem_alias_set (args[i].stack, 0);
2511 set_mem_alias_set (args[i].stack_slot, 0);
2512 }
2513 }
2514 }
2515
2516 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2517 in a call instruction.
2518
2519 FNDECL is the tree node for the target function. For an indirect call
2520 FNDECL will be NULL_TREE.
2521
2522 ADDR is the operand 0 of CALL_EXPR for this call. */
2523
2524 static rtx
2525 rtx_for_function_call (tree fndecl, tree addr)
2526 {
2527 rtx funexp;
2528
2529 /* Get the function to call, in the form of RTL. */
2530 if (fndecl)
2531 {
2532 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2533 TREE_USED (fndecl) = 1;
2534
2535 /* Get a SYMBOL_REF rtx for the function address. */
2536 funexp = XEXP (DECL_RTL (fndecl), 0);
2537 }
2538 else
2539 /* Generate an rtx (probably a pseudo-register) for the address. */
2540 {
2541 push_temp_slots ();
2542 funexp = expand_normal (addr);
2543 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2544 }
2545 return funexp;
2546 }
2547
2548 /* Return the static chain for this function, if any. */
2549
2550 rtx
2551 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2552 {
2553 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2554 return NULL;
2555
2556 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2557 }
2558
2559 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2560 static struct
2561 {
2562 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2563 or NULL_RTX if none has been scanned yet. */
2564 rtx_insn *scan_start;
2565 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2566 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2567 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2568 with fixed offset, or PC if this is with variable or unknown offset. */
2569 vec<rtx> cache;
2570 } internal_arg_pointer_exp_state;
2571
2572 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2573
2574 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2575 the tail call sequence, starting with first insn that hasn't been
2576 scanned yet, and note for each pseudo on the LHS whether it is based
2577 on crtl->args.internal_arg_pointer or not, and what offset from that
2578 that pointer it has. */
2579
2580 static void
2581 internal_arg_pointer_based_exp_scan (void)
2582 {
2583 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2584
2585 if (scan_start == NULL_RTX)
2586 insn = get_insns ();
2587 else
2588 insn = NEXT_INSN (scan_start);
2589
2590 while (insn)
2591 {
2592 rtx set = single_set (insn);
2593 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2594 {
2595 rtx val = NULL_RTX;
2596 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2597 /* Punt on pseudos set multiple times. */
2598 if (idx < internal_arg_pointer_exp_state.cache.length ()
2599 && (internal_arg_pointer_exp_state.cache[idx]
2600 != NULL_RTX))
2601 val = pc_rtx;
2602 else
2603 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2604 if (val != NULL_RTX)
2605 {
2606 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2607 internal_arg_pointer_exp_state.cache
2608 .safe_grow_cleared (idx + 1);
2609 internal_arg_pointer_exp_state.cache[idx] = val;
2610 }
2611 }
2612 if (NEXT_INSN (insn) == NULL_RTX)
2613 scan_start = insn;
2614 insn = NEXT_INSN (insn);
2615 }
2616
2617 internal_arg_pointer_exp_state.scan_start = scan_start;
2618 }
2619
2620 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2621 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2622 it with fixed offset, or PC if this is with variable or unknown offset.
2623 TOPLEVEL is true if the function is invoked at the topmost level. */
2624
2625 static rtx
2626 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2627 {
2628 if (CONSTANT_P (rtl))
2629 return NULL_RTX;
2630
2631 if (rtl == crtl->args.internal_arg_pointer)
2632 return const0_rtx;
2633
2634 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2635 return NULL_RTX;
2636
2637 poly_int64 offset;
2638 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2639 {
2640 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2641 if (val == NULL_RTX || val == pc_rtx)
2642 return val;
2643 return plus_constant (Pmode, val, offset);
2644 }
2645
2646 /* When called at the topmost level, scan pseudo assignments in between the
2647 last scanned instruction in the tail call sequence and the latest insn
2648 in that sequence. */
2649 if (toplevel)
2650 internal_arg_pointer_based_exp_scan ();
2651
2652 if (REG_P (rtl))
2653 {
2654 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2655 if (idx < internal_arg_pointer_exp_state.cache.length ())
2656 return internal_arg_pointer_exp_state.cache[idx];
2657
2658 return NULL_RTX;
2659 }
2660
2661 subrtx_iterator::array_type array;
2662 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2663 {
2664 const_rtx x = *iter;
2665 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2666 return pc_rtx;
2667 if (MEM_P (x))
2668 iter.skip_subrtxes ();
2669 }
2670
2671 return NULL_RTX;
2672 }
2673
2674 /* Return true if SIZE bytes starting from address ADDR might overlap an
2675 already-clobbered argument area. This function is used to determine
2676 if we should give up a sibcall. */
2677
2678 static bool
2679 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2680 {
2681 poly_int64 i;
2682 unsigned HOST_WIDE_INT start, end;
2683 rtx val;
2684
2685 if (bitmap_empty_p (stored_args_map)
2686 && stored_args_watermark == HOST_WIDE_INT_M1U)
2687 return false;
2688 val = internal_arg_pointer_based_exp (addr, true);
2689 if (val == NULL_RTX)
2690 return false;
2691 else if (!poly_int_rtx_p (val, &i))
2692 return true;
2693
2694 if (known_eq (size, 0U))
2695 return false;
2696
2697 if (STACK_GROWS_DOWNWARD)
2698 i -= crtl->args.pretend_args_size;
2699 else
2700 i += crtl->args.pretend_args_size;
2701
2702 if (ARGS_GROW_DOWNWARD)
2703 i = -i - size;
2704
2705 /* We can ignore any references to the function's pretend args,
2706 which at this point would manifest as negative values of I. */
2707 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2708 return false;
2709
2710 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2711 if (!(i + size).is_constant (&end))
2712 end = HOST_WIDE_INT_M1U;
2713
2714 if (end > stored_args_watermark)
2715 return true;
2716
2717 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2718 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2719 if (bitmap_bit_p (stored_args_map, k))
2720 return true;
2721
2722 return false;
2723 }
2724
2725 /* Do the register loads required for any wholly-register parms or any
2726 parms which are passed both on the stack and in a register. Their
2727 expressions were already evaluated.
2728
2729 Mark all register-parms as living through the call, putting these USE
2730 insns in the CALL_INSN_FUNCTION_USAGE field.
2731
2732 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2733 checking, setting *SIBCALL_FAILURE if appropriate. */
2734
2735 static void
2736 load_register_parameters (struct arg_data *args, int num_actuals,
2737 rtx *call_fusage, int flags, int is_sibcall,
2738 int *sibcall_failure)
2739 {
2740 int i, j;
2741
2742 for (i = 0; i < num_actuals; i++)
2743 {
2744 rtx reg = ((flags & ECF_SIBCALL)
2745 ? args[i].tail_call_reg : args[i].reg);
2746 if (reg)
2747 {
2748 int partial = args[i].partial;
2749 int nregs;
2750 poly_int64 size = 0;
2751 HOST_WIDE_INT const_size = 0;
2752 rtx_insn *before_arg = get_last_insn ();
2753 /* Set non-negative if we must move a word at a time, even if
2754 just one word (e.g, partial == 4 && mode == DFmode). Set
2755 to -1 if we just use a normal move insn. This value can be
2756 zero if the argument is a zero size structure. */
2757 nregs = -1;
2758 if (GET_CODE (reg) == PARALLEL)
2759 ;
2760 else if (partial)
2761 {
2762 gcc_assert (partial % UNITS_PER_WORD == 0);
2763 nregs = partial / UNITS_PER_WORD;
2764 }
2765 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
2766 {
2767 /* Variable-sized parameters should be described by a
2768 PARALLEL instead. */
2769 const_size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2770 gcc_assert (const_size >= 0);
2771 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2772 size = const_size;
2773 }
2774 else
2775 size = GET_MODE_SIZE (args[i].mode);
2776
2777 /* Handle calls that pass values in multiple non-contiguous
2778 locations. The Irix 6 ABI has examples of this. */
2779
2780 if (GET_CODE (reg) == PARALLEL)
2781 emit_group_move (reg, args[i].parallel_value);
2782
2783 /* If simple case, just do move. If normal partial, store_one_arg
2784 has already loaded the register for us. In all other cases,
2785 load the register(s) from memory. */
2786
2787 else if (nregs == -1)
2788 {
2789 emit_move_insn (reg, args[i].value);
2790 #ifdef BLOCK_REG_PADDING
2791 /* Handle case where we have a value that needs shifting
2792 up to the msb. eg. a QImode value and we're padding
2793 upward on a BYTES_BIG_ENDIAN machine. */
2794 if (args[i].locate.where_pad
2795 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2796 {
2797 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2798 if (maybe_lt (size, UNITS_PER_WORD))
2799 {
2800 rtx x;
2801 poly_int64 shift
2802 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2803
2804 /* Assigning REG here rather than a temp makes
2805 CALL_FUSAGE report the whole reg as used.
2806 Strictly speaking, the call only uses SIZE
2807 bytes at the msb end, but it doesn't seem worth
2808 generating rtl to say that. */
2809 reg = gen_rtx_REG (word_mode, REGNO (reg));
2810 x = expand_shift (LSHIFT_EXPR, word_mode,
2811 reg, shift, reg, 1);
2812 if (x != reg)
2813 emit_move_insn (reg, x);
2814 }
2815 }
2816 #endif
2817 }
2818
2819 /* If we have pre-computed the values to put in the registers in
2820 the case of non-aligned structures, copy them in now. */
2821
2822 else if (args[i].n_aligned_regs != 0)
2823 for (j = 0; j < args[i].n_aligned_regs; j++)
2824 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2825 args[i].aligned_regs[j]);
2826
2827 else if (partial == 0 || args[i].pass_on_stack)
2828 {
2829 /* SIZE and CONST_SIZE are 0 for partial arguments and
2830 the size of a BLKmode type otherwise. */
2831 gcc_checking_assert (known_eq (size, const_size));
2832 rtx mem = validize_mem (copy_rtx (args[i].value));
2833
2834 /* Check for overlap with already clobbered argument area,
2835 providing that this has non-zero size. */
2836 if (is_sibcall
2837 && const_size != 0
2838 && (mem_might_overlap_already_clobbered_arg_p
2839 (XEXP (args[i].value, 0), const_size)))
2840 *sibcall_failure = 1;
2841
2842 if (const_size % UNITS_PER_WORD == 0
2843 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2844 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2845 else
2846 {
2847 if (nregs > 1)
2848 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2849 args[i].mode);
2850 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2851 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2852 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2853 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2854 word_mode, word_mode, false,
2855 NULL);
2856 if (BYTES_BIG_ENDIAN)
2857 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2858 BITS_PER_WORD - bitsize, dest, 1);
2859 if (x != dest)
2860 emit_move_insn (dest, x);
2861 }
2862
2863 /* Handle a BLKmode that needs shifting. */
2864 if (nregs == 1 && const_size < UNITS_PER_WORD
2865 #ifdef BLOCK_REG_PADDING
2866 && args[i].locate.where_pad == PAD_DOWNWARD
2867 #else
2868 && BYTES_BIG_ENDIAN
2869 #endif
2870 )
2871 {
2872 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2873 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2874 enum tree_code dir = (BYTES_BIG_ENDIAN
2875 ? RSHIFT_EXPR : LSHIFT_EXPR);
2876 rtx x;
2877
2878 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2879 if (x != dest)
2880 emit_move_insn (dest, x);
2881 }
2882 }
2883
2884 /* When a parameter is a block, and perhaps in other cases, it is
2885 possible that it did a load from an argument slot that was
2886 already clobbered. */
2887 if (is_sibcall
2888 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2889 *sibcall_failure = 1;
2890
2891 /* Handle calls that pass values in multiple non-contiguous
2892 locations. The Irix 6 ABI has examples of this. */
2893 if (GET_CODE (reg) == PARALLEL)
2894 use_group_regs (call_fusage, reg);
2895 else if (nregs == -1)
2896 use_reg_mode (call_fusage, reg,
2897 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
2898 else if (nregs > 0)
2899 use_regs (call_fusage, REGNO (reg), nregs);
2900 }
2901 }
2902 }
2903
2904 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2905 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2906 bytes, then we would need to push some additional bytes to pad the
2907 arguments. So, we try to compute an adjust to the stack pointer for an
2908 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2909 bytes. Then, when the arguments are pushed the stack will be perfectly
2910 aligned.
2911
2912 Return true if this optimization is possible, storing the adjustment
2913 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2914 bytes that should be popped after the call. */
2915
2916 static bool
2917 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2918 poly_int64 unadjusted_args_size,
2919 struct args_size *args_size,
2920 unsigned int preferred_unit_stack_boundary)
2921 {
2922 /* The number of bytes to pop so that the stack will be
2923 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2924 poly_int64 adjustment;
2925 /* The alignment of the stack after the arguments are pushed, if we
2926 just pushed the arguments without adjust the stack here. */
2927 unsigned HOST_WIDE_INT unadjusted_alignment;
2928
2929 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2930 preferred_unit_stack_boundary,
2931 &unadjusted_alignment))
2932 return false;
2933
2934 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2935 as possible -- leaving just enough left to cancel out the
2936 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2937 PENDING_STACK_ADJUST is non-negative, and congruent to
2938 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2939
2940 /* Begin by trying to pop all the bytes. */
2941 unsigned HOST_WIDE_INT tmp_misalignment;
2942 if (!known_misalignment (pending_stack_adjust,
2943 preferred_unit_stack_boundary,
2944 &tmp_misalignment))
2945 return false;
2946 unadjusted_alignment -= tmp_misalignment;
2947 adjustment = pending_stack_adjust;
2948 /* Push enough additional bytes that the stack will be aligned
2949 after the arguments are pushed. */
2950 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2951 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2952
2953 /* We need to know whether the adjusted argument size
2954 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2955 or a deallocation. */
2956 if (!ordered_p (adjustment, unadjusted_args_size))
2957 return false;
2958
2959 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2960 bytes after the call. The right number is the entire
2961 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2962 by the arguments in the first place. */
2963 args_size->constant
2964 = pending_stack_adjust - adjustment + unadjusted_args_size;
2965
2966 *adjustment_out = adjustment;
2967 return true;
2968 }
2969
2970 /* Scan X expression if it does not dereference any argument slots
2971 we already clobbered by tail call arguments (as noted in stored_args_map
2972 bitmap).
2973 Return nonzero if X expression dereferences such argument slots,
2974 zero otherwise. */
2975
2976 static int
2977 check_sibcall_argument_overlap_1 (rtx x)
2978 {
2979 RTX_CODE code;
2980 int i, j;
2981 const char *fmt;
2982
2983 if (x == NULL_RTX)
2984 return 0;
2985
2986 code = GET_CODE (x);
2987
2988 /* We need not check the operands of the CALL expression itself. */
2989 if (code == CALL)
2990 return 0;
2991
2992 if (code == MEM)
2993 return (mem_might_overlap_already_clobbered_arg_p
2994 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
2995
2996 /* Scan all subexpressions. */
2997 fmt = GET_RTX_FORMAT (code);
2998 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2999 {
3000 if (*fmt == 'e')
3001 {
3002 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
3003 return 1;
3004 }
3005 else if (*fmt == 'E')
3006 {
3007 for (j = 0; j < XVECLEN (x, i); j++)
3008 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
3009 return 1;
3010 }
3011 }
3012 return 0;
3013 }
3014
3015 /* Scan sequence after INSN if it does not dereference any argument slots
3016 we already clobbered by tail call arguments (as noted in stored_args_map
3017 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3018 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3019 should be 0). Return nonzero if sequence after INSN dereferences such argument
3020 slots, zero otherwise. */
3021
3022 static int
3023 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3024 int mark_stored_args_map)
3025 {
3026 poly_uint64 low, high;
3027 unsigned HOST_WIDE_INT const_low, const_high;
3028
3029 if (insn == NULL_RTX)
3030 insn = get_insns ();
3031 else
3032 insn = NEXT_INSN (insn);
3033
3034 for (; insn; insn = NEXT_INSN (insn))
3035 if (INSN_P (insn)
3036 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3037 break;
3038
3039 if (mark_stored_args_map)
3040 {
3041 if (ARGS_GROW_DOWNWARD)
3042 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3043 else
3044 low = arg->locate.slot_offset.constant;
3045 high = low + arg->locate.size.constant;
3046
3047 const_low = constant_lower_bound (low);
3048 if (high.is_constant (&const_high))
3049 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3050 bitmap_set_bit (stored_args_map, i);
3051 else
3052 stored_args_watermark = MIN (stored_args_watermark, const_low);
3053 }
3054 return insn != NULL_RTX;
3055 }
3056
3057 /* Given that a function returns a value of mode MODE at the most
3058 significant end of hard register VALUE, shift VALUE left or right
3059 as specified by LEFT_P. Return true if some action was needed. */
3060
3061 bool
3062 shift_return_value (machine_mode mode, bool left_p, rtx value)
3063 {
3064 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3065 machine_mode value_mode = GET_MODE (value);
3066 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3067
3068 if (known_eq (shift, 0))
3069 return false;
3070
3071 /* Use ashr rather than lshr for right shifts. This is for the benefit
3072 of the MIPS port, which requires SImode values to be sign-extended
3073 when stored in 64-bit registers. */
3074 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3075 value, gen_int_shift_amount (value_mode, shift),
3076 value, 1, OPTAB_WIDEN))
3077 gcc_unreachable ();
3078 return true;
3079 }
3080
3081 /* If X is a likely-spilled register value, copy it to a pseudo
3082 register and return that register. Return X otherwise. */
3083
3084 static rtx
3085 avoid_likely_spilled_reg (rtx x)
3086 {
3087 rtx new_rtx;
3088
3089 if (REG_P (x)
3090 && HARD_REGISTER_P (x)
3091 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3092 {
3093 /* Make sure that we generate a REG rather than a CONCAT.
3094 Moves into CONCATs can need nontrivial instructions,
3095 and the whole point of this function is to avoid
3096 using the hard register directly in such a situation. */
3097 generating_concat_p = 0;
3098 new_rtx = gen_reg_rtx (GET_MODE (x));
3099 generating_concat_p = 1;
3100 emit_move_insn (new_rtx, x);
3101 return new_rtx;
3102 }
3103 return x;
3104 }
3105
3106 /* Helper function for expand_call.
3107 Return false is EXP is not implementable as a sibling call. */
3108
3109 static bool
3110 can_implement_as_sibling_call_p (tree exp,
3111 rtx structure_value_addr,
3112 tree funtype,
3113 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3114 tree fndecl,
3115 int flags,
3116 tree addr,
3117 const args_size &args_size)
3118 {
3119 if (!targetm.have_sibcall_epilogue ())
3120 {
3121 maybe_complain_about_tail_call
3122 (exp,
3123 "machine description does not have"
3124 " a sibcall_epilogue instruction pattern");
3125 return false;
3126 }
3127
3128 /* Doing sibling call optimization needs some work, since
3129 structure_value_addr can be allocated on the stack.
3130 It does not seem worth the effort since few optimizable
3131 sibling calls will return a structure. */
3132 if (structure_value_addr != NULL_RTX)
3133 {
3134 maybe_complain_about_tail_call (exp, "callee returns a structure");
3135 return false;
3136 }
3137
3138 #ifdef REG_PARM_STACK_SPACE
3139 /* If outgoing reg parm stack space changes, we cannot do sibcall. */
3140 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3141 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3142 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3143 {
3144 maybe_complain_about_tail_call (exp,
3145 "inconsistent size of stack space"
3146 " allocated for arguments which are"
3147 " passed in registers");
3148 return false;
3149 }
3150 #endif
3151
3152 /* Check whether the target is able to optimize the call
3153 into a sibcall. */
3154 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3155 {
3156 maybe_complain_about_tail_call (exp,
3157 "target is not able to optimize the"
3158 " call into a sibling call");
3159 return false;
3160 }
3161
3162 /* Functions that do not return exactly once may not be sibcall
3163 optimized. */
3164 if (flags & ECF_RETURNS_TWICE)
3165 {
3166 maybe_complain_about_tail_call (exp, "callee returns twice");
3167 return false;
3168 }
3169 if (flags & ECF_NORETURN)
3170 {
3171 maybe_complain_about_tail_call (exp, "callee does not return");
3172 return false;
3173 }
3174
3175 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3176 {
3177 maybe_complain_about_tail_call (exp, "volatile function type");
3178 return false;
3179 }
3180
3181 /* If the called function is nested in the current one, it might access
3182 some of the caller's arguments, but could clobber them beforehand if
3183 the argument areas are shared. */
3184 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3185 {
3186 maybe_complain_about_tail_call (exp, "nested function");
3187 return false;
3188 }
3189
3190 /* If this function requires more stack slots than the current
3191 function, we cannot change it into a sibling call.
3192 crtl->args.pretend_args_size is not part of the
3193 stack allocated by our caller. */
3194 if (maybe_gt (args_size.constant,
3195 crtl->args.size - crtl->args.pretend_args_size))
3196 {
3197 maybe_complain_about_tail_call (exp,
3198 "callee required more stack slots"
3199 " than the caller");
3200 return false;
3201 }
3202
3203 /* If the callee pops its own arguments, then it must pop exactly
3204 the same number of arguments as the current function. */
3205 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3206 args_size.constant),
3207 targetm.calls.return_pops_args (current_function_decl,
3208 TREE_TYPE
3209 (current_function_decl),
3210 crtl->args.size)))
3211 {
3212 maybe_complain_about_tail_call (exp,
3213 "inconsistent number of"
3214 " popped arguments");
3215 return false;
3216 }
3217
3218 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3219 {
3220 maybe_complain_about_tail_call (exp, "frontend does not support"
3221 " sibling call");
3222 return false;
3223 }
3224
3225 /* All checks passed. */
3226 return true;
3227 }
3228
3229 /* Update stack alignment when the parameter is passed in the stack
3230 since the outgoing parameter requires extra alignment on the calling
3231 function side. */
3232
3233 static void
3234 update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
3235 {
3236 if (crtl->stack_alignment_needed < locate->boundary)
3237 crtl->stack_alignment_needed = locate->boundary;
3238 if (crtl->preferred_stack_boundary < locate->boundary)
3239 crtl->preferred_stack_boundary = locate->boundary;
3240 }
3241
3242 /* Generate all the code for a CALL_EXPR exp
3243 and return an rtx for its value.
3244 Store the value in TARGET (specified as an rtx) if convenient.
3245 If the value is stored in TARGET then TARGET is returned.
3246 If IGNORE is nonzero, then we ignore the value of the function call. */
3247
3248 rtx
3249 expand_call (tree exp, rtx target, int ignore)
3250 {
3251 /* Nonzero if we are currently expanding a call. */
3252 static int currently_expanding_call = 0;
3253
3254 /* RTX for the function to be called. */
3255 rtx funexp;
3256 /* Sequence of insns to perform a normal "call". */
3257 rtx_insn *normal_call_insns = NULL;
3258 /* Sequence of insns to perform a tail "call". */
3259 rtx_insn *tail_call_insns = NULL;
3260 /* Data type of the function. */
3261 tree funtype;
3262 tree type_arg_types;
3263 tree rettype;
3264 /* Declaration of the function being called,
3265 or 0 if the function is computed (not known by name). */
3266 tree fndecl = 0;
3267 /* The type of the function being called. */
3268 tree fntype;
3269 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3270 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3271 int pass;
3272
3273 /* Register in which non-BLKmode value will be returned,
3274 or 0 if no value or if value is BLKmode. */
3275 rtx valreg;
3276 /* Address where we should return a BLKmode value;
3277 0 if value not BLKmode. */
3278 rtx structure_value_addr = 0;
3279 /* Nonzero if that address is being passed by treating it as
3280 an extra, implicit first parameter. Otherwise,
3281 it is passed by being copied directly into struct_value_rtx. */
3282 int structure_value_addr_parm = 0;
3283 /* Holds the value of implicit argument for the struct value. */
3284 tree structure_value_addr_value = NULL_TREE;
3285 /* Size of aggregate value wanted, or zero if none wanted
3286 or if we are using the non-reentrant PCC calling convention
3287 or expecting the value in registers. */
3288 poly_int64 struct_value_size = 0;
3289 /* Nonzero if called function returns an aggregate in memory PCC style,
3290 by returning the address of where to find it. */
3291 int pcc_struct_value = 0;
3292 rtx struct_value = 0;
3293
3294 /* Number of actual parameters in this call, including struct value addr. */
3295 int num_actuals;
3296 /* Number of named args. Args after this are anonymous ones
3297 and they must all go on the stack. */
3298 int n_named_args;
3299 /* Number of complex actual arguments that need to be split. */
3300 int num_complex_actuals = 0;
3301
3302 /* Vector of information about each argument.
3303 Arguments are numbered in the order they will be pushed,
3304 not the order they are written. */
3305 struct arg_data *args;
3306
3307 /* Total size in bytes of all the stack-parms scanned so far. */
3308 struct args_size args_size;
3309 struct args_size adjusted_args_size;
3310 /* Size of arguments before any adjustments (such as rounding). */
3311 poly_int64 unadjusted_args_size;
3312 /* Data on reg parms scanned so far. */
3313 CUMULATIVE_ARGS args_so_far_v;
3314 cumulative_args_t args_so_far;
3315 /* Nonzero if a reg parm has been scanned. */
3316 int reg_parm_seen;
3317 /* Nonzero if this is an indirect function call. */
3318
3319 /* Nonzero if we must avoid push-insns in the args for this call.
3320 If stack space is allocated for register parameters, but not by the
3321 caller, then it is preallocated in the fixed part of the stack frame.
3322 So the entire argument block must then be preallocated (i.e., we
3323 ignore PUSH_ROUNDING in that case). */
3324
3325 int must_preallocate = !PUSH_ARGS;
3326
3327 /* Size of the stack reserved for parameter registers. */
3328 int reg_parm_stack_space = 0;
3329
3330 /* Address of space preallocated for stack parms
3331 (on machines that lack push insns), or 0 if space not preallocated. */
3332 rtx argblock = 0;
3333
3334 /* Mask of ECF_ and ERF_ flags. */
3335 int flags = 0;
3336 int return_flags = 0;
3337 #ifdef REG_PARM_STACK_SPACE
3338 /* Define the boundary of the register parm stack space that needs to be
3339 saved, if any. */
3340 int low_to_save, high_to_save;
3341 rtx save_area = 0; /* Place that it is saved */
3342 #endif
3343
3344 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3345 char *initial_stack_usage_map = stack_usage_map;
3346 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3347 char *stack_usage_map_buf = NULL;
3348
3349 poly_int64 old_stack_allocated;
3350
3351 /* State variables to track stack modifications. */
3352 rtx old_stack_level = 0;
3353 int old_stack_arg_under_construction = 0;
3354 poly_int64 old_pending_adj = 0;
3355 int old_inhibit_defer_pop = inhibit_defer_pop;
3356
3357 /* Some stack pointer alterations we make are performed via
3358 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3359 which we then also need to save/restore along the way. */
3360 poly_int64 old_stack_pointer_delta = 0;
3361
3362 rtx call_fusage;
3363 tree addr = CALL_EXPR_FN (exp);
3364 int i;
3365 /* The alignment of the stack, in bits. */
3366 unsigned HOST_WIDE_INT preferred_stack_boundary;
3367 /* The alignment of the stack, in bytes. */
3368 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3369 /* The static chain value to use for this call. */
3370 rtx static_chain_value;
3371 /* See if this is "nothrow" function call. */
3372 if (TREE_NOTHROW (exp))
3373 flags |= ECF_NOTHROW;
3374
3375 /* See if we can find a DECL-node for the actual function, and get the
3376 function attributes (flags) from the function decl or type node. */
3377 fndecl = get_callee_fndecl (exp);
3378 if (fndecl)
3379 {
3380 fntype = TREE_TYPE (fndecl);
3381 flags |= flags_from_decl_or_type (fndecl);
3382 return_flags |= decl_return_flags (fndecl);
3383 }
3384 else
3385 {
3386 fntype = TREE_TYPE (TREE_TYPE (addr));
3387 flags |= flags_from_decl_or_type (fntype);
3388 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3389 flags |= ECF_BY_DESCRIPTOR;
3390 }
3391 rettype = TREE_TYPE (exp);
3392
3393 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3394
3395 /* Warn if this value is an aggregate type,
3396 regardless of which calling convention we are using for it. */
3397 if (AGGREGATE_TYPE_P (rettype))
3398 warning (OPT_Waggregate_return, "function call has aggregate value");
3399
3400 /* If the result of a non looping pure or const function call is
3401 ignored (or void), and none of its arguments are volatile, we can
3402 avoid expanding the call and just evaluate the arguments for
3403 side-effects. */
3404 if ((flags & (ECF_CONST | ECF_PURE))
3405 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3406 && (ignore || target == const0_rtx
3407 || TYPE_MODE (rettype) == VOIDmode))
3408 {
3409 bool volatilep = false;
3410 tree arg;
3411 call_expr_arg_iterator iter;
3412
3413 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3414 if (TREE_THIS_VOLATILE (arg))
3415 {
3416 volatilep = true;
3417 break;
3418 }
3419
3420 if (! volatilep)
3421 {
3422 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3423 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3424 return const0_rtx;
3425 }
3426 }
3427
3428 #ifdef REG_PARM_STACK_SPACE
3429 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3430 #endif
3431
3432 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3433 && reg_parm_stack_space > 0 && PUSH_ARGS)
3434 must_preallocate = 1;
3435
3436 /* Set up a place to return a structure. */
3437
3438 /* Cater to broken compilers. */
3439 if (aggregate_value_p (exp, fntype))
3440 {
3441 /* This call returns a big structure. */
3442 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3443
3444 #ifdef PCC_STATIC_STRUCT_RETURN
3445 {
3446 pcc_struct_value = 1;
3447 }
3448 #else /* not PCC_STATIC_STRUCT_RETURN */
3449 {
3450 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3451 struct_value_size = -1;
3452
3453 /* Even if it is semantically safe to use the target as the return
3454 slot, it may be not sufficiently aligned for the return type. */
3455 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3456 && target
3457 && MEM_P (target)
3458 /* If rettype is addressable, we may not create a temporary.
3459 If target is properly aligned at runtime and the compiler
3460 just doesn't know about it, it will work fine, otherwise it
3461 will be UB. */
3462 && (TREE_ADDRESSABLE (rettype)
3463 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3464 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3465 MEM_ALIGN (target)))))
3466 structure_value_addr = XEXP (target, 0);
3467 else
3468 {
3469 /* For variable-sized objects, we must be called with a target
3470 specified. If we were to allocate space on the stack here,
3471 we would have no way of knowing when to free it. */
3472 rtx d = assign_temp (rettype, 1, 1);
3473 structure_value_addr = XEXP (d, 0);
3474 target = 0;
3475 }
3476 }
3477 #endif /* not PCC_STATIC_STRUCT_RETURN */
3478 }
3479
3480 /* Figure out the amount to which the stack should be aligned. */
3481 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3482 if (fndecl)
3483 {
3484 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3485 /* Without automatic stack alignment, we can't increase preferred
3486 stack boundary. With automatic stack alignment, it is
3487 unnecessary since unless we can guarantee that all callers will
3488 align the outgoing stack properly, callee has to align its
3489 stack anyway. */
3490 if (i
3491 && i->preferred_incoming_stack_boundary
3492 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3493 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3494 }
3495
3496 /* Operand 0 is a pointer-to-function; get the type of the function. */
3497 funtype = TREE_TYPE (addr);
3498 gcc_assert (POINTER_TYPE_P (funtype));
3499 funtype = TREE_TYPE (funtype);
3500
3501 /* Count whether there are actual complex arguments that need to be split
3502 into their real and imaginary parts. Munge the type_arg_types
3503 appropriately here as well. */
3504 if (targetm.calls.split_complex_arg)
3505 {
3506 call_expr_arg_iterator iter;
3507 tree arg;
3508 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3509 {
3510 tree type = TREE_TYPE (arg);
3511 if (type && TREE_CODE (type) == COMPLEX_TYPE
3512 && targetm.calls.split_complex_arg (type))
3513 num_complex_actuals++;
3514 }
3515 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3516 }
3517 else
3518 type_arg_types = TYPE_ARG_TYPES (funtype);
3519
3520 if (flags & ECF_MAY_BE_ALLOCA)
3521 cfun->calls_alloca = 1;
3522
3523 /* If struct_value_rtx is 0, it means pass the address
3524 as if it were an extra parameter. Put the argument expression
3525 in structure_value_addr_value. */
3526 if (structure_value_addr && struct_value == 0)
3527 {
3528 /* If structure_value_addr is a REG other than
3529 virtual_outgoing_args_rtx, we can use always use it. If it
3530 is not a REG, we must always copy it into a register.
3531 If it is virtual_outgoing_args_rtx, we must copy it to another
3532 register in some cases. */
3533 rtx temp = (!REG_P (structure_value_addr)
3534 || (ACCUMULATE_OUTGOING_ARGS
3535 && stack_arg_under_construction
3536 && structure_value_addr == virtual_outgoing_args_rtx)
3537 ? copy_addr_to_reg (convert_memory_address
3538 (Pmode, structure_value_addr))
3539 : structure_value_addr);
3540
3541 structure_value_addr_value =
3542 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3543 structure_value_addr_parm = 1;
3544 }
3545
3546 /* Count the arguments and set NUM_ACTUALS. */
3547 num_actuals =
3548 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3549
3550 /* Compute number of named args.
3551 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3552
3553 if (type_arg_types != 0)
3554 n_named_args
3555 = (list_length (type_arg_types)
3556 /* Count the struct value address, if it is passed as a parm. */
3557 + structure_value_addr_parm);
3558 else
3559 /* If we know nothing, treat all args as named. */
3560 n_named_args = num_actuals;
3561
3562 /* Start updating where the next arg would go.
3563
3564 On some machines (such as the PA) indirect calls have a different
3565 calling convention than normal calls. The fourth argument in
3566 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3567 or not. */
3568 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3569 args_so_far = pack_cumulative_args (&args_so_far_v);
3570
3571 /* Now possibly adjust the number of named args.
3572 Normally, don't include the last named arg if anonymous args follow.
3573 We do include the last named arg if
3574 targetm.calls.strict_argument_naming() returns nonzero.
3575 (If no anonymous args follow, the result of list_length is actually
3576 one too large. This is harmless.)
3577
3578 If targetm.calls.pretend_outgoing_varargs_named() returns
3579 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3580 this machine will be able to place unnamed args that were passed
3581 in registers into the stack. So treat all args as named. This
3582 allows the insns emitting for a specific argument list to be
3583 independent of the function declaration.
3584
3585 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3586 we do not have any reliable way to pass unnamed args in
3587 registers, so we must force them into memory. */
3588
3589 if (type_arg_types != 0
3590 && targetm.calls.strict_argument_naming (args_so_far))
3591 ;
3592 else if (type_arg_types != 0
3593 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3594 /* Don't include the last named arg. */
3595 --n_named_args;
3596 else
3597 /* Treat all args as named. */
3598 n_named_args = num_actuals;
3599
3600 /* Make a vector to hold all the information about each arg. */
3601 args = XCNEWVEC (struct arg_data, num_actuals);
3602
3603 /* Build up entries in the ARGS array, compute the size of the
3604 arguments into ARGS_SIZE, etc. */
3605 initialize_argument_information (num_actuals, args, &args_size,
3606 n_named_args, exp,
3607 structure_value_addr_value, fndecl, fntype,
3608 args_so_far, reg_parm_stack_space,
3609 &old_stack_level, &old_pending_adj,
3610 &must_preallocate, &flags,
3611 &try_tail_call, CALL_FROM_THUNK_P (exp));
3612
3613 if (args_size.var)
3614 must_preallocate = 1;
3615
3616 /* Now make final decision about preallocating stack space. */
3617 must_preallocate = finalize_must_preallocate (must_preallocate,
3618 num_actuals, args,
3619 &args_size);
3620
3621 /* If the structure value address will reference the stack pointer, we
3622 must stabilize it. We don't need to do this if we know that we are
3623 not going to adjust the stack pointer in processing this call. */
3624
3625 if (structure_value_addr
3626 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3627 || reg_mentioned_p (virtual_outgoing_args_rtx,
3628 structure_value_addr))
3629 && (args_size.var
3630 || (!ACCUMULATE_OUTGOING_ARGS
3631 && maybe_ne (args_size.constant, 0))))
3632 structure_value_addr = copy_to_reg (structure_value_addr);
3633
3634 /* Tail calls can make things harder to debug, and we've traditionally
3635 pushed these optimizations into -O2. Don't try if we're already
3636 expanding a call, as that means we're an argument. Don't try if
3637 there's cleanups, as we know there's code to follow the call. */
3638 if (currently_expanding_call++ != 0
3639 || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp))
3640 || args_size.var
3641 || dbg_cnt (tail_call) == false)
3642 try_tail_call = 0;
3643
3644 /* Workaround buggy C/C++ wrappers around Fortran routines with
3645 character(len=constant) arguments if the hidden string length arguments
3646 are passed on the stack; if the callers forget to pass those arguments,
3647 attempting to tail call in such routines leads to stack corruption.
3648 Avoid tail calls in functions where at least one such hidden string
3649 length argument is passed (partially or fully) on the stack in the
3650 caller and the callee needs to pass any arguments on the stack.
3651 See PR90329. */
3652 if (try_tail_call && maybe_ne (args_size.constant, 0))
3653 for (tree arg = DECL_ARGUMENTS (current_function_decl);
3654 arg; arg = DECL_CHAIN (arg))
3655 if (DECL_HIDDEN_STRING_LENGTH (arg) && DECL_INCOMING_RTL (arg))
3656 {
3657 subrtx_iterator::array_type array;
3658 FOR_EACH_SUBRTX (iter, array, DECL_INCOMING_RTL (arg), NONCONST)
3659 if (MEM_P (*iter))
3660 {
3661 try_tail_call = 0;
3662 break;
3663 }
3664 }
3665
3666 /* If the user has marked the function as requiring tail-call
3667 optimization, attempt it. */
3668 if (must_tail_call)
3669 try_tail_call = 1;
3670
3671 /* Rest of purposes for tail call optimizations to fail. */
3672 if (try_tail_call)
3673 try_tail_call = can_implement_as_sibling_call_p (exp,
3674 structure_value_addr,
3675 funtype,
3676 reg_parm_stack_space,
3677 fndecl,
3678 flags, addr, args_size);
3679
3680 /* Check if caller and callee disagree in promotion of function
3681 return value. */
3682 if (try_tail_call)
3683 {
3684 machine_mode caller_mode, caller_promoted_mode;
3685 machine_mode callee_mode, callee_promoted_mode;
3686 int caller_unsignedp, callee_unsignedp;
3687 tree caller_res = DECL_RESULT (current_function_decl);
3688
3689 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3690 caller_mode = DECL_MODE (caller_res);
3691 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3692 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3693 caller_promoted_mode
3694 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3695 &caller_unsignedp,
3696 TREE_TYPE (current_function_decl), 1);
3697 callee_promoted_mode
3698 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3699 &callee_unsignedp,
3700 funtype, 1);
3701 if (caller_mode != VOIDmode
3702 && (caller_promoted_mode != callee_promoted_mode
3703 || ((caller_mode != caller_promoted_mode
3704 || callee_mode != callee_promoted_mode)
3705 && (caller_unsignedp != callee_unsignedp
3706 || partial_subreg_p (caller_mode, callee_mode)))))
3707 {
3708 try_tail_call = 0;
3709 maybe_complain_about_tail_call (exp,
3710 "caller and callee disagree in"
3711 " promotion of function"
3712 " return value");
3713 }
3714 }
3715
3716 /* Ensure current function's preferred stack boundary is at least
3717 what we need. Stack alignment may also increase preferred stack
3718 boundary. */
3719 for (i = 0; i < num_actuals; i++)
3720 if (reg_parm_stack_space > 0
3721 || args[i].reg == 0
3722 || args[i].partial != 0
3723 || args[i].pass_on_stack)
3724 update_stack_alignment_for_call (&args[i].locate);
3725 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3726 crtl->preferred_stack_boundary = preferred_stack_boundary;
3727 else
3728 preferred_stack_boundary = crtl->preferred_stack_boundary;
3729
3730 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3731
3732 /* We want to make two insn chains; one for a sibling call, the other
3733 for a normal call. We will select one of the two chains after
3734 initial RTL generation is complete. */
3735 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3736 {
3737 int sibcall_failure = 0;
3738 /* We want to emit any pending stack adjustments before the tail
3739 recursion "call". That way we know any adjustment after the tail
3740 recursion call can be ignored if we indeed use the tail
3741 call expansion. */
3742 saved_pending_stack_adjust save;
3743 rtx_insn *insns, *before_call, *after_args;
3744 rtx next_arg_reg;
3745
3746 if (pass == 0)
3747 {
3748 /* State variables we need to save and restore between
3749 iterations. */
3750 save_pending_stack_adjust (&save);
3751 }
3752 if (pass)
3753 flags &= ~ECF_SIBCALL;
3754 else
3755 flags |= ECF_SIBCALL;
3756
3757 /* Other state variables that we must reinitialize each time
3758 through the loop (that are not initialized by the loop itself). */
3759 argblock = 0;
3760 call_fusage = 0;
3761
3762 /* Start a new sequence for the normal call case.
3763
3764 From this point on, if the sibling call fails, we want to set
3765 sibcall_failure instead of continuing the loop. */
3766 start_sequence ();
3767
3768 /* Don't let pending stack adjusts add up to too much.
3769 Also, do all pending adjustments now if there is any chance
3770 this might be a call to alloca or if we are expanding a sibling
3771 call sequence.
3772 Also do the adjustments before a throwing call, otherwise
3773 exception handling can fail; PR 19225. */
3774 if (maybe_ge (pending_stack_adjust, 32)
3775 || (maybe_ne (pending_stack_adjust, 0)
3776 && (flags & ECF_MAY_BE_ALLOCA))
3777 || (maybe_ne (pending_stack_adjust, 0)
3778 && flag_exceptions && !(flags & ECF_NOTHROW))
3779 || pass == 0)
3780 do_pending_stack_adjust ();
3781
3782 /* Precompute any arguments as needed. */
3783 if (pass)
3784 precompute_arguments (num_actuals, args);
3785
3786 /* Now we are about to start emitting insns that can be deleted
3787 if a libcall is deleted. */
3788 if (pass && (flags & ECF_MALLOC))
3789 start_sequence ();
3790
3791 if (pass == 0
3792 && crtl->stack_protect_guard
3793 && targetm.stack_protect_runtime_enabled_p ())
3794 stack_protect_epilogue ();
3795
3796 adjusted_args_size = args_size;
3797 /* Compute the actual size of the argument block required. The variable
3798 and constant sizes must be combined, the size may have to be rounded,
3799 and there may be a minimum required size. When generating a sibcall
3800 pattern, do not round up, since we'll be re-using whatever space our
3801 caller provided. */
3802 unadjusted_args_size
3803 = compute_argument_block_size (reg_parm_stack_space,
3804 &adjusted_args_size,
3805 fndecl, fntype,
3806 (pass == 0 ? 0
3807 : preferred_stack_boundary));
3808
3809 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3810
3811 /* The argument block when performing a sibling call is the
3812 incoming argument block. */
3813 if (pass == 0)
3814 {
3815 argblock = crtl->args.internal_arg_pointer;
3816 if (STACK_GROWS_DOWNWARD)
3817 argblock
3818 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3819 else
3820 argblock
3821 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3822
3823 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3824 stored_args_map = sbitmap_alloc (map_size);
3825 bitmap_clear (stored_args_map);
3826 stored_args_watermark = HOST_WIDE_INT_M1U;
3827 }
3828
3829 /* If we have no actual push instructions, or shouldn't use them,
3830 make space for all args right now. */
3831 else if (adjusted_args_size.var != 0)
3832 {
3833 if (old_stack_level == 0)
3834 {
3835 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3836 old_stack_pointer_delta = stack_pointer_delta;
3837 old_pending_adj = pending_stack_adjust;
3838 pending_stack_adjust = 0;
3839 /* stack_arg_under_construction says whether a stack arg is
3840 being constructed at the old stack level. Pushing the stack
3841 gets a clean outgoing argument block. */
3842 old_stack_arg_under_construction = stack_arg_under_construction;
3843 stack_arg_under_construction = 0;
3844 }
3845 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3846 if (flag_stack_usage_info)
3847 current_function_has_unbounded_dynamic_stack_size = 1;
3848 }
3849 else
3850 {
3851 /* Note that we must go through the motions of allocating an argument
3852 block even if the size is zero because we may be storing args
3853 in the area reserved for register arguments, which may be part of
3854 the stack frame. */
3855
3856 poly_int64 needed = adjusted_args_size.constant;
3857
3858 /* Store the maximum argument space used. It will be pushed by
3859 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3860 checking). */
3861
3862 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3863 needed);
3864
3865 if (must_preallocate)
3866 {
3867 if (ACCUMULATE_OUTGOING_ARGS)
3868 {
3869 /* Since the stack pointer will never be pushed, it is
3870 possible for the evaluation of a parm to clobber
3871 something we have already written to the stack.
3872 Since most function calls on RISC machines do not use
3873 the stack, this is uncommon, but must work correctly.
3874
3875 Therefore, we save any area of the stack that was already
3876 written and that we are using. Here we set up to do this
3877 by making a new stack usage map from the old one. The
3878 actual save will be done by store_one_arg.
3879
3880 Another approach might be to try to reorder the argument
3881 evaluations to avoid this conflicting stack usage. */
3882
3883 /* Since we will be writing into the entire argument area,
3884 the map must be allocated for its entire size, not just
3885 the part that is the responsibility of the caller. */
3886 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3887 needed += reg_parm_stack_space;
3888
3889 poly_int64 limit = needed;
3890 if (ARGS_GROW_DOWNWARD)
3891 limit += 1;
3892
3893 /* For polynomial sizes, this is the maximum possible
3894 size needed for arguments with a constant size
3895 and offset. */
3896 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3897 highest_outgoing_arg_in_use
3898 = MAX (initial_highest_arg_in_use, const_limit);
3899
3900 free (stack_usage_map_buf);
3901 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3902 stack_usage_map = stack_usage_map_buf;
3903
3904 if (initial_highest_arg_in_use)
3905 memcpy (stack_usage_map, initial_stack_usage_map,
3906 initial_highest_arg_in_use);
3907
3908 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3909 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3910 (highest_outgoing_arg_in_use
3911 - initial_highest_arg_in_use));
3912 needed = 0;
3913
3914 /* The address of the outgoing argument list must not be
3915 copied to a register here, because argblock would be left
3916 pointing to the wrong place after the call to
3917 allocate_dynamic_stack_space below. */
3918
3919 argblock = virtual_outgoing_args_rtx;
3920 }
3921 else
3922 {
3923 /* Try to reuse some or all of the pending_stack_adjust
3924 to get this space. */
3925 if (inhibit_defer_pop == 0
3926 && (combine_pending_stack_adjustment_and_call
3927 (&needed,
3928 unadjusted_args_size,
3929 &adjusted_args_size,
3930 preferred_unit_stack_boundary)))
3931 {
3932 /* combine_pending_stack_adjustment_and_call computes
3933 an adjustment before the arguments are allocated.
3934 Account for them and see whether or not the stack
3935 needs to go up or down. */
3936 needed = unadjusted_args_size - needed;
3937
3938 /* Checked by
3939 combine_pending_stack_adjustment_and_call. */
3940 gcc_checking_assert (ordered_p (needed, 0));
3941 if (maybe_lt (needed, 0))
3942 {
3943 /* We're releasing stack space. */
3944 /* ??? We can avoid any adjustment at all if we're
3945 already aligned. FIXME. */
3946 pending_stack_adjust = -needed;
3947 do_pending_stack_adjust ();
3948 needed = 0;
3949 }
3950 else
3951 /* We need to allocate space. We'll do that in
3952 push_block below. */
3953 pending_stack_adjust = 0;
3954 }
3955
3956 /* Special case this because overhead of `push_block' in
3957 this case is non-trivial. */
3958 if (known_eq (needed, 0))
3959 argblock = virtual_outgoing_args_rtx;
3960 else
3961 {
3962 rtx needed_rtx = gen_int_mode (needed, Pmode);
3963 argblock = push_block (needed_rtx, 0, 0);
3964 if (ARGS_GROW_DOWNWARD)
3965 argblock = plus_constant (Pmode, argblock, needed);
3966 }
3967
3968 /* We only really need to call `copy_to_reg' in the case
3969 where push insns are going to be used to pass ARGBLOCK
3970 to a function call in ARGS. In that case, the stack
3971 pointer changes value from the allocation point to the
3972 call point, and hence the value of
3973 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3974 as well always do it. */
3975 argblock = copy_to_reg (argblock);
3976 }
3977 }
3978 }
3979
3980 if (ACCUMULATE_OUTGOING_ARGS)
3981 {
3982 /* The save/restore code in store_one_arg handles all
3983 cases except one: a constructor call (including a C
3984 function returning a BLKmode struct) to initialize
3985 an argument. */
3986 if (stack_arg_under_construction)
3987 {
3988 rtx push_size
3989 = (gen_int_mode
3990 (adjusted_args_size.constant
3991 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
3992 : TREE_TYPE (fndecl))
3993 ? 0 : reg_parm_stack_space), Pmode));
3994 if (old_stack_level == 0)
3995 {
3996 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3997 old_stack_pointer_delta = stack_pointer_delta;
3998 old_pending_adj = pending_stack_adjust;
3999 pending_stack_adjust = 0;
4000 /* stack_arg_under_construction says whether a stack
4001 arg is being constructed at the old stack level.
4002 Pushing the stack gets a clean outgoing argument
4003 block. */
4004 old_stack_arg_under_construction
4005 = stack_arg_under_construction;
4006 stack_arg_under_construction = 0;
4007 /* Make a new map for the new argument list. */
4008 free (stack_usage_map_buf);
4009 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
4010 stack_usage_map = stack_usage_map_buf;
4011 highest_outgoing_arg_in_use = 0;
4012 stack_usage_watermark = HOST_WIDE_INT_M1U;
4013 }
4014 /* We can pass TRUE as the 4th argument because we just
4015 saved the stack pointer and will restore it right after
4016 the call. */
4017 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
4018 -1, true);
4019 }
4020
4021 /* If argument evaluation might modify the stack pointer,
4022 copy the address of the argument list to a register. */
4023 for (i = 0; i < num_actuals; i++)
4024 if (args[i].pass_on_stack)
4025 {
4026 argblock = copy_addr_to_reg (argblock);
4027 break;
4028 }
4029 }
4030
4031 compute_argument_addresses (args, argblock, num_actuals);
4032
4033 /* Stack is properly aligned, pops can't safely be deferred during
4034 the evaluation of the arguments. */
4035 NO_DEFER_POP;
4036
4037 /* Precompute all register parameters. It isn't safe to compute
4038 anything once we have started filling any specific hard regs.
4039 TLS symbols sometimes need a call to resolve. Precompute
4040 register parameters before any stack pointer manipulation
4041 to avoid unaligned stack in the called function. */
4042 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
4043
4044 OK_DEFER_POP;
4045
4046 /* Perform stack alignment before the first push (the last arg). */
4047 if (argblock == 0
4048 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
4049 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
4050 {
4051 /* When the stack adjustment is pending, we get better code
4052 by combining the adjustments. */
4053 if (maybe_ne (pending_stack_adjust, 0)
4054 && ! inhibit_defer_pop
4055 && (combine_pending_stack_adjustment_and_call
4056 (&pending_stack_adjust,
4057 unadjusted_args_size,
4058 &adjusted_args_size,
4059 preferred_unit_stack_boundary)))
4060 do_pending_stack_adjust ();
4061 else if (argblock == 0)
4062 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4063 - unadjusted_args_size,
4064 Pmode));
4065 }
4066 /* Now that the stack is properly aligned, pops can't safely
4067 be deferred during the evaluation of the arguments. */
4068 NO_DEFER_POP;
4069
4070 /* Record the maximum pushed stack space size. We need to delay
4071 doing it this far to take into account the optimization done
4072 by combine_pending_stack_adjustment_and_call. */
4073 if (flag_stack_usage_info
4074 && !ACCUMULATE_OUTGOING_ARGS
4075 && pass
4076 && adjusted_args_size.var == 0)
4077 {
4078 poly_int64 pushed = (adjusted_args_size.constant
4079 + pending_stack_adjust);
4080 current_function_pushed_stack_size
4081 = upper_bound (current_function_pushed_stack_size, pushed);
4082 }
4083
4084 funexp = rtx_for_function_call (fndecl, addr);
4085
4086 if (CALL_EXPR_STATIC_CHAIN (exp))
4087 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4088 else
4089 static_chain_value = 0;
4090
4091 #ifdef REG_PARM_STACK_SPACE
4092 /* Save the fixed argument area if it's part of the caller's frame and
4093 is clobbered by argument setup for this call. */
4094 if (ACCUMULATE_OUTGOING_ARGS && pass)
4095 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4096 &low_to_save, &high_to_save);
4097 #endif
4098
4099 /* Now store (and compute if necessary) all non-register parms.
4100 These come before register parms, since they can require block-moves,
4101 which could clobber the registers used for register parms.
4102 Parms which have partial registers are not stored here,
4103 but we do preallocate space here if they want that. */
4104
4105 for (i = 0; i < num_actuals; i++)
4106 {
4107 if (args[i].reg == 0 || args[i].pass_on_stack)
4108 {
4109 rtx_insn *before_arg = get_last_insn ();
4110
4111 /* We don't allow passing huge (> 2^30 B) arguments
4112 by value. It would cause an overflow later on. */
4113 if (constant_lower_bound (adjusted_args_size.constant)
4114 >= (1 << (HOST_BITS_PER_INT - 2)))
4115 {
4116 sorry ("passing too large argument on stack");
4117 continue;
4118 }
4119
4120 if (store_one_arg (&args[i], argblock, flags,
4121 adjusted_args_size.var != 0,
4122 reg_parm_stack_space)
4123 || (pass == 0
4124 && check_sibcall_argument_overlap (before_arg,
4125 &args[i], 1)))
4126 sibcall_failure = 1;
4127 }
4128
4129 if (args[i].stack)
4130 call_fusage
4131 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4132 gen_rtx_USE (VOIDmode, args[i].stack),
4133 call_fusage);
4134 }
4135
4136 /* If we have a parm that is passed in registers but not in memory
4137 and whose alignment does not permit a direct copy into registers,
4138 make a group of pseudos that correspond to each register that we
4139 will later fill. */
4140 if (STRICT_ALIGNMENT)
4141 store_unaligned_arguments_into_pseudos (args, num_actuals);
4142
4143 /* Now store any partially-in-registers parm.
4144 This is the last place a block-move can happen. */
4145 if (reg_parm_seen)
4146 for (i = 0; i < num_actuals; i++)
4147 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4148 {
4149 rtx_insn *before_arg = get_last_insn ();
4150
4151 /* On targets with weird calling conventions (e.g. PA) it's
4152 hard to ensure that all cases of argument overlap between
4153 stack and registers work. Play it safe and bail out. */
4154 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4155 {
4156 sibcall_failure = 1;
4157 break;
4158 }
4159
4160 if (store_one_arg (&args[i], argblock, flags,
4161 adjusted_args_size.var != 0,
4162 reg_parm_stack_space)
4163 || (pass == 0
4164 && check_sibcall_argument_overlap (before_arg,
4165 &args[i], 1)))
4166 sibcall_failure = 1;
4167 }
4168
4169 bool any_regs = false;
4170 for (i = 0; i < num_actuals; i++)
4171 if (args[i].reg != NULL_RTX)
4172 {
4173 any_regs = true;
4174 targetm.calls.call_args (args[i].reg, funtype);
4175 }
4176 if (!any_regs)
4177 targetm.calls.call_args (pc_rtx, funtype);
4178
4179 /* Figure out the register where the value, if any, will come back. */
4180 valreg = 0;
4181 if (TYPE_MODE (rettype) != VOIDmode
4182 && ! structure_value_addr)
4183 {
4184 if (pcc_struct_value)
4185 valreg = hard_function_value (build_pointer_type (rettype),
4186 fndecl, NULL, (pass == 0));
4187 else
4188 valreg = hard_function_value (rettype, fndecl, fntype,
4189 (pass == 0));
4190
4191 /* If VALREG is a PARALLEL whose first member has a zero
4192 offset, use that. This is for targets such as m68k that
4193 return the same value in multiple places. */
4194 if (GET_CODE (valreg) == PARALLEL)
4195 {
4196 rtx elem = XVECEXP (valreg, 0, 0);
4197 rtx where = XEXP (elem, 0);
4198 rtx offset = XEXP (elem, 1);
4199 if (offset == const0_rtx
4200 && GET_MODE (where) == GET_MODE (valreg))
4201 valreg = where;
4202 }
4203 }
4204
4205 /* If register arguments require space on the stack and stack space
4206 was not preallocated, allocate stack space here for arguments
4207 passed in registers. */
4208 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4209 && !ACCUMULATE_OUTGOING_ARGS
4210 && must_preallocate == 0 && reg_parm_stack_space > 0)
4211 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4212
4213 /* Pass the function the address in which to return a
4214 structure value. */
4215 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4216 {
4217 structure_value_addr
4218 = convert_memory_address (Pmode, structure_value_addr);
4219 emit_move_insn (struct_value,
4220 force_reg (Pmode,
4221 force_operand (structure_value_addr,
4222 NULL_RTX)));
4223
4224 if (REG_P (struct_value))
4225 use_reg (&call_fusage, struct_value);
4226 }
4227
4228 after_args = get_last_insn ();
4229 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4230 static_chain_value, &call_fusage,
4231 reg_parm_seen, flags);
4232
4233 load_register_parameters (args, num_actuals, &call_fusage, flags,
4234 pass == 0, &sibcall_failure);
4235
4236 /* Save a pointer to the last insn before the call, so that we can
4237 later safely search backwards to find the CALL_INSN. */
4238 before_call = get_last_insn ();
4239
4240 /* Set up next argument register. For sibling calls on machines
4241 with register windows this should be the incoming register. */
4242 if (pass == 0)
4243 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
4244 VOIDmode,
4245 void_type_node,
4246 true);
4247 else
4248 next_arg_reg = targetm.calls.function_arg (args_so_far,
4249 VOIDmode, void_type_node,
4250 true);
4251
4252 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4253 {
4254 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4255 arg_nr = num_actuals - arg_nr - 1;
4256 if (arg_nr >= 0
4257 && arg_nr < num_actuals
4258 && args[arg_nr].reg
4259 && valreg
4260 && REG_P (valreg)
4261 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4262 call_fusage
4263 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4264 gen_rtx_SET (valreg, args[arg_nr].reg),
4265 call_fusage);
4266 }
4267 /* All arguments and registers used for the call must be set up by
4268 now! */
4269
4270 /* Stack must be properly aligned now. */
4271 gcc_assert (!pass
4272 || multiple_p (stack_pointer_delta,
4273 preferred_unit_stack_boundary));
4274
4275 /* Generate the actual call instruction. */
4276 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4277 adjusted_args_size.constant, struct_value_size,
4278 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4279 flags, args_so_far);
4280
4281 if (flag_ipa_ra)
4282 {
4283 rtx_call_insn *last;
4284 rtx datum = NULL_RTX;
4285 if (fndecl != NULL_TREE)
4286 {
4287 datum = XEXP (DECL_RTL (fndecl), 0);
4288 gcc_assert (datum != NULL_RTX
4289 && GET_CODE (datum) == SYMBOL_REF);
4290 }
4291 last = last_call_insn ();
4292 add_reg_note (last, REG_CALL_DECL, datum);
4293 }
4294
4295 /* If the call setup or the call itself overlaps with anything
4296 of the argument setup we probably clobbered our call address.
4297 In that case we can't do sibcalls. */
4298 if (pass == 0
4299 && check_sibcall_argument_overlap (after_args, 0, 0))
4300 sibcall_failure = 1;
4301
4302 /* If a non-BLKmode value is returned at the most significant end
4303 of a register, shift the register right by the appropriate amount
4304 and update VALREG accordingly. BLKmode values are handled by the
4305 group load/store machinery below. */
4306 if (!structure_value_addr
4307 && !pcc_struct_value
4308 && TYPE_MODE (rettype) != VOIDmode
4309 && TYPE_MODE (rettype) != BLKmode
4310 && REG_P (valreg)
4311 && targetm.calls.return_in_msb (rettype))
4312 {
4313 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4314 sibcall_failure = 1;
4315 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4316 }
4317
4318 if (pass && (flags & ECF_MALLOC))
4319 {
4320 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4321 rtx_insn *last, *insns;
4322
4323 /* The return value from a malloc-like function is a pointer. */
4324 if (TREE_CODE (rettype) == POINTER_TYPE)
4325 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4326
4327 emit_move_insn (temp, valreg);
4328
4329 /* The return value from a malloc-like function cannot alias
4330 anything else. */
4331 last = get_last_insn ();
4332 add_reg_note (last, REG_NOALIAS, temp);
4333
4334 /* Write out the sequence. */
4335 insns = get_insns ();
4336 end_sequence ();
4337 emit_insn (insns);
4338 valreg = temp;
4339 }
4340
4341 /* For calls to `setjmp', etc., inform
4342 function.c:setjmp_warnings that it should complain if
4343 nonvolatile values are live. For functions that cannot
4344 return, inform flow that control does not fall through. */
4345
4346 if ((flags & ECF_NORETURN) || pass == 0)
4347 {
4348 /* The barrier must be emitted
4349 immediately after the CALL_INSN. Some ports emit more
4350 than just a CALL_INSN above, so we must search for it here. */
4351
4352 rtx_insn *last = get_last_insn ();
4353 while (!CALL_P (last))
4354 {
4355 last = PREV_INSN (last);
4356 /* There was no CALL_INSN? */
4357 gcc_assert (last != before_call);
4358 }
4359
4360 emit_barrier_after (last);
4361
4362 /* Stack adjustments after a noreturn call are dead code.
4363 However when NO_DEFER_POP is in effect, we must preserve
4364 stack_pointer_delta. */
4365 if (inhibit_defer_pop == 0)
4366 {
4367 stack_pointer_delta = old_stack_allocated;
4368 pending_stack_adjust = 0;
4369 }
4370 }
4371
4372 /* If value type not void, return an rtx for the value. */
4373
4374 if (TYPE_MODE (rettype) == VOIDmode
4375 || ignore)
4376 target = const0_rtx;
4377 else if (structure_value_addr)
4378 {
4379 if (target == 0 || !MEM_P (target))
4380 {
4381 target
4382 = gen_rtx_MEM (TYPE_MODE (rettype),
4383 memory_address (TYPE_MODE (rettype),
4384 structure_value_addr));
4385 set_mem_attributes (target, rettype, 1);
4386 }
4387 }
4388 else if (pcc_struct_value)
4389 {
4390 /* This is the special C++ case where we need to
4391 know what the true target was. We take care to
4392 never use this value more than once in one expression. */
4393 target = gen_rtx_MEM (TYPE_MODE (rettype),
4394 copy_to_reg (valreg));
4395 set_mem_attributes (target, rettype, 1);
4396 }
4397 /* Handle calls that return values in multiple non-contiguous locations.
4398 The Irix 6 ABI has examples of this. */
4399 else if (GET_CODE (valreg) == PARALLEL)
4400 {
4401 if (target == 0)
4402 target = emit_group_move_into_temps (valreg);
4403 else if (rtx_equal_p (target, valreg))
4404 ;
4405 else if (GET_CODE (target) == PARALLEL)
4406 /* Handle the result of a emit_group_move_into_temps
4407 call in the previous pass. */
4408 emit_group_move (target, valreg);
4409 else
4410 emit_group_store (target, valreg, rettype,
4411 int_size_in_bytes (rettype));
4412 }
4413 else if (target
4414 && GET_MODE (target) == TYPE_MODE (rettype)
4415 && GET_MODE (target) == GET_MODE (valreg))
4416 {
4417 bool may_overlap = false;
4418
4419 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4420 reg to a plain register. */
4421 if (!REG_P (target) || HARD_REGISTER_P (target))
4422 valreg = avoid_likely_spilled_reg (valreg);
4423
4424 /* If TARGET is a MEM in the argument area, and we have
4425 saved part of the argument area, then we can't store
4426 directly into TARGET as it may get overwritten when we
4427 restore the argument save area below. Don't work too
4428 hard though and simply force TARGET to a register if it
4429 is a MEM; the optimizer is quite likely to sort it out. */
4430 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4431 for (i = 0; i < num_actuals; i++)
4432 if (args[i].save_area)
4433 {
4434 may_overlap = true;
4435 break;
4436 }
4437
4438 if (may_overlap)
4439 target = copy_to_reg (valreg);
4440 else
4441 {
4442 /* TARGET and VALREG cannot be equal at this point
4443 because the latter would not have
4444 REG_FUNCTION_VALUE_P true, while the former would if
4445 it were referring to the same register.
4446
4447 If they refer to the same register, this move will be
4448 a no-op, except when function inlining is being
4449 done. */
4450 emit_move_insn (target, valreg);
4451
4452 /* If we are setting a MEM, this code must be executed.
4453 Since it is emitted after the call insn, sibcall
4454 optimization cannot be performed in that case. */
4455 if (MEM_P (target))
4456 sibcall_failure = 1;
4457 }
4458 }
4459 else
4460 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4461
4462 /* If we promoted this return value, make the proper SUBREG.
4463 TARGET might be const0_rtx here, so be careful. */
4464 if (REG_P (target)
4465 && TYPE_MODE (rettype) != BLKmode
4466 && GET_MODE (target) != TYPE_MODE (rettype))
4467 {
4468 tree type = rettype;
4469 int unsignedp = TYPE_UNSIGNED (type);
4470 machine_mode pmode;
4471
4472 /* Ensure we promote as expected, and get the new unsignedness. */
4473 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4474 funtype, 1);
4475 gcc_assert (GET_MODE (target) == pmode);
4476
4477 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4478 GET_MODE (target));
4479 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4480 SUBREG_PROMOTED_VAR_P (target) = 1;
4481 SUBREG_PROMOTED_SET (target, unsignedp);
4482 }
4483
4484 /* If size of args is variable or this was a constructor call for a stack
4485 argument, restore saved stack-pointer value. */
4486
4487 if (old_stack_level)
4488 {
4489 rtx_insn *prev = get_last_insn ();
4490
4491 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4492 stack_pointer_delta = old_stack_pointer_delta;
4493
4494 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4495
4496 pending_stack_adjust = old_pending_adj;
4497 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4498 stack_arg_under_construction = old_stack_arg_under_construction;
4499 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4500 stack_usage_map = initial_stack_usage_map;
4501 stack_usage_watermark = initial_stack_usage_watermark;
4502 sibcall_failure = 1;
4503 }
4504 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4505 {
4506 #ifdef REG_PARM_STACK_SPACE
4507 if (save_area)
4508 restore_fixed_argument_area (save_area, argblock,
4509 high_to_save, low_to_save);
4510 #endif
4511
4512 /* If we saved any argument areas, restore them. */
4513 for (i = 0; i < num_actuals; i++)
4514 if (args[i].save_area)
4515 {
4516 machine_mode save_mode = GET_MODE (args[i].save_area);
4517 rtx stack_area
4518 = gen_rtx_MEM (save_mode,
4519 memory_address (save_mode,
4520 XEXP (args[i].stack_slot, 0)));
4521
4522 if (save_mode != BLKmode)
4523 emit_move_insn (stack_area, args[i].save_area);
4524 else
4525 emit_block_move (stack_area, args[i].save_area,
4526 (gen_int_mode
4527 (args[i].locate.size.constant, Pmode)),
4528 BLOCK_OP_CALL_PARM);
4529 }
4530
4531 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4532 stack_usage_map = initial_stack_usage_map;
4533 stack_usage_watermark = initial_stack_usage_watermark;
4534 }
4535
4536 /* If this was alloca, record the new stack level. */
4537 if (flags & ECF_MAY_BE_ALLOCA)
4538 record_new_stack_level ();
4539
4540 /* Free up storage we no longer need. */
4541 for (i = 0; i < num_actuals; ++i)
4542 free (args[i].aligned_regs);
4543
4544 targetm.calls.end_call_args ();
4545
4546 insns = get_insns ();
4547 end_sequence ();
4548
4549 if (pass == 0)
4550 {
4551 tail_call_insns = insns;
4552
4553 /* Restore the pending stack adjustment now that we have
4554 finished generating the sibling call sequence. */
4555
4556 restore_pending_stack_adjust (&save);
4557
4558 /* Prepare arg structure for next iteration. */
4559 for (i = 0; i < num_actuals; i++)
4560 {
4561 args[i].value = 0;
4562 args[i].aligned_regs = 0;
4563 args[i].stack = 0;
4564 }
4565
4566 sbitmap_free (stored_args_map);
4567 internal_arg_pointer_exp_state.scan_start = NULL;
4568 internal_arg_pointer_exp_state.cache.release ();
4569 }
4570 else
4571 {
4572 normal_call_insns = insns;
4573
4574 /* Verify that we've deallocated all the stack we used. */
4575 gcc_assert ((flags & ECF_NORETURN)
4576 || known_eq (old_stack_allocated,
4577 stack_pointer_delta
4578 - pending_stack_adjust));
4579 }
4580
4581 /* If something prevents making this a sibling call,
4582 zero out the sequence. */
4583 if (sibcall_failure)
4584 tail_call_insns = NULL;
4585 else
4586 break;
4587 }
4588
4589 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4590 arguments too, as argument area is now clobbered by the call. */
4591 if (tail_call_insns)
4592 {
4593 emit_insn (tail_call_insns);
4594 crtl->tail_call_emit = true;
4595 }
4596 else
4597 {
4598 emit_insn (normal_call_insns);
4599 if (try_tail_call)
4600 /* Ideally we'd emit a message for all of the ways that it could
4601 have failed. */
4602 maybe_complain_about_tail_call (exp, "tail call production failed");
4603 }
4604
4605 currently_expanding_call--;
4606
4607 free (stack_usage_map_buf);
4608 free (args);
4609 return target;
4610 }
4611
4612 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4613 this function's incoming arguments.
4614
4615 At the start of RTL generation we know the only REG_EQUIV notes
4616 in the rtl chain are those for incoming arguments, so we can look
4617 for REG_EQUIV notes between the start of the function and the
4618 NOTE_INSN_FUNCTION_BEG.
4619
4620 This is (slight) overkill. We could keep track of the highest
4621 argument we clobber and be more selective in removing notes, but it
4622 does not seem to be worth the effort. */
4623
4624 void
4625 fixup_tail_calls (void)
4626 {
4627 rtx_insn *insn;
4628
4629 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4630 {
4631 rtx note;
4632
4633 /* There are never REG_EQUIV notes for the incoming arguments
4634 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4635 if (NOTE_P (insn)
4636 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4637 break;
4638
4639 note = find_reg_note (insn, REG_EQUIV, 0);
4640 if (note)
4641 remove_note (insn, note);
4642 note = find_reg_note (insn, REG_EQUIV, 0);
4643 gcc_assert (!note);
4644 }
4645 }
4646
4647 /* Traverse a list of TYPES and expand all complex types into their
4648 components. */
4649 static tree
4650 split_complex_types (tree types)
4651 {
4652 tree p;
4653
4654 /* Before allocating memory, check for the common case of no complex. */
4655 for (p = types; p; p = TREE_CHAIN (p))
4656 {
4657 tree type = TREE_VALUE (p);
4658 if (TREE_CODE (type) == COMPLEX_TYPE
4659 && targetm.calls.split_complex_arg (type))
4660 goto found;
4661 }
4662 return types;
4663
4664 found:
4665 types = copy_list (types);
4666
4667 for (p = types; p; p = TREE_CHAIN (p))
4668 {
4669 tree complex_type = TREE_VALUE (p);
4670
4671 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4672 && targetm.calls.split_complex_arg (complex_type))
4673 {
4674 tree next, imag;
4675
4676 /* Rewrite complex type with component type. */
4677 TREE_VALUE (p) = TREE_TYPE (complex_type);
4678 next = TREE_CHAIN (p);
4679
4680 /* Add another component type for the imaginary part. */
4681 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4682 TREE_CHAIN (p) = imag;
4683 TREE_CHAIN (imag) = next;
4684
4685 /* Skip the newly created node. */
4686 p = TREE_CHAIN (p);
4687 }
4688 }
4689
4690 return types;
4691 }
4692 \f
4693 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4694 for a value of mode OUTMODE,
4695 with NARGS different arguments, passed as ARGS.
4696 Store the return value if RETVAL is nonzero: store it in VALUE if
4697 VALUE is nonnull, otherwise pick a convenient location. In either
4698 case return the location of the stored value.
4699
4700 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4701 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4702 other types of library calls. */
4703
4704 rtx
4705 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4706 enum libcall_type fn_type,
4707 machine_mode outmode, int nargs, rtx_mode_t *args)
4708 {
4709 /* Total size in bytes of all the stack-parms scanned so far. */
4710 struct args_size args_size;
4711 /* Size of arguments before any adjustments (such as rounding). */
4712 struct args_size original_args_size;
4713 int argnum;
4714 rtx fun;
4715 /* Todo, choose the correct decl type of orgfun. Sadly this information
4716 isn't present here, so we default to native calling abi here. */
4717 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4718 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4719 int count;
4720 rtx argblock = 0;
4721 CUMULATIVE_ARGS args_so_far_v;
4722 cumulative_args_t args_so_far;
4723 struct arg
4724 {
4725 rtx value;
4726 machine_mode mode;
4727 rtx reg;
4728 int partial;
4729 struct locate_and_pad_arg_data locate;
4730 rtx save_area;
4731 };
4732 struct arg *argvec;
4733 int old_inhibit_defer_pop = inhibit_defer_pop;
4734 rtx call_fusage = 0;
4735 rtx mem_value = 0;
4736 rtx valreg;
4737 int pcc_struct_value = 0;
4738 poly_int64 struct_value_size = 0;
4739 int flags;
4740 int reg_parm_stack_space = 0;
4741 poly_int64 needed;
4742 rtx_insn *before_call;
4743 bool have_push_fusage;
4744 tree tfom; /* type_for_mode (outmode, 0) */
4745
4746 #ifdef REG_PARM_STACK_SPACE
4747 /* Define the boundary of the register parm stack space that needs to be
4748 save, if any. */
4749 int low_to_save = 0, high_to_save = 0;
4750 rtx save_area = 0; /* Place that it is saved. */
4751 #endif
4752
4753 /* Size of the stack reserved for parameter registers. */
4754 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4755 char *initial_stack_usage_map = stack_usage_map;
4756 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4757 char *stack_usage_map_buf = NULL;
4758
4759 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4760
4761 #ifdef REG_PARM_STACK_SPACE
4762 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4763 #endif
4764
4765 /* By default, library functions cannot throw. */
4766 flags = ECF_NOTHROW;
4767
4768 switch (fn_type)
4769 {
4770 case LCT_NORMAL:
4771 break;
4772 case LCT_CONST:
4773 flags |= ECF_CONST;
4774 break;
4775 case LCT_PURE:
4776 flags |= ECF_PURE;
4777 break;
4778 case LCT_NORETURN:
4779 flags |= ECF_NORETURN;
4780 break;
4781 case LCT_THROW:
4782 flags &= ~ECF_NOTHROW;
4783 break;
4784 case LCT_RETURNS_TWICE:
4785 flags = ECF_RETURNS_TWICE;
4786 break;
4787 }
4788 fun = orgfun;
4789
4790 /* Ensure current function's preferred stack boundary is at least
4791 what we need. */
4792 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4793 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4794
4795 /* If this kind of value comes back in memory,
4796 decide where in memory it should come back. */
4797 if (outmode != VOIDmode)
4798 {
4799 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4800 if (aggregate_value_p (tfom, 0))
4801 {
4802 #ifdef PCC_STATIC_STRUCT_RETURN
4803 rtx pointer_reg
4804 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4805 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4806 pcc_struct_value = 1;
4807 if (value == 0)
4808 value = gen_reg_rtx (outmode);
4809 #else /* not PCC_STATIC_STRUCT_RETURN */
4810 struct_value_size = GET_MODE_SIZE (outmode);
4811 if (value != 0 && MEM_P (value))
4812 mem_value = value;
4813 else
4814 mem_value = assign_temp (tfom, 1, 1);
4815 #endif
4816 /* This call returns a big structure. */
4817 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4818 }
4819 }
4820 else
4821 tfom = void_type_node;
4822
4823 /* ??? Unfinished: must pass the memory address as an argument. */
4824
4825 /* Copy all the libcall-arguments out of the varargs data
4826 and into a vector ARGVEC.
4827
4828 Compute how to pass each argument. We only support a very small subset
4829 of the full argument passing conventions to limit complexity here since
4830 library functions shouldn't have many args. */
4831
4832 argvec = XALLOCAVEC (struct arg, nargs + 1);
4833 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4834
4835 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4836 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4837 #else
4838 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4839 #endif
4840 args_so_far = pack_cumulative_args (&args_so_far_v);
4841
4842 args_size.constant = 0;
4843 args_size.var = 0;
4844
4845 count = 0;
4846
4847 push_temp_slots ();
4848
4849 /* If there's a structure value address to be passed,
4850 either pass it in the special place, or pass it as an extra argument. */
4851 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4852 {
4853 rtx addr = XEXP (mem_value, 0);
4854
4855 nargs++;
4856
4857 /* Make sure it is a reasonable operand for a move or push insn. */
4858 if (!REG_P (addr) && !MEM_P (addr)
4859 && !(CONSTANT_P (addr)
4860 && targetm.legitimate_constant_p (Pmode, addr)))
4861 addr = force_operand (addr, NULL_RTX);
4862
4863 argvec[count].value = addr;
4864 argvec[count].mode = Pmode;
4865 argvec[count].partial = 0;
4866
4867 argvec[count].reg = targetm.calls.function_arg (args_so_far,
4868 Pmode, NULL_TREE, true);
4869 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
4870 NULL_TREE, 1) == 0);
4871
4872 locate_and_pad_parm (Pmode, NULL_TREE,
4873 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4874 1,
4875 #else
4876 argvec[count].reg != 0,
4877 #endif
4878 reg_parm_stack_space, 0,
4879 NULL_TREE, &args_size, &argvec[count].locate);
4880
4881 if (argvec[count].reg == 0 || argvec[count].partial != 0
4882 || reg_parm_stack_space > 0)
4883 args_size.constant += argvec[count].locate.size.constant;
4884
4885 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
4886
4887 count++;
4888 }
4889
4890 for (unsigned int i = 0; count < nargs; i++, count++)
4891 {
4892 rtx val = args[i].first;
4893 machine_mode mode = args[i].second;
4894 int unsigned_p = 0;
4895
4896 /* We cannot convert the arg value to the mode the library wants here;
4897 must do it earlier where we know the signedness of the arg. */
4898 gcc_assert (mode != BLKmode
4899 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
4900
4901 /* Make sure it is a reasonable operand for a move or push insn. */
4902 if (!REG_P (val) && !MEM_P (val)
4903 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
4904 val = force_operand (val, NULL_RTX);
4905
4906 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
4907 {
4908 rtx slot;
4909 int must_copy
4910 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
4911
4912 /* If this was a CONST function, it is now PURE since it now
4913 reads memory. */
4914 if (flags & ECF_CONST)
4915 {
4916 flags &= ~ECF_CONST;
4917 flags |= ECF_PURE;
4918 }
4919
4920 if (MEM_P (val) && !must_copy)
4921 {
4922 tree val_expr = MEM_EXPR (val);
4923 if (val_expr)
4924 mark_addressable (val_expr);
4925 slot = val;
4926 }
4927 else
4928 {
4929 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
4930 1, 1);
4931 emit_move_insn (slot, val);
4932 }
4933
4934 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4935 gen_rtx_USE (VOIDmode, slot),
4936 call_fusage);
4937 if (must_copy)
4938 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4939 gen_rtx_CLOBBER (VOIDmode,
4940 slot),
4941 call_fusage);
4942
4943 mode = Pmode;
4944 val = force_operand (XEXP (slot, 0), NULL_RTX);
4945 }
4946
4947 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
4948 argvec[count].mode = mode;
4949 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
4950 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
4951 NULL_TREE, true);
4952
4953 argvec[count].partial
4954 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
4955
4956 if (argvec[count].reg == 0
4957 || argvec[count].partial != 0
4958 || reg_parm_stack_space > 0)
4959 {
4960 locate_and_pad_parm (mode, NULL_TREE,
4961 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4962 1,
4963 #else
4964 argvec[count].reg != 0,
4965 #endif
4966 reg_parm_stack_space, argvec[count].partial,
4967 NULL_TREE, &args_size, &argvec[count].locate);
4968 args_size.constant += argvec[count].locate.size.constant;
4969 gcc_assert (!argvec[count].locate.size.var);
4970 }
4971 #ifdef BLOCK_REG_PADDING
4972 else
4973 /* The argument is passed entirely in registers. See at which
4974 end it should be padded. */
4975 argvec[count].locate.where_pad =
4976 BLOCK_REG_PADDING (mode, NULL_TREE,
4977 known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD));
4978 #endif
4979
4980 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
4981 }
4982
4983 for (int i = 0; i < nargs; i++)
4984 if (reg_parm_stack_space > 0
4985 || argvec[i].reg == 0
4986 || argvec[i].partial != 0)
4987 update_stack_alignment_for_call (&argvec[i].locate);
4988
4989 /* If this machine requires an external definition for library
4990 functions, write one out. */
4991 assemble_external_libcall (fun);
4992
4993 original_args_size = args_size;
4994 args_size.constant = (aligned_upper_bound (args_size.constant
4995 + stack_pointer_delta,
4996 STACK_BYTES)
4997 - stack_pointer_delta);
4998
4999 args_size.constant = upper_bound (args_size.constant,
5000 reg_parm_stack_space);
5001
5002 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5003 args_size.constant -= reg_parm_stack_space;
5004
5005 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
5006 args_size.constant);
5007
5008 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
5009 {
5010 poly_int64 pushed = args_size.constant + pending_stack_adjust;
5011 current_function_pushed_stack_size
5012 = upper_bound (current_function_pushed_stack_size, pushed);
5013 }
5014
5015 if (ACCUMULATE_OUTGOING_ARGS)
5016 {
5017 /* Since the stack pointer will never be pushed, it is possible for
5018 the evaluation of a parm to clobber something we have already
5019 written to the stack. Since most function calls on RISC machines
5020 do not use the stack, this is uncommon, but must work correctly.
5021
5022 Therefore, we save any area of the stack that was already written
5023 and that we are using. Here we set up to do this by making a new
5024 stack usage map from the old one.
5025
5026 Another approach might be to try to reorder the argument
5027 evaluations to avoid this conflicting stack usage. */
5028
5029 needed = args_size.constant;
5030
5031 /* Since we will be writing into the entire argument area, the
5032 map must be allocated for its entire size, not just the part that
5033 is the responsibility of the caller. */
5034 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5035 needed += reg_parm_stack_space;
5036
5037 poly_int64 limit = needed;
5038 if (ARGS_GROW_DOWNWARD)
5039 limit += 1;
5040
5041 /* For polynomial sizes, this is the maximum possible size needed
5042 for arguments with a constant size and offset. */
5043 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5044 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5045 const_limit);
5046
5047 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5048 stack_usage_map = stack_usage_map_buf;
5049
5050 if (initial_highest_arg_in_use)
5051 memcpy (stack_usage_map, initial_stack_usage_map,
5052 initial_highest_arg_in_use);
5053
5054 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5055 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5056 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5057 needed = 0;
5058
5059 /* We must be careful to use virtual regs before they're instantiated,
5060 and real regs afterwards. Loop optimization, for example, can create
5061 new libcalls after we've instantiated the virtual regs, and if we
5062 use virtuals anyway, they won't match the rtl patterns. */
5063
5064 if (virtuals_instantiated)
5065 argblock = plus_constant (Pmode, stack_pointer_rtx,
5066 STACK_POINTER_OFFSET);
5067 else
5068 argblock = virtual_outgoing_args_rtx;
5069 }
5070 else
5071 {
5072 if (!PUSH_ARGS)
5073 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5074 }
5075
5076 /* We push args individually in reverse order, perform stack alignment
5077 before the first push (the last arg). */
5078 if (argblock == 0)
5079 anti_adjust_stack (gen_int_mode (args_size.constant
5080 - original_args_size.constant,
5081 Pmode));
5082
5083 argnum = nargs - 1;
5084
5085 #ifdef REG_PARM_STACK_SPACE
5086 if (ACCUMULATE_OUTGOING_ARGS)
5087 {
5088 /* The argument list is the property of the called routine and it
5089 may clobber it. If the fixed area has been used for previous
5090 parameters, we must save and restore it. */
5091 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5092 &low_to_save, &high_to_save);
5093 }
5094 #endif
5095
5096 /* When expanding a normal call, args are stored in push order,
5097 which is the reverse of what we have here. */
5098 bool any_regs = false;
5099 for (int i = nargs; i-- > 0; )
5100 if (argvec[i].reg != NULL_RTX)
5101 {
5102 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5103 any_regs = true;
5104 }
5105 if (!any_regs)
5106 targetm.calls.call_args (pc_rtx, NULL_TREE);
5107
5108 /* Push the args that need to be pushed. */
5109
5110 have_push_fusage = false;
5111
5112 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5113 are to be pushed. */
5114 for (count = 0; count < nargs; count++, argnum--)
5115 {
5116 machine_mode mode = argvec[argnum].mode;
5117 rtx val = argvec[argnum].value;
5118 rtx reg = argvec[argnum].reg;
5119 int partial = argvec[argnum].partial;
5120 unsigned int parm_align = argvec[argnum].locate.boundary;
5121 poly_int64 lower_bound = 0, upper_bound = 0;
5122
5123 if (! (reg != 0 && partial == 0))
5124 {
5125 rtx use;
5126
5127 if (ACCUMULATE_OUTGOING_ARGS)
5128 {
5129 /* If this is being stored into a pre-allocated, fixed-size,
5130 stack area, save any previous data at that location. */
5131
5132 if (ARGS_GROW_DOWNWARD)
5133 {
5134 /* stack_slot is negative, but we want to index stack_usage_map
5135 with positive values. */
5136 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5137 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5138 }
5139 else
5140 {
5141 lower_bound = argvec[argnum].locate.slot_offset.constant;
5142 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5143 }
5144
5145 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5146 reg_parm_stack_space))
5147 {
5148 /* We need to make a save area. */
5149 poly_uint64 size
5150 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5151 machine_mode save_mode
5152 = int_mode_for_size (size, 1).else_blk ();
5153 rtx adr
5154 = plus_constant (Pmode, argblock,
5155 argvec[argnum].locate.offset.constant);
5156 rtx stack_area
5157 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5158
5159 if (save_mode == BLKmode)
5160 {
5161 argvec[argnum].save_area
5162 = assign_stack_temp (BLKmode,
5163 argvec[argnum].locate.size.constant
5164 );
5165
5166 emit_block_move (validize_mem
5167 (copy_rtx (argvec[argnum].save_area)),
5168 stack_area,
5169 (gen_int_mode
5170 (argvec[argnum].locate.size.constant,
5171 Pmode)),
5172 BLOCK_OP_CALL_PARM);
5173 }
5174 else
5175 {
5176 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5177
5178 emit_move_insn (argvec[argnum].save_area, stack_area);
5179 }
5180 }
5181 }
5182
5183 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5184 partial, reg, 0, argblock,
5185 (gen_int_mode
5186 (argvec[argnum].locate.offset.constant, Pmode)),
5187 reg_parm_stack_space,
5188 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5189
5190 /* Now mark the segment we just used. */
5191 if (ACCUMULATE_OUTGOING_ARGS)
5192 mark_stack_region_used (lower_bound, upper_bound);
5193
5194 NO_DEFER_POP;
5195
5196 /* Indicate argument access so that alias.c knows that these
5197 values are live. */
5198 if (argblock)
5199 use = plus_constant (Pmode, argblock,
5200 argvec[argnum].locate.offset.constant);
5201 else if (have_push_fusage)
5202 continue;
5203 else
5204 {
5205 /* When arguments are pushed, trying to tell alias.c where
5206 exactly this argument is won't work, because the
5207 auto-increment causes confusion. So we merely indicate
5208 that we access something with a known mode somewhere on
5209 the stack. */
5210 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5211 gen_rtx_SCRATCH (Pmode));
5212 have_push_fusage = true;
5213 }
5214 use = gen_rtx_MEM (argvec[argnum].mode, use);
5215 use = gen_rtx_USE (VOIDmode, use);
5216 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5217 }
5218 }
5219
5220 argnum = nargs - 1;
5221
5222 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5223
5224 /* Now load any reg parms into their regs. */
5225
5226 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5227 are to be pushed. */
5228 for (count = 0; count < nargs; count++, argnum--)
5229 {
5230 machine_mode mode = argvec[argnum].mode;
5231 rtx val = argvec[argnum].value;
5232 rtx reg = argvec[argnum].reg;
5233 int partial = argvec[argnum].partial;
5234
5235 /* Handle calls that pass values in multiple non-contiguous
5236 locations. The PA64 has examples of this for library calls. */
5237 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5238 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5239 else if (reg != 0 && partial == 0)
5240 {
5241 emit_move_insn (reg, val);
5242 #ifdef BLOCK_REG_PADDING
5243 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5244
5245 /* Copied from load_register_parameters. */
5246
5247 /* Handle case where we have a value that needs shifting
5248 up to the msb. eg. a QImode value and we're padding
5249 upward on a BYTES_BIG_ENDIAN machine. */
5250 if (known_lt (size, UNITS_PER_WORD)
5251 && (argvec[argnum].locate.where_pad
5252 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5253 {
5254 rtx x;
5255 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5256
5257 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5258 report the whole reg as used. Strictly speaking, the
5259 call only uses SIZE bytes at the msb end, but it doesn't
5260 seem worth generating rtl to say that. */
5261 reg = gen_rtx_REG (word_mode, REGNO (reg));
5262 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5263 if (x != reg)
5264 emit_move_insn (reg, x);
5265 }
5266 #endif
5267 }
5268
5269 NO_DEFER_POP;
5270 }
5271
5272 /* Any regs containing parms remain in use through the call. */
5273 for (count = 0; count < nargs; count++)
5274 {
5275 rtx reg = argvec[count].reg;
5276 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5277 use_group_regs (&call_fusage, reg);
5278 else if (reg != 0)
5279 {
5280 int partial = argvec[count].partial;
5281 if (partial)
5282 {
5283 int nregs;
5284 gcc_assert (partial % UNITS_PER_WORD == 0);
5285 nregs = partial / UNITS_PER_WORD;
5286 use_regs (&call_fusage, REGNO (reg), nregs);
5287 }
5288 else
5289 use_reg (&call_fusage, reg);
5290 }
5291 }
5292
5293 /* Pass the function the address in which to return a structure value. */
5294 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5295 {
5296 emit_move_insn (struct_value,
5297 force_reg (Pmode,
5298 force_operand (XEXP (mem_value, 0),
5299 NULL_RTX)));
5300 if (REG_P (struct_value))
5301 use_reg (&call_fusage, struct_value);
5302 }
5303
5304 /* Don't allow popping to be deferred, since then
5305 cse'ing of library calls could delete a call and leave the pop. */
5306 NO_DEFER_POP;
5307 valreg = (mem_value == 0 && outmode != VOIDmode
5308 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5309
5310 /* Stack must be properly aligned now. */
5311 gcc_assert (multiple_p (stack_pointer_delta,
5312 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5313
5314 before_call = get_last_insn ();
5315
5316 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5317 will set inhibit_defer_pop to that value. */
5318 /* The return type is needed to decide how many bytes the function pops.
5319 Signedness plays no role in that, so for simplicity, we pretend it's
5320 always signed. We also assume that the list of arguments passed has
5321 no impact, so we pretend it is unknown. */
5322
5323 emit_call_1 (fun, NULL,
5324 get_identifier (XSTR (orgfun, 0)),
5325 build_function_type (tfom, NULL_TREE),
5326 original_args_size.constant, args_size.constant,
5327 struct_value_size,
5328 targetm.calls.function_arg (args_so_far,
5329 VOIDmode, void_type_node, true),
5330 valreg,
5331 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5332
5333 if (flag_ipa_ra)
5334 {
5335 rtx datum = orgfun;
5336 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5337 rtx_call_insn *last = last_call_insn ();
5338 add_reg_note (last, REG_CALL_DECL, datum);
5339 }
5340
5341 /* Right-shift returned value if necessary. */
5342 if (!pcc_struct_value
5343 && TYPE_MODE (tfom) != BLKmode
5344 && targetm.calls.return_in_msb (tfom))
5345 {
5346 shift_return_value (TYPE_MODE (tfom), false, valreg);
5347 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5348 }
5349
5350 targetm.calls.end_call_args ();
5351
5352 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5353 that it should complain if nonvolatile values are live. For
5354 functions that cannot return, inform flow that control does not
5355 fall through. */
5356 if (flags & ECF_NORETURN)
5357 {
5358 /* The barrier note must be emitted
5359 immediately after the CALL_INSN. Some ports emit more than
5360 just a CALL_INSN above, so we must search for it here. */
5361 rtx_insn *last = get_last_insn ();
5362 while (!CALL_P (last))
5363 {
5364 last = PREV_INSN (last);
5365 /* There was no CALL_INSN? */
5366 gcc_assert (last != before_call);
5367 }
5368
5369 emit_barrier_after (last);
5370 }
5371
5372 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5373 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5374 if (flags & ECF_NOTHROW)
5375 {
5376 rtx_insn *last = get_last_insn ();
5377 while (!CALL_P (last))
5378 {
5379 last = PREV_INSN (last);
5380 /* There was no CALL_INSN? */
5381 gcc_assert (last != before_call);
5382 }
5383
5384 make_reg_eh_region_note_nothrow_nononlocal (last);
5385 }
5386
5387 /* Now restore inhibit_defer_pop to its actual original value. */
5388 OK_DEFER_POP;
5389
5390 pop_temp_slots ();
5391
5392 /* Copy the value to the right place. */
5393 if (outmode != VOIDmode && retval)
5394 {
5395 if (mem_value)
5396 {
5397 if (value == 0)
5398 value = mem_value;
5399 if (value != mem_value)
5400 emit_move_insn (value, mem_value);
5401 }
5402 else if (GET_CODE (valreg) == PARALLEL)
5403 {
5404 if (value == 0)
5405 value = gen_reg_rtx (outmode);
5406 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5407 }
5408 else
5409 {
5410 /* Convert to the proper mode if a promotion has been active. */
5411 if (GET_MODE (valreg) != outmode)
5412 {
5413 int unsignedp = TYPE_UNSIGNED (tfom);
5414
5415 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5416 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5417 == GET_MODE (valreg));
5418 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5419 }
5420
5421 if (value != 0)
5422 emit_move_insn (value, valreg);
5423 else
5424 value = valreg;
5425 }
5426 }
5427
5428 if (ACCUMULATE_OUTGOING_ARGS)
5429 {
5430 #ifdef REG_PARM_STACK_SPACE
5431 if (save_area)
5432 restore_fixed_argument_area (save_area, argblock,
5433 high_to_save, low_to_save);
5434 #endif
5435
5436 /* If we saved any argument areas, restore them. */
5437 for (count = 0; count < nargs; count++)
5438 if (argvec[count].save_area)
5439 {
5440 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5441 rtx adr = plus_constant (Pmode, argblock,
5442 argvec[count].locate.offset.constant);
5443 rtx stack_area = gen_rtx_MEM (save_mode,
5444 memory_address (save_mode, adr));
5445
5446 if (save_mode == BLKmode)
5447 emit_block_move (stack_area,
5448 validize_mem
5449 (copy_rtx (argvec[count].save_area)),
5450 (gen_int_mode
5451 (argvec[count].locate.size.constant, Pmode)),
5452 BLOCK_OP_CALL_PARM);
5453 else
5454 emit_move_insn (stack_area, argvec[count].save_area);
5455 }
5456
5457 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5458 stack_usage_map = initial_stack_usage_map;
5459 stack_usage_watermark = initial_stack_usage_watermark;
5460 }
5461
5462 free (stack_usage_map_buf);
5463
5464 return value;
5465
5466 }
5467 \f
5468
5469 /* Store a single argument for a function call
5470 into the register or memory area where it must be passed.
5471 *ARG describes the argument value and where to pass it.
5472
5473 ARGBLOCK is the address of the stack-block for all the arguments,
5474 or 0 on a machine where arguments are pushed individually.
5475
5476 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5477 so must be careful about how the stack is used.
5478
5479 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5480 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5481 that we need not worry about saving and restoring the stack.
5482
5483 FNDECL is the declaration of the function we are calling.
5484
5485 Return nonzero if this arg should cause sibcall failure,
5486 zero otherwise. */
5487
5488 static int
5489 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5490 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5491 {
5492 tree pval = arg->tree_value;
5493 rtx reg = 0;
5494 int partial = 0;
5495 poly_int64 used = 0;
5496 poly_int64 lower_bound = 0, upper_bound = 0;
5497 int sibcall_failure = 0;
5498
5499 if (TREE_CODE (pval) == ERROR_MARK)
5500 return 1;
5501
5502 /* Push a new temporary level for any temporaries we make for
5503 this argument. */
5504 push_temp_slots ();
5505
5506 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5507 {
5508 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5509 save any previous data at that location. */
5510 if (argblock && ! variable_size && arg->stack)
5511 {
5512 if (ARGS_GROW_DOWNWARD)
5513 {
5514 /* stack_slot is negative, but we want to index stack_usage_map
5515 with positive values. */
5516 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5517 {
5518 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5519 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5520 }
5521 else
5522 upper_bound = 0;
5523
5524 lower_bound = upper_bound - arg->locate.size.constant;
5525 }
5526 else
5527 {
5528 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5529 {
5530 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5531 lower_bound = rtx_to_poly_int64 (offset);
5532 }
5533 else
5534 lower_bound = 0;
5535
5536 upper_bound = lower_bound + arg->locate.size.constant;
5537 }
5538
5539 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5540 reg_parm_stack_space))
5541 {
5542 /* We need to make a save area. */
5543 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5544 machine_mode save_mode
5545 = int_mode_for_size (size, 1).else_blk ();
5546 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5547 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5548
5549 if (save_mode == BLKmode)
5550 {
5551 arg->save_area
5552 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5553 preserve_temp_slots (arg->save_area);
5554 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5555 stack_area,
5556 (gen_int_mode
5557 (arg->locate.size.constant, Pmode)),
5558 BLOCK_OP_CALL_PARM);
5559 }
5560 else
5561 {
5562 arg->save_area = gen_reg_rtx (save_mode);
5563 emit_move_insn (arg->save_area, stack_area);
5564 }
5565 }
5566 }
5567 }
5568
5569 /* If this isn't going to be placed on both the stack and in registers,
5570 set up the register and number of words. */
5571 if (! arg->pass_on_stack)
5572 {
5573 if (flags & ECF_SIBCALL)
5574 reg = arg->tail_call_reg;
5575 else
5576 reg = arg->reg;
5577 partial = arg->partial;
5578 }
5579
5580 /* Being passed entirely in a register. We shouldn't be called in
5581 this case. */
5582 gcc_assert (reg == 0 || partial != 0);
5583
5584 /* If this arg needs special alignment, don't load the registers
5585 here. */
5586 if (arg->n_aligned_regs != 0)
5587 reg = 0;
5588
5589 /* If this is being passed partially in a register, we can't evaluate
5590 it directly into its stack slot. Otherwise, we can. */
5591 if (arg->value == 0)
5592 {
5593 /* stack_arg_under_construction is nonzero if a function argument is
5594 being evaluated directly into the outgoing argument list and
5595 expand_call must take special action to preserve the argument list
5596 if it is called recursively.
5597
5598 For scalar function arguments stack_usage_map is sufficient to
5599 determine which stack slots must be saved and restored. Scalar
5600 arguments in general have pass_on_stack == 0.
5601
5602 If this argument is initialized by a function which takes the
5603 address of the argument (a C++ constructor or a C function
5604 returning a BLKmode structure), then stack_usage_map is
5605 insufficient and expand_call must push the stack around the
5606 function call. Such arguments have pass_on_stack == 1.
5607
5608 Note that it is always safe to set stack_arg_under_construction,
5609 but this generates suboptimal code if set when not needed. */
5610
5611 if (arg->pass_on_stack)
5612 stack_arg_under_construction++;
5613
5614 arg->value = expand_expr (pval,
5615 (partial
5616 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5617 ? NULL_RTX : arg->stack,
5618 VOIDmode, EXPAND_STACK_PARM);
5619
5620 /* If we are promoting object (or for any other reason) the mode
5621 doesn't agree, convert the mode. */
5622
5623 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5624 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5625 arg->value, arg->unsignedp);
5626
5627 if (arg->pass_on_stack)
5628 stack_arg_under_construction--;
5629 }
5630
5631 /* Check for overlap with already clobbered argument area. */
5632 if ((flags & ECF_SIBCALL)
5633 && MEM_P (arg->value)
5634 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5635 arg->locate.size.constant))
5636 sibcall_failure = 1;
5637
5638 /* Don't allow anything left on stack from computation
5639 of argument to alloca. */
5640 if (flags & ECF_MAY_BE_ALLOCA)
5641 do_pending_stack_adjust ();
5642
5643 if (arg->value == arg->stack)
5644 /* If the value is already in the stack slot, we are done. */
5645 ;
5646 else if (arg->mode != BLKmode)
5647 {
5648 unsigned int parm_align;
5649
5650 /* Argument is a scalar, not entirely passed in registers.
5651 (If part is passed in registers, arg->partial says how much
5652 and emit_push_insn will take care of putting it there.)
5653
5654 Push it, and if its size is less than the
5655 amount of space allocated to it,
5656 also bump stack pointer by the additional space.
5657 Note that in C the default argument promotions
5658 will prevent such mismatches. */
5659
5660 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5661 ? 0 : GET_MODE_SIZE (arg->mode));
5662
5663 /* Compute how much space the push instruction will push.
5664 On many machines, pushing a byte will advance the stack
5665 pointer by a halfword. */
5666 #ifdef PUSH_ROUNDING
5667 size = PUSH_ROUNDING (size);
5668 #endif
5669 used = size;
5670
5671 /* Compute how much space the argument should get:
5672 round up to a multiple of the alignment for arguments. */
5673 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5674 != PAD_NONE)
5675 /* At the moment we don't (need to) support ABIs for which the
5676 padding isn't known at compile time. In principle it should
5677 be easy to add though. */
5678 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5679
5680 /* Compute the alignment of the pushed argument. */
5681 parm_align = arg->locate.boundary;
5682 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5683 == PAD_DOWNWARD)
5684 {
5685 poly_int64 pad = used - size;
5686 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5687 if (pad_align != 0)
5688 parm_align = MIN (parm_align, pad_align);
5689 }
5690
5691 /* This isn't already where we want it on the stack, so put it there.
5692 This can either be done with push or copy insns. */
5693 if (maybe_ne (used, 0)
5694 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5695 NULL_RTX, parm_align, partial, reg, used - size,
5696 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5697 reg_parm_stack_space,
5698 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5699 sibcall_failure = 1;
5700
5701 /* Unless this is a partially-in-register argument, the argument is now
5702 in the stack. */
5703 if (partial == 0)
5704 arg->value = arg->stack;
5705 }
5706 else
5707 {
5708 /* BLKmode, at least partly to be pushed. */
5709
5710 unsigned int parm_align;
5711 poly_int64 excess;
5712 rtx size_rtx;
5713
5714 /* Pushing a nonscalar.
5715 If part is passed in registers, PARTIAL says how much
5716 and emit_push_insn will take care of putting it there. */
5717
5718 /* Round its size up to a multiple
5719 of the allocation unit for arguments. */
5720
5721 if (arg->locate.size.var != 0)
5722 {
5723 excess = 0;
5724 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5725 }
5726 else
5727 {
5728 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5729 for BLKmode is careful to avoid it. */
5730 excess = (arg->locate.size.constant
5731 - arg_int_size_in_bytes (TREE_TYPE (pval))
5732 + partial);
5733 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5734 NULL_RTX, TYPE_MODE (sizetype),
5735 EXPAND_NORMAL);
5736 }
5737
5738 parm_align = arg->locate.boundary;
5739
5740 /* When an argument is padded down, the block is aligned to
5741 PARM_BOUNDARY, but the actual argument isn't. */
5742 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5743 == PAD_DOWNWARD)
5744 {
5745 if (arg->locate.size.var)
5746 parm_align = BITS_PER_UNIT;
5747 else
5748 {
5749 unsigned int excess_align
5750 = known_alignment (excess) * BITS_PER_UNIT;
5751 if (excess_align != 0)
5752 parm_align = MIN (parm_align, excess_align);
5753 }
5754 }
5755
5756 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5757 {
5758 /* emit_push_insn might not work properly if arg->value and
5759 argblock + arg->locate.offset areas overlap. */
5760 rtx x = arg->value;
5761 poly_int64 i = 0;
5762
5763 if (strip_offset (XEXP (x, 0), &i)
5764 == crtl->args.internal_arg_pointer)
5765 {
5766 /* arg.locate doesn't contain the pretend_args_size offset,
5767 it's part of argblock. Ensure we don't count it in I. */
5768 if (STACK_GROWS_DOWNWARD)
5769 i -= crtl->args.pretend_args_size;
5770 else
5771 i += crtl->args.pretend_args_size;
5772
5773 /* expand_call should ensure this. */
5774 gcc_assert (!arg->locate.offset.var
5775 && arg->locate.size.var == 0);
5776 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5777
5778 if (known_eq (arg->locate.offset.constant, i))
5779 {
5780 /* Even though they appear to be at the same location,
5781 if part of the outgoing argument is in registers,
5782 they aren't really at the same location. Check for
5783 this by making sure that the incoming size is the
5784 same as the outgoing size. */
5785 if (maybe_ne (arg->locate.size.constant, size_val))
5786 sibcall_failure = 1;
5787 }
5788 else if (maybe_in_range_p (arg->locate.offset.constant,
5789 i, size_val))
5790 sibcall_failure = 1;
5791 /* Use arg->locate.size.constant instead of size_rtx
5792 because we only care about the part of the argument
5793 on the stack. */
5794 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5795 arg->locate.size.constant))
5796 sibcall_failure = 1;
5797 }
5798 }
5799
5800 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5801 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5802 parm_align, partial, reg, excess, argblock,
5803 ARGS_SIZE_RTX (arg->locate.offset),
5804 reg_parm_stack_space,
5805 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5806
5807 /* Unless this is a partially-in-register argument, the argument is now
5808 in the stack.
5809
5810 ??? Unlike the case above, in which we want the actual
5811 address of the data, so that we can load it directly into a
5812 register, here we want the address of the stack slot, so that
5813 it's properly aligned for word-by-word copying or something
5814 like that. It's not clear that this is always correct. */
5815 if (partial == 0)
5816 arg->value = arg->stack_slot;
5817 }
5818
5819 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5820 {
5821 tree type = TREE_TYPE (arg->tree_value);
5822 arg->parallel_value
5823 = emit_group_load_into_temps (arg->reg, arg->value, type,
5824 int_size_in_bytes (type));
5825 }
5826
5827 /* Mark all slots this store used. */
5828 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5829 && argblock && ! variable_size && arg->stack)
5830 mark_stack_region_used (lower_bound, upper_bound);
5831
5832 /* Once we have pushed something, pops can't safely
5833 be deferred during the rest of the arguments. */
5834 NO_DEFER_POP;
5835
5836 /* Free any temporary slots made in processing this argument. */
5837 pop_temp_slots ();
5838
5839 return sibcall_failure;
5840 }
5841
5842 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5843
5844 bool
5845 must_pass_in_stack_var_size (machine_mode mode ATTRIBUTE_UNUSED,
5846 const_tree type)
5847 {
5848 if (!type)
5849 return false;
5850
5851 /* If the type has variable size... */
5852 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5853 return true;
5854
5855 /* If the type is marked as addressable (it is required
5856 to be constructed into the stack)... */
5857 if (TREE_ADDRESSABLE (type))
5858 return true;
5859
5860 return false;
5861 }
5862
5863 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5864 takes trailing padding of a structure into account. */
5865 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5866
5867 bool
5868 must_pass_in_stack_var_size_or_pad (machine_mode mode, const_tree type)
5869 {
5870 if (!type)
5871 return false;
5872
5873 /* If the type has variable size... */
5874 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5875 return true;
5876
5877 /* If the type is marked as addressable (it is required
5878 to be constructed into the stack)... */
5879 if (TREE_ADDRESSABLE (type))
5880 return true;
5881
5882 if (TYPE_EMPTY_P (type))
5883 return false;
5884
5885 /* If the padding and mode of the type is such that a copy into
5886 a register would put it into the wrong part of the register. */
5887 if (mode == BLKmode
5888 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5889 && (targetm.calls.function_arg_padding (mode, type)
5890 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5891 return true;
5892
5893 return false;
5894 }
5895
5896 /* Tell the garbage collector about GTY markers in this source file. */
5897 #include "gt-calls.h"