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Improve warning suppression for inlined functions.
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1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2021 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 #define INCLUDE_STRING
21 #include "config.h"
22 #include "system.h"
23 #include "coretypes.h"
24 #include "backend.h"
25 #include "target.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "gimple.h"
29 #include "predict.h"
30 #include "memmodel.h"
31 #include "tm_p.h"
32 #include "stringpool.h"
33 #include "expmed.h"
34 #include "optabs.h"
35 #include "emit-rtl.h"
36 #include "cgraph.h"
37 #include "diagnostic-core.h"
38 #include "fold-const.h"
39 #include "stor-layout.h"
40 #include "varasm.h"
41 #include "internal-fn.h"
42 #include "dojump.h"
43 #include "explow.h"
44 #include "calls.h"
45 #include "expr.h"
46 #include "output.h"
47 #include "langhooks.h"
48 #include "except.h"
49 #include "dbgcnt.h"
50 #include "rtl-iter.h"
51 #include "tree-vrp.h"
52 #include "tree-ssanames.h"
53 #include "tree-ssa-strlen.h"
54 #include "intl.h"
55 #include "stringpool.h"
56 #include "hash-map.h"
57 #include "hash-traits.h"
58 #include "attribs.h"
59 #include "builtins.h"
60 #include "gimple-fold.h"
61 #include "attr-fnspec.h"
62 #include "value-query.h"
63
64 #include "tree-pretty-print.h"
65
66 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
67 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
68
69 /* Data structure and subroutines used within expand_call. */
70
71 struct arg_data
72 {
73 /* Tree node for this argument. */
74 tree tree_value;
75 /* Mode for value; TYPE_MODE unless promoted. */
76 machine_mode mode;
77 /* Current RTL value for argument, or 0 if it isn't precomputed. */
78 rtx value;
79 /* Initially-compute RTL value for argument; only for const functions. */
80 rtx initial_value;
81 /* Register to pass this argument in, 0 if passed on stack, or an
82 PARALLEL if the arg is to be copied into multiple non-contiguous
83 registers. */
84 rtx reg;
85 /* Register to pass this argument in when generating tail call sequence.
86 This is not the same register as for normal calls on machines with
87 register windows. */
88 rtx tail_call_reg;
89 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
90 form for emit_group_move. */
91 rtx parallel_value;
92 /* If REG was promoted from the actual mode of the argument expression,
93 indicates whether the promotion is sign- or zero-extended. */
94 int unsignedp;
95 /* Number of bytes to put in registers. 0 means put the whole arg
96 in registers. Also 0 if not passed in registers. */
97 int partial;
98 /* Nonzero if argument must be passed on stack.
99 Note that some arguments may be passed on the stack
100 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
101 pass_on_stack identifies arguments that *cannot* go in registers. */
102 int pass_on_stack;
103 /* Some fields packaged up for locate_and_pad_parm. */
104 struct locate_and_pad_arg_data locate;
105 /* Location on the stack at which parameter should be stored. The store
106 has already been done if STACK == VALUE. */
107 rtx stack;
108 /* Location on the stack of the start of this argument slot. This can
109 differ from STACK if this arg pads downward. This location is known
110 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
111 rtx stack_slot;
112 /* Place that this stack area has been saved, if needed. */
113 rtx save_area;
114 /* If an argument's alignment does not permit direct copying into registers,
115 copy in smaller-sized pieces into pseudos. These are stored in a
116 block pointed to by this field. The next field says how many
117 word-sized pseudos we made. */
118 rtx *aligned_regs;
119 int n_aligned_regs;
120 };
121
122 /* A vector of one char per byte of stack space. A byte if nonzero if
123 the corresponding stack location has been used.
124 This vector is used to prevent a function call within an argument from
125 clobbering any stack already set up. */
126 static char *stack_usage_map;
127
128 /* Size of STACK_USAGE_MAP. */
129 static unsigned int highest_outgoing_arg_in_use;
130
131 /* Assume that any stack location at this byte index is used,
132 without checking the contents of stack_usage_map. */
133 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
134
135 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
136 stack location's tail call argument has been already stored into the stack.
137 This bitmap is used to prevent sibling call optimization if function tries
138 to use parent's incoming argument slots when they have been already
139 overwritten with tail call arguments. */
140 static sbitmap stored_args_map;
141
142 /* Assume that any virtual-incoming location at this byte index has been
143 stored, without checking the contents of stored_args_map. */
144 static unsigned HOST_WIDE_INT stored_args_watermark;
145
146 /* stack_arg_under_construction is nonzero when an argument may be
147 initialized with a constructor call (including a C function that
148 returns a BLKmode struct) and expand_call must take special action
149 to make sure the object being constructed does not overlap the
150 argument list for the constructor call. */
151 static int stack_arg_under_construction;
152
153 static void precompute_register_parameters (int, struct arg_data *, int *);
154 static int store_one_arg (struct arg_data *, rtx, int, int, int);
155 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
156 static int finalize_must_preallocate (int, int, struct arg_data *,
157 struct args_size *);
158 static void precompute_arguments (int, struct arg_data *);
159 static void compute_argument_addresses (struct arg_data *, rtx, int);
160 static rtx rtx_for_function_call (tree, tree);
161 static void load_register_parameters (struct arg_data *, int, rtx *, int,
162 int, int *);
163 static int special_function_p (const_tree, int);
164 static int check_sibcall_argument_overlap_1 (rtx);
165 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
166
167 static tree split_complex_types (tree);
168
169 #ifdef REG_PARM_STACK_SPACE
170 static rtx save_fixed_argument_area (int, rtx, int *, int *);
171 static void restore_fixed_argument_area (rtx, rtx, int, int);
172 #endif
173 \f
174 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
175 stack region might already be in use. */
176
177 static bool
178 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
179 unsigned int reg_parm_stack_space)
180 {
181 unsigned HOST_WIDE_INT const_lower, const_upper;
182 const_lower = constant_lower_bound (lower_bound);
183 if (!upper_bound.is_constant (&const_upper))
184 const_upper = HOST_WIDE_INT_M1U;
185
186 if (const_upper > stack_usage_watermark)
187 return true;
188
189 /* Don't worry about things in the fixed argument area;
190 it has already been saved. */
191 const_lower = MAX (const_lower, reg_parm_stack_space);
192 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
193 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
194 if (stack_usage_map[i])
195 return true;
196 return false;
197 }
198
199 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
200 stack region are now in use. */
201
202 static void
203 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
204 {
205 unsigned HOST_WIDE_INT const_lower, const_upper;
206 const_lower = constant_lower_bound (lower_bound);
207 if (upper_bound.is_constant (&const_upper))
208 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
209 stack_usage_map[i] = 1;
210 else
211 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
212 }
213
214 /* Force FUNEXP into a form suitable for the address of a CALL,
215 and return that as an rtx. Also load the static chain register
216 if FNDECL is a nested function.
217
218 CALL_FUSAGE points to a variable holding the prospective
219 CALL_INSN_FUNCTION_USAGE information. */
220
221 rtx
222 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
223 rtx *call_fusage, int reg_parm_seen, int flags)
224 {
225 /* Make a valid memory address and copy constants through pseudo-regs,
226 but not for a constant address if -fno-function-cse. */
227 if (GET_CODE (funexp) != SYMBOL_REF)
228 {
229 /* If it's an indirect call by descriptor, generate code to perform
230 runtime identification of the pointer and load the descriptor. */
231 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
232 {
233 const int bit_val = targetm.calls.custom_function_descriptors;
234 rtx call_lab = gen_label_rtx ();
235
236 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
237 fndecl_or_type
238 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
239 fndecl_or_type);
240 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
241 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
242
243 if (GET_MODE (funexp) != Pmode)
244 funexp = convert_memory_address (Pmode, funexp);
245
246 /* Avoid long live ranges around function calls. */
247 funexp = copy_to_mode_reg (Pmode, funexp);
248
249 if (REG_P (chain))
250 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
251
252 /* Emit the runtime identification pattern. */
253 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
254 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
255 call_lab);
256
257 /* Statically predict the branch to very likely taken. */
258 rtx_insn *insn = get_last_insn ();
259 if (JUMP_P (insn))
260 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
261
262 /* Load the descriptor. */
263 rtx mem = gen_rtx_MEM (ptr_mode,
264 plus_constant (Pmode, funexp, - bit_val));
265 MEM_NOTRAP_P (mem) = 1;
266 mem = convert_memory_address (Pmode, mem);
267 emit_move_insn (chain, mem);
268
269 mem = gen_rtx_MEM (ptr_mode,
270 plus_constant (Pmode, funexp,
271 POINTER_SIZE / BITS_PER_UNIT
272 - bit_val));
273 MEM_NOTRAP_P (mem) = 1;
274 mem = convert_memory_address (Pmode, mem);
275 emit_move_insn (funexp, mem);
276
277 emit_label (call_lab);
278
279 if (REG_P (chain))
280 {
281 use_reg (call_fusage, chain);
282 STATIC_CHAIN_REG_P (chain) = 1;
283 }
284
285 /* Make sure we're not going to be overwritten below. */
286 gcc_assert (!static_chain_value);
287 }
288
289 /* If we are using registers for parameters, force the
290 function address into a register now. */
291 funexp = ((reg_parm_seen
292 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
293 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
294 : memory_address (FUNCTION_MODE, funexp));
295 }
296 else
297 {
298 /* funexp could be a SYMBOL_REF represents a function pointer which is
299 of ptr_mode. In this case, it should be converted into address mode
300 to be a valid address for memory rtx pattern. See PR 64971. */
301 if (GET_MODE (funexp) != Pmode)
302 funexp = convert_memory_address (Pmode, funexp);
303
304 if (!(flags & ECF_SIBCALL))
305 {
306 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
307 funexp = force_reg (Pmode, funexp);
308 }
309 }
310
311 if (static_chain_value != 0
312 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
313 || DECL_STATIC_CHAIN (fndecl_or_type)))
314 {
315 rtx chain;
316
317 chain = targetm.calls.static_chain (fndecl_or_type, false);
318 static_chain_value = convert_memory_address (Pmode, static_chain_value);
319
320 emit_move_insn (chain, static_chain_value);
321 if (REG_P (chain))
322 {
323 use_reg (call_fusage, chain);
324 STATIC_CHAIN_REG_P (chain) = 1;
325 }
326 }
327
328 return funexp;
329 }
330
331 /* Generate instructions to call function FUNEXP,
332 and optionally pop the results.
333 The CALL_INSN is the first insn generated.
334
335 FNDECL is the declaration node of the function. This is given to the
336 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
337 its own args.
338
339 FUNTYPE is the data type of the function. This is given to the hook
340 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
341 own args. We used to allow an identifier for library functions, but
342 that doesn't work when the return type is an aggregate type and the
343 calling convention says that the pointer to this aggregate is to be
344 popped by the callee.
345
346 STACK_SIZE is the number of bytes of arguments on the stack,
347 ROUNDED_STACK_SIZE is that number rounded up to
348 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
349 both to put into the call insn and to generate explicit popping
350 code if necessary.
351
352 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
353 It is zero if this call doesn't want a structure value.
354
355 NEXT_ARG_REG is the rtx that results from executing
356 targetm.calls.function_arg (&args_so_far,
357 function_arg_info::end_marker ());
358 just after all the args have had their registers assigned.
359 This could be whatever you like, but normally it is the first
360 arg-register beyond those used for args in this call,
361 or 0 if all the arg-registers are used in this call.
362 It is passed on to `gen_call' so you can put this info in the call insn.
363
364 VALREG is a hard register in which a value is returned,
365 or 0 if the call does not return a value.
366
367 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
368 the args to this call were processed.
369 We restore `inhibit_defer_pop' to that value.
370
371 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
372 denote registers used by the called function. */
373
374 static void
375 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
376 tree funtype ATTRIBUTE_UNUSED,
377 poly_int64 stack_size ATTRIBUTE_UNUSED,
378 poly_int64 rounded_stack_size,
379 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
380 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
381 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
382 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
383 {
384 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
385 rtx call, funmem, pat;
386 int already_popped = 0;
387 poly_int64 n_popped = 0;
388
389 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
390 patterns exist). Any popping that the callee does on return will
391 be from our caller's frame rather than ours. */
392 if (!(ecf_flags & ECF_SIBCALL))
393 {
394 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
395
396 #ifdef CALL_POPS_ARGS
397 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
398 #endif
399 }
400
401 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
402 and we don't want to load it into a register as an optimization,
403 because prepare_call_address already did it if it should be done. */
404 if (GET_CODE (funexp) != SYMBOL_REF)
405 funexp = memory_address (FUNCTION_MODE, funexp);
406
407 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
408 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
409 {
410 tree t = fndecl;
411
412 /* Although a built-in FUNCTION_DECL and its non-__builtin
413 counterpart compare equal and get a shared mem_attrs, they
414 produce different dump output in compare-debug compilations,
415 if an entry gets garbage collected in one compilation, then
416 adds a different (but equivalent) entry, while the other
417 doesn't run the garbage collector at the same spot and then
418 shares the mem_attr with the equivalent entry. */
419 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
420 {
421 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
422 if (t2)
423 t = t2;
424 }
425
426 set_mem_expr (funmem, t);
427 }
428 else if (fntree)
429 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
430
431 if (ecf_flags & ECF_SIBCALL)
432 {
433 if (valreg)
434 pat = targetm.gen_sibcall_value (valreg, funmem,
435 rounded_stack_size_rtx,
436 next_arg_reg, NULL_RTX);
437 else
438 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
439 next_arg_reg,
440 gen_int_mode (struct_value_size, Pmode));
441 }
442 /* If the target has "call" or "call_value" insns, then prefer them
443 if no arguments are actually popped. If the target does not have
444 "call" or "call_value" insns, then we must use the popping versions
445 even if the call has no arguments to pop. */
446 else if (maybe_ne (n_popped, 0)
447 || !(valreg
448 ? targetm.have_call_value ()
449 : targetm.have_call ()))
450 {
451 rtx n_pop = gen_int_mode (n_popped, Pmode);
452
453 /* If this subroutine pops its own args, record that in the call insn
454 if possible, for the sake of frame pointer elimination. */
455
456 if (valreg)
457 pat = targetm.gen_call_value_pop (valreg, funmem,
458 rounded_stack_size_rtx,
459 next_arg_reg, n_pop);
460 else
461 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
462 next_arg_reg, n_pop);
463
464 already_popped = 1;
465 }
466 else
467 {
468 if (valreg)
469 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
470 next_arg_reg, NULL_RTX);
471 else
472 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
473 gen_int_mode (struct_value_size, Pmode));
474 }
475 emit_insn (pat);
476
477 /* Find the call we just emitted. */
478 rtx_call_insn *call_insn = last_call_insn ();
479
480 /* Some target create a fresh MEM instead of reusing the one provided
481 above. Set its MEM_EXPR. */
482 call = get_call_rtx_from (call_insn);
483 if (call
484 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
485 && MEM_EXPR (funmem) != NULL_TREE)
486 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
487
488 /* Put the register usage information there. */
489 add_function_usage_to (call_insn, call_fusage);
490
491 /* If this is a const call, then set the insn's unchanging bit. */
492 if (ecf_flags & ECF_CONST)
493 RTL_CONST_CALL_P (call_insn) = 1;
494
495 /* If this is a pure call, then set the insn's unchanging bit. */
496 if (ecf_flags & ECF_PURE)
497 RTL_PURE_CALL_P (call_insn) = 1;
498
499 /* If this is a const call, then set the insn's unchanging bit. */
500 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
501 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
502
503 /* Create a nothrow REG_EH_REGION note, if needed. */
504 make_reg_eh_region_note (call_insn, ecf_flags, 0);
505
506 if (ecf_flags & ECF_NORETURN)
507 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
508
509 if (ecf_flags & ECF_RETURNS_TWICE)
510 {
511 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
512 cfun->calls_setjmp = 1;
513 }
514
515 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
516
517 /* Restore this now, so that we do defer pops for this call's args
518 if the context of the call as a whole permits. */
519 inhibit_defer_pop = old_inhibit_defer_pop;
520
521 if (maybe_ne (n_popped, 0))
522 {
523 if (!already_popped)
524 CALL_INSN_FUNCTION_USAGE (call_insn)
525 = gen_rtx_EXPR_LIST (VOIDmode,
526 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
527 CALL_INSN_FUNCTION_USAGE (call_insn));
528 rounded_stack_size -= n_popped;
529 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
530 stack_pointer_delta -= n_popped;
531
532 add_args_size_note (call_insn, stack_pointer_delta);
533
534 /* If popup is needed, stack realign must use DRAP */
535 if (SUPPORTS_STACK_ALIGNMENT)
536 crtl->need_drap = true;
537 }
538 /* For noreturn calls when not accumulating outgoing args force
539 REG_ARGS_SIZE note to prevent crossjumping of calls with different
540 args sizes. */
541 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
542 add_args_size_note (call_insn, stack_pointer_delta);
543
544 if (!ACCUMULATE_OUTGOING_ARGS)
545 {
546 /* If returning from the subroutine does not automatically pop the args,
547 we need an instruction to pop them sooner or later.
548 Perhaps do it now; perhaps just record how much space to pop later.
549
550 If returning from the subroutine does pop the args, indicate that the
551 stack pointer will be changed. */
552
553 if (maybe_ne (rounded_stack_size, 0))
554 {
555 if (ecf_flags & ECF_NORETURN)
556 /* Just pretend we did the pop. */
557 stack_pointer_delta -= rounded_stack_size;
558 else if (flag_defer_pop && inhibit_defer_pop == 0
559 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
560 pending_stack_adjust += rounded_stack_size;
561 else
562 adjust_stack (rounded_stack_size_rtx);
563 }
564 }
565 /* When we accumulate outgoing args, we must avoid any stack manipulations.
566 Restore the stack pointer to its original value now. Usually
567 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
568 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
569 popping variants of functions exist as well.
570
571 ??? We may optimize similar to defer_pop above, but it is
572 probably not worthwhile.
573
574 ??? It will be worthwhile to enable combine_stack_adjustments even for
575 such machines. */
576 else if (maybe_ne (n_popped, 0))
577 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
578 }
579
580 /* Determine if the function identified by FNDECL is one with
581 special properties we wish to know about. Modify FLAGS accordingly.
582
583 For example, if the function might return more than one time (setjmp), then
584 set ECF_RETURNS_TWICE.
585
586 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
587 space from the stack such as alloca. */
588
589 static int
590 special_function_p (const_tree fndecl, int flags)
591 {
592 tree name_decl = DECL_NAME (fndecl);
593
594 if (maybe_special_function_p (fndecl)
595 && IDENTIFIER_LENGTH (name_decl) <= 11)
596 {
597 const char *name = IDENTIFIER_POINTER (name_decl);
598 const char *tname = name;
599
600 /* We assume that alloca will always be called by name. It
601 makes no sense to pass it as a pointer-to-function to
602 anything that does not understand its behavior. */
603 if (IDENTIFIER_LENGTH (name_decl) == 6
604 && name[0] == 'a'
605 && ! strcmp (name, "alloca"))
606 flags |= ECF_MAY_BE_ALLOCA;
607
608 /* Disregard prefix _ or __. */
609 if (name[0] == '_')
610 {
611 if (name[1] == '_')
612 tname += 2;
613 else
614 tname += 1;
615 }
616
617 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
618 if (! strcmp (tname, "setjmp")
619 || ! strcmp (tname, "sigsetjmp")
620 || ! strcmp (name, "savectx")
621 || ! strcmp (name, "vfork")
622 || ! strcmp (name, "getcontext"))
623 flags |= ECF_RETURNS_TWICE;
624 }
625
626 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
627 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
628 flags |= ECF_MAY_BE_ALLOCA;
629
630 return flags;
631 }
632
633 /* Return fnspec for DECL. */
634
635 static attr_fnspec
636 decl_fnspec (tree fndecl)
637 {
638 tree attr;
639 tree type = TREE_TYPE (fndecl);
640 if (type)
641 {
642 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
643 if (attr)
644 {
645 return TREE_VALUE (TREE_VALUE (attr));
646 }
647 }
648 if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
649 return builtin_fnspec (fndecl);
650 return "";
651 }
652
653 /* Similar to special_function_p; return a set of ERF_ flags for the
654 function FNDECL. */
655 static int
656 decl_return_flags (tree fndecl)
657 {
658 attr_fnspec fnspec = decl_fnspec (fndecl);
659
660 unsigned int arg;
661 if (fnspec.returns_arg (&arg))
662 return ERF_RETURNS_ARG | arg;
663
664 if (fnspec.returns_noalias_p ())
665 return ERF_NOALIAS;
666 return 0;
667 }
668
669 /* Return nonzero when FNDECL represents a call to setjmp. */
670
671 int
672 setjmp_call_p (const_tree fndecl)
673 {
674 if (DECL_IS_RETURNS_TWICE (fndecl))
675 return ECF_RETURNS_TWICE;
676 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
677 }
678
679
680 /* Return true if STMT may be an alloca call. */
681
682 bool
683 gimple_maybe_alloca_call_p (const gimple *stmt)
684 {
685 tree fndecl;
686
687 if (!is_gimple_call (stmt))
688 return false;
689
690 fndecl = gimple_call_fndecl (stmt);
691 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
692 return true;
693
694 return false;
695 }
696
697 /* Return true if STMT is a builtin alloca call. */
698
699 bool
700 gimple_alloca_call_p (const gimple *stmt)
701 {
702 tree fndecl;
703
704 if (!is_gimple_call (stmt))
705 return false;
706
707 fndecl = gimple_call_fndecl (stmt);
708 if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
709 switch (DECL_FUNCTION_CODE (fndecl))
710 {
711 CASE_BUILT_IN_ALLOCA:
712 return gimple_call_num_args (stmt) > 0;
713 default:
714 break;
715 }
716
717 return false;
718 }
719
720 /* Return true when exp contains a builtin alloca call. */
721
722 bool
723 alloca_call_p (const_tree exp)
724 {
725 tree fndecl;
726 if (TREE_CODE (exp) == CALL_EXPR
727 && (fndecl = get_callee_fndecl (exp))
728 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
729 switch (DECL_FUNCTION_CODE (fndecl))
730 {
731 CASE_BUILT_IN_ALLOCA:
732 return true;
733 default:
734 break;
735 }
736
737 return false;
738 }
739
740 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
741 function. Return FALSE otherwise. */
742
743 static bool
744 is_tm_builtin (const_tree fndecl)
745 {
746 if (fndecl == NULL)
747 return false;
748
749 if (decl_is_tm_clone (fndecl))
750 return true;
751
752 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
753 {
754 switch (DECL_FUNCTION_CODE (fndecl))
755 {
756 case BUILT_IN_TM_COMMIT:
757 case BUILT_IN_TM_COMMIT_EH:
758 case BUILT_IN_TM_ABORT:
759 case BUILT_IN_TM_IRREVOCABLE:
760 case BUILT_IN_TM_GETTMCLONE_IRR:
761 case BUILT_IN_TM_MEMCPY:
762 case BUILT_IN_TM_MEMMOVE:
763 case BUILT_IN_TM_MEMSET:
764 CASE_BUILT_IN_TM_STORE (1):
765 CASE_BUILT_IN_TM_STORE (2):
766 CASE_BUILT_IN_TM_STORE (4):
767 CASE_BUILT_IN_TM_STORE (8):
768 CASE_BUILT_IN_TM_STORE (FLOAT):
769 CASE_BUILT_IN_TM_STORE (DOUBLE):
770 CASE_BUILT_IN_TM_STORE (LDOUBLE):
771 CASE_BUILT_IN_TM_STORE (M64):
772 CASE_BUILT_IN_TM_STORE (M128):
773 CASE_BUILT_IN_TM_STORE (M256):
774 CASE_BUILT_IN_TM_LOAD (1):
775 CASE_BUILT_IN_TM_LOAD (2):
776 CASE_BUILT_IN_TM_LOAD (4):
777 CASE_BUILT_IN_TM_LOAD (8):
778 CASE_BUILT_IN_TM_LOAD (FLOAT):
779 CASE_BUILT_IN_TM_LOAD (DOUBLE):
780 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
781 CASE_BUILT_IN_TM_LOAD (M64):
782 CASE_BUILT_IN_TM_LOAD (M128):
783 CASE_BUILT_IN_TM_LOAD (M256):
784 case BUILT_IN_TM_LOG:
785 case BUILT_IN_TM_LOG_1:
786 case BUILT_IN_TM_LOG_2:
787 case BUILT_IN_TM_LOG_4:
788 case BUILT_IN_TM_LOG_8:
789 case BUILT_IN_TM_LOG_FLOAT:
790 case BUILT_IN_TM_LOG_DOUBLE:
791 case BUILT_IN_TM_LOG_LDOUBLE:
792 case BUILT_IN_TM_LOG_M64:
793 case BUILT_IN_TM_LOG_M128:
794 case BUILT_IN_TM_LOG_M256:
795 return true;
796 default:
797 break;
798 }
799 }
800 return false;
801 }
802
803 /* Detect flags (function attributes) from the function decl or type node. */
804
805 int
806 flags_from_decl_or_type (const_tree exp)
807 {
808 int flags = 0;
809
810 if (DECL_P (exp))
811 {
812 /* The function exp may have the `malloc' attribute. */
813 if (DECL_IS_MALLOC (exp))
814 flags |= ECF_MALLOC;
815
816 /* The function exp may have the `returns_twice' attribute. */
817 if (DECL_IS_RETURNS_TWICE (exp))
818 flags |= ECF_RETURNS_TWICE;
819
820 /* Process the pure and const attributes. */
821 if (TREE_READONLY (exp))
822 flags |= ECF_CONST;
823 if (DECL_PURE_P (exp))
824 flags |= ECF_PURE;
825 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
826 flags |= ECF_LOOPING_CONST_OR_PURE;
827
828 if (DECL_IS_NOVOPS (exp))
829 flags |= ECF_NOVOPS;
830 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
831 flags |= ECF_LEAF;
832 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
833 flags |= ECF_COLD;
834
835 if (TREE_NOTHROW (exp))
836 flags |= ECF_NOTHROW;
837
838 if (flag_tm)
839 {
840 if (is_tm_builtin (exp))
841 flags |= ECF_TM_BUILTIN;
842 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
843 || lookup_attribute ("transaction_pure",
844 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
845 flags |= ECF_TM_PURE;
846 }
847
848 flags = special_function_p (exp, flags);
849 }
850 else if (TYPE_P (exp))
851 {
852 if (TYPE_READONLY (exp))
853 flags |= ECF_CONST;
854
855 if (flag_tm
856 && ((flags & ECF_CONST) != 0
857 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
858 flags |= ECF_TM_PURE;
859 }
860 else
861 gcc_unreachable ();
862
863 if (TREE_THIS_VOLATILE (exp))
864 {
865 flags |= ECF_NORETURN;
866 if (flags & (ECF_CONST|ECF_PURE))
867 flags |= ECF_LOOPING_CONST_OR_PURE;
868 }
869
870 return flags;
871 }
872
873 /* Detect flags from a CALL_EXPR. */
874
875 int
876 call_expr_flags (const_tree t)
877 {
878 int flags;
879 tree decl = get_callee_fndecl (t);
880
881 if (decl)
882 flags = flags_from_decl_or_type (decl);
883 else if (CALL_EXPR_FN (t) == NULL_TREE)
884 flags = internal_fn_flags (CALL_EXPR_IFN (t));
885 else
886 {
887 tree type = TREE_TYPE (CALL_EXPR_FN (t));
888 if (type && TREE_CODE (type) == POINTER_TYPE)
889 flags = flags_from_decl_or_type (TREE_TYPE (type));
890 else
891 flags = 0;
892 if (CALL_EXPR_BY_DESCRIPTOR (t))
893 flags |= ECF_BY_DESCRIPTOR;
894 }
895
896 return flags;
897 }
898
899 /* Return true if ARG should be passed by invisible reference. */
900
901 bool
902 pass_by_reference (CUMULATIVE_ARGS *ca, function_arg_info arg)
903 {
904 if (tree type = arg.type)
905 {
906 /* If this type contains non-trivial constructors, then it is
907 forbidden for the middle-end to create any new copies. */
908 if (TREE_ADDRESSABLE (type))
909 return true;
910
911 /* GCC post 3.4 passes *all* variable sized types by reference. */
912 if (!TYPE_SIZE (type) || !poly_int_tree_p (TYPE_SIZE (type)))
913 return true;
914
915 /* If a record type should be passed the same as its first (and only)
916 member, use the type and mode of that member. */
917 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
918 {
919 arg.type = TREE_TYPE (first_field (type));
920 arg.mode = TYPE_MODE (arg.type);
921 }
922 }
923
924 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), arg);
925 }
926
927 /* Return true if TYPE should be passed by reference when passed to
928 the "..." arguments of a function. */
929
930 bool
931 pass_va_arg_by_reference (tree type)
932 {
933 return pass_by_reference (NULL, function_arg_info (type, /*named=*/false));
934 }
935
936 /* Decide whether ARG, which occurs in the state described by CA,
937 should be passed by reference. Return true if so and update
938 ARG accordingly. */
939
940 bool
941 apply_pass_by_reference_rules (CUMULATIVE_ARGS *ca, function_arg_info &arg)
942 {
943 if (pass_by_reference (ca, arg))
944 {
945 arg.type = build_pointer_type (arg.type);
946 arg.mode = TYPE_MODE (arg.type);
947 arg.pass_by_reference = true;
948 return true;
949 }
950 return false;
951 }
952
953 /* Return true if ARG, which is passed by reference, should be callee
954 copied instead of caller copied. */
955
956 bool
957 reference_callee_copied (CUMULATIVE_ARGS *ca, const function_arg_info &arg)
958 {
959 if (arg.type && TREE_ADDRESSABLE (arg.type))
960 return false;
961 return targetm.calls.callee_copies (pack_cumulative_args (ca), arg);
962 }
963
964
965 /* Precompute all register parameters as described by ARGS, storing values
966 into fields within the ARGS array.
967
968 NUM_ACTUALS indicates the total number elements in the ARGS array.
969
970 Set REG_PARM_SEEN if we encounter a register parameter. */
971
972 static void
973 precompute_register_parameters (int num_actuals, struct arg_data *args,
974 int *reg_parm_seen)
975 {
976 int i;
977
978 *reg_parm_seen = 0;
979
980 for (i = 0; i < num_actuals; i++)
981 if (args[i].reg != 0 && ! args[i].pass_on_stack)
982 {
983 *reg_parm_seen = 1;
984
985 if (args[i].value == 0)
986 {
987 push_temp_slots ();
988 args[i].value = expand_normal (args[i].tree_value);
989 preserve_temp_slots (args[i].value);
990 pop_temp_slots ();
991 }
992
993 /* If we are to promote the function arg to a wider mode,
994 do it now. */
995
996 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
997 args[i].value
998 = convert_modes (args[i].mode,
999 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1000 args[i].value, args[i].unsignedp);
1001
1002 /* If the value is a non-legitimate constant, force it into a
1003 pseudo now. TLS symbols sometimes need a call to resolve. */
1004 if (CONSTANT_P (args[i].value)
1005 && (!targetm.legitimate_constant_p (args[i].mode, args[i].value)
1006 || targetm.precompute_tls_p (args[i].mode, args[i].value)))
1007 args[i].value = force_reg (args[i].mode, args[i].value);
1008
1009 /* If we're going to have to load the value by parts, pull the
1010 parts into pseudos. The part extraction process can involve
1011 non-trivial computation. */
1012 if (GET_CODE (args[i].reg) == PARALLEL)
1013 {
1014 tree type = TREE_TYPE (args[i].tree_value);
1015 args[i].parallel_value
1016 = emit_group_load_into_temps (args[i].reg, args[i].value,
1017 type, int_size_in_bytes (type));
1018 }
1019
1020 /* If the value is expensive, and we are inside an appropriately
1021 short loop, put the value into a pseudo and then put the pseudo
1022 into the hard reg.
1023
1024 For small register classes, also do this if this call uses
1025 register parameters. This is to avoid reload conflicts while
1026 loading the parameters registers. */
1027
1028 else if ((! (REG_P (args[i].value)
1029 || (GET_CODE (args[i].value) == SUBREG
1030 && REG_P (SUBREG_REG (args[i].value)))))
1031 && args[i].mode != BLKmode
1032 && (set_src_cost (args[i].value, args[i].mode,
1033 optimize_insn_for_speed_p ())
1034 > COSTS_N_INSNS (1))
1035 && ((*reg_parm_seen
1036 && targetm.small_register_classes_for_mode_p (args[i].mode))
1037 || optimize))
1038 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1039 }
1040 }
1041
1042 #ifdef REG_PARM_STACK_SPACE
1043
1044 /* The argument list is the property of the called routine and it
1045 may clobber it. If the fixed area has been used for previous
1046 parameters, we must save and restore it. */
1047
1048 static rtx
1049 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1050 {
1051 unsigned int low;
1052 unsigned int high;
1053
1054 /* Compute the boundary of the area that needs to be saved, if any. */
1055 high = reg_parm_stack_space;
1056 if (ARGS_GROW_DOWNWARD)
1057 high += 1;
1058
1059 if (high > highest_outgoing_arg_in_use)
1060 high = highest_outgoing_arg_in_use;
1061
1062 for (low = 0; low < high; low++)
1063 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1064 {
1065 int num_to_save;
1066 machine_mode save_mode;
1067 int delta;
1068 rtx addr;
1069 rtx stack_area;
1070 rtx save_area;
1071
1072 while (stack_usage_map[--high] == 0)
1073 ;
1074
1075 *low_to_save = low;
1076 *high_to_save = high;
1077
1078 num_to_save = high - low + 1;
1079
1080 /* If we don't have the required alignment, must do this
1081 in BLKmode. */
1082 scalar_int_mode imode;
1083 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1084 && (low & (MIN (GET_MODE_SIZE (imode),
1085 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1086 save_mode = imode;
1087 else
1088 save_mode = BLKmode;
1089
1090 if (ARGS_GROW_DOWNWARD)
1091 delta = -high;
1092 else
1093 delta = low;
1094
1095 addr = plus_constant (Pmode, argblock, delta);
1096 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1097
1098 set_mem_align (stack_area, PARM_BOUNDARY);
1099 if (save_mode == BLKmode)
1100 {
1101 save_area = assign_stack_temp (BLKmode, num_to_save);
1102 emit_block_move (validize_mem (save_area), stack_area,
1103 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1104 }
1105 else
1106 {
1107 save_area = gen_reg_rtx (save_mode);
1108 emit_move_insn (save_area, stack_area);
1109 }
1110
1111 return save_area;
1112 }
1113
1114 return NULL_RTX;
1115 }
1116
1117 static void
1118 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1119 {
1120 machine_mode save_mode = GET_MODE (save_area);
1121 int delta;
1122 rtx addr, stack_area;
1123
1124 if (ARGS_GROW_DOWNWARD)
1125 delta = -high_to_save;
1126 else
1127 delta = low_to_save;
1128
1129 addr = plus_constant (Pmode, argblock, delta);
1130 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1131 set_mem_align (stack_area, PARM_BOUNDARY);
1132
1133 if (save_mode != BLKmode)
1134 emit_move_insn (stack_area, save_area);
1135 else
1136 emit_block_move (stack_area, validize_mem (save_area),
1137 GEN_INT (high_to_save - low_to_save + 1),
1138 BLOCK_OP_CALL_PARM);
1139 }
1140 #endif /* REG_PARM_STACK_SPACE */
1141
1142 /* If any elements in ARGS refer to parameters that are to be passed in
1143 registers, but not in memory, and whose alignment does not permit a
1144 direct copy into registers. Copy the values into a group of pseudos
1145 which we will later copy into the appropriate hard registers.
1146
1147 Pseudos for each unaligned argument will be stored into the array
1148 args[argnum].aligned_regs. The caller is responsible for deallocating
1149 the aligned_regs array if it is nonzero. */
1150
1151 static void
1152 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1153 {
1154 int i, j;
1155
1156 for (i = 0; i < num_actuals; i++)
1157 if (args[i].reg != 0 && ! args[i].pass_on_stack
1158 && GET_CODE (args[i].reg) != PARALLEL
1159 && args[i].mode == BLKmode
1160 && MEM_P (args[i].value)
1161 && (MEM_ALIGN (args[i].value)
1162 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1163 {
1164 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1165 int endian_correction = 0;
1166
1167 if (args[i].partial)
1168 {
1169 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1170 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1171 }
1172 else
1173 {
1174 args[i].n_aligned_regs
1175 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1176 }
1177
1178 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1179
1180 /* Structures smaller than a word are normally aligned to the
1181 least significant byte. On a BYTES_BIG_ENDIAN machine,
1182 this means we must skip the empty high order bytes when
1183 calculating the bit offset. */
1184 if (bytes < UNITS_PER_WORD
1185 #ifdef BLOCK_REG_PADDING
1186 && (BLOCK_REG_PADDING (args[i].mode,
1187 TREE_TYPE (args[i].tree_value), 1)
1188 == PAD_DOWNWARD)
1189 #else
1190 && BYTES_BIG_ENDIAN
1191 #endif
1192 )
1193 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1194
1195 for (j = 0; j < args[i].n_aligned_regs; j++)
1196 {
1197 rtx reg = gen_reg_rtx (word_mode);
1198 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1199 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1200
1201 args[i].aligned_regs[j] = reg;
1202 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1203 word_mode, word_mode, false, NULL);
1204
1205 /* There is no need to restrict this code to loading items
1206 in TYPE_ALIGN sized hunks. The bitfield instructions can
1207 load up entire word sized registers efficiently.
1208
1209 ??? This may not be needed anymore.
1210 We use to emit a clobber here but that doesn't let later
1211 passes optimize the instructions we emit. By storing 0 into
1212 the register later passes know the first AND to zero out the
1213 bitfield being set in the register is unnecessary. The store
1214 of 0 will be deleted as will at least the first AND. */
1215
1216 emit_move_insn (reg, const0_rtx);
1217
1218 bytes -= bitsize / BITS_PER_UNIT;
1219 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1220 word_mode, word, false);
1221 }
1222 }
1223 }
1224
1225 /* The limit set by -Walloc-larger-than=. */
1226 static GTY(()) tree alloc_object_size_limit;
1227
1228 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1229 setting if the option is specified, or to the maximum object size if it
1230 is not. Return the initialized value. */
1231
1232 static tree
1233 alloc_max_size (void)
1234 {
1235 if (alloc_object_size_limit)
1236 return alloc_object_size_limit;
1237
1238 HOST_WIDE_INT limit = warn_alloc_size_limit;
1239 if (limit == HOST_WIDE_INT_MAX)
1240 limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node));
1241
1242 alloc_object_size_limit = build_int_cst (size_type_node, limit);
1243
1244 return alloc_object_size_limit;
1245 }
1246
1247 /* Return true when EXP's range can be determined and set RANGE[] to it
1248 after adjusting it if necessary to make EXP a represents a valid size
1249 of object, or a valid size argument to an allocation function declared
1250 with attribute alloc_size (whose argument may be signed), or to a string
1251 manipulation function like memset.
1252 When ALLOW_ZERO is set in FLAGS, allow returning a range of [0, 0] for
1253 a size in an anti-range [1, N] where N > PTRDIFF_MAX. A zero range is
1254 a (nearly) invalid argument to allocation functions like malloc but it
1255 is a valid argument to functions like memset.
1256 When USE_LARGEST is set in FLAGS set RANGE to the largest valid subrange
1257 in a multi-range, otherwise to the smallest valid subrange. */
1258
1259 bool
1260 get_size_range (range_query *query, tree exp, gimple *stmt, tree range[2],
1261 int flags /* = 0 */)
1262 {
1263 if (!exp)
1264 return false;
1265
1266 if (tree_fits_uhwi_p (exp))
1267 {
1268 /* EXP is a constant. */
1269 range[0] = range[1] = exp;
1270 return true;
1271 }
1272
1273 tree exptype = TREE_TYPE (exp);
1274 bool integral = INTEGRAL_TYPE_P (exptype);
1275
1276 wide_int min, max;
1277 enum value_range_kind range_type;
1278
1279 if (!query)
1280 query = get_global_range_query ();
1281
1282 if (integral)
1283 {
1284 value_range vr;
1285
1286 query->range_of_expr (vr, exp, stmt);
1287
1288 if (vr.undefined_p ())
1289 vr.set_varying (TREE_TYPE (exp));
1290 range_type = vr.kind ();
1291 min = wi::to_wide (vr.min ());
1292 max = wi::to_wide (vr.max ());
1293 }
1294 else
1295 range_type = VR_VARYING;
1296
1297 if (range_type == VR_VARYING)
1298 {
1299 if (integral)
1300 {
1301 /* Use the full range of the type of the expression when
1302 no value range information is available. */
1303 range[0] = TYPE_MIN_VALUE (exptype);
1304 range[1] = TYPE_MAX_VALUE (exptype);
1305 return true;
1306 }
1307
1308 range[0] = NULL_TREE;
1309 range[1] = NULL_TREE;
1310 return false;
1311 }
1312
1313 unsigned expprec = TYPE_PRECISION (exptype);
1314
1315 bool signed_p = !TYPE_UNSIGNED (exptype);
1316
1317 if (range_type == VR_ANTI_RANGE)
1318 {
1319 if (signed_p)
1320 {
1321 if (wi::les_p (max, 0))
1322 {
1323 /* EXP is not in a strictly negative range. That means
1324 it must be in some (not necessarily strictly) positive
1325 range which includes zero. Since in signed to unsigned
1326 conversions negative values end up converted to large
1327 positive values, and otherwise they are not valid sizes,
1328 the resulting range is in both cases [0, TYPE_MAX]. */
1329 min = wi::zero (expprec);
1330 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1331 }
1332 else if (wi::les_p (min - 1, 0))
1333 {
1334 /* EXP is not in a negative-positive range. That means EXP
1335 is either negative, or greater than max. Since negative
1336 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1337 min = max + 1;
1338 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1339 }
1340 else
1341 {
1342 max = min - 1;
1343 min = wi::zero (expprec);
1344 }
1345 }
1346 else
1347 {
1348 wide_int maxsize = wi::to_wide (max_object_size ());
1349 min = wide_int::from (min, maxsize.get_precision (), UNSIGNED);
1350 max = wide_int::from (max, maxsize.get_precision (), UNSIGNED);
1351 if (wi::eq_p (0, min - 1))
1352 {
1353 /* EXP is unsigned and not in the range [1, MAX]. That means
1354 it's either zero or greater than MAX. Even though 0 would
1355 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1356 is set, set the range to [MAX, TYPE_MAX] so that when MAX
1357 is greater than the limit the whole range is diagnosed. */
1358 wide_int maxsize = wi::to_wide (max_object_size ());
1359 if (flags & SR_ALLOW_ZERO)
1360 {
1361 if (wi::leu_p (maxsize, max + 1)
1362 || !(flags & SR_USE_LARGEST))
1363 min = max = wi::zero (expprec);
1364 else
1365 {
1366 min = max + 1;
1367 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1368 }
1369 }
1370 else
1371 {
1372 min = max + 1;
1373 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1374 }
1375 }
1376 else if ((flags & SR_USE_LARGEST)
1377 && wi::ltu_p (max + 1, maxsize))
1378 {
1379 /* When USE_LARGEST is set and the larger of the two subranges
1380 is a valid size, use it... */
1381 min = max + 1;
1382 max = maxsize;
1383 }
1384 else
1385 {
1386 /* ...otherwise use the smaller subrange. */
1387 max = min - 1;
1388 min = wi::zero (expprec);
1389 }
1390 }
1391 }
1392
1393 range[0] = wide_int_to_tree (exptype, min);
1394 range[1] = wide_int_to_tree (exptype, max);
1395
1396 return true;
1397 }
1398
1399 bool
1400 get_size_range (tree exp, tree range[2], int flags /* = 0 */)
1401 {
1402 return get_size_range (/*query=*/NULL, exp, /*stmt=*/NULL, range, flags);
1403 }
1404
1405 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1406 whose argument numbers given by IDX with values given by ARGS exceed
1407 the maximum object size or cause an unsigned oveflow (wrapping) when
1408 multiplied. FN is null when EXP is a call via a function pointer.
1409 When ARGS[0] is null the function does nothing. ARGS[1] may be null
1410 for functions like malloc, and non-null for those like calloc that
1411 are decorated with a two-argument attribute alloc_size. */
1412
1413 void
1414 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1415 {
1416 /* The range each of the (up to) two arguments is known to be in. */
1417 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1418
1419 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1420 tree maxobjsize = alloc_max_size ();
1421
1422 location_t loc = EXPR_LOCATION (exp);
1423
1424 tree fntype = fn ? TREE_TYPE (fn) : TREE_TYPE (TREE_TYPE (exp));
1425 bool warned = false;
1426
1427 /* Validate each argument individually. */
1428 for (unsigned i = 0; i != 2 && args[i]; ++i)
1429 {
1430 if (TREE_CODE (args[i]) == INTEGER_CST)
1431 {
1432 argrange[i][0] = args[i];
1433 argrange[i][1] = args[i];
1434
1435 if (tree_int_cst_lt (args[i], integer_zero_node))
1436 {
1437 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1438 "argument %i value %qE is negative",
1439 idx[i] + 1, args[i]);
1440 }
1441 else if (integer_zerop (args[i]))
1442 {
1443 /* Avoid issuing -Walloc-zero for allocation functions other
1444 than __builtin_alloca that are declared with attribute
1445 returns_nonnull because there's no portability risk. This
1446 avoids warning for such calls to libiberty's xmalloc and
1447 friends.
1448 Also avoid issuing the warning for calls to function named
1449 "alloca". */
1450 if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA)
1451 ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6
1452 : !lookup_attribute ("returns_nonnull",
1453 TYPE_ATTRIBUTES (fntype)))
1454 warned = warning_at (loc, OPT_Walloc_zero,
1455 "argument %i value is zero",
1456 idx[i] + 1);
1457 }
1458 else if (tree_int_cst_lt (maxobjsize, args[i]))
1459 {
1460 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1461 mode and with -fno-exceptions as a way to indicate array
1462 size overflow. There's no good way to detect C++98 here
1463 so avoid diagnosing these calls for all C++ modes. */
1464 if (i == 0
1465 && fn
1466 && !args[1]
1467 && lang_GNU_CXX ()
1468 && DECL_IS_OPERATOR_NEW_P (fn)
1469 && integer_all_onesp (args[i]))
1470 continue;
1471
1472 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1473 "argument %i value %qE exceeds "
1474 "maximum object size %E",
1475 idx[i] + 1, args[i], maxobjsize);
1476 }
1477 }
1478 else if (TREE_CODE (args[i]) == SSA_NAME
1479 && get_size_range (args[i], argrange[i]))
1480 {
1481 /* Verify that the argument's range is not negative (including
1482 upper bound of zero). */
1483 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1484 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1485 {
1486 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1487 "argument %i range [%E, %E] is negative",
1488 idx[i] + 1,
1489 argrange[i][0], argrange[i][1]);
1490 }
1491 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1492 {
1493 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1494 "argument %i range [%E, %E] exceeds "
1495 "maximum object size %E",
1496 idx[i] + 1,
1497 argrange[i][0], argrange[i][1],
1498 maxobjsize);
1499 }
1500 }
1501 }
1502
1503 if (!argrange[0])
1504 return;
1505
1506 /* For a two-argument alloc_size, validate the product of the two
1507 arguments if both of their values or ranges are known. */
1508 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1509 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1510 && !integer_onep (argrange[0][0])
1511 && !integer_onep (argrange[1][0]))
1512 {
1513 /* Check for overflow in the product of a function decorated with
1514 attribute alloc_size (X, Y). */
1515 unsigned szprec = TYPE_PRECISION (size_type_node);
1516 wide_int x = wi::to_wide (argrange[0][0], szprec);
1517 wide_int y = wi::to_wide (argrange[1][0], szprec);
1518
1519 wi::overflow_type vflow;
1520 wide_int prod = wi::umul (x, y, &vflow);
1521
1522 if (vflow)
1523 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1524 "product %<%E * %E%> of arguments %i and %i "
1525 "exceeds %<SIZE_MAX%>",
1526 argrange[0][0], argrange[1][0],
1527 idx[0] + 1, idx[1] + 1);
1528 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1529 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1530 "product %<%E * %E%> of arguments %i and %i "
1531 "exceeds maximum object size %E",
1532 argrange[0][0], argrange[1][0],
1533 idx[0] + 1, idx[1] + 1,
1534 maxobjsize);
1535
1536 if (warned)
1537 {
1538 /* Print the full range of each of the two arguments to make
1539 it clear when it is, in fact, in a range and not constant. */
1540 if (argrange[0][0] != argrange [0][1])
1541 inform (loc, "argument %i in the range [%E, %E]",
1542 idx[0] + 1, argrange[0][0], argrange[0][1]);
1543 if (argrange[1][0] != argrange [1][1])
1544 inform (loc, "argument %i in the range [%E, %E]",
1545 idx[1] + 1, argrange[1][0], argrange[1][1]);
1546 }
1547 }
1548
1549 if (warned && fn)
1550 {
1551 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1552
1553 if (DECL_IS_UNDECLARED_BUILTIN (fn))
1554 inform (loc,
1555 "in a call to built-in allocation function %qD", fn);
1556 else
1557 inform (fnloc,
1558 "in a call to allocation function %qD declared here", fn);
1559 }
1560 }
1561
1562 /* If EXPR refers to a character array or pointer declared attribute
1563 nonstring return a decl for that array or pointer and set *REF to
1564 the referenced enclosing object or pointer. Otherwise returns
1565 null. */
1566
1567 tree
1568 get_attr_nonstring_decl (tree expr, tree *ref)
1569 {
1570 tree decl = expr;
1571 tree var = NULL_TREE;
1572 if (TREE_CODE (decl) == SSA_NAME)
1573 {
1574 gimple *def = SSA_NAME_DEF_STMT (decl);
1575
1576 if (is_gimple_assign (def))
1577 {
1578 tree_code code = gimple_assign_rhs_code (def);
1579 if (code == ADDR_EXPR
1580 || code == COMPONENT_REF
1581 || code == VAR_DECL)
1582 decl = gimple_assign_rhs1 (def);
1583 }
1584 else
1585 var = SSA_NAME_VAR (decl);
1586 }
1587
1588 if (TREE_CODE (decl) == ADDR_EXPR)
1589 decl = TREE_OPERAND (decl, 0);
1590
1591 /* To simplify calling code, store the referenced DECL regardless of
1592 the attribute determined below, but avoid storing the SSA_NAME_VAR
1593 obtained above (it's not useful for dataflow purposes). */
1594 if (ref)
1595 *ref = decl;
1596
1597 /* Use the SSA_NAME_VAR that was determined above to see if it's
1598 declared nonstring. Otherwise drill down into the referenced
1599 DECL. */
1600 if (var)
1601 decl = var;
1602 else if (TREE_CODE (decl) == ARRAY_REF)
1603 decl = TREE_OPERAND (decl, 0);
1604 else if (TREE_CODE (decl) == COMPONENT_REF)
1605 decl = TREE_OPERAND (decl, 1);
1606 else if (TREE_CODE (decl) == MEM_REF)
1607 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1608
1609 if (DECL_P (decl)
1610 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1611 return decl;
1612
1613 return NULL_TREE;
1614 }
1615
1616 /* Warn about passing a non-string array/pointer to a built-in function
1617 that expects a nul-terminated string argument. Returns true if
1618 a warning has been issued.*/
1619
1620 bool
1621 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1622 {
1623 if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
1624 return false;
1625
1626 if (!warn_stringop_overread || warning_suppressed_p (exp, OPT_Wstringop_overread))
1627 return false;
1628
1629 /* Avoid clearly invalid calls (more checking done below). */
1630 unsigned nargs = call_expr_nargs (exp);
1631 if (!nargs)
1632 return false;
1633
1634 /* The bound argument to a bounded string function like strncpy. */
1635 tree bound = NULL_TREE;
1636
1637 /* The longest known or possible string argument to one of the comparison
1638 functions. If the length is less than the bound it is used instead.
1639 Since the length is only used for warning and not for code generation
1640 disable strict mode in the calls to get_range_strlen below. */
1641 tree maxlen = NULL_TREE;
1642
1643 /* It's safe to call "bounded" string functions with a non-string
1644 argument since the functions provide an explicit bound for this
1645 purpose. The exception is strncat where the bound may refer to
1646 either the destination or the source. */
1647 int fncode = DECL_FUNCTION_CODE (fndecl);
1648 switch (fncode)
1649 {
1650 case BUILT_IN_STRCMP:
1651 case BUILT_IN_STRNCMP:
1652 case BUILT_IN_STRNCASECMP:
1653 {
1654 /* For these, if one argument refers to one or more of a set
1655 of string constants or arrays of known size, determine
1656 the range of their known or possible lengths and use it
1657 conservatively as the bound for the unbounded function,
1658 and to adjust the range of the bound of the bounded ones. */
1659 for (unsigned argno = 0;
1660 argno < MIN (nargs, 2)
1661 && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++)
1662 {
1663 tree arg = CALL_EXPR_ARG (exp, argno);
1664 if (!get_attr_nonstring_decl (arg))
1665 {
1666 c_strlen_data lendata = { };
1667 /* Set MAXBOUND to an arbitrary non-null non-integer
1668 node as a request to have it set to the length of
1669 the longest string in a PHI. */
1670 lendata.maxbound = arg;
1671 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1672 maxlen = lendata.maxbound;
1673 }
1674 }
1675 }
1676 /* Fall through. */
1677
1678 case BUILT_IN_STRNCAT:
1679 case BUILT_IN_STPNCPY:
1680 case BUILT_IN_STRNCPY:
1681 if (nargs > 2)
1682 bound = CALL_EXPR_ARG (exp, 2);
1683 break;
1684
1685 case BUILT_IN_STRNDUP:
1686 if (nargs > 1)
1687 bound = CALL_EXPR_ARG (exp, 1);
1688 break;
1689
1690 case BUILT_IN_STRNLEN:
1691 {
1692 tree arg = CALL_EXPR_ARG (exp, 0);
1693 if (!get_attr_nonstring_decl (arg))
1694 {
1695 c_strlen_data lendata = { };
1696 /* Set MAXBOUND to an arbitrary non-null non-integer
1697 node as a request to have it set to the length of
1698 the longest string in a PHI. */
1699 lendata.maxbound = arg;
1700 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1701 maxlen = lendata.maxbound;
1702 }
1703 if (nargs > 1)
1704 bound = CALL_EXPR_ARG (exp, 1);
1705 break;
1706 }
1707
1708 default:
1709 break;
1710 }
1711
1712 /* Determine the range of the bound argument (if specified). */
1713 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1714 if (bound)
1715 {
1716 STRIP_NOPS (bound);
1717 get_size_range (bound, bndrng);
1718 }
1719
1720 location_t loc = EXPR_LOCATION (exp);
1721
1722 if (bndrng[0])
1723 {
1724 /* Diagnose excessive bound prior to the adjustment below and
1725 regardless of attribute nonstring. */
1726 tree maxobjsize = max_object_size ();
1727 if (tree_int_cst_lt (maxobjsize, bndrng[0]))
1728 {
1729 bool warned = false;
1730 if (tree_int_cst_equal (bndrng[0], bndrng[1]))
1731 warned = warning_at (loc, OPT_Wstringop_overread,
1732 "%qD specified bound %E "
1733 "exceeds maximum object size %E",
1734 fndecl, bndrng[0], maxobjsize);
1735 else
1736 warned = warning_at (loc, OPT_Wstringop_overread,
1737 "%qD specified bound [%E, %E] "
1738 "exceeds maximum object size %E",
1739 fndecl, bndrng[0], bndrng[1],
1740 maxobjsize);
1741 if (warned)
1742 suppress_warning (exp, OPT_Wstringop_overread);
1743
1744 return warned;
1745 }
1746 }
1747
1748 if (maxlen && !integer_all_onesp (maxlen))
1749 {
1750 /* Add one for the nul. */
1751 maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen,
1752 size_one_node);
1753
1754 if (!bndrng[0])
1755 {
1756 /* Conservatively use the upper bound of the lengths for
1757 both the lower and the upper bound of the operation. */
1758 bndrng[0] = maxlen;
1759 bndrng[1] = maxlen;
1760 bound = void_type_node;
1761 }
1762 else if (maxlen)
1763 {
1764 /* Replace the bound on the operation with the upper bound
1765 of the length of the string if the latter is smaller. */
1766 if (tree_int_cst_lt (maxlen, bndrng[0]))
1767 bndrng[0] = maxlen;
1768 else if (tree_int_cst_lt (maxlen, bndrng[1]))
1769 bndrng[1] = maxlen;
1770 }
1771 }
1772
1773 bool any_arg_warned = false;
1774 /* Iterate over the built-in function's formal arguments and check
1775 each const char* against the actual argument. If the actual
1776 argument is declared attribute non-string issue a warning unless
1777 the argument's maximum length is bounded. */
1778 function_args_iterator it;
1779 function_args_iter_init (&it, TREE_TYPE (fndecl));
1780
1781 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1782 {
1783 /* Avoid iterating past the declared argument in a call
1784 to function declared without a prototype. */
1785 if (argno >= nargs)
1786 break;
1787
1788 tree argtype = function_args_iter_cond (&it);
1789 if (!argtype)
1790 break;
1791
1792 if (TREE_CODE (argtype) != POINTER_TYPE)
1793 continue;
1794
1795 argtype = TREE_TYPE (argtype);
1796
1797 if (TREE_CODE (argtype) != INTEGER_TYPE
1798 || !TYPE_READONLY (argtype))
1799 continue;
1800
1801 argtype = TYPE_MAIN_VARIANT (argtype);
1802 if (argtype != char_type_node)
1803 continue;
1804
1805 tree callarg = CALL_EXPR_ARG (exp, argno);
1806 if (TREE_CODE (callarg) == ADDR_EXPR)
1807 callarg = TREE_OPERAND (callarg, 0);
1808
1809 /* See if the destination is declared with attribute "nonstring". */
1810 tree decl = get_attr_nonstring_decl (callarg);
1811 if (!decl)
1812 continue;
1813
1814 /* The maximum number of array elements accessed. */
1815 offset_int wibnd = 0;
1816
1817 if (argno && fncode == BUILT_IN_STRNCAT)
1818 {
1819 /* See if the bound in strncat is derived from the length
1820 of the strlen of the destination (as it's expected to be).
1821 If so, reset BOUND and FNCODE to trigger a warning. */
1822 tree dstarg = CALL_EXPR_ARG (exp, 0);
1823 if (is_strlen_related_p (dstarg, bound))
1824 {
1825 /* The bound applies to the destination, not to the source,
1826 so reset these to trigger a warning without mentioning
1827 the bound. */
1828 bound = NULL;
1829 fncode = 0;
1830 }
1831 else if (bndrng[1])
1832 /* Use the upper bound of the range for strncat. */
1833 wibnd = wi::to_offset (bndrng[1]);
1834 }
1835 else if (bndrng[0])
1836 /* Use the lower bound of the range for functions other than
1837 strncat. */
1838 wibnd = wi::to_offset (bndrng[0]);
1839
1840 /* Determine the size of the argument array if it is one. */
1841 offset_int asize = wibnd;
1842 bool known_size = false;
1843 tree type = TREE_TYPE (decl);
1844
1845 /* Determine the array size. For arrays of unknown bound and
1846 pointers reset BOUND to trigger the appropriate warning. */
1847 if (TREE_CODE (type) == ARRAY_TYPE)
1848 {
1849 if (tree arrbnd = TYPE_DOMAIN (type))
1850 {
1851 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1852 {
1853 asize = wi::to_offset (arrbnd) + 1;
1854 known_size = true;
1855 }
1856 }
1857 else if (bound == void_type_node)
1858 bound = NULL_TREE;
1859 }
1860 else if (bound == void_type_node)
1861 bound = NULL_TREE;
1862
1863 /* In a call to strncat with a bound in a range whose lower but
1864 not upper bound is less than the array size, reset ASIZE to
1865 be the same as the bound and the other variable to trigger
1866 the apprpriate warning below. */
1867 if (fncode == BUILT_IN_STRNCAT
1868 && bndrng[0] != bndrng[1]
1869 && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
1870 && (!known_size
1871 || wi::ltu_p (asize, wibnd)))
1872 {
1873 asize = wibnd;
1874 bound = NULL_TREE;
1875 fncode = 0;
1876 }
1877
1878 bool warned = false;
1879
1880 auto_diagnostic_group d;
1881 if (wi::ltu_p (asize, wibnd))
1882 {
1883 if (bndrng[0] == bndrng[1])
1884 warned = warning_at (loc, OPT_Wstringop_overread,
1885 "%qD argument %i declared attribute "
1886 "%<nonstring%> is smaller than the specified "
1887 "bound %wu",
1888 fndecl, argno + 1, wibnd.to_uhwi ());
1889 else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
1890 warned = warning_at (loc, OPT_Wstringop_overread,
1891 "%qD argument %i declared attribute "
1892 "%<nonstring%> is smaller than "
1893 "the specified bound [%E, %E]",
1894 fndecl, argno + 1, bndrng[0], bndrng[1]);
1895 else
1896 warned = warning_at (loc, OPT_Wstringop_overread,
1897 "%qD argument %i declared attribute "
1898 "%<nonstring%> may be smaller than "
1899 "the specified bound [%E, %E]",
1900 fndecl, argno + 1, bndrng[0], bndrng[1]);
1901 }
1902 else if (fncode == BUILT_IN_STRNCAT)
1903 ; /* Avoid warning for calls to strncat() when the bound
1904 is equal to the size of the non-string argument. */
1905 else if (!bound)
1906 warned = warning_at (loc, OPT_Wstringop_overread,
1907 "%qD argument %i declared attribute %<nonstring%>",
1908 fndecl, argno + 1);
1909
1910 if (warned)
1911 {
1912 inform (DECL_SOURCE_LOCATION (decl),
1913 "argument %qD declared here", decl);
1914 any_arg_warned = true;
1915 }
1916 }
1917
1918 if (any_arg_warned)
1919 suppress_warning (exp, OPT_Wstringop_overread);
1920
1921 return any_arg_warned;
1922 }
1923
1924 /* Issue an error if CALL_EXPR was flagged as requiring
1925 tall-call optimization. */
1926
1927 void
1928 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1929 {
1930 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1931 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1932 return;
1933
1934 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1935 }
1936
1937 /* Returns the type of the argument ARGNO to function with type FNTYPE
1938 or null when the typoe cannot be determined or no such argument exists. */
1939
1940 static tree
1941 fntype_argno_type (tree fntype, unsigned argno)
1942 {
1943 if (!prototype_p (fntype))
1944 return NULL_TREE;
1945
1946 tree argtype;
1947 function_args_iterator it;
1948 FOREACH_FUNCTION_ARGS (fntype, argtype, it)
1949 if (argno-- == 0)
1950 return argtype;
1951
1952 return NULL_TREE;
1953 }
1954
1955 /* Helper to append the "human readable" attribute access specification
1956 described by ACCESS to the array ATTRSTR with size STRSIZE. Used in
1957 diagnostics. */
1958
1959 static inline void
1960 append_attrname (const std::pair<int, attr_access> &access,
1961 char *attrstr, size_t strsize)
1962 {
1963 if (access.second.internal_p)
1964 return;
1965
1966 tree str = access.second.to_external_string ();
1967 gcc_assert (strsize >= (size_t) TREE_STRING_LENGTH (str));
1968 strcpy (attrstr, TREE_STRING_POINTER (str));
1969 }
1970
1971 /* Iterate over attribute access read-only, read-write, and write-only
1972 arguments and diagnose past-the-end accesses and related problems
1973 in the function call EXP. */
1974
1975 static void
1976 maybe_warn_rdwr_sizes (rdwr_map *rwm, tree fndecl, tree fntype, tree exp)
1977 {
1978 auto_diagnostic_group adg;
1979
1980 /* Set if a warning has been issued for any argument (used to decide
1981 whether to emit an informational note at the end). */
1982 opt_code opt_warned = N_OPTS;
1983
1984 /* A string describing the attributes that the warnings issued by this
1985 function apply to. Used to print one informational note per function
1986 call, rather than one per warning. That reduces clutter. */
1987 char attrstr[80];
1988 attrstr[0] = 0;
1989
1990 for (rdwr_map::iterator it = rwm->begin (); it != rwm->end (); ++it)
1991 {
1992 std::pair<int, attr_access> access = *it;
1993
1994 /* Get the function call arguments corresponding to the attribute's
1995 positional arguments. When both arguments have been specified
1996 there will be two entries in *RWM, one for each. They are
1997 cross-referenced by their respective argument numbers in
1998 ACCESS.PTRARG and ACCESS.SIZARG. */
1999 const int ptridx = access.second.ptrarg;
2000 const int sizidx = access.second.sizarg;
2001
2002 gcc_assert (ptridx != -1);
2003 gcc_assert (access.first == ptridx || access.first == sizidx);
2004
2005 /* The pointer is set to null for the entry corresponding to
2006 the size argument. Skip it. It's handled when the entry
2007 corresponding to the pointer argument comes up. */
2008 if (!access.second.ptr)
2009 continue;
2010
2011 tree ptrtype = fntype_argno_type (fntype, ptridx);
2012 tree argtype = TREE_TYPE (ptrtype);
2013
2014 /* The size of the access by the call. */
2015 tree access_size;
2016 if (sizidx == -1)
2017 {
2018 /* If only the pointer attribute operand was specified and
2019 not size, set SIZE to the greater of MINSIZE or size of
2020 one element of the pointed to type to detect smaller
2021 objects (null pointers are diagnosed in this case only
2022 if the pointer is also declared with attribute nonnull. */
2023 if (access.second.minsize
2024 && access.second.minsize != HOST_WIDE_INT_M1U)
2025 access_size = build_int_cstu (sizetype, access.second.minsize);
2026 else
2027 access_size = size_one_node;
2028 }
2029 else
2030 access_size = rwm->get (sizidx)->size;
2031
2032 /* Format the value or range to avoid an explosion of messages. */
2033 char sizstr[80];
2034 tree sizrng[2] = { size_zero_node, build_all_ones_cst (sizetype) };
2035 if (get_size_range (access_size, sizrng, true))
2036 {
2037 char *s0 = print_generic_expr_to_str (sizrng[0]);
2038 if (tree_int_cst_equal (sizrng[0], sizrng[1]))
2039 {
2040 gcc_checking_assert (strlen (s0) < sizeof sizstr);
2041 strcpy (sizstr, s0);
2042 }
2043 else
2044 {
2045 char *s1 = print_generic_expr_to_str (sizrng[1]);
2046 gcc_checking_assert (strlen (s0) + strlen (s1)
2047 < sizeof sizstr - 4);
2048 sprintf (sizstr, "[%s, %s]", s0, s1);
2049 free (s1);
2050 }
2051 free (s0);
2052 }
2053 else
2054 *sizstr = '\0';
2055
2056 /* Set if a warning has been issued for the current argument. */
2057 opt_code arg_warned = no_warning;
2058 location_t loc = EXPR_LOCATION (exp);
2059 tree ptr = access.second.ptr;
2060 if (*sizstr
2061 && tree_int_cst_sgn (sizrng[0]) < 0
2062 && tree_int_cst_sgn (sizrng[1]) < 0)
2063 {
2064 /* Warn about negative sizes. */
2065 if (access.second.internal_p)
2066 {
2067 const std::string argtypestr
2068 = access.second.array_as_string (ptrtype);
2069
2070 if (warning_at (loc, OPT_Wstringop_overflow_,
2071 "bound argument %i value %s is "
2072 "negative for a variable length array "
2073 "argument %i of type %s",
2074 sizidx + 1, sizstr,
2075 ptridx + 1, argtypestr.c_str ()))
2076 arg_warned = OPT_Wstringop_overflow_;
2077 }
2078 else if (warning_at (loc, OPT_Wstringop_overflow_,
2079 "argument %i value %s is negative",
2080 sizidx + 1, sizstr))
2081 arg_warned = OPT_Wstringop_overflow_;
2082
2083 if (arg_warned != no_warning)
2084 {
2085 append_attrname (access, attrstr, sizeof attrstr);
2086 /* Remember a warning has been issued and avoid warning
2087 again below for the same attribute. */
2088 opt_warned = arg_warned;
2089 continue;
2090 }
2091 }
2092
2093 if (tree_int_cst_sgn (sizrng[0]) >= 0)
2094 {
2095 if (COMPLETE_TYPE_P (argtype))
2096 {
2097 /* Multiply ACCESS_SIZE by the size of the type the pointer
2098 argument points to. If it's incomplete the size is used
2099 as is. */
2100 if (tree argsize = TYPE_SIZE_UNIT (argtype))
2101 if (TREE_CODE (argsize) == INTEGER_CST)
2102 {
2103 const int prec = TYPE_PRECISION (sizetype);
2104 wide_int minsize = wi::to_wide (sizrng[0], prec);
2105 minsize *= wi::to_wide (argsize, prec);
2106 access_size = wide_int_to_tree (sizetype, minsize);
2107 }
2108 }
2109 }
2110 else
2111 access_size = NULL_TREE;
2112
2113 if (integer_zerop (ptr))
2114 {
2115 if (sizidx >= 0 && tree_int_cst_sgn (sizrng[0]) > 0)
2116 {
2117 /* Warn about null pointers with positive sizes. This is
2118 different from also declaring the pointer argument with
2119 attribute nonnull when the function accepts null pointers
2120 only when the corresponding size is zero. */
2121 if (access.second.internal_p)
2122 {
2123 const std::string argtypestr
2124 = access.second.array_as_string (ptrtype);
2125
2126 if (warning_at (loc, OPT_Wnonnull,
2127 "argument %i of variable length "
2128 "array %s is null but "
2129 "the corresponding bound argument "
2130 "%i value is %s",
2131 sizidx + 1, argtypestr.c_str (),
2132 ptridx + 1, sizstr))
2133 arg_warned = OPT_Wnonnull;
2134 }
2135 else if (warning_at (loc, OPT_Wnonnull,
2136 "argument %i is null but "
2137 "the corresponding size argument "
2138 "%i value is %s",
2139 ptridx + 1, sizidx + 1, sizstr))
2140 arg_warned = OPT_Wnonnull;
2141 }
2142 else if (access_size && access.second.static_p)
2143 {
2144 /* Warn about null pointers for [static N] array arguments
2145 but do not warn for ordinary (i.e., nonstatic) arrays. */
2146 if (warning_at (loc, OPT_Wnonnull,
2147 "argument %i to %<%T[static %E]%> "
2148 "is null where non-null expected",
2149 ptridx + 1, argtype, access_size))
2150 arg_warned = OPT_Wnonnull;
2151 }
2152
2153 if (arg_warned != no_warning)
2154 {
2155 append_attrname (access, attrstr, sizeof attrstr);
2156 /* Remember a warning has been issued and avoid warning
2157 again below for the same attribute. */
2158 opt_warned = OPT_Wnonnull;
2159 continue;
2160 }
2161 }
2162
2163 access_data data (ptr, access.second.mode, NULL_TREE, false,
2164 NULL_TREE, false);
2165 access_ref* const pobj = (access.second.mode == access_write_only
2166 ? &data.dst : &data.src);
2167 tree objsize = compute_objsize (ptr, 1, pobj);
2168
2169 /* The size of the destination or source object. */
2170 tree dstsize = NULL_TREE, srcsize = NULL_TREE;
2171 if (access.second.mode == access_read_only
2172 || access.second.mode == access_none)
2173 {
2174 /* For a read-only argument there is no destination. For
2175 no access, set the source as well and differentiate via
2176 the access flag below. */
2177 srcsize = objsize;
2178 if (access.second.mode == access_read_only
2179 || access.second.mode == access_none)
2180 {
2181 /* For a read-only attribute there is no destination so
2182 clear OBJSIZE. This emits "reading N bytes" kind of
2183 diagnostics instead of the "writing N bytes" kind,
2184 unless MODE is none. */
2185 objsize = NULL_TREE;
2186 }
2187 }
2188 else
2189 dstsize = objsize;
2190
2191 /* Clear the no-warning bit in case it was set by check_access
2192 in a prior iteration so that accesses via different arguments
2193 are diagnosed. */
2194 suppress_warning (exp, OPT_Wstringop_overflow_, false);
2195 access_mode mode = data.mode;
2196 if (mode == access_deferred)
2197 mode = TYPE_READONLY (argtype) ? access_read_only : access_read_write;
2198 check_access (exp, access_size, /*maxread=*/ NULL_TREE, srcsize,
2199 dstsize, mode, &data);
2200
2201 if (warning_suppressed_p (exp, OPT_Wstringop_overflow_))
2202 opt_warned = OPT_Wstringop_overflow_;
2203 if (opt_warned != N_OPTS)
2204 {
2205 if (access.second.internal_p)
2206 inform (loc, "referencing argument %u of type %qT",
2207 ptridx + 1, ptrtype);
2208 else
2209 /* If check_access issued a warning above, append the relevant
2210 attribute to the string. */
2211 append_attrname (access, attrstr, sizeof attrstr);
2212 }
2213 }
2214
2215 if (*attrstr)
2216 {
2217 if (fndecl)
2218 inform (DECL_SOURCE_LOCATION (fndecl),
2219 "in a call to function %qD declared with attribute %qs",
2220 fndecl, attrstr);
2221 else
2222 inform (EXPR_LOCATION (fndecl),
2223 "in a call with type %qT and attribute %qs",
2224 fntype, attrstr);
2225 }
2226 else if (opt_warned != N_OPTS)
2227 {
2228 if (fndecl)
2229 inform (DECL_SOURCE_LOCATION (fndecl),
2230 "in a call to function %qD", fndecl);
2231 else
2232 inform (EXPR_LOCATION (fndecl),
2233 "in a call with type %qT", fntype);
2234 }
2235
2236 /* Set the bit in case if was cleared and not set above. */
2237 if (opt_warned != N_OPTS)
2238 suppress_warning (exp, opt_warned);
2239 }
2240
2241 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
2242 CALL_EXPR EXP.
2243
2244 NUM_ACTUALS is the total number of parameters.
2245
2246 N_NAMED_ARGS is the total number of named arguments.
2247
2248 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
2249 value, or null.
2250
2251 FNDECL is the tree code for the target of this call (if known)
2252
2253 ARGS_SO_FAR holds state needed by the target to know where to place
2254 the next argument.
2255
2256 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
2257 for arguments which are passed in registers.
2258
2259 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
2260 and may be modified by this routine.
2261
2262 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
2263 flags which may be modified by this routine.
2264
2265 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
2266 that requires allocation of stack space.
2267
2268 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
2269 the thunked-to function. */
2270
2271 static void
2272 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
2273 struct arg_data *args,
2274 struct args_size *args_size,
2275 int n_named_args ATTRIBUTE_UNUSED,
2276 tree exp, tree struct_value_addr_value,
2277 tree fndecl, tree fntype,
2278 cumulative_args_t args_so_far,
2279 int reg_parm_stack_space,
2280 rtx *old_stack_level,
2281 poly_int64_pod *old_pending_adj,
2282 int *must_preallocate, int *ecf_flags,
2283 bool *may_tailcall, bool call_from_thunk_p)
2284 {
2285 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
2286 location_t loc = EXPR_LOCATION (exp);
2287
2288 /* Count arg position in order args appear. */
2289 int argpos;
2290
2291 int i;
2292
2293 args_size->constant = 0;
2294 args_size->var = 0;
2295
2296 bitmap_obstack_initialize (NULL);
2297
2298 /* In this loop, we consider args in the order they are written.
2299 We fill up ARGS from the back. */
2300
2301 i = num_actuals - 1;
2302 {
2303 int j = i;
2304 call_expr_arg_iterator iter;
2305 tree arg;
2306 bitmap slots = NULL;
2307
2308 if (struct_value_addr_value)
2309 {
2310 args[j].tree_value = struct_value_addr_value;
2311 j--;
2312 }
2313 argpos = 0;
2314 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2315 {
2316 tree argtype = TREE_TYPE (arg);
2317
2318 if (targetm.calls.split_complex_arg
2319 && argtype
2320 && TREE_CODE (argtype) == COMPLEX_TYPE
2321 && targetm.calls.split_complex_arg (argtype))
2322 {
2323 tree subtype = TREE_TYPE (argtype);
2324 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
2325 j--;
2326 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
2327 }
2328 else
2329 args[j].tree_value = arg;
2330 j--;
2331 argpos++;
2332 }
2333
2334 if (slots)
2335 BITMAP_FREE (slots);
2336 }
2337
2338 bitmap_obstack_release (NULL);
2339
2340 tree fntypeattrs = TYPE_ATTRIBUTES (fntype);
2341 /* Extract attribute alloc_size from the type of the called expression
2342 (which could be a function or a function pointer) and if set, store
2343 the indices of the corresponding arguments in ALLOC_IDX, and then
2344 the actual argument(s) at those indices in ALLOC_ARGS. */
2345 int alloc_idx[2] = { -1, -1 };
2346 if (tree alloc_size = lookup_attribute ("alloc_size", fntypeattrs))
2347 {
2348 tree args = TREE_VALUE (alloc_size);
2349 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
2350 if (TREE_CHAIN (args))
2351 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
2352 }
2353
2354 /* Array for up to the two attribute alloc_size arguments. */
2355 tree alloc_args[] = { NULL_TREE, NULL_TREE };
2356
2357 /* Map of attribute accewss specifications for function arguments. */
2358 rdwr_map rdwr_idx;
2359 init_attr_rdwr_indices (&rdwr_idx, fntypeattrs);
2360
2361 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
2362 for (argpos = 0; argpos < num_actuals; i--, argpos++)
2363 {
2364 tree type = TREE_TYPE (args[i].tree_value);
2365 int unsignedp;
2366
2367 /* Replace erroneous argument with constant zero. */
2368 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2369 args[i].tree_value = integer_zero_node, type = integer_type_node;
2370
2371 /* If TYPE is a transparent union or record, pass things the way
2372 we would pass the first field of the union or record. We have
2373 already verified that the modes are the same. */
2374 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
2375 type = TREE_TYPE (first_field (type));
2376
2377 /* Decide where to pass this arg.
2378
2379 args[i].reg is nonzero if all or part is passed in registers.
2380
2381 args[i].partial is nonzero if part but not all is passed in registers,
2382 and the exact value says how many bytes are passed in registers.
2383
2384 args[i].pass_on_stack is nonzero if the argument must at least be
2385 computed on the stack. It may then be loaded back into registers
2386 if args[i].reg is nonzero.
2387
2388 These decisions are driven by the FUNCTION_... macros and must agree
2389 with those made by function.c. */
2390
2391 /* See if this argument should be passed by invisible reference. */
2392 function_arg_info arg (type, argpos < n_named_args);
2393 if (pass_by_reference (args_so_far_pnt, arg))
2394 {
2395 const bool callee_copies
2396 = reference_callee_copied (args_so_far_pnt, arg);
2397 tree base;
2398
2399 /* If we're compiling a thunk, pass directly the address of an object
2400 already in memory, instead of making a copy. Likewise if we want
2401 to make the copy in the callee instead of the caller. */
2402 if ((call_from_thunk_p || callee_copies)
2403 && TREE_CODE (args[i].tree_value) != WITH_SIZE_EXPR
2404 && ((base = get_base_address (args[i].tree_value)), true)
2405 && TREE_CODE (base) != SSA_NAME
2406 && (!DECL_P (base) || MEM_P (DECL_RTL (base))))
2407 {
2408 /* We may have turned the parameter value into an SSA name.
2409 Go back to the original parameter so we can take the
2410 address. */
2411 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
2412 {
2413 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
2414 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
2415 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
2416 }
2417 /* Argument setup code may have copied the value to register. We
2418 revert that optimization now because the tail call code must
2419 use the original location. */
2420 if (TREE_CODE (args[i].tree_value) == PARM_DECL
2421 && !MEM_P (DECL_RTL (args[i].tree_value))
2422 && DECL_INCOMING_RTL (args[i].tree_value)
2423 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
2424 set_decl_rtl (args[i].tree_value,
2425 DECL_INCOMING_RTL (args[i].tree_value));
2426
2427 mark_addressable (args[i].tree_value);
2428
2429 /* We can't use sibcalls if a callee-copied argument is
2430 stored in the current function's frame. */
2431 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2432 {
2433 *may_tailcall = false;
2434 maybe_complain_about_tail_call (exp,
2435 "a callee-copied argument is"
2436 " stored in the current"
2437 " function's frame");
2438 }
2439
2440 args[i].tree_value = build_fold_addr_expr_loc (loc,
2441 args[i].tree_value);
2442 type = TREE_TYPE (args[i].tree_value);
2443
2444 if (*ecf_flags & ECF_CONST)
2445 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2446 }
2447 else
2448 {
2449 /* We make a copy of the object and pass the address to the
2450 function being called. */
2451 rtx copy;
2452
2453 if (!COMPLETE_TYPE_P (type)
2454 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2455 || (flag_stack_check == GENERIC_STACK_CHECK
2456 && compare_tree_int (TYPE_SIZE_UNIT (type),
2457 STACK_CHECK_MAX_VAR_SIZE) > 0))
2458 {
2459 /* This is a variable-sized object. Make space on the stack
2460 for it. */
2461 rtx size_rtx = expr_size (args[i].tree_value);
2462
2463 if (*old_stack_level == 0)
2464 {
2465 emit_stack_save (SAVE_BLOCK, old_stack_level);
2466 *old_pending_adj = pending_stack_adjust;
2467 pending_stack_adjust = 0;
2468 }
2469
2470 /* We can pass TRUE as the 4th argument because we just
2471 saved the stack pointer and will restore it right after
2472 the call. */
2473 copy = allocate_dynamic_stack_space (size_rtx,
2474 TYPE_ALIGN (type),
2475 TYPE_ALIGN (type),
2476 max_int_size_in_bytes
2477 (type),
2478 true);
2479 copy = gen_rtx_MEM (BLKmode, copy);
2480 set_mem_attributes (copy, type, 1);
2481 }
2482 else
2483 copy = assign_temp (type, 1, 0);
2484
2485 store_expr (args[i].tree_value, copy, 0, false, false);
2486
2487 /* Just change the const function to pure and then let
2488 the next test clear the pure based on
2489 callee_copies. */
2490 if (*ecf_flags & ECF_CONST)
2491 {
2492 *ecf_flags &= ~ECF_CONST;
2493 *ecf_flags |= ECF_PURE;
2494 }
2495
2496 if (!callee_copies && *ecf_flags & ECF_PURE)
2497 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2498
2499 args[i].tree_value
2500 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2501 type = TREE_TYPE (args[i].tree_value);
2502 *may_tailcall = false;
2503 maybe_complain_about_tail_call (exp,
2504 "argument must be passed"
2505 " by copying");
2506 }
2507 arg.pass_by_reference = true;
2508 }
2509
2510 unsignedp = TYPE_UNSIGNED (type);
2511 arg.type = type;
2512 arg.mode
2513 = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2514 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2515
2516 args[i].unsignedp = unsignedp;
2517 args[i].mode = arg.mode;
2518
2519 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2520
2521 args[i].reg = targetm.calls.function_arg (args_so_far, arg);
2522
2523 if (args[i].reg && CONST_INT_P (args[i].reg))
2524 args[i].reg = NULL;
2525
2526 /* If this is a sibling call and the machine has register windows, the
2527 register window has to be unwinded before calling the routine, so
2528 arguments have to go into the incoming registers. */
2529 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2530 args[i].tail_call_reg
2531 = targetm.calls.function_incoming_arg (args_so_far, arg);
2532 else
2533 args[i].tail_call_reg = args[i].reg;
2534
2535 if (args[i].reg)
2536 args[i].partial = targetm.calls.arg_partial_bytes (args_so_far, arg);
2537
2538 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (arg);
2539
2540 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2541 it means that we are to pass this arg in the register(s) designated
2542 by the PARALLEL, but also to pass it in the stack. */
2543 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2544 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2545 args[i].pass_on_stack = 1;
2546
2547 /* If this is an addressable type, we must preallocate the stack
2548 since we must evaluate the object into its final location.
2549
2550 If this is to be passed in both registers and the stack, it is simpler
2551 to preallocate. */
2552 if (TREE_ADDRESSABLE (type)
2553 || (args[i].pass_on_stack && args[i].reg != 0))
2554 *must_preallocate = 1;
2555
2556 /* Compute the stack-size of this argument. */
2557 if (args[i].reg == 0 || args[i].partial != 0
2558 || reg_parm_stack_space > 0
2559 || args[i].pass_on_stack)
2560 locate_and_pad_parm (arg.mode, type,
2561 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2562 1,
2563 #else
2564 args[i].reg != 0,
2565 #endif
2566 reg_parm_stack_space,
2567 args[i].pass_on_stack ? 0 : args[i].partial,
2568 fndecl, args_size, &args[i].locate);
2569 #ifdef BLOCK_REG_PADDING
2570 else
2571 /* The argument is passed entirely in registers. See at which
2572 end it should be padded. */
2573 args[i].locate.where_pad =
2574 BLOCK_REG_PADDING (arg.mode, type,
2575 int_size_in_bytes (type) <= UNITS_PER_WORD);
2576 #endif
2577
2578 /* Update ARGS_SIZE, the total stack space for args so far. */
2579
2580 args_size->constant += args[i].locate.size.constant;
2581 if (args[i].locate.size.var)
2582 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2583
2584 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2585 have been used, etc. */
2586
2587 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
2588 promoted_mode used for function_arg above. However, the
2589 corresponding handling of incoming arguments in function.c
2590 does pass the promoted mode. */
2591 arg.mode = TYPE_MODE (type);
2592 targetm.calls.function_arg_advance (args_so_far, arg);
2593
2594 /* Store argument values for functions decorated with attribute
2595 alloc_size. */
2596 if (argpos == alloc_idx[0])
2597 alloc_args[0] = args[i].tree_value;
2598 else if (argpos == alloc_idx[1])
2599 alloc_args[1] = args[i].tree_value;
2600
2601 /* Save the actual argument that corresponds to the access attribute
2602 operand for later processing. */
2603 if (attr_access *access = rdwr_idx.get (argpos))
2604 {
2605 if (POINTER_TYPE_P (type))
2606 {
2607 access->ptr = args[i].tree_value;
2608 // A nonnull ACCESS->SIZE contains VLA bounds. */
2609 }
2610 else
2611 {
2612 access->size = args[i].tree_value;
2613 gcc_assert (access->ptr == NULL_TREE);
2614 }
2615 }
2616 }
2617
2618 if (alloc_args[0])
2619 {
2620 /* Check the arguments of functions decorated with attribute
2621 alloc_size. */
2622 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2623 }
2624
2625 /* Detect passing non-string arguments to functions expecting
2626 nul-terminated strings. */
2627 maybe_warn_nonstring_arg (fndecl, exp);
2628
2629 /* Check attribute access arguments. */
2630 maybe_warn_rdwr_sizes (&rdwr_idx, fndecl, fntype, exp);
2631
2632 /* Check calls to operator new for mismatched forms and attempts
2633 to deallocate unallocated objects. */
2634 maybe_emit_free_warning (exp);
2635 }
2636
2637 /* Update ARGS_SIZE to contain the total size for the argument block.
2638 Return the original constant component of the argument block's size.
2639
2640 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2641 for arguments passed in registers. */
2642
2643 static poly_int64
2644 compute_argument_block_size (int reg_parm_stack_space,
2645 struct args_size *args_size,
2646 tree fndecl ATTRIBUTE_UNUSED,
2647 tree fntype ATTRIBUTE_UNUSED,
2648 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2649 {
2650 poly_int64 unadjusted_args_size = args_size->constant;
2651
2652 /* For accumulate outgoing args mode we don't need to align, since the frame
2653 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2654 backends from generating misaligned frame sizes. */
2655 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2656 preferred_stack_boundary = STACK_BOUNDARY;
2657
2658 /* Compute the actual size of the argument block required. The variable
2659 and constant sizes must be combined, the size may have to be rounded,
2660 and there may be a minimum required size. */
2661
2662 if (args_size->var)
2663 {
2664 args_size->var = ARGS_SIZE_TREE (*args_size);
2665 args_size->constant = 0;
2666
2667 preferred_stack_boundary /= BITS_PER_UNIT;
2668 if (preferred_stack_boundary > 1)
2669 {
2670 /* We don't handle this case yet. To handle it correctly we have
2671 to add the delta, round and subtract the delta.
2672 Currently no machine description requires this support. */
2673 gcc_assert (multiple_p (stack_pointer_delta,
2674 preferred_stack_boundary));
2675 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2676 }
2677
2678 if (reg_parm_stack_space > 0)
2679 {
2680 args_size->var
2681 = size_binop (MAX_EXPR, args_size->var,
2682 ssize_int (reg_parm_stack_space));
2683
2684 /* The area corresponding to register parameters is not to count in
2685 the size of the block we need. So make the adjustment. */
2686 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2687 args_size->var
2688 = size_binop (MINUS_EXPR, args_size->var,
2689 ssize_int (reg_parm_stack_space));
2690 }
2691 }
2692 else
2693 {
2694 preferred_stack_boundary /= BITS_PER_UNIT;
2695 if (preferred_stack_boundary < 1)
2696 preferred_stack_boundary = 1;
2697 args_size->constant = (aligned_upper_bound (args_size->constant
2698 + stack_pointer_delta,
2699 preferred_stack_boundary)
2700 - stack_pointer_delta);
2701
2702 args_size->constant = upper_bound (args_size->constant,
2703 reg_parm_stack_space);
2704
2705 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2706 args_size->constant -= reg_parm_stack_space;
2707 }
2708 return unadjusted_args_size;
2709 }
2710
2711 /* Precompute parameters as needed for a function call.
2712
2713 FLAGS is mask of ECF_* constants.
2714
2715 NUM_ACTUALS is the number of arguments.
2716
2717 ARGS is an array containing information for each argument; this
2718 routine fills in the INITIAL_VALUE and VALUE fields for each
2719 precomputed argument. */
2720
2721 static void
2722 precompute_arguments (int num_actuals, struct arg_data *args)
2723 {
2724 int i;
2725
2726 /* If this is a libcall, then precompute all arguments so that we do not
2727 get extraneous instructions emitted as part of the libcall sequence. */
2728
2729 /* If we preallocated the stack space, and some arguments must be passed
2730 on the stack, then we must precompute any parameter which contains a
2731 function call which will store arguments on the stack.
2732 Otherwise, evaluating the parameter may clobber previous parameters
2733 which have already been stored into the stack. (we have code to avoid
2734 such case by saving the outgoing stack arguments, but it results in
2735 worse code) */
2736 if (!ACCUMULATE_OUTGOING_ARGS)
2737 return;
2738
2739 for (i = 0; i < num_actuals; i++)
2740 {
2741 tree type;
2742 machine_mode mode;
2743
2744 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2745 continue;
2746
2747 /* If this is an addressable type, we cannot pre-evaluate it. */
2748 type = TREE_TYPE (args[i].tree_value);
2749 gcc_assert (!TREE_ADDRESSABLE (type));
2750
2751 args[i].initial_value = args[i].value
2752 = expand_normal (args[i].tree_value);
2753
2754 mode = TYPE_MODE (type);
2755 if (mode != args[i].mode)
2756 {
2757 int unsignedp = args[i].unsignedp;
2758 args[i].value
2759 = convert_modes (args[i].mode, mode,
2760 args[i].value, args[i].unsignedp);
2761
2762 /* CSE will replace this only if it contains args[i].value
2763 pseudo, so convert it down to the declared mode using
2764 a SUBREG. */
2765 if (REG_P (args[i].value)
2766 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2767 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2768 {
2769 args[i].initial_value
2770 = gen_lowpart_SUBREG (mode, args[i].value);
2771 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2772 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2773 }
2774 }
2775 }
2776 }
2777
2778 /* Given the current state of MUST_PREALLOCATE and information about
2779 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2780 compute and return the final value for MUST_PREALLOCATE. */
2781
2782 static int
2783 finalize_must_preallocate (int must_preallocate, int num_actuals,
2784 struct arg_data *args, struct args_size *args_size)
2785 {
2786 /* See if we have or want to preallocate stack space.
2787
2788 If we would have to push a partially-in-regs parm
2789 before other stack parms, preallocate stack space instead.
2790
2791 If the size of some parm is not a multiple of the required stack
2792 alignment, we must preallocate.
2793
2794 If the total size of arguments that would otherwise create a copy in
2795 a temporary (such as a CALL) is more than half the total argument list
2796 size, preallocation is faster.
2797
2798 Another reason to preallocate is if we have a machine (like the m88k)
2799 where stack alignment is required to be maintained between every
2800 pair of insns, not just when the call is made. However, we assume here
2801 that such machines either do not have push insns (and hence preallocation
2802 would occur anyway) or the problem is taken care of with
2803 PUSH_ROUNDING. */
2804
2805 if (! must_preallocate)
2806 {
2807 int partial_seen = 0;
2808 poly_int64 copy_to_evaluate_size = 0;
2809 int i;
2810
2811 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2812 {
2813 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2814 partial_seen = 1;
2815 else if (partial_seen && args[i].reg == 0)
2816 must_preallocate = 1;
2817
2818 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2819 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2820 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2821 || TREE_CODE (args[i].tree_value) == COND_EXPR
2822 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2823 copy_to_evaluate_size
2824 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2825 }
2826
2827 if (maybe_ne (args_size->constant, 0)
2828 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2829 must_preallocate = 1;
2830 }
2831 return must_preallocate;
2832 }
2833
2834 /* If we preallocated stack space, compute the address of each argument
2835 and store it into the ARGS array.
2836
2837 We need not ensure it is a valid memory address here; it will be
2838 validized when it is used.
2839
2840 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2841
2842 static void
2843 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2844 {
2845 if (argblock)
2846 {
2847 rtx arg_reg = argblock;
2848 int i;
2849 poly_int64 arg_offset = 0;
2850
2851 if (GET_CODE (argblock) == PLUS)
2852 {
2853 arg_reg = XEXP (argblock, 0);
2854 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2855 }
2856
2857 for (i = 0; i < num_actuals; i++)
2858 {
2859 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2860 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2861 rtx addr;
2862 unsigned int align, boundary;
2863 poly_uint64 units_on_stack = 0;
2864 machine_mode partial_mode = VOIDmode;
2865
2866 /* Skip this parm if it will not be passed on the stack. */
2867 if (! args[i].pass_on_stack
2868 && args[i].reg != 0
2869 && args[i].partial == 0)
2870 continue;
2871
2872 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2873 continue;
2874
2875 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2876 addr = plus_constant (Pmode, addr, arg_offset);
2877
2878 if (args[i].partial != 0)
2879 {
2880 /* Only part of the parameter is being passed on the stack.
2881 Generate a simple memory reference of the correct size. */
2882 units_on_stack = args[i].locate.size.constant;
2883 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2884 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2885 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2886 set_mem_size (args[i].stack, units_on_stack);
2887 }
2888 else
2889 {
2890 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2891 set_mem_attributes (args[i].stack,
2892 TREE_TYPE (args[i].tree_value), 1);
2893 }
2894 align = BITS_PER_UNIT;
2895 boundary = args[i].locate.boundary;
2896 poly_int64 offset_val;
2897 if (args[i].locate.where_pad != PAD_DOWNWARD)
2898 align = boundary;
2899 else if (poly_int_rtx_p (offset, &offset_val))
2900 {
2901 align = least_bit_hwi (boundary);
2902 unsigned int offset_align
2903 = known_alignment (offset_val) * BITS_PER_UNIT;
2904 if (offset_align != 0)
2905 align = MIN (align, offset_align);
2906 }
2907 set_mem_align (args[i].stack, align);
2908
2909 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2910 addr = plus_constant (Pmode, addr, arg_offset);
2911
2912 if (args[i].partial != 0)
2913 {
2914 /* Only part of the parameter is being passed on the stack.
2915 Generate a simple memory reference of the correct size.
2916 */
2917 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2918 set_mem_size (args[i].stack_slot, units_on_stack);
2919 }
2920 else
2921 {
2922 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2923 set_mem_attributes (args[i].stack_slot,
2924 TREE_TYPE (args[i].tree_value), 1);
2925 }
2926 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2927
2928 /* Function incoming arguments may overlap with sibling call
2929 outgoing arguments and we cannot allow reordering of reads
2930 from function arguments with stores to outgoing arguments
2931 of sibling calls. */
2932 set_mem_alias_set (args[i].stack, 0);
2933 set_mem_alias_set (args[i].stack_slot, 0);
2934 }
2935 }
2936 }
2937
2938 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2939 in a call instruction.
2940
2941 FNDECL is the tree node for the target function. For an indirect call
2942 FNDECL will be NULL_TREE.
2943
2944 ADDR is the operand 0 of CALL_EXPR for this call. */
2945
2946 static rtx
2947 rtx_for_function_call (tree fndecl, tree addr)
2948 {
2949 rtx funexp;
2950
2951 /* Get the function to call, in the form of RTL. */
2952 if (fndecl)
2953 {
2954 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2955 TREE_USED (fndecl) = 1;
2956
2957 /* Get a SYMBOL_REF rtx for the function address. */
2958 funexp = XEXP (DECL_RTL (fndecl), 0);
2959 }
2960 else
2961 /* Generate an rtx (probably a pseudo-register) for the address. */
2962 {
2963 push_temp_slots ();
2964 funexp = expand_normal (addr);
2965 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2966 }
2967 return funexp;
2968 }
2969
2970 /* Return the static chain for this function, if any. */
2971
2972 rtx
2973 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2974 {
2975 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2976 return NULL;
2977
2978 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2979 }
2980
2981 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2982 static struct
2983 {
2984 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2985 or NULL_RTX if none has been scanned yet. */
2986 rtx_insn *scan_start;
2987 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2988 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2989 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2990 with fixed offset, or PC if this is with variable or unknown offset. */
2991 vec<rtx> cache;
2992 } internal_arg_pointer_exp_state;
2993
2994 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2995
2996 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2997 the tail call sequence, starting with first insn that hasn't been
2998 scanned yet, and note for each pseudo on the LHS whether it is based
2999 on crtl->args.internal_arg_pointer or not, and what offset from that
3000 that pointer it has. */
3001
3002 static void
3003 internal_arg_pointer_based_exp_scan (void)
3004 {
3005 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
3006
3007 if (scan_start == NULL_RTX)
3008 insn = get_insns ();
3009 else
3010 insn = NEXT_INSN (scan_start);
3011
3012 while (insn)
3013 {
3014 rtx set = single_set (insn);
3015 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
3016 {
3017 rtx val = NULL_RTX;
3018 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
3019 /* Punt on pseudos set multiple times. */
3020 if (idx < internal_arg_pointer_exp_state.cache.length ()
3021 && (internal_arg_pointer_exp_state.cache[idx]
3022 != NULL_RTX))
3023 val = pc_rtx;
3024 else
3025 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
3026 if (val != NULL_RTX)
3027 {
3028 if (idx >= internal_arg_pointer_exp_state.cache.length ())
3029 internal_arg_pointer_exp_state.cache
3030 .safe_grow_cleared (idx + 1, true);
3031 internal_arg_pointer_exp_state.cache[idx] = val;
3032 }
3033 }
3034 if (NEXT_INSN (insn) == NULL_RTX)
3035 scan_start = insn;
3036 insn = NEXT_INSN (insn);
3037 }
3038
3039 internal_arg_pointer_exp_state.scan_start = scan_start;
3040 }
3041
3042 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
3043 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
3044 it with fixed offset, or PC if this is with variable or unknown offset.
3045 TOPLEVEL is true if the function is invoked at the topmost level. */
3046
3047 static rtx
3048 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
3049 {
3050 if (CONSTANT_P (rtl))
3051 return NULL_RTX;
3052
3053 if (rtl == crtl->args.internal_arg_pointer)
3054 return const0_rtx;
3055
3056 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
3057 return NULL_RTX;
3058
3059 poly_int64 offset;
3060 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
3061 {
3062 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
3063 if (val == NULL_RTX || val == pc_rtx)
3064 return val;
3065 return plus_constant (Pmode, val, offset);
3066 }
3067
3068 /* When called at the topmost level, scan pseudo assignments in between the
3069 last scanned instruction in the tail call sequence and the latest insn
3070 in that sequence. */
3071 if (toplevel)
3072 internal_arg_pointer_based_exp_scan ();
3073
3074 if (REG_P (rtl))
3075 {
3076 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
3077 if (idx < internal_arg_pointer_exp_state.cache.length ())
3078 return internal_arg_pointer_exp_state.cache[idx];
3079
3080 return NULL_RTX;
3081 }
3082
3083 subrtx_iterator::array_type array;
3084 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
3085 {
3086 const_rtx x = *iter;
3087 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
3088 return pc_rtx;
3089 if (MEM_P (x))
3090 iter.skip_subrtxes ();
3091 }
3092
3093 return NULL_RTX;
3094 }
3095
3096 /* Return true if SIZE bytes starting from address ADDR might overlap an
3097 already-clobbered argument area. This function is used to determine
3098 if we should give up a sibcall. */
3099
3100 static bool
3101 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
3102 {
3103 poly_int64 i;
3104 unsigned HOST_WIDE_INT start, end;
3105 rtx val;
3106
3107 if (bitmap_empty_p (stored_args_map)
3108 && stored_args_watermark == HOST_WIDE_INT_M1U)
3109 return false;
3110 val = internal_arg_pointer_based_exp (addr, true);
3111 if (val == NULL_RTX)
3112 return false;
3113 else if (!poly_int_rtx_p (val, &i))
3114 return true;
3115
3116 if (known_eq (size, 0U))
3117 return false;
3118
3119 if (STACK_GROWS_DOWNWARD)
3120 i -= crtl->args.pretend_args_size;
3121 else
3122 i += crtl->args.pretend_args_size;
3123
3124 if (ARGS_GROW_DOWNWARD)
3125 i = -i - size;
3126
3127 /* We can ignore any references to the function's pretend args,
3128 which at this point would manifest as negative values of I. */
3129 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
3130 return false;
3131
3132 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
3133 if (!(i + size).is_constant (&end))
3134 end = HOST_WIDE_INT_M1U;
3135
3136 if (end > stored_args_watermark)
3137 return true;
3138
3139 end = MIN (end, SBITMAP_SIZE (stored_args_map));
3140 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
3141 if (bitmap_bit_p (stored_args_map, k))
3142 return true;
3143
3144 return false;
3145 }
3146
3147 /* Do the register loads required for any wholly-register parms or any
3148 parms which are passed both on the stack and in a register. Their
3149 expressions were already evaluated.
3150
3151 Mark all register-parms as living through the call, putting these USE
3152 insns in the CALL_INSN_FUNCTION_USAGE field.
3153
3154 When IS_SIBCALL, perform the check_sibcall_argument_overlap
3155 checking, setting *SIBCALL_FAILURE if appropriate. */
3156
3157 static void
3158 load_register_parameters (struct arg_data *args, int num_actuals,
3159 rtx *call_fusage, int flags, int is_sibcall,
3160 int *sibcall_failure)
3161 {
3162 int i, j;
3163
3164 for (i = 0; i < num_actuals; i++)
3165 {
3166 rtx reg = ((flags & ECF_SIBCALL)
3167 ? args[i].tail_call_reg : args[i].reg);
3168 if (reg)
3169 {
3170 int partial = args[i].partial;
3171 int nregs;
3172 poly_int64 size = 0;
3173 HOST_WIDE_INT const_size = 0;
3174 rtx_insn *before_arg = get_last_insn ();
3175 tree type = TREE_TYPE (args[i].tree_value);
3176 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
3177 type = TREE_TYPE (first_field (type));
3178 /* Set non-negative if we must move a word at a time, even if
3179 just one word (e.g, partial == 4 && mode == DFmode). Set
3180 to -1 if we just use a normal move insn. This value can be
3181 zero if the argument is a zero size structure. */
3182 nregs = -1;
3183 if (GET_CODE (reg) == PARALLEL)
3184 ;
3185 else if (partial)
3186 {
3187 gcc_assert (partial % UNITS_PER_WORD == 0);
3188 nregs = partial / UNITS_PER_WORD;
3189 }
3190 else if (TYPE_MODE (type) == BLKmode)
3191 {
3192 /* Variable-sized parameters should be described by a
3193 PARALLEL instead. */
3194 const_size = int_size_in_bytes (type);
3195 gcc_assert (const_size >= 0);
3196 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
3197 size = const_size;
3198 }
3199 else
3200 size = GET_MODE_SIZE (args[i].mode);
3201
3202 /* Handle calls that pass values in multiple non-contiguous
3203 locations. The Irix 6 ABI has examples of this. */
3204
3205 if (GET_CODE (reg) == PARALLEL)
3206 emit_group_move (reg, args[i].parallel_value);
3207
3208 /* If simple case, just do move. If normal partial, store_one_arg
3209 has already loaded the register for us. In all other cases,
3210 load the register(s) from memory. */
3211
3212 else if (nregs == -1)
3213 {
3214 emit_move_insn (reg, args[i].value);
3215 #ifdef BLOCK_REG_PADDING
3216 /* Handle case where we have a value that needs shifting
3217 up to the msb. eg. a QImode value and we're padding
3218 upward on a BYTES_BIG_ENDIAN machine. */
3219 if (args[i].locate.where_pad
3220 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
3221 {
3222 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
3223 if (maybe_lt (size, UNITS_PER_WORD))
3224 {
3225 rtx x;
3226 poly_int64 shift
3227 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
3228
3229 /* Assigning REG here rather than a temp makes
3230 CALL_FUSAGE report the whole reg as used.
3231 Strictly speaking, the call only uses SIZE
3232 bytes at the msb end, but it doesn't seem worth
3233 generating rtl to say that. */
3234 reg = gen_rtx_REG (word_mode, REGNO (reg));
3235 x = expand_shift (LSHIFT_EXPR, word_mode,
3236 reg, shift, reg, 1);
3237 if (x != reg)
3238 emit_move_insn (reg, x);
3239 }
3240 }
3241 #endif
3242 }
3243
3244 /* If we have pre-computed the values to put in the registers in
3245 the case of non-aligned structures, copy them in now. */
3246
3247 else if (args[i].n_aligned_regs != 0)
3248 for (j = 0; j < args[i].n_aligned_regs; j++)
3249 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
3250 args[i].aligned_regs[j]);
3251
3252 else if (partial == 0 || args[i].pass_on_stack)
3253 {
3254 /* SIZE and CONST_SIZE are 0 for partial arguments and
3255 the size of a BLKmode type otherwise. */
3256 gcc_checking_assert (known_eq (size, const_size));
3257 rtx mem = validize_mem (copy_rtx (args[i].value));
3258
3259 /* Check for overlap with already clobbered argument area,
3260 providing that this has non-zero size. */
3261 if (is_sibcall
3262 && const_size != 0
3263 && (mem_might_overlap_already_clobbered_arg_p
3264 (XEXP (args[i].value, 0), const_size)))
3265 *sibcall_failure = 1;
3266
3267 if (const_size % UNITS_PER_WORD == 0
3268 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
3269 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
3270 else
3271 {
3272 if (nregs > 1)
3273 move_block_to_reg (REGNO (reg), mem, nregs - 1,
3274 args[i].mode);
3275 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
3276 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
3277 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
3278 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
3279 word_mode, word_mode, false,
3280 NULL);
3281 if (BYTES_BIG_ENDIAN)
3282 x = expand_shift (LSHIFT_EXPR, word_mode, x,
3283 BITS_PER_WORD - bitsize, dest, 1);
3284 if (x != dest)
3285 emit_move_insn (dest, x);
3286 }
3287
3288 /* Handle a BLKmode that needs shifting. */
3289 if (nregs == 1 && const_size < UNITS_PER_WORD
3290 #ifdef BLOCK_REG_PADDING
3291 && args[i].locate.where_pad == PAD_DOWNWARD
3292 #else
3293 && BYTES_BIG_ENDIAN
3294 #endif
3295 )
3296 {
3297 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
3298 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
3299 enum tree_code dir = (BYTES_BIG_ENDIAN
3300 ? RSHIFT_EXPR : LSHIFT_EXPR);
3301 rtx x;
3302
3303 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
3304 if (x != dest)
3305 emit_move_insn (dest, x);
3306 }
3307 }
3308
3309 /* When a parameter is a block, and perhaps in other cases, it is
3310 possible that it did a load from an argument slot that was
3311 already clobbered. */
3312 if (is_sibcall
3313 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
3314 *sibcall_failure = 1;
3315
3316 /* Handle calls that pass values in multiple non-contiguous
3317 locations. The Irix 6 ABI has examples of this. */
3318 if (GET_CODE (reg) == PARALLEL)
3319 use_group_regs (call_fusage, reg);
3320 else if (nregs == -1)
3321 use_reg_mode (call_fusage, reg, TYPE_MODE (type));
3322 else if (nregs > 0)
3323 use_regs (call_fusage, REGNO (reg), nregs);
3324 }
3325 }
3326 }
3327
3328 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
3329 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
3330 bytes, then we would need to push some additional bytes to pad the
3331 arguments. So, we try to compute an adjust to the stack pointer for an
3332 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
3333 bytes. Then, when the arguments are pushed the stack will be perfectly
3334 aligned.
3335
3336 Return true if this optimization is possible, storing the adjustment
3337 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
3338 bytes that should be popped after the call. */
3339
3340 static bool
3341 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
3342 poly_int64 unadjusted_args_size,
3343 struct args_size *args_size,
3344 unsigned int preferred_unit_stack_boundary)
3345 {
3346 /* The number of bytes to pop so that the stack will be
3347 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
3348 poly_int64 adjustment;
3349 /* The alignment of the stack after the arguments are pushed, if we
3350 just pushed the arguments without adjust the stack here. */
3351 unsigned HOST_WIDE_INT unadjusted_alignment;
3352
3353 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
3354 preferred_unit_stack_boundary,
3355 &unadjusted_alignment))
3356 return false;
3357
3358 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
3359 as possible -- leaving just enough left to cancel out the
3360 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
3361 PENDING_STACK_ADJUST is non-negative, and congruent to
3362 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
3363
3364 /* Begin by trying to pop all the bytes. */
3365 unsigned HOST_WIDE_INT tmp_misalignment;
3366 if (!known_misalignment (pending_stack_adjust,
3367 preferred_unit_stack_boundary,
3368 &tmp_misalignment))
3369 return false;
3370 unadjusted_alignment -= tmp_misalignment;
3371 adjustment = pending_stack_adjust;
3372 /* Push enough additional bytes that the stack will be aligned
3373 after the arguments are pushed. */
3374 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
3375 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
3376
3377 /* We need to know whether the adjusted argument size
3378 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
3379 or a deallocation. */
3380 if (!ordered_p (adjustment, unadjusted_args_size))
3381 return false;
3382
3383 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
3384 bytes after the call. The right number is the entire
3385 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
3386 by the arguments in the first place. */
3387 args_size->constant
3388 = pending_stack_adjust - adjustment + unadjusted_args_size;
3389
3390 *adjustment_out = adjustment;
3391 return true;
3392 }
3393
3394 /* Scan X expression if it does not dereference any argument slots
3395 we already clobbered by tail call arguments (as noted in stored_args_map
3396 bitmap).
3397 Return nonzero if X expression dereferences such argument slots,
3398 zero otherwise. */
3399
3400 static int
3401 check_sibcall_argument_overlap_1 (rtx x)
3402 {
3403 RTX_CODE code;
3404 int i, j;
3405 const char *fmt;
3406
3407 if (x == NULL_RTX)
3408 return 0;
3409
3410 code = GET_CODE (x);
3411
3412 /* We need not check the operands of the CALL expression itself. */
3413 if (code == CALL)
3414 return 0;
3415
3416 if (code == MEM)
3417 return (mem_might_overlap_already_clobbered_arg_p
3418 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
3419
3420 /* Scan all subexpressions. */
3421 fmt = GET_RTX_FORMAT (code);
3422 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3423 {
3424 if (*fmt == 'e')
3425 {
3426 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
3427 return 1;
3428 }
3429 else if (*fmt == 'E')
3430 {
3431 for (j = 0; j < XVECLEN (x, i); j++)
3432 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
3433 return 1;
3434 }
3435 }
3436 return 0;
3437 }
3438
3439 /* Scan sequence after INSN if it does not dereference any argument slots
3440 we already clobbered by tail call arguments (as noted in stored_args_map
3441 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3442 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3443 should be 0). Return nonzero if sequence after INSN dereferences such argument
3444 slots, zero otherwise. */
3445
3446 static int
3447 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3448 int mark_stored_args_map)
3449 {
3450 poly_uint64 low, high;
3451 unsigned HOST_WIDE_INT const_low, const_high;
3452
3453 if (insn == NULL_RTX)
3454 insn = get_insns ();
3455 else
3456 insn = NEXT_INSN (insn);
3457
3458 for (; insn; insn = NEXT_INSN (insn))
3459 if (INSN_P (insn)
3460 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3461 break;
3462
3463 if (mark_stored_args_map)
3464 {
3465 if (ARGS_GROW_DOWNWARD)
3466 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3467 else
3468 low = arg->locate.slot_offset.constant;
3469 high = low + arg->locate.size.constant;
3470
3471 const_low = constant_lower_bound (low);
3472 if (high.is_constant (&const_high))
3473 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3474 bitmap_set_bit (stored_args_map, i);
3475 else
3476 stored_args_watermark = MIN (stored_args_watermark, const_low);
3477 }
3478 return insn != NULL_RTX;
3479 }
3480
3481 /* Given that a function returns a value of mode MODE at the most
3482 significant end of hard register VALUE, shift VALUE left or right
3483 as specified by LEFT_P. Return true if some action was needed. */
3484
3485 bool
3486 shift_return_value (machine_mode mode, bool left_p, rtx value)
3487 {
3488 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3489 machine_mode value_mode = GET_MODE (value);
3490 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3491
3492 if (known_eq (shift, 0))
3493 return false;
3494
3495 /* Use ashr rather than lshr for right shifts. This is for the benefit
3496 of the MIPS port, which requires SImode values to be sign-extended
3497 when stored in 64-bit registers. */
3498 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3499 value, gen_int_shift_amount (value_mode, shift),
3500 value, 1, OPTAB_WIDEN))
3501 gcc_unreachable ();
3502 return true;
3503 }
3504
3505 /* If X is a likely-spilled register value, copy it to a pseudo
3506 register and return that register. Return X otherwise. */
3507
3508 static rtx
3509 avoid_likely_spilled_reg (rtx x)
3510 {
3511 rtx new_rtx;
3512
3513 if (REG_P (x)
3514 && HARD_REGISTER_P (x)
3515 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3516 {
3517 /* Make sure that we generate a REG rather than a CONCAT.
3518 Moves into CONCATs can need nontrivial instructions,
3519 and the whole point of this function is to avoid
3520 using the hard register directly in such a situation. */
3521 generating_concat_p = 0;
3522 new_rtx = gen_reg_rtx (GET_MODE (x));
3523 generating_concat_p = 1;
3524 emit_move_insn (new_rtx, x);
3525 return new_rtx;
3526 }
3527 return x;
3528 }
3529
3530 /* Helper function for expand_call.
3531 Return false is EXP is not implementable as a sibling call. */
3532
3533 static bool
3534 can_implement_as_sibling_call_p (tree exp,
3535 rtx structure_value_addr,
3536 tree funtype,
3537 tree fndecl,
3538 int flags,
3539 tree addr,
3540 const args_size &args_size)
3541 {
3542 if (!targetm.have_sibcall_epilogue ())
3543 {
3544 maybe_complain_about_tail_call
3545 (exp,
3546 "machine description does not have"
3547 " a sibcall_epilogue instruction pattern");
3548 return false;
3549 }
3550
3551 /* Doing sibling call optimization needs some work, since
3552 structure_value_addr can be allocated on the stack.
3553 It does not seem worth the effort since few optimizable
3554 sibling calls will return a structure. */
3555 if (structure_value_addr != NULL_RTX)
3556 {
3557 maybe_complain_about_tail_call (exp, "callee returns a structure");
3558 return false;
3559 }
3560
3561 /* Check whether the target is able to optimize the call
3562 into a sibcall. */
3563 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3564 {
3565 maybe_complain_about_tail_call (exp,
3566 "target is not able to optimize the"
3567 " call into a sibling call");
3568 return false;
3569 }
3570
3571 /* Functions that do not return exactly once may not be sibcall
3572 optimized. */
3573 if (flags & ECF_RETURNS_TWICE)
3574 {
3575 maybe_complain_about_tail_call (exp, "callee returns twice");
3576 return false;
3577 }
3578 if (flags & ECF_NORETURN)
3579 {
3580 maybe_complain_about_tail_call (exp, "callee does not return");
3581 return false;
3582 }
3583
3584 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3585 {
3586 maybe_complain_about_tail_call (exp, "volatile function type");
3587 return false;
3588 }
3589
3590 /* If the called function is nested in the current one, it might access
3591 some of the caller's arguments, but could clobber them beforehand if
3592 the argument areas are shared. */
3593 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3594 {
3595 maybe_complain_about_tail_call (exp, "nested function");
3596 return false;
3597 }
3598
3599 /* If this function requires more stack slots than the current
3600 function, we cannot change it into a sibling call.
3601 crtl->args.pretend_args_size is not part of the
3602 stack allocated by our caller. */
3603 if (maybe_gt (args_size.constant,
3604 crtl->args.size - crtl->args.pretend_args_size))
3605 {
3606 maybe_complain_about_tail_call (exp,
3607 "callee required more stack slots"
3608 " than the caller");
3609 return false;
3610 }
3611
3612 /* If the callee pops its own arguments, then it must pop exactly
3613 the same number of arguments as the current function. */
3614 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3615 args_size.constant),
3616 targetm.calls.return_pops_args (current_function_decl,
3617 TREE_TYPE
3618 (current_function_decl),
3619 crtl->args.size)))
3620 {
3621 maybe_complain_about_tail_call (exp,
3622 "inconsistent number of"
3623 " popped arguments");
3624 return false;
3625 }
3626
3627 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3628 {
3629 maybe_complain_about_tail_call (exp, "frontend does not support"
3630 " sibling call");
3631 return false;
3632 }
3633
3634 /* All checks passed. */
3635 return true;
3636 }
3637
3638 /* Update stack alignment when the parameter is passed in the stack
3639 since the outgoing parameter requires extra alignment on the calling
3640 function side. */
3641
3642 static void
3643 update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
3644 {
3645 if (crtl->stack_alignment_needed < locate->boundary)
3646 crtl->stack_alignment_needed = locate->boundary;
3647 if (crtl->preferred_stack_boundary < locate->boundary)
3648 crtl->preferred_stack_boundary = locate->boundary;
3649 }
3650
3651 /* Generate all the code for a CALL_EXPR exp
3652 and return an rtx for its value.
3653 Store the value in TARGET (specified as an rtx) if convenient.
3654 If the value is stored in TARGET then TARGET is returned.
3655 If IGNORE is nonzero, then we ignore the value of the function call. */
3656
3657 rtx
3658 expand_call (tree exp, rtx target, int ignore)
3659 {
3660 /* Nonzero if we are currently expanding a call. */
3661 static int currently_expanding_call = 0;
3662
3663 /* RTX for the function to be called. */
3664 rtx funexp;
3665 /* Sequence of insns to perform a normal "call". */
3666 rtx_insn *normal_call_insns = NULL;
3667 /* Sequence of insns to perform a tail "call". */
3668 rtx_insn *tail_call_insns = NULL;
3669 /* Data type of the function. */
3670 tree funtype;
3671 tree type_arg_types;
3672 tree rettype;
3673 /* Declaration of the function being called,
3674 or 0 if the function is computed (not known by name). */
3675 tree fndecl = 0;
3676 /* The type of the function being called. */
3677 tree fntype;
3678 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3679 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3680 int pass;
3681
3682 /* Register in which non-BLKmode value will be returned,
3683 or 0 if no value or if value is BLKmode. */
3684 rtx valreg;
3685 /* Address where we should return a BLKmode value;
3686 0 if value not BLKmode. */
3687 rtx structure_value_addr = 0;
3688 /* Nonzero if that address is being passed by treating it as
3689 an extra, implicit first parameter. Otherwise,
3690 it is passed by being copied directly into struct_value_rtx. */
3691 int structure_value_addr_parm = 0;
3692 /* Holds the value of implicit argument for the struct value. */
3693 tree structure_value_addr_value = NULL_TREE;
3694 /* Size of aggregate value wanted, or zero if none wanted
3695 or if we are using the non-reentrant PCC calling convention
3696 or expecting the value in registers. */
3697 poly_int64 struct_value_size = 0;
3698 /* Nonzero if called function returns an aggregate in memory PCC style,
3699 by returning the address of where to find it. */
3700 int pcc_struct_value = 0;
3701 rtx struct_value = 0;
3702
3703 /* Number of actual parameters in this call, including struct value addr. */
3704 int num_actuals;
3705 /* Number of named args. Args after this are anonymous ones
3706 and they must all go on the stack. */
3707 int n_named_args;
3708 /* Number of complex actual arguments that need to be split. */
3709 int num_complex_actuals = 0;
3710
3711 /* Vector of information about each argument.
3712 Arguments are numbered in the order they will be pushed,
3713 not the order they are written. */
3714 struct arg_data *args;
3715
3716 /* Total size in bytes of all the stack-parms scanned so far. */
3717 struct args_size args_size;
3718 struct args_size adjusted_args_size;
3719 /* Size of arguments before any adjustments (such as rounding). */
3720 poly_int64 unadjusted_args_size;
3721 /* Data on reg parms scanned so far. */
3722 CUMULATIVE_ARGS args_so_far_v;
3723 cumulative_args_t args_so_far;
3724 /* Nonzero if a reg parm has been scanned. */
3725 int reg_parm_seen;
3726 /* Nonzero if this is an indirect function call. */
3727
3728 /* Nonzero if we must avoid push-insns in the args for this call.
3729 If stack space is allocated for register parameters, but not by the
3730 caller, then it is preallocated in the fixed part of the stack frame.
3731 So the entire argument block must then be preallocated (i.e., we
3732 ignore PUSH_ROUNDING in that case). */
3733
3734 int must_preallocate = !targetm.calls.push_argument (0);
3735
3736 /* Size of the stack reserved for parameter registers. */
3737 int reg_parm_stack_space = 0;
3738
3739 /* Address of space preallocated for stack parms
3740 (on machines that lack push insns), or 0 if space not preallocated. */
3741 rtx argblock = 0;
3742
3743 /* Mask of ECF_ and ERF_ flags. */
3744 int flags = 0;
3745 int return_flags = 0;
3746 #ifdef REG_PARM_STACK_SPACE
3747 /* Define the boundary of the register parm stack space that needs to be
3748 saved, if any. */
3749 int low_to_save, high_to_save;
3750 rtx save_area = 0; /* Place that it is saved */
3751 #endif
3752
3753 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3754 char *initial_stack_usage_map = stack_usage_map;
3755 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3756 char *stack_usage_map_buf = NULL;
3757
3758 poly_int64 old_stack_allocated;
3759
3760 /* State variables to track stack modifications. */
3761 rtx old_stack_level = 0;
3762 int old_stack_arg_under_construction = 0;
3763 poly_int64 old_pending_adj = 0;
3764 int old_inhibit_defer_pop = inhibit_defer_pop;
3765
3766 /* Some stack pointer alterations we make are performed via
3767 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3768 which we then also need to save/restore along the way. */
3769 poly_int64 old_stack_pointer_delta = 0;
3770
3771 rtx call_fusage;
3772 tree addr = CALL_EXPR_FN (exp);
3773 int i;
3774 /* The alignment of the stack, in bits. */
3775 unsigned HOST_WIDE_INT preferred_stack_boundary;
3776 /* The alignment of the stack, in bytes. */
3777 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3778 /* The static chain value to use for this call. */
3779 rtx static_chain_value;
3780 /* See if this is "nothrow" function call. */
3781 if (TREE_NOTHROW (exp))
3782 flags |= ECF_NOTHROW;
3783
3784 /* See if we can find a DECL-node for the actual function, and get the
3785 function attributes (flags) from the function decl or type node. */
3786 fndecl = get_callee_fndecl (exp);
3787 if (fndecl)
3788 {
3789 fntype = TREE_TYPE (fndecl);
3790 flags |= flags_from_decl_or_type (fndecl);
3791 return_flags |= decl_return_flags (fndecl);
3792 }
3793 else
3794 {
3795 fntype = TREE_TYPE (TREE_TYPE (addr));
3796 flags |= flags_from_decl_or_type (fntype);
3797 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3798 flags |= ECF_BY_DESCRIPTOR;
3799 }
3800 rettype = TREE_TYPE (exp);
3801
3802 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3803
3804 /* Warn if this value is an aggregate type,
3805 regardless of which calling convention we are using for it. */
3806 if (AGGREGATE_TYPE_P (rettype))
3807 warning (OPT_Waggregate_return, "function call has aggregate value");
3808
3809 /* If the result of a non looping pure or const function call is
3810 ignored (or void), and none of its arguments are volatile, we can
3811 avoid expanding the call and just evaluate the arguments for
3812 side-effects. */
3813 if ((flags & (ECF_CONST | ECF_PURE))
3814 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3815 && (flags & ECF_NOTHROW)
3816 && (ignore || target == const0_rtx
3817 || TYPE_MODE (rettype) == VOIDmode))
3818 {
3819 bool volatilep = false;
3820 tree arg;
3821 call_expr_arg_iterator iter;
3822
3823 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3824 if (TREE_THIS_VOLATILE (arg))
3825 {
3826 volatilep = true;
3827 break;
3828 }
3829
3830 if (! volatilep)
3831 {
3832 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3833 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3834 return const0_rtx;
3835 }
3836 }
3837
3838 #ifdef REG_PARM_STACK_SPACE
3839 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3840 #endif
3841
3842 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3843 && reg_parm_stack_space > 0 && targetm.calls.push_argument (0))
3844 must_preallocate = 1;
3845
3846 /* Set up a place to return a structure. */
3847
3848 /* Cater to broken compilers. */
3849 if (aggregate_value_p (exp, fntype))
3850 {
3851 /* This call returns a big structure. */
3852 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3853
3854 #ifdef PCC_STATIC_STRUCT_RETURN
3855 {
3856 pcc_struct_value = 1;
3857 }
3858 #else /* not PCC_STATIC_STRUCT_RETURN */
3859 {
3860 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3861 struct_value_size = -1;
3862
3863 /* Even if it is semantically safe to use the target as the return
3864 slot, it may be not sufficiently aligned for the return type. */
3865 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3866 && target
3867 && MEM_P (target)
3868 /* If rettype is addressable, we may not create a temporary.
3869 If target is properly aligned at runtime and the compiler
3870 just doesn't know about it, it will work fine, otherwise it
3871 will be UB. */
3872 && (TREE_ADDRESSABLE (rettype)
3873 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3874 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3875 MEM_ALIGN (target)))))
3876 structure_value_addr = XEXP (target, 0);
3877 else
3878 {
3879 /* For variable-sized objects, we must be called with a target
3880 specified. If we were to allocate space on the stack here,
3881 we would have no way of knowing when to free it. */
3882 rtx d = assign_temp (rettype, 1, 1);
3883 structure_value_addr = XEXP (d, 0);
3884 target = 0;
3885 }
3886 }
3887 #endif /* not PCC_STATIC_STRUCT_RETURN */
3888 }
3889
3890 /* Figure out the amount to which the stack should be aligned. */
3891 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3892 if (fndecl)
3893 {
3894 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3895 /* Without automatic stack alignment, we can't increase preferred
3896 stack boundary. With automatic stack alignment, it is
3897 unnecessary since unless we can guarantee that all callers will
3898 align the outgoing stack properly, callee has to align its
3899 stack anyway. */
3900 if (i
3901 && i->preferred_incoming_stack_boundary
3902 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3903 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3904 }
3905
3906 /* Operand 0 is a pointer-to-function; get the type of the function. */
3907 funtype = TREE_TYPE (addr);
3908 gcc_assert (POINTER_TYPE_P (funtype));
3909 funtype = TREE_TYPE (funtype);
3910
3911 /* Count whether there are actual complex arguments that need to be split
3912 into their real and imaginary parts. Munge the type_arg_types
3913 appropriately here as well. */
3914 if (targetm.calls.split_complex_arg)
3915 {
3916 call_expr_arg_iterator iter;
3917 tree arg;
3918 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3919 {
3920 tree type = TREE_TYPE (arg);
3921 if (type && TREE_CODE (type) == COMPLEX_TYPE
3922 && targetm.calls.split_complex_arg (type))
3923 num_complex_actuals++;
3924 }
3925 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3926 }
3927 else
3928 type_arg_types = TYPE_ARG_TYPES (funtype);
3929
3930 if (flags & ECF_MAY_BE_ALLOCA)
3931 cfun->calls_alloca = 1;
3932
3933 /* If struct_value_rtx is 0, it means pass the address
3934 as if it were an extra parameter. Put the argument expression
3935 in structure_value_addr_value. */
3936 if (structure_value_addr && struct_value == 0)
3937 {
3938 /* If structure_value_addr is a REG other than
3939 virtual_outgoing_args_rtx, we can use always use it. If it
3940 is not a REG, we must always copy it into a register.
3941 If it is virtual_outgoing_args_rtx, we must copy it to another
3942 register in some cases. */
3943 rtx temp = (!REG_P (structure_value_addr)
3944 || (ACCUMULATE_OUTGOING_ARGS
3945 && stack_arg_under_construction
3946 && structure_value_addr == virtual_outgoing_args_rtx)
3947 ? copy_addr_to_reg (convert_memory_address
3948 (Pmode, structure_value_addr))
3949 : structure_value_addr);
3950
3951 structure_value_addr_value =
3952 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3953 structure_value_addr_parm = 1;
3954 }
3955
3956 /* Count the arguments and set NUM_ACTUALS. */
3957 num_actuals =
3958 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3959
3960 /* Compute number of named args.
3961 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3962
3963 if (type_arg_types != 0)
3964 n_named_args
3965 = (list_length (type_arg_types)
3966 /* Count the struct value address, if it is passed as a parm. */
3967 + structure_value_addr_parm);
3968 else
3969 /* If we know nothing, treat all args as named. */
3970 n_named_args = num_actuals;
3971
3972 /* Start updating where the next arg would go.
3973
3974 On some machines (such as the PA) indirect calls have a different
3975 calling convention than normal calls. The fourth argument in
3976 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3977 or not. */
3978 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3979 args_so_far = pack_cumulative_args (&args_so_far_v);
3980
3981 /* Now possibly adjust the number of named args.
3982 Normally, don't include the last named arg if anonymous args follow.
3983 We do include the last named arg if
3984 targetm.calls.strict_argument_naming() returns nonzero.
3985 (If no anonymous args follow, the result of list_length is actually
3986 one too large. This is harmless.)
3987
3988 If targetm.calls.pretend_outgoing_varargs_named() returns
3989 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3990 this machine will be able to place unnamed args that were passed
3991 in registers into the stack. So treat all args as named. This
3992 allows the insns emitting for a specific argument list to be
3993 independent of the function declaration.
3994
3995 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3996 we do not have any reliable way to pass unnamed args in
3997 registers, so we must force them into memory. */
3998
3999 if (type_arg_types != 0
4000 && targetm.calls.strict_argument_naming (args_so_far))
4001 ;
4002 else if (type_arg_types != 0
4003 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
4004 /* Don't include the last named arg. */
4005 --n_named_args;
4006 else
4007 /* Treat all args as named. */
4008 n_named_args = num_actuals;
4009
4010 /* Make a vector to hold all the information about each arg. */
4011 args = XCNEWVEC (struct arg_data, num_actuals);
4012
4013 /* Build up entries in the ARGS array, compute the size of the
4014 arguments into ARGS_SIZE, etc. */
4015 initialize_argument_information (num_actuals, args, &args_size,
4016 n_named_args, exp,
4017 structure_value_addr_value, fndecl, fntype,
4018 args_so_far, reg_parm_stack_space,
4019 &old_stack_level, &old_pending_adj,
4020 &must_preallocate, &flags,
4021 &try_tail_call, CALL_FROM_THUNK_P (exp));
4022
4023 if (args_size.var)
4024 must_preallocate = 1;
4025
4026 /* Now make final decision about preallocating stack space. */
4027 must_preallocate = finalize_must_preallocate (must_preallocate,
4028 num_actuals, args,
4029 &args_size);
4030
4031 /* If the structure value address will reference the stack pointer, we
4032 must stabilize it. We don't need to do this if we know that we are
4033 not going to adjust the stack pointer in processing this call. */
4034
4035 if (structure_value_addr
4036 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
4037 || reg_mentioned_p (virtual_outgoing_args_rtx,
4038 structure_value_addr))
4039 && (args_size.var
4040 || (!ACCUMULATE_OUTGOING_ARGS
4041 && maybe_ne (args_size.constant, 0))))
4042 structure_value_addr = copy_to_reg (structure_value_addr);
4043
4044 /* Tail calls can make things harder to debug, and we've traditionally
4045 pushed these optimizations into -O2. Don't try if we're already
4046 expanding a call, as that means we're an argument. Don't try if
4047 there's cleanups, as we know there's code to follow the call. */
4048 if (currently_expanding_call++ != 0
4049 || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp))
4050 || args_size.var
4051 || dbg_cnt (tail_call) == false)
4052 try_tail_call = 0;
4053
4054 /* Workaround buggy C/C++ wrappers around Fortran routines with
4055 character(len=constant) arguments if the hidden string length arguments
4056 are passed on the stack; if the callers forget to pass those arguments,
4057 attempting to tail call in such routines leads to stack corruption.
4058 Avoid tail calls in functions where at least one such hidden string
4059 length argument is passed (partially or fully) on the stack in the
4060 caller and the callee needs to pass any arguments on the stack.
4061 See PR90329. */
4062 if (try_tail_call && maybe_ne (args_size.constant, 0))
4063 for (tree arg = DECL_ARGUMENTS (current_function_decl);
4064 arg; arg = DECL_CHAIN (arg))
4065 if (DECL_HIDDEN_STRING_LENGTH (arg) && DECL_INCOMING_RTL (arg))
4066 {
4067 subrtx_iterator::array_type array;
4068 FOR_EACH_SUBRTX (iter, array, DECL_INCOMING_RTL (arg), NONCONST)
4069 if (MEM_P (*iter))
4070 {
4071 try_tail_call = 0;
4072 break;
4073 }
4074 }
4075
4076 /* If the user has marked the function as requiring tail-call
4077 optimization, attempt it. */
4078 if (must_tail_call)
4079 try_tail_call = 1;
4080
4081 /* Rest of purposes for tail call optimizations to fail. */
4082 if (try_tail_call)
4083 try_tail_call = can_implement_as_sibling_call_p (exp,
4084 structure_value_addr,
4085 funtype,
4086 fndecl,
4087 flags, addr, args_size);
4088
4089 /* Check if caller and callee disagree in promotion of function
4090 return value. */
4091 if (try_tail_call)
4092 {
4093 machine_mode caller_mode, caller_promoted_mode;
4094 machine_mode callee_mode, callee_promoted_mode;
4095 int caller_unsignedp, callee_unsignedp;
4096 tree caller_res = DECL_RESULT (current_function_decl);
4097
4098 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
4099 caller_mode = DECL_MODE (caller_res);
4100 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
4101 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
4102 caller_promoted_mode
4103 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
4104 &caller_unsignedp,
4105 TREE_TYPE (current_function_decl), 1);
4106 callee_promoted_mode
4107 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
4108 &callee_unsignedp,
4109 funtype, 1);
4110 if (caller_mode != VOIDmode
4111 && (caller_promoted_mode != callee_promoted_mode
4112 || ((caller_mode != caller_promoted_mode
4113 || callee_mode != callee_promoted_mode)
4114 && (caller_unsignedp != callee_unsignedp
4115 || partial_subreg_p (caller_mode, callee_mode)))))
4116 {
4117 try_tail_call = 0;
4118 maybe_complain_about_tail_call (exp,
4119 "caller and callee disagree in"
4120 " promotion of function"
4121 " return value");
4122 }
4123 }
4124
4125 /* Ensure current function's preferred stack boundary is at least
4126 what we need. Stack alignment may also increase preferred stack
4127 boundary. */
4128 for (i = 0; i < num_actuals; i++)
4129 if (reg_parm_stack_space > 0
4130 || args[i].reg == 0
4131 || args[i].partial != 0
4132 || args[i].pass_on_stack)
4133 update_stack_alignment_for_call (&args[i].locate);
4134 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
4135 crtl->preferred_stack_boundary = preferred_stack_boundary;
4136 else
4137 preferred_stack_boundary = crtl->preferred_stack_boundary;
4138
4139 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
4140
4141 if (flag_callgraph_info)
4142 record_final_call (fndecl, EXPR_LOCATION (exp));
4143
4144 /* We want to make two insn chains; one for a sibling call, the other
4145 for a normal call. We will select one of the two chains after
4146 initial RTL generation is complete. */
4147 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
4148 {
4149 int sibcall_failure = 0;
4150 /* We want to emit any pending stack adjustments before the tail
4151 recursion "call". That way we know any adjustment after the tail
4152 recursion call can be ignored if we indeed use the tail
4153 call expansion. */
4154 saved_pending_stack_adjust save;
4155 rtx_insn *insns, *before_call, *after_args;
4156 rtx next_arg_reg;
4157
4158 if (pass == 0)
4159 {
4160 /* State variables we need to save and restore between
4161 iterations. */
4162 save_pending_stack_adjust (&save);
4163 }
4164 if (pass)
4165 flags &= ~ECF_SIBCALL;
4166 else
4167 flags |= ECF_SIBCALL;
4168
4169 /* Other state variables that we must reinitialize each time
4170 through the loop (that are not initialized by the loop itself). */
4171 argblock = 0;
4172 call_fusage = 0;
4173
4174 /* Start a new sequence for the normal call case.
4175
4176 From this point on, if the sibling call fails, we want to set
4177 sibcall_failure instead of continuing the loop. */
4178 start_sequence ();
4179
4180 /* Don't let pending stack adjusts add up to too much.
4181 Also, do all pending adjustments now if there is any chance
4182 this might be a call to alloca or if we are expanding a sibling
4183 call sequence.
4184 Also do the adjustments before a throwing call, otherwise
4185 exception handling can fail; PR 19225. */
4186 if (maybe_ge (pending_stack_adjust, 32)
4187 || (maybe_ne (pending_stack_adjust, 0)
4188 && (flags & ECF_MAY_BE_ALLOCA))
4189 || (maybe_ne (pending_stack_adjust, 0)
4190 && flag_exceptions && !(flags & ECF_NOTHROW))
4191 || pass == 0)
4192 do_pending_stack_adjust ();
4193
4194 /* Precompute any arguments as needed. */
4195 if (pass)
4196 precompute_arguments (num_actuals, args);
4197
4198 /* Now we are about to start emitting insns that can be deleted
4199 if a libcall is deleted. */
4200 if (pass && (flags & ECF_MALLOC))
4201 start_sequence ();
4202
4203 if (pass == 0
4204 && crtl->stack_protect_guard
4205 && targetm.stack_protect_runtime_enabled_p ())
4206 stack_protect_epilogue ();
4207
4208 adjusted_args_size = args_size;
4209 /* Compute the actual size of the argument block required. The variable
4210 and constant sizes must be combined, the size may have to be rounded,
4211 and there may be a minimum required size. When generating a sibcall
4212 pattern, do not round up, since we'll be re-using whatever space our
4213 caller provided. */
4214 unadjusted_args_size
4215 = compute_argument_block_size (reg_parm_stack_space,
4216 &adjusted_args_size,
4217 fndecl, fntype,
4218 (pass == 0 ? 0
4219 : preferred_stack_boundary));
4220
4221 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4222
4223 /* The argument block when performing a sibling call is the
4224 incoming argument block. */
4225 if (pass == 0)
4226 {
4227 argblock = crtl->args.internal_arg_pointer;
4228 if (STACK_GROWS_DOWNWARD)
4229 argblock
4230 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
4231 else
4232 argblock
4233 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
4234
4235 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
4236 stored_args_map = sbitmap_alloc (map_size);
4237 bitmap_clear (stored_args_map);
4238 stored_args_watermark = HOST_WIDE_INT_M1U;
4239 }
4240
4241 /* If we have no actual push instructions, or shouldn't use them,
4242 make space for all args right now. */
4243 else if (adjusted_args_size.var != 0)
4244 {
4245 if (old_stack_level == 0)
4246 {
4247 emit_stack_save (SAVE_BLOCK, &old_stack_level);
4248 old_stack_pointer_delta = stack_pointer_delta;
4249 old_pending_adj = pending_stack_adjust;
4250 pending_stack_adjust = 0;
4251 /* stack_arg_under_construction says whether a stack arg is
4252 being constructed at the old stack level. Pushing the stack
4253 gets a clean outgoing argument block. */
4254 old_stack_arg_under_construction = stack_arg_under_construction;
4255 stack_arg_under_construction = 0;
4256 }
4257 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
4258 if (flag_stack_usage_info)
4259 current_function_has_unbounded_dynamic_stack_size = 1;
4260 }
4261 else
4262 {
4263 /* Note that we must go through the motions of allocating an argument
4264 block even if the size is zero because we may be storing args
4265 in the area reserved for register arguments, which may be part of
4266 the stack frame. */
4267
4268 poly_int64 needed = adjusted_args_size.constant;
4269
4270 /* Store the maximum argument space used. It will be pushed by
4271 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
4272 checking). */
4273
4274 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
4275 needed);
4276
4277 if (must_preallocate)
4278 {
4279 if (ACCUMULATE_OUTGOING_ARGS)
4280 {
4281 /* Since the stack pointer will never be pushed, it is
4282 possible for the evaluation of a parm to clobber
4283 something we have already written to the stack.
4284 Since most function calls on RISC machines do not use
4285 the stack, this is uncommon, but must work correctly.
4286
4287 Therefore, we save any area of the stack that was already
4288 written and that we are using. Here we set up to do this
4289 by making a new stack usage map from the old one. The
4290 actual save will be done by store_one_arg.
4291
4292 Another approach might be to try to reorder the argument
4293 evaluations to avoid this conflicting stack usage. */
4294
4295 /* Since we will be writing into the entire argument area,
4296 the map must be allocated for its entire size, not just
4297 the part that is the responsibility of the caller. */
4298 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4299 needed += reg_parm_stack_space;
4300
4301 poly_int64 limit = needed;
4302 if (ARGS_GROW_DOWNWARD)
4303 limit += 1;
4304
4305 /* For polynomial sizes, this is the maximum possible
4306 size needed for arguments with a constant size
4307 and offset. */
4308 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
4309 highest_outgoing_arg_in_use
4310 = MAX (initial_highest_arg_in_use, const_limit);
4311
4312 free (stack_usage_map_buf);
4313 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
4314 stack_usage_map = stack_usage_map_buf;
4315
4316 if (initial_highest_arg_in_use)
4317 memcpy (stack_usage_map, initial_stack_usage_map,
4318 initial_highest_arg_in_use);
4319
4320 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
4321 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
4322 (highest_outgoing_arg_in_use
4323 - initial_highest_arg_in_use));
4324 needed = 0;
4325
4326 /* The address of the outgoing argument list must not be
4327 copied to a register here, because argblock would be left
4328 pointing to the wrong place after the call to
4329 allocate_dynamic_stack_space below. */
4330
4331 argblock = virtual_outgoing_args_rtx;
4332 }
4333 else
4334 {
4335 /* Try to reuse some or all of the pending_stack_adjust
4336 to get this space. */
4337 if (inhibit_defer_pop == 0
4338 && (combine_pending_stack_adjustment_and_call
4339 (&needed,
4340 unadjusted_args_size,
4341 &adjusted_args_size,
4342 preferred_unit_stack_boundary)))
4343 {
4344 /* combine_pending_stack_adjustment_and_call computes
4345 an adjustment before the arguments are allocated.
4346 Account for them and see whether or not the stack
4347 needs to go up or down. */
4348 needed = unadjusted_args_size - needed;
4349
4350 /* Checked by
4351 combine_pending_stack_adjustment_and_call. */
4352 gcc_checking_assert (ordered_p (needed, 0));
4353 if (maybe_lt (needed, 0))
4354 {
4355 /* We're releasing stack space. */
4356 /* ??? We can avoid any adjustment at all if we're
4357 already aligned. FIXME. */
4358 pending_stack_adjust = -needed;
4359 do_pending_stack_adjust ();
4360 needed = 0;
4361 }
4362 else
4363 /* We need to allocate space. We'll do that in
4364 push_block below. */
4365 pending_stack_adjust = 0;
4366 }
4367
4368 /* Special case this because overhead of `push_block' in
4369 this case is non-trivial. */
4370 if (known_eq (needed, 0))
4371 argblock = virtual_outgoing_args_rtx;
4372 else
4373 {
4374 rtx needed_rtx = gen_int_mode (needed, Pmode);
4375 argblock = push_block (needed_rtx, 0, 0);
4376 if (ARGS_GROW_DOWNWARD)
4377 argblock = plus_constant (Pmode, argblock, needed);
4378 }
4379
4380 /* We only really need to call `copy_to_reg' in the case
4381 where push insns are going to be used to pass ARGBLOCK
4382 to a function call in ARGS. In that case, the stack
4383 pointer changes value from the allocation point to the
4384 call point, and hence the value of
4385 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
4386 as well always do it. */
4387 argblock = copy_to_reg (argblock);
4388 }
4389 }
4390 }
4391
4392 if (ACCUMULATE_OUTGOING_ARGS)
4393 {
4394 /* The save/restore code in store_one_arg handles all
4395 cases except one: a constructor call (including a C
4396 function returning a BLKmode struct) to initialize
4397 an argument. */
4398 if (stack_arg_under_construction)
4399 {
4400 rtx push_size
4401 = (gen_int_mode
4402 (adjusted_args_size.constant
4403 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
4404 : TREE_TYPE (fndecl))
4405 ? 0 : reg_parm_stack_space), Pmode));
4406 if (old_stack_level == 0)
4407 {
4408 emit_stack_save (SAVE_BLOCK, &old_stack_level);
4409 old_stack_pointer_delta = stack_pointer_delta;
4410 old_pending_adj = pending_stack_adjust;
4411 pending_stack_adjust = 0;
4412 /* stack_arg_under_construction says whether a stack
4413 arg is being constructed at the old stack level.
4414 Pushing the stack gets a clean outgoing argument
4415 block. */
4416 old_stack_arg_under_construction
4417 = stack_arg_under_construction;
4418 stack_arg_under_construction = 0;
4419 /* Make a new map for the new argument list. */
4420 free (stack_usage_map_buf);
4421 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
4422 stack_usage_map = stack_usage_map_buf;
4423 highest_outgoing_arg_in_use = 0;
4424 stack_usage_watermark = HOST_WIDE_INT_M1U;
4425 }
4426 /* We can pass TRUE as the 4th argument because we just
4427 saved the stack pointer and will restore it right after
4428 the call. */
4429 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
4430 -1, true);
4431 }
4432
4433 /* If argument evaluation might modify the stack pointer,
4434 copy the address of the argument list to a register. */
4435 for (i = 0; i < num_actuals; i++)
4436 if (args[i].pass_on_stack)
4437 {
4438 argblock = copy_addr_to_reg (argblock);
4439 break;
4440 }
4441 }
4442
4443 compute_argument_addresses (args, argblock, num_actuals);
4444
4445 /* Stack is properly aligned, pops can't safely be deferred during
4446 the evaluation of the arguments. */
4447 NO_DEFER_POP;
4448
4449 /* Precompute all register parameters. It isn't safe to compute
4450 anything once we have started filling any specific hard regs.
4451 TLS symbols sometimes need a call to resolve. Precompute
4452 register parameters before any stack pointer manipulation
4453 to avoid unaligned stack in the called function. */
4454 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
4455
4456 OK_DEFER_POP;
4457
4458 /* Perform stack alignment before the first push (the last arg). */
4459 if (argblock == 0
4460 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
4461 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
4462 {
4463 /* When the stack adjustment is pending, we get better code
4464 by combining the adjustments. */
4465 if (maybe_ne (pending_stack_adjust, 0)
4466 && ! inhibit_defer_pop
4467 && (combine_pending_stack_adjustment_and_call
4468 (&pending_stack_adjust,
4469 unadjusted_args_size,
4470 &adjusted_args_size,
4471 preferred_unit_stack_boundary)))
4472 do_pending_stack_adjust ();
4473 else if (argblock == 0)
4474 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4475 - unadjusted_args_size,
4476 Pmode));
4477 }
4478 /* Now that the stack is properly aligned, pops can't safely
4479 be deferred during the evaluation of the arguments. */
4480 NO_DEFER_POP;
4481
4482 /* Record the maximum pushed stack space size. We need to delay
4483 doing it this far to take into account the optimization done
4484 by combine_pending_stack_adjustment_and_call. */
4485 if (flag_stack_usage_info
4486 && !ACCUMULATE_OUTGOING_ARGS
4487 && pass
4488 && adjusted_args_size.var == 0)
4489 {
4490 poly_int64 pushed = (adjusted_args_size.constant
4491 + pending_stack_adjust);
4492 current_function_pushed_stack_size
4493 = upper_bound (current_function_pushed_stack_size, pushed);
4494 }
4495
4496 funexp = rtx_for_function_call (fndecl, addr);
4497
4498 if (CALL_EXPR_STATIC_CHAIN (exp))
4499 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4500 else
4501 static_chain_value = 0;
4502
4503 #ifdef REG_PARM_STACK_SPACE
4504 /* Save the fixed argument area if it's part of the caller's frame and
4505 is clobbered by argument setup for this call. */
4506 if (ACCUMULATE_OUTGOING_ARGS && pass)
4507 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4508 &low_to_save, &high_to_save);
4509 #endif
4510
4511 /* Now store (and compute if necessary) all non-register parms.
4512 These come before register parms, since they can require block-moves,
4513 which could clobber the registers used for register parms.
4514 Parms which have partial registers are not stored here,
4515 but we do preallocate space here if they want that. */
4516
4517 for (i = 0; i < num_actuals; i++)
4518 {
4519 if (args[i].reg == 0 || args[i].pass_on_stack)
4520 {
4521 rtx_insn *before_arg = get_last_insn ();
4522
4523 /* We don't allow passing huge (> 2^30 B) arguments
4524 by value. It would cause an overflow later on. */
4525 if (constant_lower_bound (adjusted_args_size.constant)
4526 >= (1 << (HOST_BITS_PER_INT - 2)))
4527 {
4528 sorry ("passing too large argument on stack");
4529 continue;
4530 }
4531
4532 if (store_one_arg (&args[i], argblock, flags,
4533 adjusted_args_size.var != 0,
4534 reg_parm_stack_space)
4535 || (pass == 0
4536 && check_sibcall_argument_overlap (before_arg,
4537 &args[i], 1)))
4538 sibcall_failure = 1;
4539 }
4540
4541 if (args[i].stack)
4542 call_fusage
4543 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4544 gen_rtx_USE (VOIDmode, args[i].stack),
4545 call_fusage);
4546 }
4547
4548 /* If we have a parm that is passed in registers but not in memory
4549 and whose alignment does not permit a direct copy into registers,
4550 make a group of pseudos that correspond to each register that we
4551 will later fill. */
4552 if (STRICT_ALIGNMENT)
4553 store_unaligned_arguments_into_pseudos (args, num_actuals);
4554
4555 /* Now store any partially-in-registers parm.
4556 This is the last place a block-move can happen. */
4557 if (reg_parm_seen)
4558 for (i = 0; i < num_actuals; i++)
4559 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4560 {
4561 rtx_insn *before_arg = get_last_insn ();
4562
4563 /* On targets with weird calling conventions (e.g. PA) it's
4564 hard to ensure that all cases of argument overlap between
4565 stack and registers work. Play it safe and bail out. */
4566 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4567 {
4568 sibcall_failure = 1;
4569 break;
4570 }
4571
4572 if (store_one_arg (&args[i], argblock, flags,
4573 adjusted_args_size.var != 0,
4574 reg_parm_stack_space)
4575 || (pass == 0
4576 && check_sibcall_argument_overlap (before_arg,
4577 &args[i], 1)))
4578 sibcall_failure = 1;
4579 }
4580
4581 bool any_regs = false;
4582 for (i = 0; i < num_actuals; i++)
4583 if (args[i].reg != NULL_RTX)
4584 {
4585 any_regs = true;
4586 targetm.calls.call_args (args[i].reg, funtype);
4587 }
4588 if (!any_regs)
4589 targetm.calls.call_args (pc_rtx, funtype);
4590
4591 /* Figure out the register where the value, if any, will come back. */
4592 valreg = 0;
4593 if (TYPE_MODE (rettype) != VOIDmode
4594 && ! structure_value_addr)
4595 {
4596 if (pcc_struct_value)
4597 valreg = hard_function_value (build_pointer_type (rettype),
4598 fndecl, NULL, (pass == 0));
4599 else
4600 valreg = hard_function_value (rettype, fndecl, fntype,
4601 (pass == 0));
4602
4603 /* If VALREG is a PARALLEL whose first member has a zero
4604 offset, use that. This is for targets such as m68k that
4605 return the same value in multiple places. */
4606 if (GET_CODE (valreg) == PARALLEL)
4607 {
4608 rtx elem = XVECEXP (valreg, 0, 0);
4609 rtx where = XEXP (elem, 0);
4610 rtx offset = XEXP (elem, 1);
4611 if (offset == const0_rtx
4612 && GET_MODE (where) == GET_MODE (valreg))
4613 valreg = where;
4614 }
4615 }
4616
4617 /* If register arguments require space on the stack and stack space
4618 was not preallocated, allocate stack space here for arguments
4619 passed in registers. */
4620 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4621 && !ACCUMULATE_OUTGOING_ARGS
4622 && must_preallocate == 0 && reg_parm_stack_space > 0)
4623 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4624
4625 /* Pass the function the address in which to return a
4626 structure value. */
4627 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4628 {
4629 structure_value_addr
4630 = convert_memory_address (Pmode, structure_value_addr);
4631 emit_move_insn (struct_value,
4632 force_reg (Pmode,
4633 force_operand (structure_value_addr,
4634 NULL_RTX)));
4635
4636 if (REG_P (struct_value))
4637 use_reg (&call_fusage, struct_value);
4638 }
4639
4640 after_args = get_last_insn ();
4641 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4642 static_chain_value, &call_fusage,
4643 reg_parm_seen, flags);
4644
4645 load_register_parameters (args, num_actuals, &call_fusage, flags,
4646 pass == 0, &sibcall_failure);
4647
4648 /* Save a pointer to the last insn before the call, so that we can
4649 later safely search backwards to find the CALL_INSN. */
4650 before_call = get_last_insn ();
4651
4652 /* Set up next argument register. For sibling calls on machines
4653 with register windows this should be the incoming register. */
4654 if (pass == 0)
4655 next_arg_reg = targetm.calls.function_incoming_arg
4656 (args_so_far, function_arg_info::end_marker ());
4657 else
4658 next_arg_reg = targetm.calls.function_arg
4659 (args_so_far, function_arg_info::end_marker ());
4660
4661 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4662 {
4663 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4664 arg_nr = num_actuals - arg_nr - 1;
4665 if (arg_nr >= 0
4666 && arg_nr < num_actuals
4667 && args[arg_nr].reg
4668 && valreg
4669 && REG_P (valreg)
4670 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4671 call_fusage
4672 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4673 gen_rtx_SET (valreg, args[arg_nr].reg),
4674 call_fusage);
4675 }
4676 /* All arguments and registers used for the call must be set up by
4677 now! */
4678
4679 /* Stack must be properly aligned now. */
4680 gcc_assert (!pass
4681 || multiple_p (stack_pointer_delta,
4682 preferred_unit_stack_boundary));
4683
4684 /* Generate the actual call instruction. */
4685 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4686 adjusted_args_size.constant, struct_value_size,
4687 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4688 flags, args_so_far);
4689
4690 if (flag_ipa_ra)
4691 {
4692 rtx_call_insn *last;
4693 rtx datum = NULL_RTX;
4694 if (fndecl != NULL_TREE)
4695 {
4696 datum = XEXP (DECL_RTL (fndecl), 0);
4697 gcc_assert (datum != NULL_RTX
4698 && GET_CODE (datum) == SYMBOL_REF);
4699 }
4700 last = last_call_insn ();
4701 add_reg_note (last, REG_CALL_DECL, datum);
4702 }
4703
4704 /* If the call setup or the call itself overlaps with anything
4705 of the argument setup we probably clobbered our call address.
4706 In that case we can't do sibcalls. */
4707 if (pass == 0
4708 && check_sibcall_argument_overlap (after_args, 0, 0))
4709 sibcall_failure = 1;
4710
4711 /* If a non-BLKmode value is returned at the most significant end
4712 of a register, shift the register right by the appropriate amount
4713 and update VALREG accordingly. BLKmode values are handled by the
4714 group load/store machinery below. */
4715 if (!structure_value_addr
4716 && !pcc_struct_value
4717 && TYPE_MODE (rettype) != VOIDmode
4718 && TYPE_MODE (rettype) != BLKmode
4719 && REG_P (valreg)
4720 && targetm.calls.return_in_msb (rettype))
4721 {
4722 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4723 sibcall_failure = 1;
4724 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4725 }
4726
4727 if (pass && (flags & ECF_MALLOC))
4728 {
4729 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4730 rtx_insn *last, *insns;
4731
4732 /* The return value from a malloc-like function is a pointer. */
4733 if (TREE_CODE (rettype) == POINTER_TYPE)
4734 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4735
4736 emit_move_insn (temp, valreg);
4737
4738 /* The return value from a malloc-like function cannot alias
4739 anything else. */
4740 last = get_last_insn ();
4741 add_reg_note (last, REG_NOALIAS, temp);
4742
4743 /* Write out the sequence. */
4744 insns = get_insns ();
4745 end_sequence ();
4746 emit_insn (insns);
4747 valreg = temp;
4748 }
4749
4750 /* For calls to `setjmp', etc., inform
4751 function.c:setjmp_warnings that it should complain if
4752 nonvolatile values are live. For functions that cannot
4753 return, inform flow that control does not fall through. */
4754
4755 if ((flags & ECF_NORETURN) || pass == 0)
4756 {
4757 /* The barrier must be emitted
4758 immediately after the CALL_INSN. Some ports emit more
4759 than just a CALL_INSN above, so we must search for it here. */
4760
4761 rtx_insn *last = get_last_insn ();
4762 while (!CALL_P (last))
4763 {
4764 last = PREV_INSN (last);
4765 /* There was no CALL_INSN? */
4766 gcc_assert (last != before_call);
4767 }
4768
4769 emit_barrier_after (last);
4770
4771 /* Stack adjustments after a noreturn call are dead code.
4772 However when NO_DEFER_POP is in effect, we must preserve
4773 stack_pointer_delta. */
4774 if (inhibit_defer_pop == 0)
4775 {
4776 stack_pointer_delta = old_stack_allocated;
4777 pending_stack_adjust = 0;
4778 }
4779 }
4780
4781 /* If value type not void, return an rtx for the value. */
4782
4783 if (TYPE_MODE (rettype) == VOIDmode
4784 || ignore)
4785 target = const0_rtx;
4786 else if (structure_value_addr)
4787 {
4788 if (target == 0 || !MEM_P (target))
4789 {
4790 target
4791 = gen_rtx_MEM (TYPE_MODE (rettype),
4792 memory_address (TYPE_MODE (rettype),
4793 structure_value_addr));
4794 set_mem_attributes (target, rettype, 1);
4795 }
4796 }
4797 else if (pcc_struct_value)
4798 {
4799 /* This is the special C++ case where we need to
4800 know what the true target was. We take care to
4801 never use this value more than once in one expression. */
4802 target = gen_rtx_MEM (TYPE_MODE (rettype),
4803 copy_to_reg (valreg));
4804 set_mem_attributes (target, rettype, 1);
4805 }
4806 /* Handle calls that return values in multiple non-contiguous locations.
4807 The Irix 6 ABI has examples of this. */
4808 else if (GET_CODE (valreg) == PARALLEL)
4809 {
4810 if (target == 0)
4811 target = emit_group_move_into_temps (valreg);
4812 else if (rtx_equal_p (target, valreg))
4813 ;
4814 else if (GET_CODE (target) == PARALLEL)
4815 /* Handle the result of a emit_group_move_into_temps
4816 call in the previous pass. */
4817 emit_group_move (target, valreg);
4818 else
4819 emit_group_store (target, valreg, rettype,
4820 int_size_in_bytes (rettype));
4821 }
4822 else if (target
4823 && GET_MODE (target) == TYPE_MODE (rettype)
4824 && GET_MODE (target) == GET_MODE (valreg))
4825 {
4826 bool may_overlap = false;
4827
4828 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4829 reg to a plain register. */
4830 if (!REG_P (target) || HARD_REGISTER_P (target))
4831 valreg = avoid_likely_spilled_reg (valreg);
4832
4833 /* If TARGET is a MEM in the argument area, and we have
4834 saved part of the argument area, then we can't store
4835 directly into TARGET as it may get overwritten when we
4836 restore the argument save area below. Don't work too
4837 hard though and simply force TARGET to a register if it
4838 is a MEM; the optimizer is quite likely to sort it out. */
4839 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4840 for (i = 0; i < num_actuals; i++)
4841 if (args[i].save_area)
4842 {
4843 may_overlap = true;
4844 break;
4845 }
4846
4847 if (may_overlap)
4848 target = copy_to_reg (valreg);
4849 else
4850 {
4851 /* TARGET and VALREG cannot be equal at this point
4852 because the latter would not have
4853 REG_FUNCTION_VALUE_P true, while the former would if
4854 it were referring to the same register.
4855
4856 If they refer to the same register, this move will be
4857 a no-op, except when function inlining is being
4858 done. */
4859 emit_move_insn (target, valreg);
4860
4861 /* If we are setting a MEM, this code must be executed.
4862 Since it is emitted after the call insn, sibcall
4863 optimization cannot be performed in that case. */
4864 if (MEM_P (target))
4865 sibcall_failure = 1;
4866 }
4867 }
4868 else
4869 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4870
4871 /* If we promoted this return value, make the proper SUBREG.
4872 TARGET might be const0_rtx here, so be careful. */
4873 if (REG_P (target)
4874 && TYPE_MODE (rettype) != BLKmode
4875 && GET_MODE (target) != TYPE_MODE (rettype))
4876 {
4877 tree type = rettype;
4878 int unsignedp = TYPE_UNSIGNED (type);
4879 machine_mode pmode;
4880
4881 /* Ensure we promote as expected, and get the new unsignedness. */
4882 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4883 funtype, 1);
4884 gcc_assert (GET_MODE (target) == pmode);
4885
4886 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4887 GET_MODE (target));
4888 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4889 SUBREG_PROMOTED_VAR_P (target) = 1;
4890 SUBREG_PROMOTED_SET (target, unsignedp);
4891 }
4892
4893 /* If size of args is variable or this was a constructor call for a stack
4894 argument, restore saved stack-pointer value. */
4895
4896 if (old_stack_level)
4897 {
4898 rtx_insn *prev = get_last_insn ();
4899
4900 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4901 stack_pointer_delta = old_stack_pointer_delta;
4902
4903 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4904
4905 pending_stack_adjust = old_pending_adj;
4906 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4907 stack_arg_under_construction = old_stack_arg_under_construction;
4908 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4909 stack_usage_map = initial_stack_usage_map;
4910 stack_usage_watermark = initial_stack_usage_watermark;
4911 sibcall_failure = 1;
4912 }
4913 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4914 {
4915 #ifdef REG_PARM_STACK_SPACE
4916 if (save_area)
4917 restore_fixed_argument_area (save_area, argblock,
4918 high_to_save, low_to_save);
4919 #endif
4920
4921 /* If we saved any argument areas, restore them. */
4922 for (i = 0; i < num_actuals; i++)
4923 if (args[i].save_area)
4924 {
4925 machine_mode save_mode = GET_MODE (args[i].save_area);
4926 rtx stack_area
4927 = gen_rtx_MEM (save_mode,
4928 memory_address (save_mode,
4929 XEXP (args[i].stack_slot, 0)));
4930
4931 if (save_mode != BLKmode)
4932 emit_move_insn (stack_area, args[i].save_area);
4933 else
4934 emit_block_move (stack_area, args[i].save_area,
4935 (gen_int_mode
4936 (args[i].locate.size.constant, Pmode)),
4937 BLOCK_OP_CALL_PARM);
4938 }
4939
4940 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4941 stack_usage_map = initial_stack_usage_map;
4942 stack_usage_watermark = initial_stack_usage_watermark;
4943 }
4944
4945 /* If this was alloca, record the new stack level. */
4946 if (flags & ECF_MAY_BE_ALLOCA)
4947 record_new_stack_level ();
4948
4949 /* Free up storage we no longer need. */
4950 for (i = 0; i < num_actuals; ++i)
4951 free (args[i].aligned_regs);
4952
4953 targetm.calls.end_call_args ();
4954
4955 insns = get_insns ();
4956 end_sequence ();
4957
4958 if (pass == 0)
4959 {
4960 tail_call_insns = insns;
4961
4962 /* Restore the pending stack adjustment now that we have
4963 finished generating the sibling call sequence. */
4964
4965 restore_pending_stack_adjust (&save);
4966
4967 /* Prepare arg structure for next iteration. */
4968 for (i = 0; i < num_actuals; i++)
4969 {
4970 args[i].value = 0;
4971 args[i].aligned_regs = 0;
4972 args[i].stack = 0;
4973 }
4974
4975 sbitmap_free (stored_args_map);
4976 internal_arg_pointer_exp_state.scan_start = NULL;
4977 internal_arg_pointer_exp_state.cache.release ();
4978 }
4979 else
4980 {
4981 normal_call_insns = insns;
4982
4983 /* Verify that we've deallocated all the stack we used. */
4984 gcc_assert ((flags & ECF_NORETURN)
4985 || known_eq (old_stack_allocated,
4986 stack_pointer_delta
4987 - pending_stack_adjust));
4988 }
4989
4990 /* If something prevents making this a sibling call,
4991 zero out the sequence. */
4992 if (sibcall_failure)
4993 tail_call_insns = NULL;
4994 else
4995 break;
4996 }
4997
4998 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4999 arguments too, as argument area is now clobbered by the call. */
5000 if (tail_call_insns)
5001 {
5002 emit_insn (tail_call_insns);
5003 crtl->tail_call_emit = true;
5004 }
5005 else
5006 {
5007 emit_insn (normal_call_insns);
5008 if (try_tail_call)
5009 /* Ideally we'd emit a message for all of the ways that it could
5010 have failed. */
5011 maybe_complain_about_tail_call (exp, "tail call production failed");
5012 }
5013
5014 currently_expanding_call--;
5015
5016 free (stack_usage_map_buf);
5017 free (args);
5018 return target;
5019 }
5020
5021 /* A sibling call sequence invalidates any REG_EQUIV notes made for
5022 this function's incoming arguments.
5023
5024 At the start of RTL generation we know the only REG_EQUIV notes
5025 in the rtl chain are those for incoming arguments, so we can look
5026 for REG_EQUIV notes between the start of the function and the
5027 NOTE_INSN_FUNCTION_BEG.
5028
5029 This is (slight) overkill. We could keep track of the highest
5030 argument we clobber and be more selective in removing notes, but it
5031 does not seem to be worth the effort. */
5032
5033 void
5034 fixup_tail_calls (void)
5035 {
5036 rtx_insn *insn;
5037
5038 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
5039 {
5040 rtx note;
5041
5042 /* There are never REG_EQUIV notes for the incoming arguments
5043 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
5044 if (NOTE_P (insn)
5045 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
5046 break;
5047
5048 note = find_reg_note (insn, REG_EQUIV, 0);
5049 if (note)
5050 remove_note (insn, note);
5051 note = find_reg_note (insn, REG_EQUIV, 0);
5052 gcc_assert (!note);
5053 }
5054 }
5055
5056 /* Traverse a list of TYPES and expand all complex types into their
5057 components. */
5058 static tree
5059 split_complex_types (tree types)
5060 {
5061 tree p;
5062
5063 /* Before allocating memory, check for the common case of no complex. */
5064 for (p = types; p; p = TREE_CHAIN (p))
5065 {
5066 tree type = TREE_VALUE (p);
5067 if (TREE_CODE (type) == COMPLEX_TYPE
5068 && targetm.calls.split_complex_arg (type))
5069 goto found;
5070 }
5071 return types;
5072
5073 found:
5074 types = copy_list (types);
5075
5076 for (p = types; p; p = TREE_CHAIN (p))
5077 {
5078 tree complex_type = TREE_VALUE (p);
5079
5080 if (TREE_CODE (complex_type) == COMPLEX_TYPE
5081 && targetm.calls.split_complex_arg (complex_type))
5082 {
5083 tree next, imag;
5084
5085 /* Rewrite complex type with component type. */
5086 TREE_VALUE (p) = TREE_TYPE (complex_type);
5087 next = TREE_CHAIN (p);
5088
5089 /* Add another component type for the imaginary part. */
5090 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
5091 TREE_CHAIN (p) = imag;
5092 TREE_CHAIN (imag) = next;
5093
5094 /* Skip the newly created node. */
5095 p = TREE_CHAIN (p);
5096 }
5097 }
5098
5099 return types;
5100 }
5101 \f
5102 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
5103 for a value of mode OUTMODE,
5104 with NARGS different arguments, passed as ARGS.
5105 Store the return value if RETVAL is nonzero: store it in VALUE if
5106 VALUE is nonnull, otherwise pick a convenient location. In either
5107 case return the location of the stored value.
5108
5109 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
5110 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
5111 other types of library calls. */
5112
5113 rtx
5114 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
5115 enum libcall_type fn_type,
5116 machine_mode outmode, int nargs, rtx_mode_t *args)
5117 {
5118 /* Total size in bytes of all the stack-parms scanned so far. */
5119 struct args_size args_size;
5120 /* Size of arguments before any adjustments (such as rounding). */
5121 struct args_size original_args_size;
5122 int argnum;
5123 rtx fun;
5124 /* Todo, choose the correct decl type of orgfun. Sadly this information
5125 isn't present here, so we default to native calling abi here. */
5126 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
5127 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
5128 int count;
5129 rtx argblock = 0;
5130 CUMULATIVE_ARGS args_so_far_v;
5131 cumulative_args_t args_so_far;
5132 struct arg
5133 {
5134 rtx value;
5135 machine_mode mode;
5136 rtx reg;
5137 int partial;
5138 struct locate_and_pad_arg_data locate;
5139 rtx save_area;
5140 };
5141 struct arg *argvec;
5142 int old_inhibit_defer_pop = inhibit_defer_pop;
5143 rtx call_fusage = 0;
5144 rtx mem_value = 0;
5145 rtx valreg;
5146 int pcc_struct_value = 0;
5147 poly_int64 struct_value_size = 0;
5148 int flags;
5149 int reg_parm_stack_space = 0;
5150 poly_int64 needed;
5151 rtx_insn *before_call;
5152 bool have_push_fusage;
5153 tree tfom; /* type_for_mode (outmode, 0) */
5154
5155 #ifdef REG_PARM_STACK_SPACE
5156 /* Define the boundary of the register parm stack space that needs to be
5157 save, if any. */
5158 int low_to_save = 0, high_to_save = 0;
5159 rtx save_area = 0; /* Place that it is saved. */
5160 #endif
5161
5162 /* Size of the stack reserved for parameter registers. */
5163 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
5164 char *initial_stack_usage_map = stack_usage_map;
5165 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
5166 char *stack_usage_map_buf = NULL;
5167
5168 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
5169
5170 #ifdef REG_PARM_STACK_SPACE
5171 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
5172 #endif
5173
5174 /* By default, library functions cannot throw. */
5175 flags = ECF_NOTHROW;
5176
5177 switch (fn_type)
5178 {
5179 case LCT_NORMAL:
5180 break;
5181 case LCT_CONST:
5182 flags |= ECF_CONST;
5183 break;
5184 case LCT_PURE:
5185 flags |= ECF_PURE;
5186 break;
5187 case LCT_NORETURN:
5188 flags |= ECF_NORETURN;
5189 break;
5190 case LCT_THROW:
5191 flags &= ~ECF_NOTHROW;
5192 break;
5193 case LCT_RETURNS_TWICE:
5194 flags = ECF_RETURNS_TWICE;
5195 break;
5196 }
5197 fun = orgfun;
5198
5199 /* Ensure current function's preferred stack boundary is at least
5200 what we need. */
5201 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
5202 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
5203
5204 /* If this kind of value comes back in memory,
5205 decide where in memory it should come back. */
5206 if (outmode != VOIDmode)
5207 {
5208 tfom = lang_hooks.types.type_for_mode (outmode, 0);
5209 if (aggregate_value_p (tfom, 0))
5210 {
5211 #ifdef PCC_STATIC_STRUCT_RETURN
5212 rtx pointer_reg
5213 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
5214 mem_value = gen_rtx_MEM (outmode, pointer_reg);
5215 pcc_struct_value = 1;
5216 if (value == 0)
5217 value = gen_reg_rtx (outmode);
5218 #else /* not PCC_STATIC_STRUCT_RETURN */
5219 struct_value_size = GET_MODE_SIZE (outmode);
5220 if (value != 0 && MEM_P (value))
5221 mem_value = value;
5222 else
5223 mem_value = assign_temp (tfom, 1, 1);
5224 #endif
5225 /* This call returns a big structure. */
5226 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
5227 }
5228 }
5229 else
5230 tfom = void_type_node;
5231
5232 /* ??? Unfinished: must pass the memory address as an argument. */
5233
5234 /* Copy all the libcall-arguments out of the varargs data
5235 and into a vector ARGVEC.
5236
5237 Compute how to pass each argument. We only support a very small subset
5238 of the full argument passing conventions to limit complexity here since
5239 library functions shouldn't have many args. */
5240
5241 argvec = XALLOCAVEC (struct arg, nargs + 1);
5242 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
5243
5244 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
5245 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
5246 #else
5247 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
5248 #endif
5249 args_so_far = pack_cumulative_args (&args_so_far_v);
5250
5251 args_size.constant = 0;
5252 args_size.var = 0;
5253
5254 count = 0;
5255
5256 push_temp_slots ();
5257
5258 /* If there's a structure value address to be passed,
5259 either pass it in the special place, or pass it as an extra argument. */
5260 if (mem_value && struct_value == 0 && ! pcc_struct_value)
5261 {
5262 rtx addr = XEXP (mem_value, 0);
5263
5264 nargs++;
5265
5266 /* Make sure it is a reasonable operand for a move or push insn. */
5267 if (!REG_P (addr) && !MEM_P (addr)
5268 && !(CONSTANT_P (addr)
5269 && targetm.legitimate_constant_p (Pmode, addr)))
5270 addr = force_operand (addr, NULL_RTX);
5271
5272 argvec[count].value = addr;
5273 argvec[count].mode = Pmode;
5274 argvec[count].partial = 0;
5275
5276 function_arg_info ptr_arg (Pmode, /*named=*/true);
5277 argvec[count].reg = targetm.calls.function_arg (args_so_far, ptr_arg);
5278 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, ptr_arg) == 0);
5279
5280 locate_and_pad_parm (Pmode, NULL_TREE,
5281 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5282 1,
5283 #else
5284 argvec[count].reg != 0,
5285 #endif
5286 reg_parm_stack_space, 0,
5287 NULL_TREE, &args_size, &argvec[count].locate);
5288
5289 if (argvec[count].reg == 0 || argvec[count].partial != 0
5290 || reg_parm_stack_space > 0)
5291 args_size.constant += argvec[count].locate.size.constant;
5292
5293 targetm.calls.function_arg_advance (args_so_far, ptr_arg);
5294
5295 count++;
5296 }
5297
5298 for (unsigned int i = 0; count < nargs; i++, count++)
5299 {
5300 rtx val = args[i].first;
5301 function_arg_info arg (args[i].second, /*named=*/true);
5302 int unsigned_p = 0;
5303
5304 /* We cannot convert the arg value to the mode the library wants here;
5305 must do it earlier where we know the signedness of the arg. */
5306 gcc_assert (arg.mode != BLKmode
5307 && (GET_MODE (val) == arg.mode
5308 || GET_MODE (val) == VOIDmode));
5309
5310 /* Make sure it is a reasonable operand for a move or push insn. */
5311 if (!REG_P (val) && !MEM_P (val)
5312 && !(CONSTANT_P (val)
5313 && targetm.legitimate_constant_p (arg.mode, val)))
5314 val = force_operand (val, NULL_RTX);
5315
5316 if (pass_by_reference (&args_so_far_v, arg))
5317 {
5318 rtx slot;
5319 int must_copy = !reference_callee_copied (&args_so_far_v, arg);
5320
5321 /* If this was a CONST function, it is now PURE since it now
5322 reads memory. */
5323 if (flags & ECF_CONST)
5324 {
5325 flags &= ~ECF_CONST;
5326 flags |= ECF_PURE;
5327 }
5328
5329 if (MEM_P (val) && !must_copy)
5330 {
5331 tree val_expr = MEM_EXPR (val);
5332 if (val_expr)
5333 mark_addressable (val_expr);
5334 slot = val;
5335 }
5336 else
5337 {
5338 slot = assign_temp (lang_hooks.types.type_for_mode (arg.mode, 0),
5339 1, 1);
5340 emit_move_insn (slot, val);
5341 }
5342
5343 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
5344 gen_rtx_USE (VOIDmode, slot),
5345 call_fusage);
5346 if (must_copy)
5347 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
5348 gen_rtx_CLOBBER (VOIDmode,
5349 slot),
5350 call_fusage);
5351
5352 arg.mode = Pmode;
5353 arg.pass_by_reference = true;
5354 val = force_operand (XEXP (slot, 0), NULL_RTX);
5355 }
5356
5357 arg.mode = promote_function_mode (NULL_TREE, arg.mode, &unsigned_p,
5358 NULL_TREE, 0);
5359 argvec[count].mode = arg.mode;
5360 argvec[count].value = convert_modes (arg.mode, GET_MODE (val), val,
5361 unsigned_p);
5362 argvec[count].reg = targetm.calls.function_arg (args_so_far, arg);
5363
5364 argvec[count].partial
5365 = targetm.calls.arg_partial_bytes (args_so_far, arg);
5366
5367 if (argvec[count].reg == 0
5368 || argvec[count].partial != 0
5369 || reg_parm_stack_space > 0)
5370 {
5371 locate_and_pad_parm (arg.mode, NULL_TREE,
5372 #ifdef STACK_PARMS_IN_REG_PARM_AREA
5373 1,
5374 #else
5375 argvec[count].reg != 0,
5376 #endif
5377 reg_parm_stack_space, argvec[count].partial,
5378 NULL_TREE, &args_size, &argvec[count].locate);
5379 args_size.constant += argvec[count].locate.size.constant;
5380 gcc_assert (!argvec[count].locate.size.var);
5381 }
5382 #ifdef BLOCK_REG_PADDING
5383 else
5384 /* The argument is passed entirely in registers. See at which
5385 end it should be padded. */
5386 argvec[count].locate.where_pad =
5387 BLOCK_REG_PADDING (arg.mode, NULL_TREE,
5388 known_le (GET_MODE_SIZE (arg.mode),
5389 UNITS_PER_WORD));
5390 #endif
5391
5392 targetm.calls.function_arg_advance (args_so_far, arg);
5393 }
5394
5395 for (int i = 0; i < nargs; i++)
5396 if (reg_parm_stack_space > 0
5397 || argvec[i].reg == 0
5398 || argvec[i].partial != 0)
5399 update_stack_alignment_for_call (&argvec[i].locate);
5400
5401 /* If this machine requires an external definition for library
5402 functions, write one out. */
5403 assemble_external_libcall (fun);
5404
5405 original_args_size = args_size;
5406 args_size.constant = (aligned_upper_bound (args_size.constant
5407 + stack_pointer_delta,
5408 STACK_BYTES)
5409 - stack_pointer_delta);
5410
5411 args_size.constant = upper_bound (args_size.constant,
5412 reg_parm_stack_space);
5413
5414 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5415 args_size.constant -= reg_parm_stack_space;
5416
5417 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
5418 args_size.constant);
5419
5420 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
5421 {
5422 poly_int64 pushed = args_size.constant + pending_stack_adjust;
5423 current_function_pushed_stack_size
5424 = upper_bound (current_function_pushed_stack_size, pushed);
5425 }
5426
5427 if (ACCUMULATE_OUTGOING_ARGS)
5428 {
5429 /* Since the stack pointer will never be pushed, it is possible for
5430 the evaluation of a parm to clobber something we have already
5431 written to the stack. Since most function calls on RISC machines
5432 do not use the stack, this is uncommon, but must work correctly.
5433
5434 Therefore, we save any area of the stack that was already written
5435 and that we are using. Here we set up to do this by making a new
5436 stack usage map from the old one.
5437
5438 Another approach might be to try to reorder the argument
5439 evaluations to avoid this conflicting stack usage. */
5440
5441 needed = args_size.constant;
5442
5443 /* Since we will be writing into the entire argument area, the
5444 map must be allocated for its entire size, not just the part that
5445 is the responsibility of the caller. */
5446 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5447 needed += reg_parm_stack_space;
5448
5449 poly_int64 limit = needed;
5450 if (ARGS_GROW_DOWNWARD)
5451 limit += 1;
5452
5453 /* For polynomial sizes, this is the maximum possible size needed
5454 for arguments with a constant size and offset. */
5455 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5456 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5457 const_limit);
5458
5459 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5460 stack_usage_map = stack_usage_map_buf;
5461
5462 if (initial_highest_arg_in_use)
5463 memcpy (stack_usage_map, initial_stack_usage_map,
5464 initial_highest_arg_in_use);
5465
5466 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5467 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5468 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5469 needed = 0;
5470
5471 /* We must be careful to use virtual regs before they're instantiated,
5472 and real regs afterwards. Loop optimization, for example, can create
5473 new libcalls after we've instantiated the virtual regs, and if we
5474 use virtuals anyway, they won't match the rtl patterns. */
5475
5476 if (virtuals_instantiated)
5477 argblock = plus_constant (Pmode, stack_pointer_rtx,
5478 STACK_POINTER_OFFSET);
5479 else
5480 argblock = virtual_outgoing_args_rtx;
5481 }
5482 else
5483 {
5484 if (!targetm.calls.push_argument (0))
5485 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5486 }
5487
5488 /* We push args individually in reverse order, perform stack alignment
5489 before the first push (the last arg). */
5490 if (argblock == 0)
5491 anti_adjust_stack (gen_int_mode (args_size.constant
5492 - original_args_size.constant,
5493 Pmode));
5494
5495 argnum = nargs - 1;
5496
5497 #ifdef REG_PARM_STACK_SPACE
5498 if (ACCUMULATE_OUTGOING_ARGS)
5499 {
5500 /* The argument list is the property of the called routine and it
5501 may clobber it. If the fixed area has been used for previous
5502 parameters, we must save and restore it. */
5503 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5504 &low_to_save, &high_to_save);
5505 }
5506 #endif
5507
5508 /* When expanding a normal call, args are stored in push order,
5509 which is the reverse of what we have here. */
5510 bool any_regs = false;
5511 for (int i = nargs; i-- > 0; )
5512 if (argvec[i].reg != NULL_RTX)
5513 {
5514 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5515 any_regs = true;
5516 }
5517 if (!any_regs)
5518 targetm.calls.call_args (pc_rtx, NULL_TREE);
5519
5520 /* Push the args that need to be pushed. */
5521
5522 have_push_fusage = false;
5523
5524 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5525 are to be pushed. */
5526 for (count = 0; count < nargs; count++, argnum--)
5527 {
5528 machine_mode mode = argvec[argnum].mode;
5529 rtx val = argvec[argnum].value;
5530 rtx reg = argvec[argnum].reg;
5531 int partial = argvec[argnum].partial;
5532 unsigned int parm_align = argvec[argnum].locate.boundary;
5533 poly_int64 lower_bound = 0, upper_bound = 0;
5534
5535 if (! (reg != 0 && partial == 0))
5536 {
5537 rtx use;
5538
5539 if (ACCUMULATE_OUTGOING_ARGS)
5540 {
5541 /* If this is being stored into a pre-allocated, fixed-size,
5542 stack area, save any previous data at that location. */
5543
5544 if (ARGS_GROW_DOWNWARD)
5545 {
5546 /* stack_slot is negative, but we want to index stack_usage_map
5547 with positive values. */
5548 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5549 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5550 }
5551 else
5552 {
5553 lower_bound = argvec[argnum].locate.slot_offset.constant;
5554 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5555 }
5556
5557 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5558 reg_parm_stack_space))
5559 {
5560 /* We need to make a save area. */
5561 poly_uint64 size
5562 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5563 machine_mode save_mode
5564 = int_mode_for_size (size, 1).else_blk ();
5565 rtx adr
5566 = plus_constant (Pmode, argblock,
5567 argvec[argnum].locate.offset.constant);
5568 rtx stack_area
5569 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5570
5571 if (save_mode == BLKmode)
5572 {
5573 argvec[argnum].save_area
5574 = assign_stack_temp (BLKmode,
5575 argvec[argnum].locate.size.constant
5576 );
5577
5578 emit_block_move (validize_mem
5579 (copy_rtx (argvec[argnum].save_area)),
5580 stack_area,
5581 (gen_int_mode
5582 (argvec[argnum].locate.size.constant,
5583 Pmode)),
5584 BLOCK_OP_CALL_PARM);
5585 }
5586 else
5587 {
5588 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5589
5590 emit_move_insn (argvec[argnum].save_area, stack_area);
5591 }
5592 }
5593 }
5594
5595 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5596 partial, reg, 0, argblock,
5597 (gen_int_mode
5598 (argvec[argnum].locate.offset.constant, Pmode)),
5599 reg_parm_stack_space,
5600 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5601
5602 /* Now mark the segment we just used. */
5603 if (ACCUMULATE_OUTGOING_ARGS)
5604 mark_stack_region_used (lower_bound, upper_bound);
5605
5606 NO_DEFER_POP;
5607
5608 /* Indicate argument access so that alias.c knows that these
5609 values are live. */
5610 if (argblock)
5611 use = plus_constant (Pmode, argblock,
5612 argvec[argnum].locate.offset.constant);
5613 else if (have_push_fusage)
5614 continue;
5615 else
5616 {
5617 /* When arguments are pushed, trying to tell alias.c where
5618 exactly this argument is won't work, because the
5619 auto-increment causes confusion. So we merely indicate
5620 that we access something with a known mode somewhere on
5621 the stack. */
5622 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5623 gen_rtx_SCRATCH (Pmode));
5624 have_push_fusage = true;
5625 }
5626 use = gen_rtx_MEM (argvec[argnum].mode, use);
5627 use = gen_rtx_USE (VOIDmode, use);
5628 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5629 }
5630 }
5631
5632 argnum = nargs - 1;
5633
5634 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5635
5636 /* Now load any reg parms into their regs. */
5637
5638 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5639 are to be pushed. */
5640 for (count = 0; count < nargs; count++, argnum--)
5641 {
5642 machine_mode mode = argvec[argnum].mode;
5643 rtx val = argvec[argnum].value;
5644 rtx reg = argvec[argnum].reg;
5645 int partial = argvec[argnum].partial;
5646
5647 /* Handle calls that pass values in multiple non-contiguous
5648 locations. The PA64 has examples of this for library calls. */
5649 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5650 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5651 else if (reg != 0 && partial == 0)
5652 {
5653 emit_move_insn (reg, val);
5654 #ifdef BLOCK_REG_PADDING
5655 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5656
5657 /* Copied from load_register_parameters. */
5658
5659 /* Handle case where we have a value that needs shifting
5660 up to the msb. eg. a QImode value and we're padding
5661 upward on a BYTES_BIG_ENDIAN machine. */
5662 if (known_lt (size, UNITS_PER_WORD)
5663 && (argvec[argnum].locate.where_pad
5664 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5665 {
5666 rtx x;
5667 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5668
5669 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5670 report the whole reg as used. Strictly speaking, the
5671 call only uses SIZE bytes at the msb end, but it doesn't
5672 seem worth generating rtl to say that. */
5673 reg = gen_rtx_REG (word_mode, REGNO (reg));
5674 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5675 if (x != reg)
5676 emit_move_insn (reg, x);
5677 }
5678 #endif
5679 }
5680
5681 NO_DEFER_POP;
5682 }
5683
5684 /* Any regs containing parms remain in use through the call. */
5685 for (count = 0; count < nargs; count++)
5686 {
5687 rtx reg = argvec[count].reg;
5688 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5689 use_group_regs (&call_fusage, reg);
5690 else if (reg != 0)
5691 {
5692 int partial = argvec[count].partial;
5693 if (partial)
5694 {
5695 int nregs;
5696 gcc_assert (partial % UNITS_PER_WORD == 0);
5697 nregs = partial / UNITS_PER_WORD;
5698 use_regs (&call_fusage, REGNO (reg), nregs);
5699 }
5700 else
5701 use_reg (&call_fusage, reg);
5702 }
5703 }
5704
5705 /* Pass the function the address in which to return a structure value. */
5706 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5707 {
5708 emit_move_insn (struct_value,
5709 force_reg (Pmode,
5710 force_operand (XEXP (mem_value, 0),
5711 NULL_RTX)));
5712 if (REG_P (struct_value))
5713 use_reg (&call_fusage, struct_value);
5714 }
5715
5716 /* Don't allow popping to be deferred, since then
5717 cse'ing of library calls could delete a call and leave the pop. */
5718 NO_DEFER_POP;
5719 valreg = (mem_value == 0 && outmode != VOIDmode
5720 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5721
5722 /* Stack must be properly aligned now. */
5723 gcc_assert (multiple_p (stack_pointer_delta,
5724 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5725
5726 before_call = get_last_insn ();
5727
5728 if (flag_callgraph_info)
5729 record_final_call (SYMBOL_REF_DECL (orgfun), UNKNOWN_LOCATION);
5730
5731 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5732 will set inhibit_defer_pop to that value. */
5733 /* The return type is needed to decide how many bytes the function pops.
5734 Signedness plays no role in that, so for simplicity, we pretend it's
5735 always signed. We also assume that the list of arguments passed has
5736 no impact, so we pretend it is unknown. */
5737
5738 emit_call_1 (fun, NULL,
5739 get_identifier (XSTR (orgfun, 0)),
5740 build_function_type (tfom, NULL_TREE),
5741 original_args_size.constant, args_size.constant,
5742 struct_value_size,
5743 targetm.calls.function_arg (args_so_far,
5744 function_arg_info::end_marker ()),
5745 valreg,
5746 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5747
5748 if (flag_ipa_ra)
5749 {
5750 rtx datum = orgfun;
5751 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5752 rtx_call_insn *last = last_call_insn ();
5753 add_reg_note (last, REG_CALL_DECL, datum);
5754 }
5755
5756 /* Right-shift returned value if necessary. */
5757 if (!pcc_struct_value
5758 && TYPE_MODE (tfom) != BLKmode
5759 && targetm.calls.return_in_msb (tfom))
5760 {
5761 shift_return_value (TYPE_MODE (tfom), false, valreg);
5762 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5763 }
5764
5765 targetm.calls.end_call_args ();
5766
5767 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5768 that it should complain if nonvolatile values are live. For
5769 functions that cannot return, inform flow that control does not
5770 fall through. */
5771 if (flags & ECF_NORETURN)
5772 {
5773 /* The barrier note must be emitted
5774 immediately after the CALL_INSN. Some ports emit more than
5775 just a CALL_INSN above, so we must search for it here. */
5776 rtx_insn *last = get_last_insn ();
5777 while (!CALL_P (last))
5778 {
5779 last = PREV_INSN (last);
5780 /* There was no CALL_INSN? */
5781 gcc_assert (last != before_call);
5782 }
5783
5784 emit_barrier_after (last);
5785 }
5786
5787 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5788 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5789 if (flags & ECF_NOTHROW)
5790 {
5791 rtx_insn *last = get_last_insn ();
5792 while (!CALL_P (last))
5793 {
5794 last = PREV_INSN (last);
5795 /* There was no CALL_INSN? */
5796 gcc_assert (last != before_call);
5797 }
5798
5799 make_reg_eh_region_note_nothrow_nononlocal (last);
5800 }
5801
5802 /* Now restore inhibit_defer_pop to its actual original value. */
5803 OK_DEFER_POP;
5804
5805 pop_temp_slots ();
5806
5807 /* Copy the value to the right place. */
5808 if (outmode != VOIDmode && retval)
5809 {
5810 if (mem_value)
5811 {
5812 if (value == 0)
5813 value = mem_value;
5814 if (value != mem_value)
5815 emit_move_insn (value, mem_value);
5816 }
5817 else if (GET_CODE (valreg) == PARALLEL)
5818 {
5819 if (value == 0)
5820 value = gen_reg_rtx (outmode);
5821 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5822 }
5823 else
5824 {
5825 /* Convert to the proper mode if a promotion has been active. */
5826 if (GET_MODE (valreg) != outmode)
5827 {
5828 int unsignedp = TYPE_UNSIGNED (tfom);
5829
5830 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5831 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5832 == GET_MODE (valreg));
5833 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5834 }
5835
5836 if (value != 0)
5837 emit_move_insn (value, valreg);
5838 else
5839 value = valreg;
5840 }
5841 }
5842
5843 if (ACCUMULATE_OUTGOING_ARGS)
5844 {
5845 #ifdef REG_PARM_STACK_SPACE
5846 if (save_area)
5847 restore_fixed_argument_area (save_area, argblock,
5848 high_to_save, low_to_save);
5849 #endif
5850
5851 /* If we saved any argument areas, restore them. */
5852 for (count = 0; count < nargs; count++)
5853 if (argvec[count].save_area)
5854 {
5855 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5856 rtx adr = plus_constant (Pmode, argblock,
5857 argvec[count].locate.offset.constant);
5858 rtx stack_area = gen_rtx_MEM (save_mode,
5859 memory_address (save_mode, adr));
5860
5861 if (save_mode == BLKmode)
5862 emit_block_move (stack_area,
5863 validize_mem
5864 (copy_rtx (argvec[count].save_area)),
5865 (gen_int_mode
5866 (argvec[count].locate.size.constant, Pmode)),
5867 BLOCK_OP_CALL_PARM);
5868 else
5869 emit_move_insn (stack_area, argvec[count].save_area);
5870 }
5871
5872 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5873 stack_usage_map = initial_stack_usage_map;
5874 stack_usage_watermark = initial_stack_usage_watermark;
5875 }
5876
5877 free (stack_usage_map_buf);
5878
5879 return value;
5880
5881 }
5882 \f
5883
5884 /* Store a single argument for a function call
5885 into the register or memory area where it must be passed.
5886 *ARG describes the argument value and where to pass it.
5887
5888 ARGBLOCK is the address of the stack-block for all the arguments,
5889 or 0 on a machine where arguments are pushed individually.
5890
5891 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5892 so must be careful about how the stack is used.
5893
5894 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5895 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5896 that we need not worry about saving and restoring the stack.
5897
5898 FNDECL is the declaration of the function we are calling.
5899
5900 Return nonzero if this arg should cause sibcall failure,
5901 zero otherwise. */
5902
5903 static int
5904 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5905 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5906 {
5907 tree pval = arg->tree_value;
5908 rtx reg = 0;
5909 int partial = 0;
5910 poly_int64 used = 0;
5911 poly_int64 lower_bound = 0, upper_bound = 0;
5912 int sibcall_failure = 0;
5913
5914 if (TREE_CODE (pval) == ERROR_MARK)
5915 return 1;
5916
5917 /* Push a new temporary level for any temporaries we make for
5918 this argument. */
5919 push_temp_slots ();
5920
5921 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5922 {
5923 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5924 save any previous data at that location. */
5925 if (argblock && ! variable_size && arg->stack)
5926 {
5927 if (ARGS_GROW_DOWNWARD)
5928 {
5929 /* stack_slot is negative, but we want to index stack_usage_map
5930 with positive values. */
5931 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5932 {
5933 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5934 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5935 }
5936 else
5937 upper_bound = 0;
5938
5939 lower_bound = upper_bound - arg->locate.size.constant;
5940 }
5941 else
5942 {
5943 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5944 {
5945 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5946 lower_bound = rtx_to_poly_int64 (offset);
5947 }
5948 else
5949 lower_bound = 0;
5950
5951 upper_bound = lower_bound + arg->locate.size.constant;
5952 }
5953
5954 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5955 reg_parm_stack_space))
5956 {
5957 /* We need to make a save area. */
5958 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5959 machine_mode save_mode
5960 = int_mode_for_size (size, 1).else_blk ();
5961 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5962 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5963
5964 if (save_mode == BLKmode)
5965 {
5966 arg->save_area
5967 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5968 preserve_temp_slots (arg->save_area);
5969 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5970 stack_area,
5971 (gen_int_mode
5972 (arg->locate.size.constant, Pmode)),
5973 BLOCK_OP_CALL_PARM);
5974 }
5975 else
5976 {
5977 arg->save_area = gen_reg_rtx (save_mode);
5978 emit_move_insn (arg->save_area, stack_area);
5979 }
5980 }
5981 }
5982 }
5983
5984 /* If this isn't going to be placed on both the stack and in registers,
5985 set up the register and number of words. */
5986 if (! arg->pass_on_stack)
5987 {
5988 if (flags & ECF_SIBCALL)
5989 reg = arg->tail_call_reg;
5990 else
5991 reg = arg->reg;
5992 partial = arg->partial;
5993 }
5994
5995 /* Being passed entirely in a register. We shouldn't be called in
5996 this case. */
5997 gcc_assert (reg == 0 || partial != 0);
5998
5999 /* If this arg needs special alignment, don't load the registers
6000 here. */
6001 if (arg->n_aligned_regs != 0)
6002 reg = 0;
6003
6004 /* If this is being passed partially in a register, we can't evaluate
6005 it directly into its stack slot. Otherwise, we can. */
6006 if (arg->value == 0)
6007 {
6008 /* stack_arg_under_construction is nonzero if a function argument is
6009 being evaluated directly into the outgoing argument list and
6010 expand_call must take special action to preserve the argument list
6011 if it is called recursively.
6012
6013 For scalar function arguments stack_usage_map is sufficient to
6014 determine which stack slots must be saved and restored. Scalar
6015 arguments in general have pass_on_stack == 0.
6016
6017 If this argument is initialized by a function which takes the
6018 address of the argument (a C++ constructor or a C function
6019 returning a BLKmode structure), then stack_usage_map is
6020 insufficient and expand_call must push the stack around the
6021 function call. Such arguments have pass_on_stack == 1.
6022
6023 Note that it is always safe to set stack_arg_under_construction,
6024 but this generates suboptimal code if set when not needed. */
6025
6026 if (arg->pass_on_stack)
6027 stack_arg_under_construction++;
6028
6029 arg->value = expand_expr (pval,
6030 (partial
6031 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
6032 ? NULL_RTX : arg->stack,
6033 VOIDmode, EXPAND_STACK_PARM);
6034
6035 /* If we are promoting object (or for any other reason) the mode
6036 doesn't agree, convert the mode. */
6037
6038 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
6039 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
6040 arg->value, arg->unsignedp);
6041
6042 if (arg->pass_on_stack)
6043 stack_arg_under_construction--;
6044 }
6045
6046 /* Check for overlap with already clobbered argument area. */
6047 if ((flags & ECF_SIBCALL)
6048 && MEM_P (arg->value)
6049 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
6050 arg->locate.size.constant))
6051 sibcall_failure = 1;
6052
6053 /* Don't allow anything left on stack from computation
6054 of argument to alloca. */
6055 if (flags & ECF_MAY_BE_ALLOCA)
6056 do_pending_stack_adjust ();
6057
6058 if (arg->value == arg->stack)
6059 /* If the value is already in the stack slot, we are done. */
6060 ;
6061 else if (arg->mode != BLKmode)
6062 {
6063 unsigned int parm_align;
6064
6065 /* Argument is a scalar, not entirely passed in registers.
6066 (If part is passed in registers, arg->partial says how much
6067 and emit_push_insn will take care of putting it there.)
6068
6069 Push it, and if its size is less than the
6070 amount of space allocated to it,
6071 also bump stack pointer by the additional space.
6072 Note that in C the default argument promotions
6073 will prevent such mismatches. */
6074
6075 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
6076 ? 0 : GET_MODE_SIZE (arg->mode));
6077
6078 /* Compute how much space the push instruction will push.
6079 On many machines, pushing a byte will advance the stack
6080 pointer by a halfword. */
6081 #ifdef PUSH_ROUNDING
6082 size = PUSH_ROUNDING (size);
6083 #endif
6084 used = size;
6085
6086 /* Compute how much space the argument should get:
6087 round up to a multiple of the alignment for arguments. */
6088 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
6089 != PAD_NONE)
6090 /* At the moment we don't (need to) support ABIs for which the
6091 padding isn't known at compile time. In principle it should
6092 be easy to add though. */
6093 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
6094
6095 /* Compute the alignment of the pushed argument. */
6096 parm_align = arg->locate.boundary;
6097 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
6098 == PAD_DOWNWARD)
6099 {
6100 poly_int64 pad = used - size;
6101 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
6102 if (pad_align != 0)
6103 parm_align = MIN (parm_align, pad_align);
6104 }
6105
6106 /* This isn't already where we want it on the stack, so put it there.
6107 This can either be done with push or copy insns. */
6108 if (maybe_ne (used, 0)
6109 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
6110 NULL_RTX, parm_align, partial, reg, used - size,
6111 argblock, ARGS_SIZE_RTX (arg->locate.offset),
6112 reg_parm_stack_space,
6113 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
6114 sibcall_failure = 1;
6115
6116 /* Unless this is a partially-in-register argument, the argument is now
6117 in the stack. */
6118 if (partial == 0)
6119 arg->value = arg->stack;
6120 }
6121 else
6122 {
6123 /* BLKmode, at least partly to be pushed. */
6124
6125 unsigned int parm_align;
6126 poly_int64 excess;
6127 rtx size_rtx;
6128
6129 /* Pushing a nonscalar.
6130 If part is passed in registers, PARTIAL says how much
6131 and emit_push_insn will take care of putting it there. */
6132
6133 /* Round its size up to a multiple
6134 of the allocation unit for arguments. */
6135
6136 if (arg->locate.size.var != 0)
6137 {
6138 excess = 0;
6139 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
6140 }
6141 else
6142 {
6143 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
6144 for BLKmode is careful to avoid it. */
6145 excess = (arg->locate.size.constant
6146 - arg_int_size_in_bytes (TREE_TYPE (pval))
6147 + partial);
6148 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
6149 NULL_RTX, TYPE_MODE (sizetype),
6150 EXPAND_NORMAL);
6151 }
6152
6153 parm_align = arg->locate.boundary;
6154
6155 /* When an argument is padded down, the block is aligned to
6156 PARM_BOUNDARY, but the actual argument isn't. */
6157 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
6158 == PAD_DOWNWARD)
6159 {
6160 if (arg->locate.size.var)
6161 parm_align = BITS_PER_UNIT;
6162 else
6163 {
6164 unsigned int excess_align
6165 = known_alignment (excess) * BITS_PER_UNIT;
6166 if (excess_align != 0)
6167 parm_align = MIN (parm_align, excess_align);
6168 }
6169 }
6170
6171 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
6172 {
6173 /* emit_push_insn might not work properly if arg->value and
6174 argblock + arg->locate.offset areas overlap. */
6175 rtx x = arg->value;
6176 poly_int64 i = 0;
6177
6178 if (strip_offset (XEXP (x, 0), &i)
6179 == crtl->args.internal_arg_pointer)
6180 {
6181 /* arg.locate doesn't contain the pretend_args_size offset,
6182 it's part of argblock. Ensure we don't count it in I. */
6183 if (STACK_GROWS_DOWNWARD)
6184 i -= crtl->args.pretend_args_size;
6185 else
6186 i += crtl->args.pretend_args_size;
6187
6188 /* expand_call should ensure this. */
6189 gcc_assert (!arg->locate.offset.var
6190 && arg->locate.size.var == 0);
6191 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
6192
6193 if (known_eq (arg->locate.offset.constant, i))
6194 {
6195 /* Even though they appear to be at the same location,
6196 if part of the outgoing argument is in registers,
6197 they aren't really at the same location. Check for
6198 this by making sure that the incoming size is the
6199 same as the outgoing size. */
6200 if (maybe_ne (arg->locate.size.constant, size_val))
6201 sibcall_failure = 1;
6202 }
6203 else if (maybe_in_range_p (arg->locate.offset.constant,
6204 i, size_val))
6205 sibcall_failure = 1;
6206 /* Use arg->locate.size.constant instead of size_rtx
6207 because we only care about the part of the argument
6208 on the stack. */
6209 else if (maybe_in_range_p (i, arg->locate.offset.constant,
6210 arg->locate.size.constant))
6211 sibcall_failure = 1;
6212 }
6213 }
6214
6215 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
6216 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
6217 parm_align, partial, reg, excess, argblock,
6218 ARGS_SIZE_RTX (arg->locate.offset),
6219 reg_parm_stack_space,
6220 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
6221
6222 /* Unless this is a partially-in-register argument, the argument is now
6223 in the stack.
6224
6225 ??? Unlike the case above, in which we want the actual
6226 address of the data, so that we can load it directly into a
6227 register, here we want the address of the stack slot, so that
6228 it's properly aligned for word-by-word copying or something
6229 like that. It's not clear that this is always correct. */
6230 if (partial == 0)
6231 arg->value = arg->stack_slot;
6232 }
6233
6234 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
6235 {
6236 tree type = TREE_TYPE (arg->tree_value);
6237 arg->parallel_value
6238 = emit_group_load_into_temps (arg->reg, arg->value, type,
6239 int_size_in_bytes (type));
6240 }
6241
6242 /* Mark all slots this store used. */
6243 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
6244 && argblock && ! variable_size && arg->stack)
6245 mark_stack_region_used (lower_bound, upper_bound);
6246
6247 /* Once we have pushed something, pops can't safely
6248 be deferred during the rest of the arguments. */
6249 NO_DEFER_POP;
6250
6251 /* Free any temporary slots made in processing this argument. */
6252 pop_temp_slots ();
6253
6254 return sibcall_failure;
6255 }
6256
6257 /* Nonzero if we do not know how to pass ARG solely in registers. */
6258
6259 bool
6260 must_pass_in_stack_var_size (const function_arg_info &arg)
6261 {
6262 if (!arg.type)
6263 return false;
6264
6265 /* If the type has variable size... */
6266 if (!poly_int_tree_p (TYPE_SIZE (arg.type)))
6267 return true;
6268
6269 /* If the type is marked as addressable (it is required
6270 to be constructed into the stack)... */
6271 if (TREE_ADDRESSABLE (arg.type))
6272 return true;
6273
6274 return false;
6275 }
6276
6277 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
6278 takes trailing padding of a structure into account. */
6279 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
6280
6281 bool
6282 must_pass_in_stack_var_size_or_pad (const function_arg_info &arg)
6283 {
6284 if (!arg.type)
6285 return false;
6286
6287 /* If the type has variable size... */
6288 if (TREE_CODE (TYPE_SIZE (arg.type)) != INTEGER_CST)
6289 return true;
6290
6291 /* If the type is marked as addressable (it is required
6292 to be constructed into the stack)... */
6293 if (TREE_ADDRESSABLE (arg.type))
6294 return true;
6295
6296 if (TYPE_EMPTY_P (arg.type))
6297 return false;
6298
6299 /* If the padding and mode of the type is such that a copy into
6300 a register would put it into the wrong part of the register. */
6301 if (arg.mode == BLKmode
6302 && int_size_in_bytes (arg.type) % (PARM_BOUNDARY / BITS_PER_UNIT)
6303 && (targetm.calls.function_arg_padding (arg.mode, arg.type)
6304 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
6305 return true;
6306
6307 return false;
6308 }
6309
6310 /* Return true if TYPE must be passed on the stack when passed to
6311 the "..." arguments of a function. */
6312
6313 bool
6314 must_pass_va_arg_in_stack (tree type)
6315 {
6316 function_arg_info arg (type, /*named=*/false);
6317 return targetm.calls.must_pass_in_stack (arg);
6318 }
6319
6320 /* Return true if FIELD is the C++17 empty base field that should
6321 be ignored for ABI calling convention decisions in order to
6322 maintain ABI compatibility between C++14 and earlier, which doesn't
6323 add this FIELD to classes with empty bases, and C++17 and later
6324 which does. */
6325
6326 bool
6327 cxx17_empty_base_field_p (const_tree field)
6328 {
6329 return (DECL_FIELD_ABI_IGNORED (field)
6330 && DECL_ARTIFICIAL (field)
6331 && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field))
6332 && !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (field)));
6333 }
6334
6335 /* Tell the garbage collector about GTY markers in this source file. */
6336 #include "gt-calls.h"