typeck.c (cp_truthvalue_conversion): Add tsubst_flags_t parameter and use it in calls...
[official-gcc.git] / gcc / calls.c
blob62921351b112c7fdd9004924fd44a854c0763da7
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2019 Free Software Foundation, Inc.
4 This file is part of GCC.
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.
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.
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/>. */
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "target.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "predict.h"
29 #include "memmodel.h"
30 #include "tm_p.h"
31 #include "stringpool.h"
32 #include "expmed.h"
33 #include "optabs.h"
34 #include "emit-rtl.h"
35 #include "cgraph.h"
36 #include "diagnostic-core.h"
37 #include "fold-const.h"
38 #include "stor-layout.h"
39 #include "varasm.h"
40 #include "internal-fn.h"
41 #include "dojump.h"
42 #include "explow.h"
43 #include "calls.h"
44 #include "expr.h"
45 #include "output.h"
46 #include "langhooks.h"
47 #include "except.h"
48 #include "dbgcnt.h"
49 #include "rtl-iter.h"
50 #include "tree-vrp.h"
51 #include "tree-ssanames.h"
52 #include "tree-ssa-strlen.h"
53 #include "intl.h"
54 #include "stringpool.h"
55 #include "attribs.h"
56 #include "builtins.h"
57 #include "gimple-fold.h"
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
62 /* Data structure and subroutines used within expand_call. */
64 struct arg_data
66 /* Tree node for this argument. */
67 tree tree_value;
68 /* Mode for value; TYPE_MODE unless promoted. */
69 machine_mode mode;
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
71 rtx value;
72 /* Initially-compute RTL value for argument; only for const functions. */
73 rtx initial_value;
74 /* Register to pass this argument in, 0 if passed on stack, or an
75 PARALLEL if the arg is to be copied into multiple non-contiguous
76 registers. */
77 rtx reg;
78 /* Register to pass this argument in when generating tail call sequence.
79 This is not the same register as for normal calls on machines with
80 register windows. */
81 rtx tail_call_reg;
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
84 rtx parallel_value;
85 /* If REG was promoted from the actual mode of the argument expression,
86 indicates whether the promotion is sign- or zero-extended. */
87 int unsignedp;
88 /* Number of bytes to put in registers. 0 means put the whole arg
89 in registers. Also 0 if not passed in registers. */
90 int partial;
91 /* Nonzero if argument must be passed on stack.
92 Note that some arguments may be passed on the stack
93 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
94 pass_on_stack identifies arguments that *cannot* go in registers. */
95 int pass_on_stack;
96 /* Some fields packaged up for locate_and_pad_parm. */
97 struct locate_and_pad_arg_data locate;
98 /* Location on the stack at which parameter should be stored. The store
99 has already been done if STACK == VALUE. */
100 rtx stack;
101 /* Location on the stack of the start of this argument slot. This can
102 differ from STACK if this arg pads downward. This location is known
103 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
104 rtx stack_slot;
105 /* Place that this stack area has been saved, if needed. */
106 rtx save_area;
107 /* If an argument's alignment does not permit direct copying into registers,
108 copy in smaller-sized pieces into pseudos. These are stored in a
109 block pointed to by this field. The next field says how many
110 word-sized pseudos we made. */
111 rtx *aligned_regs;
112 int n_aligned_regs;
115 /* A vector of one char per byte of stack space. A byte if nonzero if
116 the corresponding stack location has been used.
117 This vector is used to prevent a function call within an argument from
118 clobbering any stack already set up. */
119 static char *stack_usage_map;
121 /* Size of STACK_USAGE_MAP. */
122 static unsigned int highest_outgoing_arg_in_use;
124 /* Assume that any stack location at this byte index is used,
125 without checking the contents of stack_usage_map. */
126 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
128 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
129 stack location's tail call argument has been already stored into the stack.
130 This bitmap is used to prevent sibling call optimization if function tries
131 to use parent's incoming argument slots when they have been already
132 overwritten with tail call arguments. */
133 static sbitmap stored_args_map;
135 /* Assume that any virtual-incoming location at this byte index has been
136 stored, without checking the contents of stored_args_map. */
137 static unsigned HOST_WIDE_INT stored_args_watermark;
139 /* stack_arg_under_construction is nonzero when an argument may be
140 initialized with a constructor call (including a C function that
141 returns a BLKmode struct) and expand_call must take special action
142 to make sure the object being constructed does not overlap the
143 argument list for the constructor call. */
144 static int stack_arg_under_construction;
146 static void precompute_register_parameters (int, struct arg_data *, int *);
147 static int store_one_arg (struct arg_data *, rtx, int, int, int);
148 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
149 static int finalize_must_preallocate (int, int, struct arg_data *,
150 struct args_size *);
151 static void precompute_arguments (int, struct arg_data *);
152 static void compute_argument_addresses (struct arg_data *, rtx, int);
153 static rtx rtx_for_function_call (tree, tree);
154 static void load_register_parameters (struct arg_data *, int, rtx *, int,
155 int, int *);
156 static int special_function_p (const_tree, int);
157 static int check_sibcall_argument_overlap_1 (rtx);
158 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
160 static tree split_complex_types (tree);
162 #ifdef REG_PARM_STACK_SPACE
163 static rtx save_fixed_argument_area (int, rtx, int *, int *);
164 static void restore_fixed_argument_area (rtx, rtx, int, int);
165 #endif
167 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
168 stack region might already be in use. */
170 static bool
171 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
172 unsigned int reg_parm_stack_space)
174 unsigned HOST_WIDE_INT const_lower, const_upper;
175 const_lower = constant_lower_bound (lower_bound);
176 if (!upper_bound.is_constant (&const_upper))
177 const_upper = HOST_WIDE_INT_M1U;
179 if (const_upper > stack_usage_watermark)
180 return true;
182 /* Don't worry about things in the fixed argument area;
183 it has already been saved. */
184 const_lower = MAX (const_lower, reg_parm_stack_space);
185 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
186 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
187 if (stack_usage_map[i])
188 return true;
189 return false;
192 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
193 stack region are now in use. */
195 static void
196 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
198 unsigned HOST_WIDE_INT const_lower, const_upper;
199 const_lower = constant_lower_bound (lower_bound);
200 if (upper_bound.is_constant (&const_upper))
201 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
202 stack_usage_map[i] = 1;
203 else
204 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
207 /* Force FUNEXP into a form suitable for the address of a CALL,
208 and return that as an rtx. Also load the static chain register
209 if FNDECL is a nested function.
211 CALL_FUSAGE points to a variable holding the prospective
212 CALL_INSN_FUNCTION_USAGE information. */
215 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
216 rtx *call_fusage, int reg_parm_seen, int flags)
218 /* Make a valid memory address and copy constants through pseudo-regs,
219 but not for a constant address if -fno-function-cse. */
220 if (GET_CODE (funexp) != SYMBOL_REF)
222 /* If it's an indirect call by descriptor, generate code to perform
223 runtime identification of the pointer and load the descriptor. */
224 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
226 const int bit_val = targetm.calls.custom_function_descriptors;
227 rtx call_lab = gen_label_rtx ();
229 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
230 fndecl_or_type
231 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
232 fndecl_or_type);
233 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
234 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
236 if (GET_MODE (funexp) != Pmode)
237 funexp = convert_memory_address (Pmode, funexp);
239 /* Avoid long live ranges around function calls. */
240 funexp = copy_to_mode_reg (Pmode, funexp);
242 if (REG_P (chain))
243 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
245 /* Emit the runtime identification pattern. */
246 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
247 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
248 call_lab);
250 /* Statically predict the branch to very likely taken. */
251 rtx_insn *insn = get_last_insn ();
252 if (JUMP_P (insn))
253 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
255 /* Load the descriptor. */
256 rtx mem = gen_rtx_MEM (ptr_mode,
257 plus_constant (Pmode, funexp, - bit_val));
258 MEM_NOTRAP_P (mem) = 1;
259 mem = convert_memory_address (Pmode, mem);
260 emit_move_insn (chain, mem);
262 mem = gen_rtx_MEM (ptr_mode,
263 plus_constant (Pmode, funexp,
264 POINTER_SIZE / BITS_PER_UNIT
265 - bit_val));
266 MEM_NOTRAP_P (mem) = 1;
267 mem = convert_memory_address (Pmode, mem);
268 emit_move_insn (funexp, mem);
270 emit_label (call_lab);
272 if (REG_P (chain))
274 use_reg (call_fusage, chain);
275 STATIC_CHAIN_REG_P (chain) = 1;
278 /* Make sure we're not going to be overwritten below. */
279 gcc_assert (!static_chain_value);
282 /* If we are using registers for parameters, force the
283 function address into a register now. */
284 funexp = ((reg_parm_seen
285 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
286 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
287 : memory_address (FUNCTION_MODE, funexp));
289 else
291 /* funexp could be a SYMBOL_REF represents a function pointer which is
292 of ptr_mode. In this case, it should be converted into address mode
293 to be a valid address for memory rtx pattern. See PR 64971. */
294 if (GET_MODE (funexp) != Pmode)
295 funexp = convert_memory_address (Pmode, funexp);
297 if (!(flags & ECF_SIBCALL))
299 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
300 funexp = force_reg (Pmode, funexp);
304 if (static_chain_value != 0
305 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
306 || DECL_STATIC_CHAIN (fndecl_or_type)))
308 rtx chain;
310 chain = targetm.calls.static_chain (fndecl_or_type, false);
311 static_chain_value = convert_memory_address (Pmode, static_chain_value);
313 emit_move_insn (chain, static_chain_value);
314 if (REG_P (chain))
316 use_reg (call_fusage, chain);
317 STATIC_CHAIN_REG_P (chain) = 1;
321 return funexp;
324 /* Generate instructions to call function FUNEXP,
325 and optionally pop the results.
326 The CALL_INSN is the first insn generated.
328 FNDECL is the declaration node of the function. This is given to the
329 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
330 its own args.
332 FUNTYPE is the data type of the function. This is given to the hook
333 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
334 own args. We used to allow an identifier for library functions, but
335 that doesn't work when the return type is an aggregate type and the
336 calling convention says that the pointer to this aggregate is to be
337 popped by the callee.
339 STACK_SIZE is the number of bytes of arguments on the stack,
340 ROUNDED_STACK_SIZE is that number rounded up to
341 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
342 both to put into the call insn and to generate explicit popping
343 code if necessary.
345 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
346 It is zero if this call doesn't want a structure value.
348 NEXT_ARG_REG is the rtx that results from executing
349 targetm.calls.function_arg (&args_so_far,
350 function_arg_info::end_marker ());
351 just after all the args have had their registers assigned.
352 This could be whatever you like, but normally it is the first
353 arg-register beyond those used for args in this call,
354 or 0 if all the arg-registers are used in this call.
355 It is passed on to `gen_call' so you can put this info in the call insn.
357 VALREG is a hard register in which a value is returned,
358 or 0 if the call does not return a value.
360 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
361 the args to this call were processed.
362 We restore `inhibit_defer_pop' to that value.
364 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
365 denote registers used by the called function. */
367 static void
368 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
369 tree funtype ATTRIBUTE_UNUSED,
370 poly_int64 stack_size ATTRIBUTE_UNUSED,
371 poly_int64 rounded_stack_size,
372 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
373 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
374 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
375 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
377 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
378 rtx call, funmem, pat;
379 int already_popped = 0;
380 poly_int64 n_popped = 0;
382 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
383 patterns exist). Any popping that the callee does on return will
384 be from our caller's frame rather than ours. */
385 if (!(ecf_flags & ECF_SIBCALL))
387 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
389 #ifdef CALL_POPS_ARGS
390 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
391 #endif
394 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
395 and we don't want to load it into a register as an optimization,
396 because prepare_call_address already did it if it should be done. */
397 if (GET_CODE (funexp) != SYMBOL_REF)
398 funexp = memory_address (FUNCTION_MODE, funexp);
400 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
401 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
403 tree t = fndecl;
405 /* Although a built-in FUNCTION_DECL and its non-__builtin
406 counterpart compare equal and get a shared mem_attrs, they
407 produce different dump output in compare-debug compilations,
408 if an entry gets garbage collected in one compilation, then
409 adds a different (but equivalent) entry, while the other
410 doesn't run the garbage collector at the same spot and then
411 shares the mem_attr with the equivalent entry. */
412 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
414 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
415 if (t2)
416 t = t2;
419 set_mem_expr (funmem, t);
421 else if (fntree)
422 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
424 if (ecf_flags & ECF_SIBCALL)
426 if (valreg)
427 pat = targetm.gen_sibcall_value (valreg, funmem,
428 rounded_stack_size_rtx,
429 next_arg_reg, NULL_RTX);
430 else
431 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
432 next_arg_reg,
433 gen_int_mode (struct_value_size, Pmode));
435 /* If the target has "call" or "call_value" insns, then prefer them
436 if no arguments are actually popped. If the target does not have
437 "call" or "call_value" insns, then we must use the popping versions
438 even if the call has no arguments to pop. */
439 else if (maybe_ne (n_popped, 0)
440 || !(valreg
441 ? targetm.have_call_value ()
442 : targetm.have_call ()))
444 rtx n_pop = gen_int_mode (n_popped, Pmode);
446 /* If this subroutine pops its own args, record that in the call insn
447 if possible, for the sake of frame pointer elimination. */
449 if (valreg)
450 pat = targetm.gen_call_value_pop (valreg, funmem,
451 rounded_stack_size_rtx,
452 next_arg_reg, n_pop);
453 else
454 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
455 next_arg_reg, n_pop);
457 already_popped = 1;
459 else
461 if (valreg)
462 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
463 next_arg_reg, NULL_RTX);
464 else
465 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
466 gen_int_mode (struct_value_size, Pmode));
468 emit_insn (pat);
470 /* Find the call we just emitted. */
471 rtx_call_insn *call_insn = last_call_insn ();
473 /* Some target create a fresh MEM instead of reusing the one provided
474 above. Set its MEM_EXPR. */
475 call = get_call_rtx_from (call_insn);
476 if (call
477 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
478 && MEM_EXPR (funmem) != NULL_TREE)
479 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
481 /* Put the register usage information there. */
482 add_function_usage_to (call_insn, call_fusage);
484 /* If this is a const call, then set the insn's unchanging bit. */
485 if (ecf_flags & ECF_CONST)
486 RTL_CONST_CALL_P (call_insn) = 1;
488 /* If this is a pure call, then set the insn's unchanging bit. */
489 if (ecf_flags & ECF_PURE)
490 RTL_PURE_CALL_P (call_insn) = 1;
492 /* If this is a const call, then set the insn's unchanging bit. */
493 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
494 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
496 /* Create a nothrow REG_EH_REGION note, if needed. */
497 make_reg_eh_region_note (call_insn, ecf_flags, 0);
499 if (ecf_flags & ECF_NORETURN)
500 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
502 if (ecf_flags & ECF_RETURNS_TWICE)
504 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
505 cfun->calls_setjmp = 1;
508 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
510 /* Restore this now, so that we do defer pops for this call's args
511 if the context of the call as a whole permits. */
512 inhibit_defer_pop = old_inhibit_defer_pop;
514 if (maybe_ne (n_popped, 0))
516 if (!already_popped)
517 CALL_INSN_FUNCTION_USAGE (call_insn)
518 = gen_rtx_EXPR_LIST (VOIDmode,
519 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
520 CALL_INSN_FUNCTION_USAGE (call_insn));
521 rounded_stack_size -= n_popped;
522 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
523 stack_pointer_delta -= n_popped;
525 add_args_size_note (call_insn, stack_pointer_delta);
527 /* If popup is needed, stack realign must use DRAP */
528 if (SUPPORTS_STACK_ALIGNMENT)
529 crtl->need_drap = true;
531 /* For noreturn calls when not accumulating outgoing args force
532 REG_ARGS_SIZE note to prevent crossjumping of calls with different
533 args sizes. */
534 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
535 add_args_size_note (call_insn, stack_pointer_delta);
537 if (!ACCUMULATE_OUTGOING_ARGS)
539 /* If returning from the subroutine does not automatically pop the args,
540 we need an instruction to pop them sooner or later.
541 Perhaps do it now; perhaps just record how much space to pop later.
543 If returning from the subroutine does pop the args, indicate that the
544 stack pointer will be changed. */
546 if (maybe_ne (rounded_stack_size, 0))
548 if (ecf_flags & ECF_NORETURN)
549 /* Just pretend we did the pop. */
550 stack_pointer_delta -= rounded_stack_size;
551 else if (flag_defer_pop && inhibit_defer_pop == 0
552 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
553 pending_stack_adjust += rounded_stack_size;
554 else
555 adjust_stack (rounded_stack_size_rtx);
558 /* When we accumulate outgoing args, we must avoid any stack manipulations.
559 Restore the stack pointer to its original value now. Usually
560 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
561 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
562 popping variants of functions exist as well.
564 ??? We may optimize similar to defer_pop above, but it is
565 probably not worthwhile.
567 ??? It will be worthwhile to enable combine_stack_adjustments even for
568 such machines. */
569 else if (maybe_ne (n_popped, 0))
570 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
573 /* Determine if the function identified by FNDECL is one with
574 special properties we wish to know about. Modify FLAGS accordingly.
576 For example, if the function might return more than one time (setjmp), then
577 set ECF_RETURNS_TWICE.
579 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
580 space from the stack such as alloca. */
582 static int
583 special_function_p (const_tree fndecl, int flags)
585 tree name_decl = DECL_NAME (fndecl);
587 if (fndecl && name_decl
588 && IDENTIFIER_LENGTH (name_decl) <= 11
589 /* Exclude functions not at the file scope, or not `extern',
590 since they are not the magic functions we would otherwise
591 think they are.
592 FIXME: this should be handled with attributes, not with this
593 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
594 because you can declare fork() inside a function if you
595 wish. */
596 && (DECL_CONTEXT (fndecl) == NULL_TREE
597 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
598 && TREE_PUBLIC (fndecl))
600 const char *name = IDENTIFIER_POINTER (name_decl);
601 const char *tname = name;
603 /* We assume that alloca will always be called by name. It
604 makes no sense to pass it as a pointer-to-function to
605 anything that does not understand its behavior. */
606 if (IDENTIFIER_LENGTH (name_decl) == 6
607 && name[0] == 'a'
608 && ! strcmp (name, "alloca"))
609 flags |= ECF_MAY_BE_ALLOCA;
611 /* Disregard prefix _ or __. */
612 if (name[0] == '_')
614 if (name[1] == '_')
615 tname += 2;
616 else
617 tname += 1;
620 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
621 if (! strcmp (tname, "setjmp")
622 || ! strcmp (tname, "sigsetjmp")
623 || ! strcmp (name, "savectx")
624 || ! strcmp (name, "vfork")
625 || ! strcmp (name, "getcontext"))
626 flags |= ECF_RETURNS_TWICE;
629 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
630 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
631 flags |= ECF_MAY_BE_ALLOCA;
633 return flags;
636 /* Similar to special_function_p; return a set of ERF_ flags for the
637 function FNDECL. */
638 static int
639 decl_return_flags (tree fndecl)
641 tree attr;
642 tree type = TREE_TYPE (fndecl);
643 if (!type)
644 return 0;
646 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
647 if (!attr)
648 return 0;
650 attr = TREE_VALUE (TREE_VALUE (attr));
651 if (!attr || TREE_STRING_LENGTH (attr) < 1)
652 return 0;
654 switch (TREE_STRING_POINTER (attr)[0])
656 case '1':
657 case '2':
658 case '3':
659 case '4':
660 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
662 case 'm':
663 return ERF_NOALIAS;
665 case '.':
666 default:
667 return 0;
671 /* Return nonzero when FNDECL represents a call to setjmp. */
674 setjmp_call_p (const_tree fndecl)
676 if (DECL_IS_RETURNS_TWICE (fndecl))
677 return ECF_RETURNS_TWICE;
678 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
682 /* Return true if STMT may be an alloca call. */
684 bool
685 gimple_maybe_alloca_call_p (const gimple *stmt)
687 tree fndecl;
689 if (!is_gimple_call (stmt))
690 return false;
692 fndecl = gimple_call_fndecl (stmt);
693 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
694 return true;
696 return false;
699 /* Return true if STMT is a builtin alloca call. */
701 bool
702 gimple_alloca_call_p (const gimple *stmt)
704 tree fndecl;
706 if (!is_gimple_call (stmt))
707 return false;
709 fndecl = gimple_call_fndecl (stmt);
710 if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
711 switch (DECL_FUNCTION_CODE (fndecl))
713 CASE_BUILT_IN_ALLOCA:
714 return gimple_call_num_args (stmt) > 0;
715 default:
716 break;
719 return false;
722 /* Return true when exp contains a builtin alloca call. */
724 bool
725 alloca_call_p (const_tree exp)
727 tree fndecl;
728 if (TREE_CODE (exp) == CALL_EXPR
729 && (fndecl = get_callee_fndecl (exp))
730 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
731 switch (DECL_FUNCTION_CODE (fndecl))
733 CASE_BUILT_IN_ALLOCA:
734 return true;
735 default:
736 break;
739 return false;
742 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
743 function. Return FALSE otherwise. */
745 static bool
746 is_tm_builtin (const_tree fndecl)
748 if (fndecl == NULL)
749 return false;
751 if (decl_is_tm_clone (fndecl))
752 return true;
754 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
756 switch (DECL_FUNCTION_CODE (fndecl))
758 case BUILT_IN_TM_COMMIT:
759 case BUILT_IN_TM_COMMIT_EH:
760 case BUILT_IN_TM_ABORT:
761 case BUILT_IN_TM_IRREVOCABLE:
762 case BUILT_IN_TM_GETTMCLONE_IRR:
763 case BUILT_IN_TM_MEMCPY:
764 case BUILT_IN_TM_MEMMOVE:
765 case BUILT_IN_TM_MEMSET:
766 CASE_BUILT_IN_TM_STORE (1):
767 CASE_BUILT_IN_TM_STORE (2):
768 CASE_BUILT_IN_TM_STORE (4):
769 CASE_BUILT_IN_TM_STORE (8):
770 CASE_BUILT_IN_TM_STORE (FLOAT):
771 CASE_BUILT_IN_TM_STORE (DOUBLE):
772 CASE_BUILT_IN_TM_STORE (LDOUBLE):
773 CASE_BUILT_IN_TM_STORE (M64):
774 CASE_BUILT_IN_TM_STORE (M128):
775 CASE_BUILT_IN_TM_STORE (M256):
776 CASE_BUILT_IN_TM_LOAD (1):
777 CASE_BUILT_IN_TM_LOAD (2):
778 CASE_BUILT_IN_TM_LOAD (4):
779 CASE_BUILT_IN_TM_LOAD (8):
780 CASE_BUILT_IN_TM_LOAD (FLOAT):
781 CASE_BUILT_IN_TM_LOAD (DOUBLE):
782 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
783 CASE_BUILT_IN_TM_LOAD (M64):
784 CASE_BUILT_IN_TM_LOAD (M128):
785 CASE_BUILT_IN_TM_LOAD (M256):
786 case BUILT_IN_TM_LOG:
787 case BUILT_IN_TM_LOG_1:
788 case BUILT_IN_TM_LOG_2:
789 case BUILT_IN_TM_LOG_4:
790 case BUILT_IN_TM_LOG_8:
791 case BUILT_IN_TM_LOG_FLOAT:
792 case BUILT_IN_TM_LOG_DOUBLE:
793 case BUILT_IN_TM_LOG_LDOUBLE:
794 case BUILT_IN_TM_LOG_M64:
795 case BUILT_IN_TM_LOG_M128:
796 case BUILT_IN_TM_LOG_M256:
797 return true;
798 default:
799 break;
802 return false;
805 /* Detect flags (function attributes) from the function decl or type node. */
808 flags_from_decl_or_type (const_tree exp)
810 int flags = 0;
812 if (DECL_P (exp))
814 /* The function exp may have the `malloc' attribute. */
815 if (DECL_IS_MALLOC (exp))
816 flags |= ECF_MALLOC;
818 /* The function exp may have the `returns_twice' attribute. */
819 if (DECL_IS_RETURNS_TWICE (exp))
820 flags |= ECF_RETURNS_TWICE;
822 /* Process the pure and const attributes. */
823 if (TREE_READONLY (exp))
824 flags |= ECF_CONST;
825 if (DECL_PURE_P (exp))
826 flags |= ECF_PURE;
827 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
828 flags |= ECF_LOOPING_CONST_OR_PURE;
830 if (DECL_IS_NOVOPS (exp))
831 flags |= ECF_NOVOPS;
832 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
833 flags |= ECF_LEAF;
834 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
835 flags |= ECF_COLD;
837 if (TREE_NOTHROW (exp))
838 flags |= ECF_NOTHROW;
840 if (flag_tm)
842 if (is_tm_builtin (exp))
843 flags |= ECF_TM_BUILTIN;
844 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
845 || lookup_attribute ("transaction_pure",
846 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
847 flags |= ECF_TM_PURE;
850 flags = special_function_p (exp, flags);
852 else if (TYPE_P (exp))
854 if (TYPE_READONLY (exp))
855 flags |= ECF_CONST;
857 if (flag_tm
858 && ((flags & ECF_CONST) != 0
859 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
860 flags |= ECF_TM_PURE;
862 else
863 gcc_unreachable ();
865 if (TREE_THIS_VOLATILE (exp))
867 flags |= ECF_NORETURN;
868 if (flags & (ECF_CONST|ECF_PURE))
869 flags |= ECF_LOOPING_CONST_OR_PURE;
872 return flags;
875 /* Detect flags from a CALL_EXPR. */
878 call_expr_flags (const_tree t)
880 int flags;
881 tree decl = get_callee_fndecl (t);
883 if (decl)
884 flags = flags_from_decl_or_type (decl);
885 else if (CALL_EXPR_FN (t) == NULL_TREE)
886 flags = internal_fn_flags (CALL_EXPR_IFN (t));
887 else
889 tree type = TREE_TYPE (CALL_EXPR_FN (t));
890 if (type && TREE_CODE (type) == POINTER_TYPE)
891 flags = flags_from_decl_or_type (TREE_TYPE (type));
892 else
893 flags = 0;
894 if (CALL_EXPR_BY_DESCRIPTOR (t))
895 flags |= ECF_BY_DESCRIPTOR;
898 return flags;
901 /* Return true if ARG should be passed by invisible reference. */
903 bool
904 pass_by_reference (CUMULATIVE_ARGS *ca, function_arg_info arg)
906 if (tree type = arg.type)
908 /* If this type contains non-trivial constructors, then it is
909 forbidden for the middle-end to create any new copies. */
910 if (TREE_ADDRESSABLE (type))
911 return true;
913 /* GCC post 3.4 passes *all* variable sized types by reference. */
914 if (!TYPE_SIZE (type) || !poly_int_tree_p (TYPE_SIZE (type)))
915 return true;
917 /* If a record type should be passed the same as its first (and only)
918 member, use the type and mode of that member. */
919 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
921 arg.type = TREE_TYPE (first_field (type));
922 arg.mode = TYPE_MODE (arg.type);
926 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), arg);
929 /* Return true if TYPE should be passed by reference when passed to
930 the "..." arguments of a function. */
932 bool
933 pass_va_arg_by_reference (tree type)
935 return pass_by_reference (NULL, function_arg_info (type, /*named=*/false));
938 /* Decide whether ARG, which occurs in the state described by CA,
939 should be passed by reference. Return true if so and update
940 ARG accordingly. */
942 bool
943 apply_pass_by_reference_rules (CUMULATIVE_ARGS *ca, function_arg_info &arg)
945 if (pass_by_reference (ca, arg))
947 arg.type = build_pointer_type (arg.type);
948 arg.mode = TYPE_MODE (arg.type);
949 arg.pass_by_reference = true;
950 return true;
952 return false;
955 /* Return true if ARG, which is passed by reference, should be callee
956 copied instead of caller copied. */
958 bool
959 reference_callee_copied (CUMULATIVE_ARGS *ca, const function_arg_info &arg)
961 if (arg.type && TREE_ADDRESSABLE (arg.type))
962 return false;
963 return targetm.calls.callee_copies (pack_cumulative_args (ca), arg);
967 /* Precompute all register parameters as described by ARGS, storing values
968 into fields within the ARGS array.
970 NUM_ACTUALS indicates the total number elements in the ARGS array.
972 Set REG_PARM_SEEN if we encounter a register parameter. */
974 static void
975 precompute_register_parameters (int num_actuals, struct arg_data *args,
976 int *reg_parm_seen)
978 int i;
980 *reg_parm_seen = 0;
982 for (i = 0; i < num_actuals; i++)
983 if (args[i].reg != 0 && ! args[i].pass_on_stack)
985 *reg_parm_seen = 1;
987 if (args[i].value == 0)
989 push_temp_slots ();
990 args[i].value = expand_normal (args[i].tree_value);
991 preserve_temp_slots (args[i].value);
992 pop_temp_slots ();
995 /* If we are to promote the function arg to a wider mode,
996 do it now. */
998 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
999 args[i].value
1000 = convert_modes (args[i].mode,
1001 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1002 args[i].value, args[i].unsignedp);
1004 /* If the value is a non-legitimate constant, force it into a
1005 pseudo now. TLS symbols sometimes need a call to resolve. */
1006 if (CONSTANT_P (args[i].value)
1007 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
1008 args[i].value = force_reg (args[i].mode, args[i].value);
1010 /* If we're going to have to load the value by parts, pull the
1011 parts into pseudos. The part extraction process can involve
1012 non-trivial computation. */
1013 if (GET_CODE (args[i].reg) == PARALLEL)
1015 tree type = TREE_TYPE (args[i].tree_value);
1016 args[i].parallel_value
1017 = emit_group_load_into_temps (args[i].reg, args[i].value,
1018 type, int_size_in_bytes (type));
1021 /* If the value is expensive, and we are inside an appropriately
1022 short loop, put the value into a pseudo and then put the pseudo
1023 into the hard reg.
1025 For small register classes, also do this if this call uses
1026 register parameters. This is to avoid reload conflicts while
1027 loading the parameters registers. */
1029 else if ((! (REG_P (args[i].value)
1030 || (GET_CODE (args[i].value) == SUBREG
1031 && REG_P (SUBREG_REG (args[i].value)))))
1032 && args[i].mode != BLKmode
1033 && (set_src_cost (args[i].value, args[i].mode,
1034 optimize_insn_for_speed_p ())
1035 > COSTS_N_INSNS (1))
1036 && ((*reg_parm_seen
1037 && targetm.small_register_classes_for_mode_p (args[i].mode))
1038 || optimize))
1039 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1043 #ifdef REG_PARM_STACK_SPACE
1045 /* The argument list is the property of the called routine and it
1046 may clobber it. If the fixed area has been used for previous
1047 parameters, we must save and restore it. */
1049 static rtx
1050 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1052 unsigned int low;
1053 unsigned int high;
1055 /* Compute the boundary of the area that needs to be saved, if any. */
1056 high = reg_parm_stack_space;
1057 if (ARGS_GROW_DOWNWARD)
1058 high += 1;
1060 if (high > highest_outgoing_arg_in_use)
1061 high = highest_outgoing_arg_in_use;
1063 for (low = 0; low < high; low++)
1064 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1066 int num_to_save;
1067 machine_mode save_mode;
1068 int delta;
1069 rtx addr;
1070 rtx stack_area;
1071 rtx save_area;
1073 while (stack_usage_map[--high] == 0)
1076 *low_to_save = low;
1077 *high_to_save = high;
1079 num_to_save = high - low + 1;
1081 /* If we don't have the required alignment, must do this
1082 in BLKmode. */
1083 scalar_int_mode imode;
1084 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1085 && (low & (MIN (GET_MODE_SIZE (imode),
1086 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1087 save_mode = imode;
1088 else
1089 save_mode = BLKmode;
1091 if (ARGS_GROW_DOWNWARD)
1092 delta = -high;
1093 else
1094 delta = low;
1096 addr = plus_constant (Pmode, argblock, delta);
1097 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1099 set_mem_align (stack_area, PARM_BOUNDARY);
1100 if (save_mode == BLKmode)
1102 save_area = assign_stack_temp (BLKmode, num_to_save);
1103 emit_block_move (validize_mem (save_area), stack_area,
1104 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1106 else
1108 save_area = gen_reg_rtx (save_mode);
1109 emit_move_insn (save_area, stack_area);
1112 return save_area;
1115 return NULL_RTX;
1118 static void
1119 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1121 machine_mode save_mode = GET_MODE (save_area);
1122 int delta;
1123 rtx addr, stack_area;
1125 if (ARGS_GROW_DOWNWARD)
1126 delta = -high_to_save;
1127 else
1128 delta = low_to_save;
1130 addr = plus_constant (Pmode, argblock, delta);
1131 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1132 set_mem_align (stack_area, PARM_BOUNDARY);
1134 if (save_mode != BLKmode)
1135 emit_move_insn (stack_area, save_area);
1136 else
1137 emit_block_move (stack_area, validize_mem (save_area),
1138 GEN_INT (high_to_save - low_to_save + 1),
1139 BLOCK_OP_CALL_PARM);
1141 #endif /* REG_PARM_STACK_SPACE */
1143 /* If any elements in ARGS refer to parameters that are to be passed in
1144 registers, but not in memory, and whose alignment does not permit a
1145 direct copy into registers. Copy the values into a group of pseudos
1146 which we will later copy into the appropriate hard registers.
1148 Pseudos for each unaligned argument will be stored into the array
1149 args[argnum].aligned_regs. The caller is responsible for deallocating
1150 the aligned_regs array if it is nonzero. */
1152 static void
1153 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1155 int i, j;
1157 for (i = 0; i < num_actuals; i++)
1158 if (args[i].reg != 0 && ! args[i].pass_on_stack
1159 && GET_CODE (args[i].reg) != PARALLEL
1160 && args[i].mode == BLKmode
1161 && MEM_P (args[i].value)
1162 && (MEM_ALIGN (args[i].value)
1163 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1165 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1166 int endian_correction = 0;
1168 if (args[i].partial)
1170 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1171 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1173 else
1175 args[i].n_aligned_regs
1176 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1179 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1181 /* Structures smaller than a word are normally aligned to the
1182 least significant byte. On a BYTES_BIG_ENDIAN machine,
1183 this means we must skip the empty high order bytes when
1184 calculating the bit offset. */
1185 if (bytes < UNITS_PER_WORD
1186 #ifdef BLOCK_REG_PADDING
1187 && (BLOCK_REG_PADDING (args[i].mode,
1188 TREE_TYPE (args[i].tree_value), 1)
1189 == PAD_DOWNWARD)
1190 #else
1191 && BYTES_BIG_ENDIAN
1192 #endif
1194 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1196 for (j = 0; j < args[i].n_aligned_regs; j++)
1198 rtx reg = gen_reg_rtx (word_mode);
1199 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1200 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1202 args[i].aligned_regs[j] = reg;
1203 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1204 word_mode, word_mode, false, NULL);
1206 /* There is no need to restrict this code to loading items
1207 in TYPE_ALIGN sized hunks. The bitfield instructions can
1208 load up entire word sized registers efficiently.
1210 ??? This may not be needed anymore.
1211 We use to emit a clobber here but that doesn't let later
1212 passes optimize the instructions we emit. By storing 0 into
1213 the register later passes know the first AND to zero out the
1214 bitfield being set in the register is unnecessary. The store
1215 of 0 will be deleted as will at least the first AND. */
1217 emit_move_insn (reg, const0_rtx);
1219 bytes -= bitsize / BITS_PER_UNIT;
1220 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1221 word_mode, word, false);
1226 /* The limit set by -Walloc-larger-than=. */
1227 static GTY(()) tree alloc_object_size_limit;
1229 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1230 setting if the option is specified, or to the maximum object size if it
1231 is not. Return the initialized value. */
1233 static tree
1234 alloc_max_size (void)
1236 if (alloc_object_size_limit)
1237 return alloc_object_size_limit;
1239 HOST_WIDE_INT limit = warn_alloc_size_limit;
1240 if (limit == HOST_WIDE_INT_MAX)
1241 limit = tree_to_shwi (TYPE_MAX_VALUE (ptrdiff_type_node));
1243 alloc_object_size_limit = build_int_cst (size_type_node, limit);
1245 return alloc_object_size_limit;
1248 /* Return true when EXP's range can be determined and set RANGE[] to it
1249 after adjusting it if necessary to make EXP a represents a valid size
1250 of object, or a valid size argument to an allocation function declared
1251 with attribute alloc_size (whose argument may be signed), or to a string
1252 manipulation function like memset. When ALLOW_ZERO is true, allow
1253 returning a range of [0, 0] for a size in an anti-range [1, N] where
1254 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1255 allocation functions like malloc but it is a valid argument to
1256 functions like memset. */
1258 bool
1259 get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
1261 if (tree_fits_uhwi_p (exp))
1263 /* EXP is a constant. */
1264 range[0] = range[1] = exp;
1265 return true;
1268 tree exptype = TREE_TYPE (exp);
1269 bool integral = INTEGRAL_TYPE_P (exptype);
1271 wide_int min, max;
1272 enum value_range_kind range_type;
1274 if (integral)
1275 range_type = determine_value_range (exp, &min, &max);
1276 else
1277 range_type = VR_VARYING;
1279 if (range_type == VR_VARYING)
1281 if (integral)
1283 /* Use the full range of the type of the expression when
1284 no value range information is available. */
1285 range[0] = TYPE_MIN_VALUE (exptype);
1286 range[1] = TYPE_MAX_VALUE (exptype);
1287 return true;
1290 range[0] = NULL_TREE;
1291 range[1] = NULL_TREE;
1292 return false;
1295 unsigned expprec = TYPE_PRECISION (exptype);
1297 bool signed_p = !TYPE_UNSIGNED (exptype);
1299 if (range_type == VR_ANTI_RANGE)
1301 if (signed_p)
1303 if (wi::les_p (max, 0))
1305 /* EXP is not in a strictly negative range. That means
1306 it must be in some (not necessarily strictly) positive
1307 range which includes zero. Since in signed to unsigned
1308 conversions negative values end up converted to large
1309 positive values, and otherwise they are not valid sizes,
1310 the resulting range is in both cases [0, TYPE_MAX]. */
1311 min = wi::zero (expprec);
1312 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1314 else if (wi::les_p (min - 1, 0))
1316 /* EXP is not in a negative-positive range. That means EXP
1317 is either negative, or greater than max. Since negative
1318 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1319 min = max + 1;
1320 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1322 else
1324 max = min - 1;
1325 min = wi::zero (expprec);
1328 else if (wi::eq_p (0, min - 1))
1330 /* EXP is unsigned and not in the range [1, MAX]. That means
1331 it's either zero or greater than MAX. Even though 0 would
1332 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1333 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1334 is greater than the limit the whole range is diagnosed. */
1335 if (allow_zero)
1336 min = max = wi::zero (expprec);
1337 else
1339 min = max + 1;
1340 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1343 else
1345 max = min - 1;
1346 min = wi::zero (expprec);
1350 range[0] = wide_int_to_tree (exptype, min);
1351 range[1] = wide_int_to_tree (exptype, max);
1353 return true;
1356 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1357 whose argument numbers given by IDX with values given by ARGS exceed
1358 the maximum object size or cause an unsigned oveflow (wrapping) when
1359 multiplied. FN is null when EXP is a call via a function pointer.
1360 When ARGS[0] is null the function does nothing. ARGS[1] may be null
1361 for functions like malloc, and non-null for those like calloc that
1362 are decorated with a two-argument attribute alloc_size. */
1364 void
1365 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1367 /* The range each of the (up to) two arguments is known to be in. */
1368 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1370 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1371 tree maxobjsize = alloc_max_size ();
1373 location_t loc = EXPR_LOCATION (exp);
1375 tree fntype = fn ? TREE_TYPE (fn) : TREE_TYPE (TREE_TYPE (exp));
1376 bool warned = false;
1378 /* Validate each argument individually. */
1379 for (unsigned i = 0; i != 2 && args[i]; ++i)
1381 if (TREE_CODE (args[i]) == INTEGER_CST)
1383 argrange[i][0] = args[i];
1384 argrange[i][1] = args[i];
1386 if (tree_int_cst_lt (args[i], integer_zero_node))
1388 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1389 "%Kargument %i value %qE is negative",
1390 exp, idx[i] + 1, args[i]);
1392 else if (integer_zerop (args[i]))
1394 /* Avoid issuing -Walloc-zero for allocation functions other
1395 than __builtin_alloca that are declared with attribute
1396 returns_nonnull because there's no portability risk. This
1397 avoids warning for such calls to libiberty's xmalloc and
1398 friends.
1399 Also avoid issuing the warning for calls to function named
1400 "alloca". */
1401 if (fn && fndecl_built_in_p (fn, BUILT_IN_ALLOCA)
1402 ? IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6
1403 : !lookup_attribute ("returns_nonnull",
1404 TYPE_ATTRIBUTES (fntype)))
1405 warned = warning_at (loc, OPT_Walloc_zero,
1406 "%Kargument %i value is zero",
1407 exp, idx[i] + 1);
1409 else if (tree_int_cst_lt (maxobjsize, args[i]))
1411 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1412 mode and with -fno-exceptions as a way to indicate array
1413 size overflow. There's no good way to detect C++98 here
1414 so avoid diagnosing these calls for all C++ modes. */
1415 if (i == 0
1416 && fn
1417 && !args[1]
1418 && lang_GNU_CXX ()
1419 && DECL_IS_OPERATOR_NEW_P (fn)
1420 && integer_all_onesp (args[i]))
1421 continue;
1423 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1424 "%Kargument %i value %qE exceeds "
1425 "maximum object size %E",
1426 exp, idx[i] + 1, args[i], maxobjsize);
1429 else if (TREE_CODE (args[i]) == SSA_NAME
1430 && get_size_range (args[i], argrange[i]))
1432 /* Verify that the argument's range is not negative (including
1433 upper bound of zero). */
1434 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1435 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1437 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1438 "%Kargument %i range [%E, %E] is negative",
1439 exp, idx[i] + 1,
1440 argrange[i][0], argrange[i][1]);
1442 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1444 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1445 "%Kargument %i range [%E, %E] exceeds "
1446 "maximum object size %E",
1447 exp, idx[i] + 1,
1448 argrange[i][0], argrange[i][1],
1449 maxobjsize);
1454 if (!argrange[0])
1455 return;
1457 /* For a two-argument alloc_size, validate the product of the two
1458 arguments if both of their values or ranges are known. */
1459 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1460 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1461 && !integer_onep (argrange[0][0])
1462 && !integer_onep (argrange[1][0]))
1464 /* Check for overflow in the product of a function decorated with
1465 attribute alloc_size (X, Y). */
1466 unsigned szprec = TYPE_PRECISION (size_type_node);
1467 wide_int x = wi::to_wide (argrange[0][0], szprec);
1468 wide_int y = wi::to_wide (argrange[1][0], szprec);
1470 wi::overflow_type vflow;
1471 wide_int prod = wi::umul (x, y, &vflow);
1473 if (vflow)
1474 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1475 "%Kproduct %<%E * %E%> of arguments %i and %i "
1476 "exceeds %<SIZE_MAX%>",
1477 exp, argrange[0][0], argrange[1][0],
1478 idx[0] + 1, idx[1] + 1);
1479 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1480 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1481 "%Kproduct %<%E * %E%> of arguments %i and %i "
1482 "exceeds maximum object size %E",
1483 exp, argrange[0][0], argrange[1][0],
1484 idx[0] + 1, idx[1] + 1,
1485 maxobjsize);
1487 if (warned)
1489 /* Print the full range of each of the two arguments to make
1490 it clear when it is, in fact, in a range and not constant. */
1491 if (argrange[0][0] != argrange [0][1])
1492 inform (loc, "argument %i in the range [%E, %E]",
1493 idx[0] + 1, argrange[0][0], argrange[0][1]);
1494 if (argrange[1][0] != argrange [1][1])
1495 inform (loc, "argument %i in the range [%E, %E]",
1496 idx[1] + 1, argrange[1][0], argrange[1][1]);
1500 if (warned && fn)
1502 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1504 if (DECL_IS_BUILTIN (fn))
1505 inform (loc,
1506 "in a call to built-in allocation function %qD", fn);
1507 else
1508 inform (fnloc,
1509 "in a call to allocation function %qD declared here", fn);
1513 /* If EXPR refers to a character array or pointer declared attribute
1514 nonstring return a decl for that array or pointer and set *REF to
1515 the referenced enclosing object or pointer. Otherwise returns
1516 null. */
1518 tree
1519 get_attr_nonstring_decl (tree expr, tree *ref)
1521 tree decl = expr;
1522 tree var = NULL_TREE;
1523 if (TREE_CODE (decl) == SSA_NAME)
1525 gimple *def = SSA_NAME_DEF_STMT (decl);
1527 if (is_gimple_assign (def))
1529 tree_code code = gimple_assign_rhs_code (def);
1530 if (code == ADDR_EXPR
1531 || code == COMPONENT_REF
1532 || code == VAR_DECL)
1533 decl = gimple_assign_rhs1 (def);
1535 else
1536 var = SSA_NAME_VAR (decl);
1539 if (TREE_CODE (decl) == ADDR_EXPR)
1540 decl = TREE_OPERAND (decl, 0);
1542 /* To simplify calling code, store the referenced DECL regardless of
1543 the attribute determined below, but avoid storing the SSA_NAME_VAR
1544 obtained above (it's not useful for dataflow purposes). */
1545 if (ref)
1546 *ref = decl;
1548 /* Use the SSA_NAME_VAR that was determined above to see if it's
1549 declared nonstring. Otherwise drill down into the referenced
1550 DECL. */
1551 if (var)
1552 decl = var;
1553 else if (TREE_CODE (decl) == ARRAY_REF)
1554 decl = TREE_OPERAND (decl, 0);
1555 else if (TREE_CODE (decl) == COMPONENT_REF)
1556 decl = TREE_OPERAND (decl, 1);
1557 else if (TREE_CODE (decl) == MEM_REF)
1558 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1560 if (DECL_P (decl)
1561 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1562 return decl;
1564 return NULL_TREE;
1567 /* Warn about passing a non-string array/pointer to a function that
1568 expects a nul-terminated string argument. */
1570 void
1571 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1573 if (!fndecl || !fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
1574 return;
1576 if (TREE_NO_WARNING (exp) || !warn_stringop_overflow)
1577 return;
1579 /* Avoid clearly invalid calls (more checking done below). */
1580 unsigned nargs = call_expr_nargs (exp);
1581 if (!nargs)
1582 return;
1584 /* The bound argument to a bounded string function like strncpy. */
1585 tree bound = NULL_TREE;
1587 /* The longest known or possible string argument to one of the comparison
1588 functions. If the length is less than the bound it is used instead.
1589 Since the length is only used for warning and not for code generation
1590 disable strict mode in the calls to get_range_strlen below. */
1591 tree maxlen = NULL_TREE;
1593 /* It's safe to call "bounded" string functions with a non-string
1594 argument since the functions provide an explicit bound for this
1595 purpose. The exception is strncat where the bound may refer to
1596 either the destination or the source. */
1597 int fncode = DECL_FUNCTION_CODE (fndecl);
1598 switch (fncode)
1600 case BUILT_IN_STRCMP:
1601 case BUILT_IN_STRNCMP:
1602 case BUILT_IN_STRNCASECMP:
1604 /* For these, if one argument refers to one or more of a set
1605 of string constants or arrays of known size, determine
1606 the range of their known or possible lengths and use it
1607 conservatively as the bound for the unbounded function,
1608 and to adjust the range of the bound of the bounded ones. */
1609 for (unsigned argno = 0;
1610 argno < MIN (nargs, 2)
1611 && !(maxlen && TREE_CODE (maxlen) == INTEGER_CST); argno++)
1613 tree arg = CALL_EXPR_ARG (exp, argno);
1614 if (!get_attr_nonstring_decl (arg))
1616 c_strlen_data lendata = { };
1617 /* Set MAXBOUND to an arbitrary non-null non-integer
1618 node as a request to have it set to the length of
1619 the longest string in a PHI. */
1620 lendata.maxbound = arg;
1621 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1622 maxlen = lendata.maxbound;
1626 /* Fall through. */
1628 case BUILT_IN_STRNCAT:
1629 case BUILT_IN_STPNCPY:
1630 case BUILT_IN_STRNCPY:
1631 if (nargs > 2)
1632 bound = CALL_EXPR_ARG (exp, 2);
1633 break;
1635 case BUILT_IN_STRNDUP:
1636 if (nargs > 1)
1637 bound = CALL_EXPR_ARG (exp, 1);
1638 break;
1640 case BUILT_IN_STRNLEN:
1642 tree arg = CALL_EXPR_ARG (exp, 0);
1643 if (!get_attr_nonstring_decl (arg))
1645 c_strlen_data lendata = { };
1646 /* Set MAXBOUND to an arbitrary non-null non-integer
1647 node as a request to have it set to the length of
1648 the longest string in a PHI. */
1649 lendata.maxbound = arg;
1650 get_range_strlen (arg, &lendata, /* eltsize = */ 1);
1651 maxlen = lendata.maxbound;
1653 if (nargs > 1)
1654 bound = CALL_EXPR_ARG (exp, 1);
1655 break;
1658 default:
1659 break;
1662 /* Determine the range of the bound argument (if specified). */
1663 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1664 if (bound)
1666 STRIP_NOPS (bound);
1667 get_size_range (bound, bndrng);
1670 location_t loc = EXPR_LOCATION (exp);
1672 if (bndrng[0])
1674 /* Diagnose excessive bound prior the adjustment below and
1675 regardless of attribute nonstring. */
1676 tree maxobjsize = max_object_size ();
1677 if (tree_int_cst_lt (maxobjsize, bndrng[0]))
1679 if (tree_int_cst_equal (bndrng[0], bndrng[1]))
1680 warning_at (loc, OPT_Wstringop_overflow_,
1681 "%K%qD specified bound %E "
1682 "exceeds maximum object size %E",
1683 exp, fndecl, bndrng[0], maxobjsize);
1684 else
1685 warning_at (loc, OPT_Wstringop_overflow_,
1686 "%K%qD specified bound [%E, %E] "
1687 "exceeds maximum object size %E",
1688 exp, fndecl, bndrng[0], bndrng[1], maxobjsize);
1689 return;
1693 if (maxlen && !integer_all_onesp (maxlen))
1695 /* Add one for the nul. */
1696 maxlen = const_binop (PLUS_EXPR, TREE_TYPE (maxlen), maxlen,
1697 size_one_node);
1699 if (!bndrng[0])
1701 /* Conservatively use the upper bound of the lengths for
1702 both the lower and the upper bound of the operation. */
1703 bndrng[0] = maxlen;
1704 bndrng[1] = maxlen;
1705 bound = void_type_node;
1707 else if (maxlen)
1709 /* Replace the bound on the operation with the upper bound
1710 of the length of the string if the latter is smaller. */
1711 if (tree_int_cst_lt (maxlen, bndrng[0]))
1712 bndrng[0] = maxlen;
1713 else if (tree_int_cst_lt (maxlen, bndrng[1]))
1714 bndrng[1] = maxlen;
1718 /* Iterate over the built-in function's formal arguments and check
1719 each const char* against the actual argument. If the actual
1720 argument is declared attribute non-string issue a warning unless
1721 the argument's maximum length is bounded. */
1722 function_args_iterator it;
1723 function_args_iter_init (&it, TREE_TYPE (fndecl));
1725 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1727 /* Avoid iterating past the declared argument in a call
1728 to function declared without a prototype. */
1729 if (argno >= nargs)
1730 break;
1732 tree argtype = function_args_iter_cond (&it);
1733 if (!argtype)
1734 break;
1736 if (TREE_CODE (argtype) != POINTER_TYPE)
1737 continue;
1739 argtype = TREE_TYPE (argtype);
1741 if (TREE_CODE (argtype) != INTEGER_TYPE
1742 || !TYPE_READONLY (argtype))
1743 continue;
1745 argtype = TYPE_MAIN_VARIANT (argtype);
1746 if (argtype != char_type_node)
1747 continue;
1749 tree callarg = CALL_EXPR_ARG (exp, argno);
1750 if (TREE_CODE (callarg) == ADDR_EXPR)
1751 callarg = TREE_OPERAND (callarg, 0);
1753 /* See if the destination is declared with attribute "nonstring". */
1754 tree decl = get_attr_nonstring_decl (callarg);
1755 if (!decl)
1756 continue;
1758 /* The maximum number of array elements accessed. */
1759 offset_int wibnd = 0;
1761 if (argno && fncode == BUILT_IN_STRNCAT)
1763 /* See if the bound in strncat is derived from the length
1764 of the strlen of the destination (as it's expected to be).
1765 If so, reset BOUND and FNCODE to trigger a warning. */
1766 tree dstarg = CALL_EXPR_ARG (exp, 0);
1767 if (is_strlen_related_p (dstarg, bound))
1769 /* The bound applies to the destination, not to the source,
1770 so reset these to trigger a warning without mentioning
1771 the bound. */
1772 bound = NULL;
1773 fncode = 0;
1775 else if (bndrng[1])
1776 /* Use the upper bound of the range for strncat. */
1777 wibnd = wi::to_offset (bndrng[1]);
1779 else if (bndrng[0])
1780 /* Use the lower bound of the range for functions other than
1781 strncat. */
1782 wibnd = wi::to_offset (bndrng[0]);
1784 /* Determine the size of the argument array if it is one. */
1785 offset_int asize = wibnd;
1786 bool known_size = false;
1787 tree type = TREE_TYPE (decl);
1789 /* Determine the array size. For arrays of unknown bound and
1790 pointers reset BOUND to trigger the appropriate warning. */
1791 if (TREE_CODE (type) == ARRAY_TYPE)
1793 if (tree arrbnd = TYPE_DOMAIN (type))
1795 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1797 asize = wi::to_offset (arrbnd) + 1;
1798 known_size = true;
1801 else if (bound == void_type_node)
1802 bound = NULL_TREE;
1804 else if (bound == void_type_node)
1805 bound = NULL_TREE;
1807 /* In a call to strncat with a bound in a range whose lower but
1808 not upper bound is less than the array size, reset ASIZE to
1809 be the same as the bound and the other variable to trigger
1810 the apprpriate warning below. */
1811 if (fncode == BUILT_IN_STRNCAT
1812 && bndrng[0] != bndrng[1]
1813 && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
1814 && (!known_size
1815 || wi::ltu_p (asize, wibnd)))
1817 asize = wibnd;
1818 bound = NULL_TREE;
1819 fncode = 0;
1822 bool warned = false;
1824 auto_diagnostic_group d;
1825 if (wi::ltu_p (asize, wibnd))
1827 if (bndrng[0] == bndrng[1])
1828 warned = warning_at (loc, OPT_Wstringop_overflow_,
1829 "%qD argument %i declared attribute "
1830 "%<nonstring%> is smaller than the specified "
1831 "bound %wu",
1832 fndecl, argno + 1, wibnd.to_uhwi ());
1833 else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
1834 warned = warning_at (loc, OPT_Wstringop_overflow_,
1835 "%qD argument %i declared attribute "
1836 "%<nonstring%> is smaller than "
1837 "the specified bound [%E, %E]",
1838 fndecl, argno + 1, bndrng[0], bndrng[1]);
1839 else
1840 warned = warning_at (loc, OPT_Wstringop_overflow_,
1841 "%qD argument %i declared attribute "
1842 "%<nonstring%> may be smaller than "
1843 "the specified bound [%E, %E]",
1844 fndecl, argno + 1, bndrng[0], bndrng[1]);
1846 else if (fncode == BUILT_IN_STRNCAT)
1847 ; /* Avoid warning for calls to strncat() when the bound
1848 is equal to the size of the non-string argument. */
1849 else if (!bound)
1850 warned = warning_at (loc, OPT_Wstringop_overflow_,
1851 "%qD argument %i declared attribute %<nonstring%>",
1852 fndecl, argno + 1);
1854 if (warned)
1855 inform (DECL_SOURCE_LOCATION (decl),
1856 "argument %qD declared here", decl);
1860 /* Issue an error if CALL_EXPR was flagged as requiring
1861 tall-call optimization. */
1863 static void
1864 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1866 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1867 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1868 return;
1870 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1873 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1874 CALL_EXPR EXP.
1876 NUM_ACTUALS is the total number of parameters.
1878 N_NAMED_ARGS is the total number of named arguments.
1880 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1881 value, or null.
1883 FNDECL is the tree code for the target of this call (if known)
1885 ARGS_SO_FAR holds state needed by the target to know where to place
1886 the next argument.
1888 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1889 for arguments which are passed in registers.
1891 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1892 and may be modified by this routine.
1894 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1895 flags which may be modified by this routine.
1897 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1898 that requires allocation of stack space.
1900 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1901 the thunked-to function. */
1903 static void
1904 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1905 struct arg_data *args,
1906 struct args_size *args_size,
1907 int n_named_args ATTRIBUTE_UNUSED,
1908 tree exp, tree struct_value_addr_value,
1909 tree fndecl, tree fntype,
1910 cumulative_args_t args_so_far,
1911 int reg_parm_stack_space,
1912 rtx *old_stack_level,
1913 poly_int64_pod *old_pending_adj,
1914 int *must_preallocate, int *ecf_flags,
1915 bool *may_tailcall, bool call_from_thunk_p)
1917 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1918 location_t loc = EXPR_LOCATION (exp);
1920 /* Count arg position in order args appear. */
1921 int argpos;
1923 int i;
1925 args_size->constant = 0;
1926 args_size->var = 0;
1928 bitmap_obstack_initialize (NULL);
1930 /* In this loop, we consider args in the order they are written.
1931 We fill up ARGS from the back. */
1933 i = num_actuals - 1;
1935 int j = i;
1936 call_expr_arg_iterator iter;
1937 tree arg;
1938 bitmap slots = NULL;
1940 if (struct_value_addr_value)
1942 args[j].tree_value = struct_value_addr_value;
1943 j--;
1945 argpos = 0;
1946 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1948 tree argtype = TREE_TYPE (arg);
1950 if (targetm.calls.split_complex_arg
1951 && argtype
1952 && TREE_CODE (argtype) == COMPLEX_TYPE
1953 && targetm.calls.split_complex_arg (argtype))
1955 tree subtype = TREE_TYPE (argtype);
1956 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1957 j--;
1958 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1960 else
1961 args[j].tree_value = arg;
1962 j--;
1963 argpos++;
1966 if (slots)
1967 BITMAP_FREE (slots);
1970 bitmap_obstack_release (NULL);
1972 /* Extract attribute alloc_size from the type of the called expression
1973 (which could be a function or a function pointer) and if set, store
1974 the indices of the corresponding arguments in ALLOC_IDX, and then
1975 the actual argument(s) at those indices in ALLOC_ARGS. */
1976 int alloc_idx[2] = { -1, -1 };
1977 if (tree alloc_size = lookup_attribute ("alloc_size",
1978 TYPE_ATTRIBUTES (fntype)))
1980 tree args = TREE_VALUE (alloc_size);
1981 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
1982 if (TREE_CHAIN (args))
1983 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
1986 /* Array for up to the two attribute alloc_size arguments. */
1987 tree alloc_args[] = { NULL_TREE, NULL_TREE };
1989 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1990 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1992 tree type = TREE_TYPE (args[i].tree_value);
1993 int unsignedp;
1995 /* Replace erroneous argument with constant zero. */
1996 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1997 args[i].tree_value = integer_zero_node, type = integer_type_node;
1999 /* If TYPE is a transparent union or record, pass things the way
2000 we would pass the first field of the union or record. We have
2001 already verified that the modes are the same. */
2002 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
2003 type = TREE_TYPE (first_field (type));
2005 /* Decide where to pass this arg.
2007 args[i].reg is nonzero if all or part is passed in registers.
2009 args[i].partial is nonzero if part but not all is passed in registers,
2010 and the exact value says how many bytes are passed in registers.
2012 args[i].pass_on_stack is nonzero if the argument must at least be
2013 computed on the stack. It may then be loaded back into registers
2014 if args[i].reg is nonzero.
2016 These decisions are driven by the FUNCTION_... macros and must agree
2017 with those made by function.c. */
2019 /* See if this argument should be passed by invisible reference. */
2020 function_arg_info arg (type, argpos < n_named_args);
2021 if (pass_by_reference (args_so_far_pnt, arg))
2023 bool callee_copies;
2024 tree base = NULL_TREE;
2026 callee_copies = reference_callee_copied (args_so_far_pnt, arg);
2028 /* If we're compiling a thunk, pass through invisible references
2029 instead of making a copy. */
2030 if (call_from_thunk_p
2031 || (callee_copies
2032 && !TREE_ADDRESSABLE (type)
2033 && (base = get_base_address (args[i].tree_value))
2034 && TREE_CODE (base) != SSA_NAME
2035 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
2037 /* We may have turned the parameter value into an SSA name.
2038 Go back to the original parameter so we can take the
2039 address. */
2040 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
2042 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
2043 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
2044 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
2046 /* Argument setup code may have copied the value to register. We
2047 revert that optimization now because the tail call code must
2048 use the original location. */
2049 if (TREE_CODE (args[i].tree_value) == PARM_DECL
2050 && !MEM_P (DECL_RTL (args[i].tree_value))
2051 && DECL_INCOMING_RTL (args[i].tree_value)
2052 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
2053 set_decl_rtl (args[i].tree_value,
2054 DECL_INCOMING_RTL (args[i].tree_value));
2056 mark_addressable (args[i].tree_value);
2058 /* We can't use sibcalls if a callee-copied argument is
2059 stored in the current function's frame. */
2060 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2062 *may_tailcall = false;
2063 maybe_complain_about_tail_call (exp,
2064 "a callee-copied argument is"
2065 " stored in the current"
2066 " function's frame");
2069 args[i].tree_value = build_fold_addr_expr_loc (loc,
2070 args[i].tree_value);
2071 type = TREE_TYPE (args[i].tree_value);
2073 if (*ecf_flags & ECF_CONST)
2074 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2076 else
2078 /* We make a copy of the object and pass the address to the
2079 function being called. */
2080 rtx copy;
2082 if (!COMPLETE_TYPE_P (type)
2083 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2084 || (flag_stack_check == GENERIC_STACK_CHECK
2085 && compare_tree_int (TYPE_SIZE_UNIT (type),
2086 STACK_CHECK_MAX_VAR_SIZE) > 0))
2088 /* This is a variable-sized object. Make space on the stack
2089 for it. */
2090 rtx size_rtx = expr_size (args[i].tree_value);
2092 if (*old_stack_level == 0)
2094 emit_stack_save (SAVE_BLOCK, old_stack_level);
2095 *old_pending_adj = pending_stack_adjust;
2096 pending_stack_adjust = 0;
2099 /* We can pass TRUE as the 4th argument because we just
2100 saved the stack pointer and will restore it right after
2101 the call. */
2102 copy = allocate_dynamic_stack_space (size_rtx,
2103 TYPE_ALIGN (type),
2104 TYPE_ALIGN (type),
2105 max_int_size_in_bytes
2106 (type),
2107 true);
2108 copy = gen_rtx_MEM (BLKmode, copy);
2109 set_mem_attributes (copy, type, 1);
2111 else
2112 copy = assign_temp (type, 1, 0);
2114 store_expr (args[i].tree_value, copy, 0, false, false);
2116 /* Just change the const function to pure and then let
2117 the next test clear the pure based on
2118 callee_copies. */
2119 if (*ecf_flags & ECF_CONST)
2121 *ecf_flags &= ~ECF_CONST;
2122 *ecf_flags |= ECF_PURE;
2125 if (!callee_copies && *ecf_flags & ECF_PURE)
2126 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2128 args[i].tree_value
2129 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2130 type = TREE_TYPE (args[i].tree_value);
2131 *may_tailcall = false;
2132 maybe_complain_about_tail_call (exp,
2133 "argument must be passed"
2134 " by copying");
2136 arg.pass_by_reference = true;
2139 unsignedp = TYPE_UNSIGNED (type);
2140 arg.type = type;
2141 arg.mode
2142 = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2143 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2145 args[i].unsignedp = unsignedp;
2146 args[i].mode = arg.mode;
2148 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2150 args[i].reg = targetm.calls.function_arg (args_so_far, arg);
2152 if (args[i].reg && CONST_INT_P (args[i].reg))
2153 args[i].reg = NULL;
2155 /* If this is a sibling call and the machine has register windows, the
2156 register window has to be unwinded before calling the routine, so
2157 arguments have to go into the incoming registers. */
2158 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2159 args[i].tail_call_reg
2160 = targetm.calls.function_incoming_arg (args_so_far, arg);
2161 else
2162 args[i].tail_call_reg = args[i].reg;
2164 if (args[i].reg)
2165 args[i].partial = targetm.calls.arg_partial_bytes (args_so_far, arg);
2167 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (arg);
2169 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2170 it means that we are to pass this arg in the register(s) designated
2171 by the PARALLEL, but also to pass it in the stack. */
2172 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2173 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2174 args[i].pass_on_stack = 1;
2176 /* If this is an addressable type, we must preallocate the stack
2177 since we must evaluate the object into its final location.
2179 If this is to be passed in both registers and the stack, it is simpler
2180 to preallocate. */
2181 if (TREE_ADDRESSABLE (type)
2182 || (args[i].pass_on_stack && args[i].reg != 0))
2183 *must_preallocate = 1;
2185 /* Compute the stack-size of this argument. */
2186 if (args[i].reg == 0 || args[i].partial != 0
2187 || reg_parm_stack_space > 0
2188 || args[i].pass_on_stack)
2189 locate_and_pad_parm (arg.mode, type,
2190 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2192 #else
2193 args[i].reg != 0,
2194 #endif
2195 reg_parm_stack_space,
2196 args[i].pass_on_stack ? 0 : args[i].partial,
2197 fndecl, args_size, &args[i].locate);
2198 #ifdef BLOCK_REG_PADDING
2199 else
2200 /* The argument is passed entirely in registers. See at which
2201 end it should be padded. */
2202 args[i].locate.where_pad =
2203 BLOCK_REG_PADDING (arg.mode, type,
2204 int_size_in_bytes (type) <= UNITS_PER_WORD);
2205 #endif
2207 /* Update ARGS_SIZE, the total stack space for args so far. */
2209 args_size->constant += args[i].locate.size.constant;
2210 if (args[i].locate.size.var)
2211 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2213 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2214 have been used, etc. */
2216 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
2217 promoted_mode used for function_arg above. However, the
2218 corresponding handling of incoming arguments in function.c
2219 does pass the promoted mode. */
2220 arg.mode = TYPE_MODE (type);
2221 targetm.calls.function_arg_advance (args_so_far, arg);
2223 /* Store argument values for functions decorated with attribute
2224 alloc_size. */
2225 if (argpos == alloc_idx[0])
2226 alloc_args[0] = args[i].tree_value;
2227 else if (argpos == alloc_idx[1])
2228 alloc_args[1] = args[i].tree_value;
2231 if (alloc_args[0])
2233 /* Check the arguments of functions decorated with attribute
2234 alloc_size. */
2235 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2238 /* Detect passing non-string arguments to functions expecting
2239 nul-terminated strings. */
2240 maybe_warn_nonstring_arg (fndecl, exp);
2243 /* Update ARGS_SIZE to contain the total size for the argument block.
2244 Return the original constant component of the argument block's size.
2246 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2247 for arguments passed in registers. */
2249 static poly_int64
2250 compute_argument_block_size (int reg_parm_stack_space,
2251 struct args_size *args_size,
2252 tree fndecl ATTRIBUTE_UNUSED,
2253 tree fntype ATTRIBUTE_UNUSED,
2254 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2256 poly_int64 unadjusted_args_size = args_size->constant;
2258 /* For accumulate outgoing args mode we don't need to align, since the frame
2259 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2260 backends from generating misaligned frame sizes. */
2261 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2262 preferred_stack_boundary = STACK_BOUNDARY;
2264 /* Compute the actual size of the argument block required. The variable
2265 and constant sizes must be combined, the size may have to be rounded,
2266 and there may be a minimum required size. */
2268 if (args_size->var)
2270 args_size->var = ARGS_SIZE_TREE (*args_size);
2271 args_size->constant = 0;
2273 preferred_stack_boundary /= BITS_PER_UNIT;
2274 if (preferred_stack_boundary > 1)
2276 /* We don't handle this case yet. To handle it correctly we have
2277 to add the delta, round and subtract the delta.
2278 Currently no machine description requires this support. */
2279 gcc_assert (multiple_p (stack_pointer_delta,
2280 preferred_stack_boundary));
2281 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2284 if (reg_parm_stack_space > 0)
2286 args_size->var
2287 = size_binop (MAX_EXPR, args_size->var,
2288 ssize_int (reg_parm_stack_space));
2290 /* The area corresponding to register parameters is not to count in
2291 the size of the block we need. So make the adjustment. */
2292 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2293 args_size->var
2294 = size_binop (MINUS_EXPR, args_size->var,
2295 ssize_int (reg_parm_stack_space));
2298 else
2300 preferred_stack_boundary /= BITS_PER_UNIT;
2301 if (preferred_stack_boundary < 1)
2302 preferred_stack_boundary = 1;
2303 args_size->constant = (aligned_upper_bound (args_size->constant
2304 + stack_pointer_delta,
2305 preferred_stack_boundary)
2306 - stack_pointer_delta);
2308 args_size->constant = upper_bound (args_size->constant,
2309 reg_parm_stack_space);
2311 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2312 args_size->constant -= reg_parm_stack_space;
2314 return unadjusted_args_size;
2317 /* Precompute parameters as needed for a function call.
2319 FLAGS is mask of ECF_* constants.
2321 NUM_ACTUALS is the number of arguments.
2323 ARGS is an array containing information for each argument; this
2324 routine fills in the INITIAL_VALUE and VALUE fields for each
2325 precomputed argument. */
2327 static void
2328 precompute_arguments (int num_actuals, struct arg_data *args)
2330 int i;
2332 /* If this is a libcall, then precompute all arguments so that we do not
2333 get extraneous instructions emitted as part of the libcall sequence. */
2335 /* If we preallocated the stack space, and some arguments must be passed
2336 on the stack, then we must precompute any parameter which contains a
2337 function call which will store arguments on the stack.
2338 Otherwise, evaluating the parameter may clobber previous parameters
2339 which have already been stored into the stack. (we have code to avoid
2340 such case by saving the outgoing stack arguments, but it results in
2341 worse code) */
2342 if (!ACCUMULATE_OUTGOING_ARGS)
2343 return;
2345 for (i = 0; i < num_actuals; i++)
2347 tree type;
2348 machine_mode mode;
2350 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2351 continue;
2353 /* If this is an addressable type, we cannot pre-evaluate it. */
2354 type = TREE_TYPE (args[i].tree_value);
2355 gcc_assert (!TREE_ADDRESSABLE (type));
2357 args[i].initial_value = args[i].value
2358 = expand_normal (args[i].tree_value);
2360 mode = TYPE_MODE (type);
2361 if (mode != args[i].mode)
2363 int unsignedp = args[i].unsignedp;
2364 args[i].value
2365 = convert_modes (args[i].mode, mode,
2366 args[i].value, args[i].unsignedp);
2368 /* CSE will replace this only if it contains args[i].value
2369 pseudo, so convert it down to the declared mode using
2370 a SUBREG. */
2371 if (REG_P (args[i].value)
2372 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2373 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2375 args[i].initial_value
2376 = gen_lowpart_SUBREG (mode, args[i].value);
2377 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2378 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2384 /* Given the current state of MUST_PREALLOCATE and information about
2385 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2386 compute and return the final value for MUST_PREALLOCATE. */
2388 static int
2389 finalize_must_preallocate (int must_preallocate, int num_actuals,
2390 struct arg_data *args, struct args_size *args_size)
2392 /* See if we have or want to preallocate stack space.
2394 If we would have to push a partially-in-regs parm
2395 before other stack parms, preallocate stack space instead.
2397 If the size of some parm is not a multiple of the required stack
2398 alignment, we must preallocate.
2400 If the total size of arguments that would otherwise create a copy in
2401 a temporary (such as a CALL) is more than half the total argument list
2402 size, preallocation is faster.
2404 Another reason to preallocate is if we have a machine (like the m88k)
2405 where stack alignment is required to be maintained between every
2406 pair of insns, not just when the call is made. However, we assume here
2407 that such machines either do not have push insns (and hence preallocation
2408 would occur anyway) or the problem is taken care of with
2409 PUSH_ROUNDING. */
2411 if (! must_preallocate)
2413 int partial_seen = 0;
2414 poly_int64 copy_to_evaluate_size = 0;
2415 int i;
2417 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2419 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2420 partial_seen = 1;
2421 else if (partial_seen && args[i].reg == 0)
2422 must_preallocate = 1;
2424 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2425 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2426 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2427 || TREE_CODE (args[i].tree_value) == COND_EXPR
2428 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2429 copy_to_evaluate_size
2430 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2433 if (maybe_ne (args_size->constant, 0)
2434 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2435 must_preallocate = 1;
2437 return must_preallocate;
2440 /* If we preallocated stack space, compute the address of each argument
2441 and store it into the ARGS array.
2443 We need not ensure it is a valid memory address here; it will be
2444 validized when it is used.
2446 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2448 static void
2449 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2451 if (argblock)
2453 rtx arg_reg = argblock;
2454 int i;
2455 poly_int64 arg_offset = 0;
2457 if (GET_CODE (argblock) == PLUS)
2459 arg_reg = XEXP (argblock, 0);
2460 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2463 for (i = 0; i < num_actuals; i++)
2465 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2466 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2467 rtx addr;
2468 unsigned int align, boundary;
2469 poly_uint64 units_on_stack = 0;
2470 machine_mode partial_mode = VOIDmode;
2472 /* Skip this parm if it will not be passed on the stack. */
2473 if (! args[i].pass_on_stack
2474 && args[i].reg != 0
2475 && args[i].partial == 0)
2476 continue;
2478 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2479 continue;
2481 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2482 addr = plus_constant (Pmode, addr, arg_offset);
2484 if (args[i].partial != 0)
2486 /* Only part of the parameter is being passed on the stack.
2487 Generate a simple memory reference of the correct size. */
2488 units_on_stack = args[i].locate.size.constant;
2489 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2490 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2491 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2492 set_mem_size (args[i].stack, units_on_stack);
2494 else
2496 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2497 set_mem_attributes (args[i].stack,
2498 TREE_TYPE (args[i].tree_value), 1);
2500 align = BITS_PER_UNIT;
2501 boundary = args[i].locate.boundary;
2502 poly_int64 offset_val;
2503 if (args[i].locate.where_pad != PAD_DOWNWARD)
2504 align = boundary;
2505 else if (poly_int_rtx_p (offset, &offset_val))
2507 align = least_bit_hwi (boundary);
2508 unsigned int offset_align
2509 = known_alignment (offset_val) * BITS_PER_UNIT;
2510 if (offset_align != 0)
2511 align = MIN (align, offset_align);
2513 set_mem_align (args[i].stack, align);
2515 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2516 addr = plus_constant (Pmode, addr, arg_offset);
2518 if (args[i].partial != 0)
2520 /* Only part of the parameter is being passed on the stack.
2521 Generate a simple memory reference of the correct size.
2523 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2524 set_mem_size (args[i].stack_slot, units_on_stack);
2526 else
2528 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2529 set_mem_attributes (args[i].stack_slot,
2530 TREE_TYPE (args[i].tree_value), 1);
2532 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2534 /* Function incoming arguments may overlap with sibling call
2535 outgoing arguments and we cannot allow reordering of reads
2536 from function arguments with stores to outgoing arguments
2537 of sibling calls. */
2538 set_mem_alias_set (args[i].stack, 0);
2539 set_mem_alias_set (args[i].stack_slot, 0);
2544 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2545 in a call instruction.
2547 FNDECL is the tree node for the target function. For an indirect call
2548 FNDECL will be NULL_TREE.
2550 ADDR is the operand 0 of CALL_EXPR for this call. */
2552 static rtx
2553 rtx_for_function_call (tree fndecl, tree addr)
2555 rtx funexp;
2557 /* Get the function to call, in the form of RTL. */
2558 if (fndecl)
2560 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2561 TREE_USED (fndecl) = 1;
2563 /* Get a SYMBOL_REF rtx for the function address. */
2564 funexp = XEXP (DECL_RTL (fndecl), 0);
2566 else
2567 /* Generate an rtx (probably a pseudo-register) for the address. */
2569 push_temp_slots ();
2570 funexp = expand_normal (addr);
2571 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2573 return funexp;
2576 /* Return the static chain for this function, if any. */
2579 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2581 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2582 return NULL;
2584 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2587 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2588 static struct
2590 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2591 or NULL_RTX if none has been scanned yet. */
2592 rtx_insn *scan_start;
2593 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2594 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2595 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2596 with fixed offset, or PC if this is with variable or unknown offset. */
2597 vec<rtx> cache;
2598 } internal_arg_pointer_exp_state;
2600 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2602 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2603 the tail call sequence, starting with first insn that hasn't been
2604 scanned yet, and note for each pseudo on the LHS whether it is based
2605 on crtl->args.internal_arg_pointer or not, and what offset from that
2606 that pointer it has. */
2608 static void
2609 internal_arg_pointer_based_exp_scan (void)
2611 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2613 if (scan_start == NULL_RTX)
2614 insn = get_insns ();
2615 else
2616 insn = NEXT_INSN (scan_start);
2618 while (insn)
2620 rtx set = single_set (insn);
2621 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2623 rtx val = NULL_RTX;
2624 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2625 /* Punt on pseudos set multiple times. */
2626 if (idx < internal_arg_pointer_exp_state.cache.length ()
2627 && (internal_arg_pointer_exp_state.cache[idx]
2628 != NULL_RTX))
2629 val = pc_rtx;
2630 else
2631 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2632 if (val != NULL_RTX)
2634 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2635 internal_arg_pointer_exp_state.cache
2636 .safe_grow_cleared (idx + 1);
2637 internal_arg_pointer_exp_state.cache[idx] = val;
2640 if (NEXT_INSN (insn) == NULL_RTX)
2641 scan_start = insn;
2642 insn = NEXT_INSN (insn);
2645 internal_arg_pointer_exp_state.scan_start = scan_start;
2648 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2649 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2650 it with fixed offset, or PC if this is with variable or unknown offset.
2651 TOPLEVEL is true if the function is invoked at the topmost level. */
2653 static rtx
2654 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2656 if (CONSTANT_P (rtl))
2657 return NULL_RTX;
2659 if (rtl == crtl->args.internal_arg_pointer)
2660 return const0_rtx;
2662 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2663 return NULL_RTX;
2665 poly_int64 offset;
2666 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2668 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2669 if (val == NULL_RTX || val == pc_rtx)
2670 return val;
2671 return plus_constant (Pmode, val, offset);
2674 /* When called at the topmost level, scan pseudo assignments in between the
2675 last scanned instruction in the tail call sequence and the latest insn
2676 in that sequence. */
2677 if (toplevel)
2678 internal_arg_pointer_based_exp_scan ();
2680 if (REG_P (rtl))
2682 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2683 if (idx < internal_arg_pointer_exp_state.cache.length ())
2684 return internal_arg_pointer_exp_state.cache[idx];
2686 return NULL_RTX;
2689 subrtx_iterator::array_type array;
2690 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2692 const_rtx x = *iter;
2693 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2694 return pc_rtx;
2695 if (MEM_P (x))
2696 iter.skip_subrtxes ();
2699 return NULL_RTX;
2702 /* Return true if SIZE bytes starting from address ADDR might overlap an
2703 already-clobbered argument area. This function is used to determine
2704 if we should give up a sibcall. */
2706 static bool
2707 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2709 poly_int64 i;
2710 unsigned HOST_WIDE_INT start, end;
2711 rtx val;
2713 if (bitmap_empty_p (stored_args_map)
2714 && stored_args_watermark == HOST_WIDE_INT_M1U)
2715 return false;
2716 val = internal_arg_pointer_based_exp (addr, true);
2717 if (val == NULL_RTX)
2718 return false;
2719 else if (!poly_int_rtx_p (val, &i))
2720 return true;
2722 if (known_eq (size, 0U))
2723 return false;
2725 if (STACK_GROWS_DOWNWARD)
2726 i -= crtl->args.pretend_args_size;
2727 else
2728 i += crtl->args.pretend_args_size;
2730 if (ARGS_GROW_DOWNWARD)
2731 i = -i - size;
2733 /* We can ignore any references to the function's pretend args,
2734 which at this point would manifest as negative values of I. */
2735 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2736 return false;
2738 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2739 if (!(i + size).is_constant (&end))
2740 end = HOST_WIDE_INT_M1U;
2742 if (end > stored_args_watermark)
2743 return true;
2745 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2746 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2747 if (bitmap_bit_p (stored_args_map, k))
2748 return true;
2750 return false;
2753 /* Do the register loads required for any wholly-register parms or any
2754 parms which are passed both on the stack and in a register. Their
2755 expressions were already evaluated.
2757 Mark all register-parms as living through the call, putting these USE
2758 insns in the CALL_INSN_FUNCTION_USAGE field.
2760 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2761 checking, setting *SIBCALL_FAILURE if appropriate. */
2763 static void
2764 load_register_parameters (struct arg_data *args, int num_actuals,
2765 rtx *call_fusage, int flags, int is_sibcall,
2766 int *sibcall_failure)
2768 int i, j;
2770 for (i = 0; i < num_actuals; i++)
2772 rtx reg = ((flags & ECF_SIBCALL)
2773 ? args[i].tail_call_reg : args[i].reg);
2774 if (reg)
2776 int partial = args[i].partial;
2777 int nregs;
2778 poly_int64 size = 0;
2779 HOST_WIDE_INT const_size = 0;
2780 rtx_insn *before_arg = get_last_insn ();
2781 tree type = TREE_TYPE (args[i].tree_value);
2782 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
2783 type = TREE_TYPE (first_field (type));
2784 /* Set non-negative if we must move a word at a time, even if
2785 just one word (e.g, partial == 4 && mode == DFmode). Set
2786 to -1 if we just use a normal move insn. This value can be
2787 zero if the argument is a zero size structure. */
2788 nregs = -1;
2789 if (GET_CODE (reg) == PARALLEL)
2791 else if (partial)
2793 gcc_assert (partial % UNITS_PER_WORD == 0);
2794 nregs = partial / UNITS_PER_WORD;
2796 else if (TYPE_MODE (type) == BLKmode)
2798 /* Variable-sized parameters should be described by a
2799 PARALLEL instead. */
2800 const_size = int_size_in_bytes (type);
2801 gcc_assert (const_size >= 0);
2802 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2803 size = const_size;
2805 else
2806 size = GET_MODE_SIZE (args[i].mode);
2808 /* Handle calls that pass values in multiple non-contiguous
2809 locations. The Irix 6 ABI has examples of this. */
2811 if (GET_CODE (reg) == PARALLEL)
2812 emit_group_move (reg, args[i].parallel_value);
2814 /* If simple case, just do move. If normal partial, store_one_arg
2815 has already loaded the register for us. In all other cases,
2816 load the register(s) from memory. */
2818 else if (nregs == -1)
2820 emit_move_insn (reg, args[i].value);
2821 #ifdef BLOCK_REG_PADDING
2822 /* Handle case where we have a value that needs shifting
2823 up to the msb. eg. a QImode value and we're padding
2824 upward on a BYTES_BIG_ENDIAN machine. */
2825 if (args[i].locate.where_pad
2826 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2828 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2829 if (maybe_lt (size, UNITS_PER_WORD))
2831 rtx x;
2832 poly_int64 shift
2833 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2835 /* Assigning REG here rather than a temp makes
2836 CALL_FUSAGE report the whole reg as used.
2837 Strictly speaking, the call only uses SIZE
2838 bytes at the msb end, but it doesn't seem worth
2839 generating rtl to say that. */
2840 reg = gen_rtx_REG (word_mode, REGNO (reg));
2841 x = expand_shift (LSHIFT_EXPR, word_mode,
2842 reg, shift, reg, 1);
2843 if (x != reg)
2844 emit_move_insn (reg, x);
2847 #endif
2850 /* If we have pre-computed the values to put in the registers in
2851 the case of non-aligned structures, copy them in now. */
2853 else if (args[i].n_aligned_regs != 0)
2854 for (j = 0; j < args[i].n_aligned_regs; j++)
2855 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2856 args[i].aligned_regs[j]);
2858 else if (partial == 0 || args[i].pass_on_stack)
2860 /* SIZE and CONST_SIZE are 0 for partial arguments and
2861 the size of a BLKmode type otherwise. */
2862 gcc_checking_assert (known_eq (size, const_size));
2863 rtx mem = validize_mem (copy_rtx (args[i].value));
2865 /* Check for overlap with already clobbered argument area,
2866 providing that this has non-zero size. */
2867 if (is_sibcall
2868 && const_size != 0
2869 && (mem_might_overlap_already_clobbered_arg_p
2870 (XEXP (args[i].value, 0), const_size)))
2871 *sibcall_failure = 1;
2873 if (const_size % UNITS_PER_WORD == 0
2874 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2875 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2876 else
2878 if (nregs > 1)
2879 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2880 args[i].mode);
2881 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2882 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2883 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2884 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2885 word_mode, word_mode, false,
2886 NULL);
2887 if (BYTES_BIG_ENDIAN)
2888 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2889 BITS_PER_WORD - bitsize, dest, 1);
2890 if (x != dest)
2891 emit_move_insn (dest, x);
2894 /* Handle a BLKmode that needs shifting. */
2895 if (nregs == 1 && const_size < UNITS_PER_WORD
2896 #ifdef BLOCK_REG_PADDING
2897 && args[i].locate.where_pad == PAD_DOWNWARD
2898 #else
2899 && BYTES_BIG_ENDIAN
2900 #endif
2903 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2904 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2905 enum tree_code dir = (BYTES_BIG_ENDIAN
2906 ? RSHIFT_EXPR : LSHIFT_EXPR);
2907 rtx x;
2909 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2910 if (x != dest)
2911 emit_move_insn (dest, x);
2915 /* When a parameter is a block, and perhaps in other cases, it is
2916 possible that it did a load from an argument slot that was
2917 already clobbered. */
2918 if (is_sibcall
2919 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2920 *sibcall_failure = 1;
2922 /* Handle calls that pass values in multiple non-contiguous
2923 locations. The Irix 6 ABI has examples of this. */
2924 if (GET_CODE (reg) == PARALLEL)
2925 use_group_regs (call_fusage, reg);
2926 else if (nregs == -1)
2927 use_reg_mode (call_fusage, reg, TYPE_MODE (type));
2928 else if (nregs > 0)
2929 use_regs (call_fusage, REGNO (reg), nregs);
2934 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2935 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2936 bytes, then we would need to push some additional bytes to pad the
2937 arguments. So, we try to compute an adjust to the stack pointer for an
2938 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2939 bytes. Then, when the arguments are pushed the stack will be perfectly
2940 aligned.
2942 Return true if this optimization is possible, storing the adjustment
2943 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2944 bytes that should be popped after the call. */
2946 static bool
2947 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2948 poly_int64 unadjusted_args_size,
2949 struct args_size *args_size,
2950 unsigned int preferred_unit_stack_boundary)
2952 /* The number of bytes to pop so that the stack will be
2953 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2954 poly_int64 adjustment;
2955 /* The alignment of the stack after the arguments are pushed, if we
2956 just pushed the arguments without adjust the stack here. */
2957 unsigned HOST_WIDE_INT unadjusted_alignment;
2959 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2960 preferred_unit_stack_boundary,
2961 &unadjusted_alignment))
2962 return false;
2964 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2965 as possible -- leaving just enough left to cancel out the
2966 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2967 PENDING_STACK_ADJUST is non-negative, and congruent to
2968 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2970 /* Begin by trying to pop all the bytes. */
2971 unsigned HOST_WIDE_INT tmp_misalignment;
2972 if (!known_misalignment (pending_stack_adjust,
2973 preferred_unit_stack_boundary,
2974 &tmp_misalignment))
2975 return false;
2976 unadjusted_alignment -= tmp_misalignment;
2977 adjustment = pending_stack_adjust;
2978 /* Push enough additional bytes that the stack will be aligned
2979 after the arguments are pushed. */
2980 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2981 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2983 /* We need to know whether the adjusted argument size
2984 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2985 or a deallocation. */
2986 if (!ordered_p (adjustment, unadjusted_args_size))
2987 return false;
2989 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2990 bytes after the call. The right number is the entire
2991 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2992 by the arguments in the first place. */
2993 args_size->constant
2994 = pending_stack_adjust - adjustment + unadjusted_args_size;
2996 *adjustment_out = adjustment;
2997 return true;
3000 /* Scan X expression if it does not dereference any argument slots
3001 we already clobbered by tail call arguments (as noted in stored_args_map
3002 bitmap).
3003 Return nonzero if X expression dereferences such argument slots,
3004 zero otherwise. */
3006 static int
3007 check_sibcall_argument_overlap_1 (rtx x)
3009 RTX_CODE code;
3010 int i, j;
3011 const char *fmt;
3013 if (x == NULL_RTX)
3014 return 0;
3016 code = GET_CODE (x);
3018 /* We need not check the operands of the CALL expression itself. */
3019 if (code == CALL)
3020 return 0;
3022 if (code == MEM)
3023 return (mem_might_overlap_already_clobbered_arg_p
3024 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
3026 /* Scan all subexpressions. */
3027 fmt = GET_RTX_FORMAT (code);
3028 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3030 if (*fmt == 'e')
3032 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
3033 return 1;
3035 else if (*fmt == 'E')
3037 for (j = 0; j < XVECLEN (x, i); j++)
3038 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
3039 return 1;
3042 return 0;
3045 /* Scan sequence after INSN if it does not dereference any argument slots
3046 we already clobbered by tail call arguments (as noted in stored_args_map
3047 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3048 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3049 should be 0). Return nonzero if sequence after INSN dereferences such argument
3050 slots, zero otherwise. */
3052 static int
3053 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3054 int mark_stored_args_map)
3056 poly_uint64 low, high;
3057 unsigned HOST_WIDE_INT const_low, const_high;
3059 if (insn == NULL_RTX)
3060 insn = get_insns ();
3061 else
3062 insn = NEXT_INSN (insn);
3064 for (; insn; insn = NEXT_INSN (insn))
3065 if (INSN_P (insn)
3066 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3067 break;
3069 if (mark_stored_args_map)
3071 if (ARGS_GROW_DOWNWARD)
3072 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3073 else
3074 low = arg->locate.slot_offset.constant;
3075 high = low + arg->locate.size.constant;
3077 const_low = constant_lower_bound (low);
3078 if (high.is_constant (&const_high))
3079 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3080 bitmap_set_bit (stored_args_map, i);
3081 else
3082 stored_args_watermark = MIN (stored_args_watermark, const_low);
3084 return insn != NULL_RTX;
3087 /* Given that a function returns a value of mode MODE at the most
3088 significant end of hard register VALUE, shift VALUE left or right
3089 as specified by LEFT_P. Return true if some action was needed. */
3091 bool
3092 shift_return_value (machine_mode mode, bool left_p, rtx value)
3094 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3095 machine_mode value_mode = GET_MODE (value);
3096 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3098 if (known_eq (shift, 0))
3099 return false;
3101 /* Use ashr rather than lshr for right shifts. This is for the benefit
3102 of the MIPS port, which requires SImode values to be sign-extended
3103 when stored in 64-bit registers. */
3104 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3105 value, gen_int_shift_amount (value_mode, shift),
3106 value, 1, OPTAB_WIDEN))
3107 gcc_unreachable ();
3108 return true;
3111 /* If X is a likely-spilled register value, copy it to a pseudo
3112 register and return that register. Return X otherwise. */
3114 static rtx
3115 avoid_likely_spilled_reg (rtx x)
3117 rtx new_rtx;
3119 if (REG_P (x)
3120 && HARD_REGISTER_P (x)
3121 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3123 /* Make sure that we generate a REG rather than a CONCAT.
3124 Moves into CONCATs can need nontrivial instructions,
3125 and the whole point of this function is to avoid
3126 using the hard register directly in such a situation. */
3127 generating_concat_p = 0;
3128 new_rtx = gen_reg_rtx (GET_MODE (x));
3129 generating_concat_p = 1;
3130 emit_move_insn (new_rtx, x);
3131 return new_rtx;
3133 return x;
3136 /* Helper function for expand_call.
3137 Return false is EXP is not implementable as a sibling call. */
3139 static bool
3140 can_implement_as_sibling_call_p (tree exp,
3141 rtx structure_value_addr,
3142 tree funtype,
3143 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3144 tree fndecl,
3145 int flags,
3146 tree addr,
3147 const args_size &args_size)
3149 if (!targetm.have_sibcall_epilogue ())
3151 maybe_complain_about_tail_call
3152 (exp,
3153 "machine description does not have"
3154 " a sibcall_epilogue instruction pattern");
3155 return false;
3158 /* Doing sibling call optimization needs some work, since
3159 structure_value_addr can be allocated on the stack.
3160 It does not seem worth the effort since few optimizable
3161 sibling calls will return a structure. */
3162 if (structure_value_addr != NULL_RTX)
3164 maybe_complain_about_tail_call (exp, "callee returns a structure");
3165 return false;
3168 #ifdef REG_PARM_STACK_SPACE
3169 /* If outgoing reg parm stack space changes, we cannot do sibcall. */
3170 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3171 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3172 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3174 maybe_complain_about_tail_call (exp,
3175 "inconsistent size of stack space"
3176 " allocated for arguments which are"
3177 " passed in registers");
3178 return false;
3180 #endif
3182 /* Check whether the target is able to optimize the call
3183 into a sibcall. */
3184 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3186 maybe_complain_about_tail_call (exp,
3187 "target is not able to optimize the"
3188 " call into a sibling call");
3189 return false;
3192 /* Functions that do not return exactly once may not be sibcall
3193 optimized. */
3194 if (flags & ECF_RETURNS_TWICE)
3196 maybe_complain_about_tail_call (exp, "callee returns twice");
3197 return false;
3199 if (flags & ECF_NORETURN)
3201 maybe_complain_about_tail_call (exp, "callee does not return");
3202 return false;
3205 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3207 maybe_complain_about_tail_call (exp, "volatile function type");
3208 return false;
3211 /* If the called function is nested in the current one, it might access
3212 some of the caller's arguments, but could clobber them beforehand if
3213 the argument areas are shared. */
3214 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3216 maybe_complain_about_tail_call (exp, "nested function");
3217 return false;
3220 /* If this function requires more stack slots than the current
3221 function, we cannot change it into a sibling call.
3222 crtl->args.pretend_args_size is not part of the
3223 stack allocated by our caller. */
3224 if (maybe_gt (args_size.constant,
3225 crtl->args.size - crtl->args.pretend_args_size))
3227 maybe_complain_about_tail_call (exp,
3228 "callee required more stack slots"
3229 " than the caller");
3230 return false;
3233 /* If the callee pops its own arguments, then it must pop exactly
3234 the same number of arguments as the current function. */
3235 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3236 args_size.constant),
3237 targetm.calls.return_pops_args (current_function_decl,
3238 TREE_TYPE
3239 (current_function_decl),
3240 crtl->args.size)))
3242 maybe_complain_about_tail_call (exp,
3243 "inconsistent number of"
3244 " popped arguments");
3245 return false;
3248 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3250 maybe_complain_about_tail_call (exp, "frontend does not support"
3251 " sibling call");
3252 return false;
3255 /* All checks passed. */
3256 return true;
3259 /* Update stack alignment when the parameter is passed in the stack
3260 since the outgoing parameter requires extra alignment on the calling
3261 function side. */
3263 static void
3264 update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
3266 if (crtl->stack_alignment_needed < locate->boundary)
3267 crtl->stack_alignment_needed = locate->boundary;
3268 if (crtl->preferred_stack_boundary < locate->boundary)
3269 crtl->preferred_stack_boundary = locate->boundary;
3272 /* Generate all the code for a CALL_EXPR exp
3273 and return an rtx for its value.
3274 Store the value in TARGET (specified as an rtx) if convenient.
3275 If the value is stored in TARGET then TARGET is returned.
3276 If IGNORE is nonzero, then we ignore the value of the function call. */
3279 expand_call (tree exp, rtx target, int ignore)
3281 /* Nonzero if we are currently expanding a call. */
3282 static int currently_expanding_call = 0;
3284 /* RTX for the function to be called. */
3285 rtx funexp;
3286 /* Sequence of insns to perform a normal "call". */
3287 rtx_insn *normal_call_insns = NULL;
3288 /* Sequence of insns to perform a tail "call". */
3289 rtx_insn *tail_call_insns = NULL;
3290 /* Data type of the function. */
3291 tree funtype;
3292 tree type_arg_types;
3293 tree rettype;
3294 /* Declaration of the function being called,
3295 or 0 if the function is computed (not known by name). */
3296 tree fndecl = 0;
3297 /* The type of the function being called. */
3298 tree fntype;
3299 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3300 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3301 int pass;
3303 /* Register in which non-BLKmode value will be returned,
3304 or 0 if no value or if value is BLKmode. */
3305 rtx valreg;
3306 /* Address where we should return a BLKmode value;
3307 0 if value not BLKmode. */
3308 rtx structure_value_addr = 0;
3309 /* Nonzero if that address is being passed by treating it as
3310 an extra, implicit first parameter. Otherwise,
3311 it is passed by being copied directly into struct_value_rtx. */
3312 int structure_value_addr_parm = 0;
3313 /* Holds the value of implicit argument for the struct value. */
3314 tree structure_value_addr_value = NULL_TREE;
3315 /* Size of aggregate value wanted, or zero if none wanted
3316 or if we are using the non-reentrant PCC calling convention
3317 or expecting the value in registers. */
3318 poly_int64 struct_value_size = 0;
3319 /* Nonzero if called function returns an aggregate in memory PCC style,
3320 by returning the address of where to find it. */
3321 int pcc_struct_value = 0;
3322 rtx struct_value = 0;
3324 /* Number of actual parameters in this call, including struct value addr. */
3325 int num_actuals;
3326 /* Number of named args. Args after this are anonymous ones
3327 and they must all go on the stack. */
3328 int n_named_args;
3329 /* Number of complex actual arguments that need to be split. */
3330 int num_complex_actuals = 0;
3332 /* Vector of information about each argument.
3333 Arguments are numbered in the order they will be pushed,
3334 not the order they are written. */
3335 struct arg_data *args;
3337 /* Total size in bytes of all the stack-parms scanned so far. */
3338 struct args_size args_size;
3339 struct args_size adjusted_args_size;
3340 /* Size of arguments before any adjustments (such as rounding). */
3341 poly_int64 unadjusted_args_size;
3342 /* Data on reg parms scanned so far. */
3343 CUMULATIVE_ARGS args_so_far_v;
3344 cumulative_args_t args_so_far;
3345 /* Nonzero if a reg parm has been scanned. */
3346 int reg_parm_seen;
3347 /* Nonzero if this is an indirect function call. */
3349 /* Nonzero if we must avoid push-insns in the args for this call.
3350 If stack space is allocated for register parameters, but not by the
3351 caller, then it is preallocated in the fixed part of the stack frame.
3352 So the entire argument block must then be preallocated (i.e., we
3353 ignore PUSH_ROUNDING in that case). */
3355 int must_preallocate = !PUSH_ARGS;
3357 /* Size of the stack reserved for parameter registers. */
3358 int reg_parm_stack_space = 0;
3360 /* Address of space preallocated for stack parms
3361 (on machines that lack push insns), or 0 if space not preallocated. */
3362 rtx argblock = 0;
3364 /* Mask of ECF_ and ERF_ flags. */
3365 int flags = 0;
3366 int return_flags = 0;
3367 #ifdef REG_PARM_STACK_SPACE
3368 /* Define the boundary of the register parm stack space that needs to be
3369 saved, if any. */
3370 int low_to_save, high_to_save;
3371 rtx save_area = 0; /* Place that it is saved */
3372 #endif
3374 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3375 char *initial_stack_usage_map = stack_usage_map;
3376 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3377 char *stack_usage_map_buf = NULL;
3379 poly_int64 old_stack_allocated;
3381 /* State variables to track stack modifications. */
3382 rtx old_stack_level = 0;
3383 int old_stack_arg_under_construction = 0;
3384 poly_int64 old_pending_adj = 0;
3385 int old_inhibit_defer_pop = inhibit_defer_pop;
3387 /* Some stack pointer alterations we make are performed via
3388 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3389 which we then also need to save/restore along the way. */
3390 poly_int64 old_stack_pointer_delta = 0;
3392 rtx call_fusage;
3393 tree addr = CALL_EXPR_FN (exp);
3394 int i;
3395 /* The alignment of the stack, in bits. */
3396 unsigned HOST_WIDE_INT preferred_stack_boundary;
3397 /* The alignment of the stack, in bytes. */
3398 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3399 /* The static chain value to use for this call. */
3400 rtx static_chain_value;
3401 /* See if this is "nothrow" function call. */
3402 if (TREE_NOTHROW (exp))
3403 flags |= ECF_NOTHROW;
3405 /* See if we can find a DECL-node for the actual function, and get the
3406 function attributes (flags) from the function decl or type node. */
3407 fndecl = get_callee_fndecl (exp);
3408 if (fndecl)
3410 fntype = TREE_TYPE (fndecl);
3411 flags |= flags_from_decl_or_type (fndecl);
3412 return_flags |= decl_return_flags (fndecl);
3414 else
3416 fntype = TREE_TYPE (TREE_TYPE (addr));
3417 flags |= flags_from_decl_or_type (fntype);
3418 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3419 flags |= ECF_BY_DESCRIPTOR;
3421 rettype = TREE_TYPE (exp);
3423 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3425 /* Warn if this value is an aggregate type,
3426 regardless of which calling convention we are using for it. */
3427 if (AGGREGATE_TYPE_P (rettype))
3428 warning (OPT_Waggregate_return, "function call has aggregate value");
3430 /* If the result of a non looping pure or const function call is
3431 ignored (or void), and none of its arguments are volatile, we can
3432 avoid expanding the call and just evaluate the arguments for
3433 side-effects. */
3434 if ((flags & (ECF_CONST | ECF_PURE))
3435 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3436 && (ignore || target == const0_rtx
3437 || TYPE_MODE (rettype) == VOIDmode))
3439 bool volatilep = false;
3440 tree arg;
3441 call_expr_arg_iterator iter;
3443 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3444 if (TREE_THIS_VOLATILE (arg))
3446 volatilep = true;
3447 break;
3450 if (! volatilep)
3452 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3453 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3454 return const0_rtx;
3458 #ifdef REG_PARM_STACK_SPACE
3459 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3460 #endif
3462 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3463 && reg_parm_stack_space > 0 && PUSH_ARGS)
3464 must_preallocate = 1;
3466 /* Set up a place to return a structure. */
3468 /* Cater to broken compilers. */
3469 if (aggregate_value_p (exp, fntype))
3471 /* This call returns a big structure. */
3472 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3474 #ifdef PCC_STATIC_STRUCT_RETURN
3476 pcc_struct_value = 1;
3478 #else /* not PCC_STATIC_STRUCT_RETURN */
3480 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3481 struct_value_size = -1;
3483 /* Even if it is semantically safe to use the target as the return
3484 slot, it may be not sufficiently aligned for the return type. */
3485 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3486 && target
3487 && MEM_P (target)
3488 /* If rettype is addressable, we may not create a temporary.
3489 If target is properly aligned at runtime and the compiler
3490 just doesn't know about it, it will work fine, otherwise it
3491 will be UB. */
3492 && (TREE_ADDRESSABLE (rettype)
3493 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3494 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3495 MEM_ALIGN (target)))))
3496 structure_value_addr = XEXP (target, 0);
3497 else
3499 /* For variable-sized objects, we must be called with a target
3500 specified. If we were to allocate space on the stack here,
3501 we would have no way of knowing when to free it. */
3502 rtx d = assign_temp (rettype, 1, 1);
3503 structure_value_addr = XEXP (d, 0);
3504 target = 0;
3507 #endif /* not PCC_STATIC_STRUCT_RETURN */
3510 /* Figure out the amount to which the stack should be aligned. */
3511 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3512 if (fndecl)
3514 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3515 /* Without automatic stack alignment, we can't increase preferred
3516 stack boundary. With automatic stack alignment, it is
3517 unnecessary since unless we can guarantee that all callers will
3518 align the outgoing stack properly, callee has to align its
3519 stack anyway. */
3520 if (i
3521 && i->preferred_incoming_stack_boundary
3522 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3523 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3526 /* Operand 0 is a pointer-to-function; get the type of the function. */
3527 funtype = TREE_TYPE (addr);
3528 gcc_assert (POINTER_TYPE_P (funtype));
3529 funtype = TREE_TYPE (funtype);
3531 /* Count whether there are actual complex arguments that need to be split
3532 into their real and imaginary parts. Munge the type_arg_types
3533 appropriately here as well. */
3534 if (targetm.calls.split_complex_arg)
3536 call_expr_arg_iterator iter;
3537 tree arg;
3538 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3540 tree type = TREE_TYPE (arg);
3541 if (type && TREE_CODE (type) == COMPLEX_TYPE
3542 && targetm.calls.split_complex_arg (type))
3543 num_complex_actuals++;
3545 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3547 else
3548 type_arg_types = TYPE_ARG_TYPES (funtype);
3550 if (flags & ECF_MAY_BE_ALLOCA)
3551 cfun->calls_alloca = 1;
3553 /* If struct_value_rtx is 0, it means pass the address
3554 as if it were an extra parameter. Put the argument expression
3555 in structure_value_addr_value. */
3556 if (structure_value_addr && struct_value == 0)
3558 /* If structure_value_addr is a REG other than
3559 virtual_outgoing_args_rtx, we can use always use it. If it
3560 is not a REG, we must always copy it into a register.
3561 If it is virtual_outgoing_args_rtx, we must copy it to another
3562 register in some cases. */
3563 rtx temp = (!REG_P (structure_value_addr)
3564 || (ACCUMULATE_OUTGOING_ARGS
3565 && stack_arg_under_construction
3566 && structure_value_addr == virtual_outgoing_args_rtx)
3567 ? copy_addr_to_reg (convert_memory_address
3568 (Pmode, structure_value_addr))
3569 : structure_value_addr);
3571 structure_value_addr_value =
3572 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3573 structure_value_addr_parm = 1;
3576 /* Count the arguments and set NUM_ACTUALS. */
3577 num_actuals =
3578 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3580 /* Compute number of named args.
3581 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3583 if (type_arg_types != 0)
3584 n_named_args
3585 = (list_length (type_arg_types)
3586 /* Count the struct value address, if it is passed as a parm. */
3587 + structure_value_addr_parm);
3588 else
3589 /* If we know nothing, treat all args as named. */
3590 n_named_args = num_actuals;
3592 /* Start updating where the next arg would go.
3594 On some machines (such as the PA) indirect calls have a different
3595 calling convention than normal calls. The fourth argument in
3596 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3597 or not. */
3598 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3599 args_so_far = pack_cumulative_args (&args_so_far_v);
3601 /* Now possibly adjust the number of named args.
3602 Normally, don't include the last named arg if anonymous args follow.
3603 We do include the last named arg if
3604 targetm.calls.strict_argument_naming() returns nonzero.
3605 (If no anonymous args follow, the result of list_length is actually
3606 one too large. This is harmless.)
3608 If targetm.calls.pretend_outgoing_varargs_named() returns
3609 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3610 this machine will be able to place unnamed args that were passed
3611 in registers into the stack. So treat all args as named. This
3612 allows the insns emitting for a specific argument list to be
3613 independent of the function declaration.
3615 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3616 we do not have any reliable way to pass unnamed args in
3617 registers, so we must force them into memory. */
3619 if (type_arg_types != 0
3620 && targetm.calls.strict_argument_naming (args_so_far))
3622 else if (type_arg_types != 0
3623 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3624 /* Don't include the last named arg. */
3625 --n_named_args;
3626 else
3627 /* Treat all args as named. */
3628 n_named_args = num_actuals;
3630 /* Make a vector to hold all the information about each arg. */
3631 args = XCNEWVEC (struct arg_data, num_actuals);
3633 /* Build up entries in the ARGS array, compute the size of the
3634 arguments into ARGS_SIZE, etc. */
3635 initialize_argument_information (num_actuals, args, &args_size,
3636 n_named_args, exp,
3637 structure_value_addr_value, fndecl, fntype,
3638 args_so_far, reg_parm_stack_space,
3639 &old_stack_level, &old_pending_adj,
3640 &must_preallocate, &flags,
3641 &try_tail_call, CALL_FROM_THUNK_P (exp));
3643 if (args_size.var)
3644 must_preallocate = 1;
3646 /* Now make final decision about preallocating stack space. */
3647 must_preallocate = finalize_must_preallocate (must_preallocate,
3648 num_actuals, args,
3649 &args_size);
3651 /* If the structure value address will reference the stack pointer, we
3652 must stabilize it. We don't need to do this if we know that we are
3653 not going to adjust the stack pointer in processing this call. */
3655 if (structure_value_addr
3656 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3657 || reg_mentioned_p (virtual_outgoing_args_rtx,
3658 structure_value_addr))
3659 && (args_size.var
3660 || (!ACCUMULATE_OUTGOING_ARGS
3661 && maybe_ne (args_size.constant, 0))))
3662 structure_value_addr = copy_to_reg (structure_value_addr);
3664 /* Tail calls can make things harder to debug, and we've traditionally
3665 pushed these optimizations into -O2. Don't try if we're already
3666 expanding a call, as that means we're an argument. Don't try if
3667 there's cleanups, as we know there's code to follow the call. */
3668 if (currently_expanding_call++ != 0
3669 || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp))
3670 || args_size.var
3671 || dbg_cnt (tail_call) == false)
3672 try_tail_call = 0;
3674 /* Workaround buggy C/C++ wrappers around Fortran routines with
3675 character(len=constant) arguments if the hidden string length arguments
3676 are passed on the stack; if the callers forget to pass those arguments,
3677 attempting to tail call in such routines leads to stack corruption.
3678 Avoid tail calls in functions where at least one such hidden string
3679 length argument is passed (partially or fully) on the stack in the
3680 caller and the callee needs to pass any arguments on the stack.
3681 See PR90329. */
3682 if (try_tail_call && maybe_ne (args_size.constant, 0))
3683 for (tree arg = DECL_ARGUMENTS (current_function_decl);
3684 arg; arg = DECL_CHAIN (arg))
3685 if (DECL_HIDDEN_STRING_LENGTH (arg) && DECL_INCOMING_RTL (arg))
3687 subrtx_iterator::array_type array;
3688 FOR_EACH_SUBRTX (iter, array, DECL_INCOMING_RTL (arg), NONCONST)
3689 if (MEM_P (*iter))
3691 try_tail_call = 0;
3692 break;
3696 /* If the user has marked the function as requiring tail-call
3697 optimization, attempt it. */
3698 if (must_tail_call)
3699 try_tail_call = 1;
3701 /* Rest of purposes for tail call optimizations to fail. */
3702 if (try_tail_call)
3703 try_tail_call = can_implement_as_sibling_call_p (exp,
3704 structure_value_addr,
3705 funtype,
3706 reg_parm_stack_space,
3707 fndecl,
3708 flags, addr, args_size);
3710 /* Check if caller and callee disagree in promotion of function
3711 return value. */
3712 if (try_tail_call)
3714 machine_mode caller_mode, caller_promoted_mode;
3715 machine_mode callee_mode, callee_promoted_mode;
3716 int caller_unsignedp, callee_unsignedp;
3717 tree caller_res = DECL_RESULT (current_function_decl);
3719 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3720 caller_mode = DECL_MODE (caller_res);
3721 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3722 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3723 caller_promoted_mode
3724 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3725 &caller_unsignedp,
3726 TREE_TYPE (current_function_decl), 1);
3727 callee_promoted_mode
3728 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3729 &callee_unsignedp,
3730 funtype, 1);
3731 if (caller_mode != VOIDmode
3732 && (caller_promoted_mode != callee_promoted_mode
3733 || ((caller_mode != caller_promoted_mode
3734 || callee_mode != callee_promoted_mode)
3735 && (caller_unsignedp != callee_unsignedp
3736 || partial_subreg_p (caller_mode, callee_mode)))))
3738 try_tail_call = 0;
3739 maybe_complain_about_tail_call (exp,
3740 "caller and callee disagree in"
3741 " promotion of function"
3742 " return value");
3746 /* Ensure current function's preferred stack boundary is at least
3747 what we need. Stack alignment may also increase preferred stack
3748 boundary. */
3749 for (i = 0; i < num_actuals; i++)
3750 if (reg_parm_stack_space > 0
3751 || args[i].reg == 0
3752 || args[i].partial != 0
3753 || args[i].pass_on_stack)
3754 update_stack_alignment_for_call (&args[i].locate);
3755 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3756 crtl->preferred_stack_boundary = preferred_stack_boundary;
3757 else
3758 preferred_stack_boundary = crtl->preferred_stack_boundary;
3760 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3762 if (flag_callgraph_info)
3763 record_final_call (fndecl, EXPR_LOCATION (exp));
3765 /* We want to make two insn chains; one for a sibling call, the other
3766 for a normal call. We will select one of the two chains after
3767 initial RTL generation is complete. */
3768 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3770 int sibcall_failure = 0;
3771 /* We want to emit any pending stack adjustments before the tail
3772 recursion "call". That way we know any adjustment after the tail
3773 recursion call can be ignored if we indeed use the tail
3774 call expansion. */
3775 saved_pending_stack_adjust save;
3776 rtx_insn *insns, *before_call, *after_args;
3777 rtx next_arg_reg;
3779 if (pass == 0)
3781 /* State variables we need to save and restore between
3782 iterations. */
3783 save_pending_stack_adjust (&save);
3785 if (pass)
3786 flags &= ~ECF_SIBCALL;
3787 else
3788 flags |= ECF_SIBCALL;
3790 /* Other state variables that we must reinitialize each time
3791 through the loop (that are not initialized by the loop itself). */
3792 argblock = 0;
3793 call_fusage = 0;
3795 /* Start a new sequence for the normal call case.
3797 From this point on, if the sibling call fails, we want to set
3798 sibcall_failure instead of continuing the loop. */
3799 start_sequence ();
3801 /* Don't let pending stack adjusts add up to too much.
3802 Also, do all pending adjustments now if there is any chance
3803 this might be a call to alloca or if we are expanding a sibling
3804 call sequence.
3805 Also do the adjustments before a throwing call, otherwise
3806 exception handling can fail; PR 19225. */
3807 if (maybe_ge (pending_stack_adjust, 32)
3808 || (maybe_ne (pending_stack_adjust, 0)
3809 && (flags & ECF_MAY_BE_ALLOCA))
3810 || (maybe_ne (pending_stack_adjust, 0)
3811 && flag_exceptions && !(flags & ECF_NOTHROW))
3812 || pass == 0)
3813 do_pending_stack_adjust ();
3815 /* Precompute any arguments as needed. */
3816 if (pass)
3817 precompute_arguments (num_actuals, args);
3819 /* Now we are about to start emitting insns that can be deleted
3820 if a libcall is deleted. */
3821 if (pass && (flags & ECF_MALLOC))
3822 start_sequence ();
3824 if (pass == 0
3825 && crtl->stack_protect_guard
3826 && targetm.stack_protect_runtime_enabled_p ())
3827 stack_protect_epilogue ();
3829 adjusted_args_size = args_size;
3830 /* Compute the actual size of the argument block required. The variable
3831 and constant sizes must be combined, the size may have to be rounded,
3832 and there may be a minimum required size. When generating a sibcall
3833 pattern, do not round up, since we'll be re-using whatever space our
3834 caller provided. */
3835 unadjusted_args_size
3836 = compute_argument_block_size (reg_parm_stack_space,
3837 &adjusted_args_size,
3838 fndecl, fntype,
3839 (pass == 0 ? 0
3840 : preferred_stack_boundary));
3842 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3844 /* The argument block when performing a sibling call is the
3845 incoming argument block. */
3846 if (pass == 0)
3848 argblock = crtl->args.internal_arg_pointer;
3849 if (STACK_GROWS_DOWNWARD)
3850 argblock
3851 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3852 else
3853 argblock
3854 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3856 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3857 stored_args_map = sbitmap_alloc (map_size);
3858 bitmap_clear (stored_args_map);
3859 stored_args_watermark = HOST_WIDE_INT_M1U;
3862 /* If we have no actual push instructions, or shouldn't use them,
3863 make space for all args right now. */
3864 else if (adjusted_args_size.var != 0)
3866 if (old_stack_level == 0)
3868 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3869 old_stack_pointer_delta = stack_pointer_delta;
3870 old_pending_adj = pending_stack_adjust;
3871 pending_stack_adjust = 0;
3872 /* stack_arg_under_construction says whether a stack arg is
3873 being constructed at the old stack level. Pushing the stack
3874 gets a clean outgoing argument block. */
3875 old_stack_arg_under_construction = stack_arg_under_construction;
3876 stack_arg_under_construction = 0;
3878 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3879 if (flag_stack_usage_info)
3880 current_function_has_unbounded_dynamic_stack_size = 1;
3882 else
3884 /* Note that we must go through the motions of allocating an argument
3885 block even if the size is zero because we may be storing args
3886 in the area reserved for register arguments, which may be part of
3887 the stack frame. */
3889 poly_int64 needed = adjusted_args_size.constant;
3891 /* Store the maximum argument space used. It will be pushed by
3892 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3893 checking). */
3895 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3896 needed);
3898 if (must_preallocate)
3900 if (ACCUMULATE_OUTGOING_ARGS)
3902 /* Since the stack pointer will never be pushed, it is
3903 possible for the evaluation of a parm to clobber
3904 something we have already written to the stack.
3905 Since most function calls on RISC machines do not use
3906 the stack, this is uncommon, but must work correctly.
3908 Therefore, we save any area of the stack that was already
3909 written and that we are using. Here we set up to do this
3910 by making a new stack usage map from the old one. The
3911 actual save will be done by store_one_arg.
3913 Another approach might be to try to reorder the argument
3914 evaluations to avoid this conflicting stack usage. */
3916 /* Since we will be writing into the entire argument area,
3917 the map must be allocated for its entire size, not just
3918 the part that is the responsibility of the caller. */
3919 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3920 needed += reg_parm_stack_space;
3922 poly_int64 limit = needed;
3923 if (ARGS_GROW_DOWNWARD)
3924 limit += 1;
3926 /* For polynomial sizes, this is the maximum possible
3927 size needed for arguments with a constant size
3928 and offset. */
3929 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3930 highest_outgoing_arg_in_use
3931 = MAX (initial_highest_arg_in_use, const_limit);
3933 free (stack_usage_map_buf);
3934 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3935 stack_usage_map = stack_usage_map_buf;
3937 if (initial_highest_arg_in_use)
3938 memcpy (stack_usage_map, initial_stack_usage_map,
3939 initial_highest_arg_in_use);
3941 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3942 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3943 (highest_outgoing_arg_in_use
3944 - initial_highest_arg_in_use));
3945 needed = 0;
3947 /* The address of the outgoing argument list must not be
3948 copied to a register here, because argblock would be left
3949 pointing to the wrong place after the call to
3950 allocate_dynamic_stack_space below. */
3952 argblock = virtual_outgoing_args_rtx;
3954 else
3956 /* Try to reuse some or all of the pending_stack_adjust
3957 to get this space. */
3958 if (inhibit_defer_pop == 0
3959 && (combine_pending_stack_adjustment_and_call
3960 (&needed,
3961 unadjusted_args_size,
3962 &adjusted_args_size,
3963 preferred_unit_stack_boundary)))
3965 /* combine_pending_stack_adjustment_and_call computes
3966 an adjustment before the arguments are allocated.
3967 Account for them and see whether or not the stack
3968 needs to go up or down. */
3969 needed = unadjusted_args_size - needed;
3971 /* Checked by
3972 combine_pending_stack_adjustment_and_call. */
3973 gcc_checking_assert (ordered_p (needed, 0));
3974 if (maybe_lt (needed, 0))
3976 /* We're releasing stack space. */
3977 /* ??? We can avoid any adjustment at all if we're
3978 already aligned. FIXME. */
3979 pending_stack_adjust = -needed;
3980 do_pending_stack_adjust ();
3981 needed = 0;
3983 else
3984 /* We need to allocate space. We'll do that in
3985 push_block below. */
3986 pending_stack_adjust = 0;
3989 /* Special case this because overhead of `push_block' in
3990 this case is non-trivial. */
3991 if (known_eq (needed, 0))
3992 argblock = virtual_outgoing_args_rtx;
3993 else
3995 rtx needed_rtx = gen_int_mode (needed, Pmode);
3996 argblock = push_block (needed_rtx, 0, 0);
3997 if (ARGS_GROW_DOWNWARD)
3998 argblock = plus_constant (Pmode, argblock, needed);
4001 /* We only really need to call `copy_to_reg' in the case
4002 where push insns are going to be used to pass ARGBLOCK
4003 to a function call in ARGS. In that case, the stack
4004 pointer changes value from the allocation point to the
4005 call point, and hence the value of
4006 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
4007 as well always do it. */
4008 argblock = copy_to_reg (argblock);
4013 if (ACCUMULATE_OUTGOING_ARGS)
4015 /* The save/restore code in store_one_arg handles all
4016 cases except one: a constructor call (including a C
4017 function returning a BLKmode struct) to initialize
4018 an argument. */
4019 if (stack_arg_under_construction)
4021 rtx push_size
4022 = (gen_int_mode
4023 (adjusted_args_size.constant
4024 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
4025 : TREE_TYPE (fndecl))
4026 ? 0 : reg_parm_stack_space), Pmode));
4027 if (old_stack_level == 0)
4029 emit_stack_save (SAVE_BLOCK, &old_stack_level);
4030 old_stack_pointer_delta = stack_pointer_delta;
4031 old_pending_adj = pending_stack_adjust;
4032 pending_stack_adjust = 0;
4033 /* stack_arg_under_construction says whether a stack
4034 arg is being constructed at the old stack level.
4035 Pushing the stack gets a clean outgoing argument
4036 block. */
4037 old_stack_arg_under_construction
4038 = stack_arg_under_construction;
4039 stack_arg_under_construction = 0;
4040 /* Make a new map for the new argument list. */
4041 free (stack_usage_map_buf);
4042 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
4043 stack_usage_map = stack_usage_map_buf;
4044 highest_outgoing_arg_in_use = 0;
4045 stack_usage_watermark = HOST_WIDE_INT_M1U;
4047 /* We can pass TRUE as the 4th argument because we just
4048 saved the stack pointer and will restore it right after
4049 the call. */
4050 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
4051 -1, true);
4054 /* If argument evaluation might modify the stack pointer,
4055 copy the address of the argument list to a register. */
4056 for (i = 0; i < num_actuals; i++)
4057 if (args[i].pass_on_stack)
4059 argblock = copy_addr_to_reg (argblock);
4060 break;
4064 compute_argument_addresses (args, argblock, num_actuals);
4066 /* Stack is properly aligned, pops can't safely be deferred during
4067 the evaluation of the arguments. */
4068 NO_DEFER_POP;
4070 /* Precompute all register parameters. It isn't safe to compute
4071 anything once we have started filling any specific hard regs.
4072 TLS symbols sometimes need a call to resolve. Precompute
4073 register parameters before any stack pointer manipulation
4074 to avoid unaligned stack in the called function. */
4075 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
4077 OK_DEFER_POP;
4079 /* Perform stack alignment before the first push (the last arg). */
4080 if (argblock == 0
4081 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
4082 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
4084 /* When the stack adjustment is pending, we get better code
4085 by combining the adjustments. */
4086 if (maybe_ne (pending_stack_adjust, 0)
4087 && ! inhibit_defer_pop
4088 && (combine_pending_stack_adjustment_and_call
4089 (&pending_stack_adjust,
4090 unadjusted_args_size,
4091 &adjusted_args_size,
4092 preferred_unit_stack_boundary)))
4093 do_pending_stack_adjust ();
4094 else if (argblock == 0)
4095 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4096 - unadjusted_args_size,
4097 Pmode));
4099 /* Now that the stack is properly aligned, pops can't safely
4100 be deferred during the evaluation of the arguments. */
4101 NO_DEFER_POP;
4103 /* Record the maximum pushed stack space size. We need to delay
4104 doing it this far to take into account the optimization done
4105 by combine_pending_stack_adjustment_and_call. */
4106 if (flag_stack_usage_info
4107 && !ACCUMULATE_OUTGOING_ARGS
4108 && pass
4109 && adjusted_args_size.var == 0)
4111 poly_int64 pushed = (adjusted_args_size.constant
4112 + pending_stack_adjust);
4113 current_function_pushed_stack_size
4114 = upper_bound (current_function_pushed_stack_size, pushed);
4117 funexp = rtx_for_function_call (fndecl, addr);
4119 if (CALL_EXPR_STATIC_CHAIN (exp))
4120 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4121 else
4122 static_chain_value = 0;
4124 #ifdef REG_PARM_STACK_SPACE
4125 /* Save the fixed argument area if it's part of the caller's frame and
4126 is clobbered by argument setup for this call. */
4127 if (ACCUMULATE_OUTGOING_ARGS && pass)
4128 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4129 &low_to_save, &high_to_save);
4130 #endif
4132 /* Now store (and compute if necessary) all non-register parms.
4133 These come before register parms, since they can require block-moves,
4134 which could clobber the registers used for register parms.
4135 Parms which have partial registers are not stored here,
4136 but we do preallocate space here if they want that. */
4138 for (i = 0; i < num_actuals; i++)
4140 if (args[i].reg == 0 || args[i].pass_on_stack)
4142 rtx_insn *before_arg = get_last_insn ();
4144 /* We don't allow passing huge (> 2^30 B) arguments
4145 by value. It would cause an overflow later on. */
4146 if (constant_lower_bound (adjusted_args_size.constant)
4147 >= (1 << (HOST_BITS_PER_INT - 2)))
4149 sorry ("passing too large argument on stack");
4150 continue;
4153 if (store_one_arg (&args[i], argblock, flags,
4154 adjusted_args_size.var != 0,
4155 reg_parm_stack_space)
4156 || (pass == 0
4157 && check_sibcall_argument_overlap (before_arg,
4158 &args[i], 1)))
4159 sibcall_failure = 1;
4162 if (args[i].stack)
4163 call_fusage
4164 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4165 gen_rtx_USE (VOIDmode, args[i].stack),
4166 call_fusage);
4169 /* If we have a parm that is passed in registers but not in memory
4170 and whose alignment does not permit a direct copy into registers,
4171 make a group of pseudos that correspond to each register that we
4172 will later fill. */
4173 if (STRICT_ALIGNMENT)
4174 store_unaligned_arguments_into_pseudos (args, num_actuals);
4176 /* Now store any partially-in-registers parm.
4177 This is the last place a block-move can happen. */
4178 if (reg_parm_seen)
4179 for (i = 0; i < num_actuals; i++)
4180 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4182 rtx_insn *before_arg = get_last_insn ();
4184 /* On targets with weird calling conventions (e.g. PA) it's
4185 hard to ensure that all cases of argument overlap between
4186 stack and registers work. Play it safe and bail out. */
4187 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4189 sibcall_failure = 1;
4190 break;
4193 if (store_one_arg (&args[i], argblock, flags,
4194 adjusted_args_size.var != 0,
4195 reg_parm_stack_space)
4196 || (pass == 0
4197 && check_sibcall_argument_overlap (before_arg,
4198 &args[i], 1)))
4199 sibcall_failure = 1;
4202 bool any_regs = false;
4203 for (i = 0; i < num_actuals; i++)
4204 if (args[i].reg != NULL_RTX)
4206 any_regs = true;
4207 targetm.calls.call_args (args[i].reg, funtype);
4209 if (!any_regs)
4210 targetm.calls.call_args (pc_rtx, funtype);
4212 /* Figure out the register where the value, if any, will come back. */
4213 valreg = 0;
4214 if (TYPE_MODE (rettype) != VOIDmode
4215 && ! structure_value_addr)
4217 if (pcc_struct_value)
4218 valreg = hard_function_value (build_pointer_type (rettype),
4219 fndecl, NULL, (pass == 0));
4220 else
4221 valreg = hard_function_value (rettype, fndecl, fntype,
4222 (pass == 0));
4224 /* If VALREG is a PARALLEL whose first member has a zero
4225 offset, use that. This is for targets such as m68k that
4226 return the same value in multiple places. */
4227 if (GET_CODE (valreg) == PARALLEL)
4229 rtx elem = XVECEXP (valreg, 0, 0);
4230 rtx where = XEXP (elem, 0);
4231 rtx offset = XEXP (elem, 1);
4232 if (offset == const0_rtx
4233 && GET_MODE (where) == GET_MODE (valreg))
4234 valreg = where;
4238 /* If register arguments require space on the stack and stack space
4239 was not preallocated, allocate stack space here for arguments
4240 passed in registers. */
4241 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4242 && !ACCUMULATE_OUTGOING_ARGS
4243 && must_preallocate == 0 && reg_parm_stack_space > 0)
4244 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4246 /* Pass the function the address in which to return a
4247 structure value. */
4248 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4250 structure_value_addr
4251 = convert_memory_address (Pmode, structure_value_addr);
4252 emit_move_insn (struct_value,
4253 force_reg (Pmode,
4254 force_operand (structure_value_addr,
4255 NULL_RTX)));
4257 if (REG_P (struct_value))
4258 use_reg (&call_fusage, struct_value);
4261 after_args = get_last_insn ();
4262 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4263 static_chain_value, &call_fusage,
4264 reg_parm_seen, flags);
4266 load_register_parameters (args, num_actuals, &call_fusage, flags,
4267 pass == 0, &sibcall_failure);
4269 /* Save a pointer to the last insn before the call, so that we can
4270 later safely search backwards to find the CALL_INSN. */
4271 before_call = get_last_insn ();
4273 /* Set up next argument register. For sibling calls on machines
4274 with register windows this should be the incoming register. */
4275 if (pass == 0)
4276 next_arg_reg = targetm.calls.function_incoming_arg
4277 (args_so_far, function_arg_info::end_marker ());
4278 else
4279 next_arg_reg = targetm.calls.function_arg
4280 (args_so_far, function_arg_info::end_marker ());
4282 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4284 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4285 arg_nr = num_actuals - arg_nr - 1;
4286 if (arg_nr >= 0
4287 && arg_nr < num_actuals
4288 && args[arg_nr].reg
4289 && valreg
4290 && REG_P (valreg)
4291 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4292 call_fusage
4293 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4294 gen_rtx_SET (valreg, args[arg_nr].reg),
4295 call_fusage);
4297 /* All arguments and registers used for the call must be set up by
4298 now! */
4300 /* Stack must be properly aligned now. */
4301 gcc_assert (!pass
4302 || multiple_p (stack_pointer_delta,
4303 preferred_unit_stack_boundary));
4305 /* Generate the actual call instruction. */
4306 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4307 adjusted_args_size.constant, struct_value_size,
4308 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4309 flags, args_so_far);
4311 if (flag_ipa_ra)
4313 rtx_call_insn *last;
4314 rtx datum = NULL_RTX;
4315 if (fndecl != NULL_TREE)
4317 datum = XEXP (DECL_RTL (fndecl), 0);
4318 gcc_assert (datum != NULL_RTX
4319 && GET_CODE (datum) == SYMBOL_REF);
4321 last = last_call_insn ();
4322 add_reg_note (last, REG_CALL_DECL, datum);
4325 /* If the call setup or the call itself overlaps with anything
4326 of the argument setup we probably clobbered our call address.
4327 In that case we can't do sibcalls. */
4328 if (pass == 0
4329 && check_sibcall_argument_overlap (after_args, 0, 0))
4330 sibcall_failure = 1;
4332 /* If a non-BLKmode value is returned at the most significant end
4333 of a register, shift the register right by the appropriate amount
4334 and update VALREG accordingly. BLKmode values are handled by the
4335 group load/store machinery below. */
4336 if (!structure_value_addr
4337 && !pcc_struct_value
4338 && TYPE_MODE (rettype) != VOIDmode
4339 && TYPE_MODE (rettype) != BLKmode
4340 && REG_P (valreg)
4341 && targetm.calls.return_in_msb (rettype))
4343 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4344 sibcall_failure = 1;
4345 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4348 if (pass && (flags & ECF_MALLOC))
4350 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4351 rtx_insn *last, *insns;
4353 /* The return value from a malloc-like function is a pointer. */
4354 if (TREE_CODE (rettype) == POINTER_TYPE)
4355 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4357 emit_move_insn (temp, valreg);
4359 /* The return value from a malloc-like function cannot alias
4360 anything else. */
4361 last = get_last_insn ();
4362 add_reg_note (last, REG_NOALIAS, temp);
4364 /* Write out the sequence. */
4365 insns = get_insns ();
4366 end_sequence ();
4367 emit_insn (insns);
4368 valreg = temp;
4371 /* For calls to `setjmp', etc., inform
4372 function.c:setjmp_warnings that it should complain if
4373 nonvolatile values are live. For functions that cannot
4374 return, inform flow that control does not fall through. */
4376 if ((flags & ECF_NORETURN) || pass == 0)
4378 /* The barrier must be emitted
4379 immediately after the CALL_INSN. Some ports emit more
4380 than just a CALL_INSN above, so we must search for it here. */
4382 rtx_insn *last = get_last_insn ();
4383 while (!CALL_P (last))
4385 last = PREV_INSN (last);
4386 /* There was no CALL_INSN? */
4387 gcc_assert (last != before_call);
4390 emit_barrier_after (last);
4392 /* Stack adjustments after a noreturn call are dead code.
4393 However when NO_DEFER_POP is in effect, we must preserve
4394 stack_pointer_delta. */
4395 if (inhibit_defer_pop == 0)
4397 stack_pointer_delta = old_stack_allocated;
4398 pending_stack_adjust = 0;
4402 /* If value type not void, return an rtx for the value. */
4404 if (TYPE_MODE (rettype) == VOIDmode
4405 || ignore)
4406 target = const0_rtx;
4407 else if (structure_value_addr)
4409 if (target == 0 || !MEM_P (target))
4411 target
4412 = gen_rtx_MEM (TYPE_MODE (rettype),
4413 memory_address (TYPE_MODE (rettype),
4414 structure_value_addr));
4415 set_mem_attributes (target, rettype, 1);
4418 else if (pcc_struct_value)
4420 /* This is the special C++ case where we need to
4421 know what the true target was. We take care to
4422 never use this value more than once in one expression. */
4423 target = gen_rtx_MEM (TYPE_MODE (rettype),
4424 copy_to_reg (valreg));
4425 set_mem_attributes (target, rettype, 1);
4427 /* Handle calls that return values in multiple non-contiguous locations.
4428 The Irix 6 ABI has examples of this. */
4429 else if (GET_CODE (valreg) == PARALLEL)
4431 if (target == 0)
4432 target = emit_group_move_into_temps (valreg);
4433 else if (rtx_equal_p (target, valreg))
4435 else if (GET_CODE (target) == PARALLEL)
4436 /* Handle the result of a emit_group_move_into_temps
4437 call in the previous pass. */
4438 emit_group_move (target, valreg);
4439 else
4440 emit_group_store (target, valreg, rettype,
4441 int_size_in_bytes (rettype));
4443 else if (target
4444 && GET_MODE (target) == TYPE_MODE (rettype)
4445 && GET_MODE (target) == GET_MODE (valreg))
4447 bool may_overlap = false;
4449 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4450 reg to a plain register. */
4451 if (!REG_P (target) || HARD_REGISTER_P (target))
4452 valreg = avoid_likely_spilled_reg (valreg);
4454 /* If TARGET is a MEM in the argument area, and we have
4455 saved part of the argument area, then we can't store
4456 directly into TARGET as it may get overwritten when we
4457 restore the argument save area below. Don't work too
4458 hard though and simply force TARGET to a register if it
4459 is a MEM; the optimizer is quite likely to sort it out. */
4460 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4461 for (i = 0; i < num_actuals; i++)
4462 if (args[i].save_area)
4464 may_overlap = true;
4465 break;
4468 if (may_overlap)
4469 target = copy_to_reg (valreg);
4470 else
4472 /* TARGET and VALREG cannot be equal at this point
4473 because the latter would not have
4474 REG_FUNCTION_VALUE_P true, while the former would if
4475 it were referring to the same register.
4477 If they refer to the same register, this move will be
4478 a no-op, except when function inlining is being
4479 done. */
4480 emit_move_insn (target, valreg);
4482 /* If we are setting a MEM, this code must be executed.
4483 Since it is emitted after the call insn, sibcall
4484 optimization cannot be performed in that case. */
4485 if (MEM_P (target))
4486 sibcall_failure = 1;
4489 else
4490 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4492 /* If we promoted this return value, make the proper SUBREG.
4493 TARGET might be const0_rtx here, so be careful. */
4494 if (REG_P (target)
4495 && TYPE_MODE (rettype) != BLKmode
4496 && GET_MODE (target) != TYPE_MODE (rettype))
4498 tree type = rettype;
4499 int unsignedp = TYPE_UNSIGNED (type);
4500 machine_mode pmode;
4502 /* Ensure we promote as expected, and get the new unsignedness. */
4503 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4504 funtype, 1);
4505 gcc_assert (GET_MODE (target) == pmode);
4507 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4508 GET_MODE (target));
4509 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4510 SUBREG_PROMOTED_VAR_P (target) = 1;
4511 SUBREG_PROMOTED_SET (target, unsignedp);
4514 /* If size of args is variable or this was a constructor call for a stack
4515 argument, restore saved stack-pointer value. */
4517 if (old_stack_level)
4519 rtx_insn *prev = get_last_insn ();
4521 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4522 stack_pointer_delta = old_stack_pointer_delta;
4524 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4526 pending_stack_adjust = old_pending_adj;
4527 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4528 stack_arg_under_construction = old_stack_arg_under_construction;
4529 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4530 stack_usage_map = initial_stack_usage_map;
4531 stack_usage_watermark = initial_stack_usage_watermark;
4532 sibcall_failure = 1;
4534 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4536 #ifdef REG_PARM_STACK_SPACE
4537 if (save_area)
4538 restore_fixed_argument_area (save_area, argblock,
4539 high_to_save, low_to_save);
4540 #endif
4542 /* If we saved any argument areas, restore them. */
4543 for (i = 0; i < num_actuals; i++)
4544 if (args[i].save_area)
4546 machine_mode save_mode = GET_MODE (args[i].save_area);
4547 rtx stack_area
4548 = gen_rtx_MEM (save_mode,
4549 memory_address (save_mode,
4550 XEXP (args[i].stack_slot, 0)));
4552 if (save_mode != BLKmode)
4553 emit_move_insn (stack_area, args[i].save_area);
4554 else
4555 emit_block_move (stack_area, args[i].save_area,
4556 (gen_int_mode
4557 (args[i].locate.size.constant, Pmode)),
4558 BLOCK_OP_CALL_PARM);
4561 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4562 stack_usage_map = initial_stack_usage_map;
4563 stack_usage_watermark = initial_stack_usage_watermark;
4566 /* If this was alloca, record the new stack level. */
4567 if (flags & ECF_MAY_BE_ALLOCA)
4568 record_new_stack_level ();
4570 /* Free up storage we no longer need. */
4571 for (i = 0; i < num_actuals; ++i)
4572 free (args[i].aligned_regs);
4574 targetm.calls.end_call_args ();
4576 insns = get_insns ();
4577 end_sequence ();
4579 if (pass == 0)
4581 tail_call_insns = insns;
4583 /* Restore the pending stack adjustment now that we have
4584 finished generating the sibling call sequence. */
4586 restore_pending_stack_adjust (&save);
4588 /* Prepare arg structure for next iteration. */
4589 for (i = 0; i < num_actuals; i++)
4591 args[i].value = 0;
4592 args[i].aligned_regs = 0;
4593 args[i].stack = 0;
4596 sbitmap_free (stored_args_map);
4597 internal_arg_pointer_exp_state.scan_start = NULL;
4598 internal_arg_pointer_exp_state.cache.release ();
4600 else
4602 normal_call_insns = insns;
4604 /* Verify that we've deallocated all the stack we used. */
4605 gcc_assert ((flags & ECF_NORETURN)
4606 || known_eq (old_stack_allocated,
4607 stack_pointer_delta
4608 - pending_stack_adjust));
4611 /* If something prevents making this a sibling call,
4612 zero out the sequence. */
4613 if (sibcall_failure)
4614 tail_call_insns = NULL;
4615 else
4616 break;
4619 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4620 arguments too, as argument area is now clobbered by the call. */
4621 if (tail_call_insns)
4623 emit_insn (tail_call_insns);
4624 crtl->tail_call_emit = true;
4626 else
4628 emit_insn (normal_call_insns);
4629 if (try_tail_call)
4630 /* Ideally we'd emit a message for all of the ways that it could
4631 have failed. */
4632 maybe_complain_about_tail_call (exp, "tail call production failed");
4635 currently_expanding_call--;
4637 free (stack_usage_map_buf);
4638 free (args);
4639 return target;
4642 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4643 this function's incoming arguments.
4645 At the start of RTL generation we know the only REG_EQUIV notes
4646 in the rtl chain are those for incoming arguments, so we can look
4647 for REG_EQUIV notes between the start of the function and the
4648 NOTE_INSN_FUNCTION_BEG.
4650 This is (slight) overkill. We could keep track of the highest
4651 argument we clobber and be more selective in removing notes, but it
4652 does not seem to be worth the effort. */
4654 void
4655 fixup_tail_calls (void)
4657 rtx_insn *insn;
4659 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4661 rtx note;
4663 /* There are never REG_EQUIV notes for the incoming arguments
4664 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4665 if (NOTE_P (insn)
4666 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4667 break;
4669 note = find_reg_note (insn, REG_EQUIV, 0);
4670 if (note)
4671 remove_note (insn, note);
4672 note = find_reg_note (insn, REG_EQUIV, 0);
4673 gcc_assert (!note);
4677 /* Traverse a list of TYPES and expand all complex types into their
4678 components. */
4679 static tree
4680 split_complex_types (tree types)
4682 tree p;
4684 /* Before allocating memory, check for the common case of no complex. */
4685 for (p = types; p; p = TREE_CHAIN (p))
4687 tree type = TREE_VALUE (p);
4688 if (TREE_CODE (type) == COMPLEX_TYPE
4689 && targetm.calls.split_complex_arg (type))
4690 goto found;
4692 return types;
4694 found:
4695 types = copy_list (types);
4697 for (p = types; p; p = TREE_CHAIN (p))
4699 tree complex_type = TREE_VALUE (p);
4701 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4702 && targetm.calls.split_complex_arg (complex_type))
4704 tree next, imag;
4706 /* Rewrite complex type with component type. */
4707 TREE_VALUE (p) = TREE_TYPE (complex_type);
4708 next = TREE_CHAIN (p);
4710 /* Add another component type for the imaginary part. */
4711 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4712 TREE_CHAIN (p) = imag;
4713 TREE_CHAIN (imag) = next;
4715 /* Skip the newly created node. */
4716 p = TREE_CHAIN (p);
4720 return types;
4723 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4724 for a value of mode OUTMODE,
4725 with NARGS different arguments, passed as ARGS.
4726 Store the return value if RETVAL is nonzero: store it in VALUE if
4727 VALUE is nonnull, otherwise pick a convenient location. In either
4728 case return the location of the stored value.
4730 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4731 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4732 other types of library calls. */
4735 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4736 enum libcall_type fn_type,
4737 machine_mode outmode, int nargs, rtx_mode_t *args)
4739 /* Total size in bytes of all the stack-parms scanned so far. */
4740 struct args_size args_size;
4741 /* Size of arguments before any adjustments (such as rounding). */
4742 struct args_size original_args_size;
4743 int argnum;
4744 rtx fun;
4745 /* Todo, choose the correct decl type of orgfun. Sadly this information
4746 isn't present here, so we default to native calling abi here. */
4747 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4748 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4749 int count;
4750 rtx argblock = 0;
4751 CUMULATIVE_ARGS args_so_far_v;
4752 cumulative_args_t args_so_far;
4753 struct arg
4755 rtx value;
4756 machine_mode mode;
4757 rtx reg;
4758 int partial;
4759 struct locate_and_pad_arg_data locate;
4760 rtx save_area;
4762 struct arg *argvec;
4763 int old_inhibit_defer_pop = inhibit_defer_pop;
4764 rtx call_fusage = 0;
4765 rtx mem_value = 0;
4766 rtx valreg;
4767 int pcc_struct_value = 0;
4768 poly_int64 struct_value_size = 0;
4769 int flags;
4770 int reg_parm_stack_space = 0;
4771 poly_int64 needed;
4772 rtx_insn *before_call;
4773 bool have_push_fusage;
4774 tree tfom; /* type_for_mode (outmode, 0) */
4776 #ifdef REG_PARM_STACK_SPACE
4777 /* Define the boundary of the register parm stack space that needs to be
4778 save, if any. */
4779 int low_to_save = 0, high_to_save = 0;
4780 rtx save_area = 0; /* Place that it is saved. */
4781 #endif
4783 /* Size of the stack reserved for parameter registers. */
4784 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4785 char *initial_stack_usage_map = stack_usage_map;
4786 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4787 char *stack_usage_map_buf = NULL;
4789 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4791 #ifdef REG_PARM_STACK_SPACE
4792 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4793 #endif
4795 /* By default, library functions cannot throw. */
4796 flags = ECF_NOTHROW;
4798 switch (fn_type)
4800 case LCT_NORMAL:
4801 break;
4802 case LCT_CONST:
4803 flags |= ECF_CONST;
4804 break;
4805 case LCT_PURE:
4806 flags |= ECF_PURE;
4807 break;
4808 case LCT_NORETURN:
4809 flags |= ECF_NORETURN;
4810 break;
4811 case LCT_THROW:
4812 flags &= ~ECF_NOTHROW;
4813 break;
4814 case LCT_RETURNS_TWICE:
4815 flags = ECF_RETURNS_TWICE;
4816 break;
4818 fun = orgfun;
4820 /* Ensure current function's preferred stack boundary is at least
4821 what we need. */
4822 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4823 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4825 /* If this kind of value comes back in memory,
4826 decide where in memory it should come back. */
4827 if (outmode != VOIDmode)
4829 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4830 if (aggregate_value_p (tfom, 0))
4832 #ifdef PCC_STATIC_STRUCT_RETURN
4833 rtx pointer_reg
4834 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4835 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4836 pcc_struct_value = 1;
4837 if (value == 0)
4838 value = gen_reg_rtx (outmode);
4839 #else /* not PCC_STATIC_STRUCT_RETURN */
4840 struct_value_size = GET_MODE_SIZE (outmode);
4841 if (value != 0 && MEM_P (value))
4842 mem_value = value;
4843 else
4844 mem_value = assign_temp (tfom, 1, 1);
4845 #endif
4846 /* This call returns a big structure. */
4847 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4850 else
4851 tfom = void_type_node;
4853 /* ??? Unfinished: must pass the memory address as an argument. */
4855 /* Copy all the libcall-arguments out of the varargs data
4856 and into a vector ARGVEC.
4858 Compute how to pass each argument. We only support a very small subset
4859 of the full argument passing conventions to limit complexity here since
4860 library functions shouldn't have many args. */
4862 argvec = XALLOCAVEC (struct arg, nargs + 1);
4863 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4865 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4866 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4867 #else
4868 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4869 #endif
4870 args_so_far = pack_cumulative_args (&args_so_far_v);
4872 args_size.constant = 0;
4873 args_size.var = 0;
4875 count = 0;
4877 push_temp_slots ();
4879 /* If there's a structure value address to be passed,
4880 either pass it in the special place, or pass it as an extra argument. */
4881 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4883 rtx addr = XEXP (mem_value, 0);
4885 nargs++;
4887 /* Make sure it is a reasonable operand for a move or push insn. */
4888 if (!REG_P (addr) && !MEM_P (addr)
4889 && !(CONSTANT_P (addr)
4890 && targetm.legitimate_constant_p (Pmode, addr)))
4891 addr = force_operand (addr, NULL_RTX);
4893 argvec[count].value = addr;
4894 argvec[count].mode = Pmode;
4895 argvec[count].partial = 0;
4897 function_arg_info ptr_arg (Pmode, /*named=*/true);
4898 argvec[count].reg = targetm.calls.function_arg (args_so_far, ptr_arg);
4899 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, ptr_arg) == 0);
4901 locate_and_pad_parm (Pmode, NULL_TREE,
4902 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4904 #else
4905 argvec[count].reg != 0,
4906 #endif
4907 reg_parm_stack_space, 0,
4908 NULL_TREE, &args_size, &argvec[count].locate);
4910 if (argvec[count].reg == 0 || argvec[count].partial != 0
4911 || reg_parm_stack_space > 0)
4912 args_size.constant += argvec[count].locate.size.constant;
4914 targetm.calls.function_arg_advance (args_so_far, ptr_arg);
4916 count++;
4919 for (unsigned int i = 0; count < nargs; i++, count++)
4921 rtx val = args[i].first;
4922 function_arg_info arg (args[i].second, /*named=*/true);
4923 int unsigned_p = 0;
4925 /* We cannot convert the arg value to the mode the library wants here;
4926 must do it earlier where we know the signedness of the arg. */
4927 gcc_assert (arg.mode != BLKmode
4928 && (GET_MODE (val) == arg.mode
4929 || GET_MODE (val) == VOIDmode));
4931 /* Make sure it is a reasonable operand for a move or push insn. */
4932 if (!REG_P (val) && !MEM_P (val)
4933 && !(CONSTANT_P (val)
4934 && targetm.legitimate_constant_p (arg.mode, val)))
4935 val = force_operand (val, NULL_RTX);
4937 if (pass_by_reference (&args_so_far_v, arg))
4939 rtx slot;
4940 int must_copy = !reference_callee_copied (&args_so_far_v, arg);
4942 /* If this was a CONST function, it is now PURE since it now
4943 reads memory. */
4944 if (flags & ECF_CONST)
4946 flags &= ~ECF_CONST;
4947 flags |= ECF_PURE;
4950 if (MEM_P (val) && !must_copy)
4952 tree val_expr = MEM_EXPR (val);
4953 if (val_expr)
4954 mark_addressable (val_expr);
4955 slot = val;
4957 else
4959 slot = assign_temp (lang_hooks.types.type_for_mode (arg.mode, 0),
4960 1, 1);
4961 emit_move_insn (slot, val);
4964 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4965 gen_rtx_USE (VOIDmode, slot),
4966 call_fusage);
4967 if (must_copy)
4968 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4969 gen_rtx_CLOBBER (VOIDmode,
4970 slot),
4971 call_fusage);
4973 arg.mode = Pmode;
4974 arg.pass_by_reference = true;
4975 val = force_operand (XEXP (slot, 0), NULL_RTX);
4978 arg.mode = promote_function_mode (NULL_TREE, arg.mode, &unsigned_p,
4979 NULL_TREE, 0);
4980 argvec[count].mode = arg.mode;
4981 argvec[count].value = convert_modes (arg.mode, GET_MODE (val), val,
4982 unsigned_p);
4983 argvec[count].reg = targetm.calls.function_arg (args_so_far, arg);
4985 argvec[count].partial
4986 = targetm.calls.arg_partial_bytes (args_so_far, arg);
4988 if (argvec[count].reg == 0
4989 || argvec[count].partial != 0
4990 || reg_parm_stack_space > 0)
4992 locate_and_pad_parm (arg.mode, NULL_TREE,
4993 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4995 #else
4996 argvec[count].reg != 0,
4997 #endif
4998 reg_parm_stack_space, argvec[count].partial,
4999 NULL_TREE, &args_size, &argvec[count].locate);
5000 args_size.constant += argvec[count].locate.size.constant;
5001 gcc_assert (!argvec[count].locate.size.var);
5003 #ifdef BLOCK_REG_PADDING
5004 else
5005 /* The argument is passed entirely in registers. See at which
5006 end it should be padded. */
5007 argvec[count].locate.where_pad =
5008 BLOCK_REG_PADDING (arg.mode, NULL_TREE,
5009 known_le (GET_MODE_SIZE (arg.mode),
5010 UNITS_PER_WORD));
5011 #endif
5013 targetm.calls.function_arg_advance (args_so_far, arg);
5016 for (int i = 0; i < nargs; i++)
5017 if (reg_parm_stack_space > 0
5018 || argvec[i].reg == 0
5019 || argvec[i].partial != 0)
5020 update_stack_alignment_for_call (&argvec[i].locate);
5022 /* If this machine requires an external definition for library
5023 functions, write one out. */
5024 assemble_external_libcall (fun);
5026 original_args_size = args_size;
5027 args_size.constant = (aligned_upper_bound (args_size.constant
5028 + stack_pointer_delta,
5029 STACK_BYTES)
5030 - stack_pointer_delta);
5032 args_size.constant = upper_bound (args_size.constant,
5033 reg_parm_stack_space);
5035 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5036 args_size.constant -= reg_parm_stack_space;
5038 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
5039 args_size.constant);
5041 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
5043 poly_int64 pushed = args_size.constant + pending_stack_adjust;
5044 current_function_pushed_stack_size
5045 = upper_bound (current_function_pushed_stack_size, pushed);
5048 if (ACCUMULATE_OUTGOING_ARGS)
5050 /* Since the stack pointer will never be pushed, it is possible for
5051 the evaluation of a parm to clobber something we have already
5052 written to the stack. Since most function calls on RISC machines
5053 do not use the stack, this is uncommon, but must work correctly.
5055 Therefore, we save any area of the stack that was already written
5056 and that we are using. Here we set up to do this by making a new
5057 stack usage map from the old one.
5059 Another approach might be to try to reorder the argument
5060 evaluations to avoid this conflicting stack usage. */
5062 needed = args_size.constant;
5064 /* Since we will be writing into the entire argument area, the
5065 map must be allocated for its entire size, not just the part that
5066 is the responsibility of the caller. */
5067 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5068 needed += reg_parm_stack_space;
5070 poly_int64 limit = needed;
5071 if (ARGS_GROW_DOWNWARD)
5072 limit += 1;
5074 /* For polynomial sizes, this is the maximum possible size needed
5075 for arguments with a constant size and offset. */
5076 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5077 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5078 const_limit);
5080 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5081 stack_usage_map = stack_usage_map_buf;
5083 if (initial_highest_arg_in_use)
5084 memcpy (stack_usage_map, initial_stack_usage_map,
5085 initial_highest_arg_in_use);
5087 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5088 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5089 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5090 needed = 0;
5092 /* We must be careful to use virtual regs before they're instantiated,
5093 and real regs afterwards. Loop optimization, for example, can create
5094 new libcalls after we've instantiated the virtual regs, and if we
5095 use virtuals anyway, they won't match the rtl patterns. */
5097 if (virtuals_instantiated)
5098 argblock = plus_constant (Pmode, stack_pointer_rtx,
5099 STACK_POINTER_OFFSET);
5100 else
5101 argblock = virtual_outgoing_args_rtx;
5103 else
5105 if (!PUSH_ARGS)
5106 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5109 /* We push args individually in reverse order, perform stack alignment
5110 before the first push (the last arg). */
5111 if (argblock == 0)
5112 anti_adjust_stack (gen_int_mode (args_size.constant
5113 - original_args_size.constant,
5114 Pmode));
5116 argnum = nargs - 1;
5118 #ifdef REG_PARM_STACK_SPACE
5119 if (ACCUMULATE_OUTGOING_ARGS)
5121 /* The argument list is the property of the called routine and it
5122 may clobber it. If the fixed area has been used for previous
5123 parameters, we must save and restore it. */
5124 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5125 &low_to_save, &high_to_save);
5127 #endif
5129 /* When expanding a normal call, args are stored in push order,
5130 which is the reverse of what we have here. */
5131 bool any_regs = false;
5132 for (int i = nargs; i-- > 0; )
5133 if (argvec[i].reg != NULL_RTX)
5135 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5136 any_regs = true;
5138 if (!any_regs)
5139 targetm.calls.call_args (pc_rtx, NULL_TREE);
5141 /* Push the args that need to be pushed. */
5143 have_push_fusage = false;
5145 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5146 are to be pushed. */
5147 for (count = 0; count < nargs; count++, argnum--)
5149 machine_mode mode = argvec[argnum].mode;
5150 rtx val = argvec[argnum].value;
5151 rtx reg = argvec[argnum].reg;
5152 int partial = argvec[argnum].partial;
5153 unsigned int parm_align = argvec[argnum].locate.boundary;
5154 poly_int64 lower_bound = 0, upper_bound = 0;
5156 if (! (reg != 0 && partial == 0))
5158 rtx use;
5160 if (ACCUMULATE_OUTGOING_ARGS)
5162 /* If this is being stored into a pre-allocated, fixed-size,
5163 stack area, save any previous data at that location. */
5165 if (ARGS_GROW_DOWNWARD)
5167 /* stack_slot is negative, but we want to index stack_usage_map
5168 with positive values. */
5169 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5170 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5172 else
5174 lower_bound = argvec[argnum].locate.slot_offset.constant;
5175 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5178 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5179 reg_parm_stack_space))
5181 /* We need to make a save area. */
5182 poly_uint64 size
5183 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5184 machine_mode save_mode
5185 = int_mode_for_size (size, 1).else_blk ();
5186 rtx adr
5187 = plus_constant (Pmode, argblock,
5188 argvec[argnum].locate.offset.constant);
5189 rtx stack_area
5190 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5192 if (save_mode == BLKmode)
5194 argvec[argnum].save_area
5195 = assign_stack_temp (BLKmode,
5196 argvec[argnum].locate.size.constant
5199 emit_block_move (validize_mem
5200 (copy_rtx (argvec[argnum].save_area)),
5201 stack_area,
5202 (gen_int_mode
5203 (argvec[argnum].locate.size.constant,
5204 Pmode)),
5205 BLOCK_OP_CALL_PARM);
5207 else
5209 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5211 emit_move_insn (argvec[argnum].save_area, stack_area);
5216 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5217 partial, reg, 0, argblock,
5218 (gen_int_mode
5219 (argvec[argnum].locate.offset.constant, Pmode)),
5220 reg_parm_stack_space,
5221 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5223 /* Now mark the segment we just used. */
5224 if (ACCUMULATE_OUTGOING_ARGS)
5225 mark_stack_region_used (lower_bound, upper_bound);
5227 NO_DEFER_POP;
5229 /* Indicate argument access so that alias.c knows that these
5230 values are live. */
5231 if (argblock)
5232 use = plus_constant (Pmode, argblock,
5233 argvec[argnum].locate.offset.constant);
5234 else if (have_push_fusage)
5235 continue;
5236 else
5238 /* When arguments are pushed, trying to tell alias.c where
5239 exactly this argument is won't work, because the
5240 auto-increment causes confusion. So we merely indicate
5241 that we access something with a known mode somewhere on
5242 the stack. */
5243 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5244 gen_rtx_SCRATCH (Pmode));
5245 have_push_fusage = true;
5247 use = gen_rtx_MEM (argvec[argnum].mode, use);
5248 use = gen_rtx_USE (VOIDmode, use);
5249 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5253 argnum = nargs - 1;
5255 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5257 /* Now load any reg parms into their regs. */
5259 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5260 are to be pushed. */
5261 for (count = 0; count < nargs; count++, argnum--)
5263 machine_mode mode = argvec[argnum].mode;
5264 rtx val = argvec[argnum].value;
5265 rtx reg = argvec[argnum].reg;
5266 int partial = argvec[argnum].partial;
5268 /* Handle calls that pass values in multiple non-contiguous
5269 locations. The PA64 has examples of this for library calls. */
5270 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5271 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5272 else if (reg != 0 && partial == 0)
5274 emit_move_insn (reg, val);
5275 #ifdef BLOCK_REG_PADDING
5276 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5278 /* Copied from load_register_parameters. */
5280 /* Handle case where we have a value that needs shifting
5281 up to the msb. eg. a QImode value and we're padding
5282 upward on a BYTES_BIG_ENDIAN machine. */
5283 if (known_lt (size, UNITS_PER_WORD)
5284 && (argvec[argnum].locate.where_pad
5285 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5287 rtx x;
5288 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5290 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5291 report the whole reg as used. Strictly speaking, the
5292 call only uses SIZE bytes at the msb end, but it doesn't
5293 seem worth generating rtl to say that. */
5294 reg = gen_rtx_REG (word_mode, REGNO (reg));
5295 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5296 if (x != reg)
5297 emit_move_insn (reg, x);
5299 #endif
5302 NO_DEFER_POP;
5305 /* Any regs containing parms remain in use through the call. */
5306 for (count = 0; count < nargs; count++)
5308 rtx reg = argvec[count].reg;
5309 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5310 use_group_regs (&call_fusage, reg);
5311 else if (reg != 0)
5313 int partial = argvec[count].partial;
5314 if (partial)
5316 int nregs;
5317 gcc_assert (partial % UNITS_PER_WORD == 0);
5318 nregs = partial / UNITS_PER_WORD;
5319 use_regs (&call_fusage, REGNO (reg), nregs);
5321 else
5322 use_reg (&call_fusage, reg);
5326 /* Pass the function the address in which to return a structure value. */
5327 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5329 emit_move_insn (struct_value,
5330 force_reg (Pmode,
5331 force_operand (XEXP (mem_value, 0),
5332 NULL_RTX)));
5333 if (REG_P (struct_value))
5334 use_reg (&call_fusage, struct_value);
5337 /* Don't allow popping to be deferred, since then
5338 cse'ing of library calls could delete a call and leave the pop. */
5339 NO_DEFER_POP;
5340 valreg = (mem_value == 0 && outmode != VOIDmode
5341 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5343 /* Stack must be properly aligned now. */
5344 gcc_assert (multiple_p (stack_pointer_delta,
5345 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5347 before_call = get_last_insn ();
5349 if (flag_callgraph_info)
5350 record_final_call (SYMBOL_REF_DECL (orgfun), UNKNOWN_LOCATION);
5352 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5353 will set inhibit_defer_pop to that value. */
5354 /* The return type is needed to decide how many bytes the function pops.
5355 Signedness plays no role in that, so for simplicity, we pretend it's
5356 always signed. We also assume that the list of arguments passed has
5357 no impact, so we pretend it is unknown. */
5359 emit_call_1 (fun, NULL,
5360 get_identifier (XSTR (orgfun, 0)),
5361 build_function_type (tfom, NULL_TREE),
5362 original_args_size.constant, args_size.constant,
5363 struct_value_size,
5364 targetm.calls.function_arg (args_so_far,
5365 function_arg_info::end_marker ()),
5366 valreg,
5367 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5369 if (flag_ipa_ra)
5371 rtx datum = orgfun;
5372 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5373 rtx_call_insn *last = last_call_insn ();
5374 add_reg_note (last, REG_CALL_DECL, datum);
5377 /* Right-shift returned value if necessary. */
5378 if (!pcc_struct_value
5379 && TYPE_MODE (tfom) != BLKmode
5380 && targetm.calls.return_in_msb (tfom))
5382 shift_return_value (TYPE_MODE (tfom), false, valreg);
5383 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5386 targetm.calls.end_call_args ();
5388 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5389 that it should complain if nonvolatile values are live. For
5390 functions that cannot return, inform flow that control does not
5391 fall through. */
5392 if (flags & ECF_NORETURN)
5394 /* The barrier note must be emitted
5395 immediately after the CALL_INSN. Some ports emit more than
5396 just a CALL_INSN above, so we must search for it here. */
5397 rtx_insn *last = get_last_insn ();
5398 while (!CALL_P (last))
5400 last = PREV_INSN (last);
5401 /* There was no CALL_INSN? */
5402 gcc_assert (last != before_call);
5405 emit_barrier_after (last);
5408 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5409 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5410 if (flags & ECF_NOTHROW)
5412 rtx_insn *last = get_last_insn ();
5413 while (!CALL_P (last))
5415 last = PREV_INSN (last);
5416 /* There was no CALL_INSN? */
5417 gcc_assert (last != before_call);
5420 make_reg_eh_region_note_nothrow_nononlocal (last);
5423 /* Now restore inhibit_defer_pop to its actual original value. */
5424 OK_DEFER_POP;
5426 pop_temp_slots ();
5428 /* Copy the value to the right place. */
5429 if (outmode != VOIDmode && retval)
5431 if (mem_value)
5433 if (value == 0)
5434 value = mem_value;
5435 if (value != mem_value)
5436 emit_move_insn (value, mem_value);
5438 else if (GET_CODE (valreg) == PARALLEL)
5440 if (value == 0)
5441 value = gen_reg_rtx (outmode);
5442 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5444 else
5446 /* Convert to the proper mode if a promotion has been active. */
5447 if (GET_MODE (valreg) != outmode)
5449 int unsignedp = TYPE_UNSIGNED (tfom);
5451 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5452 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5453 == GET_MODE (valreg));
5454 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5457 if (value != 0)
5458 emit_move_insn (value, valreg);
5459 else
5460 value = valreg;
5464 if (ACCUMULATE_OUTGOING_ARGS)
5466 #ifdef REG_PARM_STACK_SPACE
5467 if (save_area)
5468 restore_fixed_argument_area (save_area, argblock,
5469 high_to_save, low_to_save);
5470 #endif
5472 /* If we saved any argument areas, restore them. */
5473 for (count = 0; count < nargs; count++)
5474 if (argvec[count].save_area)
5476 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5477 rtx adr = plus_constant (Pmode, argblock,
5478 argvec[count].locate.offset.constant);
5479 rtx stack_area = gen_rtx_MEM (save_mode,
5480 memory_address (save_mode, adr));
5482 if (save_mode == BLKmode)
5483 emit_block_move (stack_area,
5484 validize_mem
5485 (copy_rtx (argvec[count].save_area)),
5486 (gen_int_mode
5487 (argvec[count].locate.size.constant, Pmode)),
5488 BLOCK_OP_CALL_PARM);
5489 else
5490 emit_move_insn (stack_area, argvec[count].save_area);
5493 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5494 stack_usage_map = initial_stack_usage_map;
5495 stack_usage_watermark = initial_stack_usage_watermark;
5498 free (stack_usage_map_buf);
5500 return value;
5505 /* Store a single argument for a function call
5506 into the register or memory area where it must be passed.
5507 *ARG describes the argument value and where to pass it.
5509 ARGBLOCK is the address of the stack-block for all the arguments,
5510 or 0 on a machine where arguments are pushed individually.
5512 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5513 so must be careful about how the stack is used.
5515 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5516 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5517 that we need not worry about saving and restoring the stack.
5519 FNDECL is the declaration of the function we are calling.
5521 Return nonzero if this arg should cause sibcall failure,
5522 zero otherwise. */
5524 static int
5525 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5526 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5528 tree pval = arg->tree_value;
5529 rtx reg = 0;
5530 int partial = 0;
5531 poly_int64 used = 0;
5532 poly_int64 lower_bound = 0, upper_bound = 0;
5533 int sibcall_failure = 0;
5535 if (TREE_CODE (pval) == ERROR_MARK)
5536 return 1;
5538 /* Push a new temporary level for any temporaries we make for
5539 this argument. */
5540 push_temp_slots ();
5542 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5544 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5545 save any previous data at that location. */
5546 if (argblock && ! variable_size && arg->stack)
5548 if (ARGS_GROW_DOWNWARD)
5550 /* stack_slot is negative, but we want to index stack_usage_map
5551 with positive values. */
5552 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5554 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5555 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5557 else
5558 upper_bound = 0;
5560 lower_bound = upper_bound - arg->locate.size.constant;
5562 else
5564 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5566 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5567 lower_bound = rtx_to_poly_int64 (offset);
5569 else
5570 lower_bound = 0;
5572 upper_bound = lower_bound + arg->locate.size.constant;
5575 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5576 reg_parm_stack_space))
5578 /* We need to make a save area. */
5579 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5580 machine_mode save_mode
5581 = int_mode_for_size (size, 1).else_blk ();
5582 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5583 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5585 if (save_mode == BLKmode)
5587 arg->save_area
5588 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5589 preserve_temp_slots (arg->save_area);
5590 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5591 stack_area,
5592 (gen_int_mode
5593 (arg->locate.size.constant, Pmode)),
5594 BLOCK_OP_CALL_PARM);
5596 else
5598 arg->save_area = gen_reg_rtx (save_mode);
5599 emit_move_insn (arg->save_area, stack_area);
5605 /* If this isn't going to be placed on both the stack and in registers,
5606 set up the register and number of words. */
5607 if (! arg->pass_on_stack)
5609 if (flags & ECF_SIBCALL)
5610 reg = arg->tail_call_reg;
5611 else
5612 reg = arg->reg;
5613 partial = arg->partial;
5616 /* Being passed entirely in a register. We shouldn't be called in
5617 this case. */
5618 gcc_assert (reg == 0 || partial != 0);
5620 /* If this arg needs special alignment, don't load the registers
5621 here. */
5622 if (arg->n_aligned_regs != 0)
5623 reg = 0;
5625 /* If this is being passed partially in a register, we can't evaluate
5626 it directly into its stack slot. Otherwise, we can. */
5627 if (arg->value == 0)
5629 /* stack_arg_under_construction is nonzero if a function argument is
5630 being evaluated directly into the outgoing argument list and
5631 expand_call must take special action to preserve the argument list
5632 if it is called recursively.
5634 For scalar function arguments stack_usage_map is sufficient to
5635 determine which stack slots must be saved and restored. Scalar
5636 arguments in general have pass_on_stack == 0.
5638 If this argument is initialized by a function which takes the
5639 address of the argument (a C++ constructor or a C function
5640 returning a BLKmode structure), then stack_usage_map is
5641 insufficient and expand_call must push the stack around the
5642 function call. Such arguments have pass_on_stack == 1.
5644 Note that it is always safe to set stack_arg_under_construction,
5645 but this generates suboptimal code if set when not needed. */
5647 if (arg->pass_on_stack)
5648 stack_arg_under_construction++;
5650 arg->value = expand_expr (pval,
5651 (partial
5652 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5653 ? NULL_RTX : arg->stack,
5654 VOIDmode, EXPAND_STACK_PARM);
5656 /* If we are promoting object (or for any other reason) the mode
5657 doesn't agree, convert the mode. */
5659 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5660 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5661 arg->value, arg->unsignedp);
5663 if (arg->pass_on_stack)
5664 stack_arg_under_construction--;
5667 /* Check for overlap with already clobbered argument area. */
5668 if ((flags & ECF_SIBCALL)
5669 && MEM_P (arg->value)
5670 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5671 arg->locate.size.constant))
5672 sibcall_failure = 1;
5674 /* Don't allow anything left on stack from computation
5675 of argument to alloca. */
5676 if (flags & ECF_MAY_BE_ALLOCA)
5677 do_pending_stack_adjust ();
5679 if (arg->value == arg->stack)
5680 /* If the value is already in the stack slot, we are done. */
5682 else if (arg->mode != BLKmode)
5684 unsigned int parm_align;
5686 /* Argument is a scalar, not entirely passed in registers.
5687 (If part is passed in registers, arg->partial says how much
5688 and emit_push_insn will take care of putting it there.)
5690 Push it, and if its size is less than the
5691 amount of space allocated to it,
5692 also bump stack pointer by the additional space.
5693 Note that in C the default argument promotions
5694 will prevent such mismatches. */
5696 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5697 ? 0 : GET_MODE_SIZE (arg->mode));
5699 /* Compute how much space the push instruction will push.
5700 On many machines, pushing a byte will advance the stack
5701 pointer by a halfword. */
5702 #ifdef PUSH_ROUNDING
5703 size = PUSH_ROUNDING (size);
5704 #endif
5705 used = size;
5707 /* Compute how much space the argument should get:
5708 round up to a multiple of the alignment for arguments. */
5709 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5710 != PAD_NONE)
5711 /* At the moment we don't (need to) support ABIs for which the
5712 padding isn't known at compile time. In principle it should
5713 be easy to add though. */
5714 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5716 /* Compute the alignment of the pushed argument. */
5717 parm_align = arg->locate.boundary;
5718 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5719 == PAD_DOWNWARD)
5721 poly_int64 pad = used - size;
5722 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5723 if (pad_align != 0)
5724 parm_align = MIN (parm_align, pad_align);
5727 /* This isn't already where we want it on the stack, so put it there.
5728 This can either be done with push or copy insns. */
5729 if (maybe_ne (used, 0)
5730 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5731 NULL_RTX, parm_align, partial, reg, used - size,
5732 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5733 reg_parm_stack_space,
5734 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5735 sibcall_failure = 1;
5737 /* Unless this is a partially-in-register argument, the argument is now
5738 in the stack. */
5739 if (partial == 0)
5740 arg->value = arg->stack;
5742 else
5744 /* BLKmode, at least partly to be pushed. */
5746 unsigned int parm_align;
5747 poly_int64 excess;
5748 rtx size_rtx;
5750 /* Pushing a nonscalar.
5751 If part is passed in registers, PARTIAL says how much
5752 and emit_push_insn will take care of putting it there. */
5754 /* Round its size up to a multiple
5755 of the allocation unit for arguments. */
5757 if (arg->locate.size.var != 0)
5759 excess = 0;
5760 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5762 else
5764 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5765 for BLKmode is careful to avoid it. */
5766 excess = (arg->locate.size.constant
5767 - arg_int_size_in_bytes (TREE_TYPE (pval))
5768 + partial);
5769 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5770 NULL_RTX, TYPE_MODE (sizetype),
5771 EXPAND_NORMAL);
5774 parm_align = arg->locate.boundary;
5776 /* When an argument is padded down, the block is aligned to
5777 PARM_BOUNDARY, but the actual argument isn't. */
5778 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5779 == PAD_DOWNWARD)
5781 if (arg->locate.size.var)
5782 parm_align = BITS_PER_UNIT;
5783 else
5785 unsigned int excess_align
5786 = known_alignment (excess) * BITS_PER_UNIT;
5787 if (excess_align != 0)
5788 parm_align = MIN (parm_align, excess_align);
5792 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5794 /* emit_push_insn might not work properly if arg->value and
5795 argblock + arg->locate.offset areas overlap. */
5796 rtx x = arg->value;
5797 poly_int64 i = 0;
5799 if (strip_offset (XEXP (x, 0), &i)
5800 == crtl->args.internal_arg_pointer)
5802 /* arg.locate doesn't contain the pretend_args_size offset,
5803 it's part of argblock. Ensure we don't count it in I. */
5804 if (STACK_GROWS_DOWNWARD)
5805 i -= crtl->args.pretend_args_size;
5806 else
5807 i += crtl->args.pretend_args_size;
5809 /* expand_call should ensure this. */
5810 gcc_assert (!arg->locate.offset.var
5811 && arg->locate.size.var == 0);
5812 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5814 if (known_eq (arg->locate.offset.constant, i))
5816 /* Even though they appear to be at the same location,
5817 if part of the outgoing argument is in registers,
5818 they aren't really at the same location. Check for
5819 this by making sure that the incoming size is the
5820 same as the outgoing size. */
5821 if (maybe_ne (arg->locate.size.constant, size_val))
5822 sibcall_failure = 1;
5824 else if (maybe_in_range_p (arg->locate.offset.constant,
5825 i, size_val))
5826 sibcall_failure = 1;
5827 /* Use arg->locate.size.constant instead of size_rtx
5828 because we only care about the part of the argument
5829 on the stack. */
5830 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5831 arg->locate.size.constant))
5832 sibcall_failure = 1;
5836 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5837 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5838 parm_align, partial, reg, excess, argblock,
5839 ARGS_SIZE_RTX (arg->locate.offset),
5840 reg_parm_stack_space,
5841 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5843 /* Unless this is a partially-in-register argument, the argument is now
5844 in the stack.
5846 ??? Unlike the case above, in which we want the actual
5847 address of the data, so that we can load it directly into a
5848 register, here we want the address of the stack slot, so that
5849 it's properly aligned for word-by-word copying or something
5850 like that. It's not clear that this is always correct. */
5851 if (partial == 0)
5852 arg->value = arg->stack_slot;
5855 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5857 tree type = TREE_TYPE (arg->tree_value);
5858 arg->parallel_value
5859 = emit_group_load_into_temps (arg->reg, arg->value, type,
5860 int_size_in_bytes (type));
5863 /* Mark all slots this store used. */
5864 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5865 && argblock && ! variable_size && arg->stack)
5866 mark_stack_region_used (lower_bound, upper_bound);
5868 /* Once we have pushed something, pops can't safely
5869 be deferred during the rest of the arguments. */
5870 NO_DEFER_POP;
5872 /* Free any temporary slots made in processing this argument. */
5873 pop_temp_slots ();
5875 return sibcall_failure;
5878 /* Nonzero if we do not know how to pass ARG solely in registers. */
5880 bool
5881 must_pass_in_stack_var_size (const function_arg_info &arg)
5883 if (!arg.type)
5884 return false;
5886 /* If the type has variable size... */
5887 if (!poly_int_tree_p (TYPE_SIZE (arg.type)))
5888 return true;
5890 /* If the type is marked as addressable (it is required
5891 to be constructed into the stack)... */
5892 if (TREE_ADDRESSABLE (arg.type))
5893 return true;
5895 return false;
5898 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5899 takes trailing padding of a structure into account. */
5900 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5902 bool
5903 must_pass_in_stack_var_size_or_pad (const function_arg_info &arg)
5905 if (!arg.type)
5906 return false;
5908 /* If the type has variable size... */
5909 if (TREE_CODE (TYPE_SIZE (arg.type)) != INTEGER_CST)
5910 return true;
5912 /* If the type is marked as addressable (it is required
5913 to be constructed into the stack)... */
5914 if (TREE_ADDRESSABLE (arg.type))
5915 return true;
5917 if (TYPE_EMPTY_P (arg.type))
5918 return false;
5920 /* If the padding and mode of the type is such that a copy into
5921 a register would put it into the wrong part of the register. */
5922 if (arg.mode == BLKmode
5923 && int_size_in_bytes (arg.type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5924 && (targetm.calls.function_arg_padding (arg.mode, arg.type)
5925 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5926 return true;
5928 return false;
5931 /* Return true if TYPE must be passed on the stack when passed to
5932 the "..." arguments of a function. */
5934 bool
5935 must_pass_va_arg_in_stack (tree type)
5937 function_arg_info arg (type, /*named=*/false);
5938 return targetm.calls.must_pass_in_stack (arg);
5941 /* Tell the garbage collector about GTY markers in this source file. */
5942 #include "gt-calls.h"