Add assember CFI directives to millicode division and remainder routines.
[official-gcc.git] / gcc / calls.cc
blob4d7f6c3d2912c9dcb150d8d219dce07d99ada0a6
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2023 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 "intl.h"
53 #include "stringpool.h"
54 #include "hash-map.h"
55 #include "hash-traits.h"
56 #include "attribs.h"
57 #include "builtins.h"
58 #include "gimple-iterator.h"
59 #include "gimple-fold.h"
60 #include "attr-fnspec.h"
61 #include "value-query.h"
62 #include "tree-pretty-print.h"
63 #include "tree-eh.h"
65 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
66 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
68 /* Data structure and subroutines used within expand_call. */
70 struct arg_data
72 /* Tree node for this argument. */
73 tree tree_value;
74 /* Mode for value; TYPE_MODE unless promoted. */
75 machine_mode mode;
76 /* Current RTL value for argument, or 0 if it isn't precomputed. */
77 rtx value;
78 /* Initially-compute RTL value for argument; only for const functions. */
79 rtx initial_value;
80 /* Register to pass this argument in, 0 if passed on stack, or an
81 PARALLEL if the arg is to be copied into multiple non-contiguous
82 registers. */
83 rtx reg;
84 /* Register to pass this argument in when generating tail call sequence.
85 This is not the same register as for normal calls on machines with
86 register windows. */
87 rtx tail_call_reg;
88 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
89 form for emit_group_move. */
90 rtx parallel_value;
91 /* If REG was promoted from the actual mode of the argument expression,
92 indicates whether the promotion is sign- or zero-extended. */
93 int unsignedp;
94 /* Number of bytes to put in registers. 0 means put the whole arg
95 in registers. Also 0 if not passed in registers. */
96 int partial;
97 /* Nonzero if argument must be passed on stack.
98 Note that some arguments may be passed on the stack
99 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
100 pass_on_stack identifies arguments that *cannot* go in registers. */
101 int pass_on_stack;
102 /* Some fields packaged up for locate_and_pad_parm. */
103 struct locate_and_pad_arg_data locate;
104 /* Location on the stack at which parameter should be stored. The store
105 has already been done if STACK == VALUE. */
106 rtx stack;
107 /* Location on the stack of the start of this argument slot. This can
108 differ from STACK if this arg pads downward. This location is known
109 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
110 rtx stack_slot;
111 /* Place that this stack area has been saved, if needed. */
112 rtx save_area;
113 /* If an argument's alignment does not permit direct copying into registers,
114 copy in smaller-sized pieces into pseudos. These are stored in a
115 block pointed to by this field. The next field says how many
116 word-sized pseudos we made. */
117 rtx *aligned_regs;
118 int n_aligned_regs;
121 /* A vector of one char per byte of stack space. A byte if nonzero if
122 the corresponding stack location has been used.
123 This vector is used to prevent a function call within an argument from
124 clobbering any stack already set up. */
125 static char *stack_usage_map;
127 /* Size of STACK_USAGE_MAP. */
128 static unsigned int highest_outgoing_arg_in_use;
130 /* Assume that any stack location at this byte index is used,
131 without checking the contents of stack_usage_map. */
132 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
134 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
135 stack location's tail call argument has been already stored into the stack.
136 This bitmap is used to prevent sibling call optimization if function tries
137 to use parent's incoming argument slots when they have been already
138 overwritten with tail call arguments. */
139 static sbitmap stored_args_map;
141 /* Assume that any virtual-incoming location at this byte index has been
142 stored, without checking the contents of stored_args_map. */
143 static unsigned HOST_WIDE_INT stored_args_watermark;
145 /* stack_arg_under_construction is nonzero when an argument may be
146 initialized with a constructor call (including a C function that
147 returns a BLKmode struct) and expand_call must take special action
148 to make sure the object being constructed does not overlap the
149 argument list for the constructor call. */
150 static int stack_arg_under_construction;
152 static void precompute_register_parameters (int, struct arg_data *, int *);
153 static int store_one_arg (struct arg_data *, rtx, int, int, int);
154 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
155 static int finalize_must_preallocate (int, int, struct arg_data *,
156 struct args_size *);
157 static void precompute_arguments (int, struct arg_data *);
158 static void compute_argument_addresses (struct arg_data *, rtx, int);
159 static rtx rtx_for_function_call (tree, tree);
160 static void load_register_parameters (struct arg_data *, int, rtx *, int,
161 int, int *);
162 static int special_function_p (const_tree, int);
163 static int check_sibcall_argument_overlap_1 (rtx);
164 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
166 static tree split_complex_types (tree);
168 #ifdef REG_PARM_STACK_SPACE
169 static rtx save_fixed_argument_area (int, rtx, int *, int *);
170 static void restore_fixed_argument_area (rtx, rtx, int, int);
171 #endif
173 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
174 stack region might already be in use. */
176 static bool
177 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
178 unsigned int reg_parm_stack_space)
180 unsigned HOST_WIDE_INT const_lower, const_upper;
181 const_lower = constant_lower_bound (lower_bound);
182 if (!upper_bound.is_constant (&const_upper))
183 const_upper = HOST_WIDE_INT_M1U;
185 if (const_upper > stack_usage_watermark)
186 return true;
188 /* Don't worry about things in the fixed argument area;
189 it has already been saved. */
190 const_lower = MAX (const_lower, reg_parm_stack_space);
191 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
192 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
193 if (stack_usage_map[i])
194 return true;
195 return false;
198 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
199 stack region are now in use. */
201 static void
202 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
204 unsigned HOST_WIDE_INT const_lower, const_upper;
205 const_lower = constant_lower_bound (lower_bound);
206 if (upper_bound.is_constant (&const_upper)
207 && const_upper <= highest_outgoing_arg_in_use)
208 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
209 stack_usage_map[i] = 1;
210 else
211 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
214 /* Force FUNEXP into a form suitable for the address of a CALL,
215 and return that as an rtx. Also load the static chain register
216 if FNDECL is a nested function.
218 CALL_FUSAGE points to a variable holding the prospective
219 CALL_INSN_FUNCTION_USAGE information. */
222 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
223 rtx *call_fusage, int reg_parm_seen, int flags)
225 /* Make a valid memory address and copy constants through pseudo-regs,
226 but not for a constant address if -fno-function-cse. */
227 if (GET_CODE (funexp) != SYMBOL_REF)
229 /* If it's an indirect call by descriptor, generate code to perform
230 runtime identification of the pointer and load the descriptor. */
231 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
233 const int bit_val = targetm.calls.custom_function_descriptors;
234 rtx call_lab = gen_label_rtx ();
236 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
237 fndecl_or_type
238 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
239 fndecl_or_type);
240 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
241 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
243 if (GET_MODE (funexp) != Pmode)
244 funexp = convert_memory_address (Pmode, funexp);
246 /* Avoid long live ranges around function calls. */
247 funexp = copy_to_mode_reg (Pmode, funexp);
249 if (REG_P (chain))
250 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
252 /* Emit the runtime identification pattern. */
253 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
254 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
255 call_lab);
257 /* Statically predict the branch to very likely taken. */
258 rtx_insn *insn = get_last_insn ();
259 if (JUMP_P (insn))
260 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
262 /* Load the descriptor. */
263 rtx mem = gen_rtx_MEM (ptr_mode,
264 plus_constant (Pmode, funexp, - bit_val));
265 MEM_NOTRAP_P (mem) = 1;
266 mem = convert_memory_address (Pmode, mem);
267 emit_move_insn (chain, mem);
269 mem = gen_rtx_MEM (ptr_mode,
270 plus_constant (Pmode, funexp,
271 POINTER_SIZE / BITS_PER_UNIT
272 - bit_val));
273 MEM_NOTRAP_P (mem) = 1;
274 mem = convert_memory_address (Pmode, mem);
275 emit_move_insn (funexp, mem);
277 emit_label (call_lab);
279 if (REG_P (chain))
281 use_reg (call_fusage, chain);
282 STATIC_CHAIN_REG_P (chain) = 1;
285 /* Make sure we're not going to be overwritten below. */
286 gcc_assert (!static_chain_value);
289 /* If we are using registers for parameters, force the
290 function address into a register now. */
291 funexp = ((reg_parm_seen
292 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
293 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
294 : memory_address (FUNCTION_MODE, funexp));
296 else
298 /* funexp could be a SYMBOL_REF represents a function pointer which is
299 of ptr_mode. In this case, it should be converted into address mode
300 to be a valid address for memory rtx pattern. See PR 64971. */
301 if (GET_MODE (funexp) != Pmode)
302 funexp = convert_memory_address (Pmode, funexp);
304 if (!(flags & ECF_SIBCALL))
306 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
307 funexp = force_reg (Pmode, funexp);
311 if (static_chain_value != 0
312 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
313 || DECL_STATIC_CHAIN (fndecl_or_type)))
315 rtx chain;
317 chain = targetm.calls.static_chain (fndecl_or_type, false);
318 static_chain_value = convert_memory_address (Pmode, static_chain_value);
320 emit_move_insn (chain, static_chain_value);
321 if (REG_P (chain))
323 use_reg (call_fusage, chain);
324 STATIC_CHAIN_REG_P (chain) = 1;
328 return funexp;
331 /* Generate instructions to call function FUNEXP,
332 and optionally pop the results.
333 The CALL_INSN is the first insn generated.
335 FNDECL is the declaration node of the function. This is given to the
336 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
337 its own args.
339 FUNTYPE is the data type of the function. This is given to the hook
340 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
341 own args. We used to allow an identifier for library functions, but
342 that doesn't work when the return type is an aggregate type and the
343 calling convention says that the pointer to this aggregate is to be
344 popped by the callee.
346 STACK_SIZE is the number of bytes of arguments on the stack,
347 ROUNDED_STACK_SIZE is that number rounded up to
348 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
349 both to put into the call insn and to generate explicit popping
350 code if necessary.
352 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
353 It is zero if this call doesn't want a structure value.
355 NEXT_ARG_REG is the rtx that results from executing
356 targetm.calls.function_arg (&args_so_far,
357 function_arg_info::end_marker ());
358 just after all the args have had their registers assigned.
359 This could be whatever you like, but normally it is the first
360 arg-register beyond those used for args in this call,
361 or 0 if all the arg-registers are used in this call.
362 It is passed on to `gen_call' so you can put this info in the call insn.
364 VALREG is a hard register in which a value is returned,
365 or 0 if the call does not return a value.
367 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
368 the args to this call were processed.
369 We restore `inhibit_defer_pop' to that value.
371 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
372 denote registers used by the called function. */
374 static void
375 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
376 tree funtype ATTRIBUTE_UNUSED,
377 poly_int64 stack_size ATTRIBUTE_UNUSED,
378 poly_int64 rounded_stack_size,
379 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
380 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
381 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
382 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
384 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
385 rtx call, funmem, pat;
386 int already_popped = 0;
387 poly_int64 n_popped = 0;
389 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
390 patterns exist). Any popping that the callee does on return will
391 be from our caller's frame rather than ours. */
392 if (!(ecf_flags & ECF_SIBCALL))
394 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
396 #ifdef CALL_POPS_ARGS
397 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
398 #endif
401 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
402 and we don't want to load it into a register as an optimization,
403 because prepare_call_address already did it if it should be done. */
404 if (GET_CODE (funexp) != SYMBOL_REF)
405 funexp = memory_address (FUNCTION_MODE, funexp);
407 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
408 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
410 tree t = fndecl;
412 /* Although a built-in FUNCTION_DECL and its non-__builtin
413 counterpart compare equal and get a shared mem_attrs, they
414 produce different dump output in compare-debug compilations,
415 if an entry gets garbage collected in one compilation, then
416 adds a different (but equivalent) entry, while the other
417 doesn't run the garbage collector at the same spot and then
418 shares the mem_attr with the equivalent entry. */
419 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
421 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
422 if (t2)
423 t = t2;
426 set_mem_expr (funmem, t);
428 else if (fntree)
429 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
431 if (ecf_flags & ECF_SIBCALL)
433 if (valreg)
434 pat = targetm.gen_sibcall_value (valreg, funmem,
435 rounded_stack_size_rtx,
436 next_arg_reg, NULL_RTX);
437 else
438 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
439 next_arg_reg,
440 gen_int_mode (struct_value_size, Pmode));
442 /* If the target has "call" or "call_value" insns, then prefer them
443 if no arguments are actually popped. If the target does not have
444 "call" or "call_value" insns, then we must use the popping versions
445 even if the call has no arguments to pop. */
446 else if (maybe_ne (n_popped, 0)
447 || !(valreg
448 ? targetm.have_call_value ()
449 : targetm.have_call ()))
451 rtx n_pop = gen_int_mode (n_popped, Pmode);
453 /* If this subroutine pops its own args, record that in the call insn
454 if possible, for the sake of frame pointer elimination. */
456 if (valreg)
457 pat = targetm.gen_call_value_pop (valreg, funmem,
458 rounded_stack_size_rtx,
459 next_arg_reg, n_pop);
460 else
461 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
462 next_arg_reg, n_pop);
464 already_popped = 1;
466 else
468 if (valreg)
469 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
470 next_arg_reg, NULL_RTX);
471 else
472 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
473 gen_int_mode (struct_value_size, Pmode));
475 emit_insn (pat);
477 /* Find the call we just emitted. */
478 rtx_call_insn *call_insn = last_call_insn ();
480 /* Some target create a fresh MEM instead of reusing the one provided
481 above. Set its MEM_EXPR. */
482 call = get_call_rtx_from (call_insn);
483 if (call
484 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
485 && MEM_EXPR (funmem) != NULL_TREE)
486 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
488 /* Put the register usage information there. */
489 add_function_usage_to (call_insn, call_fusage);
491 /* If this is a const call, then set the insn's unchanging bit. */
492 if (ecf_flags & ECF_CONST)
493 RTL_CONST_CALL_P (call_insn) = 1;
495 /* If this is a pure call, then set the insn's unchanging bit. */
496 if (ecf_flags & ECF_PURE)
497 RTL_PURE_CALL_P (call_insn) = 1;
499 /* If this is a const call, then set the insn's unchanging bit. */
500 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
501 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
503 /* Create a nothrow REG_EH_REGION note, if needed. */
504 make_reg_eh_region_note (call_insn, ecf_flags, 0);
506 if (ecf_flags & ECF_NORETURN)
507 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
509 if (ecf_flags & ECF_RETURNS_TWICE)
511 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
512 cfun->calls_setjmp = 1;
515 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
517 /* Restore this now, so that we do defer pops for this call's args
518 if the context of the call as a whole permits. */
519 inhibit_defer_pop = old_inhibit_defer_pop;
521 if (maybe_ne (n_popped, 0))
523 if (!already_popped)
524 CALL_INSN_FUNCTION_USAGE (call_insn)
525 = gen_rtx_EXPR_LIST (VOIDmode,
526 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
527 CALL_INSN_FUNCTION_USAGE (call_insn));
528 rounded_stack_size -= n_popped;
529 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
530 stack_pointer_delta -= n_popped;
532 add_args_size_note (call_insn, stack_pointer_delta);
534 /* If popup is needed, stack realign must use DRAP */
535 if (SUPPORTS_STACK_ALIGNMENT)
536 crtl->need_drap = true;
538 /* For noreturn calls when not accumulating outgoing args force
539 REG_ARGS_SIZE note to prevent crossjumping of calls with different
540 args sizes. */
541 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
542 add_args_size_note (call_insn, stack_pointer_delta);
544 if (!ACCUMULATE_OUTGOING_ARGS)
546 /* If returning from the subroutine does not automatically pop the args,
547 we need an instruction to pop them sooner or later.
548 Perhaps do it now; perhaps just record how much space to pop later.
550 If returning from the subroutine does pop the args, indicate that the
551 stack pointer will be changed. */
553 if (maybe_ne (rounded_stack_size, 0))
555 if (ecf_flags & ECF_NORETURN)
556 /* Just pretend we did the pop. */
557 stack_pointer_delta -= rounded_stack_size;
558 else if (flag_defer_pop && inhibit_defer_pop == 0
559 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
560 pending_stack_adjust += rounded_stack_size;
561 else
562 adjust_stack (rounded_stack_size_rtx);
565 /* When we accumulate outgoing args, we must avoid any stack manipulations.
566 Restore the stack pointer to its original value now. Usually
567 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
568 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
569 popping variants of functions exist as well.
571 ??? We may optimize similar to defer_pop above, but it is
572 probably not worthwhile.
574 ??? It will be worthwhile to enable combine_stack_adjustments even for
575 such machines. */
576 else if (maybe_ne (n_popped, 0))
577 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
580 /* Determine if the function identified by FNDECL is one with
581 special properties we wish to know about. Modify FLAGS accordingly.
583 For example, if the function might return more than one time (setjmp), then
584 set ECF_RETURNS_TWICE.
586 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
587 space from the stack such as alloca. */
589 static int
590 special_function_p (const_tree fndecl, int flags)
592 tree name_decl = DECL_NAME (fndecl);
594 if (maybe_special_function_p (fndecl)
595 && IDENTIFIER_LENGTH (name_decl) <= 11)
597 const char *name = IDENTIFIER_POINTER (name_decl);
598 const char *tname = name;
600 /* We assume that alloca will always be called by name. It
601 makes no sense to pass it as a pointer-to-function to
602 anything that does not understand its behavior. */
603 if (IDENTIFIER_LENGTH (name_decl) == 6
604 && name[0] == 'a'
605 && ! strcmp (name, "alloca"))
606 flags |= ECF_MAY_BE_ALLOCA;
608 /* Disregard prefix _ or __. */
609 if (name[0] == '_')
611 if (name[1] == '_')
612 tname += 2;
613 else
614 tname += 1;
617 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
618 if (! strcmp (tname, "setjmp")
619 || ! strcmp (tname, "sigsetjmp")
620 || ! strcmp (name, "savectx")
621 || ! strcmp (name, "vfork")
622 || ! strcmp (name, "getcontext"))
623 flags |= ECF_RETURNS_TWICE;
626 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
627 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
628 flags |= ECF_MAY_BE_ALLOCA;
630 return flags;
633 /* Return fnspec for DECL. */
635 static attr_fnspec
636 decl_fnspec (tree fndecl)
638 tree attr;
639 tree type = TREE_TYPE (fndecl);
640 if (type)
642 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
643 if (attr)
645 return TREE_VALUE (TREE_VALUE (attr));
648 if (fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
649 return builtin_fnspec (fndecl);
650 return "";
653 /* Similar to special_function_p; return a set of ERF_ flags for the
654 function FNDECL. */
655 static int
656 decl_return_flags (tree fndecl)
658 attr_fnspec fnspec = decl_fnspec (fndecl);
660 unsigned int arg;
661 if (fnspec.returns_arg (&arg))
662 return ERF_RETURNS_ARG | arg;
664 if (fnspec.returns_noalias_p ())
665 return ERF_NOALIAS;
666 return 0;
669 /* Return nonzero when FNDECL represents a call to setjmp. */
672 setjmp_call_p (const_tree fndecl)
674 if (DECL_IS_RETURNS_TWICE (fndecl))
675 return ECF_RETURNS_TWICE;
676 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
680 /* Return true if STMT may be an alloca call. */
682 bool
683 gimple_maybe_alloca_call_p (const gimple *stmt)
685 tree fndecl;
687 if (!is_gimple_call (stmt))
688 return false;
690 fndecl = gimple_call_fndecl (stmt);
691 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
692 return true;
694 return false;
697 /* Return true if STMT is a builtin alloca call. */
699 bool
700 gimple_alloca_call_p (const gimple *stmt)
702 tree fndecl;
704 if (!is_gimple_call (stmt))
705 return false;
707 fndecl = gimple_call_fndecl (stmt);
708 if (fndecl && fndecl_built_in_p (fndecl, BUILT_IN_NORMAL))
709 switch (DECL_FUNCTION_CODE (fndecl))
711 CASE_BUILT_IN_ALLOCA:
712 return gimple_call_num_args (stmt) > 0;
713 default:
714 break;
717 return false;
720 /* Return true when exp contains a builtin alloca call. */
722 bool
723 alloca_call_p (const_tree exp)
725 tree fndecl;
726 if (TREE_CODE (exp) == CALL_EXPR
727 && (fndecl = get_callee_fndecl (exp))
728 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
729 switch (DECL_FUNCTION_CODE (fndecl))
731 CASE_BUILT_IN_ALLOCA:
732 return true;
733 default:
734 break;
737 return false;
740 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
741 function. Return FALSE otherwise. */
743 static bool
744 is_tm_builtin (const_tree fndecl)
746 if (fndecl == NULL)
747 return false;
749 if (decl_is_tm_clone (fndecl))
750 return true;
752 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
754 switch (DECL_FUNCTION_CODE (fndecl))
756 case BUILT_IN_TM_COMMIT:
757 case BUILT_IN_TM_COMMIT_EH:
758 case BUILT_IN_TM_ABORT:
759 case BUILT_IN_TM_IRREVOCABLE:
760 case BUILT_IN_TM_GETTMCLONE_IRR:
761 case BUILT_IN_TM_MEMCPY:
762 case BUILT_IN_TM_MEMMOVE:
763 case BUILT_IN_TM_MEMSET:
764 CASE_BUILT_IN_TM_STORE (1):
765 CASE_BUILT_IN_TM_STORE (2):
766 CASE_BUILT_IN_TM_STORE (4):
767 CASE_BUILT_IN_TM_STORE (8):
768 CASE_BUILT_IN_TM_STORE (FLOAT):
769 CASE_BUILT_IN_TM_STORE (DOUBLE):
770 CASE_BUILT_IN_TM_STORE (LDOUBLE):
771 CASE_BUILT_IN_TM_STORE (M64):
772 CASE_BUILT_IN_TM_STORE (M128):
773 CASE_BUILT_IN_TM_STORE (M256):
774 CASE_BUILT_IN_TM_LOAD (1):
775 CASE_BUILT_IN_TM_LOAD (2):
776 CASE_BUILT_IN_TM_LOAD (4):
777 CASE_BUILT_IN_TM_LOAD (8):
778 CASE_BUILT_IN_TM_LOAD (FLOAT):
779 CASE_BUILT_IN_TM_LOAD (DOUBLE):
780 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
781 CASE_BUILT_IN_TM_LOAD (M64):
782 CASE_BUILT_IN_TM_LOAD (M128):
783 CASE_BUILT_IN_TM_LOAD (M256):
784 case BUILT_IN_TM_LOG:
785 case BUILT_IN_TM_LOG_1:
786 case BUILT_IN_TM_LOG_2:
787 case BUILT_IN_TM_LOG_4:
788 case BUILT_IN_TM_LOG_8:
789 case BUILT_IN_TM_LOG_FLOAT:
790 case BUILT_IN_TM_LOG_DOUBLE:
791 case BUILT_IN_TM_LOG_LDOUBLE:
792 case BUILT_IN_TM_LOG_M64:
793 case BUILT_IN_TM_LOG_M128:
794 case BUILT_IN_TM_LOG_M256:
795 return true;
796 default:
797 break;
800 return false;
803 /* Detect flags (function attributes) from the function decl or type node. */
806 flags_from_decl_or_type (const_tree exp)
808 int flags = 0;
810 if (DECL_P (exp))
812 /* The function exp may have the `malloc' attribute. */
813 if (DECL_IS_MALLOC (exp))
814 flags |= ECF_MALLOC;
816 /* The function exp may have the `returns_twice' attribute. */
817 if (DECL_IS_RETURNS_TWICE (exp))
818 flags |= ECF_RETURNS_TWICE;
820 /* Process the pure and const attributes. */
821 if (TREE_READONLY (exp))
822 flags |= ECF_CONST;
823 if (DECL_PURE_P (exp))
824 flags |= ECF_PURE;
825 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
826 flags |= ECF_LOOPING_CONST_OR_PURE;
828 if (DECL_IS_NOVOPS (exp))
829 flags |= ECF_NOVOPS;
830 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
831 flags |= ECF_LEAF;
832 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
833 flags |= ECF_COLD;
835 if (TREE_NOTHROW (exp))
836 flags |= ECF_NOTHROW;
838 if (flag_tm)
840 if (is_tm_builtin (exp))
841 flags |= ECF_TM_BUILTIN;
842 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
843 || lookup_attribute ("transaction_pure",
844 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
845 flags |= ECF_TM_PURE;
848 flags = special_function_p (exp, flags);
850 else if (TYPE_P (exp))
852 if (TYPE_READONLY (exp))
853 flags |= ECF_CONST;
855 if (flag_tm
856 && ((flags & ECF_CONST) != 0
857 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
858 flags |= ECF_TM_PURE;
860 else
861 gcc_unreachable ();
863 if (TREE_THIS_VOLATILE (exp))
865 flags |= ECF_NORETURN;
866 if (flags & (ECF_CONST|ECF_PURE))
867 flags |= ECF_LOOPING_CONST_OR_PURE;
870 return flags;
873 /* Detect flags from a CALL_EXPR. */
876 call_expr_flags (const_tree t)
878 int flags;
879 tree decl = get_callee_fndecl (t);
881 if (decl)
882 flags = flags_from_decl_or_type (decl);
883 else if (CALL_EXPR_FN (t) == NULL_TREE)
884 flags = internal_fn_flags (CALL_EXPR_IFN (t));
885 else
887 tree type = TREE_TYPE (CALL_EXPR_FN (t));
888 if (type && TREE_CODE (type) == POINTER_TYPE)
889 flags = flags_from_decl_or_type (TREE_TYPE (type));
890 else
891 flags = 0;
892 if (CALL_EXPR_BY_DESCRIPTOR (t))
893 flags |= ECF_BY_DESCRIPTOR;
896 return flags;
899 /* Return true if ARG should be passed by invisible reference. */
901 bool
902 pass_by_reference (CUMULATIVE_ARGS *ca, function_arg_info arg)
904 if (tree type = arg.type)
906 /* If this type contains non-trivial constructors, then it is
907 forbidden for the middle-end to create any new copies. */
908 if (TREE_ADDRESSABLE (type))
909 return true;
911 /* GCC post 3.4 passes *all* variable sized types by reference. */
912 if (!TYPE_SIZE (type) || !poly_int_tree_p (TYPE_SIZE (type)))
913 return true;
915 /* If a record type should be passed the same as its first (and only)
916 member, use the type and mode of that member. */
917 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
919 arg.type = TREE_TYPE (first_field (type));
920 arg.mode = TYPE_MODE (arg.type);
924 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), arg);
927 /* Return true if TYPE should be passed by reference when passed to
928 the "..." arguments of a function. */
930 bool
931 pass_va_arg_by_reference (tree type)
933 return pass_by_reference (NULL, function_arg_info (type, /*named=*/false));
936 /* Decide whether ARG, which occurs in the state described by CA,
937 should be passed by reference. Return true if so and update
938 ARG accordingly. */
940 bool
941 apply_pass_by_reference_rules (CUMULATIVE_ARGS *ca, function_arg_info &arg)
943 if (pass_by_reference (ca, arg))
945 arg.type = build_pointer_type (arg.type);
946 arg.mode = TYPE_MODE (arg.type);
947 arg.pass_by_reference = true;
948 return true;
950 return false;
953 /* Return true if ARG, which is passed by reference, should be callee
954 copied instead of caller copied. */
956 bool
957 reference_callee_copied (CUMULATIVE_ARGS *ca, const function_arg_info &arg)
959 if (arg.type && TREE_ADDRESSABLE (arg.type))
960 return false;
961 return targetm.calls.callee_copies (pack_cumulative_args (ca), arg);
965 /* Precompute all register parameters as described by ARGS, storing values
966 into fields within the ARGS array.
968 NUM_ACTUALS indicates the total number elements in the ARGS array.
970 Set REG_PARM_SEEN if we encounter a register parameter. */
972 static void
973 precompute_register_parameters (int num_actuals, struct arg_data *args,
974 int *reg_parm_seen)
976 int i;
978 *reg_parm_seen = 0;
980 for (i = 0; i < num_actuals; i++)
981 if (args[i].reg != 0 && ! args[i].pass_on_stack)
983 *reg_parm_seen = 1;
985 if (args[i].value == 0)
987 push_temp_slots ();
988 args[i].value = expand_normal (args[i].tree_value);
989 preserve_temp_slots (args[i].value);
990 pop_temp_slots ();
993 /* If we are to promote the function arg to a wider mode,
994 do it now. */
996 machine_mode old_mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
998 /* Some ABIs require scalar floating point modes to be returned
999 in a wider scalar integer mode. We need to explicitly
1000 reinterpret to an integer mode of the correct precision
1001 before extending to the desired result. */
1002 if (SCALAR_INT_MODE_P (args[i].mode)
1003 && SCALAR_FLOAT_MODE_P (old_mode)
1004 && known_gt (GET_MODE_SIZE (args[i].mode),
1005 GET_MODE_SIZE (old_mode)))
1006 args[i].value = convert_float_to_wider_int (args[i].mode, old_mode,
1007 args[i].value);
1008 else if (args[i].mode != old_mode)
1009 args[i].value = convert_modes (args[i].mode, old_mode,
1010 args[i].value, args[i].unsignedp);
1012 /* If the value is a non-legitimate constant, force it into a
1013 pseudo now. TLS symbols sometimes need a call to resolve. */
1014 if (CONSTANT_P (args[i].value)
1015 && (!targetm.legitimate_constant_p (args[i].mode, args[i].value)
1016 || targetm.precompute_tls_p (args[i].mode, args[i].value)))
1017 args[i].value = force_reg (args[i].mode, args[i].value);
1019 /* If we're going to have to load the value by parts, pull the
1020 parts into pseudos. The part extraction process can involve
1021 non-trivial computation. */
1022 if (GET_CODE (args[i].reg) == PARALLEL)
1024 tree type = TREE_TYPE (args[i].tree_value);
1025 args[i].parallel_value
1026 = emit_group_load_into_temps (args[i].reg, args[i].value,
1027 type, int_size_in_bytes (type));
1030 /* If the value is expensive, and we are inside an appropriately
1031 short loop, put the value into a pseudo and then put the pseudo
1032 into the hard reg.
1034 For small register classes, also do this if this call uses
1035 register parameters. This is to avoid reload conflicts while
1036 loading the parameters registers. */
1038 else if ((! (REG_P (args[i].value)
1039 || (GET_CODE (args[i].value) == SUBREG
1040 && REG_P (SUBREG_REG (args[i].value)))))
1041 && args[i].mode != BLKmode
1042 && (set_src_cost (args[i].value, args[i].mode,
1043 optimize_insn_for_speed_p ())
1044 > COSTS_N_INSNS (1))
1045 && ((*reg_parm_seen
1046 && targetm.small_register_classes_for_mode_p (args[i].mode))
1047 || optimize))
1048 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1052 #ifdef REG_PARM_STACK_SPACE
1054 /* The argument list is the property of the called routine and it
1055 may clobber it. If the fixed area has been used for previous
1056 parameters, we must save and restore it. */
1058 static rtx
1059 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1061 unsigned int low;
1062 unsigned int high;
1064 /* Compute the boundary of the area that needs to be saved, if any. */
1065 high = reg_parm_stack_space;
1066 if (ARGS_GROW_DOWNWARD)
1067 high += 1;
1069 if (high > highest_outgoing_arg_in_use)
1070 high = highest_outgoing_arg_in_use;
1072 for (low = 0; low < high; low++)
1073 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1075 int num_to_save;
1076 machine_mode save_mode;
1077 int delta;
1078 rtx addr;
1079 rtx stack_area;
1080 rtx save_area;
1082 while (stack_usage_map[--high] == 0)
1085 *low_to_save = low;
1086 *high_to_save = high;
1088 num_to_save = high - low + 1;
1090 /* If we don't have the required alignment, must do this
1091 in BLKmode. */
1092 scalar_int_mode imode;
1093 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1094 && (low & (MIN (GET_MODE_SIZE (imode),
1095 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1096 save_mode = imode;
1097 else
1098 save_mode = BLKmode;
1100 if (ARGS_GROW_DOWNWARD)
1101 delta = -high;
1102 else
1103 delta = low;
1105 addr = plus_constant (Pmode, argblock, delta);
1106 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1108 set_mem_align (stack_area, PARM_BOUNDARY);
1109 if (save_mode == BLKmode)
1111 save_area = assign_stack_temp (BLKmode, num_to_save);
1112 emit_block_move (validize_mem (save_area), stack_area,
1113 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1115 else
1117 save_area = gen_reg_rtx (save_mode);
1118 emit_move_insn (save_area, stack_area);
1121 return save_area;
1124 return NULL_RTX;
1127 static void
1128 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1130 machine_mode save_mode = GET_MODE (save_area);
1131 int delta;
1132 rtx addr, stack_area;
1134 if (ARGS_GROW_DOWNWARD)
1135 delta = -high_to_save;
1136 else
1137 delta = low_to_save;
1139 addr = plus_constant (Pmode, argblock, delta);
1140 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1141 set_mem_align (stack_area, PARM_BOUNDARY);
1143 if (save_mode != BLKmode)
1144 emit_move_insn (stack_area, save_area);
1145 else
1146 emit_block_move (stack_area, validize_mem (save_area),
1147 GEN_INT (high_to_save - low_to_save + 1),
1148 BLOCK_OP_CALL_PARM);
1150 #endif /* REG_PARM_STACK_SPACE */
1152 /* If any elements in ARGS refer to parameters that are to be passed in
1153 registers, but not in memory, and whose alignment does not permit a
1154 direct copy into registers. Copy the values into a group of pseudos
1155 which we will later copy into the appropriate hard registers.
1157 Pseudos for each unaligned argument will be stored into the array
1158 args[argnum].aligned_regs. The caller is responsible for deallocating
1159 the aligned_regs array if it is nonzero. */
1161 static void
1162 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1164 int i, j;
1166 for (i = 0; i < num_actuals; i++)
1167 if (args[i].reg != 0 && ! args[i].pass_on_stack
1168 && GET_CODE (args[i].reg) != PARALLEL
1169 && args[i].mode == BLKmode
1170 && MEM_P (args[i].value)
1171 && (MEM_ALIGN (args[i].value)
1172 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1174 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1175 int endian_correction = 0;
1177 if (args[i].partial)
1179 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1180 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1182 else
1184 args[i].n_aligned_regs
1185 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1188 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1190 /* Structures smaller than a word are normally aligned to the
1191 least significant byte. On a BYTES_BIG_ENDIAN machine,
1192 this means we must skip the empty high order bytes when
1193 calculating the bit offset. */
1194 if (bytes < UNITS_PER_WORD
1195 #ifdef BLOCK_REG_PADDING
1196 && (BLOCK_REG_PADDING (args[i].mode,
1197 TREE_TYPE (args[i].tree_value), 1)
1198 == PAD_DOWNWARD)
1199 #else
1200 && BYTES_BIG_ENDIAN
1201 #endif
1203 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1205 for (j = 0; j < args[i].n_aligned_regs; j++)
1207 rtx reg = gen_reg_rtx (word_mode);
1208 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1209 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1211 args[i].aligned_regs[j] = reg;
1212 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1213 word_mode, word_mode, false, NULL);
1215 /* There is no need to restrict this code to loading items
1216 in TYPE_ALIGN sized hunks. The bitfield instructions can
1217 load up entire word sized registers efficiently.
1219 ??? This may not be needed anymore.
1220 We use to emit a clobber here but that doesn't let later
1221 passes optimize the instructions we emit. By storing 0 into
1222 the register later passes know the first AND to zero out the
1223 bitfield being set in the register is unnecessary. The store
1224 of 0 will be deleted as will at least the first AND. */
1226 emit_move_insn (reg, const0_rtx);
1228 bytes -= bitsize / BITS_PER_UNIT;
1229 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1230 word_mode, word, false, false);
1235 /* Issue an error if CALL_EXPR was flagged as requiring
1236 tall-call optimization. */
1238 void
1239 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1241 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1242 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1243 return;
1245 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1248 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1249 CALL_EXPR EXP.
1251 NUM_ACTUALS is the total number of parameters.
1253 N_NAMED_ARGS is the total number of named arguments.
1255 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1256 value, or null.
1258 FNDECL is the tree code for the target of this call (if known)
1260 ARGS_SO_FAR holds state needed by the target to know where to place
1261 the next argument.
1263 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1264 for arguments which are passed in registers.
1266 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1267 and may be modified by this routine.
1269 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1270 flags which may be modified by this routine.
1272 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1273 that requires allocation of stack space.
1275 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1276 the thunked-to function. */
1278 static void
1279 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1280 struct arg_data *args,
1281 struct args_size *args_size,
1282 int n_named_args ATTRIBUTE_UNUSED,
1283 tree exp, tree struct_value_addr_value,
1284 tree fndecl, tree fntype,
1285 cumulative_args_t args_so_far,
1286 int reg_parm_stack_space,
1287 rtx *old_stack_level,
1288 poly_int64_pod *old_pending_adj,
1289 int *must_preallocate, int *ecf_flags,
1290 bool *may_tailcall, bool call_from_thunk_p)
1292 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1293 location_t loc = EXPR_LOCATION (exp);
1295 /* Count arg position in order args appear. */
1296 int argpos;
1298 int i;
1300 args_size->constant = 0;
1301 args_size->var = 0;
1303 /* In this loop, we consider args in the order they are written.
1304 We fill up ARGS from the back. */
1306 i = num_actuals - 1;
1308 int j = i;
1309 call_expr_arg_iterator iter;
1310 tree arg;
1312 if (struct_value_addr_value)
1314 args[j].tree_value = struct_value_addr_value;
1315 j--;
1317 argpos = 0;
1318 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1320 tree argtype = TREE_TYPE (arg);
1322 if (targetm.calls.split_complex_arg
1323 && argtype
1324 && TREE_CODE (argtype) == COMPLEX_TYPE
1325 && targetm.calls.split_complex_arg (argtype))
1327 tree subtype = TREE_TYPE (argtype);
1328 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1329 j--;
1330 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1332 else
1333 args[j].tree_value = arg;
1334 j--;
1335 argpos++;
1339 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1340 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1342 tree type = TREE_TYPE (args[i].tree_value);
1343 int unsignedp;
1345 /* Replace erroneous argument with constant zero. */
1346 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1347 args[i].tree_value = integer_zero_node, type = integer_type_node;
1349 /* If TYPE is a transparent union or record, pass things the way
1350 we would pass the first field of the union or record. We have
1351 already verified that the modes are the same. */
1352 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
1353 type = TREE_TYPE (first_field (type));
1355 /* Decide where to pass this arg.
1357 args[i].reg is nonzero if all or part is passed in registers.
1359 args[i].partial is nonzero if part but not all is passed in registers,
1360 and the exact value says how many bytes are passed in registers.
1362 args[i].pass_on_stack is nonzero if the argument must at least be
1363 computed on the stack. It may then be loaded back into registers
1364 if args[i].reg is nonzero.
1366 These decisions are driven by the FUNCTION_... macros and must agree
1367 with those made by function.cc. */
1369 /* See if this argument should be passed by invisible reference. */
1370 function_arg_info arg (type, argpos < n_named_args);
1371 if (pass_by_reference (args_so_far_pnt, arg))
1373 const bool callee_copies
1374 = reference_callee_copied (args_so_far_pnt, arg);
1375 tree base;
1377 /* If we're compiling a thunk, pass directly the address of an object
1378 already in memory, instead of making a copy. Likewise if we want
1379 to make the copy in the callee instead of the caller. */
1380 if ((call_from_thunk_p || callee_copies)
1381 && TREE_CODE (args[i].tree_value) != WITH_SIZE_EXPR
1382 && ((base = get_base_address (args[i].tree_value)), true)
1383 && TREE_CODE (base) != SSA_NAME
1384 && (!DECL_P (base) || MEM_P (DECL_RTL (base))))
1386 /* We may have turned the parameter value into an SSA name.
1387 Go back to the original parameter so we can take the
1388 address. */
1389 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
1391 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
1392 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
1393 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
1395 /* Argument setup code may have copied the value to register. We
1396 revert that optimization now because the tail call code must
1397 use the original location. */
1398 if (TREE_CODE (args[i].tree_value) == PARM_DECL
1399 && !MEM_P (DECL_RTL (args[i].tree_value))
1400 && DECL_INCOMING_RTL (args[i].tree_value)
1401 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
1402 set_decl_rtl (args[i].tree_value,
1403 DECL_INCOMING_RTL (args[i].tree_value));
1405 mark_addressable (args[i].tree_value);
1407 /* We can't use sibcalls if a callee-copied argument is
1408 stored in the current function's frame. */
1409 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1411 *may_tailcall = false;
1412 maybe_complain_about_tail_call (exp,
1413 "a callee-copied argument is"
1414 " stored in the current"
1415 " function's frame");
1418 args[i].tree_value = build_fold_addr_expr_loc (loc,
1419 args[i].tree_value);
1420 type = TREE_TYPE (args[i].tree_value);
1422 if (*ecf_flags & ECF_CONST)
1423 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1425 else
1427 /* We make a copy of the object and pass the address to the
1428 function being called. */
1429 rtx copy;
1431 if (!COMPLETE_TYPE_P (type)
1432 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1433 || (flag_stack_check == GENERIC_STACK_CHECK
1434 && compare_tree_int (TYPE_SIZE_UNIT (type),
1435 STACK_CHECK_MAX_VAR_SIZE) > 0))
1437 /* This is a variable-sized object. Make space on the stack
1438 for it. */
1439 rtx size_rtx = expr_size (args[i].tree_value);
1441 if (*old_stack_level == 0)
1443 emit_stack_save (SAVE_BLOCK, old_stack_level);
1444 *old_pending_adj = pending_stack_adjust;
1445 pending_stack_adjust = 0;
1448 /* We can pass TRUE as the 4th argument because we just
1449 saved the stack pointer and will restore it right after
1450 the call. */
1451 copy = allocate_dynamic_stack_space (size_rtx,
1452 TYPE_ALIGN (type),
1453 TYPE_ALIGN (type),
1454 max_int_size_in_bytes
1455 (type),
1456 true);
1457 copy = gen_rtx_MEM (BLKmode, copy);
1458 set_mem_attributes (copy, type, 1);
1460 else
1461 copy = assign_temp (type, 1, 0);
1463 store_expr (args[i].tree_value, copy, 0, false, false);
1465 /* Just change the const function to pure and then let
1466 the next test clear the pure based on
1467 callee_copies. */
1468 if (*ecf_flags & ECF_CONST)
1470 *ecf_flags &= ~ECF_CONST;
1471 *ecf_flags |= ECF_PURE;
1474 if (!callee_copies && *ecf_flags & ECF_PURE)
1475 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1477 args[i].tree_value
1478 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1479 type = TREE_TYPE (args[i].tree_value);
1480 *may_tailcall = false;
1481 maybe_complain_about_tail_call (exp,
1482 "argument must be passed"
1483 " by copying");
1485 arg.pass_by_reference = true;
1488 unsignedp = TYPE_UNSIGNED (type);
1489 arg.type = type;
1490 arg.mode
1491 = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1492 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1494 args[i].unsignedp = unsignedp;
1495 args[i].mode = arg.mode;
1497 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
1499 args[i].reg = targetm.calls.function_arg (args_so_far, arg);
1501 /* If this is a sibling call and the machine has register windows, the
1502 register window has to be unwinded before calling the routine, so
1503 arguments have to go into the incoming registers. */
1504 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
1505 args[i].tail_call_reg
1506 = targetm.calls.function_incoming_arg (args_so_far, arg);
1507 else
1508 args[i].tail_call_reg = args[i].reg;
1510 if (args[i].reg)
1511 args[i].partial = targetm.calls.arg_partial_bytes (args_so_far, arg);
1513 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (arg);
1515 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1516 it means that we are to pass this arg in the register(s) designated
1517 by the PARALLEL, but also to pass it in the stack. */
1518 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1519 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1520 args[i].pass_on_stack = 1;
1522 /* If this is an addressable type, we must preallocate the stack
1523 since we must evaluate the object into its final location.
1525 If this is to be passed in both registers and the stack, it is simpler
1526 to preallocate. */
1527 if (TREE_ADDRESSABLE (type)
1528 || (args[i].pass_on_stack && args[i].reg != 0))
1529 *must_preallocate = 1;
1531 /* Compute the stack-size of this argument. */
1532 if (args[i].reg == 0 || args[i].partial != 0
1533 || reg_parm_stack_space > 0
1534 || args[i].pass_on_stack)
1535 locate_and_pad_parm (arg.mode, type,
1536 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1538 #else
1539 args[i].reg != 0,
1540 #endif
1541 reg_parm_stack_space,
1542 args[i].pass_on_stack ? 0 : args[i].partial,
1543 fndecl, args_size, &args[i].locate);
1544 #ifdef BLOCK_REG_PADDING
1545 else
1546 /* The argument is passed entirely in registers. See at which
1547 end it should be padded. */
1548 args[i].locate.where_pad =
1549 BLOCK_REG_PADDING (arg.mode, type,
1550 int_size_in_bytes (type) <= UNITS_PER_WORD);
1551 #endif
1553 /* Update ARGS_SIZE, the total stack space for args so far. */
1555 args_size->constant += args[i].locate.size.constant;
1556 if (args[i].locate.size.var)
1557 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1559 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1560 have been used, etc. */
1562 /* ??? Traditionally we've passed TYPE_MODE here, instead of the
1563 promoted_mode used for function_arg above. However, the
1564 corresponding handling of incoming arguments in function.cc
1565 does pass the promoted mode. */
1566 arg.mode = TYPE_MODE (type);
1567 targetm.calls.function_arg_advance (args_so_far, arg);
1571 /* Update ARGS_SIZE to contain the total size for the argument block.
1572 Return the original constant component of the argument block's size.
1574 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1575 for arguments passed in registers. */
1577 static poly_int64
1578 compute_argument_block_size (int reg_parm_stack_space,
1579 struct args_size *args_size,
1580 tree fndecl ATTRIBUTE_UNUSED,
1581 tree fntype ATTRIBUTE_UNUSED,
1582 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1584 poly_int64 unadjusted_args_size = args_size->constant;
1586 /* For accumulate outgoing args mode we don't need to align, since the frame
1587 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1588 backends from generating misaligned frame sizes. */
1589 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1590 preferred_stack_boundary = STACK_BOUNDARY;
1592 /* Compute the actual size of the argument block required. The variable
1593 and constant sizes must be combined, the size may have to be rounded,
1594 and there may be a minimum required size. */
1596 if (args_size->var)
1598 args_size->var = ARGS_SIZE_TREE (*args_size);
1599 args_size->constant = 0;
1601 preferred_stack_boundary /= BITS_PER_UNIT;
1602 if (preferred_stack_boundary > 1)
1604 /* We don't handle this case yet. To handle it correctly we have
1605 to add the delta, round and subtract the delta.
1606 Currently no machine description requires this support. */
1607 gcc_assert (multiple_p (stack_pointer_delta,
1608 preferred_stack_boundary));
1609 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1612 if (reg_parm_stack_space > 0)
1614 args_size->var
1615 = size_binop (MAX_EXPR, args_size->var,
1616 ssize_int (reg_parm_stack_space));
1618 /* The area corresponding to register parameters is not to count in
1619 the size of the block we need. So make the adjustment. */
1620 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1621 args_size->var
1622 = size_binop (MINUS_EXPR, args_size->var,
1623 ssize_int (reg_parm_stack_space));
1626 else
1628 preferred_stack_boundary /= BITS_PER_UNIT;
1629 if (preferred_stack_boundary < 1)
1630 preferred_stack_boundary = 1;
1631 args_size->constant = (aligned_upper_bound (args_size->constant
1632 + stack_pointer_delta,
1633 preferred_stack_boundary)
1634 - stack_pointer_delta);
1636 args_size->constant = upper_bound (args_size->constant,
1637 reg_parm_stack_space);
1639 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1640 args_size->constant -= reg_parm_stack_space;
1642 return unadjusted_args_size;
1645 /* Precompute parameters as needed for a function call.
1647 FLAGS is mask of ECF_* constants.
1649 NUM_ACTUALS is the number of arguments.
1651 ARGS is an array containing information for each argument; this
1652 routine fills in the INITIAL_VALUE and VALUE fields for each
1653 precomputed argument. */
1655 static void
1656 precompute_arguments (int num_actuals, struct arg_data *args)
1658 int i;
1660 /* If this is a libcall, then precompute all arguments so that we do not
1661 get extraneous instructions emitted as part of the libcall sequence. */
1663 /* If we preallocated the stack space, and some arguments must be passed
1664 on the stack, then we must precompute any parameter which contains a
1665 function call which will store arguments on the stack.
1666 Otherwise, evaluating the parameter may clobber previous parameters
1667 which have already been stored into the stack. (we have code to avoid
1668 such case by saving the outgoing stack arguments, but it results in
1669 worse code) */
1670 if (!ACCUMULATE_OUTGOING_ARGS)
1671 return;
1673 for (i = 0; i < num_actuals; i++)
1675 tree type;
1676 machine_mode mode;
1678 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1679 continue;
1681 /* If this is an addressable type, we cannot pre-evaluate it. */
1682 type = TREE_TYPE (args[i].tree_value);
1683 gcc_assert (!TREE_ADDRESSABLE (type));
1685 args[i].initial_value = args[i].value
1686 = expand_normal (args[i].tree_value);
1688 mode = TYPE_MODE (type);
1689 if (mode != args[i].mode)
1691 int unsignedp = args[i].unsignedp;
1692 args[i].value
1693 = convert_modes (args[i].mode, mode,
1694 args[i].value, args[i].unsignedp);
1696 /* CSE will replace this only if it contains args[i].value
1697 pseudo, so convert it down to the declared mode using
1698 a SUBREG. */
1699 if (REG_P (args[i].value)
1700 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1701 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1703 args[i].initial_value
1704 = gen_lowpart_SUBREG (mode, args[i].value);
1705 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1706 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
1712 /* Given the current state of MUST_PREALLOCATE and information about
1713 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1714 compute and return the final value for MUST_PREALLOCATE. */
1716 static int
1717 finalize_must_preallocate (int must_preallocate, int num_actuals,
1718 struct arg_data *args, struct args_size *args_size)
1720 /* See if we have or want to preallocate stack space.
1722 If we would have to push a partially-in-regs parm
1723 before other stack parms, preallocate stack space instead.
1725 If the size of some parm is not a multiple of the required stack
1726 alignment, we must preallocate.
1728 If the total size of arguments that would otherwise create a copy in
1729 a temporary (such as a CALL) is more than half the total argument list
1730 size, preallocation is faster.
1732 Another reason to preallocate is if we have a machine (like the m88k)
1733 where stack alignment is required to be maintained between every
1734 pair of insns, not just when the call is made. However, we assume here
1735 that such machines either do not have push insns (and hence preallocation
1736 would occur anyway) or the problem is taken care of with
1737 PUSH_ROUNDING. */
1739 if (! must_preallocate)
1741 int partial_seen = 0;
1742 poly_int64 copy_to_evaluate_size = 0;
1743 int i;
1745 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1747 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1748 partial_seen = 1;
1749 else if (partial_seen && args[i].reg == 0)
1750 must_preallocate = 1;
1752 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1753 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1754 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1755 || TREE_CODE (args[i].tree_value) == COND_EXPR
1756 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1757 copy_to_evaluate_size
1758 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1761 if (maybe_ne (args_size->constant, 0)
1762 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
1763 must_preallocate = 1;
1765 return must_preallocate;
1768 /* If we preallocated stack space, compute the address of each argument
1769 and store it into the ARGS array.
1771 We need not ensure it is a valid memory address here; it will be
1772 validized when it is used.
1774 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1776 static void
1777 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1779 if (argblock)
1781 rtx arg_reg = argblock;
1782 int i;
1783 poly_int64 arg_offset = 0;
1785 if (GET_CODE (argblock) == PLUS)
1787 arg_reg = XEXP (argblock, 0);
1788 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
1791 for (i = 0; i < num_actuals; i++)
1793 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1794 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1795 rtx addr;
1796 unsigned int align, boundary;
1797 poly_uint64 units_on_stack = 0;
1798 machine_mode partial_mode = VOIDmode;
1800 /* Skip this parm if it will not be passed on the stack. */
1801 if (! args[i].pass_on_stack
1802 && args[i].reg != 0
1803 && args[i].partial == 0)
1804 continue;
1806 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
1807 continue;
1809 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
1810 addr = plus_constant (Pmode, addr, arg_offset);
1812 if (args[i].partial != 0)
1814 /* Only part of the parameter is being passed on the stack.
1815 Generate a simple memory reference of the correct size. */
1816 units_on_stack = args[i].locate.size.constant;
1817 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
1818 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
1819 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1820 set_mem_size (args[i].stack, units_on_stack);
1822 else
1824 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1825 set_mem_attributes (args[i].stack,
1826 TREE_TYPE (args[i].tree_value), 1);
1828 align = BITS_PER_UNIT;
1829 boundary = args[i].locate.boundary;
1830 poly_int64 offset_val;
1831 if (args[i].locate.where_pad != PAD_DOWNWARD)
1832 align = boundary;
1833 else if (poly_int_rtx_p (offset, &offset_val))
1835 align = least_bit_hwi (boundary);
1836 unsigned int offset_align
1837 = known_alignment (offset_val) * BITS_PER_UNIT;
1838 if (offset_align != 0)
1839 align = MIN (align, offset_align);
1841 set_mem_align (args[i].stack, align);
1843 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
1844 addr = plus_constant (Pmode, addr, arg_offset);
1846 if (args[i].partial != 0)
1848 /* Only part of the parameter is being passed on the stack.
1849 Generate a simple memory reference of the correct size.
1851 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1852 set_mem_size (args[i].stack_slot, units_on_stack);
1854 else
1856 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1857 set_mem_attributes (args[i].stack_slot,
1858 TREE_TYPE (args[i].tree_value), 1);
1860 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1862 /* Function incoming arguments may overlap with sibling call
1863 outgoing arguments and we cannot allow reordering of reads
1864 from function arguments with stores to outgoing arguments
1865 of sibling calls. */
1866 set_mem_alias_set (args[i].stack, 0);
1867 set_mem_alias_set (args[i].stack_slot, 0);
1872 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1873 in a call instruction.
1875 FNDECL is the tree node for the target function. For an indirect call
1876 FNDECL will be NULL_TREE.
1878 ADDR is the operand 0 of CALL_EXPR for this call. */
1880 static rtx
1881 rtx_for_function_call (tree fndecl, tree addr)
1883 rtx funexp;
1885 /* Get the function to call, in the form of RTL. */
1886 if (fndecl)
1888 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1889 TREE_USED (fndecl) = 1;
1891 /* Get a SYMBOL_REF rtx for the function address. */
1892 funexp = XEXP (DECL_RTL (fndecl), 0);
1894 else
1895 /* Generate an rtx (probably a pseudo-register) for the address. */
1897 push_temp_slots ();
1898 funexp = expand_normal (addr);
1899 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1901 return funexp;
1904 /* Return the static chain for this function, if any. */
1907 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
1909 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
1910 return NULL;
1912 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
1915 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
1916 static struct
1918 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
1919 or NULL_RTX if none has been scanned yet. */
1920 rtx_insn *scan_start;
1921 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
1922 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
1923 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
1924 with fixed offset, or PC if this is with variable or unknown offset. */
1925 vec<rtx> cache;
1926 } internal_arg_pointer_exp_state;
1928 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
1930 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
1931 the tail call sequence, starting with first insn that hasn't been
1932 scanned yet, and note for each pseudo on the LHS whether it is based
1933 on crtl->args.internal_arg_pointer or not, and what offset from that
1934 that pointer it has. */
1936 static void
1937 internal_arg_pointer_based_exp_scan (void)
1939 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
1941 if (scan_start == NULL_RTX)
1942 insn = get_insns ();
1943 else
1944 insn = NEXT_INSN (scan_start);
1946 while (insn)
1948 rtx set = single_set (insn);
1949 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
1951 rtx val = NULL_RTX;
1952 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
1953 /* Punt on pseudos set multiple times. */
1954 if (idx < internal_arg_pointer_exp_state.cache.length ()
1955 && (internal_arg_pointer_exp_state.cache[idx]
1956 != NULL_RTX))
1957 val = pc_rtx;
1958 else
1959 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
1960 if (val != NULL_RTX)
1962 if (idx >= internal_arg_pointer_exp_state.cache.length ())
1963 internal_arg_pointer_exp_state.cache
1964 .safe_grow_cleared (idx + 1, true);
1965 internal_arg_pointer_exp_state.cache[idx] = val;
1968 if (NEXT_INSN (insn) == NULL_RTX)
1969 scan_start = insn;
1970 insn = NEXT_INSN (insn);
1973 internal_arg_pointer_exp_state.scan_start = scan_start;
1976 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
1977 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
1978 it with fixed offset, or PC if this is with variable or unknown offset.
1979 TOPLEVEL is true if the function is invoked at the topmost level. */
1981 static rtx
1982 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
1984 if (CONSTANT_P (rtl))
1985 return NULL_RTX;
1987 if (rtl == crtl->args.internal_arg_pointer)
1988 return const0_rtx;
1990 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
1991 return NULL_RTX;
1993 poly_int64 offset;
1994 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
1996 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
1997 if (val == NULL_RTX || val == pc_rtx)
1998 return val;
1999 return plus_constant (Pmode, val, offset);
2002 /* When called at the topmost level, scan pseudo assignments in between the
2003 last scanned instruction in the tail call sequence and the latest insn
2004 in that sequence. */
2005 if (toplevel)
2006 internal_arg_pointer_based_exp_scan ();
2008 if (REG_P (rtl))
2010 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2011 if (idx < internal_arg_pointer_exp_state.cache.length ())
2012 return internal_arg_pointer_exp_state.cache[idx];
2014 return NULL_RTX;
2017 subrtx_iterator::array_type array;
2018 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2020 const_rtx x = *iter;
2021 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2022 return pc_rtx;
2023 if (MEM_P (x))
2024 iter.skip_subrtxes ();
2027 return NULL_RTX;
2030 /* Return true if SIZE bytes starting from address ADDR might overlap an
2031 already-clobbered argument area. This function is used to determine
2032 if we should give up a sibcall. */
2034 static bool
2035 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2037 poly_int64 i;
2038 unsigned HOST_WIDE_INT start, end;
2039 rtx val;
2041 if (bitmap_empty_p (stored_args_map)
2042 && stored_args_watermark == HOST_WIDE_INT_M1U)
2043 return false;
2044 val = internal_arg_pointer_based_exp (addr, true);
2045 if (val == NULL_RTX)
2046 return false;
2047 else if (!poly_int_rtx_p (val, &i))
2048 return true;
2050 if (known_eq (size, 0U))
2051 return false;
2053 if (STACK_GROWS_DOWNWARD)
2054 i -= crtl->args.pretend_args_size;
2055 else
2056 i += crtl->args.pretend_args_size;
2058 if (ARGS_GROW_DOWNWARD)
2059 i = -i - size;
2061 /* We can ignore any references to the function's pretend args,
2062 which at this point would manifest as negative values of I. */
2063 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2064 return false;
2066 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2067 if (!(i + size).is_constant (&end))
2068 end = HOST_WIDE_INT_M1U;
2070 if (end > stored_args_watermark)
2071 return true;
2073 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2074 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2075 if (bitmap_bit_p (stored_args_map, k))
2076 return true;
2078 return false;
2081 /* Do the register loads required for any wholly-register parms or any
2082 parms which are passed both on the stack and in a register. Their
2083 expressions were already evaluated.
2085 Mark all register-parms as living through the call, putting these USE
2086 insns in the CALL_INSN_FUNCTION_USAGE field.
2088 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2089 checking, setting *SIBCALL_FAILURE if appropriate. */
2091 static void
2092 load_register_parameters (struct arg_data *args, int num_actuals,
2093 rtx *call_fusage, int flags, int is_sibcall,
2094 int *sibcall_failure)
2096 int i, j;
2098 for (i = 0; i < num_actuals; i++)
2100 rtx reg = ((flags & ECF_SIBCALL)
2101 ? args[i].tail_call_reg : args[i].reg);
2102 if (reg)
2104 int partial = args[i].partial;
2105 int nregs;
2106 poly_int64 size = 0;
2107 HOST_WIDE_INT const_size = 0;
2108 rtx_insn *before_arg = get_last_insn ();
2109 tree tree_value = args[i].tree_value;
2110 tree type = TREE_TYPE (tree_value);
2111 if (RECORD_OR_UNION_TYPE_P (type) && TYPE_TRANSPARENT_AGGR (type))
2112 type = TREE_TYPE (first_field (type));
2113 /* Set non-negative if we must move a word at a time, even if
2114 just one word (e.g, partial == 4 && mode == DFmode). Set
2115 to -1 if we just use a normal move insn. This value can be
2116 zero if the argument is a zero size structure. */
2117 nregs = -1;
2118 if (GET_CODE (reg) == PARALLEL)
2120 else if (partial)
2122 gcc_assert (partial % UNITS_PER_WORD == 0);
2123 nregs = partial / UNITS_PER_WORD;
2125 else if (TYPE_MODE (type) == BLKmode)
2127 /* Variable-sized parameters should be described by a
2128 PARALLEL instead. */
2129 const_size = int_size_in_bytes (type);
2130 gcc_assert (const_size >= 0);
2131 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2132 size = const_size;
2134 else
2135 size = GET_MODE_SIZE (args[i].mode);
2137 /* Handle calls that pass values in multiple non-contiguous
2138 locations. The Irix 6 ABI has examples of this. */
2140 if (GET_CODE (reg) == PARALLEL)
2141 emit_group_move (reg, args[i].parallel_value);
2143 /* If simple case, just do move. If normal partial, store_one_arg
2144 has already loaded the register for us. In all other cases,
2145 load the register(s) from memory. */
2147 else if (nregs == -1)
2149 emit_move_insn (reg, args[i].value);
2150 #ifdef BLOCK_REG_PADDING
2151 /* Handle case where we have a value that needs shifting
2152 up to the msb. eg. a QImode value and we're padding
2153 upward on a BYTES_BIG_ENDIAN machine. */
2154 if (args[i].locate.where_pad
2155 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2157 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2158 if (maybe_lt (size, UNITS_PER_WORD))
2160 rtx x;
2161 poly_int64 shift
2162 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2164 /* Assigning REG here rather than a temp makes
2165 CALL_FUSAGE report the whole reg as used.
2166 Strictly speaking, the call only uses SIZE
2167 bytes at the msb end, but it doesn't seem worth
2168 generating rtl to say that. */
2169 reg = gen_rtx_REG (word_mode, REGNO (reg));
2170 x = expand_shift (LSHIFT_EXPR, word_mode,
2171 reg, shift, reg, 1);
2172 if (x != reg)
2173 emit_move_insn (reg, x);
2176 #endif
2179 /* If we have pre-computed the values to put in the registers in
2180 the case of non-aligned structures, copy them in now. */
2182 else if (args[i].n_aligned_regs != 0)
2183 for (j = 0; j < args[i].n_aligned_regs; j++)
2184 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2185 args[i].aligned_regs[j]);
2187 /* If we need a single register and the source is a constant
2188 VAR_DECL with a simple constructor, expand that constructor
2189 via a pseudo rather than read from (possibly misaligned)
2190 memory. PR middle-end/95126. */
2191 else if (nregs == 1
2192 && partial == 0
2193 && !args[i].pass_on_stack
2194 && VAR_P (tree_value)
2195 && TREE_READONLY (tree_value)
2196 && !TREE_SIDE_EFFECTS (tree_value)
2197 && immediate_const_ctor_p (DECL_INITIAL (tree_value)))
2199 rtx target = gen_reg_rtx (word_mode);
2200 store_constructor (DECL_INITIAL (tree_value), target, 0,
2201 int_expr_size (DECL_INITIAL (tree_value)),
2202 false);
2203 reg = gen_rtx_REG (word_mode, REGNO (reg));
2204 emit_move_insn (reg, target);
2206 else if (partial == 0 || args[i].pass_on_stack)
2208 /* SIZE and CONST_SIZE are 0 for partial arguments and
2209 the size of a BLKmode type otherwise. */
2210 gcc_checking_assert (known_eq (size, const_size));
2211 rtx mem = validize_mem (copy_rtx (args[i].value));
2213 /* Check for overlap with already clobbered argument area,
2214 providing that this has non-zero size. */
2215 if (is_sibcall
2216 && const_size != 0
2217 && (mem_might_overlap_already_clobbered_arg_p
2218 (XEXP (args[i].value, 0), const_size)))
2219 *sibcall_failure = 1;
2221 if (const_size % UNITS_PER_WORD == 0
2222 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2223 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2224 else
2226 if (nregs > 1)
2227 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2228 args[i].mode);
2229 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2230 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2231 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2232 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2233 word_mode, word_mode, false,
2234 NULL);
2235 if (BYTES_BIG_ENDIAN)
2236 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2237 BITS_PER_WORD - bitsize, dest, 1);
2238 if (x != dest)
2239 emit_move_insn (dest, x);
2242 /* Handle a BLKmode that needs shifting. */
2243 if (nregs == 1 && const_size < UNITS_PER_WORD
2244 #ifdef BLOCK_REG_PADDING
2245 && args[i].locate.where_pad == PAD_DOWNWARD
2246 #else
2247 && BYTES_BIG_ENDIAN
2248 #endif
2251 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2252 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2253 enum tree_code dir = (BYTES_BIG_ENDIAN
2254 ? RSHIFT_EXPR : LSHIFT_EXPR);
2255 rtx x;
2257 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2258 if (x != dest)
2259 emit_move_insn (dest, x);
2263 /* When a parameter is a block, and perhaps in other cases, it is
2264 possible that it did a load from an argument slot that was
2265 already clobbered. */
2266 if (is_sibcall
2267 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2268 *sibcall_failure = 1;
2270 /* Handle calls that pass values in multiple non-contiguous
2271 locations. The Irix 6 ABI has examples of this. */
2272 if (GET_CODE (reg) == PARALLEL)
2273 use_group_regs (call_fusage, reg);
2274 else if (nregs == -1)
2275 use_reg_mode (call_fusage, reg, TYPE_MODE (type));
2276 else if (nregs > 0)
2277 use_regs (call_fusage, REGNO (reg), nregs);
2282 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2283 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2284 bytes, then we would need to push some additional bytes to pad the
2285 arguments. So, we try to compute an adjust to the stack pointer for an
2286 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2287 bytes. Then, when the arguments are pushed the stack will be perfectly
2288 aligned.
2290 Return true if this optimization is possible, storing the adjustment
2291 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2292 bytes that should be popped after the call. */
2294 static bool
2295 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2296 poly_int64 unadjusted_args_size,
2297 struct args_size *args_size,
2298 unsigned int preferred_unit_stack_boundary)
2300 /* The number of bytes to pop so that the stack will be
2301 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2302 poly_int64 adjustment;
2303 /* The alignment of the stack after the arguments are pushed, if we
2304 just pushed the arguments without adjust the stack here. */
2305 unsigned HOST_WIDE_INT unadjusted_alignment;
2307 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2308 preferred_unit_stack_boundary,
2309 &unadjusted_alignment))
2310 return false;
2312 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2313 as possible -- leaving just enough left to cancel out the
2314 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2315 PENDING_STACK_ADJUST is non-negative, and congruent to
2316 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2318 /* Begin by trying to pop all the bytes. */
2319 unsigned HOST_WIDE_INT tmp_misalignment;
2320 if (!known_misalignment (pending_stack_adjust,
2321 preferred_unit_stack_boundary,
2322 &tmp_misalignment))
2323 return false;
2324 unadjusted_alignment -= tmp_misalignment;
2325 adjustment = pending_stack_adjust;
2326 /* Push enough additional bytes that the stack will be aligned
2327 after the arguments are pushed. */
2328 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2329 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2331 /* We need to know whether the adjusted argument size
2332 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2333 or a deallocation. */
2334 if (!ordered_p (adjustment, unadjusted_args_size))
2335 return false;
2337 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2338 bytes after the call. The right number is the entire
2339 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2340 by the arguments in the first place. */
2341 args_size->constant
2342 = pending_stack_adjust - adjustment + unadjusted_args_size;
2344 *adjustment_out = adjustment;
2345 return true;
2348 /* Scan X expression if it does not dereference any argument slots
2349 we already clobbered by tail call arguments (as noted in stored_args_map
2350 bitmap).
2351 Return nonzero if X expression dereferences such argument slots,
2352 zero otherwise. */
2354 static int
2355 check_sibcall_argument_overlap_1 (rtx x)
2357 RTX_CODE code;
2358 int i, j;
2359 const char *fmt;
2361 if (x == NULL_RTX)
2362 return 0;
2364 code = GET_CODE (x);
2366 /* We need not check the operands of the CALL expression itself. */
2367 if (code == CALL)
2368 return 0;
2370 if (code == MEM)
2371 return (mem_might_overlap_already_clobbered_arg_p
2372 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
2374 /* Scan all subexpressions. */
2375 fmt = GET_RTX_FORMAT (code);
2376 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2378 if (*fmt == 'e')
2380 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2381 return 1;
2383 else if (*fmt == 'E')
2385 for (j = 0; j < XVECLEN (x, i); j++)
2386 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2387 return 1;
2390 return 0;
2393 /* Scan sequence after INSN if it does not dereference any argument slots
2394 we already clobbered by tail call arguments (as noted in stored_args_map
2395 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2396 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2397 should be 0). Return nonzero if sequence after INSN dereferences such argument
2398 slots, zero otherwise. */
2400 static int
2401 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
2402 int mark_stored_args_map)
2404 poly_uint64 low, high;
2405 unsigned HOST_WIDE_INT const_low, const_high;
2407 if (insn == NULL_RTX)
2408 insn = get_insns ();
2409 else
2410 insn = NEXT_INSN (insn);
2412 for (; insn; insn = NEXT_INSN (insn))
2413 if (INSN_P (insn)
2414 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2415 break;
2417 if (mark_stored_args_map)
2419 if (ARGS_GROW_DOWNWARD)
2420 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2421 else
2422 low = arg->locate.slot_offset.constant;
2423 high = low + arg->locate.size.constant;
2425 const_low = constant_lower_bound (low);
2426 if (high.is_constant (&const_high))
2427 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
2428 bitmap_set_bit (stored_args_map, i);
2429 else
2430 stored_args_watermark = MIN (stored_args_watermark, const_low);
2432 return insn != NULL_RTX;
2435 /* Given that a function returns a value of mode MODE at the most
2436 significant end of hard register VALUE, shift VALUE left or right
2437 as specified by LEFT_P. Return true if some action was needed. */
2439 bool
2440 shift_return_value (machine_mode mode, bool left_p, rtx value)
2442 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
2443 machine_mode value_mode = GET_MODE (value);
2444 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
2446 if (known_eq (shift, 0))
2447 return false;
2449 /* Use ashr rather than lshr for right shifts. This is for the benefit
2450 of the MIPS port, which requires SImode values to be sign-extended
2451 when stored in 64-bit registers. */
2452 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
2453 value, gen_int_shift_amount (value_mode, shift),
2454 value, 1, OPTAB_WIDEN))
2455 gcc_unreachable ();
2456 return true;
2459 /* If X is a likely-spilled register value, copy it to a pseudo
2460 register and return that register. Return X otherwise. */
2462 static rtx
2463 avoid_likely_spilled_reg (rtx x)
2465 rtx new_rtx;
2467 if (REG_P (x)
2468 && HARD_REGISTER_P (x)
2469 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
2471 /* Make sure that we generate a REG rather than a CONCAT.
2472 Moves into CONCATs can need nontrivial instructions,
2473 and the whole point of this function is to avoid
2474 using the hard register directly in such a situation. */
2475 generating_concat_p = 0;
2476 new_rtx = gen_reg_rtx (GET_MODE (x));
2477 generating_concat_p = 1;
2478 emit_move_insn (new_rtx, x);
2479 return new_rtx;
2481 return x;
2484 /* Helper function for expand_call.
2485 Return false is EXP is not implementable as a sibling call. */
2487 static bool
2488 can_implement_as_sibling_call_p (tree exp,
2489 rtx structure_value_addr,
2490 tree funtype,
2491 tree fndecl,
2492 int flags,
2493 tree addr,
2494 const args_size &args_size)
2496 if (!targetm.have_sibcall_epilogue ())
2498 maybe_complain_about_tail_call
2499 (exp,
2500 "machine description does not have"
2501 " a sibcall_epilogue instruction pattern");
2502 return false;
2505 /* Doing sibling call optimization needs some work, since
2506 structure_value_addr can be allocated on the stack.
2507 It does not seem worth the effort since few optimizable
2508 sibling calls will return a structure. */
2509 if (structure_value_addr != NULL_RTX)
2511 maybe_complain_about_tail_call (exp, "callee returns a structure");
2512 return false;
2515 /* Check whether the target is able to optimize the call
2516 into a sibcall. */
2517 if (!targetm.function_ok_for_sibcall (fndecl, exp))
2519 maybe_complain_about_tail_call (exp,
2520 "target is not able to optimize the"
2521 " call into a sibling call");
2522 return false;
2525 /* Functions that do not return exactly once may not be sibcall
2526 optimized. */
2527 if (flags & ECF_RETURNS_TWICE)
2529 maybe_complain_about_tail_call (exp, "callee returns twice");
2530 return false;
2532 if (flags & ECF_NORETURN)
2534 maybe_complain_about_tail_call (exp, "callee does not return");
2535 return false;
2538 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
2540 maybe_complain_about_tail_call (exp, "volatile function type");
2541 return false;
2544 /* If the called function is nested in the current one, it might access
2545 some of the caller's arguments, but could clobber them beforehand if
2546 the argument areas are shared. */
2547 if (fndecl && decl_function_context (fndecl) == current_function_decl)
2549 maybe_complain_about_tail_call (exp, "nested function");
2550 return false;
2553 /* If this function requires more stack slots than the current
2554 function, we cannot change it into a sibling call.
2555 crtl->args.pretend_args_size is not part of the
2556 stack allocated by our caller. */
2557 if (maybe_gt (args_size.constant,
2558 crtl->args.size - crtl->args.pretend_args_size))
2560 maybe_complain_about_tail_call (exp,
2561 "callee required more stack slots"
2562 " than the caller");
2563 return false;
2566 /* If the callee pops its own arguments, then it must pop exactly
2567 the same number of arguments as the current function. */
2568 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
2569 args_size.constant),
2570 targetm.calls.return_pops_args (current_function_decl,
2571 TREE_TYPE
2572 (current_function_decl),
2573 crtl->args.size)))
2575 maybe_complain_about_tail_call (exp,
2576 "inconsistent number of"
2577 " popped arguments");
2578 return false;
2581 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
2583 maybe_complain_about_tail_call (exp, "frontend does not support"
2584 " sibling call");
2585 return false;
2588 /* All checks passed. */
2589 return true;
2592 /* Update stack alignment when the parameter is passed in the stack
2593 since the outgoing parameter requires extra alignment on the calling
2594 function side. */
2596 static void
2597 update_stack_alignment_for_call (struct locate_and_pad_arg_data *locate)
2599 if (crtl->stack_alignment_needed < locate->boundary)
2600 crtl->stack_alignment_needed = locate->boundary;
2601 if (crtl->preferred_stack_boundary < locate->boundary)
2602 crtl->preferred_stack_boundary = locate->boundary;
2605 /* Generate all the code for a CALL_EXPR exp
2606 and return an rtx for its value.
2607 Store the value in TARGET (specified as an rtx) if convenient.
2608 If the value is stored in TARGET then TARGET is returned.
2609 If IGNORE is nonzero, then we ignore the value of the function call. */
2612 expand_call (tree exp, rtx target, int ignore)
2614 /* Nonzero if we are currently expanding a call. */
2615 static int currently_expanding_call = 0;
2617 /* RTX for the function to be called. */
2618 rtx funexp;
2619 /* Sequence of insns to perform a normal "call". */
2620 rtx_insn *normal_call_insns = NULL;
2621 /* Sequence of insns to perform a tail "call". */
2622 rtx_insn *tail_call_insns = NULL;
2623 /* Data type of the function. */
2624 tree funtype;
2625 tree type_arg_types;
2626 tree rettype;
2627 /* Declaration of the function being called,
2628 or 0 if the function is computed (not known by name). */
2629 tree fndecl = 0;
2630 /* The type of the function being called. */
2631 tree fntype;
2632 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
2633 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
2634 int pass;
2636 /* Register in which non-BLKmode value will be returned,
2637 or 0 if no value or if value is BLKmode. */
2638 rtx valreg;
2639 /* Address where we should return a BLKmode value;
2640 0 if value not BLKmode. */
2641 rtx structure_value_addr = 0;
2642 /* Nonzero if that address is being passed by treating it as
2643 an extra, implicit first parameter. Otherwise,
2644 it is passed by being copied directly into struct_value_rtx. */
2645 int structure_value_addr_parm = 0;
2646 /* Holds the value of implicit argument for the struct value. */
2647 tree structure_value_addr_value = NULL_TREE;
2648 /* Size of aggregate value wanted, or zero if none wanted
2649 or if we are using the non-reentrant PCC calling convention
2650 or expecting the value in registers. */
2651 poly_int64 struct_value_size = 0;
2652 /* Nonzero if called function returns an aggregate in memory PCC style,
2653 by returning the address of where to find it. */
2654 int pcc_struct_value = 0;
2655 rtx struct_value = 0;
2657 /* Number of actual parameters in this call, including struct value addr. */
2658 int num_actuals;
2659 /* Number of named args. Args after this are anonymous ones
2660 and they must all go on the stack. */
2661 int n_named_args;
2662 /* Number of complex actual arguments that need to be split. */
2663 int num_complex_actuals = 0;
2665 /* Vector of information about each argument.
2666 Arguments are numbered in the order they will be pushed,
2667 not the order they are written. */
2668 struct arg_data *args;
2670 /* Total size in bytes of all the stack-parms scanned so far. */
2671 struct args_size args_size;
2672 struct args_size adjusted_args_size;
2673 /* Size of arguments before any adjustments (such as rounding). */
2674 poly_int64 unadjusted_args_size;
2675 /* Data on reg parms scanned so far. */
2676 CUMULATIVE_ARGS args_so_far_v;
2677 cumulative_args_t args_so_far;
2678 /* Nonzero if a reg parm has been scanned. */
2679 int reg_parm_seen;
2680 /* Nonzero if this is an indirect function call. */
2682 /* Nonzero if we must avoid push-insns in the args for this call.
2683 If stack space is allocated for register parameters, but not by the
2684 caller, then it is preallocated in the fixed part of the stack frame.
2685 So the entire argument block must then be preallocated (i.e., we
2686 ignore PUSH_ROUNDING in that case). */
2688 int must_preallocate = !targetm.calls.push_argument (0);
2690 /* Size of the stack reserved for parameter registers. */
2691 int reg_parm_stack_space = 0;
2693 /* Address of space preallocated for stack parms
2694 (on machines that lack push insns), or 0 if space not preallocated. */
2695 rtx argblock = 0;
2697 /* Mask of ECF_ and ERF_ flags. */
2698 int flags = 0;
2699 int return_flags = 0;
2700 #ifdef REG_PARM_STACK_SPACE
2701 /* Define the boundary of the register parm stack space that needs to be
2702 saved, if any. */
2703 int low_to_save, high_to_save;
2704 rtx save_area = 0; /* Place that it is saved */
2705 #endif
2707 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2708 char *initial_stack_usage_map = stack_usage_map;
2709 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
2710 char *stack_usage_map_buf = NULL;
2712 poly_int64 old_stack_allocated;
2714 /* State variables to track stack modifications. */
2715 rtx old_stack_level = 0;
2716 int old_stack_arg_under_construction = 0;
2717 poly_int64 old_pending_adj = 0;
2718 int old_inhibit_defer_pop = inhibit_defer_pop;
2720 /* Some stack pointer alterations we make are performed via
2721 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2722 which we then also need to save/restore along the way. */
2723 poly_int64 old_stack_pointer_delta = 0;
2725 rtx call_fusage;
2726 tree addr = CALL_EXPR_FN (exp);
2727 int i;
2728 /* The alignment of the stack, in bits. */
2729 unsigned HOST_WIDE_INT preferred_stack_boundary;
2730 /* The alignment of the stack, in bytes. */
2731 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2732 /* The static chain value to use for this call. */
2733 rtx static_chain_value;
2734 /* See if this is "nothrow" function call. */
2735 if (TREE_NOTHROW (exp))
2736 flags |= ECF_NOTHROW;
2738 /* See if we can find a DECL-node for the actual function, and get the
2739 function attributes (flags) from the function decl or type node. */
2740 fndecl = get_callee_fndecl (exp);
2741 if (fndecl)
2743 fntype = TREE_TYPE (fndecl);
2744 flags |= flags_from_decl_or_type (fndecl);
2745 return_flags |= decl_return_flags (fndecl);
2747 else
2749 fntype = TREE_TYPE (TREE_TYPE (addr));
2750 flags |= flags_from_decl_or_type (fntype);
2751 if (CALL_EXPR_BY_DESCRIPTOR (exp))
2752 flags |= ECF_BY_DESCRIPTOR;
2754 rettype = TREE_TYPE (exp);
2756 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2758 /* Warn if this value is an aggregate type,
2759 regardless of which calling convention we are using for it. */
2760 if (AGGREGATE_TYPE_P (rettype))
2761 warning (OPT_Waggregate_return, "function call has aggregate value");
2763 /* If the result of a non looping pure or const function call is
2764 ignored (or void), and none of its arguments are volatile, we can
2765 avoid expanding the call and just evaluate the arguments for
2766 side-effects. */
2767 if ((flags & (ECF_CONST | ECF_PURE))
2768 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2769 && (flags & ECF_NOTHROW)
2770 && (ignore || target == const0_rtx
2771 || TYPE_MODE (rettype) == VOIDmode))
2773 bool volatilep = false;
2774 tree arg;
2775 call_expr_arg_iterator iter;
2777 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2778 if (TREE_THIS_VOLATILE (arg))
2780 volatilep = true;
2781 break;
2784 if (! volatilep)
2786 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2787 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2788 return const0_rtx;
2792 #ifdef REG_PARM_STACK_SPACE
2793 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2794 #endif
2796 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2797 && reg_parm_stack_space > 0 && targetm.calls.push_argument (0))
2798 must_preallocate = 1;
2800 /* Set up a place to return a structure. */
2802 /* Cater to broken compilers. */
2803 if (aggregate_value_p (exp, fntype))
2805 /* This call returns a big structure. */
2806 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2808 #ifdef PCC_STATIC_STRUCT_RETURN
2810 pcc_struct_value = 1;
2812 #else /* not PCC_STATIC_STRUCT_RETURN */
2814 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
2815 struct_value_size = -1;
2817 /* Even if it is semantically safe to use the target as the return
2818 slot, it may be not sufficiently aligned for the return type. */
2819 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
2820 && target
2821 && MEM_P (target)
2822 /* If rettype is addressable, we may not create a temporary.
2823 If target is properly aligned at runtime and the compiler
2824 just doesn't know about it, it will work fine, otherwise it
2825 will be UB. */
2826 && (TREE_ADDRESSABLE (rettype)
2827 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
2828 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
2829 MEM_ALIGN (target)))))
2830 structure_value_addr = XEXP (target, 0);
2831 else
2833 /* For variable-sized objects, we must be called with a target
2834 specified. If we were to allocate space on the stack here,
2835 we would have no way of knowing when to free it. */
2836 rtx d = assign_temp (rettype, 1, 1);
2837 structure_value_addr = XEXP (d, 0);
2838 target = 0;
2841 #endif /* not PCC_STATIC_STRUCT_RETURN */
2844 /* Figure out the amount to which the stack should be aligned. */
2845 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2846 if (fndecl)
2848 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
2849 /* Without automatic stack alignment, we can't increase preferred
2850 stack boundary. With automatic stack alignment, it is
2851 unnecessary since unless we can guarantee that all callers will
2852 align the outgoing stack properly, callee has to align its
2853 stack anyway. */
2854 if (i
2855 && i->preferred_incoming_stack_boundary
2856 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2857 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2860 /* Operand 0 is a pointer-to-function; get the type of the function. */
2861 funtype = TREE_TYPE (addr);
2862 gcc_assert (POINTER_TYPE_P (funtype));
2863 funtype = TREE_TYPE (funtype);
2865 /* Count whether there are actual complex arguments that need to be split
2866 into their real and imaginary parts. Munge the type_arg_types
2867 appropriately here as well. */
2868 if (targetm.calls.split_complex_arg)
2870 call_expr_arg_iterator iter;
2871 tree arg;
2872 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2874 tree type = TREE_TYPE (arg);
2875 if (type && TREE_CODE (type) == COMPLEX_TYPE
2876 && targetm.calls.split_complex_arg (type))
2877 num_complex_actuals++;
2879 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2881 else
2882 type_arg_types = TYPE_ARG_TYPES (funtype);
2884 if (flags & ECF_MAY_BE_ALLOCA)
2885 cfun->calls_alloca = 1;
2887 /* If struct_value_rtx is 0, it means pass the address
2888 as if it were an extra parameter. Put the argument expression
2889 in structure_value_addr_value. */
2890 if (structure_value_addr && struct_value == 0)
2892 /* If structure_value_addr is a REG other than
2893 virtual_outgoing_args_rtx, we can use always use it. If it
2894 is not a REG, we must always copy it into a register.
2895 If it is virtual_outgoing_args_rtx, we must copy it to another
2896 register in some cases. */
2897 rtx temp = (!REG_P (structure_value_addr)
2898 || (ACCUMULATE_OUTGOING_ARGS
2899 && stack_arg_under_construction
2900 && structure_value_addr == virtual_outgoing_args_rtx)
2901 ? copy_addr_to_reg (convert_memory_address
2902 (Pmode, structure_value_addr))
2903 : structure_value_addr);
2905 structure_value_addr_value =
2906 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2907 structure_value_addr_parm = 1;
2910 /* Count the arguments and set NUM_ACTUALS. */
2911 num_actuals
2912 = call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2914 /* Compute number of named args.
2915 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2917 if (type_arg_types != 0)
2918 n_named_args
2919 = (list_length (type_arg_types)
2920 /* Count the struct value address, if it is passed as a parm. */
2921 + structure_value_addr_parm);
2922 else if (TYPE_NO_NAMED_ARGS_STDARG_P (funtype))
2923 n_named_args = 0;
2924 else
2925 /* If we know nothing, treat all args as named. */
2926 n_named_args = num_actuals;
2928 /* Start updating where the next arg would go.
2930 On some machines (such as the PA) indirect calls have a different
2931 calling convention than normal calls. The fourth argument in
2932 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2933 or not. */
2934 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
2935 args_so_far = pack_cumulative_args (&args_so_far_v);
2937 /* Now possibly adjust the number of named args.
2938 Normally, don't include the last named arg if anonymous args follow.
2939 We do include the last named arg if
2940 targetm.calls.strict_argument_naming() returns nonzero.
2941 (If no anonymous args follow, the result of list_length is actually
2942 one too large. This is harmless.)
2944 If targetm.calls.pretend_outgoing_varargs_named() returns
2945 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2946 this machine will be able to place unnamed args that were passed
2947 in registers into the stack. So treat all args as named. This
2948 allows the insns emitting for a specific argument list to be
2949 independent of the function declaration.
2951 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2952 we do not have any reliable way to pass unnamed args in
2953 registers, so we must force them into memory. */
2955 if (type_arg_types != 0
2956 && targetm.calls.strict_argument_naming (args_so_far))
2958 else if (type_arg_types != 0
2959 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
2960 /* Don't include the last named arg. */
2961 --n_named_args;
2962 else if (TYPE_NO_NAMED_ARGS_STDARG_P (funtype))
2963 n_named_args = 0;
2964 else
2965 /* Treat all args as named. */
2966 n_named_args = num_actuals;
2968 /* Make a vector to hold all the information about each arg. */
2969 args = XCNEWVEC (struct arg_data, num_actuals);
2971 /* Build up entries in the ARGS array, compute the size of the
2972 arguments into ARGS_SIZE, etc. */
2973 initialize_argument_information (num_actuals, args, &args_size,
2974 n_named_args, exp,
2975 structure_value_addr_value, fndecl, fntype,
2976 args_so_far, reg_parm_stack_space,
2977 &old_stack_level, &old_pending_adj,
2978 &must_preallocate, &flags,
2979 &try_tail_call, CALL_FROM_THUNK_P (exp));
2981 if (args_size.var)
2982 must_preallocate = 1;
2984 /* Now make final decision about preallocating stack space. */
2985 must_preallocate = finalize_must_preallocate (must_preallocate,
2986 num_actuals, args,
2987 &args_size);
2989 /* If the structure value address will reference the stack pointer, we
2990 must stabilize it. We don't need to do this if we know that we are
2991 not going to adjust the stack pointer in processing this call. */
2993 if (structure_value_addr
2994 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2995 || reg_mentioned_p (virtual_outgoing_args_rtx,
2996 structure_value_addr))
2997 && (args_size.var
2998 || (!ACCUMULATE_OUTGOING_ARGS
2999 && maybe_ne (args_size.constant, 0))))
3000 structure_value_addr = copy_to_reg (structure_value_addr);
3002 /* Tail calls can make things harder to debug, and we've traditionally
3003 pushed these optimizations into -O2. Don't try if we're already
3004 expanding a call, as that means we're an argument. Don't try if
3005 there's cleanups, as we know there's code to follow the call. */
3006 if (currently_expanding_call++ != 0
3007 || (!flag_optimize_sibling_calls && !CALL_FROM_THUNK_P (exp))
3008 || args_size.var
3009 || dbg_cnt (tail_call) == false)
3010 try_tail_call = 0;
3012 /* Workaround buggy C/C++ wrappers around Fortran routines with
3013 character(len=constant) arguments if the hidden string length arguments
3014 are passed on the stack; if the callers forget to pass those arguments,
3015 attempting to tail call in such routines leads to stack corruption.
3016 Avoid tail calls in functions where at least one such hidden string
3017 length argument is passed (partially or fully) on the stack in the
3018 caller and the callee needs to pass any arguments on the stack.
3019 See PR90329. */
3020 if (try_tail_call && maybe_ne (args_size.constant, 0))
3021 for (tree arg = DECL_ARGUMENTS (current_function_decl);
3022 arg; arg = DECL_CHAIN (arg))
3023 if (DECL_HIDDEN_STRING_LENGTH (arg) && DECL_INCOMING_RTL (arg))
3025 subrtx_iterator::array_type array;
3026 FOR_EACH_SUBRTX (iter, array, DECL_INCOMING_RTL (arg), NONCONST)
3027 if (MEM_P (*iter))
3029 try_tail_call = 0;
3030 break;
3034 /* If the user has marked the function as requiring tail-call
3035 optimization, attempt it. */
3036 if (must_tail_call)
3037 try_tail_call = 1;
3039 /* Rest of purposes for tail call optimizations to fail. */
3040 if (try_tail_call)
3041 try_tail_call = can_implement_as_sibling_call_p (exp,
3042 structure_value_addr,
3043 funtype,
3044 fndecl,
3045 flags, addr, args_size);
3047 /* Check if caller and callee disagree in promotion of function
3048 return value. */
3049 if (try_tail_call)
3051 machine_mode caller_mode, caller_promoted_mode;
3052 machine_mode callee_mode, callee_promoted_mode;
3053 int caller_unsignedp, callee_unsignedp;
3054 tree caller_res = DECL_RESULT (current_function_decl);
3056 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3057 caller_mode = DECL_MODE (caller_res);
3058 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3059 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3060 caller_promoted_mode
3061 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3062 &caller_unsignedp,
3063 TREE_TYPE (current_function_decl), 1);
3064 callee_promoted_mode
3065 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3066 &callee_unsignedp,
3067 funtype, 1);
3068 if (caller_mode != VOIDmode
3069 && (caller_promoted_mode != callee_promoted_mode
3070 || ((caller_mode != caller_promoted_mode
3071 || callee_mode != callee_promoted_mode)
3072 && (caller_unsignedp != callee_unsignedp
3073 || partial_subreg_p (caller_mode, callee_mode)))))
3075 try_tail_call = 0;
3076 maybe_complain_about_tail_call (exp,
3077 "caller and callee disagree in"
3078 " promotion of function"
3079 " return value");
3083 /* Ensure current function's preferred stack boundary is at least
3084 what we need. Stack alignment may also increase preferred stack
3085 boundary. */
3086 for (i = 0; i < num_actuals; i++)
3087 if (reg_parm_stack_space > 0
3088 || args[i].reg == 0
3089 || args[i].partial != 0
3090 || args[i].pass_on_stack)
3091 update_stack_alignment_for_call (&args[i].locate);
3092 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3093 crtl->preferred_stack_boundary = preferred_stack_boundary;
3094 else
3095 preferred_stack_boundary = crtl->preferred_stack_boundary;
3097 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3099 if (flag_callgraph_info)
3100 record_final_call (fndecl, EXPR_LOCATION (exp));
3102 /* We want to make two insn chains; one for a sibling call, the other
3103 for a normal call. We will select one of the two chains after
3104 initial RTL generation is complete. */
3105 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3107 int sibcall_failure = 0;
3108 bool normal_failure = false;
3109 /* We want to emit any pending stack adjustments before the tail
3110 recursion "call". That way we know any adjustment after the tail
3111 recursion call can be ignored if we indeed use the tail
3112 call expansion. */
3113 saved_pending_stack_adjust save;
3114 rtx_insn *insns, *before_call, *after_args;
3115 rtx next_arg_reg;
3117 if (pass == 0)
3119 /* State variables we need to save and restore between
3120 iterations. */
3121 save_pending_stack_adjust (&save);
3123 if (pass)
3124 flags &= ~ECF_SIBCALL;
3125 else
3126 flags |= ECF_SIBCALL;
3128 /* Other state variables that we must reinitialize each time
3129 through the loop (that are not initialized by the loop itself). */
3130 argblock = 0;
3131 call_fusage = 0;
3133 /* Start a new sequence for the normal call case.
3135 From this point on, if the sibling call fails, we want to set
3136 sibcall_failure instead of continuing the loop. */
3137 start_sequence ();
3139 /* Don't let pending stack adjusts add up to too much.
3140 Also, do all pending adjustments now if there is any chance
3141 this might be a call to alloca or if we are expanding a sibling
3142 call sequence.
3143 Also do the adjustments before a throwing call, otherwise
3144 exception handling can fail; PR 19225. */
3145 if (maybe_ge (pending_stack_adjust, 32)
3146 || (maybe_ne (pending_stack_adjust, 0)
3147 && (flags & ECF_MAY_BE_ALLOCA))
3148 || (maybe_ne (pending_stack_adjust, 0)
3149 && flag_exceptions && !(flags & ECF_NOTHROW))
3150 || pass == 0)
3151 do_pending_stack_adjust ();
3153 /* Precompute any arguments as needed. */
3154 if (pass)
3155 precompute_arguments (num_actuals, args);
3157 /* Now we are about to start emitting insns that can be deleted
3158 if a libcall is deleted. */
3159 if (pass && (flags & ECF_MALLOC))
3160 start_sequence ();
3162 /* Check the canary value for sibcall or function which doesn't
3163 return and could throw. */
3164 if ((pass == 0
3165 || ((flags & ECF_NORETURN) != 0 && tree_could_throw_p (exp)))
3166 && crtl->stack_protect_guard
3167 && targetm.stack_protect_runtime_enabled_p ())
3168 stack_protect_epilogue ();
3170 adjusted_args_size = args_size;
3171 /* Compute the actual size of the argument block required. The variable
3172 and constant sizes must be combined, the size may have to be rounded,
3173 and there may be a minimum required size. When generating a sibcall
3174 pattern, do not round up, since we'll be re-using whatever space our
3175 caller provided. */
3176 unadjusted_args_size
3177 = compute_argument_block_size (reg_parm_stack_space,
3178 &adjusted_args_size,
3179 fndecl, fntype,
3180 (pass == 0 ? 0
3181 : preferred_stack_boundary));
3183 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3185 /* The argument block when performing a sibling call is the
3186 incoming argument block. */
3187 if (pass == 0)
3189 argblock = crtl->args.internal_arg_pointer;
3190 if (STACK_GROWS_DOWNWARD)
3191 argblock
3192 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3193 else
3194 argblock
3195 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3197 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3198 stored_args_map = sbitmap_alloc (map_size);
3199 bitmap_clear (stored_args_map);
3200 stored_args_watermark = HOST_WIDE_INT_M1U;
3203 /* If we have no actual push instructions, or shouldn't use them,
3204 make space for all args right now. */
3205 else if (adjusted_args_size.var != 0)
3207 if (old_stack_level == 0)
3209 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3210 old_stack_pointer_delta = stack_pointer_delta;
3211 old_pending_adj = pending_stack_adjust;
3212 pending_stack_adjust = 0;
3213 /* stack_arg_under_construction says whether a stack arg is
3214 being constructed at the old stack level. Pushing the stack
3215 gets a clean outgoing argument block. */
3216 old_stack_arg_under_construction = stack_arg_under_construction;
3217 stack_arg_under_construction = 0;
3219 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3220 if (flag_stack_usage_info)
3221 current_function_has_unbounded_dynamic_stack_size = 1;
3223 else
3225 /* Note that we must go through the motions of allocating an argument
3226 block even if the size is zero because we may be storing args
3227 in the area reserved for register arguments, which may be part of
3228 the stack frame. */
3230 poly_int64 needed = adjusted_args_size.constant;
3232 /* Store the maximum argument space used. It will be pushed by
3233 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3234 checking). */
3236 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3237 needed);
3239 if (must_preallocate)
3241 if (ACCUMULATE_OUTGOING_ARGS)
3243 /* Since the stack pointer will never be pushed, it is
3244 possible for the evaluation of a parm to clobber
3245 something we have already written to the stack.
3246 Since most function calls on RISC machines do not use
3247 the stack, this is uncommon, but must work correctly.
3249 Therefore, we save any area of the stack that was already
3250 written and that we are using. Here we set up to do this
3251 by making a new stack usage map from the old one. The
3252 actual save will be done by store_one_arg.
3254 Another approach might be to try to reorder the argument
3255 evaluations to avoid this conflicting stack usage. */
3257 /* Since we will be writing into the entire argument area,
3258 the map must be allocated for its entire size, not just
3259 the part that is the responsibility of the caller. */
3260 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3261 needed += reg_parm_stack_space;
3263 poly_int64 limit = needed;
3264 if (ARGS_GROW_DOWNWARD)
3265 limit += 1;
3267 /* For polynomial sizes, this is the maximum possible
3268 size needed for arguments with a constant size
3269 and offset. */
3270 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3271 highest_outgoing_arg_in_use
3272 = MAX (initial_highest_arg_in_use, const_limit);
3274 free (stack_usage_map_buf);
3275 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3276 stack_usage_map = stack_usage_map_buf;
3278 if (initial_highest_arg_in_use)
3279 memcpy (stack_usage_map, initial_stack_usage_map,
3280 initial_highest_arg_in_use);
3282 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3283 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3284 (highest_outgoing_arg_in_use
3285 - initial_highest_arg_in_use));
3286 needed = 0;
3288 /* The address of the outgoing argument list must not be
3289 copied to a register here, because argblock would be left
3290 pointing to the wrong place after the call to
3291 allocate_dynamic_stack_space below. */
3293 argblock = virtual_outgoing_args_rtx;
3295 else
3297 /* Try to reuse some or all of the pending_stack_adjust
3298 to get this space. */
3299 if (inhibit_defer_pop == 0
3300 && (combine_pending_stack_adjustment_and_call
3301 (&needed,
3302 unadjusted_args_size,
3303 &adjusted_args_size,
3304 preferred_unit_stack_boundary)))
3306 /* combine_pending_stack_adjustment_and_call computes
3307 an adjustment before the arguments are allocated.
3308 Account for them and see whether or not the stack
3309 needs to go up or down. */
3310 needed = unadjusted_args_size - needed;
3312 /* Checked by
3313 combine_pending_stack_adjustment_and_call. */
3314 gcc_checking_assert (ordered_p (needed, 0));
3315 if (maybe_lt (needed, 0))
3317 /* We're releasing stack space. */
3318 /* ??? We can avoid any adjustment at all if we're
3319 already aligned. FIXME. */
3320 pending_stack_adjust = -needed;
3321 do_pending_stack_adjust ();
3322 needed = 0;
3324 else
3325 /* We need to allocate space. We'll do that in
3326 push_block below. */
3327 pending_stack_adjust = 0;
3330 /* Special case this because overhead of `push_block' in
3331 this case is non-trivial. */
3332 if (known_eq (needed, 0))
3333 argblock = virtual_outgoing_args_rtx;
3334 else
3336 rtx needed_rtx = gen_int_mode (needed, Pmode);
3337 argblock = push_block (needed_rtx, 0, 0);
3338 if (ARGS_GROW_DOWNWARD)
3339 argblock = plus_constant (Pmode, argblock, needed);
3342 /* We only really need to call `copy_to_reg' in the case
3343 where push insns are going to be used to pass ARGBLOCK
3344 to a function call in ARGS. In that case, the stack
3345 pointer changes value from the allocation point to the
3346 call point, and hence the value of
3347 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3348 as well always do it. */
3349 argblock = copy_to_reg (argblock);
3354 if (ACCUMULATE_OUTGOING_ARGS)
3356 /* The save/restore code in store_one_arg handles all
3357 cases except one: a constructor call (including a C
3358 function returning a BLKmode struct) to initialize
3359 an argument. */
3360 if (stack_arg_under_construction)
3362 rtx push_size
3363 = (gen_int_mode
3364 (adjusted_args_size.constant
3365 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
3366 : TREE_TYPE (fndecl))
3367 ? 0 : reg_parm_stack_space), Pmode));
3368 if (old_stack_level == 0)
3370 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3371 old_stack_pointer_delta = stack_pointer_delta;
3372 old_pending_adj = pending_stack_adjust;
3373 pending_stack_adjust = 0;
3374 /* stack_arg_under_construction says whether a stack
3375 arg is being constructed at the old stack level.
3376 Pushing the stack gets a clean outgoing argument
3377 block. */
3378 old_stack_arg_under_construction
3379 = stack_arg_under_construction;
3380 stack_arg_under_construction = 0;
3381 /* Make a new map for the new argument list. */
3382 free (stack_usage_map_buf);
3383 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
3384 stack_usage_map = stack_usage_map_buf;
3385 highest_outgoing_arg_in_use = 0;
3386 stack_usage_watermark = HOST_WIDE_INT_M1U;
3388 /* We can pass TRUE as the 4th argument because we just
3389 saved the stack pointer and will restore it right after
3390 the call. */
3391 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
3392 -1, true);
3395 /* If argument evaluation might modify the stack pointer,
3396 copy the address of the argument list to a register. */
3397 for (i = 0; i < num_actuals; i++)
3398 if (args[i].pass_on_stack)
3400 argblock = copy_addr_to_reg (argblock);
3401 break;
3405 compute_argument_addresses (args, argblock, num_actuals);
3407 /* Stack is properly aligned, pops can't safely be deferred during
3408 the evaluation of the arguments. */
3409 NO_DEFER_POP;
3411 /* Precompute all register parameters. It isn't safe to compute
3412 anything once we have started filling any specific hard regs.
3413 TLS symbols sometimes need a call to resolve. Precompute
3414 register parameters before any stack pointer manipulation
3415 to avoid unaligned stack in the called function. */
3416 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3418 OK_DEFER_POP;
3420 /* Perform stack alignment before the first push (the last arg). */
3421 if (argblock == 0
3422 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
3423 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
3425 /* When the stack adjustment is pending, we get better code
3426 by combining the adjustments. */
3427 if (maybe_ne (pending_stack_adjust, 0)
3428 && ! inhibit_defer_pop
3429 && (combine_pending_stack_adjustment_and_call
3430 (&pending_stack_adjust,
3431 unadjusted_args_size,
3432 &adjusted_args_size,
3433 preferred_unit_stack_boundary)))
3434 do_pending_stack_adjust ();
3435 else if (argblock == 0)
3436 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
3437 - unadjusted_args_size,
3438 Pmode));
3440 /* Now that the stack is properly aligned, pops can't safely
3441 be deferred during the evaluation of the arguments. */
3442 NO_DEFER_POP;
3444 /* Record the maximum pushed stack space size. We need to delay
3445 doing it this far to take into account the optimization done
3446 by combine_pending_stack_adjustment_and_call. */
3447 if (flag_stack_usage_info
3448 && !ACCUMULATE_OUTGOING_ARGS
3449 && pass
3450 && adjusted_args_size.var == 0)
3452 poly_int64 pushed = (adjusted_args_size.constant
3453 + pending_stack_adjust);
3454 current_function_pushed_stack_size
3455 = upper_bound (current_function_pushed_stack_size, pushed);
3458 funexp = rtx_for_function_call (fndecl, addr);
3460 if (CALL_EXPR_STATIC_CHAIN (exp))
3461 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
3462 else
3463 static_chain_value = 0;
3465 #ifdef REG_PARM_STACK_SPACE
3466 /* Save the fixed argument area if it's part of the caller's frame and
3467 is clobbered by argument setup for this call. */
3468 if (ACCUMULATE_OUTGOING_ARGS && pass)
3469 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3470 &low_to_save, &high_to_save);
3471 #endif
3473 /* Now store (and compute if necessary) all non-register parms.
3474 These come before register parms, since they can require block-moves,
3475 which could clobber the registers used for register parms.
3476 Parms which have partial registers are not stored here,
3477 but we do preallocate space here if they want that. */
3479 for (i = 0; i < num_actuals; i++)
3481 if (args[i].reg == 0 || args[i].pass_on_stack)
3483 rtx_insn *before_arg = get_last_insn ();
3485 /* We don't allow passing huge (> 2^30 B) arguments
3486 by value. It would cause an overflow later on. */
3487 if (constant_lower_bound (adjusted_args_size.constant)
3488 >= (1 << (HOST_BITS_PER_INT - 2)))
3490 sorry ("passing too large argument on stack");
3491 /* Don't worry about stack clean-up. */
3492 if (pass == 0)
3493 sibcall_failure = 1;
3494 else
3495 normal_failure = true;
3496 continue;
3499 if (store_one_arg (&args[i], argblock, flags,
3500 adjusted_args_size.var != 0,
3501 reg_parm_stack_space)
3502 || (pass == 0
3503 && check_sibcall_argument_overlap (before_arg,
3504 &args[i], 1)))
3505 sibcall_failure = 1;
3508 if (args[i].stack)
3509 call_fusage
3510 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
3511 gen_rtx_USE (VOIDmode, args[i].stack),
3512 call_fusage);
3515 /* If we have a parm that is passed in registers but not in memory
3516 and whose alignment does not permit a direct copy into registers,
3517 make a group of pseudos that correspond to each register that we
3518 will later fill. */
3519 if (STRICT_ALIGNMENT)
3520 store_unaligned_arguments_into_pseudos (args, num_actuals);
3522 /* Now store any partially-in-registers parm.
3523 This is the last place a block-move can happen. */
3524 if (reg_parm_seen)
3525 for (i = 0; i < num_actuals; i++)
3526 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3528 rtx_insn *before_arg = get_last_insn ();
3530 /* On targets with weird calling conventions (e.g. PA) it's
3531 hard to ensure that all cases of argument overlap between
3532 stack and registers work. Play it safe and bail out. */
3533 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
3535 sibcall_failure = 1;
3536 break;
3539 if (store_one_arg (&args[i], argblock, flags,
3540 adjusted_args_size.var != 0,
3541 reg_parm_stack_space)
3542 || (pass == 0
3543 && check_sibcall_argument_overlap (before_arg,
3544 &args[i], 1)))
3545 sibcall_failure = 1;
3548 bool any_regs = false;
3549 for (i = 0; i < num_actuals; i++)
3550 if (args[i].reg != NULL_RTX)
3552 any_regs = true;
3553 targetm.calls.call_args (args[i].reg, funtype);
3555 if (!any_regs)
3556 targetm.calls.call_args (pc_rtx, funtype);
3558 /* Figure out the register where the value, if any, will come back. */
3559 valreg = 0;
3560 if (TYPE_MODE (rettype) != VOIDmode
3561 && ! structure_value_addr)
3563 if (pcc_struct_value)
3564 valreg = hard_function_value (build_pointer_type (rettype),
3565 fndecl, NULL, (pass == 0));
3566 else
3567 valreg = hard_function_value (rettype, fndecl, fntype,
3568 (pass == 0));
3570 /* If VALREG is a PARALLEL whose first member has a zero
3571 offset, use that. This is for targets such as m68k that
3572 return the same value in multiple places. */
3573 if (GET_CODE (valreg) == PARALLEL)
3575 rtx elem = XVECEXP (valreg, 0, 0);
3576 rtx where = XEXP (elem, 0);
3577 rtx offset = XEXP (elem, 1);
3578 if (offset == const0_rtx
3579 && GET_MODE (where) == GET_MODE (valreg))
3580 valreg = where;
3584 /* If register arguments require space on the stack and stack space
3585 was not preallocated, allocate stack space here for arguments
3586 passed in registers. */
3587 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3588 && !ACCUMULATE_OUTGOING_ARGS
3589 && must_preallocate == 0 && reg_parm_stack_space > 0)
3590 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3592 /* Pass the function the address in which to return a
3593 structure value. */
3594 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3596 structure_value_addr
3597 = convert_memory_address (Pmode, structure_value_addr);
3598 emit_move_insn (struct_value,
3599 force_reg (Pmode,
3600 force_operand (structure_value_addr,
3601 NULL_RTX)));
3603 if (REG_P (struct_value))
3604 use_reg (&call_fusage, struct_value);
3607 after_args = get_last_insn ();
3608 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
3609 static_chain_value, &call_fusage,
3610 reg_parm_seen, flags);
3612 load_register_parameters (args, num_actuals, &call_fusage, flags,
3613 pass == 0, &sibcall_failure);
3615 /* Save a pointer to the last insn before the call, so that we can
3616 later safely search backwards to find the CALL_INSN. */
3617 before_call = get_last_insn ();
3619 /* Set up next argument register. For sibling calls on machines
3620 with register windows this should be the incoming register. */
3621 if (pass == 0)
3622 next_arg_reg = targetm.calls.function_incoming_arg
3623 (args_so_far, function_arg_info::end_marker ());
3624 else
3625 next_arg_reg = targetm.calls.function_arg
3626 (args_so_far, function_arg_info::end_marker ());
3628 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
3630 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
3631 arg_nr = num_actuals - arg_nr - 1;
3632 if (arg_nr >= 0
3633 && arg_nr < num_actuals
3634 && args[arg_nr].reg
3635 && valreg
3636 && REG_P (valreg)
3637 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
3638 call_fusage
3639 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
3640 gen_rtx_SET (valreg, args[arg_nr].reg),
3641 call_fusage);
3643 /* All arguments and registers used for the call must be set up by
3644 now! */
3646 /* Stack must be properly aligned now. */
3647 gcc_assert (!pass
3648 || multiple_p (stack_pointer_delta,
3649 preferred_unit_stack_boundary));
3651 /* Generate the actual call instruction. */
3652 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
3653 adjusted_args_size.constant, struct_value_size,
3654 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3655 flags, args_so_far);
3657 if (flag_ipa_ra)
3659 rtx_call_insn *last;
3660 rtx datum = NULL_RTX;
3661 if (fndecl != NULL_TREE)
3663 datum = XEXP (DECL_RTL (fndecl), 0);
3664 gcc_assert (datum != NULL_RTX
3665 && GET_CODE (datum) == SYMBOL_REF);
3667 last = last_call_insn ();
3668 add_reg_note (last, REG_CALL_DECL, datum);
3671 /* If the call setup or the call itself overlaps with anything
3672 of the argument setup we probably clobbered our call address.
3673 In that case we can't do sibcalls. */
3674 if (pass == 0
3675 && check_sibcall_argument_overlap (after_args, 0, 0))
3676 sibcall_failure = 1;
3678 /* If a non-BLKmode value is returned at the most significant end
3679 of a register, shift the register right by the appropriate amount
3680 and update VALREG accordingly. BLKmode values are handled by the
3681 group load/store machinery below. */
3682 if (!structure_value_addr
3683 && !pcc_struct_value
3684 && TYPE_MODE (rettype) != VOIDmode
3685 && TYPE_MODE (rettype) != BLKmode
3686 && REG_P (valreg)
3687 && targetm.calls.return_in_msb (rettype))
3689 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
3690 sibcall_failure = 1;
3691 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
3694 if (pass && (flags & ECF_MALLOC))
3696 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3697 rtx_insn *last, *insns;
3699 /* The return value from a malloc-like function is a pointer. */
3700 if (TREE_CODE (rettype) == POINTER_TYPE)
3701 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
3703 emit_move_insn (temp, valreg);
3705 /* The return value from a malloc-like function cannot alias
3706 anything else. */
3707 last = get_last_insn ();
3708 add_reg_note (last, REG_NOALIAS, temp);
3710 /* Write out the sequence. */
3711 insns = get_insns ();
3712 end_sequence ();
3713 emit_insn (insns);
3714 valreg = temp;
3717 /* For calls to `setjmp', etc., inform
3718 function.cc:setjmp_warnings that it should complain if
3719 nonvolatile values are live. For functions that cannot
3720 return, inform flow that control does not fall through. */
3722 if ((flags & ECF_NORETURN) || pass == 0)
3724 /* The barrier must be emitted
3725 immediately after the CALL_INSN. Some ports emit more
3726 than just a CALL_INSN above, so we must search for it here. */
3728 rtx_insn *last = get_last_insn ();
3729 while (!CALL_P (last))
3731 last = PREV_INSN (last);
3732 /* There was no CALL_INSN? */
3733 gcc_assert (last != before_call);
3736 emit_barrier_after (last);
3738 /* Stack adjustments after a noreturn call are dead code.
3739 However when NO_DEFER_POP is in effect, we must preserve
3740 stack_pointer_delta. */
3741 if (inhibit_defer_pop == 0)
3743 stack_pointer_delta = old_stack_allocated;
3744 pending_stack_adjust = 0;
3748 /* If value type not void, return an rtx for the value. */
3750 if (TYPE_MODE (rettype) == VOIDmode
3751 || ignore)
3752 target = const0_rtx;
3753 else if (structure_value_addr)
3755 if (target == 0 || !MEM_P (target))
3757 target
3758 = gen_rtx_MEM (TYPE_MODE (rettype),
3759 memory_address (TYPE_MODE (rettype),
3760 structure_value_addr));
3761 set_mem_attributes (target, rettype, 1);
3764 else if (pcc_struct_value)
3766 /* This is the special C++ case where we need to
3767 know what the true target was. We take care to
3768 never use this value more than once in one expression. */
3769 target = gen_rtx_MEM (TYPE_MODE (rettype),
3770 copy_to_reg (valreg));
3771 set_mem_attributes (target, rettype, 1);
3773 /* Handle calls that return values in multiple non-contiguous locations.
3774 The Irix 6 ABI has examples of this. */
3775 else if (GET_CODE (valreg) == PARALLEL)
3777 if (target == 0)
3778 target = emit_group_move_into_temps (valreg);
3779 else if (rtx_equal_p (target, valreg))
3781 else if (GET_CODE (target) == PARALLEL)
3782 /* Handle the result of a emit_group_move_into_temps
3783 call in the previous pass. */
3784 emit_group_move (target, valreg);
3785 else
3786 emit_group_store (target, valreg, rettype,
3787 int_size_in_bytes (rettype));
3789 else if (target
3790 && GET_MODE (target) == TYPE_MODE (rettype)
3791 && GET_MODE (target) == GET_MODE (valreg))
3793 bool may_overlap = false;
3795 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3796 reg to a plain register. */
3797 if (!REG_P (target) || HARD_REGISTER_P (target))
3798 valreg = avoid_likely_spilled_reg (valreg);
3800 /* If TARGET is a MEM in the argument area, and we have
3801 saved part of the argument area, then we can't store
3802 directly into TARGET as it may get overwritten when we
3803 restore the argument save area below. Don't work too
3804 hard though and simply force TARGET to a register if it
3805 is a MEM; the optimizer is quite likely to sort it out. */
3806 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
3807 for (i = 0; i < num_actuals; i++)
3808 if (args[i].save_area)
3810 may_overlap = true;
3811 break;
3814 if (may_overlap)
3815 target = copy_to_reg (valreg);
3816 else
3818 /* TARGET and VALREG cannot be equal at this point
3819 because the latter would not have
3820 REG_FUNCTION_VALUE_P true, while the former would if
3821 it were referring to the same register.
3823 If they refer to the same register, this move will be
3824 a no-op, except when function inlining is being
3825 done. */
3826 emit_move_insn (target, valreg);
3828 /* If we are setting a MEM, this code must be executed.
3829 Since it is emitted after the call insn, sibcall
3830 optimization cannot be performed in that case. */
3831 if (MEM_P (target))
3832 sibcall_failure = 1;
3835 else
3836 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3838 /* If we promoted this return value, make the proper SUBREG.
3839 TARGET might be const0_rtx here, so be careful. */
3840 if (REG_P (target)
3841 && TYPE_MODE (rettype) != BLKmode
3842 && GET_MODE (target) != TYPE_MODE (rettype))
3844 tree type = rettype;
3845 int unsignedp = TYPE_UNSIGNED (type);
3846 machine_mode ret_mode = TYPE_MODE (type);
3847 machine_mode pmode;
3849 /* Ensure we promote as expected, and get the new unsignedness. */
3850 pmode = promote_function_mode (type, ret_mode, &unsignedp,
3851 funtype, 1);
3852 gcc_assert (GET_MODE (target) == pmode);
3854 if (SCALAR_INT_MODE_P (pmode)
3855 && SCALAR_FLOAT_MODE_P (ret_mode)
3856 && known_gt (GET_MODE_SIZE (pmode), GET_MODE_SIZE (ret_mode)))
3857 target = convert_wider_int_to_float (ret_mode, pmode, target);
3858 else
3860 target = gen_lowpart_SUBREG (ret_mode, target);
3861 SUBREG_PROMOTED_VAR_P (target) = 1;
3862 SUBREG_PROMOTED_SET (target, unsignedp);
3866 /* If size of args is variable or this was a constructor call for a stack
3867 argument, restore saved stack-pointer value. */
3869 if (old_stack_level)
3871 rtx_insn *prev = get_last_insn ();
3873 emit_stack_restore (SAVE_BLOCK, old_stack_level);
3874 stack_pointer_delta = old_stack_pointer_delta;
3876 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
3878 pending_stack_adjust = old_pending_adj;
3879 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3880 stack_arg_under_construction = old_stack_arg_under_construction;
3881 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3882 stack_usage_map = initial_stack_usage_map;
3883 stack_usage_watermark = initial_stack_usage_watermark;
3884 sibcall_failure = 1;
3886 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3888 #ifdef REG_PARM_STACK_SPACE
3889 if (save_area)
3890 restore_fixed_argument_area (save_area, argblock,
3891 high_to_save, low_to_save);
3892 #endif
3894 /* If we saved any argument areas, restore them. */
3895 for (i = 0; i < num_actuals; i++)
3896 if (args[i].save_area)
3898 machine_mode save_mode = GET_MODE (args[i].save_area);
3899 rtx stack_area
3900 = gen_rtx_MEM (save_mode,
3901 memory_address (save_mode,
3902 XEXP (args[i].stack_slot, 0)));
3904 if (save_mode != BLKmode)
3905 emit_move_insn (stack_area, args[i].save_area);
3906 else
3907 emit_block_move (stack_area, args[i].save_area,
3908 (gen_int_mode
3909 (args[i].locate.size.constant, Pmode)),
3910 BLOCK_OP_CALL_PARM);
3913 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3914 stack_usage_map = initial_stack_usage_map;
3915 stack_usage_watermark = initial_stack_usage_watermark;
3918 /* If this was alloca, record the new stack level. */
3919 if (flags & ECF_MAY_BE_ALLOCA)
3920 record_new_stack_level ();
3922 /* Free up storage we no longer need. */
3923 for (i = 0; i < num_actuals; ++i)
3924 free (args[i].aligned_regs);
3926 targetm.calls.end_call_args ();
3928 insns = get_insns ();
3929 end_sequence ();
3931 if (pass == 0)
3933 tail_call_insns = insns;
3935 /* Restore the pending stack adjustment now that we have
3936 finished generating the sibling call sequence. */
3938 restore_pending_stack_adjust (&save);
3940 /* Prepare arg structure for next iteration. */
3941 for (i = 0; i < num_actuals; i++)
3943 args[i].value = 0;
3944 args[i].aligned_regs = 0;
3945 args[i].stack = 0;
3948 sbitmap_free (stored_args_map);
3949 internal_arg_pointer_exp_state.scan_start = NULL;
3950 internal_arg_pointer_exp_state.cache.release ();
3952 else
3954 normal_call_insns = insns;
3956 /* Verify that we've deallocated all the stack we used. */
3957 gcc_assert ((flags & ECF_NORETURN)
3958 || normal_failure
3959 || known_eq (old_stack_allocated,
3960 stack_pointer_delta
3961 - pending_stack_adjust));
3962 if (normal_failure)
3963 normal_call_insns = NULL;
3966 /* If something prevents making this a sibling call,
3967 zero out the sequence. */
3968 if (sibcall_failure)
3969 tail_call_insns = NULL;
3970 else
3971 break;
3974 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3975 arguments too, as argument area is now clobbered by the call. */
3976 if (tail_call_insns)
3978 emit_insn (tail_call_insns);
3979 crtl->tail_call_emit = true;
3981 else
3983 emit_insn (normal_call_insns);
3984 if (try_tail_call)
3985 /* Ideally we'd emit a message for all of the ways that it could
3986 have failed. */
3987 maybe_complain_about_tail_call (exp, "tail call production failed");
3990 currently_expanding_call--;
3992 free (stack_usage_map_buf);
3993 free (args);
3994 return target;
3997 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3998 this function's incoming arguments.
4000 At the start of RTL generation we know the only REG_EQUIV notes
4001 in the rtl chain are those for incoming arguments, so we can look
4002 for REG_EQUIV notes between the start of the function and the
4003 NOTE_INSN_FUNCTION_BEG.
4005 This is (slight) overkill. We could keep track of the highest
4006 argument we clobber and be more selective in removing notes, but it
4007 does not seem to be worth the effort. */
4009 void
4010 fixup_tail_calls (void)
4012 rtx_insn *insn;
4014 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4016 rtx note;
4018 /* There are never REG_EQUIV notes for the incoming arguments
4019 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4020 if (NOTE_P (insn)
4021 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4022 break;
4024 note = find_reg_note (insn, REG_EQUIV, 0);
4025 if (note)
4026 remove_note (insn, note);
4027 note = find_reg_note (insn, REG_EQUIV, 0);
4028 gcc_assert (!note);
4032 /* Traverse a list of TYPES and expand all complex types into their
4033 components. */
4034 static tree
4035 split_complex_types (tree types)
4037 tree p;
4039 /* Before allocating memory, check for the common case of no complex. */
4040 for (p = types; p; p = TREE_CHAIN (p))
4042 tree type = TREE_VALUE (p);
4043 if (TREE_CODE (type) == COMPLEX_TYPE
4044 && targetm.calls.split_complex_arg (type))
4045 goto found;
4047 return types;
4049 found:
4050 types = copy_list (types);
4052 for (p = types; p; p = TREE_CHAIN (p))
4054 tree complex_type = TREE_VALUE (p);
4056 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4057 && targetm.calls.split_complex_arg (complex_type))
4059 tree next, imag;
4061 /* Rewrite complex type with component type. */
4062 TREE_VALUE (p) = TREE_TYPE (complex_type);
4063 next = TREE_CHAIN (p);
4065 /* Add another component type for the imaginary part. */
4066 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4067 TREE_CHAIN (p) = imag;
4068 TREE_CHAIN (imag) = next;
4070 /* Skip the newly created node. */
4071 p = TREE_CHAIN (p);
4075 return types;
4078 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4079 for a value of mode OUTMODE,
4080 with NARGS different arguments, passed as ARGS.
4081 Store the return value if RETVAL is nonzero: store it in VALUE if
4082 VALUE is nonnull, otherwise pick a convenient location. In either
4083 case return the location of the stored value.
4085 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4086 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4087 other types of library calls. */
4090 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4091 enum libcall_type fn_type,
4092 machine_mode outmode, int nargs, rtx_mode_t *args)
4094 /* Total size in bytes of all the stack-parms scanned so far. */
4095 struct args_size args_size;
4096 /* Size of arguments before any adjustments (such as rounding). */
4097 struct args_size original_args_size;
4098 int argnum;
4099 rtx fun;
4100 /* Todo, choose the correct decl type of orgfun. Sadly this information
4101 isn't present here, so we default to native calling abi here. */
4102 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4103 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4104 int count;
4105 rtx argblock = 0;
4106 CUMULATIVE_ARGS args_so_far_v;
4107 cumulative_args_t args_so_far;
4108 struct arg
4110 rtx value;
4111 machine_mode mode;
4112 rtx reg;
4113 int partial;
4114 struct locate_and_pad_arg_data locate;
4115 rtx save_area;
4117 struct arg *argvec;
4118 int old_inhibit_defer_pop = inhibit_defer_pop;
4119 rtx call_fusage = 0;
4120 rtx mem_value = 0;
4121 rtx valreg;
4122 int pcc_struct_value = 0;
4123 poly_int64 struct_value_size = 0;
4124 int flags;
4125 int reg_parm_stack_space = 0;
4126 poly_int64 needed;
4127 rtx_insn *before_call;
4128 bool have_push_fusage;
4129 tree tfom; /* type_for_mode (outmode, 0) */
4131 #ifdef REG_PARM_STACK_SPACE
4132 /* Define the boundary of the register parm stack space that needs to be
4133 save, if any. */
4134 int low_to_save = 0, high_to_save = 0;
4135 rtx save_area = 0; /* Place that it is saved. */
4136 #endif
4138 /* Size of the stack reserved for parameter registers. */
4139 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4140 char *initial_stack_usage_map = stack_usage_map;
4141 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4142 char *stack_usage_map_buf = NULL;
4144 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4146 #ifdef REG_PARM_STACK_SPACE
4147 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4148 #endif
4150 /* By default, library functions cannot throw. */
4151 flags = ECF_NOTHROW;
4153 switch (fn_type)
4155 case LCT_NORMAL:
4156 break;
4157 case LCT_CONST:
4158 flags |= ECF_CONST;
4159 break;
4160 case LCT_PURE:
4161 flags |= ECF_PURE;
4162 break;
4163 case LCT_NORETURN:
4164 flags |= ECF_NORETURN;
4165 break;
4166 case LCT_THROW:
4167 flags &= ~ECF_NOTHROW;
4168 break;
4169 case LCT_RETURNS_TWICE:
4170 flags = ECF_RETURNS_TWICE;
4171 break;
4173 fun = orgfun;
4175 /* Ensure current function's preferred stack boundary is at least
4176 what we need. */
4177 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4178 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4180 /* If this kind of value comes back in memory,
4181 decide where in memory it should come back. */
4182 if (outmode != VOIDmode)
4184 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4185 if (aggregate_value_p (tfom, 0))
4187 #ifdef PCC_STATIC_STRUCT_RETURN
4188 rtx pointer_reg
4189 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4190 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4191 pcc_struct_value = 1;
4192 if (value == 0)
4193 value = gen_reg_rtx (outmode);
4194 #else /* not PCC_STATIC_STRUCT_RETURN */
4195 struct_value_size = GET_MODE_SIZE (outmode);
4196 if (value != 0 && MEM_P (value))
4197 mem_value = value;
4198 else
4199 mem_value = assign_temp (tfom, 1, 1);
4200 #endif
4201 /* This call returns a big structure. */
4202 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4205 else
4206 tfom = void_type_node;
4208 /* ??? Unfinished: must pass the memory address as an argument. */
4210 /* Copy all the libcall-arguments out of the varargs data
4211 and into a vector ARGVEC.
4213 Compute how to pass each argument. We only support a very small subset
4214 of the full argument passing conventions to limit complexity here since
4215 library functions shouldn't have many args. */
4217 argvec = XALLOCAVEC (struct arg, nargs + 1);
4218 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4220 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4221 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4222 #else
4223 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4224 #endif
4225 args_so_far = pack_cumulative_args (&args_so_far_v);
4227 args_size.constant = 0;
4228 args_size.var = 0;
4230 count = 0;
4232 push_temp_slots ();
4234 /* If there's a structure value address to be passed,
4235 either pass it in the special place, or pass it as an extra argument. */
4236 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4238 rtx addr = XEXP (mem_value, 0);
4240 nargs++;
4242 /* Make sure it is a reasonable operand for a move or push insn. */
4243 if (!REG_P (addr) && !MEM_P (addr)
4244 && !(CONSTANT_P (addr)
4245 && targetm.legitimate_constant_p (Pmode, addr)))
4246 addr = force_operand (addr, NULL_RTX);
4248 argvec[count].value = addr;
4249 argvec[count].mode = Pmode;
4250 argvec[count].partial = 0;
4252 function_arg_info ptr_arg (Pmode, /*named=*/true);
4253 argvec[count].reg = targetm.calls.function_arg (args_so_far, ptr_arg);
4254 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, ptr_arg) == 0);
4256 locate_and_pad_parm (Pmode, NULL_TREE,
4257 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4259 #else
4260 argvec[count].reg != 0,
4261 #endif
4262 reg_parm_stack_space, 0,
4263 NULL_TREE, &args_size, &argvec[count].locate);
4265 if (argvec[count].reg == 0 || argvec[count].partial != 0
4266 || reg_parm_stack_space > 0)
4267 args_size.constant += argvec[count].locate.size.constant;
4269 targetm.calls.function_arg_advance (args_so_far, ptr_arg);
4271 count++;
4274 for (unsigned int i = 0; count < nargs; i++, count++)
4276 rtx val = args[i].first;
4277 function_arg_info arg (args[i].second, /*named=*/true);
4278 int unsigned_p = 0;
4280 /* We cannot convert the arg value to the mode the library wants here;
4281 must do it earlier where we know the signedness of the arg. */
4282 gcc_assert (arg.mode != BLKmode
4283 && (GET_MODE (val) == arg.mode
4284 || GET_MODE (val) == VOIDmode));
4286 /* Make sure it is a reasonable operand for a move or push insn. */
4287 if (!REG_P (val) && !MEM_P (val)
4288 && !(CONSTANT_P (val)
4289 && targetm.legitimate_constant_p (arg.mode, val)))
4290 val = force_operand (val, NULL_RTX);
4292 if (pass_by_reference (&args_so_far_v, arg))
4294 rtx slot;
4295 int must_copy = !reference_callee_copied (&args_so_far_v, arg);
4297 /* If this was a CONST function, it is now PURE since it now
4298 reads memory. */
4299 if (flags & ECF_CONST)
4301 flags &= ~ECF_CONST;
4302 flags |= ECF_PURE;
4305 if (MEM_P (val) && !must_copy)
4307 tree val_expr = MEM_EXPR (val);
4308 if (val_expr)
4309 mark_addressable (val_expr);
4310 slot = val;
4312 else
4314 slot = assign_temp (lang_hooks.types.type_for_mode (arg.mode, 0),
4315 1, 1);
4316 emit_move_insn (slot, val);
4319 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4320 gen_rtx_USE (VOIDmode, slot),
4321 call_fusage);
4322 if (must_copy)
4323 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4324 gen_rtx_CLOBBER (VOIDmode,
4325 slot),
4326 call_fusage);
4328 arg.mode = Pmode;
4329 arg.pass_by_reference = true;
4330 val = force_operand (XEXP (slot, 0), NULL_RTX);
4333 arg.mode = promote_function_mode (NULL_TREE, arg.mode, &unsigned_p,
4334 NULL_TREE, 0);
4335 argvec[count].mode = arg.mode;
4336 argvec[count].value = convert_modes (arg.mode, GET_MODE (val), val,
4337 unsigned_p);
4338 argvec[count].reg = targetm.calls.function_arg (args_so_far, arg);
4340 argvec[count].partial
4341 = targetm.calls.arg_partial_bytes (args_so_far, arg);
4343 if (argvec[count].reg == 0
4344 || argvec[count].partial != 0
4345 || reg_parm_stack_space > 0)
4347 locate_and_pad_parm (arg.mode, NULL_TREE,
4348 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4350 #else
4351 argvec[count].reg != 0,
4352 #endif
4353 reg_parm_stack_space, argvec[count].partial,
4354 NULL_TREE, &args_size, &argvec[count].locate);
4355 args_size.constant += argvec[count].locate.size.constant;
4356 gcc_assert (!argvec[count].locate.size.var);
4358 #ifdef BLOCK_REG_PADDING
4359 else
4360 /* The argument is passed entirely in registers. See at which
4361 end it should be padded. */
4362 argvec[count].locate.where_pad =
4363 BLOCK_REG_PADDING (arg.mode, NULL_TREE,
4364 known_le (GET_MODE_SIZE (arg.mode),
4365 UNITS_PER_WORD));
4366 #endif
4368 targetm.calls.function_arg_advance (args_so_far, arg);
4371 for (int i = 0; i < nargs; i++)
4372 if (reg_parm_stack_space > 0
4373 || argvec[i].reg == 0
4374 || argvec[i].partial != 0)
4375 update_stack_alignment_for_call (&argvec[i].locate);
4377 /* If this machine requires an external definition for library
4378 functions, write one out. */
4379 assemble_external_libcall (fun);
4381 original_args_size = args_size;
4382 args_size.constant = (aligned_upper_bound (args_size.constant
4383 + stack_pointer_delta,
4384 STACK_BYTES)
4385 - stack_pointer_delta);
4387 args_size.constant = upper_bound (args_size.constant,
4388 reg_parm_stack_space);
4390 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4391 args_size.constant -= reg_parm_stack_space;
4393 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
4394 args_size.constant);
4396 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
4398 poly_int64 pushed = args_size.constant + pending_stack_adjust;
4399 current_function_pushed_stack_size
4400 = upper_bound (current_function_pushed_stack_size, pushed);
4403 if (ACCUMULATE_OUTGOING_ARGS)
4405 /* Since the stack pointer will never be pushed, it is possible for
4406 the evaluation of a parm to clobber something we have already
4407 written to the stack. Since most function calls on RISC machines
4408 do not use the stack, this is uncommon, but must work correctly.
4410 Therefore, we save any area of the stack that was already written
4411 and that we are using. Here we set up to do this by making a new
4412 stack usage map from the old one.
4414 Another approach might be to try to reorder the argument
4415 evaluations to avoid this conflicting stack usage. */
4417 needed = args_size.constant;
4419 /* Since we will be writing into the entire argument area, the
4420 map must be allocated for its entire size, not just the part that
4421 is the responsibility of the caller. */
4422 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4423 needed += reg_parm_stack_space;
4425 poly_int64 limit = needed;
4426 if (ARGS_GROW_DOWNWARD)
4427 limit += 1;
4429 /* For polynomial sizes, this is the maximum possible size needed
4430 for arguments with a constant size and offset. */
4431 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
4432 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
4433 const_limit);
4435 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
4436 stack_usage_map = stack_usage_map_buf;
4438 if (initial_highest_arg_in_use)
4439 memcpy (stack_usage_map, initial_stack_usage_map,
4440 initial_highest_arg_in_use);
4442 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
4443 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
4444 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
4445 needed = 0;
4447 /* We must be careful to use virtual regs before they're instantiated,
4448 and real regs afterwards. Loop optimization, for example, can create
4449 new libcalls after we've instantiated the virtual regs, and if we
4450 use virtuals anyway, they won't match the rtl patterns. */
4452 if (virtuals_instantiated)
4453 argblock = plus_constant (Pmode, stack_pointer_rtx,
4454 STACK_POINTER_OFFSET);
4455 else
4456 argblock = virtual_outgoing_args_rtx;
4458 else
4460 if (!targetm.calls.push_argument (0))
4461 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
4464 /* We push args individually in reverse order, perform stack alignment
4465 before the first push (the last arg). */
4466 if (argblock == 0)
4467 anti_adjust_stack (gen_int_mode (args_size.constant
4468 - original_args_size.constant,
4469 Pmode));
4471 argnum = nargs - 1;
4473 #ifdef REG_PARM_STACK_SPACE
4474 if (ACCUMULATE_OUTGOING_ARGS)
4476 /* The argument list is the property of the called routine and it
4477 may clobber it. If the fixed area has been used for previous
4478 parameters, we must save and restore it. */
4479 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4480 &low_to_save, &high_to_save);
4482 #endif
4484 /* When expanding a normal call, args are stored in push order,
4485 which is the reverse of what we have here. */
4486 bool any_regs = false;
4487 for (int i = nargs; i-- > 0; )
4488 if (argvec[i].reg != NULL_RTX)
4490 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
4491 any_regs = true;
4493 if (!any_regs)
4494 targetm.calls.call_args (pc_rtx, NULL_TREE);
4496 /* Push the args that need to be pushed. */
4498 have_push_fusage = false;
4500 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4501 are to be pushed. */
4502 for (count = 0; count < nargs; count++, argnum--)
4504 machine_mode mode = argvec[argnum].mode;
4505 rtx val = argvec[argnum].value;
4506 rtx reg = argvec[argnum].reg;
4507 int partial = argvec[argnum].partial;
4508 unsigned int parm_align = argvec[argnum].locate.boundary;
4509 poly_int64 lower_bound = 0, upper_bound = 0;
4511 if (! (reg != 0 && partial == 0))
4513 rtx use;
4515 if (ACCUMULATE_OUTGOING_ARGS)
4517 /* If this is being stored into a pre-allocated, fixed-size,
4518 stack area, save any previous data at that location. */
4520 if (ARGS_GROW_DOWNWARD)
4522 /* stack_slot is negative, but we want to index stack_usage_map
4523 with positive values. */
4524 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
4525 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
4527 else
4529 lower_bound = argvec[argnum].locate.slot_offset.constant;
4530 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
4533 if (stack_region_maybe_used_p (lower_bound, upper_bound,
4534 reg_parm_stack_space))
4536 /* We need to make a save area. */
4537 poly_uint64 size
4538 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4539 machine_mode save_mode
4540 = int_mode_for_size (size, 1).else_blk ();
4541 rtx adr
4542 = plus_constant (Pmode, argblock,
4543 argvec[argnum].locate.offset.constant);
4544 rtx stack_area
4545 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4547 if (save_mode == BLKmode)
4549 argvec[argnum].save_area
4550 = assign_stack_temp (BLKmode,
4551 argvec[argnum].locate.size.constant
4554 emit_block_move (validize_mem
4555 (copy_rtx (argvec[argnum].save_area)),
4556 stack_area,
4557 (gen_int_mode
4558 (argvec[argnum].locate.size.constant,
4559 Pmode)),
4560 BLOCK_OP_CALL_PARM);
4562 else
4564 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4566 emit_move_insn (argvec[argnum].save_area, stack_area);
4571 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
4572 partial, reg, 0, argblock,
4573 (gen_int_mode
4574 (argvec[argnum].locate.offset.constant, Pmode)),
4575 reg_parm_stack_space,
4576 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
4578 /* Now mark the segment we just used. */
4579 if (ACCUMULATE_OUTGOING_ARGS)
4580 mark_stack_region_used (lower_bound, upper_bound);
4582 NO_DEFER_POP;
4584 /* Indicate argument access so that alias.cc knows that these
4585 values are live. */
4586 if (argblock)
4587 use = plus_constant (Pmode, argblock,
4588 argvec[argnum].locate.offset.constant);
4589 else if (have_push_fusage)
4590 continue;
4591 else
4593 /* When arguments are pushed, trying to tell alias.cc where
4594 exactly this argument is won't work, because the
4595 auto-increment causes confusion. So we merely indicate
4596 that we access something with a known mode somewhere on
4597 the stack. */
4598 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
4599 gen_rtx_SCRATCH (Pmode));
4600 have_push_fusage = true;
4602 use = gen_rtx_MEM (argvec[argnum].mode, use);
4603 use = gen_rtx_USE (VOIDmode, use);
4604 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
4608 argnum = nargs - 1;
4610 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
4612 /* Now load any reg parms into their regs. */
4614 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4615 are to be pushed. */
4616 for (count = 0; count < nargs; count++, argnum--)
4618 machine_mode mode = argvec[argnum].mode;
4619 rtx val = argvec[argnum].value;
4620 rtx reg = argvec[argnum].reg;
4621 int partial = argvec[argnum].partial;
4623 /* Handle calls that pass values in multiple non-contiguous
4624 locations. The PA64 has examples of this for library calls. */
4625 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4626 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
4627 else if (reg != 0 && partial == 0)
4629 emit_move_insn (reg, val);
4630 #ifdef BLOCK_REG_PADDING
4631 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
4633 /* Copied from load_register_parameters. */
4635 /* Handle case where we have a value that needs shifting
4636 up to the msb. eg. a QImode value and we're padding
4637 upward on a BYTES_BIG_ENDIAN machine. */
4638 if (known_lt (size, UNITS_PER_WORD)
4639 && (argvec[argnum].locate.where_pad
4640 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
4642 rtx x;
4643 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4645 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4646 report the whole reg as used. Strictly speaking, the
4647 call only uses SIZE bytes at the msb end, but it doesn't
4648 seem worth generating rtl to say that. */
4649 reg = gen_rtx_REG (word_mode, REGNO (reg));
4650 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
4651 if (x != reg)
4652 emit_move_insn (reg, x);
4654 #endif
4657 NO_DEFER_POP;
4660 /* Any regs containing parms remain in use through the call. */
4661 for (count = 0; count < nargs; count++)
4663 rtx reg = argvec[count].reg;
4664 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4665 use_group_regs (&call_fusage, reg);
4666 else if (reg != 0)
4668 int partial = argvec[count].partial;
4669 if (partial)
4671 int nregs;
4672 gcc_assert (partial % UNITS_PER_WORD == 0);
4673 nregs = partial / UNITS_PER_WORD;
4674 use_regs (&call_fusage, REGNO (reg), nregs);
4676 else
4677 use_reg (&call_fusage, reg);
4681 /* Pass the function the address in which to return a structure value. */
4682 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4684 emit_move_insn (struct_value,
4685 force_reg (Pmode,
4686 force_operand (XEXP (mem_value, 0),
4687 NULL_RTX)));
4688 if (REG_P (struct_value))
4689 use_reg (&call_fusage, struct_value);
4692 /* Don't allow popping to be deferred, since then
4693 cse'ing of library calls could delete a call and leave the pop. */
4694 NO_DEFER_POP;
4695 valreg = (mem_value == 0 && outmode != VOIDmode
4696 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
4698 /* Stack must be properly aligned now. */
4699 gcc_assert (multiple_p (stack_pointer_delta,
4700 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
4702 before_call = get_last_insn ();
4704 if (flag_callgraph_info)
4705 record_final_call (SYMBOL_REF_DECL (orgfun), UNKNOWN_LOCATION);
4707 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4708 will set inhibit_defer_pop to that value. */
4709 /* The return type is needed to decide how many bytes the function pops.
4710 Signedness plays no role in that, so for simplicity, we pretend it's
4711 always signed. We also assume that the list of arguments passed has
4712 no impact, so we pretend it is unknown. */
4714 emit_call_1 (fun, NULL,
4715 get_identifier (XSTR (orgfun, 0)),
4716 build_function_type (tfom, NULL_TREE),
4717 original_args_size.constant, args_size.constant,
4718 struct_value_size,
4719 targetm.calls.function_arg (args_so_far,
4720 function_arg_info::end_marker ()),
4721 valreg,
4722 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
4724 if (flag_ipa_ra)
4726 rtx datum = orgfun;
4727 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
4728 rtx_call_insn *last = last_call_insn ();
4729 add_reg_note (last, REG_CALL_DECL, datum);
4732 /* Right-shift returned value if necessary. */
4733 if (!pcc_struct_value
4734 && TYPE_MODE (tfom) != BLKmode
4735 && targetm.calls.return_in_msb (tfom))
4737 shift_return_value (TYPE_MODE (tfom), false, valreg);
4738 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
4741 targetm.calls.end_call_args ();
4743 /* For calls to `setjmp', etc., inform function.cc:setjmp_warnings
4744 that it should complain if nonvolatile values are live. For
4745 functions that cannot return, inform flow that control does not
4746 fall through. */
4747 if (flags & ECF_NORETURN)
4749 /* The barrier note must be emitted
4750 immediately after the CALL_INSN. Some ports emit more than
4751 just a CALL_INSN above, so we must search for it here. */
4752 rtx_insn *last = get_last_insn ();
4753 while (!CALL_P (last))
4755 last = PREV_INSN (last);
4756 /* There was no CALL_INSN? */
4757 gcc_assert (last != before_call);
4760 emit_barrier_after (last);
4763 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
4764 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
4765 if (flags & ECF_NOTHROW)
4767 rtx_insn *last = get_last_insn ();
4768 while (!CALL_P (last))
4770 last = PREV_INSN (last);
4771 /* There was no CALL_INSN? */
4772 gcc_assert (last != before_call);
4775 make_reg_eh_region_note_nothrow_nononlocal (last);
4778 /* Now restore inhibit_defer_pop to its actual original value. */
4779 OK_DEFER_POP;
4781 pop_temp_slots ();
4783 /* Copy the value to the right place. */
4784 if (outmode != VOIDmode && retval)
4786 if (mem_value)
4788 if (value == 0)
4789 value = mem_value;
4790 if (value != mem_value)
4791 emit_move_insn (value, mem_value);
4793 else if (GET_CODE (valreg) == PARALLEL)
4795 if (value == 0)
4796 value = gen_reg_rtx (outmode);
4797 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4799 else
4801 /* Convert to the proper mode if a promotion has been active. */
4802 if (GET_MODE (valreg) != outmode)
4804 int unsignedp = TYPE_UNSIGNED (tfom);
4806 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
4807 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
4808 == GET_MODE (valreg));
4809 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
4812 if (value != 0)
4813 emit_move_insn (value, valreg);
4814 else
4815 value = valreg;
4819 if (ACCUMULATE_OUTGOING_ARGS)
4821 #ifdef REG_PARM_STACK_SPACE
4822 if (save_area)
4823 restore_fixed_argument_area (save_area, argblock,
4824 high_to_save, low_to_save);
4825 #endif
4827 /* If we saved any argument areas, restore them. */
4828 for (count = 0; count < nargs; count++)
4829 if (argvec[count].save_area)
4831 machine_mode save_mode = GET_MODE (argvec[count].save_area);
4832 rtx adr = plus_constant (Pmode, argblock,
4833 argvec[count].locate.offset.constant);
4834 rtx stack_area = gen_rtx_MEM (save_mode,
4835 memory_address (save_mode, adr));
4837 if (save_mode == BLKmode)
4838 emit_block_move (stack_area,
4839 validize_mem
4840 (copy_rtx (argvec[count].save_area)),
4841 (gen_int_mode
4842 (argvec[count].locate.size.constant, Pmode)),
4843 BLOCK_OP_CALL_PARM);
4844 else
4845 emit_move_insn (stack_area, argvec[count].save_area);
4848 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4849 stack_usage_map = initial_stack_usage_map;
4850 stack_usage_watermark = initial_stack_usage_watermark;
4853 free (stack_usage_map_buf);
4855 return value;
4860 /* Store a single argument for a function call
4861 into the register or memory area where it must be passed.
4862 *ARG describes the argument value and where to pass it.
4864 ARGBLOCK is the address of the stack-block for all the arguments,
4865 or 0 on a machine where arguments are pushed individually.
4867 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4868 so must be careful about how the stack is used.
4870 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4871 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4872 that we need not worry about saving and restoring the stack.
4874 FNDECL is the declaration of the function we are calling.
4876 Return nonzero if this arg should cause sibcall failure,
4877 zero otherwise. */
4879 static int
4880 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4881 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4883 tree pval = arg->tree_value;
4884 rtx reg = 0;
4885 int partial = 0;
4886 poly_int64 used = 0;
4887 poly_int64 lower_bound = 0, upper_bound = 0;
4888 int sibcall_failure = 0;
4890 if (TREE_CODE (pval) == ERROR_MARK)
4891 return 1;
4893 /* Push a new temporary level for any temporaries we make for
4894 this argument. */
4895 push_temp_slots ();
4897 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4899 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4900 save any previous data at that location. */
4901 if (argblock && ! variable_size && arg->stack)
4903 if (ARGS_GROW_DOWNWARD)
4905 /* stack_slot is negative, but we want to index stack_usage_map
4906 with positive values. */
4907 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4909 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
4910 upper_bound = -rtx_to_poly_int64 (offset) + 1;
4912 else
4913 upper_bound = 0;
4915 lower_bound = upper_bound - arg->locate.size.constant;
4917 else
4919 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4921 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
4922 lower_bound = rtx_to_poly_int64 (offset);
4924 else
4925 lower_bound = 0;
4927 upper_bound = lower_bound + arg->locate.size.constant;
4930 if (stack_region_maybe_used_p (lower_bound, upper_bound,
4931 reg_parm_stack_space))
4933 /* We need to make a save area. */
4934 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
4935 machine_mode save_mode
4936 = int_mode_for_size (size, 1).else_blk ();
4937 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4938 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4940 if (save_mode == BLKmode)
4942 arg->save_area
4943 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
4944 preserve_temp_slots (arg->save_area);
4945 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
4946 stack_area,
4947 (gen_int_mode
4948 (arg->locate.size.constant, Pmode)),
4949 BLOCK_OP_CALL_PARM);
4951 else
4953 arg->save_area = gen_reg_rtx (save_mode);
4954 emit_move_insn (arg->save_area, stack_area);
4960 /* If this isn't going to be placed on both the stack and in registers,
4961 set up the register and number of words. */
4962 if (! arg->pass_on_stack)
4964 if (flags & ECF_SIBCALL)
4965 reg = arg->tail_call_reg;
4966 else
4967 reg = arg->reg;
4968 partial = arg->partial;
4971 /* Being passed entirely in a register. We shouldn't be called in
4972 this case. */
4973 gcc_assert (reg == 0 || partial != 0);
4975 /* If this arg needs special alignment, don't load the registers
4976 here. */
4977 if (arg->n_aligned_regs != 0)
4978 reg = 0;
4980 /* If this is being passed partially in a register, we can't evaluate
4981 it directly into its stack slot. Otherwise, we can. */
4982 if (arg->value == 0)
4984 /* stack_arg_under_construction is nonzero if a function argument is
4985 being evaluated directly into the outgoing argument list and
4986 expand_call must take special action to preserve the argument list
4987 if it is called recursively.
4989 For scalar function arguments stack_usage_map is sufficient to
4990 determine which stack slots must be saved and restored. Scalar
4991 arguments in general have pass_on_stack == 0.
4993 If this argument is initialized by a function which takes the
4994 address of the argument (a C++ constructor or a C function
4995 returning a BLKmode structure), then stack_usage_map is
4996 insufficient and expand_call must push the stack around the
4997 function call. Such arguments have pass_on_stack == 1.
4999 Note that it is always safe to set stack_arg_under_construction,
5000 but this generates suboptimal code if set when not needed. */
5002 if (arg->pass_on_stack)
5003 stack_arg_under_construction++;
5005 arg->value = expand_expr (pval,
5006 (partial
5007 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5008 ? NULL_RTX : arg->stack,
5009 VOIDmode, EXPAND_STACK_PARM);
5011 /* If we are promoting object (or for any other reason) the mode
5012 doesn't agree, convert the mode. */
5014 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5015 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5016 arg->value, arg->unsignedp);
5018 if (arg->pass_on_stack)
5019 stack_arg_under_construction--;
5022 /* Check for overlap with already clobbered argument area. */
5023 if ((flags & ECF_SIBCALL)
5024 && MEM_P (arg->value)
5025 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5026 arg->locate.size.constant))
5027 sibcall_failure = 1;
5029 /* Don't allow anything left on stack from computation
5030 of argument to alloca. */
5031 if (flags & ECF_MAY_BE_ALLOCA)
5032 do_pending_stack_adjust ();
5034 if (arg->value == arg->stack)
5035 /* If the value is already in the stack slot, we are done. */
5037 else if (arg->mode != BLKmode)
5039 unsigned int parm_align;
5041 /* Argument is a scalar, not entirely passed in registers.
5042 (If part is passed in registers, arg->partial says how much
5043 and emit_push_insn will take care of putting it there.)
5045 Push it, and if its size is less than the
5046 amount of space allocated to it,
5047 also bump stack pointer by the additional space.
5048 Note that in C the default argument promotions
5049 will prevent such mismatches. */
5051 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5052 ? 0 : GET_MODE_SIZE (arg->mode));
5054 /* Compute how much space the push instruction will push.
5055 On many machines, pushing a byte will advance the stack
5056 pointer by a halfword. */
5057 #ifdef PUSH_ROUNDING
5058 size = PUSH_ROUNDING (size);
5059 #endif
5060 used = size;
5062 /* Compute how much space the argument should get:
5063 round up to a multiple of the alignment for arguments. */
5064 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5065 != PAD_NONE)
5066 /* At the moment we don't (need to) support ABIs for which the
5067 padding isn't known at compile time. In principle it should
5068 be easy to add though. */
5069 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5071 /* Compute the alignment of the pushed argument. */
5072 parm_align = arg->locate.boundary;
5073 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5074 == PAD_DOWNWARD)
5076 poly_int64 pad = used - size;
5077 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5078 if (pad_align != 0)
5079 parm_align = MIN (parm_align, pad_align);
5082 /* This isn't already where we want it on the stack, so put it there.
5083 This can either be done with push or copy insns. */
5084 if (maybe_ne (used, 0)
5085 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5086 NULL_RTX, parm_align, partial, reg, used - size,
5087 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5088 reg_parm_stack_space,
5089 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5090 sibcall_failure = 1;
5092 /* Unless this is a partially-in-register argument, the argument is now
5093 in the stack. */
5094 if (partial == 0)
5095 arg->value = arg->stack;
5097 else
5099 /* BLKmode, at least partly to be pushed. */
5101 unsigned int parm_align;
5102 poly_int64 excess;
5103 rtx size_rtx;
5105 /* Pushing a nonscalar.
5106 If part is passed in registers, PARTIAL says how much
5107 and emit_push_insn will take care of putting it there. */
5109 /* Round its size up to a multiple
5110 of the allocation unit for arguments. */
5112 if (arg->locate.size.var != 0)
5114 excess = 0;
5115 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5117 else
5119 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5120 for BLKmode is careful to avoid it. */
5121 excess = (arg->locate.size.constant
5122 - arg_int_size_in_bytes (TREE_TYPE (pval))
5123 + partial);
5124 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5125 NULL_RTX, TYPE_MODE (sizetype),
5126 EXPAND_NORMAL);
5129 parm_align = arg->locate.boundary;
5131 /* When an argument is padded down, the block is aligned to
5132 PARM_BOUNDARY, but the actual argument isn't. */
5133 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5134 == PAD_DOWNWARD)
5136 if (arg->locate.size.var)
5137 parm_align = BITS_PER_UNIT;
5138 else
5140 unsigned int excess_align
5141 = known_alignment (excess) * BITS_PER_UNIT;
5142 if (excess_align != 0)
5143 parm_align = MIN (parm_align, excess_align);
5147 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5149 /* emit_push_insn might not work properly if arg->value and
5150 argblock + arg->locate.offset areas overlap. */
5151 rtx x = arg->value;
5152 poly_int64 i = 0;
5154 if (strip_offset (XEXP (x, 0), &i)
5155 == crtl->args.internal_arg_pointer)
5157 /* arg.locate doesn't contain the pretend_args_size offset,
5158 it's part of argblock. Ensure we don't count it in I. */
5159 if (STACK_GROWS_DOWNWARD)
5160 i -= crtl->args.pretend_args_size;
5161 else
5162 i += crtl->args.pretend_args_size;
5164 /* expand_call should ensure this. */
5165 gcc_assert (!arg->locate.offset.var
5166 && arg->locate.size.var == 0);
5167 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5169 if (known_eq (arg->locate.offset.constant, i))
5171 /* Even though they appear to be at the same location,
5172 if part of the outgoing argument is in registers,
5173 they aren't really at the same location. Check for
5174 this by making sure that the incoming size is the
5175 same as the outgoing size. */
5176 if (maybe_ne (arg->locate.size.constant, size_val))
5177 sibcall_failure = 1;
5179 else if (maybe_in_range_p (arg->locate.offset.constant,
5180 i, size_val))
5181 sibcall_failure = 1;
5182 /* Use arg->locate.size.constant instead of size_rtx
5183 because we only care about the part of the argument
5184 on the stack. */
5185 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5186 arg->locate.size.constant))
5187 sibcall_failure = 1;
5191 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5192 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5193 parm_align, partial, reg, excess, argblock,
5194 ARGS_SIZE_RTX (arg->locate.offset),
5195 reg_parm_stack_space,
5196 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5197 /* If we bypass emit_push_insn because it is a zero sized argument,
5198 we still might need to adjust stack if such argument requires
5199 extra alignment. See PR104558. */
5200 else if ((arg->locate.alignment_pad.var
5201 || maybe_ne (arg->locate.alignment_pad.constant, 0))
5202 && !argblock)
5203 anti_adjust_stack (ARGS_SIZE_RTX (arg->locate.alignment_pad));
5205 /* Unless this is a partially-in-register argument, the argument is now
5206 in the stack.
5208 ??? Unlike the case above, in which we want the actual
5209 address of the data, so that we can load it directly into a
5210 register, here we want the address of the stack slot, so that
5211 it's properly aligned for word-by-word copying or something
5212 like that. It's not clear that this is always correct. */
5213 if (partial == 0)
5214 arg->value = arg->stack_slot;
5217 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5219 tree type = TREE_TYPE (arg->tree_value);
5220 arg->parallel_value
5221 = emit_group_load_into_temps (arg->reg, arg->value, type,
5222 int_size_in_bytes (type));
5225 /* Mark all slots this store used. */
5226 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5227 && argblock && ! variable_size && arg->stack)
5228 mark_stack_region_used (lower_bound, upper_bound);
5230 /* Once we have pushed something, pops can't safely
5231 be deferred during the rest of the arguments. */
5232 NO_DEFER_POP;
5234 /* Free any temporary slots made in processing this argument. */
5235 pop_temp_slots ();
5237 return sibcall_failure;
5240 /* Nonzero if we do not know how to pass ARG solely in registers. */
5242 bool
5243 must_pass_in_stack_var_size (const function_arg_info &arg)
5245 if (!arg.type)
5246 return false;
5248 /* If the type has variable size... */
5249 if (!poly_int_tree_p (TYPE_SIZE (arg.type)))
5250 return true;
5252 /* If the type is marked as addressable (it is required
5253 to be constructed into the stack)... */
5254 if (TREE_ADDRESSABLE (arg.type))
5255 return true;
5257 return false;
5260 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5261 takes trailing padding of a structure into account. */
5262 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5264 bool
5265 must_pass_in_stack_var_size_or_pad (const function_arg_info &arg)
5267 if (!arg.type)
5268 return false;
5270 /* If the type has variable size... */
5271 if (TREE_CODE (TYPE_SIZE (arg.type)) != INTEGER_CST)
5272 return true;
5274 /* If the type is marked as addressable (it is required
5275 to be constructed into the stack)... */
5276 if (TREE_ADDRESSABLE (arg.type))
5277 return true;
5279 if (TYPE_EMPTY_P (arg.type))
5280 return false;
5282 /* If the padding and mode of the type is such that a copy into
5283 a register would put it into the wrong part of the register. */
5284 if (arg.mode == BLKmode
5285 && int_size_in_bytes (arg.type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5286 && (targetm.calls.function_arg_padding (arg.mode, arg.type)
5287 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5288 return true;
5290 return false;
5293 /* Return true if TYPE must be passed on the stack when passed to
5294 the "..." arguments of a function. */
5296 bool
5297 must_pass_va_arg_in_stack (tree type)
5299 function_arg_info arg (type, /*named=*/false);
5300 return targetm.calls.must_pass_in_stack (arg);
5303 /* Return true if FIELD is the C++17 empty base field that should
5304 be ignored for ABI calling convention decisions in order to
5305 maintain ABI compatibility between C++14 and earlier, which doesn't
5306 add this FIELD to classes with empty bases, and C++17 and later
5307 which does. */
5309 bool
5310 cxx17_empty_base_field_p (const_tree field)
5312 return (DECL_FIELD_ABI_IGNORED (field)
5313 && DECL_ARTIFICIAL (field)
5314 && RECORD_OR_UNION_TYPE_P (TREE_TYPE (field))
5315 && !lookup_attribute ("no_unique_address", DECL_ATTRIBUTES (field)));