2018-07-13 Richard Biener <rguenther@suse.de>
[official-gcc.git] / gcc / calls.c
blob2a08822d310f4b7e448949b69ece562f42364a1b
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2018 Free Software Foundation, Inc.
4 This file is part of GCC.
6 GCC is free software; you can redistribute it and/or modify it under
7 the terms of the GNU General Public License as published by the Free
8 Software Foundation; either version 3, or (at your option) any later
9 version.
11 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 for more details.
16 You should have received a copy of the GNU General Public License
17 along with GCC; see the file COPYING3. If not see
18 <http://www.gnu.org/licenses/>. */
20 #include "config.h"
21 #include "system.h"
22 #include "coretypes.h"
23 #include "backend.h"
24 #include "target.h"
25 #include "rtl.h"
26 #include "tree.h"
27 #include "gimple.h"
28 #include "predict.h"
29 #include "memmodel.h"
30 #include "tm_p.h"
31 #include "stringpool.h"
32 #include "expmed.h"
33 #include "optabs.h"
34 #include "emit-rtl.h"
35 #include "cgraph.h"
36 #include "diagnostic-core.h"
37 #include "fold-const.h"
38 #include "stor-layout.h"
39 #include "varasm.h"
40 #include "internal-fn.h"
41 #include "dojump.h"
42 #include "explow.h"
43 #include "calls.h"
44 #include "expr.h"
45 #include "output.h"
46 #include "langhooks.h"
47 #include "except.h"
48 #include "dbgcnt.h"
49 #include "rtl-iter.h"
50 #include "tree-vrp.h"
51 #include "tree-ssanames.h"
52 #include "tree-ssa-strlen.h"
53 #include "intl.h"
54 #include "stringpool.h"
55 #include "attribs.h"
56 #include "builtins.h"
57 #include "gimple-fold.h"
59 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
60 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
62 /* Data structure and subroutines used within expand_call. */
64 struct arg_data
66 /* Tree node for this argument. */
67 tree tree_value;
68 /* Mode for value; TYPE_MODE unless promoted. */
69 machine_mode mode;
70 /* Current RTL value for argument, or 0 if it isn't precomputed. */
71 rtx value;
72 /* Initially-compute RTL value for argument; only for const functions. */
73 rtx initial_value;
74 /* Register to pass this argument in, 0 if passed on stack, or an
75 PARALLEL if the arg is to be copied into multiple non-contiguous
76 registers. */
77 rtx reg;
78 /* Register to pass this argument in when generating tail call sequence.
79 This is not the same register as for normal calls on machines with
80 register windows. */
81 rtx tail_call_reg;
82 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
83 form for emit_group_move. */
84 rtx parallel_value;
85 /* If value is passed in neither reg nor stack, this field holds a number
86 of a special slot to be used. */
87 rtx special_slot;
88 /* For pointer bounds hold an index of parm bounds are bound to. -1 if
89 there is no such pointer. */
90 int pointer_arg;
91 /* If pointer_arg refers a structure, then pointer_offset holds an offset
92 of a pointer in this structure. */
93 int pointer_offset;
94 /* If REG was promoted from the actual mode of the argument expression,
95 indicates whether the promotion is sign- or zero-extended. */
96 int unsignedp;
97 /* Number of bytes to put in registers. 0 means put the whole arg
98 in registers. Also 0 if not passed in registers. */
99 int partial;
100 /* Nonzero if argument must be passed on stack.
101 Note that some arguments may be passed on the stack
102 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
103 pass_on_stack identifies arguments that *cannot* go in registers. */
104 int pass_on_stack;
105 /* Some fields packaged up for locate_and_pad_parm. */
106 struct locate_and_pad_arg_data locate;
107 /* Location on the stack at which parameter should be stored. The store
108 has already been done if STACK == VALUE. */
109 rtx stack;
110 /* Location on the stack of the start of this argument slot. This can
111 differ from STACK if this arg pads downward. This location is known
112 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
113 rtx stack_slot;
114 /* Place that this stack area has been saved, if needed. */
115 rtx save_area;
116 /* If an argument's alignment does not permit direct copying into registers,
117 copy in smaller-sized pieces into pseudos. These are stored in a
118 block pointed to by this field. The next field says how many
119 word-sized pseudos we made. */
120 rtx *aligned_regs;
121 int n_aligned_regs;
124 /* A vector of one char per byte of stack space. A byte if nonzero if
125 the corresponding stack location has been used.
126 This vector is used to prevent a function call within an argument from
127 clobbering any stack already set up. */
128 static char *stack_usage_map;
130 /* Size of STACK_USAGE_MAP. */
131 static unsigned int highest_outgoing_arg_in_use;
133 /* Assume that any stack location at this byte index is used,
134 without checking the contents of stack_usage_map. */
135 static unsigned HOST_WIDE_INT stack_usage_watermark = HOST_WIDE_INT_M1U;
137 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
138 stack location's tail call argument has been already stored into the stack.
139 This bitmap is used to prevent sibling call optimization if function tries
140 to use parent's incoming argument slots when they have been already
141 overwritten with tail call arguments. */
142 static sbitmap stored_args_map;
144 /* Assume that any virtual-incoming location at this byte index has been
145 stored, without checking the contents of stored_args_map. */
146 static unsigned HOST_WIDE_INT stored_args_watermark;
148 /* stack_arg_under_construction is nonzero when an argument may be
149 initialized with a constructor call (including a C function that
150 returns a BLKmode struct) and expand_call must take special action
151 to make sure the object being constructed does not overlap the
152 argument list for the constructor call. */
153 static int stack_arg_under_construction;
155 static void precompute_register_parameters (int, struct arg_data *, int *);
156 static int store_one_arg (struct arg_data *, rtx, int, int, int);
157 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
158 static int finalize_must_preallocate (int, int, struct arg_data *,
159 struct args_size *);
160 static void precompute_arguments (int, struct arg_data *);
161 static void compute_argument_addresses (struct arg_data *, rtx, int);
162 static rtx rtx_for_function_call (tree, tree);
163 static void load_register_parameters (struct arg_data *, int, rtx *, int,
164 int, int *);
165 static int special_function_p (const_tree, int);
166 static int check_sibcall_argument_overlap_1 (rtx);
167 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
169 static tree split_complex_types (tree);
171 #ifdef REG_PARM_STACK_SPACE
172 static rtx save_fixed_argument_area (int, rtx, int *, int *);
173 static void restore_fixed_argument_area (rtx, rtx, int, int);
174 #endif
176 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
177 stack region might already be in use. */
179 static bool
180 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
181 unsigned int reg_parm_stack_space)
183 unsigned HOST_WIDE_INT const_lower, const_upper;
184 const_lower = constant_lower_bound (lower_bound);
185 if (!upper_bound.is_constant (&const_upper))
186 const_upper = HOST_WIDE_INT_M1U;
188 if (const_upper > stack_usage_watermark)
189 return true;
191 /* Don't worry about things in the fixed argument area;
192 it has already been saved. */
193 const_lower = MAX (const_lower, reg_parm_stack_space);
194 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
195 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
196 if (stack_usage_map[i])
197 return true;
198 return false;
201 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
202 stack region are now in use. */
204 static void
205 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
207 unsigned HOST_WIDE_INT const_lower, const_upper;
208 const_lower = constant_lower_bound (lower_bound);
209 if (upper_bound.is_constant (&const_upper))
210 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
211 stack_usage_map[i] = 1;
212 else
213 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
216 /* Force FUNEXP into a form suitable for the address of a CALL,
217 and return that as an rtx. Also load the static chain register
218 if FNDECL is a nested function.
220 CALL_FUSAGE points to a variable holding the prospective
221 CALL_INSN_FUNCTION_USAGE information. */
224 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
225 rtx *call_fusage, int reg_parm_seen, int flags)
227 /* Make a valid memory address and copy constants through pseudo-regs,
228 but not for a constant address if -fno-function-cse. */
229 if (GET_CODE (funexp) != SYMBOL_REF)
231 /* If it's an indirect call by descriptor, generate code to perform
232 runtime identification of the pointer and load the descriptor. */
233 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
235 const int bit_val = targetm.calls.custom_function_descriptors;
236 rtx call_lab = gen_label_rtx ();
238 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
239 fndecl_or_type
240 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
241 fndecl_or_type);
242 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
243 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
245 if (GET_MODE (funexp) != Pmode)
246 funexp = convert_memory_address (Pmode, funexp);
248 /* Avoid long live ranges around function calls. */
249 funexp = copy_to_mode_reg (Pmode, funexp);
251 if (REG_P (chain))
252 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
254 /* Emit the runtime identification pattern. */
255 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
256 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
257 call_lab);
259 /* Statically predict the branch to very likely taken. */
260 rtx_insn *insn = get_last_insn ();
261 if (JUMP_P (insn))
262 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
264 /* Load the descriptor. */
265 rtx mem = gen_rtx_MEM (ptr_mode,
266 plus_constant (Pmode, funexp, - bit_val));
267 MEM_NOTRAP_P (mem) = 1;
268 mem = convert_memory_address (Pmode, mem);
269 emit_move_insn (chain, mem);
271 mem = gen_rtx_MEM (ptr_mode,
272 plus_constant (Pmode, funexp,
273 POINTER_SIZE / BITS_PER_UNIT
274 - bit_val));
275 MEM_NOTRAP_P (mem) = 1;
276 mem = convert_memory_address (Pmode, mem);
277 emit_move_insn (funexp, mem);
279 emit_label (call_lab);
281 if (REG_P (chain))
283 use_reg (call_fusage, chain);
284 STATIC_CHAIN_REG_P (chain) = 1;
287 /* Make sure we're not going to be overwritten below. */
288 gcc_assert (!static_chain_value);
291 /* If we are using registers for parameters, force the
292 function address into a register now. */
293 funexp = ((reg_parm_seen
294 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
295 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
296 : memory_address (FUNCTION_MODE, funexp));
298 else
300 /* funexp could be a SYMBOL_REF represents a function pointer which is
301 of ptr_mode. In this case, it should be converted into address mode
302 to be a valid address for memory rtx pattern. See PR 64971. */
303 if (GET_MODE (funexp) != Pmode)
304 funexp = convert_memory_address (Pmode, funexp);
306 if (!(flags & ECF_SIBCALL))
308 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
309 funexp = force_reg (Pmode, funexp);
313 if (static_chain_value != 0
314 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
315 || DECL_STATIC_CHAIN (fndecl_or_type)))
317 rtx chain;
319 chain = targetm.calls.static_chain (fndecl_or_type, false);
320 static_chain_value = convert_memory_address (Pmode, static_chain_value);
322 emit_move_insn (chain, static_chain_value);
323 if (REG_P (chain))
325 use_reg (call_fusage, chain);
326 STATIC_CHAIN_REG_P (chain) = 1;
330 return funexp;
333 /* Generate instructions to call function FUNEXP,
334 and optionally pop the results.
335 The CALL_INSN is the first insn generated.
337 FNDECL is the declaration node of the function. This is given to the
338 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
339 its own args.
341 FUNTYPE is the data type of the function. This is given to the hook
342 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
343 own args. We used to allow an identifier for library functions, but
344 that doesn't work when the return type is an aggregate type and the
345 calling convention says that the pointer to this aggregate is to be
346 popped by the callee.
348 STACK_SIZE is the number of bytes of arguments on the stack,
349 ROUNDED_STACK_SIZE is that number rounded up to
350 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
351 both to put into the call insn and to generate explicit popping
352 code if necessary.
354 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
355 It is zero if this call doesn't want a structure value.
357 NEXT_ARG_REG is the rtx that results from executing
358 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
359 just after all the args have had their registers assigned.
360 This could be whatever you like, but normally it is the first
361 arg-register beyond those used for args in this call,
362 or 0 if all the arg-registers are used in this call.
363 It is passed on to `gen_call' so you can put this info in the call insn.
365 VALREG is a hard register in which a value is returned,
366 or 0 if the call does not return a value.
368 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
369 the args to this call were processed.
370 We restore `inhibit_defer_pop' to that value.
372 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
373 denote registers used by the called function. */
375 static void
376 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
377 tree funtype ATTRIBUTE_UNUSED,
378 poly_int64 stack_size ATTRIBUTE_UNUSED,
379 poly_int64 rounded_stack_size,
380 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
381 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
382 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
383 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
385 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
386 rtx call, funmem, pat;
387 int already_popped = 0;
388 poly_int64 n_popped = 0;
390 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
391 patterns exist). Any popping that the callee does on return will
392 be from our caller's frame rather than ours. */
393 if (!(ecf_flags & ECF_SIBCALL))
395 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
397 #ifdef CALL_POPS_ARGS
398 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
399 #endif
402 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
403 and we don't want to load it into a register as an optimization,
404 because prepare_call_address already did it if it should be done. */
405 if (GET_CODE (funexp) != SYMBOL_REF)
406 funexp = memory_address (FUNCTION_MODE, funexp);
408 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
409 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
411 tree t = fndecl;
413 /* Although a built-in FUNCTION_DECL and its non-__builtin
414 counterpart compare equal and get a shared mem_attrs, they
415 produce different dump output in compare-debug compilations,
416 if an entry gets garbage collected in one compilation, then
417 adds a different (but equivalent) entry, while the other
418 doesn't run the garbage collector at the same spot and then
419 shares the mem_attr with the equivalent entry. */
420 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
422 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
423 if (t2)
424 t = t2;
427 set_mem_expr (funmem, t);
429 else if (fntree)
430 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
432 if (ecf_flags & ECF_SIBCALL)
434 if (valreg)
435 pat = targetm.gen_sibcall_value (valreg, funmem,
436 rounded_stack_size_rtx,
437 next_arg_reg, NULL_RTX);
438 else
439 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
440 next_arg_reg,
441 gen_int_mode (struct_value_size, Pmode));
443 /* If the target has "call" or "call_value" insns, then prefer them
444 if no arguments are actually popped. If the target does not have
445 "call" or "call_value" insns, then we must use the popping versions
446 even if the call has no arguments to pop. */
447 else if (maybe_ne (n_popped, 0)
448 || !(valreg
449 ? targetm.have_call_value ()
450 : targetm.have_call ()))
452 rtx n_pop = gen_int_mode (n_popped, Pmode);
454 /* If this subroutine pops its own args, record that in the call insn
455 if possible, for the sake of frame pointer elimination. */
457 if (valreg)
458 pat = targetm.gen_call_value_pop (valreg, funmem,
459 rounded_stack_size_rtx,
460 next_arg_reg, n_pop);
461 else
462 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
463 next_arg_reg, n_pop);
465 already_popped = 1;
467 else
469 if (valreg)
470 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
471 next_arg_reg, NULL_RTX);
472 else
473 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
474 gen_int_mode (struct_value_size, Pmode));
476 emit_insn (pat);
478 /* Find the call we just emitted. */
479 rtx_call_insn *call_insn = last_call_insn ();
481 /* Some target create a fresh MEM instead of reusing the one provided
482 above. Set its MEM_EXPR. */
483 call = get_call_rtx_from (call_insn);
484 if (call
485 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
486 && MEM_EXPR (funmem) != NULL_TREE)
487 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
489 /* Put the register usage information there. */
490 add_function_usage_to (call_insn, call_fusage);
492 /* If this is a const call, then set the insn's unchanging bit. */
493 if (ecf_flags & ECF_CONST)
494 RTL_CONST_CALL_P (call_insn) = 1;
496 /* If this is a pure call, then set the insn's unchanging bit. */
497 if (ecf_flags & ECF_PURE)
498 RTL_PURE_CALL_P (call_insn) = 1;
500 /* If this is a const call, then set the insn's unchanging bit. */
501 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
502 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
504 /* Create a nothrow REG_EH_REGION note, if needed. */
505 make_reg_eh_region_note (call_insn, ecf_flags, 0);
507 if (ecf_flags & ECF_NORETURN)
508 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
510 if (ecf_flags & ECF_RETURNS_TWICE)
512 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
513 cfun->calls_setjmp = 1;
516 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
518 /* Restore this now, so that we do defer pops for this call's args
519 if the context of the call as a whole permits. */
520 inhibit_defer_pop = old_inhibit_defer_pop;
522 if (maybe_ne (n_popped, 0))
524 if (!already_popped)
525 CALL_INSN_FUNCTION_USAGE (call_insn)
526 = gen_rtx_EXPR_LIST (VOIDmode,
527 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
528 CALL_INSN_FUNCTION_USAGE (call_insn));
529 rounded_stack_size -= n_popped;
530 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
531 stack_pointer_delta -= n_popped;
533 add_args_size_note (call_insn, stack_pointer_delta);
535 /* If popup is needed, stack realign must use DRAP */
536 if (SUPPORTS_STACK_ALIGNMENT)
537 crtl->need_drap = true;
539 /* For noreturn calls when not accumulating outgoing args force
540 REG_ARGS_SIZE note to prevent crossjumping of calls with different
541 args sizes. */
542 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
543 add_args_size_note (call_insn, stack_pointer_delta);
545 if (!ACCUMULATE_OUTGOING_ARGS)
547 /* If returning from the subroutine does not automatically pop the args,
548 we need an instruction to pop them sooner or later.
549 Perhaps do it now; perhaps just record how much space to pop later.
551 If returning from the subroutine does pop the args, indicate that the
552 stack pointer will be changed. */
554 if (maybe_ne (rounded_stack_size, 0))
556 if (ecf_flags & ECF_NORETURN)
557 /* Just pretend we did the pop. */
558 stack_pointer_delta -= rounded_stack_size;
559 else if (flag_defer_pop && inhibit_defer_pop == 0
560 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
561 pending_stack_adjust += rounded_stack_size;
562 else
563 adjust_stack (rounded_stack_size_rtx);
566 /* When we accumulate outgoing args, we must avoid any stack manipulations.
567 Restore the stack pointer to its original value now. Usually
568 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
569 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
570 popping variants of functions exist as well.
572 ??? We may optimize similar to defer_pop above, but it is
573 probably not worthwhile.
575 ??? It will be worthwhile to enable combine_stack_adjustments even for
576 such machines. */
577 else if (maybe_ne (n_popped, 0))
578 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
581 /* Determine if the function identified by FNDECL is one with
582 special properties we wish to know about. Modify FLAGS accordingly.
584 For example, if the function might return more than one time (setjmp), then
585 set ECF_RETURNS_TWICE.
587 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
588 space from the stack such as alloca. */
590 static int
591 special_function_p (const_tree fndecl, int flags)
593 tree name_decl = DECL_NAME (fndecl);
595 if (fndecl && name_decl
596 && IDENTIFIER_LENGTH (name_decl) <= 11
597 /* Exclude functions not at the file scope, or not `extern',
598 since they are not the magic functions we would otherwise
599 think they are.
600 FIXME: this should be handled with attributes, not with this
601 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
602 because you can declare fork() inside a function if you
603 wish. */
604 && (DECL_CONTEXT (fndecl) == NULL_TREE
605 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
606 && TREE_PUBLIC (fndecl))
608 const char *name = IDENTIFIER_POINTER (name_decl);
609 const char *tname = name;
611 /* We assume that alloca will always be called by name. It
612 makes no sense to pass it as a pointer-to-function to
613 anything that does not understand its behavior. */
614 if (IDENTIFIER_LENGTH (name_decl) == 6
615 && name[0] == 'a'
616 && ! strcmp (name, "alloca"))
617 flags |= ECF_MAY_BE_ALLOCA;
619 /* Disregard prefix _ or __. */
620 if (name[0] == '_')
622 if (name[1] == '_')
623 tname += 2;
624 else
625 tname += 1;
628 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
629 if (! strcmp (tname, "setjmp")
630 || ! strcmp (tname, "sigsetjmp")
631 || ! strcmp (name, "savectx")
632 || ! strcmp (name, "vfork")
633 || ! strcmp (name, "getcontext"))
634 flags |= ECF_RETURNS_TWICE;
637 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
638 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
639 flags |= ECF_MAY_BE_ALLOCA;
641 return flags;
644 /* Similar to special_function_p; return a set of ERF_ flags for the
645 function FNDECL. */
646 static int
647 decl_return_flags (tree fndecl)
649 tree attr;
650 tree type = TREE_TYPE (fndecl);
651 if (!type)
652 return 0;
654 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
655 if (!attr)
656 return 0;
658 attr = TREE_VALUE (TREE_VALUE (attr));
659 if (!attr || TREE_STRING_LENGTH (attr) < 1)
660 return 0;
662 switch (TREE_STRING_POINTER (attr)[0])
664 case '1':
665 case '2':
666 case '3':
667 case '4':
668 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
670 case 'm':
671 return ERF_NOALIAS;
673 case '.':
674 default:
675 return 0;
679 /* Return nonzero when FNDECL represents a call to setjmp. */
682 setjmp_call_p (const_tree fndecl)
684 if (DECL_IS_RETURNS_TWICE (fndecl))
685 return ECF_RETURNS_TWICE;
686 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
690 /* Return true if STMT may be an alloca call. */
692 bool
693 gimple_maybe_alloca_call_p (const gimple *stmt)
695 tree fndecl;
697 if (!is_gimple_call (stmt))
698 return false;
700 fndecl = gimple_call_fndecl (stmt);
701 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
702 return true;
704 return false;
707 /* Return true if STMT is a builtin alloca call. */
709 bool
710 gimple_alloca_call_p (const gimple *stmt)
712 tree fndecl;
714 if (!is_gimple_call (stmt))
715 return false;
717 fndecl = gimple_call_fndecl (stmt);
718 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
719 switch (DECL_FUNCTION_CODE (fndecl))
721 CASE_BUILT_IN_ALLOCA:
722 return gimple_call_num_args (stmt) > 0;
723 default:
724 break;
727 return false;
730 /* Return true when exp contains a builtin alloca call. */
732 bool
733 alloca_call_p (const_tree exp)
735 tree fndecl;
736 if (TREE_CODE (exp) == CALL_EXPR
737 && (fndecl = get_callee_fndecl (exp))
738 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
739 switch (DECL_FUNCTION_CODE (fndecl))
741 CASE_BUILT_IN_ALLOCA:
742 return true;
743 default:
744 break;
747 return false;
750 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
751 function. Return FALSE otherwise. */
753 static bool
754 is_tm_builtin (const_tree fndecl)
756 if (fndecl == NULL)
757 return false;
759 if (decl_is_tm_clone (fndecl))
760 return true;
762 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
764 switch (DECL_FUNCTION_CODE (fndecl))
766 case BUILT_IN_TM_COMMIT:
767 case BUILT_IN_TM_COMMIT_EH:
768 case BUILT_IN_TM_ABORT:
769 case BUILT_IN_TM_IRREVOCABLE:
770 case BUILT_IN_TM_GETTMCLONE_IRR:
771 case BUILT_IN_TM_MEMCPY:
772 case BUILT_IN_TM_MEMMOVE:
773 case BUILT_IN_TM_MEMSET:
774 CASE_BUILT_IN_TM_STORE (1):
775 CASE_BUILT_IN_TM_STORE (2):
776 CASE_BUILT_IN_TM_STORE (4):
777 CASE_BUILT_IN_TM_STORE (8):
778 CASE_BUILT_IN_TM_STORE (FLOAT):
779 CASE_BUILT_IN_TM_STORE (DOUBLE):
780 CASE_BUILT_IN_TM_STORE (LDOUBLE):
781 CASE_BUILT_IN_TM_STORE (M64):
782 CASE_BUILT_IN_TM_STORE (M128):
783 CASE_BUILT_IN_TM_STORE (M256):
784 CASE_BUILT_IN_TM_LOAD (1):
785 CASE_BUILT_IN_TM_LOAD (2):
786 CASE_BUILT_IN_TM_LOAD (4):
787 CASE_BUILT_IN_TM_LOAD (8):
788 CASE_BUILT_IN_TM_LOAD (FLOAT):
789 CASE_BUILT_IN_TM_LOAD (DOUBLE):
790 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
791 CASE_BUILT_IN_TM_LOAD (M64):
792 CASE_BUILT_IN_TM_LOAD (M128):
793 CASE_BUILT_IN_TM_LOAD (M256):
794 case BUILT_IN_TM_LOG:
795 case BUILT_IN_TM_LOG_1:
796 case BUILT_IN_TM_LOG_2:
797 case BUILT_IN_TM_LOG_4:
798 case BUILT_IN_TM_LOG_8:
799 case BUILT_IN_TM_LOG_FLOAT:
800 case BUILT_IN_TM_LOG_DOUBLE:
801 case BUILT_IN_TM_LOG_LDOUBLE:
802 case BUILT_IN_TM_LOG_M64:
803 case BUILT_IN_TM_LOG_M128:
804 case BUILT_IN_TM_LOG_M256:
805 return true;
806 default:
807 break;
810 return false;
813 /* Detect flags (function attributes) from the function decl or type node. */
816 flags_from_decl_or_type (const_tree exp)
818 int flags = 0;
820 if (DECL_P (exp))
822 /* The function exp may have the `malloc' attribute. */
823 if (DECL_IS_MALLOC (exp))
824 flags |= ECF_MALLOC;
826 /* The function exp may have the `returns_twice' attribute. */
827 if (DECL_IS_RETURNS_TWICE (exp))
828 flags |= ECF_RETURNS_TWICE;
830 /* Process the pure and const attributes. */
831 if (TREE_READONLY (exp))
832 flags |= ECF_CONST;
833 if (DECL_PURE_P (exp))
834 flags |= ECF_PURE;
835 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
836 flags |= ECF_LOOPING_CONST_OR_PURE;
838 if (DECL_IS_NOVOPS (exp))
839 flags |= ECF_NOVOPS;
840 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
841 flags |= ECF_LEAF;
842 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
843 flags |= ECF_COLD;
845 if (TREE_NOTHROW (exp))
846 flags |= ECF_NOTHROW;
848 if (flag_tm)
850 if (is_tm_builtin (exp))
851 flags |= ECF_TM_BUILTIN;
852 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
853 || lookup_attribute ("transaction_pure",
854 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
855 flags |= ECF_TM_PURE;
858 flags = special_function_p (exp, flags);
860 else if (TYPE_P (exp))
862 if (TYPE_READONLY (exp))
863 flags |= ECF_CONST;
865 if (flag_tm
866 && ((flags & ECF_CONST) != 0
867 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
868 flags |= ECF_TM_PURE;
870 else
871 gcc_unreachable ();
873 if (TREE_THIS_VOLATILE (exp))
875 flags |= ECF_NORETURN;
876 if (flags & (ECF_CONST|ECF_PURE))
877 flags |= ECF_LOOPING_CONST_OR_PURE;
880 return flags;
883 /* Detect flags from a CALL_EXPR. */
886 call_expr_flags (const_tree t)
888 int flags;
889 tree decl = get_callee_fndecl (t);
891 if (decl)
892 flags = flags_from_decl_or_type (decl);
893 else if (CALL_EXPR_FN (t) == NULL_TREE)
894 flags = internal_fn_flags (CALL_EXPR_IFN (t));
895 else
897 tree type = TREE_TYPE (CALL_EXPR_FN (t));
898 if (type && TREE_CODE (type) == POINTER_TYPE)
899 flags = flags_from_decl_or_type (TREE_TYPE (type));
900 else
901 flags = 0;
902 if (CALL_EXPR_BY_DESCRIPTOR (t))
903 flags |= ECF_BY_DESCRIPTOR;
906 return flags;
909 /* Return true if TYPE should be passed by invisible reference. */
911 bool
912 pass_by_reference (CUMULATIVE_ARGS *ca, machine_mode mode,
913 tree type, bool named_arg)
915 if (type)
917 /* If this type contains non-trivial constructors, then it is
918 forbidden for the middle-end to create any new copies. */
919 if (TREE_ADDRESSABLE (type))
920 return true;
922 /* GCC post 3.4 passes *all* variable sized types by reference. */
923 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
924 return true;
926 /* If a record type should be passed the same as its first (and only)
927 member, use the type and mode of that member. */
928 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
930 type = TREE_TYPE (first_field (type));
931 mode = TYPE_MODE (type);
935 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), mode,
936 type, named_arg);
939 /* Return true if TYPE, which is passed by reference, should be callee
940 copied instead of caller copied. */
942 bool
943 reference_callee_copied (CUMULATIVE_ARGS *ca, machine_mode mode,
944 tree type, bool named_arg)
946 if (type && TREE_ADDRESSABLE (type))
947 return false;
948 return targetm.calls.callee_copies (pack_cumulative_args (ca), mode, type,
949 named_arg);
953 /* Precompute all register parameters as described by ARGS, storing values
954 into fields within the ARGS array.
956 NUM_ACTUALS indicates the total number elements in the ARGS array.
958 Set REG_PARM_SEEN if we encounter a register parameter. */
960 static void
961 precompute_register_parameters (int num_actuals, struct arg_data *args,
962 int *reg_parm_seen)
964 int i;
966 *reg_parm_seen = 0;
968 for (i = 0; i < num_actuals; i++)
969 if (args[i].reg != 0 && ! args[i].pass_on_stack)
971 *reg_parm_seen = 1;
973 if (args[i].value == 0)
975 push_temp_slots ();
976 args[i].value = expand_normal (args[i].tree_value);
977 preserve_temp_slots (args[i].value);
978 pop_temp_slots ();
981 /* If we are to promote the function arg to a wider mode,
982 do it now. */
984 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
985 args[i].value
986 = convert_modes (args[i].mode,
987 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
988 args[i].value, args[i].unsignedp);
990 /* If the value is a non-legitimate constant, force it into a
991 pseudo now. TLS symbols sometimes need a call to resolve. */
992 if (CONSTANT_P (args[i].value)
993 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
994 args[i].value = force_reg (args[i].mode, args[i].value);
996 /* If we're going to have to load the value by parts, pull the
997 parts into pseudos. The part extraction process can involve
998 non-trivial computation. */
999 if (GET_CODE (args[i].reg) == PARALLEL)
1001 tree type = TREE_TYPE (args[i].tree_value);
1002 args[i].parallel_value
1003 = emit_group_load_into_temps (args[i].reg, args[i].value,
1004 type, int_size_in_bytes (type));
1007 /* If the value is expensive, and we are inside an appropriately
1008 short loop, put the value into a pseudo and then put the pseudo
1009 into the hard reg.
1011 For small register classes, also do this if this call uses
1012 register parameters. This is to avoid reload conflicts while
1013 loading the parameters registers. */
1015 else if ((! (REG_P (args[i].value)
1016 || (GET_CODE (args[i].value) == SUBREG
1017 && REG_P (SUBREG_REG (args[i].value)))))
1018 && args[i].mode != BLKmode
1019 && (set_src_cost (args[i].value, args[i].mode,
1020 optimize_insn_for_speed_p ())
1021 > COSTS_N_INSNS (1))
1022 && ((*reg_parm_seen
1023 && targetm.small_register_classes_for_mode_p (args[i].mode))
1024 || optimize))
1025 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1029 #ifdef REG_PARM_STACK_SPACE
1031 /* The argument list is the property of the called routine and it
1032 may clobber it. If the fixed area has been used for previous
1033 parameters, we must save and restore it. */
1035 static rtx
1036 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1038 unsigned int low;
1039 unsigned int high;
1041 /* Compute the boundary of the area that needs to be saved, if any. */
1042 high = reg_parm_stack_space;
1043 if (ARGS_GROW_DOWNWARD)
1044 high += 1;
1046 if (high > highest_outgoing_arg_in_use)
1047 high = highest_outgoing_arg_in_use;
1049 for (low = 0; low < high; low++)
1050 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1052 int num_to_save;
1053 machine_mode save_mode;
1054 int delta;
1055 rtx addr;
1056 rtx stack_area;
1057 rtx save_area;
1059 while (stack_usage_map[--high] == 0)
1062 *low_to_save = low;
1063 *high_to_save = high;
1065 num_to_save = high - low + 1;
1067 /* If we don't have the required alignment, must do this
1068 in BLKmode. */
1069 scalar_int_mode imode;
1070 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1071 && (low & (MIN (GET_MODE_SIZE (imode),
1072 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1073 save_mode = imode;
1074 else
1075 save_mode = BLKmode;
1077 if (ARGS_GROW_DOWNWARD)
1078 delta = -high;
1079 else
1080 delta = low;
1082 addr = plus_constant (Pmode, argblock, delta);
1083 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1085 set_mem_align (stack_area, PARM_BOUNDARY);
1086 if (save_mode == BLKmode)
1088 save_area = assign_stack_temp (BLKmode, num_to_save);
1089 emit_block_move (validize_mem (save_area), stack_area,
1090 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1092 else
1094 save_area = gen_reg_rtx (save_mode);
1095 emit_move_insn (save_area, stack_area);
1098 return save_area;
1101 return NULL_RTX;
1104 static void
1105 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1107 machine_mode save_mode = GET_MODE (save_area);
1108 int delta;
1109 rtx addr, stack_area;
1111 if (ARGS_GROW_DOWNWARD)
1112 delta = -high_to_save;
1113 else
1114 delta = low_to_save;
1116 addr = plus_constant (Pmode, argblock, delta);
1117 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1118 set_mem_align (stack_area, PARM_BOUNDARY);
1120 if (save_mode != BLKmode)
1121 emit_move_insn (stack_area, save_area);
1122 else
1123 emit_block_move (stack_area, validize_mem (save_area),
1124 GEN_INT (high_to_save - low_to_save + 1),
1125 BLOCK_OP_CALL_PARM);
1127 #endif /* REG_PARM_STACK_SPACE */
1129 /* If any elements in ARGS refer to parameters that are to be passed in
1130 registers, but not in memory, and whose alignment does not permit a
1131 direct copy into registers. Copy the values into a group of pseudos
1132 which we will later copy into the appropriate hard registers.
1134 Pseudos for each unaligned argument will be stored into the array
1135 args[argnum].aligned_regs. The caller is responsible for deallocating
1136 the aligned_regs array if it is nonzero. */
1138 static void
1139 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1141 int i, j;
1143 for (i = 0; i < num_actuals; i++)
1144 if (args[i].reg != 0 && ! args[i].pass_on_stack
1145 && GET_CODE (args[i].reg) != PARALLEL
1146 && args[i].mode == BLKmode
1147 && MEM_P (args[i].value)
1148 && (MEM_ALIGN (args[i].value)
1149 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1151 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1152 int endian_correction = 0;
1154 if (args[i].partial)
1156 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1157 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1159 else
1161 args[i].n_aligned_regs
1162 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1165 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1167 /* Structures smaller than a word are normally aligned to the
1168 least significant byte. On a BYTES_BIG_ENDIAN machine,
1169 this means we must skip the empty high order bytes when
1170 calculating the bit offset. */
1171 if (bytes < UNITS_PER_WORD
1172 #ifdef BLOCK_REG_PADDING
1173 && (BLOCK_REG_PADDING (args[i].mode,
1174 TREE_TYPE (args[i].tree_value), 1)
1175 == PAD_DOWNWARD)
1176 #else
1177 && BYTES_BIG_ENDIAN
1178 #endif
1180 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1182 for (j = 0; j < args[i].n_aligned_regs; j++)
1184 rtx reg = gen_reg_rtx (word_mode);
1185 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1186 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1188 args[i].aligned_regs[j] = reg;
1189 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1190 word_mode, word_mode, false, NULL);
1192 /* There is no need to restrict this code to loading items
1193 in TYPE_ALIGN sized hunks. The bitfield instructions can
1194 load up entire word sized registers efficiently.
1196 ??? This may not be needed anymore.
1197 We use to emit a clobber here but that doesn't let later
1198 passes optimize the instructions we emit. By storing 0 into
1199 the register later passes know the first AND to zero out the
1200 bitfield being set in the register is unnecessary. The store
1201 of 0 will be deleted as will at least the first AND. */
1203 emit_move_insn (reg, const0_rtx);
1205 bytes -= bitsize / BITS_PER_UNIT;
1206 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1207 word_mode, word, false);
1212 /* The limit set by -Walloc-larger-than=. */
1213 static GTY(()) tree alloc_object_size_limit;
1215 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1216 setting if the option is specified, or to the maximum object size if it
1217 is not. Return the initialized value. */
1219 static tree
1220 alloc_max_size (void)
1222 if (alloc_object_size_limit)
1223 return alloc_object_size_limit;
1225 alloc_object_size_limit = max_object_size ();
1227 if (!warn_alloc_size_limit)
1228 return alloc_object_size_limit;
1230 const char *optname = "-Walloc-size-larger-than=";
1232 char *end = NULL;
1233 errno = 0;
1234 unsigned HOST_WIDE_INT unit = 1;
1235 unsigned HOST_WIDE_INT limit
1236 = strtoull (warn_alloc_size_limit, &end, 10);
1238 /* If the value is too large to be represented use the maximum
1239 representable value that strtoull sets limit to (setting
1240 errno to ERANGE). */
1242 if (end && *end)
1244 /* Numeric option arguments are at most INT_MAX. Make it
1245 possible to specify a larger value by accepting common
1246 suffixes. */
1247 if (!strcmp (end, "kB"))
1248 unit = 1000;
1249 else if (!strcasecmp (end, "KiB") || !strcmp (end, "KB"))
1250 unit = 1024;
1251 else if (!strcmp (end, "MB"))
1252 unit = HOST_WIDE_INT_UC (1000) * 1000;
1253 else if (!strcasecmp (end, "MiB"))
1254 unit = HOST_WIDE_INT_UC (1024) * 1024;
1255 else if (!strcasecmp (end, "GB"))
1256 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000;
1257 else if (!strcasecmp (end, "GiB"))
1258 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024;
1259 else if (!strcasecmp (end, "TB"))
1260 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000;
1261 else if (!strcasecmp (end, "TiB"))
1262 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024;
1263 else if (!strcasecmp (end, "PB"))
1264 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000;
1265 else if (!strcasecmp (end, "PiB"))
1266 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024;
1267 else if (!strcasecmp (end, "EB"))
1268 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000
1269 * 1000;
1270 else if (!strcasecmp (end, "EiB"))
1271 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024
1272 * 1024;
1273 else
1275 /* This could mean an unknown suffix or a bad prefix, like
1276 "+-1". */
1277 warning_at (UNKNOWN_LOCATION, 0,
1278 "invalid argument %qs to %qs",
1279 warn_alloc_size_limit, optname);
1281 /* Ignore the limit extracted by strtoull. */
1282 unit = 0;
1286 if (unit)
1288 widest_int w = wi::mul (limit, unit);
1289 if (w < wi::to_widest (alloc_object_size_limit))
1290 alloc_object_size_limit
1291 = wide_int_to_tree (ptrdiff_type_node, w);
1292 else
1293 alloc_object_size_limit = build_all_ones_cst (size_type_node);
1297 return alloc_object_size_limit;
1300 /* Return true when EXP's range can be determined and set RANGE[] to it
1301 after adjusting it if necessary to make EXP a represents a valid size
1302 of object, or a valid size argument to an allocation function declared
1303 with attribute alloc_size (whose argument may be signed), or to a string
1304 manipulation function like memset. When ALLOW_ZERO is true, allow
1305 returning a range of [0, 0] for a size in an anti-range [1, N] where
1306 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1307 allocation functions like malloc but it is a valid argument to
1308 functions like memset. */
1310 bool
1311 get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
1313 if (tree_fits_uhwi_p (exp))
1315 /* EXP is a constant. */
1316 range[0] = range[1] = exp;
1317 return true;
1320 tree exptype = TREE_TYPE (exp);
1321 bool integral = INTEGRAL_TYPE_P (exptype);
1323 wide_int min, max;
1324 enum value_range_type range_type;
1326 if (integral)
1327 range_type = determine_value_range (exp, &min, &max);
1328 else
1329 range_type = VR_VARYING;
1331 if (range_type == VR_VARYING)
1333 if (integral)
1335 /* Use the full range of the type of the expression when
1336 no value range information is available. */
1337 range[0] = TYPE_MIN_VALUE (exptype);
1338 range[1] = TYPE_MAX_VALUE (exptype);
1339 return true;
1342 range[0] = NULL_TREE;
1343 range[1] = NULL_TREE;
1344 return false;
1347 unsigned expprec = TYPE_PRECISION (exptype);
1349 bool signed_p = !TYPE_UNSIGNED (exptype);
1351 if (range_type == VR_ANTI_RANGE)
1353 if (signed_p)
1355 if (wi::les_p (max, 0))
1357 /* EXP is not in a strictly negative range. That means
1358 it must be in some (not necessarily strictly) positive
1359 range which includes zero. Since in signed to unsigned
1360 conversions negative values end up converted to large
1361 positive values, and otherwise they are not valid sizes,
1362 the resulting range is in both cases [0, TYPE_MAX]. */
1363 min = wi::zero (expprec);
1364 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1366 else if (wi::les_p (min - 1, 0))
1368 /* EXP is not in a negative-positive range. That means EXP
1369 is either negative, or greater than max. Since negative
1370 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1371 min = max + 1;
1372 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1374 else
1376 max = min - 1;
1377 min = wi::zero (expprec);
1380 else if (wi::eq_p (0, min - 1))
1382 /* EXP is unsigned and not in the range [1, MAX]. That means
1383 it's either zero or greater than MAX. Even though 0 would
1384 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1385 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1386 is greater than the limit the whole range is diagnosed. */
1387 if (allow_zero)
1388 min = max = wi::zero (expprec);
1389 else
1391 min = max + 1;
1392 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1395 else
1397 max = min - 1;
1398 min = wi::zero (expprec);
1402 range[0] = wide_int_to_tree (exptype, min);
1403 range[1] = wide_int_to_tree (exptype, max);
1405 return true;
1408 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1409 whose argument numbers given by IDX with values given by ARGS exceed
1410 the maximum object size or cause an unsigned oveflow (wrapping) when
1411 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1412 may be null for functions like malloc, and non-null for those like
1413 calloc that are decorated with a two-argument attribute alloc_size. */
1415 void
1416 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1418 /* The range each of the (up to) two arguments is known to be in. */
1419 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1421 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1422 tree maxobjsize = alloc_max_size ();
1424 location_t loc = EXPR_LOCATION (exp);
1426 bool warned = false;
1428 /* Validate each argument individually. */
1429 for (unsigned i = 0; i != 2 && args[i]; ++i)
1431 if (TREE_CODE (args[i]) == INTEGER_CST)
1433 argrange[i][0] = args[i];
1434 argrange[i][1] = args[i];
1436 if (tree_int_cst_lt (args[i], integer_zero_node))
1438 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1439 "%Kargument %i value %qE is negative",
1440 exp, idx[i] + 1, args[i]);
1442 else if (integer_zerop (args[i]))
1444 /* Avoid issuing -Walloc-zero for allocation functions other
1445 than __builtin_alloca that are declared with attribute
1446 returns_nonnull because there's no portability risk. This
1447 avoids warning for such calls to libiberty's xmalloc and
1448 friends.
1449 Also avoid issuing the warning for calls to function named
1450 "alloca". */
1451 if ((DECL_FUNCTION_CODE (fn) == BUILT_IN_ALLOCA
1452 && IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6)
1453 || (DECL_FUNCTION_CODE (fn) != BUILT_IN_ALLOCA
1454 && !lookup_attribute ("returns_nonnull",
1455 TYPE_ATTRIBUTES (TREE_TYPE (fn)))))
1456 warned = warning_at (loc, OPT_Walloc_zero,
1457 "%Kargument %i value is zero",
1458 exp, idx[i] + 1);
1460 else if (tree_int_cst_lt (maxobjsize, args[i]))
1462 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1463 mode and with -fno-exceptions as a way to indicate array
1464 size overflow. There's no good way to detect C++98 here
1465 so avoid diagnosing these calls for all C++ modes. */
1466 if (i == 0
1467 && !args[1]
1468 && lang_GNU_CXX ()
1469 && DECL_IS_OPERATOR_NEW (fn)
1470 && integer_all_onesp (args[i]))
1471 continue;
1473 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1474 "%Kargument %i value %qE exceeds "
1475 "maximum object size %E",
1476 exp, idx[i] + 1, args[i], maxobjsize);
1479 else if (TREE_CODE (args[i]) == SSA_NAME
1480 && get_size_range (args[i], argrange[i]))
1482 /* Verify that the argument's range is not negative (including
1483 upper bound of zero). */
1484 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1485 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1487 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1488 "%Kargument %i range [%E, %E] is negative",
1489 exp, idx[i] + 1,
1490 argrange[i][0], argrange[i][1]);
1492 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1494 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1495 "%Kargument %i range [%E, %E] exceeds "
1496 "maximum object size %E",
1497 exp, idx[i] + 1,
1498 argrange[i][0], argrange[i][1],
1499 maxobjsize);
1504 if (!argrange[0])
1505 return;
1507 /* For a two-argument alloc_size, validate the product of the two
1508 arguments if both of their values or ranges are known. */
1509 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1510 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1511 && !integer_onep (argrange[0][0])
1512 && !integer_onep (argrange[1][0]))
1514 /* Check for overflow in the product of a function decorated with
1515 attribute alloc_size (X, Y). */
1516 unsigned szprec = TYPE_PRECISION (size_type_node);
1517 wide_int x = wi::to_wide (argrange[0][0], szprec);
1518 wide_int y = wi::to_wide (argrange[1][0], szprec);
1520 wi::overflow_type vflow;
1521 wide_int prod = wi::umul (x, y, &vflow);
1523 if (vflow)
1524 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1525 "%Kproduct %<%E * %E%> of arguments %i and %i "
1526 "exceeds %<SIZE_MAX%>",
1527 exp, argrange[0][0], argrange[1][0],
1528 idx[0] + 1, idx[1] + 1);
1529 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1530 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1531 "%Kproduct %<%E * %E%> of arguments %i and %i "
1532 "exceeds maximum object size %E",
1533 exp, argrange[0][0], argrange[1][0],
1534 idx[0] + 1, idx[1] + 1,
1535 maxobjsize);
1537 if (warned)
1539 /* Print the full range of each of the two arguments to make
1540 it clear when it is, in fact, in a range and not constant. */
1541 if (argrange[0][0] != argrange [0][1])
1542 inform (loc, "argument %i in the range [%E, %E]",
1543 idx[0] + 1, argrange[0][0], argrange[0][1]);
1544 if (argrange[1][0] != argrange [1][1])
1545 inform (loc, "argument %i in the range [%E, %E]",
1546 idx[1] + 1, argrange[1][0], argrange[1][1]);
1550 if (warned)
1552 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1554 if (DECL_IS_BUILTIN (fn))
1555 inform (loc,
1556 "in a call to built-in allocation function %qD", fn);
1557 else
1558 inform (fnloc,
1559 "in a call to allocation function %qD declared here", fn);
1563 /* If EXPR refers to a character array or pointer declared attribute
1564 nonstring return a decl for that array or pointer and set *REF to
1565 the referenced enclosing object or pointer. Otherwise returns
1566 null. */
1568 tree
1569 get_attr_nonstring_decl (tree expr, tree *ref)
1571 tree decl = expr;
1572 if (TREE_CODE (decl) == SSA_NAME)
1574 gimple *def = SSA_NAME_DEF_STMT (decl);
1576 if (is_gimple_assign (def))
1578 tree_code code = gimple_assign_rhs_code (def);
1579 if (code == ADDR_EXPR
1580 || code == COMPONENT_REF
1581 || code == VAR_DECL)
1582 decl = gimple_assign_rhs1 (def);
1584 else if (tree var = SSA_NAME_VAR (decl))
1585 decl = var;
1588 if (TREE_CODE (decl) == ADDR_EXPR)
1589 decl = TREE_OPERAND (decl, 0);
1591 if (ref)
1592 *ref = decl;
1594 if (TREE_CODE (decl) == ARRAY_REF)
1595 decl = TREE_OPERAND (decl, 0);
1596 else if (TREE_CODE (decl) == COMPONENT_REF)
1597 decl = TREE_OPERAND (decl, 1);
1598 else if (TREE_CODE (decl) == MEM_REF)
1599 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1601 if (DECL_P (decl)
1602 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1603 return decl;
1605 return NULL_TREE;
1608 /* Warn about passing a non-string array/pointer to a function that
1609 expects a nul-terminated string argument. */
1611 void
1612 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1614 if (!fndecl || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
1615 return;
1617 if (TREE_NO_WARNING (exp))
1618 return;
1620 unsigned nargs = call_expr_nargs (exp);
1622 /* The bound argument to a bounded string function like strncpy. */
1623 tree bound = NULL_TREE;
1625 /* The range of lengths of a string argument to one of the comparison
1626 functions. If the length is less than the bound it is used instead. */
1627 tree lenrng[2] = { NULL_TREE, NULL_TREE };
1629 /* It's safe to call "bounded" string functions with a non-string
1630 argument since the functions provide an explicit bound for this
1631 purpose. The exception is strncat where the bound may refer to
1632 either the destination or the source. */
1633 int fncode = DECL_FUNCTION_CODE (fndecl);
1634 switch (fncode)
1636 case BUILT_IN_STRCMP:
1637 case BUILT_IN_STRNCMP:
1638 case BUILT_IN_STRNCASECMP:
1640 /* For these, if one argument refers to one or more of a set
1641 of string constants or arrays of known size, determine
1642 the range of their known or possible lengths and use it
1643 conservatively as the bound for the unbounded function,
1644 and to adjust the range of the bound of the bounded ones. */
1645 for (unsigned argno = 0; argno < nargs && !*lenrng; argno ++)
1647 tree arg = CALL_EXPR_ARG (exp, argno);
1648 if (!get_attr_nonstring_decl (arg))
1649 get_range_strlen (arg, lenrng);
1652 /* Fall through. */
1654 case BUILT_IN_STRNCAT:
1655 case BUILT_IN_STPNCPY:
1656 case BUILT_IN_STRNCPY:
1657 if (2 < nargs)
1658 bound = CALL_EXPR_ARG (exp, 2);
1659 break;
1661 case BUILT_IN_STRNDUP:
1662 if (1 < nargs)
1663 bound = CALL_EXPR_ARG (exp, 1);
1664 break;
1666 case BUILT_IN_STRNLEN:
1668 tree arg = CALL_EXPR_ARG (exp, 0);
1669 if (!get_attr_nonstring_decl (arg))
1670 get_range_strlen (arg, lenrng);
1672 if (1 < nargs)
1673 bound = CALL_EXPR_ARG (exp, 1);
1674 break;
1677 default:
1678 break;
1681 /* Determine the range of the bound argument (if specified). */
1682 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1683 if (bound)
1685 STRIP_NOPS (bound);
1686 get_size_range (bound, bndrng);
1689 location_t loc = EXPR_LOCATION (exp);
1691 if (bndrng[0])
1693 /* Diagnose excessive bound prior the adjustment below and
1694 regardless of attribute nonstring. */
1695 tree maxobjsize = max_object_size ();
1696 if (tree_int_cst_lt (maxobjsize, bndrng[0]))
1698 if (tree_int_cst_equal (bndrng[0], bndrng[1]))
1699 warning_at (loc, OPT_Wstringop_overflow_,
1700 "%K%qD specified bound %E "
1701 "exceeds maximum object size %E",
1702 exp, fndecl, bndrng[0], maxobjsize);
1703 else
1704 warning_at (loc, OPT_Wstringop_overflow_,
1705 "%K%qD specified bound [%E, %E] "
1706 "exceeds maximum object size %E",
1707 exp, fndecl, bndrng[0], bndrng[1], maxobjsize);
1708 return;
1712 if (*lenrng)
1714 /* Add one for the nul. */
1715 lenrng[0] = const_binop (PLUS_EXPR, TREE_TYPE (lenrng[0]),
1716 lenrng[0], size_one_node);
1717 lenrng[1] = const_binop (PLUS_EXPR, TREE_TYPE (lenrng[1]),
1718 lenrng[1], size_one_node);
1720 if (!bndrng[0])
1722 /* Conservatively use the upper bound of the lengths for
1723 both the lower and the upper bound of the operation. */
1724 bndrng[0] = lenrng[1];
1725 bndrng[1] = lenrng[1];
1726 bound = void_type_node;
1728 else
1730 /* Replace the bound on the operation with the upper bound
1731 of the length of the string if the latter is smaller. */
1732 if (tree_int_cst_lt (lenrng[1], bndrng[0]))
1733 bndrng[0] = lenrng[1];
1734 else if (tree_int_cst_lt (lenrng[1], bndrng[1]))
1735 bndrng[1] = lenrng[1];
1739 /* Iterate over the built-in function's formal arguments and check
1740 each const char* against the actual argument. If the actual
1741 argument is declared attribute non-string issue a warning unless
1742 the argument's maximum length is bounded. */
1743 function_args_iterator it;
1744 function_args_iter_init (&it, TREE_TYPE (fndecl));
1746 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1748 /* Avoid iterating past the declared argument in a call
1749 to function declared without a prototype. */
1750 if (argno >= nargs)
1751 break;
1753 tree argtype = function_args_iter_cond (&it);
1754 if (!argtype)
1755 break;
1757 if (TREE_CODE (argtype) != POINTER_TYPE)
1758 continue;
1760 argtype = TREE_TYPE (argtype);
1762 if (TREE_CODE (argtype) != INTEGER_TYPE
1763 || !TYPE_READONLY (argtype))
1764 continue;
1766 argtype = TYPE_MAIN_VARIANT (argtype);
1767 if (argtype != char_type_node)
1768 continue;
1770 tree callarg = CALL_EXPR_ARG (exp, argno);
1771 if (TREE_CODE (callarg) == ADDR_EXPR)
1772 callarg = TREE_OPERAND (callarg, 0);
1774 /* See if the destination is declared with attribute "nonstring". */
1775 tree decl = get_attr_nonstring_decl (callarg);
1776 if (!decl)
1777 continue;
1779 /* The maximum number of array elements accessed. */
1780 offset_int wibnd = 0;
1782 if (argno && fncode == BUILT_IN_STRNCAT)
1784 /* See if the bound in strncat is derived from the length
1785 of the strlen of the destination (as it's expected to be).
1786 If so, reset BOUND and FNCODE to trigger a warning. */
1787 tree dstarg = CALL_EXPR_ARG (exp, 0);
1788 if (is_strlen_related_p (dstarg, bound))
1790 /* The bound applies to the destination, not to the source,
1791 so reset these to trigger a warning without mentioning
1792 the bound. */
1793 bound = NULL;
1794 fncode = 0;
1796 else if (bndrng[1])
1797 /* Use the upper bound of the range for strncat. */
1798 wibnd = wi::to_offset (bndrng[1]);
1800 else if (bndrng[0])
1801 /* Use the lower bound of the range for functions other than
1802 strncat. */
1803 wibnd = wi::to_offset (bndrng[0]);
1805 /* Determine the size of the argument array if it is one. */
1806 offset_int asize = wibnd;
1807 bool known_size = false;
1808 tree type = TREE_TYPE (decl);
1810 /* Determine the array size. For arrays of unknown bound and
1811 pointers reset BOUND to trigger the appropriate warning. */
1812 if (TREE_CODE (type) == ARRAY_TYPE)
1814 if (tree arrbnd = TYPE_DOMAIN (type))
1816 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1818 asize = wi::to_offset (arrbnd) + 1;
1819 known_size = true;
1822 else if (bound == void_type_node)
1823 bound = NULL_TREE;
1825 else if (bound == void_type_node)
1826 bound = NULL_TREE;
1828 /* In a call to strncat with a bound in a range whose lower but
1829 not upper bound is less than the array size, reset ASIZE to
1830 be the same as the bound and the other variable to trigger
1831 the apprpriate warning below. */
1832 if (fncode == BUILT_IN_STRNCAT
1833 && bndrng[0] != bndrng[1]
1834 && wi::ltu_p (wi::to_offset (bndrng[0]), asize)
1835 && (!known_size
1836 || wi::ltu_p (asize, wibnd)))
1838 asize = wibnd;
1839 bound = NULL_TREE;
1840 fncode = 0;
1843 bool warned = false;
1845 if (wi::ltu_p (asize, wibnd))
1847 if (bndrng[0] == bndrng[1])
1848 warned = warning_at (loc, OPT_Wstringop_overflow_,
1849 "%qD argument %i declared attribute "
1850 "%<nonstring%> is smaller than the specified "
1851 "bound %wu",
1852 fndecl, argno + 1, wibnd.to_uhwi ());
1853 else if (wi::ltu_p (asize, wi::to_offset (bndrng[0])))
1854 warned = warning_at (loc, OPT_Wstringop_overflow_,
1855 "%qD argument %i declared attribute "
1856 "%<nonstring%> is smaller than "
1857 "the specified bound [%E, %E]",
1858 fndecl, argno + 1, bndrng[0], bndrng[1]);
1859 else
1860 warned = warning_at (loc, OPT_Wstringop_overflow_,
1861 "%qD argument %i declared attribute "
1862 "%<nonstring%> may be smaller than "
1863 "the specified bound [%E, %E]",
1864 fndecl, argno + 1, bndrng[0], bndrng[1]);
1866 else if (fncode == BUILT_IN_STRNCAT)
1867 ; /* Avoid warning for calls to strncat() when the bound
1868 is equal to the size of the non-string argument. */
1869 else if (!bound)
1870 warned = warning_at (loc, OPT_Wstringop_overflow_,
1871 "%qD argument %i declared attribute %<nonstring%>",
1872 fndecl, argno + 1);
1874 if (warned)
1875 inform (DECL_SOURCE_LOCATION (decl),
1876 "argument %qD declared here", decl);
1880 /* Issue an error if CALL_EXPR was flagged as requiring
1881 tall-call optimization. */
1883 static void
1884 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1886 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1887 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1888 return;
1890 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1893 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1894 CALL_EXPR EXP.
1896 NUM_ACTUALS is the total number of parameters.
1898 N_NAMED_ARGS is the total number of named arguments.
1900 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1901 value, or null.
1903 FNDECL is the tree code for the target of this call (if known)
1905 ARGS_SO_FAR holds state needed by the target to know where to place
1906 the next argument.
1908 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1909 for arguments which are passed in registers.
1911 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1912 and may be modified by this routine.
1914 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1915 flags which may be modified by this routine.
1917 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1918 that requires allocation of stack space.
1920 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1921 the thunked-to function. */
1923 static void
1924 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1925 struct arg_data *args,
1926 struct args_size *args_size,
1927 int n_named_args ATTRIBUTE_UNUSED,
1928 tree exp, tree struct_value_addr_value,
1929 tree fndecl, tree fntype,
1930 cumulative_args_t args_so_far,
1931 int reg_parm_stack_space,
1932 rtx *old_stack_level,
1933 poly_int64_pod *old_pending_adj,
1934 int *must_preallocate, int *ecf_flags,
1935 bool *may_tailcall, bool call_from_thunk_p)
1937 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1938 location_t loc = EXPR_LOCATION (exp);
1940 /* Count arg position in order args appear. */
1941 int argpos;
1943 int i;
1945 args_size->constant = 0;
1946 args_size->var = 0;
1948 bitmap_obstack_initialize (NULL);
1950 /* In this loop, we consider args in the order they are written.
1951 We fill up ARGS from the back. */
1953 i = num_actuals - 1;
1955 int j = i;
1956 call_expr_arg_iterator iter;
1957 tree arg;
1958 bitmap slots = NULL;
1960 if (struct_value_addr_value)
1962 args[j].tree_value = struct_value_addr_value;
1963 j--;
1965 argpos = 0;
1966 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1968 tree argtype = TREE_TYPE (arg);
1970 if (targetm.calls.split_complex_arg
1971 && argtype
1972 && TREE_CODE (argtype) == COMPLEX_TYPE
1973 && targetm.calls.split_complex_arg (argtype))
1975 tree subtype = TREE_TYPE (argtype);
1976 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1977 j--;
1978 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1980 else
1981 args[j].tree_value = arg;
1982 j--;
1983 argpos++;
1986 if (slots)
1987 BITMAP_FREE (slots);
1990 bitmap_obstack_release (NULL);
1992 /* Extract attribute alloc_size and if set, store the indices of
1993 the corresponding arguments in ALLOC_IDX, and then the actual
1994 argument(s) at those indices in ALLOC_ARGS. */
1995 int alloc_idx[2] = { -1, -1 };
1996 if (tree alloc_size
1997 = (fndecl ? lookup_attribute ("alloc_size",
1998 TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))
1999 : NULL_TREE))
2001 tree args = TREE_VALUE (alloc_size);
2002 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
2003 if (TREE_CHAIN (args))
2004 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
2007 /* Array for up to the two attribute alloc_size arguments. */
2008 tree alloc_args[] = { NULL_TREE, NULL_TREE };
2010 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
2011 for (argpos = 0; argpos < num_actuals; i--, argpos++)
2013 tree type = TREE_TYPE (args[i].tree_value);
2014 int unsignedp;
2015 machine_mode mode;
2017 /* Replace erroneous argument with constant zero. */
2018 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
2019 args[i].tree_value = integer_zero_node, type = integer_type_node;
2021 /* If TYPE is a transparent union or record, pass things the way
2022 we would pass the first field of the union or record. We have
2023 already verified that the modes are the same. */
2024 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
2025 && TYPE_TRANSPARENT_AGGR (type))
2026 type = TREE_TYPE (first_field (type));
2028 /* Decide where to pass this arg.
2030 args[i].reg is nonzero if all or part is passed in registers.
2032 args[i].partial is nonzero if part but not all is passed in registers,
2033 and the exact value says how many bytes are passed in registers.
2035 args[i].pass_on_stack is nonzero if the argument must at least be
2036 computed on the stack. It may then be loaded back into registers
2037 if args[i].reg is nonzero.
2039 These decisions are driven by the FUNCTION_... macros and must agree
2040 with those made by function.c. */
2042 /* See if this argument should be passed by invisible reference. */
2043 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
2044 type, argpos < n_named_args))
2046 bool callee_copies;
2047 tree base = NULL_TREE;
2049 callee_copies
2050 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
2051 type, argpos < n_named_args);
2053 /* If we're compiling a thunk, pass through invisible references
2054 instead of making a copy. */
2055 if (call_from_thunk_p
2056 || (callee_copies
2057 && !TREE_ADDRESSABLE (type)
2058 && (base = get_base_address (args[i].tree_value))
2059 && TREE_CODE (base) != SSA_NAME
2060 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
2062 /* We may have turned the parameter value into an SSA name.
2063 Go back to the original parameter so we can take the
2064 address. */
2065 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
2067 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
2068 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
2069 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
2071 /* Argument setup code may have copied the value to register. We
2072 revert that optimization now because the tail call code must
2073 use the original location. */
2074 if (TREE_CODE (args[i].tree_value) == PARM_DECL
2075 && !MEM_P (DECL_RTL (args[i].tree_value))
2076 && DECL_INCOMING_RTL (args[i].tree_value)
2077 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
2078 set_decl_rtl (args[i].tree_value,
2079 DECL_INCOMING_RTL (args[i].tree_value));
2081 mark_addressable (args[i].tree_value);
2083 /* We can't use sibcalls if a callee-copied argument is
2084 stored in the current function's frame. */
2085 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2087 *may_tailcall = false;
2088 maybe_complain_about_tail_call (exp,
2089 "a callee-copied argument is"
2090 " stored in the current"
2091 " function's frame");
2094 args[i].tree_value = build_fold_addr_expr_loc (loc,
2095 args[i].tree_value);
2096 type = TREE_TYPE (args[i].tree_value);
2098 if (*ecf_flags & ECF_CONST)
2099 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2101 else
2103 /* We make a copy of the object and pass the address to the
2104 function being called. */
2105 rtx copy;
2107 if (!COMPLETE_TYPE_P (type)
2108 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2109 || (flag_stack_check == GENERIC_STACK_CHECK
2110 && compare_tree_int (TYPE_SIZE_UNIT (type),
2111 STACK_CHECK_MAX_VAR_SIZE) > 0))
2113 /* This is a variable-sized object. Make space on the stack
2114 for it. */
2115 rtx size_rtx = expr_size (args[i].tree_value);
2117 if (*old_stack_level == 0)
2119 emit_stack_save (SAVE_BLOCK, old_stack_level);
2120 *old_pending_adj = pending_stack_adjust;
2121 pending_stack_adjust = 0;
2124 /* We can pass TRUE as the 4th argument because we just
2125 saved the stack pointer and will restore it right after
2126 the call. */
2127 copy = allocate_dynamic_stack_space (size_rtx,
2128 TYPE_ALIGN (type),
2129 TYPE_ALIGN (type),
2130 max_int_size_in_bytes
2131 (type),
2132 true);
2133 copy = gen_rtx_MEM (BLKmode, copy);
2134 set_mem_attributes (copy, type, 1);
2136 else
2137 copy = assign_temp (type, 1, 0);
2139 store_expr (args[i].tree_value, copy, 0, false, false);
2141 /* Just change the const function to pure and then let
2142 the next test clear the pure based on
2143 callee_copies. */
2144 if (*ecf_flags & ECF_CONST)
2146 *ecf_flags &= ~ECF_CONST;
2147 *ecf_flags |= ECF_PURE;
2150 if (!callee_copies && *ecf_flags & ECF_PURE)
2151 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2153 args[i].tree_value
2154 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2155 type = TREE_TYPE (args[i].tree_value);
2156 *may_tailcall = false;
2157 maybe_complain_about_tail_call (exp,
2158 "argument must be passed"
2159 " by copying");
2163 unsignedp = TYPE_UNSIGNED (type);
2164 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2165 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2167 args[i].unsignedp = unsignedp;
2168 args[i].mode = mode;
2170 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2172 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
2173 argpos < n_named_args);
2175 if (args[i].reg && CONST_INT_P (args[i].reg))
2177 args[i].special_slot = args[i].reg;
2178 args[i].reg = NULL;
2181 /* If this is a sibling call and the machine has register windows, the
2182 register window has to be unwinded before calling the routine, so
2183 arguments have to go into the incoming registers. */
2184 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2185 args[i].tail_call_reg
2186 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
2187 argpos < n_named_args);
2188 else
2189 args[i].tail_call_reg = args[i].reg;
2191 if (args[i].reg)
2192 args[i].partial
2193 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
2194 argpos < n_named_args);
2196 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
2198 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2199 it means that we are to pass this arg in the register(s) designated
2200 by the PARALLEL, but also to pass it in the stack. */
2201 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2202 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2203 args[i].pass_on_stack = 1;
2205 /* If this is an addressable type, we must preallocate the stack
2206 since we must evaluate the object into its final location.
2208 If this is to be passed in both registers and the stack, it is simpler
2209 to preallocate. */
2210 if (TREE_ADDRESSABLE (type)
2211 || (args[i].pass_on_stack && args[i].reg != 0))
2212 *must_preallocate = 1;
2214 /* Compute the stack-size of this argument. */
2215 if (args[i].reg == 0 || args[i].partial != 0
2216 || reg_parm_stack_space > 0
2217 || args[i].pass_on_stack)
2218 locate_and_pad_parm (mode, type,
2219 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2221 #else
2222 args[i].reg != 0,
2223 #endif
2224 reg_parm_stack_space,
2225 args[i].pass_on_stack ? 0 : args[i].partial,
2226 fndecl, args_size, &args[i].locate);
2227 #ifdef BLOCK_REG_PADDING
2228 else
2229 /* The argument is passed entirely in registers. See at which
2230 end it should be padded. */
2231 args[i].locate.where_pad =
2232 BLOCK_REG_PADDING (mode, type,
2233 int_size_in_bytes (type) <= UNITS_PER_WORD);
2234 #endif
2236 /* Update ARGS_SIZE, the total stack space for args so far. */
2238 args_size->constant += args[i].locate.size.constant;
2239 if (args[i].locate.size.var)
2240 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2242 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2243 have been used, etc. */
2245 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
2246 type, argpos < n_named_args);
2248 /* Store argument values for functions decorated with attribute
2249 alloc_size. */
2250 if (argpos == alloc_idx[0])
2251 alloc_args[0] = args[i].tree_value;
2252 else if (argpos == alloc_idx[1])
2253 alloc_args[1] = args[i].tree_value;
2256 if (alloc_args[0])
2258 /* Check the arguments of functions decorated with attribute
2259 alloc_size. */
2260 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2263 /* Detect passing non-string arguments to functions expecting
2264 nul-terminated strings. */
2265 maybe_warn_nonstring_arg (fndecl, exp);
2268 /* Update ARGS_SIZE to contain the total size for the argument block.
2269 Return the original constant component of the argument block's size.
2271 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2272 for arguments passed in registers. */
2274 static poly_int64
2275 compute_argument_block_size (int reg_parm_stack_space,
2276 struct args_size *args_size,
2277 tree fndecl ATTRIBUTE_UNUSED,
2278 tree fntype ATTRIBUTE_UNUSED,
2279 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2281 poly_int64 unadjusted_args_size = args_size->constant;
2283 /* For accumulate outgoing args mode we don't need to align, since the frame
2284 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2285 backends from generating misaligned frame sizes. */
2286 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2287 preferred_stack_boundary = STACK_BOUNDARY;
2289 /* Compute the actual size of the argument block required. The variable
2290 and constant sizes must be combined, the size may have to be rounded,
2291 and there may be a minimum required size. */
2293 if (args_size->var)
2295 args_size->var = ARGS_SIZE_TREE (*args_size);
2296 args_size->constant = 0;
2298 preferred_stack_boundary /= BITS_PER_UNIT;
2299 if (preferred_stack_boundary > 1)
2301 /* We don't handle this case yet. To handle it correctly we have
2302 to add the delta, round and subtract the delta.
2303 Currently no machine description requires this support. */
2304 gcc_assert (multiple_p (stack_pointer_delta,
2305 preferred_stack_boundary));
2306 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2309 if (reg_parm_stack_space > 0)
2311 args_size->var
2312 = size_binop (MAX_EXPR, args_size->var,
2313 ssize_int (reg_parm_stack_space));
2315 /* The area corresponding to register parameters is not to count in
2316 the size of the block we need. So make the adjustment. */
2317 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2318 args_size->var
2319 = size_binop (MINUS_EXPR, args_size->var,
2320 ssize_int (reg_parm_stack_space));
2323 else
2325 preferred_stack_boundary /= BITS_PER_UNIT;
2326 if (preferred_stack_boundary < 1)
2327 preferred_stack_boundary = 1;
2328 args_size->constant = (aligned_upper_bound (args_size->constant
2329 + stack_pointer_delta,
2330 preferred_stack_boundary)
2331 - stack_pointer_delta);
2333 args_size->constant = upper_bound (args_size->constant,
2334 reg_parm_stack_space);
2336 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2337 args_size->constant -= reg_parm_stack_space;
2339 return unadjusted_args_size;
2342 /* Precompute parameters as needed for a function call.
2344 FLAGS is mask of ECF_* constants.
2346 NUM_ACTUALS is the number of arguments.
2348 ARGS is an array containing information for each argument; this
2349 routine fills in the INITIAL_VALUE and VALUE fields for each
2350 precomputed argument. */
2352 static void
2353 precompute_arguments (int num_actuals, struct arg_data *args)
2355 int i;
2357 /* If this is a libcall, then precompute all arguments so that we do not
2358 get extraneous instructions emitted as part of the libcall sequence. */
2360 /* If we preallocated the stack space, and some arguments must be passed
2361 on the stack, then we must precompute any parameter which contains a
2362 function call which will store arguments on the stack.
2363 Otherwise, evaluating the parameter may clobber previous parameters
2364 which have already been stored into the stack. (we have code to avoid
2365 such case by saving the outgoing stack arguments, but it results in
2366 worse code) */
2367 if (!ACCUMULATE_OUTGOING_ARGS)
2368 return;
2370 for (i = 0; i < num_actuals; i++)
2372 tree type;
2373 machine_mode mode;
2375 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2376 continue;
2378 /* If this is an addressable type, we cannot pre-evaluate it. */
2379 type = TREE_TYPE (args[i].tree_value);
2380 gcc_assert (!TREE_ADDRESSABLE (type));
2382 args[i].initial_value = args[i].value
2383 = expand_normal (args[i].tree_value);
2385 mode = TYPE_MODE (type);
2386 if (mode != args[i].mode)
2388 int unsignedp = args[i].unsignedp;
2389 args[i].value
2390 = convert_modes (args[i].mode, mode,
2391 args[i].value, args[i].unsignedp);
2393 /* CSE will replace this only if it contains args[i].value
2394 pseudo, so convert it down to the declared mode using
2395 a SUBREG. */
2396 if (REG_P (args[i].value)
2397 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2398 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2400 args[i].initial_value
2401 = gen_lowpart_SUBREG (mode, args[i].value);
2402 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2403 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2409 /* Given the current state of MUST_PREALLOCATE and information about
2410 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2411 compute and return the final value for MUST_PREALLOCATE. */
2413 static int
2414 finalize_must_preallocate (int must_preallocate, int num_actuals,
2415 struct arg_data *args, struct args_size *args_size)
2417 /* See if we have or want to preallocate stack space.
2419 If we would have to push a partially-in-regs parm
2420 before other stack parms, preallocate stack space instead.
2422 If the size of some parm is not a multiple of the required stack
2423 alignment, we must preallocate.
2425 If the total size of arguments that would otherwise create a copy in
2426 a temporary (such as a CALL) is more than half the total argument list
2427 size, preallocation is faster.
2429 Another reason to preallocate is if we have a machine (like the m88k)
2430 where stack alignment is required to be maintained between every
2431 pair of insns, not just when the call is made. However, we assume here
2432 that such machines either do not have push insns (and hence preallocation
2433 would occur anyway) or the problem is taken care of with
2434 PUSH_ROUNDING. */
2436 if (! must_preallocate)
2438 int partial_seen = 0;
2439 poly_int64 copy_to_evaluate_size = 0;
2440 int i;
2442 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2444 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2445 partial_seen = 1;
2446 else if (partial_seen && args[i].reg == 0)
2447 must_preallocate = 1;
2449 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2450 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2451 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2452 || TREE_CODE (args[i].tree_value) == COND_EXPR
2453 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2454 copy_to_evaluate_size
2455 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2458 if (maybe_ne (args_size->constant, 0)
2459 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2460 must_preallocate = 1;
2462 return must_preallocate;
2465 /* If we preallocated stack space, compute the address of each argument
2466 and store it into the ARGS array.
2468 We need not ensure it is a valid memory address here; it will be
2469 validized when it is used.
2471 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2473 static void
2474 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2476 if (argblock)
2478 rtx arg_reg = argblock;
2479 int i;
2480 poly_int64 arg_offset = 0;
2482 if (GET_CODE (argblock) == PLUS)
2484 arg_reg = XEXP (argblock, 0);
2485 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2488 for (i = 0; i < num_actuals; i++)
2490 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2491 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2492 rtx addr;
2493 unsigned int align, boundary;
2494 poly_uint64 units_on_stack = 0;
2495 machine_mode partial_mode = VOIDmode;
2497 /* Skip this parm if it will not be passed on the stack. */
2498 if (! args[i].pass_on_stack
2499 && args[i].reg != 0
2500 && args[i].partial == 0)
2501 continue;
2503 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2504 continue;
2506 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2507 addr = plus_constant (Pmode, addr, arg_offset);
2509 if (args[i].partial != 0)
2511 /* Only part of the parameter is being passed on the stack.
2512 Generate a simple memory reference of the correct size. */
2513 units_on_stack = args[i].locate.size.constant;
2514 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2515 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2516 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2517 set_mem_size (args[i].stack, units_on_stack);
2519 else
2521 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2522 set_mem_attributes (args[i].stack,
2523 TREE_TYPE (args[i].tree_value), 1);
2525 align = BITS_PER_UNIT;
2526 boundary = args[i].locate.boundary;
2527 poly_int64 offset_val;
2528 if (args[i].locate.where_pad != PAD_DOWNWARD)
2529 align = boundary;
2530 else if (poly_int_rtx_p (offset, &offset_val))
2532 align = least_bit_hwi (boundary);
2533 unsigned int offset_align
2534 = known_alignment (offset_val) * BITS_PER_UNIT;
2535 if (offset_align != 0)
2536 align = MIN (align, offset_align);
2538 set_mem_align (args[i].stack, align);
2540 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2541 addr = plus_constant (Pmode, addr, arg_offset);
2543 if (args[i].partial != 0)
2545 /* Only part of the parameter is being passed on the stack.
2546 Generate a simple memory reference of the correct size.
2548 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2549 set_mem_size (args[i].stack_slot, units_on_stack);
2551 else
2553 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2554 set_mem_attributes (args[i].stack_slot,
2555 TREE_TYPE (args[i].tree_value), 1);
2557 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2559 /* Function incoming arguments may overlap with sibling call
2560 outgoing arguments and we cannot allow reordering of reads
2561 from function arguments with stores to outgoing arguments
2562 of sibling calls. */
2563 set_mem_alias_set (args[i].stack, 0);
2564 set_mem_alias_set (args[i].stack_slot, 0);
2569 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2570 in a call instruction.
2572 FNDECL is the tree node for the target function. For an indirect call
2573 FNDECL will be NULL_TREE.
2575 ADDR is the operand 0 of CALL_EXPR for this call. */
2577 static rtx
2578 rtx_for_function_call (tree fndecl, tree addr)
2580 rtx funexp;
2582 /* Get the function to call, in the form of RTL. */
2583 if (fndecl)
2585 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2586 TREE_USED (fndecl) = 1;
2588 /* Get a SYMBOL_REF rtx for the function address. */
2589 funexp = XEXP (DECL_RTL (fndecl), 0);
2591 else
2592 /* Generate an rtx (probably a pseudo-register) for the address. */
2594 push_temp_slots ();
2595 funexp = expand_normal (addr);
2596 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2598 return funexp;
2601 /* Return the static chain for this function, if any. */
2604 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2606 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2607 return NULL;
2609 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2612 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2613 static struct
2615 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2616 or NULL_RTX if none has been scanned yet. */
2617 rtx_insn *scan_start;
2618 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2619 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2620 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2621 with fixed offset, or PC if this is with variable or unknown offset. */
2622 vec<rtx> cache;
2623 } internal_arg_pointer_exp_state;
2625 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2627 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2628 the tail call sequence, starting with first insn that hasn't been
2629 scanned yet, and note for each pseudo on the LHS whether it is based
2630 on crtl->args.internal_arg_pointer or not, and what offset from that
2631 that pointer it has. */
2633 static void
2634 internal_arg_pointer_based_exp_scan (void)
2636 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2638 if (scan_start == NULL_RTX)
2639 insn = get_insns ();
2640 else
2641 insn = NEXT_INSN (scan_start);
2643 while (insn)
2645 rtx set = single_set (insn);
2646 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2648 rtx val = NULL_RTX;
2649 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2650 /* Punt on pseudos set multiple times. */
2651 if (idx < internal_arg_pointer_exp_state.cache.length ()
2652 && (internal_arg_pointer_exp_state.cache[idx]
2653 != NULL_RTX))
2654 val = pc_rtx;
2655 else
2656 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2657 if (val != NULL_RTX)
2659 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2660 internal_arg_pointer_exp_state.cache
2661 .safe_grow_cleared (idx + 1);
2662 internal_arg_pointer_exp_state.cache[idx] = val;
2665 if (NEXT_INSN (insn) == NULL_RTX)
2666 scan_start = insn;
2667 insn = NEXT_INSN (insn);
2670 internal_arg_pointer_exp_state.scan_start = scan_start;
2673 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2674 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2675 it with fixed offset, or PC if this is with variable or unknown offset.
2676 TOPLEVEL is true if the function is invoked at the topmost level. */
2678 static rtx
2679 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2681 if (CONSTANT_P (rtl))
2682 return NULL_RTX;
2684 if (rtl == crtl->args.internal_arg_pointer)
2685 return const0_rtx;
2687 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2688 return NULL_RTX;
2690 poly_int64 offset;
2691 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2693 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2694 if (val == NULL_RTX || val == pc_rtx)
2695 return val;
2696 return plus_constant (Pmode, val, offset);
2699 /* When called at the topmost level, scan pseudo assignments in between the
2700 last scanned instruction in the tail call sequence and the latest insn
2701 in that sequence. */
2702 if (toplevel)
2703 internal_arg_pointer_based_exp_scan ();
2705 if (REG_P (rtl))
2707 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2708 if (idx < internal_arg_pointer_exp_state.cache.length ())
2709 return internal_arg_pointer_exp_state.cache[idx];
2711 return NULL_RTX;
2714 subrtx_iterator::array_type array;
2715 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2717 const_rtx x = *iter;
2718 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2719 return pc_rtx;
2720 if (MEM_P (x))
2721 iter.skip_subrtxes ();
2724 return NULL_RTX;
2727 /* Return true if SIZE bytes starting from address ADDR might overlap an
2728 already-clobbered argument area. This function is used to determine
2729 if we should give up a sibcall. */
2731 static bool
2732 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2734 poly_int64 i;
2735 unsigned HOST_WIDE_INT start, end;
2736 rtx val;
2738 if (bitmap_empty_p (stored_args_map)
2739 && stored_args_watermark == HOST_WIDE_INT_M1U)
2740 return false;
2741 val = internal_arg_pointer_based_exp (addr, true);
2742 if (val == NULL_RTX)
2743 return false;
2744 else if (!poly_int_rtx_p (val, &i))
2745 return true;
2747 if (known_eq (size, 0U))
2748 return false;
2750 if (STACK_GROWS_DOWNWARD)
2751 i -= crtl->args.pretend_args_size;
2752 else
2753 i += crtl->args.pretend_args_size;
2755 if (ARGS_GROW_DOWNWARD)
2756 i = -i - size;
2758 /* We can ignore any references to the function's pretend args,
2759 which at this point would manifest as negative values of I. */
2760 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2761 return false;
2763 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2764 if (!(i + size).is_constant (&end))
2765 end = HOST_WIDE_INT_M1U;
2767 if (end > stored_args_watermark)
2768 return true;
2770 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2771 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2772 if (bitmap_bit_p (stored_args_map, k))
2773 return true;
2775 return false;
2778 /* Do the register loads required for any wholly-register parms or any
2779 parms which are passed both on the stack and in a register. Their
2780 expressions were already evaluated.
2782 Mark all register-parms as living through the call, putting these USE
2783 insns in the CALL_INSN_FUNCTION_USAGE field.
2785 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2786 checking, setting *SIBCALL_FAILURE if appropriate. */
2788 static void
2789 load_register_parameters (struct arg_data *args, int num_actuals,
2790 rtx *call_fusage, int flags, int is_sibcall,
2791 int *sibcall_failure)
2793 int i, j;
2795 for (i = 0; i < num_actuals; i++)
2797 rtx reg = ((flags & ECF_SIBCALL)
2798 ? args[i].tail_call_reg : args[i].reg);
2799 if (reg)
2801 int partial = args[i].partial;
2802 int nregs;
2803 poly_int64 size = 0;
2804 HOST_WIDE_INT const_size = 0;
2805 rtx_insn *before_arg = get_last_insn ();
2806 /* Set non-negative if we must move a word at a time, even if
2807 just one word (e.g, partial == 4 && mode == DFmode). Set
2808 to -1 if we just use a normal move insn. This value can be
2809 zero if the argument is a zero size structure. */
2810 nregs = -1;
2811 if (GET_CODE (reg) == PARALLEL)
2813 else if (partial)
2815 gcc_assert (partial % UNITS_PER_WORD == 0);
2816 nregs = partial / UNITS_PER_WORD;
2818 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
2820 /* Variable-sized parameters should be described by a
2821 PARALLEL instead. */
2822 const_size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2823 gcc_assert (const_size >= 0);
2824 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2825 size = const_size;
2827 else
2828 size = GET_MODE_SIZE (args[i].mode);
2830 /* Handle calls that pass values in multiple non-contiguous
2831 locations. The Irix 6 ABI has examples of this. */
2833 if (GET_CODE (reg) == PARALLEL)
2834 emit_group_move (reg, args[i].parallel_value);
2836 /* If simple case, just do move. If normal partial, store_one_arg
2837 has already loaded the register for us. In all other cases,
2838 load the register(s) from memory. */
2840 else if (nregs == -1)
2842 emit_move_insn (reg, args[i].value);
2843 #ifdef BLOCK_REG_PADDING
2844 /* Handle case where we have a value that needs shifting
2845 up to the msb. eg. a QImode value and we're padding
2846 upward on a BYTES_BIG_ENDIAN machine. */
2847 if (args[i].locate.where_pad
2848 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2850 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2851 if (maybe_lt (size, UNITS_PER_WORD))
2853 rtx x;
2854 poly_int64 shift
2855 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2857 /* Assigning REG here rather than a temp makes
2858 CALL_FUSAGE report the whole reg as used.
2859 Strictly speaking, the call only uses SIZE
2860 bytes at the msb end, but it doesn't seem worth
2861 generating rtl to say that. */
2862 reg = gen_rtx_REG (word_mode, REGNO (reg));
2863 x = expand_shift (LSHIFT_EXPR, word_mode,
2864 reg, shift, reg, 1);
2865 if (x != reg)
2866 emit_move_insn (reg, x);
2869 #endif
2872 /* If we have pre-computed the values to put in the registers in
2873 the case of non-aligned structures, copy them in now. */
2875 else if (args[i].n_aligned_regs != 0)
2876 for (j = 0; j < args[i].n_aligned_regs; j++)
2877 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2878 args[i].aligned_regs[j]);
2880 else if (partial == 0 || args[i].pass_on_stack)
2882 /* SIZE and CONST_SIZE are 0 for partial arguments and
2883 the size of a BLKmode type otherwise. */
2884 gcc_checking_assert (known_eq (size, const_size));
2885 rtx mem = validize_mem (copy_rtx (args[i].value));
2887 /* Check for overlap with already clobbered argument area,
2888 providing that this has non-zero size. */
2889 if (is_sibcall
2890 && const_size != 0
2891 && (mem_might_overlap_already_clobbered_arg_p
2892 (XEXP (args[i].value, 0), const_size)))
2893 *sibcall_failure = 1;
2895 if (const_size % UNITS_PER_WORD == 0
2896 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2897 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2898 else
2900 if (nregs > 1)
2901 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2902 args[i].mode);
2903 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2904 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2905 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2906 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2907 word_mode, word_mode, false,
2908 NULL);
2909 if (BYTES_BIG_ENDIAN)
2910 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2911 BITS_PER_WORD - bitsize, dest, 1);
2912 if (x != dest)
2913 emit_move_insn (dest, x);
2916 /* Handle a BLKmode that needs shifting. */
2917 if (nregs == 1 && const_size < UNITS_PER_WORD
2918 #ifdef BLOCK_REG_PADDING
2919 && args[i].locate.where_pad == PAD_DOWNWARD
2920 #else
2921 && BYTES_BIG_ENDIAN
2922 #endif
2925 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2926 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2927 enum tree_code dir = (BYTES_BIG_ENDIAN
2928 ? RSHIFT_EXPR : LSHIFT_EXPR);
2929 rtx x;
2931 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2932 if (x != dest)
2933 emit_move_insn (dest, x);
2937 /* When a parameter is a block, and perhaps in other cases, it is
2938 possible that it did a load from an argument slot that was
2939 already clobbered. */
2940 if (is_sibcall
2941 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2942 *sibcall_failure = 1;
2944 /* Handle calls that pass values in multiple non-contiguous
2945 locations. The Irix 6 ABI has examples of this. */
2946 if (GET_CODE (reg) == PARALLEL)
2947 use_group_regs (call_fusage, reg);
2948 else if (nregs == -1)
2949 use_reg_mode (call_fusage, reg,
2950 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
2951 else if (nregs > 0)
2952 use_regs (call_fusage, REGNO (reg), nregs);
2957 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2958 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2959 bytes, then we would need to push some additional bytes to pad the
2960 arguments. So, we try to compute an adjust to the stack pointer for an
2961 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2962 bytes. Then, when the arguments are pushed the stack will be perfectly
2963 aligned.
2965 Return true if this optimization is possible, storing the adjustment
2966 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2967 bytes that should be popped after the call. */
2969 static bool
2970 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2971 poly_int64 unadjusted_args_size,
2972 struct args_size *args_size,
2973 unsigned int preferred_unit_stack_boundary)
2975 /* The number of bytes to pop so that the stack will be
2976 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2977 poly_int64 adjustment;
2978 /* The alignment of the stack after the arguments are pushed, if we
2979 just pushed the arguments without adjust the stack here. */
2980 unsigned HOST_WIDE_INT unadjusted_alignment;
2982 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2983 preferred_unit_stack_boundary,
2984 &unadjusted_alignment))
2985 return false;
2987 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2988 as possible -- leaving just enough left to cancel out the
2989 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2990 PENDING_STACK_ADJUST is non-negative, and congruent to
2991 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2993 /* Begin by trying to pop all the bytes. */
2994 unsigned HOST_WIDE_INT tmp_misalignment;
2995 if (!known_misalignment (pending_stack_adjust,
2996 preferred_unit_stack_boundary,
2997 &tmp_misalignment))
2998 return false;
2999 unadjusted_alignment -= tmp_misalignment;
3000 adjustment = pending_stack_adjust;
3001 /* Push enough additional bytes that the stack will be aligned
3002 after the arguments are pushed. */
3003 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
3004 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
3006 /* We need to know whether the adjusted argument size
3007 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
3008 or a deallocation. */
3009 if (!ordered_p (adjustment, unadjusted_args_size))
3010 return false;
3012 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
3013 bytes after the call. The right number is the entire
3014 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
3015 by the arguments in the first place. */
3016 args_size->constant
3017 = pending_stack_adjust - adjustment + unadjusted_args_size;
3019 *adjustment_out = adjustment;
3020 return true;
3023 /* Scan X expression if it does not dereference any argument slots
3024 we already clobbered by tail call arguments (as noted in stored_args_map
3025 bitmap).
3026 Return nonzero if X expression dereferences such argument slots,
3027 zero otherwise. */
3029 static int
3030 check_sibcall_argument_overlap_1 (rtx x)
3032 RTX_CODE code;
3033 int i, j;
3034 const char *fmt;
3036 if (x == NULL_RTX)
3037 return 0;
3039 code = GET_CODE (x);
3041 /* We need not check the operands of the CALL expression itself. */
3042 if (code == CALL)
3043 return 0;
3045 if (code == MEM)
3046 return (mem_might_overlap_already_clobbered_arg_p
3047 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
3049 /* Scan all subexpressions. */
3050 fmt = GET_RTX_FORMAT (code);
3051 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
3053 if (*fmt == 'e')
3055 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
3056 return 1;
3058 else if (*fmt == 'E')
3060 for (j = 0; j < XVECLEN (x, i); j++)
3061 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
3062 return 1;
3065 return 0;
3068 /* Scan sequence after INSN if it does not dereference any argument slots
3069 we already clobbered by tail call arguments (as noted in stored_args_map
3070 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3071 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3072 should be 0). Return nonzero if sequence after INSN dereferences such argument
3073 slots, zero otherwise. */
3075 static int
3076 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3077 int mark_stored_args_map)
3079 poly_uint64 low, high;
3080 unsigned HOST_WIDE_INT const_low, const_high;
3082 if (insn == NULL_RTX)
3083 insn = get_insns ();
3084 else
3085 insn = NEXT_INSN (insn);
3087 for (; insn; insn = NEXT_INSN (insn))
3088 if (INSN_P (insn)
3089 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3090 break;
3092 if (mark_stored_args_map)
3094 if (ARGS_GROW_DOWNWARD)
3095 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3096 else
3097 low = arg->locate.slot_offset.constant;
3098 high = low + arg->locate.size.constant;
3100 const_low = constant_lower_bound (low);
3101 if (high.is_constant (&const_high))
3102 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3103 bitmap_set_bit (stored_args_map, i);
3104 else
3105 stored_args_watermark = MIN (stored_args_watermark, const_low);
3107 return insn != NULL_RTX;
3110 /* Given that a function returns a value of mode MODE at the most
3111 significant end of hard register VALUE, shift VALUE left or right
3112 as specified by LEFT_P. Return true if some action was needed. */
3114 bool
3115 shift_return_value (machine_mode mode, bool left_p, rtx value)
3117 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3118 machine_mode value_mode = GET_MODE (value);
3119 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3121 if (known_eq (shift, 0))
3122 return false;
3124 /* Use ashr rather than lshr for right shifts. This is for the benefit
3125 of the MIPS port, which requires SImode values to be sign-extended
3126 when stored in 64-bit registers. */
3127 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3128 value, gen_int_shift_amount (value_mode, shift),
3129 value, 1, OPTAB_WIDEN))
3130 gcc_unreachable ();
3131 return true;
3134 /* If X is a likely-spilled register value, copy it to a pseudo
3135 register and return that register. Return X otherwise. */
3137 static rtx
3138 avoid_likely_spilled_reg (rtx x)
3140 rtx new_rtx;
3142 if (REG_P (x)
3143 && HARD_REGISTER_P (x)
3144 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3146 /* Make sure that we generate a REG rather than a CONCAT.
3147 Moves into CONCATs can need nontrivial instructions,
3148 and the whole point of this function is to avoid
3149 using the hard register directly in such a situation. */
3150 generating_concat_p = 0;
3151 new_rtx = gen_reg_rtx (GET_MODE (x));
3152 generating_concat_p = 1;
3153 emit_move_insn (new_rtx, x);
3154 return new_rtx;
3156 return x;
3159 /* Helper function for expand_call.
3160 Return false is EXP is not implementable as a sibling call. */
3162 static bool
3163 can_implement_as_sibling_call_p (tree exp,
3164 rtx structure_value_addr,
3165 tree funtype,
3166 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3167 tree fndecl,
3168 int flags,
3169 tree addr,
3170 const args_size &args_size)
3172 if (!targetm.have_sibcall_epilogue ())
3174 maybe_complain_about_tail_call
3175 (exp,
3176 "machine description does not have"
3177 " a sibcall_epilogue instruction pattern");
3178 return false;
3181 /* Doing sibling call optimization needs some work, since
3182 structure_value_addr can be allocated on the stack.
3183 It does not seem worth the effort since few optimizable
3184 sibling calls will return a structure. */
3185 if (structure_value_addr != NULL_RTX)
3187 maybe_complain_about_tail_call (exp, "callee returns a structure");
3188 return false;
3191 #ifdef REG_PARM_STACK_SPACE
3192 /* If outgoing reg parm stack space changes, we can not do sibcall. */
3193 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3194 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3195 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3197 maybe_complain_about_tail_call (exp,
3198 "inconsistent size of stack space"
3199 " allocated for arguments which are"
3200 " passed in registers");
3201 return false;
3203 #endif
3205 /* Check whether the target is able to optimize the call
3206 into a sibcall. */
3207 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3209 maybe_complain_about_tail_call (exp,
3210 "target is not able to optimize the"
3211 " call into a sibling call");
3212 return false;
3215 /* Functions that do not return exactly once may not be sibcall
3216 optimized. */
3217 if (flags & ECF_RETURNS_TWICE)
3219 maybe_complain_about_tail_call (exp, "callee returns twice");
3220 return false;
3222 if (flags & ECF_NORETURN)
3224 maybe_complain_about_tail_call (exp, "callee does not return");
3225 return false;
3228 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3230 maybe_complain_about_tail_call (exp, "volatile function type");
3231 return false;
3234 /* If the called function is nested in the current one, it might access
3235 some of the caller's arguments, but could clobber them beforehand if
3236 the argument areas are shared. */
3237 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3239 maybe_complain_about_tail_call (exp, "nested function");
3240 return false;
3243 /* If this function requires more stack slots than the current
3244 function, we cannot change it into a sibling call.
3245 crtl->args.pretend_args_size is not part of the
3246 stack allocated by our caller. */
3247 if (maybe_gt (args_size.constant,
3248 crtl->args.size - crtl->args.pretend_args_size))
3250 maybe_complain_about_tail_call (exp,
3251 "callee required more stack slots"
3252 " than the caller");
3253 return false;
3256 /* If the callee pops its own arguments, then it must pop exactly
3257 the same number of arguments as the current function. */
3258 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3259 args_size.constant),
3260 targetm.calls.return_pops_args (current_function_decl,
3261 TREE_TYPE
3262 (current_function_decl),
3263 crtl->args.size)))
3265 maybe_complain_about_tail_call (exp,
3266 "inconsistent number of"
3267 " popped arguments");
3268 return false;
3271 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3273 maybe_complain_about_tail_call (exp, "frontend does not support"
3274 " sibling call");
3275 return false;
3278 /* All checks passed. */
3279 return true;
3282 /* Generate all the code for a CALL_EXPR exp
3283 and return an rtx for its value.
3284 Store the value in TARGET (specified as an rtx) if convenient.
3285 If the value is stored in TARGET then TARGET is returned.
3286 If IGNORE is nonzero, then we ignore the value of the function call. */
3289 expand_call (tree exp, rtx target, int ignore)
3291 /* Nonzero if we are currently expanding a call. */
3292 static int currently_expanding_call = 0;
3294 /* RTX for the function to be called. */
3295 rtx funexp;
3296 /* Sequence of insns to perform a normal "call". */
3297 rtx_insn *normal_call_insns = NULL;
3298 /* Sequence of insns to perform a tail "call". */
3299 rtx_insn *tail_call_insns = NULL;
3300 /* Data type of the function. */
3301 tree funtype;
3302 tree type_arg_types;
3303 tree rettype;
3304 /* Declaration of the function being called,
3305 or 0 if the function is computed (not known by name). */
3306 tree fndecl = 0;
3307 /* The type of the function being called. */
3308 tree fntype;
3309 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3310 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3311 int pass;
3313 /* Register in which non-BLKmode value will be returned,
3314 or 0 if no value or if value is BLKmode. */
3315 rtx valreg;
3316 /* Address where we should return a BLKmode value;
3317 0 if value not BLKmode. */
3318 rtx structure_value_addr = 0;
3319 /* Nonzero if that address is being passed by treating it as
3320 an extra, implicit first parameter. Otherwise,
3321 it is passed by being copied directly into struct_value_rtx. */
3322 int structure_value_addr_parm = 0;
3323 /* Holds the value of implicit argument for the struct value. */
3324 tree structure_value_addr_value = NULL_TREE;
3325 /* Size of aggregate value wanted, or zero if none wanted
3326 or if we are using the non-reentrant PCC calling convention
3327 or expecting the value in registers. */
3328 poly_int64 struct_value_size = 0;
3329 /* Nonzero if called function returns an aggregate in memory PCC style,
3330 by returning the address of where to find it. */
3331 int pcc_struct_value = 0;
3332 rtx struct_value = 0;
3334 /* Number of actual parameters in this call, including struct value addr. */
3335 int num_actuals;
3336 /* Number of named args. Args after this are anonymous ones
3337 and they must all go on the stack. */
3338 int n_named_args;
3339 /* Number of complex actual arguments that need to be split. */
3340 int num_complex_actuals = 0;
3342 /* Vector of information about each argument.
3343 Arguments are numbered in the order they will be pushed,
3344 not the order they are written. */
3345 struct arg_data *args;
3347 /* Total size in bytes of all the stack-parms scanned so far. */
3348 struct args_size args_size;
3349 struct args_size adjusted_args_size;
3350 /* Size of arguments before any adjustments (such as rounding). */
3351 poly_int64 unadjusted_args_size;
3352 /* Data on reg parms scanned so far. */
3353 CUMULATIVE_ARGS args_so_far_v;
3354 cumulative_args_t args_so_far;
3355 /* Nonzero if a reg parm has been scanned. */
3356 int reg_parm_seen;
3357 /* Nonzero if this is an indirect function call. */
3359 /* Nonzero if we must avoid push-insns in the args for this call.
3360 If stack space is allocated for register parameters, but not by the
3361 caller, then it is preallocated in the fixed part of the stack frame.
3362 So the entire argument block must then be preallocated (i.e., we
3363 ignore PUSH_ROUNDING in that case). */
3365 int must_preallocate = !PUSH_ARGS;
3367 /* Size of the stack reserved for parameter registers. */
3368 int reg_parm_stack_space = 0;
3370 /* Address of space preallocated for stack parms
3371 (on machines that lack push insns), or 0 if space not preallocated. */
3372 rtx argblock = 0;
3374 /* Mask of ECF_ and ERF_ flags. */
3375 int flags = 0;
3376 int return_flags = 0;
3377 #ifdef REG_PARM_STACK_SPACE
3378 /* Define the boundary of the register parm stack space that needs to be
3379 saved, if any. */
3380 int low_to_save, high_to_save;
3381 rtx save_area = 0; /* Place that it is saved */
3382 #endif
3384 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3385 char *initial_stack_usage_map = stack_usage_map;
3386 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3387 char *stack_usage_map_buf = NULL;
3389 poly_int64 old_stack_allocated;
3391 /* State variables to track stack modifications. */
3392 rtx old_stack_level = 0;
3393 int old_stack_arg_under_construction = 0;
3394 poly_int64 old_pending_adj = 0;
3395 int old_inhibit_defer_pop = inhibit_defer_pop;
3397 /* Some stack pointer alterations we make are performed via
3398 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3399 which we then also need to save/restore along the way. */
3400 poly_int64 old_stack_pointer_delta = 0;
3402 rtx call_fusage;
3403 tree addr = CALL_EXPR_FN (exp);
3404 int i;
3405 /* The alignment of the stack, in bits. */
3406 unsigned HOST_WIDE_INT preferred_stack_boundary;
3407 /* The alignment of the stack, in bytes. */
3408 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3409 /* The static chain value to use for this call. */
3410 rtx static_chain_value;
3411 /* See if this is "nothrow" function call. */
3412 if (TREE_NOTHROW (exp))
3413 flags |= ECF_NOTHROW;
3415 /* See if we can find a DECL-node for the actual function, and get the
3416 function attributes (flags) from the function decl or type node. */
3417 fndecl = get_callee_fndecl (exp);
3418 if (fndecl)
3420 fntype = TREE_TYPE (fndecl);
3421 flags |= flags_from_decl_or_type (fndecl);
3422 return_flags |= decl_return_flags (fndecl);
3424 else
3426 fntype = TREE_TYPE (TREE_TYPE (addr));
3427 flags |= flags_from_decl_or_type (fntype);
3428 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3429 flags |= ECF_BY_DESCRIPTOR;
3431 rettype = TREE_TYPE (exp);
3433 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3435 /* Warn if this value is an aggregate type,
3436 regardless of which calling convention we are using for it. */
3437 if (AGGREGATE_TYPE_P (rettype))
3438 warning (OPT_Waggregate_return, "function call has aggregate value");
3440 /* If the result of a non looping pure or const function call is
3441 ignored (or void), and none of its arguments are volatile, we can
3442 avoid expanding the call and just evaluate the arguments for
3443 side-effects. */
3444 if ((flags & (ECF_CONST | ECF_PURE))
3445 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3446 && (ignore || target == const0_rtx
3447 || TYPE_MODE (rettype) == VOIDmode))
3449 bool volatilep = false;
3450 tree arg;
3451 call_expr_arg_iterator iter;
3453 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3454 if (TREE_THIS_VOLATILE (arg))
3456 volatilep = true;
3457 break;
3460 if (! volatilep)
3462 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3463 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3464 return const0_rtx;
3468 #ifdef REG_PARM_STACK_SPACE
3469 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3470 #endif
3472 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3473 && reg_parm_stack_space > 0 && PUSH_ARGS)
3474 must_preallocate = 1;
3476 /* Set up a place to return a structure. */
3478 /* Cater to broken compilers. */
3479 if (aggregate_value_p (exp, fntype))
3481 /* This call returns a big structure. */
3482 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3484 #ifdef PCC_STATIC_STRUCT_RETURN
3486 pcc_struct_value = 1;
3488 #else /* not PCC_STATIC_STRUCT_RETURN */
3490 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3491 struct_value_size = -1;
3493 /* Even if it is semantically safe to use the target as the return
3494 slot, it may be not sufficiently aligned for the return type. */
3495 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3496 && target
3497 && MEM_P (target)
3498 /* If rettype is addressable, we may not create a temporary.
3499 If target is properly aligned at runtime and the compiler
3500 just doesn't know about it, it will work fine, otherwise it
3501 will be UB. */
3502 && (TREE_ADDRESSABLE (rettype)
3503 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3504 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3505 MEM_ALIGN (target)))))
3506 structure_value_addr = XEXP (target, 0);
3507 else
3509 /* For variable-sized objects, we must be called with a target
3510 specified. If we were to allocate space on the stack here,
3511 we would have no way of knowing when to free it. */
3512 rtx d = assign_temp (rettype, 1, 1);
3513 structure_value_addr = XEXP (d, 0);
3514 target = 0;
3517 #endif /* not PCC_STATIC_STRUCT_RETURN */
3520 /* Figure out the amount to which the stack should be aligned. */
3521 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3522 if (fndecl)
3524 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3525 /* Without automatic stack alignment, we can't increase preferred
3526 stack boundary. With automatic stack alignment, it is
3527 unnecessary since unless we can guarantee that all callers will
3528 align the outgoing stack properly, callee has to align its
3529 stack anyway. */
3530 if (i
3531 && i->preferred_incoming_stack_boundary
3532 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3533 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3536 /* Operand 0 is a pointer-to-function; get the type of the function. */
3537 funtype = TREE_TYPE (addr);
3538 gcc_assert (POINTER_TYPE_P (funtype));
3539 funtype = TREE_TYPE (funtype);
3541 /* Count whether there are actual complex arguments that need to be split
3542 into their real and imaginary parts. Munge the type_arg_types
3543 appropriately here as well. */
3544 if (targetm.calls.split_complex_arg)
3546 call_expr_arg_iterator iter;
3547 tree arg;
3548 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3550 tree type = TREE_TYPE (arg);
3551 if (type && TREE_CODE (type) == COMPLEX_TYPE
3552 && targetm.calls.split_complex_arg (type))
3553 num_complex_actuals++;
3555 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3557 else
3558 type_arg_types = TYPE_ARG_TYPES (funtype);
3560 if (flags & ECF_MAY_BE_ALLOCA)
3561 cfun->calls_alloca = 1;
3563 /* If struct_value_rtx is 0, it means pass the address
3564 as if it were an extra parameter. Put the argument expression
3565 in structure_value_addr_value. */
3566 if (structure_value_addr && struct_value == 0)
3568 /* If structure_value_addr is a REG other than
3569 virtual_outgoing_args_rtx, we can use always use it. If it
3570 is not a REG, we must always copy it into a register.
3571 If it is virtual_outgoing_args_rtx, we must copy it to another
3572 register in some cases. */
3573 rtx temp = (!REG_P (structure_value_addr)
3574 || (ACCUMULATE_OUTGOING_ARGS
3575 && stack_arg_under_construction
3576 && structure_value_addr == virtual_outgoing_args_rtx)
3577 ? copy_addr_to_reg (convert_memory_address
3578 (Pmode, structure_value_addr))
3579 : structure_value_addr);
3581 structure_value_addr_value =
3582 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3583 structure_value_addr_parm = 1;
3586 /* Count the arguments and set NUM_ACTUALS. */
3587 num_actuals =
3588 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3590 /* Compute number of named args.
3591 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3593 if (type_arg_types != 0)
3594 n_named_args
3595 = (list_length (type_arg_types)
3596 /* Count the struct value address, if it is passed as a parm. */
3597 + structure_value_addr_parm);
3598 else
3599 /* If we know nothing, treat all args as named. */
3600 n_named_args = num_actuals;
3602 /* Start updating where the next arg would go.
3604 On some machines (such as the PA) indirect calls have a different
3605 calling convention than normal calls. The fourth argument in
3606 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3607 or not. */
3608 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3609 args_so_far = pack_cumulative_args (&args_so_far_v);
3611 /* Now possibly adjust the number of named args.
3612 Normally, don't include the last named arg if anonymous args follow.
3613 We do include the last named arg if
3614 targetm.calls.strict_argument_naming() returns nonzero.
3615 (If no anonymous args follow, the result of list_length is actually
3616 one too large. This is harmless.)
3618 If targetm.calls.pretend_outgoing_varargs_named() returns
3619 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3620 this machine will be able to place unnamed args that were passed
3621 in registers into the stack. So treat all args as named. This
3622 allows the insns emitting for a specific argument list to be
3623 independent of the function declaration.
3625 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3626 we do not have any reliable way to pass unnamed args in
3627 registers, so we must force them into memory. */
3629 if (type_arg_types != 0
3630 && targetm.calls.strict_argument_naming (args_so_far))
3632 else if (type_arg_types != 0
3633 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3634 /* Don't include the last named arg. */
3635 --n_named_args;
3636 else
3637 /* Treat all args as named. */
3638 n_named_args = num_actuals;
3640 /* Make a vector to hold all the information about each arg. */
3641 args = XCNEWVEC (struct arg_data, num_actuals);
3643 /* Build up entries in the ARGS array, compute the size of the
3644 arguments into ARGS_SIZE, etc. */
3645 initialize_argument_information (num_actuals, args, &args_size,
3646 n_named_args, exp,
3647 structure_value_addr_value, fndecl, fntype,
3648 args_so_far, reg_parm_stack_space,
3649 &old_stack_level, &old_pending_adj,
3650 &must_preallocate, &flags,
3651 &try_tail_call, CALL_FROM_THUNK_P (exp));
3653 if (args_size.var)
3654 must_preallocate = 1;
3656 /* Now make final decision about preallocating stack space. */
3657 must_preallocate = finalize_must_preallocate (must_preallocate,
3658 num_actuals, args,
3659 &args_size);
3661 /* If the structure value address will reference the stack pointer, we
3662 must stabilize it. We don't need to do this if we know that we are
3663 not going to adjust the stack pointer in processing this call. */
3665 if (structure_value_addr
3666 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3667 || reg_mentioned_p (virtual_outgoing_args_rtx,
3668 structure_value_addr))
3669 && (args_size.var
3670 || (!ACCUMULATE_OUTGOING_ARGS
3671 && maybe_ne (args_size.constant, 0))))
3672 structure_value_addr = copy_to_reg (structure_value_addr);
3674 /* Tail calls can make things harder to debug, and we've traditionally
3675 pushed these optimizations into -O2. Don't try if we're already
3676 expanding a call, as that means we're an argument. Don't try if
3677 there's cleanups, as we know there's code to follow the call. */
3679 if (currently_expanding_call++ != 0
3680 || !flag_optimize_sibling_calls
3681 || args_size.var
3682 || dbg_cnt (tail_call) == false)
3683 try_tail_call = 0;
3685 /* If the user has marked the function as requiring tail-call
3686 optimization, attempt it. */
3687 if (must_tail_call)
3688 try_tail_call = 1;
3690 /* Rest of purposes for tail call optimizations to fail. */
3691 if (try_tail_call)
3692 try_tail_call = can_implement_as_sibling_call_p (exp,
3693 structure_value_addr,
3694 funtype,
3695 reg_parm_stack_space,
3696 fndecl,
3697 flags, addr, args_size);
3699 /* Check if caller and callee disagree in promotion of function
3700 return value. */
3701 if (try_tail_call)
3703 machine_mode caller_mode, caller_promoted_mode;
3704 machine_mode callee_mode, callee_promoted_mode;
3705 int caller_unsignedp, callee_unsignedp;
3706 tree caller_res = DECL_RESULT (current_function_decl);
3708 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3709 caller_mode = DECL_MODE (caller_res);
3710 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3711 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3712 caller_promoted_mode
3713 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3714 &caller_unsignedp,
3715 TREE_TYPE (current_function_decl), 1);
3716 callee_promoted_mode
3717 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3718 &callee_unsignedp,
3719 funtype, 1);
3720 if (caller_mode != VOIDmode
3721 && (caller_promoted_mode != callee_promoted_mode
3722 || ((caller_mode != caller_promoted_mode
3723 || callee_mode != callee_promoted_mode)
3724 && (caller_unsignedp != callee_unsignedp
3725 || partial_subreg_p (caller_mode, callee_mode)))))
3727 try_tail_call = 0;
3728 maybe_complain_about_tail_call (exp,
3729 "caller and callee disagree in"
3730 " promotion of function"
3731 " return value");
3735 /* Ensure current function's preferred stack boundary is at least
3736 what we need. Stack alignment may also increase preferred stack
3737 boundary. */
3738 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3739 crtl->preferred_stack_boundary = preferred_stack_boundary;
3740 else
3741 preferred_stack_boundary = crtl->preferred_stack_boundary;
3743 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3745 /* We want to make two insn chains; one for a sibling call, the other
3746 for a normal call. We will select one of the two chains after
3747 initial RTL generation is complete. */
3748 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3750 int sibcall_failure = 0;
3751 /* We want to emit any pending stack adjustments before the tail
3752 recursion "call". That way we know any adjustment after the tail
3753 recursion call can be ignored if we indeed use the tail
3754 call expansion. */
3755 saved_pending_stack_adjust save;
3756 rtx_insn *insns, *before_call, *after_args;
3757 rtx next_arg_reg;
3759 if (pass == 0)
3761 /* State variables we need to save and restore between
3762 iterations. */
3763 save_pending_stack_adjust (&save);
3765 if (pass)
3766 flags &= ~ECF_SIBCALL;
3767 else
3768 flags |= ECF_SIBCALL;
3770 /* Other state variables that we must reinitialize each time
3771 through the loop (that are not initialized by the loop itself). */
3772 argblock = 0;
3773 call_fusage = 0;
3775 /* Start a new sequence for the normal call case.
3777 From this point on, if the sibling call fails, we want to set
3778 sibcall_failure instead of continuing the loop. */
3779 start_sequence ();
3781 /* Don't let pending stack adjusts add up to too much.
3782 Also, do all pending adjustments now if there is any chance
3783 this might be a call to alloca or if we are expanding a sibling
3784 call sequence.
3785 Also do the adjustments before a throwing call, otherwise
3786 exception handling can fail; PR 19225. */
3787 if (maybe_ge (pending_stack_adjust, 32)
3788 || (maybe_ne (pending_stack_adjust, 0)
3789 && (flags & ECF_MAY_BE_ALLOCA))
3790 || (maybe_ne (pending_stack_adjust, 0)
3791 && flag_exceptions && !(flags & ECF_NOTHROW))
3792 || pass == 0)
3793 do_pending_stack_adjust ();
3795 /* Precompute any arguments as needed. */
3796 if (pass)
3797 precompute_arguments (num_actuals, args);
3799 /* Now we are about to start emitting insns that can be deleted
3800 if a libcall is deleted. */
3801 if (pass && (flags & ECF_MALLOC))
3802 start_sequence ();
3804 if (pass == 0
3805 && crtl->stack_protect_guard
3806 && targetm.stack_protect_runtime_enabled_p ())
3807 stack_protect_epilogue ();
3809 adjusted_args_size = args_size;
3810 /* Compute the actual size of the argument block required. The variable
3811 and constant sizes must be combined, the size may have to be rounded,
3812 and there may be a minimum required size. When generating a sibcall
3813 pattern, do not round up, since we'll be re-using whatever space our
3814 caller provided. */
3815 unadjusted_args_size
3816 = compute_argument_block_size (reg_parm_stack_space,
3817 &adjusted_args_size,
3818 fndecl, fntype,
3819 (pass == 0 ? 0
3820 : preferred_stack_boundary));
3822 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3824 /* The argument block when performing a sibling call is the
3825 incoming argument block. */
3826 if (pass == 0)
3828 argblock = crtl->args.internal_arg_pointer;
3829 if (STACK_GROWS_DOWNWARD)
3830 argblock
3831 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3832 else
3833 argblock
3834 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3836 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3837 stored_args_map = sbitmap_alloc (map_size);
3838 bitmap_clear (stored_args_map);
3839 stored_args_watermark = HOST_WIDE_INT_M1U;
3842 /* If we have no actual push instructions, or shouldn't use them,
3843 make space for all args right now. */
3844 else if (adjusted_args_size.var != 0)
3846 if (old_stack_level == 0)
3848 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3849 old_stack_pointer_delta = stack_pointer_delta;
3850 old_pending_adj = pending_stack_adjust;
3851 pending_stack_adjust = 0;
3852 /* stack_arg_under_construction says whether a stack arg is
3853 being constructed at the old stack level. Pushing the stack
3854 gets a clean outgoing argument block. */
3855 old_stack_arg_under_construction = stack_arg_under_construction;
3856 stack_arg_under_construction = 0;
3858 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3859 if (flag_stack_usage_info)
3860 current_function_has_unbounded_dynamic_stack_size = 1;
3862 else
3864 /* Note that we must go through the motions of allocating an argument
3865 block even if the size is zero because we may be storing args
3866 in the area reserved for register arguments, which may be part of
3867 the stack frame. */
3869 poly_int64 needed = adjusted_args_size.constant;
3871 /* Store the maximum argument space used. It will be pushed by
3872 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3873 checking). */
3875 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3876 needed);
3878 if (must_preallocate)
3880 if (ACCUMULATE_OUTGOING_ARGS)
3882 /* Since the stack pointer will never be pushed, it is
3883 possible for the evaluation of a parm to clobber
3884 something we have already written to the stack.
3885 Since most function calls on RISC machines do not use
3886 the stack, this is uncommon, but must work correctly.
3888 Therefore, we save any area of the stack that was already
3889 written and that we are using. Here we set up to do this
3890 by making a new stack usage map from the old one. The
3891 actual save will be done by store_one_arg.
3893 Another approach might be to try to reorder the argument
3894 evaluations to avoid this conflicting stack usage. */
3896 /* Since we will be writing into the entire argument area,
3897 the map must be allocated for its entire size, not just
3898 the part that is the responsibility of the caller. */
3899 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3900 needed += reg_parm_stack_space;
3902 poly_int64 limit = needed;
3903 if (ARGS_GROW_DOWNWARD)
3904 limit += 1;
3906 /* For polynomial sizes, this is the maximum possible
3907 size needed for arguments with a constant size
3908 and offset. */
3909 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3910 highest_outgoing_arg_in_use
3911 = MAX (initial_highest_arg_in_use, const_limit);
3913 free (stack_usage_map_buf);
3914 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3915 stack_usage_map = stack_usage_map_buf;
3917 if (initial_highest_arg_in_use)
3918 memcpy (stack_usage_map, initial_stack_usage_map,
3919 initial_highest_arg_in_use);
3921 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3922 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3923 (highest_outgoing_arg_in_use
3924 - initial_highest_arg_in_use));
3925 needed = 0;
3927 /* The address of the outgoing argument list must not be
3928 copied to a register here, because argblock would be left
3929 pointing to the wrong place after the call to
3930 allocate_dynamic_stack_space below. */
3932 argblock = virtual_outgoing_args_rtx;
3934 else
3936 /* Try to reuse some or all of the pending_stack_adjust
3937 to get this space. */
3938 if (inhibit_defer_pop == 0
3939 && (combine_pending_stack_adjustment_and_call
3940 (&needed,
3941 unadjusted_args_size,
3942 &adjusted_args_size,
3943 preferred_unit_stack_boundary)))
3945 /* combine_pending_stack_adjustment_and_call computes
3946 an adjustment before the arguments are allocated.
3947 Account for them and see whether or not the stack
3948 needs to go up or down. */
3949 needed = unadjusted_args_size - needed;
3951 /* Checked by
3952 combine_pending_stack_adjustment_and_call. */
3953 gcc_checking_assert (ordered_p (needed, 0));
3954 if (maybe_lt (needed, 0))
3956 /* We're releasing stack space. */
3957 /* ??? We can avoid any adjustment at all if we're
3958 already aligned. FIXME. */
3959 pending_stack_adjust = -needed;
3960 do_pending_stack_adjust ();
3961 needed = 0;
3963 else
3964 /* We need to allocate space. We'll do that in
3965 push_block below. */
3966 pending_stack_adjust = 0;
3969 /* Special case this because overhead of `push_block' in
3970 this case is non-trivial. */
3971 if (known_eq (needed, 0))
3972 argblock = virtual_outgoing_args_rtx;
3973 else
3975 rtx needed_rtx = gen_int_mode (needed, Pmode);
3976 argblock = push_block (needed_rtx, 0, 0);
3977 if (ARGS_GROW_DOWNWARD)
3978 argblock = plus_constant (Pmode, argblock, needed);
3981 /* We only really need to call `copy_to_reg' in the case
3982 where push insns are going to be used to pass ARGBLOCK
3983 to a function call in ARGS. In that case, the stack
3984 pointer changes value from the allocation point to the
3985 call point, and hence the value of
3986 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3987 as well always do it. */
3988 argblock = copy_to_reg (argblock);
3993 if (ACCUMULATE_OUTGOING_ARGS)
3995 /* The save/restore code in store_one_arg handles all
3996 cases except one: a constructor call (including a C
3997 function returning a BLKmode struct) to initialize
3998 an argument. */
3999 if (stack_arg_under_construction)
4001 rtx push_size
4002 = (gen_int_mode
4003 (adjusted_args_size.constant
4004 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
4005 : TREE_TYPE (fndecl))
4006 ? 0 : reg_parm_stack_space), Pmode));
4007 if (old_stack_level == 0)
4009 emit_stack_save (SAVE_BLOCK, &old_stack_level);
4010 old_stack_pointer_delta = stack_pointer_delta;
4011 old_pending_adj = pending_stack_adjust;
4012 pending_stack_adjust = 0;
4013 /* stack_arg_under_construction says whether a stack
4014 arg is being constructed at the old stack level.
4015 Pushing the stack gets a clean outgoing argument
4016 block. */
4017 old_stack_arg_under_construction
4018 = stack_arg_under_construction;
4019 stack_arg_under_construction = 0;
4020 /* Make a new map for the new argument list. */
4021 free (stack_usage_map_buf);
4022 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
4023 stack_usage_map = stack_usage_map_buf;
4024 highest_outgoing_arg_in_use = 0;
4025 stack_usage_watermark = HOST_WIDE_INT_M1U;
4027 /* We can pass TRUE as the 4th argument because we just
4028 saved the stack pointer and will restore it right after
4029 the call. */
4030 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
4031 -1, true);
4034 /* If argument evaluation might modify the stack pointer,
4035 copy the address of the argument list to a register. */
4036 for (i = 0; i < num_actuals; i++)
4037 if (args[i].pass_on_stack)
4039 argblock = copy_addr_to_reg (argblock);
4040 break;
4044 compute_argument_addresses (args, argblock, num_actuals);
4046 /* Stack is properly aligned, pops can't safely be deferred during
4047 the evaluation of the arguments. */
4048 NO_DEFER_POP;
4050 /* Precompute all register parameters. It isn't safe to compute
4051 anything once we have started filling any specific hard regs.
4052 TLS symbols sometimes need a call to resolve. Precompute
4053 register parameters before any stack pointer manipulation
4054 to avoid unaligned stack in the called function. */
4055 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
4057 OK_DEFER_POP;
4059 /* Perform stack alignment before the first push (the last arg). */
4060 if (argblock == 0
4061 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
4062 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
4064 /* When the stack adjustment is pending, we get better code
4065 by combining the adjustments. */
4066 if (maybe_ne (pending_stack_adjust, 0)
4067 && ! inhibit_defer_pop
4068 && (combine_pending_stack_adjustment_and_call
4069 (&pending_stack_adjust,
4070 unadjusted_args_size,
4071 &adjusted_args_size,
4072 preferred_unit_stack_boundary)))
4073 do_pending_stack_adjust ();
4074 else if (argblock == 0)
4075 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4076 - unadjusted_args_size,
4077 Pmode));
4079 /* Now that the stack is properly aligned, pops can't safely
4080 be deferred during the evaluation of the arguments. */
4081 NO_DEFER_POP;
4083 /* Record the maximum pushed stack space size. We need to delay
4084 doing it this far to take into account the optimization done
4085 by combine_pending_stack_adjustment_and_call. */
4086 if (flag_stack_usage_info
4087 && !ACCUMULATE_OUTGOING_ARGS
4088 && pass
4089 && adjusted_args_size.var == 0)
4091 poly_int64 pushed = (adjusted_args_size.constant
4092 + pending_stack_adjust);
4093 current_function_pushed_stack_size
4094 = upper_bound (current_function_pushed_stack_size, pushed);
4097 funexp = rtx_for_function_call (fndecl, addr);
4099 if (CALL_EXPR_STATIC_CHAIN (exp))
4100 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4101 else
4102 static_chain_value = 0;
4104 #ifdef REG_PARM_STACK_SPACE
4105 /* Save the fixed argument area if it's part of the caller's frame and
4106 is clobbered by argument setup for this call. */
4107 if (ACCUMULATE_OUTGOING_ARGS && pass)
4108 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4109 &low_to_save, &high_to_save);
4110 #endif
4112 /* Now store (and compute if necessary) all non-register parms.
4113 These come before register parms, since they can require block-moves,
4114 which could clobber the registers used for register parms.
4115 Parms which have partial registers are not stored here,
4116 but we do preallocate space here if they want that. */
4118 for (i = 0; i < num_actuals; i++)
4120 if (args[i].reg == 0 || args[i].pass_on_stack)
4122 rtx_insn *before_arg = get_last_insn ();
4124 /* We don't allow passing huge (> 2^30 B) arguments
4125 by value. It would cause an overflow later on. */
4126 if (constant_lower_bound (adjusted_args_size.constant)
4127 >= (1 << (HOST_BITS_PER_INT - 2)))
4129 sorry ("passing too large argument on stack");
4130 continue;
4133 if (store_one_arg (&args[i], argblock, flags,
4134 adjusted_args_size.var != 0,
4135 reg_parm_stack_space)
4136 || (pass == 0
4137 && check_sibcall_argument_overlap (before_arg,
4138 &args[i], 1)))
4139 sibcall_failure = 1;
4142 if (args[i].stack)
4143 call_fusage
4144 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4145 gen_rtx_USE (VOIDmode, args[i].stack),
4146 call_fusage);
4149 /* If we have a parm that is passed in registers but not in memory
4150 and whose alignment does not permit a direct copy into registers,
4151 make a group of pseudos that correspond to each register that we
4152 will later fill. */
4153 if (STRICT_ALIGNMENT)
4154 store_unaligned_arguments_into_pseudos (args, num_actuals);
4156 /* Now store any partially-in-registers parm.
4157 This is the last place a block-move can happen. */
4158 if (reg_parm_seen)
4159 for (i = 0; i < num_actuals; i++)
4160 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4162 rtx_insn *before_arg = get_last_insn ();
4164 /* On targets with weird calling conventions (e.g. PA) it's
4165 hard to ensure that all cases of argument overlap between
4166 stack and registers work. Play it safe and bail out. */
4167 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4169 sibcall_failure = 1;
4170 break;
4173 if (store_one_arg (&args[i], argblock, flags,
4174 adjusted_args_size.var != 0,
4175 reg_parm_stack_space)
4176 || (pass == 0
4177 && check_sibcall_argument_overlap (before_arg,
4178 &args[i], 1)))
4179 sibcall_failure = 1;
4182 bool any_regs = false;
4183 for (i = 0; i < num_actuals; i++)
4184 if (args[i].reg != NULL_RTX)
4186 any_regs = true;
4187 targetm.calls.call_args (args[i].reg, funtype);
4189 if (!any_regs)
4190 targetm.calls.call_args (pc_rtx, funtype);
4192 /* Figure out the register where the value, if any, will come back. */
4193 valreg = 0;
4194 if (TYPE_MODE (rettype) != VOIDmode
4195 && ! structure_value_addr)
4197 if (pcc_struct_value)
4198 valreg = hard_function_value (build_pointer_type (rettype),
4199 fndecl, NULL, (pass == 0));
4200 else
4201 valreg = hard_function_value (rettype, fndecl, fntype,
4202 (pass == 0));
4204 /* If VALREG is a PARALLEL whose first member has a zero
4205 offset, use that. This is for targets such as m68k that
4206 return the same value in multiple places. */
4207 if (GET_CODE (valreg) == PARALLEL)
4209 rtx elem = XVECEXP (valreg, 0, 0);
4210 rtx where = XEXP (elem, 0);
4211 rtx offset = XEXP (elem, 1);
4212 if (offset == const0_rtx
4213 && GET_MODE (where) == GET_MODE (valreg))
4214 valreg = where;
4218 /* If register arguments require space on the stack and stack space
4219 was not preallocated, allocate stack space here for arguments
4220 passed in registers. */
4221 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4222 && !ACCUMULATE_OUTGOING_ARGS
4223 && must_preallocate == 0 && reg_parm_stack_space > 0)
4224 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4226 /* Pass the function the address in which to return a
4227 structure value. */
4228 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4230 structure_value_addr
4231 = convert_memory_address (Pmode, structure_value_addr);
4232 emit_move_insn (struct_value,
4233 force_reg (Pmode,
4234 force_operand (structure_value_addr,
4235 NULL_RTX)));
4237 if (REG_P (struct_value))
4238 use_reg (&call_fusage, struct_value);
4241 after_args = get_last_insn ();
4242 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4243 static_chain_value, &call_fusage,
4244 reg_parm_seen, flags);
4246 load_register_parameters (args, num_actuals, &call_fusage, flags,
4247 pass == 0, &sibcall_failure);
4249 /* Save a pointer to the last insn before the call, so that we can
4250 later safely search backwards to find the CALL_INSN. */
4251 before_call = get_last_insn ();
4253 /* Set up next argument register. For sibling calls on machines
4254 with register windows this should be the incoming register. */
4255 if (pass == 0)
4256 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
4257 VOIDmode,
4258 void_type_node,
4259 true);
4260 else
4261 next_arg_reg = targetm.calls.function_arg (args_so_far,
4262 VOIDmode, void_type_node,
4263 true);
4265 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4267 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4268 arg_nr = num_actuals - arg_nr - 1;
4269 if (arg_nr >= 0
4270 && arg_nr < num_actuals
4271 && args[arg_nr].reg
4272 && valreg
4273 && REG_P (valreg)
4274 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4275 call_fusage
4276 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4277 gen_rtx_SET (valreg, args[arg_nr].reg),
4278 call_fusage);
4280 /* All arguments and registers used for the call must be set up by
4281 now! */
4283 /* Stack must be properly aligned now. */
4284 gcc_assert (!pass
4285 || multiple_p (stack_pointer_delta,
4286 preferred_unit_stack_boundary));
4288 /* Generate the actual call instruction. */
4289 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4290 adjusted_args_size.constant, struct_value_size,
4291 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4292 flags, args_so_far);
4294 if (flag_ipa_ra)
4296 rtx_call_insn *last;
4297 rtx datum = NULL_RTX;
4298 if (fndecl != NULL_TREE)
4300 datum = XEXP (DECL_RTL (fndecl), 0);
4301 gcc_assert (datum != NULL_RTX
4302 && GET_CODE (datum) == SYMBOL_REF);
4304 last = last_call_insn ();
4305 add_reg_note (last, REG_CALL_DECL, datum);
4308 /* If the call setup or the call itself overlaps with anything
4309 of the argument setup we probably clobbered our call address.
4310 In that case we can't do sibcalls. */
4311 if (pass == 0
4312 && check_sibcall_argument_overlap (after_args, 0, 0))
4313 sibcall_failure = 1;
4315 /* If a non-BLKmode value is returned at the most significant end
4316 of a register, shift the register right by the appropriate amount
4317 and update VALREG accordingly. BLKmode values are handled by the
4318 group load/store machinery below. */
4319 if (!structure_value_addr
4320 && !pcc_struct_value
4321 && TYPE_MODE (rettype) != VOIDmode
4322 && TYPE_MODE (rettype) != BLKmode
4323 && REG_P (valreg)
4324 && targetm.calls.return_in_msb (rettype))
4326 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4327 sibcall_failure = 1;
4328 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4331 if (pass && (flags & ECF_MALLOC))
4333 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4334 rtx_insn *last, *insns;
4336 /* The return value from a malloc-like function is a pointer. */
4337 if (TREE_CODE (rettype) == POINTER_TYPE)
4338 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4340 emit_move_insn (temp, valreg);
4342 /* The return value from a malloc-like function can not alias
4343 anything else. */
4344 last = get_last_insn ();
4345 add_reg_note (last, REG_NOALIAS, temp);
4347 /* Write out the sequence. */
4348 insns = get_insns ();
4349 end_sequence ();
4350 emit_insn (insns);
4351 valreg = temp;
4354 /* For calls to `setjmp', etc., inform
4355 function.c:setjmp_warnings that it should complain if
4356 nonvolatile values are live. For functions that cannot
4357 return, inform flow that control does not fall through. */
4359 if ((flags & ECF_NORETURN) || pass == 0)
4361 /* The barrier must be emitted
4362 immediately after the CALL_INSN. Some ports emit more
4363 than just a CALL_INSN above, so we must search for it here. */
4365 rtx_insn *last = get_last_insn ();
4366 while (!CALL_P (last))
4368 last = PREV_INSN (last);
4369 /* There was no CALL_INSN? */
4370 gcc_assert (last != before_call);
4373 emit_barrier_after (last);
4375 /* Stack adjustments after a noreturn call are dead code.
4376 However when NO_DEFER_POP is in effect, we must preserve
4377 stack_pointer_delta. */
4378 if (inhibit_defer_pop == 0)
4380 stack_pointer_delta = old_stack_allocated;
4381 pending_stack_adjust = 0;
4385 /* If value type not void, return an rtx for the value. */
4387 if (TYPE_MODE (rettype) == VOIDmode
4388 || ignore)
4389 target = const0_rtx;
4390 else if (structure_value_addr)
4392 if (target == 0 || !MEM_P (target))
4394 target
4395 = gen_rtx_MEM (TYPE_MODE (rettype),
4396 memory_address (TYPE_MODE (rettype),
4397 structure_value_addr));
4398 set_mem_attributes (target, rettype, 1);
4401 else if (pcc_struct_value)
4403 /* This is the special C++ case where we need to
4404 know what the true target was. We take care to
4405 never use this value more than once in one expression. */
4406 target = gen_rtx_MEM (TYPE_MODE (rettype),
4407 copy_to_reg (valreg));
4408 set_mem_attributes (target, rettype, 1);
4410 /* Handle calls that return values in multiple non-contiguous locations.
4411 The Irix 6 ABI has examples of this. */
4412 else if (GET_CODE (valreg) == PARALLEL)
4414 if (target == 0)
4415 target = emit_group_move_into_temps (valreg);
4416 else if (rtx_equal_p (target, valreg))
4418 else if (GET_CODE (target) == PARALLEL)
4419 /* Handle the result of a emit_group_move_into_temps
4420 call in the previous pass. */
4421 emit_group_move (target, valreg);
4422 else
4423 emit_group_store (target, valreg, rettype,
4424 int_size_in_bytes (rettype));
4426 else if (target
4427 && GET_MODE (target) == TYPE_MODE (rettype)
4428 && GET_MODE (target) == GET_MODE (valreg))
4430 bool may_overlap = false;
4432 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4433 reg to a plain register. */
4434 if (!REG_P (target) || HARD_REGISTER_P (target))
4435 valreg = avoid_likely_spilled_reg (valreg);
4437 /* If TARGET is a MEM in the argument area, and we have
4438 saved part of the argument area, then we can't store
4439 directly into TARGET as it may get overwritten when we
4440 restore the argument save area below. Don't work too
4441 hard though and simply force TARGET to a register if it
4442 is a MEM; the optimizer is quite likely to sort it out. */
4443 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4444 for (i = 0; i < num_actuals; i++)
4445 if (args[i].save_area)
4447 may_overlap = true;
4448 break;
4451 if (may_overlap)
4452 target = copy_to_reg (valreg);
4453 else
4455 /* TARGET and VALREG cannot be equal at this point
4456 because the latter would not have
4457 REG_FUNCTION_VALUE_P true, while the former would if
4458 it were referring to the same register.
4460 If they refer to the same register, this move will be
4461 a no-op, except when function inlining is being
4462 done. */
4463 emit_move_insn (target, valreg);
4465 /* If we are setting a MEM, this code must be executed.
4466 Since it is emitted after the call insn, sibcall
4467 optimization cannot be performed in that case. */
4468 if (MEM_P (target))
4469 sibcall_failure = 1;
4472 else
4473 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4475 /* If we promoted this return value, make the proper SUBREG.
4476 TARGET might be const0_rtx here, so be careful. */
4477 if (REG_P (target)
4478 && TYPE_MODE (rettype) != BLKmode
4479 && GET_MODE (target) != TYPE_MODE (rettype))
4481 tree type = rettype;
4482 int unsignedp = TYPE_UNSIGNED (type);
4483 machine_mode pmode;
4485 /* Ensure we promote as expected, and get the new unsignedness. */
4486 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4487 funtype, 1);
4488 gcc_assert (GET_MODE (target) == pmode);
4490 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4491 GET_MODE (target));
4492 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4493 SUBREG_PROMOTED_VAR_P (target) = 1;
4494 SUBREG_PROMOTED_SET (target, unsignedp);
4497 /* If size of args is variable or this was a constructor call for a stack
4498 argument, restore saved stack-pointer value. */
4500 if (old_stack_level)
4502 rtx_insn *prev = get_last_insn ();
4504 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4505 stack_pointer_delta = old_stack_pointer_delta;
4507 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4509 pending_stack_adjust = old_pending_adj;
4510 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4511 stack_arg_under_construction = old_stack_arg_under_construction;
4512 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4513 stack_usage_map = initial_stack_usage_map;
4514 stack_usage_watermark = initial_stack_usage_watermark;
4515 sibcall_failure = 1;
4517 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4519 #ifdef REG_PARM_STACK_SPACE
4520 if (save_area)
4521 restore_fixed_argument_area (save_area, argblock,
4522 high_to_save, low_to_save);
4523 #endif
4525 /* If we saved any argument areas, restore them. */
4526 for (i = 0; i < num_actuals; i++)
4527 if (args[i].save_area)
4529 machine_mode save_mode = GET_MODE (args[i].save_area);
4530 rtx stack_area
4531 = gen_rtx_MEM (save_mode,
4532 memory_address (save_mode,
4533 XEXP (args[i].stack_slot, 0)));
4535 if (save_mode != BLKmode)
4536 emit_move_insn (stack_area, args[i].save_area);
4537 else
4538 emit_block_move (stack_area, args[i].save_area,
4539 (gen_int_mode
4540 (args[i].locate.size.constant, Pmode)),
4541 BLOCK_OP_CALL_PARM);
4544 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4545 stack_usage_map = initial_stack_usage_map;
4546 stack_usage_watermark = initial_stack_usage_watermark;
4549 /* If this was alloca, record the new stack level. */
4550 if (flags & ECF_MAY_BE_ALLOCA)
4551 record_new_stack_level ();
4553 /* Free up storage we no longer need. */
4554 for (i = 0; i < num_actuals; ++i)
4555 free (args[i].aligned_regs);
4557 targetm.calls.end_call_args ();
4559 insns = get_insns ();
4560 end_sequence ();
4562 if (pass == 0)
4564 tail_call_insns = insns;
4566 /* Restore the pending stack adjustment now that we have
4567 finished generating the sibling call sequence. */
4569 restore_pending_stack_adjust (&save);
4571 /* Prepare arg structure for next iteration. */
4572 for (i = 0; i < num_actuals; i++)
4574 args[i].value = 0;
4575 args[i].aligned_regs = 0;
4576 args[i].stack = 0;
4579 sbitmap_free (stored_args_map);
4580 internal_arg_pointer_exp_state.scan_start = NULL;
4581 internal_arg_pointer_exp_state.cache.release ();
4583 else
4585 normal_call_insns = insns;
4587 /* Verify that we've deallocated all the stack we used. */
4588 gcc_assert ((flags & ECF_NORETURN)
4589 || known_eq (old_stack_allocated,
4590 stack_pointer_delta
4591 - pending_stack_adjust));
4594 /* If something prevents making this a sibling call,
4595 zero out the sequence. */
4596 if (sibcall_failure)
4597 tail_call_insns = NULL;
4598 else
4599 break;
4602 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4603 arguments too, as argument area is now clobbered by the call. */
4604 if (tail_call_insns)
4606 emit_insn (tail_call_insns);
4607 crtl->tail_call_emit = true;
4609 else
4611 emit_insn (normal_call_insns);
4612 if (try_tail_call)
4613 /* Ideally we'd emit a message for all of the ways that it could
4614 have failed. */
4615 maybe_complain_about_tail_call (exp, "tail call production failed");
4618 currently_expanding_call--;
4620 free (stack_usage_map_buf);
4621 free (args);
4622 return target;
4625 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4626 this function's incoming arguments.
4628 At the start of RTL generation we know the only REG_EQUIV notes
4629 in the rtl chain are those for incoming arguments, so we can look
4630 for REG_EQUIV notes between the start of the function and the
4631 NOTE_INSN_FUNCTION_BEG.
4633 This is (slight) overkill. We could keep track of the highest
4634 argument we clobber and be more selective in removing notes, but it
4635 does not seem to be worth the effort. */
4637 void
4638 fixup_tail_calls (void)
4640 rtx_insn *insn;
4642 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4644 rtx note;
4646 /* There are never REG_EQUIV notes for the incoming arguments
4647 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4648 if (NOTE_P (insn)
4649 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4650 break;
4652 note = find_reg_note (insn, REG_EQUIV, 0);
4653 if (note)
4654 remove_note (insn, note);
4655 note = find_reg_note (insn, REG_EQUIV, 0);
4656 gcc_assert (!note);
4660 /* Traverse a list of TYPES and expand all complex types into their
4661 components. */
4662 static tree
4663 split_complex_types (tree types)
4665 tree p;
4667 /* Before allocating memory, check for the common case of no complex. */
4668 for (p = types; p; p = TREE_CHAIN (p))
4670 tree type = TREE_VALUE (p);
4671 if (TREE_CODE (type) == COMPLEX_TYPE
4672 && targetm.calls.split_complex_arg (type))
4673 goto found;
4675 return types;
4677 found:
4678 types = copy_list (types);
4680 for (p = types; p; p = TREE_CHAIN (p))
4682 tree complex_type = TREE_VALUE (p);
4684 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4685 && targetm.calls.split_complex_arg (complex_type))
4687 tree next, imag;
4689 /* Rewrite complex type with component type. */
4690 TREE_VALUE (p) = TREE_TYPE (complex_type);
4691 next = TREE_CHAIN (p);
4693 /* Add another component type for the imaginary part. */
4694 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4695 TREE_CHAIN (p) = imag;
4696 TREE_CHAIN (imag) = next;
4698 /* Skip the newly created node. */
4699 p = TREE_CHAIN (p);
4703 return types;
4706 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4707 for a value of mode OUTMODE,
4708 with NARGS different arguments, passed as ARGS.
4709 Store the return value if RETVAL is nonzero: store it in VALUE if
4710 VALUE is nonnull, otherwise pick a convenient location. In either
4711 case return the location of the stored value.
4713 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4714 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4715 other types of library calls. */
4718 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4719 enum libcall_type fn_type,
4720 machine_mode outmode, int nargs, rtx_mode_t *args)
4722 /* Total size in bytes of all the stack-parms scanned so far. */
4723 struct args_size args_size;
4724 /* Size of arguments before any adjustments (such as rounding). */
4725 struct args_size original_args_size;
4726 int argnum;
4727 rtx fun;
4728 /* Todo, choose the correct decl type of orgfun. Sadly this information
4729 isn't present here, so we default to native calling abi here. */
4730 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4731 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4732 int count;
4733 rtx argblock = 0;
4734 CUMULATIVE_ARGS args_so_far_v;
4735 cumulative_args_t args_so_far;
4736 struct arg
4738 rtx value;
4739 machine_mode mode;
4740 rtx reg;
4741 int partial;
4742 struct locate_and_pad_arg_data locate;
4743 rtx save_area;
4745 struct arg *argvec;
4746 int old_inhibit_defer_pop = inhibit_defer_pop;
4747 rtx call_fusage = 0;
4748 rtx mem_value = 0;
4749 rtx valreg;
4750 int pcc_struct_value = 0;
4751 poly_int64 struct_value_size = 0;
4752 int flags;
4753 int reg_parm_stack_space = 0;
4754 poly_int64 needed;
4755 rtx_insn *before_call;
4756 bool have_push_fusage;
4757 tree tfom; /* type_for_mode (outmode, 0) */
4759 #ifdef REG_PARM_STACK_SPACE
4760 /* Define the boundary of the register parm stack space that needs to be
4761 save, if any. */
4762 int low_to_save = 0, high_to_save = 0;
4763 rtx save_area = 0; /* Place that it is saved. */
4764 #endif
4766 /* Size of the stack reserved for parameter registers. */
4767 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4768 char *initial_stack_usage_map = stack_usage_map;
4769 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4770 char *stack_usage_map_buf = NULL;
4772 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4774 #ifdef REG_PARM_STACK_SPACE
4775 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4776 #endif
4778 /* By default, library functions cannot throw. */
4779 flags = ECF_NOTHROW;
4781 switch (fn_type)
4783 case LCT_NORMAL:
4784 break;
4785 case LCT_CONST:
4786 flags |= ECF_CONST;
4787 break;
4788 case LCT_PURE:
4789 flags |= ECF_PURE;
4790 break;
4791 case LCT_NORETURN:
4792 flags |= ECF_NORETURN;
4793 break;
4794 case LCT_THROW:
4795 flags &= ~ECF_NOTHROW;
4796 break;
4797 case LCT_RETURNS_TWICE:
4798 flags = ECF_RETURNS_TWICE;
4799 break;
4801 fun = orgfun;
4803 /* Ensure current function's preferred stack boundary is at least
4804 what we need. */
4805 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4806 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4808 /* If this kind of value comes back in memory,
4809 decide where in memory it should come back. */
4810 if (outmode != VOIDmode)
4812 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4813 if (aggregate_value_p (tfom, 0))
4815 #ifdef PCC_STATIC_STRUCT_RETURN
4816 rtx pointer_reg
4817 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4818 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4819 pcc_struct_value = 1;
4820 if (value == 0)
4821 value = gen_reg_rtx (outmode);
4822 #else /* not PCC_STATIC_STRUCT_RETURN */
4823 struct_value_size = GET_MODE_SIZE (outmode);
4824 if (value != 0 && MEM_P (value))
4825 mem_value = value;
4826 else
4827 mem_value = assign_temp (tfom, 1, 1);
4828 #endif
4829 /* This call returns a big structure. */
4830 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4833 else
4834 tfom = void_type_node;
4836 /* ??? Unfinished: must pass the memory address as an argument. */
4838 /* Copy all the libcall-arguments out of the varargs data
4839 and into a vector ARGVEC.
4841 Compute how to pass each argument. We only support a very small subset
4842 of the full argument passing conventions to limit complexity here since
4843 library functions shouldn't have many args. */
4845 argvec = XALLOCAVEC (struct arg, nargs + 1);
4846 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4848 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4849 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4850 #else
4851 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4852 #endif
4853 args_so_far = pack_cumulative_args (&args_so_far_v);
4855 args_size.constant = 0;
4856 args_size.var = 0;
4858 count = 0;
4860 push_temp_slots ();
4862 /* If there's a structure value address to be passed,
4863 either pass it in the special place, or pass it as an extra argument. */
4864 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4866 rtx addr = XEXP (mem_value, 0);
4868 nargs++;
4870 /* Make sure it is a reasonable operand for a move or push insn. */
4871 if (!REG_P (addr) && !MEM_P (addr)
4872 && !(CONSTANT_P (addr)
4873 && targetm.legitimate_constant_p (Pmode, addr)))
4874 addr = force_operand (addr, NULL_RTX);
4876 argvec[count].value = addr;
4877 argvec[count].mode = Pmode;
4878 argvec[count].partial = 0;
4880 argvec[count].reg = targetm.calls.function_arg (args_so_far,
4881 Pmode, NULL_TREE, true);
4882 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
4883 NULL_TREE, 1) == 0);
4885 locate_and_pad_parm (Pmode, NULL_TREE,
4886 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4888 #else
4889 argvec[count].reg != 0,
4890 #endif
4891 reg_parm_stack_space, 0,
4892 NULL_TREE, &args_size, &argvec[count].locate);
4894 if (argvec[count].reg == 0 || argvec[count].partial != 0
4895 || reg_parm_stack_space > 0)
4896 args_size.constant += argvec[count].locate.size.constant;
4898 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
4900 count++;
4903 for (unsigned int i = 0; count < nargs; i++, count++)
4905 rtx val = args[i].first;
4906 machine_mode mode = args[i].second;
4907 int unsigned_p = 0;
4909 /* We cannot convert the arg value to the mode the library wants here;
4910 must do it earlier where we know the signedness of the arg. */
4911 gcc_assert (mode != BLKmode
4912 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
4914 /* Make sure it is a reasonable operand for a move or push insn. */
4915 if (!REG_P (val) && !MEM_P (val)
4916 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
4917 val = force_operand (val, NULL_RTX);
4919 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
4921 rtx slot;
4922 int must_copy
4923 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
4925 /* If this was a CONST function, it is now PURE since it now
4926 reads memory. */
4927 if (flags & ECF_CONST)
4929 flags &= ~ECF_CONST;
4930 flags |= ECF_PURE;
4933 if (MEM_P (val) && !must_copy)
4935 tree val_expr = MEM_EXPR (val);
4936 if (val_expr)
4937 mark_addressable (val_expr);
4938 slot = val;
4940 else
4942 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
4943 1, 1);
4944 emit_move_insn (slot, val);
4947 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4948 gen_rtx_USE (VOIDmode, slot),
4949 call_fusage);
4950 if (must_copy)
4951 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4952 gen_rtx_CLOBBER (VOIDmode,
4953 slot),
4954 call_fusage);
4956 mode = Pmode;
4957 val = force_operand (XEXP (slot, 0), NULL_RTX);
4960 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
4961 argvec[count].mode = mode;
4962 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
4963 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
4964 NULL_TREE, true);
4966 argvec[count].partial
4967 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
4969 if (argvec[count].reg == 0
4970 || argvec[count].partial != 0
4971 || reg_parm_stack_space > 0)
4973 locate_and_pad_parm (mode, NULL_TREE,
4974 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4976 #else
4977 argvec[count].reg != 0,
4978 #endif
4979 reg_parm_stack_space, argvec[count].partial,
4980 NULL_TREE, &args_size, &argvec[count].locate);
4981 args_size.constant += argvec[count].locate.size.constant;
4982 gcc_assert (!argvec[count].locate.size.var);
4984 #ifdef BLOCK_REG_PADDING
4985 else
4986 /* The argument is passed entirely in registers. See at which
4987 end it should be padded. */
4988 argvec[count].locate.where_pad =
4989 BLOCK_REG_PADDING (mode, NULL_TREE,
4990 known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD));
4991 #endif
4993 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
4996 /* If this machine requires an external definition for library
4997 functions, write one out. */
4998 assemble_external_libcall (fun);
5000 original_args_size = args_size;
5001 args_size.constant = (aligned_upper_bound (args_size.constant
5002 + stack_pointer_delta,
5003 STACK_BYTES)
5004 - stack_pointer_delta);
5006 args_size.constant = upper_bound (args_size.constant,
5007 reg_parm_stack_space);
5009 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5010 args_size.constant -= reg_parm_stack_space;
5012 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
5013 args_size.constant);
5015 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
5017 poly_int64 pushed = args_size.constant + pending_stack_adjust;
5018 current_function_pushed_stack_size
5019 = upper_bound (current_function_pushed_stack_size, pushed);
5022 if (ACCUMULATE_OUTGOING_ARGS)
5024 /* Since the stack pointer will never be pushed, it is possible for
5025 the evaluation of a parm to clobber something we have already
5026 written to the stack. Since most function calls on RISC machines
5027 do not use the stack, this is uncommon, but must work correctly.
5029 Therefore, we save any area of the stack that was already written
5030 and that we are using. Here we set up to do this by making a new
5031 stack usage map from the old one.
5033 Another approach might be to try to reorder the argument
5034 evaluations to avoid this conflicting stack usage. */
5036 needed = args_size.constant;
5038 /* Since we will be writing into the entire argument area, the
5039 map must be allocated for its entire size, not just the part that
5040 is the responsibility of the caller. */
5041 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5042 needed += reg_parm_stack_space;
5044 poly_int64 limit = needed;
5045 if (ARGS_GROW_DOWNWARD)
5046 limit += 1;
5048 /* For polynomial sizes, this is the maximum possible size needed
5049 for arguments with a constant size and offset. */
5050 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5051 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5052 const_limit);
5054 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5055 stack_usage_map = stack_usage_map_buf;
5057 if (initial_highest_arg_in_use)
5058 memcpy (stack_usage_map, initial_stack_usage_map,
5059 initial_highest_arg_in_use);
5061 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5062 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5063 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5064 needed = 0;
5066 /* We must be careful to use virtual regs before they're instantiated,
5067 and real regs afterwards. Loop optimization, for example, can create
5068 new libcalls after we've instantiated the virtual regs, and if we
5069 use virtuals anyway, they won't match the rtl patterns. */
5071 if (virtuals_instantiated)
5072 argblock = plus_constant (Pmode, stack_pointer_rtx,
5073 STACK_POINTER_OFFSET);
5074 else
5075 argblock = virtual_outgoing_args_rtx;
5077 else
5079 if (!PUSH_ARGS)
5080 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5083 /* We push args individually in reverse order, perform stack alignment
5084 before the first push (the last arg). */
5085 if (argblock == 0)
5086 anti_adjust_stack (gen_int_mode (args_size.constant
5087 - original_args_size.constant,
5088 Pmode));
5090 argnum = nargs - 1;
5092 #ifdef REG_PARM_STACK_SPACE
5093 if (ACCUMULATE_OUTGOING_ARGS)
5095 /* The argument list is the property of the called routine and it
5096 may clobber it. If the fixed area has been used for previous
5097 parameters, we must save and restore it. */
5098 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5099 &low_to_save, &high_to_save);
5101 #endif
5103 /* When expanding a normal call, args are stored in push order,
5104 which is the reverse of what we have here. */
5105 bool any_regs = false;
5106 for (int i = nargs; i-- > 0; )
5107 if (argvec[i].reg != NULL_RTX)
5109 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5110 any_regs = true;
5112 if (!any_regs)
5113 targetm.calls.call_args (pc_rtx, NULL_TREE);
5115 /* Push the args that need to be pushed. */
5117 have_push_fusage = false;
5119 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5120 are to be pushed. */
5121 for (count = 0; count < nargs; count++, argnum--)
5123 machine_mode mode = argvec[argnum].mode;
5124 rtx val = argvec[argnum].value;
5125 rtx reg = argvec[argnum].reg;
5126 int partial = argvec[argnum].partial;
5127 unsigned int parm_align = argvec[argnum].locate.boundary;
5128 poly_int64 lower_bound = 0, upper_bound = 0;
5130 if (! (reg != 0 && partial == 0))
5132 rtx use;
5134 if (ACCUMULATE_OUTGOING_ARGS)
5136 /* If this is being stored into a pre-allocated, fixed-size,
5137 stack area, save any previous data at that location. */
5139 if (ARGS_GROW_DOWNWARD)
5141 /* stack_slot is negative, but we want to index stack_usage_map
5142 with positive values. */
5143 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5144 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5146 else
5148 lower_bound = argvec[argnum].locate.slot_offset.constant;
5149 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5152 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5153 reg_parm_stack_space))
5155 /* We need to make a save area. */
5156 poly_uint64 size
5157 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5158 machine_mode save_mode
5159 = int_mode_for_size (size, 1).else_blk ();
5160 rtx adr
5161 = plus_constant (Pmode, argblock,
5162 argvec[argnum].locate.offset.constant);
5163 rtx stack_area
5164 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5166 if (save_mode == BLKmode)
5168 argvec[argnum].save_area
5169 = assign_stack_temp (BLKmode,
5170 argvec[argnum].locate.size.constant
5173 emit_block_move (validize_mem
5174 (copy_rtx (argvec[argnum].save_area)),
5175 stack_area,
5176 (gen_int_mode
5177 (argvec[argnum].locate.size.constant,
5178 Pmode)),
5179 BLOCK_OP_CALL_PARM);
5181 else
5183 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5185 emit_move_insn (argvec[argnum].save_area, stack_area);
5190 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5191 partial, reg, 0, argblock,
5192 (gen_int_mode
5193 (argvec[argnum].locate.offset.constant, Pmode)),
5194 reg_parm_stack_space,
5195 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5197 /* Now mark the segment we just used. */
5198 if (ACCUMULATE_OUTGOING_ARGS)
5199 mark_stack_region_used (lower_bound, upper_bound);
5201 NO_DEFER_POP;
5203 /* Indicate argument access so that alias.c knows that these
5204 values are live. */
5205 if (argblock)
5206 use = plus_constant (Pmode, argblock,
5207 argvec[argnum].locate.offset.constant);
5208 else if (have_push_fusage)
5209 continue;
5210 else
5212 /* When arguments are pushed, trying to tell alias.c where
5213 exactly this argument is won't work, because the
5214 auto-increment causes confusion. So we merely indicate
5215 that we access something with a known mode somewhere on
5216 the stack. */
5217 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5218 gen_rtx_SCRATCH (Pmode));
5219 have_push_fusage = true;
5221 use = gen_rtx_MEM (argvec[argnum].mode, use);
5222 use = gen_rtx_USE (VOIDmode, use);
5223 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5227 argnum = nargs - 1;
5229 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5231 /* Now load any reg parms into their regs. */
5233 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5234 are to be pushed. */
5235 for (count = 0; count < nargs; count++, argnum--)
5237 machine_mode mode = argvec[argnum].mode;
5238 rtx val = argvec[argnum].value;
5239 rtx reg = argvec[argnum].reg;
5240 int partial = argvec[argnum].partial;
5242 /* Handle calls that pass values in multiple non-contiguous
5243 locations. The PA64 has examples of this for library calls. */
5244 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5245 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5246 else if (reg != 0 && partial == 0)
5248 emit_move_insn (reg, val);
5249 #ifdef BLOCK_REG_PADDING
5250 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5252 /* Copied from load_register_parameters. */
5254 /* Handle case where we have a value that needs shifting
5255 up to the msb. eg. a QImode value and we're padding
5256 upward on a BYTES_BIG_ENDIAN machine. */
5257 if (known_lt (size, UNITS_PER_WORD)
5258 && (argvec[argnum].locate.where_pad
5259 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5261 rtx x;
5262 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5264 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5265 report the whole reg as used. Strictly speaking, the
5266 call only uses SIZE bytes at the msb end, but it doesn't
5267 seem worth generating rtl to say that. */
5268 reg = gen_rtx_REG (word_mode, REGNO (reg));
5269 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5270 if (x != reg)
5271 emit_move_insn (reg, x);
5273 #endif
5276 NO_DEFER_POP;
5279 /* Any regs containing parms remain in use through the call. */
5280 for (count = 0; count < nargs; count++)
5282 rtx reg = argvec[count].reg;
5283 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5284 use_group_regs (&call_fusage, reg);
5285 else if (reg != 0)
5287 int partial = argvec[count].partial;
5288 if (partial)
5290 int nregs;
5291 gcc_assert (partial % UNITS_PER_WORD == 0);
5292 nregs = partial / UNITS_PER_WORD;
5293 use_regs (&call_fusage, REGNO (reg), nregs);
5295 else
5296 use_reg (&call_fusage, reg);
5300 /* Pass the function the address in which to return a structure value. */
5301 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5303 emit_move_insn (struct_value,
5304 force_reg (Pmode,
5305 force_operand (XEXP (mem_value, 0),
5306 NULL_RTX)));
5307 if (REG_P (struct_value))
5308 use_reg (&call_fusage, struct_value);
5311 /* Don't allow popping to be deferred, since then
5312 cse'ing of library calls could delete a call and leave the pop. */
5313 NO_DEFER_POP;
5314 valreg = (mem_value == 0 && outmode != VOIDmode
5315 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5317 /* Stack must be properly aligned now. */
5318 gcc_assert (multiple_p (stack_pointer_delta,
5319 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5321 before_call = get_last_insn ();
5323 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5324 will set inhibit_defer_pop to that value. */
5325 /* The return type is needed to decide how many bytes the function pops.
5326 Signedness plays no role in that, so for simplicity, we pretend it's
5327 always signed. We also assume that the list of arguments passed has
5328 no impact, so we pretend it is unknown. */
5330 emit_call_1 (fun, NULL,
5331 get_identifier (XSTR (orgfun, 0)),
5332 build_function_type (tfom, NULL_TREE),
5333 original_args_size.constant, args_size.constant,
5334 struct_value_size,
5335 targetm.calls.function_arg (args_so_far,
5336 VOIDmode, void_type_node, true),
5337 valreg,
5338 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5340 if (flag_ipa_ra)
5342 rtx datum = orgfun;
5343 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5344 rtx_call_insn *last = last_call_insn ();
5345 add_reg_note (last, REG_CALL_DECL, datum);
5348 /* Right-shift returned value if necessary. */
5349 if (!pcc_struct_value
5350 && TYPE_MODE (tfom) != BLKmode
5351 && targetm.calls.return_in_msb (tfom))
5353 shift_return_value (TYPE_MODE (tfom), false, valreg);
5354 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5357 targetm.calls.end_call_args ();
5359 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5360 that it should complain if nonvolatile values are live. For
5361 functions that cannot return, inform flow that control does not
5362 fall through. */
5363 if (flags & ECF_NORETURN)
5365 /* The barrier note must be emitted
5366 immediately after the CALL_INSN. Some ports emit more than
5367 just a CALL_INSN above, so we must search for it here. */
5368 rtx_insn *last = get_last_insn ();
5369 while (!CALL_P (last))
5371 last = PREV_INSN (last);
5372 /* There was no CALL_INSN? */
5373 gcc_assert (last != before_call);
5376 emit_barrier_after (last);
5379 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5380 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5381 if (flags & ECF_NOTHROW)
5383 rtx_insn *last = get_last_insn ();
5384 while (!CALL_P (last))
5386 last = PREV_INSN (last);
5387 /* There was no CALL_INSN? */
5388 gcc_assert (last != before_call);
5391 make_reg_eh_region_note_nothrow_nononlocal (last);
5394 /* Now restore inhibit_defer_pop to its actual original value. */
5395 OK_DEFER_POP;
5397 pop_temp_slots ();
5399 /* Copy the value to the right place. */
5400 if (outmode != VOIDmode && retval)
5402 if (mem_value)
5404 if (value == 0)
5405 value = mem_value;
5406 if (value != mem_value)
5407 emit_move_insn (value, mem_value);
5409 else if (GET_CODE (valreg) == PARALLEL)
5411 if (value == 0)
5412 value = gen_reg_rtx (outmode);
5413 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5415 else
5417 /* Convert to the proper mode if a promotion has been active. */
5418 if (GET_MODE (valreg) != outmode)
5420 int unsignedp = TYPE_UNSIGNED (tfom);
5422 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5423 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5424 == GET_MODE (valreg));
5425 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5428 if (value != 0)
5429 emit_move_insn (value, valreg);
5430 else
5431 value = valreg;
5435 if (ACCUMULATE_OUTGOING_ARGS)
5437 #ifdef REG_PARM_STACK_SPACE
5438 if (save_area)
5439 restore_fixed_argument_area (save_area, argblock,
5440 high_to_save, low_to_save);
5441 #endif
5443 /* If we saved any argument areas, restore them. */
5444 for (count = 0; count < nargs; count++)
5445 if (argvec[count].save_area)
5447 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5448 rtx adr = plus_constant (Pmode, argblock,
5449 argvec[count].locate.offset.constant);
5450 rtx stack_area = gen_rtx_MEM (save_mode,
5451 memory_address (save_mode, adr));
5453 if (save_mode == BLKmode)
5454 emit_block_move (stack_area,
5455 validize_mem
5456 (copy_rtx (argvec[count].save_area)),
5457 (gen_int_mode
5458 (argvec[count].locate.size.constant, Pmode)),
5459 BLOCK_OP_CALL_PARM);
5460 else
5461 emit_move_insn (stack_area, argvec[count].save_area);
5464 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5465 stack_usage_map = initial_stack_usage_map;
5466 stack_usage_watermark = initial_stack_usage_watermark;
5469 free (stack_usage_map_buf);
5471 return value;
5476 /* Store a single argument for a function call
5477 into the register or memory area where it must be passed.
5478 *ARG describes the argument value and where to pass it.
5480 ARGBLOCK is the address of the stack-block for all the arguments,
5481 or 0 on a machine where arguments are pushed individually.
5483 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5484 so must be careful about how the stack is used.
5486 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5487 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5488 that we need not worry about saving and restoring the stack.
5490 FNDECL is the declaration of the function we are calling.
5492 Return nonzero if this arg should cause sibcall failure,
5493 zero otherwise. */
5495 static int
5496 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5497 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5499 tree pval = arg->tree_value;
5500 rtx reg = 0;
5501 int partial = 0;
5502 poly_int64 used = 0;
5503 poly_int64 lower_bound = 0, upper_bound = 0;
5504 int sibcall_failure = 0;
5506 if (TREE_CODE (pval) == ERROR_MARK)
5507 return 1;
5509 /* Push a new temporary level for any temporaries we make for
5510 this argument. */
5511 push_temp_slots ();
5513 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5515 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5516 save any previous data at that location. */
5517 if (argblock && ! variable_size && arg->stack)
5519 if (ARGS_GROW_DOWNWARD)
5521 /* stack_slot is negative, but we want to index stack_usage_map
5522 with positive values. */
5523 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5525 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5526 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5528 else
5529 upper_bound = 0;
5531 lower_bound = upper_bound - arg->locate.size.constant;
5533 else
5535 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5537 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5538 lower_bound = rtx_to_poly_int64 (offset);
5540 else
5541 lower_bound = 0;
5543 upper_bound = lower_bound + arg->locate.size.constant;
5546 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5547 reg_parm_stack_space))
5549 /* We need to make a save area. */
5550 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5551 machine_mode save_mode
5552 = int_mode_for_size (size, 1).else_blk ();
5553 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5554 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5556 if (save_mode == BLKmode)
5558 arg->save_area
5559 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5560 preserve_temp_slots (arg->save_area);
5561 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5562 stack_area,
5563 (gen_int_mode
5564 (arg->locate.size.constant, Pmode)),
5565 BLOCK_OP_CALL_PARM);
5567 else
5569 arg->save_area = gen_reg_rtx (save_mode);
5570 emit_move_insn (arg->save_area, stack_area);
5576 /* If this isn't going to be placed on both the stack and in registers,
5577 set up the register and number of words. */
5578 if (! arg->pass_on_stack)
5580 if (flags & ECF_SIBCALL)
5581 reg = arg->tail_call_reg;
5582 else
5583 reg = arg->reg;
5584 partial = arg->partial;
5587 /* Being passed entirely in a register. We shouldn't be called in
5588 this case. */
5589 gcc_assert (reg == 0 || partial != 0);
5591 /* If this arg needs special alignment, don't load the registers
5592 here. */
5593 if (arg->n_aligned_regs != 0)
5594 reg = 0;
5596 /* If this is being passed partially in a register, we can't evaluate
5597 it directly into its stack slot. Otherwise, we can. */
5598 if (arg->value == 0)
5600 /* stack_arg_under_construction is nonzero if a function argument is
5601 being evaluated directly into the outgoing argument list and
5602 expand_call must take special action to preserve the argument list
5603 if it is called recursively.
5605 For scalar function arguments stack_usage_map is sufficient to
5606 determine which stack slots must be saved and restored. Scalar
5607 arguments in general have pass_on_stack == 0.
5609 If this argument is initialized by a function which takes the
5610 address of the argument (a C++ constructor or a C function
5611 returning a BLKmode structure), then stack_usage_map is
5612 insufficient and expand_call must push the stack around the
5613 function call. Such arguments have pass_on_stack == 1.
5615 Note that it is always safe to set stack_arg_under_construction,
5616 but this generates suboptimal code if set when not needed. */
5618 if (arg->pass_on_stack)
5619 stack_arg_under_construction++;
5621 arg->value = expand_expr (pval,
5622 (partial
5623 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5624 ? NULL_RTX : arg->stack,
5625 VOIDmode, EXPAND_STACK_PARM);
5627 /* If we are promoting object (or for any other reason) the mode
5628 doesn't agree, convert the mode. */
5630 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5631 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5632 arg->value, arg->unsignedp);
5634 if (arg->pass_on_stack)
5635 stack_arg_under_construction--;
5638 /* Check for overlap with already clobbered argument area. */
5639 if ((flags & ECF_SIBCALL)
5640 && MEM_P (arg->value)
5641 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5642 arg->locate.size.constant))
5643 sibcall_failure = 1;
5645 /* Don't allow anything left on stack from computation
5646 of argument to alloca. */
5647 if (flags & ECF_MAY_BE_ALLOCA)
5648 do_pending_stack_adjust ();
5650 if (arg->value == arg->stack)
5651 /* If the value is already in the stack slot, we are done. */
5653 else if (arg->mode != BLKmode)
5655 unsigned int parm_align;
5657 /* Argument is a scalar, not entirely passed in registers.
5658 (If part is passed in registers, arg->partial says how much
5659 and emit_push_insn will take care of putting it there.)
5661 Push it, and if its size is less than the
5662 amount of space allocated to it,
5663 also bump stack pointer by the additional space.
5664 Note that in C the default argument promotions
5665 will prevent such mismatches. */
5667 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5668 ? 0 : GET_MODE_SIZE (arg->mode));
5670 /* Compute how much space the push instruction will push.
5671 On many machines, pushing a byte will advance the stack
5672 pointer by a halfword. */
5673 #ifdef PUSH_ROUNDING
5674 size = PUSH_ROUNDING (size);
5675 #endif
5676 used = size;
5678 /* Compute how much space the argument should get:
5679 round up to a multiple of the alignment for arguments. */
5680 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5681 != PAD_NONE)
5682 /* At the moment we don't (need to) support ABIs for which the
5683 padding isn't known at compile time. In principle it should
5684 be easy to add though. */
5685 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5687 /* Compute the alignment of the pushed argument. */
5688 parm_align = arg->locate.boundary;
5689 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5690 == PAD_DOWNWARD)
5692 poly_int64 pad = used - size;
5693 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5694 if (pad_align != 0)
5695 parm_align = MIN (parm_align, pad_align);
5698 /* This isn't already where we want it on the stack, so put it there.
5699 This can either be done with push or copy insns. */
5700 if (maybe_ne (used, 0)
5701 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5702 NULL_RTX, parm_align, partial, reg, used - size,
5703 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5704 reg_parm_stack_space,
5705 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5706 sibcall_failure = 1;
5708 /* Unless this is a partially-in-register argument, the argument is now
5709 in the stack. */
5710 if (partial == 0)
5711 arg->value = arg->stack;
5713 else
5715 /* BLKmode, at least partly to be pushed. */
5717 unsigned int parm_align;
5718 poly_int64 excess;
5719 rtx size_rtx;
5721 /* Pushing a nonscalar.
5722 If part is passed in registers, PARTIAL says how much
5723 and emit_push_insn will take care of putting it there. */
5725 /* Round its size up to a multiple
5726 of the allocation unit for arguments. */
5728 if (arg->locate.size.var != 0)
5730 excess = 0;
5731 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5733 else
5735 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5736 for BLKmode is careful to avoid it. */
5737 excess = (arg->locate.size.constant
5738 - arg_int_size_in_bytes (TREE_TYPE (pval))
5739 + partial);
5740 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5741 NULL_RTX, TYPE_MODE (sizetype),
5742 EXPAND_NORMAL);
5745 parm_align = arg->locate.boundary;
5747 /* When an argument is padded down, the block is aligned to
5748 PARM_BOUNDARY, but the actual argument isn't. */
5749 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5750 == PAD_DOWNWARD)
5752 if (arg->locate.size.var)
5753 parm_align = BITS_PER_UNIT;
5754 else
5756 unsigned int excess_align
5757 = known_alignment (excess) * BITS_PER_UNIT;
5758 if (excess_align != 0)
5759 parm_align = MIN (parm_align, excess_align);
5763 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5765 /* emit_push_insn might not work properly if arg->value and
5766 argblock + arg->locate.offset areas overlap. */
5767 rtx x = arg->value;
5768 poly_int64 i = 0;
5770 if (strip_offset (XEXP (x, 0), &i)
5771 == crtl->args.internal_arg_pointer)
5773 /* arg.locate doesn't contain the pretend_args_size offset,
5774 it's part of argblock. Ensure we don't count it in I. */
5775 if (STACK_GROWS_DOWNWARD)
5776 i -= crtl->args.pretend_args_size;
5777 else
5778 i += crtl->args.pretend_args_size;
5780 /* expand_call should ensure this. */
5781 gcc_assert (!arg->locate.offset.var
5782 && arg->locate.size.var == 0);
5783 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5785 if (known_eq (arg->locate.offset.constant, i))
5787 /* Even though they appear to be at the same location,
5788 if part of the outgoing argument is in registers,
5789 they aren't really at the same location. Check for
5790 this by making sure that the incoming size is the
5791 same as the outgoing size. */
5792 if (maybe_ne (arg->locate.size.constant, size_val))
5793 sibcall_failure = 1;
5795 else if (maybe_in_range_p (arg->locate.offset.constant,
5796 i, size_val))
5797 sibcall_failure = 1;
5798 /* Use arg->locate.size.constant instead of size_rtx
5799 because we only care about the part of the argument
5800 on the stack. */
5801 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5802 arg->locate.size.constant))
5803 sibcall_failure = 1;
5807 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5808 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5809 parm_align, partial, reg, excess, argblock,
5810 ARGS_SIZE_RTX (arg->locate.offset),
5811 reg_parm_stack_space,
5812 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5814 /* Unless this is a partially-in-register argument, the argument is now
5815 in the stack.
5817 ??? Unlike the case above, in which we want the actual
5818 address of the data, so that we can load it directly into a
5819 register, here we want the address of the stack slot, so that
5820 it's properly aligned for word-by-word copying or something
5821 like that. It's not clear that this is always correct. */
5822 if (partial == 0)
5823 arg->value = arg->stack_slot;
5826 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5828 tree type = TREE_TYPE (arg->tree_value);
5829 arg->parallel_value
5830 = emit_group_load_into_temps (arg->reg, arg->value, type,
5831 int_size_in_bytes (type));
5834 /* Mark all slots this store used. */
5835 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5836 && argblock && ! variable_size && arg->stack)
5837 mark_stack_region_used (lower_bound, upper_bound);
5839 /* Once we have pushed something, pops can't safely
5840 be deferred during the rest of the arguments. */
5841 NO_DEFER_POP;
5843 /* Free any temporary slots made in processing this argument. */
5844 pop_temp_slots ();
5846 return sibcall_failure;
5849 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5851 bool
5852 must_pass_in_stack_var_size (machine_mode mode ATTRIBUTE_UNUSED,
5853 const_tree type)
5855 if (!type)
5856 return false;
5858 /* If the type has variable size... */
5859 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5860 return true;
5862 /* If the type is marked as addressable (it is required
5863 to be constructed into the stack)... */
5864 if (TREE_ADDRESSABLE (type))
5865 return true;
5867 return false;
5870 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5871 takes trailing padding of a structure into account. */
5872 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5874 bool
5875 must_pass_in_stack_var_size_or_pad (machine_mode mode, const_tree type)
5877 if (!type)
5878 return false;
5880 /* If the type has variable size... */
5881 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5882 return true;
5884 /* If the type is marked as addressable (it is required
5885 to be constructed into the stack)... */
5886 if (TREE_ADDRESSABLE (type))
5887 return true;
5889 if (TYPE_EMPTY_P (type))
5890 return false;
5892 /* If the padding and mode of the type is such that a copy into
5893 a register would put it into the wrong part of the register. */
5894 if (mode == BLKmode
5895 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5896 && (targetm.calls.function_arg_padding (mode, type)
5897 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5898 return true;
5900 return false;
5903 /* Tell the garbage collector about GTY markers in this source file. */
5904 #include "gt-calls.h"