2018-05-17 Richard Biener <rguenther@suse.de>
[official-gcc.git] / gcc / calls.c
blobf0e9d3b1cbbe7ce92eff78ac8eb3961ae10366fb
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-chkp.h"
51 #include "tree-vrp.h"
52 #include "tree-ssanames.h"
53 #include "rtl-chkp.h"
54 #include "intl.h"
55 #include "stringpool.h"
56 #include "attribs.h"
57 #include "builtins.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 void store_bounds (struct arg_data *, struct arg_data *);
157 static int store_one_arg (struct arg_data *, rtx, int, int, int);
158 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
159 static int finalize_must_preallocate (int, int, struct arg_data *,
160 struct args_size *);
161 static void precompute_arguments (int, struct arg_data *);
162 static void compute_argument_addresses (struct arg_data *, rtx, int);
163 static rtx rtx_for_function_call (tree, tree);
164 static void load_register_parameters (struct arg_data *, int, rtx *, int,
165 int, int *);
166 static int special_function_p (const_tree, int);
167 static int check_sibcall_argument_overlap_1 (rtx);
168 static int check_sibcall_argument_overlap (rtx_insn *, struct arg_data *, int);
170 static tree split_complex_types (tree);
172 #ifdef REG_PARM_STACK_SPACE
173 static rtx save_fixed_argument_area (int, rtx, int *, int *);
174 static void restore_fixed_argument_area (rtx, rtx, int, int);
175 #endif
177 /* Return true if bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
178 stack region might already be in use. */
180 static bool
181 stack_region_maybe_used_p (poly_uint64 lower_bound, poly_uint64 upper_bound,
182 unsigned int reg_parm_stack_space)
184 unsigned HOST_WIDE_INT const_lower, const_upper;
185 const_lower = constant_lower_bound (lower_bound);
186 if (!upper_bound.is_constant (&const_upper))
187 const_upper = HOST_WIDE_INT_M1U;
189 if (const_upper > stack_usage_watermark)
190 return true;
192 /* Don't worry about things in the fixed argument area;
193 it has already been saved. */
194 const_lower = MAX (const_lower, reg_parm_stack_space);
195 const_upper = MIN (const_upper, highest_outgoing_arg_in_use);
196 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
197 if (stack_usage_map[i])
198 return true;
199 return false;
202 /* Record that bytes [LOWER_BOUND, UPPER_BOUND) of the outgoing
203 stack region are now in use. */
205 static void
206 mark_stack_region_used (poly_uint64 lower_bound, poly_uint64 upper_bound)
208 unsigned HOST_WIDE_INT const_lower, const_upper;
209 const_lower = constant_lower_bound (lower_bound);
210 if (upper_bound.is_constant (&const_upper))
211 for (unsigned HOST_WIDE_INT i = const_lower; i < const_upper; ++i)
212 stack_usage_map[i] = 1;
213 else
214 stack_usage_watermark = MIN (stack_usage_watermark, const_lower);
217 /* Force FUNEXP into a form suitable for the address of a CALL,
218 and return that as an rtx. Also load the static chain register
219 if FNDECL is a nested function.
221 CALL_FUSAGE points to a variable holding the prospective
222 CALL_INSN_FUNCTION_USAGE information. */
225 prepare_call_address (tree fndecl_or_type, rtx funexp, rtx static_chain_value,
226 rtx *call_fusage, int reg_parm_seen, int flags)
228 /* Make a valid memory address and copy constants through pseudo-regs,
229 but not for a constant address if -fno-function-cse. */
230 if (GET_CODE (funexp) != SYMBOL_REF)
232 /* If it's an indirect call by descriptor, generate code to perform
233 runtime identification of the pointer and load the descriptor. */
234 if ((flags & ECF_BY_DESCRIPTOR) && !flag_trampolines)
236 const int bit_val = targetm.calls.custom_function_descriptors;
237 rtx call_lab = gen_label_rtx ();
239 gcc_assert (fndecl_or_type && TYPE_P (fndecl_or_type));
240 fndecl_or_type
241 = build_decl (UNKNOWN_LOCATION, FUNCTION_DECL, NULL_TREE,
242 fndecl_or_type);
243 DECL_STATIC_CHAIN (fndecl_or_type) = 1;
244 rtx chain = targetm.calls.static_chain (fndecl_or_type, false);
246 if (GET_MODE (funexp) != Pmode)
247 funexp = convert_memory_address (Pmode, funexp);
249 /* Avoid long live ranges around function calls. */
250 funexp = copy_to_mode_reg (Pmode, funexp);
252 if (REG_P (chain))
253 emit_insn (gen_rtx_CLOBBER (VOIDmode, chain));
255 /* Emit the runtime identification pattern. */
256 rtx mask = gen_rtx_AND (Pmode, funexp, GEN_INT (bit_val));
257 emit_cmp_and_jump_insns (mask, const0_rtx, EQ, NULL_RTX, Pmode, 1,
258 call_lab);
260 /* Statically predict the branch to very likely taken. */
261 rtx_insn *insn = get_last_insn ();
262 if (JUMP_P (insn))
263 predict_insn_def (insn, PRED_BUILTIN_EXPECT, TAKEN);
265 /* Load the descriptor. */
266 rtx mem = gen_rtx_MEM (ptr_mode,
267 plus_constant (Pmode, funexp, - bit_val));
268 MEM_NOTRAP_P (mem) = 1;
269 mem = convert_memory_address (Pmode, mem);
270 emit_move_insn (chain, mem);
272 mem = gen_rtx_MEM (ptr_mode,
273 plus_constant (Pmode, funexp,
274 POINTER_SIZE / BITS_PER_UNIT
275 - bit_val));
276 MEM_NOTRAP_P (mem) = 1;
277 mem = convert_memory_address (Pmode, mem);
278 emit_move_insn (funexp, mem);
280 emit_label (call_lab);
282 if (REG_P (chain))
284 use_reg (call_fusage, chain);
285 STATIC_CHAIN_REG_P (chain) = 1;
288 /* Make sure we're not going to be overwritten below. */
289 gcc_assert (!static_chain_value);
292 /* If we are using registers for parameters, force the
293 function address into a register now. */
294 funexp = ((reg_parm_seen
295 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
296 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
297 : memory_address (FUNCTION_MODE, funexp));
299 else
301 /* funexp could be a SYMBOL_REF represents a function pointer which is
302 of ptr_mode. In this case, it should be converted into address mode
303 to be a valid address for memory rtx pattern. See PR 64971. */
304 if (GET_MODE (funexp) != Pmode)
305 funexp = convert_memory_address (Pmode, funexp);
307 if (!(flags & ECF_SIBCALL))
309 if (!NO_FUNCTION_CSE && optimize && ! flag_no_function_cse)
310 funexp = force_reg (Pmode, funexp);
314 if (static_chain_value != 0
315 && (TREE_CODE (fndecl_or_type) != FUNCTION_DECL
316 || DECL_STATIC_CHAIN (fndecl_or_type)))
318 rtx chain;
320 chain = targetm.calls.static_chain (fndecl_or_type, false);
321 static_chain_value = convert_memory_address (Pmode, static_chain_value);
323 emit_move_insn (chain, static_chain_value);
324 if (REG_P (chain))
326 use_reg (call_fusage, chain);
327 STATIC_CHAIN_REG_P (chain) = 1;
331 return funexp;
334 /* Generate instructions to call function FUNEXP,
335 and optionally pop the results.
336 The CALL_INSN is the first insn generated.
338 FNDECL is the declaration node of the function. This is given to the
339 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
340 its own args.
342 FUNTYPE is the data type of the function. This is given to the hook
343 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
344 own args. We used to allow an identifier for library functions, but
345 that doesn't work when the return type is an aggregate type and the
346 calling convention says that the pointer to this aggregate is to be
347 popped by the callee.
349 STACK_SIZE is the number of bytes of arguments on the stack,
350 ROUNDED_STACK_SIZE is that number rounded up to
351 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
352 both to put into the call insn and to generate explicit popping
353 code if necessary.
355 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
356 It is zero if this call doesn't want a structure value.
358 NEXT_ARG_REG is the rtx that results from executing
359 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
360 just after all the args have had their registers assigned.
361 This could be whatever you like, but normally it is the first
362 arg-register beyond those used for args in this call,
363 or 0 if all the arg-registers are used in this call.
364 It is passed on to `gen_call' so you can put this info in the call insn.
366 VALREG is a hard register in which a value is returned,
367 or 0 if the call does not return a value.
369 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
370 the args to this call were processed.
371 We restore `inhibit_defer_pop' to that value.
373 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
374 denote registers used by the called function. */
376 static void
377 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
378 tree funtype ATTRIBUTE_UNUSED,
379 poly_int64 stack_size ATTRIBUTE_UNUSED,
380 poly_int64 rounded_stack_size,
381 poly_int64 struct_value_size ATTRIBUTE_UNUSED,
382 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
383 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
384 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
386 rtx rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
387 rtx call, funmem, pat;
388 int already_popped = 0;
389 poly_int64 n_popped = 0;
391 /* Sibling call patterns never pop arguments (no sibcall(_value)_pop
392 patterns exist). Any popping that the callee does on return will
393 be from our caller's frame rather than ours. */
394 if (!(ecf_flags & ECF_SIBCALL))
396 n_popped += targetm.calls.return_pops_args (fndecl, funtype, stack_size);
398 #ifdef CALL_POPS_ARGS
399 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
400 #endif
403 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
404 and we don't want to load it into a register as an optimization,
405 because prepare_call_address already did it if it should be done. */
406 if (GET_CODE (funexp) != SYMBOL_REF)
407 funexp = memory_address (FUNCTION_MODE, funexp);
409 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
410 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
412 tree t = fndecl;
414 /* Although a built-in FUNCTION_DECL and its non-__builtin
415 counterpart compare equal and get a shared mem_attrs, they
416 produce different dump output in compare-debug compilations,
417 if an entry gets garbage collected in one compilation, then
418 adds a different (but equivalent) entry, while the other
419 doesn't run the garbage collector at the same spot and then
420 shares the mem_attr with the equivalent entry. */
421 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
423 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
424 if (t2)
425 t = t2;
428 set_mem_expr (funmem, t);
430 else if (fntree)
431 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
433 if (ecf_flags & ECF_SIBCALL)
435 if (valreg)
436 pat = targetm.gen_sibcall_value (valreg, funmem,
437 rounded_stack_size_rtx,
438 next_arg_reg, NULL_RTX);
439 else
440 pat = targetm.gen_sibcall (funmem, rounded_stack_size_rtx,
441 next_arg_reg,
442 gen_int_mode (struct_value_size, Pmode));
444 /* If the target has "call" or "call_value" insns, then prefer them
445 if no arguments are actually popped. If the target does not have
446 "call" or "call_value" insns, then we must use the popping versions
447 even if the call has no arguments to pop. */
448 else if (maybe_ne (n_popped, 0)
449 || !(valreg
450 ? targetm.have_call_value ()
451 : targetm.have_call ()))
453 rtx n_pop = gen_int_mode (n_popped, Pmode);
455 /* If this subroutine pops its own args, record that in the call insn
456 if possible, for the sake of frame pointer elimination. */
458 if (valreg)
459 pat = targetm.gen_call_value_pop (valreg, funmem,
460 rounded_stack_size_rtx,
461 next_arg_reg, n_pop);
462 else
463 pat = targetm.gen_call_pop (funmem, rounded_stack_size_rtx,
464 next_arg_reg, n_pop);
466 already_popped = 1;
468 else
470 if (valreg)
471 pat = targetm.gen_call_value (valreg, funmem, rounded_stack_size_rtx,
472 next_arg_reg, NULL_RTX);
473 else
474 pat = targetm.gen_call (funmem, rounded_stack_size_rtx, next_arg_reg,
475 gen_int_mode (struct_value_size, Pmode));
477 emit_insn (pat);
479 /* Find the call we just emitted. */
480 rtx_call_insn *call_insn = last_call_insn ();
482 /* Some target create a fresh MEM instead of reusing the one provided
483 above. Set its MEM_EXPR. */
484 call = get_call_rtx_from (call_insn);
485 if (call
486 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
487 && MEM_EXPR (funmem) != NULL_TREE)
488 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
490 /* Mark instrumented calls. */
491 if (call && fntree)
492 CALL_EXPR_WITH_BOUNDS_P (call) = CALL_WITH_BOUNDS_P (fntree);
494 /* Put the register usage information there. */
495 add_function_usage_to (call_insn, call_fusage);
497 /* If this is a const call, then set the insn's unchanging bit. */
498 if (ecf_flags & ECF_CONST)
499 RTL_CONST_CALL_P (call_insn) = 1;
501 /* If this is a pure call, then set the insn's unchanging bit. */
502 if (ecf_flags & ECF_PURE)
503 RTL_PURE_CALL_P (call_insn) = 1;
505 /* If this is a const call, then set the insn's unchanging bit. */
506 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
507 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
509 /* Create a nothrow REG_EH_REGION note, if needed. */
510 make_reg_eh_region_note (call_insn, ecf_flags, 0);
512 if (ecf_flags & ECF_NORETURN)
513 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
515 if (ecf_flags & ECF_RETURNS_TWICE)
517 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
518 cfun->calls_setjmp = 1;
521 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
523 /* Restore this now, so that we do defer pops for this call's args
524 if the context of the call as a whole permits. */
525 inhibit_defer_pop = old_inhibit_defer_pop;
527 if (maybe_ne (n_popped, 0))
529 if (!already_popped)
530 CALL_INSN_FUNCTION_USAGE (call_insn)
531 = gen_rtx_EXPR_LIST (VOIDmode,
532 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
533 CALL_INSN_FUNCTION_USAGE (call_insn));
534 rounded_stack_size -= n_popped;
535 rounded_stack_size_rtx = gen_int_mode (rounded_stack_size, Pmode);
536 stack_pointer_delta -= n_popped;
538 add_args_size_note (call_insn, stack_pointer_delta);
540 /* If popup is needed, stack realign must use DRAP */
541 if (SUPPORTS_STACK_ALIGNMENT)
542 crtl->need_drap = true;
544 /* For noreturn calls when not accumulating outgoing args force
545 REG_ARGS_SIZE note to prevent crossjumping of calls with different
546 args sizes. */
547 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
548 add_args_size_note (call_insn, stack_pointer_delta);
550 if (!ACCUMULATE_OUTGOING_ARGS)
552 /* If returning from the subroutine does not automatically pop the args,
553 we need an instruction to pop them sooner or later.
554 Perhaps do it now; perhaps just record how much space to pop later.
556 If returning from the subroutine does pop the args, indicate that the
557 stack pointer will be changed. */
559 if (maybe_ne (rounded_stack_size, 0))
561 if (ecf_flags & ECF_NORETURN)
562 /* Just pretend we did the pop. */
563 stack_pointer_delta -= rounded_stack_size;
564 else if (flag_defer_pop && inhibit_defer_pop == 0
565 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
566 pending_stack_adjust += rounded_stack_size;
567 else
568 adjust_stack (rounded_stack_size_rtx);
571 /* When we accumulate outgoing args, we must avoid any stack manipulations.
572 Restore the stack pointer to its original value now. Usually
573 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
574 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
575 popping variants of functions exist as well.
577 ??? We may optimize similar to defer_pop above, but it is
578 probably not worthwhile.
580 ??? It will be worthwhile to enable combine_stack_adjustments even for
581 such machines. */
582 else if (maybe_ne (n_popped, 0))
583 anti_adjust_stack (gen_int_mode (n_popped, Pmode));
586 /* Determine if the function identified by FNDECL is one with
587 special properties we wish to know about. Modify FLAGS accordingly.
589 For example, if the function might return more than one time (setjmp), then
590 set ECF_RETURNS_TWICE.
592 Set ECF_MAY_BE_ALLOCA for any memory allocation function that might allocate
593 space from the stack such as alloca. */
595 static int
596 special_function_p (const_tree fndecl, int flags)
598 tree name_decl = DECL_NAME (fndecl);
600 /* For instrumentation clones we want to derive flags
601 from the original name. */
602 if (cgraph_node::get (fndecl)
603 && cgraph_node::get (fndecl)->instrumentation_clone)
604 name_decl = DECL_NAME (cgraph_node::get (fndecl)->orig_decl);
606 if (fndecl && name_decl
607 && IDENTIFIER_LENGTH (name_decl) <= 11
608 /* Exclude functions not at the file scope, or not `extern',
609 since they are not the magic functions we would otherwise
610 think they are.
611 FIXME: this should be handled with attributes, not with this
612 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
613 because you can declare fork() inside a function if you
614 wish. */
615 && (DECL_CONTEXT (fndecl) == NULL_TREE
616 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
617 && TREE_PUBLIC (fndecl))
619 const char *name = IDENTIFIER_POINTER (name_decl);
620 const char *tname = name;
622 /* We assume that alloca will always be called by name. It
623 makes no sense to pass it as a pointer-to-function to
624 anything that does not understand its behavior. */
625 if (IDENTIFIER_LENGTH (name_decl) == 6
626 && name[0] == 'a'
627 && ! strcmp (name, "alloca"))
628 flags |= ECF_MAY_BE_ALLOCA;
630 /* Disregard prefix _ or __. */
631 if (name[0] == '_')
633 if (name[1] == '_')
634 tname += 2;
635 else
636 tname += 1;
639 /* ECF_RETURNS_TWICE is safe even for -ffreestanding. */
640 if (! strcmp (tname, "setjmp")
641 || ! strcmp (tname, "sigsetjmp")
642 || ! strcmp (name, "savectx")
643 || ! strcmp (name, "vfork")
644 || ! strcmp (name, "getcontext"))
645 flags |= ECF_RETURNS_TWICE;
648 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
649 && ALLOCA_FUNCTION_CODE_P (DECL_FUNCTION_CODE (fndecl)))
650 flags |= ECF_MAY_BE_ALLOCA;
652 return flags;
655 /* Similar to special_function_p; return a set of ERF_ flags for the
656 function FNDECL. */
657 static int
658 decl_return_flags (tree fndecl)
660 tree attr;
661 tree type = TREE_TYPE (fndecl);
662 if (!type)
663 return 0;
665 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
666 if (!attr)
667 return 0;
669 attr = TREE_VALUE (TREE_VALUE (attr));
670 if (!attr || TREE_STRING_LENGTH (attr) < 1)
671 return 0;
673 switch (TREE_STRING_POINTER (attr)[0])
675 case '1':
676 case '2':
677 case '3':
678 case '4':
679 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
681 case 'm':
682 return ERF_NOALIAS;
684 case '.':
685 default:
686 return 0;
690 /* Return nonzero when FNDECL represents a call to setjmp. */
693 setjmp_call_p (const_tree fndecl)
695 if (DECL_IS_RETURNS_TWICE (fndecl))
696 return ECF_RETURNS_TWICE;
697 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
701 /* Return true if STMT may be an alloca call. */
703 bool
704 gimple_maybe_alloca_call_p (const gimple *stmt)
706 tree fndecl;
708 if (!is_gimple_call (stmt))
709 return false;
711 fndecl = gimple_call_fndecl (stmt);
712 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
713 return true;
715 return false;
718 /* Return true if STMT is a builtin alloca call. */
720 bool
721 gimple_alloca_call_p (const gimple *stmt)
723 tree fndecl;
725 if (!is_gimple_call (stmt))
726 return false;
728 fndecl = gimple_call_fndecl (stmt);
729 if (fndecl && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
730 switch (DECL_FUNCTION_CODE (fndecl))
732 CASE_BUILT_IN_ALLOCA:
733 return gimple_call_num_args (stmt) > 0;
734 default:
735 break;
738 return false;
741 /* Return true when exp contains a builtin alloca call. */
743 bool
744 alloca_call_p (const_tree exp)
746 tree fndecl;
747 if (TREE_CODE (exp) == CALL_EXPR
748 && (fndecl = get_callee_fndecl (exp))
749 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
750 switch (DECL_FUNCTION_CODE (fndecl))
752 CASE_BUILT_IN_ALLOCA:
753 return true;
754 default:
755 break;
758 return false;
761 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
762 function. Return FALSE otherwise. */
764 static bool
765 is_tm_builtin (const_tree fndecl)
767 if (fndecl == NULL)
768 return false;
770 if (decl_is_tm_clone (fndecl))
771 return true;
773 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
775 switch (DECL_FUNCTION_CODE (fndecl))
777 case BUILT_IN_TM_COMMIT:
778 case BUILT_IN_TM_COMMIT_EH:
779 case BUILT_IN_TM_ABORT:
780 case BUILT_IN_TM_IRREVOCABLE:
781 case BUILT_IN_TM_GETTMCLONE_IRR:
782 case BUILT_IN_TM_MEMCPY:
783 case BUILT_IN_TM_MEMMOVE:
784 case BUILT_IN_TM_MEMSET:
785 CASE_BUILT_IN_TM_STORE (1):
786 CASE_BUILT_IN_TM_STORE (2):
787 CASE_BUILT_IN_TM_STORE (4):
788 CASE_BUILT_IN_TM_STORE (8):
789 CASE_BUILT_IN_TM_STORE (FLOAT):
790 CASE_BUILT_IN_TM_STORE (DOUBLE):
791 CASE_BUILT_IN_TM_STORE (LDOUBLE):
792 CASE_BUILT_IN_TM_STORE (M64):
793 CASE_BUILT_IN_TM_STORE (M128):
794 CASE_BUILT_IN_TM_STORE (M256):
795 CASE_BUILT_IN_TM_LOAD (1):
796 CASE_BUILT_IN_TM_LOAD (2):
797 CASE_BUILT_IN_TM_LOAD (4):
798 CASE_BUILT_IN_TM_LOAD (8):
799 CASE_BUILT_IN_TM_LOAD (FLOAT):
800 CASE_BUILT_IN_TM_LOAD (DOUBLE):
801 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
802 CASE_BUILT_IN_TM_LOAD (M64):
803 CASE_BUILT_IN_TM_LOAD (M128):
804 CASE_BUILT_IN_TM_LOAD (M256):
805 case BUILT_IN_TM_LOG:
806 case BUILT_IN_TM_LOG_1:
807 case BUILT_IN_TM_LOG_2:
808 case BUILT_IN_TM_LOG_4:
809 case BUILT_IN_TM_LOG_8:
810 case BUILT_IN_TM_LOG_FLOAT:
811 case BUILT_IN_TM_LOG_DOUBLE:
812 case BUILT_IN_TM_LOG_LDOUBLE:
813 case BUILT_IN_TM_LOG_M64:
814 case BUILT_IN_TM_LOG_M128:
815 case BUILT_IN_TM_LOG_M256:
816 return true;
817 default:
818 break;
821 return false;
824 /* Detect flags (function attributes) from the function decl or type node. */
827 flags_from_decl_or_type (const_tree exp)
829 int flags = 0;
831 if (DECL_P (exp))
833 /* The function exp may have the `malloc' attribute. */
834 if (DECL_IS_MALLOC (exp))
835 flags |= ECF_MALLOC;
837 /* The function exp may have the `returns_twice' attribute. */
838 if (DECL_IS_RETURNS_TWICE (exp))
839 flags |= ECF_RETURNS_TWICE;
841 /* Process the pure and const attributes. */
842 if (TREE_READONLY (exp))
843 flags |= ECF_CONST;
844 if (DECL_PURE_P (exp))
845 flags |= ECF_PURE;
846 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
847 flags |= ECF_LOOPING_CONST_OR_PURE;
849 if (DECL_IS_NOVOPS (exp))
850 flags |= ECF_NOVOPS;
851 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
852 flags |= ECF_LEAF;
853 if (lookup_attribute ("cold", DECL_ATTRIBUTES (exp)))
854 flags |= ECF_COLD;
856 if (TREE_NOTHROW (exp))
857 flags |= ECF_NOTHROW;
859 if (flag_tm)
861 if (is_tm_builtin (exp))
862 flags |= ECF_TM_BUILTIN;
863 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
864 || lookup_attribute ("transaction_pure",
865 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
866 flags |= ECF_TM_PURE;
869 flags = special_function_p (exp, flags);
871 else if (TYPE_P (exp))
873 if (TYPE_READONLY (exp))
874 flags |= ECF_CONST;
876 if (flag_tm
877 && ((flags & ECF_CONST) != 0
878 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
879 flags |= ECF_TM_PURE;
881 else
882 gcc_unreachable ();
884 if (TREE_THIS_VOLATILE (exp))
886 flags |= ECF_NORETURN;
887 if (flags & (ECF_CONST|ECF_PURE))
888 flags |= ECF_LOOPING_CONST_OR_PURE;
891 return flags;
894 /* Detect flags from a CALL_EXPR. */
897 call_expr_flags (const_tree t)
899 int flags;
900 tree decl = get_callee_fndecl (t);
902 if (decl)
903 flags = flags_from_decl_or_type (decl);
904 else if (CALL_EXPR_FN (t) == NULL_TREE)
905 flags = internal_fn_flags (CALL_EXPR_IFN (t));
906 else
908 tree type = TREE_TYPE (CALL_EXPR_FN (t));
909 if (type && TREE_CODE (type) == POINTER_TYPE)
910 flags = flags_from_decl_or_type (TREE_TYPE (type));
911 else
912 flags = 0;
913 if (CALL_EXPR_BY_DESCRIPTOR (t))
914 flags |= ECF_BY_DESCRIPTOR;
917 return flags;
920 /* Return true if TYPE should be passed by invisible reference. */
922 bool
923 pass_by_reference (CUMULATIVE_ARGS *ca, machine_mode mode,
924 tree type, bool named_arg)
926 if (type)
928 /* If this type contains non-trivial constructors, then it is
929 forbidden for the middle-end to create any new copies. */
930 if (TREE_ADDRESSABLE (type))
931 return true;
933 /* GCC post 3.4 passes *all* variable sized types by reference. */
934 if (!TYPE_SIZE (type) || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
935 return true;
937 /* If a record type should be passed the same as its first (and only)
938 member, use the type and mode of that member. */
939 if (TREE_CODE (type) == RECORD_TYPE && TYPE_TRANSPARENT_AGGR (type))
941 type = TREE_TYPE (first_field (type));
942 mode = TYPE_MODE (type);
946 return targetm.calls.pass_by_reference (pack_cumulative_args (ca), mode,
947 type, named_arg);
950 /* Return true if TYPE, which is passed by reference, should be callee
951 copied instead of caller copied. */
953 bool
954 reference_callee_copied (CUMULATIVE_ARGS *ca, machine_mode mode,
955 tree type, bool named_arg)
957 if (type && TREE_ADDRESSABLE (type))
958 return false;
959 return targetm.calls.callee_copies (pack_cumulative_args (ca), mode, type,
960 named_arg);
964 /* Precompute all register parameters as described by ARGS, storing values
965 into fields within the ARGS array.
967 NUM_ACTUALS indicates the total number elements in the ARGS array.
969 Set REG_PARM_SEEN if we encounter a register parameter. */
971 static void
972 precompute_register_parameters (int num_actuals, struct arg_data *args,
973 int *reg_parm_seen)
975 int i;
977 *reg_parm_seen = 0;
979 for (i = 0; i < num_actuals; i++)
980 if (args[i].reg != 0 && ! args[i].pass_on_stack)
982 *reg_parm_seen = 1;
984 if (args[i].value == 0)
986 push_temp_slots ();
987 args[i].value = expand_normal (args[i].tree_value);
988 preserve_temp_slots (args[i].value);
989 pop_temp_slots ();
992 /* If we are to promote the function arg to a wider mode,
993 do it now. */
995 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
996 args[i].value
997 = convert_modes (args[i].mode,
998 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
999 args[i].value, args[i].unsignedp);
1001 /* If the value is a non-legitimate constant, force it into a
1002 pseudo now. TLS symbols sometimes need a call to resolve. */
1003 if (CONSTANT_P (args[i].value)
1004 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
1005 args[i].value = force_reg (args[i].mode, args[i].value);
1007 /* If we're going to have to load the value by parts, pull the
1008 parts into pseudos. The part extraction process can involve
1009 non-trivial computation. */
1010 if (GET_CODE (args[i].reg) == PARALLEL)
1012 tree type = TREE_TYPE (args[i].tree_value);
1013 args[i].parallel_value
1014 = emit_group_load_into_temps (args[i].reg, args[i].value,
1015 type, int_size_in_bytes (type));
1018 /* If the value is expensive, and we are inside an appropriately
1019 short loop, put the value into a pseudo and then put the pseudo
1020 into the hard reg.
1022 For small register classes, also do this if this call uses
1023 register parameters. This is to avoid reload conflicts while
1024 loading the parameters registers. */
1026 else if ((! (REG_P (args[i].value)
1027 || (GET_CODE (args[i].value) == SUBREG
1028 && REG_P (SUBREG_REG (args[i].value)))))
1029 && args[i].mode != BLKmode
1030 && (set_src_cost (args[i].value, args[i].mode,
1031 optimize_insn_for_speed_p ())
1032 > COSTS_N_INSNS (1))
1033 && ((*reg_parm_seen
1034 && targetm.small_register_classes_for_mode_p (args[i].mode))
1035 || optimize))
1036 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
1040 #ifdef REG_PARM_STACK_SPACE
1042 /* The argument list is the property of the called routine and it
1043 may clobber it. If the fixed area has been used for previous
1044 parameters, we must save and restore it. */
1046 static rtx
1047 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
1049 unsigned int low;
1050 unsigned int high;
1052 /* Compute the boundary of the area that needs to be saved, if any. */
1053 high = reg_parm_stack_space;
1054 if (ARGS_GROW_DOWNWARD)
1055 high += 1;
1057 if (high > highest_outgoing_arg_in_use)
1058 high = highest_outgoing_arg_in_use;
1060 for (low = 0; low < high; low++)
1061 if (stack_usage_map[low] != 0 || low >= stack_usage_watermark)
1063 int num_to_save;
1064 machine_mode save_mode;
1065 int delta;
1066 rtx addr;
1067 rtx stack_area;
1068 rtx save_area;
1070 while (stack_usage_map[--high] == 0)
1073 *low_to_save = low;
1074 *high_to_save = high;
1076 num_to_save = high - low + 1;
1078 /* If we don't have the required alignment, must do this
1079 in BLKmode. */
1080 scalar_int_mode imode;
1081 if (int_mode_for_size (num_to_save * BITS_PER_UNIT, 1).exists (&imode)
1082 && (low & (MIN (GET_MODE_SIZE (imode),
1083 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)) == 0)
1084 save_mode = imode;
1085 else
1086 save_mode = BLKmode;
1088 if (ARGS_GROW_DOWNWARD)
1089 delta = -high;
1090 else
1091 delta = low;
1093 addr = plus_constant (Pmode, argblock, delta);
1094 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1096 set_mem_align (stack_area, PARM_BOUNDARY);
1097 if (save_mode == BLKmode)
1099 save_area = assign_stack_temp (BLKmode, num_to_save);
1100 emit_block_move (validize_mem (save_area), stack_area,
1101 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
1103 else
1105 save_area = gen_reg_rtx (save_mode);
1106 emit_move_insn (save_area, stack_area);
1109 return save_area;
1112 return NULL_RTX;
1115 static void
1116 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
1118 machine_mode save_mode = GET_MODE (save_area);
1119 int delta;
1120 rtx addr, stack_area;
1122 if (ARGS_GROW_DOWNWARD)
1123 delta = -high_to_save;
1124 else
1125 delta = low_to_save;
1127 addr = plus_constant (Pmode, argblock, delta);
1128 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
1129 set_mem_align (stack_area, PARM_BOUNDARY);
1131 if (save_mode != BLKmode)
1132 emit_move_insn (stack_area, save_area);
1133 else
1134 emit_block_move (stack_area, validize_mem (save_area),
1135 GEN_INT (high_to_save - low_to_save + 1),
1136 BLOCK_OP_CALL_PARM);
1138 #endif /* REG_PARM_STACK_SPACE */
1140 /* If any elements in ARGS refer to parameters that are to be passed in
1141 registers, but not in memory, and whose alignment does not permit a
1142 direct copy into registers. Copy the values into a group of pseudos
1143 which we will later copy into the appropriate hard registers.
1145 Pseudos for each unaligned argument will be stored into the array
1146 args[argnum].aligned_regs. The caller is responsible for deallocating
1147 the aligned_regs array if it is nonzero. */
1149 static void
1150 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
1152 int i, j;
1154 for (i = 0; i < num_actuals; i++)
1155 if (args[i].reg != 0 && ! args[i].pass_on_stack
1156 && GET_CODE (args[i].reg) != PARALLEL
1157 && args[i].mode == BLKmode
1158 && MEM_P (args[i].value)
1159 && (MEM_ALIGN (args[i].value)
1160 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1162 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1163 int endian_correction = 0;
1165 if (args[i].partial)
1167 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
1168 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1170 else
1172 args[i].n_aligned_regs
1173 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1176 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1178 /* Structures smaller than a word are normally aligned to the
1179 least significant byte. On a BYTES_BIG_ENDIAN machine,
1180 this means we must skip the empty high order bytes when
1181 calculating the bit offset. */
1182 if (bytes < UNITS_PER_WORD
1183 #ifdef BLOCK_REG_PADDING
1184 && (BLOCK_REG_PADDING (args[i].mode,
1185 TREE_TYPE (args[i].tree_value), 1)
1186 == PAD_DOWNWARD)
1187 #else
1188 && BYTES_BIG_ENDIAN
1189 #endif
1191 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1193 for (j = 0; j < args[i].n_aligned_regs; j++)
1195 rtx reg = gen_reg_rtx (word_mode);
1196 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1197 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1199 args[i].aligned_regs[j] = reg;
1200 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1201 word_mode, word_mode, false, NULL);
1203 /* There is no need to restrict this code to loading items
1204 in TYPE_ALIGN sized hunks. The bitfield instructions can
1205 load up entire word sized registers efficiently.
1207 ??? This may not be needed anymore.
1208 We use to emit a clobber here but that doesn't let later
1209 passes optimize the instructions we emit. By storing 0 into
1210 the register later passes know the first AND to zero out the
1211 bitfield being set in the register is unnecessary. The store
1212 of 0 will be deleted as will at least the first AND. */
1214 emit_move_insn (reg, const0_rtx);
1216 bytes -= bitsize / BITS_PER_UNIT;
1217 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1218 word_mode, word, false);
1223 /* The limit set by -Walloc-larger-than=. */
1224 static GTY(()) tree alloc_object_size_limit;
1226 /* Initialize ALLOC_OBJECT_SIZE_LIMIT based on the -Walloc-size-larger-than=
1227 setting if the option is specified, or to the maximum object size if it
1228 is not. Return the initialized value. */
1230 static tree
1231 alloc_max_size (void)
1233 if (!alloc_object_size_limit)
1235 alloc_object_size_limit = max_object_size ();
1237 if (warn_alloc_size_limit)
1239 char *end = NULL;
1240 errno = 0;
1241 unsigned HOST_WIDE_INT unit = 1;
1242 unsigned HOST_WIDE_INT limit
1243 = strtoull (warn_alloc_size_limit, &end, 10);
1245 if (!errno)
1247 if (end && *end)
1249 /* Numeric option arguments are at most INT_MAX. Make it
1250 possible to specify a larger value by accepting common
1251 suffixes. */
1252 if (!strcmp (end, "kB"))
1253 unit = 1000;
1254 else if (!strcasecmp (end, "KiB") || strcmp (end, "KB"))
1255 unit = 1024;
1256 else if (!strcmp (end, "MB"))
1257 unit = HOST_WIDE_INT_UC (1000) * 1000;
1258 else if (!strcasecmp (end, "MiB"))
1259 unit = HOST_WIDE_INT_UC (1024) * 1024;
1260 else if (!strcasecmp (end, "GB"))
1261 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000;
1262 else if (!strcasecmp (end, "GiB"))
1263 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024;
1264 else if (!strcasecmp (end, "TB"))
1265 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000;
1266 else if (!strcasecmp (end, "TiB"))
1267 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024;
1268 else if (!strcasecmp (end, "PB"))
1269 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000;
1270 else if (!strcasecmp (end, "PiB"))
1271 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024;
1272 else if (!strcasecmp (end, "EB"))
1273 unit = HOST_WIDE_INT_UC (1000) * 1000 * 1000 * 1000 * 1000
1274 * 1000;
1275 else if (!strcasecmp (end, "EiB"))
1276 unit = HOST_WIDE_INT_UC (1024) * 1024 * 1024 * 1024 * 1024
1277 * 1024;
1278 else
1279 unit = 0;
1282 if (unit)
1284 widest_int w = wi::mul (limit, unit);
1285 if (w < wi::to_widest (alloc_object_size_limit))
1286 alloc_object_size_limit
1287 = wide_int_to_tree (ptrdiff_type_node, w);
1292 return alloc_object_size_limit;
1295 /* Return true when EXP's range can be determined and set RANGE[] to it
1296 after adjusting it if necessary to make EXP a represents a valid size
1297 of object, or a valid size argument to an allocation function declared
1298 with attribute alloc_size (whose argument may be signed), or to a string
1299 manipulation function like memset. When ALLOW_ZERO is true, allow
1300 returning a range of [0, 0] for a size in an anti-range [1, N] where
1301 N > PTRDIFF_MAX. A zero range is a (nearly) invalid argument to
1302 allocation functions like malloc but it is a valid argument to
1303 functions like memset. */
1305 bool
1306 get_size_range (tree exp, tree range[2], bool allow_zero /* = false */)
1308 if (tree_fits_uhwi_p (exp))
1310 /* EXP is a constant. */
1311 range[0] = range[1] = exp;
1312 return true;
1315 tree exptype = TREE_TYPE (exp);
1316 bool integral = INTEGRAL_TYPE_P (exptype);
1318 wide_int min, max;
1319 enum value_range_type range_type;
1321 if (TREE_CODE (exp) == SSA_NAME && integral)
1322 range_type = get_range_info (exp, &min, &max);
1323 else
1324 range_type = VR_VARYING;
1326 if (range_type == VR_VARYING)
1328 if (integral)
1330 /* Use the full range of the type of the expression when
1331 no value range information is available. */
1332 range[0] = TYPE_MIN_VALUE (exptype);
1333 range[1] = TYPE_MAX_VALUE (exptype);
1334 return true;
1337 range[0] = NULL_TREE;
1338 range[1] = NULL_TREE;
1339 return false;
1342 unsigned expprec = TYPE_PRECISION (exptype);
1344 bool signed_p = !TYPE_UNSIGNED (exptype);
1346 if (range_type == VR_ANTI_RANGE)
1348 if (signed_p)
1350 if (wi::les_p (max, 0))
1352 /* EXP is not in a strictly negative range. That means
1353 it must be in some (not necessarily strictly) positive
1354 range which includes zero. Since in signed to unsigned
1355 conversions negative values end up converted to large
1356 positive values, and otherwise they are not valid sizes,
1357 the resulting range is in both cases [0, TYPE_MAX]. */
1358 min = wi::zero (expprec);
1359 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1361 else if (wi::les_p (min - 1, 0))
1363 /* EXP is not in a negative-positive range. That means EXP
1364 is either negative, or greater than max. Since negative
1365 sizes are invalid make the range [MAX + 1, TYPE_MAX]. */
1366 min = max + 1;
1367 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1369 else
1371 max = min - 1;
1372 min = wi::zero (expprec);
1375 else if (wi::eq_p (0, min - 1))
1377 /* EXP is unsigned and not in the range [1, MAX]. That means
1378 it's either zero or greater than MAX. Even though 0 would
1379 normally be detected by -Walloc-zero, unless ALLOW_ZERO
1380 is true, set the range to [MAX, TYPE_MAX] so that when MAX
1381 is greater than the limit the whole range is diagnosed. */
1382 if (allow_zero)
1383 min = max = wi::zero (expprec);
1384 else
1386 min = max + 1;
1387 max = wi::to_wide (TYPE_MAX_VALUE (exptype));
1390 else
1392 max = min - 1;
1393 min = wi::zero (expprec);
1397 range[0] = wide_int_to_tree (exptype, min);
1398 range[1] = wide_int_to_tree (exptype, max);
1400 return true;
1403 /* Diagnose a call EXP to function FN decorated with attribute alloc_size
1404 whose argument numbers given by IDX with values given by ARGS exceed
1405 the maximum object size or cause an unsigned oveflow (wrapping) when
1406 multiplied. When ARGS[0] is null the function does nothing. ARGS[1]
1407 may be null for functions like malloc, and non-null for those like
1408 calloc that are decorated with a two-argument attribute alloc_size. */
1410 void
1411 maybe_warn_alloc_args_overflow (tree fn, tree exp, tree args[2], int idx[2])
1413 /* The range each of the (up to) two arguments is known to be in. */
1414 tree argrange[2][2] = { { NULL_TREE, NULL_TREE }, { NULL_TREE, NULL_TREE } };
1416 /* Maximum object size set by -Walloc-size-larger-than= or SIZE_MAX / 2. */
1417 tree maxobjsize = alloc_max_size ();
1419 location_t loc = EXPR_LOCATION (exp);
1421 bool warned = false;
1423 /* Validate each argument individually. */
1424 for (unsigned i = 0; i != 2 && args[i]; ++i)
1426 if (TREE_CODE (args[i]) == INTEGER_CST)
1428 argrange[i][0] = args[i];
1429 argrange[i][1] = args[i];
1431 if (tree_int_cst_lt (args[i], integer_zero_node))
1433 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1434 "%Kargument %i value %qE is negative",
1435 exp, idx[i] + 1, args[i]);
1437 else if (integer_zerop (args[i]))
1439 /* Avoid issuing -Walloc-zero for allocation functions other
1440 than __builtin_alloca that are declared with attribute
1441 returns_nonnull because there's no portability risk. This
1442 avoids warning for such calls to libiberty's xmalloc and
1443 friends.
1444 Also avoid issuing the warning for calls to function named
1445 "alloca". */
1446 if ((DECL_FUNCTION_CODE (fn) == BUILT_IN_ALLOCA
1447 && IDENTIFIER_LENGTH (DECL_NAME (fn)) != 6)
1448 || (DECL_FUNCTION_CODE (fn) != BUILT_IN_ALLOCA
1449 && !lookup_attribute ("returns_nonnull",
1450 TYPE_ATTRIBUTES (TREE_TYPE (fn)))))
1451 warned = warning_at (loc, OPT_Walloc_zero,
1452 "%Kargument %i value is zero",
1453 exp, idx[i] + 1);
1455 else if (tree_int_cst_lt (maxobjsize, args[i]))
1457 /* G++ emits calls to ::operator new[](SIZE_MAX) in C++98
1458 mode and with -fno-exceptions as a way to indicate array
1459 size overflow. There's no good way to detect C++98 here
1460 so avoid diagnosing these calls for all C++ modes. */
1461 if (i == 0
1462 && !args[1]
1463 && lang_GNU_CXX ()
1464 && DECL_IS_OPERATOR_NEW (fn)
1465 && integer_all_onesp (args[i]))
1466 continue;
1468 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1469 "%Kargument %i value %qE exceeds "
1470 "maximum object size %E",
1471 exp, idx[i] + 1, args[i], maxobjsize);
1474 else if (TREE_CODE (args[i]) == SSA_NAME
1475 && get_size_range (args[i], argrange[i]))
1477 /* Verify that the argument's range is not negative (including
1478 upper bound of zero). */
1479 if (tree_int_cst_lt (argrange[i][0], integer_zero_node)
1480 && tree_int_cst_le (argrange[i][1], integer_zero_node))
1482 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1483 "%Kargument %i range [%E, %E] is negative",
1484 exp, idx[i] + 1,
1485 argrange[i][0], argrange[i][1]);
1487 else if (tree_int_cst_lt (maxobjsize, argrange[i][0]))
1489 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1490 "%Kargument %i range [%E, %E] exceeds "
1491 "maximum object size %E",
1492 exp, idx[i] + 1,
1493 argrange[i][0], argrange[i][1],
1494 maxobjsize);
1499 if (!argrange[0])
1500 return;
1502 /* For a two-argument alloc_size, validate the product of the two
1503 arguments if both of their values or ranges are known. */
1504 if (!warned && tree_fits_uhwi_p (argrange[0][0])
1505 && argrange[1][0] && tree_fits_uhwi_p (argrange[1][0])
1506 && !integer_onep (argrange[0][0])
1507 && !integer_onep (argrange[1][0]))
1509 /* Check for overflow in the product of a function decorated with
1510 attribute alloc_size (X, Y). */
1511 unsigned szprec = TYPE_PRECISION (size_type_node);
1512 wide_int x = wi::to_wide (argrange[0][0], szprec);
1513 wide_int y = wi::to_wide (argrange[1][0], szprec);
1515 bool vflow;
1516 wide_int prod = wi::umul (x, y, &vflow);
1518 if (vflow)
1519 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1520 "%Kproduct %<%E * %E%> of arguments %i and %i "
1521 "exceeds %<SIZE_MAX%>",
1522 exp, argrange[0][0], argrange[1][0],
1523 idx[0] + 1, idx[1] + 1);
1524 else if (wi::ltu_p (wi::to_wide (maxobjsize, szprec), prod))
1525 warned = warning_at (loc, OPT_Walloc_size_larger_than_,
1526 "%Kproduct %<%E * %E%> of arguments %i and %i "
1527 "exceeds maximum object size %E",
1528 exp, argrange[0][0], argrange[1][0],
1529 idx[0] + 1, idx[1] + 1,
1530 maxobjsize);
1532 if (warned)
1534 /* Print the full range of each of the two arguments to make
1535 it clear when it is, in fact, in a range and not constant. */
1536 if (argrange[0][0] != argrange [0][1])
1537 inform (loc, "argument %i in the range [%E, %E]",
1538 idx[0] + 1, argrange[0][0], argrange[0][1]);
1539 if (argrange[1][0] != argrange [1][1])
1540 inform (loc, "argument %i in the range [%E, %E]",
1541 idx[1] + 1, argrange[1][0], argrange[1][1]);
1545 if (warned)
1547 location_t fnloc = DECL_SOURCE_LOCATION (fn);
1549 if (DECL_IS_BUILTIN (fn))
1550 inform (loc,
1551 "in a call to built-in allocation function %qD", fn);
1552 else
1553 inform (fnloc,
1554 "in a call to allocation function %qD declared here", fn);
1558 /* If EXPR refers to a character array or pointer declared attribute
1559 nonstring return a decl for that array or pointer and set *REF to
1560 the referenced enclosing object or pointer. Otherwise returns
1561 null. */
1563 tree
1564 get_attr_nonstring_decl (tree expr, tree *ref)
1566 tree decl = expr;
1567 if (TREE_CODE (decl) == SSA_NAME)
1569 gimple *def = SSA_NAME_DEF_STMT (decl);
1571 if (is_gimple_assign (def))
1573 tree_code code = gimple_assign_rhs_code (def);
1574 if (code == ADDR_EXPR
1575 || code == COMPONENT_REF
1576 || code == VAR_DECL)
1577 decl = gimple_assign_rhs1 (def);
1579 else if (tree var = SSA_NAME_VAR (decl))
1580 decl = var;
1583 if (TREE_CODE (decl) == ADDR_EXPR)
1584 decl = TREE_OPERAND (decl, 0);
1586 if (ref)
1587 *ref = decl;
1589 if (TREE_CODE (decl) == ARRAY_REF)
1590 decl = TREE_OPERAND (decl, 0);
1591 else if (TREE_CODE (decl) == COMPONENT_REF)
1592 decl = TREE_OPERAND (decl, 1);
1593 else if (TREE_CODE (decl) == MEM_REF)
1594 return get_attr_nonstring_decl (TREE_OPERAND (decl, 0), ref);
1596 if (DECL_P (decl)
1597 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1598 return decl;
1600 return NULL_TREE;
1603 /* Warn about passing a non-string array/pointer to a function that
1604 expects a nul-terminated string argument. */
1606 void
1607 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1609 if (!fndecl || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
1610 return;
1612 bool with_bounds = CALL_WITH_BOUNDS_P (exp);
1614 unsigned nargs = call_expr_nargs (exp);
1616 /* The bound argument to a bounded string function like strncpy. */
1617 tree bound = NULL_TREE;
1619 /* It's safe to call "bounded" string functions with a non-string
1620 argument since the functions provide an explicit bound for this
1621 purpose. */
1622 switch (DECL_FUNCTION_CODE (fndecl))
1624 case BUILT_IN_STPNCPY:
1625 case BUILT_IN_STPNCPY_CHK:
1626 case BUILT_IN_STRNCMP:
1627 case BUILT_IN_STRNCASECMP:
1628 case BUILT_IN_STRNCPY:
1629 case BUILT_IN_STRNCPY_CHK:
1631 unsigned argno = with_bounds ? 4 : 2;
1632 if (argno < nargs)
1633 bound = CALL_EXPR_ARG (exp, argno);
1634 break;
1637 case BUILT_IN_STRNDUP:
1639 unsigned argno = with_bounds ? 2 : 1;
1640 if (argno < nargs)
1641 bound = CALL_EXPR_ARG (exp, argno);
1642 break;
1645 default:
1646 break;
1649 /* Determine the range of the bound argument (if specified). */
1650 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1651 if (bound)
1652 get_size_range (bound, bndrng);
1654 /* Iterate over the built-in function's formal arguments and check
1655 each const char* against the actual argument. If the actual
1656 argument is declared attribute non-string issue a warning unless
1657 the argument's maximum length is bounded. */
1658 function_args_iterator it;
1659 function_args_iter_init (&it, TREE_TYPE (fndecl));
1661 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1663 /* Avoid iterating past the declared argument in a call
1664 to function declared without a prototype. */
1665 if (argno >= nargs)
1666 break;
1668 tree argtype = function_args_iter_cond (&it);
1669 if (!argtype)
1670 break;
1672 if (TREE_CODE (argtype) != POINTER_TYPE)
1673 continue;
1675 argtype = TREE_TYPE (argtype);
1677 if (TREE_CODE (argtype) != INTEGER_TYPE
1678 || !TYPE_READONLY (argtype))
1679 continue;
1681 argtype = TYPE_MAIN_VARIANT (argtype);
1682 if (argtype != char_type_node)
1683 continue;
1685 tree callarg = CALL_EXPR_ARG (exp, argno);
1686 if (TREE_CODE (callarg) == ADDR_EXPR)
1687 callarg = TREE_OPERAND (callarg, 0);
1689 /* See if the destination is declared with attribute "nonstring". */
1690 tree decl = get_attr_nonstring_decl (callarg);
1691 if (!decl)
1692 continue;
1694 tree type = TREE_TYPE (decl);
1696 offset_int wibnd = 0;
1697 if (bndrng[0])
1698 wibnd = wi::to_offset (bndrng[0]);
1700 offset_int asize = wibnd;
1702 if (TREE_CODE (type) == ARRAY_TYPE)
1703 if (tree arrbnd = TYPE_DOMAIN (type))
1705 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1706 asize = wi::to_offset (arrbnd) + 1;
1709 location_t loc = EXPR_LOCATION (exp);
1711 bool warned = false;
1713 if (wi::ltu_p (asize, wibnd))
1714 warned = warning_at (loc, OPT_Wstringop_overflow_,
1715 "%qD argument %i declared attribute %<nonstring%> "
1716 "is smaller than the specified bound %E",
1717 fndecl, argno + 1, bndrng[0]);
1718 else if (!bound)
1719 warned = warning_at (loc, OPT_Wstringop_overflow_,
1720 "%qD argument %i declared attribute %<nonstring%>",
1721 fndecl, argno + 1);
1723 if (warned)
1724 inform (DECL_SOURCE_LOCATION (decl),
1725 "argument %qD declared here", decl);
1729 /* Issue an error if CALL_EXPR was flagged as requiring
1730 tall-call optimization. */
1732 static void
1733 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1735 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1736 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1737 return;
1739 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1742 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1743 CALL_EXPR EXP.
1745 NUM_ACTUALS is the total number of parameters.
1747 N_NAMED_ARGS is the total number of named arguments.
1749 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1750 value, or null.
1752 FNDECL is the tree code for the target of this call (if known)
1754 ARGS_SO_FAR holds state needed by the target to know where to place
1755 the next argument.
1757 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1758 for arguments which are passed in registers.
1760 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1761 and may be modified by this routine.
1763 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1764 flags which may be modified by this routine.
1766 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1767 that requires allocation of stack space.
1769 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1770 the thunked-to function. */
1772 static void
1773 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1774 struct arg_data *args,
1775 struct args_size *args_size,
1776 int n_named_args ATTRIBUTE_UNUSED,
1777 tree exp, tree struct_value_addr_value,
1778 tree fndecl, tree fntype,
1779 cumulative_args_t args_so_far,
1780 int reg_parm_stack_space,
1781 rtx *old_stack_level,
1782 poly_int64_pod *old_pending_adj,
1783 int *must_preallocate, int *ecf_flags,
1784 bool *may_tailcall, bool call_from_thunk_p)
1786 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1787 location_t loc = EXPR_LOCATION (exp);
1789 /* Count arg position in order args appear. */
1790 int argpos;
1792 int i;
1794 args_size->constant = 0;
1795 args_size->var = 0;
1797 bitmap_obstack_initialize (NULL);
1799 /* In this loop, we consider args in the order they are written.
1800 We fill up ARGS from the back. */
1802 i = num_actuals - 1;
1804 int j = i, ptr_arg = -1;
1805 call_expr_arg_iterator iter;
1806 tree arg;
1807 bitmap slots = NULL;
1809 if (struct_value_addr_value)
1811 args[j].tree_value = struct_value_addr_value;
1812 j--;
1814 /* If we pass structure address then we need to
1815 create bounds for it. Since created bounds is
1816 a call statement, we expand it right here to avoid
1817 fixing all other places where it may be expanded. */
1818 if (CALL_WITH_BOUNDS_P (exp))
1820 args[j].value = gen_reg_rtx (targetm.chkp_bound_mode ());
1821 args[j].tree_value
1822 = chkp_make_bounds_for_struct_addr (struct_value_addr_value);
1823 expand_expr_real (args[j].tree_value, args[j].value, VOIDmode,
1824 EXPAND_NORMAL, 0, false);
1825 args[j].pointer_arg = j + 1;
1826 j--;
1829 argpos = 0;
1830 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1832 tree argtype = TREE_TYPE (arg);
1834 /* Remember last param with pointer and associate it
1835 with following pointer bounds. */
1836 if (CALL_WITH_BOUNDS_P (exp)
1837 && chkp_type_has_pointer (argtype))
1839 if (slots)
1840 BITMAP_FREE (slots);
1841 ptr_arg = j;
1842 if (!BOUNDED_TYPE_P (argtype))
1844 slots = BITMAP_ALLOC (NULL);
1845 chkp_find_bound_slots (argtype, slots);
1848 else if (CALL_WITH_BOUNDS_P (exp)
1849 && pass_by_reference (NULL, TYPE_MODE (argtype), argtype,
1850 argpos < n_named_args))
1852 if (slots)
1853 BITMAP_FREE (slots);
1854 ptr_arg = j;
1856 else if (POINTER_BOUNDS_TYPE_P (argtype))
1858 /* We expect bounds in instrumented calls only.
1859 Otherwise it is a sign we lost flag due to some optimization
1860 and may emit call args incorrectly. */
1861 gcc_assert (CALL_WITH_BOUNDS_P (exp));
1863 /* For structures look for the next available pointer. */
1864 if (ptr_arg != -1 && slots)
1866 unsigned bnd_no = bitmap_first_set_bit (slots);
1867 args[j].pointer_offset =
1868 bnd_no * POINTER_SIZE / BITS_PER_UNIT;
1870 bitmap_clear_bit (slots, bnd_no);
1872 /* Check we have no more pointers in the structure. */
1873 if (bitmap_empty_p (slots))
1874 BITMAP_FREE (slots);
1876 args[j].pointer_arg = ptr_arg;
1878 /* Check we covered all pointers in the previous
1879 non bounds arg. */
1880 if (!slots)
1881 ptr_arg = -1;
1883 else
1884 ptr_arg = -1;
1886 if (targetm.calls.split_complex_arg
1887 && argtype
1888 && TREE_CODE (argtype) == COMPLEX_TYPE
1889 && targetm.calls.split_complex_arg (argtype))
1891 tree subtype = TREE_TYPE (argtype);
1892 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1893 j--;
1894 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1896 else
1897 args[j].tree_value = arg;
1898 j--;
1899 argpos++;
1902 if (slots)
1903 BITMAP_FREE (slots);
1906 bitmap_obstack_release (NULL);
1908 /* Extract attribute alloc_size and if set, store the indices of
1909 the corresponding arguments in ALLOC_IDX, and then the actual
1910 argument(s) at those indices in ALLOC_ARGS. */
1911 int alloc_idx[2] = { -1, -1 };
1912 if (tree alloc_size
1913 = (fndecl ? lookup_attribute ("alloc_size",
1914 TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))
1915 : NULL_TREE))
1917 tree args = TREE_VALUE (alloc_size);
1918 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
1919 if (TREE_CHAIN (args))
1920 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
1923 /* Array for up to the two attribute alloc_size arguments. */
1924 tree alloc_args[] = { NULL_TREE, NULL_TREE };
1926 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1927 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1929 tree type = TREE_TYPE (args[i].tree_value);
1930 int unsignedp;
1931 machine_mode mode;
1933 /* Replace erroneous argument with constant zero. */
1934 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1935 args[i].tree_value = integer_zero_node, type = integer_type_node;
1937 /* If TYPE is a transparent union or record, pass things the way
1938 we would pass the first field of the union or record. We have
1939 already verified that the modes are the same. */
1940 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1941 && TYPE_TRANSPARENT_AGGR (type))
1942 type = TREE_TYPE (first_field (type));
1944 /* Decide where to pass this arg.
1946 args[i].reg is nonzero if all or part is passed in registers.
1948 args[i].partial is nonzero if part but not all is passed in registers,
1949 and the exact value says how many bytes are passed in registers.
1951 args[i].pass_on_stack is nonzero if the argument must at least be
1952 computed on the stack. It may then be loaded back into registers
1953 if args[i].reg is nonzero.
1955 These decisions are driven by the FUNCTION_... macros and must agree
1956 with those made by function.c. */
1958 /* See if this argument should be passed by invisible reference. */
1959 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1960 type, argpos < n_named_args))
1962 bool callee_copies;
1963 tree base = NULL_TREE;
1965 callee_copies
1966 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
1967 type, argpos < n_named_args);
1969 /* If we're compiling a thunk, pass through invisible references
1970 instead of making a copy. */
1971 if (call_from_thunk_p
1972 || (callee_copies
1973 && !TREE_ADDRESSABLE (type)
1974 && (base = get_base_address (args[i].tree_value))
1975 && TREE_CODE (base) != SSA_NAME
1976 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1978 /* We may have turned the parameter value into an SSA name.
1979 Go back to the original parameter so we can take the
1980 address. */
1981 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
1983 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
1984 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
1985 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
1987 /* Argument setup code may have copied the value to register. We
1988 revert that optimization now because the tail call code must
1989 use the original location. */
1990 if (TREE_CODE (args[i].tree_value) == PARM_DECL
1991 && !MEM_P (DECL_RTL (args[i].tree_value))
1992 && DECL_INCOMING_RTL (args[i].tree_value)
1993 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
1994 set_decl_rtl (args[i].tree_value,
1995 DECL_INCOMING_RTL (args[i].tree_value));
1997 mark_addressable (args[i].tree_value);
1999 /* We can't use sibcalls if a callee-copied argument is
2000 stored in the current function's frame. */
2001 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
2003 *may_tailcall = false;
2004 maybe_complain_about_tail_call (exp,
2005 "a callee-copied argument is"
2006 " stored in the current"
2007 " function's frame");
2010 args[i].tree_value = build_fold_addr_expr_loc (loc,
2011 args[i].tree_value);
2012 type = TREE_TYPE (args[i].tree_value);
2014 if (*ecf_flags & ECF_CONST)
2015 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
2017 else
2019 /* We make a copy of the object and pass the address to the
2020 function being called. */
2021 rtx copy;
2023 if (!COMPLETE_TYPE_P (type)
2024 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2025 || (flag_stack_check == GENERIC_STACK_CHECK
2026 && compare_tree_int (TYPE_SIZE_UNIT (type),
2027 STACK_CHECK_MAX_VAR_SIZE) > 0))
2029 /* This is a variable-sized object. Make space on the stack
2030 for it. */
2031 rtx size_rtx = expr_size (args[i].tree_value);
2033 if (*old_stack_level == 0)
2035 emit_stack_save (SAVE_BLOCK, old_stack_level);
2036 *old_pending_adj = pending_stack_adjust;
2037 pending_stack_adjust = 0;
2040 /* We can pass TRUE as the 4th argument because we just
2041 saved the stack pointer and will restore it right after
2042 the call. */
2043 copy = allocate_dynamic_stack_space (size_rtx,
2044 TYPE_ALIGN (type),
2045 TYPE_ALIGN (type),
2046 max_int_size_in_bytes
2047 (type),
2048 true);
2049 copy = gen_rtx_MEM (BLKmode, copy);
2050 set_mem_attributes (copy, type, 1);
2052 else
2053 copy = assign_temp (type, 1, 0);
2055 store_expr (args[i].tree_value, copy, 0, false, false);
2057 /* Just change the const function to pure and then let
2058 the next test clear the pure based on
2059 callee_copies. */
2060 if (*ecf_flags & ECF_CONST)
2062 *ecf_flags &= ~ECF_CONST;
2063 *ecf_flags |= ECF_PURE;
2066 if (!callee_copies && *ecf_flags & ECF_PURE)
2067 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2069 args[i].tree_value
2070 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2071 type = TREE_TYPE (args[i].tree_value);
2072 *may_tailcall = false;
2073 maybe_complain_about_tail_call (exp,
2074 "argument must be passed"
2075 " by copying");
2079 unsignedp = TYPE_UNSIGNED (type);
2080 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2081 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2083 args[i].unsignedp = unsignedp;
2084 args[i].mode = mode;
2086 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2088 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
2089 argpos < n_named_args);
2091 if (args[i].reg && CONST_INT_P (args[i].reg))
2093 args[i].special_slot = args[i].reg;
2094 args[i].reg = NULL;
2097 /* If this is a sibling call and the machine has register windows, the
2098 register window has to be unwinded before calling the routine, so
2099 arguments have to go into the incoming registers. */
2100 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2101 args[i].tail_call_reg
2102 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
2103 argpos < n_named_args);
2104 else
2105 args[i].tail_call_reg = args[i].reg;
2107 if (args[i].reg)
2108 args[i].partial
2109 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
2110 argpos < n_named_args);
2112 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
2114 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2115 it means that we are to pass this arg in the register(s) designated
2116 by the PARALLEL, but also to pass it in the stack. */
2117 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2118 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2119 args[i].pass_on_stack = 1;
2121 /* If this is an addressable type, we must preallocate the stack
2122 since we must evaluate the object into its final location.
2124 If this is to be passed in both registers and the stack, it is simpler
2125 to preallocate. */
2126 if (TREE_ADDRESSABLE (type)
2127 || (args[i].pass_on_stack && args[i].reg != 0))
2128 *must_preallocate = 1;
2130 /* No stack allocation and padding for bounds. */
2131 if (POINTER_BOUNDS_P (args[i].tree_value))
2133 /* Compute the stack-size of this argument. */
2134 else if (args[i].reg == 0 || args[i].partial != 0
2135 || reg_parm_stack_space > 0
2136 || args[i].pass_on_stack)
2137 locate_and_pad_parm (mode, type,
2138 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2140 #else
2141 args[i].reg != 0,
2142 #endif
2143 reg_parm_stack_space,
2144 args[i].pass_on_stack ? 0 : args[i].partial,
2145 fndecl, args_size, &args[i].locate);
2146 #ifdef BLOCK_REG_PADDING
2147 else
2148 /* The argument is passed entirely in registers. See at which
2149 end it should be padded. */
2150 args[i].locate.where_pad =
2151 BLOCK_REG_PADDING (mode, type,
2152 int_size_in_bytes (type) <= UNITS_PER_WORD);
2153 #endif
2155 /* Update ARGS_SIZE, the total stack space for args so far. */
2157 args_size->constant += args[i].locate.size.constant;
2158 if (args[i].locate.size.var)
2159 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2161 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2162 have been used, etc. */
2164 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
2165 type, argpos < n_named_args);
2167 /* Store argument values for functions decorated with attribute
2168 alloc_size. */
2169 if (argpos == alloc_idx[0])
2170 alloc_args[0] = args[i].tree_value;
2171 else if (argpos == alloc_idx[1])
2172 alloc_args[1] = args[i].tree_value;
2175 if (alloc_args[0])
2177 /* Check the arguments of functions decorated with attribute
2178 alloc_size. */
2179 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2182 /* Detect passing non-string arguments to functions expecting
2183 nul-terminated strings. */
2184 maybe_warn_nonstring_arg (fndecl, exp);
2187 /* Update ARGS_SIZE to contain the total size for the argument block.
2188 Return the original constant component of the argument block's size.
2190 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2191 for arguments passed in registers. */
2193 static poly_int64
2194 compute_argument_block_size (int reg_parm_stack_space,
2195 struct args_size *args_size,
2196 tree fndecl ATTRIBUTE_UNUSED,
2197 tree fntype ATTRIBUTE_UNUSED,
2198 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2200 poly_int64 unadjusted_args_size = args_size->constant;
2202 /* For accumulate outgoing args mode we don't need to align, since the frame
2203 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2204 backends from generating misaligned frame sizes. */
2205 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2206 preferred_stack_boundary = STACK_BOUNDARY;
2208 /* Compute the actual size of the argument block required. The variable
2209 and constant sizes must be combined, the size may have to be rounded,
2210 and there may be a minimum required size. */
2212 if (args_size->var)
2214 args_size->var = ARGS_SIZE_TREE (*args_size);
2215 args_size->constant = 0;
2217 preferred_stack_boundary /= BITS_PER_UNIT;
2218 if (preferred_stack_boundary > 1)
2220 /* We don't handle this case yet. To handle it correctly we have
2221 to add the delta, round and subtract the delta.
2222 Currently no machine description requires this support. */
2223 gcc_assert (multiple_p (stack_pointer_delta,
2224 preferred_stack_boundary));
2225 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2228 if (reg_parm_stack_space > 0)
2230 args_size->var
2231 = size_binop (MAX_EXPR, args_size->var,
2232 ssize_int (reg_parm_stack_space));
2234 /* The area corresponding to register parameters is not to count in
2235 the size of the block we need. So make the adjustment. */
2236 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2237 args_size->var
2238 = size_binop (MINUS_EXPR, args_size->var,
2239 ssize_int (reg_parm_stack_space));
2242 else
2244 preferred_stack_boundary /= BITS_PER_UNIT;
2245 if (preferred_stack_boundary < 1)
2246 preferred_stack_boundary = 1;
2247 args_size->constant = (aligned_upper_bound (args_size->constant
2248 + stack_pointer_delta,
2249 preferred_stack_boundary)
2250 - stack_pointer_delta);
2252 args_size->constant = upper_bound (args_size->constant,
2253 reg_parm_stack_space);
2255 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2256 args_size->constant -= reg_parm_stack_space;
2258 return unadjusted_args_size;
2261 /* Precompute parameters as needed for a function call.
2263 FLAGS is mask of ECF_* constants.
2265 NUM_ACTUALS is the number of arguments.
2267 ARGS is an array containing information for each argument; this
2268 routine fills in the INITIAL_VALUE and VALUE fields for each
2269 precomputed argument. */
2271 static void
2272 precompute_arguments (int num_actuals, struct arg_data *args)
2274 int i;
2276 /* If this is a libcall, then precompute all arguments so that we do not
2277 get extraneous instructions emitted as part of the libcall sequence. */
2279 /* If we preallocated the stack space, and some arguments must be passed
2280 on the stack, then we must precompute any parameter which contains a
2281 function call which will store arguments on the stack.
2282 Otherwise, evaluating the parameter may clobber previous parameters
2283 which have already been stored into the stack. (we have code to avoid
2284 such case by saving the outgoing stack arguments, but it results in
2285 worse code) */
2286 if (!ACCUMULATE_OUTGOING_ARGS)
2287 return;
2289 for (i = 0; i < num_actuals; i++)
2291 tree type;
2292 machine_mode mode;
2294 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2295 continue;
2297 /* If this is an addressable type, we cannot pre-evaluate it. */
2298 type = TREE_TYPE (args[i].tree_value);
2299 gcc_assert (!TREE_ADDRESSABLE (type));
2301 args[i].initial_value = args[i].value
2302 = expand_normal (args[i].tree_value);
2304 mode = TYPE_MODE (type);
2305 if (mode != args[i].mode)
2307 int unsignedp = args[i].unsignedp;
2308 args[i].value
2309 = convert_modes (args[i].mode, mode,
2310 args[i].value, args[i].unsignedp);
2312 /* CSE will replace this only if it contains args[i].value
2313 pseudo, so convert it down to the declared mode using
2314 a SUBREG. */
2315 if (REG_P (args[i].value)
2316 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2317 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2319 args[i].initial_value
2320 = gen_lowpart_SUBREG (mode, args[i].value);
2321 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2322 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2328 /* Given the current state of MUST_PREALLOCATE and information about
2329 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2330 compute and return the final value for MUST_PREALLOCATE. */
2332 static int
2333 finalize_must_preallocate (int must_preallocate, int num_actuals,
2334 struct arg_data *args, struct args_size *args_size)
2336 /* See if we have or want to preallocate stack space.
2338 If we would have to push a partially-in-regs parm
2339 before other stack parms, preallocate stack space instead.
2341 If the size of some parm is not a multiple of the required stack
2342 alignment, we must preallocate.
2344 If the total size of arguments that would otherwise create a copy in
2345 a temporary (such as a CALL) is more than half the total argument list
2346 size, preallocation is faster.
2348 Another reason to preallocate is if we have a machine (like the m88k)
2349 where stack alignment is required to be maintained between every
2350 pair of insns, not just when the call is made. However, we assume here
2351 that such machines either do not have push insns (and hence preallocation
2352 would occur anyway) or the problem is taken care of with
2353 PUSH_ROUNDING. */
2355 if (! must_preallocate)
2357 int partial_seen = 0;
2358 poly_int64 copy_to_evaluate_size = 0;
2359 int i;
2361 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2363 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2364 partial_seen = 1;
2365 else if (partial_seen && args[i].reg == 0)
2366 must_preallocate = 1;
2367 /* We preallocate in case there are bounds passed
2368 in the bounds table to have precomputed address
2369 for bounds association. */
2370 else if (POINTER_BOUNDS_P (args[i].tree_value)
2371 && !args[i].reg)
2372 must_preallocate = 1;
2374 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2375 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2376 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2377 || TREE_CODE (args[i].tree_value) == COND_EXPR
2378 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2379 copy_to_evaluate_size
2380 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2383 if (maybe_ne (args_size->constant, 0)
2384 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2385 must_preallocate = 1;
2387 return must_preallocate;
2390 /* If we preallocated stack space, compute the address of each argument
2391 and store it into the ARGS array.
2393 We need not ensure it is a valid memory address here; it will be
2394 validized when it is used.
2396 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2398 static void
2399 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2401 if (argblock)
2403 rtx arg_reg = argblock;
2404 int i;
2405 poly_int64 arg_offset = 0;
2407 if (GET_CODE (argblock) == PLUS)
2409 arg_reg = XEXP (argblock, 0);
2410 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2413 for (i = 0; i < num_actuals; i++)
2415 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2416 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2417 rtx addr;
2418 unsigned int align, boundary;
2419 poly_uint64 units_on_stack = 0;
2420 machine_mode partial_mode = VOIDmode;
2422 /* Skip this parm if it will not be passed on the stack. */
2423 if (! args[i].pass_on_stack
2424 && args[i].reg != 0
2425 && args[i].partial == 0)
2426 continue;
2428 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2429 continue;
2431 /* Pointer Bounds are never passed on the stack. */
2432 if (POINTER_BOUNDS_P (args[i].tree_value))
2433 continue;
2435 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2436 addr = plus_constant (Pmode, addr, arg_offset);
2438 if (args[i].partial != 0)
2440 /* Only part of the parameter is being passed on the stack.
2441 Generate a simple memory reference of the correct size. */
2442 units_on_stack = args[i].locate.size.constant;
2443 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2444 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2445 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2446 set_mem_size (args[i].stack, units_on_stack);
2448 else
2450 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2451 set_mem_attributes (args[i].stack,
2452 TREE_TYPE (args[i].tree_value), 1);
2454 align = BITS_PER_UNIT;
2455 boundary = args[i].locate.boundary;
2456 poly_int64 offset_val;
2457 if (args[i].locate.where_pad != PAD_DOWNWARD)
2458 align = boundary;
2459 else if (poly_int_rtx_p (offset, &offset_val))
2461 align = least_bit_hwi (boundary);
2462 unsigned int offset_align
2463 = known_alignment (offset_val) * BITS_PER_UNIT;
2464 if (offset_align != 0)
2465 align = MIN (align, offset_align);
2467 set_mem_align (args[i].stack, align);
2469 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2470 addr = plus_constant (Pmode, addr, arg_offset);
2472 if (args[i].partial != 0)
2474 /* Only part of the parameter is being passed on the stack.
2475 Generate a simple memory reference of the correct size.
2477 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2478 set_mem_size (args[i].stack_slot, units_on_stack);
2480 else
2482 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2483 set_mem_attributes (args[i].stack_slot,
2484 TREE_TYPE (args[i].tree_value), 1);
2486 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2488 /* Function incoming arguments may overlap with sibling call
2489 outgoing arguments and we cannot allow reordering of reads
2490 from function arguments with stores to outgoing arguments
2491 of sibling calls. */
2492 set_mem_alias_set (args[i].stack, 0);
2493 set_mem_alias_set (args[i].stack_slot, 0);
2498 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2499 in a call instruction.
2501 FNDECL is the tree node for the target function. For an indirect call
2502 FNDECL will be NULL_TREE.
2504 ADDR is the operand 0 of CALL_EXPR for this call. */
2506 static rtx
2507 rtx_for_function_call (tree fndecl, tree addr)
2509 rtx funexp;
2511 /* Get the function to call, in the form of RTL. */
2512 if (fndecl)
2514 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2515 TREE_USED (fndecl) = 1;
2517 /* Get a SYMBOL_REF rtx for the function address. */
2518 funexp = XEXP (DECL_RTL (fndecl), 0);
2520 else
2521 /* Generate an rtx (probably a pseudo-register) for the address. */
2523 push_temp_slots ();
2524 funexp = expand_normal (addr);
2525 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2527 return funexp;
2530 /* Return the static chain for this function, if any. */
2533 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2535 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2536 return NULL;
2538 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2541 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2542 static struct
2544 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2545 or NULL_RTX if none has been scanned yet. */
2546 rtx_insn *scan_start;
2547 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2548 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2549 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2550 with fixed offset, or PC if this is with variable or unknown offset. */
2551 vec<rtx> cache;
2552 } internal_arg_pointer_exp_state;
2554 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2556 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2557 the tail call sequence, starting with first insn that hasn't been
2558 scanned yet, and note for each pseudo on the LHS whether it is based
2559 on crtl->args.internal_arg_pointer or not, and what offset from that
2560 that pointer it has. */
2562 static void
2563 internal_arg_pointer_based_exp_scan (void)
2565 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2567 if (scan_start == NULL_RTX)
2568 insn = get_insns ();
2569 else
2570 insn = NEXT_INSN (scan_start);
2572 while (insn)
2574 rtx set = single_set (insn);
2575 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2577 rtx val = NULL_RTX;
2578 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2579 /* Punt on pseudos set multiple times. */
2580 if (idx < internal_arg_pointer_exp_state.cache.length ()
2581 && (internal_arg_pointer_exp_state.cache[idx]
2582 != NULL_RTX))
2583 val = pc_rtx;
2584 else
2585 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2586 if (val != NULL_RTX)
2588 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2589 internal_arg_pointer_exp_state.cache
2590 .safe_grow_cleared (idx + 1);
2591 internal_arg_pointer_exp_state.cache[idx] = val;
2594 if (NEXT_INSN (insn) == NULL_RTX)
2595 scan_start = insn;
2596 insn = NEXT_INSN (insn);
2599 internal_arg_pointer_exp_state.scan_start = scan_start;
2602 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2603 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2604 it with fixed offset, or PC if this is with variable or unknown offset.
2605 TOPLEVEL is true if the function is invoked at the topmost level. */
2607 static rtx
2608 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2610 if (CONSTANT_P (rtl))
2611 return NULL_RTX;
2613 if (rtl == crtl->args.internal_arg_pointer)
2614 return const0_rtx;
2616 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2617 return NULL_RTX;
2619 poly_int64 offset;
2620 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2622 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2623 if (val == NULL_RTX || val == pc_rtx)
2624 return val;
2625 return plus_constant (Pmode, val, offset);
2628 /* When called at the topmost level, scan pseudo assignments in between the
2629 last scanned instruction in the tail call sequence and the latest insn
2630 in that sequence. */
2631 if (toplevel)
2632 internal_arg_pointer_based_exp_scan ();
2634 if (REG_P (rtl))
2636 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2637 if (idx < internal_arg_pointer_exp_state.cache.length ())
2638 return internal_arg_pointer_exp_state.cache[idx];
2640 return NULL_RTX;
2643 subrtx_iterator::array_type array;
2644 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2646 const_rtx x = *iter;
2647 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2648 return pc_rtx;
2649 if (MEM_P (x))
2650 iter.skip_subrtxes ();
2653 return NULL_RTX;
2656 /* Return true if SIZE bytes starting from address ADDR might overlap an
2657 already-clobbered argument area. This function is used to determine
2658 if we should give up a sibcall. */
2660 static bool
2661 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2663 poly_int64 i;
2664 unsigned HOST_WIDE_INT start, end;
2665 rtx val;
2667 if (bitmap_empty_p (stored_args_map)
2668 && stored_args_watermark == HOST_WIDE_INT_M1U)
2669 return false;
2670 val = internal_arg_pointer_based_exp (addr, true);
2671 if (val == NULL_RTX)
2672 return false;
2673 else if (!poly_int_rtx_p (val, &i))
2674 return true;
2676 if (known_eq (size, 0U))
2677 return false;
2679 if (STACK_GROWS_DOWNWARD)
2680 i -= crtl->args.pretend_args_size;
2681 else
2682 i += crtl->args.pretend_args_size;
2684 if (ARGS_GROW_DOWNWARD)
2685 i = -i - size;
2687 /* We can ignore any references to the function's pretend args,
2688 which at this point would manifest as negative values of I. */
2689 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2690 return false;
2692 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2693 if (!(i + size).is_constant (&end))
2694 end = HOST_WIDE_INT_M1U;
2696 if (end > stored_args_watermark)
2697 return true;
2699 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2700 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2701 if (bitmap_bit_p (stored_args_map, k))
2702 return true;
2704 return false;
2707 /* Do the register loads required for any wholly-register parms or any
2708 parms which are passed both on the stack and in a register. Their
2709 expressions were already evaluated.
2711 Mark all register-parms as living through the call, putting these USE
2712 insns in the CALL_INSN_FUNCTION_USAGE field.
2714 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2715 checking, setting *SIBCALL_FAILURE if appropriate. */
2717 static void
2718 load_register_parameters (struct arg_data *args, int num_actuals,
2719 rtx *call_fusage, int flags, int is_sibcall,
2720 int *sibcall_failure)
2722 int i, j;
2724 for (i = 0; i < num_actuals; i++)
2726 rtx reg = ((flags & ECF_SIBCALL)
2727 ? args[i].tail_call_reg : args[i].reg);
2728 if (reg)
2730 int partial = args[i].partial;
2731 int nregs;
2732 poly_int64 size = 0;
2733 HOST_WIDE_INT const_size = 0;
2734 rtx_insn *before_arg = get_last_insn ();
2735 /* Set non-negative if we must move a word at a time, even if
2736 just one word (e.g, partial == 4 && mode == DFmode). Set
2737 to -1 if we just use a normal move insn. This value can be
2738 zero if the argument is a zero size structure. */
2739 nregs = -1;
2740 if (GET_CODE (reg) == PARALLEL)
2742 else if (partial)
2744 gcc_assert (partial % UNITS_PER_WORD == 0);
2745 nregs = partial / UNITS_PER_WORD;
2747 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
2749 /* Variable-sized parameters should be described by a
2750 PARALLEL instead. */
2751 const_size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2752 gcc_assert (const_size >= 0);
2753 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2754 size = const_size;
2756 else
2757 size = GET_MODE_SIZE (args[i].mode);
2759 /* Handle calls that pass values in multiple non-contiguous
2760 locations. The Irix 6 ABI has examples of this. */
2762 if (GET_CODE (reg) == PARALLEL)
2763 emit_group_move (reg, args[i].parallel_value);
2765 /* If simple case, just do move. If normal partial, store_one_arg
2766 has already loaded the register for us. In all other cases,
2767 load the register(s) from memory. */
2769 else if (nregs == -1)
2771 emit_move_insn (reg, args[i].value);
2772 #ifdef BLOCK_REG_PADDING
2773 /* Handle case where we have a value that needs shifting
2774 up to the msb. eg. a QImode value and we're padding
2775 upward on a BYTES_BIG_ENDIAN machine. */
2776 if (args[i].locate.where_pad
2777 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2779 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2780 if (maybe_lt (size, UNITS_PER_WORD))
2782 rtx x;
2783 poly_int64 shift
2784 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2786 /* Assigning REG here rather than a temp makes
2787 CALL_FUSAGE report the whole reg as used.
2788 Strictly speaking, the call only uses SIZE
2789 bytes at the msb end, but it doesn't seem worth
2790 generating rtl to say that. */
2791 reg = gen_rtx_REG (word_mode, REGNO (reg));
2792 x = expand_shift (LSHIFT_EXPR, word_mode,
2793 reg, shift, reg, 1);
2794 if (x != reg)
2795 emit_move_insn (reg, x);
2798 #endif
2801 /* If we have pre-computed the values to put in the registers in
2802 the case of non-aligned structures, copy them in now. */
2804 else if (args[i].n_aligned_regs != 0)
2805 for (j = 0; j < args[i].n_aligned_regs; j++)
2806 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2807 args[i].aligned_regs[j]);
2809 else if (partial == 0 || args[i].pass_on_stack)
2811 /* SIZE and CONST_SIZE are 0 for partial arguments and
2812 the size of a BLKmode type otherwise. */
2813 gcc_checking_assert (known_eq (size, const_size));
2814 rtx mem = validize_mem (copy_rtx (args[i].value));
2816 /* Check for overlap with already clobbered argument area,
2817 providing that this has non-zero size. */
2818 if (is_sibcall
2819 && const_size != 0
2820 && (mem_might_overlap_already_clobbered_arg_p
2821 (XEXP (args[i].value, 0), const_size)))
2822 *sibcall_failure = 1;
2824 if (const_size % UNITS_PER_WORD == 0
2825 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2826 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2827 else
2829 if (nregs > 1)
2830 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2831 args[i].mode);
2832 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2833 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2834 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2835 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2836 word_mode, word_mode, false,
2837 NULL);
2838 if (BYTES_BIG_ENDIAN)
2839 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2840 BITS_PER_WORD - bitsize, dest, 1);
2841 if (x != dest)
2842 emit_move_insn (dest, x);
2845 /* Handle a BLKmode that needs shifting. */
2846 if (nregs == 1 && const_size < UNITS_PER_WORD
2847 #ifdef BLOCK_REG_PADDING
2848 && args[i].locate.where_pad == PAD_DOWNWARD
2849 #else
2850 && BYTES_BIG_ENDIAN
2851 #endif
2854 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2855 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2856 enum tree_code dir = (BYTES_BIG_ENDIAN
2857 ? RSHIFT_EXPR : LSHIFT_EXPR);
2858 rtx x;
2860 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2861 if (x != dest)
2862 emit_move_insn (dest, x);
2866 /* When a parameter is a block, and perhaps in other cases, it is
2867 possible that it did a load from an argument slot that was
2868 already clobbered. */
2869 if (is_sibcall
2870 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2871 *sibcall_failure = 1;
2873 /* Handle calls that pass values in multiple non-contiguous
2874 locations. The Irix 6 ABI has examples of this. */
2875 if (GET_CODE (reg) == PARALLEL)
2876 use_group_regs (call_fusage, reg);
2877 else if (nregs == -1)
2878 use_reg_mode (call_fusage, reg,
2879 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
2880 else if (nregs > 0)
2881 use_regs (call_fusage, REGNO (reg), nregs);
2886 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2887 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2888 bytes, then we would need to push some additional bytes to pad the
2889 arguments. So, we try to compute an adjust to the stack pointer for an
2890 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2891 bytes. Then, when the arguments are pushed the stack will be perfectly
2892 aligned.
2894 Return true if this optimization is possible, storing the adjustment
2895 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2896 bytes that should be popped after the call. */
2898 static bool
2899 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2900 poly_int64 unadjusted_args_size,
2901 struct args_size *args_size,
2902 unsigned int preferred_unit_stack_boundary)
2904 /* The number of bytes to pop so that the stack will be
2905 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2906 poly_int64 adjustment;
2907 /* The alignment of the stack after the arguments are pushed, if we
2908 just pushed the arguments without adjust the stack here. */
2909 unsigned HOST_WIDE_INT unadjusted_alignment;
2911 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2912 preferred_unit_stack_boundary,
2913 &unadjusted_alignment))
2914 return false;
2916 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2917 as possible -- leaving just enough left to cancel out the
2918 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2919 PENDING_STACK_ADJUST is non-negative, and congruent to
2920 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2922 /* Begin by trying to pop all the bytes. */
2923 unsigned HOST_WIDE_INT tmp_misalignment;
2924 if (!known_misalignment (pending_stack_adjust,
2925 preferred_unit_stack_boundary,
2926 &tmp_misalignment))
2927 return false;
2928 unadjusted_alignment -= tmp_misalignment;
2929 adjustment = pending_stack_adjust;
2930 /* Push enough additional bytes that the stack will be aligned
2931 after the arguments are pushed. */
2932 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2933 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2935 /* We need to know whether the adjusted argument size
2936 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2937 or a deallocation. */
2938 if (!ordered_p (adjustment, unadjusted_args_size))
2939 return false;
2941 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2942 bytes after the call. The right number is the entire
2943 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2944 by the arguments in the first place. */
2945 args_size->constant
2946 = pending_stack_adjust - adjustment + unadjusted_args_size;
2948 *adjustment_out = adjustment;
2949 return true;
2952 /* Scan X expression if it does not dereference any argument slots
2953 we already clobbered by tail call arguments (as noted in stored_args_map
2954 bitmap).
2955 Return nonzero if X expression dereferences such argument slots,
2956 zero otherwise. */
2958 static int
2959 check_sibcall_argument_overlap_1 (rtx x)
2961 RTX_CODE code;
2962 int i, j;
2963 const char *fmt;
2965 if (x == NULL_RTX)
2966 return 0;
2968 code = GET_CODE (x);
2970 /* We need not check the operands of the CALL expression itself. */
2971 if (code == CALL)
2972 return 0;
2974 if (code == MEM)
2975 return (mem_might_overlap_already_clobbered_arg_p
2976 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
2978 /* Scan all subexpressions. */
2979 fmt = GET_RTX_FORMAT (code);
2980 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2982 if (*fmt == 'e')
2984 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2985 return 1;
2987 else if (*fmt == 'E')
2989 for (j = 0; j < XVECLEN (x, i); j++)
2990 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2991 return 1;
2994 return 0;
2997 /* Scan sequence after INSN if it does not dereference any argument slots
2998 we already clobbered by tail call arguments (as noted in stored_args_map
2999 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
3000 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
3001 should be 0). Return nonzero if sequence after INSN dereferences such argument
3002 slots, zero otherwise. */
3004 static int
3005 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
3006 int mark_stored_args_map)
3008 poly_uint64 low, high;
3009 unsigned HOST_WIDE_INT const_low, const_high;
3011 if (insn == NULL_RTX)
3012 insn = get_insns ();
3013 else
3014 insn = NEXT_INSN (insn);
3016 for (; insn; insn = NEXT_INSN (insn))
3017 if (INSN_P (insn)
3018 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3019 break;
3021 if (mark_stored_args_map)
3023 if (ARGS_GROW_DOWNWARD)
3024 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3025 else
3026 low = arg->locate.slot_offset.constant;
3027 high = low + arg->locate.size.constant;
3029 const_low = constant_lower_bound (low);
3030 if (high.is_constant (&const_high))
3031 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3032 bitmap_set_bit (stored_args_map, i);
3033 else
3034 stored_args_watermark = MIN (stored_args_watermark, const_low);
3036 return insn != NULL_RTX;
3039 /* Given that a function returns a value of mode MODE at the most
3040 significant end of hard register VALUE, shift VALUE left or right
3041 as specified by LEFT_P. Return true if some action was needed. */
3043 bool
3044 shift_return_value (machine_mode mode, bool left_p, rtx value)
3046 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3047 machine_mode value_mode = GET_MODE (value);
3048 poly_int64 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3050 if (known_eq (shift, 0))
3051 return false;
3053 /* Use ashr rather than lshr for right shifts. This is for the benefit
3054 of the MIPS port, which requires SImode values to be sign-extended
3055 when stored in 64-bit registers. */
3056 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3057 value, gen_int_shift_amount (value_mode, shift),
3058 value, 1, OPTAB_WIDEN))
3059 gcc_unreachable ();
3060 return true;
3063 /* If X is a likely-spilled register value, copy it to a pseudo
3064 register and return that register. Return X otherwise. */
3066 static rtx
3067 avoid_likely_spilled_reg (rtx x)
3069 rtx new_rtx;
3071 if (REG_P (x)
3072 && HARD_REGISTER_P (x)
3073 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3075 /* Make sure that we generate a REG rather than a CONCAT.
3076 Moves into CONCATs can need nontrivial instructions,
3077 and the whole point of this function is to avoid
3078 using the hard register directly in such a situation. */
3079 generating_concat_p = 0;
3080 new_rtx = gen_reg_rtx (GET_MODE (x));
3081 generating_concat_p = 1;
3082 emit_move_insn (new_rtx, x);
3083 return new_rtx;
3085 return x;
3088 /* Helper function for expand_call.
3089 Return false is EXP is not implementable as a sibling call. */
3091 static bool
3092 can_implement_as_sibling_call_p (tree exp,
3093 rtx structure_value_addr,
3094 tree funtype,
3095 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3096 tree fndecl,
3097 int flags,
3098 tree addr,
3099 const args_size &args_size)
3101 if (!targetm.have_sibcall_epilogue ())
3103 maybe_complain_about_tail_call
3104 (exp,
3105 "machine description does not have"
3106 " a sibcall_epilogue instruction pattern");
3107 return false;
3110 /* Doing sibling call optimization needs some work, since
3111 structure_value_addr can be allocated on the stack.
3112 It does not seem worth the effort since few optimizable
3113 sibling calls will return a structure. */
3114 if (structure_value_addr != NULL_RTX)
3116 maybe_complain_about_tail_call (exp, "callee returns a structure");
3117 return false;
3120 #ifdef REG_PARM_STACK_SPACE
3121 /* If outgoing reg parm stack space changes, we can not do sibcall. */
3122 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3123 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3124 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3126 maybe_complain_about_tail_call (exp,
3127 "inconsistent size of stack space"
3128 " allocated for arguments which are"
3129 " passed in registers");
3130 return false;
3132 #endif
3134 /* Check whether the target is able to optimize the call
3135 into a sibcall. */
3136 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3138 maybe_complain_about_tail_call (exp,
3139 "target is not able to optimize the"
3140 " call into a sibling call");
3141 return false;
3144 /* Functions that do not return exactly once may not be sibcall
3145 optimized. */
3146 if (flags & ECF_RETURNS_TWICE)
3148 maybe_complain_about_tail_call (exp, "callee returns twice");
3149 return false;
3151 if (flags & ECF_NORETURN)
3153 maybe_complain_about_tail_call (exp, "callee does not return");
3154 return false;
3157 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3159 maybe_complain_about_tail_call (exp, "volatile function type");
3160 return false;
3163 /* If the called function is nested in the current one, it might access
3164 some of the caller's arguments, but could clobber them beforehand if
3165 the argument areas are shared. */
3166 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3168 maybe_complain_about_tail_call (exp, "nested function");
3169 return false;
3172 /* If this function requires more stack slots than the current
3173 function, we cannot change it into a sibling call.
3174 crtl->args.pretend_args_size is not part of the
3175 stack allocated by our caller. */
3176 if (maybe_gt (args_size.constant,
3177 crtl->args.size - crtl->args.pretend_args_size))
3179 maybe_complain_about_tail_call (exp,
3180 "callee required more stack slots"
3181 " than the caller");
3182 return false;
3185 /* If the callee pops its own arguments, then it must pop exactly
3186 the same number of arguments as the current function. */
3187 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3188 args_size.constant),
3189 targetm.calls.return_pops_args (current_function_decl,
3190 TREE_TYPE
3191 (current_function_decl),
3192 crtl->args.size)))
3194 maybe_complain_about_tail_call (exp,
3195 "inconsistent number of"
3196 " popped arguments");
3197 return false;
3200 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3202 maybe_complain_about_tail_call (exp, "frontend does not support"
3203 " sibling call");
3204 return false;
3207 /* All checks passed. */
3208 return true;
3211 /* Generate all the code for a CALL_EXPR exp
3212 and return an rtx for its value.
3213 Store the value in TARGET (specified as an rtx) if convenient.
3214 If the value is stored in TARGET then TARGET is returned.
3215 If IGNORE is nonzero, then we ignore the value of the function call. */
3218 expand_call (tree exp, rtx target, int ignore)
3220 /* Nonzero if we are currently expanding a call. */
3221 static int currently_expanding_call = 0;
3223 /* RTX for the function to be called. */
3224 rtx funexp;
3225 /* Sequence of insns to perform a normal "call". */
3226 rtx_insn *normal_call_insns = NULL;
3227 /* Sequence of insns to perform a tail "call". */
3228 rtx_insn *tail_call_insns = NULL;
3229 /* Data type of the function. */
3230 tree funtype;
3231 tree type_arg_types;
3232 tree rettype;
3233 /* Declaration of the function being called,
3234 or 0 if the function is computed (not known by name). */
3235 tree fndecl = 0;
3236 /* The type of the function being called. */
3237 tree fntype;
3238 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3239 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3240 int pass;
3242 /* Register in which non-BLKmode value will be returned,
3243 or 0 if no value or if value is BLKmode. */
3244 rtx valreg;
3245 /* Register(s) in which bounds are returned. */
3246 rtx valbnd = NULL;
3247 /* Address where we should return a BLKmode value;
3248 0 if value not BLKmode. */
3249 rtx structure_value_addr = 0;
3250 /* Nonzero if that address is being passed by treating it as
3251 an extra, implicit first parameter. Otherwise,
3252 it is passed by being copied directly into struct_value_rtx. */
3253 int structure_value_addr_parm = 0;
3254 /* Holds the value of implicit argument for the struct value. */
3255 tree structure_value_addr_value = NULL_TREE;
3256 /* Size of aggregate value wanted, or zero if none wanted
3257 or if we are using the non-reentrant PCC calling convention
3258 or expecting the value in registers. */
3259 poly_int64 struct_value_size = 0;
3260 /* Nonzero if called function returns an aggregate in memory PCC style,
3261 by returning the address of where to find it. */
3262 int pcc_struct_value = 0;
3263 rtx struct_value = 0;
3265 /* Number of actual parameters in this call, including struct value addr. */
3266 int num_actuals;
3267 /* Number of named args. Args after this are anonymous ones
3268 and they must all go on the stack. */
3269 int n_named_args;
3270 /* Number of complex actual arguments that need to be split. */
3271 int num_complex_actuals = 0;
3273 /* Vector of information about each argument.
3274 Arguments are numbered in the order they will be pushed,
3275 not the order they are written. */
3276 struct arg_data *args;
3278 /* Total size in bytes of all the stack-parms scanned so far. */
3279 struct args_size args_size;
3280 struct args_size adjusted_args_size;
3281 /* Size of arguments before any adjustments (such as rounding). */
3282 poly_int64 unadjusted_args_size;
3283 /* Data on reg parms scanned so far. */
3284 CUMULATIVE_ARGS args_so_far_v;
3285 cumulative_args_t args_so_far;
3286 /* Nonzero if a reg parm has been scanned. */
3287 int reg_parm_seen;
3288 /* Nonzero if this is an indirect function call. */
3290 /* Nonzero if we must avoid push-insns in the args for this call.
3291 If stack space is allocated for register parameters, but not by the
3292 caller, then it is preallocated in the fixed part of the stack frame.
3293 So the entire argument block must then be preallocated (i.e., we
3294 ignore PUSH_ROUNDING in that case). */
3296 int must_preallocate = !PUSH_ARGS;
3298 /* Size of the stack reserved for parameter registers. */
3299 int reg_parm_stack_space = 0;
3301 /* Address of space preallocated for stack parms
3302 (on machines that lack push insns), or 0 if space not preallocated. */
3303 rtx argblock = 0;
3305 /* Mask of ECF_ and ERF_ flags. */
3306 int flags = 0;
3307 int return_flags = 0;
3308 #ifdef REG_PARM_STACK_SPACE
3309 /* Define the boundary of the register parm stack space that needs to be
3310 saved, if any. */
3311 int low_to_save, high_to_save;
3312 rtx save_area = 0; /* Place that it is saved */
3313 #endif
3315 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3316 char *initial_stack_usage_map = stack_usage_map;
3317 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3318 char *stack_usage_map_buf = NULL;
3320 poly_int64 old_stack_allocated;
3322 /* State variables to track stack modifications. */
3323 rtx old_stack_level = 0;
3324 int old_stack_arg_under_construction = 0;
3325 poly_int64 old_pending_adj = 0;
3326 int old_inhibit_defer_pop = inhibit_defer_pop;
3328 /* Some stack pointer alterations we make are performed via
3329 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3330 which we then also need to save/restore along the way. */
3331 poly_int64 old_stack_pointer_delta = 0;
3333 rtx call_fusage;
3334 tree addr = CALL_EXPR_FN (exp);
3335 int i;
3336 /* The alignment of the stack, in bits. */
3337 unsigned HOST_WIDE_INT preferred_stack_boundary;
3338 /* The alignment of the stack, in bytes. */
3339 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3340 /* The static chain value to use for this call. */
3341 rtx static_chain_value;
3342 /* See if this is "nothrow" function call. */
3343 if (TREE_NOTHROW (exp))
3344 flags |= ECF_NOTHROW;
3346 /* See if we can find a DECL-node for the actual function, and get the
3347 function attributes (flags) from the function decl or type node. */
3348 fndecl = get_callee_fndecl (exp);
3349 if (fndecl)
3351 fntype = TREE_TYPE (fndecl);
3352 flags |= flags_from_decl_or_type (fndecl);
3353 return_flags |= decl_return_flags (fndecl);
3355 else
3357 fntype = TREE_TYPE (TREE_TYPE (addr));
3358 flags |= flags_from_decl_or_type (fntype);
3359 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3360 flags |= ECF_BY_DESCRIPTOR;
3362 rettype = TREE_TYPE (exp);
3364 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3366 /* Warn if this value is an aggregate type,
3367 regardless of which calling convention we are using for it. */
3368 if (AGGREGATE_TYPE_P (rettype))
3369 warning (OPT_Waggregate_return, "function call has aggregate value");
3371 /* If the result of a non looping pure or const function call is
3372 ignored (or void), and none of its arguments are volatile, we can
3373 avoid expanding the call and just evaluate the arguments for
3374 side-effects. */
3375 if ((flags & (ECF_CONST | ECF_PURE))
3376 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3377 && (ignore || target == const0_rtx
3378 || TYPE_MODE (rettype) == VOIDmode))
3380 bool volatilep = false;
3381 tree arg;
3382 call_expr_arg_iterator iter;
3384 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3385 if (TREE_THIS_VOLATILE (arg))
3387 volatilep = true;
3388 break;
3391 if (! volatilep)
3393 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3394 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3395 return const0_rtx;
3399 #ifdef REG_PARM_STACK_SPACE
3400 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3401 #endif
3403 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3404 && reg_parm_stack_space > 0 && PUSH_ARGS)
3405 must_preallocate = 1;
3407 /* Set up a place to return a structure. */
3409 /* Cater to broken compilers. */
3410 if (aggregate_value_p (exp, fntype))
3412 /* This call returns a big structure. */
3413 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3415 #ifdef PCC_STATIC_STRUCT_RETURN
3417 pcc_struct_value = 1;
3419 #else /* not PCC_STATIC_STRUCT_RETURN */
3421 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3422 struct_value_size = -1;
3424 /* Even if it is semantically safe to use the target as the return
3425 slot, it may be not sufficiently aligned for the return type. */
3426 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3427 && target
3428 && MEM_P (target)
3429 /* If rettype is addressable, we may not create a temporary.
3430 If target is properly aligned at runtime and the compiler
3431 just doesn't know about it, it will work fine, otherwise it
3432 will be UB. */
3433 && (TREE_ADDRESSABLE (rettype)
3434 || !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3435 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3436 MEM_ALIGN (target)))))
3437 structure_value_addr = XEXP (target, 0);
3438 else
3440 /* For variable-sized objects, we must be called with a target
3441 specified. If we were to allocate space on the stack here,
3442 we would have no way of knowing when to free it. */
3443 rtx d = assign_temp (rettype, 1, 1);
3444 structure_value_addr = XEXP (d, 0);
3445 target = 0;
3448 #endif /* not PCC_STATIC_STRUCT_RETURN */
3451 /* Figure out the amount to which the stack should be aligned. */
3452 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3453 if (fndecl)
3455 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3456 /* Without automatic stack alignment, we can't increase preferred
3457 stack boundary. With automatic stack alignment, it is
3458 unnecessary since unless we can guarantee that all callers will
3459 align the outgoing stack properly, callee has to align its
3460 stack anyway. */
3461 if (i
3462 && i->preferred_incoming_stack_boundary
3463 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3464 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3467 /* Operand 0 is a pointer-to-function; get the type of the function. */
3468 funtype = TREE_TYPE (addr);
3469 gcc_assert (POINTER_TYPE_P (funtype));
3470 funtype = TREE_TYPE (funtype);
3472 /* Count whether there are actual complex arguments that need to be split
3473 into their real and imaginary parts. Munge the type_arg_types
3474 appropriately here as well. */
3475 if (targetm.calls.split_complex_arg)
3477 call_expr_arg_iterator iter;
3478 tree arg;
3479 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3481 tree type = TREE_TYPE (arg);
3482 if (type && TREE_CODE (type) == COMPLEX_TYPE
3483 && targetm.calls.split_complex_arg (type))
3484 num_complex_actuals++;
3486 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3488 else
3489 type_arg_types = TYPE_ARG_TYPES (funtype);
3491 if (flags & ECF_MAY_BE_ALLOCA)
3492 cfun->calls_alloca = 1;
3494 /* If struct_value_rtx is 0, it means pass the address
3495 as if it were an extra parameter. Put the argument expression
3496 in structure_value_addr_value. */
3497 if (structure_value_addr && struct_value == 0)
3499 /* If structure_value_addr is a REG other than
3500 virtual_outgoing_args_rtx, we can use always use it. If it
3501 is not a REG, we must always copy it into a register.
3502 If it is virtual_outgoing_args_rtx, we must copy it to another
3503 register in some cases. */
3504 rtx temp = (!REG_P (structure_value_addr)
3505 || (ACCUMULATE_OUTGOING_ARGS
3506 && stack_arg_under_construction
3507 && structure_value_addr == virtual_outgoing_args_rtx)
3508 ? copy_addr_to_reg (convert_memory_address
3509 (Pmode, structure_value_addr))
3510 : structure_value_addr);
3512 structure_value_addr_value =
3513 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3514 structure_value_addr_parm = CALL_WITH_BOUNDS_P (exp) ? 2 : 1;
3517 /* Count the arguments and set NUM_ACTUALS. */
3518 num_actuals =
3519 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3521 /* Compute number of named args.
3522 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3524 if (type_arg_types != 0)
3525 n_named_args
3526 = (list_length (type_arg_types)
3527 /* Count the struct value address, if it is passed as a parm. */
3528 + structure_value_addr_parm);
3529 else
3530 /* If we know nothing, treat all args as named. */
3531 n_named_args = num_actuals;
3533 /* Start updating where the next arg would go.
3535 On some machines (such as the PA) indirect calls have a different
3536 calling convention than normal calls. The fourth argument in
3537 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3538 or not. */
3539 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3540 args_so_far = pack_cumulative_args (&args_so_far_v);
3542 /* Now possibly adjust the number of named args.
3543 Normally, don't include the last named arg if anonymous args follow.
3544 We do include the last named arg if
3545 targetm.calls.strict_argument_naming() returns nonzero.
3546 (If no anonymous args follow, the result of list_length is actually
3547 one too large. This is harmless.)
3549 If targetm.calls.pretend_outgoing_varargs_named() returns
3550 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3551 this machine will be able to place unnamed args that were passed
3552 in registers into the stack. So treat all args as named. This
3553 allows the insns emitting for a specific argument list to be
3554 independent of the function declaration.
3556 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3557 we do not have any reliable way to pass unnamed args in
3558 registers, so we must force them into memory. */
3560 if (type_arg_types != 0
3561 && targetm.calls.strict_argument_naming (args_so_far))
3563 else if (type_arg_types != 0
3564 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3565 /* Don't include the last named arg. */
3566 --n_named_args;
3567 else
3568 /* Treat all args as named. */
3569 n_named_args = num_actuals;
3571 /* Make a vector to hold all the information about each arg. */
3572 args = XCNEWVEC (struct arg_data, num_actuals);
3574 /* Build up entries in the ARGS array, compute the size of the
3575 arguments into ARGS_SIZE, etc. */
3576 initialize_argument_information (num_actuals, args, &args_size,
3577 n_named_args, exp,
3578 structure_value_addr_value, fndecl, fntype,
3579 args_so_far, reg_parm_stack_space,
3580 &old_stack_level, &old_pending_adj,
3581 &must_preallocate, &flags,
3582 &try_tail_call, CALL_FROM_THUNK_P (exp));
3584 if (args_size.var)
3585 must_preallocate = 1;
3587 /* Now make final decision about preallocating stack space. */
3588 must_preallocate = finalize_must_preallocate (must_preallocate,
3589 num_actuals, args,
3590 &args_size);
3592 /* If the structure value address will reference the stack pointer, we
3593 must stabilize it. We don't need to do this if we know that we are
3594 not going to adjust the stack pointer in processing this call. */
3596 if (structure_value_addr
3597 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3598 || reg_mentioned_p (virtual_outgoing_args_rtx,
3599 structure_value_addr))
3600 && (args_size.var
3601 || (!ACCUMULATE_OUTGOING_ARGS
3602 && maybe_ne (args_size.constant, 0))))
3603 structure_value_addr = copy_to_reg (structure_value_addr);
3605 /* Tail calls can make things harder to debug, and we've traditionally
3606 pushed these optimizations into -O2. Don't try if we're already
3607 expanding a call, as that means we're an argument. Don't try if
3608 there's cleanups, as we know there's code to follow the call. */
3610 if (currently_expanding_call++ != 0
3611 || !flag_optimize_sibling_calls
3612 || args_size.var
3613 || dbg_cnt (tail_call) == false)
3614 try_tail_call = 0;
3616 /* If the user has marked the function as requiring tail-call
3617 optimization, attempt it. */
3618 if (must_tail_call)
3619 try_tail_call = 1;
3621 /* Rest of purposes for tail call optimizations to fail. */
3622 if (try_tail_call)
3623 try_tail_call = can_implement_as_sibling_call_p (exp,
3624 structure_value_addr,
3625 funtype,
3626 reg_parm_stack_space,
3627 fndecl,
3628 flags, addr, args_size);
3630 /* Check if caller and callee disagree in promotion of function
3631 return value. */
3632 if (try_tail_call)
3634 machine_mode caller_mode, caller_promoted_mode;
3635 machine_mode callee_mode, callee_promoted_mode;
3636 int caller_unsignedp, callee_unsignedp;
3637 tree caller_res = DECL_RESULT (current_function_decl);
3639 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3640 caller_mode = DECL_MODE (caller_res);
3641 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3642 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3643 caller_promoted_mode
3644 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3645 &caller_unsignedp,
3646 TREE_TYPE (current_function_decl), 1);
3647 callee_promoted_mode
3648 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3649 &callee_unsignedp,
3650 funtype, 1);
3651 if (caller_mode != VOIDmode
3652 && (caller_promoted_mode != callee_promoted_mode
3653 || ((caller_mode != caller_promoted_mode
3654 || callee_mode != callee_promoted_mode)
3655 && (caller_unsignedp != callee_unsignedp
3656 || partial_subreg_p (caller_mode, callee_mode)))))
3658 try_tail_call = 0;
3659 maybe_complain_about_tail_call (exp,
3660 "caller and callee disagree in"
3661 " promotion of function"
3662 " return value");
3666 /* Ensure current function's preferred stack boundary is at least
3667 what we need. Stack alignment may also increase preferred stack
3668 boundary. */
3669 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3670 crtl->preferred_stack_boundary = preferred_stack_boundary;
3671 else
3672 preferred_stack_boundary = crtl->preferred_stack_boundary;
3674 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3676 /* We want to make two insn chains; one for a sibling call, the other
3677 for a normal call. We will select one of the two chains after
3678 initial RTL generation is complete. */
3679 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3681 int sibcall_failure = 0;
3682 /* We want to emit any pending stack adjustments before the tail
3683 recursion "call". That way we know any adjustment after the tail
3684 recursion call can be ignored if we indeed use the tail
3685 call expansion. */
3686 saved_pending_stack_adjust save;
3687 rtx_insn *insns, *before_call, *after_args;
3688 rtx next_arg_reg;
3690 if (pass == 0)
3692 /* State variables we need to save and restore between
3693 iterations. */
3694 save_pending_stack_adjust (&save);
3696 if (pass)
3697 flags &= ~ECF_SIBCALL;
3698 else
3699 flags |= ECF_SIBCALL;
3701 /* Other state variables that we must reinitialize each time
3702 through the loop (that are not initialized by the loop itself). */
3703 argblock = 0;
3704 call_fusage = 0;
3706 /* Start a new sequence for the normal call case.
3708 From this point on, if the sibling call fails, we want to set
3709 sibcall_failure instead of continuing the loop. */
3710 start_sequence ();
3712 /* Don't let pending stack adjusts add up to too much.
3713 Also, do all pending adjustments now if there is any chance
3714 this might be a call to alloca or if we are expanding a sibling
3715 call sequence.
3716 Also do the adjustments before a throwing call, otherwise
3717 exception handling can fail; PR 19225. */
3718 if (maybe_ge (pending_stack_adjust, 32)
3719 || (maybe_ne (pending_stack_adjust, 0)
3720 && (flags & ECF_MAY_BE_ALLOCA))
3721 || (maybe_ne (pending_stack_adjust, 0)
3722 && flag_exceptions && !(flags & ECF_NOTHROW))
3723 || pass == 0)
3724 do_pending_stack_adjust ();
3726 /* Precompute any arguments as needed. */
3727 if (pass)
3728 precompute_arguments (num_actuals, args);
3730 /* Now we are about to start emitting insns that can be deleted
3731 if a libcall is deleted. */
3732 if (pass && (flags & ECF_MALLOC))
3733 start_sequence ();
3735 if (pass == 0
3736 && crtl->stack_protect_guard
3737 && targetm.stack_protect_runtime_enabled_p ())
3738 stack_protect_epilogue ();
3740 adjusted_args_size = args_size;
3741 /* Compute the actual size of the argument block required. The variable
3742 and constant sizes must be combined, the size may have to be rounded,
3743 and there may be a minimum required size. When generating a sibcall
3744 pattern, do not round up, since we'll be re-using whatever space our
3745 caller provided. */
3746 unadjusted_args_size
3747 = compute_argument_block_size (reg_parm_stack_space,
3748 &adjusted_args_size,
3749 fndecl, fntype,
3750 (pass == 0 ? 0
3751 : preferred_stack_boundary));
3753 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3755 /* The argument block when performing a sibling call is the
3756 incoming argument block. */
3757 if (pass == 0)
3759 argblock = crtl->args.internal_arg_pointer;
3760 if (STACK_GROWS_DOWNWARD)
3761 argblock
3762 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3763 else
3764 argblock
3765 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3767 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3768 stored_args_map = sbitmap_alloc (map_size);
3769 bitmap_clear (stored_args_map);
3770 stored_args_watermark = HOST_WIDE_INT_M1U;
3773 /* If we have no actual push instructions, or shouldn't use them,
3774 make space for all args right now. */
3775 else if (adjusted_args_size.var != 0)
3777 if (old_stack_level == 0)
3779 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3780 old_stack_pointer_delta = stack_pointer_delta;
3781 old_pending_adj = pending_stack_adjust;
3782 pending_stack_adjust = 0;
3783 /* stack_arg_under_construction says whether a stack arg is
3784 being constructed at the old stack level. Pushing the stack
3785 gets a clean outgoing argument block. */
3786 old_stack_arg_under_construction = stack_arg_under_construction;
3787 stack_arg_under_construction = 0;
3789 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3790 if (flag_stack_usage_info)
3791 current_function_has_unbounded_dynamic_stack_size = 1;
3793 else
3795 /* Note that we must go through the motions of allocating an argument
3796 block even if the size is zero because we may be storing args
3797 in the area reserved for register arguments, which may be part of
3798 the stack frame. */
3800 poly_int64 needed = adjusted_args_size.constant;
3802 /* Store the maximum argument space used. It will be pushed by
3803 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3804 checking). */
3806 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3807 needed);
3809 if (must_preallocate)
3811 if (ACCUMULATE_OUTGOING_ARGS)
3813 /* Since the stack pointer will never be pushed, it is
3814 possible for the evaluation of a parm to clobber
3815 something we have already written to the stack.
3816 Since most function calls on RISC machines do not use
3817 the stack, this is uncommon, but must work correctly.
3819 Therefore, we save any area of the stack that was already
3820 written and that we are using. Here we set up to do this
3821 by making a new stack usage map from the old one. The
3822 actual save will be done by store_one_arg.
3824 Another approach might be to try to reorder the argument
3825 evaluations to avoid this conflicting stack usage. */
3827 /* Since we will be writing into the entire argument area,
3828 the map must be allocated for its entire size, not just
3829 the part that is the responsibility of the caller. */
3830 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3831 needed += reg_parm_stack_space;
3833 poly_int64 limit = needed;
3834 if (ARGS_GROW_DOWNWARD)
3835 limit += 1;
3837 /* For polynomial sizes, this is the maximum possible
3838 size needed for arguments with a constant size
3839 and offset. */
3840 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3841 highest_outgoing_arg_in_use
3842 = MAX (initial_highest_arg_in_use, const_limit);
3844 free (stack_usage_map_buf);
3845 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3846 stack_usage_map = stack_usage_map_buf;
3848 if (initial_highest_arg_in_use)
3849 memcpy (stack_usage_map, initial_stack_usage_map,
3850 initial_highest_arg_in_use);
3852 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3853 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3854 (highest_outgoing_arg_in_use
3855 - initial_highest_arg_in_use));
3856 needed = 0;
3858 /* The address of the outgoing argument list must not be
3859 copied to a register here, because argblock would be left
3860 pointing to the wrong place after the call to
3861 allocate_dynamic_stack_space below. */
3863 argblock = virtual_outgoing_args_rtx;
3865 else
3867 /* Try to reuse some or all of the pending_stack_adjust
3868 to get this space. */
3869 if (inhibit_defer_pop == 0
3870 && (combine_pending_stack_adjustment_and_call
3871 (&needed,
3872 unadjusted_args_size,
3873 &adjusted_args_size,
3874 preferred_unit_stack_boundary)))
3876 /* combine_pending_stack_adjustment_and_call computes
3877 an adjustment before the arguments are allocated.
3878 Account for them and see whether or not the stack
3879 needs to go up or down. */
3880 needed = unadjusted_args_size - needed;
3882 /* Checked by
3883 combine_pending_stack_adjustment_and_call. */
3884 gcc_checking_assert (ordered_p (needed, 0));
3885 if (maybe_lt (needed, 0))
3887 /* We're releasing stack space. */
3888 /* ??? We can avoid any adjustment at all if we're
3889 already aligned. FIXME. */
3890 pending_stack_adjust = -needed;
3891 do_pending_stack_adjust ();
3892 needed = 0;
3894 else
3895 /* We need to allocate space. We'll do that in
3896 push_block below. */
3897 pending_stack_adjust = 0;
3900 /* Special case this because overhead of `push_block' in
3901 this case is non-trivial. */
3902 if (known_eq (needed, 0))
3903 argblock = virtual_outgoing_args_rtx;
3904 else
3906 rtx needed_rtx = gen_int_mode (needed, Pmode);
3907 argblock = push_block (needed_rtx, 0, 0);
3908 if (ARGS_GROW_DOWNWARD)
3909 argblock = plus_constant (Pmode, argblock, needed);
3912 /* We only really need to call `copy_to_reg' in the case
3913 where push insns are going to be used to pass ARGBLOCK
3914 to a function call in ARGS. In that case, the stack
3915 pointer changes value from the allocation point to the
3916 call point, and hence the value of
3917 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3918 as well always do it. */
3919 argblock = copy_to_reg (argblock);
3924 if (ACCUMULATE_OUTGOING_ARGS)
3926 /* The save/restore code in store_one_arg handles all
3927 cases except one: a constructor call (including a C
3928 function returning a BLKmode struct) to initialize
3929 an argument. */
3930 if (stack_arg_under_construction)
3932 rtx push_size
3933 = (gen_int_mode
3934 (adjusted_args_size.constant
3935 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
3936 : TREE_TYPE (fndecl))
3937 ? 0 : reg_parm_stack_space), Pmode));
3938 if (old_stack_level == 0)
3940 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3941 old_stack_pointer_delta = stack_pointer_delta;
3942 old_pending_adj = pending_stack_adjust;
3943 pending_stack_adjust = 0;
3944 /* stack_arg_under_construction says whether a stack
3945 arg is being constructed at the old stack level.
3946 Pushing the stack gets a clean outgoing argument
3947 block. */
3948 old_stack_arg_under_construction
3949 = stack_arg_under_construction;
3950 stack_arg_under_construction = 0;
3951 /* Make a new map for the new argument list. */
3952 free (stack_usage_map_buf);
3953 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
3954 stack_usage_map = stack_usage_map_buf;
3955 highest_outgoing_arg_in_use = 0;
3956 stack_usage_watermark = HOST_WIDE_INT_M1U;
3958 /* We can pass TRUE as the 4th argument because we just
3959 saved the stack pointer and will restore it right after
3960 the call. */
3961 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
3962 -1, true);
3965 /* If argument evaluation might modify the stack pointer,
3966 copy the address of the argument list to a register. */
3967 for (i = 0; i < num_actuals; i++)
3968 if (args[i].pass_on_stack)
3970 argblock = copy_addr_to_reg (argblock);
3971 break;
3975 compute_argument_addresses (args, argblock, num_actuals);
3977 /* Stack is properly aligned, pops can't safely be deferred during
3978 the evaluation of the arguments. */
3979 NO_DEFER_POP;
3981 /* Precompute all register parameters. It isn't safe to compute
3982 anything once we have started filling any specific hard regs.
3983 TLS symbols sometimes need a call to resolve. Precompute
3984 register parameters before any stack pointer manipulation
3985 to avoid unaligned stack in the called function. */
3986 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3988 OK_DEFER_POP;
3990 /* Perform stack alignment before the first push (the last arg). */
3991 if (argblock == 0
3992 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
3993 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
3995 /* When the stack adjustment is pending, we get better code
3996 by combining the adjustments. */
3997 if (maybe_ne (pending_stack_adjust, 0)
3998 && ! inhibit_defer_pop
3999 && (combine_pending_stack_adjustment_and_call
4000 (&pending_stack_adjust,
4001 unadjusted_args_size,
4002 &adjusted_args_size,
4003 preferred_unit_stack_boundary)))
4004 do_pending_stack_adjust ();
4005 else if (argblock == 0)
4006 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
4007 - unadjusted_args_size,
4008 Pmode));
4010 /* Now that the stack is properly aligned, pops can't safely
4011 be deferred during the evaluation of the arguments. */
4012 NO_DEFER_POP;
4014 /* Record the maximum pushed stack space size. We need to delay
4015 doing it this far to take into account the optimization done
4016 by combine_pending_stack_adjustment_and_call. */
4017 if (flag_stack_usage_info
4018 && !ACCUMULATE_OUTGOING_ARGS
4019 && pass
4020 && adjusted_args_size.var == 0)
4022 poly_int64 pushed = (adjusted_args_size.constant
4023 + pending_stack_adjust);
4024 current_function_pushed_stack_size
4025 = upper_bound (current_function_pushed_stack_size, pushed);
4028 funexp = rtx_for_function_call (fndecl, addr);
4030 if (CALL_EXPR_STATIC_CHAIN (exp))
4031 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4032 else
4033 static_chain_value = 0;
4035 #ifdef REG_PARM_STACK_SPACE
4036 /* Save the fixed argument area if it's part of the caller's frame and
4037 is clobbered by argument setup for this call. */
4038 if (ACCUMULATE_OUTGOING_ARGS && pass)
4039 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4040 &low_to_save, &high_to_save);
4041 #endif
4043 /* Now store (and compute if necessary) all non-register parms.
4044 These come before register parms, since they can require block-moves,
4045 which could clobber the registers used for register parms.
4046 Parms which have partial registers are not stored here,
4047 but we do preallocate space here if they want that. */
4049 for (i = 0; i < num_actuals; i++)
4051 /* Delay bounds until all other args are stored. */
4052 if (POINTER_BOUNDS_P (args[i].tree_value))
4053 continue;
4054 else if (args[i].reg == 0 || args[i].pass_on_stack)
4056 rtx_insn *before_arg = get_last_insn ();
4058 /* We don't allow passing huge (> 2^30 B) arguments
4059 by value. It would cause an overflow later on. */
4060 if (constant_lower_bound (adjusted_args_size.constant)
4061 >= (1 << (HOST_BITS_PER_INT - 2)))
4063 sorry ("passing too large argument on stack");
4064 continue;
4067 if (store_one_arg (&args[i], argblock, flags,
4068 adjusted_args_size.var != 0,
4069 reg_parm_stack_space)
4070 || (pass == 0
4071 && check_sibcall_argument_overlap (before_arg,
4072 &args[i], 1)))
4073 sibcall_failure = 1;
4076 if (args[i].stack)
4077 call_fusage
4078 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4079 gen_rtx_USE (VOIDmode, args[i].stack),
4080 call_fusage);
4083 /* If we have a parm that is passed in registers but not in memory
4084 and whose alignment does not permit a direct copy into registers,
4085 make a group of pseudos that correspond to each register that we
4086 will later fill. */
4087 if (STRICT_ALIGNMENT)
4088 store_unaligned_arguments_into_pseudos (args, num_actuals);
4090 /* Now store any partially-in-registers parm.
4091 This is the last place a block-move can happen. */
4092 if (reg_parm_seen)
4093 for (i = 0; i < num_actuals; i++)
4094 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4096 rtx_insn *before_arg = get_last_insn ();
4098 /* On targets with weird calling conventions (e.g. PA) it's
4099 hard to ensure that all cases of argument overlap between
4100 stack and registers work. Play it safe and bail out. */
4101 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4103 sibcall_failure = 1;
4104 break;
4107 if (store_one_arg (&args[i], argblock, flags,
4108 adjusted_args_size.var != 0,
4109 reg_parm_stack_space)
4110 || (pass == 0
4111 && check_sibcall_argument_overlap (before_arg,
4112 &args[i], 1)))
4113 sibcall_failure = 1;
4116 bool any_regs = false;
4117 for (i = 0; i < num_actuals; i++)
4118 if (args[i].reg != NULL_RTX)
4120 any_regs = true;
4121 targetm.calls.call_args (args[i].reg, funtype);
4123 if (!any_regs)
4124 targetm.calls.call_args (pc_rtx, funtype);
4126 /* Figure out the register where the value, if any, will come back. */
4127 valreg = 0;
4128 valbnd = 0;
4129 if (TYPE_MODE (rettype) != VOIDmode
4130 && ! structure_value_addr)
4132 if (pcc_struct_value)
4134 valreg = hard_function_value (build_pointer_type (rettype),
4135 fndecl, NULL, (pass == 0));
4136 if (CALL_WITH_BOUNDS_P (exp))
4137 valbnd = targetm.calls.
4138 chkp_function_value_bounds (build_pointer_type (rettype),
4139 fndecl, (pass == 0));
4141 else
4143 valreg = hard_function_value (rettype, fndecl, fntype,
4144 (pass == 0));
4145 if (CALL_WITH_BOUNDS_P (exp))
4146 valbnd = targetm.calls.chkp_function_value_bounds (rettype,
4147 fndecl,
4148 (pass == 0));
4151 /* If VALREG is a PARALLEL whose first member has a zero
4152 offset, use that. This is for targets such as m68k that
4153 return the same value in multiple places. */
4154 if (GET_CODE (valreg) == PARALLEL)
4156 rtx elem = XVECEXP (valreg, 0, 0);
4157 rtx where = XEXP (elem, 0);
4158 rtx offset = XEXP (elem, 1);
4159 if (offset == const0_rtx
4160 && GET_MODE (where) == GET_MODE (valreg))
4161 valreg = where;
4165 /* Store all bounds not passed in registers. */
4166 for (i = 0; i < num_actuals; i++)
4168 if (POINTER_BOUNDS_P (args[i].tree_value)
4169 && !args[i].reg)
4170 store_bounds (&args[i],
4171 args[i].pointer_arg == -1
4172 ? NULL
4173 : &args[args[i].pointer_arg]);
4176 /* If register arguments require space on the stack and stack space
4177 was not preallocated, allocate stack space here for arguments
4178 passed in registers. */
4179 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4180 && !ACCUMULATE_OUTGOING_ARGS
4181 && must_preallocate == 0 && reg_parm_stack_space > 0)
4182 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4184 /* Pass the function the address in which to return a
4185 structure value. */
4186 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4188 structure_value_addr
4189 = convert_memory_address (Pmode, structure_value_addr);
4190 emit_move_insn (struct_value,
4191 force_reg (Pmode,
4192 force_operand (structure_value_addr,
4193 NULL_RTX)));
4195 if (REG_P (struct_value))
4196 use_reg (&call_fusage, struct_value);
4199 after_args = get_last_insn ();
4200 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4201 static_chain_value, &call_fusage,
4202 reg_parm_seen, flags);
4204 load_register_parameters (args, num_actuals, &call_fusage, flags,
4205 pass == 0, &sibcall_failure);
4207 /* Save a pointer to the last insn before the call, so that we can
4208 later safely search backwards to find the CALL_INSN. */
4209 before_call = get_last_insn ();
4211 /* Set up next argument register. For sibling calls on machines
4212 with register windows this should be the incoming register. */
4213 if (pass == 0)
4214 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
4215 VOIDmode,
4216 void_type_node,
4217 true);
4218 else
4219 next_arg_reg = targetm.calls.function_arg (args_so_far,
4220 VOIDmode, void_type_node,
4221 true);
4223 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4225 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4226 arg_nr = num_actuals - arg_nr - 1;
4227 if (arg_nr >= 0
4228 && arg_nr < num_actuals
4229 && args[arg_nr].reg
4230 && valreg
4231 && REG_P (valreg)
4232 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4233 call_fusage
4234 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4235 gen_rtx_SET (valreg, args[arg_nr].reg),
4236 call_fusage);
4238 /* All arguments and registers used for the call must be set up by
4239 now! */
4241 /* Stack must be properly aligned now. */
4242 gcc_assert (!pass
4243 || multiple_p (stack_pointer_delta,
4244 preferred_unit_stack_boundary));
4246 /* Generate the actual call instruction. */
4247 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4248 adjusted_args_size.constant, struct_value_size,
4249 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4250 flags, args_so_far);
4252 if (flag_ipa_ra)
4254 rtx_call_insn *last;
4255 rtx datum = NULL_RTX;
4256 if (fndecl != NULL_TREE)
4258 datum = XEXP (DECL_RTL (fndecl), 0);
4259 gcc_assert (datum != NULL_RTX
4260 && GET_CODE (datum) == SYMBOL_REF);
4262 last = last_call_insn ();
4263 add_reg_note (last, REG_CALL_DECL, datum);
4266 /* If the call setup or the call itself overlaps with anything
4267 of the argument setup we probably clobbered our call address.
4268 In that case we can't do sibcalls. */
4269 if (pass == 0
4270 && check_sibcall_argument_overlap (after_args, 0, 0))
4271 sibcall_failure = 1;
4273 /* If a non-BLKmode value is returned at the most significant end
4274 of a register, shift the register right by the appropriate amount
4275 and update VALREG accordingly. BLKmode values are handled by the
4276 group load/store machinery below. */
4277 if (!structure_value_addr
4278 && !pcc_struct_value
4279 && TYPE_MODE (rettype) != VOIDmode
4280 && TYPE_MODE (rettype) != BLKmode
4281 && REG_P (valreg)
4282 && targetm.calls.return_in_msb (rettype))
4284 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4285 sibcall_failure = 1;
4286 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4289 if (pass && (flags & ECF_MALLOC))
4291 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4292 rtx_insn *last, *insns;
4294 /* The return value from a malloc-like function is a pointer. */
4295 if (TREE_CODE (rettype) == POINTER_TYPE)
4296 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4298 emit_move_insn (temp, valreg);
4300 /* The return value from a malloc-like function can not alias
4301 anything else. */
4302 last = get_last_insn ();
4303 add_reg_note (last, REG_NOALIAS, temp);
4305 /* Write out the sequence. */
4306 insns = get_insns ();
4307 end_sequence ();
4308 emit_insn (insns);
4309 valreg = temp;
4312 /* For calls to `setjmp', etc., inform
4313 function.c:setjmp_warnings that it should complain if
4314 nonvolatile values are live. For functions that cannot
4315 return, inform flow that control does not fall through. */
4317 if ((flags & ECF_NORETURN) || pass == 0)
4319 /* The barrier must be emitted
4320 immediately after the CALL_INSN. Some ports emit more
4321 than just a CALL_INSN above, so we must search for it here. */
4323 rtx_insn *last = get_last_insn ();
4324 while (!CALL_P (last))
4326 last = PREV_INSN (last);
4327 /* There was no CALL_INSN? */
4328 gcc_assert (last != before_call);
4331 emit_barrier_after (last);
4333 /* Stack adjustments after a noreturn call are dead code.
4334 However when NO_DEFER_POP is in effect, we must preserve
4335 stack_pointer_delta. */
4336 if (inhibit_defer_pop == 0)
4338 stack_pointer_delta = old_stack_allocated;
4339 pending_stack_adjust = 0;
4343 /* If value type not void, return an rtx for the value. */
4345 if (TYPE_MODE (rettype) == VOIDmode
4346 || ignore)
4347 target = const0_rtx;
4348 else if (structure_value_addr)
4350 if (target == 0 || !MEM_P (target))
4352 target
4353 = gen_rtx_MEM (TYPE_MODE (rettype),
4354 memory_address (TYPE_MODE (rettype),
4355 structure_value_addr));
4356 set_mem_attributes (target, rettype, 1);
4359 else if (pcc_struct_value)
4361 /* This is the special C++ case where we need to
4362 know what the true target was. We take care to
4363 never use this value more than once in one expression. */
4364 target = gen_rtx_MEM (TYPE_MODE (rettype),
4365 copy_to_reg (valreg));
4366 set_mem_attributes (target, rettype, 1);
4368 /* Handle calls that return values in multiple non-contiguous locations.
4369 The Irix 6 ABI has examples of this. */
4370 else if (GET_CODE (valreg) == PARALLEL)
4372 if (target == 0)
4373 target = emit_group_move_into_temps (valreg);
4374 else if (rtx_equal_p (target, valreg))
4376 else if (GET_CODE (target) == PARALLEL)
4377 /* Handle the result of a emit_group_move_into_temps
4378 call in the previous pass. */
4379 emit_group_move (target, valreg);
4380 else
4381 emit_group_store (target, valreg, rettype,
4382 int_size_in_bytes (rettype));
4384 else if (target
4385 && GET_MODE (target) == TYPE_MODE (rettype)
4386 && GET_MODE (target) == GET_MODE (valreg))
4388 bool may_overlap = false;
4390 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4391 reg to a plain register. */
4392 if (!REG_P (target) || HARD_REGISTER_P (target))
4393 valreg = avoid_likely_spilled_reg (valreg);
4395 /* If TARGET is a MEM in the argument area, and we have
4396 saved part of the argument area, then we can't store
4397 directly into TARGET as it may get overwritten when we
4398 restore the argument save area below. Don't work too
4399 hard though and simply force TARGET to a register if it
4400 is a MEM; the optimizer is quite likely to sort it out. */
4401 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4402 for (i = 0; i < num_actuals; i++)
4403 if (args[i].save_area)
4405 may_overlap = true;
4406 break;
4409 if (may_overlap)
4410 target = copy_to_reg (valreg);
4411 else
4413 /* TARGET and VALREG cannot be equal at this point
4414 because the latter would not have
4415 REG_FUNCTION_VALUE_P true, while the former would if
4416 it were referring to the same register.
4418 If they refer to the same register, this move will be
4419 a no-op, except when function inlining is being
4420 done. */
4421 emit_move_insn (target, valreg);
4423 /* If we are setting a MEM, this code must be executed.
4424 Since it is emitted after the call insn, sibcall
4425 optimization cannot be performed in that case. */
4426 if (MEM_P (target))
4427 sibcall_failure = 1;
4430 else
4431 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4433 /* If we promoted this return value, make the proper SUBREG.
4434 TARGET might be const0_rtx here, so be careful. */
4435 if (REG_P (target)
4436 && TYPE_MODE (rettype) != BLKmode
4437 && GET_MODE (target) != TYPE_MODE (rettype))
4439 tree type = rettype;
4440 int unsignedp = TYPE_UNSIGNED (type);
4441 machine_mode pmode;
4443 /* Ensure we promote as expected, and get the new unsignedness. */
4444 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4445 funtype, 1);
4446 gcc_assert (GET_MODE (target) == pmode);
4448 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4449 GET_MODE (target));
4450 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4451 SUBREG_PROMOTED_VAR_P (target) = 1;
4452 SUBREG_PROMOTED_SET (target, unsignedp);
4455 /* If size of args is variable or this was a constructor call for a stack
4456 argument, restore saved stack-pointer value. */
4458 if (old_stack_level)
4460 rtx_insn *prev = get_last_insn ();
4462 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4463 stack_pointer_delta = old_stack_pointer_delta;
4465 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4467 pending_stack_adjust = old_pending_adj;
4468 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4469 stack_arg_under_construction = old_stack_arg_under_construction;
4470 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4471 stack_usage_map = initial_stack_usage_map;
4472 stack_usage_watermark = initial_stack_usage_watermark;
4473 sibcall_failure = 1;
4475 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4477 #ifdef REG_PARM_STACK_SPACE
4478 if (save_area)
4479 restore_fixed_argument_area (save_area, argblock,
4480 high_to_save, low_to_save);
4481 #endif
4483 /* If we saved any argument areas, restore them. */
4484 for (i = 0; i < num_actuals; i++)
4485 if (args[i].save_area)
4487 machine_mode save_mode = GET_MODE (args[i].save_area);
4488 rtx stack_area
4489 = gen_rtx_MEM (save_mode,
4490 memory_address (save_mode,
4491 XEXP (args[i].stack_slot, 0)));
4493 if (save_mode != BLKmode)
4494 emit_move_insn (stack_area, args[i].save_area);
4495 else
4496 emit_block_move (stack_area, args[i].save_area,
4497 (gen_int_mode
4498 (args[i].locate.size.constant, Pmode)),
4499 BLOCK_OP_CALL_PARM);
4502 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4503 stack_usage_map = initial_stack_usage_map;
4504 stack_usage_watermark = initial_stack_usage_watermark;
4507 /* If this was alloca, record the new stack level. */
4508 if (flags & ECF_MAY_BE_ALLOCA)
4509 record_new_stack_level ();
4511 /* Free up storage we no longer need. */
4512 for (i = 0; i < num_actuals; ++i)
4513 free (args[i].aligned_regs);
4515 targetm.calls.end_call_args ();
4517 insns = get_insns ();
4518 end_sequence ();
4520 if (pass == 0)
4522 tail_call_insns = insns;
4524 /* Restore the pending stack adjustment now that we have
4525 finished generating the sibling call sequence. */
4527 restore_pending_stack_adjust (&save);
4529 /* Prepare arg structure for next iteration. */
4530 for (i = 0; i < num_actuals; i++)
4532 args[i].value = 0;
4533 args[i].aligned_regs = 0;
4534 args[i].stack = 0;
4537 sbitmap_free (stored_args_map);
4538 internal_arg_pointer_exp_state.scan_start = NULL;
4539 internal_arg_pointer_exp_state.cache.release ();
4541 else
4543 normal_call_insns = insns;
4545 /* Verify that we've deallocated all the stack we used. */
4546 gcc_assert ((flags & ECF_NORETURN)
4547 || known_eq (old_stack_allocated,
4548 stack_pointer_delta
4549 - pending_stack_adjust));
4552 /* If something prevents making this a sibling call,
4553 zero out the sequence. */
4554 if (sibcall_failure)
4555 tail_call_insns = NULL;
4556 else
4557 break;
4560 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4561 arguments too, as argument area is now clobbered by the call. */
4562 if (tail_call_insns)
4564 emit_insn (tail_call_insns);
4565 crtl->tail_call_emit = true;
4567 else
4569 emit_insn (normal_call_insns);
4570 if (try_tail_call)
4571 /* Ideally we'd emit a message for all of the ways that it could
4572 have failed. */
4573 maybe_complain_about_tail_call (exp, "tail call production failed");
4576 currently_expanding_call--;
4578 free (stack_usage_map_buf);
4579 free (args);
4581 /* Join result with returned bounds so caller may use them if needed. */
4582 target = chkp_join_splitted_slot (target, valbnd);
4584 return target;
4587 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4588 this function's incoming arguments.
4590 At the start of RTL generation we know the only REG_EQUIV notes
4591 in the rtl chain are those for incoming arguments, so we can look
4592 for REG_EQUIV notes between the start of the function and the
4593 NOTE_INSN_FUNCTION_BEG.
4595 This is (slight) overkill. We could keep track of the highest
4596 argument we clobber and be more selective in removing notes, but it
4597 does not seem to be worth the effort. */
4599 void
4600 fixup_tail_calls (void)
4602 rtx_insn *insn;
4604 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4606 rtx note;
4608 /* There are never REG_EQUIV notes for the incoming arguments
4609 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4610 if (NOTE_P (insn)
4611 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4612 break;
4614 note = find_reg_note (insn, REG_EQUIV, 0);
4615 if (note)
4616 remove_note (insn, note);
4617 note = find_reg_note (insn, REG_EQUIV, 0);
4618 gcc_assert (!note);
4622 /* Traverse a list of TYPES and expand all complex types into their
4623 components. */
4624 static tree
4625 split_complex_types (tree types)
4627 tree p;
4629 /* Before allocating memory, check for the common case of no complex. */
4630 for (p = types; p; p = TREE_CHAIN (p))
4632 tree type = TREE_VALUE (p);
4633 if (TREE_CODE (type) == COMPLEX_TYPE
4634 && targetm.calls.split_complex_arg (type))
4635 goto found;
4637 return types;
4639 found:
4640 types = copy_list (types);
4642 for (p = types; p; p = TREE_CHAIN (p))
4644 tree complex_type = TREE_VALUE (p);
4646 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4647 && targetm.calls.split_complex_arg (complex_type))
4649 tree next, imag;
4651 /* Rewrite complex type with component type. */
4652 TREE_VALUE (p) = TREE_TYPE (complex_type);
4653 next = TREE_CHAIN (p);
4655 /* Add another component type for the imaginary part. */
4656 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4657 TREE_CHAIN (p) = imag;
4658 TREE_CHAIN (imag) = next;
4660 /* Skip the newly created node. */
4661 p = TREE_CHAIN (p);
4665 return types;
4668 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4669 for a value of mode OUTMODE,
4670 with NARGS different arguments, passed as ARGS.
4671 Store the return value if RETVAL is nonzero: store it in VALUE if
4672 VALUE is nonnull, otherwise pick a convenient location. In either
4673 case return the location of the stored value.
4675 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4676 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4677 other types of library calls. */
4680 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4681 enum libcall_type fn_type,
4682 machine_mode outmode, int nargs, rtx_mode_t *args)
4684 /* Total size in bytes of all the stack-parms scanned so far. */
4685 struct args_size args_size;
4686 /* Size of arguments before any adjustments (such as rounding). */
4687 struct args_size original_args_size;
4688 int argnum;
4689 rtx fun;
4690 /* Todo, choose the correct decl type of orgfun. Sadly this information
4691 isn't present here, so we default to native calling abi here. */
4692 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4693 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4694 int count;
4695 rtx argblock = 0;
4696 CUMULATIVE_ARGS args_so_far_v;
4697 cumulative_args_t args_so_far;
4698 struct arg
4700 rtx value;
4701 machine_mode mode;
4702 rtx reg;
4703 int partial;
4704 struct locate_and_pad_arg_data locate;
4705 rtx save_area;
4707 struct arg *argvec;
4708 int old_inhibit_defer_pop = inhibit_defer_pop;
4709 rtx call_fusage = 0;
4710 rtx mem_value = 0;
4711 rtx valreg;
4712 int pcc_struct_value = 0;
4713 poly_int64 struct_value_size = 0;
4714 int flags;
4715 int reg_parm_stack_space = 0;
4716 poly_int64 needed;
4717 rtx_insn *before_call;
4718 bool have_push_fusage;
4719 tree tfom; /* type_for_mode (outmode, 0) */
4721 #ifdef REG_PARM_STACK_SPACE
4722 /* Define the boundary of the register parm stack space that needs to be
4723 save, if any. */
4724 int low_to_save = 0, high_to_save = 0;
4725 rtx save_area = 0; /* Place that it is saved. */
4726 #endif
4728 /* Size of the stack reserved for parameter registers. */
4729 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4730 char *initial_stack_usage_map = stack_usage_map;
4731 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4732 char *stack_usage_map_buf = NULL;
4734 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4736 #ifdef REG_PARM_STACK_SPACE
4737 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4738 #endif
4740 /* By default, library functions cannot throw. */
4741 flags = ECF_NOTHROW;
4743 switch (fn_type)
4745 case LCT_NORMAL:
4746 break;
4747 case LCT_CONST:
4748 flags |= ECF_CONST;
4749 break;
4750 case LCT_PURE:
4751 flags |= ECF_PURE;
4752 break;
4753 case LCT_NORETURN:
4754 flags |= ECF_NORETURN;
4755 break;
4756 case LCT_THROW:
4757 flags &= ~ECF_NOTHROW;
4758 break;
4759 case LCT_RETURNS_TWICE:
4760 flags = ECF_RETURNS_TWICE;
4761 break;
4763 fun = orgfun;
4765 /* Ensure current function's preferred stack boundary is at least
4766 what we need. */
4767 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4768 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4770 /* If this kind of value comes back in memory,
4771 decide where in memory it should come back. */
4772 if (outmode != VOIDmode)
4774 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4775 if (aggregate_value_p (tfom, 0))
4777 #ifdef PCC_STATIC_STRUCT_RETURN
4778 rtx pointer_reg
4779 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4780 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4781 pcc_struct_value = 1;
4782 if (value == 0)
4783 value = gen_reg_rtx (outmode);
4784 #else /* not PCC_STATIC_STRUCT_RETURN */
4785 struct_value_size = GET_MODE_SIZE (outmode);
4786 if (value != 0 && MEM_P (value))
4787 mem_value = value;
4788 else
4789 mem_value = assign_temp (tfom, 1, 1);
4790 #endif
4791 /* This call returns a big structure. */
4792 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4795 else
4796 tfom = void_type_node;
4798 /* ??? Unfinished: must pass the memory address as an argument. */
4800 /* Copy all the libcall-arguments out of the varargs data
4801 and into a vector ARGVEC.
4803 Compute how to pass each argument. We only support a very small subset
4804 of the full argument passing conventions to limit complexity here since
4805 library functions shouldn't have many args. */
4807 argvec = XALLOCAVEC (struct arg, nargs + 1);
4808 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4810 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4811 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4812 #else
4813 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4814 #endif
4815 args_so_far = pack_cumulative_args (&args_so_far_v);
4817 args_size.constant = 0;
4818 args_size.var = 0;
4820 count = 0;
4822 push_temp_slots ();
4824 /* If there's a structure value address to be passed,
4825 either pass it in the special place, or pass it as an extra argument. */
4826 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4828 rtx addr = XEXP (mem_value, 0);
4830 nargs++;
4832 /* Make sure it is a reasonable operand for a move or push insn. */
4833 if (!REG_P (addr) && !MEM_P (addr)
4834 && !(CONSTANT_P (addr)
4835 && targetm.legitimate_constant_p (Pmode, addr)))
4836 addr = force_operand (addr, NULL_RTX);
4838 argvec[count].value = addr;
4839 argvec[count].mode = Pmode;
4840 argvec[count].partial = 0;
4842 argvec[count].reg = targetm.calls.function_arg (args_so_far,
4843 Pmode, NULL_TREE, true);
4844 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
4845 NULL_TREE, 1) == 0);
4847 locate_and_pad_parm (Pmode, NULL_TREE,
4848 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4850 #else
4851 argvec[count].reg != 0,
4852 #endif
4853 reg_parm_stack_space, 0,
4854 NULL_TREE, &args_size, &argvec[count].locate);
4856 if (argvec[count].reg == 0 || argvec[count].partial != 0
4857 || reg_parm_stack_space > 0)
4858 args_size.constant += argvec[count].locate.size.constant;
4860 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
4862 count++;
4865 for (unsigned int i = 0; count < nargs; i++, count++)
4867 rtx val = args[i].first;
4868 machine_mode mode = args[i].second;
4869 int unsigned_p = 0;
4871 /* We cannot convert the arg value to the mode the library wants here;
4872 must do it earlier where we know the signedness of the arg. */
4873 gcc_assert (mode != BLKmode
4874 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
4876 /* Make sure it is a reasonable operand for a move or push insn. */
4877 if (!REG_P (val) && !MEM_P (val)
4878 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
4879 val = force_operand (val, NULL_RTX);
4881 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
4883 rtx slot;
4884 int must_copy
4885 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
4887 /* If this was a CONST function, it is now PURE since it now
4888 reads memory. */
4889 if (flags & ECF_CONST)
4891 flags &= ~ECF_CONST;
4892 flags |= ECF_PURE;
4895 if (MEM_P (val) && !must_copy)
4897 tree val_expr = MEM_EXPR (val);
4898 if (val_expr)
4899 mark_addressable (val_expr);
4900 slot = val;
4902 else
4904 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
4905 1, 1);
4906 emit_move_insn (slot, val);
4909 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4910 gen_rtx_USE (VOIDmode, slot),
4911 call_fusage);
4912 if (must_copy)
4913 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4914 gen_rtx_CLOBBER (VOIDmode,
4915 slot),
4916 call_fusage);
4918 mode = Pmode;
4919 val = force_operand (XEXP (slot, 0), NULL_RTX);
4922 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
4923 argvec[count].mode = mode;
4924 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
4925 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
4926 NULL_TREE, true);
4928 argvec[count].partial
4929 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
4931 if (argvec[count].reg == 0
4932 || argvec[count].partial != 0
4933 || reg_parm_stack_space > 0)
4935 locate_and_pad_parm (mode, NULL_TREE,
4936 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4938 #else
4939 argvec[count].reg != 0,
4940 #endif
4941 reg_parm_stack_space, argvec[count].partial,
4942 NULL_TREE, &args_size, &argvec[count].locate);
4943 args_size.constant += argvec[count].locate.size.constant;
4944 gcc_assert (!argvec[count].locate.size.var);
4946 #ifdef BLOCK_REG_PADDING
4947 else
4948 /* The argument is passed entirely in registers. See at which
4949 end it should be padded. */
4950 argvec[count].locate.where_pad =
4951 BLOCK_REG_PADDING (mode, NULL_TREE,
4952 known_le (GET_MODE_SIZE (mode), UNITS_PER_WORD));
4953 #endif
4955 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
4958 /* If this machine requires an external definition for library
4959 functions, write one out. */
4960 assemble_external_libcall (fun);
4962 original_args_size = args_size;
4963 args_size.constant = (aligned_upper_bound (args_size.constant
4964 + stack_pointer_delta,
4965 STACK_BYTES)
4966 - stack_pointer_delta);
4968 args_size.constant = upper_bound (args_size.constant,
4969 reg_parm_stack_space);
4971 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4972 args_size.constant -= reg_parm_stack_space;
4974 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
4975 args_size.constant);
4977 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
4979 poly_int64 pushed = args_size.constant + pending_stack_adjust;
4980 current_function_pushed_stack_size
4981 = upper_bound (current_function_pushed_stack_size, pushed);
4984 if (ACCUMULATE_OUTGOING_ARGS)
4986 /* Since the stack pointer will never be pushed, it is possible for
4987 the evaluation of a parm to clobber something we have already
4988 written to the stack. Since most function calls on RISC machines
4989 do not use the stack, this is uncommon, but must work correctly.
4991 Therefore, we save any area of the stack that was already written
4992 and that we are using. Here we set up to do this by making a new
4993 stack usage map from the old one.
4995 Another approach might be to try to reorder the argument
4996 evaluations to avoid this conflicting stack usage. */
4998 needed = args_size.constant;
5000 /* Since we will be writing into the entire argument area, the
5001 map must be allocated for its entire size, not just the part that
5002 is the responsibility of the caller. */
5003 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
5004 needed += reg_parm_stack_space;
5006 poly_int64 limit = needed;
5007 if (ARGS_GROW_DOWNWARD)
5008 limit += 1;
5010 /* For polynomial sizes, this is the maximum possible size needed
5011 for arguments with a constant size and offset. */
5012 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
5013 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
5014 const_limit);
5016 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
5017 stack_usage_map = stack_usage_map_buf;
5019 if (initial_highest_arg_in_use)
5020 memcpy (stack_usage_map, initial_stack_usage_map,
5021 initial_highest_arg_in_use);
5023 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5024 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5025 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5026 needed = 0;
5028 /* We must be careful to use virtual regs before they're instantiated,
5029 and real regs afterwards. Loop optimization, for example, can create
5030 new libcalls after we've instantiated the virtual regs, and if we
5031 use virtuals anyway, they won't match the rtl patterns. */
5033 if (virtuals_instantiated)
5034 argblock = plus_constant (Pmode, stack_pointer_rtx,
5035 STACK_POINTER_OFFSET);
5036 else
5037 argblock = virtual_outgoing_args_rtx;
5039 else
5041 if (!PUSH_ARGS)
5042 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5045 /* We push args individually in reverse order, perform stack alignment
5046 before the first push (the last arg). */
5047 if (argblock == 0)
5048 anti_adjust_stack (gen_int_mode (args_size.constant
5049 - original_args_size.constant,
5050 Pmode));
5052 argnum = nargs - 1;
5054 #ifdef REG_PARM_STACK_SPACE
5055 if (ACCUMULATE_OUTGOING_ARGS)
5057 /* The argument list is the property of the called routine and it
5058 may clobber it. If the fixed area has been used for previous
5059 parameters, we must save and restore it. */
5060 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5061 &low_to_save, &high_to_save);
5063 #endif
5065 /* When expanding a normal call, args are stored in push order,
5066 which is the reverse of what we have here. */
5067 bool any_regs = false;
5068 for (int i = nargs; i-- > 0; )
5069 if (argvec[i].reg != NULL_RTX)
5071 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5072 any_regs = true;
5074 if (!any_regs)
5075 targetm.calls.call_args (pc_rtx, NULL_TREE);
5077 /* Push the args that need to be pushed. */
5079 have_push_fusage = false;
5081 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5082 are to be pushed. */
5083 for (count = 0; count < nargs; count++, argnum--)
5085 machine_mode mode = argvec[argnum].mode;
5086 rtx val = argvec[argnum].value;
5087 rtx reg = argvec[argnum].reg;
5088 int partial = argvec[argnum].partial;
5089 unsigned int parm_align = argvec[argnum].locate.boundary;
5090 poly_int64 lower_bound = 0, upper_bound = 0;
5092 if (! (reg != 0 && partial == 0))
5094 rtx use;
5096 if (ACCUMULATE_OUTGOING_ARGS)
5098 /* If this is being stored into a pre-allocated, fixed-size,
5099 stack area, save any previous data at that location. */
5101 if (ARGS_GROW_DOWNWARD)
5103 /* stack_slot is negative, but we want to index stack_usage_map
5104 with positive values. */
5105 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5106 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5108 else
5110 lower_bound = argvec[argnum].locate.slot_offset.constant;
5111 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5114 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5115 reg_parm_stack_space))
5117 /* We need to make a save area. */
5118 poly_uint64 size
5119 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5120 machine_mode save_mode
5121 = int_mode_for_size (size, 1).else_blk ();
5122 rtx adr
5123 = plus_constant (Pmode, argblock,
5124 argvec[argnum].locate.offset.constant);
5125 rtx stack_area
5126 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5128 if (save_mode == BLKmode)
5130 argvec[argnum].save_area
5131 = assign_stack_temp (BLKmode,
5132 argvec[argnum].locate.size.constant
5135 emit_block_move (validize_mem
5136 (copy_rtx (argvec[argnum].save_area)),
5137 stack_area,
5138 (gen_int_mode
5139 (argvec[argnum].locate.size.constant,
5140 Pmode)),
5141 BLOCK_OP_CALL_PARM);
5143 else
5145 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5147 emit_move_insn (argvec[argnum].save_area, stack_area);
5152 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5153 partial, reg, 0, argblock,
5154 (gen_int_mode
5155 (argvec[argnum].locate.offset.constant, Pmode)),
5156 reg_parm_stack_space,
5157 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5159 /* Now mark the segment we just used. */
5160 if (ACCUMULATE_OUTGOING_ARGS)
5161 mark_stack_region_used (lower_bound, upper_bound);
5163 NO_DEFER_POP;
5165 /* Indicate argument access so that alias.c knows that these
5166 values are live. */
5167 if (argblock)
5168 use = plus_constant (Pmode, argblock,
5169 argvec[argnum].locate.offset.constant);
5170 else if (have_push_fusage)
5171 continue;
5172 else
5174 /* When arguments are pushed, trying to tell alias.c where
5175 exactly this argument is won't work, because the
5176 auto-increment causes confusion. So we merely indicate
5177 that we access something with a known mode somewhere on
5178 the stack. */
5179 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5180 gen_rtx_SCRATCH (Pmode));
5181 have_push_fusage = true;
5183 use = gen_rtx_MEM (argvec[argnum].mode, use);
5184 use = gen_rtx_USE (VOIDmode, use);
5185 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5189 argnum = nargs - 1;
5191 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5193 /* Now load any reg parms into their regs. */
5195 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5196 are to be pushed. */
5197 for (count = 0; count < nargs; count++, argnum--)
5199 machine_mode mode = argvec[argnum].mode;
5200 rtx val = argvec[argnum].value;
5201 rtx reg = argvec[argnum].reg;
5202 int partial = argvec[argnum].partial;
5204 /* Handle calls that pass values in multiple non-contiguous
5205 locations. The PA64 has examples of this for library calls. */
5206 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5207 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5208 else if (reg != 0 && partial == 0)
5210 emit_move_insn (reg, val);
5211 #ifdef BLOCK_REG_PADDING
5212 poly_int64 size = GET_MODE_SIZE (argvec[argnum].mode);
5214 /* Copied from load_register_parameters. */
5216 /* Handle case where we have a value that needs shifting
5217 up to the msb. eg. a QImode value and we're padding
5218 upward on a BYTES_BIG_ENDIAN machine. */
5219 if (known_lt (size, UNITS_PER_WORD)
5220 && (argvec[argnum].locate.where_pad
5221 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5223 rtx x;
5224 poly_int64 shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5226 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5227 report the whole reg as used. Strictly speaking, the
5228 call only uses SIZE bytes at the msb end, but it doesn't
5229 seem worth generating rtl to say that. */
5230 reg = gen_rtx_REG (word_mode, REGNO (reg));
5231 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5232 if (x != reg)
5233 emit_move_insn (reg, x);
5235 #endif
5238 NO_DEFER_POP;
5241 /* Any regs containing parms remain in use through the call. */
5242 for (count = 0; count < nargs; count++)
5244 rtx reg = argvec[count].reg;
5245 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5246 use_group_regs (&call_fusage, reg);
5247 else if (reg != 0)
5249 int partial = argvec[count].partial;
5250 if (partial)
5252 int nregs;
5253 gcc_assert (partial % UNITS_PER_WORD == 0);
5254 nregs = partial / UNITS_PER_WORD;
5255 use_regs (&call_fusage, REGNO (reg), nregs);
5257 else
5258 use_reg (&call_fusage, reg);
5262 /* Pass the function the address in which to return a structure value. */
5263 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5265 emit_move_insn (struct_value,
5266 force_reg (Pmode,
5267 force_operand (XEXP (mem_value, 0),
5268 NULL_RTX)));
5269 if (REG_P (struct_value))
5270 use_reg (&call_fusage, struct_value);
5273 /* Don't allow popping to be deferred, since then
5274 cse'ing of library calls could delete a call and leave the pop. */
5275 NO_DEFER_POP;
5276 valreg = (mem_value == 0 && outmode != VOIDmode
5277 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5279 /* Stack must be properly aligned now. */
5280 gcc_assert (multiple_p (stack_pointer_delta,
5281 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5283 before_call = get_last_insn ();
5285 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5286 will set inhibit_defer_pop to that value. */
5287 /* The return type is needed to decide how many bytes the function pops.
5288 Signedness plays no role in that, so for simplicity, we pretend it's
5289 always signed. We also assume that the list of arguments passed has
5290 no impact, so we pretend it is unknown. */
5292 emit_call_1 (fun, NULL,
5293 get_identifier (XSTR (orgfun, 0)),
5294 build_function_type (tfom, NULL_TREE),
5295 original_args_size.constant, args_size.constant,
5296 struct_value_size,
5297 targetm.calls.function_arg (args_so_far,
5298 VOIDmode, void_type_node, true),
5299 valreg,
5300 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5302 if (flag_ipa_ra)
5304 rtx datum = orgfun;
5305 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5306 rtx_call_insn *last = last_call_insn ();
5307 add_reg_note (last, REG_CALL_DECL, datum);
5310 /* Right-shift returned value if necessary. */
5311 if (!pcc_struct_value
5312 && TYPE_MODE (tfom) != BLKmode
5313 && targetm.calls.return_in_msb (tfom))
5315 shift_return_value (TYPE_MODE (tfom), false, valreg);
5316 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5319 targetm.calls.end_call_args ();
5321 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5322 that it should complain if nonvolatile values are live. For
5323 functions that cannot return, inform flow that control does not
5324 fall through. */
5325 if (flags & ECF_NORETURN)
5327 /* The barrier note must be emitted
5328 immediately after the CALL_INSN. Some ports emit more than
5329 just a CALL_INSN above, so we must search for it here. */
5330 rtx_insn *last = get_last_insn ();
5331 while (!CALL_P (last))
5333 last = PREV_INSN (last);
5334 /* There was no CALL_INSN? */
5335 gcc_assert (last != before_call);
5338 emit_barrier_after (last);
5341 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5342 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5343 if (flags & ECF_NOTHROW)
5345 rtx_insn *last = get_last_insn ();
5346 while (!CALL_P (last))
5348 last = PREV_INSN (last);
5349 /* There was no CALL_INSN? */
5350 gcc_assert (last != before_call);
5353 make_reg_eh_region_note_nothrow_nononlocal (last);
5356 /* Now restore inhibit_defer_pop to its actual original value. */
5357 OK_DEFER_POP;
5359 pop_temp_slots ();
5361 /* Copy the value to the right place. */
5362 if (outmode != VOIDmode && retval)
5364 if (mem_value)
5366 if (value == 0)
5367 value = mem_value;
5368 if (value != mem_value)
5369 emit_move_insn (value, mem_value);
5371 else if (GET_CODE (valreg) == PARALLEL)
5373 if (value == 0)
5374 value = gen_reg_rtx (outmode);
5375 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5377 else
5379 /* Convert to the proper mode if a promotion has been active. */
5380 if (GET_MODE (valreg) != outmode)
5382 int unsignedp = TYPE_UNSIGNED (tfom);
5384 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5385 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5386 == GET_MODE (valreg));
5387 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5390 if (value != 0)
5391 emit_move_insn (value, valreg);
5392 else
5393 value = valreg;
5397 if (ACCUMULATE_OUTGOING_ARGS)
5399 #ifdef REG_PARM_STACK_SPACE
5400 if (save_area)
5401 restore_fixed_argument_area (save_area, argblock,
5402 high_to_save, low_to_save);
5403 #endif
5405 /* If we saved any argument areas, restore them. */
5406 for (count = 0; count < nargs; count++)
5407 if (argvec[count].save_area)
5409 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5410 rtx adr = plus_constant (Pmode, argblock,
5411 argvec[count].locate.offset.constant);
5412 rtx stack_area = gen_rtx_MEM (save_mode,
5413 memory_address (save_mode, adr));
5415 if (save_mode == BLKmode)
5416 emit_block_move (stack_area,
5417 validize_mem
5418 (copy_rtx (argvec[count].save_area)),
5419 (gen_int_mode
5420 (argvec[count].locate.size.constant, Pmode)),
5421 BLOCK_OP_CALL_PARM);
5422 else
5423 emit_move_insn (stack_area, argvec[count].save_area);
5426 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5427 stack_usage_map = initial_stack_usage_map;
5428 stack_usage_watermark = initial_stack_usage_watermark;
5431 free (stack_usage_map_buf);
5433 return value;
5438 /* Store pointer bounds argument ARG into Bounds Table entry
5439 associated with PARM. */
5440 static void
5441 store_bounds (struct arg_data *arg, struct arg_data *parm)
5443 rtx slot = NULL, ptr = NULL, addr = NULL;
5445 /* We may pass bounds not associated with any pointer. */
5446 if (!parm)
5448 gcc_assert (arg->special_slot);
5449 slot = arg->special_slot;
5450 ptr = const0_rtx;
5452 /* Find pointer associated with bounds and where it is
5453 passed. */
5454 else
5456 if (!parm->reg)
5458 gcc_assert (!arg->special_slot);
5460 addr = adjust_address (parm->stack, Pmode, arg->pointer_offset);
5462 else if (REG_P (parm->reg))
5464 gcc_assert (arg->special_slot);
5465 slot = arg->special_slot;
5467 if (MEM_P (parm->value))
5468 addr = adjust_address (parm->value, Pmode, arg->pointer_offset);
5469 else if (REG_P (parm->value))
5470 ptr = gen_rtx_SUBREG (Pmode, parm->value, arg->pointer_offset);
5471 else
5473 gcc_assert (!arg->pointer_offset);
5474 ptr = parm->value;
5477 else
5479 gcc_assert (GET_CODE (parm->reg) == PARALLEL);
5481 gcc_assert (arg->special_slot);
5482 slot = arg->special_slot;
5484 if (parm->parallel_value)
5485 ptr = chkp_get_value_with_offs (parm->parallel_value,
5486 GEN_INT (arg->pointer_offset));
5487 else
5488 gcc_unreachable ();
5492 /* Expand bounds. */
5493 if (!arg->value)
5494 arg->value = expand_normal (arg->tree_value);
5496 targetm.calls.store_bounds_for_arg (ptr, addr, arg->value, slot);
5499 /* Store a single argument for a function call
5500 into the register or memory area where it must be passed.
5501 *ARG describes the argument value and where to pass it.
5503 ARGBLOCK is the address of the stack-block for all the arguments,
5504 or 0 on a machine where arguments are pushed individually.
5506 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5507 so must be careful about how the stack is used.
5509 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5510 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5511 that we need not worry about saving and restoring the stack.
5513 FNDECL is the declaration of the function we are calling.
5515 Return nonzero if this arg should cause sibcall failure,
5516 zero otherwise. */
5518 static int
5519 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5520 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5522 tree pval = arg->tree_value;
5523 rtx reg = 0;
5524 int partial = 0;
5525 poly_int64 used = 0;
5526 poly_int64 lower_bound = 0, upper_bound = 0;
5527 int sibcall_failure = 0;
5529 if (TREE_CODE (pval) == ERROR_MARK)
5530 return 1;
5532 /* Push a new temporary level for any temporaries we make for
5533 this argument. */
5534 push_temp_slots ();
5536 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5538 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5539 save any previous data at that location. */
5540 if (argblock && ! variable_size && arg->stack)
5542 if (ARGS_GROW_DOWNWARD)
5544 /* stack_slot is negative, but we want to index stack_usage_map
5545 with positive values. */
5546 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5548 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5549 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5551 else
5552 upper_bound = 0;
5554 lower_bound = upper_bound - arg->locate.size.constant;
5556 else
5558 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5560 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5561 lower_bound = rtx_to_poly_int64 (offset);
5563 else
5564 lower_bound = 0;
5566 upper_bound = lower_bound + arg->locate.size.constant;
5569 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5570 reg_parm_stack_space))
5572 /* We need to make a save area. */
5573 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5574 machine_mode save_mode
5575 = int_mode_for_size (size, 1).else_blk ();
5576 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5577 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5579 if (save_mode == BLKmode)
5581 arg->save_area
5582 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5583 preserve_temp_slots (arg->save_area);
5584 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5585 stack_area,
5586 (gen_int_mode
5587 (arg->locate.size.constant, Pmode)),
5588 BLOCK_OP_CALL_PARM);
5590 else
5592 arg->save_area = gen_reg_rtx (save_mode);
5593 emit_move_insn (arg->save_area, stack_area);
5599 /* If this isn't going to be placed on both the stack and in registers,
5600 set up the register and number of words. */
5601 if (! arg->pass_on_stack)
5603 if (flags & ECF_SIBCALL)
5604 reg = arg->tail_call_reg;
5605 else
5606 reg = arg->reg;
5607 partial = arg->partial;
5610 /* Being passed entirely in a register. We shouldn't be called in
5611 this case. */
5612 gcc_assert (reg == 0 || partial != 0);
5614 /* If this arg needs special alignment, don't load the registers
5615 here. */
5616 if (arg->n_aligned_regs != 0)
5617 reg = 0;
5619 /* If this is being passed partially in a register, we can't evaluate
5620 it directly into its stack slot. Otherwise, we can. */
5621 if (arg->value == 0)
5623 /* stack_arg_under_construction is nonzero if a function argument is
5624 being evaluated directly into the outgoing argument list and
5625 expand_call must take special action to preserve the argument list
5626 if it is called recursively.
5628 For scalar function arguments stack_usage_map is sufficient to
5629 determine which stack slots must be saved and restored. Scalar
5630 arguments in general have pass_on_stack == 0.
5632 If this argument is initialized by a function which takes the
5633 address of the argument (a C++ constructor or a C function
5634 returning a BLKmode structure), then stack_usage_map is
5635 insufficient and expand_call must push the stack around the
5636 function call. Such arguments have pass_on_stack == 1.
5638 Note that it is always safe to set stack_arg_under_construction,
5639 but this generates suboptimal code if set when not needed. */
5641 if (arg->pass_on_stack)
5642 stack_arg_under_construction++;
5644 arg->value = expand_expr (pval,
5645 (partial
5646 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5647 ? NULL_RTX : arg->stack,
5648 VOIDmode, EXPAND_STACK_PARM);
5650 /* If we are promoting object (or for any other reason) the mode
5651 doesn't agree, convert the mode. */
5653 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5654 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5655 arg->value, arg->unsignedp);
5657 if (arg->pass_on_stack)
5658 stack_arg_under_construction--;
5661 /* Check for overlap with already clobbered argument area. */
5662 if ((flags & ECF_SIBCALL)
5663 && MEM_P (arg->value)
5664 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5665 arg->locate.size.constant))
5666 sibcall_failure = 1;
5668 /* Don't allow anything left on stack from computation
5669 of argument to alloca. */
5670 if (flags & ECF_MAY_BE_ALLOCA)
5671 do_pending_stack_adjust ();
5673 if (arg->value == arg->stack)
5674 /* If the value is already in the stack slot, we are done. */
5676 else if (arg->mode != BLKmode)
5678 unsigned int parm_align;
5680 /* Argument is a scalar, not entirely passed in registers.
5681 (If part is passed in registers, arg->partial says how much
5682 and emit_push_insn will take care of putting it there.)
5684 Push it, and if its size is less than the
5685 amount of space allocated to it,
5686 also bump stack pointer by the additional space.
5687 Note that in C the default argument promotions
5688 will prevent such mismatches. */
5690 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5691 ? 0 : GET_MODE_SIZE (arg->mode));
5693 /* Compute how much space the push instruction will push.
5694 On many machines, pushing a byte will advance the stack
5695 pointer by a halfword. */
5696 #ifdef PUSH_ROUNDING
5697 size = PUSH_ROUNDING (size);
5698 #endif
5699 used = size;
5701 /* Compute how much space the argument should get:
5702 round up to a multiple of the alignment for arguments. */
5703 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5704 != PAD_NONE)
5705 /* At the moment we don't (need to) support ABIs for which the
5706 padding isn't known at compile time. In principle it should
5707 be easy to add though. */
5708 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5710 /* Compute the alignment of the pushed argument. */
5711 parm_align = arg->locate.boundary;
5712 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5713 == PAD_DOWNWARD)
5715 poly_int64 pad = used - size;
5716 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5717 if (pad_align != 0)
5718 parm_align = MIN (parm_align, pad_align);
5721 /* This isn't already where we want it on the stack, so put it there.
5722 This can either be done with push or copy insns. */
5723 if (maybe_ne (used, 0)
5724 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5725 NULL_RTX, parm_align, partial, reg, used - size,
5726 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5727 reg_parm_stack_space,
5728 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5729 sibcall_failure = 1;
5731 /* Unless this is a partially-in-register argument, the argument is now
5732 in the stack. */
5733 if (partial == 0)
5734 arg->value = arg->stack;
5736 else
5738 /* BLKmode, at least partly to be pushed. */
5740 unsigned int parm_align;
5741 poly_int64 excess;
5742 rtx size_rtx;
5744 /* Pushing a nonscalar.
5745 If part is passed in registers, PARTIAL says how much
5746 and emit_push_insn will take care of putting it there. */
5748 /* Round its size up to a multiple
5749 of the allocation unit for arguments. */
5751 if (arg->locate.size.var != 0)
5753 excess = 0;
5754 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5756 else
5758 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5759 for BLKmode is careful to avoid it. */
5760 excess = (arg->locate.size.constant
5761 - arg_int_size_in_bytes (TREE_TYPE (pval))
5762 + partial);
5763 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5764 NULL_RTX, TYPE_MODE (sizetype),
5765 EXPAND_NORMAL);
5768 parm_align = arg->locate.boundary;
5770 /* When an argument is padded down, the block is aligned to
5771 PARM_BOUNDARY, but the actual argument isn't. */
5772 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5773 == PAD_DOWNWARD)
5775 if (arg->locate.size.var)
5776 parm_align = BITS_PER_UNIT;
5777 else
5779 unsigned int excess_align
5780 = known_alignment (excess) * BITS_PER_UNIT;
5781 if (excess_align != 0)
5782 parm_align = MIN (parm_align, excess_align);
5786 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5788 /* emit_push_insn might not work properly if arg->value and
5789 argblock + arg->locate.offset areas overlap. */
5790 rtx x = arg->value;
5791 poly_int64 i = 0;
5793 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
5794 || (GET_CODE (XEXP (x, 0)) == PLUS
5795 && XEXP (XEXP (x, 0), 0) ==
5796 crtl->args.internal_arg_pointer
5797 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
5799 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
5800 i = rtx_to_poly_int64 (XEXP (XEXP (x, 0), 1));
5802 /* arg.locate doesn't contain the pretend_args_size offset,
5803 it's part of argblock. Ensure we don't count it in I. */
5804 if (STACK_GROWS_DOWNWARD)
5805 i -= crtl->args.pretend_args_size;
5806 else
5807 i += crtl->args.pretend_args_size;
5809 /* expand_call should ensure this. */
5810 gcc_assert (!arg->locate.offset.var
5811 && arg->locate.size.var == 0);
5812 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5814 if (known_eq (arg->locate.offset.constant, i))
5816 /* Even though they appear to be at the same location,
5817 if part of the outgoing argument is in registers,
5818 they aren't really at the same location. Check for
5819 this by making sure that the incoming size is the
5820 same as the outgoing size. */
5821 if (maybe_ne (arg->locate.size.constant, size_val))
5822 sibcall_failure = 1;
5824 else if (maybe_in_range_p (arg->locate.offset.constant,
5825 i, size_val))
5826 sibcall_failure = 1;
5827 /* Use arg->locate.size.constant instead of size_rtx
5828 because we only care about the part of the argument
5829 on the stack. */
5830 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5831 arg->locate.size.constant))
5832 sibcall_failure = 1;
5836 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5837 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5838 parm_align, partial, reg, excess, argblock,
5839 ARGS_SIZE_RTX (arg->locate.offset),
5840 reg_parm_stack_space,
5841 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5843 /* Unless this is a partially-in-register argument, the argument is now
5844 in the stack.
5846 ??? Unlike the case above, in which we want the actual
5847 address of the data, so that we can load it directly into a
5848 register, here we want the address of the stack slot, so that
5849 it's properly aligned for word-by-word copying or something
5850 like that. It's not clear that this is always correct. */
5851 if (partial == 0)
5852 arg->value = arg->stack_slot;
5855 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5857 tree type = TREE_TYPE (arg->tree_value);
5858 arg->parallel_value
5859 = emit_group_load_into_temps (arg->reg, arg->value, type,
5860 int_size_in_bytes (type));
5863 /* Mark all slots this store used. */
5864 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5865 && argblock && ! variable_size && arg->stack)
5866 mark_stack_region_used (lower_bound, upper_bound);
5868 /* Once we have pushed something, pops can't safely
5869 be deferred during the rest of the arguments. */
5870 NO_DEFER_POP;
5872 /* Free any temporary slots made in processing this argument. */
5873 pop_temp_slots ();
5875 return sibcall_failure;
5878 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5880 bool
5881 must_pass_in_stack_var_size (machine_mode mode ATTRIBUTE_UNUSED,
5882 const_tree type)
5884 if (!type)
5885 return false;
5887 /* If the type has variable size... */
5888 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5889 return true;
5891 /* If the type is marked as addressable (it is required
5892 to be constructed into the stack)... */
5893 if (TREE_ADDRESSABLE (type))
5894 return true;
5896 return false;
5899 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5900 takes trailing padding of a structure into account. */
5901 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5903 bool
5904 must_pass_in_stack_var_size_or_pad (machine_mode mode, const_tree type)
5906 if (!type)
5907 return false;
5909 /* If the type has variable size... */
5910 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5911 return true;
5913 /* If the type is marked as addressable (it is required
5914 to be constructed into the stack)... */
5915 if (TREE_ADDRESSABLE (type))
5916 return true;
5918 if (TYPE_EMPTY_P (type))
5919 return false;
5921 /* If the padding and mode of the type is such that a copy into
5922 a register would put it into the wrong part of the register. */
5923 if (mode == BLKmode
5924 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5925 && (targetm.calls.function_arg_padding (mode, type)
5926 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5927 return true;
5929 return false;
5932 /* Tell the garbage collector about GTY markers in this source file. */
5933 #include "gt-calls.h"