Add a fixed_size_mode_pod class
[official-gcc.git] / gcc / calls.c
blob4cce11a404707b4b6e5aab3b739c8988aa69ec96
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 true;
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) == COMPONENT_REF)
1590 decl = TREE_OPERAND (decl, 1);
1592 if (DECL_P (decl)
1593 && lookup_attribute ("nonstring", DECL_ATTRIBUTES (decl)))
1594 return decl;
1596 return NULL_TREE;
1599 /* Warn about passing a non-string array/pointer to a function that
1600 expects a nul-terminated string argument. */
1602 void
1603 maybe_warn_nonstring_arg (tree fndecl, tree exp)
1605 if (!fndecl || DECL_BUILT_IN_CLASS (fndecl) != BUILT_IN_NORMAL)
1606 return;
1608 bool with_bounds = CALL_WITH_BOUNDS_P (exp);
1610 /* The bound argument to a bounded string function like strncpy. */
1611 tree bound = NULL_TREE;
1613 /* It's safe to call "bounded" string functions with a non-string
1614 argument since the functions provide an explicit bound for this
1615 purpose. */
1616 switch (DECL_FUNCTION_CODE (fndecl))
1618 case BUILT_IN_STPNCPY:
1619 case BUILT_IN_STPNCPY_CHK:
1620 case BUILT_IN_STRNCMP:
1621 case BUILT_IN_STRNCASECMP:
1622 case BUILT_IN_STRNCPY:
1623 case BUILT_IN_STRNCPY_CHK:
1624 bound = CALL_EXPR_ARG (exp, with_bounds ? 4 : 2);
1625 break;
1627 case BUILT_IN_STRNDUP:
1628 bound = CALL_EXPR_ARG (exp, with_bounds ? 2 : 1);
1629 break;
1631 default:
1632 break;
1635 /* Determine the range of the bound argument (if specified). */
1636 tree bndrng[2] = { NULL_TREE, NULL_TREE };
1637 if (bound)
1638 get_size_range (bound, bndrng);
1640 /* Iterate over the built-in function's formal arguments and check
1641 each const char* against the actual argument. If the actual
1642 argument is declared attribute non-string issue a warning unless
1643 the argument's maximum length is bounded. */
1644 function_args_iterator it;
1645 function_args_iter_init (&it, TREE_TYPE (fndecl));
1647 for (unsigned argno = 0; ; ++argno, function_args_iter_next (&it))
1649 tree argtype = function_args_iter_cond (&it);
1650 if (!argtype)
1651 break;
1653 if (TREE_CODE (argtype) != POINTER_TYPE)
1654 continue;
1656 argtype = TREE_TYPE (argtype);
1658 if (TREE_CODE (argtype) != INTEGER_TYPE
1659 || !TYPE_READONLY (argtype))
1660 continue;
1662 argtype = TYPE_MAIN_VARIANT (argtype);
1663 if (argtype != char_type_node)
1664 continue;
1666 tree callarg = CALL_EXPR_ARG (exp, argno);
1667 if (TREE_CODE (callarg) == ADDR_EXPR)
1668 callarg = TREE_OPERAND (callarg, 0);
1670 /* See if the destination is declared with attribute "nonstring". */
1671 tree decl = get_attr_nonstring_decl (callarg);
1672 if (!decl)
1673 continue;
1675 tree type = TREE_TYPE (decl);
1677 offset_int wibnd = 0;
1678 if (bndrng[0])
1679 wibnd = wi::to_offset (bndrng[0]);
1681 offset_int asize = wibnd;
1683 if (TREE_CODE (type) == ARRAY_TYPE)
1684 if (tree arrbnd = TYPE_DOMAIN (type))
1686 if ((arrbnd = TYPE_MAX_VALUE (arrbnd)))
1687 asize = wi::to_offset (arrbnd) + 1;
1690 location_t loc = EXPR_LOCATION (exp);
1692 bool warned = false;
1694 if (wi::ltu_p (asize, wibnd))
1695 warned = warning_at (loc, OPT_Wstringop_overflow_,
1696 "%qD argument %i declared attribute %<nonstring%> "
1697 "is smaller than the specified bound %E",
1698 fndecl, argno + 1, bndrng[0]);
1699 else if (!bound)
1700 warned = warning_at (loc, OPT_Wstringop_overflow_,
1701 "%qD argument %i declared attribute %<nonstring%>",
1702 fndecl, argno + 1);
1704 if (warned)
1705 inform (DECL_SOURCE_LOCATION (decl),
1706 "argument %qD declared here", decl);
1710 /* Issue an error if CALL_EXPR was flagged as requiring
1711 tall-call optimization. */
1713 static void
1714 maybe_complain_about_tail_call (tree call_expr, const char *reason)
1716 gcc_assert (TREE_CODE (call_expr) == CALL_EXPR);
1717 if (!CALL_EXPR_MUST_TAIL_CALL (call_expr))
1718 return;
1720 error_at (EXPR_LOCATION (call_expr), "cannot tail-call: %s", reason);
1723 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1724 CALL_EXPR EXP.
1726 NUM_ACTUALS is the total number of parameters.
1728 N_NAMED_ARGS is the total number of named arguments.
1730 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1731 value, or null.
1733 FNDECL is the tree code for the target of this call (if known)
1735 ARGS_SO_FAR holds state needed by the target to know where to place
1736 the next argument.
1738 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1739 for arguments which are passed in registers.
1741 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1742 and may be modified by this routine.
1744 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1745 flags which may be modified by this routine.
1747 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1748 that requires allocation of stack space.
1750 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1751 the thunked-to function. */
1753 static void
1754 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1755 struct arg_data *args,
1756 struct args_size *args_size,
1757 int n_named_args ATTRIBUTE_UNUSED,
1758 tree exp, tree struct_value_addr_value,
1759 tree fndecl, tree fntype,
1760 cumulative_args_t args_so_far,
1761 int reg_parm_stack_space,
1762 rtx *old_stack_level,
1763 poly_int64_pod *old_pending_adj,
1764 int *must_preallocate, int *ecf_flags,
1765 bool *may_tailcall, bool call_from_thunk_p)
1767 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1768 location_t loc = EXPR_LOCATION (exp);
1770 /* Count arg position in order args appear. */
1771 int argpos;
1773 int i;
1775 args_size->constant = 0;
1776 args_size->var = 0;
1778 bitmap_obstack_initialize (NULL);
1780 /* In this loop, we consider args in the order they are written.
1781 We fill up ARGS from the back. */
1783 i = num_actuals - 1;
1785 int j = i, ptr_arg = -1;
1786 call_expr_arg_iterator iter;
1787 tree arg;
1788 bitmap slots = NULL;
1790 if (struct_value_addr_value)
1792 args[j].tree_value = struct_value_addr_value;
1793 j--;
1795 /* If we pass structure address then we need to
1796 create bounds for it. Since created bounds is
1797 a call statement, we expand it right here to avoid
1798 fixing all other places where it may be expanded. */
1799 if (CALL_WITH_BOUNDS_P (exp))
1801 args[j].value = gen_reg_rtx (targetm.chkp_bound_mode ());
1802 args[j].tree_value
1803 = chkp_make_bounds_for_struct_addr (struct_value_addr_value);
1804 expand_expr_real (args[j].tree_value, args[j].value, VOIDmode,
1805 EXPAND_NORMAL, 0, false);
1806 args[j].pointer_arg = j + 1;
1807 j--;
1810 argpos = 0;
1811 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1813 tree argtype = TREE_TYPE (arg);
1815 /* Remember last param with pointer and associate it
1816 with following pointer bounds. */
1817 if (CALL_WITH_BOUNDS_P (exp)
1818 && chkp_type_has_pointer (argtype))
1820 if (slots)
1821 BITMAP_FREE (slots);
1822 ptr_arg = j;
1823 if (!BOUNDED_TYPE_P (argtype))
1825 slots = BITMAP_ALLOC (NULL);
1826 chkp_find_bound_slots (argtype, slots);
1829 else if (CALL_WITH_BOUNDS_P (exp)
1830 && pass_by_reference (NULL, TYPE_MODE (argtype), argtype,
1831 argpos < n_named_args))
1833 if (slots)
1834 BITMAP_FREE (slots);
1835 ptr_arg = j;
1837 else if (POINTER_BOUNDS_TYPE_P (argtype))
1839 /* We expect bounds in instrumented calls only.
1840 Otherwise it is a sign we lost flag due to some optimization
1841 and may emit call args incorrectly. */
1842 gcc_assert (CALL_WITH_BOUNDS_P (exp));
1844 /* For structures look for the next available pointer. */
1845 if (ptr_arg != -1 && slots)
1847 unsigned bnd_no = bitmap_first_set_bit (slots);
1848 args[j].pointer_offset =
1849 bnd_no * POINTER_SIZE / BITS_PER_UNIT;
1851 bitmap_clear_bit (slots, bnd_no);
1853 /* Check we have no more pointers in the structure. */
1854 if (bitmap_empty_p (slots))
1855 BITMAP_FREE (slots);
1857 args[j].pointer_arg = ptr_arg;
1859 /* Check we covered all pointers in the previous
1860 non bounds arg. */
1861 if (!slots)
1862 ptr_arg = -1;
1864 else
1865 ptr_arg = -1;
1867 if (targetm.calls.split_complex_arg
1868 && argtype
1869 && TREE_CODE (argtype) == COMPLEX_TYPE
1870 && targetm.calls.split_complex_arg (argtype))
1872 tree subtype = TREE_TYPE (argtype);
1873 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1874 j--;
1875 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1877 else
1878 args[j].tree_value = arg;
1879 j--;
1880 argpos++;
1883 if (slots)
1884 BITMAP_FREE (slots);
1887 bitmap_obstack_release (NULL);
1889 /* Extract attribute alloc_size and if set, store the indices of
1890 the corresponding arguments in ALLOC_IDX, and then the actual
1891 argument(s) at those indices in ALLOC_ARGS. */
1892 int alloc_idx[2] = { -1, -1 };
1893 if (tree alloc_size
1894 = (fndecl ? lookup_attribute ("alloc_size",
1895 TYPE_ATTRIBUTES (TREE_TYPE (fndecl)))
1896 : NULL_TREE))
1898 tree args = TREE_VALUE (alloc_size);
1899 alloc_idx[0] = TREE_INT_CST_LOW (TREE_VALUE (args)) - 1;
1900 if (TREE_CHAIN (args))
1901 alloc_idx[1] = TREE_INT_CST_LOW (TREE_VALUE (TREE_CHAIN (args))) - 1;
1904 /* Array for up to the two attribute alloc_size arguments. */
1905 tree alloc_args[] = { NULL_TREE, NULL_TREE };
1907 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1908 for (argpos = 0; argpos < num_actuals; i--, argpos++)
1910 tree type = TREE_TYPE (args[i].tree_value);
1911 int unsignedp;
1912 machine_mode mode;
1914 /* Replace erroneous argument with constant zero. */
1915 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1916 args[i].tree_value = integer_zero_node, type = integer_type_node;
1918 /* If TYPE is a transparent union or record, pass things the way
1919 we would pass the first field of the union or record. We have
1920 already verified that the modes are the same. */
1921 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1922 && TYPE_TRANSPARENT_AGGR (type))
1923 type = TREE_TYPE (first_field (type));
1925 /* Decide where to pass this arg.
1927 args[i].reg is nonzero if all or part is passed in registers.
1929 args[i].partial is nonzero if part but not all is passed in registers,
1930 and the exact value says how many bytes are passed in registers.
1932 args[i].pass_on_stack is nonzero if the argument must at least be
1933 computed on the stack. It may then be loaded back into registers
1934 if args[i].reg is nonzero.
1936 These decisions are driven by the FUNCTION_... macros and must agree
1937 with those made by function.c. */
1939 /* See if this argument should be passed by invisible reference. */
1940 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1941 type, argpos < n_named_args))
1943 bool callee_copies;
1944 tree base = NULL_TREE;
1946 callee_copies
1947 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
1948 type, argpos < n_named_args);
1950 /* If we're compiling a thunk, pass through invisible references
1951 instead of making a copy. */
1952 if (call_from_thunk_p
1953 || (callee_copies
1954 && !TREE_ADDRESSABLE (type)
1955 && (base = get_base_address (args[i].tree_value))
1956 && TREE_CODE (base) != SSA_NAME
1957 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1959 /* We may have turned the parameter value into an SSA name.
1960 Go back to the original parameter so we can take the
1961 address. */
1962 if (TREE_CODE (args[i].tree_value) == SSA_NAME)
1964 gcc_assert (SSA_NAME_IS_DEFAULT_DEF (args[i].tree_value));
1965 args[i].tree_value = SSA_NAME_VAR (args[i].tree_value);
1966 gcc_assert (TREE_CODE (args[i].tree_value) == PARM_DECL);
1968 /* Argument setup code may have copied the value to register. We
1969 revert that optimization now because the tail call code must
1970 use the original location. */
1971 if (TREE_CODE (args[i].tree_value) == PARM_DECL
1972 && !MEM_P (DECL_RTL (args[i].tree_value))
1973 && DECL_INCOMING_RTL (args[i].tree_value)
1974 && MEM_P (DECL_INCOMING_RTL (args[i].tree_value)))
1975 set_decl_rtl (args[i].tree_value,
1976 DECL_INCOMING_RTL (args[i].tree_value));
1978 mark_addressable (args[i].tree_value);
1980 /* We can't use sibcalls if a callee-copied argument is
1981 stored in the current function's frame. */
1982 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1984 *may_tailcall = false;
1985 maybe_complain_about_tail_call (exp,
1986 "a callee-copied argument is"
1987 " stored in the current "
1988 " function's frame");
1991 args[i].tree_value = build_fold_addr_expr_loc (loc,
1992 args[i].tree_value);
1993 type = TREE_TYPE (args[i].tree_value);
1995 if (*ecf_flags & ECF_CONST)
1996 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1998 else
2000 /* We make a copy of the object and pass the address to the
2001 function being called. */
2002 rtx copy;
2004 if (!COMPLETE_TYPE_P (type)
2005 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
2006 || (flag_stack_check == GENERIC_STACK_CHECK
2007 && compare_tree_int (TYPE_SIZE_UNIT (type),
2008 STACK_CHECK_MAX_VAR_SIZE) > 0))
2010 /* This is a variable-sized object. Make space on the stack
2011 for it. */
2012 rtx size_rtx = expr_size (args[i].tree_value);
2014 if (*old_stack_level == 0)
2016 emit_stack_save (SAVE_BLOCK, old_stack_level);
2017 *old_pending_adj = pending_stack_adjust;
2018 pending_stack_adjust = 0;
2021 /* We can pass TRUE as the 4th argument because we just
2022 saved the stack pointer and will restore it right after
2023 the call. */
2024 copy = allocate_dynamic_stack_space (size_rtx,
2025 TYPE_ALIGN (type),
2026 TYPE_ALIGN (type),
2027 max_int_size_in_bytes
2028 (type),
2029 true);
2030 copy = gen_rtx_MEM (BLKmode, copy);
2031 set_mem_attributes (copy, type, 1);
2033 else
2034 copy = assign_temp (type, 1, 0);
2036 store_expr (args[i].tree_value, copy, 0, false, false);
2038 /* Just change the const function to pure and then let
2039 the next test clear the pure based on
2040 callee_copies. */
2041 if (*ecf_flags & ECF_CONST)
2043 *ecf_flags &= ~ECF_CONST;
2044 *ecf_flags |= ECF_PURE;
2047 if (!callee_copies && *ecf_flags & ECF_PURE)
2048 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2050 args[i].tree_value
2051 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
2052 type = TREE_TYPE (args[i].tree_value);
2053 *may_tailcall = false;
2054 maybe_complain_about_tail_call (exp,
2055 "argument must be passed"
2056 " by copying");
2060 unsignedp = TYPE_UNSIGNED (type);
2061 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
2062 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
2064 args[i].unsignedp = unsignedp;
2065 args[i].mode = mode;
2067 targetm.calls.warn_parameter_passing_abi (args_so_far, type);
2069 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
2070 argpos < n_named_args);
2072 if (args[i].reg && CONST_INT_P (args[i].reg))
2074 args[i].special_slot = args[i].reg;
2075 args[i].reg = NULL;
2078 /* If this is a sibling call and the machine has register windows, the
2079 register window has to be unwinded before calling the routine, so
2080 arguments have to go into the incoming registers. */
2081 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
2082 args[i].tail_call_reg
2083 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
2084 argpos < n_named_args);
2085 else
2086 args[i].tail_call_reg = args[i].reg;
2088 if (args[i].reg)
2089 args[i].partial
2090 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
2091 argpos < n_named_args);
2093 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
2095 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
2096 it means that we are to pass this arg in the register(s) designated
2097 by the PARALLEL, but also to pass it in the stack. */
2098 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
2099 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
2100 args[i].pass_on_stack = 1;
2102 /* If this is an addressable type, we must preallocate the stack
2103 since we must evaluate the object into its final location.
2105 If this is to be passed in both registers and the stack, it is simpler
2106 to preallocate. */
2107 if (TREE_ADDRESSABLE (type)
2108 || (args[i].pass_on_stack && args[i].reg != 0))
2109 *must_preallocate = 1;
2111 /* No stack allocation and padding for bounds. */
2112 if (POINTER_BOUNDS_P (args[i].tree_value))
2114 /* Compute the stack-size of this argument. */
2115 else if (args[i].reg == 0 || args[i].partial != 0
2116 || reg_parm_stack_space > 0
2117 || args[i].pass_on_stack)
2118 locate_and_pad_parm (mode, type,
2119 #ifdef STACK_PARMS_IN_REG_PARM_AREA
2121 #else
2122 args[i].reg != 0,
2123 #endif
2124 reg_parm_stack_space,
2125 args[i].pass_on_stack ? 0 : args[i].partial,
2126 fndecl, args_size, &args[i].locate);
2127 #ifdef BLOCK_REG_PADDING
2128 else
2129 /* The argument is passed entirely in registers. See at which
2130 end it should be padded. */
2131 args[i].locate.where_pad =
2132 BLOCK_REG_PADDING (mode, type,
2133 int_size_in_bytes (type) <= UNITS_PER_WORD);
2134 #endif
2136 /* Update ARGS_SIZE, the total stack space for args so far. */
2138 args_size->constant += args[i].locate.size.constant;
2139 if (args[i].locate.size.var)
2140 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
2142 /* Increment ARGS_SO_FAR, which has info about which arg-registers
2143 have been used, etc. */
2145 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
2146 type, argpos < n_named_args);
2148 /* Store argument values for functions decorated with attribute
2149 alloc_size. */
2150 if (argpos == alloc_idx[0])
2151 alloc_args[0] = args[i].tree_value;
2152 else if (argpos == alloc_idx[1])
2153 alloc_args[1] = args[i].tree_value;
2156 if (alloc_args[0])
2158 /* Check the arguments of functions decorated with attribute
2159 alloc_size. */
2160 maybe_warn_alloc_args_overflow (fndecl, exp, alloc_args, alloc_idx);
2163 /* Detect passing non-string arguments to functions expecting
2164 nul-terminated strings. */
2165 maybe_warn_nonstring_arg (fndecl, exp);
2168 /* Update ARGS_SIZE to contain the total size for the argument block.
2169 Return the original constant component of the argument block's size.
2171 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
2172 for arguments passed in registers. */
2174 static poly_int64
2175 compute_argument_block_size (int reg_parm_stack_space,
2176 struct args_size *args_size,
2177 tree fndecl ATTRIBUTE_UNUSED,
2178 tree fntype ATTRIBUTE_UNUSED,
2179 int preferred_stack_boundary ATTRIBUTE_UNUSED)
2181 poly_int64 unadjusted_args_size = args_size->constant;
2183 /* For accumulate outgoing args mode we don't need to align, since the frame
2184 will be already aligned. Align to STACK_BOUNDARY in order to prevent
2185 backends from generating misaligned frame sizes. */
2186 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
2187 preferred_stack_boundary = STACK_BOUNDARY;
2189 /* Compute the actual size of the argument block required. The variable
2190 and constant sizes must be combined, the size may have to be rounded,
2191 and there may be a minimum required size. */
2193 if (args_size->var)
2195 args_size->var = ARGS_SIZE_TREE (*args_size);
2196 args_size->constant = 0;
2198 preferred_stack_boundary /= BITS_PER_UNIT;
2199 if (preferred_stack_boundary > 1)
2201 /* We don't handle this case yet. To handle it correctly we have
2202 to add the delta, round and subtract the delta.
2203 Currently no machine description requires this support. */
2204 gcc_assert (multiple_p (stack_pointer_delta,
2205 preferred_stack_boundary));
2206 args_size->var = round_up (args_size->var, preferred_stack_boundary);
2209 if (reg_parm_stack_space > 0)
2211 args_size->var
2212 = size_binop (MAX_EXPR, args_size->var,
2213 ssize_int (reg_parm_stack_space));
2215 /* The area corresponding to register parameters is not to count in
2216 the size of the block we need. So make the adjustment. */
2217 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2218 args_size->var
2219 = size_binop (MINUS_EXPR, args_size->var,
2220 ssize_int (reg_parm_stack_space));
2223 else
2225 preferred_stack_boundary /= BITS_PER_UNIT;
2226 if (preferred_stack_boundary < 1)
2227 preferred_stack_boundary = 1;
2228 args_size->constant = (aligned_upper_bound (args_size->constant
2229 + stack_pointer_delta,
2230 preferred_stack_boundary)
2231 - stack_pointer_delta);
2233 args_size->constant = upper_bound (args_size->constant,
2234 reg_parm_stack_space);
2236 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2237 args_size->constant -= reg_parm_stack_space;
2239 return unadjusted_args_size;
2242 /* Precompute parameters as needed for a function call.
2244 FLAGS is mask of ECF_* constants.
2246 NUM_ACTUALS is the number of arguments.
2248 ARGS is an array containing information for each argument; this
2249 routine fills in the INITIAL_VALUE and VALUE fields for each
2250 precomputed argument. */
2252 static void
2253 precompute_arguments (int num_actuals, struct arg_data *args)
2255 int i;
2257 /* If this is a libcall, then precompute all arguments so that we do not
2258 get extraneous instructions emitted as part of the libcall sequence. */
2260 /* If we preallocated the stack space, and some arguments must be passed
2261 on the stack, then we must precompute any parameter which contains a
2262 function call which will store arguments on the stack.
2263 Otherwise, evaluating the parameter may clobber previous parameters
2264 which have already been stored into the stack. (we have code to avoid
2265 such case by saving the outgoing stack arguments, but it results in
2266 worse code) */
2267 if (!ACCUMULATE_OUTGOING_ARGS)
2268 return;
2270 for (i = 0; i < num_actuals; i++)
2272 tree type;
2273 machine_mode mode;
2275 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
2276 continue;
2278 /* If this is an addressable type, we cannot pre-evaluate it. */
2279 type = TREE_TYPE (args[i].tree_value);
2280 gcc_assert (!TREE_ADDRESSABLE (type));
2282 args[i].initial_value = args[i].value
2283 = expand_normal (args[i].tree_value);
2285 mode = TYPE_MODE (type);
2286 if (mode != args[i].mode)
2288 int unsignedp = args[i].unsignedp;
2289 args[i].value
2290 = convert_modes (args[i].mode, mode,
2291 args[i].value, args[i].unsignedp);
2293 /* CSE will replace this only if it contains args[i].value
2294 pseudo, so convert it down to the declared mode using
2295 a SUBREG. */
2296 if (REG_P (args[i].value)
2297 && GET_MODE_CLASS (args[i].mode) == MODE_INT
2298 && promote_mode (type, mode, &unsignedp) != args[i].mode)
2300 args[i].initial_value
2301 = gen_lowpart_SUBREG (mode, args[i].value);
2302 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
2303 SUBREG_PROMOTED_SET (args[i].initial_value, args[i].unsignedp);
2309 /* Given the current state of MUST_PREALLOCATE and information about
2310 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
2311 compute and return the final value for MUST_PREALLOCATE. */
2313 static int
2314 finalize_must_preallocate (int must_preallocate, int num_actuals,
2315 struct arg_data *args, struct args_size *args_size)
2317 /* See if we have or want to preallocate stack space.
2319 If we would have to push a partially-in-regs parm
2320 before other stack parms, preallocate stack space instead.
2322 If the size of some parm is not a multiple of the required stack
2323 alignment, we must preallocate.
2325 If the total size of arguments that would otherwise create a copy in
2326 a temporary (such as a CALL) is more than half the total argument list
2327 size, preallocation is faster.
2329 Another reason to preallocate is if we have a machine (like the m88k)
2330 where stack alignment is required to be maintained between every
2331 pair of insns, not just when the call is made. However, we assume here
2332 that such machines either do not have push insns (and hence preallocation
2333 would occur anyway) or the problem is taken care of with
2334 PUSH_ROUNDING. */
2336 if (! must_preallocate)
2338 int partial_seen = 0;
2339 poly_int64 copy_to_evaluate_size = 0;
2340 int i;
2342 for (i = 0; i < num_actuals && ! must_preallocate; i++)
2344 if (args[i].partial > 0 && ! args[i].pass_on_stack)
2345 partial_seen = 1;
2346 else if (partial_seen && args[i].reg == 0)
2347 must_preallocate = 1;
2348 /* We preallocate in case there are bounds passed
2349 in the bounds table to have precomputed address
2350 for bounds association. */
2351 else if (POINTER_BOUNDS_P (args[i].tree_value)
2352 && !args[i].reg)
2353 must_preallocate = 1;
2355 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
2356 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
2357 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
2358 || TREE_CODE (args[i].tree_value) == COND_EXPR
2359 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
2360 copy_to_evaluate_size
2361 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2364 if (maybe_ne (args_size->constant, 0)
2365 && maybe_ge (copy_to_evaluate_size * 2, args_size->constant))
2366 must_preallocate = 1;
2368 return must_preallocate;
2371 /* If we preallocated stack space, compute the address of each argument
2372 and store it into the ARGS array.
2374 We need not ensure it is a valid memory address here; it will be
2375 validized when it is used.
2377 ARGBLOCK is an rtx for the address of the outgoing arguments. */
2379 static void
2380 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
2382 if (argblock)
2384 rtx arg_reg = argblock;
2385 int i;
2386 poly_int64 arg_offset = 0;
2388 if (GET_CODE (argblock) == PLUS)
2390 arg_reg = XEXP (argblock, 0);
2391 arg_offset = rtx_to_poly_int64 (XEXP (argblock, 1));
2394 for (i = 0; i < num_actuals; i++)
2396 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
2397 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
2398 rtx addr;
2399 unsigned int align, boundary;
2400 poly_uint64 units_on_stack = 0;
2401 machine_mode partial_mode = VOIDmode;
2403 /* Skip this parm if it will not be passed on the stack. */
2404 if (! args[i].pass_on_stack
2405 && args[i].reg != 0
2406 && args[i].partial == 0)
2407 continue;
2409 if (TYPE_EMPTY_P (TREE_TYPE (args[i].tree_value)))
2410 continue;
2412 /* Pointer Bounds are never passed on the stack. */
2413 if (POINTER_BOUNDS_P (args[i].tree_value))
2414 continue;
2416 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, offset);
2417 addr = plus_constant (Pmode, addr, arg_offset);
2419 if (args[i].partial != 0)
2421 /* Only part of the parameter is being passed on the stack.
2422 Generate a simple memory reference of the correct size. */
2423 units_on_stack = args[i].locate.size.constant;
2424 poly_uint64 bits_on_stack = units_on_stack * BITS_PER_UNIT;
2425 partial_mode = int_mode_for_size (bits_on_stack, 1).else_blk ();
2426 args[i].stack = gen_rtx_MEM (partial_mode, addr);
2427 set_mem_size (args[i].stack, units_on_stack);
2429 else
2431 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
2432 set_mem_attributes (args[i].stack,
2433 TREE_TYPE (args[i].tree_value), 1);
2435 align = BITS_PER_UNIT;
2436 boundary = args[i].locate.boundary;
2437 poly_int64 offset_val;
2438 if (args[i].locate.where_pad != PAD_DOWNWARD)
2439 align = boundary;
2440 else if (poly_int_rtx_p (offset, &offset_val))
2442 align = least_bit_hwi (boundary);
2443 unsigned int offset_align
2444 = known_alignment (offset_val) * BITS_PER_UNIT;
2445 if (offset_align != 0)
2446 align = MIN (align, offset_align);
2448 set_mem_align (args[i].stack, align);
2450 addr = simplify_gen_binary (PLUS, Pmode, arg_reg, slot_offset);
2451 addr = plus_constant (Pmode, addr, arg_offset);
2453 if (args[i].partial != 0)
2455 /* Only part of the parameter is being passed on the stack.
2456 Generate a simple memory reference of the correct size.
2458 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
2459 set_mem_size (args[i].stack_slot, units_on_stack);
2461 else
2463 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
2464 set_mem_attributes (args[i].stack_slot,
2465 TREE_TYPE (args[i].tree_value), 1);
2467 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
2469 /* Function incoming arguments may overlap with sibling call
2470 outgoing arguments and we cannot allow reordering of reads
2471 from function arguments with stores to outgoing arguments
2472 of sibling calls. */
2473 set_mem_alias_set (args[i].stack, 0);
2474 set_mem_alias_set (args[i].stack_slot, 0);
2479 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
2480 in a call instruction.
2482 FNDECL is the tree node for the target function. For an indirect call
2483 FNDECL will be NULL_TREE.
2485 ADDR is the operand 0 of CALL_EXPR for this call. */
2487 static rtx
2488 rtx_for_function_call (tree fndecl, tree addr)
2490 rtx funexp;
2492 /* Get the function to call, in the form of RTL. */
2493 if (fndecl)
2495 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
2496 TREE_USED (fndecl) = 1;
2498 /* Get a SYMBOL_REF rtx for the function address. */
2499 funexp = XEXP (DECL_RTL (fndecl), 0);
2501 else
2502 /* Generate an rtx (probably a pseudo-register) for the address. */
2504 push_temp_slots ();
2505 funexp = expand_normal (addr);
2506 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
2508 return funexp;
2511 /* Return the static chain for this function, if any. */
2514 rtx_for_static_chain (const_tree fndecl_or_type, bool incoming_p)
2516 if (DECL_P (fndecl_or_type) && !DECL_STATIC_CHAIN (fndecl_or_type))
2517 return NULL;
2519 return targetm.calls.static_chain (fndecl_or_type, incoming_p);
2522 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
2523 static struct
2525 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
2526 or NULL_RTX if none has been scanned yet. */
2527 rtx_insn *scan_start;
2528 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
2529 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
2530 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
2531 with fixed offset, or PC if this is with variable or unknown offset. */
2532 vec<rtx> cache;
2533 } internal_arg_pointer_exp_state;
2535 static rtx internal_arg_pointer_based_exp (const_rtx, bool);
2537 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
2538 the tail call sequence, starting with first insn that hasn't been
2539 scanned yet, and note for each pseudo on the LHS whether it is based
2540 on crtl->args.internal_arg_pointer or not, and what offset from that
2541 that pointer it has. */
2543 static void
2544 internal_arg_pointer_based_exp_scan (void)
2546 rtx_insn *insn, *scan_start = internal_arg_pointer_exp_state.scan_start;
2548 if (scan_start == NULL_RTX)
2549 insn = get_insns ();
2550 else
2551 insn = NEXT_INSN (scan_start);
2553 while (insn)
2555 rtx set = single_set (insn);
2556 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
2558 rtx val = NULL_RTX;
2559 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
2560 /* Punt on pseudos set multiple times. */
2561 if (idx < internal_arg_pointer_exp_state.cache.length ()
2562 && (internal_arg_pointer_exp_state.cache[idx]
2563 != NULL_RTX))
2564 val = pc_rtx;
2565 else
2566 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
2567 if (val != NULL_RTX)
2569 if (idx >= internal_arg_pointer_exp_state.cache.length ())
2570 internal_arg_pointer_exp_state.cache
2571 .safe_grow_cleared (idx + 1);
2572 internal_arg_pointer_exp_state.cache[idx] = val;
2575 if (NEXT_INSN (insn) == NULL_RTX)
2576 scan_start = insn;
2577 insn = NEXT_INSN (insn);
2580 internal_arg_pointer_exp_state.scan_start = scan_start;
2583 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
2584 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
2585 it with fixed offset, or PC if this is with variable or unknown offset.
2586 TOPLEVEL is true if the function is invoked at the topmost level. */
2588 static rtx
2589 internal_arg_pointer_based_exp (const_rtx rtl, bool toplevel)
2591 if (CONSTANT_P (rtl))
2592 return NULL_RTX;
2594 if (rtl == crtl->args.internal_arg_pointer)
2595 return const0_rtx;
2597 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
2598 return NULL_RTX;
2600 poly_int64 offset;
2601 if (GET_CODE (rtl) == PLUS && poly_int_rtx_p (XEXP (rtl, 1), &offset))
2603 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
2604 if (val == NULL_RTX || val == pc_rtx)
2605 return val;
2606 return plus_constant (Pmode, val, offset);
2609 /* When called at the topmost level, scan pseudo assignments in between the
2610 last scanned instruction in the tail call sequence and the latest insn
2611 in that sequence. */
2612 if (toplevel)
2613 internal_arg_pointer_based_exp_scan ();
2615 if (REG_P (rtl))
2617 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
2618 if (idx < internal_arg_pointer_exp_state.cache.length ())
2619 return internal_arg_pointer_exp_state.cache[idx];
2621 return NULL_RTX;
2624 subrtx_iterator::array_type array;
2625 FOR_EACH_SUBRTX (iter, array, rtl, NONCONST)
2627 const_rtx x = *iter;
2628 if (REG_P (x) && internal_arg_pointer_based_exp (x, false) != NULL_RTX)
2629 return pc_rtx;
2630 if (MEM_P (x))
2631 iter.skip_subrtxes ();
2634 return NULL_RTX;
2637 /* Return true if SIZE bytes starting from address ADDR might overlap an
2638 already-clobbered argument area. This function is used to determine
2639 if we should give up a sibcall. */
2641 static bool
2642 mem_might_overlap_already_clobbered_arg_p (rtx addr, poly_uint64 size)
2644 poly_int64 i;
2645 unsigned HOST_WIDE_INT start, end;
2646 rtx val;
2648 if (bitmap_empty_p (stored_args_map)
2649 && stored_args_watermark == HOST_WIDE_INT_M1U)
2650 return false;
2651 val = internal_arg_pointer_based_exp (addr, true);
2652 if (val == NULL_RTX)
2653 return false;
2654 else if (!poly_int_rtx_p (val, &i))
2655 return true;
2657 if (known_eq (size, 0U))
2658 return false;
2660 if (STACK_GROWS_DOWNWARD)
2661 i -= crtl->args.pretend_args_size;
2662 else
2663 i += crtl->args.pretend_args_size;
2665 if (ARGS_GROW_DOWNWARD)
2666 i = -i - size;
2668 /* We can ignore any references to the function's pretend args,
2669 which at this point would manifest as negative values of I. */
2670 if (known_le (i, 0) && known_le (size, poly_uint64 (-i)))
2671 return false;
2673 start = maybe_lt (i, 0) ? 0 : constant_lower_bound (i);
2674 if (!(i + size).is_constant (&end))
2675 end = HOST_WIDE_INT_M1U;
2677 if (end > stored_args_watermark)
2678 return true;
2680 end = MIN (end, SBITMAP_SIZE (stored_args_map));
2681 for (unsigned HOST_WIDE_INT k = start; k < end; ++k)
2682 if (bitmap_bit_p (stored_args_map, k))
2683 return true;
2685 return false;
2688 /* Do the register loads required for any wholly-register parms or any
2689 parms which are passed both on the stack and in a register. Their
2690 expressions were already evaluated.
2692 Mark all register-parms as living through the call, putting these USE
2693 insns in the CALL_INSN_FUNCTION_USAGE field.
2695 When IS_SIBCALL, perform the check_sibcall_argument_overlap
2696 checking, setting *SIBCALL_FAILURE if appropriate. */
2698 static void
2699 load_register_parameters (struct arg_data *args, int num_actuals,
2700 rtx *call_fusage, int flags, int is_sibcall,
2701 int *sibcall_failure)
2703 int i, j;
2705 for (i = 0; i < num_actuals; i++)
2707 rtx reg = ((flags & ECF_SIBCALL)
2708 ? args[i].tail_call_reg : args[i].reg);
2709 if (reg)
2711 int partial = args[i].partial;
2712 int nregs;
2713 poly_int64 size = 0;
2714 HOST_WIDE_INT const_size = 0;
2715 rtx_insn *before_arg = get_last_insn ();
2716 /* Set non-negative if we must move a word at a time, even if
2717 just one word (e.g, partial == 4 && mode == DFmode). Set
2718 to -1 if we just use a normal move insn. This value can be
2719 zero if the argument is a zero size structure. */
2720 nregs = -1;
2721 if (GET_CODE (reg) == PARALLEL)
2723 else if (partial)
2725 gcc_assert (partial % UNITS_PER_WORD == 0);
2726 nregs = partial / UNITS_PER_WORD;
2728 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
2730 /* Variable-sized parameters should be described by a
2731 PARALLEL instead. */
2732 const_size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
2733 gcc_assert (const_size >= 0);
2734 nregs = (const_size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
2735 size = const_size;
2737 else
2738 size = GET_MODE_SIZE (args[i].mode);
2740 /* Handle calls that pass values in multiple non-contiguous
2741 locations. The Irix 6 ABI has examples of this. */
2743 if (GET_CODE (reg) == PARALLEL)
2744 emit_group_move (reg, args[i].parallel_value);
2746 /* If simple case, just do move. If normal partial, store_one_arg
2747 has already loaded the register for us. In all other cases,
2748 load the register(s) from memory. */
2750 else if (nregs == -1)
2752 emit_move_insn (reg, args[i].value);
2753 #ifdef BLOCK_REG_PADDING
2754 /* Handle case where we have a value that needs shifting
2755 up to the msb. eg. a QImode value and we're padding
2756 upward on a BYTES_BIG_ENDIAN machine. */
2757 if (args[i].locate.where_pad
2758 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD))
2760 gcc_checking_assert (ordered_p (size, UNITS_PER_WORD));
2761 if (maybe_lt (size, UNITS_PER_WORD))
2763 rtx x;
2764 poly_int64 shift
2765 = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
2767 /* Assigning REG here rather than a temp makes
2768 CALL_FUSAGE report the whole reg as used.
2769 Strictly speaking, the call only uses SIZE
2770 bytes at the msb end, but it doesn't seem worth
2771 generating rtl to say that. */
2772 reg = gen_rtx_REG (word_mode, REGNO (reg));
2773 x = expand_shift (LSHIFT_EXPR, word_mode,
2774 reg, shift, reg, 1);
2775 if (x != reg)
2776 emit_move_insn (reg, x);
2779 #endif
2782 /* If we have pre-computed the values to put in the registers in
2783 the case of non-aligned structures, copy them in now. */
2785 else if (args[i].n_aligned_regs != 0)
2786 for (j = 0; j < args[i].n_aligned_regs; j++)
2787 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
2788 args[i].aligned_regs[j]);
2790 else if (partial == 0 || args[i].pass_on_stack)
2792 /* SIZE and CONST_SIZE are 0 for partial arguments and
2793 the size of a BLKmode type otherwise. */
2794 gcc_checking_assert (known_eq (size, const_size));
2795 rtx mem = validize_mem (copy_rtx (args[i].value));
2797 /* Check for overlap with already clobbered argument area,
2798 providing that this has non-zero size. */
2799 if (is_sibcall
2800 && const_size != 0
2801 && (mem_might_overlap_already_clobbered_arg_p
2802 (XEXP (args[i].value, 0), const_size)))
2803 *sibcall_failure = 1;
2805 if (const_size % UNITS_PER_WORD == 0
2806 || MEM_ALIGN (mem) % BITS_PER_WORD == 0)
2807 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
2808 else
2810 if (nregs > 1)
2811 move_block_to_reg (REGNO (reg), mem, nregs - 1,
2812 args[i].mode);
2813 rtx dest = gen_rtx_REG (word_mode, REGNO (reg) + nregs - 1);
2814 unsigned int bitoff = (nregs - 1) * BITS_PER_WORD;
2815 unsigned int bitsize = const_size * BITS_PER_UNIT - bitoff;
2816 rtx x = extract_bit_field (mem, bitsize, bitoff, 1, dest,
2817 word_mode, word_mode, false,
2818 NULL);
2819 if (BYTES_BIG_ENDIAN)
2820 x = expand_shift (LSHIFT_EXPR, word_mode, x,
2821 BITS_PER_WORD - bitsize, dest, 1);
2822 if (x != dest)
2823 emit_move_insn (dest, x);
2826 /* Handle a BLKmode that needs shifting. */
2827 if (nregs == 1 && const_size < UNITS_PER_WORD
2828 #ifdef BLOCK_REG_PADDING
2829 && args[i].locate.where_pad == PAD_DOWNWARD
2830 #else
2831 && BYTES_BIG_ENDIAN
2832 #endif
2835 rtx dest = gen_rtx_REG (word_mode, REGNO (reg));
2836 int shift = (UNITS_PER_WORD - const_size) * BITS_PER_UNIT;
2837 enum tree_code dir = (BYTES_BIG_ENDIAN
2838 ? RSHIFT_EXPR : LSHIFT_EXPR);
2839 rtx x;
2841 x = expand_shift (dir, word_mode, dest, shift, dest, 1);
2842 if (x != dest)
2843 emit_move_insn (dest, x);
2847 /* When a parameter is a block, and perhaps in other cases, it is
2848 possible that it did a load from an argument slot that was
2849 already clobbered. */
2850 if (is_sibcall
2851 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
2852 *sibcall_failure = 1;
2854 /* Handle calls that pass values in multiple non-contiguous
2855 locations. The Irix 6 ABI has examples of this. */
2856 if (GET_CODE (reg) == PARALLEL)
2857 use_group_regs (call_fusage, reg);
2858 else if (nregs == -1)
2859 use_reg_mode (call_fusage, reg,
2860 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
2861 else if (nregs > 0)
2862 use_regs (call_fusage, REGNO (reg), nregs);
2867 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2868 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2869 bytes, then we would need to push some additional bytes to pad the
2870 arguments. So, we try to compute an adjust to the stack pointer for an
2871 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2872 bytes. Then, when the arguments are pushed the stack will be perfectly
2873 aligned.
2875 Return true if this optimization is possible, storing the adjustment
2876 in ADJUSTMENT_OUT and setting ARGS_SIZE->CONSTANT to the number of
2877 bytes that should be popped after the call. */
2879 static bool
2880 combine_pending_stack_adjustment_and_call (poly_int64_pod *adjustment_out,
2881 poly_int64 unadjusted_args_size,
2882 struct args_size *args_size,
2883 unsigned int preferred_unit_stack_boundary)
2885 /* The number of bytes to pop so that the stack will be
2886 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2887 poly_int64 adjustment;
2888 /* The alignment of the stack after the arguments are pushed, if we
2889 just pushed the arguments without adjust the stack here. */
2890 unsigned HOST_WIDE_INT unadjusted_alignment;
2892 if (!known_misalignment (stack_pointer_delta + unadjusted_args_size,
2893 preferred_unit_stack_boundary,
2894 &unadjusted_alignment))
2895 return false;
2897 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2898 as possible -- leaving just enough left to cancel out the
2899 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2900 PENDING_STACK_ADJUST is non-negative, and congruent to
2901 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2903 /* Begin by trying to pop all the bytes. */
2904 unsigned HOST_WIDE_INT tmp_misalignment;
2905 if (!known_misalignment (pending_stack_adjust,
2906 preferred_unit_stack_boundary,
2907 &tmp_misalignment))
2908 return false;
2909 unadjusted_alignment -= tmp_misalignment;
2910 adjustment = pending_stack_adjust;
2911 /* Push enough additional bytes that the stack will be aligned
2912 after the arguments are pushed. */
2913 if (preferred_unit_stack_boundary > 1 && unadjusted_alignment)
2914 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2916 /* We need to know whether the adjusted argument size
2917 (UNADJUSTED_ARGS_SIZE - ADJUSTMENT) constitutes an allocation
2918 or a deallocation. */
2919 if (!ordered_p (adjustment, unadjusted_args_size))
2920 return false;
2922 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2923 bytes after the call. The right number is the entire
2924 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2925 by the arguments in the first place. */
2926 args_size->constant
2927 = pending_stack_adjust - adjustment + unadjusted_args_size;
2929 *adjustment_out = adjustment;
2930 return true;
2933 /* Scan X expression if it does not dereference any argument slots
2934 we already clobbered by tail call arguments (as noted in stored_args_map
2935 bitmap).
2936 Return nonzero if X expression dereferences such argument slots,
2937 zero otherwise. */
2939 static int
2940 check_sibcall_argument_overlap_1 (rtx x)
2942 RTX_CODE code;
2943 int i, j;
2944 const char *fmt;
2946 if (x == NULL_RTX)
2947 return 0;
2949 code = GET_CODE (x);
2951 /* We need not check the operands of the CALL expression itself. */
2952 if (code == CALL)
2953 return 0;
2955 if (code == MEM)
2956 return (mem_might_overlap_already_clobbered_arg_p
2957 (XEXP (x, 0), GET_MODE_SIZE (GET_MODE (x))));
2959 /* Scan all subexpressions. */
2960 fmt = GET_RTX_FORMAT (code);
2961 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2963 if (*fmt == 'e')
2965 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2966 return 1;
2968 else if (*fmt == 'E')
2970 for (j = 0; j < XVECLEN (x, i); j++)
2971 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2972 return 1;
2975 return 0;
2978 /* Scan sequence after INSN if it does not dereference any argument slots
2979 we already clobbered by tail call arguments (as noted in stored_args_map
2980 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2981 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2982 should be 0). Return nonzero if sequence after INSN dereferences such argument
2983 slots, zero otherwise. */
2985 static int
2986 check_sibcall_argument_overlap (rtx_insn *insn, struct arg_data *arg,
2987 int mark_stored_args_map)
2989 poly_uint64 low, high;
2990 unsigned HOST_WIDE_INT const_low, const_high;
2992 if (insn == NULL_RTX)
2993 insn = get_insns ();
2994 else
2995 insn = NEXT_INSN (insn);
2997 for (; insn; insn = NEXT_INSN (insn))
2998 if (INSN_P (insn)
2999 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
3000 break;
3002 if (mark_stored_args_map)
3004 if (ARGS_GROW_DOWNWARD)
3005 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
3006 else
3007 low = arg->locate.slot_offset.constant;
3008 high = low + arg->locate.size.constant;
3010 const_low = constant_lower_bound (low);
3011 if (high.is_constant (&const_high))
3012 for (unsigned HOST_WIDE_INT i = const_low; i < const_high; ++i)
3013 bitmap_set_bit (stored_args_map, i);
3014 else
3015 stored_args_watermark = MIN (stored_args_watermark, const_low);
3017 return insn != NULL_RTX;
3020 /* Given that a function returns a value of mode MODE at the most
3021 significant end of hard register VALUE, shift VALUE left or right
3022 as specified by LEFT_P. Return true if some action was needed. */
3024 bool
3025 shift_return_value (machine_mode mode, bool left_p, rtx value)
3027 HOST_WIDE_INT shift;
3029 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
3030 machine_mode value_mode = GET_MODE (value);
3031 shift = GET_MODE_BITSIZE (value_mode) - GET_MODE_BITSIZE (mode);
3032 if (shift == 0)
3033 return false;
3035 /* Use ashr rather than lshr for right shifts. This is for the benefit
3036 of the MIPS port, which requires SImode values to be sign-extended
3037 when stored in 64-bit registers. */
3038 if (!force_expand_binop (value_mode, left_p ? ashl_optab : ashr_optab,
3039 value, gen_int_shift_amount (value_mode, shift),
3040 value, 1, OPTAB_WIDEN))
3041 gcc_unreachable ();
3042 return true;
3045 /* If X is a likely-spilled register value, copy it to a pseudo
3046 register and return that register. Return X otherwise. */
3048 static rtx
3049 avoid_likely_spilled_reg (rtx x)
3051 rtx new_rtx;
3053 if (REG_P (x)
3054 && HARD_REGISTER_P (x)
3055 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
3057 /* Make sure that we generate a REG rather than a CONCAT.
3058 Moves into CONCATs can need nontrivial instructions,
3059 and the whole point of this function is to avoid
3060 using the hard register directly in such a situation. */
3061 generating_concat_p = 0;
3062 new_rtx = gen_reg_rtx (GET_MODE (x));
3063 generating_concat_p = 1;
3064 emit_move_insn (new_rtx, x);
3065 return new_rtx;
3067 return x;
3070 /* Helper function for expand_call.
3071 Return false is EXP is not implementable as a sibling call. */
3073 static bool
3074 can_implement_as_sibling_call_p (tree exp,
3075 rtx structure_value_addr,
3076 tree funtype,
3077 int reg_parm_stack_space ATTRIBUTE_UNUSED,
3078 tree fndecl,
3079 int flags,
3080 tree addr,
3081 const args_size &args_size)
3083 if (!targetm.have_sibcall_epilogue ())
3085 maybe_complain_about_tail_call
3086 (exp,
3087 "machine description does not have"
3088 " a sibcall_epilogue instruction pattern");
3089 return false;
3092 /* Doing sibling call optimization needs some work, since
3093 structure_value_addr can be allocated on the stack.
3094 It does not seem worth the effort since few optimizable
3095 sibling calls will return a structure. */
3096 if (structure_value_addr != NULL_RTX)
3098 maybe_complain_about_tail_call (exp, "callee returns a structure");
3099 return false;
3102 #ifdef REG_PARM_STACK_SPACE
3103 /* If outgoing reg parm stack space changes, we can not do sibcall. */
3104 if (OUTGOING_REG_PARM_STACK_SPACE (funtype)
3105 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl))
3106 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (current_function_decl)))
3108 maybe_complain_about_tail_call (exp,
3109 "inconsistent size of stack space"
3110 " allocated for arguments which are"
3111 " passed in registers");
3112 return false;
3114 #endif
3116 /* Check whether the target is able to optimize the call
3117 into a sibcall. */
3118 if (!targetm.function_ok_for_sibcall (fndecl, exp))
3120 maybe_complain_about_tail_call (exp,
3121 "target is not able to optimize the"
3122 " call into a sibling call");
3123 return false;
3126 /* Functions that do not return exactly once may not be sibcall
3127 optimized. */
3128 if (flags & ECF_RETURNS_TWICE)
3130 maybe_complain_about_tail_call (exp, "callee returns twice");
3131 return false;
3133 if (flags & ECF_NORETURN)
3135 maybe_complain_about_tail_call (exp, "callee does not return");
3136 return false;
3139 if (TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr))))
3141 maybe_complain_about_tail_call (exp, "volatile function type");
3142 return false;
3145 /* If the called function is nested in the current one, it might access
3146 some of the caller's arguments, but could clobber them beforehand if
3147 the argument areas are shared. */
3148 if (fndecl && decl_function_context (fndecl) == current_function_decl)
3150 maybe_complain_about_tail_call (exp, "nested function");
3151 return false;
3154 /* If this function requires more stack slots than the current
3155 function, we cannot change it into a sibling call.
3156 crtl->args.pretend_args_size is not part of the
3157 stack allocated by our caller. */
3158 if (maybe_gt (args_size.constant,
3159 crtl->args.size - crtl->args.pretend_args_size))
3161 maybe_complain_about_tail_call (exp,
3162 "callee required more stack slots"
3163 " than the caller");
3164 return false;
3167 /* If the callee pops its own arguments, then it must pop exactly
3168 the same number of arguments as the current function. */
3169 if (maybe_ne (targetm.calls.return_pops_args (fndecl, funtype,
3170 args_size.constant),
3171 targetm.calls.return_pops_args (current_function_decl,
3172 TREE_TYPE
3173 (current_function_decl),
3174 crtl->args.size)))
3176 maybe_complain_about_tail_call (exp,
3177 "inconsistent number of"
3178 " popped arguments");
3179 return false;
3182 if (!lang_hooks.decls.ok_for_sibcall (fndecl))
3184 maybe_complain_about_tail_call (exp, "frontend does not support"
3185 " sibling call");
3186 return false;
3189 /* All checks passed. */
3190 return true;
3193 /* Generate all the code for a CALL_EXPR exp
3194 and return an rtx for its value.
3195 Store the value in TARGET (specified as an rtx) if convenient.
3196 If the value is stored in TARGET then TARGET is returned.
3197 If IGNORE is nonzero, then we ignore the value of the function call. */
3200 expand_call (tree exp, rtx target, int ignore)
3202 /* Nonzero if we are currently expanding a call. */
3203 static int currently_expanding_call = 0;
3205 /* RTX for the function to be called. */
3206 rtx funexp;
3207 /* Sequence of insns to perform a normal "call". */
3208 rtx_insn *normal_call_insns = NULL;
3209 /* Sequence of insns to perform a tail "call". */
3210 rtx_insn *tail_call_insns = NULL;
3211 /* Data type of the function. */
3212 tree funtype;
3213 tree type_arg_types;
3214 tree rettype;
3215 /* Declaration of the function being called,
3216 or 0 if the function is computed (not known by name). */
3217 tree fndecl = 0;
3218 /* The type of the function being called. */
3219 tree fntype;
3220 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
3221 bool must_tail_call = CALL_EXPR_MUST_TAIL_CALL (exp);
3222 int pass;
3224 /* Register in which non-BLKmode value will be returned,
3225 or 0 if no value or if value is BLKmode. */
3226 rtx valreg;
3227 /* Register(s) in which bounds are returned. */
3228 rtx valbnd = NULL;
3229 /* Address where we should return a BLKmode value;
3230 0 if value not BLKmode. */
3231 rtx structure_value_addr = 0;
3232 /* Nonzero if that address is being passed by treating it as
3233 an extra, implicit first parameter. Otherwise,
3234 it is passed by being copied directly into struct_value_rtx. */
3235 int structure_value_addr_parm = 0;
3236 /* Holds the value of implicit argument for the struct value. */
3237 tree structure_value_addr_value = NULL_TREE;
3238 /* Size of aggregate value wanted, or zero if none wanted
3239 or if we are using the non-reentrant PCC calling convention
3240 or expecting the value in registers. */
3241 poly_int64 struct_value_size = 0;
3242 /* Nonzero if called function returns an aggregate in memory PCC style,
3243 by returning the address of where to find it. */
3244 int pcc_struct_value = 0;
3245 rtx struct_value = 0;
3247 /* Number of actual parameters in this call, including struct value addr. */
3248 int num_actuals;
3249 /* Number of named args. Args after this are anonymous ones
3250 and they must all go on the stack. */
3251 int n_named_args;
3252 /* Number of complex actual arguments that need to be split. */
3253 int num_complex_actuals = 0;
3255 /* Vector of information about each argument.
3256 Arguments are numbered in the order they will be pushed,
3257 not the order they are written. */
3258 struct arg_data *args;
3260 /* Total size in bytes of all the stack-parms scanned so far. */
3261 struct args_size args_size;
3262 struct args_size adjusted_args_size;
3263 /* Size of arguments before any adjustments (such as rounding). */
3264 poly_int64 unadjusted_args_size;
3265 /* Data on reg parms scanned so far. */
3266 CUMULATIVE_ARGS args_so_far_v;
3267 cumulative_args_t args_so_far;
3268 /* Nonzero if a reg parm has been scanned. */
3269 int reg_parm_seen;
3270 /* Nonzero if this is an indirect function call. */
3272 /* Nonzero if we must avoid push-insns in the args for this call.
3273 If stack space is allocated for register parameters, but not by the
3274 caller, then it is preallocated in the fixed part of the stack frame.
3275 So the entire argument block must then be preallocated (i.e., we
3276 ignore PUSH_ROUNDING in that case). */
3278 int must_preallocate = !PUSH_ARGS;
3280 /* Size of the stack reserved for parameter registers. */
3281 int reg_parm_stack_space = 0;
3283 /* Address of space preallocated for stack parms
3284 (on machines that lack push insns), or 0 if space not preallocated. */
3285 rtx argblock = 0;
3287 /* Mask of ECF_ and ERF_ flags. */
3288 int flags = 0;
3289 int return_flags = 0;
3290 #ifdef REG_PARM_STACK_SPACE
3291 /* Define the boundary of the register parm stack space that needs to be
3292 saved, if any. */
3293 int low_to_save, high_to_save;
3294 rtx save_area = 0; /* Place that it is saved */
3295 #endif
3297 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3298 char *initial_stack_usage_map = stack_usage_map;
3299 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
3300 char *stack_usage_map_buf = NULL;
3302 poly_int64 old_stack_allocated;
3304 /* State variables to track stack modifications. */
3305 rtx old_stack_level = 0;
3306 int old_stack_arg_under_construction = 0;
3307 poly_int64 old_pending_adj = 0;
3308 int old_inhibit_defer_pop = inhibit_defer_pop;
3310 /* Some stack pointer alterations we make are performed via
3311 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
3312 which we then also need to save/restore along the way. */
3313 poly_int64 old_stack_pointer_delta = 0;
3315 rtx call_fusage;
3316 tree addr = CALL_EXPR_FN (exp);
3317 int i;
3318 /* The alignment of the stack, in bits. */
3319 unsigned HOST_WIDE_INT preferred_stack_boundary;
3320 /* The alignment of the stack, in bytes. */
3321 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
3322 /* The static chain value to use for this call. */
3323 rtx static_chain_value;
3324 /* See if this is "nothrow" function call. */
3325 if (TREE_NOTHROW (exp))
3326 flags |= ECF_NOTHROW;
3328 /* See if we can find a DECL-node for the actual function, and get the
3329 function attributes (flags) from the function decl or type node. */
3330 fndecl = get_callee_fndecl (exp);
3331 if (fndecl)
3333 fntype = TREE_TYPE (fndecl);
3334 flags |= flags_from_decl_or_type (fndecl);
3335 return_flags |= decl_return_flags (fndecl);
3337 else
3339 fntype = TREE_TYPE (TREE_TYPE (addr));
3340 flags |= flags_from_decl_or_type (fntype);
3341 if (CALL_EXPR_BY_DESCRIPTOR (exp))
3342 flags |= ECF_BY_DESCRIPTOR;
3344 rettype = TREE_TYPE (exp);
3346 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
3348 /* Warn if this value is an aggregate type,
3349 regardless of which calling convention we are using for it. */
3350 if (AGGREGATE_TYPE_P (rettype))
3351 warning (OPT_Waggregate_return, "function call has aggregate value");
3353 /* If the result of a non looping pure or const function call is
3354 ignored (or void), and none of its arguments are volatile, we can
3355 avoid expanding the call and just evaluate the arguments for
3356 side-effects. */
3357 if ((flags & (ECF_CONST | ECF_PURE))
3358 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
3359 && (ignore || target == const0_rtx
3360 || TYPE_MODE (rettype) == VOIDmode))
3362 bool volatilep = false;
3363 tree arg;
3364 call_expr_arg_iterator iter;
3366 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3367 if (TREE_THIS_VOLATILE (arg))
3369 volatilep = true;
3370 break;
3373 if (! volatilep)
3375 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3376 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
3377 return const0_rtx;
3381 #ifdef REG_PARM_STACK_SPACE
3382 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
3383 #endif
3385 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3386 && reg_parm_stack_space > 0 && PUSH_ARGS)
3387 must_preallocate = 1;
3389 /* Set up a place to return a structure. */
3391 /* Cater to broken compilers. */
3392 if (aggregate_value_p (exp, fntype))
3394 /* This call returns a big structure. */
3395 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3397 #ifdef PCC_STATIC_STRUCT_RETURN
3399 pcc_struct_value = 1;
3401 #else /* not PCC_STATIC_STRUCT_RETURN */
3403 if (!poly_int_tree_p (TYPE_SIZE_UNIT (rettype), &struct_value_size))
3404 struct_value_size = -1;
3406 /* Even if it is semantically safe to use the target as the return
3407 slot, it may be not sufficiently aligned for the return type. */
3408 if (CALL_EXPR_RETURN_SLOT_OPT (exp)
3409 && target
3410 && MEM_P (target)
3411 && !(MEM_ALIGN (target) < TYPE_ALIGN (rettype)
3412 && targetm.slow_unaligned_access (TYPE_MODE (rettype),
3413 MEM_ALIGN (target))))
3414 structure_value_addr = XEXP (target, 0);
3415 else
3417 /* For variable-sized objects, we must be called with a target
3418 specified. If we were to allocate space on the stack here,
3419 we would have no way of knowing when to free it. */
3420 rtx d = assign_temp (rettype, 1, 1);
3421 structure_value_addr = XEXP (d, 0);
3422 target = 0;
3425 #endif /* not PCC_STATIC_STRUCT_RETURN */
3428 /* Figure out the amount to which the stack should be aligned. */
3429 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3430 if (fndecl)
3432 struct cgraph_rtl_info *i = cgraph_node::rtl_info (fndecl);
3433 /* Without automatic stack alignment, we can't increase preferred
3434 stack boundary. With automatic stack alignment, it is
3435 unnecessary since unless we can guarantee that all callers will
3436 align the outgoing stack properly, callee has to align its
3437 stack anyway. */
3438 if (i
3439 && i->preferred_incoming_stack_boundary
3440 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
3441 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
3444 /* Operand 0 is a pointer-to-function; get the type of the function. */
3445 funtype = TREE_TYPE (addr);
3446 gcc_assert (POINTER_TYPE_P (funtype));
3447 funtype = TREE_TYPE (funtype);
3449 /* Count whether there are actual complex arguments that need to be split
3450 into their real and imaginary parts. Munge the type_arg_types
3451 appropriately here as well. */
3452 if (targetm.calls.split_complex_arg)
3454 call_expr_arg_iterator iter;
3455 tree arg;
3456 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
3458 tree type = TREE_TYPE (arg);
3459 if (type && TREE_CODE (type) == COMPLEX_TYPE
3460 && targetm.calls.split_complex_arg (type))
3461 num_complex_actuals++;
3463 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
3465 else
3466 type_arg_types = TYPE_ARG_TYPES (funtype);
3468 if (flags & ECF_MAY_BE_ALLOCA)
3469 cfun->calls_alloca = 1;
3471 /* If struct_value_rtx is 0, it means pass the address
3472 as if it were an extra parameter. Put the argument expression
3473 in structure_value_addr_value. */
3474 if (structure_value_addr && struct_value == 0)
3476 /* If structure_value_addr is a REG other than
3477 virtual_outgoing_args_rtx, we can use always use it. If it
3478 is not a REG, we must always copy it into a register.
3479 If it is virtual_outgoing_args_rtx, we must copy it to another
3480 register in some cases. */
3481 rtx temp = (!REG_P (structure_value_addr)
3482 || (ACCUMULATE_OUTGOING_ARGS
3483 && stack_arg_under_construction
3484 && structure_value_addr == virtual_outgoing_args_rtx)
3485 ? copy_addr_to_reg (convert_memory_address
3486 (Pmode, structure_value_addr))
3487 : structure_value_addr);
3489 structure_value_addr_value =
3490 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
3491 structure_value_addr_parm = CALL_WITH_BOUNDS_P (exp) ? 2 : 1;
3494 /* Count the arguments and set NUM_ACTUALS. */
3495 num_actuals =
3496 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
3498 /* Compute number of named args.
3499 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
3501 if (type_arg_types != 0)
3502 n_named_args
3503 = (list_length (type_arg_types)
3504 /* Count the struct value address, if it is passed as a parm. */
3505 + structure_value_addr_parm);
3506 else
3507 /* If we know nothing, treat all args as named. */
3508 n_named_args = num_actuals;
3510 /* Start updating where the next arg would go.
3512 On some machines (such as the PA) indirect calls have a different
3513 calling convention than normal calls. The fourth argument in
3514 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
3515 or not. */
3516 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
3517 args_so_far = pack_cumulative_args (&args_so_far_v);
3519 /* Now possibly adjust the number of named args.
3520 Normally, don't include the last named arg if anonymous args follow.
3521 We do include the last named arg if
3522 targetm.calls.strict_argument_naming() returns nonzero.
3523 (If no anonymous args follow, the result of list_length is actually
3524 one too large. This is harmless.)
3526 If targetm.calls.pretend_outgoing_varargs_named() returns
3527 nonzero, and targetm.calls.strict_argument_naming() returns zero,
3528 this machine will be able to place unnamed args that were passed
3529 in registers into the stack. So treat all args as named. This
3530 allows the insns emitting for a specific argument list to be
3531 independent of the function declaration.
3533 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
3534 we do not have any reliable way to pass unnamed args in
3535 registers, so we must force them into memory. */
3537 if (type_arg_types != 0
3538 && targetm.calls.strict_argument_naming (args_so_far))
3540 else if (type_arg_types != 0
3541 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
3542 /* Don't include the last named arg. */
3543 --n_named_args;
3544 else
3545 /* Treat all args as named. */
3546 n_named_args = num_actuals;
3548 /* Make a vector to hold all the information about each arg. */
3549 args = XCNEWVEC (struct arg_data, num_actuals);
3551 /* Build up entries in the ARGS array, compute the size of the
3552 arguments into ARGS_SIZE, etc. */
3553 initialize_argument_information (num_actuals, args, &args_size,
3554 n_named_args, exp,
3555 structure_value_addr_value, fndecl, fntype,
3556 args_so_far, reg_parm_stack_space,
3557 &old_stack_level, &old_pending_adj,
3558 &must_preallocate, &flags,
3559 &try_tail_call, CALL_FROM_THUNK_P (exp));
3561 if (args_size.var)
3562 must_preallocate = 1;
3564 /* Now make final decision about preallocating stack space. */
3565 must_preallocate = finalize_must_preallocate (must_preallocate,
3566 num_actuals, args,
3567 &args_size);
3569 /* If the structure value address will reference the stack pointer, we
3570 must stabilize it. We don't need to do this if we know that we are
3571 not going to adjust the stack pointer in processing this call. */
3573 if (structure_value_addr
3574 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
3575 || reg_mentioned_p (virtual_outgoing_args_rtx,
3576 structure_value_addr))
3577 && (args_size.var
3578 || (!ACCUMULATE_OUTGOING_ARGS
3579 && maybe_ne (args_size.constant, 0))))
3580 structure_value_addr = copy_to_reg (structure_value_addr);
3582 /* Tail calls can make things harder to debug, and we've traditionally
3583 pushed these optimizations into -O2. Don't try if we're already
3584 expanding a call, as that means we're an argument. Don't try if
3585 there's cleanups, as we know there's code to follow the call. */
3587 if (currently_expanding_call++ != 0
3588 || !flag_optimize_sibling_calls
3589 || args_size.var
3590 || dbg_cnt (tail_call) == false)
3591 try_tail_call = 0;
3593 /* If the user has marked the function as requiring tail-call
3594 optimization, attempt it. */
3595 if (must_tail_call)
3596 try_tail_call = 1;
3598 /* Rest of purposes for tail call optimizations to fail. */
3599 if (try_tail_call)
3600 try_tail_call = can_implement_as_sibling_call_p (exp,
3601 structure_value_addr,
3602 funtype,
3603 reg_parm_stack_space,
3604 fndecl,
3605 flags, addr, args_size);
3607 /* Check if caller and callee disagree in promotion of function
3608 return value. */
3609 if (try_tail_call)
3611 machine_mode caller_mode, caller_promoted_mode;
3612 machine_mode callee_mode, callee_promoted_mode;
3613 int caller_unsignedp, callee_unsignedp;
3614 tree caller_res = DECL_RESULT (current_function_decl);
3616 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
3617 caller_mode = DECL_MODE (caller_res);
3618 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
3619 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
3620 caller_promoted_mode
3621 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
3622 &caller_unsignedp,
3623 TREE_TYPE (current_function_decl), 1);
3624 callee_promoted_mode
3625 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
3626 &callee_unsignedp,
3627 funtype, 1);
3628 if (caller_mode != VOIDmode
3629 && (caller_promoted_mode != callee_promoted_mode
3630 || ((caller_mode != caller_promoted_mode
3631 || callee_mode != callee_promoted_mode)
3632 && (caller_unsignedp != callee_unsignedp
3633 || partial_subreg_p (caller_mode, callee_mode)))))
3635 try_tail_call = 0;
3636 maybe_complain_about_tail_call (exp,
3637 "caller and callee disagree in"
3638 " promotion of function"
3639 " return value");
3643 /* Ensure current function's preferred stack boundary is at least
3644 what we need. Stack alignment may also increase preferred stack
3645 boundary. */
3646 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
3647 crtl->preferred_stack_boundary = preferred_stack_boundary;
3648 else
3649 preferred_stack_boundary = crtl->preferred_stack_boundary;
3651 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
3653 /* We want to make two insn chains; one for a sibling call, the other
3654 for a normal call. We will select one of the two chains after
3655 initial RTL generation is complete. */
3656 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
3658 int sibcall_failure = 0;
3659 /* We want to emit any pending stack adjustments before the tail
3660 recursion "call". That way we know any adjustment after the tail
3661 recursion call can be ignored if we indeed use the tail
3662 call expansion. */
3663 saved_pending_stack_adjust save;
3664 rtx_insn *insns, *before_call, *after_args;
3665 rtx next_arg_reg;
3667 if (pass == 0)
3669 /* State variables we need to save and restore between
3670 iterations. */
3671 save_pending_stack_adjust (&save);
3673 if (pass)
3674 flags &= ~ECF_SIBCALL;
3675 else
3676 flags |= ECF_SIBCALL;
3678 /* Other state variables that we must reinitialize each time
3679 through the loop (that are not initialized by the loop itself). */
3680 argblock = 0;
3681 call_fusage = 0;
3683 /* Start a new sequence for the normal call case.
3685 From this point on, if the sibling call fails, we want to set
3686 sibcall_failure instead of continuing the loop. */
3687 start_sequence ();
3689 /* Don't let pending stack adjusts add up to too much.
3690 Also, do all pending adjustments now if there is any chance
3691 this might be a call to alloca or if we are expanding a sibling
3692 call sequence.
3693 Also do the adjustments before a throwing call, otherwise
3694 exception handling can fail; PR 19225. */
3695 if (maybe_ge (pending_stack_adjust, 32)
3696 || (maybe_ne (pending_stack_adjust, 0)
3697 && (flags & ECF_MAY_BE_ALLOCA))
3698 || (maybe_ne (pending_stack_adjust, 0)
3699 && flag_exceptions && !(flags & ECF_NOTHROW))
3700 || pass == 0)
3701 do_pending_stack_adjust ();
3703 /* Precompute any arguments as needed. */
3704 if (pass)
3705 precompute_arguments (num_actuals, args);
3707 /* Now we are about to start emitting insns that can be deleted
3708 if a libcall is deleted. */
3709 if (pass && (flags & ECF_MALLOC))
3710 start_sequence ();
3712 if (pass == 0
3713 && crtl->stack_protect_guard
3714 && targetm.stack_protect_runtime_enabled_p ())
3715 stack_protect_epilogue ();
3717 adjusted_args_size = args_size;
3718 /* Compute the actual size of the argument block required. The variable
3719 and constant sizes must be combined, the size may have to be rounded,
3720 and there may be a minimum required size. When generating a sibcall
3721 pattern, do not round up, since we'll be re-using whatever space our
3722 caller provided. */
3723 unadjusted_args_size
3724 = compute_argument_block_size (reg_parm_stack_space,
3725 &adjusted_args_size,
3726 fndecl, fntype,
3727 (pass == 0 ? 0
3728 : preferred_stack_boundary));
3730 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3732 /* The argument block when performing a sibling call is the
3733 incoming argument block. */
3734 if (pass == 0)
3736 argblock = crtl->args.internal_arg_pointer;
3737 if (STACK_GROWS_DOWNWARD)
3738 argblock
3739 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
3740 else
3741 argblock
3742 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
3744 HOST_WIDE_INT map_size = constant_lower_bound (args_size.constant);
3745 stored_args_map = sbitmap_alloc (map_size);
3746 bitmap_clear (stored_args_map);
3747 stored_args_watermark = HOST_WIDE_INT_M1U;
3750 /* If we have no actual push instructions, or shouldn't use them,
3751 make space for all args right now. */
3752 else if (adjusted_args_size.var != 0)
3754 if (old_stack_level == 0)
3756 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3757 old_stack_pointer_delta = stack_pointer_delta;
3758 old_pending_adj = pending_stack_adjust;
3759 pending_stack_adjust = 0;
3760 /* stack_arg_under_construction says whether a stack arg is
3761 being constructed at the old stack level. Pushing the stack
3762 gets a clean outgoing argument block. */
3763 old_stack_arg_under_construction = stack_arg_under_construction;
3764 stack_arg_under_construction = 0;
3766 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
3767 if (flag_stack_usage_info)
3768 current_function_has_unbounded_dynamic_stack_size = 1;
3770 else
3772 /* Note that we must go through the motions of allocating an argument
3773 block even if the size is zero because we may be storing args
3774 in the area reserved for register arguments, which may be part of
3775 the stack frame. */
3777 poly_int64 needed = adjusted_args_size.constant;
3779 /* Store the maximum argument space used. It will be pushed by
3780 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
3781 checking). */
3783 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
3784 needed);
3786 if (must_preallocate)
3788 if (ACCUMULATE_OUTGOING_ARGS)
3790 /* Since the stack pointer will never be pushed, it is
3791 possible for the evaluation of a parm to clobber
3792 something we have already written to the stack.
3793 Since most function calls on RISC machines do not use
3794 the stack, this is uncommon, but must work correctly.
3796 Therefore, we save any area of the stack that was already
3797 written and that we are using. Here we set up to do this
3798 by making a new stack usage map from the old one. The
3799 actual save will be done by store_one_arg.
3801 Another approach might be to try to reorder the argument
3802 evaluations to avoid this conflicting stack usage. */
3804 /* Since we will be writing into the entire argument area,
3805 the map must be allocated for its entire size, not just
3806 the part that is the responsibility of the caller. */
3807 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3808 needed += reg_parm_stack_space;
3810 poly_int64 limit = needed;
3811 if (ARGS_GROW_DOWNWARD)
3812 limit += 1;
3814 /* For polynomial sizes, this is the maximum possible
3815 size needed for arguments with a constant size
3816 and offset. */
3817 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
3818 highest_outgoing_arg_in_use
3819 = MAX (initial_highest_arg_in_use, const_limit);
3821 free (stack_usage_map_buf);
3822 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3823 stack_usage_map = stack_usage_map_buf;
3825 if (initial_highest_arg_in_use)
3826 memcpy (stack_usage_map, initial_stack_usage_map,
3827 initial_highest_arg_in_use);
3829 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3830 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3831 (highest_outgoing_arg_in_use
3832 - initial_highest_arg_in_use));
3833 needed = 0;
3835 /* The address of the outgoing argument list must not be
3836 copied to a register here, because argblock would be left
3837 pointing to the wrong place after the call to
3838 allocate_dynamic_stack_space below. */
3840 argblock = virtual_outgoing_args_rtx;
3842 else
3844 /* Try to reuse some or all of the pending_stack_adjust
3845 to get this space. */
3846 if (inhibit_defer_pop == 0
3847 && (combine_pending_stack_adjustment_and_call
3848 (&needed,
3849 unadjusted_args_size,
3850 &adjusted_args_size,
3851 preferred_unit_stack_boundary)))
3853 /* combine_pending_stack_adjustment_and_call computes
3854 an adjustment before the arguments are allocated.
3855 Account for them and see whether or not the stack
3856 needs to go up or down. */
3857 needed = unadjusted_args_size - needed;
3859 /* Checked by
3860 combine_pending_stack_adjustment_and_call. */
3861 gcc_checking_assert (ordered_p (needed, 0));
3862 if (maybe_lt (needed, 0))
3864 /* We're releasing stack space. */
3865 /* ??? We can avoid any adjustment at all if we're
3866 already aligned. FIXME. */
3867 pending_stack_adjust = -needed;
3868 do_pending_stack_adjust ();
3869 needed = 0;
3871 else
3872 /* We need to allocate space. We'll do that in
3873 push_block below. */
3874 pending_stack_adjust = 0;
3877 /* Special case this because overhead of `push_block' in
3878 this case is non-trivial. */
3879 if (known_eq (needed, 0))
3880 argblock = virtual_outgoing_args_rtx;
3881 else
3883 rtx needed_rtx = gen_int_mode (needed, Pmode);
3884 argblock = push_block (needed_rtx, 0, 0);
3885 if (ARGS_GROW_DOWNWARD)
3886 argblock = plus_constant (Pmode, argblock, needed);
3889 /* We only really need to call `copy_to_reg' in the case
3890 where push insns are going to be used to pass ARGBLOCK
3891 to a function call in ARGS. In that case, the stack
3892 pointer changes value from the allocation point to the
3893 call point, and hence the value of
3894 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
3895 as well always do it. */
3896 argblock = copy_to_reg (argblock);
3901 if (ACCUMULATE_OUTGOING_ARGS)
3903 /* The save/restore code in store_one_arg handles all
3904 cases except one: a constructor call (including a C
3905 function returning a BLKmode struct) to initialize
3906 an argument. */
3907 if (stack_arg_under_construction)
3909 rtx push_size
3910 = (gen_int_mode
3911 (adjusted_args_size.constant
3912 + (OUTGOING_REG_PARM_STACK_SPACE (!fndecl ? fntype
3913 : TREE_TYPE (fndecl))
3914 ? 0 : reg_parm_stack_space), Pmode));
3915 if (old_stack_level == 0)
3917 emit_stack_save (SAVE_BLOCK, &old_stack_level);
3918 old_stack_pointer_delta = stack_pointer_delta;
3919 old_pending_adj = pending_stack_adjust;
3920 pending_stack_adjust = 0;
3921 /* stack_arg_under_construction says whether a stack
3922 arg is being constructed at the old stack level.
3923 Pushing the stack gets a clean outgoing argument
3924 block. */
3925 old_stack_arg_under_construction
3926 = stack_arg_under_construction;
3927 stack_arg_under_construction = 0;
3928 /* Make a new map for the new argument list. */
3929 free (stack_usage_map_buf);
3930 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
3931 stack_usage_map = stack_usage_map_buf;
3932 highest_outgoing_arg_in_use = 0;
3933 stack_usage_watermark = HOST_WIDE_INT_M1U;
3935 /* We can pass TRUE as the 4th argument because we just
3936 saved the stack pointer and will restore it right after
3937 the call. */
3938 allocate_dynamic_stack_space (push_size, 0, BIGGEST_ALIGNMENT,
3939 -1, true);
3942 /* If argument evaluation might modify the stack pointer,
3943 copy the address of the argument list to a register. */
3944 for (i = 0; i < num_actuals; i++)
3945 if (args[i].pass_on_stack)
3947 argblock = copy_addr_to_reg (argblock);
3948 break;
3952 compute_argument_addresses (args, argblock, num_actuals);
3954 /* Stack is properly aligned, pops can't safely be deferred during
3955 the evaluation of the arguments. */
3956 NO_DEFER_POP;
3958 /* Precompute all register parameters. It isn't safe to compute
3959 anything once we have started filling any specific hard regs.
3960 TLS symbols sometimes need a call to resolve. Precompute
3961 register parameters before any stack pointer manipulation
3962 to avoid unaligned stack in the called function. */
3963 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3965 OK_DEFER_POP;
3967 /* Perform stack alignment before the first push (the last arg). */
3968 if (argblock == 0
3969 && maybe_gt (adjusted_args_size.constant, reg_parm_stack_space)
3970 && maybe_ne (adjusted_args_size.constant, unadjusted_args_size))
3972 /* When the stack adjustment is pending, we get better code
3973 by combining the adjustments. */
3974 if (maybe_ne (pending_stack_adjust, 0)
3975 && ! inhibit_defer_pop
3976 && (combine_pending_stack_adjustment_and_call
3977 (&pending_stack_adjust,
3978 unadjusted_args_size,
3979 &adjusted_args_size,
3980 preferred_unit_stack_boundary)))
3981 do_pending_stack_adjust ();
3982 else if (argblock == 0)
3983 anti_adjust_stack (gen_int_mode (adjusted_args_size.constant
3984 - unadjusted_args_size,
3985 Pmode));
3987 /* Now that the stack is properly aligned, pops can't safely
3988 be deferred during the evaluation of the arguments. */
3989 NO_DEFER_POP;
3991 /* Record the maximum pushed stack space size. We need to delay
3992 doing it this far to take into account the optimization done
3993 by combine_pending_stack_adjustment_and_call. */
3994 if (flag_stack_usage_info
3995 && !ACCUMULATE_OUTGOING_ARGS
3996 && pass
3997 && adjusted_args_size.var == 0)
3999 poly_int64 pushed = (adjusted_args_size.constant
4000 + pending_stack_adjust);
4001 current_function_pushed_stack_size
4002 = upper_bound (current_function_pushed_stack_size, pushed);
4005 funexp = rtx_for_function_call (fndecl, addr);
4007 if (CALL_EXPR_STATIC_CHAIN (exp))
4008 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
4009 else
4010 static_chain_value = 0;
4012 #ifdef REG_PARM_STACK_SPACE
4013 /* Save the fixed argument area if it's part of the caller's frame and
4014 is clobbered by argument setup for this call. */
4015 if (ACCUMULATE_OUTGOING_ARGS && pass)
4016 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4017 &low_to_save, &high_to_save);
4018 #endif
4020 /* Now store (and compute if necessary) all non-register parms.
4021 These come before register parms, since they can require block-moves,
4022 which could clobber the registers used for register parms.
4023 Parms which have partial registers are not stored here,
4024 but we do preallocate space here if they want that. */
4026 for (i = 0; i < num_actuals; i++)
4028 /* Delay bounds until all other args are stored. */
4029 if (POINTER_BOUNDS_P (args[i].tree_value))
4030 continue;
4031 else if (args[i].reg == 0 || args[i].pass_on_stack)
4033 rtx_insn *before_arg = get_last_insn ();
4035 /* We don't allow passing huge (> 2^30 B) arguments
4036 by value. It would cause an overflow later on. */
4037 if (constant_lower_bound (adjusted_args_size.constant)
4038 >= (1 << (HOST_BITS_PER_INT - 2)))
4040 sorry ("passing too large argument on stack");
4041 continue;
4044 if (store_one_arg (&args[i], argblock, flags,
4045 adjusted_args_size.var != 0,
4046 reg_parm_stack_space)
4047 || (pass == 0
4048 && check_sibcall_argument_overlap (before_arg,
4049 &args[i], 1)))
4050 sibcall_failure = 1;
4053 if (args[i].stack)
4054 call_fusage
4055 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
4056 gen_rtx_USE (VOIDmode, args[i].stack),
4057 call_fusage);
4060 /* If we have a parm that is passed in registers but not in memory
4061 and whose alignment does not permit a direct copy into registers,
4062 make a group of pseudos that correspond to each register that we
4063 will later fill. */
4064 if (STRICT_ALIGNMENT)
4065 store_unaligned_arguments_into_pseudos (args, num_actuals);
4067 /* Now store any partially-in-registers parm.
4068 This is the last place a block-move can happen. */
4069 if (reg_parm_seen)
4070 for (i = 0; i < num_actuals; i++)
4071 if (args[i].partial != 0 && ! args[i].pass_on_stack)
4073 rtx_insn *before_arg = get_last_insn ();
4075 /* On targets with weird calling conventions (e.g. PA) it's
4076 hard to ensure that all cases of argument overlap between
4077 stack and registers work. Play it safe and bail out. */
4078 if (ARGS_GROW_DOWNWARD && !STACK_GROWS_DOWNWARD)
4080 sibcall_failure = 1;
4081 break;
4084 if (store_one_arg (&args[i], argblock, flags,
4085 adjusted_args_size.var != 0,
4086 reg_parm_stack_space)
4087 || (pass == 0
4088 && check_sibcall_argument_overlap (before_arg,
4089 &args[i], 1)))
4090 sibcall_failure = 1;
4093 bool any_regs = false;
4094 for (i = 0; i < num_actuals; i++)
4095 if (args[i].reg != NULL_RTX)
4097 any_regs = true;
4098 targetm.calls.call_args (args[i].reg, funtype);
4100 if (!any_regs)
4101 targetm.calls.call_args (pc_rtx, funtype);
4103 /* Figure out the register where the value, if any, will come back. */
4104 valreg = 0;
4105 valbnd = 0;
4106 if (TYPE_MODE (rettype) != VOIDmode
4107 && ! structure_value_addr)
4109 if (pcc_struct_value)
4111 valreg = hard_function_value (build_pointer_type (rettype),
4112 fndecl, NULL, (pass == 0));
4113 if (CALL_WITH_BOUNDS_P (exp))
4114 valbnd = targetm.calls.
4115 chkp_function_value_bounds (build_pointer_type (rettype),
4116 fndecl, (pass == 0));
4118 else
4120 valreg = hard_function_value (rettype, fndecl, fntype,
4121 (pass == 0));
4122 if (CALL_WITH_BOUNDS_P (exp))
4123 valbnd = targetm.calls.chkp_function_value_bounds (rettype,
4124 fndecl,
4125 (pass == 0));
4128 /* If VALREG is a PARALLEL whose first member has a zero
4129 offset, use that. This is for targets such as m68k that
4130 return the same value in multiple places. */
4131 if (GET_CODE (valreg) == PARALLEL)
4133 rtx elem = XVECEXP (valreg, 0, 0);
4134 rtx where = XEXP (elem, 0);
4135 rtx offset = XEXP (elem, 1);
4136 if (offset == const0_rtx
4137 && GET_MODE (where) == GET_MODE (valreg))
4138 valreg = where;
4142 /* Store all bounds not passed in registers. */
4143 for (i = 0; i < num_actuals; i++)
4145 if (POINTER_BOUNDS_P (args[i].tree_value)
4146 && !args[i].reg)
4147 store_bounds (&args[i],
4148 args[i].pointer_arg == -1
4149 ? NULL
4150 : &args[args[i].pointer_arg]);
4153 /* If register arguments require space on the stack and stack space
4154 was not preallocated, allocate stack space here for arguments
4155 passed in registers. */
4156 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
4157 && !ACCUMULATE_OUTGOING_ARGS
4158 && must_preallocate == 0 && reg_parm_stack_space > 0)
4159 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
4161 /* Pass the function the address in which to return a
4162 structure value. */
4163 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
4165 structure_value_addr
4166 = convert_memory_address (Pmode, structure_value_addr);
4167 emit_move_insn (struct_value,
4168 force_reg (Pmode,
4169 force_operand (structure_value_addr,
4170 NULL_RTX)));
4172 if (REG_P (struct_value))
4173 use_reg (&call_fusage, struct_value);
4176 after_args = get_last_insn ();
4177 funexp = prepare_call_address (fndecl ? fndecl : fntype, funexp,
4178 static_chain_value, &call_fusage,
4179 reg_parm_seen, flags);
4181 load_register_parameters (args, num_actuals, &call_fusage, flags,
4182 pass == 0, &sibcall_failure);
4184 /* Save a pointer to the last insn before the call, so that we can
4185 later safely search backwards to find the CALL_INSN. */
4186 before_call = get_last_insn ();
4188 /* Set up next argument register. For sibling calls on machines
4189 with register windows this should be the incoming register. */
4190 if (pass == 0)
4191 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
4192 VOIDmode,
4193 void_type_node,
4194 true);
4195 else
4196 next_arg_reg = targetm.calls.function_arg (args_so_far,
4197 VOIDmode, void_type_node,
4198 true);
4200 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
4202 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
4203 arg_nr = num_actuals - arg_nr - 1;
4204 if (arg_nr >= 0
4205 && arg_nr < num_actuals
4206 && args[arg_nr].reg
4207 && valreg
4208 && REG_P (valreg)
4209 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
4210 call_fusage
4211 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
4212 gen_rtx_SET (valreg, args[arg_nr].reg),
4213 call_fusage);
4215 /* All arguments and registers used for the call must be set up by
4216 now! */
4218 /* Stack must be properly aligned now. */
4219 gcc_assert (!pass
4220 || multiple_p (stack_pointer_delta,
4221 preferred_unit_stack_boundary));
4223 /* Generate the actual call instruction. */
4224 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
4225 adjusted_args_size.constant, struct_value_size,
4226 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
4227 flags, args_so_far);
4229 if (flag_ipa_ra)
4231 rtx_call_insn *last;
4232 rtx datum = NULL_RTX;
4233 if (fndecl != NULL_TREE)
4235 datum = XEXP (DECL_RTL (fndecl), 0);
4236 gcc_assert (datum != NULL_RTX
4237 && GET_CODE (datum) == SYMBOL_REF);
4239 last = last_call_insn ();
4240 add_reg_note (last, REG_CALL_DECL, datum);
4243 /* If the call setup or the call itself overlaps with anything
4244 of the argument setup we probably clobbered our call address.
4245 In that case we can't do sibcalls. */
4246 if (pass == 0
4247 && check_sibcall_argument_overlap (after_args, 0, 0))
4248 sibcall_failure = 1;
4250 /* If a non-BLKmode value is returned at the most significant end
4251 of a register, shift the register right by the appropriate amount
4252 and update VALREG accordingly. BLKmode values are handled by the
4253 group load/store machinery below. */
4254 if (!structure_value_addr
4255 && !pcc_struct_value
4256 && TYPE_MODE (rettype) != VOIDmode
4257 && TYPE_MODE (rettype) != BLKmode
4258 && REG_P (valreg)
4259 && targetm.calls.return_in_msb (rettype))
4261 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
4262 sibcall_failure = 1;
4263 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
4266 if (pass && (flags & ECF_MALLOC))
4268 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4269 rtx_insn *last, *insns;
4271 /* The return value from a malloc-like function is a pointer. */
4272 if (TREE_CODE (rettype) == POINTER_TYPE)
4273 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
4275 emit_move_insn (temp, valreg);
4277 /* The return value from a malloc-like function can not alias
4278 anything else. */
4279 last = get_last_insn ();
4280 add_reg_note (last, REG_NOALIAS, temp);
4282 /* Write out the sequence. */
4283 insns = get_insns ();
4284 end_sequence ();
4285 emit_insn (insns);
4286 valreg = temp;
4289 /* For calls to `setjmp', etc., inform
4290 function.c:setjmp_warnings that it should complain if
4291 nonvolatile values are live. For functions that cannot
4292 return, inform flow that control does not fall through. */
4294 if ((flags & ECF_NORETURN) || pass == 0)
4296 /* The barrier must be emitted
4297 immediately after the CALL_INSN. Some ports emit more
4298 than just a CALL_INSN above, so we must search for it here. */
4300 rtx_insn *last = get_last_insn ();
4301 while (!CALL_P (last))
4303 last = PREV_INSN (last);
4304 /* There was no CALL_INSN? */
4305 gcc_assert (last != before_call);
4308 emit_barrier_after (last);
4310 /* Stack adjustments after a noreturn call are dead code.
4311 However when NO_DEFER_POP is in effect, we must preserve
4312 stack_pointer_delta. */
4313 if (inhibit_defer_pop == 0)
4315 stack_pointer_delta = old_stack_allocated;
4316 pending_stack_adjust = 0;
4320 /* If value type not void, return an rtx for the value. */
4322 if (TYPE_MODE (rettype) == VOIDmode
4323 || ignore)
4324 target = const0_rtx;
4325 else if (structure_value_addr)
4327 if (target == 0 || !MEM_P (target))
4329 target
4330 = gen_rtx_MEM (TYPE_MODE (rettype),
4331 memory_address (TYPE_MODE (rettype),
4332 structure_value_addr));
4333 set_mem_attributes (target, rettype, 1);
4336 else if (pcc_struct_value)
4338 /* This is the special C++ case where we need to
4339 know what the true target was. We take care to
4340 never use this value more than once in one expression. */
4341 target = gen_rtx_MEM (TYPE_MODE (rettype),
4342 copy_to_reg (valreg));
4343 set_mem_attributes (target, rettype, 1);
4345 /* Handle calls that return values in multiple non-contiguous locations.
4346 The Irix 6 ABI has examples of this. */
4347 else if (GET_CODE (valreg) == PARALLEL)
4349 if (target == 0)
4350 target = emit_group_move_into_temps (valreg);
4351 else if (rtx_equal_p (target, valreg))
4353 else if (GET_CODE (target) == PARALLEL)
4354 /* Handle the result of a emit_group_move_into_temps
4355 call in the previous pass. */
4356 emit_group_move (target, valreg);
4357 else
4358 emit_group_store (target, valreg, rettype,
4359 int_size_in_bytes (rettype));
4361 else if (target
4362 && GET_MODE (target) == TYPE_MODE (rettype)
4363 && GET_MODE (target) == GET_MODE (valreg))
4365 bool may_overlap = false;
4367 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
4368 reg to a plain register. */
4369 if (!REG_P (target) || HARD_REGISTER_P (target))
4370 valreg = avoid_likely_spilled_reg (valreg);
4372 /* If TARGET is a MEM in the argument area, and we have
4373 saved part of the argument area, then we can't store
4374 directly into TARGET as it may get overwritten when we
4375 restore the argument save area below. Don't work too
4376 hard though and simply force TARGET to a register if it
4377 is a MEM; the optimizer is quite likely to sort it out. */
4378 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
4379 for (i = 0; i < num_actuals; i++)
4380 if (args[i].save_area)
4382 may_overlap = true;
4383 break;
4386 if (may_overlap)
4387 target = copy_to_reg (valreg);
4388 else
4390 /* TARGET and VALREG cannot be equal at this point
4391 because the latter would not have
4392 REG_FUNCTION_VALUE_P true, while the former would if
4393 it were referring to the same register.
4395 If they refer to the same register, this move will be
4396 a no-op, except when function inlining is being
4397 done. */
4398 emit_move_insn (target, valreg);
4400 /* If we are setting a MEM, this code must be executed.
4401 Since it is emitted after the call insn, sibcall
4402 optimization cannot be performed in that case. */
4403 if (MEM_P (target))
4404 sibcall_failure = 1;
4407 else
4408 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
4410 /* If we promoted this return value, make the proper SUBREG.
4411 TARGET might be const0_rtx here, so be careful. */
4412 if (REG_P (target)
4413 && TYPE_MODE (rettype) != BLKmode
4414 && GET_MODE (target) != TYPE_MODE (rettype))
4416 tree type = rettype;
4417 int unsignedp = TYPE_UNSIGNED (type);
4418 machine_mode pmode;
4420 /* Ensure we promote as expected, and get the new unsignedness. */
4421 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
4422 funtype, 1);
4423 gcc_assert (GET_MODE (target) == pmode);
4425 poly_uint64 offset = subreg_lowpart_offset (TYPE_MODE (type),
4426 GET_MODE (target));
4427 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
4428 SUBREG_PROMOTED_VAR_P (target) = 1;
4429 SUBREG_PROMOTED_SET (target, unsignedp);
4432 /* If size of args is variable or this was a constructor call for a stack
4433 argument, restore saved stack-pointer value. */
4435 if (old_stack_level)
4437 rtx_insn *prev = get_last_insn ();
4439 emit_stack_restore (SAVE_BLOCK, old_stack_level);
4440 stack_pointer_delta = old_stack_pointer_delta;
4442 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
4444 pending_stack_adjust = old_pending_adj;
4445 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
4446 stack_arg_under_construction = old_stack_arg_under_construction;
4447 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4448 stack_usage_map = initial_stack_usage_map;
4449 stack_usage_watermark = initial_stack_usage_watermark;
4450 sibcall_failure = 1;
4452 else if (ACCUMULATE_OUTGOING_ARGS && pass)
4454 #ifdef REG_PARM_STACK_SPACE
4455 if (save_area)
4456 restore_fixed_argument_area (save_area, argblock,
4457 high_to_save, low_to_save);
4458 #endif
4460 /* If we saved any argument areas, restore them. */
4461 for (i = 0; i < num_actuals; i++)
4462 if (args[i].save_area)
4464 machine_mode save_mode = GET_MODE (args[i].save_area);
4465 rtx stack_area
4466 = gen_rtx_MEM (save_mode,
4467 memory_address (save_mode,
4468 XEXP (args[i].stack_slot, 0)));
4470 if (save_mode != BLKmode)
4471 emit_move_insn (stack_area, args[i].save_area);
4472 else
4473 emit_block_move (stack_area, args[i].save_area,
4474 (gen_int_mode
4475 (args[i].locate.size.constant, Pmode)),
4476 BLOCK_OP_CALL_PARM);
4479 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4480 stack_usage_map = initial_stack_usage_map;
4481 stack_usage_watermark = initial_stack_usage_watermark;
4484 /* If this was alloca, record the new stack level. */
4485 if (flags & ECF_MAY_BE_ALLOCA)
4486 record_new_stack_level ();
4488 /* Free up storage we no longer need. */
4489 for (i = 0; i < num_actuals; ++i)
4490 free (args[i].aligned_regs);
4492 targetm.calls.end_call_args ();
4494 insns = get_insns ();
4495 end_sequence ();
4497 if (pass == 0)
4499 tail_call_insns = insns;
4501 /* Restore the pending stack adjustment now that we have
4502 finished generating the sibling call sequence. */
4504 restore_pending_stack_adjust (&save);
4506 /* Prepare arg structure for next iteration. */
4507 for (i = 0; i < num_actuals; i++)
4509 args[i].value = 0;
4510 args[i].aligned_regs = 0;
4511 args[i].stack = 0;
4514 sbitmap_free (stored_args_map);
4515 internal_arg_pointer_exp_state.scan_start = NULL;
4516 internal_arg_pointer_exp_state.cache.release ();
4518 else
4520 normal_call_insns = insns;
4522 /* Verify that we've deallocated all the stack we used. */
4523 gcc_assert ((flags & ECF_NORETURN)
4524 || known_eq (old_stack_allocated,
4525 stack_pointer_delta
4526 - pending_stack_adjust));
4529 /* If something prevents making this a sibling call,
4530 zero out the sequence. */
4531 if (sibcall_failure)
4532 tail_call_insns = NULL;
4533 else
4534 break;
4537 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
4538 arguments too, as argument area is now clobbered by the call. */
4539 if (tail_call_insns)
4541 emit_insn (tail_call_insns);
4542 crtl->tail_call_emit = true;
4544 else
4546 emit_insn (normal_call_insns);
4547 if (try_tail_call)
4548 /* Ideally we'd emit a message for all of the ways that it could
4549 have failed. */
4550 maybe_complain_about_tail_call (exp, "tail call production failed");
4553 currently_expanding_call--;
4555 free (stack_usage_map_buf);
4556 free (args);
4558 /* Join result with returned bounds so caller may use them if needed. */
4559 target = chkp_join_splitted_slot (target, valbnd);
4561 return target;
4564 /* A sibling call sequence invalidates any REG_EQUIV notes made for
4565 this function's incoming arguments.
4567 At the start of RTL generation we know the only REG_EQUIV notes
4568 in the rtl chain are those for incoming arguments, so we can look
4569 for REG_EQUIV notes between the start of the function and the
4570 NOTE_INSN_FUNCTION_BEG.
4572 This is (slight) overkill. We could keep track of the highest
4573 argument we clobber and be more selective in removing notes, but it
4574 does not seem to be worth the effort. */
4576 void
4577 fixup_tail_calls (void)
4579 rtx_insn *insn;
4581 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
4583 rtx note;
4585 /* There are never REG_EQUIV notes for the incoming arguments
4586 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
4587 if (NOTE_P (insn)
4588 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
4589 break;
4591 note = find_reg_note (insn, REG_EQUIV, 0);
4592 if (note)
4593 remove_note (insn, note);
4594 note = find_reg_note (insn, REG_EQUIV, 0);
4595 gcc_assert (!note);
4599 /* Traverse a list of TYPES and expand all complex types into their
4600 components. */
4601 static tree
4602 split_complex_types (tree types)
4604 tree p;
4606 /* Before allocating memory, check for the common case of no complex. */
4607 for (p = types; p; p = TREE_CHAIN (p))
4609 tree type = TREE_VALUE (p);
4610 if (TREE_CODE (type) == COMPLEX_TYPE
4611 && targetm.calls.split_complex_arg (type))
4612 goto found;
4614 return types;
4616 found:
4617 types = copy_list (types);
4619 for (p = types; p; p = TREE_CHAIN (p))
4621 tree complex_type = TREE_VALUE (p);
4623 if (TREE_CODE (complex_type) == COMPLEX_TYPE
4624 && targetm.calls.split_complex_arg (complex_type))
4626 tree next, imag;
4628 /* Rewrite complex type with component type. */
4629 TREE_VALUE (p) = TREE_TYPE (complex_type);
4630 next = TREE_CHAIN (p);
4632 /* Add another component type for the imaginary part. */
4633 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
4634 TREE_CHAIN (p) = imag;
4635 TREE_CHAIN (imag) = next;
4637 /* Skip the newly created node. */
4638 p = TREE_CHAIN (p);
4642 return types;
4645 /* Output a library call to function ORGFUN (a SYMBOL_REF rtx)
4646 for a value of mode OUTMODE,
4647 with NARGS different arguments, passed as ARGS.
4648 Store the return value if RETVAL is nonzero: store it in VALUE if
4649 VALUE is nonnull, otherwise pick a convenient location. In either
4650 case return the location of the stored value.
4652 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4653 `const' calls, LCT_PURE for `pure' calls, or another LCT_ value for
4654 other types of library calls. */
4657 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
4658 enum libcall_type fn_type,
4659 machine_mode outmode, int nargs, rtx_mode_t *args)
4661 /* Total size in bytes of all the stack-parms scanned so far. */
4662 struct args_size args_size;
4663 /* Size of arguments before any adjustments (such as rounding). */
4664 struct args_size original_args_size;
4665 int argnum;
4666 rtx fun;
4667 /* Todo, choose the correct decl type of orgfun. Sadly this information
4668 isn't present here, so we default to native calling abi here. */
4669 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4670 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
4671 int count;
4672 rtx argblock = 0;
4673 CUMULATIVE_ARGS args_so_far_v;
4674 cumulative_args_t args_so_far;
4675 struct arg
4677 rtx value;
4678 machine_mode mode;
4679 rtx reg;
4680 int partial;
4681 struct locate_and_pad_arg_data locate;
4682 rtx save_area;
4684 struct arg *argvec;
4685 int old_inhibit_defer_pop = inhibit_defer_pop;
4686 rtx call_fusage = 0;
4687 rtx mem_value = 0;
4688 rtx valreg;
4689 int pcc_struct_value = 0;
4690 int struct_value_size = 0;
4691 int flags;
4692 int reg_parm_stack_space = 0;
4693 poly_int64 needed;
4694 rtx_insn *before_call;
4695 bool have_push_fusage;
4696 tree tfom; /* type_for_mode (outmode, 0) */
4698 #ifdef REG_PARM_STACK_SPACE
4699 /* Define the boundary of the register parm stack space that needs to be
4700 save, if any. */
4701 int low_to_save = 0, high_to_save = 0;
4702 rtx save_area = 0; /* Place that it is saved. */
4703 #endif
4705 /* Size of the stack reserved for parameter registers. */
4706 unsigned int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
4707 char *initial_stack_usage_map = stack_usage_map;
4708 unsigned HOST_WIDE_INT initial_stack_usage_watermark = stack_usage_watermark;
4709 char *stack_usage_map_buf = NULL;
4711 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
4713 #ifdef REG_PARM_STACK_SPACE
4714 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
4715 #endif
4717 /* By default, library functions cannot throw. */
4718 flags = ECF_NOTHROW;
4720 switch (fn_type)
4722 case LCT_NORMAL:
4723 break;
4724 case LCT_CONST:
4725 flags |= ECF_CONST;
4726 break;
4727 case LCT_PURE:
4728 flags |= ECF_PURE;
4729 break;
4730 case LCT_NORETURN:
4731 flags |= ECF_NORETURN;
4732 break;
4733 case LCT_THROW:
4734 flags &= ~ECF_NOTHROW;
4735 break;
4736 case LCT_RETURNS_TWICE:
4737 flags = ECF_RETURNS_TWICE;
4738 break;
4740 fun = orgfun;
4742 /* Ensure current function's preferred stack boundary is at least
4743 what we need. */
4744 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
4745 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
4747 /* If this kind of value comes back in memory,
4748 decide where in memory it should come back. */
4749 if (outmode != VOIDmode)
4751 tfom = lang_hooks.types.type_for_mode (outmode, 0);
4752 if (aggregate_value_p (tfom, 0))
4754 #ifdef PCC_STATIC_STRUCT_RETURN
4755 rtx pointer_reg
4756 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
4757 mem_value = gen_rtx_MEM (outmode, pointer_reg);
4758 pcc_struct_value = 1;
4759 if (value == 0)
4760 value = gen_reg_rtx (outmode);
4761 #else /* not PCC_STATIC_STRUCT_RETURN */
4762 struct_value_size = GET_MODE_SIZE (outmode);
4763 if (value != 0 && MEM_P (value))
4764 mem_value = value;
4765 else
4766 mem_value = assign_temp (tfom, 1, 1);
4767 #endif
4768 /* This call returns a big structure. */
4769 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
4772 else
4773 tfom = void_type_node;
4775 /* ??? Unfinished: must pass the memory address as an argument. */
4777 /* Copy all the libcall-arguments out of the varargs data
4778 and into a vector ARGVEC.
4780 Compute how to pass each argument. We only support a very small subset
4781 of the full argument passing conventions to limit complexity here since
4782 library functions shouldn't have many args. */
4784 argvec = XALLOCAVEC (struct arg, nargs + 1);
4785 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
4787 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
4788 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
4789 #else
4790 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
4791 #endif
4792 args_so_far = pack_cumulative_args (&args_so_far_v);
4794 args_size.constant = 0;
4795 args_size.var = 0;
4797 count = 0;
4799 push_temp_slots ();
4801 /* If there's a structure value address to be passed,
4802 either pass it in the special place, or pass it as an extra argument. */
4803 if (mem_value && struct_value == 0 && ! pcc_struct_value)
4805 rtx addr = XEXP (mem_value, 0);
4807 nargs++;
4809 /* Make sure it is a reasonable operand for a move or push insn. */
4810 if (!REG_P (addr) && !MEM_P (addr)
4811 && !(CONSTANT_P (addr)
4812 && targetm.legitimate_constant_p (Pmode, addr)))
4813 addr = force_operand (addr, NULL_RTX);
4815 argvec[count].value = addr;
4816 argvec[count].mode = Pmode;
4817 argvec[count].partial = 0;
4819 argvec[count].reg = targetm.calls.function_arg (args_so_far,
4820 Pmode, NULL_TREE, true);
4821 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
4822 NULL_TREE, 1) == 0);
4824 locate_and_pad_parm (Pmode, NULL_TREE,
4825 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4827 #else
4828 argvec[count].reg != 0,
4829 #endif
4830 reg_parm_stack_space, 0,
4831 NULL_TREE, &args_size, &argvec[count].locate);
4833 if (argvec[count].reg == 0 || argvec[count].partial != 0
4834 || reg_parm_stack_space > 0)
4835 args_size.constant += argvec[count].locate.size.constant;
4837 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
4839 count++;
4842 for (unsigned int i = 0; count < nargs; i++, count++)
4844 rtx val = args[i].first;
4845 machine_mode mode = args[i].second;
4846 int unsigned_p = 0;
4848 /* We cannot convert the arg value to the mode the library wants here;
4849 must do it earlier where we know the signedness of the arg. */
4850 gcc_assert (mode != BLKmode
4851 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
4853 /* Make sure it is a reasonable operand for a move or push insn. */
4854 if (!REG_P (val) && !MEM_P (val)
4855 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
4856 val = force_operand (val, NULL_RTX);
4858 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
4860 rtx slot;
4861 int must_copy
4862 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
4864 /* If this was a CONST function, it is now PURE since it now
4865 reads memory. */
4866 if (flags & ECF_CONST)
4868 flags &= ~ECF_CONST;
4869 flags |= ECF_PURE;
4872 if (MEM_P (val) && !must_copy)
4874 tree val_expr = MEM_EXPR (val);
4875 if (val_expr)
4876 mark_addressable (val_expr);
4877 slot = val;
4879 else
4881 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
4882 1, 1);
4883 emit_move_insn (slot, val);
4886 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4887 gen_rtx_USE (VOIDmode, slot),
4888 call_fusage);
4889 if (must_copy)
4890 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
4891 gen_rtx_CLOBBER (VOIDmode,
4892 slot),
4893 call_fusage);
4895 mode = Pmode;
4896 val = force_operand (XEXP (slot, 0), NULL_RTX);
4899 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
4900 argvec[count].mode = mode;
4901 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
4902 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
4903 NULL_TREE, true);
4905 argvec[count].partial
4906 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
4908 if (argvec[count].reg == 0
4909 || argvec[count].partial != 0
4910 || reg_parm_stack_space > 0)
4912 locate_and_pad_parm (mode, NULL_TREE,
4913 #ifdef STACK_PARMS_IN_REG_PARM_AREA
4915 #else
4916 argvec[count].reg != 0,
4917 #endif
4918 reg_parm_stack_space, argvec[count].partial,
4919 NULL_TREE, &args_size, &argvec[count].locate);
4920 args_size.constant += argvec[count].locate.size.constant;
4921 gcc_assert (!argvec[count].locate.size.var);
4923 #ifdef BLOCK_REG_PADDING
4924 else
4925 /* The argument is passed entirely in registers. See at which
4926 end it should be padded. */
4927 argvec[count].locate.where_pad =
4928 BLOCK_REG_PADDING (mode, NULL_TREE,
4929 GET_MODE_SIZE (mode) <= UNITS_PER_WORD);
4930 #endif
4932 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
4935 /* If this machine requires an external definition for library
4936 functions, write one out. */
4937 assemble_external_libcall (fun);
4939 original_args_size = args_size;
4940 args_size.constant = (aligned_upper_bound (args_size.constant
4941 + stack_pointer_delta,
4942 STACK_BYTES)
4943 - stack_pointer_delta);
4945 args_size.constant = upper_bound (args_size.constant,
4946 reg_parm_stack_space);
4948 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4949 args_size.constant -= reg_parm_stack_space;
4951 crtl->outgoing_args_size = upper_bound (crtl->outgoing_args_size,
4952 args_size.constant);
4954 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
4956 poly_int64 pushed = args_size.constant + pending_stack_adjust;
4957 current_function_pushed_stack_size
4958 = upper_bound (current_function_pushed_stack_size, pushed);
4961 if (ACCUMULATE_OUTGOING_ARGS)
4963 /* Since the stack pointer will never be pushed, it is possible for
4964 the evaluation of a parm to clobber something we have already
4965 written to the stack. Since most function calls on RISC machines
4966 do not use the stack, this is uncommon, but must work correctly.
4968 Therefore, we save any area of the stack that was already written
4969 and that we are using. Here we set up to do this by making a new
4970 stack usage map from the old one.
4972 Another approach might be to try to reorder the argument
4973 evaluations to avoid this conflicting stack usage. */
4975 needed = args_size.constant;
4977 /* Since we will be writing into the entire argument area, the
4978 map must be allocated for its entire size, not just the part that
4979 is the responsibility of the caller. */
4980 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
4981 needed += reg_parm_stack_space;
4983 poly_int64 limit = needed;
4984 if (ARGS_GROW_DOWNWARD)
4985 limit += 1;
4987 /* For polynomial sizes, this is the maximum possible size needed
4988 for arguments with a constant size and offset. */
4989 HOST_WIDE_INT const_limit = constant_lower_bound (limit);
4990 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
4991 const_limit);
4993 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
4994 stack_usage_map = stack_usage_map_buf;
4996 if (initial_highest_arg_in_use)
4997 memcpy (stack_usage_map, initial_stack_usage_map,
4998 initial_highest_arg_in_use);
5000 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
5001 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
5002 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
5003 needed = 0;
5005 /* We must be careful to use virtual regs before they're instantiated,
5006 and real regs afterwards. Loop optimization, for example, can create
5007 new libcalls after we've instantiated the virtual regs, and if we
5008 use virtuals anyway, they won't match the rtl patterns. */
5010 if (virtuals_instantiated)
5011 argblock = plus_constant (Pmode, stack_pointer_rtx,
5012 STACK_POINTER_OFFSET);
5013 else
5014 argblock = virtual_outgoing_args_rtx;
5016 else
5018 if (!PUSH_ARGS)
5019 argblock = push_block (gen_int_mode (args_size.constant, Pmode), 0, 0);
5022 /* We push args individually in reverse order, perform stack alignment
5023 before the first push (the last arg). */
5024 if (argblock == 0)
5025 anti_adjust_stack (gen_int_mode (args_size.constant
5026 - original_args_size.constant,
5027 Pmode));
5029 argnum = nargs - 1;
5031 #ifdef REG_PARM_STACK_SPACE
5032 if (ACCUMULATE_OUTGOING_ARGS)
5034 /* The argument list is the property of the called routine and it
5035 may clobber it. If the fixed area has been used for previous
5036 parameters, we must save and restore it. */
5037 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
5038 &low_to_save, &high_to_save);
5040 #endif
5042 /* When expanding a normal call, args are stored in push order,
5043 which is the reverse of what we have here. */
5044 bool any_regs = false;
5045 for (int i = nargs; i-- > 0; )
5046 if (argvec[i].reg != NULL_RTX)
5048 targetm.calls.call_args (argvec[i].reg, NULL_TREE);
5049 any_regs = true;
5051 if (!any_regs)
5052 targetm.calls.call_args (pc_rtx, NULL_TREE);
5054 /* Push the args that need to be pushed. */
5056 have_push_fusage = false;
5058 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5059 are to be pushed. */
5060 for (count = 0; count < nargs; count++, argnum--)
5062 machine_mode mode = argvec[argnum].mode;
5063 rtx val = argvec[argnum].value;
5064 rtx reg = argvec[argnum].reg;
5065 int partial = argvec[argnum].partial;
5066 unsigned int parm_align = argvec[argnum].locate.boundary;
5067 poly_int64 lower_bound = 0, upper_bound = 0;
5069 if (! (reg != 0 && partial == 0))
5071 rtx use;
5073 if (ACCUMULATE_OUTGOING_ARGS)
5075 /* If this is being stored into a pre-allocated, fixed-size,
5076 stack area, save any previous data at that location. */
5078 if (ARGS_GROW_DOWNWARD)
5080 /* stack_slot is negative, but we want to index stack_usage_map
5081 with positive values. */
5082 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
5083 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
5085 else
5087 lower_bound = argvec[argnum].locate.slot_offset.constant;
5088 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
5091 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5092 reg_parm_stack_space))
5094 /* We need to make a save area. */
5095 poly_uint64 size
5096 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
5097 machine_mode save_mode
5098 = int_mode_for_size (size, 1).else_blk ();
5099 rtx adr
5100 = plus_constant (Pmode, argblock,
5101 argvec[argnum].locate.offset.constant);
5102 rtx stack_area
5103 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
5105 if (save_mode == BLKmode)
5107 argvec[argnum].save_area
5108 = assign_stack_temp (BLKmode,
5109 argvec[argnum].locate.size.constant
5112 emit_block_move (validize_mem
5113 (copy_rtx (argvec[argnum].save_area)),
5114 stack_area,
5115 (gen_int_mode
5116 (argvec[argnum].locate.size.constant,
5117 Pmode)),
5118 BLOCK_OP_CALL_PARM);
5120 else
5122 argvec[argnum].save_area = gen_reg_rtx (save_mode);
5124 emit_move_insn (argvec[argnum].save_area, stack_area);
5129 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
5130 partial, reg, 0, argblock,
5131 (gen_int_mode
5132 (argvec[argnum].locate.offset.constant, Pmode)),
5133 reg_parm_stack_space,
5134 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad), false);
5136 /* Now mark the segment we just used. */
5137 if (ACCUMULATE_OUTGOING_ARGS)
5138 mark_stack_region_used (lower_bound, upper_bound);
5140 NO_DEFER_POP;
5142 /* Indicate argument access so that alias.c knows that these
5143 values are live. */
5144 if (argblock)
5145 use = plus_constant (Pmode, argblock,
5146 argvec[argnum].locate.offset.constant);
5147 else if (have_push_fusage)
5148 continue;
5149 else
5151 /* When arguments are pushed, trying to tell alias.c where
5152 exactly this argument is won't work, because the
5153 auto-increment causes confusion. So we merely indicate
5154 that we access something with a known mode somewhere on
5155 the stack. */
5156 use = gen_rtx_PLUS (Pmode, stack_pointer_rtx,
5157 gen_rtx_SCRATCH (Pmode));
5158 have_push_fusage = true;
5160 use = gen_rtx_MEM (argvec[argnum].mode, use);
5161 use = gen_rtx_USE (VOIDmode, use);
5162 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
5166 argnum = nargs - 1;
5168 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
5170 /* Now load any reg parms into their regs. */
5172 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
5173 are to be pushed. */
5174 for (count = 0; count < nargs; count++, argnum--)
5176 machine_mode mode = argvec[argnum].mode;
5177 rtx val = argvec[argnum].value;
5178 rtx reg = argvec[argnum].reg;
5179 int partial = argvec[argnum].partial;
5180 #ifdef BLOCK_REG_PADDING
5181 int size = 0;
5182 #endif
5184 /* Handle calls that pass values in multiple non-contiguous
5185 locations. The PA64 has examples of this for library calls. */
5186 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5187 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
5188 else if (reg != 0 && partial == 0)
5190 emit_move_insn (reg, val);
5191 #ifdef BLOCK_REG_PADDING
5192 size = GET_MODE_SIZE (argvec[argnum].mode);
5194 /* Copied from load_register_parameters. */
5196 /* Handle case where we have a value that needs shifting
5197 up to the msb. eg. a QImode value and we're padding
5198 upward on a BYTES_BIG_ENDIAN machine. */
5199 if (size < UNITS_PER_WORD
5200 && (argvec[argnum].locate.where_pad
5201 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5203 rtx x;
5204 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
5206 /* Assigning REG here rather than a temp makes CALL_FUSAGE
5207 report the whole reg as used. Strictly speaking, the
5208 call only uses SIZE bytes at the msb end, but it doesn't
5209 seem worth generating rtl to say that. */
5210 reg = gen_rtx_REG (word_mode, REGNO (reg));
5211 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
5212 if (x != reg)
5213 emit_move_insn (reg, x);
5215 #endif
5218 NO_DEFER_POP;
5221 /* Any regs containing parms remain in use through the call. */
5222 for (count = 0; count < nargs; count++)
5224 rtx reg = argvec[count].reg;
5225 if (reg != 0 && GET_CODE (reg) == PARALLEL)
5226 use_group_regs (&call_fusage, reg);
5227 else if (reg != 0)
5229 int partial = argvec[count].partial;
5230 if (partial)
5232 int nregs;
5233 gcc_assert (partial % UNITS_PER_WORD == 0);
5234 nregs = partial / UNITS_PER_WORD;
5235 use_regs (&call_fusage, REGNO (reg), nregs);
5237 else
5238 use_reg (&call_fusage, reg);
5242 /* Pass the function the address in which to return a structure value. */
5243 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
5245 emit_move_insn (struct_value,
5246 force_reg (Pmode,
5247 force_operand (XEXP (mem_value, 0),
5248 NULL_RTX)));
5249 if (REG_P (struct_value))
5250 use_reg (&call_fusage, struct_value);
5253 /* Don't allow popping to be deferred, since then
5254 cse'ing of library calls could delete a call and leave the pop. */
5255 NO_DEFER_POP;
5256 valreg = (mem_value == 0 && outmode != VOIDmode
5257 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
5259 /* Stack must be properly aligned now. */
5260 gcc_assert (multiple_p (stack_pointer_delta,
5261 PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT));
5263 before_call = get_last_insn ();
5265 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
5266 will set inhibit_defer_pop to that value. */
5267 /* The return type is needed to decide how many bytes the function pops.
5268 Signedness plays no role in that, so for simplicity, we pretend it's
5269 always signed. We also assume that the list of arguments passed has
5270 no impact, so we pretend it is unknown. */
5272 emit_call_1 (fun, NULL,
5273 get_identifier (XSTR (orgfun, 0)),
5274 build_function_type (tfom, NULL_TREE),
5275 original_args_size.constant, args_size.constant,
5276 struct_value_size,
5277 targetm.calls.function_arg (args_so_far,
5278 VOIDmode, void_type_node, true),
5279 valreg,
5280 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
5282 if (flag_ipa_ra)
5284 rtx datum = orgfun;
5285 gcc_assert (GET_CODE (datum) == SYMBOL_REF);
5286 rtx_call_insn *last = last_call_insn ();
5287 add_reg_note (last, REG_CALL_DECL, datum);
5290 /* Right-shift returned value if necessary. */
5291 if (!pcc_struct_value
5292 && TYPE_MODE (tfom) != BLKmode
5293 && targetm.calls.return_in_msb (tfom))
5295 shift_return_value (TYPE_MODE (tfom), false, valreg);
5296 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
5299 targetm.calls.end_call_args ();
5301 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
5302 that it should complain if nonvolatile values are live. For
5303 functions that cannot return, inform flow that control does not
5304 fall through. */
5305 if (flags & ECF_NORETURN)
5307 /* The barrier note must be emitted
5308 immediately after the CALL_INSN. Some ports emit more than
5309 just a CALL_INSN above, so we must search for it here. */
5310 rtx_insn *last = get_last_insn ();
5311 while (!CALL_P (last))
5313 last = PREV_INSN (last);
5314 /* There was no CALL_INSN? */
5315 gcc_assert (last != before_call);
5318 emit_barrier_after (last);
5321 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
5322 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
5323 if (flags & ECF_NOTHROW)
5325 rtx_insn *last = get_last_insn ();
5326 while (!CALL_P (last))
5328 last = PREV_INSN (last);
5329 /* There was no CALL_INSN? */
5330 gcc_assert (last != before_call);
5333 make_reg_eh_region_note_nothrow_nononlocal (last);
5336 /* Now restore inhibit_defer_pop to its actual original value. */
5337 OK_DEFER_POP;
5339 pop_temp_slots ();
5341 /* Copy the value to the right place. */
5342 if (outmode != VOIDmode && retval)
5344 if (mem_value)
5346 if (value == 0)
5347 value = mem_value;
5348 if (value != mem_value)
5349 emit_move_insn (value, mem_value);
5351 else if (GET_CODE (valreg) == PARALLEL)
5353 if (value == 0)
5354 value = gen_reg_rtx (outmode);
5355 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
5357 else
5359 /* Convert to the proper mode if a promotion has been active. */
5360 if (GET_MODE (valreg) != outmode)
5362 int unsignedp = TYPE_UNSIGNED (tfom);
5364 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
5365 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
5366 == GET_MODE (valreg));
5367 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
5370 if (value != 0)
5371 emit_move_insn (value, valreg);
5372 else
5373 value = valreg;
5377 if (ACCUMULATE_OUTGOING_ARGS)
5379 #ifdef REG_PARM_STACK_SPACE
5380 if (save_area)
5381 restore_fixed_argument_area (save_area, argblock,
5382 high_to_save, low_to_save);
5383 #endif
5385 /* If we saved any argument areas, restore them. */
5386 for (count = 0; count < nargs; count++)
5387 if (argvec[count].save_area)
5389 machine_mode save_mode = GET_MODE (argvec[count].save_area);
5390 rtx adr = plus_constant (Pmode, argblock,
5391 argvec[count].locate.offset.constant);
5392 rtx stack_area = gen_rtx_MEM (save_mode,
5393 memory_address (save_mode, adr));
5395 if (save_mode == BLKmode)
5396 emit_block_move (stack_area,
5397 validize_mem
5398 (copy_rtx (argvec[count].save_area)),
5399 (gen_int_mode
5400 (argvec[count].locate.size.constant, Pmode)),
5401 BLOCK_OP_CALL_PARM);
5402 else
5403 emit_move_insn (stack_area, argvec[count].save_area);
5406 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
5407 stack_usage_map = initial_stack_usage_map;
5408 stack_usage_watermark = initial_stack_usage_watermark;
5411 free (stack_usage_map_buf);
5413 return value;
5418 /* Store pointer bounds argument ARG into Bounds Table entry
5419 associated with PARM. */
5420 static void
5421 store_bounds (struct arg_data *arg, struct arg_data *parm)
5423 rtx slot = NULL, ptr = NULL, addr = NULL;
5425 /* We may pass bounds not associated with any pointer. */
5426 if (!parm)
5428 gcc_assert (arg->special_slot);
5429 slot = arg->special_slot;
5430 ptr = const0_rtx;
5432 /* Find pointer associated with bounds and where it is
5433 passed. */
5434 else
5436 if (!parm->reg)
5438 gcc_assert (!arg->special_slot);
5440 addr = adjust_address (parm->stack, Pmode, arg->pointer_offset);
5442 else if (REG_P (parm->reg))
5444 gcc_assert (arg->special_slot);
5445 slot = arg->special_slot;
5447 if (MEM_P (parm->value))
5448 addr = adjust_address (parm->value, Pmode, arg->pointer_offset);
5449 else if (REG_P (parm->value))
5450 ptr = gen_rtx_SUBREG (Pmode, parm->value, arg->pointer_offset);
5451 else
5453 gcc_assert (!arg->pointer_offset);
5454 ptr = parm->value;
5457 else
5459 gcc_assert (GET_CODE (parm->reg) == PARALLEL);
5461 gcc_assert (arg->special_slot);
5462 slot = arg->special_slot;
5464 if (parm->parallel_value)
5465 ptr = chkp_get_value_with_offs (parm->parallel_value,
5466 GEN_INT (arg->pointer_offset));
5467 else
5468 gcc_unreachable ();
5472 /* Expand bounds. */
5473 if (!arg->value)
5474 arg->value = expand_normal (arg->tree_value);
5476 targetm.calls.store_bounds_for_arg (ptr, addr, arg->value, slot);
5479 /* Store a single argument for a function call
5480 into the register or memory area where it must be passed.
5481 *ARG describes the argument value and where to pass it.
5483 ARGBLOCK is the address of the stack-block for all the arguments,
5484 or 0 on a machine where arguments are pushed individually.
5486 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
5487 so must be careful about how the stack is used.
5489 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
5490 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
5491 that we need not worry about saving and restoring the stack.
5493 FNDECL is the declaration of the function we are calling.
5495 Return nonzero if this arg should cause sibcall failure,
5496 zero otherwise. */
5498 static int
5499 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
5500 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
5502 tree pval = arg->tree_value;
5503 rtx reg = 0;
5504 int partial = 0;
5505 poly_int64 used = 0;
5506 poly_int64 lower_bound = 0, upper_bound = 0;
5507 int sibcall_failure = 0;
5509 if (TREE_CODE (pval) == ERROR_MARK)
5510 return 1;
5512 /* Push a new temporary level for any temporaries we make for
5513 this argument. */
5514 push_temp_slots ();
5516 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
5518 /* If this is being stored into a pre-allocated, fixed-size, stack area,
5519 save any previous data at that location. */
5520 if (argblock && ! variable_size && arg->stack)
5522 if (ARGS_GROW_DOWNWARD)
5524 /* stack_slot is negative, but we want to index stack_usage_map
5525 with positive values. */
5526 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5528 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5529 upper_bound = -rtx_to_poly_int64 (offset) + 1;
5531 else
5532 upper_bound = 0;
5534 lower_bound = upper_bound - arg->locate.size.constant;
5536 else
5538 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
5540 rtx offset = XEXP (XEXP (arg->stack_slot, 0), 1);
5541 lower_bound = rtx_to_poly_int64 (offset);
5543 else
5544 lower_bound = 0;
5546 upper_bound = lower_bound + arg->locate.size.constant;
5549 if (stack_region_maybe_used_p (lower_bound, upper_bound,
5550 reg_parm_stack_space))
5552 /* We need to make a save area. */
5553 poly_uint64 size = arg->locate.size.constant * BITS_PER_UNIT;
5554 machine_mode save_mode
5555 = int_mode_for_size (size, 1).else_blk ();
5556 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
5557 rtx stack_area = gen_rtx_MEM (save_mode, adr);
5559 if (save_mode == BLKmode)
5561 arg->save_area
5562 = assign_temp (TREE_TYPE (arg->tree_value), 1, 1);
5563 preserve_temp_slots (arg->save_area);
5564 emit_block_move (validize_mem (copy_rtx (arg->save_area)),
5565 stack_area,
5566 (gen_int_mode
5567 (arg->locate.size.constant, Pmode)),
5568 BLOCK_OP_CALL_PARM);
5570 else
5572 arg->save_area = gen_reg_rtx (save_mode);
5573 emit_move_insn (arg->save_area, stack_area);
5579 /* If this isn't going to be placed on both the stack and in registers,
5580 set up the register and number of words. */
5581 if (! arg->pass_on_stack)
5583 if (flags & ECF_SIBCALL)
5584 reg = arg->tail_call_reg;
5585 else
5586 reg = arg->reg;
5587 partial = arg->partial;
5590 /* Being passed entirely in a register. We shouldn't be called in
5591 this case. */
5592 gcc_assert (reg == 0 || partial != 0);
5594 /* If this arg needs special alignment, don't load the registers
5595 here. */
5596 if (arg->n_aligned_regs != 0)
5597 reg = 0;
5599 /* If this is being passed partially in a register, we can't evaluate
5600 it directly into its stack slot. Otherwise, we can. */
5601 if (arg->value == 0)
5603 /* stack_arg_under_construction is nonzero if a function argument is
5604 being evaluated directly into the outgoing argument list and
5605 expand_call must take special action to preserve the argument list
5606 if it is called recursively.
5608 For scalar function arguments stack_usage_map is sufficient to
5609 determine which stack slots must be saved and restored. Scalar
5610 arguments in general have pass_on_stack == 0.
5612 If this argument is initialized by a function which takes the
5613 address of the argument (a C++ constructor or a C function
5614 returning a BLKmode structure), then stack_usage_map is
5615 insufficient and expand_call must push the stack around the
5616 function call. Such arguments have pass_on_stack == 1.
5618 Note that it is always safe to set stack_arg_under_construction,
5619 but this generates suboptimal code if set when not needed. */
5621 if (arg->pass_on_stack)
5622 stack_arg_under_construction++;
5624 arg->value = expand_expr (pval,
5625 (partial
5626 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
5627 ? NULL_RTX : arg->stack,
5628 VOIDmode, EXPAND_STACK_PARM);
5630 /* If we are promoting object (or for any other reason) the mode
5631 doesn't agree, convert the mode. */
5633 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
5634 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
5635 arg->value, arg->unsignedp);
5637 if (arg->pass_on_stack)
5638 stack_arg_under_construction--;
5641 /* Check for overlap with already clobbered argument area. */
5642 if ((flags & ECF_SIBCALL)
5643 && MEM_P (arg->value)
5644 && mem_might_overlap_already_clobbered_arg_p (XEXP (arg->value, 0),
5645 arg->locate.size.constant))
5646 sibcall_failure = 1;
5648 /* Don't allow anything left on stack from computation
5649 of argument to alloca. */
5650 if (flags & ECF_MAY_BE_ALLOCA)
5651 do_pending_stack_adjust ();
5653 if (arg->value == arg->stack)
5654 /* If the value is already in the stack slot, we are done. */
5656 else if (arg->mode != BLKmode)
5658 unsigned int parm_align;
5660 /* Argument is a scalar, not entirely passed in registers.
5661 (If part is passed in registers, arg->partial says how much
5662 and emit_push_insn will take care of putting it there.)
5664 Push it, and if its size is less than the
5665 amount of space allocated to it,
5666 also bump stack pointer by the additional space.
5667 Note that in C the default argument promotions
5668 will prevent such mismatches. */
5670 poly_int64 size = (TYPE_EMPTY_P (TREE_TYPE (pval))
5671 ? 0 : GET_MODE_SIZE (arg->mode));
5673 /* Compute how much space the push instruction will push.
5674 On many machines, pushing a byte will advance the stack
5675 pointer by a halfword. */
5676 #ifdef PUSH_ROUNDING
5677 size = PUSH_ROUNDING (size);
5678 #endif
5679 used = size;
5681 /* Compute how much space the argument should get:
5682 round up to a multiple of the alignment for arguments. */
5683 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5684 != PAD_NONE)
5685 /* At the moment we don't (need to) support ABIs for which the
5686 padding isn't known at compile time. In principle it should
5687 be easy to add though. */
5688 used = force_align_up (size, PARM_BOUNDARY / BITS_PER_UNIT);
5690 /* Compute the alignment of the pushed argument. */
5691 parm_align = arg->locate.boundary;
5692 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5693 == PAD_DOWNWARD)
5695 poly_int64 pad = used - size;
5696 unsigned int pad_align = known_alignment (pad) * BITS_PER_UNIT;
5697 if (pad_align != 0)
5698 parm_align = MIN (parm_align, pad_align);
5701 /* This isn't already where we want it on the stack, so put it there.
5702 This can either be done with push or copy insns. */
5703 if (maybe_ne (used, 0)
5704 && !emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval),
5705 NULL_RTX, parm_align, partial, reg, used - size,
5706 argblock, ARGS_SIZE_RTX (arg->locate.offset),
5707 reg_parm_stack_space,
5708 ARGS_SIZE_RTX (arg->locate.alignment_pad), true))
5709 sibcall_failure = 1;
5711 /* Unless this is a partially-in-register argument, the argument is now
5712 in the stack. */
5713 if (partial == 0)
5714 arg->value = arg->stack;
5716 else
5718 /* BLKmode, at least partly to be pushed. */
5720 unsigned int parm_align;
5721 poly_int64 excess;
5722 rtx size_rtx;
5724 /* Pushing a nonscalar.
5725 If part is passed in registers, PARTIAL says how much
5726 and emit_push_insn will take care of putting it there. */
5728 /* Round its size up to a multiple
5729 of the allocation unit for arguments. */
5731 if (arg->locate.size.var != 0)
5733 excess = 0;
5734 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
5736 else
5738 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
5739 for BLKmode is careful to avoid it. */
5740 excess = (arg->locate.size.constant
5741 - arg_int_size_in_bytes (TREE_TYPE (pval))
5742 + partial);
5743 size_rtx = expand_expr (arg_size_in_bytes (TREE_TYPE (pval)),
5744 NULL_RTX, TYPE_MODE (sizetype),
5745 EXPAND_NORMAL);
5748 parm_align = arg->locate.boundary;
5750 /* When an argument is padded down, the block is aligned to
5751 PARM_BOUNDARY, but the actual argument isn't. */
5752 if (targetm.calls.function_arg_padding (arg->mode, TREE_TYPE (pval))
5753 == PAD_DOWNWARD)
5755 if (arg->locate.size.var)
5756 parm_align = BITS_PER_UNIT;
5757 else
5759 unsigned int excess_align
5760 = known_alignment (excess) * BITS_PER_UNIT;
5761 if (excess_align != 0)
5762 parm_align = MIN (parm_align, excess_align);
5766 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
5768 /* emit_push_insn might not work properly if arg->value and
5769 argblock + arg->locate.offset areas overlap. */
5770 rtx x = arg->value;
5771 poly_int64 i = 0;
5773 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
5774 || (GET_CODE (XEXP (x, 0)) == PLUS
5775 && XEXP (XEXP (x, 0), 0) ==
5776 crtl->args.internal_arg_pointer
5777 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
5779 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
5780 i = rtx_to_poly_int64 (XEXP (XEXP (x, 0), 1));
5782 /* arg.locate doesn't contain the pretend_args_size offset,
5783 it's part of argblock. Ensure we don't count it in I. */
5784 if (STACK_GROWS_DOWNWARD)
5785 i -= crtl->args.pretend_args_size;
5786 else
5787 i += crtl->args.pretend_args_size;
5789 /* expand_call should ensure this. */
5790 gcc_assert (!arg->locate.offset.var
5791 && arg->locate.size.var == 0);
5792 poly_int64 size_val = rtx_to_poly_int64 (size_rtx);
5794 if (known_eq (arg->locate.offset.constant, i))
5796 /* Even though they appear to be at the same location,
5797 if part of the outgoing argument is in registers,
5798 they aren't really at the same location. Check for
5799 this by making sure that the incoming size is the
5800 same as the outgoing size. */
5801 if (maybe_ne (arg->locate.size.constant, size_val))
5802 sibcall_failure = 1;
5804 else if (maybe_in_range_p (arg->locate.offset.constant,
5805 i, size_val))
5806 sibcall_failure = 1;
5807 /* Use arg->locate.size.constant instead of size_rtx
5808 because we only care about the part of the argument
5809 on the stack. */
5810 else if (maybe_in_range_p (i, arg->locate.offset.constant,
5811 arg->locate.size.constant))
5812 sibcall_failure = 1;
5816 if (!CONST_INT_P (size_rtx) || INTVAL (size_rtx) != 0)
5817 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
5818 parm_align, partial, reg, excess, argblock,
5819 ARGS_SIZE_RTX (arg->locate.offset),
5820 reg_parm_stack_space,
5821 ARGS_SIZE_RTX (arg->locate.alignment_pad), false);
5823 /* Unless this is a partially-in-register argument, the argument is now
5824 in the stack.
5826 ??? Unlike the case above, in which we want the actual
5827 address of the data, so that we can load it directly into a
5828 register, here we want the address of the stack slot, so that
5829 it's properly aligned for word-by-word copying or something
5830 like that. It's not clear that this is always correct. */
5831 if (partial == 0)
5832 arg->value = arg->stack_slot;
5835 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
5837 tree type = TREE_TYPE (arg->tree_value);
5838 arg->parallel_value
5839 = emit_group_load_into_temps (arg->reg, arg->value, type,
5840 int_size_in_bytes (type));
5843 /* Mark all slots this store used. */
5844 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
5845 && argblock && ! variable_size && arg->stack)
5846 mark_stack_region_used (lower_bound, upper_bound);
5848 /* Once we have pushed something, pops can't safely
5849 be deferred during the rest of the arguments. */
5850 NO_DEFER_POP;
5852 /* Free any temporary slots made in processing this argument. */
5853 pop_temp_slots ();
5855 return sibcall_failure;
5858 /* Nonzero if we do not know how to pass TYPE solely in registers. */
5860 bool
5861 must_pass_in_stack_var_size (machine_mode mode ATTRIBUTE_UNUSED,
5862 const_tree type)
5864 if (!type)
5865 return false;
5867 /* If the type has variable size... */
5868 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5869 return true;
5871 /* If the type is marked as addressable (it is required
5872 to be constructed into the stack)... */
5873 if (TREE_ADDRESSABLE (type))
5874 return true;
5876 return false;
5879 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
5880 takes trailing padding of a structure into account. */
5881 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
5883 bool
5884 must_pass_in_stack_var_size_or_pad (machine_mode mode, const_tree type)
5886 if (!type)
5887 return false;
5889 /* If the type has variable size... */
5890 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
5891 return true;
5893 /* If the type is marked as addressable (it is required
5894 to be constructed into the stack)... */
5895 if (TREE_ADDRESSABLE (type))
5896 return true;
5898 if (TYPE_EMPTY_P (type))
5899 return false;
5901 /* If the padding and mode of the type is such that a copy into
5902 a register would put it into the wrong part of the register. */
5903 if (mode == BLKmode
5904 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
5905 && (targetm.calls.function_arg_padding (mode, type)
5906 == (BYTES_BIG_ENDIAN ? PAD_UPWARD : PAD_DOWNWARD)))
5907 return true;
5909 return false;
5912 /* Tell the garbage collector about GTY markers in this source file. */
5913 #include "gt-calls.h"