re PR target/57744 (Power8 support has problems with quad word atomic instructions)
[official-gcc.git] / gcc / calls.c
blob0c7f22566bca805af477585aaa0991f2a8bce27a
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989-2013 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 "tm.h"
24 #include "rtl.h"
25 #include "tree.h"
26 #include "gimple.h"
27 #include "flags.h"
28 #include "expr.h"
29 #include "optabs.h"
30 #include "libfuncs.h"
31 #include "function.h"
32 #include "regs.h"
33 #include "diagnostic-core.h"
34 #include "output.h"
35 #include "tm_p.h"
36 #include "timevar.h"
37 #include "sbitmap.h"
38 #include "langhooks.h"
39 #include "target.h"
40 #include "cgraph.h"
41 #include "except.h"
42 #include "dbgcnt.h"
43 #include "tree-flow.h"
45 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
46 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
48 /* Data structure and subroutines used within expand_call. */
50 struct arg_data
52 /* Tree node for this argument. */
53 tree tree_value;
54 /* Mode for value; TYPE_MODE unless promoted. */
55 enum machine_mode mode;
56 /* Current RTL value for argument, or 0 if it isn't precomputed. */
57 rtx value;
58 /* Initially-compute RTL value for argument; only for const functions. */
59 rtx initial_value;
60 /* Register to pass this argument in, 0 if passed on stack, or an
61 PARALLEL if the arg is to be copied into multiple non-contiguous
62 registers. */
63 rtx reg;
64 /* Register to pass this argument in when generating tail call sequence.
65 This is not the same register as for normal calls on machines with
66 register windows. */
67 rtx tail_call_reg;
68 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
69 form for emit_group_move. */
70 rtx parallel_value;
71 /* If REG was promoted from the actual mode of the argument expression,
72 indicates whether the promotion is sign- or zero-extended. */
73 int unsignedp;
74 /* Number of bytes to put in registers. 0 means put the whole arg
75 in registers. Also 0 if not passed in registers. */
76 int partial;
77 /* Nonzero if argument must be passed on stack.
78 Note that some arguments may be passed on the stack
79 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
80 pass_on_stack identifies arguments that *cannot* go in registers. */
81 int pass_on_stack;
82 /* Some fields packaged up for locate_and_pad_parm. */
83 struct locate_and_pad_arg_data locate;
84 /* Location on the stack at which parameter should be stored. The store
85 has already been done if STACK == VALUE. */
86 rtx stack;
87 /* Location on the stack of the start of this argument slot. This can
88 differ from STACK if this arg pads downward. This location is known
89 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
90 rtx stack_slot;
91 /* Place that this stack area has been saved, if needed. */
92 rtx save_area;
93 /* If an argument's alignment does not permit direct copying into registers,
94 copy in smaller-sized pieces into pseudos. These are stored in a
95 block pointed to by this field. The next field says how many
96 word-sized pseudos we made. */
97 rtx *aligned_regs;
98 int n_aligned_regs;
101 /* A vector of one char per byte of stack space. A byte if nonzero if
102 the corresponding stack location has been used.
103 This vector is used to prevent a function call within an argument from
104 clobbering any stack already set up. */
105 static char *stack_usage_map;
107 /* Size of STACK_USAGE_MAP. */
108 static int highest_outgoing_arg_in_use;
110 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
111 stack location's tail call argument has been already stored into the stack.
112 This bitmap is used to prevent sibling call optimization if function tries
113 to use parent's incoming argument slots when they have been already
114 overwritten with tail call arguments. */
115 static sbitmap stored_args_map;
117 /* stack_arg_under_construction is nonzero when an argument may be
118 initialized with a constructor call (including a C function that
119 returns a BLKmode struct) and expand_call must take special action
120 to make sure the object being constructed does not overlap the
121 argument list for the constructor call. */
122 static int stack_arg_under_construction;
124 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
125 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
126 cumulative_args_t);
127 static void precompute_register_parameters (int, struct arg_data *, int *);
128 static int store_one_arg (struct arg_data *, rtx, int, int, int);
129 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
130 static int finalize_must_preallocate (int, int, struct arg_data *,
131 struct args_size *);
132 static void precompute_arguments (int, struct arg_data *);
133 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
134 static void initialize_argument_information (int, struct arg_data *,
135 struct args_size *, int,
136 tree, tree,
137 tree, tree, cumulative_args_t, int,
138 rtx *, int *, int *, int *,
139 bool *, bool);
140 static void compute_argument_addresses (struct arg_data *, rtx, int);
141 static rtx rtx_for_function_call (tree, tree);
142 static void load_register_parameters (struct arg_data *, int, rtx *, int,
143 int, int *);
144 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
145 enum machine_mode, int, va_list);
146 static int special_function_p (const_tree, int);
147 static int check_sibcall_argument_overlap_1 (rtx);
148 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
150 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
151 unsigned int);
152 static tree split_complex_types (tree);
154 #ifdef REG_PARM_STACK_SPACE
155 static rtx save_fixed_argument_area (int, rtx, int *, int *);
156 static void restore_fixed_argument_area (rtx, rtx, int, int);
157 #endif
159 /* Force FUNEXP into a form suitable for the address of a CALL,
160 and return that as an rtx. Also load the static chain register
161 if FNDECL is a nested function.
163 CALL_FUSAGE points to a variable holding the prospective
164 CALL_INSN_FUNCTION_USAGE information. */
167 prepare_call_address (tree fndecl, rtx funexp, rtx static_chain_value,
168 rtx *call_fusage, int reg_parm_seen, int sibcallp)
170 /* Make a valid memory address and copy constants through pseudo-regs,
171 but not for a constant address if -fno-function-cse. */
172 if (GET_CODE (funexp) != SYMBOL_REF)
173 /* If we are using registers for parameters, force the
174 function address into a register now. */
175 funexp = ((reg_parm_seen
176 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
177 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
178 : memory_address (FUNCTION_MODE, funexp));
179 else if (! sibcallp)
181 #ifndef NO_FUNCTION_CSE
182 if (optimize && ! flag_no_function_cse)
183 funexp = force_reg (Pmode, funexp);
184 #endif
187 if (static_chain_value != 0)
189 rtx chain;
191 gcc_assert (fndecl);
192 chain = targetm.calls.static_chain (fndecl, false);
193 static_chain_value = convert_memory_address (Pmode, static_chain_value);
195 emit_move_insn (chain, static_chain_value);
196 if (REG_P (chain))
197 use_reg (call_fusage, chain);
200 return funexp;
203 /* Generate instructions to call function FUNEXP,
204 and optionally pop the results.
205 The CALL_INSN is the first insn generated.
207 FNDECL is the declaration node of the function. This is given to the
208 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
209 its own args.
211 FUNTYPE is the data type of the function. This is given to the hook
212 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
213 own args. We used to allow an identifier for library functions, but
214 that doesn't work when the return type is an aggregate type and the
215 calling convention says that the pointer to this aggregate is to be
216 popped by the callee.
218 STACK_SIZE is the number of bytes of arguments on the stack,
219 ROUNDED_STACK_SIZE is that number rounded up to
220 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
221 both to put into the call insn and to generate explicit popping
222 code if necessary.
224 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
225 It is zero if this call doesn't want a structure value.
227 NEXT_ARG_REG is the rtx that results from executing
228 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
229 just after all the args have had their registers assigned.
230 This could be whatever you like, but normally it is the first
231 arg-register beyond those used for args in this call,
232 or 0 if all the arg-registers are used in this call.
233 It is passed on to `gen_call' so you can put this info in the call insn.
235 VALREG is a hard register in which a value is returned,
236 or 0 if the call does not return a value.
238 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
239 the args to this call were processed.
240 We restore `inhibit_defer_pop' to that value.
242 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
243 denote registers used by the called function. */
245 static void
246 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
247 tree funtype ATTRIBUTE_UNUSED,
248 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
249 HOST_WIDE_INT rounded_stack_size,
250 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
251 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
252 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
253 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
255 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
256 rtx call_insn, call, funmem;
257 int already_popped = 0;
258 HOST_WIDE_INT n_popped
259 = targetm.calls.return_pops_args (fndecl, funtype, stack_size);
261 #ifdef CALL_POPS_ARGS
262 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
263 #endif
265 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
266 and we don't want to load it into a register as an optimization,
267 because prepare_call_address already did it if it should be done. */
268 if (GET_CODE (funexp) != SYMBOL_REF)
269 funexp = memory_address (FUNCTION_MODE, funexp);
271 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
272 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
274 tree t = fndecl;
276 /* Although a built-in FUNCTION_DECL and its non-__builtin
277 counterpart compare equal and get a shared mem_attrs, they
278 produce different dump output in compare-debug compilations,
279 if an entry gets garbage collected in one compilation, then
280 adds a different (but equivalent) entry, while the other
281 doesn't run the garbage collector at the same spot and then
282 shares the mem_attr with the equivalent entry. */
283 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
285 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
286 if (t2)
287 t = t2;
290 set_mem_expr (funmem, t);
292 else if (fntree)
293 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
295 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
296 if ((ecf_flags & ECF_SIBCALL)
297 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
298 && (n_popped > 0 || stack_size == 0))
300 rtx n_pop = GEN_INT (n_popped);
301 rtx pat;
303 /* If this subroutine pops its own args, record that in the call insn
304 if possible, for the sake of frame pointer elimination. */
306 if (valreg)
307 pat = GEN_SIBCALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
308 next_arg_reg, n_pop);
309 else
310 pat = GEN_SIBCALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
311 n_pop);
313 emit_call_insn (pat);
314 already_popped = 1;
316 else
317 #endif
319 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
320 /* If the target has "call" or "call_value" insns, then prefer them
321 if no arguments are actually popped. If the target does not have
322 "call" or "call_value" insns, then we must use the popping versions
323 even if the call has no arguments to pop. */
324 #if defined (HAVE_call) && defined (HAVE_call_value)
325 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
326 && n_popped > 0)
327 #else
328 if (HAVE_call_pop && HAVE_call_value_pop)
329 #endif
331 rtx n_pop = GEN_INT (n_popped);
332 rtx pat;
334 /* If this subroutine pops its own args, record that in the call insn
335 if possible, for the sake of frame pointer elimination. */
337 if (valreg)
338 pat = GEN_CALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
339 next_arg_reg, n_pop);
340 else
341 pat = GEN_CALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
342 n_pop);
344 emit_call_insn (pat);
345 already_popped = 1;
347 else
348 #endif
350 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
351 if ((ecf_flags & ECF_SIBCALL)
352 && HAVE_sibcall && HAVE_sibcall_value)
354 if (valreg)
355 emit_call_insn (GEN_SIBCALL_VALUE (valreg, funmem,
356 rounded_stack_size_rtx,
357 next_arg_reg, NULL_RTX));
358 else
359 emit_call_insn (GEN_SIBCALL (funmem, rounded_stack_size_rtx,
360 next_arg_reg,
361 GEN_INT (struct_value_size)));
363 else
364 #endif
366 #if defined (HAVE_call) && defined (HAVE_call_value)
367 if (HAVE_call && HAVE_call_value)
369 if (valreg)
370 emit_call_insn (GEN_CALL_VALUE (valreg, funmem, rounded_stack_size_rtx,
371 next_arg_reg, NULL_RTX));
372 else
373 emit_call_insn (GEN_CALL (funmem, rounded_stack_size_rtx, next_arg_reg,
374 GEN_INT (struct_value_size)));
376 else
377 #endif
378 gcc_unreachable ();
380 /* Find the call we just emitted. */
381 call_insn = last_call_insn ();
383 /* Some target create a fresh MEM instead of reusing the one provided
384 above. Set its MEM_EXPR. */
385 call = get_call_rtx_from (call_insn);
386 if (call
387 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
388 && MEM_EXPR (funmem) != NULL_TREE)
389 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
391 /* Put the register usage information there. */
392 add_function_usage_to (call_insn, call_fusage);
394 /* If this is a const call, then set the insn's unchanging bit. */
395 if (ecf_flags & ECF_CONST)
396 RTL_CONST_CALL_P (call_insn) = 1;
398 /* If this is a pure call, then set the insn's unchanging bit. */
399 if (ecf_flags & ECF_PURE)
400 RTL_PURE_CALL_P (call_insn) = 1;
402 /* If this is a const call, then set the insn's unchanging bit. */
403 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
404 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
406 /* Create a nothrow REG_EH_REGION note, if needed. */
407 make_reg_eh_region_note (call_insn, ecf_flags, 0);
409 if (ecf_flags & ECF_NORETURN)
410 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
412 if (ecf_flags & ECF_RETURNS_TWICE)
414 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
415 cfun->calls_setjmp = 1;
418 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
420 /* Restore this now, so that we do defer pops for this call's args
421 if the context of the call as a whole permits. */
422 inhibit_defer_pop = old_inhibit_defer_pop;
424 if (n_popped > 0)
426 if (!already_popped)
427 CALL_INSN_FUNCTION_USAGE (call_insn)
428 = gen_rtx_EXPR_LIST (VOIDmode,
429 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
430 CALL_INSN_FUNCTION_USAGE (call_insn));
431 rounded_stack_size -= n_popped;
432 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
433 stack_pointer_delta -= n_popped;
435 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
437 /* If popup is needed, stack realign must use DRAP */
438 if (SUPPORTS_STACK_ALIGNMENT)
439 crtl->need_drap = true;
441 /* For noreturn calls when not accumulating outgoing args force
442 REG_ARGS_SIZE note to prevent crossjumping of calls with different
443 args sizes. */
444 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
445 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
447 if (!ACCUMULATE_OUTGOING_ARGS)
449 /* If returning from the subroutine does not automatically pop the args,
450 we need an instruction to pop them sooner or later.
451 Perhaps do it now; perhaps just record how much space to pop later.
453 If returning from the subroutine does pop the args, indicate that the
454 stack pointer will be changed. */
456 if (rounded_stack_size != 0)
458 if (ecf_flags & ECF_NORETURN)
459 /* Just pretend we did the pop. */
460 stack_pointer_delta -= rounded_stack_size;
461 else if (flag_defer_pop && inhibit_defer_pop == 0
462 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
463 pending_stack_adjust += rounded_stack_size;
464 else
465 adjust_stack (rounded_stack_size_rtx);
468 /* When we accumulate outgoing args, we must avoid any stack manipulations.
469 Restore the stack pointer to its original value now. Usually
470 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
471 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
472 popping variants of functions exist as well.
474 ??? We may optimize similar to defer_pop above, but it is
475 probably not worthwhile.
477 ??? It will be worthwhile to enable combine_stack_adjustments even for
478 such machines. */
479 else if (n_popped)
480 anti_adjust_stack (GEN_INT (n_popped));
483 /* Determine if the function identified by NAME and FNDECL is one with
484 special properties we wish to know about.
486 For example, if the function might return more than one time (setjmp), then
487 set RETURNS_TWICE to a nonzero value.
489 Similarly set NORETURN if the function is in the longjmp family.
491 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
492 space from the stack such as alloca. */
494 static int
495 special_function_p (const_tree fndecl, int flags)
497 if (fndecl && DECL_NAME (fndecl)
498 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
499 /* Exclude functions not at the file scope, or not `extern',
500 since they are not the magic functions we would otherwise
501 think they are.
502 FIXME: this should be handled with attributes, not with this
503 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
504 because you can declare fork() inside a function if you
505 wish. */
506 && (DECL_CONTEXT (fndecl) == NULL_TREE
507 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
508 && TREE_PUBLIC (fndecl))
510 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
511 const char *tname = name;
513 /* We assume that alloca will always be called by name. It
514 makes no sense to pass it as a pointer-to-function to
515 anything that does not understand its behavior. */
516 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
517 && name[0] == 'a'
518 && ! strcmp (name, "alloca"))
519 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
520 && name[0] == '_'
521 && ! strcmp (name, "__builtin_alloca"))))
522 flags |= ECF_MAY_BE_ALLOCA;
524 /* Disregard prefix _, __, __x or __builtin_. */
525 if (name[0] == '_')
527 if (name[1] == '_'
528 && name[2] == 'b'
529 && !strncmp (name + 3, "uiltin_", 7))
530 tname += 10;
531 else if (name[1] == '_' && name[2] == 'x')
532 tname += 3;
533 else if (name[1] == '_')
534 tname += 2;
535 else
536 tname += 1;
539 if (tname[0] == 's')
541 if ((tname[1] == 'e'
542 && (! strcmp (tname, "setjmp")
543 || ! strcmp (tname, "setjmp_syscall")))
544 || (tname[1] == 'i'
545 && ! strcmp (tname, "sigsetjmp"))
546 || (tname[1] == 'a'
547 && ! strcmp (tname, "savectx")))
548 flags |= ECF_RETURNS_TWICE | ECF_LEAF;
550 if (tname[1] == 'i'
551 && ! strcmp (tname, "siglongjmp"))
552 flags |= ECF_NORETURN;
554 else if ((tname[0] == 'q' && tname[1] == 's'
555 && ! strcmp (tname, "qsetjmp"))
556 || (tname[0] == 'v' && tname[1] == 'f'
557 && ! strcmp (tname, "vfork"))
558 || (tname[0] == 'g' && tname[1] == 'e'
559 && !strcmp (tname, "getcontext")))
560 flags |= ECF_RETURNS_TWICE | ECF_LEAF;
562 else if (tname[0] == 'l' && tname[1] == 'o'
563 && ! strcmp (tname, "longjmp"))
564 flags |= ECF_NORETURN;
567 return flags;
570 /* Similar to special_function_p; return a set of ERF_ flags for the
571 function FNDECL. */
572 static int
573 decl_return_flags (tree fndecl)
575 tree attr;
576 tree type = TREE_TYPE (fndecl);
577 if (!type)
578 return 0;
580 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
581 if (!attr)
582 return 0;
584 attr = TREE_VALUE (TREE_VALUE (attr));
585 if (!attr || TREE_STRING_LENGTH (attr) < 1)
586 return 0;
588 switch (TREE_STRING_POINTER (attr)[0])
590 case '1':
591 case '2':
592 case '3':
593 case '4':
594 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
596 case 'm':
597 return ERF_NOALIAS;
599 case '.':
600 default:
601 return 0;
605 /* Return nonzero when FNDECL represents a call to setjmp. */
608 setjmp_call_p (const_tree fndecl)
610 if (DECL_IS_RETURNS_TWICE (fndecl))
611 return ECF_RETURNS_TWICE;
612 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
616 /* Return true if STMT is an alloca call. */
618 bool
619 gimple_alloca_call_p (const_gimple stmt)
621 tree fndecl;
623 if (!is_gimple_call (stmt))
624 return false;
626 fndecl = gimple_call_fndecl (stmt);
627 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
628 return true;
630 return false;
633 /* Return true when exp contains alloca call. */
635 bool
636 alloca_call_p (const_tree exp)
638 if (TREE_CODE (exp) == CALL_EXPR
639 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
640 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
641 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
642 & ECF_MAY_BE_ALLOCA))
643 return true;
644 return false;
647 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
648 function. Return FALSE otherwise. */
650 static bool
651 is_tm_builtin (const_tree fndecl)
653 if (fndecl == NULL)
654 return false;
656 if (decl_is_tm_clone (fndecl))
657 return true;
659 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
661 switch (DECL_FUNCTION_CODE (fndecl))
663 case BUILT_IN_TM_COMMIT:
664 case BUILT_IN_TM_COMMIT_EH:
665 case BUILT_IN_TM_ABORT:
666 case BUILT_IN_TM_IRREVOCABLE:
667 case BUILT_IN_TM_GETTMCLONE_IRR:
668 case BUILT_IN_TM_MEMCPY:
669 case BUILT_IN_TM_MEMMOVE:
670 case BUILT_IN_TM_MEMSET:
671 CASE_BUILT_IN_TM_STORE (1):
672 CASE_BUILT_IN_TM_STORE (2):
673 CASE_BUILT_IN_TM_STORE (4):
674 CASE_BUILT_IN_TM_STORE (8):
675 CASE_BUILT_IN_TM_STORE (FLOAT):
676 CASE_BUILT_IN_TM_STORE (DOUBLE):
677 CASE_BUILT_IN_TM_STORE (LDOUBLE):
678 CASE_BUILT_IN_TM_STORE (M64):
679 CASE_BUILT_IN_TM_STORE (M128):
680 CASE_BUILT_IN_TM_STORE (M256):
681 CASE_BUILT_IN_TM_LOAD (1):
682 CASE_BUILT_IN_TM_LOAD (2):
683 CASE_BUILT_IN_TM_LOAD (4):
684 CASE_BUILT_IN_TM_LOAD (8):
685 CASE_BUILT_IN_TM_LOAD (FLOAT):
686 CASE_BUILT_IN_TM_LOAD (DOUBLE):
687 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
688 CASE_BUILT_IN_TM_LOAD (M64):
689 CASE_BUILT_IN_TM_LOAD (M128):
690 CASE_BUILT_IN_TM_LOAD (M256):
691 case BUILT_IN_TM_LOG:
692 case BUILT_IN_TM_LOG_1:
693 case BUILT_IN_TM_LOG_2:
694 case BUILT_IN_TM_LOG_4:
695 case BUILT_IN_TM_LOG_8:
696 case BUILT_IN_TM_LOG_FLOAT:
697 case BUILT_IN_TM_LOG_DOUBLE:
698 case BUILT_IN_TM_LOG_LDOUBLE:
699 case BUILT_IN_TM_LOG_M64:
700 case BUILT_IN_TM_LOG_M128:
701 case BUILT_IN_TM_LOG_M256:
702 return true;
703 default:
704 break;
707 return false;
710 /* Detect flags (function attributes) from the function decl or type node. */
713 flags_from_decl_or_type (const_tree exp)
715 int flags = 0;
717 if (DECL_P (exp))
719 /* The function exp may have the `malloc' attribute. */
720 if (DECL_IS_MALLOC (exp))
721 flags |= ECF_MALLOC;
723 /* The function exp may have the `returns_twice' attribute. */
724 if (DECL_IS_RETURNS_TWICE (exp))
725 flags |= ECF_RETURNS_TWICE;
727 /* Process the pure and const attributes. */
728 if (TREE_READONLY (exp))
729 flags |= ECF_CONST;
730 if (DECL_PURE_P (exp))
731 flags |= ECF_PURE;
732 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
733 flags |= ECF_LOOPING_CONST_OR_PURE;
735 if (DECL_IS_NOVOPS (exp))
736 flags |= ECF_NOVOPS;
737 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
738 flags |= ECF_LEAF;
740 if (TREE_NOTHROW (exp))
741 flags |= ECF_NOTHROW;
743 if (flag_tm)
745 if (is_tm_builtin (exp))
746 flags |= ECF_TM_BUILTIN;
747 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
748 || lookup_attribute ("transaction_pure",
749 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
750 flags |= ECF_TM_PURE;
753 flags = special_function_p (exp, flags);
755 else if (TYPE_P (exp))
757 if (TYPE_READONLY (exp))
758 flags |= ECF_CONST;
760 if (flag_tm
761 && ((flags & ECF_CONST) != 0
762 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
763 flags |= ECF_TM_PURE;
766 if (TREE_THIS_VOLATILE (exp))
768 flags |= ECF_NORETURN;
769 if (flags & (ECF_CONST|ECF_PURE))
770 flags |= ECF_LOOPING_CONST_OR_PURE;
773 return flags;
776 /* Detect flags from a CALL_EXPR. */
779 call_expr_flags (const_tree t)
781 int flags;
782 tree decl = get_callee_fndecl (t);
784 if (decl)
785 flags = flags_from_decl_or_type (decl);
786 else
788 t = TREE_TYPE (CALL_EXPR_FN (t));
789 if (t && TREE_CODE (t) == POINTER_TYPE)
790 flags = flags_from_decl_or_type (TREE_TYPE (t));
791 else
792 flags = 0;
795 return flags;
798 /* Precompute all register parameters as described by ARGS, storing values
799 into fields within the ARGS array.
801 NUM_ACTUALS indicates the total number elements in the ARGS array.
803 Set REG_PARM_SEEN if we encounter a register parameter. */
805 static void
806 precompute_register_parameters (int num_actuals, struct arg_data *args,
807 int *reg_parm_seen)
809 int i;
811 *reg_parm_seen = 0;
813 for (i = 0; i < num_actuals; i++)
814 if (args[i].reg != 0 && ! args[i].pass_on_stack)
816 *reg_parm_seen = 1;
818 if (args[i].value == 0)
820 push_temp_slots ();
821 args[i].value = expand_normal (args[i].tree_value);
822 preserve_temp_slots (args[i].value);
823 pop_temp_slots ();
826 /* If we are to promote the function arg to a wider mode,
827 do it now. */
829 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
830 args[i].value
831 = convert_modes (args[i].mode,
832 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
833 args[i].value, args[i].unsignedp);
835 /* If the value is a non-legitimate constant, force it into a
836 pseudo now. TLS symbols sometimes need a call to resolve. */
837 if (CONSTANT_P (args[i].value)
838 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
839 args[i].value = force_reg (args[i].mode, args[i].value);
841 /* If we're going to have to load the value by parts, pull the
842 parts into pseudos. The part extraction process can involve
843 non-trivial computation. */
844 if (GET_CODE (args[i].reg) == PARALLEL)
846 tree type = TREE_TYPE (args[i].tree_value);
847 args[i].parallel_value
848 = emit_group_load_into_temps (args[i].reg, args[i].value,
849 type, int_size_in_bytes (type));
852 /* If the value is expensive, and we are inside an appropriately
853 short loop, put the value into a pseudo and then put the pseudo
854 into the hard reg.
856 For small register classes, also do this if this call uses
857 register parameters. This is to avoid reload conflicts while
858 loading the parameters registers. */
860 else if ((! (REG_P (args[i].value)
861 || (GET_CODE (args[i].value) == SUBREG
862 && REG_P (SUBREG_REG (args[i].value)))))
863 && args[i].mode != BLKmode
864 && set_src_cost (args[i].value, optimize_insn_for_speed_p ())
865 > COSTS_N_INSNS (1)
866 && ((*reg_parm_seen
867 && targetm.small_register_classes_for_mode_p (args[i].mode))
868 || optimize))
869 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
873 #ifdef REG_PARM_STACK_SPACE
875 /* The argument list is the property of the called routine and it
876 may clobber it. If the fixed area has been used for previous
877 parameters, we must save and restore it. */
879 static rtx
880 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
882 int low;
883 int high;
885 /* Compute the boundary of the area that needs to be saved, if any. */
886 high = reg_parm_stack_space;
887 #ifdef ARGS_GROW_DOWNWARD
888 high += 1;
889 #endif
890 if (high > highest_outgoing_arg_in_use)
891 high = highest_outgoing_arg_in_use;
893 for (low = 0; low < high; low++)
894 if (stack_usage_map[low] != 0)
896 int num_to_save;
897 enum machine_mode save_mode;
898 int delta;
899 rtx addr;
900 rtx stack_area;
901 rtx save_area;
903 while (stack_usage_map[--high] == 0)
906 *low_to_save = low;
907 *high_to_save = high;
909 num_to_save = high - low + 1;
910 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
912 /* If we don't have the required alignment, must do this
913 in BLKmode. */
914 if ((low & (MIN (GET_MODE_SIZE (save_mode),
915 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
916 save_mode = BLKmode;
918 #ifdef ARGS_GROW_DOWNWARD
919 delta = -high;
920 #else
921 delta = low;
922 #endif
923 addr = plus_constant (Pmode, argblock, delta);
924 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
926 set_mem_align (stack_area, PARM_BOUNDARY);
927 if (save_mode == BLKmode)
929 save_area = assign_stack_temp (BLKmode, num_to_save);
930 emit_block_move (validize_mem (save_area), stack_area,
931 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
933 else
935 save_area = gen_reg_rtx (save_mode);
936 emit_move_insn (save_area, stack_area);
939 return save_area;
942 return NULL_RTX;
945 static void
946 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
948 enum machine_mode save_mode = GET_MODE (save_area);
949 int delta;
950 rtx addr, stack_area;
952 #ifdef ARGS_GROW_DOWNWARD
953 delta = -high_to_save;
954 #else
955 delta = low_to_save;
956 #endif
957 addr = plus_constant (Pmode, argblock, delta);
958 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
959 set_mem_align (stack_area, PARM_BOUNDARY);
961 if (save_mode != BLKmode)
962 emit_move_insn (stack_area, save_area);
963 else
964 emit_block_move (stack_area, validize_mem (save_area),
965 GEN_INT (high_to_save - low_to_save + 1),
966 BLOCK_OP_CALL_PARM);
968 #endif /* REG_PARM_STACK_SPACE */
970 /* If any elements in ARGS refer to parameters that are to be passed in
971 registers, but not in memory, and whose alignment does not permit a
972 direct copy into registers. Copy the values into a group of pseudos
973 which we will later copy into the appropriate hard registers.
975 Pseudos for each unaligned argument will be stored into the array
976 args[argnum].aligned_regs. The caller is responsible for deallocating
977 the aligned_regs array if it is nonzero. */
979 static void
980 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
982 int i, j;
984 for (i = 0; i < num_actuals; i++)
985 if (args[i].reg != 0 && ! args[i].pass_on_stack
986 && args[i].mode == BLKmode
987 && MEM_P (args[i].value)
988 && (MEM_ALIGN (args[i].value)
989 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
991 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
992 int endian_correction = 0;
994 if (args[i].partial)
996 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
997 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
999 else
1001 args[i].n_aligned_regs
1002 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1005 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1007 /* Structures smaller than a word are normally aligned to the
1008 least significant byte. On a BYTES_BIG_ENDIAN machine,
1009 this means we must skip the empty high order bytes when
1010 calculating the bit offset. */
1011 if (bytes < UNITS_PER_WORD
1012 #ifdef BLOCK_REG_PADDING
1013 && (BLOCK_REG_PADDING (args[i].mode,
1014 TREE_TYPE (args[i].tree_value), 1)
1015 == downward)
1016 #else
1017 && BYTES_BIG_ENDIAN
1018 #endif
1020 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1022 for (j = 0; j < args[i].n_aligned_regs; j++)
1024 rtx reg = gen_reg_rtx (word_mode);
1025 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1026 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1028 args[i].aligned_regs[j] = reg;
1029 word = extract_bit_field (word, bitsize, 0, 1, false, NULL_RTX,
1030 word_mode, word_mode);
1032 /* There is no need to restrict this code to loading items
1033 in TYPE_ALIGN sized hunks. The bitfield instructions can
1034 load up entire word sized registers efficiently.
1036 ??? This may not be needed anymore.
1037 We use to emit a clobber here but that doesn't let later
1038 passes optimize the instructions we emit. By storing 0 into
1039 the register later passes know the first AND to zero out the
1040 bitfield being set in the register is unnecessary. The store
1041 of 0 will be deleted as will at least the first AND. */
1043 emit_move_insn (reg, const0_rtx);
1045 bytes -= bitsize / BITS_PER_UNIT;
1046 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1047 word_mode, word);
1052 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1053 CALL_EXPR EXP.
1055 NUM_ACTUALS is the total number of parameters.
1057 N_NAMED_ARGS is the total number of named arguments.
1059 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1060 value, or null.
1062 FNDECL is the tree code for the target of this call (if known)
1064 ARGS_SO_FAR holds state needed by the target to know where to place
1065 the next argument.
1067 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1068 for arguments which are passed in registers.
1070 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1071 and may be modified by this routine.
1073 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1074 flags which may may be modified by this routine.
1076 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1077 that requires allocation of stack space.
1079 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1080 the thunked-to function. */
1082 static void
1083 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1084 struct arg_data *args,
1085 struct args_size *args_size,
1086 int n_named_args ATTRIBUTE_UNUSED,
1087 tree exp, tree struct_value_addr_value,
1088 tree fndecl, tree fntype,
1089 cumulative_args_t args_so_far,
1090 int reg_parm_stack_space,
1091 rtx *old_stack_level, int *old_pending_adj,
1092 int *must_preallocate, int *ecf_flags,
1093 bool *may_tailcall, bool call_from_thunk_p)
1095 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1096 location_t loc = EXPR_LOCATION (exp);
1097 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1098 int inc;
1100 /* Count arg position in order args appear. */
1101 int argpos;
1103 int i;
1105 args_size->constant = 0;
1106 args_size->var = 0;
1108 /* In this loop, we consider args in the order they are written.
1109 We fill up ARGS from the front or from the back if necessary
1110 so that in any case the first arg to be pushed ends up at the front. */
1112 if (PUSH_ARGS_REVERSED)
1114 i = num_actuals - 1, inc = -1;
1115 /* In this case, must reverse order of args
1116 so that we compute and push the last arg first. */
1118 else
1120 i = 0, inc = 1;
1123 /* First fill in the actual arguments in the ARGS array, splitting
1124 complex arguments if necessary. */
1126 int j = i;
1127 call_expr_arg_iterator iter;
1128 tree arg;
1130 if (struct_value_addr_value)
1132 args[j].tree_value = struct_value_addr_value;
1133 j += inc;
1135 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1137 tree argtype = TREE_TYPE (arg);
1138 if (targetm.calls.split_complex_arg
1139 && argtype
1140 && TREE_CODE (argtype) == COMPLEX_TYPE
1141 && targetm.calls.split_complex_arg (argtype))
1143 tree subtype = TREE_TYPE (argtype);
1144 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1145 j += inc;
1146 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1148 else
1149 args[j].tree_value = arg;
1150 j += inc;
1154 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1155 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1157 tree type = TREE_TYPE (args[i].tree_value);
1158 int unsignedp;
1159 enum machine_mode mode;
1161 /* Replace erroneous argument with constant zero. */
1162 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1163 args[i].tree_value = integer_zero_node, type = integer_type_node;
1165 /* If TYPE is a transparent union or record, pass things the way
1166 we would pass the first field of the union or record. We have
1167 already verified that the modes are the same. */
1168 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1169 && TYPE_TRANSPARENT_AGGR (type))
1170 type = TREE_TYPE (first_field (type));
1172 /* Decide where to pass this arg.
1174 args[i].reg is nonzero if all or part is passed in registers.
1176 args[i].partial is nonzero if part but not all is passed in registers,
1177 and the exact value says how many bytes are passed in registers.
1179 args[i].pass_on_stack is nonzero if the argument must at least be
1180 computed on the stack. It may then be loaded back into registers
1181 if args[i].reg is nonzero.
1183 These decisions are driven by the FUNCTION_... macros and must agree
1184 with those made by function.c. */
1186 /* See if this argument should be passed by invisible reference. */
1187 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1188 type, argpos < n_named_args))
1190 bool callee_copies;
1191 tree base = NULL_TREE;
1193 callee_copies
1194 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
1195 type, argpos < n_named_args);
1197 /* If we're compiling a thunk, pass through invisible references
1198 instead of making a copy. */
1199 if (call_from_thunk_p
1200 || (callee_copies
1201 && !TREE_ADDRESSABLE (type)
1202 && (base = get_base_address (args[i].tree_value))
1203 && TREE_CODE (base) != SSA_NAME
1204 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1206 mark_addressable (args[i].tree_value);
1208 /* We can't use sibcalls if a callee-copied argument is
1209 stored in the current function's frame. */
1210 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1211 *may_tailcall = false;
1213 args[i].tree_value = build_fold_addr_expr_loc (loc,
1214 args[i].tree_value);
1215 type = TREE_TYPE (args[i].tree_value);
1217 if (*ecf_flags & ECF_CONST)
1218 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1220 else
1222 /* We make a copy of the object and pass the address to the
1223 function being called. */
1224 rtx copy;
1226 if (!COMPLETE_TYPE_P (type)
1227 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1228 || (flag_stack_check == GENERIC_STACK_CHECK
1229 && compare_tree_int (TYPE_SIZE_UNIT (type),
1230 STACK_CHECK_MAX_VAR_SIZE) > 0))
1232 /* This is a variable-sized object. Make space on the stack
1233 for it. */
1234 rtx size_rtx = expr_size (args[i].tree_value);
1236 if (*old_stack_level == 0)
1238 emit_stack_save (SAVE_BLOCK, old_stack_level);
1239 *old_pending_adj = pending_stack_adjust;
1240 pending_stack_adjust = 0;
1243 /* We can pass TRUE as the 4th argument because we just
1244 saved the stack pointer and will restore it right after
1245 the call. */
1246 copy = allocate_dynamic_stack_space (size_rtx,
1247 TYPE_ALIGN (type),
1248 TYPE_ALIGN (type),
1249 true);
1250 copy = gen_rtx_MEM (BLKmode, copy);
1251 set_mem_attributes (copy, type, 1);
1253 else
1254 copy = assign_temp (type, 1, 0);
1256 store_expr (args[i].tree_value, copy, 0, false);
1258 /* Just change the const function to pure and then let
1259 the next test clear the pure based on
1260 callee_copies. */
1261 if (*ecf_flags & ECF_CONST)
1263 *ecf_flags &= ~ECF_CONST;
1264 *ecf_flags |= ECF_PURE;
1267 if (!callee_copies && *ecf_flags & ECF_PURE)
1268 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1270 args[i].tree_value
1271 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1272 type = TREE_TYPE (args[i].tree_value);
1273 *may_tailcall = false;
1277 unsignedp = TYPE_UNSIGNED (type);
1278 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1279 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1281 args[i].unsignedp = unsignedp;
1282 args[i].mode = mode;
1284 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
1285 argpos < n_named_args);
1287 /* If this is a sibling call and the machine has register windows, the
1288 register window has to be unwinded before calling the routine, so
1289 arguments have to go into the incoming registers. */
1290 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
1291 args[i].tail_call_reg
1292 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
1293 argpos < n_named_args);
1294 else
1295 args[i].tail_call_reg = args[i].reg;
1297 if (args[i].reg)
1298 args[i].partial
1299 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1300 argpos < n_named_args);
1302 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1304 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1305 it means that we are to pass this arg in the register(s) designated
1306 by the PARALLEL, but also to pass it in the stack. */
1307 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1308 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1309 args[i].pass_on_stack = 1;
1311 /* If this is an addressable type, we must preallocate the stack
1312 since we must evaluate the object into its final location.
1314 If this is to be passed in both registers and the stack, it is simpler
1315 to preallocate. */
1316 if (TREE_ADDRESSABLE (type)
1317 || (args[i].pass_on_stack && args[i].reg != 0))
1318 *must_preallocate = 1;
1320 /* Compute the stack-size of this argument. */
1321 if (args[i].reg == 0 || args[i].partial != 0
1322 || reg_parm_stack_space > 0
1323 || args[i].pass_on_stack)
1324 locate_and_pad_parm (mode, type,
1325 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1327 #else
1328 args[i].reg != 0,
1329 #endif
1330 args[i].pass_on_stack ? 0 : args[i].partial,
1331 fndecl, args_size, &args[i].locate);
1332 #ifdef BLOCK_REG_PADDING
1333 else
1334 /* The argument is passed entirely in registers. See at which
1335 end it should be padded. */
1336 args[i].locate.where_pad =
1337 BLOCK_REG_PADDING (mode, type,
1338 int_size_in_bytes (type) <= UNITS_PER_WORD);
1339 #endif
1341 /* Update ARGS_SIZE, the total stack space for args so far. */
1343 args_size->constant += args[i].locate.size.constant;
1344 if (args[i].locate.size.var)
1345 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1347 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1348 have been used, etc. */
1350 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
1351 type, argpos < n_named_args);
1355 /* Update ARGS_SIZE to contain the total size for the argument block.
1356 Return the original constant component of the argument block's size.
1358 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1359 for arguments passed in registers. */
1361 static int
1362 compute_argument_block_size (int reg_parm_stack_space,
1363 struct args_size *args_size,
1364 tree fndecl ATTRIBUTE_UNUSED,
1365 tree fntype ATTRIBUTE_UNUSED,
1366 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1368 int unadjusted_args_size = args_size->constant;
1370 /* For accumulate outgoing args mode we don't need to align, since the frame
1371 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1372 backends from generating misaligned frame sizes. */
1373 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1374 preferred_stack_boundary = STACK_BOUNDARY;
1376 /* Compute the actual size of the argument block required. The variable
1377 and constant sizes must be combined, the size may have to be rounded,
1378 and there may be a minimum required size. */
1380 if (args_size->var)
1382 args_size->var = ARGS_SIZE_TREE (*args_size);
1383 args_size->constant = 0;
1385 preferred_stack_boundary /= BITS_PER_UNIT;
1386 if (preferred_stack_boundary > 1)
1388 /* We don't handle this case yet. To handle it correctly we have
1389 to add the delta, round and subtract the delta.
1390 Currently no machine description requires this support. */
1391 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1392 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1395 if (reg_parm_stack_space > 0)
1397 args_size->var
1398 = size_binop (MAX_EXPR, args_size->var,
1399 ssize_int (reg_parm_stack_space));
1401 /* The area corresponding to register parameters is not to count in
1402 the size of the block we need. So make the adjustment. */
1403 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1404 args_size->var
1405 = size_binop (MINUS_EXPR, args_size->var,
1406 ssize_int (reg_parm_stack_space));
1409 else
1411 preferred_stack_boundary /= BITS_PER_UNIT;
1412 if (preferred_stack_boundary < 1)
1413 preferred_stack_boundary = 1;
1414 args_size->constant = (((args_size->constant
1415 + stack_pointer_delta
1416 + preferred_stack_boundary - 1)
1417 / preferred_stack_boundary
1418 * preferred_stack_boundary)
1419 - stack_pointer_delta);
1421 args_size->constant = MAX (args_size->constant,
1422 reg_parm_stack_space);
1424 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1425 args_size->constant -= reg_parm_stack_space;
1427 return unadjusted_args_size;
1430 /* Precompute parameters as needed for a function call.
1432 FLAGS is mask of ECF_* constants.
1434 NUM_ACTUALS is the number of arguments.
1436 ARGS is an array containing information for each argument; this
1437 routine fills in the INITIAL_VALUE and VALUE fields for each
1438 precomputed argument. */
1440 static void
1441 precompute_arguments (int num_actuals, struct arg_data *args)
1443 int i;
1445 /* If this is a libcall, then precompute all arguments so that we do not
1446 get extraneous instructions emitted as part of the libcall sequence. */
1448 /* If we preallocated the stack space, and some arguments must be passed
1449 on the stack, then we must precompute any parameter which contains a
1450 function call which will store arguments on the stack.
1451 Otherwise, evaluating the parameter may clobber previous parameters
1452 which have already been stored into the stack. (we have code to avoid
1453 such case by saving the outgoing stack arguments, but it results in
1454 worse code) */
1455 if (!ACCUMULATE_OUTGOING_ARGS)
1456 return;
1458 for (i = 0; i < num_actuals; i++)
1460 tree type;
1461 enum machine_mode mode;
1463 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1464 continue;
1466 /* If this is an addressable type, we cannot pre-evaluate it. */
1467 type = TREE_TYPE (args[i].tree_value);
1468 gcc_assert (!TREE_ADDRESSABLE (type));
1470 args[i].initial_value = args[i].value
1471 = expand_normal (args[i].tree_value);
1473 mode = TYPE_MODE (type);
1474 if (mode != args[i].mode)
1476 int unsignedp = args[i].unsignedp;
1477 args[i].value
1478 = convert_modes (args[i].mode, mode,
1479 args[i].value, args[i].unsignedp);
1481 /* CSE will replace this only if it contains args[i].value
1482 pseudo, so convert it down to the declared mode using
1483 a SUBREG. */
1484 if (REG_P (args[i].value)
1485 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1486 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1488 args[i].initial_value
1489 = gen_lowpart_SUBREG (mode, args[i].value);
1490 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1491 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1492 args[i].unsignedp);
1498 /* Given the current state of MUST_PREALLOCATE and information about
1499 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1500 compute and return the final value for MUST_PREALLOCATE. */
1502 static int
1503 finalize_must_preallocate (int must_preallocate, int num_actuals,
1504 struct arg_data *args, struct args_size *args_size)
1506 /* See if we have or want to preallocate stack space.
1508 If we would have to push a partially-in-regs parm
1509 before other stack parms, preallocate stack space instead.
1511 If the size of some parm is not a multiple of the required stack
1512 alignment, we must preallocate.
1514 If the total size of arguments that would otherwise create a copy in
1515 a temporary (such as a CALL) is more than half the total argument list
1516 size, preallocation is faster.
1518 Another reason to preallocate is if we have a machine (like the m88k)
1519 where stack alignment is required to be maintained between every
1520 pair of insns, not just when the call is made. However, we assume here
1521 that such machines either do not have push insns (and hence preallocation
1522 would occur anyway) or the problem is taken care of with
1523 PUSH_ROUNDING. */
1525 if (! must_preallocate)
1527 int partial_seen = 0;
1528 int copy_to_evaluate_size = 0;
1529 int i;
1531 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1533 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1534 partial_seen = 1;
1535 else if (partial_seen && args[i].reg == 0)
1536 must_preallocate = 1;
1538 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1539 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1540 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1541 || TREE_CODE (args[i].tree_value) == COND_EXPR
1542 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1543 copy_to_evaluate_size
1544 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1547 if (copy_to_evaluate_size * 2 >= args_size->constant
1548 && args_size->constant > 0)
1549 must_preallocate = 1;
1551 return must_preallocate;
1554 /* If we preallocated stack space, compute the address of each argument
1555 and store it into the ARGS array.
1557 We need not ensure it is a valid memory address here; it will be
1558 validized when it is used.
1560 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1562 static void
1563 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1565 if (argblock)
1567 rtx arg_reg = argblock;
1568 int i, arg_offset = 0;
1570 if (GET_CODE (argblock) == PLUS)
1571 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1573 for (i = 0; i < num_actuals; i++)
1575 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1576 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1577 rtx addr;
1578 unsigned int align, boundary;
1579 unsigned int units_on_stack = 0;
1580 enum machine_mode partial_mode = VOIDmode;
1582 /* Skip this parm if it will not be passed on the stack. */
1583 if (! args[i].pass_on_stack
1584 && args[i].reg != 0
1585 && args[i].partial == 0)
1586 continue;
1588 if (CONST_INT_P (offset))
1589 addr = plus_constant (Pmode, arg_reg, INTVAL (offset));
1590 else
1591 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1593 addr = plus_constant (Pmode, addr, arg_offset);
1595 if (args[i].partial != 0)
1597 /* Only part of the parameter is being passed on the stack.
1598 Generate a simple memory reference of the correct size. */
1599 units_on_stack = args[i].locate.size.constant;
1600 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1601 MODE_INT, 1);
1602 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1603 set_mem_size (args[i].stack, units_on_stack);
1605 else
1607 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1608 set_mem_attributes (args[i].stack,
1609 TREE_TYPE (args[i].tree_value), 1);
1611 align = BITS_PER_UNIT;
1612 boundary = args[i].locate.boundary;
1613 if (args[i].locate.where_pad != downward)
1614 align = boundary;
1615 else if (CONST_INT_P (offset))
1617 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1618 align = align & -align;
1620 set_mem_align (args[i].stack, align);
1622 if (CONST_INT_P (slot_offset))
1623 addr = plus_constant (Pmode, arg_reg, INTVAL (slot_offset));
1624 else
1625 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1627 addr = plus_constant (Pmode, addr, arg_offset);
1629 if (args[i].partial != 0)
1631 /* Only part of the parameter is being passed on the stack.
1632 Generate a simple memory reference of the correct size.
1634 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1635 set_mem_size (args[i].stack_slot, units_on_stack);
1637 else
1639 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1640 set_mem_attributes (args[i].stack_slot,
1641 TREE_TYPE (args[i].tree_value), 1);
1643 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1645 /* Function incoming arguments may overlap with sibling call
1646 outgoing arguments and we cannot allow reordering of reads
1647 from function arguments with stores to outgoing arguments
1648 of sibling calls. */
1649 set_mem_alias_set (args[i].stack, 0);
1650 set_mem_alias_set (args[i].stack_slot, 0);
1655 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1656 in a call instruction.
1658 FNDECL is the tree node for the target function. For an indirect call
1659 FNDECL will be NULL_TREE.
1661 ADDR is the operand 0 of CALL_EXPR for this call. */
1663 static rtx
1664 rtx_for_function_call (tree fndecl, tree addr)
1666 rtx funexp;
1668 /* Get the function to call, in the form of RTL. */
1669 if (fndecl)
1671 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1672 TREE_USED (fndecl) = 1;
1674 /* Get a SYMBOL_REF rtx for the function address. */
1675 funexp = XEXP (DECL_RTL (fndecl), 0);
1677 else
1678 /* Generate an rtx (probably a pseudo-register) for the address. */
1680 push_temp_slots ();
1681 funexp = expand_normal (addr);
1682 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1684 return funexp;
1687 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
1688 static struct
1690 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
1691 or NULL_RTX if none has been scanned yet. */
1692 rtx scan_start;
1693 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
1694 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
1695 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
1696 with fixed offset, or PC if this is with variable or unknown offset. */
1697 vec<rtx> cache;
1698 } internal_arg_pointer_exp_state;
1700 static rtx internal_arg_pointer_based_exp (rtx, bool);
1702 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
1703 the tail call sequence, starting with first insn that hasn't been
1704 scanned yet, and note for each pseudo on the LHS whether it is based
1705 on crtl->args.internal_arg_pointer or not, and what offset from that
1706 that pointer it has. */
1708 static void
1709 internal_arg_pointer_based_exp_scan (void)
1711 rtx insn, scan_start = internal_arg_pointer_exp_state.scan_start;
1713 if (scan_start == NULL_RTX)
1714 insn = get_insns ();
1715 else
1716 insn = NEXT_INSN (scan_start);
1718 while (insn)
1720 rtx set = single_set (insn);
1721 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
1723 rtx val = NULL_RTX;
1724 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
1725 /* Punt on pseudos set multiple times. */
1726 if (idx < internal_arg_pointer_exp_state.cache.length ()
1727 && (internal_arg_pointer_exp_state.cache[idx]
1728 != NULL_RTX))
1729 val = pc_rtx;
1730 else
1731 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
1732 if (val != NULL_RTX)
1734 if (idx >= internal_arg_pointer_exp_state.cache.length ())
1735 internal_arg_pointer_exp_state.cache.safe_grow_cleared(idx + 1);
1736 internal_arg_pointer_exp_state.cache[idx] = val;
1739 if (NEXT_INSN (insn) == NULL_RTX)
1740 scan_start = insn;
1741 insn = NEXT_INSN (insn);
1744 internal_arg_pointer_exp_state.scan_start = scan_start;
1747 /* Helper function for internal_arg_pointer_based_exp, called through
1748 for_each_rtx. Return 1 if *LOC is a register based on
1749 crtl->args.internal_arg_pointer. Return -1 if *LOC is not based on it
1750 and the subexpressions need not be examined. Otherwise return 0. */
1752 static int
1753 internal_arg_pointer_based_exp_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
1755 if (REG_P (*loc) && internal_arg_pointer_based_exp (*loc, false) != NULL_RTX)
1756 return 1;
1757 if (MEM_P (*loc))
1758 return -1;
1759 return 0;
1762 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
1763 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
1764 it with fixed offset, or PC if this is with variable or unknown offset.
1765 TOPLEVEL is true if the function is invoked at the topmost level. */
1767 static rtx
1768 internal_arg_pointer_based_exp (rtx rtl, bool toplevel)
1770 if (CONSTANT_P (rtl))
1771 return NULL_RTX;
1773 if (rtl == crtl->args.internal_arg_pointer)
1774 return const0_rtx;
1776 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
1777 return NULL_RTX;
1779 if (GET_CODE (rtl) == PLUS && CONST_INT_P (XEXP (rtl, 1)))
1781 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
1782 if (val == NULL_RTX || val == pc_rtx)
1783 return val;
1784 return plus_constant (Pmode, val, INTVAL (XEXP (rtl, 1)));
1787 /* When called at the topmost level, scan pseudo assignments in between the
1788 last scanned instruction in the tail call sequence and the latest insn
1789 in that sequence. */
1790 if (toplevel)
1791 internal_arg_pointer_based_exp_scan ();
1793 if (REG_P (rtl))
1795 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
1796 if (idx < internal_arg_pointer_exp_state.cache.length ())
1797 return internal_arg_pointer_exp_state.cache[idx];
1799 return NULL_RTX;
1802 if (for_each_rtx (&rtl, internal_arg_pointer_based_exp_1, NULL))
1803 return pc_rtx;
1805 return NULL_RTX;
1808 /* Return true if and only if SIZE storage units (usually bytes)
1809 starting from address ADDR overlap with already clobbered argument
1810 area. This function is used to determine if we should give up a
1811 sibcall. */
1813 static bool
1814 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1816 HOST_WIDE_INT i;
1817 rtx val;
1819 if (bitmap_empty_p (stored_args_map))
1820 return false;
1821 val = internal_arg_pointer_based_exp (addr, true);
1822 if (val == NULL_RTX)
1823 return false;
1824 else if (val == pc_rtx)
1825 return true;
1826 else
1827 i = INTVAL (val);
1828 #ifdef STACK_GROWS_DOWNWARD
1829 i -= crtl->args.pretend_args_size;
1830 #else
1831 i += crtl->args.pretend_args_size;
1832 #endif
1834 #ifdef ARGS_GROW_DOWNWARD
1835 i = -i - size;
1836 #endif
1837 if (size > 0)
1839 unsigned HOST_WIDE_INT k;
1841 for (k = 0; k < size; k++)
1842 if (i + k < SBITMAP_SIZE (stored_args_map)
1843 && bitmap_bit_p (stored_args_map, i + k))
1844 return true;
1847 return false;
1850 /* Do the register loads required for any wholly-register parms or any
1851 parms which are passed both on the stack and in a register. Their
1852 expressions were already evaluated.
1854 Mark all register-parms as living through the call, putting these USE
1855 insns in the CALL_INSN_FUNCTION_USAGE field.
1857 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1858 checking, setting *SIBCALL_FAILURE if appropriate. */
1860 static void
1861 load_register_parameters (struct arg_data *args, int num_actuals,
1862 rtx *call_fusage, int flags, int is_sibcall,
1863 int *sibcall_failure)
1865 int i, j;
1867 for (i = 0; i < num_actuals; i++)
1869 rtx reg = ((flags & ECF_SIBCALL)
1870 ? args[i].tail_call_reg : args[i].reg);
1871 if (reg)
1873 int partial = args[i].partial;
1874 int nregs;
1875 int size = 0;
1876 rtx before_arg = get_last_insn ();
1877 /* Set non-negative if we must move a word at a time, even if
1878 just one word (e.g, partial == 4 && mode == DFmode). Set
1879 to -1 if we just use a normal move insn. This value can be
1880 zero if the argument is a zero size structure. */
1881 nregs = -1;
1882 if (GET_CODE (reg) == PARALLEL)
1884 else if (partial)
1886 gcc_assert (partial % UNITS_PER_WORD == 0);
1887 nregs = partial / UNITS_PER_WORD;
1889 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1891 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1892 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1894 else
1895 size = GET_MODE_SIZE (args[i].mode);
1897 /* Handle calls that pass values in multiple non-contiguous
1898 locations. The Irix 6 ABI has examples of this. */
1900 if (GET_CODE (reg) == PARALLEL)
1901 emit_group_move (reg, args[i].parallel_value);
1903 /* If simple case, just do move. If normal partial, store_one_arg
1904 has already loaded the register for us. In all other cases,
1905 load the register(s) from memory. */
1907 else if (nregs == -1)
1909 emit_move_insn (reg, args[i].value);
1910 #ifdef BLOCK_REG_PADDING
1911 /* Handle case where we have a value that needs shifting
1912 up to the msb. eg. a QImode value and we're padding
1913 upward on a BYTES_BIG_ENDIAN machine. */
1914 if (size < UNITS_PER_WORD
1915 && (args[i].locate.where_pad
1916 == (BYTES_BIG_ENDIAN ? upward : downward)))
1918 rtx x;
1919 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1921 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1922 report the whole reg as used. Strictly speaking, the
1923 call only uses SIZE bytes at the msb end, but it doesn't
1924 seem worth generating rtl to say that. */
1925 reg = gen_rtx_REG (word_mode, REGNO (reg));
1926 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
1927 if (x != reg)
1928 emit_move_insn (reg, x);
1930 #endif
1933 /* If we have pre-computed the values to put in the registers in
1934 the case of non-aligned structures, copy them in now. */
1936 else if (args[i].n_aligned_regs != 0)
1937 for (j = 0; j < args[i].n_aligned_regs; j++)
1938 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1939 args[i].aligned_regs[j]);
1941 else if (partial == 0 || args[i].pass_on_stack)
1943 rtx mem = validize_mem (args[i].value);
1945 /* Check for overlap with already clobbered argument area,
1946 providing that this has non-zero size. */
1947 if (is_sibcall
1948 && (size == 0
1949 || mem_overlaps_already_clobbered_arg_p
1950 (XEXP (args[i].value, 0), size)))
1951 *sibcall_failure = 1;
1953 /* Handle a BLKmode that needs shifting. */
1954 if (nregs == 1 && size < UNITS_PER_WORD
1955 #ifdef BLOCK_REG_PADDING
1956 && args[i].locate.where_pad == downward
1957 #else
1958 && BYTES_BIG_ENDIAN
1959 #endif
1962 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1963 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1964 rtx x = gen_reg_rtx (word_mode);
1965 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1966 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1967 : LSHIFT_EXPR;
1969 emit_move_insn (x, tem);
1970 x = expand_shift (dir, word_mode, x, shift, ri, 1);
1971 if (x != ri)
1972 emit_move_insn (ri, x);
1974 else
1975 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1978 /* When a parameter is a block, and perhaps in other cases, it is
1979 possible that it did a load from an argument slot that was
1980 already clobbered. */
1981 if (is_sibcall
1982 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1983 *sibcall_failure = 1;
1985 /* Handle calls that pass values in multiple non-contiguous
1986 locations. The Irix 6 ABI has examples of this. */
1987 if (GET_CODE (reg) == PARALLEL)
1988 use_group_regs (call_fusage, reg);
1989 else if (nregs == -1)
1990 use_reg_mode (call_fusage, reg,
1991 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1992 else if (nregs > 0)
1993 use_regs (call_fusage, REGNO (reg), nregs);
1998 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1999 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2000 bytes, then we would need to push some additional bytes to pad the
2001 arguments. So, we compute an adjust to the stack pointer for an
2002 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2003 bytes. Then, when the arguments are pushed the stack will be perfectly
2004 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2005 be popped after the call. Returns the adjustment. */
2007 static int
2008 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
2009 struct args_size *args_size,
2010 unsigned int preferred_unit_stack_boundary)
2012 /* The number of bytes to pop so that the stack will be
2013 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2014 HOST_WIDE_INT adjustment;
2015 /* The alignment of the stack after the arguments are pushed, if we
2016 just pushed the arguments without adjust the stack here. */
2017 unsigned HOST_WIDE_INT unadjusted_alignment;
2019 unadjusted_alignment
2020 = ((stack_pointer_delta + unadjusted_args_size)
2021 % preferred_unit_stack_boundary);
2023 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2024 as possible -- leaving just enough left to cancel out the
2025 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2026 PENDING_STACK_ADJUST is non-negative, and congruent to
2027 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2029 /* Begin by trying to pop all the bytes. */
2030 unadjusted_alignment
2031 = (unadjusted_alignment
2032 - (pending_stack_adjust % preferred_unit_stack_boundary));
2033 adjustment = pending_stack_adjust;
2034 /* Push enough additional bytes that the stack will be aligned
2035 after the arguments are pushed. */
2036 if (preferred_unit_stack_boundary > 1)
2038 if (unadjusted_alignment > 0)
2039 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2040 else
2041 adjustment += unadjusted_alignment;
2044 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2045 bytes after the call. The right number is the entire
2046 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2047 by the arguments in the first place. */
2048 args_size->constant
2049 = pending_stack_adjust - adjustment + unadjusted_args_size;
2051 return adjustment;
2054 /* Scan X expression if it does not dereference any argument slots
2055 we already clobbered by tail call arguments (as noted in stored_args_map
2056 bitmap).
2057 Return nonzero if X expression dereferences such argument slots,
2058 zero otherwise. */
2060 static int
2061 check_sibcall_argument_overlap_1 (rtx x)
2063 RTX_CODE code;
2064 int i, j;
2065 const char *fmt;
2067 if (x == NULL_RTX)
2068 return 0;
2070 code = GET_CODE (x);
2072 /* We need not check the operands of the CALL expression itself. */
2073 if (code == CALL)
2074 return 0;
2076 if (code == MEM)
2077 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
2078 GET_MODE_SIZE (GET_MODE (x)));
2080 /* Scan all subexpressions. */
2081 fmt = GET_RTX_FORMAT (code);
2082 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2084 if (*fmt == 'e')
2086 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2087 return 1;
2089 else if (*fmt == 'E')
2091 for (j = 0; j < XVECLEN (x, i); j++)
2092 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2093 return 1;
2096 return 0;
2099 /* Scan sequence after INSN if it does not dereference any argument slots
2100 we already clobbered by tail call arguments (as noted in stored_args_map
2101 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2102 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2103 should be 0). Return nonzero if sequence after INSN dereferences such argument
2104 slots, zero otherwise. */
2106 static int
2107 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
2109 int low, high;
2111 if (insn == NULL_RTX)
2112 insn = get_insns ();
2113 else
2114 insn = NEXT_INSN (insn);
2116 for (; insn; insn = NEXT_INSN (insn))
2117 if (INSN_P (insn)
2118 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2119 break;
2121 if (mark_stored_args_map)
2123 #ifdef ARGS_GROW_DOWNWARD
2124 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2125 #else
2126 low = arg->locate.slot_offset.constant;
2127 #endif
2129 for (high = low + arg->locate.size.constant; low < high; low++)
2130 bitmap_set_bit (stored_args_map, low);
2132 return insn != NULL_RTX;
2135 /* Given that a function returns a value of mode MODE at the most
2136 significant end of hard register VALUE, shift VALUE left or right
2137 as specified by LEFT_P. Return true if some action was needed. */
2139 bool
2140 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
2142 HOST_WIDE_INT shift;
2144 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
2145 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
2146 if (shift == 0)
2147 return false;
2149 /* Use ashr rather than lshr for right shifts. This is for the benefit
2150 of the MIPS port, which requires SImode values to be sign-extended
2151 when stored in 64-bit registers. */
2152 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
2153 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
2154 gcc_unreachable ();
2155 return true;
2158 /* If X is a likely-spilled register value, copy it to a pseudo
2159 register and return that register. Return X otherwise. */
2161 static rtx
2162 avoid_likely_spilled_reg (rtx x)
2164 rtx new_rtx;
2166 if (REG_P (x)
2167 && HARD_REGISTER_P (x)
2168 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
2170 /* Make sure that we generate a REG rather than a CONCAT.
2171 Moves into CONCATs can need nontrivial instructions,
2172 and the whole point of this function is to avoid
2173 using the hard register directly in such a situation. */
2174 generating_concat_p = 0;
2175 new_rtx = gen_reg_rtx (GET_MODE (x));
2176 generating_concat_p = 1;
2177 emit_move_insn (new_rtx, x);
2178 return new_rtx;
2180 return x;
2183 /* Generate all the code for a CALL_EXPR exp
2184 and return an rtx for its value.
2185 Store the value in TARGET (specified as an rtx) if convenient.
2186 If the value is stored in TARGET then TARGET is returned.
2187 If IGNORE is nonzero, then we ignore the value of the function call. */
2190 expand_call (tree exp, rtx target, int ignore)
2192 /* Nonzero if we are currently expanding a call. */
2193 static int currently_expanding_call = 0;
2195 /* RTX for the function to be called. */
2196 rtx funexp;
2197 /* Sequence of insns to perform a normal "call". */
2198 rtx normal_call_insns = NULL_RTX;
2199 /* Sequence of insns to perform a tail "call". */
2200 rtx tail_call_insns = NULL_RTX;
2201 /* Data type of the function. */
2202 tree funtype;
2203 tree type_arg_types;
2204 tree rettype;
2205 /* Declaration of the function being called,
2206 or 0 if the function is computed (not known by name). */
2207 tree fndecl = 0;
2208 /* The type of the function being called. */
2209 tree fntype;
2210 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
2211 int pass;
2213 /* Register in which non-BLKmode value will be returned,
2214 or 0 if no value or if value is BLKmode. */
2215 rtx valreg;
2216 /* Address where we should return a BLKmode value;
2217 0 if value not BLKmode. */
2218 rtx structure_value_addr = 0;
2219 /* Nonzero if that address is being passed by treating it as
2220 an extra, implicit first parameter. Otherwise,
2221 it is passed by being copied directly into struct_value_rtx. */
2222 int structure_value_addr_parm = 0;
2223 /* Holds the value of implicit argument for the struct value. */
2224 tree structure_value_addr_value = NULL_TREE;
2225 /* Size of aggregate value wanted, or zero if none wanted
2226 or if we are using the non-reentrant PCC calling convention
2227 or expecting the value in registers. */
2228 HOST_WIDE_INT struct_value_size = 0;
2229 /* Nonzero if called function returns an aggregate in memory PCC style,
2230 by returning the address of where to find it. */
2231 int pcc_struct_value = 0;
2232 rtx struct_value = 0;
2234 /* Number of actual parameters in this call, including struct value addr. */
2235 int num_actuals;
2236 /* Number of named args. Args after this are anonymous ones
2237 and they must all go on the stack. */
2238 int n_named_args;
2239 /* Number of complex actual arguments that need to be split. */
2240 int num_complex_actuals = 0;
2242 /* Vector of information about each argument.
2243 Arguments are numbered in the order they will be pushed,
2244 not the order they are written. */
2245 struct arg_data *args;
2247 /* Total size in bytes of all the stack-parms scanned so far. */
2248 struct args_size args_size;
2249 struct args_size adjusted_args_size;
2250 /* Size of arguments before any adjustments (such as rounding). */
2251 int unadjusted_args_size;
2252 /* Data on reg parms scanned so far. */
2253 CUMULATIVE_ARGS args_so_far_v;
2254 cumulative_args_t args_so_far;
2255 /* Nonzero if a reg parm has been scanned. */
2256 int reg_parm_seen;
2257 /* Nonzero if this is an indirect function call. */
2259 /* Nonzero if we must avoid push-insns in the args for this call.
2260 If stack space is allocated for register parameters, but not by the
2261 caller, then it is preallocated in the fixed part of the stack frame.
2262 So the entire argument block must then be preallocated (i.e., we
2263 ignore PUSH_ROUNDING in that case). */
2265 int must_preallocate = !PUSH_ARGS;
2267 /* Size of the stack reserved for parameter registers. */
2268 int reg_parm_stack_space = 0;
2270 /* Address of space preallocated for stack parms
2271 (on machines that lack push insns), or 0 if space not preallocated. */
2272 rtx argblock = 0;
2274 /* Mask of ECF_ and ERF_ flags. */
2275 int flags = 0;
2276 int return_flags = 0;
2277 #ifdef REG_PARM_STACK_SPACE
2278 /* Define the boundary of the register parm stack space that needs to be
2279 saved, if any. */
2280 int low_to_save, high_to_save;
2281 rtx save_area = 0; /* Place that it is saved */
2282 #endif
2284 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2285 char *initial_stack_usage_map = stack_usage_map;
2286 char *stack_usage_map_buf = NULL;
2288 int old_stack_allocated;
2290 /* State variables to track stack modifications. */
2291 rtx old_stack_level = 0;
2292 int old_stack_arg_under_construction = 0;
2293 int old_pending_adj = 0;
2294 int old_inhibit_defer_pop = inhibit_defer_pop;
2296 /* Some stack pointer alterations we make are performed via
2297 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2298 which we then also need to save/restore along the way. */
2299 int old_stack_pointer_delta = 0;
2301 rtx call_fusage;
2302 tree addr = CALL_EXPR_FN (exp);
2303 int i;
2304 /* The alignment of the stack, in bits. */
2305 unsigned HOST_WIDE_INT preferred_stack_boundary;
2306 /* The alignment of the stack, in bytes. */
2307 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2308 /* The static chain value to use for this call. */
2309 rtx static_chain_value;
2310 /* See if this is "nothrow" function call. */
2311 if (TREE_NOTHROW (exp))
2312 flags |= ECF_NOTHROW;
2314 /* See if we can find a DECL-node for the actual function, and get the
2315 function attributes (flags) from the function decl or type node. */
2316 fndecl = get_callee_fndecl (exp);
2317 if (fndecl)
2319 fntype = TREE_TYPE (fndecl);
2320 flags |= flags_from_decl_or_type (fndecl);
2321 return_flags |= decl_return_flags (fndecl);
2323 else
2325 fntype = TREE_TYPE (TREE_TYPE (addr));
2326 flags |= flags_from_decl_or_type (fntype);
2328 rettype = TREE_TYPE (exp);
2330 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2332 /* Warn if this value is an aggregate type,
2333 regardless of which calling convention we are using for it. */
2334 if (AGGREGATE_TYPE_P (rettype))
2335 warning (OPT_Waggregate_return, "function call has aggregate value");
2337 /* If the result of a non looping pure or const function call is
2338 ignored (or void), and none of its arguments are volatile, we can
2339 avoid expanding the call and just evaluate the arguments for
2340 side-effects. */
2341 if ((flags & (ECF_CONST | ECF_PURE))
2342 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2343 && (ignore || target == const0_rtx
2344 || TYPE_MODE (rettype) == VOIDmode))
2346 bool volatilep = false;
2347 tree arg;
2348 call_expr_arg_iterator iter;
2350 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2351 if (TREE_THIS_VOLATILE (arg))
2353 volatilep = true;
2354 break;
2357 if (! volatilep)
2359 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2360 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2361 return const0_rtx;
2365 #ifdef REG_PARM_STACK_SPACE
2366 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2367 #endif
2369 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2370 && reg_parm_stack_space > 0 && PUSH_ARGS)
2371 must_preallocate = 1;
2373 /* Set up a place to return a structure. */
2375 /* Cater to broken compilers. */
2376 if (aggregate_value_p (exp, fntype))
2378 /* This call returns a big structure. */
2379 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2381 #ifdef PCC_STATIC_STRUCT_RETURN
2383 pcc_struct_value = 1;
2385 #else /* not PCC_STATIC_STRUCT_RETURN */
2387 struct_value_size = int_size_in_bytes (rettype);
2389 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2390 structure_value_addr = XEXP (target, 0);
2391 else
2393 /* For variable-sized objects, we must be called with a target
2394 specified. If we were to allocate space on the stack here,
2395 we would have no way of knowing when to free it. */
2396 rtx d = assign_temp (rettype, 1, 1);
2397 structure_value_addr = XEXP (d, 0);
2398 target = 0;
2401 #endif /* not PCC_STATIC_STRUCT_RETURN */
2404 /* Figure out the amount to which the stack should be aligned. */
2405 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2406 if (fndecl)
2408 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2409 /* Without automatic stack alignment, we can't increase preferred
2410 stack boundary. With automatic stack alignment, it is
2411 unnecessary since unless we can guarantee that all callers will
2412 align the outgoing stack properly, callee has to align its
2413 stack anyway. */
2414 if (i
2415 && i->preferred_incoming_stack_boundary
2416 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2417 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2420 /* Operand 0 is a pointer-to-function; get the type of the function. */
2421 funtype = TREE_TYPE (addr);
2422 gcc_assert (POINTER_TYPE_P (funtype));
2423 funtype = TREE_TYPE (funtype);
2425 /* Count whether there are actual complex arguments that need to be split
2426 into their real and imaginary parts. Munge the type_arg_types
2427 appropriately here as well. */
2428 if (targetm.calls.split_complex_arg)
2430 call_expr_arg_iterator iter;
2431 tree arg;
2432 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2434 tree type = TREE_TYPE (arg);
2435 if (type && TREE_CODE (type) == COMPLEX_TYPE
2436 && targetm.calls.split_complex_arg (type))
2437 num_complex_actuals++;
2439 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2441 else
2442 type_arg_types = TYPE_ARG_TYPES (funtype);
2444 if (flags & ECF_MAY_BE_ALLOCA)
2445 cfun->calls_alloca = 1;
2447 /* If struct_value_rtx is 0, it means pass the address
2448 as if it were an extra parameter. Put the argument expression
2449 in structure_value_addr_value. */
2450 if (structure_value_addr && struct_value == 0)
2452 /* If structure_value_addr is a REG other than
2453 virtual_outgoing_args_rtx, we can use always use it. If it
2454 is not a REG, we must always copy it into a register.
2455 If it is virtual_outgoing_args_rtx, we must copy it to another
2456 register in some cases. */
2457 rtx temp = (!REG_P (structure_value_addr)
2458 || (ACCUMULATE_OUTGOING_ARGS
2459 && stack_arg_under_construction
2460 && structure_value_addr == virtual_outgoing_args_rtx)
2461 ? copy_addr_to_reg (convert_memory_address
2462 (Pmode, structure_value_addr))
2463 : structure_value_addr);
2465 structure_value_addr_value =
2466 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2467 structure_value_addr_parm = 1;
2470 /* Count the arguments and set NUM_ACTUALS. */
2471 num_actuals =
2472 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2474 /* Compute number of named args.
2475 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2477 if (type_arg_types != 0)
2478 n_named_args
2479 = (list_length (type_arg_types)
2480 /* Count the struct value address, if it is passed as a parm. */
2481 + structure_value_addr_parm);
2482 else
2483 /* If we know nothing, treat all args as named. */
2484 n_named_args = num_actuals;
2486 /* Start updating where the next arg would go.
2488 On some machines (such as the PA) indirect calls have a different
2489 calling convention than normal calls. The fourth argument in
2490 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2491 or not. */
2492 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
2493 args_so_far = pack_cumulative_args (&args_so_far_v);
2495 /* Now possibly adjust the number of named args.
2496 Normally, don't include the last named arg if anonymous args follow.
2497 We do include the last named arg if
2498 targetm.calls.strict_argument_naming() returns nonzero.
2499 (If no anonymous args follow, the result of list_length is actually
2500 one too large. This is harmless.)
2502 If targetm.calls.pretend_outgoing_varargs_named() returns
2503 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2504 this machine will be able to place unnamed args that were passed
2505 in registers into the stack. So treat all args as named. This
2506 allows the insns emitting for a specific argument list to be
2507 independent of the function declaration.
2509 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2510 we do not have any reliable way to pass unnamed args in
2511 registers, so we must force them into memory. */
2513 if (type_arg_types != 0
2514 && targetm.calls.strict_argument_naming (args_so_far))
2516 else if (type_arg_types != 0
2517 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
2518 /* Don't include the last named arg. */
2519 --n_named_args;
2520 else
2521 /* Treat all args as named. */
2522 n_named_args = num_actuals;
2524 /* Make a vector to hold all the information about each arg. */
2525 args = XALLOCAVEC (struct arg_data, num_actuals);
2526 memset (args, 0, num_actuals * sizeof (struct arg_data));
2528 /* Build up entries in the ARGS array, compute the size of the
2529 arguments into ARGS_SIZE, etc. */
2530 initialize_argument_information (num_actuals, args, &args_size,
2531 n_named_args, exp,
2532 structure_value_addr_value, fndecl, fntype,
2533 args_so_far, reg_parm_stack_space,
2534 &old_stack_level, &old_pending_adj,
2535 &must_preallocate, &flags,
2536 &try_tail_call, CALL_FROM_THUNK_P (exp));
2538 if (args_size.var)
2539 must_preallocate = 1;
2541 /* Now make final decision about preallocating stack space. */
2542 must_preallocate = finalize_must_preallocate (must_preallocate,
2543 num_actuals, args,
2544 &args_size);
2546 /* If the structure value address will reference the stack pointer, we
2547 must stabilize it. We don't need to do this if we know that we are
2548 not going to adjust the stack pointer in processing this call. */
2550 if (structure_value_addr
2551 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2552 || reg_mentioned_p (virtual_outgoing_args_rtx,
2553 structure_value_addr))
2554 && (args_size.var
2555 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2556 structure_value_addr = copy_to_reg (structure_value_addr);
2558 /* Tail calls can make things harder to debug, and we've traditionally
2559 pushed these optimizations into -O2. Don't try if we're already
2560 expanding a call, as that means we're an argument. Don't try if
2561 there's cleanups, as we know there's code to follow the call. */
2563 if (currently_expanding_call++ != 0
2564 || !flag_optimize_sibling_calls
2565 || args_size.var
2566 || dbg_cnt (tail_call) == false)
2567 try_tail_call = 0;
2569 /* Rest of purposes for tail call optimizations to fail. */
2570 if (
2571 #ifdef HAVE_sibcall_epilogue
2572 !HAVE_sibcall_epilogue
2573 #else
2575 #endif
2576 || !try_tail_call
2577 /* Doing sibling call optimization needs some work, since
2578 structure_value_addr can be allocated on the stack.
2579 It does not seem worth the effort since few optimizable
2580 sibling calls will return a structure. */
2581 || structure_value_addr != NULL_RTX
2582 #ifdef REG_PARM_STACK_SPACE
2583 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2584 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2585 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2586 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2587 #endif
2588 /* Check whether the target is able to optimize the call
2589 into a sibcall. */
2590 || !targetm.function_ok_for_sibcall (fndecl, exp)
2591 /* Functions that do not return exactly once may not be sibcall
2592 optimized. */
2593 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2594 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2595 /* If the called function is nested in the current one, it might access
2596 some of the caller's arguments, but could clobber them beforehand if
2597 the argument areas are shared. */
2598 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2599 /* If this function requires more stack slots than the current
2600 function, we cannot change it into a sibling call.
2601 crtl->args.pretend_args_size is not part of the
2602 stack allocated by our caller. */
2603 || args_size.constant > (crtl->args.size
2604 - crtl->args.pretend_args_size)
2605 /* If the callee pops its own arguments, then it must pop exactly
2606 the same number of arguments as the current function. */
2607 || (targetm.calls.return_pops_args (fndecl, funtype, args_size.constant)
2608 != targetm.calls.return_pops_args (current_function_decl,
2609 TREE_TYPE (current_function_decl),
2610 crtl->args.size))
2611 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2612 try_tail_call = 0;
2614 /* Check if caller and callee disagree in promotion of function
2615 return value. */
2616 if (try_tail_call)
2618 enum machine_mode caller_mode, caller_promoted_mode;
2619 enum machine_mode callee_mode, callee_promoted_mode;
2620 int caller_unsignedp, callee_unsignedp;
2621 tree caller_res = DECL_RESULT (current_function_decl);
2623 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2624 caller_mode = DECL_MODE (caller_res);
2625 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2626 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2627 caller_promoted_mode
2628 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2629 &caller_unsignedp,
2630 TREE_TYPE (current_function_decl), 1);
2631 callee_promoted_mode
2632 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2633 &callee_unsignedp,
2634 funtype, 1);
2635 if (caller_mode != VOIDmode
2636 && (caller_promoted_mode != callee_promoted_mode
2637 || ((caller_mode != caller_promoted_mode
2638 || callee_mode != callee_promoted_mode)
2639 && (caller_unsignedp != callee_unsignedp
2640 || GET_MODE_BITSIZE (caller_mode)
2641 < GET_MODE_BITSIZE (callee_mode)))))
2642 try_tail_call = 0;
2645 /* Ensure current function's preferred stack boundary is at least
2646 what we need. Stack alignment may also increase preferred stack
2647 boundary. */
2648 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2649 crtl->preferred_stack_boundary = preferred_stack_boundary;
2650 else
2651 preferred_stack_boundary = crtl->preferred_stack_boundary;
2653 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2655 /* We want to make two insn chains; one for a sibling call, the other
2656 for a normal call. We will select one of the two chains after
2657 initial RTL generation is complete. */
2658 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2660 int sibcall_failure = 0;
2661 /* We want to emit any pending stack adjustments before the tail
2662 recursion "call". That way we know any adjustment after the tail
2663 recursion call can be ignored if we indeed use the tail
2664 call expansion. */
2665 int save_pending_stack_adjust = 0;
2666 int save_stack_pointer_delta = 0;
2667 rtx insns;
2668 rtx before_call, next_arg_reg, after_args;
2670 if (pass == 0)
2672 /* State variables we need to save and restore between
2673 iterations. */
2674 save_pending_stack_adjust = pending_stack_adjust;
2675 save_stack_pointer_delta = stack_pointer_delta;
2677 if (pass)
2678 flags &= ~ECF_SIBCALL;
2679 else
2680 flags |= ECF_SIBCALL;
2682 /* Other state variables that we must reinitialize each time
2683 through the loop (that are not initialized by the loop itself). */
2684 argblock = 0;
2685 call_fusage = 0;
2687 /* Start a new sequence for the normal call case.
2689 From this point on, if the sibling call fails, we want to set
2690 sibcall_failure instead of continuing the loop. */
2691 start_sequence ();
2693 /* Don't let pending stack adjusts add up to too much.
2694 Also, do all pending adjustments now if there is any chance
2695 this might be a call to alloca or if we are expanding a sibling
2696 call sequence.
2697 Also do the adjustments before a throwing call, otherwise
2698 exception handling can fail; PR 19225. */
2699 if (pending_stack_adjust >= 32
2700 || (pending_stack_adjust > 0
2701 && (flags & ECF_MAY_BE_ALLOCA))
2702 || (pending_stack_adjust > 0
2703 && flag_exceptions && !(flags & ECF_NOTHROW))
2704 || pass == 0)
2705 do_pending_stack_adjust ();
2707 /* Precompute any arguments as needed. */
2708 if (pass)
2709 precompute_arguments (num_actuals, args);
2711 /* Now we are about to start emitting insns that can be deleted
2712 if a libcall is deleted. */
2713 if (pass && (flags & ECF_MALLOC))
2714 start_sequence ();
2716 if (pass == 0 && crtl->stack_protect_guard)
2717 stack_protect_epilogue ();
2719 adjusted_args_size = args_size;
2720 /* Compute the actual size of the argument block required. The variable
2721 and constant sizes must be combined, the size may have to be rounded,
2722 and there may be a minimum required size. When generating a sibcall
2723 pattern, do not round up, since we'll be re-using whatever space our
2724 caller provided. */
2725 unadjusted_args_size
2726 = compute_argument_block_size (reg_parm_stack_space,
2727 &adjusted_args_size,
2728 fndecl, fntype,
2729 (pass == 0 ? 0
2730 : preferred_stack_boundary));
2732 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2734 /* The argument block when performing a sibling call is the
2735 incoming argument block. */
2736 if (pass == 0)
2738 argblock = crtl->args.internal_arg_pointer;
2739 argblock
2740 #ifdef STACK_GROWS_DOWNWARD
2741 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
2742 #else
2743 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
2744 #endif
2745 stored_args_map = sbitmap_alloc (args_size.constant);
2746 bitmap_clear (stored_args_map);
2749 /* If we have no actual push instructions, or shouldn't use them,
2750 make space for all args right now. */
2751 else if (adjusted_args_size.var != 0)
2753 if (old_stack_level == 0)
2755 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2756 old_stack_pointer_delta = stack_pointer_delta;
2757 old_pending_adj = pending_stack_adjust;
2758 pending_stack_adjust = 0;
2759 /* stack_arg_under_construction says whether a stack arg is
2760 being constructed at the old stack level. Pushing the stack
2761 gets a clean outgoing argument block. */
2762 old_stack_arg_under_construction = stack_arg_under_construction;
2763 stack_arg_under_construction = 0;
2765 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2766 if (flag_stack_usage_info)
2767 current_function_has_unbounded_dynamic_stack_size = 1;
2769 else
2771 /* Note that we must go through the motions of allocating an argument
2772 block even if the size is zero because we may be storing args
2773 in the area reserved for register arguments, which may be part of
2774 the stack frame. */
2776 int needed = adjusted_args_size.constant;
2778 /* Store the maximum argument space used. It will be pushed by
2779 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2780 checking). */
2782 if (needed > crtl->outgoing_args_size)
2783 crtl->outgoing_args_size = needed;
2785 if (must_preallocate)
2787 if (ACCUMULATE_OUTGOING_ARGS)
2789 /* Since the stack pointer will never be pushed, it is
2790 possible for the evaluation of a parm to clobber
2791 something we have already written to the stack.
2792 Since most function calls on RISC machines do not use
2793 the stack, this is uncommon, but must work correctly.
2795 Therefore, we save any area of the stack that was already
2796 written and that we are using. Here we set up to do this
2797 by making a new stack usage map from the old one. The
2798 actual save will be done by store_one_arg.
2800 Another approach might be to try to reorder the argument
2801 evaluations to avoid this conflicting stack usage. */
2803 /* Since we will be writing into the entire argument area,
2804 the map must be allocated for its entire size, not just
2805 the part that is the responsibility of the caller. */
2806 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2807 needed += reg_parm_stack_space;
2809 #ifdef ARGS_GROW_DOWNWARD
2810 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2811 needed + 1);
2812 #else
2813 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2814 needed);
2815 #endif
2816 free (stack_usage_map_buf);
2817 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2818 stack_usage_map = stack_usage_map_buf;
2820 if (initial_highest_arg_in_use)
2821 memcpy (stack_usage_map, initial_stack_usage_map,
2822 initial_highest_arg_in_use);
2824 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2825 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2826 (highest_outgoing_arg_in_use
2827 - initial_highest_arg_in_use));
2828 needed = 0;
2830 /* The address of the outgoing argument list must not be
2831 copied to a register here, because argblock would be left
2832 pointing to the wrong place after the call to
2833 allocate_dynamic_stack_space below. */
2835 argblock = virtual_outgoing_args_rtx;
2837 else
2839 if (inhibit_defer_pop == 0)
2841 /* Try to reuse some or all of the pending_stack_adjust
2842 to get this space. */
2843 needed
2844 = (combine_pending_stack_adjustment_and_call
2845 (unadjusted_args_size,
2846 &adjusted_args_size,
2847 preferred_unit_stack_boundary));
2849 /* combine_pending_stack_adjustment_and_call computes
2850 an adjustment before the arguments are allocated.
2851 Account for them and see whether or not the stack
2852 needs to go up or down. */
2853 needed = unadjusted_args_size - needed;
2855 if (needed < 0)
2857 /* We're releasing stack space. */
2858 /* ??? We can avoid any adjustment at all if we're
2859 already aligned. FIXME. */
2860 pending_stack_adjust = -needed;
2861 do_pending_stack_adjust ();
2862 needed = 0;
2864 else
2865 /* We need to allocate space. We'll do that in
2866 push_block below. */
2867 pending_stack_adjust = 0;
2870 /* Special case this because overhead of `push_block' in
2871 this case is non-trivial. */
2872 if (needed == 0)
2873 argblock = virtual_outgoing_args_rtx;
2874 else
2876 argblock = push_block (GEN_INT (needed), 0, 0);
2877 #ifdef ARGS_GROW_DOWNWARD
2878 argblock = plus_constant (Pmode, argblock, needed);
2879 #endif
2882 /* We only really need to call `copy_to_reg' in the case
2883 where push insns are going to be used to pass ARGBLOCK
2884 to a function call in ARGS. In that case, the stack
2885 pointer changes value from the allocation point to the
2886 call point, and hence the value of
2887 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2888 as well always do it. */
2889 argblock = copy_to_reg (argblock);
2894 if (ACCUMULATE_OUTGOING_ARGS)
2896 /* The save/restore code in store_one_arg handles all
2897 cases except one: a constructor call (including a C
2898 function returning a BLKmode struct) to initialize
2899 an argument. */
2900 if (stack_arg_under_construction)
2902 rtx push_size
2903 = GEN_INT (adjusted_args_size.constant
2904 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2905 : TREE_TYPE (fndecl))) ? 0
2906 : reg_parm_stack_space));
2907 if (old_stack_level == 0)
2909 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2910 old_stack_pointer_delta = stack_pointer_delta;
2911 old_pending_adj = pending_stack_adjust;
2912 pending_stack_adjust = 0;
2913 /* stack_arg_under_construction says whether a stack
2914 arg is being constructed at the old stack level.
2915 Pushing the stack gets a clean outgoing argument
2916 block. */
2917 old_stack_arg_under_construction
2918 = stack_arg_under_construction;
2919 stack_arg_under_construction = 0;
2920 /* Make a new map for the new argument list. */
2921 free (stack_usage_map_buf);
2922 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2923 stack_usage_map = stack_usage_map_buf;
2924 highest_outgoing_arg_in_use = 0;
2926 /* We can pass TRUE as the 4th argument because we just
2927 saved the stack pointer and will restore it right after
2928 the call. */
2929 allocate_dynamic_stack_space (push_size, 0,
2930 BIGGEST_ALIGNMENT, true);
2933 /* If argument evaluation might modify the stack pointer,
2934 copy the address of the argument list to a register. */
2935 for (i = 0; i < num_actuals; i++)
2936 if (args[i].pass_on_stack)
2938 argblock = copy_addr_to_reg (argblock);
2939 break;
2943 compute_argument_addresses (args, argblock, num_actuals);
2945 /* If we push args individually in reverse order, perform stack alignment
2946 before the first push (the last arg). */
2947 if (PUSH_ARGS_REVERSED && argblock == 0
2948 && adjusted_args_size.constant != unadjusted_args_size)
2950 /* When the stack adjustment is pending, we get better code
2951 by combining the adjustments. */
2952 if (pending_stack_adjust
2953 && ! inhibit_defer_pop)
2955 pending_stack_adjust
2956 = (combine_pending_stack_adjustment_and_call
2957 (unadjusted_args_size,
2958 &adjusted_args_size,
2959 preferred_unit_stack_boundary));
2960 do_pending_stack_adjust ();
2962 else if (argblock == 0)
2963 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2964 - unadjusted_args_size));
2966 /* Now that the stack is properly aligned, pops can't safely
2967 be deferred during the evaluation of the arguments. */
2968 NO_DEFER_POP;
2970 /* Record the maximum pushed stack space size. We need to delay
2971 doing it this far to take into account the optimization done
2972 by combine_pending_stack_adjustment_and_call. */
2973 if (flag_stack_usage_info
2974 && !ACCUMULATE_OUTGOING_ARGS
2975 && pass
2976 && adjusted_args_size.var == 0)
2978 int pushed = adjusted_args_size.constant + pending_stack_adjust;
2979 if (pushed > current_function_pushed_stack_size)
2980 current_function_pushed_stack_size = pushed;
2983 funexp = rtx_for_function_call (fndecl, addr);
2985 /* Figure out the register where the value, if any, will come back. */
2986 valreg = 0;
2987 if (TYPE_MODE (rettype) != VOIDmode
2988 && ! structure_value_addr)
2990 if (pcc_struct_value)
2991 valreg = hard_function_value (build_pointer_type (rettype),
2992 fndecl, NULL, (pass == 0));
2993 else
2994 valreg = hard_function_value (rettype, fndecl, fntype,
2995 (pass == 0));
2997 /* If VALREG is a PARALLEL whose first member has a zero
2998 offset, use that. This is for targets such as m68k that
2999 return the same value in multiple places. */
3000 if (GET_CODE (valreg) == PARALLEL)
3002 rtx elem = XVECEXP (valreg, 0, 0);
3003 rtx where = XEXP (elem, 0);
3004 rtx offset = XEXP (elem, 1);
3005 if (offset == const0_rtx
3006 && GET_MODE (where) == GET_MODE (valreg))
3007 valreg = where;
3011 /* Precompute all register parameters. It isn't safe to compute anything
3012 once we have started filling any specific hard regs. */
3013 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3015 if (CALL_EXPR_STATIC_CHAIN (exp))
3016 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
3017 else
3018 static_chain_value = 0;
3020 #ifdef REG_PARM_STACK_SPACE
3021 /* Save the fixed argument area if it's part of the caller's frame and
3022 is clobbered by argument setup for this call. */
3023 if (ACCUMULATE_OUTGOING_ARGS && pass)
3024 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3025 &low_to_save, &high_to_save);
3026 #endif
3028 /* Now store (and compute if necessary) all non-register parms.
3029 These come before register parms, since they can require block-moves,
3030 which could clobber the registers used for register parms.
3031 Parms which have partial registers are not stored here,
3032 but we do preallocate space here if they want that. */
3034 for (i = 0; i < num_actuals; i++)
3036 if (args[i].reg == 0 || args[i].pass_on_stack)
3038 rtx before_arg = get_last_insn ();
3040 if (store_one_arg (&args[i], argblock, flags,
3041 adjusted_args_size.var != 0,
3042 reg_parm_stack_space)
3043 || (pass == 0
3044 && check_sibcall_argument_overlap (before_arg,
3045 &args[i], 1)))
3046 sibcall_failure = 1;
3049 if (args[i].stack)
3050 call_fusage
3051 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
3052 gen_rtx_USE (VOIDmode, args[i].stack),
3053 call_fusage);
3056 /* If we have a parm that is passed in registers but not in memory
3057 and whose alignment does not permit a direct copy into registers,
3058 make a group of pseudos that correspond to each register that we
3059 will later fill. */
3060 if (STRICT_ALIGNMENT)
3061 store_unaligned_arguments_into_pseudos (args, num_actuals);
3063 /* Now store any partially-in-registers parm.
3064 This is the last place a block-move can happen. */
3065 if (reg_parm_seen)
3066 for (i = 0; i < num_actuals; i++)
3067 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3069 rtx before_arg = get_last_insn ();
3071 if (store_one_arg (&args[i], argblock, flags,
3072 adjusted_args_size.var != 0,
3073 reg_parm_stack_space)
3074 || (pass == 0
3075 && check_sibcall_argument_overlap (before_arg,
3076 &args[i], 1)))
3077 sibcall_failure = 1;
3080 /* If we pushed args in forward order, perform stack alignment
3081 after pushing the last arg. */
3082 if (!PUSH_ARGS_REVERSED && argblock == 0)
3083 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3084 - unadjusted_args_size));
3086 /* If register arguments require space on the stack and stack space
3087 was not preallocated, allocate stack space here for arguments
3088 passed in registers. */
3089 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3090 && !ACCUMULATE_OUTGOING_ARGS
3091 && must_preallocate == 0 && reg_parm_stack_space > 0)
3092 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3094 /* Pass the function the address in which to return a
3095 structure value. */
3096 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3098 structure_value_addr
3099 = convert_memory_address (Pmode, structure_value_addr);
3100 emit_move_insn (struct_value,
3101 force_reg (Pmode,
3102 force_operand (structure_value_addr,
3103 NULL_RTX)));
3105 if (REG_P (struct_value))
3106 use_reg (&call_fusage, struct_value);
3109 after_args = get_last_insn ();
3110 funexp = prepare_call_address (fndecl, funexp, static_chain_value,
3111 &call_fusage, reg_parm_seen, pass == 0);
3113 load_register_parameters (args, num_actuals, &call_fusage, flags,
3114 pass == 0, &sibcall_failure);
3116 /* Save a pointer to the last insn before the call, so that we can
3117 later safely search backwards to find the CALL_INSN. */
3118 before_call = get_last_insn ();
3120 /* Set up next argument register. For sibling calls on machines
3121 with register windows this should be the incoming register. */
3122 if (pass == 0)
3123 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
3124 VOIDmode,
3125 void_type_node,
3126 true);
3127 else
3128 next_arg_reg = targetm.calls.function_arg (args_so_far,
3129 VOIDmode, void_type_node,
3130 true);
3132 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
3134 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
3135 if (PUSH_ARGS_REVERSED)
3136 arg_nr = num_actuals - arg_nr - 1;
3137 if (arg_nr >= 0
3138 && arg_nr < num_actuals
3139 && args[arg_nr].reg
3140 && valreg
3141 && REG_P (valreg)
3142 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
3143 call_fusage
3144 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
3145 gen_rtx_SET (VOIDmode, valreg, args[arg_nr].reg),
3146 call_fusage);
3148 /* All arguments and registers used for the call must be set up by
3149 now! */
3151 /* Stack must be properly aligned now. */
3152 gcc_assert (!pass
3153 || !(stack_pointer_delta % preferred_unit_stack_boundary));
3155 /* Generate the actual call instruction. */
3156 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
3157 adjusted_args_size.constant, struct_value_size,
3158 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3159 flags, args_so_far);
3161 /* If the call setup or the call itself overlaps with anything
3162 of the argument setup we probably clobbered our call address.
3163 In that case we can't do sibcalls. */
3164 if (pass == 0
3165 && check_sibcall_argument_overlap (after_args, 0, 0))
3166 sibcall_failure = 1;
3168 /* If a non-BLKmode value is returned at the most significant end
3169 of a register, shift the register right by the appropriate amount
3170 and update VALREG accordingly. BLKmode values are handled by the
3171 group load/store machinery below. */
3172 if (!structure_value_addr
3173 && !pcc_struct_value
3174 && TYPE_MODE (rettype) != VOIDmode
3175 && TYPE_MODE (rettype) != BLKmode
3176 && REG_P (valreg)
3177 && targetm.calls.return_in_msb (rettype))
3179 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
3180 sibcall_failure = 1;
3181 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
3184 if (pass && (flags & ECF_MALLOC))
3186 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3187 rtx last, insns;
3189 /* The return value from a malloc-like function is a pointer. */
3190 if (TREE_CODE (rettype) == POINTER_TYPE)
3191 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
3193 emit_move_insn (temp, valreg);
3195 /* The return value from a malloc-like function can not alias
3196 anything else. */
3197 last = get_last_insn ();
3198 add_reg_note (last, REG_NOALIAS, temp);
3200 /* Write out the sequence. */
3201 insns = get_insns ();
3202 end_sequence ();
3203 emit_insn (insns);
3204 valreg = temp;
3207 /* For calls to `setjmp', etc., inform
3208 function.c:setjmp_warnings that it should complain if
3209 nonvolatile values are live. For functions that cannot
3210 return, inform flow that control does not fall through. */
3212 if ((flags & ECF_NORETURN) || pass == 0)
3214 /* The barrier must be emitted
3215 immediately after the CALL_INSN. Some ports emit more
3216 than just a CALL_INSN above, so we must search for it here. */
3218 rtx last = get_last_insn ();
3219 while (!CALL_P (last))
3221 last = PREV_INSN (last);
3222 /* There was no CALL_INSN? */
3223 gcc_assert (last != before_call);
3226 emit_barrier_after (last);
3228 /* Stack adjustments after a noreturn call are dead code.
3229 However when NO_DEFER_POP is in effect, we must preserve
3230 stack_pointer_delta. */
3231 if (inhibit_defer_pop == 0)
3233 stack_pointer_delta = old_stack_allocated;
3234 pending_stack_adjust = 0;
3238 /* If value type not void, return an rtx for the value. */
3240 if (TYPE_MODE (rettype) == VOIDmode
3241 || ignore)
3242 target = const0_rtx;
3243 else if (structure_value_addr)
3245 if (target == 0 || !MEM_P (target))
3247 target
3248 = gen_rtx_MEM (TYPE_MODE (rettype),
3249 memory_address (TYPE_MODE (rettype),
3250 structure_value_addr));
3251 set_mem_attributes (target, rettype, 1);
3254 else if (pcc_struct_value)
3256 /* This is the special C++ case where we need to
3257 know what the true target was. We take care to
3258 never use this value more than once in one expression. */
3259 target = gen_rtx_MEM (TYPE_MODE (rettype),
3260 copy_to_reg (valreg));
3261 set_mem_attributes (target, rettype, 1);
3263 /* Handle calls that return values in multiple non-contiguous locations.
3264 The Irix 6 ABI has examples of this. */
3265 else if (GET_CODE (valreg) == PARALLEL)
3267 if (target == 0)
3268 target = emit_group_move_into_temps (valreg);
3269 else if (rtx_equal_p (target, valreg))
3271 else if (GET_CODE (target) == PARALLEL)
3272 /* Handle the result of a emit_group_move_into_temps
3273 call in the previous pass. */
3274 emit_group_move (target, valreg);
3275 else
3276 emit_group_store (target, valreg, rettype,
3277 int_size_in_bytes (rettype));
3279 else if (target
3280 && GET_MODE (target) == TYPE_MODE (rettype)
3281 && GET_MODE (target) == GET_MODE (valreg))
3283 bool may_overlap = false;
3285 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3286 reg to a plain register. */
3287 if (!REG_P (target) || HARD_REGISTER_P (target))
3288 valreg = avoid_likely_spilled_reg (valreg);
3290 /* If TARGET is a MEM in the argument area, and we have
3291 saved part of the argument area, then we can't store
3292 directly into TARGET as it may get overwritten when we
3293 restore the argument save area below. Don't work too
3294 hard though and simply force TARGET to a register if it
3295 is a MEM; the optimizer is quite likely to sort it out. */
3296 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
3297 for (i = 0; i < num_actuals; i++)
3298 if (args[i].save_area)
3300 may_overlap = true;
3301 break;
3304 if (may_overlap)
3305 target = copy_to_reg (valreg);
3306 else
3308 /* TARGET and VALREG cannot be equal at this point
3309 because the latter would not have
3310 REG_FUNCTION_VALUE_P true, while the former would if
3311 it were referring to the same register.
3313 If they refer to the same register, this move will be
3314 a no-op, except when function inlining is being
3315 done. */
3316 emit_move_insn (target, valreg);
3318 /* If we are setting a MEM, this code must be executed.
3319 Since it is emitted after the call insn, sibcall
3320 optimization cannot be performed in that case. */
3321 if (MEM_P (target))
3322 sibcall_failure = 1;
3325 else
3326 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3328 /* If we promoted this return value, make the proper SUBREG.
3329 TARGET might be const0_rtx here, so be careful. */
3330 if (REG_P (target)
3331 && TYPE_MODE (rettype) != BLKmode
3332 && GET_MODE (target) != TYPE_MODE (rettype))
3334 tree type = rettype;
3335 int unsignedp = TYPE_UNSIGNED (type);
3336 int offset = 0;
3337 enum machine_mode pmode;
3339 /* Ensure we promote as expected, and get the new unsignedness. */
3340 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3341 funtype, 1);
3342 gcc_assert (GET_MODE (target) == pmode);
3344 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3345 && (GET_MODE_SIZE (GET_MODE (target))
3346 > GET_MODE_SIZE (TYPE_MODE (type))))
3348 offset = GET_MODE_SIZE (GET_MODE (target))
3349 - GET_MODE_SIZE (TYPE_MODE (type));
3350 if (! BYTES_BIG_ENDIAN)
3351 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3352 else if (! WORDS_BIG_ENDIAN)
3353 offset %= UNITS_PER_WORD;
3356 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3357 SUBREG_PROMOTED_VAR_P (target) = 1;
3358 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3361 /* If size of args is variable or this was a constructor call for a stack
3362 argument, restore saved stack-pointer value. */
3364 if (old_stack_level)
3366 rtx prev = get_last_insn ();
3368 emit_stack_restore (SAVE_BLOCK, old_stack_level);
3369 stack_pointer_delta = old_stack_pointer_delta;
3371 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
3373 pending_stack_adjust = old_pending_adj;
3374 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3375 stack_arg_under_construction = old_stack_arg_under_construction;
3376 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3377 stack_usage_map = initial_stack_usage_map;
3378 sibcall_failure = 1;
3380 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3382 #ifdef REG_PARM_STACK_SPACE
3383 if (save_area)
3384 restore_fixed_argument_area (save_area, argblock,
3385 high_to_save, low_to_save);
3386 #endif
3388 /* If we saved any argument areas, restore them. */
3389 for (i = 0; i < num_actuals; i++)
3390 if (args[i].save_area)
3392 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3393 rtx stack_area
3394 = gen_rtx_MEM (save_mode,
3395 memory_address (save_mode,
3396 XEXP (args[i].stack_slot, 0)));
3398 if (save_mode != BLKmode)
3399 emit_move_insn (stack_area, args[i].save_area);
3400 else
3401 emit_block_move (stack_area, args[i].save_area,
3402 GEN_INT (args[i].locate.size.constant),
3403 BLOCK_OP_CALL_PARM);
3406 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3407 stack_usage_map = initial_stack_usage_map;
3410 /* If this was alloca, record the new stack level for nonlocal gotos.
3411 Check for the handler slots since we might not have a save area
3412 for non-local gotos. */
3414 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3415 update_nonlocal_goto_save_area ();
3417 /* Free up storage we no longer need. */
3418 for (i = 0; i < num_actuals; ++i)
3419 free (args[i].aligned_regs);
3421 insns = get_insns ();
3422 end_sequence ();
3424 if (pass == 0)
3426 tail_call_insns = insns;
3428 /* Restore the pending stack adjustment now that we have
3429 finished generating the sibling call sequence. */
3431 pending_stack_adjust = save_pending_stack_adjust;
3432 stack_pointer_delta = save_stack_pointer_delta;
3434 /* Prepare arg structure for next iteration. */
3435 for (i = 0; i < num_actuals; i++)
3437 args[i].value = 0;
3438 args[i].aligned_regs = 0;
3439 args[i].stack = 0;
3442 sbitmap_free (stored_args_map);
3443 internal_arg_pointer_exp_state.scan_start = NULL_RTX;
3444 internal_arg_pointer_exp_state.cache.release ();
3446 else
3448 normal_call_insns = insns;
3450 /* Verify that we've deallocated all the stack we used. */
3451 gcc_assert ((flags & ECF_NORETURN)
3452 || (old_stack_allocated
3453 == stack_pointer_delta - pending_stack_adjust));
3456 /* If something prevents making this a sibling call,
3457 zero out the sequence. */
3458 if (sibcall_failure)
3459 tail_call_insns = NULL_RTX;
3460 else
3461 break;
3464 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3465 arguments too, as argument area is now clobbered by the call. */
3466 if (tail_call_insns)
3468 emit_insn (tail_call_insns);
3469 crtl->tail_call_emit = true;
3471 else
3472 emit_insn (normal_call_insns);
3474 currently_expanding_call--;
3476 free (stack_usage_map_buf);
3478 return target;
3481 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3482 this function's incoming arguments.
3484 At the start of RTL generation we know the only REG_EQUIV notes
3485 in the rtl chain are those for incoming arguments, so we can look
3486 for REG_EQUIV notes between the start of the function and the
3487 NOTE_INSN_FUNCTION_BEG.
3489 This is (slight) overkill. We could keep track of the highest
3490 argument we clobber and be more selective in removing notes, but it
3491 does not seem to be worth the effort. */
3493 void
3494 fixup_tail_calls (void)
3496 rtx insn;
3498 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3500 rtx note;
3502 /* There are never REG_EQUIV notes for the incoming arguments
3503 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3504 if (NOTE_P (insn)
3505 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3506 break;
3508 note = find_reg_note (insn, REG_EQUIV, 0);
3509 if (note)
3510 remove_note (insn, note);
3511 note = find_reg_note (insn, REG_EQUIV, 0);
3512 gcc_assert (!note);
3516 /* Traverse a list of TYPES and expand all complex types into their
3517 components. */
3518 static tree
3519 split_complex_types (tree types)
3521 tree p;
3523 /* Before allocating memory, check for the common case of no complex. */
3524 for (p = types; p; p = TREE_CHAIN (p))
3526 tree type = TREE_VALUE (p);
3527 if (TREE_CODE (type) == COMPLEX_TYPE
3528 && targetm.calls.split_complex_arg (type))
3529 goto found;
3531 return types;
3533 found:
3534 types = copy_list (types);
3536 for (p = types; p; p = TREE_CHAIN (p))
3538 tree complex_type = TREE_VALUE (p);
3540 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3541 && targetm.calls.split_complex_arg (complex_type))
3543 tree next, imag;
3545 /* Rewrite complex type with component type. */
3546 TREE_VALUE (p) = TREE_TYPE (complex_type);
3547 next = TREE_CHAIN (p);
3549 /* Add another component type for the imaginary part. */
3550 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3551 TREE_CHAIN (p) = imag;
3552 TREE_CHAIN (imag) = next;
3554 /* Skip the newly created node. */
3555 p = TREE_CHAIN (p);
3559 return types;
3562 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3563 The RETVAL parameter specifies whether return value needs to be saved, other
3564 parameters are documented in the emit_library_call function below. */
3566 static rtx
3567 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3568 enum libcall_type fn_type,
3569 enum machine_mode outmode, int nargs, va_list p)
3571 /* Total size in bytes of all the stack-parms scanned so far. */
3572 struct args_size args_size;
3573 /* Size of arguments before any adjustments (such as rounding). */
3574 struct args_size original_args_size;
3575 int argnum;
3576 rtx fun;
3577 /* Todo, choose the correct decl type of orgfun. Sadly this information
3578 isn't present here, so we default to native calling abi here. */
3579 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3580 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3581 int inc;
3582 int count;
3583 rtx argblock = 0;
3584 CUMULATIVE_ARGS args_so_far_v;
3585 cumulative_args_t args_so_far;
3586 struct arg
3588 rtx value;
3589 enum machine_mode mode;
3590 rtx reg;
3591 int partial;
3592 struct locate_and_pad_arg_data locate;
3593 rtx save_area;
3595 struct arg *argvec;
3596 int old_inhibit_defer_pop = inhibit_defer_pop;
3597 rtx call_fusage = 0;
3598 rtx mem_value = 0;
3599 rtx valreg;
3600 int pcc_struct_value = 0;
3601 int struct_value_size = 0;
3602 int flags;
3603 int reg_parm_stack_space = 0;
3604 int needed;
3605 rtx before_call;
3606 tree tfom; /* type_for_mode (outmode, 0) */
3608 #ifdef REG_PARM_STACK_SPACE
3609 /* Define the boundary of the register parm stack space that needs to be
3610 save, if any. */
3611 int low_to_save = 0, high_to_save = 0;
3612 rtx save_area = 0; /* Place that it is saved. */
3613 #endif
3615 /* Size of the stack reserved for parameter registers. */
3616 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3617 char *initial_stack_usage_map = stack_usage_map;
3618 char *stack_usage_map_buf = NULL;
3620 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3622 #ifdef REG_PARM_STACK_SPACE
3623 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3624 #endif
3626 /* By default, library functions can not throw. */
3627 flags = ECF_NOTHROW;
3629 switch (fn_type)
3631 case LCT_NORMAL:
3632 break;
3633 case LCT_CONST:
3634 flags |= ECF_CONST;
3635 break;
3636 case LCT_PURE:
3637 flags |= ECF_PURE;
3638 break;
3639 case LCT_NORETURN:
3640 flags |= ECF_NORETURN;
3641 break;
3642 case LCT_THROW:
3643 flags = ECF_NORETURN;
3644 break;
3645 case LCT_RETURNS_TWICE:
3646 flags = ECF_RETURNS_TWICE;
3647 break;
3649 fun = orgfun;
3651 /* Ensure current function's preferred stack boundary is at least
3652 what we need. */
3653 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3654 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3656 /* If this kind of value comes back in memory,
3657 decide where in memory it should come back. */
3658 if (outmode != VOIDmode)
3660 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3661 if (aggregate_value_p (tfom, 0))
3663 #ifdef PCC_STATIC_STRUCT_RETURN
3664 rtx pointer_reg
3665 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3666 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3667 pcc_struct_value = 1;
3668 if (value == 0)
3669 value = gen_reg_rtx (outmode);
3670 #else /* not PCC_STATIC_STRUCT_RETURN */
3671 struct_value_size = GET_MODE_SIZE (outmode);
3672 if (value != 0 && MEM_P (value))
3673 mem_value = value;
3674 else
3675 mem_value = assign_temp (tfom, 1, 1);
3676 #endif
3677 /* This call returns a big structure. */
3678 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3681 else
3682 tfom = void_type_node;
3684 /* ??? Unfinished: must pass the memory address as an argument. */
3686 /* Copy all the libcall-arguments out of the varargs data
3687 and into a vector ARGVEC.
3689 Compute how to pass each argument. We only support a very small subset
3690 of the full argument passing conventions to limit complexity here since
3691 library functions shouldn't have many args. */
3693 argvec = XALLOCAVEC (struct arg, nargs + 1);
3694 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3696 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3697 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
3698 #else
3699 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
3700 #endif
3701 args_so_far = pack_cumulative_args (&args_so_far_v);
3703 args_size.constant = 0;
3704 args_size.var = 0;
3706 count = 0;
3708 push_temp_slots ();
3710 /* If there's a structure value address to be passed,
3711 either pass it in the special place, or pass it as an extra argument. */
3712 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3714 rtx addr = XEXP (mem_value, 0);
3716 nargs++;
3718 /* Make sure it is a reasonable operand for a move or push insn. */
3719 if (!REG_P (addr) && !MEM_P (addr)
3720 && !(CONSTANT_P (addr)
3721 && targetm.legitimate_constant_p (Pmode, addr)))
3722 addr = force_operand (addr, NULL_RTX);
3724 argvec[count].value = addr;
3725 argvec[count].mode = Pmode;
3726 argvec[count].partial = 0;
3728 argvec[count].reg = targetm.calls.function_arg (args_so_far,
3729 Pmode, NULL_TREE, true);
3730 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
3731 NULL_TREE, 1) == 0);
3733 locate_and_pad_parm (Pmode, NULL_TREE,
3734 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3736 #else
3737 argvec[count].reg != 0,
3738 #endif
3739 0, NULL_TREE, &args_size, &argvec[count].locate);
3741 if (argvec[count].reg == 0 || argvec[count].partial != 0
3742 || reg_parm_stack_space > 0)
3743 args_size.constant += argvec[count].locate.size.constant;
3745 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
3747 count++;
3750 for (; count < nargs; count++)
3752 rtx val = va_arg (p, rtx);
3753 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3754 int unsigned_p = 0;
3756 /* We cannot convert the arg value to the mode the library wants here;
3757 must do it earlier where we know the signedness of the arg. */
3758 gcc_assert (mode != BLKmode
3759 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3761 /* Make sure it is a reasonable operand for a move or push insn. */
3762 if (!REG_P (val) && !MEM_P (val)
3763 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
3764 val = force_operand (val, NULL_RTX);
3766 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
3768 rtx slot;
3769 int must_copy
3770 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
3772 /* If this was a CONST function, it is now PURE since it now
3773 reads memory. */
3774 if (flags & ECF_CONST)
3776 flags &= ~ECF_CONST;
3777 flags |= ECF_PURE;
3780 if (MEM_P (val) && !must_copy)
3782 tree val_expr = MEM_EXPR (val);
3783 if (val_expr)
3784 mark_addressable (val_expr);
3785 slot = val;
3787 else
3789 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3790 1, 1);
3791 emit_move_insn (slot, val);
3794 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3795 gen_rtx_USE (VOIDmode, slot),
3796 call_fusage);
3797 if (must_copy)
3798 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3799 gen_rtx_CLOBBER (VOIDmode,
3800 slot),
3801 call_fusage);
3803 mode = Pmode;
3804 val = force_operand (XEXP (slot, 0), NULL_RTX);
3807 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
3808 argvec[count].mode = mode;
3809 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
3810 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
3811 NULL_TREE, true);
3813 argvec[count].partial
3814 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
3816 if (argvec[count].reg == 0
3817 || argvec[count].partial != 0
3818 || reg_parm_stack_space > 0)
3820 locate_and_pad_parm (mode, NULL_TREE,
3821 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3823 #else
3824 argvec[count].reg != 0,
3825 #endif
3826 argvec[count].partial,
3827 NULL_TREE, &args_size, &argvec[count].locate);
3828 args_size.constant += argvec[count].locate.size.constant;
3829 gcc_assert (!argvec[count].locate.size.var);
3831 #ifdef BLOCK_REG_PADDING
3832 else
3833 /* The argument is passed entirely in registers. See at which
3834 end it should be padded. */
3835 argvec[count].locate.where_pad =
3836 BLOCK_REG_PADDING (mode, NULL_TREE,
3837 GET_MODE_SIZE (mode) <= UNITS_PER_WORD);
3838 #endif
3840 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
3843 /* If this machine requires an external definition for library
3844 functions, write one out. */
3845 assemble_external_libcall (fun);
3847 original_args_size = args_size;
3848 args_size.constant = (((args_size.constant
3849 + stack_pointer_delta
3850 + STACK_BYTES - 1)
3851 / STACK_BYTES
3852 * STACK_BYTES)
3853 - stack_pointer_delta);
3855 args_size.constant = MAX (args_size.constant,
3856 reg_parm_stack_space);
3858 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3859 args_size.constant -= reg_parm_stack_space;
3861 if (args_size.constant > crtl->outgoing_args_size)
3862 crtl->outgoing_args_size = args_size.constant;
3864 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
3866 int pushed = args_size.constant + pending_stack_adjust;
3867 if (pushed > current_function_pushed_stack_size)
3868 current_function_pushed_stack_size = pushed;
3871 if (ACCUMULATE_OUTGOING_ARGS)
3873 /* Since the stack pointer will never be pushed, it is possible for
3874 the evaluation of a parm to clobber something we have already
3875 written to the stack. Since most function calls on RISC machines
3876 do not use the stack, this is uncommon, but must work correctly.
3878 Therefore, we save any area of the stack that was already written
3879 and that we are using. Here we set up to do this by making a new
3880 stack usage map from the old one.
3882 Another approach might be to try to reorder the argument
3883 evaluations to avoid this conflicting stack usage. */
3885 needed = args_size.constant;
3887 /* Since we will be writing into the entire argument area, the
3888 map must be allocated for its entire size, not just the part that
3889 is the responsibility of the caller. */
3890 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3891 needed += reg_parm_stack_space;
3893 #ifdef ARGS_GROW_DOWNWARD
3894 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3895 needed + 1);
3896 #else
3897 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3898 needed);
3899 #endif
3900 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3901 stack_usage_map = stack_usage_map_buf;
3903 if (initial_highest_arg_in_use)
3904 memcpy (stack_usage_map, initial_stack_usage_map,
3905 initial_highest_arg_in_use);
3907 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3908 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3909 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3910 needed = 0;
3912 /* We must be careful to use virtual regs before they're instantiated,
3913 and real regs afterwards. Loop optimization, for example, can create
3914 new libcalls after we've instantiated the virtual regs, and if we
3915 use virtuals anyway, they won't match the rtl patterns. */
3917 if (virtuals_instantiated)
3918 argblock = plus_constant (Pmode, stack_pointer_rtx,
3919 STACK_POINTER_OFFSET);
3920 else
3921 argblock = virtual_outgoing_args_rtx;
3923 else
3925 if (!PUSH_ARGS)
3926 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3929 /* If we push args individually in reverse order, perform stack alignment
3930 before the first push (the last arg). */
3931 if (argblock == 0 && PUSH_ARGS_REVERSED)
3932 anti_adjust_stack (GEN_INT (args_size.constant
3933 - original_args_size.constant));
3935 if (PUSH_ARGS_REVERSED)
3937 inc = -1;
3938 argnum = nargs - 1;
3940 else
3942 inc = 1;
3943 argnum = 0;
3946 #ifdef REG_PARM_STACK_SPACE
3947 if (ACCUMULATE_OUTGOING_ARGS)
3949 /* The argument list is the property of the called routine and it
3950 may clobber it. If the fixed area has been used for previous
3951 parameters, we must save and restore it. */
3952 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3953 &low_to_save, &high_to_save);
3955 #endif
3957 /* Push the args that need to be pushed. */
3959 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3960 are to be pushed. */
3961 for (count = 0; count < nargs; count++, argnum += inc)
3963 enum machine_mode mode = argvec[argnum].mode;
3964 rtx val = argvec[argnum].value;
3965 rtx reg = argvec[argnum].reg;
3966 int partial = argvec[argnum].partial;
3967 unsigned int parm_align = argvec[argnum].locate.boundary;
3968 int lower_bound = 0, upper_bound = 0, i;
3970 if (! (reg != 0 && partial == 0))
3972 rtx use;
3974 if (ACCUMULATE_OUTGOING_ARGS)
3976 /* If this is being stored into a pre-allocated, fixed-size,
3977 stack area, save any previous data at that location. */
3979 #ifdef ARGS_GROW_DOWNWARD
3980 /* stack_slot is negative, but we want to index stack_usage_map
3981 with positive values. */
3982 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3983 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3984 #else
3985 lower_bound = argvec[argnum].locate.slot_offset.constant;
3986 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3987 #endif
3989 i = lower_bound;
3990 /* Don't worry about things in the fixed argument area;
3991 it has already been saved. */
3992 if (i < reg_parm_stack_space)
3993 i = reg_parm_stack_space;
3994 while (i < upper_bound && stack_usage_map[i] == 0)
3995 i++;
3997 if (i < upper_bound)
3999 /* We need to make a save area. */
4000 unsigned int size
4001 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4002 enum machine_mode save_mode
4003 = mode_for_size (size, MODE_INT, 1);
4004 rtx adr
4005 = plus_constant (Pmode, argblock,
4006 argvec[argnum].locate.offset.constant);
4007 rtx stack_area
4008 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4010 if (save_mode == BLKmode)
4012 argvec[argnum].save_area
4013 = assign_stack_temp (BLKmode,
4014 argvec[argnum].locate.size.constant
4017 emit_block_move (validize_mem (argvec[argnum].save_area),
4018 stack_area,
4019 GEN_INT (argvec[argnum].locate.size.constant),
4020 BLOCK_OP_CALL_PARM);
4022 else
4024 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4026 emit_move_insn (argvec[argnum].save_area, stack_area);
4031 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
4032 partial, reg, 0, argblock,
4033 GEN_INT (argvec[argnum].locate.offset.constant),
4034 reg_parm_stack_space,
4035 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4037 /* Now mark the segment we just used. */
4038 if (ACCUMULATE_OUTGOING_ARGS)
4039 for (i = lower_bound; i < upper_bound; i++)
4040 stack_usage_map[i] = 1;
4042 NO_DEFER_POP;
4044 /* Indicate argument access so that alias.c knows that these
4045 values are live. */
4046 if (argblock)
4047 use = plus_constant (Pmode, argblock,
4048 argvec[argnum].locate.offset.constant);
4049 else
4050 /* When arguments are pushed, trying to tell alias.c where
4051 exactly this argument is won't work, because the
4052 auto-increment causes confusion. So we merely indicate
4053 that we access something with a known mode somewhere on
4054 the stack. */
4055 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
4056 gen_rtx_SCRATCH (Pmode));
4057 use = gen_rtx_MEM (argvec[argnum].mode, use);
4058 use = gen_rtx_USE (VOIDmode, use);
4059 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
4063 /* If we pushed args in forward order, perform stack alignment
4064 after pushing the last arg. */
4065 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4066 anti_adjust_stack (GEN_INT (args_size.constant
4067 - original_args_size.constant));
4069 if (PUSH_ARGS_REVERSED)
4070 argnum = nargs - 1;
4071 else
4072 argnum = 0;
4074 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
4076 /* Now load any reg parms into their regs. */
4078 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4079 are to be pushed. */
4080 for (count = 0; count < nargs; count++, argnum += inc)
4082 enum machine_mode mode = argvec[argnum].mode;
4083 rtx val = argvec[argnum].value;
4084 rtx reg = argvec[argnum].reg;
4085 int partial = argvec[argnum].partial;
4086 #ifdef BLOCK_REG_PADDING
4087 int size = 0;
4088 #endif
4090 /* Handle calls that pass values in multiple non-contiguous
4091 locations. The PA64 has examples of this for library calls. */
4092 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4093 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
4094 else if (reg != 0 && partial == 0)
4096 emit_move_insn (reg, val);
4097 #ifdef BLOCK_REG_PADDING
4098 size = GET_MODE_SIZE (argvec[argnum].mode);
4100 /* Copied from load_register_parameters. */
4102 /* Handle case where we have a value that needs shifting
4103 up to the msb. eg. a QImode value and we're padding
4104 upward on a BYTES_BIG_ENDIAN machine. */
4105 if (size < UNITS_PER_WORD
4106 && (argvec[argnum].locate.where_pad
4107 == (BYTES_BIG_ENDIAN ? upward : downward)))
4109 rtx x;
4110 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4112 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4113 report the whole reg as used. Strictly speaking, the
4114 call only uses SIZE bytes at the msb end, but it doesn't
4115 seem worth generating rtl to say that. */
4116 reg = gen_rtx_REG (word_mode, REGNO (reg));
4117 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
4118 if (x != reg)
4119 emit_move_insn (reg, x);
4121 #endif
4124 NO_DEFER_POP;
4127 /* Any regs containing parms remain in use through the call. */
4128 for (count = 0; count < nargs; count++)
4130 rtx reg = argvec[count].reg;
4131 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4132 use_group_regs (&call_fusage, reg);
4133 else if (reg != 0)
4135 int partial = argvec[count].partial;
4136 if (partial)
4138 int nregs;
4139 gcc_assert (partial % UNITS_PER_WORD == 0);
4140 nregs = partial / UNITS_PER_WORD;
4141 use_regs (&call_fusage, REGNO (reg), nregs);
4143 else
4144 use_reg (&call_fusage, reg);
4148 /* Pass the function the address in which to return a structure value. */
4149 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4151 emit_move_insn (struct_value,
4152 force_reg (Pmode,
4153 force_operand (XEXP (mem_value, 0),
4154 NULL_RTX)));
4155 if (REG_P (struct_value))
4156 use_reg (&call_fusage, struct_value);
4159 /* Don't allow popping to be deferred, since then
4160 cse'ing of library calls could delete a call and leave the pop. */
4161 NO_DEFER_POP;
4162 valreg = (mem_value == 0 && outmode != VOIDmode
4163 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
4165 /* Stack must be properly aligned now. */
4166 gcc_assert (!(stack_pointer_delta
4167 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
4169 before_call = get_last_insn ();
4171 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4172 will set inhibit_defer_pop to that value. */
4173 /* The return type is needed to decide how many bytes the function pops.
4174 Signedness plays no role in that, so for simplicity, we pretend it's
4175 always signed. We also assume that the list of arguments passed has
4176 no impact, so we pretend it is unknown. */
4178 emit_call_1 (fun, NULL,
4179 get_identifier (XSTR (orgfun, 0)),
4180 build_function_type (tfom, NULL_TREE),
4181 original_args_size.constant, args_size.constant,
4182 struct_value_size,
4183 targetm.calls.function_arg (args_so_far,
4184 VOIDmode, void_type_node, true),
4185 valreg,
4186 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
4188 /* Right-shift returned value if necessary. */
4189 if (!pcc_struct_value
4190 && TYPE_MODE (tfom) != BLKmode
4191 && targetm.calls.return_in_msb (tfom))
4193 shift_return_value (TYPE_MODE (tfom), false, valreg);
4194 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
4197 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
4198 that it should complain if nonvolatile values are live. For
4199 functions that cannot return, inform flow that control does not
4200 fall through. */
4201 if (flags & ECF_NORETURN)
4203 /* The barrier note must be emitted
4204 immediately after the CALL_INSN. Some ports emit more than
4205 just a CALL_INSN above, so we must search for it here. */
4206 rtx last = get_last_insn ();
4207 while (!CALL_P (last))
4209 last = PREV_INSN (last);
4210 /* There was no CALL_INSN? */
4211 gcc_assert (last != before_call);
4214 emit_barrier_after (last);
4217 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
4218 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
4219 if (flags & ECF_NOTHROW)
4221 rtx last = get_last_insn ();
4222 while (!CALL_P (last))
4224 last = PREV_INSN (last);
4225 /* There was no CALL_INSN? */
4226 gcc_assert (last != before_call);
4229 make_reg_eh_region_note_nothrow_nononlocal (last);
4232 /* Now restore inhibit_defer_pop to its actual original value. */
4233 OK_DEFER_POP;
4235 pop_temp_slots ();
4237 /* Copy the value to the right place. */
4238 if (outmode != VOIDmode && retval)
4240 if (mem_value)
4242 if (value == 0)
4243 value = mem_value;
4244 if (value != mem_value)
4245 emit_move_insn (value, mem_value);
4247 else if (GET_CODE (valreg) == PARALLEL)
4249 if (value == 0)
4250 value = gen_reg_rtx (outmode);
4251 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4253 else
4255 /* Convert to the proper mode if a promotion has been active. */
4256 if (GET_MODE (valreg) != outmode)
4258 int unsignedp = TYPE_UNSIGNED (tfom);
4260 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
4261 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
4262 == GET_MODE (valreg));
4263 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
4266 if (value != 0)
4267 emit_move_insn (value, valreg);
4268 else
4269 value = valreg;
4273 if (ACCUMULATE_OUTGOING_ARGS)
4275 #ifdef REG_PARM_STACK_SPACE
4276 if (save_area)
4277 restore_fixed_argument_area (save_area, argblock,
4278 high_to_save, low_to_save);
4279 #endif
4281 /* If we saved any argument areas, restore them. */
4282 for (count = 0; count < nargs; count++)
4283 if (argvec[count].save_area)
4285 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4286 rtx adr = plus_constant (Pmode, argblock,
4287 argvec[count].locate.offset.constant);
4288 rtx stack_area = gen_rtx_MEM (save_mode,
4289 memory_address (save_mode, adr));
4291 if (save_mode == BLKmode)
4292 emit_block_move (stack_area,
4293 validize_mem (argvec[count].save_area),
4294 GEN_INT (argvec[count].locate.size.constant),
4295 BLOCK_OP_CALL_PARM);
4296 else
4297 emit_move_insn (stack_area, argvec[count].save_area);
4300 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4301 stack_usage_map = initial_stack_usage_map;
4304 free (stack_usage_map_buf);
4306 return value;
4310 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4311 (emitting the queue unless NO_QUEUE is nonzero),
4312 for a value of mode OUTMODE,
4313 with NARGS different arguments, passed as alternating rtx values
4314 and machine_modes to convert them to.
4316 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4317 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
4318 other types of library calls. */
4320 void
4321 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4322 enum machine_mode outmode, int nargs, ...)
4324 va_list p;
4326 va_start (p, nargs);
4327 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4328 va_end (p);
4331 /* Like emit_library_call except that an extra argument, VALUE,
4332 comes second and says where to store the result.
4333 (If VALUE is zero, this function chooses a convenient way
4334 to return the value.
4336 This function returns an rtx for where the value is to be found.
4337 If VALUE is nonzero, VALUE is returned. */
4340 emit_library_call_value (rtx orgfun, rtx value,
4341 enum libcall_type fn_type,
4342 enum machine_mode outmode, int nargs, ...)
4344 rtx result;
4345 va_list p;
4347 va_start (p, nargs);
4348 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4349 nargs, p);
4350 va_end (p);
4352 return result;
4355 /* Store a single argument for a function call
4356 into the register or memory area where it must be passed.
4357 *ARG describes the argument value and where to pass it.
4359 ARGBLOCK is the address of the stack-block for all the arguments,
4360 or 0 on a machine where arguments are pushed individually.
4362 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4363 so must be careful about how the stack is used.
4365 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4366 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4367 that we need not worry about saving and restoring the stack.
4369 FNDECL is the declaration of the function we are calling.
4371 Return nonzero if this arg should cause sibcall failure,
4372 zero otherwise. */
4374 static int
4375 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4376 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4378 tree pval = arg->tree_value;
4379 rtx reg = 0;
4380 int partial = 0;
4381 int used = 0;
4382 int i, lower_bound = 0, upper_bound = 0;
4383 int sibcall_failure = 0;
4385 if (TREE_CODE (pval) == ERROR_MARK)
4386 return 1;
4388 /* Push a new temporary level for any temporaries we make for
4389 this argument. */
4390 push_temp_slots ();
4392 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4394 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4395 save any previous data at that location. */
4396 if (argblock && ! variable_size && arg->stack)
4398 #ifdef ARGS_GROW_DOWNWARD
4399 /* stack_slot is negative, but we want to index stack_usage_map
4400 with positive values. */
4401 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4402 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4403 else
4404 upper_bound = 0;
4406 lower_bound = upper_bound - arg->locate.size.constant;
4407 #else
4408 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4409 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4410 else
4411 lower_bound = 0;
4413 upper_bound = lower_bound + arg->locate.size.constant;
4414 #endif
4416 i = lower_bound;
4417 /* Don't worry about things in the fixed argument area;
4418 it has already been saved. */
4419 if (i < reg_parm_stack_space)
4420 i = reg_parm_stack_space;
4421 while (i < upper_bound && stack_usage_map[i] == 0)
4422 i++;
4424 if (i < upper_bound)
4426 /* We need to make a save area. */
4427 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4428 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4429 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4430 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4432 if (save_mode == BLKmode)
4434 tree ot = TREE_TYPE (arg->tree_value);
4435 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4436 | TYPE_QUAL_CONST));
4438 arg->save_area = assign_temp (nt, 1, 1);
4439 preserve_temp_slots (arg->save_area);
4440 emit_block_move (validize_mem (arg->save_area), stack_area,
4441 GEN_INT (arg->locate.size.constant),
4442 BLOCK_OP_CALL_PARM);
4444 else
4446 arg->save_area = gen_reg_rtx (save_mode);
4447 emit_move_insn (arg->save_area, stack_area);
4453 /* If this isn't going to be placed on both the stack and in registers,
4454 set up the register and number of words. */
4455 if (! arg->pass_on_stack)
4457 if (flags & ECF_SIBCALL)
4458 reg = arg->tail_call_reg;
4459 else
4460 reg = arg->reg;
4461 partial = arg->partial;
4464 /* Being passed entirely in a register. We shouldn't be called in
4465 this case. */
4466 gcc_assert (reg == 0 || partial != 0);
4468 /* If this arg needs special alignment, don't load the registers
4469 here. */
4470 if (arg->n_aligned_regs != 0)
4471 reg = 0;
4473 /* If this is being passed partially in a register, we can't evaluate
4474 it directly into its stack slot. Otherwise, we can. */
4475 if (arg->value == 0)
4477 /* stack_arg_under_construction is nonzero if a function argument is
4478 being evaluated directly into the outgoing argument list and
4479 expand_call must take special action to preserve the argument list
4480 if it is called recursively.
4482 For scalar function arguments stack_usage_map is sufficient to
4483 determine which stack slots must be saved and restored. Scalar
4484 arguments in general have pass_on_stack == 0.
4486 If this argument is initialized by a function which takes the
4487 address of the argument (a C++ constructor or a C function
4488 returning a BLKmode structure), then stack_usage_map is
4489 insufficient and expand_call must push the stack around the
4490 function call. Such arguments have pass_on_stack == 1.
4492 Note that it is always safe to set stack_arg_under_construction,
4493 but this generates suboptimal code if set when not needed. */
4495 if (arg->pass_on_stack)
4496 stack_arg_under_construction++;
4498 arg->value = expand_expr (pval,
4499 (partial
4500 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4501 ? NULL_RTX : arg->stack,
4502 VOIDmode, EXPAND_STACK_PARM);
4504 /* If we are promoting object (or for any other reason) the mode
4505 doesn't agree, convert the mode. */
4507 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4508 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4509 arg->value, arg->unsignedp);
4511 if (arg->pass_on_stack)
4512 stack_arg_under_construction--;
4515 /* Check for overlap with already clobbered argument area. */
4516 if ((flags & ECF_SIBCALL)
4517 && MEM_P (arg->value)
4518 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4519 arg->locate.size.constant))
4520 sibcall_failure = 1;
4522 /* Don't allow anything left on stack from computation
4523 of argument to alloca. */
4524 if (flags & ECF_MAY_BE_ALLOCA)
4525 do_pending_stack_adjust ();
4527 if (arg->value == arg->stack)
4528 /* If the value is already in the stack slot, we are done. */
4530 else if (arg->mode != BLKmode)
4532 int size;
4533 unsigned int parm_align;
4535 /* Argument is a scalar, not entirely passed in registers.
4536 (If part is passed in registers, arg->partial says how much
4537 and emit_push_insn will take care of putting it there.)
4539 Push it, and if its size is less than the
4540 amount of space allocated to it,
4541 also bump stack pointer by the additional space.
4542 Note that in C the default argument promotions
4543 will prevent such mismatches. */
4545 size = GET_MODE_SIZE (arg->mode);
4546 /* Compute how much space the push instruction will push.
4547 On many machines, pushing a byte will advance the stack
4548 pointer by a halfword. */
4549 #ifdef PUSH_ROUNDING
4550 size = PUSH_ROUNDING (size);
4551 #endif
4552 used = size;
4554 /* Compute how much space the argument should get:
4555 round up to a multiple of the alignment for arguments. */
4556 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4557 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4558 / (PARM_BOUNDARY / BITS_PER_UNIT))
4559 * (PARM_BOUNDARY / BITS_PER_UNIT));
4561 /* Compute the alignment of the pushed argument. */
4562 parm_align = arg->locate.boundary;
4563 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4565 int pad = used - size;
4566 if (pad)
4568 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4569 parm_align = MIN (parm_align, pad_align);
4573 /* This isn't already where we want it on the stack, so put it there.
4574 This can either be done with push or copy insns. */
4575 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4576 parm_align, partial, reg, used - size, argblock,
4577 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4578 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4580 /* Unless this is a partially-in-register argument, the argument is now
4581 in the stack. */
4582 if (partial == 0)
4583 arg->value = arg->stack;
4585 else
4587 /* BLKmode, at least partly to be pushed. */
4589 unsigned int parm_align;
4590 int excess;
4591 rtx size_rtx;
4593 /* Pushing a nonscalar.
4594 If part is passed in registers, PARTIAL says how much
4595 and emit_push_insn will take care of putting it there. */
4597 /* Round its size up to a multiple
4598 of the allocation unit for arguments. */
4600 if (arg->locate.size.var != 0)
4602 excess = 0;
4603 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4605 else
4607 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4608 for BLKmode is careful to avoid it. */
4609 excess = (arg->locate.size.constant
4610 - int_size_in_bytes (TREE_TYPE (pval))
4611 + partial);
4612 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4613 NULL_RTX, TYPE_MODE (sizetype),
4614 EXPAND_NORMAL);
4617 parm_align = arg->locate.boundary;
4619 /* When an argument is padded down, the block is aligned to
4620 PARM_BOUNDARY, but the actual argument isn't. */
4621 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4623 if (arg->locate.size.var)
4624 parm_align = BITS_PER_UNIT;
4625 else if (excess)
4627 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4628 parm_align = MIN (parm_align, excess_align);
4632 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4634 /* emit_push_insn might not work properly if arg->value and
4635 argblock + arg->locate.offset areas overlap. */
4636 rtx x = arg->value;
4637 int i = 0;
4639 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4640 || (GET_CODE (XEXP (x, 0)) == PLUS
4641 && XEXP (XEXP (x, 0), 0) ==
4642 crtl->args.internal_arg_pointer
4643 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4645 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4646 i = INTVAL (XEXP (XEXP (x, 0), 1));
4648 /* expand_call should ensure this. */
4649 gcc_assert (!arg->locate.offset.var
4650 && arg->locate.size.var == 0
4651 && CONST_INT_P (size_rtx));
4653 if (arg->locate.offset.constant > i)
4655 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4656 sibcall_failure = 1;
4658 else if (arg->locate.offset.constant < i)
4660 /* Use arg->locate.size.constant instead of size_rtx
4661 because we only care about the part of the argument
4662 on the stack. */
4663 if (i < (arg->locate.offset.constant
4664 + arg->locate.size.constant))
4665 sibcall_failure = 1;
4667 else
4669 /* Even though they appear to be at the same location,
4670 if part of the outgoing argument is in registers,
4671 they aren't really at the same location. Check for
4672 this by making sure that the incoming size is the
4673 same as the outgoing size. */
4674 if (arg->locate.size.constant != INTVAL (size_rtx))
4675 sibcall_failure = 1;
4680 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4681 parm_align, partial, reg, excess, argblock,
4682 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4683 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4685 /* Unless this is a partially-in-register argument, the argument is now
4686 in the stack.
4688 ??? Unlike the case above, in which we want the actual
4689 address of the data, so that we can load it directly into a
4690 register, here we want the address of the stack slot, so that
4691 it's properly aligned for word-by-word copying or something
4692 like that. It's not clear that this is always correct. */
4693 if (partial == 0)
4694 arg->value = arg->stack_slot;
4697 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4699 tree type = TREE_TYPE (arg->tree_value);
4700 arg->parallel_value
4701 = emit_group_load_into_temps (arg->reg, arg->value, type,
4702 int_size_in_bytes (type));
4705 /* Mark all slots this store used. */
4706 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4707 && argblock && ! variable_size && arg->stack)
4708 for (i = lower_bound; i < upper_bound; i++)
4709 stack_usage_map[i] = 1;
4711 /* Once we have pushed something, pops can't safely
4712 be deferred during the rest of the arguments. */
4713 NO_DEFER_POP;
4715 /* Free any temporary slots made in processing this argument. */
4716 pop_temp_slots ();
4718 return sibcall_failure;
4721 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4723 bool
4724 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4725 const_tree type)
4727 if (!type)
4728 return false;
4730 /* If the type has variable size... */
4731 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4732 return true;
4734 /* If the type is marked as addressable (it is required
4735 to be constructed into the stack)... */
4736 if (TREE_ADDRESSABLE (type))
4737 return true;
4739 return false;
4742 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4743 takes trailing padding of a structure into account. */
4744 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4746 bool
4747 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4749 if (!type)
4750 return false;
4752 /* If the type has variable size... */
4753 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4754 return true;
4756 /* If the type is marked as addressable (it is required
4757 to be constructed into the stack)... */
4758 if (TREE_ADDRESSABLE (type))
4759 return true;
4761 /* If the padding and mode of the type is such that a copy into
4762 a register would put it into the wrong part of the register. */
4763 if (mode == BLKmode
4764 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4765 && (FUNCTION_ARG_PADDING (mode, type)
4766 == (BYTES_BIG_ENDIAN ? upward : downward)))
4767 return true;
4769 return false;