PR middle-end/59175
[official-gcc.git] / gcc / calls.c
blob4dcdb27c1c156bbb20cdd7c718fb66babe6e12e3
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"
44 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
45 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
47 /* Data structure and subroutines used within expand_call. */
49 struct arg_data
51 /* Tree node for this argument. */
52 tree tree_value;
53 /* Mode for value; TYPE_MODE unless promoted. */
54 enum machine_mode mode;
55 /* Current RTL value for argument, or 0 if it isn't precomputed. */
56 rtx value;
57 /* Initially-compute RTL value for argument; only for const functions. */
58 rtx initial_value;
59 /* Register to pass this argument in, 0 if passed on stack, or an
60 PARALLEL if the arg is to be copied into multiple non-contiguous
61 registers. */
62 rtx reg;
63 /* Register to pass this argument in when generating tail call sequence.
64 This is not the same register as for normal calls on machines with
65 register windows. */
66 rtx tail_call_reg;
67 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
68 form for emit_group_move. */
69 rtx parallel_value;
70 /* If REG was promoted from the actual mode of the argument expression,
71 indicates whether the promotion is sign- or zero-extended. */
72 int unsignedp;
73 /* Number of bytes to put in registers. 0 means put the whole arg
74 in registers. Also 0 if not passed in registers. */
75 int partial;
76 /* Nonzero if argument must be passed on stack.
77 Note that some arguments may be passed on the stack
78 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
79 pass_on_stack identifies arguments that *cannot* go in registers. */
80 int pass_on_stack;
81 /* Some fields packaged up for locate_and_pad_parm. */
82 struct locate_and_pad_arg_data locate;
83 /* Location on the stack at which parameter should be stored. The store
84 has already been done if STACK == VALUE. */
85 rtx stack;
86 /* Location on the stack of the start of this argument slot. This can
87 differ from STACK if this arg pads downward. This location is known
88 to be aligned to TARGET_FUNCTION_ARG_BOUNDARY. */
89 rtx stack_slot;
90 /* Place that this stack area has been saved, if needed. */
91 rtx save_area;
92 /* If an argument's alignment does not permit direct copying into registers,
93 copy in smaller-sized pieces into pseudos. These are stored in a
94 block pointed to by this field. The next field says how many
95 word-sized pseudos we made. */
96 rtx *aligned_regs;
97 int n_aligned_regs;
100 /* A vector of one char per byte of stack space. A byte if nonzero if
101 the corresponding stack location has been used.
102 This vector is used to prevent a function call within an argument from
103 clobbering any stack already set up. */
104 static char *stack_usage_map;
106 /* Size of STACK_USAGE_MAP. */
107 static int highest_outgoing_arg_in_use;
109 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
110 stack location's tail call argument has been already stored into the stack.
111 This bitmap is used to prevent sibling call optimization if function tries
112 to use parent's incoming argument slots when they have been already
113 overwritten with tail call arguments. */
114 static sbitmap stored_args_map;
116 /* stack_arg_under_construction is nonzero when an argument may be
117 initialized with a constructor call (including a C function that
118 returns a BLKmode struct) and expand_call must take special action
119 to make sure the object being constructed does not overlap the
120 argument list for the constructor call. */
121 static int stack_arg_under_construction;
123 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
124 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
125 cumulative_args_t);
126 static void precompute_register_parameters (int, struct arg_data *, int *);
127 static int store_one_arg (struct arg_data *, rtx, int, int, int);
128 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
129 static int finalize_must_preallocate (int, int, struct arg_data *,
130 struct args_size *);
131 static void precompute_arguments (int, struct arg_data *);
132 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
133 static void initialize_argument_information (int, struct arg_data *,
134 struct args_size *, int,
135 tree, tree,
136 tree, tree, cumulative_args_t, int,
137 rtx *, int *, int *, int *,
138 bool *, bool);
139 static void compute_argument_addresses (struct arg_data *, rtx, int);
140 static rtx rtx_for_function_call (tree, tree);
141 static void load_register_parameters (struct arg_data *, int, rtx *, int,
142 int, int *);
143 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
144 enum machine_mode, int, va_list);
145 static int special_function_p (const_tree, int);
146 static int check_sibcall_argument_overlap_1 (rtx);
147 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
149 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
150 unsigned int);
151 static tree split_complex_types (tree);
153 #ifdef REG_PARM_STACK_SPACE
154 static rtx save_fixed_argument_area (int, rtx, int *, int *);
155 static void restore_fixed_argument_area (rtx, rtx, int, int);
156 #endif
158 /* Force FUNEXP into a form suitable for the address of a CALL,
159 and return that as an rtx. Also load the static chain register
160 if FNDECL is a nested function.
162 CALL_FUSAGE points to a variable holding the prospective
163 CALL_INSN_FUNCTION_USAGE information. */
166 prepare_call_address (tree fndecl, rtx funexp, rtx static_chain_value,
167 rtx *call_fusage, int reg_parm_seen, int sibcallp)
169 /* Make a valid memory address and copy constants through pseudo-regs,
170 but not for a constant address if -fno-function-cse. */
171 if (GET_CODE (funexp) != SYMBOL_REF)
172 /* If we are using registers for parameters, force the
173 function address into a register now. */
174 funexp = ((reg_parm_seen
175 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
176 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
177 : memory_address (FUNCTION_MODE, funexp));
178 else if (! sibcallp)
180 #ifndef NO_FUNCTION_CSE
181 if (optimize && ! flag_no_function_cse)
182 funexp = force_reg (Pmode, funexp);
183 #endif
186 if (static_chain_value != 0)
188 rtx chain;
190 gcc_assert (fndecl);
191 chain = targetm.calls.static_chain (fndecl, false);
192 static_chain_value = convert_memory_address (Pmode, static_chain_value);
194 emit_move_insn (chain, static_chain_value);
195 if (REG_P (chain))
196 use_reg (call_fusage, chain);
199 return funexp;
202 /* Generate instructions to call function FUNEXP,
203 and optionally pop the results.
204 The CALL_INSN is the first insn generated.
206 FNDECL is the declaration node of the function. This is given to the
207 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
208 its own args.
210 FUNTYPE is the data type of the function. This is given to the hook
211 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
212 own args. We used to allow an identifier for library functions, but
213 that doesn't work when the return type is an aggregate type and the
214 calling convention says that the pointer to this aggregate is to be
215 popped by the callee.
217 STACK_SIZE is the number of bytes of arguments on the stack,
218 ROUNDED_STACK_SIZE is that number rounded up to
219 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
220 both to put into the call insn and to generate explicit popping
221 code if necessary.
223 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
224 It is zero if this call doesn't want a structure value.
226 NEXT_ARG_REG is the rtx that results from executing
227 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
228 just after all the args have had their registers assigned.
229 This could be whatever you like, but normally it is the first
230 arg-register beyond those used for args in this call,
231 or 0 if all the arg-registers are used in this call.
232 It is passed on to `gen_call' so you can put this info in the call insn.
234 VALREG is a hard register in which a value is returned,
235 or 0 if the call does not return a value.
237 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
238 the args to this call were processed.
239 We restore `inhibit_defer_pop' to that value.
241 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
242 denote registers used by the called function. */
244 static void
245 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
246 tree funtype ATTRIBUTE_UNUSED,
247 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
248 HOST_WIDE_INT rounded_stack_size,
249 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
250 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
251 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
252 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
254 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
255 rtx call_insn, call, funmem;
256 int already_popped = 0;
257 HOST_WIDE_INT n_popped
258 = targetm.calls.return_pops_args (fndecl, funtype, stack_size);
260 #ifdef CALL_POPS_ARGS
261 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
262 #endif
264 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
265 and we don't want to load it into a register as an optimization,
266 because prepare_call_address already did it if it should be done. */
267 if (GET_CODE (funexp) != SYMBOL_REF)
268 funexp = memory_address (FUNCTION_MODE, funexp);
270 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
271 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
273 tree t = fndecl;
275 /* Although a built-in FUNCTION_DECL and its non-__builtin
276 counterpart compare equal and get a shared mem_attrs, they
277 produce different dump output in compare-debug compilations,
278 if an entry gets garbage collected in one compilation, then
279 adds a different (but equivalent) entry, while the other
280 doesn't run the garbage collector at the same spot and then
281 shares the mem_attr with the equivalent entry. */
282 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
284 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
285 if (t2)
286 t = t2;
289 set_mem_expr (funmem, t);
291 else if (fntree)
292 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
294 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
295 if ((ecf_flags & ECF_SIBCALL)
296 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
297 && (n_popped > 0 || stack_size == 0))
299 rtx n_pop = GEN_INT (n_popped);
300 rtx pat;
302 /* If this subroutine pops its own args, record that in the call insn
303 if possible, for the sake of frame pointer elimination. */
305 if (valreg)
306 pat = GEN_SIBCALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
307 next_arg_reg, n_pop);
308 else
309 pat = GEN_SIBCALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
310 n_pop);
312 emit_call_insn (pat);
313 already_popped = 1;
315 else
316 #endif
318 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
319 /* If the target has "call" or "call_value" insns, then prefer them
320 if no arguments are actually popped. If the target does not have
321 "call" or "call_value" insns, then we must use the popping versions
322 even if the call has no arguments to pop. */
323 #if defined (HAVE_call) && defined (HAVE_call_value)
324 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
325 && n_popped > 0)
326 #else
327 if (HAVE_call_pop && HAVE_call_value_pop)
328 #endif
330 rtx n_pop = GEN_INT (n_popped);
331 rtx pat;
333 /* If this subroutine pops its own args, record that in the call insn
334 if possible, for the sake of frame pointer elimination. */
336 if (valreg)
337 pat = GEN_CALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
338 next_arg_reg, n_pop);
339 else
340 pat = GEN_CALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
341 n_pop);
343 emit_call_insn (pat);
344 already_popped = 1;
346 else
347 #endif
349 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
350 if ((ecf_flags & ECF_SIBCALL)
351 && HAVE_sibcall && HAVE_sibcall_value)
353 if (valreg)
354 emit_call_insn (GEN_SIBCALL_VALUE (valreg, funmem,
355 rounded_stack_size_rtx,
356 next_arg_reg, NULL_RTX));
357 else
358 emit_call_insn (GEN_SIBCALL (funmem, rounded_stack_size_rtx,
359 next_arg_reg,
360 GEN_INT (struct_value_size)));
362 else
363 #endif
365 #if defined (HAVE_call) && defined (HAVE_call_value)
366 if (HAVE_call && HAVE_call_value)
368 if (valreg)
369 emit_call_insn (GEN_CALL_VALUE (valreg, funmem, rounded_stack_size_rtx,
370 next_arg_reg, NULL_RTX));
371 else
372 emit_call_insn (GEN_CALL (funmem, rounded_stack_size_rtx, next_arg_reg,
373 GEN_INT (struct_value_size)));
375 else
376 #endif
377 gcc_unreachable ();
379 /* Find the call we just emitted. */
380 call_insn = last_call_insn ();
382 /* Some target create a fresh MEM instead of reusing the one provided
383 above. Set its MEM_EXPR. */
384 call = get_call_rtx_from (call_insn);
385 if (call
386 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
387 && MEM_EXPR (funmem) != NULL_TREE)
388 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
390 /* Put the register usage information there. */
391 add_function_usage_to (call_insn, call_fusage);
393 /* If this is a const call, then set the insn's unchanging bit. */
394 if (ecf_flags & ECF_CONST)
395 RTL_CONST_CALL_P (call_insn) = 1;
397 /* If this is a pure call, then set the insn's unchanging bit. */
398 if (ecf_flags & ECF_PURE)
399 RTL_PURE_CALL_P (call_insn) = 1;
401 /* If this is a const call, then set the insn's unchanging bit. */
402 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
403 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
405 /* Create a nothrow REG_EH_REGION note, if needed. */
406 make_reg_eh_region_note (call_insn, ecf_flags, 0);
408 if (ecf_flags & ECF_NORETURN)
409 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
411 if (ecf_flags & ECF_RETURNS_TWICE)
413 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
414 cfun->calls_setjmp = 1;
417 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
419 /* Restore this now, so that we do defer pops for this call's args
420 if the context of the call as a whole permits. */
421 inhibit_defer_pop = old_inhibit_defer_pop;
423 if (n_popped > 0)
425 if (!already_popped)
426 CALL_INSN_FUNCTION_USAGE (call_insn)
427 = gen_rtx_EXPR_LIST (VOIDmode,
428 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
429 CALL_INSN_FUNCTION_USAGE (call_insn));
430 rounded_stack_size -= n_popped;
431 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
432 stack_pointer_delta -= n_popped;
434 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
436 /* If popup is needed, stack realign must use DRAP */
437 if (SUPPORTS_STACK_ALIGNMENT)
438 crtl->need_drap = true;
440 /* For noreturn calls when not accumulating outgoing args force
441 REG_ARGS_SIZE note to prevent crossjumping of calls with different
442 args sizes. */
443 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
444 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
446 if (!ACCUMULATE_OUTGOING_ARGS)
448 /* If returning from the subroutine does not automatically pop the args,
449 we need an instruction to pop them sooner or later.
450 Perhaps do it now; perhaps just record how much space to pop later.
452 If returning from the subroutine does pop the args, indicate that the
453 stack pointer will be changed. */
455 if (rounded_stack_size != 0)
457 if (ecf_flags & ECF_NORETURN)
458 /* Just pretend we did the pop. */
459 stack_pointer_delta -= rounded_stack_size;
460 else if (flag_defer_pop && inhibit_defer_pop == 0
461 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
462 pending_stack_adjust += rounded_stack_size;
463 else
464 adjust_stack (rounded_stack_size_rtx);
467 /* When we accumulate outgoing args, we must avoid any stack manipulations.
468 Restore the stack pointer to its original value now. Usually
469 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
470 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
471 popping variants of functions exist as well.
473 ??? We may optimize similar to defer_pop above, but it is
474 probably not worthwhile.
476 ??? It will be worthwhile to enable combine_stack_adjustments even for
477 such machines. */
478 else if (n_popped)
479 anti_adjust_stack (GEN_INT (n_popped));
482 /* Determine if the function identified by NAME and FNDECL is one with
483 special properties we wish to know about.
485 For example, if the function might return more than one time (setjmp), then
486 set RETURNS_TWICE to a nonzero value.
488 Similarly set NORETURN if the function is in the longjmp family.
490 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
491 space from the stack such as alloca. */
493 static int
494 special_function_p (const_tree fndecl, int flags)
496 if (fndecl && DECL_NAME (fndecl)
497 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
498 /* Exclude functions not at the file scope, or not `extern',
499 since they are not the magic functions we would otherwise
500 think they are.
501 FIXME: this should be handled with attributes, not with this
502 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
503 because you can declare fork() inside a function if you
504 wish. */
505 && (DECL_CONTEXT (fndecl) == NULL_TREE
506 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
507 && TREE_PUBLIC (fndecl))
509 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
510 const char *tname = name;
512 /* We assume that alloca will always be called by name. It
513 makes no sense to pass it as a pointer-to-function to
514 anything that does not understand its behavior. */
515 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
516 && name[0] == 'a'
517 && ! strcmp (name, "alloca"))
518 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
519 && name[0] == '_'
520 && ! strcmp (name, "__builtin_alloca"))))
521 flags |= ECF_MAY_BE_ALLOCA;
523 /* Disregard prefix _, __, __x or __builtin_. */
524 if (name[0] == '_')
526 if (name[1] == '_'
527 && name[2] == 'b'
528 && !strncmp (name + 3, "uiltin_", 7))
529 tname += 10;
530 else if (name[1] == '_' && name[2] == 'x')
531 tname += 3;
532 else if (name[1] == '_')
533 tname += 2;
534 else
535 tname += 1;
538 if (tname[0] == 's')
540 if ((tname[1] == 'e'
541 && (! strcmp (tname, "setjmp")
542 || ! strcmp (tname, "setjmp_syscall")))
543 || (tname[1] == 'i'
544 && ! strcmp (tname, "sigsetjmp"))
545 || (tname[1] == 'a'
546 && ! strcmp (tname, "savectx")))
547 flags |= ECF_RETURNS_TWICE | ECF_LEAF;
549 if (tname[1] == 'i'
550 && ! strcmp (tname, "siglongjmp"))
551 flags |= ECF_NORETURN;
553 else if ((tname[0] == 'q' && tname[1] == 's'
554 && ! strcmp (tname, "qsetjmp"))
555 || (tname[0] == 'v' && tname[1] == 'f'
556 && ! strcmp (tname, "vfork"))
557 || (tname[0] == 'g' && tname[1] == 'e'
558 && !strcmp (tname, "getcontext")))
559 flags |= ECF_RETURNS_TWICE | ECF_LEAF;
561 else if (tname[0] == 'l' && tname[1] == 'o'
562 && ! strcmp (tname, "longjmp"))
563 flags |= ECF_NORETURN;
566 return flags;
569 /* Similar to special_function_p; return a set of ERF_ flags for the
570 function FNDECL. */
571 static int
572 decl_return_flags (tree fndecl)
574 tree attr;
575 tree type = TREE_TYPE (fndecl);
576 if (!type)
577 return 0;
579 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
580 if (!attr)
581 return 0;
583 attr = TREE_VALUE (TREE_VALUE (attr));
584 if (!attr || TREE_STRING_LENGTH (attr) < 1)
585 return 0;
587 switch (TREE_STRING_POINTER (attr)[0])
589 case '1':
590 case '2':
591 case '3':
592 case '4':
593 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
595 case 'm':
596 return ERF_NOALIAS;
598 case '.':
599 default:
600 return 0;
604 /* Return nonzero when FNDECL represents a call to setjmp. */
607 setjmp_call_p (const_tree fndecl)
609 if (DECL_IS_RETURNS_TWICE (fndecl))
610 return ECF_RETURNS_TWICE;
611 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
615 /* Return true if STMT is an alloca call. */
617 bool
618 gimple_alloca_call_p (const_gimple stmt)
620 tree fndecl;
622 if (!is_gimple_call (stmt))
623 return false;
625 fndecl = gimple_call_fndecl (stmt);
626 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
627 return true;
629 return false;
632 /* Return true when exp contains alloca call. */
634 bool
635 alloca_call_p (const_tree exp)
637 tree fndecl;
638 if (TREE_CODE (exp) == CALL_EXPR
639 && (fndecl = get_callee_fndecl (exp))
640 && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
641 return true;
642 return false;
645 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
646 function. Return FALSE otherwise. */
648 static bool
649 is_tm_builtin (const_tree fndecl)
651 if (fndecl == NULL)
652 return false;
654 if (decl_is_tm_clone (fndecl))
655 return true;
657 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
659 switch (DECL_FUNCTION_CODE (fndecl))
661 case BUILT_IN_TM_COMMIT:
662 case BUILT_IN_TM_COMMIT_EH:
663 case BUILT_IN_TM_ABORT:
664 case BUILT_IN_TM_IRREVOCABLE:
665 case BUILT_IN_TM_GETTMCLONE_IRR:
666 case BUILT_IN_TM_MEMCPY:
667 case BUILT_IN_TM_MEMMOVE:
668 case BUILT_IN_TM_MEMSET:
669 CASE_BUILT_IN_TM_STORE (1):
670 CASE_BUILT_IN_TM_STORE (2):
671 CASE_BUILT_IN_TM_STORE (4):
672 CASE_BUILT_IN_TM_STORE (8):
673 CASE_BUILT_IN_TM_STORE (FLOAT):
674 CASE_BUILT_IN_TM_STORE (DOUBLE):
675 CASE_BUILT_IN_TM_STORE (LDOUBLE):
676 CASE_BUILT_IN_TM_STORE (M64):
677 CASE_BUILT_IN_TM_STORE (M128):
678 CASE_BUILT_IN_TM_STORE (M256):
679 CASE_BUILT_IN_TM_LOAD (1):
680 CASE_BUILT_IN_TM_LOAD (2):
681 CASE_BUILT_IN_TM_LOAD (4):
682 CASE_BUILT_IN_TM_LOAD (8):
683 CASE_BUILT_IN_TM_LOAD (FLOAT):
684 CASE_BUILT_IN_TM_LOAD (DOUBLE):
685 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
686 CASE_BUILT_IN_TM_LOAD (M64):
687 CASE_BUILT_IN_TM_LOAD (M128):
688 CASE_BUILT_IN_TM_LOAD (M256):
689 case BUILT_IN_TM_LOG:
690 case BUILT_IN_TM_LOG_1:
691 case BUILT_IN_TM_LOG_2:
692 case BUILT_IN_TM_LOG_4:
693 case BUILT_IN_TM_LOG_8:
694 case BUILT_IN_TM_LOG_FLOAT:
695 case BUILT_IN_TM_LOG_DOUBLE:
696 case BUILT_IN_TM_LOG_LDOUBLE:
697 case BUILT_IN_TM_LOG_M64:
698 case BUILT_IN_TM_LOG_M128:
699 case BUILT_IN_TM_LOG_M256:
700 return true;
701 default:
702 break;
705 return false;
708 /* Detect flags (function attributes) from the function decl or type node. */
711 flags_from_decl_or_type (const_tree exp)
713 int flags = 0;
715 if (DECL_P (exp))
717 /* The function exp may have the `malloc' attribute. */
718 if (DECL_IS_MALLOC (exp))
719 flags |= ECF_MALLOC;
721 /* The function exp may have the `returns_twice' attribute. */
722 if (DECL_IS_RETURNS_TWICE (exp))
723 flags |= ECF_RETURNS_TWICE;
725 /* Process the pure and const attributes. */
726 if (TREE_READONLY (exp))
727 flags |= ECF_CONST;
728 if (DECL_PURE_P (exp))
729 flags |= ECF_PURE;
730 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
731 flags |= ECF_LOOPING_CONST_OR_PURE;
733 if (DECL_IS_NOVOPS (exp))
734 flags |= ECF_NOVOPS;
735 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
736 flags |= ECF_LEAF;
738 if (TREE_NOTHROW (exp))
739 flags |= ECF_NOTHROW;
741 if (flag_tm)
743 if (is_tm_builtin (exp))
744 flags |= ECF_TM_BUILTIN;
745 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
746 || lookup_attribute ("transaction_pure",
747 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
748 flags |= ECF_TM_PURE;
751 flags = special_function_p (exp, flags);
753 else if (TYPE_P (exp))
755 if (TYPE_READONLY (exp))
756 flags |= ECF_CONST;
758 if (flag_tm
759 && ((flags & ECF_CONST) != 0
760 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
761 flags |= ECF_TM_PURE;
764 if (TREE_THIS_VOLATILE (exp))
766 flags |= ECF_NORETURN;
767 if (flags & (ECF_CONST|ECF_PURE))
768 flags |= ECF_LOOPING_CONST_OR_PURE;
771 return flags;
774 /* Detect flags from a CALL_EXPR. */
777 call_expr_flags (const_tree t)
779 int flags;
780 tree decl = get_callee_fndecl (t);
782 if (decl)
783 flags = flags_from_decl_or_type (decl);
784 else
786 t = TREE_TYPE (CALL_EXPR_FN (t));
787 if (t && TREE_CODE (t) == POINTER_TYPE)
788 flags = flags_from_decl_or_type (TREE_TYPE (t));
789 else
790 flags = 0;
793 return flags;
796 /* Precompute all register parameters as described by ARGS, storing values
797 into fields within the ARGS array.
799 NUM_ACTUALS indicates the total number elements in the ARGS array.
801 Set REG_PARM_SEEN if we encounter a register parameter. */
803 static void
804 precompute_register_parameters (int num_actuals, struct arg_data *args,
805 int *reg_parm_seen)
807 int i;
809 *reg_parm_seen = 0;
811 for (i = 0; i < num_actuals; i++)
812 if (args[i].reg != 0 && ! args[i].pass_on_stack)
814 *reg_parm_seen = 1;
816 if (args[i].value == 0)
818 push_temp_slots ();
819 args[i].value = expand_normal (args[i].tree_value);
820 preserve_temp_slots (args[i].value);
821 pop_temp_slots ();
824 /* If we are to promote the function arg to a wider mode,
825 do it now. */
827 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
828 args[i].value
829 = convert_modes (args[i].mode,
830 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
831 args[i].value, args[i].unsignedp);
833 /* If the value is a non-legitimate constant, force it into a
834 pseudo now. TLS symbols sometimes need a call to resolve. */
835 if (CONSTANT_P (args[i].value)
836 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
837 args[i].value = force_reg (args[i].mode, args[i].value);
839 /* If we're going to have to load the value by parts, pull the
840 parts into pseudos. The part extraction process can involve
841 non-trivial computation. */
842 if (GET_CODE (args[i].reg) == PARALLEL)
844 tree type = TREE_TYPE (args[i].tree_value);
845 args[i].parallel_value
846 = emit_group_load_into_temps (args[i].reg, args[i].value,
847 type, int_size_in_bytes (type));
850 /* If the value is expensive, and we are inside an appropriately
851 short loop, put the value into a pseudo and then put the pseudo
852 into the hard reg.
854 For small register classes, also do this if this call uses
855 register parameters. This is to avoid reload conflicts while
856 loading the parameters registers. */
858 else if ((! (REG_P (args[i].value)
859 || (GET_CODE (args[i].value) == SUBREG
860 && REG_P (SUBREG_REG (args[i].value)))))
861 && args[i].mode != BLKmode
862 && set_src_cost (args[i].value, optimize_insn_for_speed_p ())
863 > COSTS_N_INSNS (1)
864 && ((*reg_parm_seen
865 && targetm.small_register_classes_for_mode_p (args[i].mode))
866 || optimize))
867 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
871 #ifdef REG_PARM_STACK_SPACE
873 /* The argument list is the property of the called routine and it
874 may clobber it. If the fixed area has been used for previous
875 parameters, we must save and restore it. */
877 static rtx
878 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
880 int low;
881 int high;
883 /* Compute the boundary of the area that needs to be saved, if any. */
884 high = reg_parm_stack_space;
885 #ifdef ARGS_GROW_DOWNWARD
886 high += 1;
887 #endif
888 if (high > highest_outgoing_arg_in_use)
889 high = highest_outgoing_arg_in_use;
891 for (low = 0; low < high; low++)
892 if (stack_usage_map[low] != 0)
894 int num_to_save;
895 enum machine_mode save_mode;
896 int delta;
897 rtx addr;
898 rtx stack_area;
899 rtx save_area;
901 while (stack_usage_map[--high] == 0)
904 *low_to_save = low;
905 *high_to_save = high;
907 num_to_save = high - low + 1;
908 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
910 /* If we don't have the required alignment, must do this
911 in BLKmode. */
912 if ((low & (MIN (GET_MODE_SIZE (save_mode),
913 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
914 save_mode = BLKmode;
916 #ifdef ARGS_GROW_DOWNWARD
917 delta = -high;
918 #else
919 delta = low;
920 #endif
921 addr = plus_constant (Pmode, argblock, delta);
922 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
924 set_mem_align (stack_area, PARM_BOUNDARY);
925 if (save_mode == BLKmode)
927 save_area = assign_stack_temp (BLKmode, num_to_save);
928 emit_block_move (validize_mem (save_area), stack_area,
929 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
931 else
933 save_area = gen_reg_rtx (save_mode);
934 emit_move_insn (save_area, stack_area);
937 return save_area;
940 return NULL_RTX;
943 static void
944 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
946 enum machine_mode save_mode = GET_MODE (save_area);
947 int delta;
948 rtx addr, stack_area;
950 #ifdef ARGS_GROW_DOWNWARD
951 delta = -high_to_save;
952 #else
953 delta = low_to_save;
954 #endif
955 addr = plus_constant (Pmode, argblock, delta);
956 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
957 set_mem_align (stack_area, PARM_BOUNDARY);
959 if (save_mode != BLKmode)
960 emit_move_insn (stack_area, save_area);
961 else
962 emit_block_move (stack_area, validize_mem (save_area),
963 GEN_INT (high_to_save - low_to_save + 1),
964 BLOCK_OP_CALL_PARM);
966 #endif /* REG_PARM_STACK_SPACE */
968 /* If any elements in ARGS refer to parameters that are to be passed in
969 registers, but not in memory, and whose alignment does not permit a
970 direct copy into registers. Copy the values into a group of pseudos
971 which we will later copy into the appropriate hard registers.
973 Pseudos for each unaligned argument will be stored into the array
974 args[argnum].aligned_regs. The caller is responsible for deallocating
975 the aligned_regs array if it is nonzero. */
977 static void
978 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
980 int i, j;
982 for (i = 0; i < num_actuals; i++)
983 if (args[i].reg != 0 && ! args[i].pass_on_stack
984 && GET_CODE (args[i].reg) != PARALLEL
985 && args[i].mode == BLKmode
986 && MEM_P (args[i].value)
987 && (MEM_ALIGN (args[i].value)
988 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
990 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
991 int endian_correction = 0;
993 if (args[i].partial)
995 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
996 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
998 else
1000 args[i].n_aligned_regs
1001 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1004 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1006 /* Structures smaller than a word are normally aligned to the
1007 least significant byte. On a BYTES_BIG_ENDIAN machine,
1008 this means we must skip the empty high order bytes when
1009 calculating the bit offset. */
1010 if (bytes < UNITS_PER_WORD
1011 #ifdef BLOCK_REG_PADDING
1012 && (BLOCK_REG_PADDING (args[i].mode,
1013 TREE_TYPE (args[i].tree_value), 1)
1014 == downward)
1015 #else
1016 && BYTES_BIG_ENDIAN
1017 #endif
1019 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1021 for (j = 0; j < args[i].n_aligned_regs; j++)
1023 rtx reg = gen_reg_rtx (word_mode);
1024 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1025 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1027 args[i].aligned_regs[j] = reg;
1028 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1029 word_mode, word_mode);
1031 /* There is no need to restrict this code to loading items
1032 in TYPE_ALIGN sized hunks. The bitfield instructions can
1033 load up entire word sized registers efficiently.
1035 ??? This may not be needed anymore.
1036 We use to emit a clobber here but that doesn't let later
1037 passes optimize the instructions we emit. By storing 0 into
1038 the register later passes know the first AND to zero out the
1039 bitfield being set in the register is unnecessary. The store
1040 of 0 will be deleted as will at least the first AND. */
1042 emit_move_insn (reg, const0_rtx);
1044 bytes -= bitsize / BITS_PER_UNIT;
1045 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1046 word_mode, word);
1051 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1052 CALL_EXPR EXP.
1054 NUM_ACTUALS is the total number of parameters.
1056 N_NAMED_ARGS is the total number of named arguments.
1058 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1059 value, or null.
1061 FNDECL is the tree code for the target of this call (if known)
1063 ARGS_SO_FAR holds state needed by the target to know where to place
1064 the next argument.
1066 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1067 for arguments which are passed in registers.
1069 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1070 and may be modified by this routine.
1072 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1073 flags which may may be modified by this routine.
1075 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1076 that requires allocation of stack space.
1078 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1079 the thunked-to function. */
1081 static void
1082 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1083 struct arg_data *args,
1084 struct args_size *args_size,
1085 int n_named_args ATTRIBUTE_UNUSED,
1086 tree exp, tree struct_value_addr_value,
1087 tree fndecl, tree fntype,
1088 cumulative_args_t args_so_far,
1089 int reg_parm_stack_space,
1090 rtx *old_stack_level, int *old_pending_adj,
1091 int *must_preallocate, int *ecf_flags,
1092 bool *may_tailcall, bool call_from_thunk_p)
1094 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1095 location_t loc = EXPR_LOCATION (exp);
1096 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1097 int inc;
1099 /* Count arg position in order args appear. */
1100 int argpos;
1102 int i;
1104 args_size->constant = 0;
1105 args_size->var = 0;
1107 /* In this loop, we consider args in the order they are written.
1108 We fill up ARGS from the front or from the back if necessary
1109 so that in any case the first arg to be pushed ends up at the front. */
1111 if (PUSH_ARGS_REVERSED)
1113 i = num_actuals - 1, inc = -1;
1114 /* In this case, must reverse order of args
1115 so that we compute and push the last arg first. */
1117 else
1119 i = 0, inc = 1;
1122 /* First fill in the actual arguments in the ARGS array, splitting
1123 complex arguments if necessary. */
1125 int j = i;
1126 call_expr_arg_iterator iter;
1127 tree arg;
1129 if (struct_value_addr_value)
1131 args[j].tree_value = struct_value_addr_value;
1132 j += inc;
1134 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1136 tree argtype = TREE_TYPE (arg);
1137 if (targetm.calls.split_complex_arg
1138 && argtype
1139 && TREE_CODE (argtype) == COMPLEX_TYPE
1140 && targetm.calls.split_complex_arg (argtype))
1142 tree subtype = TREE_TYPE (argtype);
1143 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1144 j += inc;
1145 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1147 else
1148 args[j].tree_value = arg;
1149 j += inc;
1153 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1154 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1156 tree type = TREE_TYPE (args[i].tree_value);
1157 int unsignedp;
1158 enum machine_mode mode;
1160 /* Replace erroneous argument with constant zero. */
1161 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1162 args[i].tree_value = integer_zero_node, type = integer_type_node;
1164 /* If TYPE is a transparent union or record, pass things the way
1165 we would pass the first field of the union or record. We have
1166 already verified that the modes are the same. */
1167 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1168 && TYPE_TRANSPARENT_AGGR (type))
1169 type = TREE_TYPE (first_field (type));
1171 /* Decide where to pass this arg.
1173 args[i].reg is nonzero if all or part is passed in registers.
1175 args[i].partial is nonzero if part but not all is passed in registers,
1176 and the exact value says how many bytes are passed in registers.
1178 args[i].pass_on_stack is nonzero if the argument must at least be
1179 computed on the stack. It may then be loaded back into registers
1180 if args[i].reg is nonzero.
1182 These decisions are driven by the FUNCTION_... macros and must agree
1183 with those made by function.c. */
1185 /* See if this argument should be passed by invisible reference. */
1186 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1187 type, argpos < n_named_args))
1189 bool callee_copies;
1190 tree base = NULL_TREE;
1192 callee_copies
1193 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
1194 type, argpos < n_named_args);
1196 /* If we're compiling a thunk, pass through invisible references
1197 instead of making a copy. */
1198 if (call_from_thunk_p
1199 || (callee_copies
1200 && !TREE_ADDRESSABLE (type)
1201 && (base = get_base_address (args[i].tree_value))
1202 && TREE_CODE (base) != SSA_NAME
1203 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1205 mark_addressable (args[i].tree_value);
1207 /* We can't use sibcalls if a callee-copied argument is
1208 stored in the current function's frame. */
1209 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1210 *may_tailcall = false;
1212 args[i].tree_value = build_fold_addr_expr_loc (loc,
1213 args[i].tree_value);
1214 type = TREE_TYPE (args[i].tree_value);
1216 if (*ecf_flags & ECF_CONST)
1217 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1219 else
1221 /* We make a copy of the object and pass the address to the
1222 function being called. */
1223 rtx copy;
1225 if (!COMPLETE_TYPE_P (type)
1226 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1227 || (flag_stack_check == GENERIC_STACK_CHECK
1228 && compare_tree_int (TYPE_SIZE_UNIT (type),
1229 STACK_CHECK_MAX_VAR_SIZE) > 0))
1231 /* This is a variable-sized object. Make space on the stack
1232 for it. */
1233 rtx size_rtx = expr_size (args[i].tree_value);
1235 if (*old_stack_level == 0)
1237 emit_stack_save (SAVE_BLOCK, old_stack_level);
1238 *old_pending_adj = pending_stack_adjust;
1239 pending_stack_adjust = 0;
1242 /* We can pass TRUE as the 4th argument because we just
1243 saved the stack pointer and will restore it right after
1244 the call. */
1245 copy = allocate_dynamic_stack_space (size_rtx,
1246 TYPE_ALIGN (type),
1247 TYPE_ALIGN (type),
1248 true);
1249 copy = gen_rtx_MEM (BLKmode, copy);
1250 set_mem_attributes (copy, type, 1);
1252 else
1253 copy = assign_temp (type, 1, 0);
1255 store_expr (args[i].tree_value, copy, 0, false);
1257 /* Just change the const function to pure and then let
1258 the next test clear the pure based on
1259 callee_copies. */
1260 if (*ecf_flags & ECF_CONST)
1262 *ecf_flags &= ~ECF_CONST;
1263 *ecf_flags |= ECF_PURE;
1266 if (!callee_copies && *ecf_flags & ECF_PURE)
1267 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1269 args[i].tree_value
1270 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1271 type = TREE_TYPE (args[i].tree_value);
1272 *may_tailcall = false;
1276 unsignedp = TYPE_UNSIGNED (type);
1277 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1278 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1280 args[i].unsignedp = unsignedp;
1281 args[i].mode = mode;
1283 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
1284 argpos < n_named_args);
1286 /* If this is a sibling call and the machine has register windows, the
1287 register window has to be unwinded before calling the routine, so
1288 arguments have to go into the incoming registers. */
1289 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
1290 args[i].tail_call_reg
1291 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
1292 argpos < n_named_args);
1293 else
1294 args[i].tail_call_reg = args[i].reg;
1296 if (args[i].reg)
1297 args[i].partial
1298 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1299 argpos < n_named_args);
1301 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1303 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1304 it means that we are to pass this arg in the register(s) designated
1305 by the PARALLEL, but also to pass it in the stack. */
1306 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1307 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1308 args[i].pass_on_stack = 1;
1310 /* If this is an addressable type, we must preallocate the stack
1311 since we must evaluate the object into its final location.
1313 If this is to be passed in both registers and the stack, it is simpler
1314 to preallocate. */
1315 if (TREE_ADDRESSABLE (type)
1316 || (args[i].pass_on_stack && args[i].reg != 0))
1317 *must_preallocate = 1;
1319 /* Compute the stack-size of this argument. */
1320 if (args[i].reg == 0 || args[i].partial != 0
1321 || reg_parm_stack_space > 0
1322 || args[i].pass_on_stack)
1323 locate_and_pad_parm (mode, type,
1324 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1326 #else
1327 args[i].reg != 0,
1328 #endif
1329 reg_parm_stack_space,
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
1736 .safe_grow_cleared (idx + 1);
1737 internal_arg_pointer_exp_state.cache[idx] = val;
1740 if (NEXT_INSN (insn) == NULL_RTX)
1741 scan_start = insn;
1742 insn = NEXT_INSN (insn);
1745 internal_arg_pointer_exp_state.scan_start = scan_start;
1748 /* Helper function for internal_arg_pointer_based_exp, called through
1749 for_each_rtx. Return 1 if *LOC is a register based on
1750 crtl->args.internal_arg_pointer. Return -1 if *LOC is not based on it
1751 and the subexpressions need not be examined. Otherwise return 0. */
1753 static int
1754 internal_arg_pointer_based_exp_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
1756 if (REG_P (*loc) && internal_arg_pointer_based_exp (*loc, false) != NULL_RTX)
1757 return 1;
1758 if (MEM_P (*loc))
1759 return -1;
1760 return 0;
1763 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
1764 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
1765 it with fixed offset, or PC if this is with variable or unknown offset.
1766 TOPLEVEL is true if the function is invoked at the topmost level. */
1768 static rtx
1769 internal_arg_pointer_based_exp (rtx rtl, bool toplevel)
1771 if (CONSTANT_P (rtl))
1772 return NULL_RTX;
1774 if (rtl == crtl->args.internal_arg_pointer)
1775 return const0_rtx;
1777 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
1778 return NULL_RTX;
1780 if (GET_CODE (rtl) == PLUS && CONST_INT_P (XEXP (rtl, 1)))
1782 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
1783 if (val == NULL_RTX || val == pc_rtx)
1784 return val;
1785 return plus_constant (Pmode, val, INTVAL (XEXP (rtl, 1)));
1788 /* When called at the topmost level, scan pseudo assignments in between the
1789 last scanned instruction in the tail call sequence and the latest insn
1790 in that sequence. */
1791 if (toplevel)
1792 internal_arg_pointer_based_exp_scan ();
1794 if (REG_P (rtl))
1796 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
1797 if (idx < internal_arg_pointer_exp_state.cache.length ())
1798 return internal_arg_pointer_exp_state.cache[idx];
1800 return NULL_RTX;
1803 if (for_each_rtx (&rtl, internal_arg_pointer_based_exp_1, NULL))
1804 return pc_rtx;
1806 return NULL_RTX;
1809 /* Return true if and only if SIZE storage units (usually bytes)
1810 starting from address ADDR overlap with already clobbered argument
1811 area. This function is used to determine if we should give up a
1812 sibcall. */
1814 static bool
1815 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1817 HOST_WIDE_INT i;
1818 rtx val;
1820 if (bitmap_empty_p (stored_args_map))
1821 return false;
1822 val = internal_arg_pointer_based_exp (addr, true);
1823 if (val == NULL_RTX)
1824 return false;
1825 else if (val == pc_rtx)
1826 return true;
1827 else
1828 i = INTVAL (val);
1829 #ifdef STACK_GROWS_DOWNWARD
1830 i -= crtl->args.pretend_args_size;
1831 #else
1832 i += crtl->args.pretend_args_size;
1833 #endif
1835 #ifdef ARGS_GROW_DOWNWARD
1836 i = -i - size;
1837 #endif
1838 if (size > 0)
1840 unsigned HOST_WIDE_INT k;
1842 for (k = 0; k < size; k++)
1843 if (i + k < SBITMAP_SIZE (stored_args_map)
1844 && bitmap_bit_p (stored_args_map, i + k))
1845 return true;
1848 return false;
1851 /* Do the register loads required for any wholly-register parms or any
1852 parms which are passed both on the stack and in a register. Their
1853 expressions were already evaluated.
1855 Mark all register-parms as living through the call, putting these USE
1856 insns in the CALL_INSN_FUNCTION_USAGE field.
1858 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1859 checking, setting *SIBCALL_FAILURE if appropriate. */
1861 static void
1862 load_register_parameters (struct arg_data *args, int num_actuals,
1863 rtx *call_fusage, int flags, int is_sibcall,
1864 int *sibcall_failure)
1866 int i, j;
1868 for (i = 0; i < num_actuals; i++)
1870 rtx reg = ((flags & ECF_SIBCALL)
1871 ? args[i].tail_call_reg : args[i].reg);
1872 if (reg)
1874 int partial = args[i].partial;
1875 int nregs;
1876 int size = 0;
1877 rtx before_arg = get_last_insn ();
1878 /* Set non-negative if we must move a word at a time, even if
1879 just one word (e.g, partial == 4 && mode == DFmode). Set
1880 to -1 if we just use a normal move insn. This value can be
1881 zero if the argument is a zero size structure. */
1882 nregs = -1;
1883 if (GET_CODE (reg) == PARALLEL)
1885 else if (partial)
1887 gcc_assert (partial % UNITS_PER_WORD == 0);
1888 nregs = partial / UNITS_PER_WORD;
1890 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1892 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1893 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1895 else
1896 size = GET_MODE_SIZE (args[i].mode);
1898 /* Handle calls that pass values in multiple non-contiguous
1899 locations. The Irix 6 ABI has examples of this. */
1901 if (GET_CODE (reg) == PARALLEL)
1902 emit_group_move (reg, args[i].parallel_value);
1904 /* If simple case, just do move. If normal partial, store_one_arg
1905 has already loaded the register for us. In all other cases,
1906 load the register(s) from memory. */
1908 else if (nregs == -1)
1910 emit_move_insn (reg, args[i].value);
1911 #ifdef BLOCK_REG_PADDING
1912 /* Handle case where we have a value that needs shifting
1913 up to the msb. eg. a QImode value and we're padding
1914 upward on a BYTES_BIG_ENDIAN machine. */
1915 if (size < UNITS_PER_WORD
1916 && (args[i].locate.where_pad
1917 == (BYTES_BIG_ENDIAN ? upward : downward)))
1919 rtx x;
1920 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1922 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1923 report the whole reg as used. Strictly speaking, the
1924 call only uses SIZE bytes at the msb end, but it doesn't
1925 seem worth generating rtl to say that. */
1926 reg = gen_rtx_REG (word_mode, REGNO (reg));
1927 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
1928 if (x != reg)
1929 emit_move_insn (reg, x);
1931 #endif
1934 /* If we have pre-computed the values to put in the registers in
1935 the case of non-aligned structures, copy them in now. */
1937 else if (args[i].n_aligned_regs != 0)
1938 for (j = 0; j < args[i].n_aligned_regs; j++)
1939 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1940 args[i].aligned_regs[j]);
1942 else if (partial == 0 || args[i].pass_on_stack)
1944 rtx mem = validize_mem (args[i].value);
1946 /* Check for overlap with already clobbered argument area,
1947 providing that this has non-zero size. */
1948 if (is_sibcall
1949 && (size == 0
1950 || mem_overlaps_already_clobbered_arg_p
1951 (XEXP (args[i].value, 0), size)))
1952 *sibcall_failure = 1;
1954 /* Handle a BLKmode that needs shifting. */
1955 if (nregs == 1 && size < UNITS_PER_WORD
1956 #ifdef BLOCK_REG_PADDING
1957 && args[i].locate.where_pad == downward
1958 #else
1959 && BYTES_BIG_ENDIAN
1960 #endif
1963 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1964 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1965 rtx x = gen_reg_rtx (word_mode);
1966 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1967 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1968 : LSHIFT_EXPR;
1970 emit_move_insn (x, tem);
1971 x = expand_shift (dir, word_mode, x, shift, ri, 1);
1972 if (x != ri)
1973 emit_move_insn (ri, x);
1975 else
1976 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1979 /* When a parameter is a block, and perhaps in other cases, it is
1980 possible that it did a load from an argument slot that was
1981 already clobbered. */
1982 if (is_sibcall
1983 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1984 *sibcall_failure = 1;
1986 /* Handle calls that pass values in multiple non-contiguous
1987 locations. The Irix 6 ABI has examples of this. */
1988 if (GET_CODE (reg) == PARALLEL)
1989 use_group_regs (call_fusage, reg);
1990 else if (nregs == -1)
1991 use_reg_mode (call_fusage, reg,
1992 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1993 else if (nregs > 0)
1994 use_regs (call_fusage, REGNO (reg), nregs);
1999 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2000 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2001 bytes, then we would need to push some additional bytes to pad the
2002 arguments. So, we compute an adjust to the stack pointer for an
2003 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2004 bytes. Then, when the arguments are pushed the stack will be perfectly
2005 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2006 be popped after the call. Returns the adjustment. */
2008 static int
2009 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
2010 struct args_size *args_size,
2011 unsigned int preferred_unit_stack_boundary)
2013 /* The number of bytes to pop so that the stack will be
2014 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2015 HOST_WIDE_INT adjustment;
2016 /* The alignment of the stack after the arguments are pushed, if we
2017 just pushed the arguments without adjust the stack here. */
2018 unsigned HOST_WIDE_INT unadjusted_alignment;
2020 unadjusted_alignment
2021 = ((stack_pointer_delta + unadjusted_args_size)
2022 % preferred_unit_stack_boundary);
2024 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2025 as possible -- leaving just enough left to cancel out the
2026 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2027 PENDING_STACK_ADJUST is non-negative, and congruent to
2028 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2030 /* Begin by trying to pop all the bytes. */
2031 unadjusted_alignment
2032 = (unadjusted_alignment
2033 - (pending_stack_adjust % preferred_unit_stack_boundary));
2034 adjustment = pending_stack_adjust;
2035 /* Push enough additional bytes that the stack will be aligned
2036 after the arguments are pushed. */
2037 if (preferred_unit_stack_boundary > 1)
2039 if (unadjusted_alignment > 0)
2040 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2041 else
2042 adjustment += unadjusted_alignment;
2045 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2046 bytes after the call. The right number is the entire
2047 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2048 by the arguments in the first place. */
2049 args_size->constant
2050 = pending_stack_adjust - adjustment + unadjusted_args_size;
2052 return adjustment;
2055 /* Scan X expression if it does not dereference any argument slots
2056 we already clobbered by tail call arguments (as noted in stored_args_map
2057 bitmap).
2058 Return nonzero if X expression dereferences such argument slots,
2059 zero otherwise. */
2061 static int
2062 check_sibcall_argument_overlap_1 (rtx x)
2064 RTX_CODE code;
2065 int i, j;
2066 const char *fmt;
2068 if (x == NULL_RTX)
2069 return 0;
2071 code = GET_CODE (x);
2073 /* We need not check the operands of the CALL expression itself. */
2074 if (code == CALL)
2075 return 0;
2077 if (code == MEM)
2078 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
2079 GET_MODE_SIZE (GET_MODE (x)));
2081 /* Scan all subexpressions. */
2082 fmt = GET_RTX_FORMAT (code);
2083 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2085 if (*fmt == 'e')
2087 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2088 return 1;
2090 else if (*fmt == 'E')
2092 for (j = 0; j < XVECLEN (x, i); j++)
2093 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2094 return 1;
2097 return 0;
2100 /* Scan sequence after INSN if it does not dereference any argument slots
2101 we already clobbered by tail call arguments (as noted in stored_args_map
2102 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2103 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2104 should be 0). Return nonzero if sequence after INSN dereferences such argument
2105 slots, zero otherwise. */
2107 static int
2108 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
2110 int low, high;
2112 if (insn == NULL_RTX)
2113 insn = get_insns ();
2114 else
2115 insn = NEXT_INSN (insn);
2117 for (; insn; insn = NEXT_INSN (insn))
2118 if (INSN_P (insn)
2119 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2120 break;
2122 if (mark_stored_args_map)
2124 #ifdef ARGS_GROW_DOWNWARD
2125 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2126 #else
2127 low = arg->locate.slot_offset.constant;
2128 #endif
2130 for (high = low + arg->locate.size.constant; low < high; low++)
2131 bitmap_set_bit (stored_args_map, low);
2133 return insn != NULL_RTX;
2136 /* Given that a function returns a value of mode MODE at the most
2137 significant end of hard register VALUE, shift VALUE left or right
2138 as specified by LEFT_P. Return true if some action was needed. */
2140 bool
2141 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
2143 HOST_WIDE_INT shift;
2145 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
2146 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
2147 if (shift == 0)
2148 return false;
2150 /* Use ashr rather than lshr for right shifts. This is for the benefit
2151 of the MIPS port, which requires SImode values to be sign-extended
2152 when stored in 64-bit registers. */
2153 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
2154 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
2155 gcc_unreachable ();
2156 return true;
2159 /* If X is a likely-spilled register value, copy it to a pseudo
2160 register and return that register. Return X otherwise. */
2162 static rtx
2163 avoid_likely_spilled_reg (rtx x)
2165 rtx new_rtx;
2167 if (REG_P (x)
2168 && HARD_REGISTER_P (x)
2169 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
2171 /* Make sure that we generate a REG rather than a CONCAT.
2172 Moves into CONCATs can need nontrivial instructions,
2173 and the whole point of this function is to avoid
2174 using the hard register directly in such a situation. */
2175 generating_concat_p = 0;
2176 new_rtx = gen_reg_rtx (GET_MODE (x));
2177 generating_concat_p = 1;
2178 emit_move_insn (new_rtx, x);
2179 return new_rtx;
2181 return x;
2184 /* Generate all the code for a CALL_EXPR exp
2185 and return an rtx for its value.
2186 Store the value in TARGET (specified as an rtx) if convenient.
2187 If the value is stored in TARGET then TARGET is returned.
2188 If IGNORE is nonzero, then we ignore the value of the function call. */
2191 expand_call (tree exp, rtx target, int ignore)
2193 /* Nonzero if we are currently expanding a call. */
2194 static int currently_expanding_call = 0;
2196 /* RTX for the function to be called. */
2197 rtx funexp;
2198 /* Sequence of insns to perform a normal "call". */
2199 rtx normal_call_insns = NULL_RTX;
2200 /* Sequence of insns to perform a tail "call". */
2201 rtx tail_call_insns = NULL_RTX;
2202 /* Data type of the function. */
2203 tree funtype;
2204 tree type_arg_types;
2205 tree rettype;
2206 /* Declaration of the function being called,
2207 or 0 if the function is computed (not known by name). */
2208 tree fndecl = 0;
2209 /* The type of the function being called. */
2210 tree fntype;
2211 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
2212 int pass;
2214 /* Register in which non-BLKmode value will be returned,
2215 or 0 if no value or if value is BLKmode. */
2216 rtx valreg;
2217 /* Address where we should return a BLKmode value;
2218 0 if value not BLKmode. */
2219 rtx structure_value_addr = 0;
2220 /* Nonzero if that address is being passed by treating it as
2221 an extra, implicit first parameter. Otherwise,
2222 it is passed by being copied directly into struct_value_rtx. */
2223 int structure_value_addr_parm = 0;
2224 /* Holds the value of implicit argument for the struct value. */
2225 tree structure_value_addr_value = NULL_TREE;
2226 /* Size of aggregate value wanted, or zero if none wanted
2227 or if we are using the non-reentrant PCC calling convention
2228 or expecting the value in registers. */
2229 HOST_WIDE_INT struct_value_size = 0;
2230 /* Nonzero if called function returns an aggregate in memory PCC style,
2231 by returning the address of where to find it. */
2232 int pcc_struct_value = 0;
2233 rtx struct_value = 0;
2235 /* Number of actual parameters in this call, including struct value addr. */
2236 int num_actuals;
2237 /* Number of named args. Args after this are anonymous ones
2238 and they must all go on the stack. */
2239 int n_named_args;
2240 /* Number of complex actual arguments that need to be split. */
2241 int num_complex_actuals = 0;
2243 /* Vector of information about each argument.
2244 Arguments are numbered in the order they will be pushed,
2245 not the order they are written. */
2246 struct arg_data *args;
2248 /* Total size in bytes of all the stack-parms scanned so far. */
2249 struct args_size args_size;
2250 struct args_size adjusted_args_size;
2251 /* Size of arguments before any adjustments (such as rounding). */
2252 int unadjusted_args_size;
2253 /* Data on reg parms scanned so far. */
2254 CUMULATIVE_ARGS args_so_far_v;
2255 cumulative_args_t args_so_far;
2256 /* Nonzero if a reg parm has been scanned. */
2257 int reg_parm_seen;
2258 /* Nonzero if this is an indirect function call. */
2260 /* Nonzero if we must avoid push-insns in the args for this call.
2261 If stack space is allocated for register parameters, but not by the
2262 caller, then it is preallocated in the fixed part of the stack frame.
2263 So the entire argument block must then be preallocated (i.e., we
2264 ignore PUSH_ROUNDING in that case). */
2266 int must_preallocate = !PUSH_ARGS;
2268 /* Size of the stack reserved for parameter registers. */
2269 int reg_parm_stack_space = 0;
2271 /* Address of space preallocated for stack parms
2272 (on machines that lack push insns), or 0 if space not preallocated. */
2273 rtx argblock = 0;
2275 /* Mask of ECF_ and ERF_ flags. */
2276 int flags = 0;
2277 int return_flags = 0;
2278 #ifdef REG_PARM_STACK_SPACE
2279 /* Define the boundary of the register parm stack space that needs to be
2280 saved, if any. */
2281 int low_to_save, high_to_save;
2282 rtx save_area = 0; /* Place that it is saved */
2283 #endif
2285 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2286 char *initial_stack_usage_map = stack_usage_map;
2287 char *stack_usage_map_buf = NULL;
2289 int old_stack_allocated;
2291 /* State variables to track stack modifications. */
2292 rtx old_stack_level = 0;
2293 int old_stack_arg_under_construction = 0;
2294 int old_pending_adj = 0;
2295 int old_inhibit_defer_pop = inhibit_defer_pop;
2297 /* Some stack pointer alterations we make are performed via
2298 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2299 which we then also need to save/restore along the way. */
2300 int old_stack_pointer_delta = 0;
2302 rtx call_fusage;
2303 tree addr = CALL_EXPR_FN (exp);
2304 int i;
2305 /* The alignment of the stack, in bits. */
2306 unsigned HOST_WIDE_INT preferred_stack_boundary;
2307 /* The alignment of the stack, in bytes. */
2308 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2309 /* The static chain value to use for this call. */
2310 rtx static_chain_value;
2311 /* See if this is "nothrow" function call. */
2312 if (TREE_NOTHROW (exp))
2313 flags |= ECF_NOTHROW;
2315 /* See if we can find a DECL-node for the actual function, and get the
2316 function attributes (flags) from the function decl or type node. */
2317 fndecl = get_callee_fndecl (exp);
2318 if (fndecl)
2320 fntype = TREE_TYPE (fndecl);
2321 flags |= flags_from_decl_or_type (fndecl);
2322 return_flags |= decl_return_flags (fndecl);
2324 else
2326 fntype = TREE_TYPE (TREE_TYPE (addr));
2327 flags |= flags_from_decl_or_type (fntype);
2329 rettype = TREE_TYPE (exp);
2331 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2333 /* Warn if this value is an aggregate type,
2334 regardless of which calling convention we are using for it. */
2335 if (AGGREGATE_TYPE_P (rettype))
2336 warning (OPT_Waggregate_return, "function call has aggregate value");
2338 /* If the result of a non looping pure or const function call is
2339 ignored (or void), and none of its arguments are volatile, we can
2340 avoid expanding the call and just evaluate the arguments for
2341 side-effects. */
2342 if ((flags & (ECF_CONST | ECF_PURE))
2343 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2344 && (ignore || target == const0_rtx
2345 || TYPE_MODE (rettype) == VOIDmode))
2347 bool volatilep = false;
2348 tree arg;
2349 call_expr_arg_iterator iter;
2351 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2352 if (TREE_THIS_VOLATILE (arg))
2354 volatilep = true;
2355 break;
2358 if (! volatilep)
2360 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2361 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2362 return const0_rtx;
2366 #ifdef REG_PARM_STACK_SPACE
2367 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2368 #endif
2370 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2371 && reg_parm_stack_space > 0 && PUSH_ARGS)
2372 must_preallocate = 1;
2374 /* Set up a place to return a structure. */
2376 /* Cater to broken compilers. */
2377 if (aggregate_value_p (exp, fntype))
2379 /* This call returns a big structure. */
2380 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2382 #ifdef PCC_STATIC_STRUCT_RETURN
2384 pcc_struct_value = 1;
2386 #else /* not PCC_STATIC_STRUCT_RETURN */
2388 struct_value_size = int_size_in_bytes (rettype);
2390 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2391 structure_value_addr = XEXP (target, 0);
2392 else
2394 /* For variable-sized objects, we must be called with a target
2395 specified. If we were to allocate space on the stack here,
2396 we would have no way of knowing when to free it. */
2397 rtx d = assign_temp (rettype, 1, 1);
2398 structure_value_addr = XEXP (d, 0);
2399 target = 0;
2402 #endif /* not PCC_STATIC_STRUCT_RETURN */
2405 /* Figure out the amount to which the stack should be aligned. */
2406 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2407 if (fndecl)
2409 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2410 /* Without automatic stack alignment, we can't increase preferred
2411 stack boundary. With automatic stack alignment, it is
2412 unnecessary since unless we can guarantee that all callers will
2413 align the outgoing stack properly, callee has to align its
2414 stack anyway. */
2415 if (i
2416 && i->preferred_incoming_stack_boundary
2417 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2418 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2421 /* Operand 0 is a pointer-to-function; get the type of the function. */
2422 funtype = TREE_TYPE (addr);
2423 gcc_assert (POINTER_TYPE_P (funtype));
2424 funtype = TREE_TYPE (funtype);
2426 /* Count whether there are actual complex arguments that need to be split
2427 into their real and imaginary parts. Munge the type_arg_types
2428 appropriately here as well. */
2429 if (targetm.calls.split_complex_arg)
2431 call_expr_arg_iterator iter;
2432 tree arg;
2433 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2435 tree type = TREE_TYPE (arg);
2436 if (type && TREE_CODE (type) == COMPLEX_TYPE
2437 && targetm.calls.split_complex_arg (type))
2438 num_complex_actuals++;
2440 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2442 else
2443 type_arg_types = TYPE_ARG_TYPES (funtype);
2445 if (flags & ECF_MAY_BE_ALLOCA)
2446 cfun->calls_alloca = 1;
2448 /* If struct_value_rtx is 0, it means pass the address
2449 as if it were an extra parameter. Put the argument expression
2450 in structure_value_addr_value. */
2451 if (structure_value_addr && struct_value == 0)
2453 /* If structure_value_addr is a REG other than
2454 virtual_outgoing_args_rtx, we can use always use it. If it
2455 is not a REG, we must always copy it into a register.
2456 If it is virtual_outgoing_args_rtx, we must copy it to another
2457 register in some cases. */
2458 rtx temp = (!REG_P (structure_value_addr)
2459 || (ACCUMULATE_OUTGOING_ARGS
2460 && stack_arg_under_construction
2461 && structure_value_addr == virtual_outgoing_args_rtx)
2462 ? copy_addr_to_reg (convert_memory_address
2463 (Pmode, structure_value_addr))
2464 : structure_value_addr);
2466 structure_value_addr_value =
2467 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2468 structure_value_addr_parm = 1;
2471 /* Count the arguments and set NUM_ACTUALS. */
2472 num_actuals =
2473 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2475 /* Compute number of named args.
2476 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2478 if (type_arg_types != 0)
2479 n_named_args
2480 = (list_length (type_arg_types)
2481 /* Count the struct value address, if it is passed as a parm. */
2482 + structure_value_addr_parm);
2483 else
2484 /* If we know nothing, treat all args as named. */
2485 n_named_args = num_actuals;
2487 /* Start updating where the next arg would go.
2489 On some machines (such as the PA) indirect calls have a different
2490 calling convention than normal calls. The fourth argument in
2491 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2492 or not. */
2493 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
2494 args_so_far = pack_cumulative_args (&args_so_far_v);
2496 /* Now possibly adjust the number of named args.
2497 Normally, don't include the last named arg if anonymous args follow.
2498 We do include the last named arg if
2499 targetm.calls.strict_argument_naming() returns nonzero.
2500 (If no anonymous args follow, the result of list_length is actually
2501 one too large. This is harmless.)
2503 If targetm.calls.pretend_outgoing_varargs_named() returns
2504 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2505 this machine will be able to place unnamed args that were passed
2506 in registers into the stack. So treat all args as named. This
2507 allows the insns emitting for a specific argument list to be
2508 independent of the function declaration.
2510 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2511 we do not have any reliable way to pass unnamed args in
2512 registers, so we must force them into memory. */
2514 if (type_arg_types != 0
2515 && targetm.calls.strict_argument_naming (args_so_far))
2517 else if (type_arg_types != 0
2518 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
2519 /* Don't include the last named arg. */
2520 --n_named_args;
2521 else
2522 /* Treat all args as named. */
2523 n_named_args = num_actuals;
2525 /* Make a vector to hold all the information about each arg. */
2526 args = XALLOCAVEC (struct arg_data, num_actuals);
2527 memset (args, 0, num_actuals * sizeof (struct arg_data));
2529 /* Build up entries in the ARGS array, compute the size of the
2530 arguments into ARGS_SIZE, etc. */
2531 initialize_argument_information (num_actuals, args, &args_size,
2532 n_named_args, exp,
2533 structure_value_addr_value, fndecl, fntype,
2534 args_so_far, reg_parm_stack_space,
2535 &old_stack_level, &old_pending_adj,
2536 &must_preallocate, &flags,
2537 &try_tail_call, CALL_FROM_THUNK_P (exp));
2539 if (args_size.var)
2540 must_preallocate = 1;
2542 /* Now make final decision about preallocating stack space. */
2543 must_preallocate = finalize_must_preallocate (must_preallocate,
2544 num_actuals, args,
2545 &args_size);
2547 /* If the structure value address will reference the stack pointer, we
2548 must stabilize it. We don't need to do this if we know that we are
2549 not going to adjust the stack pointer in processing this call. */
2551 if (structure_value_addr
2552 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2553 || reg_mentioned_p (virtual_outgoing_args_rtx,
2554 structure_value_addr))
2555 && (args_size.var
2556 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2557 structure_value_addr = copy_to_reg (structure_value_addr);
2559 /* Tail calls can make things harder to debug, and we've traditionally
2560 pushed these optimizations into -O2. Don't try if we're already
2561 expanding a call, as that means we're an argument. Don't try if
2562 there's cleanups, as we know there's code to follow the call. */
2564 if (currently_expanding_call++ != 0
2565 || !flag_optimize_sibling_calls
2566 || args_size.var
2567 || dbg_cnt (tail_call) == false)
2568 try_tail_call = 0;
2570 /* Rest of purposes for tail call optimizations to fail. */
2571 if (
2572 #ifdef HAVE_sibcall_epilogue
2573 !HAVE_sibcall_epilogue
2574 #else
2576 #endif
2577 || !try_tail_call
2578 /* Doing sibling call optimization needs some work, since
2579 structure_value_addr can be allocated on the stack.
2580 It does not seem worth the effort since few optimizable
2581 sibling calls will return a structure. */
2582 || structure_value_addr != NULL_RTX
2583 #ifdef REG_PARM_STACK_SPACE
2584 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2585 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2586 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2587 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2588 #endif
2589 /* Check whether the target is able to optimize the call
2590 into a sibcall. */
2591 || !targetm.function_ok_for_sibcall (fndecl, exp)
2592 /* Functions that do not return exactly once may not be sibcall
2593 optimized. */
2594 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2595 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2596 /* If the called function is nested in the current one, it might access
2597 some of the caller's arguments, but could clobber them beforehand if
2598 the argument areas are shared. */
2599 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2600 /* If this function requires more stack slots than the current
2601 function, we cannot change it into a sibling call.
2602 crtl->args.pretend_args_size is not part of the
2603 stack allocated by our caller. */
2604 || args_size.constant > (crtl->args.size
2605 - crtl->args.pretend_args_size)
2606 /* If the callee pops its own arguments, then it must pop exactly
2607 the same number of arguments as the current function. */
2608 || (targetm.calls.return_pops_args (fndecl, funtype, args_size.constant)
2609 != targetm.calls.return_pops_args (current_function_decl,
2610 TREE_TYPE (current_function_decl),
2611 crtl->args.size))
2612 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2613 try_tail_call = 0;
2615 /* Check if caller and callee disagree in promotion of function
2616 return value. */
2617 if (try_tail_call)
2619 enum machine_mode caller_mode, caller_promoted_mode;
2620 enum machine_mode callee_mode, callee_promoted_mode;
2621 int caller_unsignedp, callee_unsignedp;
2622 tree caller_res = DECL_RESULT (current_function_decl);
2624 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2625 caller_mode = DECL_MODE (caller_res);
2626 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2627 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2628 caller_promoted_mode
2629 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2630 &caller_unsignedp,
2631 TREE_TYPE (current_function_decl), 1);
2632 callee_promoted_mode
2633 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2634 &callee_unsignedp,
2635 funtype, 1);
2636 if (caller_mode != VOIDmode
2637 && (caller_promoted_mode != callee_promoted_mode
2638 || ((caller_mode != caller_promoted_mode
2639 || callee_mode != callee_promoted_mode)
2640 && (caller_unsignedp != callee_unsignedp
2641 || GET_MODE_BITSIZE (caller_mode)
2642 < GET_MODE_BITSIZE (callee_mode)))))
2643 try_tail_call = 0;
2646 /* Ensure current function's preferred stack boundary is at least
2647 what we need. Stack alignment may also increase preferred stack
2648 boundary. */
2649 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2650 crtl->preferred_stack_boundary = preferred_stack_boundary;
2651 else
2652 preferred_stack_boundary = crtl->preferred_stack_boundary;
2654 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2656 /* We want to make two insn chains; one for a sibling call, the other
2657 for a normal call. We will select one of the two chains after
2658 initial RTL generation is complete. */
2659 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2661 int sibcall_failure = 0;
2662 /* We want to emit any pending stack adjustments before the tail
2663 recursion "call". That way we know any adjustment after the tail
2664 recursion call can be ignored if we indeed use the tail
2665 call expansion. */
2666 int save_pending_stack_adjust = 0;
2667 int save_stack_pointer_delta = 0;
2668 rtx insns;
2669 rtx before_call, next_arg_reg, after_args;
2671 if (pass == 0)
2673 /* State variables we need to save and restore between
2674 iterations. */
2675 save_pending_stack_adjust = pending_stack_adjust;
2676 save_stack_pointer_delta = stack_pointer_delta;
2678 if (pass)
2679 flags &= ~ECF_SIBCALL;
2680 else
2681 flags |= ECF_SIBCALL;
2683 /* Other state variables that we must reinitialize each time
2684 through the loop (that are not initialized by the loop itself). */
2685 argblock = 0;
2686 call_fusage = 0;
2688 /* Start a new sequence for the normal call case.
2690 From this point on, if the sibling call fails, we want to set
2691 sibcall_failure instead of continuing the loop. */
2692 start_sequence ();
2694 /* Don't let pending stack adjusts add up to too much.
2695 Also, do all pending adjustments now if there is any chance
2696 this might be a call to alloca or if we are expanding a sibling
2697 call sequence.
2698 Also do the adjustments before a throwing call, otherwise
2699 exception handling can fail; PR 19225. */
2700 if (pending_stack_adjust >= 32
2701 || (pending_stack_adjust > 0
2702 && (flags & ECF_MAY_BE_ALLOCA))
2703 || (pending_stack_adjust > 0
2704 && flag_exceptions && !(flags & ECF_NOTHROW))
2705 || pass == 0)
2706 do_pending_stack_adjust ();
2708 /* Precompute any arguments as needed. */
2709 if (pass)
2710 precompute_arguments (num_actuals, args);
2712 /* Now we are about to start emitting insns that can be deleted
2713 if a libcall is deleted. */
2714 if (pass && (flags & ECF_MALLOC))
2715 start_sequence ();
2717 if (pass == 0 && crtl->stack_protect_guard)
2718 stack_protect_epilogue ();
2720 adjusted_args_size = args_size;
2721 /* Compute the actual size of the argument block required. The variable
2722 and constant sizes must be combined, the size may have to be rounded,
2723 and there may be a minimum required size. When generating a sibcall
2724 pattern, do not round up, since we'll be re-using whatever space our
2725 caller provided. */
2726 unadjusted_args_size
2727 = compute_argument_block_size (reg_parm_stack_space,
2728 &adjusted_args_size,
2729 fndecl, fntype,
2730 (pass == 0 ? 0
2731 : preferred_stack_boundary));
2733 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2735 /* The argument block when performing a sibling call is the
2736 incoming argument block. */
2737 if (pass == 0)
2739 argblock = crtl->args.internal_arg_pointer;
2740 argblock
2741 #ifdef STACK_GROWS_DOWNWARD
2742 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
2743 #else
2744 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
2745 #endif
2746 stored_args_map = sbitmap_alloc (args_size.constant);
2747 bitmap_clear (stored_args_map);
2750 /* If we have no actual push instructions, or shouldn't use them,
2751 make space for all args right now. */
2752 else if (adjusted_args_size.var != 0)
2754 if (old_stack_level == 0)
2756 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2757 old_stack_pointer_delta = stack_pointer_delta;
2758 old_pending_adj = pending_stack_adjust;
2759 pending_stack_adjust = 0;
2760 /* stack_arg_under_construction says whether a stack arg is
2761 being constructed at the old stack level. Pushing the stack
2762 gets a clean outgoing argument block. */
2763 old_stack_arg_under_construction = stack_arg_under_construction;
2764 stack_arg_under_construction = 0;
2766 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2767 if (flag_stack_usage_info)
2768 current_function_has_unbounded_dynamic_stack_size = 1;
2770 else
2772 /* Note that we must go through the motions of allocating an argument
2773 block even if the size is zero because we may be storing args
2774 in the area reserved for register arguments, which may be part of
2775 the stack frame. */
2777 int needed = adjusted_args_size.constant;
2779 /* Store the maximum argument space used. It will be pushed by
2780 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2781 checking). */
2783 if (needed > crtl->outgoing_args_size)
2784 crtl->outgoing_args_size = needed;
2786 if (must_preallocate)
2788 if (ACCUMULATE_OUTGOING_ARGS)
2790 /* Since the stack pointer will never be pushed, it is
2791 possible for the evaluation of a parm to clobber
2792 something we have already written to the stack.
2793 Since most function calls on RISC machines do not use
2794 the stack, this is uncommon, but must work correctly.
2796 Therefore, we save any area of the stack that was already
2797 written and that we are using. Here we set up to do this
2798 by making a new stack usage map from the old one. The
2799 actual save will be done by store_one_arg.
2801 Another approach might be to try to reorder the argument
2802 evaluations to avoid this conflicting stack usage. */
2804 /* Since we will be writing into the entire argument area,
2805 the map must be allocated for its entire size, not just
2806 the part that is the responsibility of the caller. */
2807 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2808 needed += reg_parm_stack_space;
2810 #ifdef ARGS_GROW_DOWNWARD
2811 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2812 needed + 1);
2813 #else
2814 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2815 needed);
2816 #endif
2817 free (stack_usage_map_buf);
2818 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2819 stack_usage_map = stack_usage_map_buf;
2821 if (initial_highest_arg_in_use)
2822 memcpy (stack_usage_map, initial_stack_usage_map,
2823 initial_highest_arg_in_use);
2825 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2826 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2827 (highest_outgoing_arg_in_use
2828 - initial_highest_arg_in_use));
2829 needed = 0;
2831 /* The address of the outgoing argument list must not be
2832 copied to a register here, because argblock would be left
2833 pointing to the wrong place after the call to
2834 allocate_dynamic_stack_space below. */
2836 argblock = virtual_outgoing_args_rtx;
2838 else
2840 if (inhibit_defer_pop == 0)
2842 /* Try to reuse some or all of the pending_stack_adjust
2843 to get this space. */
2844 needed
2845 = (combine_pending_stack_adjustment_and_call
2846 (unadjusted_args_size,
2847 &adjusted_args_size,
2848 preferred_unit_stack_boundary));
2850 /* combine_pending_stack_adjustment_and_call computes
2851 an adjustment before the arguments are allocated.
2852 Account for them and see whether or not the stack
2853 needs to go up or down. */
2854 needed = unadjusted_args_size - needed;
2856 if (needed < 0)
2858 /* We're releasing stack space. */
2859 /* ??? We can avoid any adjustment at all if we're
2860 already aligned. FIXME. */
2861 pending_stack_adjust = -needed;
2862 do_pending_stack_adjust ();
2863 needed = 0;
2865 else
2866 /* We need to allocate space. We'll do that in
2867 push_block below. */
2868 pending_stack_adjust = 0;
2871 /* Special case this because overhead of `push_block' in
2872 this case is non-trivial. */
2873 if (needed == 0)
2874 argblock = virtual_outgoing_args_rtx;
2875 else
2877 argblock = push_block (GEN_INT (needed), 0, 0);
2878 #ifdef ARGS_GROW_DOWNWARD
2879 argblock = plus_constant (Pmode, argblock, needed);
2880 #endif
2883 /* We only really need to call `copy_to_reg' in the case
2884 where push insns are going to be used to pass ARGBLOCK
2885 to a function call in ARGS. In that case, the stack
2886 pointer changes value from the allocation point to the
2887 call point, and hence the value of
2888 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2889 as well always do it. */
2890 argblock = copy_to_reg (argblock);
2895 if (ACCUMULATE_OUTGOING_ARGS)
2897 /* The save/restore code in store_one_arg handles all
2898 cases except one: a constructor call (including a C
2899 function returning a BLKmode struct) to initialize
2900 an argument. */
2901 if (stack_arg_under_construction)
2903 rtx push_size
2904 = GEN_INT (adjusted_args_size.constant
2905 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2906 : TREE_TYPE (fndecl))) ? 0
2907 : reg_parm_stack_space));
2908 if (old_stack_level == 0)
2910 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2911 old_stack_pointer_delta = stack_pointer_delta;
2912 old_pending_adj = pending_stack_adjust;
2913 pending_stack_adjust = 0;
2914 /* stack_arg_under_construction says whether a stack
2915 arg is being constructed at the old stack level.
2916 Pushing the stack gets a clean outgoing argument
2917 block. */
2918 old_stack_arg_under_construction
2919 = stack_arg_under_construction;
2920 stack_arg_under_construction = 0;
2921 /* Make a new map for the new argument list. */
2922 free (stack_usage_map_buf);
2923 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2924 stack_usage_map = stack_usage_map_buf;
2925 highest_outgoing_arg_in_use = 0;
2927 /* We can pass TRUE as the 4th argument because we just
2928 saved the stack pointer and will restore it right after
2929 the call. */
2930 allocate_dynamic_stack_space (push_size, 0,
2931 BIGGEST_ALIGNMENT, true);
2934 /* If argument evaluation might modify the stack pointer,
2935 copy the address of the argument list to a register. */
2936 for (i = 0; i < num_actuals; i++)
2937 if (args[i].pass_on_stack)
2939 argblock = copy_addr_to_reg (argblock);
2940 break;
2944 compute_argument_addresses (args, argblock, num_actuals);
2946 /* If we push args individually in reverse order, perform stack alignment
2947 before the first push (the last arg). */
2948 if (PUSH_ARGS_REVERSED && argblock == 0
2949 && adjusted_args_size.constant != unadjusted_args_size)
2951 /* When the stack adjustment is pending, we get better code
2952 by combining the adjustments. */
2953 if (pending_stack_adjust
2954 && ! inhibit_defer_pop)
2956 pending_stack_adjust
2957 = (combine_pending_stack_adjustment_and_call
2958 (unadjusted_args_size,
2959 &adjusted_args_size,
2960 preferred_unit_stack_boundary));
2961 do_pending_stack_adjust ();
2963 else if (argblock == 0)
2964 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2965 - unadjusted_args_size));
2967 /* Now that the stack is properly aligned, pops can't safely
2968 be deferred during the evaluation of the arguments. */
2969 NO_DEFER_POP;
2971 /* Record the maximum pushed stack space size. We need to delay
2972 doing it this far to take into account the optimization done
2973 by combine_pending_stack_adjustment_and_call. */
2974 if (flag_stack_usage_info
2975 && !ACCUMULATE_OUTGOING_ARGS
2976 && pass
2977 && adjusted_args_size.var == 0)
2979 int pushed = adjusted_args_size.constant + pending_stack_adjust;
2980 if (pushed > current_function_pushed_stack_size)
2981 current_function_pushed_stack_size = pushed;
2984 funexp = rtx_for_function_call (fndecl, addr);
2986 /* Figure out the register where the value, if any, will come back. */
2987 valreg = 0;
2988 if (TYPE_MODE (rettype) != VOIDmode
2989 && ! structure_value_addr)
2991 if (pcc_struct_value)
2992 valreg = hard_function_value (build_pointer_type (rettype),
2993 fndecl, NULL, (pass == 0));
2994 else
2995 valreg = hard_function_value (rettype, fndecl, fntype,
2996 (pass == 0));
2998 /* If VALREG is a PARALLEL whose first member has a zero
2999 offset, use that. This is for targets such as m68k that
3000 return the same value in multiple places. */
3001 if (GET_CODE (valreg) == PARALLEL)
3003 rtx elem = XVECEXP (valreg, 0, 0);
3004 rtx where = XEXP (elem, 0);
3005 rtx offset = XEXP (elem, 1);
3006 if (offset == const0_rtx
3007 && GET_MODE (where) == GET_MODE (valreg))
3008 valreg = where;
3012 /* Precompute all register parameters. It isn't safe to compute anything
3013 once we have started filling any specific hard regs. */
3014 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3016 if (CALL_EXPR_STATIC_CHAIN (exp))
3017 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
3018 else
3019 static_chain_value = 0;
3021 #ifdef REG_PARM_STACK_SPACE
3022 /* Save the fixed argument area if it's part of the caller's frame and
3023 is clobbered by argument setup for this call. */
3024 if (ACCUMULATE_OUTGOING_ARGS && pass)
3025 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3026 &low_to_save, &high_to_save);
3027 #endif
3029 /* Now store (and compute if necessary) all non-register parms.
3030 These come before register parms, since they can require block-moves,
3031 which could clobber the registers used for register parms.
3032 Parms which have partial registers are not stored here,
3033 but we do preallocate space here if they want that. */
3035 for (i = 0; i < num_actuals; i++)
3037 if (args[i].reg == 0 || args[i].pass_on_stack)
3039 rtx before_arg = get_last_insn ();
3041 if (store_one_arg (&args[i], argblock, flags,
3042 adjusted_args_size.var != 0,
3043 reg_parm_stack_space)
3044 || (pass == 0
3045 && check_sibcall_argument_overlap (before_arg,
3046 &args[i], 1)))
3047 sibcall_failure = 1;
3050 if (args[i].stack)
3051 call_fusage
3052 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
3053 gen_rtx_USE (VOIDmode, args[i].stack),
3054 call_fusage);
3057 /* If we have a parm that is passed in registers but not in memory
3058 and whose alignment does not permit a direct copy into registers,
3059 make a group of pseudos that correspond to each register that we
3060 will later fill. */
3061 if (STRICT_ALIGNMENT)
3062 store_unaligned_arguments_into_pseudos (args, num_actuals);
3064 /* Now store any partially-in-registers parm.
3065 This is the last place a block-move can happen. */
3066 if (reg_parm_seen)
3067 for (i = 0; i < num_actuals; i++)
3068 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3070 rtx before_arg = get_last_insn ();
3072 if (store_one_arg (&args[i], argblock, flags,
3073 adjusted_args_size.var != 0,
3074 reg_parm_stack_space)
3075 || (pass == 0
3076 && check_sibcall_argument_overlap (before_arg,
3077 &args[i], 1)))
3078 sibcall_failure = 1;
3081 /* If we pushed args in forward order, perform stack alignment
3082 after pushing the last arg. */
3083 if (!PUSH_ARGS_REVERSED && argblock == 0)
3084 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3085 - unadjusted_args_size));
3087 /* If register arguments require space on the stack and stack space
3088 was not preallocated, allocate stack space here for arguments
3089 passed in registers. */
3090 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3091 && !ACCUMULATE_OUTGOING_ARGS
3092 && must_preallocate == 0 && reg_parm_stack_space > 0)
3093 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3095 /* Pass the function the address in which to return a
3096 structure value. */
3097 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3099 structure_value_addr
3100 = convert_memory_address (Pmode, structure_value_addr);
3101 emit_move_insn (struct_value,
3102 force_reg (Pmode,
3103 force_operand (structure_value_addr,
3104 NULL_RTX)));
3106 if (REG_P (struct_value))
3107 use_reg (&call_fusage, struct_value);
3110 after_args = get_last_insn ();
3111 funexp = prepare_call_address (fndecl, funexp, static_chain_value,
3112 &call_fusage, reg_parm_seen, pass == 0);
3114 load_register_parameters (args, num_actuals, &call_fusage, flags,
3115 pass == 0, &sibcall_failure);
3117 /* Save a pointer to the last insn before the call, so that we can
3118 later safely search backwards to find the CALL_INSN. */
3119 before_call = get_last_insn ();
3121 /* Set up next argument register. For sibling calls on machines
3122 with register windows this should be the incoming register. */
3123 if (pass == 0)
3124 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
3125 VOIDmode,
3126 void_type_node,
3127 true);
3128 else
3129 next_arg_reg = targetm.calls.function_arg (args_so_far,
3130 VOIDmode, void_type_node,
3131 true);
3133 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
3135 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
3136 if (PUSH_ARGS_REVERSED)
3137 arg_nr = num_actuals - arg_nr - 1;
3138 if (arg_nr >= 0
3139 && arg_nr < num_actuals
3140 && args[arg_nr].reg
3141 && valreg
3142 && REG_P (valreg)
3143 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
3144 call_fusage
3145 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
3146 gen_rtx_SET (VOIDmode, valreg, args[arg_nr].reg),
3147 call_fusage);
3149 /* All arguments and registers used for the call must be set up by
3150 now! */
3152 /* Stack must be properly aligned now. */
3153 gcc_assert (!pass
3154 || !(stack_pointer_delta % preferred_unit_stack_boundary));
3156 /* Generate the actual call instruction. */
3157 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
3158 adjusted_args_size.constant, struct_value_size,
3159 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3160 flags, args_so_far);
3162 /* If the call setup or the call itself overlaps with anything
3163 of the argument setup we probably clobbered our call address.
3164 In that case we can't do sibcalls. */
3165 if (pass == 0
3166 && check_sibcall_argument_overlap (after_args, 0, 0))
3167 sibcall_failure = 1;
3169 /* If a non-BLKmode value is returned at the most significant end
3170 of a register, shift the register right by the appropriate amount
3171 and update VALREG accordingly. BLKmode values are handled by the
3172 group load/store machinery below. */
3173 if (!structure_value_addr
3174 && !pcc_struct_value
3175 && TYPE_MODE (rettype) != VOIDmode
3176 && TYPE_MODE (rettype) != BLKmode
3177 && REG_P (valreg)
3178 && targetm.calls.return_in_msb (rettype))
3180 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
3181 sibcall_failure = 1;
3182 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
3185 if (pass && (flags & ECF_MALLOC))
3187 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3188 rtx last, insns;
3190 /* The return value from a malloc-like function is a pointer. */
3191 if (TREE_CODE (rettype) == POINTER_TYPE)
3192 mark_reg_pointer (temp, MALLOC_ABI_ALIGNMENT);
3194 emit_move_insn (temp, valreg);
3196 /* The return value from a malloc-like function can not alias
3197 anything else. */
3198 last = get_last_insn ();
3199 add_reg_note (last, REG_NOALIAS, temp);
3201 /* Write out the sequence. */
3202 insns = get_insns ();
3203 end_sequence ();
3204 emit_insn (insns);
3205 valreg = temp;
3208 /* For calls to `setjmp', etc., inform
3209 function.c:setjmp_warnings that it should complain if
3210 nonvolatile values are live. For functions that cannot
3211 return, inform flow that control does not fall through. */
3213 if ((flags & ECF_NORETURN) || pass == 0)
3215 /* The barrier must be emitted
3216 immediately after the CALL_INSN. Some ports emit more
3217 than just a CALL_INSN above, so we must search for it here. */
3219 rtx last = get_last_insn ();
3220 while (!CALL_P (last))
3222 last = PREV_INSN (last);
3223 /* There was no CALL_INSN? */
3224 gcc_assert (last != before_call);
3227 emit_barrier_after (last);
3229 /* Stack adjustments after a noreturn call are dead code.
3230 However when NO_DEFER_POP is in effect, we must preserve
3231 stack_pointer_delta. */
3232 if (inhibit_defer_pop == 0)
3234 stack_pointer_delta = old_stack_allocated;
3235 pending_stack_adjust = 0;
3239 /* If value type not void, return an rtx for the value. */
3241 if (TYPE_MODE (rettype) == VOIDmode
3242 || ignore)
3243 target = const0_rtx;
3244 else if (structure_value_addr)
3246 if (target == 0 || !MEM_P (target))
3248 target
3249 = gen_rtx_MEM (TYPE_MODE (rettype),
3250 memory_address (TYPE_MODE (rettype),
3251 structure_value_addr));
3252 set_mem_attributes (target, rettype, 1);
3255 else if (pcc_struct_value)
3257 /* This is the special C++ case where we need to
3258 know what the true target was. We take care to
3259 never use this value more than once in one expression. */
3260 target = gen_rtx_MEM (TYPE_MODE (rettype),
3261 copy_to_reg (valreg));
3262 set_mem_attributes (target, rettype, 1);
3264 /* Handle calls that return values in multiple non-contiguous locations.
3265 The Irix 6 ABI has examples of this. */
3266 else if (GET_CODE (valreg) == PARALLEL)
3268 if (target == 0)
3269 target = emit_group_move_into_temps (valreg);
3270 else if (rtx_equal_p (target, valreg))
3272 else if (GET_CODE (target) == PARALLEL)
3273 /* Handle the result of a emit_group_move_into_temps
3274 call in the previous pass. */
3275 emit_group_move (target, valreg);
3276 else
3277 emit_group_store (target, valreg, rettype,
3278 int_size_in_bytes (rettype));
3280 else if (target
3281 && GET_MODE (target) == TYPE_MODE (rettype)
3282 && GET_MODE (target) == GET_MODE (valreg))
3284 bool may_overlap = false;
3286 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3287 reg to a plain register. */
3288 if (!REG_P (target) || HARD_REGISTER_P (target))
3289 valreg = avoid_likely_spilled_reg (valreg);
3291 /* If TARGET is a MEM in the argument area, and we have
3292 saved part of the argument area, then we can't store
3293 directly into TARGET as it may get overwritten when we
3294 restore the argument save area below. Don't work too
3295 hard though and simply force TARGET to a register if it
3296 is a MEM; the optimizer is quite likely to sort it out. */
3297 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
3298 for (i = 0; i < num_actuals; i++)
3299 if (args[i].save_area)
3301 may_overlap = true;
3302 break;
3305 if (may_overlap)
3306 target = copy_to_reg (valreg);
3307 else
3309 /* TARGET and VALREG cannot be equal at this point
3310 because the latter would not have
3311 REG_FUNCTION_VALUE_P true, while the former would if
3312 it were referring to the same register.
3314 If they refer to the same register, this move will be
3315 a no-op, except when function inlining is being
3316 done. */
3317 emit_move_insn (target, valreg);
3319 /* If we are setting a MEM, this code must be executed.
3320 Since it is emitted after the call insn, sibcall
3321 optimization cannot be performed in that case. */
3322 if (MEM_P (target))
3323 sibcall_failure = 1;
3326 else
3327 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3329 /* If we promoted this return value, make the proper SUBREG.
3330 TARGET might be const0_rtx here, so be careful. */
3331 if (REG_P (target)
3332 && TYPE_MODE (rettype) != BLKmode
3333 && GET_MODE (target) != TYPE_MODE (rettype))
3335 tree type = rettype;
3336 int unsignedp = TYPE_UNSIGNED (type);
3337 int offset = 0;
3338 enum machine_mode pmode;
3340 /* Ensure we promote as expected, and get the new unsignedness. */
3341 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3342 funtype, 1);
3343 gcc_assert (GET_MODE (target) == pmode);
3345 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3346 && (GET_MODE_SIZE (GET_MODE (target))
3347 > GET_MODE_SIZE (TYPE_MODE (type))))
3349 offset = GET_MODE_SIZE (GET_MODE (target))
3350 - GET_MODE_SIZE (TYPE_MODE (type));
3351 if (! BYTES_BIG_ENDIAN)
3352 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3353 else if (! WORDS_BIG_ENDIAN)
3354 offset %= UNITS_PER_WORD;
3357 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3358 SUBREG_PROMOTED_VAR_P (target) = 1;
3359 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3362 /* If size of args is variable or this was a constructor call for a stack
3363 argument, restore saved stack-pointer value. */
3365 if (old_stack_level)
3367 rtx prev = get_last_insn ();
3369 emit_stack_restore (SAVE_BLOCK, old_stack_level);
3370 stack_pointer_delta = old_stack_pointer_delta;
3372 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
3374 pending_stack_adjust = old_pending_adj;
3375 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3376 stack_arg_under_construction = old_stack_arg_under_construction;
3377 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3378 stack_usage_map = initial_stack_usage_map;
3379 sibcall_failure = 1;
3381 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3383 #ifdef REG_PARM_STACK_SPACE
3384 if (save_area)
3385 restore_fixed_argument_area (save_area, argblock,
3386 high_to_save, low_to_save);
3387 #endif
3389 /* If we saved any argument areas, restore them. */
3390 for (i = 0; i < num_actuals; i++)
3391 if (args[i].save_area)
3393 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3394 rtx stack_area
3395 = gen_rtx_MEM (save_mode,
3396 memory_address (save_mode,
3397 XEXP (args[i].stack_slot, 0)));
3399 if (save_mode != BLKmode)
3400 emit_move_insn (stack_area, args[i].save_area);
3401 else
3402 emit_block_move (stack_area, args[i].save_area,
3403 GEN_INT (args[i].locate.size.constant),
3404 BLOCK_OP_CALL_PARM);
3407 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3408 stack_usage_map = initial_stack_usage_map;
3411 /* If this was alloca, record the new stack level for nonlocal gotos.
3412 Check for the handler slots since we might not have a save area
3413 for non-local gotos. */
3415 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3416 update_nonlocal_goto_save_area ();
3418 /* Free up storage we no longer need. */
3419 for (i = 0; i < num_actuals; ++i)
3420 free (args[i].aligned_regs);
3422 insns = get_insns ();
3423 end_sequence ();
3425 if (pass == 0)
3427 tail_call_insns = insns;
3429 /* Restore the pending stack adjustment now that we have
3430 finished generating the sibling call sequence. */
3432 pending_stack_adjust = save_pending_stack_adjust;
3433 stack_pointer_delta = save_stack_pointer_delta;
3435 /* Prepare arg structure for next iteration. */
3436 for (i = 0; i < num_actuals; i++)
3438 args[i].value = 0;
3439 args[i].aligned_regs = 0;
3440 args[i].stack = 0;
3443 sbitmap_free (stored_args_map);
3444 internal_arg_pointer_exp_state.scan_start = NULL_RTX;
3445 internal_arg_pointer_exp_state.cache.release ();
3447 else
3449 normal_call_insns = insns;
3451 /* Verify that we've deallocated all the stack we used. */
3452 gcc_assert ((flags & ECF_NORETURN)
3453 || (old_stack_allocated
3454 == stack_pointer_delta - pending_stack_adjust));
3457 /* If something prevents making this a sibling call,
3458 zero out the sequence. */
3459 if (sibcall_failure)
3460 tail_call_insns = NULL_RTX;
3461 else
3462 break;
3465 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3466 arguments too, as argument area is now clobbered by the call. */
3467 if (tail_call_insns)
3469 emit_insn (tail_call_insns);
3470 crtl->tail_call_emit = true;
3472 else
3473 emit_insn (normal_call_insns);
3475 currently_expanding_call--;
3477 free (stack_usage_map_buf);
3479 return target;
3482 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3483 this function's incoming arguments.
3485 At the start of RTL generation we know the only REG_EQUIV notes
3486 in the rtl chain are those for incoming arguments, so we can look
3487 for REG_EQUIV notes between the start of the function and the
3488 NOTE_INSN_FUNCTION_BEG.
3490 This is (slight) overkill. We could keep track of the highest
3491 argument we clobber and be more selective in removing notes, but it
3492 does not seem to be worth the effort. */
3494 void
3495 fixup_tail_calls (void)
3497 rtx insn;
3499 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3501 rtx note;
3503 /* There are never REG_EQUIV notes for the incoming arguments
3504 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3505 if (NOTE_P (insn)
3506 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3507 break;
3509 note = find_reg_note (insn, REG_EQUIV, 0);
3510 if (note)
3511 remove_note (insn, note);
3512 note = find_reg_note (insn, REG_EQUIV, 0);
3513 gcc_assert (!note);
3517 /* Traverse a list of TYPES and expand all complex types into their
3518 components. */
3519 static tree
3520 split_complex_types (tree types)
3522 tree p;
3524 /* Before allocating memory, check for the common case of no complex. */
3525 for (p = types; p; p = TREE_CHAIN (p))
3527 tree type = TREE_VALUE (p);
3528 if (TREE_CODE (type) == COMPLEX_TYPE
3529 && targetm.calls.split_complex_arg (type))
3530 goto found;
3532 return types;
3534 found:
3535 types = copy_list (types);
3537 for (p = types; p; p = TREE_CHAIN (p))
3539 tree complex_type = TREE_VALUE (p);
3541 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3542 && targetm.calls.split_complex_arg (complex_type))
3544 tree next, imag;
3546 /* Rewrite complex type with component type. */
3547 TREE_VALUE (p) = TREE_TYPE (complex_type);
3548 next = TREE_CHAIN (p);
3550 /* Add another component type for the imaginary part. */
3551 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3552 TREE_CHAIN (p) = imag;
3553 TREE_CHAIN (imag) = next;
3555 /* Skip the newly created node. */
3556 p = TREE_CHAIN (p);
3560 return types;
3563 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3564 The RETVAL parameter specifies whether return value needs to be saved, other
3565 parameters are documented in the emit_library_call function below. */
3567 static rtx
3568 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3569 enum libcall_type fn_type,
3570 enum machine_mode outmode, int nargs, va_list p)
3572 /* Total size in bytes of all the stack-parms scanned so far. */
3573 struct args_size args_size;
3574 /* Size of arguments before any adjustments (such as rounding). */
3575 struct args_size original_args_size;
3576 int argnum;
3577 rtx fun;
3578 /* Todo, choose the correct decl type of orgfun. Sadly this information
3579 isn't present here, so we default to native calling abi here. */
3580 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3581 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3582 int inc;
3583 int count;
3584 rtx argblock = 0;
3585 CUMULATIVE_ARGS args_so_far_v;
3586 cumulative_args_t args_so_far;
3587 struct arg
3589 rtx value;
3590 enum machine_mode mode;
3591 rtx reg;
3592 int partial;
3593 struct locate_and_pad_arg_data locate;
3594 rtx save_area;
3596 struct arg *argvec;
3597 int old_inhibit_defer_pop = inhibit_defer_pop;
3598 rtx call_fusage = 0;
3599 rtx mem_value = 0;
3600 rtx valreg;
3601 int pcc_struct_value = 0;
3602 int struct_value_size = 0;
3603 int flags;
3604 int reg_parm_stack_space = 0;
3605 int needed;
3606 rtx before_call;
3607 tree tfom; /* type_for_mode (outmode, 0) */
3609 #ifdef REG_PARM_STACK_SPACE
3610 /* Define the boundary of the register parm stack space that needs to be
3611 save, if any. */
3612 int low_to_save = 0, high_to_save = 0;
3613 rtx save_area = 0; /* Place that it is saved. */
3614 #endif
3616 /* Size of the stack reserved for parameter registers. */
3617 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3618 char *initial_stack_usage_map = stack_usage_map;
3619 char *stack_usage_map_buf = NULL;
3621 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3623 #ifdef REG_PARM_STACK_SPACE
3624 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3625 #endif
3627 /* By default, library functions can not throw. */
3628 flags = ECF_NOTHROW;
3630 switch (fn_type)
3632 case LCT_NORMAL:
3633 break;
3634 case LCT_CONST:
3635 flags |= ECF_CONST;
3636 break;
3637 case LCT_PURE:
3638 flags |= ECF_PURE;
3639 break;
3640 case LCT_NORETURN:
3641 flags |= ECF_NORETURN;
3642 break;
3643 case LCT_THROW:
3644 flags = ECF_NORETURN;
3645 break;
3646 case LCT_RETURNS_TWICE:
3647 flags = ECF_RETURNS_TWICE;
3648 break;
3650 fun = orgfun;
3652 /* Ensure current function's preferred stack boundary is at least
3653 what we need. */
3654 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3655 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3657 /* If this kind of value comes back in memory,
3658 decide where in memory it should come back. */
3659 if (outmode != VOIDmode)
3661 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3662 if (aggregate_value_p (tfom, 0))
3664 #ifdef PCC_STATIC_STRUCT_RETURN
3665 rtx pointer_reg
3666 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3667 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3668 pcc_struct_value = 1;
3669 if (value == 0)
3670 value = gen_reg_rtx (outmode);
3671 #else /* not PCC_STATIC_STRUCT_RETURN */
3672 struct_value_size = GET_MODE_SIZE (outmode);
3673 if (value != 0 && MEM_P (value))
3674 mem_value = value;
3675 else
3676 mem_value = assign_temp (tfom, 1, 1);
3677 #endif
3678 /* This call returns a big structure. */
3679 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3682 else
3683 tfom = void_type_node;
3685 /* ??? Unfinished: must pass the memory address as an argument. */
3687 /* Copy all the libcall-arguments out of the varargs data
3688 and into a vector ARGVEC.
3690 Compute how to pass each argument. We only support a very small subset
3691 of the full argument passing conventions to limit complexity here since
3692 library functions shouldn't have many args. */
3694 argvec = XALLOCAVEC (struct arg, nargs + 1);
3695 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3697 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3698 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
3699 #else
3700 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
3701 #endif
3702 args_so_far = pack_cumulative_args (&args_so_far_v);
3704 args_size.constant = 0;
3705 args_size.var = 0;
3707 count = 0;
3709 push_temp_slots ();
3711 /* If there's a structure value address to be passed,
3712 either pass it in the special place, or pass it as an extra argument. */
3713 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3715 rtx addr = XEXP (mem_value, 0);
3717 nargs++;
3719 /* Make sure it is a reasonable operand for a move or push insn. */
3720 if (!REG_P (addr) && !MEM_P (addr)
3721 && !(CONSTANT_P (addr)
3722 && targetm.legitimate_constant_p (Pmode, addr)))
3723 addr = force_operand (addr, NULL_RTX);
3725 argvec[count].value = addr;
3726 argvec[count].mode = Pmode;
3727 argvec[count].partial = 0;
3729 argvec[count].reg = targetm.calls.function_arg (args_so_far,
3730 Pmode, NULL_TREE, true);
3731 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
3732 NULL_TREE, 1) == 0);
3734 locate_and_pad_parm (Pmode, NULL_TREE,
3735 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3737 #else
3738 argvec[count].reg != 0,
3739 #endif
3740 reg_parm_stack_space, 0,
3741 NULL_TREE, &args_size, &argvec[count].locate);
3743 if (argvec[count].reg == 0 || argvec[count].partial != 0
3744 || reg_parm_stack_space > 0)
3745 args_size.constant += argvec[count].locate.size.constant;
3747 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
3749 count++;
3752 for (; count < nargs; count++)
3754 rtx val = va_arg (p, rtx);
3755 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3756 int unsigned_p = 0;
3758 /* We cannot convert the arg value to the mode the library wants here;
3759 must do it earlier where we know the signedness of the arg. */
3760 gcc_assert (mode != BLKmode
3761 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3763 /* Make sure it is a reasonable operand for a move or push insn. */
3764 if (!REG_P (val) && !MEM_P (val)
3765 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
3766 val = force_operand (val, NULL_RTX);
3768 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
3770 rtx slot;
3771 int must_copy
3772 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
3774 /* If this was a CONST function, it is now PURE since it now
3775 reads memory. */
3776 if (flags & ECF_CONST)
3778 flags &= ~ECF_CONST;
3779 flags |= ECF_PURE;
3782 if (MEM_P (val) && !must_copy)
3784 tree val_expr = MEM_EXPR (val);
3785 if (val_expr)
3786 mark_addressable (val_expr);
3787 slot = val;
3789 else
3791 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3792 1, 1);
3793 emit_move_insn (slot, val);
3796 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3797 gen_rtx_USE (VOIDmode, slot),
3798 call_fusage);
3799 if (must_copy)
3800 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3801 gen_rtx_CLOBBER (VOIDmode,
3802 slot),
3803 call_fusage);
3805 mode = Pmode;
3806 val = force_operand (XEXP (slot, 0), NULL_RTX);
3809 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
3810 argvec[count].mode = mode;
3811 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
3812 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
3813 NULL_TREE, true);
3815 argvec[count].partial
3816 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
3818 if (argvec[count].reg == 0
3819 || argvec[count].partial != 0
3820 || reg_parm_stack_space > 0)
3822 locate_and_pad_parm (mode, NULL_TREE,
3823 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3825 #else
3826 argvec[count].reg != 0,
3827 #endif
3828 reg_parm_stack_space, argvec[count].partial,
3829 NULL_TREE, &args_size, &argvec[count].locate);
3830 args_size.constant += argvec[count].locate.size.constant;
3831 gcc_assert (!argvec[count].locate.size.var);
3833 #ifdef BLOCK_REG_PADDING
3834 else
3835 /* The argument is passed entirely in registers. See at which
3836 end it should be padded. */
3837 argvec[count].locate.where_pad =
3838 BLOCK_REG_PADDING (mode, NULL_TREE,
3839 GET_MODE_SIZE (mode) <= UNITS_PER_WORD);
3840 #endif
3842 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
3845 /* If this machine requires an external definition for library
3846 functions, write one out. */
3847 assemble_external_libcall (fun);
3849 original_args_size = args_size;
3850 args_size.constant = (((args_size.constant
3851 + stack_pointer_delta
3852 + STACK_BYTES - 1)
3853 / STACK_BYTES
3854 * STACK_BYTES)
3855 - stack_pointer_delta);
3857 args_size.constant = MAX (args_size.constant,
3858 reg_parm_stack_space);
3860 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3861 args_size.constant -= reg_parm_stack_space;
3863 if (args_size.constant > crtl->outgoing_args_size)
3864 crtl->outgoing_args_size = args_size.constant;
3866 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
3868 int pushed = args_size.constant + pending_stack_adjust;
3869 if (pushed > current_function_pushed_stack_size)
3870 current_function_pushed_stack_size = pushed;
3873 if (ACCUMULATE_OUTGOING_ARGS)
3875 /* Since the stack pointer will never be pushed, it is possible for
3876 the evaluation of a parm to clobber something we have already
3877 written to the stack. Since most function calls on RISC machines
3878 do not use the stack, this is uncommon, but must work correctly.
3880 Therefore, we save any area of the stack that was already written
3881 and that we are using. Here we set up to do this by making a new
3882 stack usage map from the old one.
3884 Another approach might be to try to reorder the argument
3885 evaluations to avoid this conflicting stack usage. */
3887 needed = args_size.constant;
3889 /* Since we will be writing into the entire argument area, the
3890 map must be allocated for its entire size, not just the part that
3891 is the responsibility of the caller. */
3892 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3893 needed += reg_parm_stack_space;
3895 #ifdef ARGS_GROW_DOWNWARD
3896 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3897 needed + 1);
3898 #else
3899 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3900 needed);
3901 #endif
3902 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3903 stack_usage_map = stack_usage_map_buf;
3905 if (initial_highest_arg_in_use)
3906 memcpy (stack_usage_map, initial_stack_usage_map,
3907 initial_highest_arg_in_use);
3909 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3910 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3911 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3912 needed = 0;
3914 /* We must be careful to use virtual regs before they're instantiated,
3915 and real regs afterwards. Loop optimization, for example, can create
3916 new libcalls after we've instantiated the virtual regs, and if we
3917 use virtuals anyway, they won't match the rtl patterns. */
3919 if (virtuals_instantiated)
3920 argblock = plus_constant (Pmode, stack_pointer_rtx,
3921 STACK_POINTER_OFFSET);
3922 else
3923 argblock = virtual_outgoing_args_rtx;
3925 else
3927 if (!PUSH_ARGS)
3928 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3931 /* If we push args individually in reverse order, perform stack alignment
3932 before the first push (the last arg). */
3933 if (argblock == 0 && PUSH_ARGS_REVERSED)
3934 anti_adjust_stack (GEN_INT (args_size.constant
3935 - original_args_size.constant));
3937 if (PUSH_ARGS_REVERSED)
3939 inc = -1;
3940 argnum = nargs - 1;
3942 else
3944 inc = 1;
3945 argnum = 0;
3948 #ifdef REG_PARM_STACK_SPACE
3949 if (ACCUMULATE_OUTGOING_ARGS)
3951 /* The argument list is the property of the called routine and it
3952 may clobber it. If the fixed area has been used for previous
3953 parameters, we must save and restore it. */
3954 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3955 &low_to_save, &high_to_save);
3957 #endif
3959 /* Push the args that need to be pushed. */
3961 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3962 are to be pushed. */
3963 for (count = 0; count < nargs; count++, argnum += inc)
3965 enum machine_mode mode = argvec[argnum].mode;
3966 rtx val = argvec[argnum].value;
3967 rtx reg = argvec[argnum].reg;
3968 int partial = argvec[argnum].partial;
3969 unsigned int parm_align = argvec[argnum].locate.boundary;
3970 int lower_bound = 0, upper_bound = 0, i;
3972 if (! (reg != 0 && partial == 0))
3974 rtx use;
3976 if (ACCUMULATE_OUTGOING_ARGS)
3978 /* If this is being stored into a pre-allocated, fixed-size,
3979 stack area, save any previous data at that location. */
3981 #ifdef ARGS_GROW_DOWNWARD
3982 /* stack_slot is negative, but we want to index stack_usage_map
3983 with positive values. */
3984 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3985 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3986 #else
3987 lower_bound = argvec[argnum].locate.slot_offset.constant;
3988 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3989 #endif
3991 i = lower_bound;
3992 /* Don't worry about things in the fixed argument area;
3993 it has already been saved. */
3994 if (i < reg_parm_stack_space)
3995 i = reg_parm_stack_space;
3996 while (i < upper_bound && stack_usage_map[i] == 0)
3997 i++;
3999 if (i < upper_bound)
4001 /* We need to make a save area. */
4002 unsigned int size
4003 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4004 enum machine_mode save_mode
4005 = mode_for_size (size, MODE_INT, 1);
4006 rtx adr
4007 = plus_constant (Pmode, argblock,
4008 argvec[argnum].locate.offset.constant);
4009 rtx stack_area
4010 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4012 if (save_mode == BLKmode)
4014 argvec[argnum].save_area
4015 = assign_stack_temp (BLKmode,
4016 argvec[argnum].locate.size.constant
4019 emit_block_move (validize_mem (argvec[argnum].save_area),
4020 stack_area,
4021 GEN_INT (argvec[argnum].locate.size.constant),
4022 BLOCK_OP_CALL_PARM);
4024 else
4026 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4028 emit_move_insn (argvec[argnum].save_area, stack_area);
4033 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
4034 partial, reg, 0, argblock,
4035 GEN_INT (argvec[argnum].locate.offset.constant),
4036 reg_parm_stack_space,
4037 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4039 /* Now mark the segment we just used. */
4040 if (ACCUMULATE_OUTGOING_ARGS)
4041 for (i = lower_bound; i < upper_bound; i++)
4042 stack_usage_map[i] = 1;
4044 NO_DEFER_POP;
4046 /* Indicate argument access so that alias.c knows that these
4047 values are live. */
4048 if (argblock)
4049 use = plus_constant (Pmode, argblock,
4050 argvec[argnum].locate.offset.constant);
4051 else
4052 /* When arguments are pushed, trying to tell alias.c where
4053 exactly this argument is won't work, because the
4054 auto-increment causes confusion. So we merely indicate
4055 that we access something with a known mode somewhere on
4056 the stack. */
4057 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
4058 gen_rtx_SCRATCH (Pmode));
4059 use = gen_rtx_MEM (argvec[argnum].mode, use);
4060 use = gen_rtx_USE (VOIDmode, use);
4061 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
4065 /* If we pushed args in forward order, perform stack alignment
4066 after pushing the last arg. */
4067 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4068 anti_adjust_stack (GEN_INT (args_size.constant
4069 - original_args_size.constant));
4071 if (PUSH_ARGS_REVERSED)
4072 argnum = nargs - 1;
4073 else
4074 argnum = 0;
4076 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
4078 /* Now load any reg parms into their regs. */
4080 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4081 are to be pushed. */
4082 for (count = 0; count < nargs; count++, argnum += inc)
4084 enum machine_mode mode = argvec[argnum].mode;
4085 rtx val = argvec[argnum].value;
4086 rtx reg = argvec[argnum].reg;
4087 int partial = argvec[argnum].partial;
4088 #ifdef BLOCK_REG_PADDING
4089 int size = 0;
4090 #endif
4092 /* Handle calls that pass values in multiple non-contiguous
4093 locations. The PA64 has examples of this for library calls. */
4094 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4095 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
4096 else if (reg != 0 && partial == 0)
4098 emit_move_insn (reg, val);
4099 #ifdef BLOCK_REG_PADDING
4100 size = GET_MODE_SIZE (argvec[argnum].mode);
4102 /* Copied from load_register_parameters. */
4104 /* Handle case where we have a value that needs shifting
4105 up to the msb. eg. a QImode value and we're padding
4106 upward on a BYTES_BIG_ENDIAN machine. */
4107 if (size < UNITS_PER_WORD
4108 && (argvec[argnum].locate.where_pad
4109 == (BYTES_BIG_ENDIAN ? upward : downward)))
4111 rtx x;
4112 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4114 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4115 report the whole reg as used. Strictly speaking, the
4116 call only uses SIZE bytes at the msb end, but it doesn't
4117 seem worth generating rtl to say that. */
4118 reg = gen_rtx_REG (word_mode, REGNO (reg));
4119 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
4120 if (x != reg)
4121 emit_move_insn (reg, x);
4123 #endif
4126 NO_DEFER_POP;
4129 /* Any regs containing parms remain in use through the call. */
4130 for (count = 0; count < nargs; count++)
4132 rtx reg = argvec[count].reg;
4133 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4134 use_group_regs (&call_fusage, reg);
4135 else if (reg != 0)
4137 int partial = argvec[count].partial;
4138 if (partial)
4140 int nregs;
4141 gcc_assert (partial % UNITS_PER_WORD == 0);
4142 nregs = partial / UNITS_PER_WORD;
4143 use_regs (&call_fusage, REGNO (reg), nregs);
4145 else
4146 use_reg (&call_fusage, reg);
4150 /* Pass the function the address in which to return a structure value. */
4151 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4153 emit_move_insn (struct_value,
4154 force_reg (Pmode,
4155 force_operand (XEXP (mem_value, 0),
4156 NULL_RTX)));
4157 if (REG_P (struct_value))
4158 use_reg (&call_fusage, struct_value);
4161 /* Don't allow popping to be deferred, since then
4162 cse'ing of library calls could delete a call and leave the pop. */
4163 NO_DEFER_POP;
4164 valreg = (mem_value == 0 && outmode != VOIDmode
4165 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
4167 /* Stack must be properly aligned now. */
4168 gcc_assert (!(stack_pointer_delta
4169 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
4171 before_call = get_last_insn ();
4173 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4174 will set inhibit_defer_pop to that value. */
4175 /* The return type is needed to decide how many bytes the function pops.
4176 Signedness plays no role in that, so for simplicity, we pretend it's
4177 always signed. We also assume that the list of arguments passed has
4178 no impact, so we pretend it is unknown. */
4180 emit_call_1 (fun, NULL,
4181 get_identifier (XSTR (orgfun, 0)),
4182 build_function_type (tfom, NULL_TREE),
4183 original_args_size.constant, args_size.constant,
4184 struct_value_size,
4185 targetm.calls.function_arg (args_so_far,
4186 VOIDmode, void_type_node, true),
4187 valreg,
4188 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
4190 /* Right-shift returned value if necessary. */
4191 if (!pcc_struct_value
4192 && TYPE_MODE (tfom) != BLKmode
4193 && targetm.calls.return_in_msb (tfom))
4195 shift_return_value (TYPE_MODE (tfom), false, valreg);
4196 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
4199 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
4200 that it should complain if nonvolatile values are live. For
4201 functions that cannot return, inform flow that control does not
4202 fall through. */
4203 if (flags & ECF_NORETURN)
4205 /* The barrier note must be emitted
4206 immediately after the CALL_INSN. Some ports emit more than
4207 just a CALL_INSN above, so we must search for it here. */
4208 rtx last = get_last_insn ();
4209 while (!CALL_P (last))
4211 last = PREV_INSN (last);
4212 /* There was no CALL_INSN? */
4213 gcc_assert (last != before_call);
4216 emit_barrier_after (last);
4219 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
4220 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
4221 if (flags & ECF_NOTHROW)
4223 rtx last = get_last_insn ();
4224 while (!CALL_P (last))
4226 last = PREV_INSN (last);
4227 /* There was no CALL_INSN? */
4228 gcc_assert (last != before_call);
4231 make_reg_eh_region_note_nothrow_nononlocal (last);
4234 /* Now restore inhibit_defer_pop to its actual original value. */
4235 OK_DEFER_POP;
4237 pop_temp_slots ();
4239 /* Copy the value to the right place. */
4240 if (outmode != VOIDmode && retval)
4242 if (mem_value)
4244 if (value == 0)
4245 value = mem_value;
4246 if (value != mem_value)
4247 emit_move_insn (value, mem_value);
4249 else if (GET_CODE (valreg) == PARALLEL)
4251 if (value == 0)
4252 value = gen_reg_rtx (outmode);
4253 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4255 else
4257 /* Convert to the proper mode if a promotion has been active. */
4258 if (GET_MODE (valreg) != outmode)
4260 int unsignedp = TYPE_UNSIGNED (tfom);
4262 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
4263 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
4264 == GET_MODE (valreg));
4265 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
4268 if (value != 0)
4269 emit_move_insn (value, valreg);
4270 else
4271 value = valreg;
4275 if (ACCUMULATE_OUTGOING_ARGS)
4277 #ifdef REG_PARM_STACK_SPACE
4278 if (save_area)
4279 restore_fixed_argument_area (save_area, argblock,
4280 high_to_save, low_to_save);
4281 #endif
4283 /* If we saved any argument areas, restore them. */
4284 for (count = 0; count < nargs; count++)
4285 if (argvec[count].save_area)
4287 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4288 rtx adr = plus_constant (Pmode, argblock,
4289 argvec[count].locate.offset.constant);
4290 rtx stack_area = gen_rtx_MEM (save_mode,
4291 memory_address (save_mode, adr));
4293 if (save_mode == BLKmode)
4294 emit_block_move (stack_area,
4295 validize_mem (argvec[count].save_area),
4296 GEN_INT (argvec[count].locate.size.constant),
4297 BLOCK_OP_CALL_PARM);
4298 else
4299 emit_move_insn (stack_area, argvec[count].save_area);
4302 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4303 stack_usage_map = initial_stack_usage_map;
4306 free (stack_usage_map_buf);
4308 return value;
4312 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4313 (emitting the queue unless NO_QUEUE is nonzero),
4314 for a value of mode OUTMODE,
4315 with NARGS different arguments, passed as alternating rtx values
4316 and machine_modes to convert them to.
4318 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4319 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
4320 other types of library calls. */
4322 void
4323 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4324 enum machine_mode outmode, int nargs, ...)
4326 va_list p;
4328 va_start (p, nargs);
4329 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4330 va_end (p);
4333 /* Like emit_library_call except that an extra argument, VALUE,
4334 comes second and says where to store the result.
4335 (If VALUE is zero, this function chooses a convenient way
4336 to return the value.
4338 This function returns an rtx for where the value is to be found.
4339 If VALUE is nonzero, VALUE is returned. */
4342 emit_library_call_value (rtx orgfun, rtx value,
4343 enum libcall_type fn_type,
4344 enum machine_mode outmode, int nargs, ...)
4346 rtx result;
4347 va_list p;
4349 va_start (p, nargs);
4350 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4351 nargs, p);
4352 va_end (p);
4354 return result;
4357 /* Store a single argument for a function call
4358 into the register or memory area where it must be passed.
4359 *ARG describes the argument value and where to pass it.
4361 ARGBLOCK is the address of the stack-block for all the arguments,
4362 or 0 on a machine where arguments are pushed individually.
4364 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4365 so must be careful about how the stack is used.
4367 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4368 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4369 that we need not worry about saving and restoring the stack.
4371 FNDECL is the declaration of the function we are calling.
4373 Return nonzero if this arg should cause sibcall failure,
4374 zero otherwise. */
4376 static int
4377 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4378 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4380 tree pval = arg->tree_value;
4381 rtx reg = 0;
4382 int partial = 0;
4383 int used = 0;
4384 int i, lower_bound = 0, upper_bound = 0;
4385 int sibcall_failure = 0;
4387 if (TREE_CODE (pval) == ERROR_MARK)
4388 return 1;
4390 /* Push a new temporary level for any temporaries we make for
4391 this argument. */
4392 push_temp_slots ();
4394 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4396 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4397 save any previous data at that location. */
4398 if (argblock && ! variable_size && arg->stack)
4400 #ifdef ARGS_GROW_DOWNWARD
4401 /* stack_slot is negative, but we want to index stack_usage_map
4402 with positive values. */
4403 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4404 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4405 else
4406 upper_bound = 0;
4408 lower_bound = upper_bound - arg->locate.size.constant;
4409 #else
4410 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4411 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4412 else
4413 lower_bound = 0;
4415 upper_bound = lower_bound + arg->locate.size.constant;
4416 #endif
4418 i = lower_bound;
4419 /* Don't worry about things in the fixed argument area;
4420 it has already been saved. */
4421 if (i < reg_parm_stack_space)
4422 i = reg_parm_stack_space;
4423 while (i < upper_bound && stack_usage_map[i] == 0)
4424 i++;
4426 if (i < upper_bound)
4428 /* We need to make a save area. */
4429 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4430 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4431 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4432 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4434 if (save_mode == BLKmode)
4436 tree ot = TREE_TYPE (arg->tree_value);
4437 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4438 | TYPE_QUAL_CONST));
4440 arg->save_area = assign_temp (nt, 1, 1);
4441 preserve_temp_slots (arg->save_area);
4442 emit_block_move (validize_mem (arg->save_area), stack_area,
4443 GEN_INT (arg->locate.size.constant),
4444 BLOCK_OP_CALL_PARM);
4446 else
4448 arg->save_area = gen_reg_rtx (save_mode);
4449 emit_move_insn (arg->save_area, stack_area);
4455 /* If this isn't going to be placed on both the stack and in registers,
4456 set up the register and number of words. */
4457 if (! arg->pass_on_stack)
4459 if (flags & ECF_SIBCALL)
4460 reg = arg->tail_call_reg;
4461 else
4462 reg = arg->reg;
4463 partial = arg->partial;
4466 /* Being passed entirely in a register. We shouldn't be called in
4467 this case. */
4468 gcc_assert (reg == 0 || partial != 0);
4470 /* If this arg needs special alignment, don't load the registers
4471 here. */
4472 if (arg->n_aligned_regs != 0)
4473 reg = 0;
4475 /* If this is being passed partially in a register, we can't evaluate
4476 it directly into its stack slot. Otherwise, we can. */
4477 if (arg->value == 0)
4479 /* stack_arg_under_construction is nonzero if a function argument is
4480 being evaluated directly into the outgoing argument list and
4481 expand_call must take special action to preserve the argument list
4482 if it is called recursively.
4484 For scalar function arguments stack_usage_map is sufficient to
4485 determine which stack slots must be saved and restored. Scalar
4486 arguments in general have pass_on_stack == 0.
4488 If this argument is initialized by a function which takes the
4489 address of the argument (a C++ constructor or a C function
4490 returning a BLKmode structure), then stack_usage_map is
4491 insufficient and expand_call must push the stack around the
4492 function call. Such arguments have pass_on_stack == 1.
4494 Note that it is always safe to set stack_arg_under_construction,
4495 but this generates suboptimal code if set when not needed. */
4497 if (arg->pass_on_stack)
4498 stack_arg_under_construction++;
4500 arg->value = expand_expr (pval,
4501 (partial
4502 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4503 ? NULL_RTX : arg->stack,
4504 VOIDmode, EXPAND_STACK_PARM);
4506 /* If we are promoting object (or for any other reason) the mode
4507 doesn't agree, convert the mode. */
4509 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4510 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4511 arg->value, arg->unsignedp);
4513 if (arg->pass_on_stack)
4514 stack_arg_under_construction--;
4517 /* Check for overlap with already clobbered argument area. */
4518 if ((flags & ECF_SIBCALL)
4519 && MEM_P (arg->value)
4520 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4521 arg->locate.size.constant))
4522 sibcall_failure = 1;
4524 /* Don't allow anything left on stack from computation
4525 of argument to alloca. */
4526 if (flags & ECF_MAY_BE_ALLOCA)
4527 do_pending_stack_adjust ();
4529 if (arg->value == arg->stack)
4530 /* If the value is already in the stack slot, we are done. */
4532 else if (arg->mode != BLKmode)
4534 int size;
4535 unsigned int parm_align;
4537 /* Argument is a scalar, not entirely passed in registers.
4538 (If part is passed in registers, arg->partial says how much
4539 and emit_push_insn will take care of putting it there.)
4541 Push it, and if its size is less than the
4542 amount of space allocated to it,
4543 also bump stack pointer by the additional space.
4544 Note that in C the default argument promotions
4545 will prevent such mismatches. */
4547 size = GET_MODE_SIZE (arg->mode);
4548 /* Compute how much space the push instruction will push.
4549 On many machines, pushing a byte will advance the stack
4550 pointer by a halfword. */
4551 #ifdef PUSH_ROUNDING
4552 size = PUSH_ROUNDING (size);
4553 #endif
4554 used = size;
4556 /* Compute how much space the argument should get:
4557 round up to a multiple of the alignment for arguments. */
4558 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4559 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4560 / (PARM_BOUNDARY / BITS_PER_UNIT))
4561 * (PARM_BOUNDARY / BITS_PER_UNIT));
4563 /* Compute the alignment of the pushed argument. */
4564 parm_align = arg->locate.boundary;
4565 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4567 int pad = used - size;
4568 if (pad)
4570 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4571 parm_align = MIN (parm_align, pad_align);
4575 /* This isn't already where we want it on the stack, so put it there.
4576 This can either be done with push or copy insns. */
4577 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4578 parm_align, partial, reg, used - size, argblock,
4579 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4580 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4582 /* Unless this is a partially-in-register argument, the argument is now
4583 in the stack. */
4584 if (partial == 0)
4585 arg->value = arg->stack;
4587 else
4589 /* BLKmode, at least partly to be pushed. */
4591 unsigned int parm_align;
4592 int excess;
4593 rtx size_rtx;
4595 /* Pushing a nonscalar.
4596 If part is passed in registers, PARTIAL says how much
4597 and emit_push_insn will take care of putting it there. */
4599 /* Round its size up to a multiple
4600 of the allocation unit for arguments. */
4602 if (arg->locate.size.var != 0)
4604 excess = 0;
4605 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4607 else
4609 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4610 for BLKmode is careful to avoid it. */
4611 excess = (arg->locate.size.constant
4612 - int_size_in_bytes (TREE_TYPE (pval))
4613 + partial);
4614 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4615 NULL_RTX, TYPE_MODE (sizetype),
4616 EXPAND_NORMAL);
4619 parm_align = arg->locate.boundary;
4621 /* When an argument is padded down, the block is aligned to
4622 PARM_BOUNDARY, but the actual argument isn't. */
4623 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4625 if (arg->locate.size.var)
4626 parm_align = BITS_PER_UNIT;
4627 else if (excess)
4629 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4630 parm_align = MIN (parm_align, excess_align);
4634 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4636 /* emit_push_insn might not work properly if arg->value and
4637 argblock + arg->locate.offset areas overlap. */
4638 rtx x = arg->value;
4639 int i = 0;
4641 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4642 || (GET_CODE (XEXP (x, 0)) == PLUS
4643 && XEXP (XEXP (x, 0), 0) ==
4644 crtl->args.internal_arg_pointer
4645 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4647 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4648 i = INTVAL (XEXP (XEXP (x, 0), 1));
4650 /* expand_call should ensure this. */
4651 gcc_assert (!arg->locate.offset.var
4652 && arg->locate.size.var == 0
4653 && CONST_INT_P (size_rtx));
4655 if (arg->locate.offset.constant > i)
4657 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4658 sibcall_failure = 1;
4660 else if (arg->locate.offset.constant < i)
4662 /* Use arg->locate.size.constant instead of size_rtx
4663 because we only care about the part of the argument
4664 on the stack. */
4665 if (i < (arg->locate.offset.constant
4666 + arg->locate.size.constant))
4667 sibcall_failure = 1;
4669 else
4671 /* Even though they appear to be at the same location,
4672 if part of the outgoing argument is in registers,
4673 they aren't really at the same location. Check for
4674 this by making sure that the incoming size is the
4675 same as the outgoing size. */
4676 if (arg->locate.size.constant != INTVAL (size_rtx))
4677 sibcall_failure = 1;
4682 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4683 parm_align, partial, reg, excess, argblock,
4684 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4685 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4687 /* Unless this is a partially-in-register argument, the argument is now
4688 in the stack.
4690 ??? Unlike the case above, in which we want the actual
4691 address of the data, so that we can load it directly into a
4692 register, here we want the address of the stack slot, so that
4693 it's properly aligned for word-by-word copying or something
4694 like that. It's not clear that this is always correct. */
4695 if (partial == 0)
4696 arg->value = arg->stack_slot;
4699 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4701 tree type = TREE_TYPE (arg->tree_value);
4702 arg->parallel_value
4703 = emit_group_load_into_temps (arg->reg, arg->value, type,
4704 int_size_in_bytes (type));
4707 /* Mark all slots this store used. */
4708 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4709 && argblock && ! variable_size && arg->stack)
4710 for (i = lower_bound; i < upper_bound; i++)
4711 stack_usage_map[i] = 1;
4713 /* Once we have pushed something, pops can't safely
4714 be deferred during the rest of the arguments. */
4715 NO_DEFER_POP;
4717 /* Free any temporary slots made in processing this argument. */
4718 pop_temp_slots ();
4720 return sibcall_failure;
4723 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4725 bool
4726 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4727 const_tree type)
4729 if (!type)
4730 return false;
4732 /* If the type has variable size... */
4733 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4734 return true;
4736 /* If the type is marked as addressable (it is required
4737 to be constructed into the stack)... */
4738 if (TREE_ADDRESSABLE (type))
4739 return true;
4741 return false;
4744 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4745 takes trailing padding of a structure into account. */
4746 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4748 bool
4749 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4751 if (!type)
4752 return false;
4754 /* If the type has variable size... */
4755 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4756 return true;
4758 /* If the type is marked as addressable (it is required
4759 to be constructed into the stack)... */
4760 if (TREE_ADDRESSABLE (type))
4761 return true;
4763 /* If the padding and mode of the type is such that a copy into
4764 a register would put it into the wrong part of the register. */
4765 if (mode == BLKmode
4766 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4767 && (FUNCTION_ARG_PADDING (mode, type)
4768 == (BYTES_BIG_ENDIAN ? upward : downward)))
4769 return true;
4771 return false;