simplify-rtx.c (simplify_rtx): Use simplify_subreg rather than simplify_gen_subreg.
[official-gcc.git] / gcc / calls.c
blobbdb8167adeff7029004601a458ba8fc666fcbc01
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
21 02110-1301, USA. */
23 #include "config.h"
24 #include "system.h"
25 #include "coretypes.h"
26 #include "tm.h"
27 #include "rtl.h"
28 #include "tree.h"
29 #include "flags.h"
30 #include "expr.h"
31 #include "optabs.h"
32 #include "libfuncs.h"
33 #include "function.h"
34 #include "regs.h"
35 #include "toplev.h"
36 #include "output.h"
37 #include "tm_p.h"
38 #include "timevar.h"
39 #include "sbitmap.h"
40 #include "langhooks.h"
41 #include "target.h"
42 #include "cgraph.h"
43 #include "except.h"
45 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
46 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
48 /* Data structure and subroutines used within expand_call. */
50 struct arg_data
52 /* Tree node for this argument. */
53 tree tree_value;
54 /* Mode for value; TYPE_MODE unless promoted. */
55 enum machine_mode mode;
56 /* Current RTL value for argument, or 0 if it isn't precomputed. */
57 rtx value;
58 /* Initially-compute RTL value for argument; only for const functions. */
59 rtx initial_value;
60 /* Register to pass this argument in, 0 if passed on stack, or an
61 PARALLEL if the arg is to be copied into multiple non-contiguous
62 registers. */
63 rtx reg;
64 /* Register to pass this argument in when generating tail call sequence.
65 This is not the same register as for normal calls on machines with
66 register windows. */
67 rtx tail_call_reg;
68 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
69 form for emit_group_move. */
70 rtx parallel_value;
71 /* If REG was promoted from the actual mode of the argument expression,
72 indicates whether the promotion is sign- or zero-extended. */
73 int unsignedp;
74 /* Number of bytes to put in registers. 0 means put the whole arg
75 in registers. Also 0 if not passed in registers. */
76 int partial;
77 /* Nonzero if argument must be passed on stack.
78 Note that some arguments may be passed on the stack
79 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
80 pass_on_stack identifies arguments that *cannot* go in registers. */
81 int pass_on_stack;
82 /* Some fields packaged up for locate_and_pad_parm. */
83 struct locate_and_pad_arg_data locate;
84 /* Location on the stack at which parameter should be stored. The store
85 has already been done if STACK == VALUE. */
86 rtx stack;
87 /* Location on the stack of the start of this argument slot. This can
88 differ from STACK if this arg pads downward. This location is known
89 to be aligned to FUNCTION_ARG_BOUNDARY. */
90 rtx stack_slot;
91 /* Place that this stack area has been saved, if needed. */
92 rtx save_area;
93 /* If an argument's alignment does not permit direct copying into registers,
94 copy in smaller-sized pieces into pseudos. These are stored in a
95 block pointed to by this field. The next field says how many
96 word-sized pseudos we made. */
97 rtx *aligned_regs;
98 int n_aligned_regs;
101 /* A vector of one char per byte of stack space. A byte if nonzero if
102 the corresponding stack location has been used.
103 This vector is used to prevent a function call within an argument from
104 clobbering any stack already set up. */
105 static char *stack_usage_map;
107 /* Size of STACK_USAGE_MAP. */
108 static int highest_outgoing_arg_in_use;
110 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
111 stack location's tail call argument has been already stored into the stack.
112 This bitmap is used to prevent sibling call optimization if function tries
113 to use parent's incoming argument slots when they have been already
114 overwritten with tail call arguments. */
115 static sbitmap stored_args_map;
117 /* stack_arg_under_construction is nonzero when an argument may be
118 initialized with a constructor call (including a C function that
119 returns a BLKmode struct) and expand_call must take special action
120 to make sure the object being constructed does not overlap the
121 argument list for the constructor call. */
122 static int stack_arg_under_construction;
124 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
125 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
126 CUMULATIVE_ARGS *);
127 static void precompute_register_parameters (int, struct arg_data *, int *);
128 static int store_one_arg (struct arg_data *, rtx, int, int, int);
129 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
130 static int finalize_must_preallocate (int, int, struct arg_data *,
131 struct args_size *);
132 static void precompute_arguments (int, int, struct arg_data *);
133 static int compute_argument_block_size (int, struct args_size *, int);
134 static void initialize_argument_information (int, struct arg_data *,
135 struct args_size *, int, tree,
136 tree, CUMULATIVE_ARGS *, 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 (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_values (tree);
152 static tree split_complex_types (tree);
154 #ifdef REG_PARM_STACK_SPACE
155 static rtx save_fixed_argument_area (int, rtx, int *, int *);
156 static void restore_fixed_argument_area (rtx, rtx, int, int);
157 #endif
159 /* Force FUNEXP into a form suitable for the address of a CALL,
160 and return that as an rtx. Also load the static chain register
161 if FNDECL is a nested function.
163 CALL_FUSAGE points to a variable holding the prospective
164 CALL_INSN_FUNCTION_USAGE information. */
167 prepare_call_address (rtx funexp, rtx static_chain_value,
168 rtx *call_fusage, int reg_parm_seen, int sibcallp)
170 /* Make a valid memory address and copy constants through pseudo-regs,
171 but not for a constant address if -fno-function-cse. */
172 if (GET_CODE (funexp) != SYMBOL_REF)
173 /* If we are using registers for parameters, force the
174 function address into a register now. */
175 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
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 static_chain_value = convert_memory_address (Pmode, static_chain_value);
189 emit_move_insn (static_chain_rtx, static_chain_value);
191 if (REG_P (static_chain_rtx))
192 use_reg (call_fusage, static_chain_rtx);
195 return funexp;
198 /* Generate instructions to call function FUNEXP,
199 and optionally pop the results.
200 The CALL_INSN is the first insn generated.
202 FNDECL is the declaration node of the function. This is given to the
203 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
205 FUNTYPE is the data type of the function. This is given to the macro
206 RETURN_POPS_ARGS to determine whether this function pops its own args.
207 We used to allow an identifier for library functions, but that doesn't
208 work when the return type is an aggregate type and the calling convention
209 says that the pointer to this aggregate is to be popped by the callee.
211 STACK_SIZE is the number of bytes of arguments on the stack,
212 ROUNDED_STACK_SIZE is that number rounded up to
213 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
214 both to put into the call insn and to generate explicit popping
215 code if necessary.
217 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
218 It is zero if this call doesn't want a structure value.
220 NEXT_ARG_REG is the rtx that results from executing
221 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
222 just after all the args have had their registers assigned.
223 This could be whatever you like, but normally it is the first
224 arg-register beyond those used for args in this call,
225 or 0 if all the arg-registers are used in this call.
226 It is passed on to `gen_call' so you can put this info in the call insn.
228 VALREG is a hard register in which a value is returned,
229 or 0 if the call does not return a value.
231 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
232 the args to this call were processed.
233 We restore `inhibit_defer_pop' to that value.
235 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
236 denote registers used by the called function. */
238 static void
239 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
240 tree funtype ATTRIBUTE_UNUSED,
241 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
242 HOST_WIDE_INT rounded_stack_size,
243 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
244 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
245 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
246 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
248 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
249 rtx call_insn;
250 int already_popped = 0;
251 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
252 #if defined (HAVE_call) && defined (HAVE_call_value)
253 rtx struct_value_size_rtx;
254 struct_value_size_rtx = GEN_INT (struct_value_size);
255 #endif
257 #ifdef CALL_POPS_ARGS
258 n_popped += CALL_POPS_ARGS (* args_so_far);
259 #endif
261 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
262 and we don't want to load it into a register as an optimization,
263 because prepare_call_address already did it if it should be done. */
264 if (GET_CODE (funexp) != SYMBOL_REF)
265 funexp = memory_address (FUNCTION_MODE, funexp);
267 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
268 if ((ecf_flags & ECF_SIBCALL)
269 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
270 && (n_popped > 0 || stack_size == 0))
272 rtx n_pop = GEN_INT (n_popped);
273 rtx pat;
275 /* If this subroutine pops its own args, record that in the call insn
276 if possible, for the sake of frame pointer elimination. */
278 if (valreg)
279 pat = GEN_SIBCALL_VALUE_POP (valreg,
280 gen_rtx_MEM (FUNCTION_MODE, funexp),
281 rounded_stack_size_rtx, next_arg_reg,
282 n_pop);
283 else
284 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
285 rounded_stack_size_rtx, next_arg_reg, n_pop);
287 emit_call_insn (pat);
288 already_popped = 1;
290 else
291 #endif
293 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
294 /* If the target has "call" or "call_value" insns, then prefer them
295 if no arguments are actually popped. If the target does not have
296 "call" or "call_value" insns, then we must use the popping versions
297 even if the call has no arguments to pop. */
298 #if defined (HAVE_call) && defined (HAVE_call_value)
299 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
300 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
301 #else
302 if (HAVE_call_pop && HAVE_call_value_pop)
303 #endif
305 rtx n_pop = GEN_INT (n_popped);
306 rtx pat;
308 /* If this subroutine pops its own args, record that in the call insn
309 if possible, for the sake of frame pointer elimination. */
311 if (valreg)
312 pat = GEN_CALL_VALUE_POP (valreg,
313 gen_rtx_MEM (FUNCTION_MODE, funexp),
314 rounded_stack_size_rtx, next_arg_reg, n_pop);
315 else
316 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
317 rounded_stack_size_rtx, next_arg_reg, n_pop);
319 emit_call_insn (pat);
320 already_popped = 1;
322 else
323 #endif
325 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
326 if ((ecf_flags & ECF_SIBCALL)
327 && HAVE_sibcall && HAVE_sibcall_value)
329 if (valreg)
330 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
331 gen_rtx_MEM (FUNCTION_MODE, funexp),
332 rounded_stack_size_rtx,
333 next_arg_reg, NULL_RTX));
334 else
335 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
336 rounded_stack_size_rtx, next_arg_reg,
337 struct_value_size_rtx));
339 else
340 #endif
342 #if defined (HAVE_call) && defined (HAVE_call_value)
343 if (HAVE_call && HAVE_call_value)
345 if (valreg)
346 emit_call_insn (GEN_CALL_VALUE (valreg,
347 gen_rtx_MEM (FUNCTION_MODE, funexp),
348 rounded_stack_size_rtx, next_arg_reg,
349 NULL_RTX));
350 else
351 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
352 rounded_stack_size_rtx, next_arg_reg,
353 struct_value_size_rtx));
355 else
356 #endif
357 gcc_unreachable ();
359 /* Find the call we just emitted. */
360 call_insn = last_call_insn ();
362 /* Mark memory as used for "pure" function call. */
363 if (ecf_flags & ECF_PURE)
364 call_fusage
365 = gen_rtx_EXPR_LIST
366 (VOIDmode,
367 gen_rtx_USE (VOIDmode,
368 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
369 call_fusage);
371 /* Put the register usage information there. */
372 add_function_usage_to (call_insn, call_fusage);
374 /* If this is a const call, then set the insn's unchanging bit. */
375 if (ecf_flags & (ECF_CONST | ECF_PURE))
376 CONST_OR_PURE_CALL_P (call_insn) = 1;
378 /* If this call can't throw, attach a REG_EH_REGION reg note to that
379 effect. */
380 if (ecf_flags & ECF_NOTHROW)
381 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
382 REG_NOTES (call_insn));
383 else
385 int rn = lookup_stmt_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
389 if (rn > 0)
390 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn),
391 REG_NOTES (call_insn));
392 note_current_region_may_contain_throw ();
395 if (ecf_flags & ECF_NORETURN)
396 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
397 REG_NOTES (call_insn));
399 if (ecf_flags & ECF_RETURNS_TWICE)
401 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
402 REG_NOTES (call_insn));
403 current_function_calls_setjmp = 1;
406 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
408 /* Restore this now, so that we do defer pops for this call's args
409 if the context of the call as a whole permits. */
410 inhibit_defer_pop = old_inhibit_defer_pop;
412 if (n_popped > 0)
414 if (!already_popped)
415 CALL_INSN_FUNCTION_USAGE (call_insn)
416 = gen_rtx_EXPR_LIST (VOIDmode,
417 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
418 CALL_INSN_FUNCTION_USAGE (call_insn));
419 rounded_stack_size -= n_popped;
420 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
421 stack_pointer_delta -= n_popped;
424 if (!ACCUMULATE_OUTGOING_ARGS)
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
433 if (rounded_stack_size != 0)
435 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN))
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
441 else
442 adjust_stack (rounded_stack_size_rtx);
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
455 such machines. */
456 else if (n_popped)
457 anti_adjust_stack (GEN_INT (n_popped));
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
466 Similarly set NORETURN if the function is in the longjmp family.
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
471 static int
472 special_function_p (tree fndecl, int flags)
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
478 think they are.
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
482 wish. */
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
494 && name[0] == 'a'
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
497 && name[0] == '_'
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
501 /* Disregard prefix _, __ or __x. */
502 if (name[0] == '_')
504 if (name[1] == '_' && name[2] == 'x')
505 tname += 3;
506 else if (name[1] == '_')
507 tname += 2;
508 else
509 tname += 1;
512 if (tname[0] == 's')
514 if ((tname[1] == 'e'
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
517 || (tname[1] == 'i'
518 && ! strcmp (tname, "sigsetjmp"))
519 || (tname[1] == 'a'
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
523 if (tname[1] == 'i'
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork"))
531 || (tname[0] == 'g' && tname[1] == 'e'
532 && !strcmp (tname, "getcontext")))
533 flags |= ECF_RETURNS_TWICE;
535 else if (tname[0] == 'l' && tname[1] == 'o'
536 && ! strcmp (tname, "longjmp"))
537 flags |= ECF_NORETURN;
540 return flags;
543 /* Return nonzero when FNDECL represents a call to setjmp. */
546 setjmp_call_p (tree fndecl)
548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
551 /* Return true when exp contains alloca call. */
552 bool
553 alloca_call_p (tree exp)
555 if (TREE_CODE (exp) == CALL_EXPR
556 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
557 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
558 == FUNCTION_DECL)
559 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
560 0) & ECF_MAY_BE_ALLOCA))
561 return true;
562 return false;
565 /* Detect flags (function attributes) from the function decl or type node. */
568 flags_from_decl_or_type (tree exp)
570 int flags = 0;
571 tree type = exp;
573 if (DECL_P (exp))
575 type = TREE_TYPE (exp);
577 /* The function exp may have the `malloc' attribute. */
578 if (DECL_IS_MALLOC (exp))
579 flags |= ECF_MALLOC;
581 /* The function exp may have the `returns_twice' attribute. */
582 if (DECL_IS_RETURNS_TWICE (exp))
583 flags |= ECF_RETURNS_TWICE;
585 /* The function exp may have the `pure' attribute. */
586 if (DECL_IS_PURE (exp))
587 flags |= ECF_PURE;
589 if (DECL_IS_NOVOPS (exp))
590 flags |= ECF_NOVOPS;
592 if (TREE_NOTHROW (exp))
593 flags |= ECF_NOTHROW;
595 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
596 flags |= ECF_CONST;
598 flags = special_function_p (exp, flags);
600 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
601 flags |= ECF_CONST;
603 if (TREE_THIS_VOLATILE (exp))
604 flags |= ECF_NORETURN;
606 /* Mark if the function returns with the stack pointer depressed. We
607 cannot consider it pure or constant in that case. */
608 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
610 flags |= ECF_SP_DEPRESSED;
611 flags &= ~(ECF_PURE | ECF_CONST);
614 return flags;
617 /* Detect flags from a CALL_EXPR. */
620 call_expr_flags (tree t)
622 int flags;
623 tree decl = get_callee_fndecl (t);
625 if (decl)
626 flags = flags_from_decl_or_type (decl);
627 else
629 t = TREE_TYPE (TREE_OPERAND (t, 0));
630 if (t && TREE_CODE (t) == POINTER_TYPE)
631 flags = flags_from_decl_or_type (TREE_TYPE (t));
632 else
633 flags = 0;
636 return flags;
639 /* Precompute all register parameters as described by ARGS, storing values
640 into fields within the ARGS array.
642 NUM_ACTUALS indicates the total number elements in the ARGS array.
644 Set REG_PARM_SEEN if we encounter a register parameter. */
646 static void
647 precompute_register_parameters (int num_actuals, struct arg_data *args,
648 int *reg_parm_seen)
650 int i;
652 *reg_parm_seen = 0;
654 for (i = 0; i < num_actuals; i++)
655 if (args[i].reg != 0 && ! args[i].pass_on_stack)
657 *reg_parm_seen = 1;
659 if (args[i].value == 0)
661 push_temp_slots ();
662 args[i].value = expand_normal (args[i].tree_value);
663 preserve_temp_slots (args[i].value);
664 pop_temp_slots ();
667 /* If the value is a non-legitimate constant, force it into a
668 pseudo now. TLS symbols sometimes need a call to resolve. */
669 if (CONSTANT_P (args[i].value)
670 && !LEGITIMATE_CONSTANT_P (args[i].value))
671 args[i].value = force_reg (args[i].mode, args[i].value);
673 /* If we are to promote the function arg to a wider mode,
674 do it now. */
676 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
677 args[i].value
678 = convert_modes (args[i].mode,
679 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
680 args[i].value, args[i].unsignedp);
682 /* If we're going to have to load the value by parts, pull the
683 parts into pseudos. The part extraction process can involve
684 non-trivial computation. */
685 if (GET_CODE (args[i].reg) == PARALLEL)
687 tree type = TREE_TYPE (args[i].tree_value);
688 args[i].parallel_value
689 = emit_group_load_into_temps (args[i].reg, args[i].value,
690 type, int_size_in_bytes (type));
693 /* If the value is expensive, and we are inside an appropriately
694 short loop, put the value into a pseudo and then put the pseudo
695 into the hard reg.
697 For small register classes, also do this if this call uses
698 register parameters. This is to avoid reload conflicts while
699 loading the parameters registers. */
701 else if ((! (REG_P (args[i].value)
702 || (GET_CODE (args[i].value) == SUBREG
703 && REG_P (SUBREG_REG (args[i].value)))))
704 && args[i].mode != BLKmode
705 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
706 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
707 || optimize))
708 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
712 #ifdef REG_PARM_STACK_SPACE
714 /* The argument list is the property of the called routine and it
715 may clobber it. If the fixed area has been used for previous
716 parameters, we must save and restore it. */
718 static rtx
719 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
721 int low;
722 int high;
724 /* Compute the boundary of the area that needs to be saved, if any. */
725 high = reg_parm_stack_space;
726 #ifdef ARGS_GROW_DOWNWARD
727 high += 1;
728 #endif
729 if (high > highest_outgoing_arg_in_use)
730 high = highest_outgoing_arg_in_use;
732 for (low = 0; low < high; low++)
733 if (stack_usage_map[low] != 0)
735 int num_to_save;
736 enum machine_mode save_mode;
737 int delta;
738 rtx stack_area;
739 rtx save_area;
741 while (stack_usage_map[--high] == 0)
744 *low_to_save = low;
745 *high_to_save = high;
747 num_to_save = high - low + 1;
748 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
750 /* If we don't have the required alignment, must do this
751 in BLKmode. */
752 if ((low & (MIN (GET_MODE_SIZE (save_mode),
753 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
754 save_mode = BLKmode;
756 #ifdef ARGS_GROW_DOWNWARD
757 delta = -high;
758 #else
759 delta = low;
760 #endif
761 stack_area = gen_rtx_MEM (save_mode,
762 memory_address (save_mode,
763 plus_constant (argblock,
764 delta)));
766 set_mem_align (stack_area, PARM_BOUNDARY);
767 if (save_mode == BLKmode)
769 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
770 emit_block_move (validize_mem (save_area), stack_area,
771 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
773 else
775 save_area = gen_reg_rtx (save_mode);
776 emit_move_insn (save_area, stack_area);
779 return save_area;
782 return NULL_RTX;
785 static void
786 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
788 enum machine_mode save_mode = GET_MODE (save_area);
789 int delta;
790 rtx stack_area;
792 #ifdef ARGS_GROW_DOWNWARD
793 delta = -high_to_save;
794 #else
795 delta = low_to_save;
796 #endif
797 stack_area = gen_rtx_MEM (save_mode,
798 memory_address (save_mode,
799 plus_constant (argblock, delta)));
800 set_mem_align (stack_area, PARM_BOUNDARY);
802 if (save_mode != BLKmode)
803 emit_move_insn (stack_area, save_area);
804 else
805 emit_block_move (stack_area, validize_mem (save_area),
806 GEN_INT (high_to_save - low_to_save + 1),
807 BLOCK_OP_CALL_PARM);
809 #endif /* REG_PARM_STACK_SPACE */
811 /* If any elements in ARGS refer to parameters that are to be passed in
812 registers, but not in memory, and whose alignment does not permit a
813 direct copy into registers. Copy the values into a group of pseudos
814 which we will later copy into the appropriate hard registers.
816 Pseudos for each unaligned argument will be stored into the array
817 args[argnum].aligned_regs. The caller is responsible for deallocating
818 the aligned_regs array if it is nonzero. */
820 static void
821 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
823 int i, j;
825 for (i = 0; i < num_actuals; i++)
826 if (args[i].reg != 0 && ! args[i].pass_on_stack
827 && args[i].mode == BLKmode
828 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
829 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
831 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
832 int endian_correction = 0;
834 if (args[i].partial)
836 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
837 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
839 else
841 args[i].n_aligned_regs
842 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
845 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
847 /* Structures smaller than a word are normally aligned to the
848 least significant byte. On a BYTES_BIG_ENDIAN machine,
849 this means we must skip the empty high order bytes when
850 calculating the bit offset. */
851 if (bytes < UNITS_PER_WORD
852 #ifdef BLOCK_REG_PADDING
853 && (BLOCK_REG_PADDING (args[i].mode,
854 TREE_TYPE (args[i].tree_value), 1)
855 == downward)
856 #else
857 && BYTES_BIG_ENDIAN
858 #endif
860 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
862 for (j = 0; j < args[i].n_aligned_regs; j++)
864 rtx reg = gen_reg_rtx (word_mode);
865 rtx word = operand_subword_force (args[i].value, j, BLKmode);
866 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
868 args[i].aligned_regs[j] = reg;
869 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
870 word_mode, word_mode);
872 /* There is no need to restrict this code to loading items
873 in TYPE_ALIGN sized hunks. The bitfield instructions can
874 load up entire word sized registers efficiently.
876 ??? This may not be needed anymore.
877 We use to emit a clobber here but that doesn't let later
878 passes optimize the instructions we emit. By storing 0 into
879 the register later passes know the first AND to zero out the
880 bitfield being set in the register is unnecessary. The store
881 of 0 will be deleted as will at least the first AND. */
883 emit_move_insn (reg, const0_rtx);
885 bytes -= bitsize / BITS_PER_UNIT;
886 store_bit_field (reg, bitsize, endian_correction, word_mode,
887 word);
892 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
893 ACTPARMS.
895 NUM_ACTUALS is the total number of parameters.
897 N_NAMED_ARGS is the total number of named arguments.
899 FNDECL is the tree code for the target of this call (if known)
901 ARGS_SO_FAR holds state needed by the target to know where to place
902 the next argument.
904 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
905 for arguments which are passed in registers.
907 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
908 and may be modified by this routine.
910 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
911 flags which may may be modified by this routine.
913 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
914 that requires allocation of stack space.
916 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
917 the thunked-to function. */
919 static void
920 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
921 struct arg_data *args,
922 struct args_size *args_size,
923 int n_named_args ATTRIBUTE_UNUSED,
924 tree actparms, tree fndecl,
925 CUMULATIVE_ARGS *args_so_far,
926 int reg_parm_stack_space,
927 rtx *old_stack_level, int *old_pending_adj,
928 int *must_preallocate, int *ecf_flags,
929 bool *may_tailcall, bool call_from_thunk_p)
931 /* 1 if scanning parms front to back, -1 if scanning back to front. */
932 int inc;
934 /* Count arg position in order args appear. */
935 int argpos;
937 int i;
938 tree p;
940 args_size->constant = 0;
941 args_size->var = 0;
943 /* In this loop, we consider args in the order they are written.
944 We fill up ARGS from the front or from the back if necessary
945 so that in any case the first arg to be pushed ends up at the front. */
947 if (PUSH_ARGS_REVERSED)
949 i = num_actuals - 1, inc = -1;
950 /* In this case, must reverse order of args
951 so that we compute and push the last arg first. */
953 else
955 i = 0, inc = 1;
958 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
959 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
961 tree type = TREE_TYPE (TREE_VALUE (p));
962 int unsignedp;
963 enum machine_mode mode;
965 args[i].tree_value = TREE_VALUE (p);
967 /* Replace erroneous argument with constant zero. */
968 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
969 args[i].tree_value = integer_zero_node, type = integer_type_node;
971 /* If TYPE is a transparent union, pass things the way we would
972 pass the first field of the union. We have already verified that
973 the modes are the same. */
974 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
975 type = TREE_TYPE (TYPE_FIELDS (type));
977 /* Decide where to pass this arg.
979 args[i].reg is nonzero if all or part is passed in registers.
981 args[i].partial is nonzero if part but not all is passed in registers,
982 and the exact value says how many bytes are passed in registers.
984 args[i].pass_on_stack is nonzero if the argument must at least be
985 computed on the stack. It may then be loaded back into registers
986 if args[i].reg is nonzero.
988 These decisions are driven by the FUNCTION_... macros and must agree
989 with those made by function.c. */
991 /* See if this argument should be passed by invisible reference. */
992 if (pass_by_reference (args_so_far, TYPE_MODE (type),
993 type, argpos < n_named_args))
995 bool callee_copies;
996 tree base;
998 callee_copies
999 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1000 type, argpos < n_named_args);
1002 /* If we're compiling a thunk, pass through invisible references
1003 instead of making a copy. */
1004 if (call_from_thunk_p
1005 || (callee_copies
1006 && !TREE_ADDRESSABLE (type)
1007 && (base = get_base_address (args[i].tree_value))
1008 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1010 /* We can't use sibcalls if a callee-copied argument is
1011 stored in the current function's frame. */
1012 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1013 *may_tailcall = false;
1015 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1016 type = TREE_TYPE (args[i].tree_value);
1018 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1020 else
1022 /* We make a copy of the object and pass the address to the
1023 function being called. */
1024 rtx copy;
1026 if (!COMPLETE_TYPE_P (type)
1027 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1028 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1029 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1030 STACK_CHECK_MAX_VAR_SIZE))))
1032 /* This is a variable-sized object. Make space on the stack
1033 for it. */
1034 rtx size_rtx = expr_size (TREE_VALUE (p));
1036 if (*old_stack_level == 0)
1038 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1039 *old_pending_adj = pending_stack_adjust;
1040 pending_stack_adjust = 0;
1043 copy = gen_rtx_MEM (BLKmode,
1044 allocate_dynamic_stack_space
1045 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1046 set_mem_attributes (copy, type, 1);
1048 else
1049 copy = assign_temp (type, 0, 1, 0);
1051 store_expr (args[i].tree_value, copy, 0);
1053 if (callee_copies)
1054 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1055 else
1056 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1058 args[i].tree_value
1059 = build_fold_addr_expr (make_tree (type, copy));
1060 type = TREE_TYPE (args[i].tree_value);
1061 *may_tailcall = false;
1065 mode = TYPE_MODE (type);
1066 unsignedp = TYPE_UNSIGNED (type);
1068 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1069 mode = promote_mode (type, mode, &unsignedp, 1);
1071 args[i].unsignedp = unsignedp;
1072 args[i].mode = mode;
1074 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1075 argpos < n_named_args);
1076 #ifdef FUNCTION_INCOMING_ARG
1077 /* If this is a sibling call and the machine has register windows, the
1078 register window has to be unwinded before calling the routine, so
1079 arguments have to go into the incoming registers. */
1080 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1081 argpos < n_named_args);
1082 #else
1083 args[i].tail_call_reg = args[i].reg;
1084 #endif
1086 if (args[i].reg)
1087 args[i].partial
1088 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1089 argpos < n_named_args);
1091 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1093 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1094 it means that we are to pass this arg in the register(s) designated
1095 by the PARALLEL, but also to pass it in the stack. */
1096 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1097 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1098 args[i].pass_on_stack = 1;
1100 /* If this is an addressable type, we must preallocate the stack
1101 since we must evaluate the object into its final location.
1103 If this is to be passed in both registers and the stack, it is simpler
1104 to preallocate. */
1105 if (TREE_ADDRESSABLE (type)
1106 || (args[i].pass_on_stack && args[i].reg != 0))
1107 *must_preallocate = 1;
1109 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1110 we cannot consider this function call constant. */
1111 if (TREE_ADDRESSABLE (type))
1112 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1114 /* Compute the stack-size of this argument. */
1115 if (args[i].reg == 0 || args[i].partial != 0
1116 || reg_parm_stack_space > 0
1117 || args[i].pass_on_stack)
1118 locate_and_pad_parm (mode, type,
1119 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1121 #else
1122 args[i].reg != 0,
1123 #endif
1124 args[i].pass_on_stack ? 0 : args[i].partial,
1125 fndecl, args_size, &args[i].locate);
1126 #ifdef BLOCK_REG_PADDING
1127 else
1128 /* The argument is passed entirely in registers. See at which
1129 end it should be padded. */
1130 args[i].locate.where_pad =
1131 BLOCK_REG_PADDING (mode, type,
1132 int_size_in_bytes (type) <= UNITS_PER_WORD);
1133 #endif
1135 /* Update ARGS_SIZE, the total stack space for args so far. */
1137 args_size->constant += args[i].locate.size.constant;
1138 if (args[i].locate.size.var)
1139 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1141 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1142 have been used, etc. */
1144 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1145 argpos < n_named_args);
1149 /* Update ARGS_SIZE to contain the total size for the argument block.
1150 Return the original constant component of the argument block's size.
1152 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1153 for arguments passed in registers. */
1155 static int
1156 compute_argument_block_size (int reg_parm_stack_space,
1157 struct args_size *args_size,
1158 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1160 int unadjusted_args_size = args_size->constant;
1162 /* For accumulate outgoing args mode we don't need to align, since the frame
1163 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1164 backends from generating misaligned frame sizes. */
1165 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1166 preferred_stack_boundary = STACK_BOUNDARY;
1168 /* Compute the actual size of the argument block required. The variable
1169 and constant sizes must be combined, the size may have to be rounded,
1170 and there may be a minimum required size. */
1172 if (args_size->var)
1174 args_size->var = ARGS_SIZE_TREE (*args_size);
1175 args_size->constant = 0;
1177 preferred_stack_boundary /= BITS_PER_UNIT;
1178 if (preferred_stack_boundary > 1)
1180 /* We don't handle this case yet. To handle it correctly we have
1181 to add the delta, round and subtract the delta.
1182 Currently no machine description requires this support. */
1183 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1184 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1187 if (reg_parm_stack_space > 0)
1189 args_size->var
1190 = size_binop (MAX_EXPR, args_size->var,
1191 ssize_int (reg_parm_stack_space));
1193 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1194 /* The area corresponding to register parameters is not to count in
1195 the size of the block we need. So make the adjustment. */
1196 args_size->var
1197 = size_binop (MINUS_EXPR, args_size->var,
1198 ssize_int (reg_parm_stack_space));
1199 #endif
1202 else
1204 preferred_stack_boundary /= BITS_PER_UNIT;
1205 if (preferred_stack_boundary < 1)
1206 preferred_stack_boundary = 1;
1207 args_size->constant = (((args_size->constant
1208 + stack_pointer_delta
1209 + preferred_stack_boundary - 1)
1210 / preferred_stack_boundary
1211 * preferred_stack_boundary)
1212 - stack_pointer_delta);
1214 args_size->constant = MAX (args_size->constant,
1215 reg_parm_stack_space);
1217 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1218 args_size->constant -= reg_parm_stack_space;
1219 #endif
1221 return unadjusted_args_size;
1224 /* Precompute parameters as needed for a function call.
1226 FLAGS is mask of ECF_* constants.
1228 NUM_ACTUALS is the number of arguments.
1230 ARGS is an array containing information for each argument; this
1231 routine fills in the INITIAL_VALUE and VALUE fields for each
1232 precomputed argument. */
1234 static void
1235 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1237 int i;
1239 /* If this is a libcall, then precompute all arguments so that we do not
1240 get extraneous instructions emitted as part of the libcall sequence. */
1241 if ((flags & ECF_LIBCALL_BLOCK) == 0)
1242 return;
1244 for (i = 0; i < num_actuals; i++)
1246 enum machine_mode mode;
1248 /* If this is an addressable type, we cannot pre-evaluate it. */
1249 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1251 args[i].initial_value = args[i].value
1252 = expand_normal (args[i].tree_value);
1254 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1255 if (mode != args[i].mode)
1257 args[i].value
1258 = convert_modes (args[i].mode, mode,
1259 args[i].value, args[i].unsignedp);
1260 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1261 /* CSE will replace this only if it contains args[i].value
1262 pseudo, so convert it down to the declared mode using
1263 a SUBREG. */
1264 if (REG_P (args[i].value)
1265 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1267 args[i].initial_value
1268 = gen_lowpart_SUBREG (mode, args[i].value);
1269 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1270 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1271 args[i].unsignedp);
1273 #endif
1278 /* Given the current state of MUST_PREALLOCATE and information about
1279 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1280 compute and return the final value for MUST_PREALLOCATE. */
1282 static int
1283 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1285 /* See if we have or want to preallocate stack space.
1287 If we would have to push a partially-in-regs parm
1288 before other stack parms, preallocate stack space instead.
1290 If the size of some parm is not a multiple of the required stack
1291 alignment, we must preallocate.
1293 If the total size of arguments that would otherwise create a copy in
1294 a temporary (such as a CALL) is more than half the total argument list
1295 size, preallocation is faster.
1297 Another reason to preallocate is if we have a machine (like the m88k)
1298 where stack alignment is required to be maintained between every
1299 pair of insns, not just when the call is made. However, we assume here
1300 that such machines either do not have push insns (and hence preallocation
1301 would occur anyway) or the problem is taken care of with
1302 PUSH_ROUNDING. */
1304 if (! must_preallocate)
1306 int partial_seen = 0;
1307 int copy_to_evaluate_size = 0;
1308 int i;
1310 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1312 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1313 partial_seen = 1;
1314 else if (partial_seen && args[i].reg == 0)
1315 must_preallocate = 1;
1317 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1318 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1319 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1320 || TREE_CODE (args[i].tree_value) == COND_EXPR
1321 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1322 copy_to_evaluate_size
1323 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1326 if (copy_to_evaluate_size * 2 >= args_size->constant
1327 && args_size->constant > 0)
1328 must_preallocate = 1;
1330 return must_preallocate;
1333 /* If we preallocated stack space, compute the address of each argument
1334 and store it into the ARGS array.
1336 We need not ensure it is a valid memory address here; it will be
1337 validized when it is used.
1339 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1341 static void
1342 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1344 if (argblock)
1346 rtx arg_reg = argblock;
1347 int i, arg_offset = 0;
1349 if (GET_CODE (argblock) == PLUS)
1350 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1352 for (i = 0; i < num_actuals; i++)
1354 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1355 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1356 rtx addr;
1357 unsigned int align, boundary;
1359 /* Skip this parm if it will not be passed on the stack. */
1360 if (! args[i].pass_on_stack && args[i].reg != 0)
1361 continue;
1363 if (GET_CODE (offset) == CONST_INT)
1364 addr = plus_constant (arg_reg, INTVAL (offset));
1365 else
1366 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1368 addr = plus_constant (addr, arg_offset);
1369 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1370 set_mem_attributes (args[i].stack,
1371 TREE_TYPE (args[i].tree_value), 1);
1372 align = BITS_PER_UNIT;
1373 boundary = args[i].locate.boundary;
1374 if (args[i].locate.where_pad != downward)
1375 align = boundary;
1376 else if (GET_CODE (offset) == CONST_INT)
1378 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1379 align = align & -align;
1381 set_mem_align (args[i].stack, align);
1383 if (GET_CODE (slot_offset) == CONST_INT)
1384 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1385 else
1386 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1388 addr = plus_constant (addr, arg_offset);
1389 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1390 set_mem_attributes (args[i].stack_slot,
1391 TREE_TYPE (args[i].tree_value), 1);
1392 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1394 /* Function incoming arguments may overlap with sibling call
1395 outgoing arguments and we cannot allow reordering of reads
1396 from function arguments with stores to outgoing arguments
1397 of sibling calls. */
1398 set_mem_alias_set (args[i].stack, 0);
1399 set_mem_alias_set (args[i].stack_slot, 0);
1404 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1405 in a call instruction.
1407 FNDECL is the tree node for the target function. For an indirect call
1408 FNDECL will be NULL_TREE.
1410 ADDR is the operand 0 of CALL_EXPR for this call. */
1412 static rtx
1413 rtx_for_function_call (tree fndecl, tree addr)
1415 rtx funexp;
1417 /* Get the function to call, in the form of RTL. */
1418 if (fndecl)
1420 /* If this is the first use of the function, see if we need to
1421 make an external definition for it. */
1422 if (! TREE_USED (fndecl))
1424 assemble_external (fndecl);
1425 TREE_USED (fndecl) = 1;
1428 /* Get a SYMBOL_REF rtx for the function address. */
1429 funexp = XEXP (DECL_RTL (fndecl), 0);
1431 else
1432 /* Generate an rtx (probably a pseudo-register) for the address. */
1434 push_temp_slots ();
1435 funexp = expand_normal (addr);
1436 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1438 return funexp;
1441 /* Return true if and only if SIZE storage units (usually bytes)
1442 starting from address ADDR overlap with already clobbered argument
1443 area. This function is used to determine if we should give up a
1444 sibcall. */
1446 static bool
1447 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1449 HOST_WIDE_INT i;
1451 if (addr == current_function_internal_arg_pointer)
1452 i = 0;
1453 else if (GET_CODE (addr) == PLUS
1454 && (XEXP (addr, 0)
1455 == current_function_internal_arg_pointer)
1456 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1457 i = INTVAL (XEXP (addr, 1));
1458 else
1459 return false;
1461 #ifdef ARGS_GROW_DOWNWARD
1462 i = -i - size;
1463 #endif
1464 if (size > 0)
1466 unsigned HOST_WIDE_INT k;
1468 for (k = 0; k < size; k++)
1469 if (i + k < stored_args_map->n_bits
1470 && TEST_BIT (stored_args_map, i + k))
1471 return true;
1474 return false;
1477 /* Do the register loads required for any wholly-register parms or any
1478 parms which are passed both on the stack and in a register. Their
1479 expressions were already evaluated.
1481 Mark all register-parms as living through the call, putting these USE
1482 insns in the CALL_INSN_FUNCTION_USAGE field.
1484 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1485 checking, setting *SIBCALL_FAILURE if appropriate. */
1487 static void
1488 load_register_parameters (struct arg_data *args, int num_actuals,
1489 rtx *call_fusage, int flags, int is_sibcall,
1490 int *sibcall_failure)
1492 int i, j;
1494 for (i = 0; i < num_actuals; i++)
1496 rtx reg = ((flags & ECF_SIBCALL)
1497 ? args[i].tail_call_reg : args[i].reg);
1498 if (reg)
1500 int partial = args[i].partial;
1501 int nregs;
1502 int size = 0;
1503 rtx before_arg = get_last_insn ();
1504 /* Set non-negative if we must move a word at a time, even if
1505 just one word (e.g, partial == 4 && mode == DFmode). Set
1506 to -1 if we just use a normal move insn. This value can be
1507 zero if the argument is a zero size structure. */
1508 nregs = -1;
1509 if (GET_CODE (reg) == PARALLEL)
1511 else if (partial)
1513 gcc_assert (partial % UNITS_PER_WORD == 0);
1514 nregs = partial / UNITS_PER_WORD;
1516 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1518 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1519 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1521 else
1522 size = GET_MODE_SIZE (args[i].mode);
1524 /* Handle calls that pass values in multiple non-contiguous
1525 locations. The Irix 6 ABI has examples of this. */
1527 if (GET_CODE (reg) == PARALLEL)
1528 emit_group_move (reg, args[i].parallel_value);
1530 /* If simple case, just do move. If normal partial, store_one_arg
1531 has already loaded the register for us. In all other cases,
1532 load the register(s) from memory. */
1534 else if (nregs == -1)
1536 emit_move_insn (reg, args[i].value);
1537 #ifdef BLOCK_REG_PADDING
1538 /* Handle case where we have a value that needs shifting
1539 up to the msb. eg. a QImode value and we're padding
1540 upward on a BYTES_BIG_ENDIAN machine. */
1541 if (size < UNITS_PER_WORD
1542 && (args[i].locate.where_pad
1543 == (BYTES_BIG_ENDIAN ? upward : downward)))
1545 rtx x;
1546 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1548 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1549 report the whole reg as used. Strictly speaking, the
1550 call only uses SIZE bytes at the msb end, but it doesn't
1551 seem worth generating rtl to say that. */
1552 reg = gen_rtx_REG (word_mode, REGNO (reg));
1553 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1554 build_int_cst (NULL_TREE, shift),
1555 reg, 1);
1556 if (x != reg)
1557 emit_move_insn (reg, x);
1559 #endif
1562 /* If we have pre-computed the values to put in the registers in
1563 the case of non-aligned structures, copy them in now. */
1565 else if (args[i].n_aligned_regs != 0)
1566 for (j = 0; j < args[i].n_aligned_regs; j++)
1567 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1568 args[i].aligned_regs[j]);
1570 else if (partial == 0 || args[i].pass_on_stack)
1572 rtx mem = validize_mem (args[i].value);
1574 /* Check for overlap with already clobbered argument area. */
1575 if (is_sibcall
1576 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1577 size))
1578 *sibcall_failure = 1;
1580 /* Handle a BLKmode that needs shifting. */
1581 if (nregs == 1 && size < UNITS_PER_WORD
1582 #ifdef BLOCK_REG_PADDING
1583 && args[i].locate.where_pad == downward
1584 #else
1585 && BYTES_BIG_ENDIAN
1586 #endif
1589 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1590 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1591 rtx x = gen_reg_rtx (word_mode);
1592 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1593 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1594 : LSHIFT_EXPR;
1596 emit_move_insn (x, tem);
1597 x = expand_shift (dir, word_mode, x,
1598 build_int_cst (NULL_TREE, shift),
1599 ri, 1);
1600 if (x != ri)
1601 emit_move_insn (ri, x);
1603 else
1604 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1607 /* When a parameter is a block, and perhaps in other cases, it is
1608 possible that it did a load from an argument slot that was
1609 already clobbered. */
1610 if (is_sibcall
1611 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1612 *sibcall_failure = 1;
1614 /* Handle calls that pass values in multiple non-contiguous
1615 locations. The Irix 6 ABI has examples of this. */
1616 if (GET_CODE (reg) == PARALLEL)
1617 use_group_regs (call_fusage, reg);
1618 else if (nregs == -1)
1619 use_reg (call_fusage, reg);
1620 else if (nregs > 0)
1621 use_regs (call_fusage, REGNO (reg), nregs);
1626 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1627 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1628 bytes, then we would need to push some additional bytes to pad the
1629 arguments. So, we compute an adjust to the stack pointer for an
1630 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1631 bytes. Then, when the arguments are pushed the stack will be perfectly
1632 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1633 be popped after the call. Returns the adjustment. */
1635 static int
1636 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1637 struct args_size *args_size,
1638 unsigned int preferred_unit_stack_boundary)
1640 /* The number of bytes to pop so that the stack will be
1641 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1642 HOST_WIDE_INT adjustment;
1643 /* The alignment of the stack after the arguments are pushed, if we
1644 just pushed the arguments without adjust the stack here. */
1645 unsigned HOST_WIDE_INT unadjusted_alignment;
1647 unadjusted_alignment
1648 = ((stack_pointer_delta + unadjusted_args_size)
1649 % preferred_unit_stack_boundary);
1651 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1652 as possible -- leaving just enough left to cancel out the
1653 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1654 PENDING_STACK_ADJUST is non-negative, and congruent to
1655 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1657 /* Begin by trying to pop all the bytes. */
1658 unadjusted_alignment
1659 = (unadjusted_alignment
1660 - (pending_stack_adjust % preferred_unit_stack_boundary));
1661 adjustment = pending_stack_adjust;
1662 /* Push enough additional bytes that the stack will be aligned
1663 after the arguments are pushed. */
1664 if (preferred_unit_stack_boundary > 1)
1666 if (unadjusted_alignment > 0)
1667 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1668 else
1669 adjustment += unadjusted_alignment;
1672 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1673 bytes after the call. The right number is the entire
1674 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1675 by the arguments in the first place. */
1676 args_size->constant
1677 = pending_stack_adjust - adjustment + unadjusted_args_size;
1679 return adjustment;
1682 /* Scan X expression if it does not dereference any argument slots
1683 we already clobbered by tail call arguments (as noted in stored_args_map
1684 bitmap).
1685 Return nonzero if X expression dereferences such argument slots,
1686 zero otherwise. */
1688 static int
1689 check_sibcall_argument_overlap_1 (rtx x)
1691 RTX_CODE code;
1692 int i, j;
1693 const char *fmt;
1695 if (x == NULL_RTX)
1696 return 0;
1698 code = GET_CODE (x);
1700 if (code == MEM)
1701 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1702 GET_MODE_SIZE (GET_MODE (x)));
1704 /* Scan all subexpressions. */
1705 fmt = GET_RTX_FORMAT (code);
1706 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1708 if (*fmt == 'e')
1710 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1711 return 1;
1713 else if (*fmt == 'E')
1715 for (j = 0; j < XVECLEN (x, i); j++)
1716 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1717 return 1;
1720 return 0;
1723 /* Scan sequence after INSN if it does not dereference any argument slots
1724 we already clobbered by tail call arguments (as noted in stored_args_map
1725 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1726 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1727 should be 0). Return nonzero if sequence after INSN dereferences such argument
1728 slots, zero otherwise. */
1730 static int
1731 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1733 int low, high;
1735 if (insn == NULL_RTX)
1736 insn = get_insns ();
1737 else
1738 insn = NEXT_INSN (insn);
1740 for (; insn; insn = NEXT_INSN (insn))
1741 if (INSN_P (insn)
1742 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1743 break;
1745 if (mark_stored_args_map)
1747 #ifdef ARGS_GROW_DOWNWARD
1748 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1749 #else
1750 low = arg->locate.slot_offset.constant;
1751 #endif
1753 for (high = low + arg->locate.size.constant; low < high; low++)
1754 SET_BIT (stored_args_map, low);
1756 return insn != NULL_RTX;
1759 /* Given that a function returns a value of mode MODE at the most
1760 significant end of hard register VALUE, shift VALUE left or right
1761 as specified by LEFT_P. Return true if some action was needed. */
1763 bool
1764 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1766 HOST_WIDE_INT shift;
1768 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1769 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1770 if (shift == 0)
1771 return false;
1773 /* Use ashr rather than lshr for right shifts. This is for the benefit
1774 of the MIPS port, which requires SImode values to be sign-extended
1775 when stored in 64-bit registers. */
1776 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1777 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1778 gcc_unreachable ();
1779 return true;
1782 /* Generate all the code for a function call
1783 and return an rtx for its value.
1784 Store the value in TARGET (specified as an rtx) if convenient.
1785 If the value is stored in TARGET then TARGET is returned.
1786 If IGNORE is nonzero, then we ignore the value of the function call. */
1789 expand_call (tree exp, rtx target, int ignore)
1791 /* Nonzero if we are currently expanding a call. */
1792 static int currently_expanding_call = 0;
1794 /* List of actual parameters. */
1795 tree actparms = TREE_OPERAND (exp, 1);
1796 /* RTX for the function to be called. */
1797 rtx funexp;
1798 /* Sequence of insns to perform a normal "call". */
1799 rtx normal_call_insns = NULL_RTX;
1800 /* Sequence of insns to perform a tail "call". */
1801 rtx tail_call_insns = NULL_RTX;
1802 /* Data type of the function. */
1803 tree funtype;
1804 tree type_arg_types;
1805 /* Declaration of the function being called,
1806 or 0 if the function is computed (not known by name). */
1807 tree fndecl = 0;
1808 /* The type of the function being called. */
1809 tree fntype;
1810 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1811 int pass;
1813 /* Register in which non-BLKmode value will be returned,
1814 or 0 if no value or if value is BLKmode. */
1815 rtx valreg;
1816 /* Address where we should return a BLKmode value;
1817 0 if value not BLKmode. */
1818 rtx structure_value_addr = 0;
1819 /* Nonzero if that address is being passed by treating it as
1820 an extra, implicit first parameter. Otherwise,
1821 it is passed by being copied directly into struct_value_rtx. */
1822 int structure_value_addr_parm = 0;
1823 /* Size of aggregate value wanted, or zero if none wanted
1824 or if we are using the non-reentrant PCC calling convention
1825 or expecting the value in registers. */
1826 HOST_WIDE_INT struct_value_size = 0;
1827 /* Nonzero if called function returns an aggregate in memory PCC style,
1828 by returning the address of where to find it. */
1829 int pcc_struct_value = 0;
1830 rtx struct_value = 0;
1832 /* Number of actual parameters in this call, including struct value addr. */
1833 int num_actuals;
1834 /* Number of named args. Args after this are anonymous ones
1835 and they must all go on the stack. */
1836 int n_named_args;
1838 /* Vector of information about each argument.
1839 Arguments are numbered in the order they will be pushed,
1840 not the order they are written. */
1841 struct arg_data *args;
1843 /* Total size in bytes of all the stack-parms scanned so far. */
1844 struct args_size args_size;
1845 struct args_size adjusted_args_size;
1846 /* Size of arguments before any adjustments (such as rounding). */
1847 int unadjusted_args_size;
1848 /* Data on reg parms scanned so far. */
1849 CUMULATIVE_ARGS args_so_far;
1850 /* Nonzero if a reg parm has been scanned. */
1851 int reg_parm_seen;
1852 /* Nonzero if this is an indirect function call. */
1854 /* Nonzero if we must avoid push-insns in the args for this call.
1855 If stack space is allocated for register parameters, but not by the
1856 caller, then it is preallocated in the fixed part of the stack frame.
1857 So the entire argument block must then be preallocated (i.e., we
1858 ignore PUSH_ROUNDING in that case). */
1860 int must_preallocate = !PUSH_ARGS;
1862 /* Size of the stack reserved for parameter registers. */
1863 int reg_parm_stack_space = 0;
1865 /* Address of space preallocated for stack parms
1866 (on machines that lack push insns), or 0 if space not preallocated. */
1867 rtx argblock = 0;
1869 /* Mask of ECF_ flags. */
1870 int flags = 0;
1871 #ifdef REG_PARM_STACK_SPACE
1872 /* Define the boundary of the register parm stack space that needs to be
1873 saved, if any. */
1874 int low_to_save, high_to_save;
1875 rtx save_area = 0; /* Place that it is saved */
1876 #endif
1878 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1879 char *initial_stack_usage_map = stack_usage_map;
1880 char *stack_usage_map_buf = NULL;
1882 int old_stack_allocated;
1884 /* State variables to track stack modifications. */
1885 rtx old_stack_level = 0;
1886 int old_stack_arg_under_construction = 0;
1887 int old_pending_adj = 0;
1888 int old_inhibit_defer_pop = inhibit_defer_pop;
1890 /* Some stack pointer alterations we make are performed via
1891 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1892 which we then also need to save/restore along the way. */
1893 int old_stack_pointer_delta = 0;
1895 rtx call_fusage;
1896 tree p = TREE_OPERAND (exp, 0);
1897 tree addr = TREE_OPERAND (exp, 0);
1898 int i;
1899 /* The alignment of the stack, in bits. */
1900 unsigned HOST_WIDE_INT preferred_stack_boundary;
1901 /* The alignment of the stack, in bytes. */
1902 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
1903 /* The static chain value to use for this call. */
1904 rtx static_chain_value;
1905 /* See if this is "nothrow" function call. */
1906 if (TREE_NOTHROW (exp))
1907 flags |= ECF_NOTHROW;
1909 /* See if we can find a DECL-node for the actual function, and get the
1910 function attributes (flags) from the function decl or type node. */
1911 fndecl = get_callee_fndecl (exp);
1912 if (fndecl)
1914 fntype = TREE_TYPE (fndecl);
1915 flags |= flags_from_decl_or_type (fndecl);
1917 else
1919 fntype = TREE_TYPE (TREE_TYPE (p));
1920 flags |= flags_from_decl_or_type (fntype);
1923 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
1925 /* Warn if this value is an aggregate type,
1926 regardless of which calling convention we are using for it. */
1927 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
1928 warning (OPT_Waggregate_return, "function call has aggregate value");
1930 /* If the result of a pure or const function call is ignored (or void),
1931 and none of its arguments are volatile, we can avoid expanding the
1932 call and just evaluate the arguments for side-effects. */
1933 if ((flags & (ECF_CONST | ECF_PURE))
1934 && (ignore || target == const0_rtx
1935 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
1937 bool volatilep = false;
1938 tree arg;
1940 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1941 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
1943 volatilep = true;
1944 break;
1947 if (! volatilep)
1949 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1950 expand_expr (TREE_VALUE (arg), const0_rtx,
1951 VOIDmode, EXPAND_NORMAL);
1952 return const0_rtx;
1956 #ifdef REG_PARM_STACK_SPACE
1957 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1958 #endif
1960 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1961 if (reg_parm_stack_space > 0 && PUSH_ARGS)
1962 must_preallocate = 1;
1963 #endif
1965 /* Set up a place to return a structure. */
1967 /* Cater to broken compilers. */
1968 if (aggregate_value_p (exp, fndecl))
1970 /* This call returns a big structure. */
1971 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1973 #ifdef PCC_STATIC_STRUCT_RETURN
1975 pcc_struct_value = 1;
1977 #else /* not PCC_STATIC_STRUCT_RETURN */
1979 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
1981 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
1982 structure_value_addr = XEXP (target, 0);
1983 else
1985 /* For variable-sized objects, we must be called with a target
1986 specified. If we were to allocate space on the stack here,
1987 we would have no way of knowing when to free it. */
1988 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
1990 mark_temp_addr_taken (d);
1991 structure_value_addr = XEXP (d, 0);
1992 target = 0;
1995 #endif /* not PCC_STATIC_STRUCT_RETURN */
1998 /* Figure out the amount to which the stack should be aligned. */
1999 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2000 if (fndecl)
2002 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2003 if (i && i->preferred_incoming_stack_boundary)
2004 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2007 /* Operand 0 is a pointer-to-function; get the type of the function. */
2008 funtype = TREE_TYPE (addr);
2009 gcc_assert (POINTER_TYPE_P (funtype));
2010 funtype = TREE_TYPE (funtype);
2012 /* Munge the tree to split complex arguments into their imaginary
2013 and real parts. */
2014 if (targetm.calls.split_complex_arg)
2016 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2017 actparms = split_complex_values (actparms);
2019 else
2020 type_arg_types = TYPE_ARG_TYPES (funtype);
2022 if (flags & ECF_MAY_BE_ALLOCA)
2023 current_function_calls_alloca = 1;
2025 /* If struct_value_rtx is 0, it means pass the address
2026 as if it were an extra parameter. */
2027 if (structure_value_addr && struct_value == 0)
2029 /* If structure_value_addr is a REG other than
2030 virtual_outgoing_args_rtx, we can use always use it. If it
2031 is not a REG, we must always copy it into a register.
2032 If it is virtual_outgoing_args_rtx, we must copy it to another
2033 register in some cases. */
2034 rtx temp = (!REG_P (structure_value_addr)
2035 || (ACCUMULATE_OUTGOING_ARGS
2036 && stack_arg_under_construction
2037 && structure_value_addr == virtual_outgoing_args_rtx)
2038 ? copy_addr_to_reg (convert_memory_address
2039 (Pmode, structure_value_addr))
2040 : structure_value_addr);
2042 actparms
2043 = tree_cons (error_mark_node,
2044 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2045 temp),
2046 actparms);
2047 structure_value_addr_parm = 1;
2050 /* Count the arguments and set NUM_ACTUALS. */
2051 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2052 num_actuals++;
2054 /* Compute number of named args.
2055 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2057 if (type_arg_types != 0)
2058 n_named_args
2059 = (list_length (type_arg_types)
2060 /* Count the struct value address, if it is passed as a parm. */
2061 + structure_value_addr_parm);
2062 else
2063 /* If we know nothing, treat all args as named. */
2064 n_named_args = num_actuals;
2066 /* Start updating where the next arg would go.
2068 On some machines (such as the PA) indirect calls have a different
2069 calling convention than normal calls. The fourth argument in
2070 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2071 or not. */
2072 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2074 /* Now possibly adjust the number of named args.
2075 Normally, don't include the last named arg if anonymous args follow.
2076 We do include the last named arg if
2077 targetm.calls.strict_argument_naming() returns nonzero.
2078 (If no anonymous args follow, the result of list_length is actually
2079 one too large. This is harmless.)
2081 If targetm.calls.pretend_outgoing_varargs_named() returns
2082 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2083 this machine will be able to place unnamed args that were passed
2084 in registers into the stack. So treat all args as named. This
2085 allows the insns emitting for a specific argument list to be
2086 independent of the function declaration.
2088 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2089 we do not have any reliable way to pass unnamed args in
2090 registers, so we must force them into memory. */
2092 if (type_arg_types != 0
2093 && targetm.calls.strict_argument_naming (&args_so_far))
2095 else if (type_arg_types != 0
2096 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2097 /* Don't include the last named arg. */
2098 --n_named_args;
2099 else
2100 /* Treat all args as named. */
2101 n_named_args = num_actuals;
2103 /* Make a vector to hold all the information about each arg. */
2104 args = alloca (num_actuals * sizeof (struct arg_data));
2105 memset (args, 0, num_actuals * sizeof (struct arg_data));
2107 /* Build up entries in the ARGS array, compute the size of the
2108 arguments into ARGS_SIZE, etc. */
2109 initialize_argument_information (num_actuals, args, &args_size,
2110 n_named_args, actparms, fndecl,
2111 &args_so_far, reg_parm_stack_space,
2112 &old_stack_level, &old_pending_adj,
2113 &must_preallocate, &flags,
2114 &try_tail_call, CALL_FROM_THUNK_P (exp));
2116 if (args_size.var)
2118 /* If this function requires a variable-sized argument list, don't
2119 try to make a cse'able block for this call. We may be able to
2120 do this eventually, but it is too complicated to keep track of
2121 what insns go in the cse'able block and which don't. */
2123 flags &= ~ECF_LIBCALL_BLOCK;
2124 must_preallocate = 1;
2127 /* Now make final decision about preallocating stack space. */
2128 must_preallocate = finalize_must_preallocate (must_preallocate,
2129 num_actuals, args,
2130 &args_size);
2132 /* If the structure value address will reference the stack pointer, we
2133 must stabilize it. We don't need to do this if we know that we are
2134 not going to adjust the stack pointer in processing this call. */
2136 if (structure_value_addr
2137 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2138 || reg_mentioned_p (virtual_outgoing_args_rtx,
2139 structure_value_addr))
2140 && (args_size.var
2141 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2142 structure_value_addr = copy_to_reg (structure_value_addr);
2144 /* Tail calls can make things harder to debug, and we've traditionally
2145 pushed these optimizations into -O2. Don't try if we're already
2146 expanding a call, as that means we're an argument. Don't try if
2147 there's cleanups, as we know there's code to follow the call. */
2149 if (currently_expanding_call++ != 0
2150 || !flag_optimize_sibling_calls
2151 || args_size.var
2152 || lookup_stmt_eh_region (exp) >= 0)
2153 try_tail_call = 0;
2155 /* Rest of purposes for tail call optimizations to fail. */
2156 if (
2157 #ifdef HAVE_sibcall_epilogue
2158 !HAVE_sibcall_epilogue
2159 #else
2161 #endif
2162 || !try_tail_call
2163 /* Doing sibling call optimization needs some work, since
2164 structure_value_addr can be allocated on the stack.
2165 It does not seem worth the effort since few optimizable
2166 sibling calls will return a structure. */
2167 || structure_value_addr != NULL_RTX
2168 /* Check whether the target is able to optimize the call
2169 into a sibcall. */
2170 || !targetm.function_ok_for_sibcall (fndecl, exp)
2171 /* Functions that do not return exactly once may not be sibcall
2172 optimized. */
2173 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2174 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2175 /* If the called function is nested in the current one, it might access
2176 some of the caller's arguments, but could clobber them beforehand if
2177 the argument areas are shared. */
2178 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2179 /* If this function requires more stack slots than the current
2180 function, we cannot change it into a sibling call.
2181 current_function_pretend_args_size is not part of the
2182 stack allocated by our caller. */
2183 || args_size.constant > (current_function_args_size
2184 - current_function_pretend_args_size)
2185 /* If the callee pops its own arguments, then it must pop exactly
2186 the same number of arguments as the current function. */
2187 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2188 != RETURN_POPS_ARGS (current_function_decl,
2189 TREE_TYPE (current_function_decl),
2190 current_function_args_size))
2191 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2192 try_tail_call = 0;
2194 /* Ensure current function's preferred stack boundary is at least
2195 what we need. We don't have to increase alignment for recursive
2196 functions. */
2197 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2198 && fndecl != current_function_decl)
2199 cfun->preferred_stack_boundary = preferred_stack_boundary;
2200 if (fndecl == current_function_decl)
2201 cfun->recursive_call_emit = true;
2203 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2205 /* We want to make two insn chains; one for a sibling call, the other
2206 for a normal call. We will select one of the two chains after
2207 initial RTL generation is complete. */
2208 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2210 int sibcall_failure = 0;
2211 /* We want to emit any pending stack adjustments before the tail
2212 recursion "call". That way we know any adjustment after the tail
2213 recursion call can be ignored if we indeed use the tail
2214 call expansion. */
2215 int save_pending_stack_adjust = 0;
2216 int save_stack_pointer_delta = 0;
2217 rtx insns;
2218 rtx before_call, next_arg_reg;
2220 if (pass == 0)
2222 /* State variables we need to save and restore between
2223 iterations. */
2224 save_pending_stack_adjust = pending_stack_adjust;
2225 save_stack_pointer_delta = stack_pointer_delta;
2227 if (pass)
2228 flags &= ~ECF_SIBCALL;
2229 else
2230 flags |= ECF_SIBCALL;
2232 /* Other state variables that we must reinitialize each time
2233 through the loop (that are not initialized by the loop itself). */
2234 argblock = 0;
2235 call_fusage = 0;
2237 /* Start a new sequence for the normal call case.
2239 From this point on, if the sibling call fails, we want to set
2240 sibcall_failure instead of continuing the loop. */
2241 start_sequence ();
2243 /* Don't let pending stack adjusts add up to too much.
2244 Also, do all pending adjustments now if there is any chance
2245 this might be a call to alloca or if we are expanding a sibling
2246 call sequence or if we are calling a function that is to return
2247 with stack pointer depressed.
2248 Also do the adjustments before a throwing call, otherwise
2249 exception handling can fail; PR 19225. */
2250 if (pending_stack_adjust >= 32
2251 || (pending_stack_adjust > 0
2252 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2253 || (pending_stack_adjust > 0
2254 && flag_exceptions && !(flags & ECF_NOTHROW))
2255 || pass == 0)
2256 do_pending_stack_adjust ();
2258 /* When calling a const function, we must pop the stack args right away,
2259 so that the pop is deleted or moved with the call. */
2260 if (pass && (flags & ECF_LIBCALL_BLOCK))
2261 NO_DEFER_POP;
2263 /* Precompute any arguments as needed. */
2264 if (pass)
2265 precompute_arguments (flags, num_actuals, args);
2267 /* Now we are about to start emitting insns that can be deleted
2268 if a libcall is deleted. */
2269 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2270 start_sequence ();
2272 if (pass == 0 && cfun->stack_protect_guard)
2273 stack_protect_epilogue ();
2275 adjusted_args_size = args_size;
2276 /* Compute the actual size of the argument block required. The variable
2277 and constant sizes must be combined, the size may have to be rounded,
2278 and there may be a minimum required size. When generating a sibcall
2279 pattern, do not round up, since we'll be re-using whatever space our
2280 caller provided. */
2281 unadjusted_args_size
2282 = compute_argument_block_size (reg_parm_stack_space,
2283 &adjusted_args_size,
2284 (pass == 0 ? 0
2285 : preferred_stack_boundary));
2287 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2289 /* The argument block when performing a sibling call is the
2290 incoming argument block. */
2291 if (pass == 0)
2293 argblock = virtual_incoming_args_rtx;
2294 argblock
2295 #ifdef STACK_GROWS_DOWNWARD
2296 = plus_constant (argblock, current_function_pretend_args_size);
2297 #else
2298 = plus_constant (argblock, -current_function_pretend_args_size);
2299 #endif
2300 stored_args_map = sbitmap_alloc (args_size.constant);
2301 sbitmap_zero (stored_args_map);
2304 /* If we have no actual push instructions, or shouldn't use them,
2305 make space for all args right now. */
2306 else if (adjusted_args_size.var != 0)
2308 if (old_stack_level == 0)
2310 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2311 old_stack_pointer_delta = stack_pointer_delta;
2312 old_pending_adj = pending_stack_adjust;
2313 pending_stack_adjust = 0;
2314 /* stack_arg_under_construction says whether a stack arg is
2315 being constructed at the old stack level. Pushing the stack
2316 gets a clean outgoing argument block. */
2317 old_stack_arg_under_construction = stack_arg_under_construction;
2318 stack_arg_under_construction = 0;
2320 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2322 else
2324 /* Note that we must go through the motions of allocating an argument
2325 block even if the size is zero because we may be storing args
2326 in the area reserved for register arguments, which may be part of
2327 the stack frame. */
2329 int needed = adjusted_args_size.constant;
2331 /* Store the maximum argument space used. It will be pushed by
2332 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2333 checking). */
2335 if (needed > current_function_outgoing_args_size)
2336 current_function_outgoing_args_size = needed;
2338 if (must_preallocate)
2340 if (ACCUMULATE_OUTGOING_ARGS)
2342 /* Since the stack pointer will never be pushed, it is
2343 possible for the evaluation of a parm to clobber
2344 something we have already written to the stack.
2345 Since most function calls on RISC machines do not use
2346 the stack, this is uncommon, but must work correctly.
2348 Therefore, we save any area of the stack that was already
2349 written and that we are using. Here we set up to do this
2350 by making a new stack usage map from the old one. The
2351 actual save will be done by store_one_arg.
2353 Another approach might be to try to reorder the argument
2354 evaluations to avoid this conflicting stack usage. */
2356 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2357 /* Since we will be writing into the entire argument area,
2358 the map must be allocated for its entire size, not just
2359 the part that is the responsibility of the caller. */
2360 needed += reg_parm_stack_space;
2361 #endif
2363 #ifdef ARGS_GROW_DOWNWARD
2364 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2365 needed + 1);
2366 #else
2367 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2368 needed);
2369 #endif
2370 if (stack_usage_map_buf)
2371 free (stack_usage_map_buf);
2372 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2373 stack_usage_map = stack_usage_map_buf;
2375 if (initial_highest_arg_in_use)
2376 memcpy (stack_usage_map, initial_stack_usage_map,
2377 initial_highest_arg_in_use);
2379 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2380 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2381 (highest_outgoing_arg_in_use
2382 - initial_highest_arg_in_use));
2383 needed = 0;
2385 /* The address of the outgoing argument list must not be
2386 copied to a register here, because argblock would be left
2387 pointing to the wrong place after the call to
2388 allocate_dynamic_stack_space below. */
2390 argblock = virtual_outgoing_args_rtx;
2392 else
2394 if (inhibit_defer_pop == 0)
2396 /* Try to reuse some or all of the pending_stack_adjust
2397 to get this space. */
2398 needed
2399 = (combine_pending_stack_adjustment_and_call
2400 (unadjusted_args_size,
2401 &adjusted_args_size,
2402 preferred_unit_stack_boundary));
2404 /* combine_pending_stack_adjustment_and_call computes
2405 an adjustment before the arguments are allocated.
2406 Account for them and see whether or not the stack
2407 needs to go up or down. */
2408 needed = unadjusted_args_size - needed;
2410 if (needed < 0)
2412 /* We're releasing stack space. */
2413 /* ??? We can avoid any adjustment at all if we're
2414 already aligned. FIXME. */
2415 pending_stack_adjust = -needed;
2416 do_pending_stack_adjust ();
2417 needed = 0;
2419 else
2420 /* We need to allocate space. We'll do that in
2421 push_block below. */
2422 pending_stack_adjust = 0;
2425 /* Special case this because overhead of `push_block' in
2426 this case is non-trivial. */
2427 if (needed == 0)
2428 argblock = virtual_outgoing_args_rtx;
2429 else
2431 argblock = push_block (GEN_INT (needed), 0, 0);
2432 #ifdef ARGS_GROW_DOWNWARD
2433 argblock = plus_constant (argblock, needed);
2434 #endif
2437 /* We only really need to call `copy_to_reg' in the case
2438 where push insns are going to be used to pass ARGBLOCK
2439 to a function call in ARGS. In that case, the stack
2440 pointer changes value from the allocation point to the
2441 call point, and hence the value of
2442 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2443 as well always do it. */
2444 argblock = copy_to_reg (argblock);
2449 if (ACCUMULATE_OUTGOING_ARGS)
2451 /* The save/restore code in store_one_arg handles all
2452 cases except one: a constructor call (including a C
2453 function returning a BLKmode struct) to initialize
2454 an argument. */
2455 if (stack_arg_under_construction)
2457 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2458 rtx push_size = GEN_INT (reg_parm_stack_space
2459 + adjusted_args_size.constant);
2460 #else
2461 rtx push_size = GEN_INT (adjusted_args_size.constant);
2462 #endif
2463 if (old_stack_level == 0)
2465 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2466 NULL_RTX);
2467 old_stack_pointer_delta = stack_pointer_delta;
2468 old_pending_adj = pending_stack_adjust;
2469 pending_stack_adjust = 0;
2470 /* stack_arg_under_construction says whether a stack
2471 arg is being constructed at the old stack level.
2472 Pushing the stack gets a clean outgoing argument
2473 block. */
2474 old_stack_arg_under_construction
2475 = stack_arg_under_construction;
2476 stack_arg_under_construction = 0;
2477 /* Make a new map for the new argument list. */
2478 if (stack_usage_map_buf)
2479 free (stack_usage_map_buf);
2480 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2481 stack_usage_map = stack_usage_map_buf;
2482 highest_outgoing_arg_in_use = 0;
2484 allocate_dynamic_stack_space (push_size, NULL_RTX,
2485 BITS_PER_UNIT);
2488 /* If argument evaluation might modify the stack pointer,
2489 copy the address of the argument list to a register. */
2490 for (i = 0; i < num_actuals; i++)
2491 if (args[i].pass_on_stack)
2493 argblock = copy_addr_to_reg (argblock);
2494 break;
2498 compute_argument_addresses (args, argblock, num_actuals);
2500 /* If we push args individually in reverse order, perform stack alignment
2501 before the first push (the last arg). */
2502 if (PUSH_ARGS_REVERSED && argblock == 0
2503 && adjusted_args_size.constant != unadjusted_args_size)
2505 /* When the stack adjustment is pending, we get better code
2506 by combining the adjustments. */
2507 if (pending_stack_adjust
2508 && ! (flags & ECF_LIBCALL_BLOCK)
2509 && ! inhibit_defer_pop)
2511 pending_stack_adjust
2512 = (combine_pending_stack_adjustment_and_call
2513 (unadjusted_args_size,
2514 &adjusted_args_size,
2515 preferred_unit_stack_boundary));
2516 do_pending_stack_adjust ();
2518 else if (argblock == 0)
2519 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2520 - unadjusted_args_size));
2522 /* Now that the stack is properly aligned, pops can't safely
2523 be deferred during the evaluation of the arguments. */
2524 NO_DEFER_POP;
2526 funexp = rtx_for_function_call (fndecl, addr);
2528 /* Figure out the register where the value, if any, will come back. */
2529 valreg = 0;
2530 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2531 && ! structure_value_addr)
2533 if (pcc_struct_value)
2534 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2535 fndecl, NULL, (pass == 0));
2536 else
2537 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2538 (pass == 0));
2541 /* Precompute all register parameters. It isn't safe to compute anything
2542 once we have started filling any specific hard regs. */
2543 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2545 if (TREE_OPERAND (exp, 2))
2546 static_chain_value = expand_normal (TREE_OPERAND (exp, 2));
2547 else
2548 static_chain_value = 0;
2550 #ifdef REG_PARM_STACK_SPACE
2551 /* Save the fixed argument area if it's part of the caller's frame and
2552 is clobbered by argument setup for this call. */
2553 if (ACCUMULATE_OUTGOING_ARGS && pass)
2554 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2555 &low_to_save, &high_to_save);
2556 #endif
2558 /* Now store (and compute if necessary) all non-register parms.
2559 These come before register parms, since they can require block-moves,
2560 which could clobber the registers used for register parms.
2561 Parms which have partial registers are not stored here,
2562 but we do preallocate space here if they want that. */
2564 for (i = 0; i < num_actuals; i++)
2565 if (args[i].reg == 0 || args[i].pass_on_stack)
2567 rtx before_arg = get_last_insn ();
2569 if (store_one_arg (&args[i], argblock, flags,
2570 adjusted_args_size.var != 0,
2571 reg_parm_stack_space)
2572 || (pass == 0
2573 && check_sibcall_argument_overlap (before_arg,
2574 &args[i], 1)))
2575 sibcall_failure = 1;
2577 if (flags & ECF_CONST
2578 && args[i].stack
2579 && args[i].value == args[i].stack)
2580 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2581 gen_rtx_USE (VOIDmode,
2582 args[i].value),
2583 call_fusage);
2586 /* If we have a parm that is passed in registers but not in memory
2587 and whose alignment does not permit a direct copy into registers,
2588 make a group of pseudos that correspond to each register that we
2589 will later fill. */
2590 if (STRICT_ALIGNMENT)
2591 store_unaligned_arguments_into_pseudos (args, num_actuals);
2593 /* Now store any partially-in-registers parm.
2594 This is the last place a block-move can happen. */
2595 if (reg_parm_seen)
2596 for (i = 0; i < num_actuals; i++)
2597 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2599 rtx before_arg = get_last_insn ();
2601 if (store_one_arg (&args[i], argblock, flags,
2602 adjusted_args_size.var != 0,
2603 reg_parm_stack_space)
2604 || (pass == 0
2605 && check_sibcall_argument_overlap (before_arg,
2606 &args[i], 1)))
2607 sibcall_failure = 1;
2610 /* If we pushed args in forward order, perform stack alignment
2611 after pushing the last arg. */
2612 if (!PUSH_ARGS_REVERSED && argblock == 0)
2613 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2614 - unadjusted_args_size));
2616 /* If register arguments require space on the stack and stack space
2617 was not preallocated, allocate stack space here for arguments
2618 passed in registers. */
2619 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2620 if (!ACCUMULATE_OUTGOING_ARGS
2621 && must_preallocate == 0 && reg_parm_stack_space > 0)
2622 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2623 #endif
2625 /* Pass the function the address in which to return a
2626 structure value. */
2627 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2629 structure_value_addr
2630 = convert_memory_address (Pmode, structure_value_addr);
2631 emit_move_insn (struct_value,
2632 force_reg (Pmode,
2633 force_operand (structure_value_addr,
2634 NULL_RTX)));
2636 if (REG_P (struct_value))
2637 use_reg (&call_fusage, struct_value);
2640 funexp = prepare_call_address (funexp, static_chain_value,
2641 &call_fusage, reg_parm_seen, pass == 0);
2643 load_register_parameters (args, num_actuals, &call_fusage, flags,
2644 pass == 0, &sibcall_failure);
2646 /* Save a pointer to the last insn before the call, so that we can
2647 later safely search backwards to find the CALL_INSN. */
2648 before_call = get_last_insn ();
2650 /* Set up next argument register. For sibling calls on machines
2651 with register windows this should be the incoming register. */
2652 #ifdef FUNCTION_INCOMING_ARG
2653 if (pass == 0)
2654 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2655 void_type_node, 1);
2656 else
2657 #endif
2658 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2659 void_type_node, 1);
2661 /* All arguments and registers used for the call must be set up by
2662 now! */
2664 /* Stack must be properly aligned now. */
2665 gcc_assert (!pass
2666 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2668 /* Generate the actual call instruction. */
2669 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2670 adjusted_args_size.constant, struct_value_size,
2671 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2672 flags, & args_so_far);
2674 /* If a non-BLKmode value is returned at the most significant end
2675 of a register, shift the register right by the appropriate amount
2676 and update VALREG accordingly. BLKmode values are handled by the
2677 group load/store machinery below. */
2678 if (!structure_value_addr
2679 && !pcc_struct_value
2680 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2681 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2683 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2684 sibcall_failure = 1;
2685 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2688 /* If call is cse'able, make appropriate pair of reg-notes around it.
2689 Test valreg so we don't crash; may safely ignore `const'
2690 if return type is void. Disable for PARALLEL return values, because
2691 we have no way to move such values into a pseudo register. */
2692 if (pass && (flags & ECF_LIBCALL_BLOCK))
2694 rtx insns;
2695 rtx insn;
2696 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2698 insns = get_insns ();
2700 /* Expansion of block moves possibly introduced a loop that may
2701 not appear inside libcall block. */
2702 for (insn = insns; insn; insn = NEXT_INSN (insn))
2703 if (JUMP_P (insn))
2704 failed = true;
2706 if (failed)
2708 end_sequence ();
2709 emit_insn (insns);
2711 else
2713 rtx note = 0;
2714 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2716 /* Mark the return value as a pointer if needed. */
2717 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2718 mark_reg_pointer (temp,
2719 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2721 end_sequence ();
2722 if (flag_unsafe_math_optimizations
2723 && fndecl
2724 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2725 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2726 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2727 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2728 note = gen_rtx_fmt_e (SQRT,
2729 GET_MODE (temp),
2730 args[0].initial_value);
2731 else
2733 /* Construct an "equal form" for the value which
2734 mentions all the arguments in order as well as
2735 the function name. */
2736 for (i = 0; i < num_actuals; i++)
2737 note = gen_rtx_EXPR_LIST (VOIDmode,
2738 args[i].initial_value, note);
2739 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2741 if (flags & ECF_PURE)
2742 note = gen_rtx_EXPR_LIST (VOIDmode,
2743 gen_rtx_USE (VOIDmode,
2744 gen_rtx_MEM (BLKmode,
2745 gen_rtx_SCRATCH (VOIDmode))),
2746 note);
2748 emit_libcall_block (insns, temp, valreg, note);
2750 valreg = temp;
2753 else if (pass && (flags & ECF_MALLOC))
2755 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2756 rtx last, insns;
2758 /* The return value from a malloc-like function is a pointer. */
2759 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2760 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2762 emit_move_insn (temp, valreg);
2764 /* The return value from a malloc-like function can not alias
2765 anything else. */
2766 last = get_last_insn ();
2767 REG_NOTES (last) =
2768 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2770 /* Write out the sequence. */
2771 insns = get_insns ();
2772 end_sequence ();
2773 emit_insn (insns);
2774 valreg = temp;
2777 /* For calls to `setjmp', etc., inform flow.c it should complain
2778 if nonvolatile values are live. For functions that cannot return,
2779 inform flow that control does not fall through. */
2781 if ((flags & ECF_NORETURN) || pass == 0)
2783 /* The barrier must be emitted
2784 immediately after the CALL_INSN. Some ports emit more
2785 than just a CALL_INSN above, so we must search for it here. */
2787 rtx last = get_last_insn ();
2788 while (!CALL_P (last))
2790 last = PREV_INSN (last);
2791 /* There was no CALL_INSN? */
2792 gcc_assert (last != before_call);
2795 emit_barrier_after (last);
2797 /* Stack adjustments after a noreturn call are dead code.
2798 However when NO_DEFER_POP is in effect, we must preserve
2799 stack_pointer_delta. */
2800 if (inhibit_defer_pop == 0)
2802 stack_pointer_delta = old_stack_allocated;
2803 pending_stack_adjust = 0;
2807 /* If value type not void, return an rtx for the value. */
2809 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2810 || ignore)
2811 target = const0_rtx;
2812 else if (structure_value_addr)
2814 if (target == 0 || !MEM_P (target))
2816 target
2817 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2818 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2819 structure_value_addr));
2820 set_mem_attributes (target, exp, 1);
2823 else if (pcc_struct_value)
2825 /* This is the special C++ case where we need to
2826 know what the true target was. We take care to
2827 never use this value more than once in one expression. */
2828 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2829 copy_to_reg (valreg));
2830 set_mem_attributes (target, exp, 1);
2832 /* Handle calls that return values in multiple non-contiguous locations.
2833 The Irix 6 ABI has examples of this. */
2834 else if (GET_CODE (valreg) == PARALLEL)
2836 if (target == 0)
2838 /* This will only be assigned once, so it can be readonly. */
2839 tree nt = build_qualified_type (TREE_TYPE (exp),
2840 (TYPE_QUALS (TREE_TYPE (exp))
2841 | TYPE_QUAL_CONST));
2843 target = assign_temp (nt, 0, 1, 1);
2846 if (! rtx_equal_p (target, valreg))
2847 emit_group_store (target, valreg, TREE_TYPE (exp),
2848 int_size_in_bytes (TREE_TYPE (exp)));
2850 /* We can not support sibling calls for this case. */
2851 sibcall_failure = 1;
2853 else if (target
2854 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2855 && GET_MODE (target) == GET_MODE (valreg))
2857 bool may_overlap = false;
2859 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2860 reg to a plain register. */
2861 if (REG_P (valreg)
2862 && HARD_REGISTER_P (valreg)
2863 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (valreg)))
2864 && !(REG_P (target) && !HARD_REGISTER_P (target)))
2865 valreg = copy_to_reg (valreg);
2867 /* If TARGET is a MEM in the argument area, and we have
2868 saved part of the argument area, then we can't store
2869 directly into TARGET as it may get overwritten when we
2870 restore the argument save area below. Don't work too
2871 hard though and simply force TARGET to a register if it
2872 is a MEM; the optimizer is quite likely to sort it out. */
2873 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2874 for (i = 0; i < num_actuals; i++)
2875 if (args[i].save_area)
2877 may_overlap = true;
2878 break;
2881 if (may_overlap)
2882 target = copy_to_reg (valreg);
2883 else
2885 /* TARGET and VALREG cannot be equal at this point
2886 because the latter would not have
2887 REG_FUNCTION_VALUE_P true, while the former would if
2888 it were referring to the same register.
2890 If they refer to the same register, this move will be
2891 a no-op, except when function inlining is being
2892 done. */
2893 emit_move_insn (target, valreg);
2895 /* If we are setting a MEM, this code must be executed.
2896 Since it is emitted after the call insn, sibcall
2897 optimization cannot be performed in that case. */
2898 if (MEM_P (target))
2899 sibcall_failure = 1;
2902 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2904 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2906 /* We can not support sibling calls for this case. */
2907 sibcall_failure = 1;
2909 else
2910 target = copy_to_reg (valreg);
2912 if (targetm.calls.promote_function_return(funtype))
2914 /* If we promoted this return value, make the proper SUBREG.
2915 TARGET might be const0_rtx here, so be careful. */
2916 if (REG_P (target)
2917 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2918 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2920 tree type = TREE_TYPE (exp);
2921 int unsignedp = TYPE_UNSIGNED (type);
2922 int offset = 0;
2923 enum machine_mode pmode;
2925 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2926 /* If we don't promote as expected, something is wrong. */
2927 gcc_assert (GET_MODE (target) == pmode);
2929 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2930 && (GET_MODE_SIZE (GET_MODE (target))
2931 > GET_MODE_SIZE (TYPE_MODE (type))))
2933 offset = GET_MODE_SIZE (GET_MODE (target))
2934 - GET_MODE_SIZE (TYPE_MODE (type));
2935 if (! BYTES_BIG_ENDIAN)
2936 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
2937 else if (! WORDS_BIG_ENDIAN)
2938 offset %= UNITS_PER_WORD;
2940 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
2941 SUBREG_PROMOTED_VAR_P (target) = 1;
2942 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
2946 /* If size of args is variable or this was a constructor call for a stack
2947 argument, restore saved stack-pointer value. */
2949 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
2951 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2952 stack_pointer_delta = old_stack_pointer_delta;
2953 pending_stack_adjust = old_pending_adj;
2954 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2955 stack_arg_under_construction = old_stack_arg_under_construction;
2956 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2957 stack_usage_map = initial_stack_usage_map;
2958 sibcall_failure = 1;
2960 else if (ACCUMULATE_OUTGOING_ARGS && pass)
2962 #ifdef REG_PARM_STACK_SPACE
2963 if (save_area)
2964 restore_fixed_argument_area (save_area, argblock,
2965 high_to_save, low_to_save);
2966 #endif
2968 /* If we saved any argument areas, restore them. */
2969 for (i = 0; i < num_actuals; i++)
2970 if (args[i].save_area)
2972 enum machine_mode save_mode = GET_MODE (args[i].save_area);
2973 rtx stack_area
2974 = gen_rtx_MEM (save_mode,
2975 memory_address (save_mode,
2976 XEXP (args[i].stack_slot, 0)));
2978 if (save_mode != BLKmode)
2979 emit_move_insn (stack_area, args[i].save_area);
2980 else
2981 emit_block_move (stack_area, args[i].save_area,
2982 GEN_INT (args[i].locate.size.constant),
2983 BLOCK_OP_CALL_PARM);
2986 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2987 stack_usage_map = initial_stack_usage_map;
2990 /* If this was alloca, record the new stack level for nonlocal gotos.
2991 Check for the handler slots since we might not have a save area
2992 for non-local gotos. */
2994 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
2995 update_nonlocal_goto_save_area ();
2997 /* Free up storage we no longer need. */
2998 for (i = 0; i < num_actuals; ++i)
2999 if (args[i].aligned_regs)
3000 free (args[i].aligned_regs);
3002 insns = get_insns ();
3003 end_sequence ();
3005 if (pass == 0)
3007 tail_call_insns = insns;
3009 /* Restore the pending stack adjustment now that we have
3010 finished generating the sibling call sequence. */
3012 pending_stack_adjust = save_pending_stack_adjust;
3013 stack_pointer_delta = save_stack_pointer_delta;
3015 /* Prepare arg structure for next iteration. */
3016 for (i = 0; i < num_actuals; i++)
3018 args[i].value = 0;
3019 args[i].aligned_regs = 0;
3020 args[i].stack = 0;
3023 sbitmap_free (stored_args_map);
3025 else
3027 normal_call_insns = insns;
3029 /* Verify that we've deallocated all the stack we used. */
3030 gcc_assert ((flags & ECF_NORETURN)
3031 || (old_stack_allocated
3032 == stack_pointer_delta - pending_stack_adjust));
3035 /* If something prevents making this a sibling call,
3036 zero out the sequence. */
3037 if (sibcall_failure)
3038 tail_call_insns = NULL_RTX;
3039 else
3040 break;
3043 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3044 arguments too, as argument area is now clobbered by the call. */
3045 if (tail_call_insns)
3047 emit_insn (tail_call_insns);
3048 cfun->tail_call_emit = true;
3050 else
3051 emit_insn (normal_call_insns);
3053 currently_expanding_call--;
3055 /* If this function returns with the stack pointer depressed, ensure
3056 this block saves and restores the stack pointer, show it was
3057 changed, and adjust for any outgoing arg space. */
3058 if (flags & ECF_SP_DEPRESSED)
3060 clear_pending_stack_adjust ();
3061 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3062 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3065 if (stack_usage_map_buf)
3066 free (stack_usage_map_buf);
3068 return target;
3071 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3072 this function's incoming arguments.
3074 At the start of RTL generation we know the only REG_EQUIV notes
3075 in the rtl chain are those for incoming arguments, so we can look
3076 for REG_EQUIV notes between the start of the function and the
3077 NOTE_INSN_FUNCTION_BEG.
3079 This is (slight) overkill. We could keep track of the highest
3080 argument we clobber and be more selective in removing notes, but it
3081 does not seem to be worth the effort. */
3083 void
3084 fixup_tail_calls (void)
3086 rtx insn;
3088 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3090 /* There are never REG_EQUIV notes for the incoming arguments
3091 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3092 if (NOTE_P (insn)
3093 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
3094 break;
3096 while (1)
3098 rtx note = find_reg_note (insn, REG_EQUIV, 0);
3099 if (note)
3101 /* Remove the note and keep looking at the notes for
3102 this insn. */
3103 remove_note (insn, note);
3104 continue;
3106 break;
3111 /* Traverse an argument list in VALUES and expand all complex
3112 arguments into their components. */
3113 static tree
3114 split_complex_values (tree values)
3116 tree p;
3118 /* Before allocating memory, check for the common case of no complex. */
3119 for (p = values; p; p = TREE_CHAIN (p))
3121 tree type = TREE_TYPE (TREE_VALUE (p));
3122 if (type && TREE_CODE (type) == COMPLEX_TYPE
3123 && targetm.calls.split_complex_arg (type))
3124 goto found;
3126 return values;
3128 found:
3129 values = copy_list (values);
3131 for (p = values; p; p = TREE_CHAIN (p))
3133 tree complex_value = TREE_VALUE (p);
3134 tree complex_type;
3136 complex_type = TREE_TYPE (complex_value);
3137 if (!complex_type)
3138 continue;
3140 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3141 && targetm.calls.split_complex_arg (complex_type))
3143 tree subtype;
3144 tree real, imag, next;
3146 subtype = TREE_TYPE (complex_type);
3147 complex_value = save_expr (complex_value);
3148 real = build1 (REALPART_EXPR, subtype, complex_value);
3149 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3151 TREE_VALUE (p) = real;
3152 next = TREE_CHAIN (p);
3153 imag = build_tree_list (NULL_TREE, imag);
3154 TREE_CHAIN (p) = imag;
3155 TREE_CHAIN (imag) = next;
3157 /* Skip the newly created node. */
3158 p = TREE_CHAIN (p);
3162 return values;
3165 /* Traverse a list of TYPES and expand all complex types into their
3166 components. */
3167 static tree
3168 split_complex_types (tree types)
3170 tree p;
3172 /* Before allocating memory, check for the common case of no complex. */
3173 for (p = types; p; p = TREE_CHAIN (p))
3175 tree type = TREE_VALUE (p);
3176 if (TREE_CODE (type) == COMPLEX_TYPE
3177 && targetm.calls.split_complex_arg (type))
3178 goto found;
3180 return types;
3182 found:
3183 types = copy_list (types);
3185 for (p = types; p; p = TREE_CHAIN (p))
3187 tree complex_type = TREE_VALUE (p);
3189 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3190 && targetm.calls.split_complex_arg (complex_type))
3192 tree next, imag;
3194 /* Rewrite complex type with component type. */
3195 TREE_VALUE (p) = TREE_TYPE (complex_type);
3196 next = TREE_CHAIN (p);
3198 /* Add another component type for the imaginary part. */
3199 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3200 TREE_CHAIN (p) = imag;
3201 TREE_CHAIN (imag) = next;
3203 /* Skip the newly created node. */
3204 p = TREE_CHAIN (p);
3208 return types;
3211 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3212 The RETVAL parameter specifies whether return value needs to be saved, other
3213 parameters are documented in the emit_library_call function below. */
3215 static rtx
3216 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3217 enum libcall_type fn_type,
3218 enum machine_mode outmode, int nargs, va_list p)
3220 /* Total size in bytes of all the stack-parms scanned so far. */
3221 struct args_size args_size;
3222 /* Size of arguments before any adjustments (such as rounding). */
3223 struct args_size original_args_size;
3224 int argnum;
3225 rtx fun;
3226 int inc;
3227 int count;
3228 rtx argblock = 0;
3229 CUMULATIVE_ARGS args_so_far;
3230 struct arg
3232 rtx value;
3233 enum machine_mode mode;
3234 rtx reg;
3235 int partial;
3236 struct locate_and_pad_arg_data locate;
3237 rtx save_area;
3239 struct arg *argvec;
3240 int old_inhibit_defer_pop = inhibit_defer_pop;
3241 rtx call_fusage = 0;
3242 rtx mem_value = 0;
3243 rtx valreg;
3244 int pcc_struct_value = 0;
3245 int struct_value_size = 0;
3246 int flags;
3247 int reg_parm_stack_space = 0;
3248 int needed;
3249 rtx before_call;
3250 tree tfom; /* type_for_mode (outmode, 0) */
3252 #ifdef REG_PARM_STACK_SPACE
3253 /* Define the boundary of the register parm stack space that needs to be
3254 save, if any. */
3255 int low_to_save, high_to_save;
3256 rtx save_area = 0; /* Place that it is saved. */
3257 #endif
3259 /* Size of the stack reserved for parameter registers. */
3260 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3261 char *initial_stack_usage_map = stack_usage_map;
3262 char *stack_usage_map_buf = NULL;
3264 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3266 #ifdef REG_PARM_STACK_SPACE
3267 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3268 #endif
3270 /* By default, library functions can not throw. */
3271 flags = ECF_NOTHROW;
3273 switch (fn_type)
3275 case LCT_NORMAL:
3276 break;
3277 case LCT_CONST:
3278 flags |= ECF_CONST;
3279 break;
3280 case LCT_PURE:
3281 flags |= ECF_PURE;
3282 break;
3283 case LCT_CONST_MAKE_BLOCK:
3284 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3285 break;
3286 case LCT_PURE_MAKE_BLOCK:
3287 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3288 break;
3289 case LCT_NORETURN:
3290 flags |= ECF_NORETURN;
3291 break;
3292 case LCT_THROW:
3293 flags = ECF_NORETURN;
3294 break;
3295 case LCT_RETURNS_TWICE:
3296 flags = ECF_RETURNS_TWICE;
3297 break;
3299 fun = orgfun;
3301 /* Ensure current function's preferred stack boundary is at least
3302 what we need. */
3303 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3304 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3306 /* If this kind of value comes back in memory,
3307 decide where in memory it should come back. */
3308 if (outmode != VOIDmode)
3310 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3311 if (aggregate_value_p (tfom, 0))
3313 #ifdef PCC_STATIC_STRUCT_RETURN
3314 rtx pointer_reg
3315 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3316 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3317 pcc_struct_value = 1;
3318 if (value == 0)
3319 value = gen_reg_rtx (outmode);
3320 #else /* not PCC_STATIC_STRUCT_RETURN */
3321 struct_value_size = GET_MODE_SIZE (outmode);
3322 if (value != 0 && MEM_P (value))
3323 mem_value = value;
3324 else
3325 mem_value = assign_temp (tfom, 0, 1, 1);
3326 #endif
3327 /* This call returns a big structure. */
3328 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3331 else
3332 tfom = void_type_node;
3334 /* ??? Unfinished: must pass the memory address as an argument. */
3336 /* Copy all the libcall-arguments out of the varargs data
3337 and into a vector ARGVEC.
3339 Compute how to pass each argument. We only support a very small subset
3340 of the full argument passing conventions to limit complexity here since
3341 library functions shouldn't have many args. */
3343 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3344 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3346 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3347 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3348 #else
3349 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3350 #endif
3352 args_size.constant = 0;
3353 args_size.var = 0;
3355 count = 0;
3357 /* Now we are about to start emitting insns that can be deleted
3358 if a libcall is deleted. */
3359 if (flags & ECF_LIBCALL_BLOCK)
3360 start_sequence ();
3362 push_temp_slots ();
3364 /* If there's a structure value address to be passed,
3365 either pass it in the special place, or pass it as an extra argument. */
3366 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3368 rtx addr = XEXP (mem_value, 0);
3370 nargs++;
3372 /* Make sure it is a reasonable operand for a move or push insn. */
3373 if (!REG_P (addr) && !MEM_P (addr)
3374 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3375 addr = force_operand (addr, NULL_RTX);
3377 argvec[count].value = addr;
3378 argvec[count].mode = Pmode;
3379 argvec[count].partial = 0;
3381 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3382 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3383 NULL_TREE, 1) == 0);
3385 locate_and_pad_parm (Pmode, NULL_TREE,
3386 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3388 #else
3389 argvec[count].reg != 0,
3390 #endif
3391 0, NULL_TREE, &args_size, &argvec[count].locate);
3393 if (argvec[count].reg == 0 || argvec[count].partial != 0
3394 || reg_parm_stack_space > 0)
3395 args_size.constant += argvec[count].locate.size.constant;
3397 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3399 count++;
3402 for (; count < nargs; count++)
3404 rtx val = va_arg (p, rtx);
3405 enum machine_mode mode = va_arg (p, enum machine_mode);
3407 /* We cannot convert the arg value to the mode the library wants here;
3408 must do it earlier where we know the signedness of the arg. */
3409 gcc_assert (mode != BLKmode
3410 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3412 /* Make sure it is a reasonable operand for a move or push insn. */
3413 if (!REG_P (val) && !MEM_P (val)
3414 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3415 val = force_operand (val, NULL_RTX);
3417 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3419 rtx slot;
3420 int must_copy
3421 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3423 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3424 functions, so we have to pretend this isn't such a function. */
3425 if (flags & ECF_LIBCALL_BLOCK)
3427 rtx insns = get_insns ();
3428 end_sequence ();
3429 emit_insn (insns);
3431 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3433 /* If this was a CONST function, it is now PURE since
3434 it now reads memory. */
3435 if (flags & ECF_CONST)
3437 flags &= ~ECF_CONST;
3438 flags |= ECF_PURE;
3441 if (GET_MODE (val) == MEM && !must_copy)
3442 slot = val;
3443 else
3445 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3446 0, 1, 1);
3447 emit_move_insn (slot, val);
3450 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3451 gen_rtx_USE (VOIDmode, slot),
3452 call_fusage);
3453 if (must_copy)
3454 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3455 gen_rtx_CLOBBER (VOIDmode,
3456 slot),
3457 call_fusage);
3459 mode = Pmode;
3460 val = force_operand (XEXP (slot, 0), NULL_RTX);
3463 argvec[count].value = val;
3464 argvec[count].mode = mode;
3466 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3468 argvec[count].partial
3469 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3471 locate_and_pad_parm (mode, NULL_TREE,
3472 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3474 #else
3475 argvec[count].reg != 0,
3476 #endif
3477 argvec[count].partial,
3478 NULL_TREE, &args_size, &argvec[count].locate);
3480 gcc_assert (!argvec[count].locate.size.var);
3482 if (argvec[count].reg == 0 || argvec[count].partial != 0
3483 || reg_parm_stack_space > 0)
3484 args_size.constant += argvec[count].locate.size.constant;
3486 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3489 /* If this machine requires an external definition for library
3490 functions, write one out. */
3491 assemble_external_libcall (fun);
3493 original_args_size = args_size;
3494 args_size.constant = (((args_size.constant
3495 + stack_pointer_delta
3496 + STACK_BYTES - 1)
3497 / STACK_BYTES
3498 * STACK_BYTES)
3499 - stack_pointer_delta);
3501 args_size.constant = MAX (args_size.constant,
3502 reg_parm_stack_space);
3504 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3505 args_size.constant -= reg_parm_stack_space;
3506 #endif
3508 if (args_size.constant > current_function_outgoing_args_size)
3509 current_function_outgoing_args_size = args_size.constant;
3511 if (ACCUMULATE_OUTGOING_ARGS)
3513 /* Since the stack pointer will never be pushed, it is possible for
3514 the evaluation of a parm to clobber something we have already
3515 written to the stack. Since most function calls on RISC machines
3516 do not use the stack, this is uncommon, but must work correctly.
3518 Therefore, we save any area of the stack that was already written
3519 and that we are using. Here we set up to do this by making a new
3520 stack usage map from the old one.
3522 Another approach might be to try to reorder the argument
3523 evaluations to avoid this conflicting stack usage. */
3525 needed = args_size.constant;
3527 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3528 /* Since we will be writing into the entire argument area, the
3529 map must be allocated for its entire size, not just the part that
3530 is the responsibility of the caller. */
3531 needed += reg_parm_stack_space;
3532 #endif
3534 #ifdef ARGS_GROW_DOWNWARD
3535 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3536 needed + 1);
3537 #else
3538 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3539 needed);
3540 #endif
3541 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3542 stack_usage_map = stack_usage_map_buf;
3544 if (initial_highest_arg_in_use)
3545 memcpy (stack_usage_map, initial_stack_usage_map,
3546 initial_highest_arg_in_use);
3548 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3549 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3550 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3551 needed = 0;
3553 /* We must be careful to use virtual regs before they're instantiated,
3554 and real regs afterwards. Loop optimization, for example, can create
3555 new libcalls after we've instantiated the virtual regs, and if we
3556 use virtuals anyway, they won't match the rtl patterns. */
3558 if (virtuals_instantiated)
3559 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3560 else
3561 argblock = virtual_outgoing_args_rtx;
3563 else
3565 if (!PUSH_ARGS)
3566 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3569 /* If we push args individually in reverse order, perform stack alignment
3570 before the first push (the last arg). */
3571 if (argblock == 0 && PUSH_ARGS_REVERSED)
3572 anti_adjust_stack (GEN_INT (args_size.constant
3573 - original_args_size.constant));
3575 if (PUSH_ARGS_REVERSED)
3577 inc = -1;
3578 argnum = nargs - 1;
3580 else
3582 inc = 1;
3583 argnum = 0;
3586 #ifdef REG_PARM_STACK_SPACE
3587 if (ACCUMULATE_OUTGOING_ARGS)
3589 /* The argument list is the property of the called routine and it
3590 may clobber it. If the fixed area has been used for previous
3591 parameters, we must save and restore it. */
3592 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3593 &low_to_save, &high_to_save);
3595 #endif
3597 /* Push the args that need to be pushed. */
3599 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3600 are to be pushed. */
3601 for (count = 0; count < nargs; count++, argnum += inc)
3603 enum machine_mode mode = argvec[argnum].mode;
3604 rtx val = argvec[argnum].value;
3605 rtx reg = argvec[argnum].reg;
3606 int partial = argvec[argnum].partial;
3607 int lower_bound = 0, upper_bound = 0, i;
3609 if (! (reg != 0 && partial == 0))
3611 if (ACCUMULATE_OUTGOING_ARGS)
3613 /* If this is being stored into a pre-allocated, fixed-size,
3614 stack area, save any previous data at that location. */
3616 #ifdef ARGS_GROW_DOWNWARD
3617 /* stack_slot is negative, but we want to index stack_usage_map
3618 with positive values. */
3619 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3620 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3621 #else
3622 lower_bound = argvec[argnum].locate.offset.constant;
3623 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3624 #endif
3626 i = lower_bound;
3627 /* Don't worry about things in the fixed argument area;
3628 it has already been saved. */
3629 if (i < reg_parm_stack_space)
3630 i = reg_parm_stack_space;
3631 while (i < upper_bound && stack_usage_map[i] == 0)
3632 i++;
3634 if (i < upper_bound)
3636 /* We need to make a save area. */
3637 unsigned int size
3638 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3639 enum machine_mode save_mode
3640 = mode_for_size (size, MODE_INT, 1);
3641 rtx adr
3642 = plus_constant (argblock,
3643 argvec[argnum].locate.offset.constant);
3644 rtx stack_area
3645 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3647 if (save_mode == BLKmode)
3649 argvec[argnum].save_area
3650 = assign_stack_temp (BLKmode,
3651 argvec[argnum].locate.size.constant,
3654 emit_block_move (validize_mem (argvec[argnum].save_area),
3655 stack_area,
3656 GEN_INT (argvec[argnum].locate.size.constant),
3657 BLOCK_OP_CALL_PARM);
3659 else
3661 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3663 emit_move_insn (argvec[argnum].save_area, stack_area);
3668 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3669 partial, reg, 0, argblock,
3670 GEN_INT (argvec[argnum].locate.offset.constant),
3671 reg_parm_stack_space,
3672 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3674 /* Now mark the segment we just used. */
3675 if (ACCUMULATE_OUTGOING_ARGS)
3676 for (i = lower_bound; i < upper_bound; i++)
3677 stack_usage_map[i] = 1;
3679 NO_DEFER_POP;
3681 if (flags & ECF_CONST)
3683 rtx use;
3685 /* Indicate argument access so that alias.c knows that these
3686 values are live. */
3687 if (argblock)
3688 use = plus_constant (argblock,
3689 argvec[argnum].locate.offset.constant);
3690 else
3691 /* When arguments are pushed, trying to tell alias.c where
3692 exactly this argument is won't work, because the
3693 auto-increment causes confusion. So we merely indicate
3694 that we access something with a known mode somewhere on
3695 the stack. */
3696 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3697 gen_rtx_SCRATCH (Pmode));
3698 use = gen_rtx_MEM (argvec[argnum].mode, use);
3699 use = gen_rtx_USE (VOIDmode, use);
3700 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3705 /* If we pushed args in forward order, perform stack alignment
3706 after pushing the last arg. */
3707 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3708 anti_adjust_stack (GEN_INT (args_size.constant
3709 - original_args_size.constant));
3711 if (PUSH_ARGS_REVERSED)
3712 argnum = nargs - 1;
3713 else
3714 argnum = 0;
3716 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3718 /* Now load any reg parms into their regs. */
3720 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3721 are to be pushed. */
3722 for (count = 0; count < nargs; count++, argnum += inc)
3724 enum machine_mode mode = argvec[argnum].mode;
3725 rtx val = argvec[argnum].value;
3726 rtx reg = argvec[argnum].reg;
3727 int partial = argvec[argnum].partial;
3729 /* Handle calls that pass values in multiple non-contiguous
3730 locations. The PA64 has examples of this for library calls. */
3731 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3732 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3733 else if (reg != 0 && partial == 0)
3734 emit_move_insn (reg, val);
3736 NO_DEFER_POP;
3739 /* Any regs containing parms remain in use through the call. */
3740 for (count = 0; count < nargs; count++)
3742 rtx reg = argvec[count].reg;
3743 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3744 use_group_regs (&call_fusage, reg);
3745 else if (reg != 0)
3746 use_reg (&call_fusage, reg);
3749 /* Pass the function the address in which to return a structure value. */
3750 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3752 emit_move_insn (struct_value,
3753 force_reg (Pmode,
3754 force_operand (XEXP (mem_value, 0),
3755 NULL_RTX)));
3756 if (REG_P (struct_value))
3757 use_reg (&call_fusage, struct_value);
3760 /* Don't allow popping to be deferred, since then
3761 cse'ing of library calls could delete a call and leave the pop. */
3762 NO_DEFER_POP;
3763 valreg = (mem_value == 0 && outmode != VOIDmode
3764 ? hard_libcall_value (outmode) : NULL_RTX);
3766 /* Stack must be properly aligned now. */
3767 gcc_assert (!(stack_pointer_delta
3768 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3770 before_call = get_last_insn ();
3772 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3773 will set inhibit_defer_pop to that value. */
3774 /* The return type is needed to decide how many bytes the function pops.
3775 Signedness plays no role in that, so for simplicity, we pretend it's
3776 always signed. We also assume that the list of arguments passed has
3777 no impact, so we pretend it is unknown. */
3779 emit_call_1 (fun, NULL,
3780 get_identifier (XSTR (orgfun, 0)),
3781 build_function_type (tfom, NULL_TREE),
3782 original_args_size.constant, args_size.constant,
3783 struct_value_size,
3784 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3785 valreg,
3786 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3788 /* For calls to `setjmp', etc., inform flow.c it should complain
3789 if nonvolatile values are live. For functions that cannot return,
3790 inform flow that control does not fall through. */
3792 if (flags & ECF_NORETURN)
3794 /* The barrier note must be emitted
3795 immediately after the CALL_INSN. Some ports emit more than
3796 just a CALL_INSN above, so we must search for it here. */
3798 rtx last = get_last_insn ();
3799 while (!CALL_P (last))
3801 last = PREV_INSN (last);
3802 /* There was no CALL_INSN? */
3803 gcc_assert (last != before_call);
3806 emit_barrier_after (last);
3809 /* Now restore inhibit_defer_pop to its actual original value. */
3810 OK_DEFER_POP;
3812 /* If call is cse'able, make appropriate pair of reg-notes around it.
3813 Test valreg so we don't crash; may safely ignore `const'
3814 if return type is void. Disable for PARALLEL return values, because
3815 we have no way to move such values into a pseudo register. */
3816 if (flags & ECF_LIBCALL_BLOCK)
3818 rtx insns;
3820 if (valreg == 0)
3822 insns = get_insns ();
3823 end_sequence ();
3824 emit_insn (insns);
3826 else
3828 rtx note = 0;
3829 rtx temp;
3830 int i;
3832 if (GET_CODE (valreg) == PARALLEL)
3834 temp = gen_reg_rtx (outmode);
3835 emit_group_store (temp, valreg, NULL_TREE,
3836 GET_MODE_SIZE (outmode));
3837 valreg = temp;
3840 temp = gen_reg_rtx (GET_MODE (valreg));
3842 /* Construct an "equal form" for the value which mentions all the
3843 arguments in order as well as the function name. */
3844 for (i = 0; i < nargs; i++)
3845 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3846 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3848 insns = get_insns ();
3849 end_sequence ();
3851 if (flags & ECF_PURE)
3852 note = gen_rtx_EXPR_LIST (VOIDmode,
3853 gen_rtx_USE (VOIDmode,
3854 gen_rtx_MEM (BLKmode,
3855 gen_rtx_SCRATCH (VOIDmode))),
3856 note);
3858 emit_libcall_block (insns, temp, valreg, note);
3860 valreg = temp;
3863 pop_temp_slots ();
3865 /* Copy the value to the right place. */
3866 if (outmode != VOIDmode && retval)
3868 if (mem_value)
3870 if (value == 0)
3871 value = mem_value;
3872 if (value != mem_value)
3873 emit_move_insn (value, mem_value);
3875 else if (GET_CODE (valreg) == PARALLEL)
3877 if (value == 0)
3878 value = gen_reg_rtx (outmode);
3879 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3881 else if (value != 0)
3882 emit_move_insn (value, valreg);
3883 else
3884 value = valreg;
3887 if (ACCUMULATE_OUTGOING_ARGS)
3889 #ifdef REG_PARM_STACK_SPACE
3890 if (save_area)
3891 restore_fixed_argument_area (save_area, argblock,
3892 high_to_save, low_to_save);
3893 #endif
3895 /* If we saved any argument areas, restore them. */
3896 for (count = 0; count < nargs; count++)
3897 if (argvec[count].save_area)
3899 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3900 rtx adr = plus_constant (argblock,
3901 argvec[count].locate.offset.constant);
3902 rtx stack_area = gen_rtx_MEM (save_mode,
3903 memory_address (save_mode, adr));
3905 if (save_mode == BLKmode)
3906 emit_block_move (stack_area,
3907 validize_mem (argvec[count].save_area),
3908 GEN_INT (argvec[count].locate.size.constant),
3909 BLOCK_OP_CALL_PARM);
3910 else
3911 emit_move_insn (stack_area, argvec[count].save_area);
3914 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3915 stack_usage_map = initial_stack_usage_map;
3918 if (stack_usage_map_buf)
3919 free (stack_usage_map_buf);
3921 return value;
3925 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3926 (emitting the queue unless NO_QUEUE is nonzero),
3927 for a value of mode OUTMODE,
3928 with NARGS different arguments, passed as alternating rtx values
3929 and machine_modes to convert them to.
3931 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
3932 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
3933 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
3934 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
3935 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
3936 or other LCT_ value for other types of library calls. */
3938 void
3939 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3940 enum machine_mode outmode, int nargs, ...)
3942 va_list p;
3944 va_start (p, nargs);
3945 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3946 va_end (p);
3949 /* Like emit_library_call except that an extra argument, VALUE,
3950 comes second and says where to store the result.
3951 (If VALUE is zero, this function chooses a convenient way
3952 to return the value.
3954 This function returns an rtx for where the value is to be found.
3955 If VALUE is nonzero, VALUE is returned. */
3958 emit_library_call_value (rtx orgfun, rtx value,
3959 enum libcall_type fn_type,
3960 enum machine_mode outmode, int nargs, ...)
3962 rtx result;
3963 va_list p;
3965 va_start (p, nargs);
3966 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3967 nargs, p);
3968 va_end (p);
3970 return result;
3973 /* Store a single argument for a function call
3974 into the register or memory area where it must be passed.
3975 *ARG describes the argument value and where to pass it.
3977 ARGBLOCK is the address of the stack-block for all the arguments,
3978 or 0 on a machine where arguments are pushed individually.
3980 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3981 so must be careful about how the stack is used.
3983 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3984 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3985 that we need not worry about saving and restoring the stack.
3987 FNDECL is the declaration of the function we are calling.
3989 Return nonzero if this arg should cause sibcall failure,
3990 zero otherwise. */
3992 static int
3993 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3994 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3996 tree pval = arg->tree_value;
3997 rtx reg = 0;
3998 int partial = 0;
3999 int used = 0;
4000 int i, lower_bound = 0, upper_bound = 0;
4001 int sibcall_failure = 0;
4003 if (TREE_CODE (pval) == ERROR_MARK)
4004 return 1;
4006 /* Push a new temporary level for any temporaries we make for
4007 this argument. */
4008 push_temp_slots ();
4010 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4012 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4013 save any previous data at that location. */
4014 if (argblock && ! variable_size && arg->stack)
4016 #ifdef ARGS_GROW_DOWNWARD
4017 /* stack_slot is negative, but we want to index stack_usage_map
4018 with positive values. */
4019 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4020 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4021 else
4022 upper_bound = 0;
4024 lower_bound = upper_bound - arg->locate.size.constant;
4025 #else
4026 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4027 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4028 else
4029 lower_bound = 0;
4031 upper_bound = lower_bound + arg->locate.size.constant;
4032 #endif
4034 i = lower_bound;
4035 /* Don't worry about things in the fixed argument area;
4036 it has already been saved. */
4037 if (i < reg_parm_stack_space)
4038 i = reg_parm_stack_space;
4039 while (i < upper_bound && stack_usage_map[i] == 0)
4040 i++;
4042 if (i < upper_bound)
4044 /* We need to make a save area. */
4045 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4046 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4047 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4048 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4050 if (save_mode == BLKmode)
4052 tree ot = TREE_TYPE (arg->tree_value);
4053 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4054 | TYPE_QUAL_CONST));
4056 arg->save_area = assign_temp (nt, 0, 1, 1);
4057 preserve_temp_slots (arg->save_area);
4058 emit_block_move (validize_mem (arg->save_area), stack_area,
4059 expr_size (arg->tree_value),
4060 BLOCK_OP_CALL_PARM);
4062 else
4064 arg->save_area = gen_reg_rtx (save_mode);
4065 emit_move_insn (arg->save_area, stack_area);
4071 /* If this isn't going to be placed on both the stack and in registers,
4072 set up the register and number of words. */
4073 if (! arg->pass_on_stack)
4075 if (flags & ECF_SIBCALL)
4076 reg = arg->tail_call_reg;
4077 else
4078 reg = arg->reg;
4079 partial = arg->partial;
4082 /* Being passed entirely in a register. We shouldn't be called in
4083 this case. */
4084 gcc_assert (reg == 0 || partial != 0);
4086 /* If this arg needs special alignment, don't load the registers
4087 here. */
4088 if (arg->n_aligned_regs != 0)
4089 reg = 0;
4091 /* If this is being passed partially in a register, we can't evaluate
4092 it directly into its stack slot. Otherwise, we can. */
4093 if (arg->value == 0)
4095 /* stack_arg_under_construction is nonzero if a function argument is
4096 being evaluated directly into the outgoing argument list and
4097 expand_call must take special action to preserve the argument list
4098 if it is called recursively.
4100 For scalar function arguments stack_usage_map is sufficient to
4101 determine which stack slots must be saved and restored. Scalar
4102 arguments in general have pass_on_stack == 0.
4104 If this argument is initialized by a function which takes the
4105 address of the argument (a C++ constructor or a C function
4106 returning a BLKmode structure), then stack_usage_map is
4107 insufficient and expand_call must push the stack around the
4108 function call. Such arguments have pass_on_stack == 1.
4110 Note that it is always safe to set stack_arg_under_construction,
4111 but this generates suboptimal code if set when not needed. */
4113 if (arg->pass_on_stack)
4114 stack_arg_under_construction++;
4116 arg->value = expand_expr (pval,
4117 (partial
4118 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4119 ? NULL_RTX : arg->stack,
4120 VOIDmode, EXPAND_STACK_PARM);
4122 /* If we are promoting object (or for any other reason) the mode
4123 doesn't agree, convert the mode. */
4125 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4126 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4127 arg->value, arg->unsignedp);
4129 if (arg->pass_on_stack)
4130 stack_arg_under_construction--;
4133 /* Check for overlap with already clobbered argument area. */
4134 if ((flags & ECF_SIBCALL)
4135 && MEM_P (arg->value)
4136 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4137 arg->locate.size.constant))
4138 sibcall_failure = 1;
4140 /* Don't allow anything left on stack from computation
4141 of argument to alloca. */
4142 if (flags & ECF_MAY_BE_ALLOCA)
4143 do_pending_stack_adjust ();
4145 if (arg->value == arg->stack)
4146 /* If the value is already in the stack slot, we are done. */
4148 else if (arg->mode != BLKmode)
4150 int size;
4152 /* Argument is a scalar, not entirely passed in registers.
4153 (If part is passed in registers, arg->partial says how much
4154 and emit_push_insn will take care of putting it there.)
4156 Push it, and if its size is less than the
4157 amount of space allocated to it,
4158 also bump stack pointer by the additional space.
4159 Note that in C the default argument promotions
4160 will prevent such mismatches. */
4162 size = GET_MODE_SIZE (arg->mode);
4163 /* Compute how much space the push instruction will push.
4164 On many machines, pushing a byte will advance the stack
4165 pointer by a halfword. */
4166 #ifdef PUSH_ROUNDING
4167 size = PUSH_ROUNDING (size);
4168 #endif
4169 used = size;
4171 /* Compute how much space the argument should get:
4172 round up to a multiple of the alignment for arguments. */
4173 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4174 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4175 / (PARM_BOUNDARY / BITS_PER_UNIT))
4176 * (PARM_BOUNDARY / BITS_PER_UNIT));
4178 /* This isn't already where we want it on the stack, so put it there.
4179 This can either be done with push or copy insns. */
4180 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4181 PARM_BOUNDARY, partial, reg, used - size, argblock,
4182 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4183 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4185 /* Unless this is a partially-in-register argument, the argument is now
4186 in the stack. */
4187 if (partial == 0)
4188 arg->value = arg->stack;
4190 else
4192 /* BLKmode, at least partly to be pushed. */
4194 unsigned int parm_align;
4195 int excess;
4196 rtx size_rtx;
4198 /* Pushing a nonscalar.
4199 If part is passed in registers, PARTIAL says how much
4200 and emit_push_insn will take care of putting it there. */
4202 /* Round its size up to a multiple
4203 of the allocation unit for arguments. */
4205 if (arg->locate.size.var != 0)
4207 excess = 0;
4208 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4210 else
4212 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4213 for BLKmode is careful to avoid it. */
4214 excess = (arg->locate.size.constant
4215 - int_size_in_bytes (TREE_TYPE (pval))
4216 + partial);
4217 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4218 NULL_RTX, TYPE_MODE (sizetype), 0);
4221 parm_align = arg->locate.boundary;
4223 /* When an argument is padded down, the block is aligned to
4224 PARM_BOUNDARY, but the actual argument isn't. */
4225 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4227 if (arg->locate.size.var)
4228 parm_align = BITS_PER_UNIT;
4229 else if (excess)
4231 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4232 parm_align = MIN (parm_align, excess_align);
4236 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4238 /* emit_push_insn might not work properly if arg->value and
4239 argblock + arg->locate.offset areas overlap. */
4240 rtx x = arg->value;
4241 int i = 0;
4243 if (XEXP (x, 0) == current_function_internal_arg_pointer
4244 || (GET_CODE (XEXP (x, 0)) == PLUS
4245 && XEXP (XEXP (x, 0), 0) ==
4246 current_function_internal_arg_pointer
4247 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4249 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4250 i = INTVAL (XEXP (XEXP (x, 0), 1));
4252 /* expand_call should ensure this. */
4253 gcc_assert (!arg->locate.offset.var
4254 && GET_CODE (size_rtx) == CONST_INT);
4256 if (arg->locate.offset.constant > i)
4258 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4259 sibcall_failure = 1;
4261 else if (arg->locate.offset.constant < i)
4263 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4264 sibcall_failure = 1;
4269 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4270 parm_align, partial, reg, excess, argblock,
4271 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4272 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4274 /* Unless this is a partially-in-register argument, the argument is now
4275 in the stack.
4277 ??? Unlike the case above, in which we want the actual
4278 address of the data, so that we can load it directly into a
4279 register, here we want the address of the stack slot, so that
4280 it's properly aligned for word-by-word copying or something
4281 like that. It's not clear that this is always correct. */
4282 if (partial == 0)
4283 arg->value = arg->stack_slot;
4286 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4288 tree type = TREE_TYPE (arg->tree_value);
4289 arg->parallel_value
4290 = emit_group_load_into_temps (arg->reg, arg->value, type,
4291 int_size_in_bytes (type));
4294 /* Mark all slots this store used. */
4295 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4296 && argblock && ! variable_size && arg->stack)
4297 for (i = lower_bound; i < upper_bound; i++)
4298 stack_usage_map[i] = 1;
4300 /* Once we have pushed something, pops can't safely
4301 be deferred during the rest of the arguments. */
4302 NO_DEFER_POP;
4304 /* Free any temporary slots made in processing this argument. Show
4305 that we might have taken the address of something and pushed that
4306 as an operand. */
4307 preserve_temp_slots (NULL_RTX);
4308 free_temp_slots ();
4309 pop_temp_slots ();
4311 return sibcall_failure;
4314 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4316 bool
4317 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4318 tree type)
4320 if (!type)
4321 return false;
4323 /* If the type has variable size... */
4324 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4325 return true;
4327 /* If the type is marked as addressable (it is required
4328 to be constructed into the stack)... */
4329 if (TREE_ADDRESSABLE (type))
4330 return true;
4332 return false;
4335 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4336 takes trailing padding of a structure into account. */
4337 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4339 bool
4340 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type)
4342 if (!type)
4343 return false;
4345 /* If the type has variable size... */
4346 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4347 return true;
4349 /* If the type is marked as addressable (it is required
4350 to be constructed into the stack)... */
4351 if (TREE_ADDRESSABLE (type))
4352 return true;
4354 /* If the padding and mode of the type is such that a copy into
4355 a register would put it into the wrong part of the register. */
4356 if (mode == BLKmode
4357 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4358 && (FUNCTION_ARG_PADDING (mode, type)
4359 == (BYTES_BIG_ENDIAN ? upward : downward)))
4360 return true;
4362 return false;