Daily bump.
[official-gcc.git] / gcc / calls.c
blob657439a60eb6c44e492e7aa51eefcd54397e6927
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, 2006, 2007
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 3, 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 COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "flags.h"
29 #include "expr.h"
30 #include "optabs.h"
31 #include "libfuncs.h"
32 #include "function.h"
33 #include "regs.h"
34 #include "toplev.h"
35 #include "output.h"
36 #include "tm_p.h"
37 #include "timevar.h"
38 #include "sbitmap.h"
39 #include "langhooks.h"
40 #include "target.h"
41 #include "cgraph.h"
42 #include "except.h"
43 #include "dbgcnt.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,
136 tree, tree,
137 tree, CUMULATIVE_ARGS *, int,
138 rtx *, int *, int *, int *,
139 bool *, bool);
140 static void compute_argument_addresses (struct arg_data *, rtx, int);
141 static rtx rtx_for_function_call (tree, tree);
142 static void load_register_parameters (struct arg_data *, int, rtx *, int,
143 int, int *);
144 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
145 enum machine_mode, int, va_list);
146 static int special_function_p (const_tree, int);
147 static int check_sibcall_argument_overlap_1 (rtx);
148 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
150 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
151 unsigned int);
152 static tree split_complex_types (tree);
154 #ifdef REG_PARM_STACK_SPACE
155 static rtx save_fixed_argument_area (int, rtx, int *, int *);
156 static void restore_fixed_argument_area (rtx, rtx, int, int);
157 #endif
159 /* Force FUNEXP into a form suitable for the address of a CALL,
160 and return that as an rtx. Also load the static chain register
161 if FNDECL is a nested function.
163 CALL_FUSAGE points to a variable holding the prospective
164 CALL_INSN_FUNCTION_USAGE information. */
167 prepare_call_address (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 (const_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 (const_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 (const_tree exp)
555 if (TREE_CODE (exp) == CALL_EXPR
556 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
557 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
558 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
559 & ECF_MAY_BE_ALLOCA))
560 return true;
561 return false;
564 /* Detect flags (function attributes) from the function decl or type node. */
567 flags_from_decl_or_type (const_tree exp)
569 int flags = 0;
570 const_tree type = exp;
572 if (DECL_P (exp))
574 type = TREE_TYPE (exp);
576 /* The function exp may have the `malloc' attribute. */
577 if (DECL_IS_MALLOC (exp))
578 flags |= ECF_MALLOC;
580 /* The function exp may have the `returns_twice' attribute. */
581 if (DECL_IS_RETURNS_TWICE (exp))
582 flags |= ECF_RETURNS_TWICE;
584 /* The function exp may have the `pure' attribute. */
585 if (DECL_IS_PURE (exp))
586 flags |= ECF_PURE;
588 if (DECL_IS_NOVOPS (exp))
589 flags |= ECF_NOVOPS;
591 if (TREE_NOTHROW (exp))
592 flags |= ECF_NOTHROW;
594 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
595 flags |= ECF_CONST;
597 flags = special_function_p (exp, flags);
599 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
600 flags |= ECF_CONST;
602 if (TREE_THIS_VOLATILE (exp))
603 flags |= ECF_NORETURN;
605 /* Mark if the function returns with the stack pointer depressed. We
606 cannot consider it pure or constant in that case. */
607 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
609 flags |= ECF_SP_DEPRESSED;
610 flags &= ~(ECF_PURE | ECF_CONST);
613 return flags;
616 /* Detect flags from a CALL_EXPR. */
619 call_expr_flags (const_tree t)
621 int flags;
622 tree decl = get_callee_fndecl (t);
624 if (decl)
625 flags = flags_from_decl_or_type (decl);
626 else
628 t = TREE_TYPE (CALL_EXPR_FN (t));
629 if (t && TREE_CODE (t) == POINTER_TYPE)
630 flags = flags_from_decl_or_type (TREE_TYPE (t));
631 else
632 flags = 0;
635 return flags;
638 /* Precompute all register parameters as described by ARGS, storing values
639 into fields within the ARGS array.
641 NUM_ACTUALS indicates the total number elements in the ARGS array.
643 Set REG_PARM_SEEN if we encounter a register parameter. */
645 static void
646 precompute_register_parameters (int num_actuals, struct arg_data *args,
647 int *reg_parm_seen)
649 int i;
651 *reg_parm_seen = 0;
653 for (i = 0; i < num_actuals; i++)
654 if (args[i].reg != 0 && ! args[i].pass_on_stack)
656 *reg_parm_seen = 1;
658 if (args[i].value == 0)
660 push_temp_slots ();
661 args[i].value = expand_normal (args[i].tree_value);
662 preserve_temp_slots (args[i].value);
663 pop_temp_slots ();
666 /* If the value is a non-legitimate constant, force it into a
667 pseudo now. TLS symbols sometimes need a call to resolve. */
668 if (CONSTANT_P (args[i].value)
669 && !LEGITIMATE_CONSTANT_P (args[i].value))
670 args[i].value = force_reg (args[i].mode, args[i].value);
672 /* If we are to promote the function arg to a wider mode,
673 do it now. */
675 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
676 args[i].value
677 = convert_modes (args[i].mode,
678 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
679 args[i].value, args[i].unsignedp);
681 /* If we're going to have to load the value by parts, pull the
682 parts into pseudos. The part extraction process can involve
683 non-trivial computation. */
684 if (GET_CODE (args[i].reg) == PARALLEL)
686 tree type = TREE_TYPE (args[i].tree_value);
687 args[i].parallel_value
688 = emit_group_load_into_temps (args[i].reg, args[i].value,
689 type, int_size_in_bytes (type));
692 /* If the value is expensive, and we are inside an appropriately
693 short loop, put the value into a pseudo and then put the pseudo
694 into the hard reg.
696 For small register classes, also do this if this call uses
697 register parameters. This is to avoid reload conflicts while
698 loading the parameters registers. */
700 else if ((! (REG_P (args[i].value)
701 || (GET_CODE (args[i].value) == SUBREG
702 && REG_P (SUBREG_REG (args[i].value)))))
703 && args[i].mode != BLKmode
704 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
705 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
706 || optimize))
707 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
711 #ifdef REG_PARM_STACK_SPACE
713 /* The argument list is the property of the called routine and it
714 may clobber it. If the fixed area has been used for previous
715 parameters, we must save and restore it. */
717 static rtx
718 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
720 int low;
721 int high;
723 /* Compute the boundary of the area that needs to be saved, if any. */
724 high = reg_parm_stack_space;
725 #ifdef ARGS_GROW_DOWNWARD
726 high += 1;
727 #endif
728 if (high > highest_outgoing_arg_in_use)
729 high = highest_outgoing_arg_in_use;
731 for (low = 0; low < high; low++)
732 if (stack_usage_map[low] != 0)
734 int num_to_save;
735 enum machine_mode save_mode;
736 int delta;
737 rtx stack_area;
738 rtx save_area;
740 while (stack_usage_map[--high] == 0)
743 *low_to_save = low;
744 *high_to_save = high;
746 num_to_save = high - low + 1;
747 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
749 /* If we don't have the required alignment, must do this
750 in BLKmode. */
751 if ((low & (MIN (GET_MODE_SIZE (save_mode),
752 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
753 save_mode = BLKmode;
755 #ifdef ARGS_GROW_DOWNWARD
756 delta = -high;
757 #else
758 delta = low;
759 #endif
760 stack_area = gen_rtx_MEM (save_mode,
761 memory_address (save_mode,
762 plus_constant (argblock,
763 delta)));
765 set_mem_align (stack_area, PARM_BOUNDARY);
766 if (save_mode == BLKmode)
768 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
769 emit_block_move (validize_mem (save_area), stack_area,
770 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
772 else
774 save_area = gen_reg_rtx (save_mode);
775 emit_move_insn (save_area, stack_area);
778 return save_area;
781 return NULL_RTX;
784 static void
785 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
787 enum machine_mode save_mode = GET_MODE (save_area);
788 int delta;
789 rtx stack_area;
791 #ifdef ARGS_GROW_DOWNWARD
792 delta = -high_to_save;
793 #else
794 delta = low_to_save;
795 #endif
796 stack_area = gen_rtx_MEM (save_mode,
797 memory_address (save_mode,
798 plus_constant (argblock, delta)));
799 set_mem_align (stack_area, PARM_BOUNDARY);
801 if (save_mode != BLKmode)
802 emit_move_insn (stack_area, save_area);
803 else
804 emit_block_move (stack_area, validize_mem (save_area),
805 GEN_INT (high_to_save - low_to_save + 1),
806 BLOCK_OP_CALL_PARM);
808 #endif /* REG_PARM_STACK_SPACE */
810 /* If any elements in ARGS refer to parameters that are to be passed in
811 registers, but not in memory, and whose alignment does not permit a
812 direct copy into registers. Copy the values into a group of pseudos
813 which we will later copy into the appropriate hard registers.
815 Pseudos for each unaligned argument will be stored into the array
816 args[argnum].aligned_regs. The caller is responsible for deallocating
817 the aligned_regs array if it is nonzero. */
819 static void
820 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
822 int i, j;
824 for (i = 0; i < num_actuals; i++)
825 if (args[i].reg != 0 && ! args[i].pass_on_stack
826 && args[i].mode == BLKmode
827 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
828 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
830 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
831 int endian_correction = 0;
833 if (args[i].partial)
835 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
836 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
838 else
840 args[i].n_aligned_regs
841 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
844 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
846 /* Structures smaller than a word are normally aligned to the
847 least significant byte. On a BYTES_BIG_ENDIAN machine,
848 this means we must skip the empty high order bytes when
849 calculating the bit offset. */
850 if (bytes < UNITS_PER_WORD
851 #ifdef BLOCK_REG_PADDING
852 && (BLOCK_REG_PADDING (args[i].mode,
853 TREE_TYPE (args[i].tree_value), 1)
854 == downward)
855 #else
856 && BYTES_BIG_ENDIAN
857 #endif
859 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
861 for (j = 0; j < args[i].n_aligned_regs; j++)
863 rtx reg = gen_reg_rtx (word_mode);
864 rtx word = operand_subword_force (args[i].value, j, BLKmode);
865 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
867 args[i].aligned_regs[j] = reg;
868 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
869 word_mode, word_mode);
871 /* There is no need to restrict this code to loading items
872 in TYPE_ALIGN sized hunks. The bitfield instructions can
873 load up entire word sized registers efficiently.
875 ??? This may not be needed anymore.
876 We use to emit a clobber here but that doesn't let later
877 passes optimize the instructions we emit. By storing 0 into
878 the register later passes know the first AND to zero out the
879 bitfield being set in the register is unnecessary. The store
880 of 0 will be deleted as will at least the first AND. */
882 emit_move_insn (reg, const0_rtx);
884 bytes -= bitsize / BITS_PER_UNIT;
885 store_bit_field (reg, bitsize, endian_correction, word_mode,
886 word);
891 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
892 CALL_EXPR EXP.
894 NUM_ACTUALS is the total number of parameters.
896 N_NAMED_ARGS is the total number of named arguments.
898 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
899 value, or null.
901 FNDECL is the tree code for the target of this call (if known)
903 ARGS_SO_FAR holds state needed by the target to know where to place
904 the next argument.
906 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
907 for arguments which are passed in registers.
909 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
910 and may be modified by this routine.
912 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
913 flags which may may be modified by this routine.
915 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
916 that requires allocation of stack space.
918 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
919 the thunked-to function. */
921 static void
922 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
923 struct arg_data *args,
924 struct args_size *args_size,
925 int n_named_args ATTRIBUTE_UNUSED,
926 tree exp, tree struct_value_addr_value,
927 tree fndecl,
928 CUMULATIVE_ARGS *args_so_far,
929 int reg_parm_stack_space,
930 rtx *old_stack_level, int *old_pending_adj,
931 int *must_preallocate, int *ecf_flags,
932 bool *may_tailcall, bool call_from_thunk_p)
934 /* 1 if scanning parms front to back, -1 if scanning back to front. */
935 int inc;
937 /* Count arg position in order args appear. */
938 int argpos;
940 int i;
942 args_size->constant = 0;
943 args_size->var = 0;
945 /* In this loop, we consider args in the order they are written.
946 We fill up ARGS from the front or from the back if necessary
947 so that in any case the first arg to be pushed ends up at the front. */
949 if (PUSH_ARGS_REVERSED)
951 i = num_actuals - 1, inc = -1;
952 /* In this case, must reverse order of args
953 so that we compute and push the last arg first. */
955 else
957 i = 0, inc = 1;
960 /* First fill in the actual arguments in the ARGS array, splitting
961 complex arguments if necessary. */
963 int j = i;
964 call_expr_arg_iterator iter;
965 tree arg;
967 if (struct_value_addr_value)
969 args[j].tree_value = struct_value_addr_value;
970 j += inc;
972 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
974 tree argtype = TREE_TYPE (arg);
975 if (targetm.calls.split_complex_arg
976 && argtype
977 && TREE_CODE (argtype) == COMPLEX_TYPE
978 && targetm.calls.split_complex_arg (argtype))
980 tree subtype = TREE_TYPE (argtype);
981 arg = save_expr (arg);
982 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
983 j += inc;
984 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
986 else
987 args[j].tree_value = arg;
988 j += inc;
992 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
993 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
995 tree type = TREE_TYPE (args[i].tree_value);
996 int unsignedp;
997 enum machine_mode mode;
999 /* Replace erroneous argument with constant zero. */
1000 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1001 args[i].tree_value = integer_zero_node, type = integer_type_node;
1003 /* If TYPE is a transparent union, pass things the way we would
1004 pass the first field of the union. We have already verified that
1005 the modes are the same. */
1006 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1007 type = TREE_TYPE (TYPE_FIELDS (type));
1009 /* Decide where to pass this arg.
1011 args[i].reg is nonzero if all or part is passed in registers.
1013 args[i].partial is nonzero if part but not all is passed in registers,
1014 and the exact value says how many bytes are passed in registers.
1016 args[i].pass_on_stack is nonzero if the argument must at least be
1017 computed on the stack. It may then be loaded back into registers
1018 if args[i].reg is nonzero.
1020 These decisions are driven by the FUNCTION_... macros and must agree
1021 with those made by function.c. */
1023 /* See if this argument should be passed by invisible reference. */
1024 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1025 type, argpos < n_named_args))
1027 bool callee_copies;
1028 tree base;
1030 callee_copies
1031 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1032 type, argpos < n_named_args);
1034 /* If we're compiling a thunk, pass through invisible references
1035 instead of making a copy. */
1036 if (call_from_thunk_p
1037 || (callee_copies
1038 && !TREE_ADDRESSABLE (type)
1039 && (base = get_base_address (args[i].tree_value))
1040 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1042 /* We can't use sibcalls if a callee-copied argument is
1043 stored in the current function's frame. */
1044 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1045 *may_tailcall = false;
1047 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1048 type = TREE_TYPE (args[i].tree_value);
1050 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1052 else
1054 /* We make a copy of the object and pass the address to the
1055 function being called. */
1056 rtx copy;
1058 if (!COMPLETE_TYPE_P (type)
1059 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1060 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1061 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1062 STACK_CHECK_MAX_VAR_SIZE))))
1064 /* This is a variable-sized object. Make space on the stack
1065 for it. */
1066 rtx size_rtx = expr_size (args[i].tree_value);
1068 if (*old_stack_level == 0)
1070 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1071 *old_pending_adj = pending_stack_adjust;
1072 pending_stack_adjust = 0;
1075 copy = gen_rtx_MEM (BLKmode,
1076 allocate_dynamic_stack_space
1077 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1078 set_mem_attributes (copy, type, 1);
1080 else
1081 copy = assign_temp (type, 0, 1, 0);
1083 store_expr (args[i].tree_value, copy, 0, false);
1085 if (callee_copies)
1086 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1087 else
1088 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1090 args[i].tree_value
1091 = build_fold_addr_expr (make_tree (type, copy));
1092 type = TREE_TYPE (args[i].tree_value);
1093 *may_tailcall = false;
1097 mode = TYPE_MODE (type);
1098 unsignedp = TYPE_UNSIGNED (type);
1100 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1101 mode = promote_mode (type, mode, &unsignedp, 1);
1103 args[i].unsignedp = unsignedp;
1104 args[i].mode = mode;
1106 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1107 argpos < n_named_args);
1108 #ifdef FUNCTION_INCOMING_ARG
1109 /* If this is a sibling call and the machine has register windows, the
1110 register window has to be unwinded before calling the routine, so
1111 arguments have to go into the incoming registers. */
1112 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1113 argpos < n_named_args);
1114 #else
1115 args[i].tail_call_reg = args[i].reg;
1116 #endif
1118 if (args[i].reg)
1119 args[i].partial
1120 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1121 argpos < n_named_args);
1123 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1125 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1126 it means that we are to pass this arg in the register(s) designated
1127 by the PARALLEL, but also to pass it in the stack. */
1128 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1129 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1130 args[i].pass_on_stack = 1;
1132 /* If this is an addressable type, we must preallocate the stack
1133 since we must evaluate the object into its final location.
1135 If this is to be passed in both registers and the stack, it is simpler
1136 to preallocate. */
1137 if (TREE_ADDRESSABLE (type)
1138 || (args[i].pass_on_stack && args[i].reg != 0))
1139 *must_preallocate = 1;
1141 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1142 we cannot consider this function call constant. */
1143 if (TREE_ADDRESSABLE (type))
1144 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1146 /* Compute the stack-size of this argument. */
1147 if (args[i].reg == 0 || args[i].partial != 0
1148 || reg_parm_stack_space > 0
1149 || args[i].pass_on_stack)
1150 locate_and_pad_parm (mode, type,
1151 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1153 #else
1154 args[i].reg != 0,
1155 #endif
1156 args[i].pass_on_stack ? 0 : args[i].partial,
1157 fndecl, args_size, &args[i].locate);
1158 #ifdef BLOCK_REG_PADDING
1159 else
1160 /* The argument is passed entirely in registers. See at which
1161 end it should be padded. */
1162 args[i].locate.where_pad =
1163 BLOCK_REG_PADDING (mode, type,
1164 int_size_in_bytes (type) <= UNITS_PER_WORD);
1165 #endif
1167 /* Update ARGS_SIZE, the total stack space for args so far. */
1169 args_size->constant += args[i].locate.size.constant;
1170 if (args[i].locate.size.var)
1171 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1173 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1174 have been used, etc. */
1176 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1177 argpos < n_named_args);
1181 /* Update ARGS_SIZE to contain the total size for the argument block.
1182 Return the original constant component of the argument block's size.
1184 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1185 for arguments passed in registers. */
1187 static int
1188 compute_argument_block_size (int reg_parm_stack_space,
1189 struct args_size *args_size,
1190 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1192 int unadjusted_args_size = args_size->constant;
1194 /* For accumulate outgoing args mode we don't need to align, since the frame
1195 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1196 backends from generating misaligned frame sizes. */
1197 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1198 preferred_stack_boundary = STACK_BOUNDARY;
1200 /* Compute the actual size of the argument block required. The variable
1201 and constant sizes must be combined, the size may have to be rounded,
1202 and there may be a minimum required size. */
1204 if (args_size->var)
1206 args_size->var = ARGS_SIZE_TREE (*args_size);
1207 args_size->constant = 0;
1209 preferred_stack_boundary /= BITS_PER_UNIT;
1210 if (preferred_stack_boundary > 1)
1212 /* We don't handle this case yet. To handle it correctly we have
1213 to add the delta, round and subtract the delta.
1214 Currently no machine description requires this support. */
1215 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1216 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1219 if (reg_parm_stack_space > 0)
1221 args_size->var
1222 = size_binop (MAX_EXPR, args_size->var,
1223 ssize_int (reg_parm_stack_space));
1225 /* The area corresponding to register parameters is not to count in
1226 the size of the block we need. So make the adjustment. */
1227 if (!OUTGOING_REG_PARM_STACK_SPACE)
1228 args_size->var
1229 = size_binop (MINUS_EXPR, args_size->var,
1230 ssize_int (reg_parm_stack_space));
1233 else
1235 preferred_stack_boundary /= BITS_PER_UNIT;
1236 if (preferred_stack_boundary < 1)
1237 preferred_stack_boundary = 1;
1238 args_size->constant = (((args_size->constant
1239 + stack_pointer_delta
1240 + preferred_stack_boundary - 1)
1241 / preferred_stack_boundary
1242 * preferred_stack_boundary)
1243 - stack_pointer_delta);
1245 args_size->constant = MAX (args_size->constant,
1246 reg_parm_stack_space);
1248 if (!OUTGOING_REG_PARM_STACK_SPACE)
1249 args_size->constant -= reg_parm_stack_space;
1251 return unadjusted_args_size;
1254 /* Precompute parameters as needed for a function call.
1256 FLAGS is mask of ECF_* constants.
1258 NUM_ACTUALS is the number of arguments.
1260 ARGS is an array containing information for each argument; this
1261 routine fills in the INITIAL_VALUE and VALUE fields for each
1262 precomputed argument. */
1264 static void
1265 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1267 int i;
1269 /* If this is a libcall, then precompute all arguments so that we do not
1270 get extraneous instructions emitted as part of the libcall sequence. */
1272 /* If we preallocated the stack space, and some arguments must be passed
1273 on the stack, then we must precompute any parameter which contains a
1274 function call which will store arguments on the stack.
1275 Otherwise, evaluating the parameter may clobber previous parameters
1276 which have already been stored into the stack. (we have code to avoid
1277 such case by saving the outgoing stack arguments, but it results in
1278 worse code) */
1279 if ((flags & ECF_LIBCALL_BLOCK) == 0 && !ACCUMULATE_OUTGOING_ARGS)
1280 return;
1282 for (i = 0; i < num_actuals; i++)
1284 enum machine_mode mode;
1286 if ((flags & ECF_LIBCALL_BLOCK) == 0
1287 && TREE_CODE (args[i].tree_value) != CALL_EXPR)
1288 continue;
1290 /* If this is an addressable type, we cannot pre-evaluate it. */
1291 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1293 args[i].initial_value = args[i].value
1294 = expand_normal (args[i].tree_value);
1296 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1297 if (mode != args[i].mode)
1299 args[i].value
1300 = convert_modes (args[i].mode, mode,
1301 args[i].value, args[i].unsignedp);
1302 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1303 /* CSE will replace this only if it contains args[i].value
1304 pseudo, so convert it down to the declared mode using
1305 a SUBREG. */
1306 if (REG_P (args[i].value)
1307 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1309 args[i].initial_value
1310 = gen_lowpart_SUBREG (mode, args[i].value);
1311 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1312 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1313 args[i].unsignedp);
1315 #endif
1320 /* Given the current state of MUST_PREALLOCATE and information about
1321 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1322 compute and return the final value for MUST_PREALLOCATE. */
1324 static int
1325 finalize_must_preallocate (int must_preallocate, int num_actuals,
1326 struct arg_data *args, struct args_size *args_size)
1328 /* See if we have or want to preallocate stack space.
1330 If we would have to push a partially-in-regs parm
1331 before other stack parms, preallocate stack space instead.
1333 If the size of some parm is not a multiple of the required stack
1334 alignment, we must preallocate.
1336 If the total size of arguments that would otherwise create a copy in
1337 a temporary (such as a CALL) is more than half the total argument list
1338 size, preallocation is faster.
1340 Another reason to preallocate is if we have a machine (like the m88k)
1341 where stack alignment is required to be maintained between every
1342 pair of insns, not just when the call is made. However, we assume here
1343 that such machines either do not have push insns (and hence preallocation
1344 would occur anyway) or the problem is taken care of with
1345 PUSH_ROUNDING. */
1347 if (! must_preallocate)
1349 int partial_seen = 0;
1350 int copy_to_evaluate_size = 0;
1351 int i;
1353 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1355 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1356 partial_seen = 1;
1357 else if (partial_seen && args[i].reg == 0)
1358 must_preallocate = 1;
1360 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1361 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1362 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1363 || TREE_CODE (args[i].tree_value) == COND_EXPR
1364 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1365 copy_to_evaluate_size
1366 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1369 if (copy_to_evaluate_size * 2 >= args_size->constant
1370 && args_size->constant > 0)
1371 must_preallocate = 1;
1373 return must_preallocate;
1376 /* If we preallocated stack space, compute the address of each argument
1377 and store it into the ARGS array.
1379 We need not ensure it is a valid memory address here; it will be
1380 validized when it is used.
1382 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1384 static void
1385 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1387 if (argblock)
1389 rtx arg_reg = argblock;
1390 int i, arg_offset = 0;
1392 if (GET_CODE (argblock) == PLUS)
1393 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1395 for (i = 0; i < num_actuals; i++)
1397 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1398 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1399 rtx addr;
1400 unsigned int align, boundary;
1401 unsigned int units_on_stack = 0;
1402 enum machine_mode partial_mode = VOIDmode;
1404 /* Skip this parm if it will not be passed on the stack. */
1405 if (! args[i].pass_on_stack
1406 && args[i].reg != 0
1407 && args[i].partial == 0)
1408 continue;
1410 if (GET_CODE (offset) == CONST_INT)
1411 addr = plus_constant (arg_reg, INTVAL (offset));
1412 else
1413 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1415 addr = plus_constant (addr, arg_offset);
1417 if (args[i].partial != 0)
1419 /* Only part of the parameter is being passed on the stack.
1420 Generate a simple memory reference of the correct size. */
1421 units_on_stack = args[i].locate.size.constant;
1422 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1423 MODE_INT, 1);
1424 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1425 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1427 else
1429 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1430 set_mem_attributes (args[i].stack,
1431 TREE_TYPE (args[i].tree_value), 1);
1433 align = BITS_PER_UNIT;
1434 boundary = args[i].locate.boundary;
1435 if (args[i].locate.where_pad != downward)
1436 align = boundary;
1437 else if (GET_CODE (offset) == CONST_INT)
1439 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1440 align = align & -align;
1442 set_mem_align (args[i].stack, align);
1444 if (GET_CODE (slot_offset) == CONST_INT)
1445 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1446 else
1447 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1449 addr = plus_constant (addr, arg_offset);
1451 if (args[i].partial != 0)
1453 /* Only part of the parameter is being passed on the stack.
1454 Generate a simple memory reference of the correct size.
1456 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1457 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1459 else
1461 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1462 set_mem_attributes (args[i].stack_slot,
1463 TREE_TYPE (args[i].tree_value), 1);
1465 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1467 /* Function incoming arguments may overlap with sibling call
1468 outgoing arguments and we cannot allow reordering of reads
1469 from function arguments with stores to outgoing arguments
1470 of sibling calls. */
1471 set_mem_alias_set (args[i].stack, 0);
1472 set_mem_alias_set (args[i].stack_slot, 0);
1477 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1478 in a call instruction.
1480 FNDECL is the tree node for the target function. For an indirect call
1481 FNDECL will be NULL_TREE.
1483 ADDR is the operand 0 of CALL_EXPR for this call. */
1485 static rtx
1486 rtx_for_function_call (tree fndecl, tree addr)
1488 rtx funexp;
1490 /* Get the function to call, in the form of RTL. */
1491 if (fndecl)
1493 /* If this is the first use of the function, see if we need to
1494 make an external definition for it. */
1495 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1497 assemble_external (fndecl);
1498 TREE_USED (fndecl) = 1;
1501 /* Get a SYMBOL_REF rtx for the function address. */
1502 funexp = XEXP (DECL_RTL (fndecl), 0);
1504 else
1505 /* Generate an rtx (probably a pseudo-register) for the address. */
1507 push_temp_slots ();
1508 funexp = expand_normal (addr);
1509 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1511 return funexp;
1514 /* Return true if and only if SIZE storage units (usually bytes)
1515 starting from address ADDR overlap with already clobbered argument
1516 area. This function is used to determine if we should give up a
1517 sibcall. */
1519 static bool
1520 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1522 HOST_WIDE_INT i;
1524 if (addr == current_function_internal_arg_pointer)
1525 i = 0;
1526 else if (GET_CODE (addr) == PLUS
1527 && XEXP (addr, 0) == current_function_internal_arg_pointer
1528 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1529 i = INTVAL (XEXP (addr, 1));
1530 /* Return true for arg pointer based indexed addressing. */
1531 else if (GET_CODE (addr) == PLUS
1532 && (XEXP (addr, 0) == current_function_internal_arg_pointer
1533 || XEXP (addr, 1) == current_function_internal_arg_pointer))
1534 return true;
1535 else
1536 return false;
1538 #ifdef ARGS_GROW_DOWNWARD
1539 i = -i - size;
1540 #endif
1541 if (size > 0)
1543 unsigned HOST_WIDE_INT k;
1545 for (k = 0; k < size; k++)
1546 if (i + k < stored_args_map->n_bits
1547 && TEST_BIT (stored_args_map, i + k))
1548 return true;
1551 return false;
1554 /* Do the register loads required for any wholly-register parms or any
1555 parms which are passed both on the stack and in a register. Their
1556 expressions were already evaluated.
1558 Mark all register-parms as living through the call, putting these USE
1559 insns in the CALL_INSN_FUNCTION_USAGE field.
1561 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1562 checking, setting *SIBCALL_FAILURE if appropriate. */
1564 static void
1565 load_register_parameters (struct arg_data *args, int num_actuals,
1566 rtx *call_fusage, int flags, int is_sibcall,
1567 int *sibcall_failure)
1569 int i, j;
1571 for (i = 0; i < num_actuals; i++)
1573 rtx reg = ((flags & ECF_SIBCALL)
1574 ? args[i].tail_call_reg : args[i].reg);
1575 if (reg)
1577 int partial = args[i].partial;
1578 int nregs;
1579 int size = 0;
1580 rtx before_arg = get_last_insn ();
1581 /* Set non-negative if we must move a word at a time, even if
1582 just one word (e.g, partial == 4 && mode == DFmode). Set
1583 to -1 if we just use a normal move insn. This value can be
1584 zero if the argument is a zero size structure. */
1585 nregs = -1;
1586 if (GET_CODE (reg) == PARALLEL)
1588 else if (partial)
1590 gcc_assert (partial % UNITS_PER_WORD == 0);
1591 nregs = partial / UNITS_PER_WORD;
1593 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1595 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1596 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1598 else
1599 size = GET_MODE_SIZE (args[i].mode);
1601 /* Handle calls that pass values in multiple non-contiguous
1602 locations. The Irix 6 ABI has examples of this. */
1604 if (GET_CODE (reg) == PARALLEL)
1605 emit_group_move (reg, args[i].parallel_value);
1607 /* If simple case, just do move. If normal partial, store_one_arg
1608 has already loaded the register for us. In all other cases,
1609 load the register(s) from memory. */
1611 else if (nregs == -1)
1613 emit_move_insn (reg, args[i].value);
1614 #ifdef BLOCK_REG_PADDING
1615 /* Handle case where we have a value that needs shifting
1616 up to the msb. eg. a QImode value and we're padding
1617 upward on a BYTES_BIG_ENDIAN machine. */
1618 if (size < UNITS_PER_WORD
1619 && (args[i].locate.where_pad
1620 == (BYTES_BIG_ENDIAN ? upward : downward)))
1622 rtx x;
1623 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1625 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1626 report the whole reg as used. Strictly speaking, the
1627 call only uses SIZE bytes at the msb end, but it doesn't
1628 seem worth generating rtl to say that. */
1629 reg = gen_rtx_REG (word_mode, REGNO (reg));
1630 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1631 build_int_cst (NULL_TREE, shift),
1632 reg, 1);
1633 if (x != reg)
1634 emit_move_insn (reg, x);
1636 #endif
1639 /* If we have pre-computed the values to put in the registers in
1640 the case of non-aligned structures, copy them in now. */
1642 else if (args[i].n_aligned_regs != 0)
1643 for (j = 0; j < args[i].n_aligned_regs; j++)
1644 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1645 args[i].aligned_regs[j]);
1647 else if (partial == 0 || args[i].pass_on_stack)
1649 rtx mem = validize_mem (args[i].value);
1651 /* Check for overlap with already clobbered argument area. */
1652 if (is_sibcall
1653 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1654 size))
1655 *sibcall_failure = 1;
1657 /* Handle a BLKmode that needs shifting. */
1658 if (nregs == 1 && size < UNITS_PER_WORD
1659 #ifdef BLOCK_REG_PADDING
1660 && args[i].locate.where_pad == downward
1661 #else
1662 && BYTES_BIG_ENDIAN
1663 #endif
1666 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1667 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1668 rtx x = gen_reg_rtx (word_mode);
1669 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1670 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1671 : LSHIFT_EXPR;
1673 emit_move_insn (x, tem);
1674 x = expand_shift (dir, word_mode, x,
1675 build_int_cst (NULL_TREE, shift),
1676 ri, 1);
1677 if (x != ri)
1678 emit_move_insn (ri, x);
1680 else
1681 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1684 /* When a parameter is a block, and perhaps in other cases, it is
1685 possible that it did a load from an argument slot that was
1686 already clobbered. */
1687 if (is_sibcall
1688 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1689 *sibcall_failure = 1;
1691 /* Handle calls that pass values in multiple non-contiguous
1692 locations. The Irix 6 ABI has examples of this. */
1693 if (GET_CODE (reg) == PARALLEL)
1694 use_group_regs (call_fusage, reg);
1695 else if (nregs == -1)
1696 use_reg (call_fusage, reg);
1697 else if (nregs > 0)
1698 use_regs (call_fusage, REGNO (reg), nregs);
1703 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1704 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1705 bytes, then we would need to push some additional bytes to pad the
1706 arguments. So, we compute an adjust to the stack pointer for an
1707 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1708 bytes. Then, when the arguments are pushed the stack will be perfectly
1709 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1710 be popped after the call. Returns the adjustment. */
1712 static int
1713 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1714 struct args_size *args_size,
1715 unsigned int preferred_unit_stack_boundary)
1717 /* The number of bytes to pop so that the stack will be
1718 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1719 HOST_WIDE_INT adjustment;
1720 /* The alignment of the stack after the arguments are pushed, if we
1721 just pushed the arguments without adjust the stack here. */
1722 unsigned HOST_WIDE_INT unadjusted_alignment;
1724 unadjusted_alignment
1725 = ((stack_pointer_delta + unadjusted_args_size)
1726 % preferred_unit_stack_boundary);
1728 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1729 as possible -- leaving just enough left to cancel out the
1730 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1731 PENDING_STACK_ADJUST is non-negative, and congruent to
1732 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1734 /* Begin by trying to pop all the bytes. */
1735 unadjusted_alignment
1736 = (unadjusted_alignment
1737 - (pending_stack_adjust % preferred_unit_stack_boundary));
1738 adjustment = pending_stack_adjust;
1739 /* Push enough additional bytes that the stack will be aligned
1740 after the arguments are pushed. */
1741 if (preferred_unit_stack_boundary > 1)
1743 if (unadjusted_alignment > 0)
1744 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1745 else
1746 adjustment += unadjusted_alignment;
1749 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1750 bytes after the call. The right number is the entire
1751 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1752 by the arguments in the first place. */
1753 args_size->constant
1754 = pending_stack_adjust - adjustment + unadjusted_args_size;
1756 return adjustment;
1759 /* Scan X expression if it does not dereference any argument slots
1760 we already clobbered by tail call arguments (as noted in stored_args_map
1761 bitmap).
1762 Return nonzero if X expression dereferences such argument slots,
1763 zero otherwise. */
1765 static int
1766 check_sibcall_argument_overlap_1 (rtx x)
1768 RTX_CODE code;
1769 int i, j;
1770 const char *fmt;
1772 if (x == NULL_RTX)
1773 return 0;
1775 code = GET_CODE (x);
1777 if (code == MEM)
1778 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1779 GET_MODE_SIZE (GET_MODE (x)));
1781 /* Scan all subexpressions. */
1782 fmt = GET_RTX_FORMAT (code);
1783 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1785 if (*fmt == 'e')
1787 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1788 return 1;
1790 else if (*fmt == 'E')
1792 for (j = 0; j < XVECLEN (x, i); j++)
1793 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1794 return 1;
1797 return 0;
1800 /* Scan sequence after INSN if it does not dereference any argument slots
1801 we already clobbered by tail call arguments (as noted in stored_args_map
1802 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1803 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1804 should be 0). Return nonzero if sequence after INSN dereferences such argument
1805 slots, zero otherwise. */
1807 static int
1808 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1810 int low, high;
1812 if (insn == NULL_RTX)
1813 insn = get_insns ();
1814 else
1815 insn = NEXT_INSN (insn);
1817 for (; insn; insn = NEXT_INSN (insn))
1818 if (INSN_P (insn)
1819 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1820 break;
1822 if (mark_stored_args_map)
1824 #ifdef ARGS_GROW_DOWNWARD
1825 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1826 #else
1827 low = arg->locate.slot_offset.constant;
1828 #endif
1830 for (high = low + arg->locate.size.constant; low < high; low++)
1831 SET_BIT (stored_args_map, low);
1833 return insn != NULL_RTX;
1836 /* Given that a function returns a value of mode MODE at the most
1837 significant end of hard register VALUE, shift VALUE left or right
1838 as specified by LEFT_P. Return true if some action was needed. */
1840 bool
1841 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1843 HOST_WIDE_INT shift;
1845 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1846 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1847 if (shift == 0)
1848 return false;
1850 /* Use ashr rather than lshr for right shifts. This is for the benefit
1851 of the MIPS port, which requires SImode values to be sign-extended
1852 when stored in 64-bit registers. */
1853 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1854 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1855 gcc_unreachable ();
1856 return true;
1859 /* If X is a likely-spilled register value, copy it to a pseudo
1860 register and return that register. Return X otherwise. */
1862 static rtx
1863 avoid_likely_spilled_reg (rtx x)
1865 rtx new;
1867 if (REG_P (x)
1868 && HARD_REGISTER_P (x)
1869 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1871 /* Make sure that we generate a REG rather than a CONCAT.
1872 Moves into CONCATs can need nontrivial instructions,
1873 and the whole point of this function is to avoid
1874 using the hard register directly in such a situation. */
1875 generating_concat_p = 0;
1876 new = gen_reg_rtx (GET_MODE (x));
1877 generating_concat_p = 1;
1878 emit_move_insn (new, x);
1879 return new;
1881 return x;
1884 /* Generate all the code for a CALL_EXPR exp
1885 and return an rtx for its value.
1886 Store the value in TARGET (specified as an rtx) if convenient.
1887 If the value is stored in TARGET then TARGET is returned.
1888 If IGNORE is nonzero, then we ignore the value of the function call. */
1891 expand_call (tree exp, rtx target, int ignore)
1893 /* Nonzero if we are currently expanding a call. */
1894 static int currently_expanding_call = 0;
1896 /* RTX for the function to be called. */
1897 rtx funexp;
1898 /* Sequence of insns to perform a normal "call". */
1899 rtx normal_call_insns = NULL_RTX;
1900 /* Sequence of insns to perform a tail "call". */
1901 rtx tail_call_insns = NULL_RTX;
1902 /* Data type of the function. */
1903 tree funtype;
1904 tree type_arg_types;
1905 /* Declaration of the function being called,
1906 or 0 if the function is computed (not known by name). */
1907 tree fndecl = 0;
1908 /* The type of the function being called. */
1909 tree fntype;
1910 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1911 int pass;
1913 /* Register in which non-BLKmode value will be returned,
1914 or 0 if no value or if value is BLKmode. */
1915 rtx valreg;
1916 /* Address where we should return a BLKmode value;
1917 0 if value not BLKmode. */
1918 rtx structure_value_addr = 0;
1919 /* Nonzero if that address is being passed by treating it as
1920 an extra, implicit first parameter. Otherwise,
1921 it is passed by being copied directly into struct_value_rtx. */
1922 int structure_value_addr_parm = 0;
1923 /* Holds the value of implicit argument for the struct value. */
1924 tree structure_value_addr_value = NULL_TREE;
1925 /* Size of aggregate value wanted, or zero if none wanted
1926 or if we are using the non-reentrant PCC calling convention
1927 or expecting the value in registers. */
1928 HOST_WIDE_INT struct_value_size = 0;
1929 /* Nonzero if called function returns an aggregate in memory PCC style,
1930 by returning the address of where to find it. */
1931 int pcc_struct_value = 0;
1932 rtx struct_value = 0;
1934 /* Number of actual parameters in this call, including struct value addr. */
1935 int num_actuals;
1936 /* Number of named args. Args after this are anonymous ones
1937 and they must all go on the stack. */
1938 int n_named_args;
1939 /* Number of complex actual arguments that need to be split. */
1940 int num_complex_actuals = 0;
1942 /* Vector of information about each argument.
1943 Arguments are numbered in the order they will be pushed,
1944 not the order they are written. */
1945 struct arg_data *args;
1947 /* Total size in bytes of all the stack-parms scanned so far. */
1948 struct args_size args_size;
1949 struct args_size adjusted_args_size;
1950 /* Size of arguments before any adjustments (such as rounding). */
1951 int unadjusted_args_size;
1952 /* Data on reg parms scanned so far. */
1953 CUMULATIVE_ARGS args_so_far;
1954 /* Nonzero if a reg parm has been scanned. */
1955 int reg_parm_seen;
1956 /* Nonzero if this is an indirect function call. */
1958 /* Nonzero if we must avoid push-insns in the args for this call.
1959 If stack space is allocated for register parameters, but not by the
1960 caller, then it is preallocated in the fixed part of the stack frame.
1961 So the entire argument block must then be preallocated (i.e., we
1962 ignore PUSH_ROUNDING in that case). */
1964 int must_preallocate = !PUSH_ARGS;
1966 /* Size of the stack reserved for parameter registers. */
1967 int reg_parm_stack_space = 0;
1969 /* Address of space preallocated for stack parms
1970 (on machines that lack push insns), or 0 if space not preallocated. */
1971 rtx argblock = 0;
1973 /* Mask of ECF_ flags. */
1974 int flags = 0;
1975 #ifdef REG_PARM_STACK_SPACE
1976 /* Define the boundary of the register parm stack space that needs to be
1977 saved, if any. */
1978 int low_to_save, high_to_save;
1979 rtx save_area = 0; /* Place that it is saved */
1980 #endif
1982 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1983 char *initial_stack_usage_map = stack_usage_map;
1984 char *stack_usage_map_buf = NULL;
1986 int old_stack_allocated;
1988 /* State variables to track stack modifications. */
1989 rtx old_stack_level = 0;
1990 int old_stack_arg_under_construction = 0;
1991 int old_pending_adj = 0;
1992 int old_inhibit_defer_pop = inhibit_defer_pop;
1994 /* Some stack pointer alterations we make are performed via
1995 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1996 which we then also need to save/restore along the way. */
1997 int old_stack_pointer_delta = 0;
1999 rtx call_fusage;
2000 tree p = CALL_EXPR_FN (exp);
2001 tree addr = CALL_EXPR_FN (exp);
2002 int i;
2003 /* The alignment of the stack, in bits. */
2004 unsigned HOST_WIDE_INT preferred_stack_boundary;
2005 /* The alignment of the stack, in bytes. */
2006 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2007 /* The static chain value to use for this call. */
2008 rtx static_chain_value;
2009 /* See if this is "nothrow" function call. */
2010 if (TREE_NOTHROW (exp))
2011 flags |= ECF_NOTHROW;
2013 /* See if we can find a DECL-node for the actual function, and get the
2014 function attributes (flags) from the function decl or type node. */
2015 fndecl = get_callee_fndecl (exp);
2016 if (fndecl)
2018 fntype = TREE_TYPE (fndecl);
2019 flags |= flags_from_decl_or_type (fndecl);
2021 else
2023 fntype = TREE_TYPE (TREE_TYPE (p));
2024 flags |= flags_from_decl_or_type (fntype);
2027 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2029 /* Warn if this value is an aggregate type,
2030 regardless of which calling convention we are using for it. */
2031 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2032 warning (OPT_Waggregate_return, "function call has aggregate value");
2034 /* If the result of a pure or const function call is ignored (or void),
2035 and none of its arguments are volatile, we can avoid expanding the
2036 call and just evaluate the arguments for side-effects. */
2037 if ((flags & (ECF_CONST | ECF_PURE))
2038 && (ignore || target == const0_rtx
2039 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2041 bool volatilep = false;
2042 tree arg;
2043 call_expr_arg_iterator iter;
2045 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2046 if (TREE_THIS_VOLATILE (arg))
2048 volatilep = true;
2049 break;
2052 if (! volatilep)
2054 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2055 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2056 return const0_rtx;
2060 #ifdef REG_PARM_STACK_SPACE
2061 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2062 #endif
2064 if (!OUTGOING_REG_PARM_STACK_SPACE && reg_parm_stack_space > 0 && PUSH_ARGS)
2065 must_preallocate = 1;
2067 /* Set up a place to return a structure. */
2069 /* Cater to broken compilers. */
2070 if (aggregate_value_p (exp, fndecl))
2072 /* This call returns a big structure. */
2073 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2075 #ifdef PCC_STATIC_STRUCT_RETURN
2077 pcc_struct_value = 1;
2079 #else /* not PCC_STATIC_STRUCT_RETURN */
2081 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2083 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2084 structure_value_addr = XEXP (target, 0);
2085 else
2087 /* For variable-sized objects, we must be called with a target
2088 specified. If we were to allocate space on the stack here,
2089 we would have no way of knowing when to free it. */
2090 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2092 mark_temp_addr_taken (d);
2093 structure_value_addr = XEXP (d, 0);
2094 target = 0;
2097 #endif /* not PCC_STATIC_STRUCT_RETURN */
2100 /* Figure out the amount to which the stack should be aligned. */
2101 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2102 if (fndecl)
2104 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2105 if (i && i->preferred_incoming_stack_boundary)
2106 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2109 /* Operand 0 is a pointer-to-function; get the type of the function. */
2110 funtype = TREE_TYPE (addr);
2111 gcc_assert (POINTER_TYPE_P (funtype));
2112 funtype = TREE_TYPE (funtype);
2114 /* Count whether there are actual complex arguments that need to be split
2115 into their real and imaginary parts. Munge the type_arg_types
2116 appropriately here as well. */
2117 if (targetm.calls.split_complex_arg)
2119 call_expr_arg_iterator iter;
2120 tree arg;
2121 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2123 tree type = TREE_TYPE (arg);
2124 if (type && TREE_CODE (type) == COMPLEX_TYPE
2125 && targetm.calls.split_complex_arg (type))
2126 num_complex_actuals++;
2128 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2130 else
2131 type_arg_types = TYPE_ARG_TYPES (funtype);
2133 if (flags & ECF_MAY_BE_ALLOCA)
2134 current_function_calls_alloca = 1;
2136 /* If struct_value_rtx is 0, it means pass the address
2137 as if it were an extra parameter. Put the argument expression
2138 in structure_value_addr_value. */
2139 if (structure_value_addr && struct_value == 0)
2141 /* If structure_value_addr is a REG other than
2142 virtual_outgoing_args_rtx, we can use always use it. If it
2143 is not a REG, we must always copy it into a register.
2144 If it is virtual_outgoing_args_rtx, we must copy it to another
2145 register in some cases. */
2146 rtx temp = (!REG_P (structure_value_addr)
2147 || (ACCUMULATE_OUTGOING_ARGS
2148 && stack_arg_under_construction
2149 && structure_value_addr == virtual_outgoing_args_rtx)
2150 ? copy_addr_to_reg (convert_memory_address
2151 (Pmode, structure_value_addr))
2152 : structure_value_addr);
2154 structure_value_addr_value =
2155 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2156 structure_value_addr_parm = 1;
2159 /* Count the arguments and set NUM_ACTUALS. */
2160 num_actuals =
2161 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2163 /* Compute number of named args.
2164 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2166 if (type_arg_types != 0)
2167 n_named_args
2168 = (list_length (type_arg_types)
2169 /* Count the struct value address, if it is passed as a parm. */
2170 + structure_value_addr_parm);
2171 else
2172 /* If we know nothing, treat all args as named. */
2173 n_named_args = num_actuals;
2175 /* Start updating where the next arg would go.
2177 On some machines (such as the PA) indirect calls have a different
2178 calling convention than normal calls. The fourth argument in
2179 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2180 or not. */
2181 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2183 /* Now possibly adjust the number of named args.
2184 Normally, don't include the last named arg if anonymous args follow.
2185 We do include the last named arg if
2186 targetm.calls.strict_argument_naming() returns nonzero.
2187 (If no anonymous args follow, the result of list_length is actually
2188 one too large. This is harmless.)
2190 If targetm.calls.pretend_outgoing_varargs_named() returns
2191 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2192 this machine will be able to place unnamed args that were passed
2193 in registers into the stack. So treat all args as named. This
2194 allows the insns emitting for a specific argument list to be
2195 independent of the function declaration.
2197 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2198 we do not have any reliable way to pass unnamed args in
2199 registers, so we must force them into memory. */
2201 if (type_arg_types != 0
2202 && targetm.calls.strict_argument_naming (&args_so_far))
2204 else if (type_arg_types != 0
2205 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2206 /* Don't include the last named arg. */
2207 --n_named_args;
2208 else
2209 /* Treat all args as named. */
2210 n_named_args = num_actuals;
2212 /* Make a vector to hold all the information about each arg. */
2213 args = alloca (num_actuals * sizeof (struct arg_data));
2214 memset (args, 0, num_actuals * sizeof (struct arg_data));
2216 /* Build up entries in the ARGS array, compute the size of the
2217 arguments into ARGS_SIZE, etc. */
2218 initialize_argument_information (num_actuals, args, &args_size,
2219 n_named_args, exp,
2220 structure_value_addr_value, fndecl,
2221 &args_so_far, reg_parm_stack_space,
2222 &old_stack_level, &old_pending_adj,
2223 &must_preallocate, &flags,
2224 &try_tail_call, CALL_FROM_THUNK_P (exp));
2226 if (args_size.var)
2228 /* If this function requires a variable-sized argument list, don't
2229 try to make a cse'able block for this call. We may be able to
2230 do this eventually, but it is too complicated to keep track of
2231 what insns go in the cse'able block and which don't. */
2233 flags &= ~ECF_LIBCALL_BLOCK;
2234 must_preallocate = 1;
2237 /* Now make final decision about preallocating stack space. */
2238 must_preallocate = finalize_must_preallocate (must_preallocate,
2239 num_actuals, args,
2240 &args_size);
2242 /* If the structure value address will reference the stack pointer, we
2243 must stabilize it. We don't need to do this if we know that we are
2244 not going to adjust the stack pointer in processing this call. */
2246 if (structure_value_addr
2247 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2248 || reg_mentioned_p (virtual_outgoing_args_rtx,
2249 structure_value_addr))
2250 && (args_size.var
2251 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2252 structure_value_addr = copy_to_reg (structure_value_addr);
2254 /* Tail calls can make things harder to debug, and we've traditionally
2255 pushed these optimizations into -O2. Don't try if we're already
2256 expanding a call, as that means we're an argument. Don't try if
2257 there's cleanups, as we know there's code to follow the call. */
2259 if (currently_expanding_call++ != 0
2260 || !flag_optimize_sibling_calls
2261 || args_size.var
2262 || lookup_stmt_eh_region (exp) >= 0
2263 || dbg_cnt (tail_call) == false)
2264 try_tail_call = 0;
2266 /* Rest of purposes for tail call optimizations to fail. */
2267 if (
2268 #ifdef HAVE_sibcall_epilogue
2269 !HAVE_sibcall_epilogue
2270 #else
2272 #endif
2273 || !try_tail_call
2274 /* Doing sibling call optimization needs some work, since
2275 structure_value_addr can be allocated on the stack.
2276 It does not seem worth the effort since few optimizable
2277 sibling calls will return a structure. */
2278 || structure_value_addr != NULL_RTX
2279 /* Check whether the target is able to optimize the call
2280 into a sibcall. */
2281 || !targetm.function_ok_for_sibcall (fndecl, exp)
2282 /* Functions that do not return exactly once may not be sibcall
2283 optimized. */
2284 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2285 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2286 /* If the called function is nested in the current one, it might access
2287 some of the caller's arguments, but could clobber them beforehand if
2288 the argument areas are shared. */
2289 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2290 /* If this function requires more stack slots than the current
2291 function, we cannot change it into a sibling call.
2292 current_function_pretend_args_size is not part of the
2293 stack allocated by our caller. */
2294 || args_size.constant > (current_function_args_size
2295 - current_function_pretend_args_size)
2296 /* If the callee pops its own arguments, then it must pop exactly
2297 the same number of arguments as the current function. */
2298 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2299 != RETURN_POPS_ARGS (current_function_decl,
2300 TREE_TYPE (current_function_decl),
2301 current_function_args_size))
2302 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2303 try_tail_call = 0;
2305 /* Ensure current function's preferred stack boundary is at least
2306 what we need. We don't have to increase alignment for recursive
2307 functions. */
2308 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2309 && fndecl != current_function_decl)
2310 cfun->preferred_stack_boundary = preferred_stack_boundary;
2311 if (fndecl == current_function_decl)
2312 cfun->recursive_call_emit = true;
2314 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2316 /* We want to make two insn chains; one for a sibling call, the other
2317 for a normal call. We will select one of the two chains after
2318 initial RTL generation is complete. */
2319 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2321 int sibcall_failure = 0;
2322 /* We want to emit any pending stack adjustments before the tail
2323 recursion "call". That way we know any adjustment after the tail
2324 recursion call can be ignored if we indeed use the tail
2325 call expansion. */
2326 int save_pending_stack_adjust = 0;
2327 int save_stack_pointer_delta = 0;
2328 rtx insns;
2329 rtx before_call, next_arg_reg;
2331 if (pass == 0)
2333 /* State variables we need to save and restore between
2334 iterations. */
2335 save_pending_stack_adjust = pending_stack_adjust;
2336 save_stack_pointer_delta = stack_pointer_delta;
2338 if (pass)
2339 flags &= ~ECF_SIBCALL;
2340 else
2341 flags |= ECF_SIBCALL;
2343 /* Other state variables that we must reinitialize each time
2344 through the loop (that are not initialized by the loop itself). */
2345 argblock = 0;
2346 call_fusage = 0;
2348 /* Start a new sequence for the normal call case.
2350 From this point on, if the sibling call fails, we want to set
2351 sibcall_failure instead of continuing the loop. */
2352 start_sequence ();
2354 /* Don't let pending stack adjusts add up to too much.
2355 Also, do all pending adjustments now if there is any chance
2356 this might be a call to alloca or if we are expanding a sibling
2357 call sequence or if we are calling a function that is to return
2358 with stack pointer depressed.
2359 Also do the adjustments before a throwing call, otherwise
2360 exception handling can fail; PR 19225. */
2361 if (pending_stack_adjust >= 32
2362 || (pending_stack_adjust > 0
2363 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2364 || (pending_stack_adjust > 0
2365 && flag_exceptions && !(flags & ECF_NOTHROW))
2366 || pass == 0)
2367 do_pending_stack_adjust ();
2369 /* When calling a const function, we must pop the stack args right away,
2370 so that the pop is deleted or moved with the call. */
2371 if (pass && (flags & ECF_LIBCALL_BLOCK))
2372 NO_DEFER_POP;
2374 /* Precompute any arguments as needed. */
2375 if (pass)
2376 precompute_arguments (flags, num_actuals, args);
2378 /* Now we are about to start emitting insns that can be deleted
2379 if a libcall is deleted. */
2380 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2381 start_sequence ();
2383 if (pass == 0 && cfun->stack_protect_guard)
2384 stack_protect_epilogue ();
2386 adjusted_args_size = args_size;
2387 /* Compute the actual size of the argument block required. The variable
2388 and constant sizes must be combined, the size may have to be rounded,
2389 and there may be a minimum required size. When generating a sibcall
2390 pattern, do not round up, since we'll be re-using whatever space our
2391 caller provided. */
2392 unadjusted_args_size
2393 = compute_argument_block_size (reg_parm_stack_space,
2394 &adjusted_args_size,
2395 (pass == 0 ? 0
2396 : preferred_stack_boundary));
2398 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2400 /* The argument block when performing a sibling call is the
2401 incoming argument block. */
2402 if (pass == 0)
2404 argblock = virtual_incoming_args_rtx;
2405 argblock
2406 #ifdef STACK_GROWS_DOWNWARD
2407 = plus_constant (argblock, current_function_pretend_args_size);
2408 #else
2409 = plus_constant (argblock, -current_function_pretend_args_size);
2410 #endif
2411 stored_args_map = sbitmap_alloc (args_size.constant);
2412 sbitmap_zero (stored_args_map);
2415 /* If we have no actual push instructions, or shouldn't use them,
2416 make space for all args right now. */
2417 else if (adjusted_args_size.var != 0)
2419 if (old_stack_level == 0)
2421 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2422 old_stack_pointer_delta = stack_pointer_delta;
2423 old_pending_adj = pending_stack_adjust;
2424 pending_stack_adjust = 0;
2425 /* stack_arg_under_construction says whether a stack arg is
2426 being constructed at the old stack level. Pushing the stack
2427 gets a clean outgoing argument block. */
2428 old_stack_arg_under_construction = stack_arg_under_construction;
2429 stack_arg_under_construction = 0;
2431 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2433 else
2435 /* Note that we must go through the motions of allocating an argument
2436 block even if the size is zero because we may be storing args
2437 in the area reserved for register arguments, which may be part of
2438 the stack frame. */
2440 int needed = adjusted_args_size.constant;
2442 /* Store the maximum argument space used. It will be pushed by
2443 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2444 checking). */
2446 if (needed > current_function_outgoing_args_size)
2447 current_function_outgoing_args_size = needed;
2449 if (must_preallocate)
2451 if (ACCUMULATE_OUTGOING_ARGS)
2453 /* Since the stack pointer will never be pushed, it is
2454 possible for the evaluation of a parm to clobber
2455 something we have already written to the stack.
2456 Since most function calls on RISC machines do not use
2457 the stack, this is uncommon, but must work correctly.
2459 Therefore, we save any area of the stack that was already
2460 written and that we are using. Here we set up to do this
2461 by making a new stack usage map from the old one. The
2462 actual save will be done by store_one_arg.
2464 Another approach might be to try to reorder the argument
2465 evaluations to avoid this conflicting stack usage. */
2467 /* Since we will be writing into the entire argument area,
2468 the map must be allocated for its entire size, not just
2469 the part that is the responsibility of the caller. */
2470 if (!OUTGOING_REG_PARM_STACK_SPACE)
2471 needed += reg_parm_stack_space;
2473 #ifdef ARGS_GROW_DOWNWARD
2474 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2475 needed + 1);
2476 #else
2477 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2478 needed);
2479 #endif
2480 if (stack_usage_map_buf)
2481 free (stack_usage_map_buf);
2482 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2483 stack_usage_map = stack_usage_map_buf;
2485 if (initial_highest_arg_in_use)
2486 memcpy (stack_usage_map, initial_stack_usage_map,
2487 initial_highest_arg_in_use);
2489 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2490 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2491 (highest_outgoing_arg_in_use
2492 - initial_highest_arg_in_use));
2493 needed = 0;
2495 /* The address of the outgoing argument list must not be
2496 copied to a register here, because argblock would be left
2497 pointing to the wrong place after the call to
2498 allocate_dynamic_stack_space below. */
2500 argblock = virtual_outgoing_args_rtx;
2502 else
2504 if (inhibit_defer_pop == 0)
2506 /* Try to reuse some or all of the pending_stack_adjust
2507 to get this space. */
2508 needed
2509 = (combine_pending_stack_adjustment_and_call
2510 (unadjusted_args_size,
2511 &adjusted_args_size,
2512 preferred_unit_stack_boundary));
2514 /* combine_pending_stack_adjustment_and_call computes
2515 an adjustment before the arguments are allocated.
2516 Account for them and see whether or not the stack
2517 needs to go up or down. */
2518 needed = unadjusted_args_size - needed;
2520 if (needed < 0)
2522 /* We're releasing stack space. */
2523 /* ??? We can avoid any adjustment at all if we're
2524 already aligned. FIXME. */
2525 pending_stack_adjust = -needed;
2526 do_pending_stack_adjust ();
2527 needed = 0;
2529 else
2530 /* We need to allocate space. We'll do that in
2531 push_block below. */
2532 pending_stack_adjust = 0;
2535 /* Special case this because overhead of `push_block' in
2536 this case is non-trivial. */
2537 if (needed == 0)
2538 argblock = virtual_outgoing_args_rtx;
2539 else
2541 argblock = push_block (GEN_INT (needed), 0, 0);
2542 #ifdef ARGS_GROW_DOWNWARD
2543 argblock = plus_constant (argblock, needed);
2544 #endif
2547 /* We only really need to call `copy_to_reg' in the case
2548 where push insns are going to be used to pass ARGBLOCK
2549 to a function call in ARGS. In that case, the stack
2550 pointer changes value from the allocation point to the
2551 call point, and hence the value of
2552 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2553 as well always do it. */
2554 argblock = copy_to_reg (argblock);
2559 if (ACCUMULATE_OUTGOING_ARGS)
2561 /* The save/restore code in store_one_arg handles all
2562 cases except one: a constructor call (including a C
2563 function returning a BLKmode struct) to initialize
2564 an argument. */
2565 if (stack_arg_under_construction)
2567 rtx push_size
2568 = GEN_INT (adjusted_args_size.constant
2569 + (OUTGOING_REG_PARM_STACK_SPACE ? 0
2570 : reg_parm_stack_space));
2571 if (old_stack_level == 0)
2573 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2574 NULL_RTX);
2575 old_stack_pointer_delta = stack_pointer_delta;
2576 old_pending_adj = pending_stack_adjust;
2577 pending_stack_adjust = 0;
2578 /* stack_arg_under_construction says whether a stack
2579 arg is being constructed at the old stack level.
2580 Pushing the stack gets a clean outgoing argument
2581 block. */
2582 old_stack_arg_under_construction
2583 = stack_arg_under_construction;
2584 stack_arg_under_construction = 0;
2585 /* Make a new map for the new argument list. */
2586 if (stack_usage_map_buf)
2587 free (stack_usage_map_buf);
2588 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2589 stack_usage_map = stack_usage_map_buf;
2590 highest_outgoing_arg_in_use = 0;
2592 allocate_dynamic_stack_space (push_size, NULL_RTX,
2593 BITS_PER_UNIT);
2596 /* If argument evaluation might modify the stack pointer,
2597 copy the address of the argument list to a register. */
2598 for (i = 0; i < num_actuals; i++)
2599 if (args[i].pass_on_stack)
2601 argblock = copy_addr_to_reg (argblock);
2602 break;
2606 compute_argument_addresses (args, argblock, num_actuals);
2608 /* If we push args individually in reverse order, perform stack alignment
2609 before the first push (the last arg). */
2610 if (PUSH_ARGS_REVERSED && argblock == 0
2611 && adjusted_args_size.constant != unadjusted_args_size)
2613 /* When the stack adjustment is pending, we get better code
2614 by combining the adjustments. */
2615 if (pending_stack_adjust
2616 && ! (flags & ECF_LIBCALL_BLOCK)
2617 && ! inhibit_defer_pop)
2619 pending_stack_adjust
2620 = (combine_pending_stack_adjustment_and_call
2621 (unadjusted_args_size,
2622 &adjusted_args_size,
2623 preferred_unit_stack_boundary));
2624 do_pending_stack_adjust ();
2626 else if (argblock == 0)
2627 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2628 - unadjusted_args_size));
2630 /* Now that the stack is properly aligned, pops can't safely
2631 be deferred during the evaluation of the arguments. */
2632 NO_DEFER_POP;
2634 funexp = rtx_for_function_call (fndecl, addr);
2636 /* Figure out the register where the value, if any, will come back. */
2637 valreg = 0;
2638 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2639 && ! structure_value_addr)
2641 if (pcc_struct_value)
2642 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2643 fndecl, NULL, (pass == 0));
2644 else
2645 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2646 (pass == 0));
2648 /* If VALREG is a PARALLEL whose first member has a zero
2649 offset, use that. This is for targets such as m68k that
2650 return the same value in multiple places. */
2651 if (GET_CODE (valreg) == PARALLEL)
2653 rtx elem = XVECEXP (valreg, 0, 0);
2654 rtx where = XEXP (elem, 0);
2655 rtx offset = XEXP (elem, 1);
2656 if (offset == const0_rtx
2657 && GET_MODE (where) == GET_MODE (valreg))
2658 valreg = where;
2662 /* Precompute all register parameters. It isn't safe to compute anything
2663 once we have started filling any specific hard regs. */
2664 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2666 if (CALL_EXPR_STATIC_CHAIN (exp))
2667 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2668 else
2669 static_chain_value = 0;
2671 #ifdef REG_PARM_STACK_SPACE
2672 /* Save the fixed argument area if it's part of the caller's frame and
2673 is clobbered by argument setup for this call. */
2674 if (ACCUMULATE_OUTGOING_ARGS && pass)
2675 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2676 &low_to_save, &high_to_save);
2677 #endif
2679 /* Now store (and compute if necessary) all non-register parms.
2680 These come before register parms, since they can require block-moves,
2681 which could clobber the registers used for register parms.
2682 Parms which have partial registers are not stored here,
2683 but we do preallocate space here if they want that. */
2685 for (i = 0; i < num_actuals; i++)
2686 if (args[i].reg == 0 || args[i].pass_on_stack)
2688 rtx before_arg = get_last_insn ();
2690 if (store_one_arg (&args[i], argblock, flags,
2691 adjusted_args_size.var != 0,
2692 reg_parm_stack_space)
2693 || (pass == 0
2694 && check_sibcall_argument_overlap (before_arg,
2695 &args[i], 1)))
2696 sibcall_failure = 1;
2698 if (flags & ECF_CONST
2699 && args[i].stack
2700 && args[i].value == args[i].stack)
2701 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2702 gen_rtx_USE (VOIDmode,
2703 args[i].value),
2704 call_fusage);
2707 /* If we have a parm that is passed in registers but not in memory
2708 and whose alignment does not permit a direct copy into registers,
2709 make a group of pseudos that correspond to each register that we
2710 will later fill. */
2711 if (STRICT_ALIGNMENT)
2712 store_unaligned_arguments_into_pseudos (args, num_actuals);
2714 /* Now store any partially-in-registers parm.
2715 This is the last place a block-move can happen. */
2716 if (reg_parm_seen)
2717 for (i = 0; i < num_actuals; i++)
2718 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2720 rtx before_arg = get_last_insn ();
2722 if (store_one_arg (&args[i], argblock, flags,
2723 adjusted_args_size.var != 0,
2724 reg_parm_stack_space)
2725 || (pass == 0
2726 && check_sibcall_argument_overlap (before_arg,
2727 &args[i], 1)))
2728 sibcall_failure = 1;
2731 /* If we pushed args in forward order, perform stack alignment
2732 after pushing the last arg. */
2733 if (!PUSH_ARGS_REVERSED && argblock == 0)
2734 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2735 - unadjusted_args_size));
2737 /* If register arguments require space on the stack and stack space
2738 was not preallocated, allocate stack space here for arguments
2739 passed in registers. */
2740 if (OUTGOING_REG_PARM_STACK_SPACE && !ACCUMULATE_OUTGOING_ARGS
2741 && must_preallocate == 0 && reg_parm_stack_space > 0)
2742 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2744 /* Pass the function the address in which to return a
2745 structure value. */
2746 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2748 structure_value_addr
2749 = convert_memory_address (Pmode, structure_value_addr);
2750 emit_move_insn (struct_value,
2751 force_reg (Pmode,
2752 force_operand (structure_value_addr,
2753 NULL_RTX)));
2755 if (REG_P (struct_value))
2756 use_reg (&call_fusage, struct_value);
2759 funexp = prepare_call_address (funexp, static_chain_value,
2760 &call_fusage, reg_parm_seen, pass == 0);
2762 load_register_parameters (args, num_actuals, &call_fusage, flags,
2763 pass == 0, &sibcall_failure);
2765 /* Save a pointer to the last insn before the call, so that we can
2766 later safely search backwards to find the CALL_INSN. */
2767 before_call = get_last_insn ();
2769 /* Set up next argument register. For sibling calls on machines
2770 with register windows this should be the incoming register. */
2771 #ifdef FUNCTION_INCOMING_ARG
2772 if (pass == 0)
2773 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2774 void_type_node, 1);
2775 else
2776 #endif
2777 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2778 void_type_node, 1);
2780 /* All arguments and registers used for the call must be set up by
2781 now! */
2783 /* Stack must be properly aligned now. */
2784 gcc_assert (!pass
2785 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2787 /* Generate the actual call instruction. */
2788 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2789 adjusted_args_size.constant, struct_value_size,
2790 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2791 flags, & args_so_far);
2793 /* If a non-BLKmode value is returned at the most significant end
2794 of a register, shift the register right by the appropriate amount
2795 and update VALREG accordingly. BLKmode values are handled by the
2796 group load/store machinery below. */
2797 if (!structure_value_addr
2798 && !pcc_struct_value
2799 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2800 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2802 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2803 sibcall_failure = 1;
2804 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2807 /* If call is cse'able, make appropriate pair of reg-notes around it.
2808 Test valreg so we don't crash; may safely ignore `const'
2809 if return type is void. Disable for PARALLEL return values, because
2810 we have no way to move such values into a pseudo register. */
2811 if (pass && (flags & ECF_LIBCALL_BLOCK))
2813 rtx insns;
2814 rtx insn;
2815 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2817 insns = get_insns ();
2819 /* Expansion of block moves possibly introduced a loop that may
2820 not appear inside libcall block. */
2821 for (insn = insns; insn; insn = NEXT_INSN (insn))
2822 if (JUMP_P (insn))
2823 failed = true;
2825 if (failed)
2827 end_sequence ();
2828 emit_insn (insns);
2830 else
2832 rtx note = 0;
2833 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2835 /* Mark the return value as a pointer if needed. */
2836 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2837 mark_reg_pointer (temp,
2838 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2840 end_sequence ();
2841 if (flag_unsafe_math_optimizations
2842 && fndecl
2843 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2844 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2845 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2846 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2847 note = gen_rtx_fmt_e (SQRT,
2848 GET_MODE (temp),
2849 args[0].initial_value);
2850 else
2852 /* Construct an "equal form" for the value which
2853 mentions all the arguments in order as well as
2854 the function name. */
2855 for (i = 0; i < num_actuals; i++)
2856 note = gen_rtx_EXPR_LIST (VOIDmode,
2857 args[i].initial_value, note);
2858 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2860 if (flags & ECF_PURE)
2861 note = gen_rtx_EXPR_LIST (VOIDmode,
2862 gen_rtx_USE (VOIDmode,
2863 gen_rtx_MEM (BLKmode,
2864 gen_rtx_SCRATCH (VOIDmode))),
2865 note);
2867 emit_libcall_block (insns, temp, valreg, note);
2869 valreg = temp;
2872 else if (pass && (flags & ECF_MALLOC))
2874 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2875 rtx last, insns;
2877 /* The return value from a malloc-like function is a pointer. */
2878 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2879 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2881 emit_move_insn (temp, valreg);
2883 /* The return value from a malloc-like function can not alias
2884 anything else. */
2885 last = get_last_insn ();
2886 REG_NOTES (last) =
2887 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2889 /* Write out the sequence. */
2890 insns = get_insns ();
2891 end_sequence ();
2892 emit_insn (insns);
2893 valreg = temp;
2896 /* For calls to `setjmp', etc., inform
2897 function.c:setjmp_warnings that it should complain if
2898 nonvolatile values are live. For functions that cannot
2899 return, inform flow that control does not fall through. */
2901 if ((flags & ECF_NORETURN) || pass == 0)
2903 /* The barrier must be emitted
2904 immediately after the CALL_INSN. Some ports emit more
2905 than just a CALL_INSN above, so we must search for it here. */
2907 rtx last = get_last_insn ();
2908 while (!CALL_P (last))
2910 last = PREV_INSN (last);
2911 /* There was no CALL_INSN? */
2912 gcc_assert (last != before_call);
2915 emit_barrier_after (last);
2917 /* Stack adjustments after a noreturn call are dead code.
2918 However when NO_DEFER_POP is in effect, we must preserve
2919 stack_pointer_delta. */
2920 if (inhibit_defer_pop == 0)
2922 stack_pointer_delta = old_stack_allocated;
2923 pending_stack_adjust = 0;
2927 /* If value type not void, return an rtx for the value. */
2929 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2930 || ignore)
2931 target = const0_rtx;
2932 else if (structure_value_addr)
2934 if (target == 0 || !MEM_P (target))
2936 target
2937 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2938 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2939 structure_value_addr));
2940 set_mem_attributes (target, exp, 1);
2943 else if (pcc_struct_value)
2945 /* This is the special C++ case where we need to
2946 know what the true target was. We take care to
2947 never use this value more than once in one expression. */
2948 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2949 copy_to_reg (valreg));
2950 set_mem_attributes (target, exp, 1);
2952 /* Handle calls that return values in multiple non-contiguous locations.
2953 The Irix 6 ABI has examples of this. */
2954 else if (GET_CODE (valreg) == PARALLEL)
2956 if (target == 0)
2958 /* This will only be assigned once, so it can be readonly. */
2959 tree nt = build_qualified_type (TREE_TYPE (exp),
2960 (TYPE_QUALS (TREE_TYPE (exp))
2961 | TYPE_QUAL_CONST));
2963 target = assign_temp (nt, 0, 1, 1);
2966 if (! rtx_equal_p (target, valreg))
2967 emit_group_store (target, valreg, TREE_TYPE (exp),
2968 int_size_in_bytes (TREE_TYPE (exp)));
2970 /* We can not support sibling calls for this case. */
2971 sibcall_failure = 1;
2973 else if (target
2974 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2975 && GET_MODE (target) == GET_MODE (valreg))
2977 bool may_overlap = false;
2979 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2980 reg to a plain register. */
2981 if (!REG_P (target) || HARD_REGISTER_P (target))
2982 valreg = avoid_likely_spilled_reg (valreg);
2984 /* If TARGET is a MEM in the argument area, and we have
2985 saved part of the argument area, then we can't store
2986 directly into TARGET as it may get overwritten when we
2987 restore the argument save area below. Don't work too
2988 hard though and simply force TARGET to a register if it
2989 is a MEM; the optimizer is quite likely to sort it out. */
2990 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2991 for (i = 0; i < num_actuals; i++)
2992 if (args[i].save_area)
2994 may_overlap = true;
2995 break;
2998 if (may_overlap)
2999 target = copy_to_reg (valreg);
3000 else
3002 /* TARGET and VALREG cannot be equal at this point
3003 because the latter would not have
3004 REG_FUNCTION_VALUE_P true, while the former would if
3005 it were referring to the same register.
3007 If they refer to the same register, this move will be
3008 a no-op, except when function inlining is being
3009 done. */
3010 emit_move_insn (target, valreg);
3012 /* If we are setting a MEM, this code must be executed.
3013 Since it is emitted after the call insn, sibcall
3014 optimization cannot be performed in that case. */
3015 if (MEM_P (target))
3016 sibcall_failure = 1;
3019 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3021 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3023 /* We can not support sibling calls for this case. */
3024 sibcall_failure = 1;
3026 else
3027 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3029 if (targetm.calls.promote_function_return(funtype))
3031 /* If we promoted this return value, make the proper SUBREG.
3032 TARGET might be const0_rtx here, so be careful. */
3033 if (REG_P (target)
3034 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3035 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3037 tree type = TREE_TYPE (exp);
3038 int unsignedp = TYPE_UNSIGNED (type);
3039 int offset = 0;
3040 enum machine_mode pmode;
3042 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
3043 /* If we don't promote as expected, something is wrong. */
3044 gcc_assert (GET_MODE (target) == pmode);
3046 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3047 && (GET_MODE_SIZE (GET_MODE (target))
3048 > GET_MODE_SIZE (TYPE_MODE (type))))
3050 offset = GET_MODE_SIZE (GET_MODE (target))
3051 - GET_MODE_SIZE (TYPE_MODE (type));
3052 if (! BYTES_BIG_ENDIAN)
3053 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3054 else if (! WORDS_BIG_ENDIAN)
3055 offset %= UNITS_PER_WORD;
3057 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3058 SUBREG_PROMOTED_VAR_P (target) = 1;
3059 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3063 /* If size of args is variable or this was a constructor call for a stack
3064 argument, restore saved stack-pointer value. */
3066 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3068 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3069 stack_pointer_delta = old_stack_pointer_delta;
3070 pending_stack_adjust = old_pending_adj;
3071 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3072 stack_arg_under_construction = old_stack_arg_under_construction;
3073 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3074 stack_usage_map = initial_stack_usage_map;
3075 sibcall_failure = 1;
3077 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3079 #ifdef REG_PARM_STACK_SPACE
3080 if (save_area)
3081 restore_fixed_argument_area (save_area, argblock,
3082 high_to_save, low_to_save);
3083 #endif
3085 /* If we saved any argument areas, restore them. */
3086 for (i = 0; i < num_actuals; i++)
3087 if (args[i].save_area)
3089 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3090 rtx stack_area
3091 = gen_rtx_MEM (save_mode,
3092 memory_address (save_mode,
3093 XEXP (args[i].stack_slot, 0)));
3095 if (save_mode != BLKmode)
3096 emit_move_insn (stack_area, args[i].save_area);
3097 else
3098 emit_block_move (stack_area, args[i].save_area,
3099 GEN_INT (args[i].locate.size.constant),
3100 BLOCK_OP_CALL_PARM);
3103 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3104 stack_usage_map = initial_stack_usage_map;
3107 /* If this was alloca, record the new stack level for nonlocal gotos.
3108 Check for the handler slots since we might not have a save area
3109 for non-local gotos. */
3111 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3112 update_nonlocal_goto_save_area ();
3114 /* Free up storage we no longer need. */
3115 for (i = 0; i < num_actuals; ++i)
3116 if (args[i].aligned_regs)
3117 free (args[i].aligned_regs);
3119 insns = get_insns ();
3120 end_sequence ();
3122 if (pass == 0)
3124 tail_call_insns = insns;
3126 /* Restore the pending stack adjustment now that we have
3127 finished generating the sibling call sequence. */
3129 pending_stack_adjust = save_pending_stack_adjust;
3130 stack_pointer_delta = save_stack_pointer_delta;
3132 /* Prepare arg structure for next iteration. */
3133 for (i = 0; i < num_actuals; i++)
3135 args[i].value = 0;
3136 args[i].aligned_regs = 0;
3137 args[i].stack = 0;
3140 sbitmap_free (stored_args_map);
3142 else
3144 normal_call_insns = insns;
3146 /* Verify that we've deallocated all the stack we used. */
3147 gcc_assert ((flags & ECF_NORETURN)
3148 || (old_stack_allocated
3149 == stack_pointer_delta - pending_stack_adjust));
3152 /* If something prevents making this a sibling call,
3153 zero out the sequence. */
3154 if (sibcall_failure)
3155 tail_call_insns = NULL_RTX;
3156 else
3157 break;
3160 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3161 arguments too, as argument area is now clobbered by the call. */
3162 if (tail_call_insns)
3164 emit_insn (tail_call_insns);
3165 cfun->tail_call_emit = true;
3167 else
3168 emit_insn (normal_call_insns);
3170 currently_expanding_call--;
3172 /* If this function returns with the stack pointer depressed, ensure
3173 this block saves and restores the stack pointer, show it was
3174 changed, and adjust for any outgoing arg space. */
3175 if (flags & ECF_SP_DEPRESSED)
3177 clear_pending_stack_adjust ();
3178 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3179 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3182 if (stack_usage_map_buf)
3183 free (stack_usage_map_buf);
3185 return target;
3188 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3189 this function's incoming arguments.
3191 At the start of RTL generation we know the only REG_EQUIV notes
3192 in the rtl chain are those for incoming arguments, so we can look
3193 for REG_EQUIV notes between the start of the function and the
3194 NOTE_INSN_FUNCTION_BEG.
3196 This is (slight) overkill. We could keep track of the highest
3197 argument we clobber and be more selective in removing notes, but it
3198 does not seem to be worth the effort. */
3200 void
3201 fixup_tail_calls (void)
3203 rtx insn;
3205 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3207 rtx note;
3209 /* There are never REG_EQUIV notes for the incoming arguments
3210 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3211 if (NOTE_P (insn)
3212 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3213 break;
3215 note = find_reg_note (insn, REG_EQUIV, 0);
3216 if (note)
3217 remove_note (insn, note);
3218 note = find_reg_note (insn, REG_EQUIV, 0);
3219 gcc_assert (!note);
3223 /* Traverse a list of TYPES and expand all complex types into their
3224 components. */
3225 static tree
3226 split_complex_types (tree types)
3228 tree p;
3230 /* Before allocating memory, check for the common case of no complex. */
3231 for (p = types; p; p = TREE_CHAIN (p))
3233 tree type = TREE_VALUE (p);
3234 if (TREE_CODE (type) == COMPLEX_TYPE
3235 && targetm.calls.split_complex_arg (type))
3236 goto found;
3238 return types;
3240 found:
3241 types = copy_list (types);
3243 for (p = types; p; p = TREE_CHAIN (p))
3245 tree complex_type = TREE_VALUE (p);
3247 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3248 && targetm.calls.split_complex_arg (complex_type))
3250 tree next, imag;
3252 /* Rewrite complex type with component type. */
3253 TREE_VALUE (p) = TREE_TYPE (complex_type);
3254 next = TREE_CHAIN (p);
3256 /* Add another component type for the imaginary part. */
3257 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3258 TREE_CHAIN (p) = imag;
3259 TREE_CHAIN (imag) = next;
3261 /* Skip the newly created node. */
3262 p = TREE_CHAIN (p);
3266 return types;
3269 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3270 The RETVAL parameter specifies whether return value needs to be saved, other
3271 parameters are documented in the emit_library_call function below. */
3273 static rtx
3274 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3275 enum libcall_type fn_type,
3276 enum machine_mode outmode, int nargs, va_list p)
3278 /* Total size in bytes of all the stack-parms scanned so far. */
3279 struct args_size args_size;
3280 /* Size of arguments before any adjustments (such as rounding). */
3281 struct args_size original_args_size;
3282 int argnum;
3283 rtx fun;
3284 int inc;
3285 int count;
3286 rtx argblock = 0;
3287 CUMULATIVE_ARGS args_so_far;
3288 struct arg
3290 rtx value;
3291 enum machine_mode mode;
3292 rtx reg;
3293 int partial;
3294 struct locate_and_pad_arg_data locate;
3295 rtx save_area;
3297 struct arg *argvec;
3298 int old_inhibit_defer_pop = inhibit_defer_pop;
3299 rtx call_fusage = 0;
3300 rtx mem_value = 0;
3301 rtx valreg;
3302 int pcc_struct_value = 0;
3303 int struct_value_size = 0;
3304 int flags;
3305 int reg_parm_stack_space = 0;
3306 int needed;
3307 rtx before_call;
3308 tree tfom; /* type_for_mode (outmode, 0) */
3310 #ifdef REG_PARM_STACK_SPACE
3311 /* Define the boundary of the register parm stack space that needs to be
3312 save, if any. */
3313 int low_to_save, high_to_save;
3314 rtx save_area = 0; /* Place that it is saved. */
3315 #endif
3317 /* Size of the stack reserved for parameter registers. */
3318 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3319 char *initial_stack_usage_map = stack_usage_map;
3320 char *stack_usage_map_buf = NULL;
3322 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3324 #ifdef REG_PARM_STACK_SPACE
3325 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3326 #endif
3328 /* By default, library functions can not throw. */
3329 flags = ECF_NOTHROW;
3331 switch (fn_type)
3333 case LCT_NORMAL:
3334 break;
3335 case LCT_CONST:
3336 flags |= ECF_CONST;
3337 break;
3338 case LCT_PURE:
3339 flags |= ECF_PURE;
3340 break;
3341 case LCT_CONST_MAKE_BLOCK:
3342 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3343 break;
3344 case LCT_PURE_MAKE_BLOCK:
3345 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3346 break;
3347 case LCT_NORETURN:
3348 flags |= ECF_NORETURN;
3349 break;
3350 case LCT_THROW:
3351 flags = ECF_NORETURN;
3352 break;
3353 case LCT_RETURNS_TWICE:
3354 flags = ECF_RETURNS_TWICE;
3355 break;
3357 fun = orgfun;
3359 /* Ensure current function's preferred stack boundary is at least
3360 what we need. */
3361 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3362 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3364 /* If this kind of value comes back in memory,
3365 decide where in memory it should come back. */
3366 if (outmode != VOIDmode)
3368 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3369 if (aggregate_value_p (tfom, 0))
3371 #ifdef PCC_STATIC_STRUCT_RETURN
3372 rtx pointer_reg
3373 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3374 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3375 pcc_struct_value = 1;
3376 if (value == 0)
3377 value = gen_reg_rtx (outmode);
3378 #else /* not PCC_STATIC_STRUCT_RETURN */
3379 struct_value_size = GET_MODE_SIZE (outmode);
3380 if (value != 0 && MEM_P (value))
3381 mem_value = value;
3382 else
3383 mem_value = assign_temp (tfom, 0, 1, 1);
3384 #endif
3385 /* This call returns a big structure. */
3386 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3389 else
3390 tfom = void_type_node;
3392 /* ??? Unfinished: must pass the memory address as an argument. */
3394 /* Copy all the libcall-arguments out of the varargs data
3395 and into a vector ARGVEC.
3397 Compute how to pass each argument. We only support a very small subset
3398 of the full argument passing conventions to limit complexity here since
3399 library functions shouldn't have many args. */
3401 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3402 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3404 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3405 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3406 #else
3407 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3408 #endif
3410 args_size.constant = 0;
3411 args_size.var = 0;
3413 count = 0;
3415 /* Now we are about to start emitting insns that can be deleted
3416 if a libcall is deleted. */
3417 if (flags & ECF_LIBCALL_BLOCK)
3418 start_sequence ();
3420 push_temp_slots ();
3422 /* If there's a structure value address to be passed,
3423 either pass it in the special place, or pass it as an extra argument. */
3424 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3426 rtx addr = XEXP (mem_value, 0);
3428 nargs++;
3430 /* Make sure it is a reasonable operand for a move or push insn. */
3431 if (!REG_P (addr) && !MEM_P (addr)
3432 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3433 addr = force_operand (addr, NULL_RTX);
3435 argvec[count].value = addr;
3436 argvec[count].mode = Pmode;
3437 argvec[count].partial = 0;
3439 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3440 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3441 NULL_TREE, 1) == 0);
3443 locate_and_pad_parm (Pmode, NULL_TREE,
3444 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3446 #else
3447 argvec[count].reg != 0,
3448 #endif
3449 0, NULL_TREE, &args_size, &argvec[count].locate);
3451 if (argvec[count].reg == 0 || argvec[count].partial != 0
3452 || reg_parm_stack_space > 0)
3453 args_size.constant += argvec[count].locate.size.constant;
3455 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3457 count++;
3460 for (; count < nargs; count++)
3462 rtx val = va_arg (p, rtx);
3463 enum machine_mode mode = va_arg (p, enum machine_mode);
3465 /* We cannot convert the arg value to the mode the library wants here;
3466 must do it earlier where we know the signedness of the arg. */
3467 gcc_assert (mode != BLKmode
3468 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3470 /* Make sure it is a reasonable operand for a move or push insn. */
3471 if (!REG_P (val) && !MEM_P (val)
3472 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3473 val = force_operand (val, NULL_RTX);
3475 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3477 rtx slot;
3478 int must_copy
3479 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3481 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3482 functions, so we have to pretend this isn't such a function. */
3483 if (flags & ECF_LIBCALL_BLOCK)
3485 rtx insns = get_insns ();
3486 end_sequence ();
3487 emit_insn (insns);
3489 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3491 /* If this was a CONST function, it is now PURE since
3492 it now reads memory. */
3493 if (flags & ECF_CONST)
3495 flags &= ~ECF_CONST;
3496 flags |= ECF_PURE;
3499 if (GET_MODE (val) == MEM && !must_copy)
3500 slot = val;
3501 else
3503 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3504 0, 1, 1);
3505 emit_move_insn (slot, val);
3508 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3509 gen_rtx_USE (VOIDmode, slot),
3510 call_fusage);
3511 if (must_copy)
3512 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3513 gen_rtx_CLOBBER (VOIDmode,
3514 slot),
3515 call_fusage);
3517 mode = Pmode;
3518 val = force_operand (XEXP (slot, 0), NULL_RTX);
3521 argvec[count].value = val;
3522 argvec[count].mode = mode;
3524 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3526 argvec[count].partial
3527 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3529 locate_and_pad_parm (mode, NULL_TREE,
3530 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3532 #else
3533 argvec[count].reg != 0,
3534 #endif
3535 argvec[count].partial,
3536 NULL_TREE, &args_size, &argvec[count].locate);
3538 gcc_assert (!argvec[count].locate.size.var);
3540 if (argvec[count].reg == 0 || argvec[count].partial != 0
3541 || reg_parm_stack_space > 0)
3542 args_size.constant += argvec[count].locate.size.constant;
3544 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3547 /* If this machine requires an external definition for library
3548 functions, write one out. */
3549 assemble_external_libcall (fun);
3551 original_args_size = args_size;
3552 args_size.constant = (((args_size.constant
3553 + stack_pointer_delta
3554 + STACK_BYTES - 1)
3555 / STACK_BYTES
3556 * STACK_BYTES)
3557 - stack_pointer_delta);
3559 args_size.constant = MAX (args_size.constant,
3560 reg_parm_stack_space);
3562 if (!OUTGOING_REG_PARM_STACK_SPACE)
3563 args_size.constant -= reg_parm_stack_space;
3565 if (args_size.constant > current_function_outgoing_args_size)
3566 current_function_outgoing_args_size = args_size.constant;
3568 if (ACCUMULATE_OUTGOING_ARGS)
3570 /* Since the stack pointer will never be pushed, it is possible for
3571 the evaluation of a parm to clobber something we have already
3572 written to the stack. Since most function calls on RISC machines
3573 do not use the stack, this is uncommon, but must work correctly.
3575 Therefore, we save any area of the stack that was already written
3576 and that we are using. Here we set up to do this by making a new
3577 stack usage map from the old one.
3579 Another approach might be to try to reorder the argument
3580 evaluations to avoid this conflicting stack usage. */
3582 needed = args_size.constant;
3584 /* Since we will be writing into the entire argument area, the
3585 map must be allocated for its entire size, not just the part that
3586 is the responsibility of the caller. */
3587 if (!OUTGOING_REG_PARM_STACK_SPACE)
3588 needed += reg_parm_stack_space;
3590 #ifdef ARGS_GROW_DOWNWARD
3591 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3592 needed + 1);
3593 #else
3594 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3595 needed);
3596 #endif
3597 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3598 stack_usage_map = stack_usage_map_buf;
3600 if (initial_highest_arg_in_use)
3601 memcpy (stack_usage_map, initial_stack_usage_map,
3602 initial_highest_arg_in_use);
3604 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3605 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3606 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3607 needed = 0;
3609 /* We must be careful to use virtual regs before they're instantiated,
3610 and real regs afterwards. Loop optimization, for example, can create
3611 new libcalls after we've instantiated the virtual regs, and if we
3612 use virtuals anyway, they won't match the rtl patterns. */
3614 if (virtuals_instantiated)
3615 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3616 else
3617 argblock = virtual_outgoing_args_rtx;
3619 else
3621 if (!PUSH_ARGS)
3622 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3625 /* If we push args individually in reverse order, perform stack alignment
3626 before the first push (the last arg). */
3627 if (argblock == 0 && PUSH_ARGS_REVERSED)
3628 anti_adjust_stack (GEN_INT (args_size.constant
3629 - original_args_size.constant));
3631 if (PUSH_ARGS_REVERSED)
3633 inc = -1;
3634 argnum = nargs - 1;
3636 else
3638 inc = 1;
3639 argnum = 0;
3642 #ifdef REG_PARM_STACK_SPACE
3643 if (ACCUMULATE_OUTGOING_ARGS)
3645 /* The argument list is the property of the called routine and it
3646 may clobber it. If the fixed area has been used for previous
3647 parameters, we must save and restore it. */
3648 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3649 &low_to_save, &high_to_save);
3651 #endif
3653 /* Push the args that need to be pushed. */
3655 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3656 are to be pushed. */
3657 for (count = 0; count < nargs; count++, argnum += inc)
3659 enum machine_mode mode = argvec[argnum].mode;
3660 rtx val = argvec[argnum].value;
3661 rtx reg = argvec[argnum].reg;
3662 int partial = argvec[argnum].partial;
3663 int lower_bound = 0, upper_bound = 0, i;
3665 if (! (reg != 0 && partial == 0))
3667 if (ACCUMULATE_OUTGOING_ARGS)
3669 /* If this is being stored into a pre-allocated, fixed-size,
3670 stack area, save any previous data at that location. */
3672 #ifdef ARGS_GROW_DOWNWARD
3673 /* stack_slot is negative, but we want to index stack_usage_map
3674 with positive values. */
3675 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3676 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3677 #else
3678 lower_bound = argvec[argnum].locate.offset.constant;
3679 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3680 #endif
3682 i = lower_bound;
3683 /* Don't worry about things in the fixed argument area;
3684 it has already been saved. */
3685 if (i < reg_parm_stack_space)
3686 i = reg_parm_stack_space;
3687 while (i < upper_bound && stack_usage_map[i] == 0)
3688 i++;
3690 if (i < upper_bound)
3692 /* We need to make a save area. */
3693 unsigned int size
3694 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3695 enum machine_mode save_mode
3696 = mode_for_size (size, MODE_INT, 1);
3697 rtx adr
3698 = plus_constant (argblock,
3699 argvec[argnum].locate.offset.constant);
3700 rtx stack_area
3701 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3703 if (save_mode == BLKmode)
3705 argvec[argnum].save_area
3706 = assign_stack_temp (BLKmode,
3707 argvec[argnum].locate.size.constant,
3710 emit_block_move (validize_mem (argvec[argnum].save_area),
3711 stack_area,
3712 GEN_INT (argvec[argnum].locate.size.constant),
3713 BLOCK_OP_CALL_PARM);
3715 else
3717 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3719 emit_move_insn (argvec[argnum].save_area, stack_area);
3724 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3725 partial, reg, 0, argblock,
3726 GEN_INT (argvec[argnum].locate.offset.constant),
3727 reg_parm_stack_space,
3728 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3730 /* Now mark the segment we just used. */
3731 if (ACCUMULATE_OUTGOING_ARGS)
3732 for (i = lower_bound; i < upper_bound; i++)
3733 stack_usage_map[i] = 1;
3735 NO_DEFER_POP;
3737 if (flags & ECF_CONST)
3739 rtx use;
3741 /* Indicate argument access so that alias.c knows that these
3742 values are live. */
3743 if (argblock)
3744 use = plus_constant (argblock,
3745 argvec[argnum].locate.offset.constant);
3746 else
3747 /* When arguments are pushed, trying to tell alias.c where
3748 exactly this argument is won't work, because the
3749 auto-increment causes confusion. So we merely indicate
3750 that we access something with a known mode somewhere on
3751 the stack. */
3752 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3753 gen_rtx_SCRATCH (Pmode));
3754 use = gen_rtx_MEM (argvec[argnum].mode, use);
3755 use = gen_rtx_USE (VOIDmode, use);
3756 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3761 /* If we pushed args in forward order, perform stack alignment
3762 after pushing the last arg. */
3763 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3764 anti_adjust_stack (GEN_INT (args_size.constant
3765 - original_args_size.constant));
3767 if (PUSH_ARGS_REVERSED)
3768 argnum = nargs - 1;
3769 else
3770 argnum = 0;
3772 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3774 /* Now load any reg parms into their regs. */
3776 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3777 are to be pushed. */
3778 for (count = 0; count < nargs; count++, argnum += inc)
3780 enum machine_mode mode = argvec[argnum].mode;
3781 rtx val = argvec[argnum].value;
3782 rtx reg = argvec[argnum].reg;
3783 int partial = argvec[argnum].partial;
3785 /* Handle calls that pass values in multiple non-contiguous
3786 locations. The PA64 has examples of this for library calls. */
3787 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3788 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3789 else if (reg != 0 && partial == 0)
3790 emit_move_insn (reg, val);
3792 NO_DEFER_POP;
3795 /* Any regs containing parms remain in use through the call. */
3796 for (count = 0; count < nargs; count++)
3798 rtx reg = argvec[count].reg;
3799 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3800 use_group_regs (&call_fusage, reg);
3801 else if (reg != 0)
3803 int partial = argvec[count].partial;
3804 if (partial)
3806 int nregs;
3807 gcc_assert (partial % UNITS_PER_WORD == 0);
3808 nregs = partial / UNITS_PER_WORD;
3809 use_regs (&call_fusage, REGNO (reg), nregs);
3811 else
3812 use_reg (&call_fusage, reg);
3816 /* Pass the function the address in which to return a structure value. */
3817 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3819 emit_move_insn (struct_value,
3820 force_reg (Pmode,
3821 force_operand (XEXP (mem_value, 0),
3822 NULL_RTX)));
3823 if (REG_P (struct_value))
3824 use_reg (&call_fusage, struct_value);
3827 /* Don't allow popping to be deferred, since then
3828 cse'ing of library calls could delete a call and leave the pop. */
3829 NO_DEFER_POP;
3830 valreg = (mem_value == 0 && outmode != VOIDmode
3831 ? hard_libcall_value (outmode) : NULL_RTX);
3833 /* Stack must be properly aligned now. */
3834 gcc_assert (!(stack_pointer_delta
3835 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3837 before_call = get_last_insn ();
3839 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3840 will set inhibit_defer_pop to that value. */
3841 /* The return type is needed to decide how many bytes the function pops.
3842 Signedness plays no role in that, so for simplicity, we pretend it's
3843 always signed. We also assume that the list of arguments passed has
3844 no impact, so we pretend it is unknown. */
3846 emit_call_1 (fun, NULL,
3847 get_identifier (XSTR (orgfun, 0)),
3848 build_function_type (tfom, NULL_TREE),
3849 original_args_size.constant, args_size.constant,
3850 struct_value_size,
3851 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3852 valreg,
3853 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3855 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3856 that it should complain if nonvolatile values are live. For
3857 functions that cannot return, inform flow that control does not
3858 fall through. */
3860 if (flags & ECF_NORETURN)
3862 /* The barrier note must be emitted
3863 immediately after the CALL_INSN. Some ports emit more than
3864 just a CALL_INSN above, so we must search for it here. */
3866 rtx last = get_last_insn ();
3867 while (!CALL_P (last))
3869 last = PREV_INSN (last);
3870 /* There was no CALL_INSN? */
3871 gcc_assert (last != before_call);
3874 emit_barrier_after (last);
3877 /* Now restore inhibit_defer_pop to its actual original value. */
3878 OK_DEFER_POP;
3880 /* If call is cse'able, make appropriate pair of reg-notes around it.
3881 Test valreg so we don't crash; may safely ignore `const'
3882 if return type is void. Disable for PARALLEL return values, because
3883 we have no way to move such values into a pseudo register. */
3884 if (flags & ECF_LIBCALL_BLOCK)
3886 rtx insns;
3888 if (valreg == 0)
3890 insns = get_insns ();
3891 end_sequence ();
3892 emit_insn (insns);
3894 else
3896 rtx note = 0;
3897 rtx temp;
3898 int i;
3900 if (GET_CODE (valreg) == PARALLEL)
3902 temp = gen_reg_rtx (outmode);
3903 emit_group_store (temp, valreg, NULL_TREE,
3904 GET_MODE_SIZE (outmode));
3905 valreg = temp;
3908 temp = gen_reg_rtx (GET_MODE (valreg));
3910 /* Construct an "equal form" for the value which mentions all the
3911 arguments in order as well as the function name. */
3912 for (i = 0; i < nargs; i++)
3913 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3914 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3916 insns = get_insns ();
3917 end_sequence ();
3919 if (flags & ECF_PURE)
3920 note = gen_rtx_EXPR_LIST (VOIDmode,
3921 gen_rtx_USE (VOIDmode,
3922 gen_rtx_MEM (BLKmode,
3923 gen_rtx_SCRATCH (VOIDmode))),
3924 note);
3926 emit_libcall_block (insns, temp, valreg, note);
3928 valreg = temp;
3931 pop_temp_slots ();
3933 /* Copy the value to the right place. */
3934 if (outmode != VOIDmode && retval)
3936 if (mem_value)
3938 if (value == 0)
3939 value = mem_value;
3940 if (value != mem_value)
3941 emit_move_insn (value, mem_value);
3943 else if (GET_CODE (valreg) == PARALLEL)
3945 if (value == 0)
3946 value = gen_reg_rtx (outmode);
3947 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3949 else
3951 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3952 if (GET_MODE (valreg) != outmode)
3954 int unsignedp = TYPE_UNSIGNED (tfom);
3956 gcc_assert (targetm.calls.promote_function_return (tfom));
3957 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3958 == GET_MODE (valreg));
3960 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3963 if (value != 0)
3964 emit_move_insn (value, valreg);
3965 else
3966 value = valreg;
3970 if (ACCUMULATE_OUTGOING_ARGS)
3972 #ifdef REG_PARM_STACK_SPACE
3973 if (save_area)
3974 restore_fixed_argument_area (save_area, argblock,
3975 high_to_save, low_to_save);
3976 #endif
3978 /* If we saved any argument areas, restore them. */
3979 for (count = 0; count < nargs; count++)
3980 if (argvec[count].save_area)
3982 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3983 rtx adr = plus_constant (argblock,
3984 argvec[count].locate.offset.constant);
3985 rtx stack_area = gen_rtx_MEM (save_mode,
3986 memory_address (save_mode, adr));
3988 if (save_mode == BLKmode)
3989 emit_block_move (stack_area,
3990 validize_mem (argvec[count].save_area),
3991 GEN_INT (argvec[count].locate.size.constant),
3992 BLOCK_OP_CALL_PARM);
3993 else
3994 emit_move_insn (stack_area, argvec[count].save_area);
3997 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3998 stack_usage_map = initial_stack_usage_map;
4001 if (stack_usage_map_buf)
4002 free (stack_usage_map_buf);
4004 return value;
4008 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4009 (emitting the queue unless NO_QUEUE is nonzero),
4010 for a value of mode OUTMODE,
4011 with NARGS different arguments, passed as alternating rtx values
4012 and machine_modes to convert them to.
4014 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4015 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4016 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4017 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4018 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4019 or other LCT_ value for other types of library calls. */
4021 void
4022 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4023 enum machine_mode outmode, int nargs, ...)
4025 va_list p;
4027 va_start (p, nargs);
4028 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4029 va_end (p);
4032 /* Like emit_library_call except that an extra argument, VALUE,
4033 comes second and says where to store the result.
4034 (If VALUE is zero, this function chooses a convenient way
4035 to return the value.
4037 This function returns an rtx for where the value is to be found.
4038 If VALUE is nonzero, VALUE is returned. */
4041 emit_library_call_value (rtx orgfun, rtx value,
4042 enum libcall_type fn_type,
4043 enum machine_mode outmode, int nargs, ...)
4045 rtx result;
4046 va_list p;
4048 va_start (p, nargs);
4049 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4050 nargs, p);
4051 va_end (p);
4053 return result;
4056 /* Store a single argument for a function call
4057 into the register or memory area where it must be passed.
4058 *ARG describes the argument value and where to pass it.
4060 ARGBLOCK is the address of the stack-block for all the arguments,
4061 or 0 on a machine where arguments are pushed individually.
4063 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4064 so must be careful about how the stack is used.
4066 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4067 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4068 that we need not worry about saving and restoring the stack.
4070 FNDECL is the declaration of the function we are calling.
4072 Return nonzero if this arg should cause sibcall failure,
4073 zero otherwise. */
4075 static int
4076 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4077 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4079 tree pval = arg->tree_value;
4080 rtx reg = 0;
4081 int partial = 0;
4082 int used = 0;
4083 int i, lower_bound = 0, upper_bound = 0;
4084 int sibcall_failure = 0;
4086 if (TREE_CODE (pval) == ERROR_MARK)
4087 return 1;
4089 /* Push a new temporary level for any temporaries we make for
4090 this argument. */
4091 push_temp_slots ();
4093 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4095 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4096 save any previous data at that location. */
4097 if (argblock && ! variable_size && arg->stack)
4099 #ifdef ARGS_GROW_DOWNWARD
4100 /* stack_slot is negative, but we want to index stack_usage_map
4101 with positive values. */
4102 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4103 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4104 else
4105 upper_bound = 0;
4107 lower_bound = upper_bound - arg->locate.size.constant;
4108 #else
4109 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4110 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4111 else
4112 lower_bound = 0;
4114 upper_bound = lower_bound + arg->locate.size.constant;
4115 #endif
4117 i = lower_bound;
4118 /* Don't worry about things in the fixed argument area;
4119 it has already been saved. */
4120 if (i < reg_parm_stack_space)
4121 i = reg_parm_stack_space;
4122 while (i < upper_bound && stack_usage_map[i] == 0)
4123 i++;
4125 if (i < upper_bound)
4127 /* We need to make a save area. */
4128 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4129 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4130 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4131 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4133 if (save_mode == BLKmode)
4135 tree ot = TREE_TYPE (arg->tree_value);
4136 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4137 | TYPE_QUAL_CONST));
4139 arg->save_area = assign_temp (nt, 0, 1, 1);
4140 preserve_temp_slots (arg->save_area);
4141 emit_block_move (validize_mem (arg->save_area), stack_area,
4142 GEN_INT (arg->locate.size.constant),
4143 BLOCK_OP_CALL_PARM);
4145 else
4147 arg->save_area = gen_reg_rtx (save_mode);
4148 emit_move_insn (arg->save_area, stack_area);
4154 /* If this isn't going to be placed on both the stack and in registers,
4155 set up the register and number of words. */
4156 if (! arg->pass_on_stack)
4158 if (flags & ECF_SIBCALL)
4159 reg = arg->tail_call_reg;
4160 else
4161 reg = arg->reg;
4162 partial = arg->partial;
4165 /* Being passed entirely in a register. We shouldn't be called in
4166 this case. */
4167 gcc_assert (reg == 0 || partial != 0);
4169 /* If this arg needs special alignment, don't load the registers
4170 here. */
4171 if (arg->n_aligned_regs != 0)
4172 reg = 0;
4174 /* If this is being passed partially in a register, we can't evaluate
4175 it directly into its stack slot. Otherwise, we can. */
4176 if (arg->value == 0)
4178 /* stack_arg_under_construction is nonzero if a function argument is
4179 being evaluated directly into the outgoing argument list and
4180 expand_call must take special action to preserve the argument list
4181 if it is called recursively.
4183 For scalar function arguments stack_usage_map is sufficient to
4184 determine which stack slots must be saved and restored. Scalar
4185 arguments in general have pass_on_stack == 0.
4187 If this argument is initialized by a function which takes the
4188 address of the argument (a C++ constructor or a C function
4189 returning a BLKmode structure), then stack_usage_map is
4190 insufficient and expand_call must push the stack around the
4191 function call. Such arguments have pass_on_stack == 1.
4193 Note that it is always safe to set stack_arg_under_construction,
4194 but this generates suboptimal code if set when not needed. */
4196 if (arg->pass_on_stack)
4197 stack_arg_under_construction++;
4199 arg->value = expand_expr (pval,
4200 (partial
4201 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4202 ? NULL_RTX : arg->stack,
4203 VOIDmode, EXPAND_STACK_PARM);
4205 /* If we are promoting object (or for any other reason) the mode
4206 doesn't agree, convert the mode. */
4208 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4209 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4210 arg->value, arg->unsignedp);
4212 if (arg->pass_on_stack)
4213 stack_arg_under_construction--;
4216 /* Check for overlap with already clobbered argument area. */
4217 if ((flags & ECF_SIBCALL)
4218 && MEM_P (arg->value)
4219 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4220 arg->locate.size.constant))
4221 sibcall_failure = 1;
4223 /* Don't allow anything left on stack from computation
4224 of argument to alloca. */
4225 if (flags & ECF_MAY_BE_ALLOCA)
4226 do_pending_stack_adjust ();
4228 if (arg->value == arg->stack)
4229 /* If the value is already in the stack slot, we are done. */
4231 else if (arg->mode != BLKmode)
4233 int size;
4234 unsigned int parm_align;
4236 /* Argument is a scalar, not entirely passed in registers.
4237 (If part is passed in registers, arg->partial says how much
4238 and emit_push_insn will take care of putting it there.)
4240 Push it, and if its size is less than the
4241 amount of space allocated to it,
4242 also bump stack pointer by the additional space.
4243 Note that in C the default argument promotions
4244 will prevent such mismatches. */
4246 size = GET_MODE_SIZE (arg->mode);
4247 /* Compute how much space the push instruction will push.
4248 On many machines, pushing a byte will advance the stack
4249 pointer by a halfword. */
4250 #ifdef PUSH_ROUNDING
4251 size = PUSH_ROUNDING (size);
4252 #endif
4253 used = size;
4255 /* Compute how much space the argument should get:
4256 round up to a multiple of the alignment for arguments. */
4257 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4258 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4259 / (PARM_BOUNDARY / BITS_PER_UNIT))
4260 * (PARM_BOUNDARY / BITS_PER_UNIT));
4262 /* Compute the alignment of the pushed argument. */
4263 parm_align = arg->locate.boundary;
4264 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4266 int pad = used - size;
4267 if (pad)
4269 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4270 parm_align = MIN (parm_align, pad_align);
4274 /* This isn't already where we want it on the stack, so put it there.
4275 This can either be done with push or copy insns. */
4276 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4277 parm_align, partial, reg, used - size, argblock,
4278 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4279 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4281 /* Unless this is a partially-in-register argument, the argument is now
4282 in the stack. */
4283 if (partial == 0)
4284 arg->value = arg->stack;
4286 else
4288 /* BLKmode, at least partly to be pushed. */
4290 unsigned int parm_align;
4291 int excess;
4292 rtx size_rtx;
4294 /* Pushing a nonscalar.
4295 If part is passed in registers, PARTIAL says how much
4296 and emit_push_insn will take care of putting it there. */
4298 /* Round its size up to a multiple
4299 of the allocation unit for arguments. */
4301 if (arg->locate.size.var != 0)
4303 excess = 0;
4304 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4306 else
4308 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4309 for BLKmode is careful to avoid it. */
4310 excess = (arg->locate.size.constant
4311 - int_size_in_bytes (TREE_TYPE (pval))
4312 + partial);
4313 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4314 NULL_RTX, TYPE_MODE (sizetype), 0);
4317 parm_align = arg->locate.boundary;
4319 /* When an argument is padded down, the block is aligned to
4320 PARM_BOUNDARY, but the actual argument isn't. */
4321 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4323 if (arg->locate.size.var)
4324 parm_align = BITS_PER_UNIT;
4325 else if (excess)
4327 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4328 parm_align = MIN (parm_align, excess_align);
4332 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4334 /* emit_push_insn might not work properly if arg->value and
4335 argblock + arg->locate.offset areas overlap. */
4336 rtx x = arg->value;
4337 int i = 0;
4339 if (XEXP (x, 0) == current_function_internal_arg_pointer
4340 || (GET_CODE (XEXP (x, 0)) == PLUS
4341 && XEXP (XEXP (x, 0), 0) ==
4342 current_function_internal_arg_pointer
4343 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4345 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4346 i = INTVAL (XEXP (XEXP (x, 0), 1));
4348 /* expand_call should ensure this. */
4349 gcc_assert (!arg->locate.offset.var
4350 && arg->locate.size.var == 0
4351 && GET_CODE (size_rtx) == CONST_INT);
4353 if (arg->locate.offset.constant > i)
4355 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4356 sibcall_failure = 1;
4358 else if (arg->locate.offset.constant < i)
4360 /* Use arg->locate.size.constant instead of size_rtx
4361 because we only care about the part of the argument
4362 on the stack. */
4363 if (i < (arg->locate.offset.constant
4364 + arg->locate.size.constant))
4365 sibcall_failure = 1;
4367 else
4369 /* Even though they appear to be at the same location,
4370 if part of the outgoing argument is in registers,
4371 they aren't really at the same location. Check for
4372 this by making sure that the incoming size is the
4373 same as the outgoing size. */
4374 if (arg->locate.size.constant != INTVAL (size_rtx))
4375 sibcall_failure = 1;
4380 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4381 parm_align, partial, reg, excess, argblock,
4382 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4383 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4385 /* Unless this is a partially-in-register argument, the argument is now
4386 in the stack.
4388 ??? Unlike the case above, in which we want the actual
4389 address of the data, so that we can load it directly into a
4390 register, here we want the address of the stack slot, so that
4391 it's properly aligned for word-by-word copying or something
4392 like that. It's not clear that this is always correct. */
4393 if (partial == 0)
4394 arg->value = arg->stack_slot;
4397 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4399 tree type = TREE_TYPE (arg->tree_value);
4400 arg->parallel_value
4401 = emit_group_load_into_temps (arg->reg, arg->value, type,
4402 int_size_in_bytes (type));
4405 /* Mark all slots this store used. */
4406 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4407 && argblock && ! variable_size && arg->stack)
4408 for (i = lower_bound; i < upper_bound; i++)
4409 stack_usage_map[i] = 1;
4411 /* Once we have pushed something, pops can't safely
4412 be deferred during the rest of the arguments. */
4413 NO_DEFER_POP;
4415 /* Free any temporary slots made in processing this argument. Show
4416 that we might have taken the address of something and pushed that
4417 as an operand. */
4418 preserve_temp_slots (NULL_RTX);
4419 free_temp_slots ();
4420 pop_temp_slots ();
4422 return sibcall_failure;
4425 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4427 bool
4428 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4429 const_tree type)
4431 if (!type)
4432 return false;
4434 /* If the type has variable size... */
4435 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4436 return true;
4438 /* If the type is marked as addressable (it is required
4439 to be constructed into the stack)... */
4440 if (TREE_ADDRESSABLE (type))
4441 return true;
4443 return false;
4446 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4447 takes trailing padding of a structure into account. */
4448 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4450 bool
4451 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4453 if (!type)
4454 return false;
4456 /* If the type has variable size... */
4457 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4458 return true;
4460 /* If the type is marked as addressable (it is required
4461 to be constructed into the stack)... */
4462 if (TREE_ADDRESSABLE (type))
4463 return true;
4465 /* If the padding and mode of the type is such that a copy into
4466 a register would put it into the wrong part of the register. */
4467 if (mode == BLKmode
4468 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4469 && (FUNCTION_ARG_PADDING (mode, type)
4470 == (BYTES_BIG_ENDIAN ? upward : downward)))
4471 return true;
4473 return false;