Merge branch 'master' of ssh://crater.dragonflybsd.org/repository/git/dragonfly
[dragonfly.git] / contrib / gcc-3.4 / gcc / calls.c
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MD
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 Free Software Foundation, Inc.
4
5This file is part of GCC.
6
7GCC is free software; you can redistribute it and/or modify it under
8the terms of the GNU General Public License as published by the Free
9Software Foundation; either version 2, or (at your option) any later
10version.
11
12GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13WARRANTY; without even the implied warranty of MERCHANTABILITY or
14FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
15for more details.
16
17You should have received a copy of the GNU General Public License
18along with GCC; see the file COPYING. If not, write to the Free
19Software Foundation, 59 Temple Place - Suite 330, Boston, MA
2002111-1307, USA. */
21
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
44/* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
45#define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
46
47/* Data structure and subroutines used within expand_call. */
48
49struct arg_data
50{
51 /* Tree node for this argument. */
52 tree tree_value;
53 /* Mode for value; TYPE_MODE unless promoted. */
54 enum machine_mode mode;
55 /* Current RTL value for argument, or 0 if it isn't precomputed. */
56 rtx value;
57 /* Initially-compute RTL value for argument; only for const functions. */
58 rtx initial_value;
59 /* Register to pass this argument in, 0 if passed on stack, or an
60 PARALLEL if the arg is to be copied into multiple non-contiguous
61 registers. */
62 rtx reg;
63 /* Register to pass this argument in when generating tail call sequence.
64 This is not the same register as for normal calls on machines with
65 register windows. */
66 rtx tail_call_reg;
67 /* If REG was promoted from the actual mode of the argument expression,
68 indicates whether the promotion is sign- or zero-extended. */
69 int unsignedp;
70 /* Number of registers to use. 0 means put the whole arg in registers.
71 Also 0 if not passed in registers. */
72 int partial;
73 /* Nonzero if argument must be passed on stack.
74 Note that some arguments may be passed on the stack
75 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
76 pass_on_stack identifies arguments that *cannot* go in registers. */
77 int pass_on_stack;
78 /* Some fields packaged up for locate_and_pad_parm. */
79 struct locate_and_pad_arg_data locate;
80 /* Location on the stack at which parameter should be stored. The store
81 has already been done if STACK == VALUE. */
82 rtx stack;
83 /* Location on the stack of the start of this argument slot. This can
84 differ from STACK if this arg pads downward. This location is known
85 to be aligned to FUNCTION_ARG_BOUNDARY. */
86 rtx stack_slot;
87 /* Place that this stack area has been saved, if needed. */
88 rtx save_area;
89 /* If an argument's alignment does not permit direct copying into registers,
90 copy in smaller-sized pieces into pseudos. These are stored in a
91 block pointed to by this field. The next field says how many
92 word-sized pseudos we made. */
93 rtx *aligned_regs;
94 int n_aligned_regs;
95};
96
97/* A vector of one char per byte of stack space. A byte if nonzero if
98 the corresponding stack location has been used.
99 This vector is used to prevent a function call within an argument from
100 clobbering any stack already set up. */
101static char *stack_usage_map;
102
103/* Size of STACK_USAGE_MAP. */
104static int highest_outgoing_arg_in_use;
105
106/* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
107 stack location's tail call argument has been already stored into the stack.
108 This bitmap is used to prevent sibling call optimization if function tries
109 to use parent's incoming argument slots when they have been already
110 overwritten with tail call arguments. */
111static sbitmap stored_args_map;
112
113/* stack_arg_under_construction is nonzero when an argument may be
114 initialized with a constructor call (including a C function that
115 returns a BLKmode struct) and expand_call must take special action
116 to make sure the object being constructed does not overlap the
117 argument list for the constructor call. */
118int stack_arg_under_construction;
119
120static int calls_function (tree, int);
121static int calls_function_1 (tree, int);
122
123static void emit_call_1 (rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
124 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
125 CUMULATIVE_ARGS *);
126static void precompute_register_parameters (int, struct arg_data *, int *);
127static int store_one_arg (struct arg_data *, rtx, int, int, int);
128static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
129static int finalize_must_preallocate (int, int, struct arg_data *,
130 struct args_size *);
131static void precompute_arguments (int, int, struct arg_data *);
132static int compute_argument_block_size (int, struct args_size *, int);
133static void initialize_argument_information (int, struct arg_data *,
134 struct args_size *, int, tree,
135 tree, CUMULATIVE_ARGS *, int,
136 rtx *, int *, int *, int *,
137 bool);
138static void compute_argument_addresses (struct arg_data *, rtx, int);
139static rtx rtx_for_function_call (tree, tree);
140static void load_register_parameters (struct arg_data *, int, rtx *, int,
141 int, int *);
142static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
143 enum machine_mode, int, va_list);
144static int special_function_p (tree, int);
145static rtx try_to_integrate (tree, tree, rtx, int, tree, rtx);
146static int check_sibcall_argument_overlap_1 (rtx);
147static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
148
149static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
150 int);
151static tree fix_unsafe_tree (tree);
152static bool shift_returned_value (tree, rtx *);
153
154#ifdef REG_PARM_STACK_SPACE
155static rtx save_fixed_argument_area (int, rtx, int *, int *);
156static void restore_fixed_argument_area (rtx, rtx, int, int);
157#endif
158\f
159/* If WHICH is 1, return 1 if EXP contains a call to the built-in function
160 `alloca'.
161
162 If WHICH is 0, return 1 if EXP contains a call to any function.
163 Actually, we only need return 1 if evaluating EXP would require pushing
164 arguments on the stack, but that is too difficult to compute, so we just
165 assume any function call might require the stack. */
166
167static tree calls_function_save_exprs;
168
169static int
170calls_function (tree exp, int which)
171{
172 int val;
173
174 calls_function_save_exprs = 0;
175 val = calls_function_1 (exp, which);
176 calls_function_save_exprs = 0;
177 return val;
178}
179
180/* Recursive function to do the work of above function. */
181
182static int
183calls_function_1 (tree exp, int which)
184{
185 int i;
186 enum tree_code code = TREE_CODE (exp);
187 int class = TREE_CODE_CLASS (code);
188 int length = first_rtl_op (code);
189
190 /* If this code is language-specific, we don't know what it will do. */
191 if ((int) code >= NUM_TREE_CODES)
192 return 1;
193
194 switch (code)
195 {
196 case CALL_EXPR:
197 if (which == 0)
198 return 1;
199 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
200 == FUNCTION_TYPE)
201 && (TYPE_RETURNS_STACK_DEPRESSED
202 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
203 return 1;
204 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
205 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
206 == FUNCTION_DECL)
207 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
208 0)
209 & ECF_MAY_BE_ALLOCA))
210 return 1;
211
212 break;
213
214 case CONSTRUCTOR:
215 {
216 tree tem;
217
218 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
219 if (calls_function_1 (TREE_VALUE (tem), which))
220 return 1;
221 }
222
223 return 0;
224
225 case SAVE_EXPR:
226 if (SAVE_EXPR_RTL (exp) != 0)
227 return 0;
228 if (value_member (exp, calls_function_save_exprs))
229 return 0;
230 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
231 calls_function_save_exprs);
232 return (TREE_OPERAND (exp, 0) != 0
233 && calls_function_1 (TREE_OPERAND (exp, 0), which));
234
235 case BLOCK:
236 {
237 tree local;
238 tree subblock;
239
240 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
241 if (DECL_INITIAL (local) != 0
242 && calls_function_1 (DECL_INITIAL (local), which))
243 return 1;
244
245 for (subblock = BLOCK_SUBBLOCKS (exp);
246 subblock;
247 subblock = TREE_CHAIN (subblock))
248 if (calls_function_1 (subblock, which))
249 return 1;
250 }
251 return 0;
252
253 case TREE_LIST:
254 for (; exp != 0; exp = TREE_CHAIN (exp))
255 if (calls_function_1 (TREE_VALUE (exp), which))
256 return 1;
257 return 0;
258
259 default:
260 break;
261 }
262
263 /* Only expressions and blocks can contain calls. */
264 if (! IS_EXPR_CODE_CLASS (class) && class != 'b')
265 return 0;
266
267 for (i = 0; i < length; i++)
268 if (TREE_OPERAND (exp, i) != 0
269 && calls_function_1 (TREE_OPERAND (exp, i), which))
270 return 1;
271
272 return 0;
273}
274\f
275/* Force FUNEXP into a form suitable for the address of a CALL,
276 and return that as an rtx. Also load the static chain register
277 if FNDECL is a nested function.
278
279 CALL_FUSAGE points to a variable holding the prospective
280 CALL_INSN_FUNCTION_USAGE information. */
281
282rtx
283prepare_call_address (rtx funexp, tree fndecl, rtx *call_fusage,
284 int reg_parm_seen, int sibcallp)
285{
286 rtx static_chain_value = 0;
287
288 funexp = protect_from_queue (funexp, 0);
289
290 if (fndecl != 0)
291 /* Get possible static chain value for nested function in C. */
292 static_chain_value = lookup_static_chain (fndecl);
293
294 /* Make a valid memory address and copy constants through pseudo-regs,
295 but not for a constant address if -fno-function-cse. */
296 if (GET_CODE (funexp) != SYMBOL_REF)
297 /* If we are using registers for parameters, force the
298 function address into a register now. */
299 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
300 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
301 : memory_address (FUNCTION_MODE, funexp));
302 else if (! sibcallp)
303 {
304#ifndef NO_FUNCTION_CSE
305 if (optimize && ! flag_no_function_cse)
306#ifdef NO_RECURSIVE_FUNCTION_CSE
307 if (fndecl != current_function_decl)
308#endif
309 funexp = force_reg (Pmode, funexp);
310#endif
311 }
312
313 if (static_chain_value != 0)
314 {
315 emit_move_insn (static_chain_rtx, static_chain_value);
316
317 if (GET_CODE (static_chain_rtx) == REG)
318 use_reg (call_fusage, static_chain_rtx);
319 }
320
321 return funexp;
322}
323
324/* Generate instructions to call function FUNEXP,
325 and optionally pop the results.
326 The CALL_INSN is the first insn generated.
327
328 FNDECL is the declaration node of the function. This is given to the
329 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
330
331 FUNTYPE is the data type of the function. This is given to the macro
332 RETURN_POPS_ARGS to determine whether this function pops its own args.
333 We used to allow an identifier for library functions, but that doesn't
334 work when the return type is an aggregate type and the calling convention
335 says that the pointer to this aggregate is to be popped by the callee.
336
337 STACK_SIZE is the number of bytes of arguments on the stack,
338 ROUNDED_STACK_SIZE is that number rounded up to
339 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
340 both to put into the call insn and to generate explicit popping
341 code if necessary.
342
343 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
344 It is zero if this call doesn't want a structure value.
345
346 NEXT_ARG_REG is the rtx that results from executing
347 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
348 just after all the args have had their registers assigned.
349 This could be whatever you like, but normally it is the first
350 arg-register beyond those used for args in this call,
351 or 0 if all the arg-registers are used in this call.
352 It is passed on to `gen_call' so you can put this info in the call insn.
353
354 VALREG is a hard register in which a value is returned,
355 or 0 if the call does not return a value.
356
357 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
358 the args to this call were processed.
359 We restore `inhibit_defer_pop' to that value.
360
361 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
362 denote registers used by the called function. */
363
364static void
365emit_call_1 (rtx funexp, tree fndecl ATTRIBUTE_UNUSED, tree funtype ATTRIBUTE_UNUSED,
366 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
367 HOST_WIDE_INT rounded_stack_size,
368 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
369 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
370 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
371 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
372{
373 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
374 rtx call_insn;
375 int already_popped = 0;
376 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
377#if defined (HAVE_call) && defined (HAVE_call_value)
378 rtx struct_value_size_rtx;
379 struct_value_size_rtx = GEN_INT (struct_value_size);
380#endif
381
382#ifdef CALL_POPS_ARGS
383 n_popped += CALL_POPS_ARGS (* args_so_far);
384#endif
385
386 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
387 and we don't want to load it into a register as an optimization,
388 because prepare_call_address already did it if it should be done. */
389 if (GET_CODE (funexp) != SYMBOL_REF)
390 funexp = memory_address (FUNCTION_MODE, funexp);
391
392#if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
393 if ((ecf_flags & ECF_SIBCALL)
394 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
395 && (n_popped > 0 || stack_size == 0))
396 {
397 rtx n_pop = GEN_INT (n_popped);
398 rtx pat;
399
400 /* If this subroutine pops its own args, record that in the call insn
401 if possible, for the sake of frame pointer elimination. */
402
403 if (valreg)
404 pat = GEN_SIBCALL_VALUE_POP (valreg,
405 gen_rtx_MEM (FUNCTION_MODE, funexp),
406 rounded_stack_size_rtx, next_arg_reg,
407 n_pop);
408 else
409 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
410 rounded_stack_size_rtx, next_arg_reg, n_pop);
411
412 emit_call_insn (pat);
413 already_popped = 1;
414 }
415 else
416#endif
417
418#if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
419 /* If the target has "call" or "call_value" insns, then prefer them
420 if no arguments are actually popped. If the target does not have
421 "call" or "call_value" insns, then we must use the popping versions
422 even if the call has no arguments to pop. */
423#if defined (HAVE_call) && defined (HAVE_call_value)
424 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
425 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
426#else
427 if (HAVE_call_pop && HAVE_call_value_pop)
428#endif
429 {
430 rtx n_pop = GEN_INT (n_popped);
431 rtx pat;
432
433 /* If this subroutine pops its own args, record that in the call insn
434 if possible, for the sake of frame pointer elimination. */
435
436 if (valreg)
437 pat = GEN_CALL_VALUE_POP (valreg,
438 gen_rtx_MEM (FUNCTION_MODE, funexp),
439 rounded_stack_size_rtx, next_arg_reg, n_pop);
440 else
441 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
442 rounded_stack_size_rtx, next_arg_reg, n_pop);
443
444 emit_call_insn (pat);
445 already_popped = 1;
446 }
447 else
448#endif
449
450#if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
451 if ((ecf_flags & ECF_SIBCALL)
452 && HAVE_sibcall && HAVE_sibcall_value)
453 {
454 if (valreg)
455 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
456 gen_rtx_MEM (FUNCTION_MODE, funexp),
457 rounded_stack_size_rtx,
458 next_arg_reg, NULL_RTX));
459 else
460 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
461 rounded_stack_size_rtx, next_arg_reg,
462 struct_value_size_rtx));
463 }
464 else
465#endif
466
467#if defined (HAVE_call) && defined (HAVE_call_value)
468 if (HAVE_call && HAVE_call_value)
469 {
470 if (valreg)
471 emit_call_insn (GEN_CALL_VALUE (valreg,
472 gen_rtx_MEM (FUNCTION_MODE, funexp),
473 rounded_stack_size_rtx, next_arg_reg,
474 NULL_RTX));
475 else
476 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
477 rounded_stack_size_rtx, next_arg_reg,
478 struct_value_size_rtx));
479 }
480 else
481#endif
482 abort ();
483
484 /* Find the call we just emitted. */
485 call_insn = last_call_insn ();
486
487 /* Mark memory as used for "pure" function call. */
488 if (ecf_flags & ECF_PURE)
489 call_fusage
490 = gen_rtx_EXPR_LIST
491 (VOIDmode,
492 gen_rtx_USE (VOIDmode,
493 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
494 call_fusage);
495
496 /* Put the register usage information there. */
497 add_function_usage_to (call_insn, call_fusage);
498
499 /* If this is a const call, then set the insn's unchanging bit. */
500 if (ecf_flags & (ECF_CONST | ECF_PURE))
501 CONST_OR_PURE_CALL_P (call_insn) = 1;
502
503 /* If this call can't throw, attach a REG_EH_REGION reg note to that
504 effect. */
505 if (ecf_flags & ECF_NOTHROW)
506 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
507 REG_NOTES (call_insn));
508 else
509 note_eh_region_may_contain_throw ();
510
511 if (ecf_flags & ECF_NORETURN)
512 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
513 REG_NOTES (call_insn));
514 if (ecf_flags & ECF_ALWAYS_RETURN)
515 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
516 REG_NOTES (call_insn));
517
518 if (ecf_flags & ECF_RETURNS_TWICE)
519 {
520 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
521 REG_NOTES (call_insn));
522 current_function_calls_setjmp = 1;
523 }
524
525 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
526
527 /* Restore this now, so that we do defer pops for this call's args
528 if the context of the call as a whole permits. */
529 inhibit_defer_pop = old_inhibit_defer_pop;
530
531 if (n_popped > 0)
532 {
533 if (!already_popped)
534 CALL_INSN_FUNCTION_USAGE (call_insn)
535 = gen_rtx_EXPR_LIST (VOIDmode,
536 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
537 CALL_INSN_FUNCTION_USAGE (call_insn));
538 rounded_stack_size -= n_popped;
539 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
540 stack_pointer_delta -= n_popped;
541 }
542
543 if (!ACCUMULATE_OUTGOING_ARGS)
544 {
545 /* If returning from the subroutine does not automatically pop the args,
546 we need an instruction to pop them sooner or later.
547 Perhaps do it now; perhaps just record how much space to pop later.
548
549 If returning from the subroutine does pop the args, indicate that the
550 stack pointer will be changed. */
551
552 if (rounded_stack_size != 0)
553 {
554 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN | ECF_LONGJMP))
555 /* Just pretend we did the pop. */
556 stack_pointer_delta -= rounded_stack_size;
557 else if (flag_defer_pop && inhibit_defer_pop == 0
558 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
559 pending_stack_adjust += rounded_stack_size;
560 else
561 adjust_stack (rounded_stack_size_rtx);
562 }
563 }
564 /* When we accumulate outgoing args, we must avoid any stack manipulations.
565 Restore the stack pointer to its original value now. Usually
566 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
567 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
568 popping variants of functions exist as well.
569
570 ??? We may optimize similar to defer_pop above, but it is
571 probably not worthwhile.
572
573 ??? It will be worthwhile to enable combine_stack_adjustments even for
574 such machines. */
575 else if (n_popped)
576 anti_adjust_stack (GEN_INT (n_popped));
577}
578
579/* Determine if the function identified by NAME and FNDECL is one with
580 special properties we wish to know about.
581
582 For example, if the function might return more than one time (setjmp), then
583 set RETURNS_TWICE to a nonzero value.
584
585 Similarly set LONGJMP for if the function is in the longjmp family.
586
587 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
588 space from the stack such as alloca. */
589
590static int
591special_function_p (tree fndecl, int flags)
592{
593 if (! (flags & ECF_MALLOC)
594 && fndecl && DECL_NAME (fndecl)
595 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
596 /* Exclude functions not at the file scope, or not `extern',
597 since they are not the magic functions we would otherwise
598 think they are.
599 FIXME: this should be handled with attributes, not with this
600 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
601 because you can declare fork() inside a function if you
602 wish. */
603 && (DECL_CONTEXT (fndecl) == NULL_TREE
604 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
605 && TREE_PUBLIC (fndecl))
606 {
607 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
608 const char *tname = name;
609
610 /* We assume that alloca will always be called by name. It
611 makes no sense to pass it as a pointer-to-function to
612 anything that does not understand its behavior. */
613 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
614 && name[0] == 'a'
615 && ! strcmp (name, "alloca"))
616 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
617 && name[0] == '_'
618 && ! strcmp (name, "__builtin_alloca"))))
619 flags |= ECF_MAY_BE_ALLOCA;
620
621 /* Disregard prefix _, __ or __x. */
622 if (name[0] == '_')
623 {
624 if (name[1] == '_' && name[2] == 'x')
625 tname += 3;
626 else if (name[1] == '_')
627 tname += 2;
628 else
629 tname += 1;
630 }
631
632 if (tname[0] == 's')
633 {
634 if ((tname[1] == 'e'
635 && (! strcmp (tname, "setjmp")
636 || ! strcmp (tname, "setjmp_syscall")))
637 || (tname[1] == 'i'
638 && ! strcmp (tname, "sigsetjmp"))
639 || (tname[1] == 'a'
640 && ! strcmp (tname, "savectx")))
641 flags |= ECF_RETURNS_TWICE;
642
643 if (tname[1] == 'i'
644 && ! strcmp (tname, "siglongjmp"))
645 flags |= ECF_LONGJMP;
646 }
647 else if ((tname[0] == 'q' && tname[1] == 's'
648 && ! strcmp (tname, "qsetjmp"))
649 || (tname[0] == 'v' && tname[1] == 'f'
650 && ! strcmp (tname, "vfork")))
651 flags |= ECF_RETURNS_TWICE;
652
653 else if (tname[0] == 'l' && tname[1] == 'o'
654 && ! strcmp (tname, "longjmp"))
655 flags |= ECF_LONGJMP;
656
657 else if ((tname[0] == 'f' && tname[1] == 'o'
658 && ! strcmp (tname, "fork"))
659 /* Linux specific: __clone. check NAME to insist on the
660 leading underscores, to avoid polluting the ISO / POSIX
661 namespace. */
662 || (name[0] == '_' && name[1] == '_'
663 && ! strcmp (tname, "clone"))
664 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
665 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
666 && (tname[5] == '\0'
667 || ((tname[5] == 'p' || tname[5] == 'e')
668 && tname[6] == '\0'))))
669 flags |= ECF_FORK_OR_EXEC;
670 }
671 return flags;
672}
673
674/* Return nonzero when tree represent call to longjmp. */
675
676int
677setjmp_call_p (tree fndecl)
678{
679 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
680}
681
682/* Return true when exp contains alloca call. */
683bool
684alloca_call_p (tree exp)
685{
686 if (TREE_CODE (exp) == CALL_EXPR
687 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
688 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
689 == FUNCTION_DECL)
690 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
691 0) & ECF_MAY_BE_ALLOCA))
692 return true;
693 return false;
694}
695
696/* Detect flags (function attributes) from the function decl or type node. */
697
698int
699flags_from_decl_or_type (tree exp)
700{
701 int flags = 0;
702 tree type = exp;
703
704 if (DECL_P (exp))
705 {
706 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
707 type = TREE_TYPE (exp);
708
709 if (i)
710 {
711 if (i->pure_function)
712 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
713 if (i->const_function)
714 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
715 }
716
717 /* The function exp may have the `malloc' attribute. */
718 if (DECL_IS_MALLOC (exp))
719 flags |= ECF_MALLOC;
720
721 /* The function exp may have the `pure' attribute. */
722 if (DECL_IS_PURE (exp))
723 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
724
725 if (TREE_NOTHROW (exp))
726 flags |= ECF_NOTHROW;
727
728 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
729 flags |= ECF_LIBCALL_BLOCK;
730 }
731
732 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
733 flags |= ECF_CONST;
734
735 if (TREE_THIS_VOLATILE (exp))
736 flags |= ECF_NORETURN;
737
738 /* Mark if the function returns with the stack pointer depressed. We
739 cannot consider it pure or constant in that case. */
740 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
741 {
742 flags |= ECF_SP_DEPRESSED;
743 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
744 }
745
746 return flags;
747}
748
749/* Detect flags from a CALL_EXPR. */
750
751int
752call_expr_flags (tree t)
753{
754 int flags;
755 tree decl = get_callee_fndecl (t);
756
757 if (decl)
758 flags = flags_from_decl_or_type (decl);
759 else
760 {
761 t = TREE_TYPE (TREE_OPERAND (t, 0));
762 if (t && TREE_CODE (t) == POINTER_TYPE)
763 flags = flags_from_decl_or_type (TREE_TYPE (t));
764 else
765 flags = 0;
766 }
767
768 return flags;
769}
770
771/* Precompute all register parameters as described by ARGS, storing values
772 into fields within the ARGS array.
773
774 NUM_ACTUALS indicates the total number elements in the ARGS array.
775
776 Set REG_PARM_SEEN if we encounter a register parameter. */
777
778static void
779precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
780{
781 int i;
782
783 *reg_parm_seen = 0;
784
785 for (i = 0; i < num_actuals; i++)
786 if (args[i].reg != 0 && ! args[i].pass_on_stack)
787 {
788 *reg_parm_seen = 1;
789
790 if (args[i].value == 0)
791 {
792 push_temp_slots ();
793 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
794 VOIDmode, 0);
795 preserve_temp_slots (args[i].value);
796 pop_temp_slots ();
797
798 /* ANSI doesn't require a sequence point here,
799 but PCC has one, so this will avoid some problems. */
800 emit_queue ();
801 }
802
803 /* If the value is a non-legitimate constant, force it into a
804 pseudo now. TLS symbols sometimes need a call to resolve. */
805 if (CONSTANT_P (args[i].value)
806 && !LEGITIMATE_CONSTANT_P (args[i].value))
807 args[i].value = force_reg (args[i].mode, args[i].value);
808
809 /* If we are to promote the function arg to a wider mode,
810 do it now. */
811
812 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
813 args[i].value
814 = convert_modes (args[i].mode,
815 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
816 args[i].value, args[i].unsignedp);
817
818 /* If the value is expensive, and we are inside an appropriately
819 short loop, put the value into a pseudo and then put the pseudo
820 into the hard reg.
821
822 For small register classes, also do this if this call uses
823 register parameters. This is to avoid reload conflicts while
824 loading the parameters registers. */
825
826 if ((! (GET_CODE (args[i].value) == REG
827 || (GET_CODE (args[i].value) == SUBREG
828 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
829 && args[i].mode != BLKmode
830 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
831 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
832 || preserve_subexpressions_p ()))
833 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
834 }
835}
836
837#ifdef REG_PARM_STACK_SPACE
838
839 /* The argument list is the property of the called routine and it
840 may clobber it. If the fixed area has been used for previous
841 parameters, we must save and restore it. */
842
843static rtx
844save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
845{
846 int low;
847 int high;
848
849 /* Compute the boundary of the area that needs to be saved, if any. */
850 high = reg_parm_stack_space;
851#ifdef ARGS_GROW_DOWNWARD
852 high += 1;
853#endif
854 if (high > highest_outgoing_arg_in_use)
855 high = highest_outgoing_arg_in_use;
856
857 for (low = 0; low < high; low++)
858 if (stack_usage_map[low] != 0)
859 {
860 int num_to_save;
861 enum machine_mode save_mode;
862 int delta;
863 rtx stack_area;
864 rtx save_area;
865
866 while (stack_usage_map[--high] == 0)
867 ;
868
869 *low_to_save = low;
870 *high_to_save = high;
871
872 num_to_save = high - low + 1;
873 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
874
875 /* If we don't have the required alignment, must do this
876 in BLKmode. */
877 if ((low & (MIN (GET_MODE_SIZE (save_mode),
878 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
879 save_mode = BLKmode;
880
881#ifdef ARGS_GROW_DOWNWARD
882 delta = -high;
883#else
884 delta = low;
885#endif
886 stack_area = gen_rtx_MEM (save_mode,
887 memory_address (save_mode,
888 plus_constant (argblock,
889 delta)));
890
891 set_mem_align (stack_area, PARM_BOUNDARY);
892 if (save_mode == BLKmode)
893 {
894 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
895 emit_block_move (validize_mem (save_area), stack_area,
896 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
897 }
898 else
899 {
900 save_area = gen_reg_rtx (save_mode);
901 emit_move_insn (save_area, stack_area);
902 }
903
904 return save_area;
905 }
906
907 return NULL_RTX;
908}
909
910static void
911restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
912{
913 enum machine_mode save_mode = GET_MODE (save_area);
914 int delta;
915 rtx stack_area;
916
917#ifdef ARGS_GROW_DOWNWARD
918 delta = -high_to_save;
919#else
920 delta = low_to_save;
921#endif
922 stack_area = gen_rtx_MEM (save_mode,
923 memory_address (save_mode,
924 plus_constant (argblock, delta)));
925 set_mem_align (stack_area, PARM_BOUNDARY);
926
927 if (save_mode != BLKmode)
928 emit_move_insn (stack_area, save_area);
929 else
930 emit_block_move (stack_area, validize_mem (save_area),
931 GEN_INT (high_to_save - low_to_save + 1),
932 BLOCK_OP_CALL_PARM);
933}
934#endif /* REG_PARM_STACK_SPACE */
935
936/* If any elements in ARGS refer to parameters that are to be passed in
937 registers, but not in memory, and whose alignment does not permit a
938 direct copy into registers. Copy the values into a group of pseudos
939 which we will later copy into the appropriate hard registers.
940
941 Pseudos for each unaligned argument will be stored into the array
942 args[argnum].aligned_regs. The caller is responsible for deallocating
943 the aligned_regs array if it is nonzero. */
944
945static void
946store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
947{
948 int i, j;
949
950 for (i = 0; i < num_actuals; i++)
951 if (args[i].reg != 0 && ! args[i].pass_on_stack
952 && args[i].mode == BLKmode
953 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
954 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
955 {
956 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
957 int nregs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
958 int endian_correction = 0;
959
960 args[i].n_aligned_regs = args[i].partial ? args[i].partial : nregs;
961 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
962
963 /* Structures smaller than a word are normally aligned to the
964 least significant byte. On a BYTES_BIG_ENDIAN machine,
965 this means we must skip the empty high order bytes when
966 calculating the bit offset. */
967 if (bytes < UNITS_PER_WORD
968#ifdef BLOCK_REG_PADDING
969 && (BLOCK_REG_PADDING (args[i].mode,
970 TREE_TYPE (args[i].tree_value), 1)
971 == downward)
972#else
973 && BYTES_BIG_ENDIAN
974#endif
975 )
976 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
977
978 for (j = 0; j < args[i].n_aligned_regs; j++)
979 {
980 rtx reg = gen_reg_rtx (word_mode);
981 rtx word = operand_subword_force (args[i].value, j, BLKmode);
982 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
983
984 args[i].aligned_regs[j] = reg;
985 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
986 word_mode, word_mode, BITS_PER_WORD);
987
988 /* There is no need to restrict this code to loading items
989 in TYPE_ALIGN sized hunks. The bitfield instructions can
990 load up entire word sized registers efficiently.
991
992 ??? This may not be needed anymore.
993 We use to emit a clobber here but that doesn't let later
994 passes optimize the instructions we emit. By storing 0 into
995 the register later passes know the first AND to zero out the
996 bitfield being set in the register is unnecessary. The store
997 of 0 will be deleted as will at least the first AND. */
998
999 emit_move_insn (reg, const0_rtx);
1000
1001 bytes -= bitsize / BITS_PER_UNIT;
1002 store_bit_field (reg, bitsize, endian_correction, word_mode,
1003 word, BITS_PER_WORD);
1004 }
1005 }
1006}
1007
1008/* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1009 ACTPARMS.
1010
1011 NUM_ACTUALS is the total number of parameters.
1012
1013 N_NAMED_ARGS is the total number of named arguments.
1014
1015 FNDECL is the tree code for the target of this call (if known)
1016
1017 ARGS_SO_FAR holds state needed by the target to know where to place
1018 the next argument.
1019
1020 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1021 for arguments which are passed in registers.
1022
1023 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1024 and may be modified by this routine.
1025
1026 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1027 flags which may may be modified by this routine.
1028
1029 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1030 the thunked-to function. */
1031
1032static void
1033initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1034 struct arg_data *args,
1035 struct args_size *args_size,
1036 int n_named_args ATTRIBUTE_UNUSED,
1037 tree actparms, tree fndecl,
1038 CUMULATIVE_ARGS *args_so_far,
1039 int reg_parm_stack_space,
1040 rtx *old_stack_level, int *old_pending_adj,
1041 int *must_preallocate, int *ecf_flags,
1042 bool call_from_thunk_p)
1043{
1044 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1045 int inc;
1046
1047 /* Count arg position in order args appear. */
1048 int argpos;
1049
1050 int i;
1051 tree p;
1052
1053 args_size->constant = 0;
1054 args_size->var = 0;
1055
1056 /* In this loop, we consider args in the order they are written.
1057 We fill up ARGS from the front or from the back if necessary
1058 so that in any case the first arg to be pushed ends up at the front. */
1059
1060 if (PUSH_ARGS_REVERSED)
1061 {
1062 i = num_actuals - 1, inc = -1;
1063 /* In this case, must reverse order of args
1064 so that we compute and push the last arg first. */
1065 }
1066 else
1067 {
1068 i = 0, inc = 1;
1069 }
1070
1071 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1072 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1073 {
1074 tree type = TREE_TYPE (TREE_VALUE (p));
1075 int unsignedp;
1076 enum machine_mode mode;
1077
1078 args[i].tree_value = TREE_VALUE (p);
1079
1080 /* Replace erroneous argument with constant zero. */
1081 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1082 args[i].tree_value = integer_zero_node, type = integer_type_node;
1083
1084 /* If TYPE is a transparent union, pass things the way we would
1085 pass the first field of the union. We have already verified that
1086 the modes are the same. */
1087 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1088 type = TREE_TYPE (TYPE_FIELDS (type));
1089
1090 /* Decide where to pass this arg.
1091
1092 args[i].reg is nonzero if all or part is passed in registers.
1093
1094 args[i].partial is nonzero if part but not all is passed in registers,
1095 and the exact value says how many words are passed in registers.
1096
1097 args[i].pass_on_stack is nonzero if the argument must at least be
1098 computed on the stack. It may then be loaded back into registers
1099 if args[i].reg is nonzero.
1100
1101 These decisions are driven by the FUNCTION_... macros and must agree
1102 with those made by function.c. */
1103
1104 /* See if this argument should be passed by invisible reference. */
1105 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1106 || TREE_ADDRESSABLE (type)
1107#ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1108 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1109 type, argpos < n_named_args)
1110#endif
1111 )
1112 {
1113 /* If we're compiling a thunk, pass through invisible
1114 references instead of making a copy. */
1115 if (call_from_thunk_p
1116#ifdef FUNCTION_ARG_CALLEE_COPIES
1117 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1118 type, argpos < n_named_args)
1119 /* If it's in a register, we must make a copy of it too. */
1120 /* ??? Is this a sufficient test? Is there a better one? */
1121 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1122 && REG_P (DECL_RTL (args[i].tree_value)))
1123 && ! TREE_ADDRESSABLE (type))
1124#endif
1125 )
1126 {
1127 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1128 new object from the argument. If we are passing by
1129 invisible reference, the callee will do that for us, so we
1130 can strip off the TARGET_EXPR. This is not always safe,
1131 but it is safe in the only case where this is a useful
1132 optimization; namely, when the argument is a plain object.
1133 In that case, the frontend is just asking the backend to
1134 make a bitwise copy of the argument. */
1135
1136 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1137 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1138 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1139 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1140
1141 args[i].tree_value = build1 (ADDR_EXPR,
1142 build_pointer_type (type),
1143 args[i].tree_value);
1144 type = build_pointer_type (type);
1145 }
1146 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1147 {
1148 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1149 We implement this by passing the address of the temporary
1150 rather than expanding it into another allocated slot. */
1151 args[i].tree_value = build1 (ADDR_EXPR,
1152 build_pointer_type (type),
1153 args[i].tree_value);
1154 type = build_pointer_type (type);
1155 }
1156 else
1157 {
1158 /* We make a copy of the object and pass the address to the
1159 function being called. */
1160 rtx copy;
1161
1162 if (!COMPLETE_TYPE_P (type)
1163 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1164 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1165 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1166 STACK_CHECK_MAX_VAR_SIZE))))
1167 {
1168 /* This is a variable-sized object. Make space on the stack
1169 for it. */
1170 rtx size_rtx = expr_size (TREE_VALUE (p));
1171
1172 if (*old_stack_level == 0)
1173 {
1174 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1175 *old_pending_adj = pending_stack_adjust;
1176 pending_stack_adjust = 0;
1177 }
1178
1179 copy = gen_rtx_MEM (BLKmode,
1180 allocate_dynamic_stack_space
1181 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1182 set_mem_attributes (copy, type, 1);
1183 }
1184 else
1185 copy = assign_temp (type, 0, 1, 0);
1186
1187 store_expr (args[i].tree_value, copy, 0);
1188 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1189
1190 args[i].tree_value = build1 (ADDR_EXPR,
1191 build_pointer_type (type),
1192 make_tree (type, copy));
1193 type = build_pointer_type (type);
1194 }
1195 }
1196
1197 mode = TYPE_MODE (type);
1198 unsignedp = TREE_UNSIGNED (type);
1199
1200 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1201 mode = promote_mode (type, mode, &unsignedp, 1);
1202
1203 args[i].unsignedp = unsignedp;
1204 args[i].mode = mode;
1205
1206 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1207 argpos < n_named_args);
1208#ifdef FUNCTION_INCOMING_ARG
1209 /* If this is a sibling call and the machine has register windows, the
1210 register window has to be unwinded before calling the routine, so
1211 arguments have to go into the incoming registers. */
1212 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1213 argpos < n_named_args);
1214#else
1215 args[i].tail_call_reg = args[i].reg;
1216#endif
1217
1218#ifdef FUNCTION_ARG_PARTIAL_NREGS
1219 if (args[i].reg)
1220 args[i].partial
1221 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1222 argpos < n_named_args);
1223#endif
1224
1225 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1226
1227 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1228 it means that we are to pass this arg in the register(s) designated
1229 by the PARALLEL, but also to pass it in the stack. */
1230 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1231 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1232 args[i].pass_on_stack = 1;
1233
1234 /* If this is an addressable type, we must preallocate the stack
1235 since we must evaluate the object into its final location.
1236
1237 If this is to be passed in both registers and the stack, it is simpler
1238 to preallocate. */
1239 if (TREE_ADDRESSABLE (type)
1240 || (args[i].pass_on_stack && args[i].reg != 0))
1241 *must_preallocate = 1;
1242
1243 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1244 we cannot consider this function call constant. */
1245 if (TREE_ADDRESSABLE (type))
1246 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1247
1248 /* Compute the stack-size of this argument. */
1249 if (args[i].reg == 0 || args[i].partial != 0
1250 || reg_parm_stack_space > 0
1251 || args[i].pass_on_stack)
1252 locate_and_pad_parm (mode, type,
1253#ifdef STACK_PARMS_IN_REG_PARM_AREA
1254 1,
1255#else
1256 args[i].reg != 0,
1257#endif
1258 args[i].pass_on_stack ? 0 : args[i].partial,
1259 fndecl, args_size, &args[i].locate);
1260#ifdef BLOCK_REG_PADDING
1261 else
1262 /* The argument is passed entirely in registers. See at which
1263 end it should be padded. */
1264 args[i].locate.where_pad =
1265 BLOCK_REG_PADDING (mode, type,
1266 int_size_in_bytes (type) <= UNITS_PER_WORD);
1267#endif
1268
1269 /* Update ARGS_SIZE, the total stack space for args so far. */
1270
1271 args_size->constant += args[i].locate.size.constant;
1272 if (args[i].locate.size.var)
1273 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1274
1275 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1276 have been used, etc. */
1277
1278 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1279 argpos < n_named_args);
1280 }
1281}
1282
1283/* Update ARGS_SIZE to contain the total size for the argument block.
1284 Return the original constant component of the argument block's size.
1285
1286 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1287 for arguments passed in registers. */
1288
1289static int
1290compute_argument_block_size (int reg_parm_stack_space,
1291 struct args_size *args_size,
1292 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1293{
1294 int unadjusted_args_size = args_size->constant;
1295
1296 /* For accumulate outgoing args mode we don't need to align, since the frame
1297 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1298 backends from generating misaligned frame sizes. */
1299 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1300 preferred_stack_boundary = STACK_BOUNDARY;
1301
1302 /* Compute the actual size of the argument block required. The variable
1303 and constant sizes must be combined, the size may have to be rounded,
1304 and there may be a minimum required size. */
1305
1306 if (args_size->var)
1307 {
1308 args_size->var = ARGS_SIZE_TREE (*args_size);
1309 args_size->constant = 0;
1310
1311 preferred_stack_boundary /= BITS_PER_UNIT;
1312 if (preferred_stack_boundary > 1)
1313 {
1314 /* We don't handle this case yet. To handle it correctly we have
1315 to add the delta, round and subtract the delta.
1316 Currently no machine description requires this support. */
1317 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1318 abort ();
1319 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1320 }
1321
1322 if (reg_parm_stack_space > 0)
1323 {
1324 args_size->var
1325 = size_binop (MAX_EXPR, args_size->var,
1326 ssize_int (reg_parm_stack_space));
1327
1328#ifndef OUTGOING_REG_PARM_STACK_SPACE
1329 /* The area corresponding to register parameters is not to count in
1330 the size of the block we need. So make the adjustment. */
1331 args_size->var
1332 = size_binop (MINUS_EXPR, args_size->var,
1333 ssize_int (reg_parm_stack_space));
1334#endif
1335 }
1336 }
1337 else
1338 {
1339 preferred_stack_boundary /= BITS_PER_UNIT;
1340 if (preferred_stack_boundary < 1)
1341 preferred_stack_boundary = 1;
1342 args_size->constant = (((args_size->constant
1343 + stack_pointer_delta
1344 + preferred_stack_boundary - 1)
1345 / preferred_stack_boundary
1346 * preferred_stack_boundary)
1347 - stack_pointer_delta);
1348
1349 args_size->constant = MAX (args_size->constant,
1350 reg_parm_stack_space);
1351
1352#ifdef MAYBE_REG_PARM_STACK_SPACE
1353 if (reg_parm_stack_space == 0)
1354 args_size->constant = 0;
1355#endif
1356
1357#ifndef OUTGOING_REG_PARM_STACK_SPACE
1358 args_size->constant -= reg_parm_stack_space;
1359#endif
1360 }
1361 return unadjusted_args_size;
1362}
1363
1364/* Precompute parameters as needed for a function call.
1365
1366 FLAGS is mask of ECF_* constants.
1367
1368 NUM_ACTUALS is the number of arguments.
1369
1370 ARGS is an array containing information for each argument; this
1371 routine fills in the INITIAL_VALUE and VALUE fields for each
1372 precomputed argument. */
1373
1374static void
1375precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1376{
1377 int i;
1378
1379 /* If this function call is cse'able, precompute all the parameters.
1380 Note that if the parameter is constructed into a temporary, this will
1381 cause an additional copy because the parameter will be constructed
1382 into a temporary location and then copied into the outgoing arguments.
1383 If a parameter contains a call to alloca and this function uses the
1384 stack, precompute the parameter. */
1385
1386 /* If we preallocated the stack space, and some arguments must be passed
1387 on the stack, then we must precompute any parameter which contains a
1388 function call which will store arguments on the stack.
1389 Otherwise, evaluating the parameter may clobber previous parameters
1390 which have already been stored into the stack. (we have code to avoid
1391 such case by saving the outgoing stack arguments, but it results in
1392 worse code) */
1393
1394 for (i = 0; i < num_actuals; i++)
1395 if ((flags & ECF_LIBCALL_BLOCK)
1396 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1397 {
1398 enum machine_mode mode;
1399
1400 /* If this is an addressable type, we cannot pre-evaluate it. */
1401 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1402 abort ();
1403
1404 args[i].value
1405 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1406
1407 /* ANSI doesn't require a sequence point here,
1408 but PCC has one, so this will avoid some problems. */
1409 emit_queue ();
1410
1411 args[i].initial_value = args[i].value
1412 = protect_from_queue (args[i].value, 0);
1413
1414 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1415 if (mode != args[i].mode)
1416 {
1417 args[i].value
1418 = convert_modes (args[i].mode, mode,
1419 args[i].value, args[i].unsignedp);
1420#ifdef PROMOTE_FOR_CALL_ONLY
1421 /* CSE will replace this only if it contains args[i].value
1422 pseudo, so convert it down to the declared mode using
1423 a SUBREG. */
1424 if (GET_CODE (args[i].value) == REG
1425 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1426 {
1427 args[i].initial_value
1428 = gen_lowpart_SUBREG (mode, args[i].value);
1429 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1430 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1431 args[i].unsignedp);
1432 }
1433#endif
1434 }
1435 }
1436}
1437
1438/* Given the current state of MUST_PREALLOCATE and information about
1439 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1440 compute and return the final value for MUST_PREALLOCATE. */
1441
1442static int
1443finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1444{
1445 /* See if we have or want to preallocate stack space.
1446
1447 If we would have to push a partially-in-regs parm
1448 before other stack parms, preallocate stack space instead.
1449
1450 If the size of some parm is not a multiple of the required stack
1451 alignment, we must preallocate.
1452
1453 If the total size of arguments that would otherwise create a copy in
1454 a temporary (such as a CALL) is more than half the total argument list
1455 size, preallocation is faster.
1456
1457 Another reason to preallocate is if we have a machine (like the m88k)
1458 where stack alignment is required to be maintained between every
1459 pair of insns, not just when the call is made. However, we assume here
1460 that such machines either do not have push insns (and hence preallocation
1461 would occur anyway) or the problem is taken care of with
1462 PUSH_ROUNDING. */
1463
1464 if (! must_preallocate)
1465 {
1466 int partial_seen = 0;
1467 int copy_to_evaluate_size = 0;
1468 int i;
1469
1470 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1471 {
1472 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1473 partial_seen = 1;
1474 else if (partial_seen && args[i].reg == 0)
1475 must_preallocate = 1;
1476
1477 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1478 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1479 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1480 || TREE_CODE (args[i].tree_value) == COND_EXPR
1481 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1482 copy_to_evaluate_size
1483 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1484 }
1485
1486 if (copy_to_evaluate_size * 2 >= args_size->constant
1487 && args_size->constant > 0)
1488 must_preallocate = 1;
1489 }
1490 return must_preallocate;
1491}
1492
1493/* If we preallocated stack space, compute the address of each argument
1494 and store it into the ARGS array.
1495
1496 We need not ensure it is a valid memory address here; it will be
1497 validized when it is used.
1498
1499 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1500
1501static void
1502compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1503{
1504 if (argblock)
1505 {
1506 rtx arg_reg = argblock;
1507 int i, arg_offset = 0;
1508
1509 if (GET_CODE (argblock) == PLUS)
1510 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1511
1512 for (i = 0; i < num_actuals; i++)
1513 {
1514 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1515 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1516 rtx addr;
1517
1518 /* Skip this parm if it will not be passed on the stack. */
1519 if (! args[i].pass_on_stack && args[i].reg != 0)
1520 continue;
1521
1522 if (GET_CODE (offset) == CONST_INT)
1523 addr = plus_constant (arg_reg, INTVAL (offset));
1524 else
1525 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1526
1527 addr = plus_constant (addr, arg_offset);
1528 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1529 set_mem_align (args[i].stack, PARM_BOUNDARY);
1530 set_mem_attributes (args[i].stack,
1531 TREE_TYPE (args[i].tree_value), 1);
1532
1533 if (GET_CODE (slot_offset) == CONST_INT)
1534 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1535 else
1536 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1537
1538 addr = plus_constant (addr, arg_offset);
1539 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1540 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1541 set_mem_attributes (args[i].stack_slot,
1542 TREE_TYPE (args[i].tree_value), 1);
1543
1544 /* Function incoming arguments may overlap with sibling call
1545 outgoing arguments and we cannot allow reordering of reads
1546 from function arguments with stores to outgoing arguments
1547 of sibling calls. */
1548 set_mem_alias_set (args[i].stack, 0);
1549 set_mem_alias_set (args[i].stack_slot, 0);
1550 }
1551 }
1552}
1553
1554/* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1555 in a call instruction.
1556
1557 FNDECL is the tree node for the target function. For an indirect call
1558 FNDECL will be NULL_TREE.
1559
1560 ADDR is the operand 0 of CALL_EXPR for this call. */
1561
1562static rtx
1563rtx_for_function_call (tree fndecl, tree addr)
1564{
1565 rtx funexp;
1566
1567 /* Get the function to call, in the form of RTL. */
1568 if (fndecl)
1569 {
1570 /* If this is the first use of the function, see if we need to
1571 make an external definition for it. */
1572 if (! TREE_USED (fndecl))
1573 {
1574 assemble_external (fndecl);
1575 TREE_USED (fndecl) = 1;
1576 }
1577
1578 /* Get a SYMBOL_REF rtx for the function address. */
1579 funexp = XEXP (DECL_RTL (fndecl), 0);
1580 }
1581 else
1582 /* Generate an rtx (probably a pseudo-register) for the address. */
1583 {
1584 push_temp_slots ();
1585 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1586 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1587 emit_queue ();
1588 }
1589 return funexp;
1590}
1591
1592/* Do the register loads required for any wholly-register parms or any
1593 parms which are passed both on the stack and in a register. Their
1594 expressions were already evaluated.
1595
1596 Mark all register-parms as living through the call, putting these USE
1597 insns in the CALL_INSN_FUNCTION_USAGE field.
1598
1599 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1600 checking, setting *SIBCALL_FAILURE if appropriate. */
1601
1602static void
1603load_register_parameters (struct arg_data *args, int num_actuals,
1604 rtx *call_fusage, int flags, int is_sibcall,
1605 int *sibcall_failure)
1606{
1607 int i, j;
1608
1609 for (i = 0; i < num_actuals; i++)
1610 {
1611 rtx reg = ((flags & ECF_SIBCALL)
1612 ? args[i].tail_call_reg : args[i].reg);
1613 if (reg)
1614 {
1615 int partial = args[i].partial;
1616 int nregs;
1617 int size = 0;
1618 rtx before_arg = get_last_insn ();
1619 /* Set to non-negative if must move a word at a time, even if just
1620 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1621 we just use a normal move insn. This value can be zero if the
1622 argument is a zero size structure with no fields. */
1623 nregs = -1;
1624 if (partial)
1625 nregs = partial;
1626 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1627 {
1628 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1629 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1630 }
1631 else
1632 size = GET_MODE_SIZE (args[i].mode);
1633
1634 /* Handle calls that pass values in multiple non-contiguous
1635 locations. The Irix 6 ABI has examples of this. */
1636
1637 if (GET_CODE (reg) == PARALLEL)
1638 {
1639 tree type = TREE_TYPE (args[i].tree_value);
1640 emit_group_load (reg, args[i].value, type,
1641 int_size_in_bytes (type));
1642 }
1643
1644 /* If simple case, just do move. If normal partial, store_one_arg
1645 has already loaded the register for us. In all other cases,
1646 load the register(s) from memory. */
1647
1648 else if (nregs == -1)
1649 {
1650 emit_move_insn (reg, args[i].value);
1651#ifdef BLOCK_REG_PADDING
1652 /* Handle case where we have a value that needs shifting
1653 up to the msb. eg. a QImode value and we're padding
1654 upward on a BYTES_BIG_ENDIAN machine. */
1655 if (size < UNITS_PER_WORD
1656 && (args[i].locate.where_pad
1657 == (BYTES_BIG_ENDIAN ? upward : downward)))
1658 {
1659 rtx x;
1660 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1661
1662 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1663 report the whole reg as used. Strictly speaking, the
1664 call only uses SIZE bytes at the msb end, but it doesn't
1665 seem worth generating rtl to say that. */
1666 reg = gen_rtx_REG (word_mode, REGNO (reg));
1667 x = expand_binop (word_mode, ashl_optab, reg,
1668 GEN_INT (shift), reg, 1, OPTAB_WIDEN);
1669 if (x != reg)
1670 emit_move_insn (reg, x);
1671 }
1672#endif
1673 }
1674
1675 /* If we have pre-computed the values to put in the registers in
1676 the case of non-aligned structures, copy them in now. */
1677
1678 else if (args[i].n_aligned_regs != 0)
1679 for (j = 0; j < args[i].n_aligned_regs; j++)
1680 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1681 args[i].aligned_regs[j]);
1682
1683 else if (partial == 0 || args[i].pass_on_stack)
1684 {
1685 rtx mem = validize_mem (args[i].value);
1686
1687#ifdef BLOCK_REG_PADDING
1688 /* Handle a BLKmode that needs shifting. */
1689 if (nregs == 1 && size < UNITS_PER_WORD
1690 && args[i].locate.where_pad == downward)
1691 {
1692 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1693 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1694 rtx x = gen_reg_rtx (word_mode);
1695 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1696 optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1697
1698 emit_move_insn (x, tem);
1699 x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1700 ri, 1, OPTAB_WIDEN);
1701 if (x != ri)
1702 emit_move_insn (ri, x);
1703 }
1704 else
1705#endif
1706 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1707 }
1708
1709 /* When a parameter is a block, and perhaps in other cases, it is
1710 possible that it did a load from an argument slot that was
1711 already clobbered. */
1712 if (is_sibcall
1713 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1714 *sibcall_failure = 1;
1715
1716 /* Handle calls that pass values in multiple non-contiguous
1717 locations. The Irix 6 ABI has examples of this. */
1718 if (GET_CODE (reg) == PARALLEL)
1719 use_group_regs (call_fusage, reg);
1720 else if (nregs == -1)
1721 use_reg (call_fusage, reg);
1c1138ce
JS
1722 else if (nregs > 0)
1723 use_regs (call_fusage, REGNO (reg), nregs);
003757ed
MD
1724 }
1725 }
1726}
1727
1728/* Try to integrate function. See expand_inline_function for documentation
1729 about the parameters. */
1730
1731static rtx
1732try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1733 tree type, rtx structure_value_addr)
1734{
1735 rtx temp;
1736 rtx before_call;
1737 int i;
1738 rtx old_stack_level = 0;
1739 int reg_parm_stack_space = 0;
1740
1741#ifdef REG_PARM_STACK_SPACE
1742#ifdef MAYBE_REG_PARM_STACK_SPACE
1743 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1744#else
1745 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1746#endif
1747#endif
1748
1749 before_call = get_last_insn ();
1750
1751 timevar_push (TV_INTEGRATION);
1752
1753 temp = expand_inline_function (fndecl, actparms, target,
1754 ignore, type,
1755 structure_value_addr);
1756
1757 timevar_pop (TV_INTEGRATION);
1758
1759 /* If inlining succeeded, return. */
1760 if (temp != (rtx) (size_t) - 1)
1761 {
1762 if (ACCUMULATE_OUTGOING_ARGS)
1763 {
1764 /* If the outgoing argument list must be preserved, push
1765 the stack before executing the inlined function if it
1766 makes any calls. */
1767
1768 i = reg_parm_stack_space;
1769 if (i > highest_outgoing_arg_in_use)
1770 i = highest_outgoing_arg_in_use;
1771 while (--i >= 0 && stack_usage_map[i] == 0)
1772 ;
1773
1774 if (stack_arg_under_construction || i >= 0)
1775 {
1776 rtx first_insn
1777 = before_call ? NEXT_INSN (before_call) : get_insns ();
1778 rtx insn = NULL_RTX, seq;
1779
1780 /* Look for a call in the inline function code.
1781 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1782 nonzero then there is a call and it is not necessary
1783 to scan the insns. */
1784
1785 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1786 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1787 if (GET_CODE (insn) == CALL_INSN)
1788 break;
1789
1790 if (insn)
1791 {
1792 /* Reserve enough stack space so that the largest
1793 argument list of any function call in the inline
1794 function does not overlap the argument list being
1795 evaluated. This is usually an overestimate because
1796 allocate_dynamic_stack_space reserves space for an
1797 outgoing argument list in addition to the requested
1798 space, but there is no way to ask for stack space such
1799 that an argument list of a certain length can be
1800 safely constructed.
1801
1802 Add the stack space reserved for register arguments, if
1803 any, in the inline function. What is really needed is the
1804 largest value of reg_parm_stack_space in the inline
1805 function, but that is not available. Using the current
1806 value of reg_parm_stack_space is wrong, but gives
1807 correct results on all supported machines. */
1808
1809 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1810 + reg_parm_stack_space);
1811
1812 start_sequence ();
1813 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1814 allocate_dynamic_stack_space (GEN_INT (adjust),
1815 NULL_RTX, BITS_PER_UNIT);
1816 seq = get_insns ();
1817 end_sequence ();
1818 emit_insn_before (seq, first_insn);
1819 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1820 }
1821 }
1822 }
1823
1824 /* If the result is equivalent to TARGET, return TARGET to simplify
1825 checks in store_expr. They can be equivalent but not equal in the
1826 case of a function that returns BLKmode. */
1827 if (temp != target && rtx_equal_p (temp, target))
1828 return target;
1829 return temp;
1830 }
1831
1832 /* If inlining failed, mark FNDECL as needing to be compiled
1833 separately after all. If function was declared inline,
1834 give a warning. */
1835 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1836 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1837 {
1838 warning ("%Jinlining failed in call to '%F'", fndecl, fndecl);
1839 warning ("called from here");
1840 }
1841 (*lang_hooks.mark_addressable) (fndecl);
1842 return (rtx) (size_t) - 1;
1843}
1844
1845/* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1846 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1847 bytes, then we would need to push some additional bytes to pad the
1848 arguments. So, we compute an adjust to the stack pointer for an
1849 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1850 bytes. Then, when the arguments are pushed the stack will be perfectly
1851 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1852 be popped after the call. Returns the adjustment. */
1853
1854static int
1855combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1856 struct args_size *args_size,
1857 int preferred_unit_stack_boundary)
1858{
1859 /* The number of bytes to pop so that the stack will be
1860 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1861 HOST_WIDE_INT adjustment;
1862 /* The alignment of the stack after the arguments are pushed, if we
1863 just pushed the arguments without adjust the stack here. */
1864 HOST_WIDE_INT unadjusted_alignment;
1865
1866 unadjusted_alignment
1867 = ((stack_pointer_delta + unadjusted_args_size)
1868 % preferred_unit_stack_boundary);
1869
1870 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1871 as possible -- leaving just enough left to cancel out the
1872 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1873 PENDING_STACK_ADJUST is non-negative, and congruent to
1874 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1875
1876 /* Begin by trying to pop all the bytes. */
1877 unadjusted_alignment
1878 = (unadjusted_alignment
1879 - (pending_stack_adjust % preferred_unit_stack_boundary));
1880 adjustment = pending_stack_adjust;
1881 /* Push enough additional bytes that the stack will be aligned
1882 after the arguments are pushed. */
1883 if (preferred_unit_stack_boundary > 1)
1884 {
1885 if (unadjusted_alignment > 0)
1886 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1887 else
1888 adjustment += unadjusted_alignment;
1889 }
1890
1891 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1892 bytes after the call. The right number is the entire
1893 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1894 by the arguments in the first place. */
1895 args_size->constant
1896 = pending_stack_adjust - adjustment + unadjusted_args_size;
1897
1898 return adjustment;
1899}
1900
1901/* Scan X expression if it does not dereference any argument slots
1902 we already clobbered by tail call arguments (as noted in stored_args_map
1903 bitmap).
1904 Return nonzero if X expression dereferences such argument slots,
1905 zero otherwise. */
1906
1907static int
1908check_sibcall_argument_overlap_1 (rtx x)
1909{
1910 RTX_CODE code;
1911 int i, j;
1912 unsigned int k;
1913 const char *fmt;
1914
1915 if (x == NULL_RTX)
1916 return 0;
1917
1918 code = GET_CODE (x);
1919
1920 if (code == MEM)
1921 {
1922 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1923 i = 0;
1924 else if (GET_CODE (XEXP (x, 0)) == PLUS
1925 && XEXP (XEXP (x, 0), 0) ==
1926 current_function_internal_arg_pointer
1927 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1928 i = INTVAL (XEXP (XEXP (x, 0), 1));
1929 else
1930 return 0;
1931
1932#ifdef ARGS_GROW_DOWNWARD
1933 i = -i - GET_MODE_SIZE (GET_MODE (x));
1934#endif
1935
1936 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1937 if (i + k < stored_args_map->n_bits
1938 && TEST_BIT (stored_args_map, i + k))
1939 return 1;
1940
1941 return 0;
1942 }
1943
1944 /* Scan all subexpressions. */
1945 fmt = GET_RTX_FORMAT (code);
1946 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1947 {
1948 if (*fmt == 'e')
1949 {
1950 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1951 return 1;
1952 }
1953 else if (*fmt == 'E')
1954 {
1955 for (j = 0; j < XVECLEN (x, i); j++)
1956 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1957 return 1;
1958 }
1959 }
1960 return 0;
1961}
1962
1963/* Scan sequence after INSN if it does not dereference any argument slots
1964 we already clobbered by tail call arguments (as noted in stored_args_map
1965 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1966 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1967 should be 0). Return nonzero if sequence after INSN dereferences such argument
1968 slots, zero otherwise. */
1969
1970static int
1971check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1972{
1973 int low, high;
1974
1975 if (insn == NULL_RTX)
1976 insn = get_insns ();
1977 else
1978 insn = NEXT_INSN (insn);
1979
1980 for (; insn; insn = NEXT_INSN (insn))
1981 if (INSN_P (insn)
1982 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1983 break;
1984
1985 if (mark_stored_args_map)
1986 {
1987#ifdef ARGS_GROW_DOWNWARD
1988 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1989#else
1990 low = arg->locate.slot_offset.constant;
1991#endif
1992
1993 for (high = low + arg->locate.size.constant; low < high; low++)
1994 SET_BIT (stored_args_map, low);
1995 }
1996 return insn != NULL_RTX;
1997}
1998
1999static tree
2000fix_unsafe_tree (tree t)
2001{
2002 switch (unsafe_for_reeval (t))
2003 {
2004 case 0: /* Safe. */
2005 break;
2006
2007 case 1: /* Mildly unsafe. */
2008 t = unsave_expr (t);
2009 break;
2010
2011 case 2: /* Wildly unsafe. */
2012 {
2013 tree var = build_decl (VAR_DECL, NULL_TREE,
2014 TREE_TYPE (t));
2015 SET_DECL_RTL (var,
2016 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2017 t = var;
2018 }
2019 break;
2020
2021 default:
2022 abort ();
2023 }
2024 return t;
2025}
2026
2027
2028/* If function value *VALUE was returned at the most significant end of a
2029 register, shift it towards the least significant end and convert it to
2030 TYPE's mode. Return true and update *VALUE if some action was needed.
2031
2032 TYPE is the type of the function's return value, which is known not
2033 to have mode BLKmode. */
2034
2035static bool
2036shift_returned_value (tree type, rtx *value)
2037{
2038 if (targetm.calls.return_in_msb (type))
2039 {
2040 HOST_WIDE_INT shift;
2041
2042 shift = (GET_MODE_BITSIZE (GET_MODE (*value))
2043 - BITS_PER_UNIT * int_size_in_bytes (type));
2044 if (shift > 0)
2045 {
2046 *value = expand_binop (GET_MODE (*value), lshr_optab, *value,
2047 GEN_INT (shift), 0, 1, OPTAB_WIDEN);
2048 *value = convert_to_mode (TYPE_MODE (type), *value, 0);
2049 return true;
2050 }
2051 }
2052 return false;
2053}
2054
2055/* Generate all the code for a function call
2056 and return an rtx for its value.
2057 Store the value in TARGET (specified as an rtx) if convenient.
2058 If the value is stored in TARGET then TARGET is returned.
2059 If IGNORE is nonzero, then we ignore the value of the function call. */
2060
2061rtx
2062expand_call (tree exp, rtx target, int ignore)
2063{
2064 /* Nonzero if we are currently expanding a call. */
2065 static int currently_expanding_call = 0;
2066
2067 /* List of actual parameters. */
2068 tree actparms = TREE_OPERAND (exp, 1);
2069 /* RTX for the function to be called. */
2070 rtx funexp;
2071 /* Sequence of insns to perform a tail recursive "call". */
2072 rtx tail_recursion_insns = NULL_RTX;
2073 /* Sequence of insns to perform a normal "call". */
2074 rtx normal_call_insns = NULL_RTX;
2075 /* Sequence of insns to perform a tail recursive "call". */
2076 rtx tail_call_insns = NULL_RTX;
2077 /* Data type of the function. */
2078 tree funtype;
2079 tree type_arg_types;
2080 /* Declaration of the function being called,
2081 or 0 if the function is computed (not known by name). */
2082 tree fndecl = 0;
2083 /* The type of the function being called. */
2084 tree fntype;
2085 rtx insn;
2086 int try_tail_call = 1;
2087 int try_tail_recursion = 1;
2088 int pass;
2089
2090 /* Register in which non-BLKmode value will be returned,
2091 or 0 if no value or if value is BLKmode. */
2092 rtx valreg;
2093 /* Address where we should return a BLKmode value;
2094 0 if value not BLKmode. */
2095 rtx structure_value_addr = 0;
2096 /* Nonzero if that address is being passed by treating it as
2097 an extra, implicit first parameter. Otherwise,
2098 it is passed by being copied directly into struct_value_rtx. */
2099 int structure_value_addr_parm = 0;
2100 /* Size of aggregate value wanted, or zero if none wanted
2101 or if we are using the non-reentrant PCC calling convention
2102 or expecting the value in registers. */
2103 HOST_WIDE_INT struct_value_size = 0;
2104 /* Nonzero if called function returns an aggregate in memory PCC style,
2105 by returning the address of where to find it. */
2106 int pcc_struct_value = 0;
2107 rtx struct_value = 0;
2108
2109 /* Number of actual parameters in this call, including struct value addr. */
2110 int num_actuals;
2111 /* Number of named args. Args after this are anonymous ones
2112 and they must all go on the stack. */
2113 int n_named_args;
2114
2115 /* Vector of information about each argument.
2116 Arguments are numbered in the order they will be pushed,
2117 not the order they are written. */
2118 struct arg_data *args;
2119
2120 /* Total size in bytes of all the stack-parms scanned so far. */
2121 struct args_size args_size;
2122 struct args_size adjusted_args_size;
2123 /* Size of arguments before any adjustments (such as rounding). */
2124 int unadjusted_args_size;
2125 /* Data on reg parms scanned so far. */
2126 CUMULATIVE_ARGS args_so_far;
2127 /* Nonzero if a reg parm has been scanned. */
2128 int reg_parm_seen;
2129 /* Nonzero if this is an indirect function call. */
2130
2131 /* Nonzero if we must avoid push-insns in the args for this call.
2132 If stack space is allocated for register parameters, but not by the
2133 caller, then it is preallocated in the fixed part of the stack frame.
2134 So the entire argument block must then be preallocated (i.e., we
2135 ignore PUSH_ROUNDING in that case). */
2136
2137 int must_preallocate = !PUSH_ARGS;
2138
2139 /* Size of the stack reserved for parameter registers. */
2140 int reg_parm_stack_space = 0;
2141
2142 /* Address of space preallocated for stack parms
2143 (on machines that lack push insns), or 0 if space not preallocated. */
2144 rtx argblock = 0;
2145
2146 /* Mask of ECF_ flags. */
2147 int flags = 0;
2148 /* Nonzero if this is a call to an inline function. */
2149 int is_integrable = 0;
2150#ifdef REG_PARM_STACK_SPACE
2151 /* Define the boundary of the register parm stack space that needs to be
2152 saved, if any. */
2153 int low_to_save, high_to_save;
2154 rtx save_area = 0; /* Place that it is saved */
2155#endif
2156
2157 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2158 rtx temp_target = 0;
2159 char *initial_stack_usage_map = stack_usage_map;
2160
2161 int old_stack_allocated;
2162
2163 /* State variables to track stack modifications. */
2164 rtx old_stack_level = 0;
2165 int old_stack_arg_under_construction = 0;
2166 int old_pending_adj = 0;
2167 int old_inhibit_defer_pop = inhibit_defer_pop;
2168
2169 /* Some stack pointer alterations we make are performed via
2170 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2171 which we then also need to save/restore along the way. */
2172 int old_stack_pointer_delta = 0;
2173
2174 rtx call_fusage;
2175 tree p = TREE_OPERAND (exp, 0);
2176 tree addr = TREE_OPERAND (exp, 0);
2177 int i;
2178 /* The alignment of the stack, in bits. */
2179 HOST_WIDE_INT preferred_stack_boundary;
2180 /* The alignment of the stack, in bytes. */
2181 HOST_WIDE_INT preferred_unit_stack_boundary;
2182
2183 /* See if this is "nothrow" function call. */
2184 if (TREE_NOTHROW (exp))
2185 flags |= ECF_NOTHROW;
2186
2187 /* See if we can find a DECL-node for the actual function.
2188 As a result, decide whether this is a call to an integrable function. */
2189
2190 fndecl = get_callee_fndecl (exp);
2191 if (fndecl)
2192 {
2193 fntype = TREE_TYPE (fndecl);
2194 if (!flag_no_inline
2195 && fndecl != current_function_decl
2196 && DECL_INLINE (fndecl)
2197 && DECL_SAVED_INSNS (fndecl)
2198 && DECL_SAVED_INSNS (fndecl)->inlinable)
2199 is_integrable = 1;
2200 else if (! TREE_ADDRESSABLE (fndecl))
2201 {
2202 /* In case this function later becomes inlinable,
2203 record that there was already a non-inline call to it.
2204
2205 Use abstraction instead of setting TREE_ADDRESSABLE
2206 directly. */
2207 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2208 && optimize > 0)
2209 {
2210 warning ("%Jcan't inline call to '%F'", fndecl, fndecl);
2211 warning ("called from here");
2212 }
2213 (*lang_hooks.mark_addressable) (fndecl);
2214 }
2215
2216 if (ignore
2217 && lookup_attribute ("warn_unused_result",
2218 TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
2219 warning ("ignoring return value of `%D', "
2220 "declared with attribute warn_unused_result", fndecl);
2221
2222 flags |= flags_from_decl_or_type (fndecl);
2223 }
2224
2225 /* If we don't have specific function to call, see if we have a
2226 attributes set in the type. */
2227 else
2228 {
2229 fntype = TREE_TYPE (TREE_TYPE (p));
2230 if (ignore
2231 && lookup_attribute ("warn_unused_result", TYPE_ATTRIBUTES (fntype)))
2232 warning ("ignoring return value of function "
2233 "declared with attribute warn_unused_result");
2234 flags |= flags_from_decl_or_type (fntype);
2235 }
2236
2237 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2238
2239 /* Warn if this value is an aggregate type,
2240 regardless of which calling convention we are using for it. */
2241 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2242 warning ("function call has aggregate value");
2243
2244 /* If the result of a pure or const function call is ignored (or void),
2245 and none of its arguments are volatile, we can avoid expanding the
2246 call and just evaluate the arguments for side-effects. */
2247 if ((flags & (ECF_CONST | ECF_PURE))
2248 && (ignore || target == const0_rtx
2249 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2250 {
2251 bool volatilep = false;
2252 tree arg;
2253
2254 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2255 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2256 {
2257 volatilep = true;
2258 break;
2259 }
2260
2261 if (! volatilep)
2262 {
2263 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2264 expand_expr (TREE_VALUE (arg), const0_rtx,
2265 VOIDmode, EXPAND_NORMAL);
2266 return const0_rtx;
2267 }
2268 }
2269
2270#ifdef REG_PARM_STACK_SPACE
2271#ifdef MAYBE_REG_PARM_STACK_SPACE
2272 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2273#else
2274 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2275#endif
2276#endif
2277
2278#ifndef OUTGOING_REG_PARM_STACK_SPACE
2279 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2280 must_preallocate = 1;
2281#endif
2282
2283 /* Set up a place to return a structure. */
2284
2285 /* Cater to broken compilers. */
2286 if (aggregate_value_p (exp, fndecl))
2287 {
2288 /* This call returns a big structure. */
2289 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2290
2291#ifdef PCC_STATIC_STRUCT_RETURN
2292 {
2293 pcc_struct_value = 1;
2294 /* Easier than making that case work right. */
2295 if (is_integrable)
2296 {
2297 /* In case this is a static function, note that it has been
2298 used. */
2299 if (! TREE_ADDRESSABLE (fndecl))
2300 (*lang_hooks.mark_addressable) (fndecl);
2301 is_integrable = 0;
2302 }
2303 }
2304#else /* not PCC_STATIC_STRUCT_RETURN */
2305 {
2306 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2307
2308 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2309 {
2310 /* The structure value address arg is already in actparms.
2311 Pull it out. It might be nice to just leave it there, but
2312 we need to set structure_value_addr. */
2313 tree return_arg = TREE_VALUE (actparms);
2314 actparms = TREE_CHAIN (actparms);
2315 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2316 VOIDmode, EXPAND_NORMAL);
2317 }
2318 else if (target && GET_CODE (target) == MEM)
2319 structure_value_addr = XEXP (target, 0);
2320 else
2321 {
2322 /* For variable-sized objects, we must be called with a target
2323 specified. If we were to allocate space on the stack here,
2324 we would have no way of knowing when to free it. */
2325 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2326
2327 mark_temp_addr_taken (d);
2328 structure_value_addr = XEXP (d, 0);
2329 target = 0;
2330 }
2331 }
2332#endif /* not PCC_STATIC_STRUCT_RETURN */
2333 }
2334
2335 /* If called function is inline, try to integrate it. */
2336
2337 if (is_integrable)
2338 {
2339 rtx temp = try_to_integrate (fndecl, actparms, target,
2340 ignore, TREE_TYPE (exp),
2341 structure_value_addr);
2342 if (temp != (rtx) (size_t) - 1)
2343 return temp;
2344 }
2345
2346 /* Figure out the amount to which the stack should be aligned. */
2347 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2348 if (fndecl)
2349 {
2350 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2351 if (i && i->preferred_incoming_stack_boundary)
2352 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2353 }
2354
2355 /* Operand 0 is a pointer-to-function; get the type of the function. */
2356 funtype = TREE_TYPE (addr);
2357 if (! POINTER_TYPE_P (funtype))
2358 abort ();
2359 funtype = TREE_TYPE (funtype);
2360
2361 /* Munge the tree to split complex arguments into their imaginary
2362 and real parts. */
2363 if (targetm.calls.split_complex_arg)
2364 {
2365 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2366 actparms = split_complex_values (actparms);
2367 }
2368 else
2369 type_arg_types = TYPE_ARG_TYPES (funtype);
2370
2371 /* See if this is a call to a function that can return more than once
2372 or a call to longjmp or malloc. */
2373 flags |= special_function_p (fndecl, flags);
2374
2375 if (flags & ECF_MAY_BE_ALLOCA)
2376 current_function_calls_alloca = 1;
2377
2378 /* If struct_value_rtx is 0, it means pass the address
2379 as if it were an extra parameter. */
2380 if (structure_value_addr && struct_value == 0)
2381 {
2382 /* If structure_value_addr is a REG other than
2383 virtual_outgoing_args_rtx, we can use always use it. If it
2384 is not a REG, we must always copy it into a register.
2385 If it is virtual_outgoing_args_rtx, we must copy it to another
2386 register in some cases. */
2387 rtx temp = (GET_CODE (structure_value_addr) != REG
2388 || (ACCUMULATE_OUTGOING_ARGS
2389 && stack_arg_under_construction
2390 && structure_value_addr == virtual_outgoing_args_rtx)
2391 ? copy_addr_to_reg (convert_memory_address
2392 (Pmode, structure_value_addr))
2393 : structure_value_addr);
2394
2395 actparms
2396 = tree_cons (error_mark_node,
2397 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2398 temp),
2399 actparms);
2400 structure_value_addr_parm = 1;
2401 }
2402
2403 /* Count the arguments and set NUM_ACTUALS. */
2404 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2405 num_actuals++;
2406
2407 /* Compute number of named args.
3a327f56
JS
2408 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2409
2410 if (type_arg_types != 0)
2411 n_named_args
2412 = (list_length (type_arg_types)
2413 /* Count the struct value address, if it is passed as a parm. */
2414 + structure_value_addr_parm);
2415 else
2416 /* If we know nothing, treat all args as named. */
2417 n_named_args = num_actuals;
2418
2419 /* Start updating where the next arg would go.
2420
2421 On some machines (such as the PA) indirect calls have a different
2422 calling convention than normal calls. The fourth argument in
2423 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2424 or not. */
2425 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2426
2427 /* Now possibly adjust the number of named args.
003757ed
MD
2428 Normally, don't include the last named arg if anonymous args follow.
2429 We do include the last named arg if
2430 targetm.calls.strict_argument_naming() returns nonzero.
2431 (If no anonymous args follow, the result of list_length is actually
2432 one too large. This is harmless.)
2433
2434 If targetm.calls.pretend_outgoing_varargs_named() returns
2435 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2436 this machine will be able to place unnamed args that were passed
2437 in registers into the stack. So treat all args as named. This
2438 allows the insns emitting for a specific argument list to be
2439 independent of the function declaration.
2440
2441 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2442 we do not have any reliable way to pass unnamed args in
2443 registers, so we must force them into memory. */
2444
3a327f56
JS
2445 if (type_arg_types != 0
2446 && targetm.calls.strict_argument_naming (&args_so_far))
2447 ;
2448 else if (type_arg_types != 0
2449 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2450 /* Don't include the last named arg. */
2451 --n_named_args;
003757ed 2452 else
3a327f56 2453 /* Treat all args as named. */
003757ed
MD
2454 n_named_args = num_actuals;
2455
003757ed
MD
2456 /* Make a vector to hold all the information about each arg. */
2457 args = alloca (num_actuals * sizeof (struct arg_data));
2458 memset (args, 0, num_actuals * sizeof (struct arg_data));
2459
2460 /* Build up entries in the ARGS array, compute the size of the
2461 arguments into ARGS_SIZE, etc. */
2462 initialize_argument_information (num_actuals, args, &args_size,
2463 n_named_args, actparms, fndecl,
2464 &args_so_far, reg_parm_stack_space,
2465 &old_stack_level, &old_pending_adj,
2466 &must_preallocate, &flags,
2467 CALL_FROM_THUNK_P (exp));
2468
2469 if (args_size.var)
2470 {
2471 /* If this function requires a variable-sized argument list, don't
2472 try to make a cse'able block for this call. We may be able to
2473 do this eventually, but it is too complicated to keep track of
2474 what insns go in the cse'able block and which don't. */
2475
2476 flags &= ~ECF_LIBCALL_BLOCK;
2477 must_preallocate = 1;
2478 }
2479
2480 /* Now make final decision about preallocating stack space. */
2481 must_preallocate = finalize_must_preallocate (must_preallocate,
2482 num_actuals, args,
2483 &args_size);
2484
2485 /* If the structure value address will reference the stack pointer, we
2486 must stabilize it. We don't need to do this if we know that we are
2487 not going to adjust the stack pointer in processing this call. */
2488
2489 if (structure_value_addr
2490 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2491 || reg_mentioned_p (virtual_outgoing_args_rtx,
2492 structure_value_addr))
2493 && (args_size.var
2494 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2495 structure_value_addr = copy_to_reg (structure_value_addr);
2496
2497 /* Tail calls can make things harder to debug, and we're traditionally
2498 pushed these optimizations into -O2. Don't try if we're already
2499 expanding a call, as that means we're an argument. Don't try if
2500 there's cleanups, as we know there's code to follow the call.
2501
2502 If rtx_equal_function_value_matters is false, that means we've
2503 finished with regular parsing. Which means that some of the
2504 machinery we use to generate tail-calls is no longer in place.
2505 This is most often true of sjlj-exceptions, which we couldn't
2506 tail-call to anyway.
2507
2508 If current_nesting_level () == 0, we're being called after
2509 the function body has been expanded. This can happen when
2510 setting up trampolines in expand_function_end. */
2511 if (currently_expanding_call++ != 0
2512 || !flag_optimize_sibling_calls
2513 || !rtx_equal_function_value_matters
2514 || current_nesting_level () == 0
2515 || any_pending_cleanups ()
2516 || args_size.var)
2517 try_tail_call = try_tail_recursion = 0;
2518
2519 /* Tail recursion fails, when we are not dealing with recursive calls. */
2520 if (!try_tail_recursion
2521 || TREE_CODE (addr) != ADDR_EXPR
2522 || TREE_OPERAND (addr, 0) != current_function_decl)
2523 try_tail_recursion = 0;
2524
2525 /* Rest of purposes for tail call optimizations to fail. */
2526 if (
2527#ifdef HAVE_sibcall_epilogue
2528 !HAVE_sibcall_epilogue
2529#else
2530 1
2531#endif
2532 || !try_tail_call
2533 /* Doing sibling call optimization needs some work, since
2534 structure_value_addr can be allocated on the stack.
2535 It does not seem worth the effort since few optimizable
2536 sibling calls will return a structure. */
2537 || structure_value_addr != NULL_RTX
2538 /* Check whether the target is able to optimize the call
2539 into a sibcall. */
2540 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2541 /* Functions that do not return exactly once may not be sibcall
2542 optimized. */
2543 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2544 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2545 /* If the called function is nested in the current one, it might access
2546 some of the caller's arguments, but could clobber them beforehand if
2547 the argument areas are shared. */
2548 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2549 /* If this function requires more stack slots than the current
2550 function, we cannot change it into a sibling call. */
2551 || args_size.constant > current_function_args_size
2552 /* If the callee pops its own arguments, then it must pop exactly
2553 the same number of arguments as the current function. */
2554 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2555 != RETURN_POPS_ARGS (current_function_decl,
2556 TREE_TYPE (current_function_decl),
2557 current_function_args_size))
2558 || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2559 try_tail_call = 0;
2560
2561 if (try_tail_call || try_tail_recursion)
2562 {
2563 int end, inc;
2564 actparms = NULL_TREE;
2565 /* Ok, we're going to give the tail call the old college try.
2566 This means we're going to evaluate the function arguments
2567 up to three times. There are two degrees of badness we can
2568 encounter, those that can be unsaved and those that can't.
2569 (See unsafe_for_reeval commentary for details.)
2570
2571 Generate a new argument list. Pass safe arguments through
2572 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2573 For hard badness, evaluate them now and put their resulting
2574 rtx in a temporary VAR_DECL.
2575
2576 initialize_argument_information has ordered the array for the
2577 order to be pushed, and we must remember this when reconstructing
2578 the original argument order. */
2579
2580 if (PUSH_ARGS_REVERSED)
2581 {
2582 inc = 1;
2583 i = 0;
2584 end = num_actuals;
2585 }
2586 else
2587 {
2588 inc = -1;
2589 i = num_actuals - 1;
2590 end = -1;
2591 }
2592
2593 for (; i != end; i += inc)
2594 {
2595 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2596 /* We need to build actparms for optimize_tail_recursion. We can
2597 safely trash away TREE_PURPOSE, since it is unused by this
2598 function. */
2599 if (try_tail_recursion)
2600 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2601 }
2602 /* Do the same for the function address if it is an expression. */
2603 if (!fndecl)
2604 addr = fix_unsafe_tree (addr);
2605 /* Expanding one of those dangerous arguments could have added
2606 cleanups, but otherwise give it a whirl. */
2607 if (any_pending_cleanups ())
2608 try_tail_call = try_tail_recursion = 0;
2609 }
2610
2611 /* Generate a tail recursion sequence when calling ourselves. */
2612
2613 if (try_tail_recursion)
2614 {
2615 /* We want to emit any pending stack adjustments before the tail
2616 recursion "call". That way we know any adjustment after the tail
2617 recursion call can be ignored if we indeed use the tail recursion
2618 call expansion. */
2619 int save_pending_stack_adjust = pending_stack_adjust;
2620 int save_stack_pointer_delta = stack_pointer_delta;
2621
2622 /* Emit any queued insns now; otherwise they would end up in
2623 only one of the alternates. */
2624 emit_queue ();
2625
2626 /* Use a new sequence to hold any RTL we generate. We do not even
2627 know if we will use this RTL yet. The final decision can not be
2628 made until after RTL generation for the entire function is
2629 complete. */
2630 start_sequence ();
2631 /* If expanding any of the arguments creates cleanups, we can't
2632 do a tailcall. So, we'll need to pop the pending cleanups
2633 list. If, however, all goes well, and there are no cleanups
2634 then the call to expand_start_target_temps will have no
2635 effect. */
2636 expand_start_target_temps ();
2637 if (optimize_tail_recursion (actparms, get_last_insn ()))
2638 {
2639 if (any_pending_cleanups ())
2640 try_tail_call = try_tail_recursion = 0;
2641 else
2642 tail_recursion_insns = get_insns ();
2643 }
2644 expand_end_target_temps ();
2645 end_sequence ();
2646
2647 /* Restore the original pending stack adjustment for the sibling and
2648 normal call cases below. */
2649 pending_stack_adjust = save_pending_stack_adjust;
2650 stack_pointer_delta = save_stack_pointer_delta;
2651 }
2652
2653 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2654 {
2655 /* A fork duplicates the profile information, and an exec discards
2656 it. We can't rely on fork/exec to be paired. So write out the
2657 profile information we have gathered so far, and clear it. */
2658 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2659 is subject to race conditions, just as with multithreaded
2660 programs. */
2661
2662 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2663 }
2664
2665 /* Ensure current function's preferred stack boundary is at least
2666 what we need. We don't have to increase alignment for recursive
2667 functions. */
2668 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2669 && fndecl != current_function_decl)
2670 cfun->preferred_stack_boundary = preferred_stack_boundary;
2671 if (fndecl == current_function_decl)
2672 cfun->recursive_call_emit = true;
2673
2674 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2675
2676 function_call_count++;
2677
2678 /* We want to make two insn chains; one for a sibling call, the other
2679 for a normal call. We will select one of the two chains after
2680 initial RTL generation is complete. */
2681 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2682 {
2683 int sibcall_failure = 0;
2684 /* We want to emit any pending stack adjustments before the tail
2685 recursion "call". That way we know any adjustment after the tail
2686 recursion call can be ignored if we indeed use the tail recursion
2687 call expansion. */
2688 int save_pending_stack_adjust = 0;
2689 int save_stack_pointer_delta = 0;
2690 rtx insns;
2691 rtx before_call, next_arg_reg;
2692
2693 if (pass == 0)
2694 {
2695 /* Emit any queued insns now; otherwise they would end up in
2696 only one of the alternates. */
2697 emit_queue ();
2698
2699 /* State variables we need to save and restore between
2700 iterations. */
2701 save_pending_stack_adjust = pending_stack_adjust;
2702 save_stack_pointer_delta = stack_pointer_delta;
2703 }
2704 if (pass)
2705 flags &= ~ECF_SIBCALL;
2706 else
2707 flags |= ECF_SIBCALL;
2708
2709 /* Other state variables that we must reinitialize each time
2710 through the loop (that are not initialized by the loop itself). */
2711 argblock = 0;
2712 call_fusage = 0;
2713
2714 /* Start a new sequence for the normal call case.
2715
2716 From this point on, if the sibling call fails, we want to set
2717 sibcall_failure instead of continuing the loop. */
2718 start_sequence ();
2719
2720 if (pass == 0)
2721 {
2722 /* We know at this point that there are not currently any
2723 pending cleanups. If, however, in the process of evaluating
2724 the arguments we were to create some, we'll need to be
2725 able to get rid of them. */
2726 expand_start_target_temps ();
2727 }
2728
2729 /* Don't let pending stack adjusts add up to too much.
2730 Also, do all pending adjustments now if there is any chance
2731 this might be a call to alloca or if we are expanding a sibling
2732 call sequence or if we are calling a function that is to return
1c1138ce
JS
2733 with stack pointer depressed.
2734 Also do the adjustments before a throwing call, otherwise
2735 exception handling can fail; PR 19225. */
003757ed
MD
2736 if (pending_stack_adjust >= 32
2737 || (pending_stack_adjust > 0
2738 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
1c1138ce
JS
2739 || (pending_stack_adjust > 0
2740 && flag_exceptions && !(flags & ECF_NOTHROW))
003757ed
MD
2741 || pass == 0)
2742 do_pending_stack_adjust ();
2743
2744 /* When calling a const function, we must pop the stack args right away,
2745 so that the pop is deleted or moved with the call. */
2746 if (pass && (flags & ECF_LIBCALL_BLOCK))
2747 NO_DEFER_POP;
2748
2749#ifdef FINAL_REG_PARM_STACK_SPACE
2750 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2751 args_size.var);
2752#endif
2753 /* Precompute any arguments as needed. */
2754 if (pass)
2755 precompute_arguments (flags, num_actuals, args);
2756
2757 /* Now we are about to start emitting insns that can be deleted
2758 if a libcall is deleted. */
2759 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2760 start_sequence ();
2761
2762 adjusted_args_size = args_size;
2763 /* Compute the actual size of the argument block required. The variable
2764 and constant sizes must be combined, the size may have to be rounded,
2765 and there may be a minimum required size. When generating a sibcall
2766 pattern, do not round up, since we'll be re-using whatever space our
2767 caller provided. */
2768 unadjusted_args_size
2769 = compute_argument_block_size (reg_parm_stack_space,
2770 &adjusted_args_size,
2771 (pass == 0 ? 0
2772 : preferred_stack_boundary));
2773
2774 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2775
2776 /* The argument block when performing a sibling call is the
2777 incoming argument block. */
2778 if (pass == 0)
2779 {
2780 argblock = virtual_incoming_args_rtx;
2781 argblock
2782#ifdef STACK_GROWS_DOWNWARD
2783 = plus_constant (argblock, current_function_pretend_args_size);
2784#else
2785 = plus_constant (argblock, -current_function_pretend_args_size);
2786#endif
2787 stored_args_map = sbitmap_alloc (args_size.constant);
2788 sbitmap_zero (stored_args_map);
2789 }
2790
2791 /* If we have no actual push instructions, or shouldn't use them,
2792 make space for all args right now. */
2793 else if (adjusted_args_size.var != 0)
2794 {
2795 if (old_stack_level == 0)
2796 {
2797 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2798 old_stack_pointer_delta = stack_pointer_delta;
2799 old_pending_adj = pending_stack_adjust;
2800 pending_stack_adjust = 0;
2801 /* stack_arg_under_construction says whether a stack arg is
2802 being constructed at the old stack level. Pushing the stack
2803 gets a clean outgoing argument block. */
2804 old_stack_arg_under_construction = stack_arg_under_construction;
2805 stack_arg_under_construction = 0;
2806 }
2807 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2808 }
2809 else
2810 {
2811 /* Note that we must go through the motions of allocating an argument
2812 block even if the size is zero because we may be storing args
2813 in the area reserved for register arguments, which may be part of
2814 the stack frame. */
2815
2816 int needed = adjusted_args_size.constant;
2817
2818 /* Store the maximum argument space used. It will be pushed by
2819 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2820 checking). */
2821
2822 if (needed > current_function_outgoing_args_size)
2823 current_function_outgoing_args_size = needed;
2824
2825 if (must_preallocate)
2826 {
2827 if (ACCUMULATE_OUTGOING_ARGS)
2828 {
2829 /* Since the stack pointer will never be pushed, it is
2830 possible for the evaluation of a parm to clobber
2831 something we have already written to the stack.
2832 Since most function calls on RISC machines do not use
2833 the stack, this is uncommon, but must work correctly.
2834
2835 Therefore, we save any area of the stack that was already
2836 written and that we are using. Here we set up to do this
2837 by making a new stack usage map from the old one. The
2838 actual save will be done by store_one_arg.
2839
2840 Another approach might be to try to reorder the argument
2841 evaluations to avoid this conflicting stack usage. */
2842
2843#ifndef OUTGOING_REG_PARM_STACK_SPACE
2844 /* Since we will be writing into the entire argument area,
2845 the map must be allocated for its entire size, not just
2846 the part that is the responsibility of the caller. */
2847 needed += reg_parm_stack_space;
2848#endif
2849
2850#ifdef ARGS_GROW_DOWNWARD
2851 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2852 needed + 1);
2853#else
2854 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2855 needed);
2856#endif
2857 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2858
2859 if (initial_highest_arg_in_use)
2860 memcpy (stack_usage_map, initial_stack_usage_map,
2861 initial_highest_arg_in_use);
2862
2863 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2864 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2865 (highest_outgoing_arg_in_use
2866 - initial_highest_arg_in_use));
2867 needed = 0;
2868
2869 /* The address of the outgoing argument list must not be
2870 copied to a register here, because argblock would be left
2871 pointing to the wrong place after the call to
2872 allocate_dynamic_stack_space below. */
2873
2874 argblock = virtual_outgoing_args_rtx;
2875 }
2876 else
2877 {
2878 if (inhibit_defer_pop == 0)
2879 {
2880 /* Try to reuse some or all of the pending_stack_adjust
2881 to get this space. */
2882 needed
2883 = (combine_pending_stack_adjustment_and_call
2884 (unadjusted_args_size,
2885 &adjusted_args_size,
2886 preferred_unit_stack_boundary));
2887
2888 /* combine_pending_stack_adjustment_and_call computes
2889 an adjustment before the arguments are allocated.
2890 Account for them and see whether or not the stack
2891 needs to go up or down. */
2892 needed = unadjusted_args_size - needed;
2893
2894 if (needed < 0)
2895 {
2896 /* We're releasing stack space. */
2897 /* ??? We can avoid any adjustment at all if we're
2898 already aligned. FIXME. */
2899 pending_stack_adjust = -needed;
2900 do_pending_stack_adjust ();
2901 needed = 0;
2902 }
2903 else
2904 /* We need to allocate space. We'll do that in
2905 push_block below. */
2906 pending_stack_adjust = 0;
2907 }
2908
2909 /* Special case this because overhead of `push_block' in
2910 this case is non-trivial. */
2911 if (needed == 0)
2912 argblock = virtual_outgoing_args_rtx;
2913 else
2914 {
2915 argblock = push_block (GEN_INT (needed), 0, 0);
2916#ifdef ARGS_GROW_DOWNWARD
2917 argblock = plus_constant (argblock, needed);
2918#endif
2919 }
2920
2921 /* We only really need to call `copy_to_reg' in the case
2922 where push insns are going to be used to pass ARGBLOCK
2923 to a function call in ARGS. In that case, the stack
2924 pointer changes value from the allocation point to the
2925 call point, and hence the value of
2926 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2927 as well always do it. */
2928 argblock = copy_to_reg (argblock);
2929 }
2930 }
2931 }
2932
2933 if (ACCUMULATE_OUTGOING_ARGS)
2934 {
2935 /* The save/restore code in store_one_arg handles all
2936 cases except one: a constructor call (including a C
2937 function returning a BLKmode struct) to initialize
2938 an argument. */
2939 if (stack_arg_under_construction)
2940 {
2941#ifndef OUTGOING_REG_PARM_STACK_SPACE
2942 rtx push_size = GEN_INT (reg_parm_stack_space
2943 + adjusted_args_size.constant);
2944#else
2945 rtx push_size = GEN_INT (adjusted_args_size.constant);
2946#endif
2947 if (old_stack_level == 0)
2948 {
2949 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2950 NULL_RTX);
2951 old_stack_pointer_delta = stack_pointer_delta;
2952 old_pending_adj = pending_stack_adjust;
2953 pending_stack_adjust = 0;
2954 /* stack_arg_under_construction says whether a stack
2955 arg is being constructed at the old stack level.
2956 Pushing the stack gets a clean outgoing argument
2957 block. */
2958 old_stack_arg_under_construction
2959 = stack_arg_under_construction;
2960 stack_arg_under_construction = 0;
2961 /* Make a new map for the new argument list. */
2962 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2963 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2964 highest_outgoing_arg_in_use = 0;
2965 }
2966 allocate_dynamic_stack_space (push_size, NULL_RTX,
2967 BITS_PER_UNIT);
2968 }
2969
2970 /* If argument evaluation might modify the stack pointer,
2971 copy the address of the argument list to a register. */
2972 for (i = 0; i < num_actuals; i++)
2973 if (args[i].pass_on_stack)
2974 {
2975 argblock = copy_addr_to_reg (argblock);
2976 break;
2977 }
2978 }
2979
2980 compute_argument_addresses (args, argblock, num_actuals);
2981
2982 /* If we push args individually in reverse order, perform stack alignment
2983 before the first push (the last arg). */
2984 if (PUSH_ARGS_REVERSED && argblock == 0
2985 && adjusted_args_size.constant != unadjusted_args_size)
2986 {
2987 /* When the stack adjustment is pending, we get better code
2988 by combining the adjustments. */
2989 if (pending_stack_adjust
2990 && ! (flags & ECF_LIBCALL_BLOCK)
2991 && ! inhibit_defer_pop)
2992 {
2993 pending_stack_adjust
2994 = (combine_pending_stack_adjustment_and_call
2995 (unadjusted_args_size,
2996 &adjusted_args_size,
2997 preferred_unit_stack_boundary));
2998 do_pending_stack_adjust ();
2999 }
3000 else if (argblock == 0)
3001 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3002 - unadjusted_args_size));
3003 }
3004 /* Now that the stack is properly aligned, pops can't safely
3005 be deferred during the evaluation of the arguments. */
3006 NO_DEFER_POP;
3007
3008 funexp = rtx_for_function_call (fndecl, addr);
3009
3010 /* Figure out the register where the value, if any, will come back. */
3011 valreg = 0;
3012 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
3013 && ! structure_value_addr)
3014 {
3015 if (pcc_struct_value)
3016 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
3017 fndecl, (pass == 0));
3018 else
3019 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
3020 }
3021
3022 /* Precompute all register parameters. It isn't safe to compute anything
3023 once we have started filling any specific hard regs. */
3024 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3025
3026#ifdef REG_PARM_STACK_SPACE
3027 /* Save the fixed argument area if it's part of the caller's frame and
3028 is clobbered by argument setup for this call. */
3029 if (ACCUMULATE_OUTGOING_ARGS && pass)
3030 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3031 &low_to_save, &high_to_save);
3032#endif
3033
3034 /* Now store (and compute if necessary) all non-register parms.
3035 These come before register parms, since they can require block-moves,
3036 which could clobber the registers used for register parms.
3037 Parms which have partial registers are not stored here,
3038 but we do preallocate space here if they want that. */
3039
3040 for (i = 0; i < num_actuals; i++)
3041 if (args[i].reg == 0 || args[i].pass_on_stack)
3042 {
3043 rtx before_arg = get_last_insn ();
3044
3045 if (store_one_arg (&args[i], argblock, flags,
3046 adjusted_args_size.var != 0,
3047 reg_parm_stack_space)
3048 || (pass == 0
3049 && check_sibcall_argument_overlap (before_arg,
3050 &args[i], 1)))
3051 sibcall_failure = 1;
3052
3053 if (flags & ECF_CONST
3054 && args[i].stack
3055 && args[i].value == args[i].stack)
3056 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3057 gen_rtx_USE (VOIDmode,
3058 args[i].value),
3059 call_fusage);
3060 }
3061
3062 /* If we have a parm that is passed in registers but not in memory
3063 and whose alignment does not permit a direct copy into registers,
3064 make a group of pseudos that correspond to each register that we
3065 will later fill. */
3066 if (STRICT_ALIGNMENT)
3067 store_unaligned_arguments_into_pseudos (args, num_actuals);
3068
3069 /* Now store any partially-in-registers parm.
3070 This is the last place a block-move can happen. */
3071 if (reg_parm_seen)
3072 for (i = 0; i < num_actuals; i++)
3073 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3074 {
3075 rtx before_arg = get_last_insn ();
3076
3077 if (store_one_arg (&args[i], argblock, flags,
3078 adjusted_args_size.var != 0,
3079 reg_parm_stack_space)
3080 || (pass == 0
3081 && check_sibcall_argument_overlap (before_arg,
3082 &args[i], 1)))
3083 sibcall_failure = 1;
3084 }
3085
3086 /* If we pushed args in forward order, perform stack alignment
3087 after pushing the last arg. */
3088 if (!PUSH_ARGS_REVERSED && argblock == 0)
3089 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3090 - unadjusted_args_size));
3091
3092 /* If register arguments require space on the stack and stack space
3093 was not preallocated, allocate stack space here for arguments
3094 passed in registers. */
3095#ifdef OUTGOING_REG_PARM_STACK_SPACE
3096 if (!ACCUMULATE_OUTGOING_ARGS
3097 && must_preallocate == 0 && reg_parm_stack_space > 0)
3098 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3099#endif
3100
3101 /* Pass the function the address in which to return a
3102 structure value. */
3103 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3104 {
3105 structure_value_addr
3106 = convert_memory_address (Pmode, structure_value_addr);
3107 emit_move_insn (struct_value,
3108 force_reg (Pmode,
3109 force_operand (structure_value_addr,
3110 NULL_RTX)));
3111
3112 if (GET_CODE (struct_value) == REG)
3113 use_reg (&call_fusage, struct_value);
3114 }
3115
3116 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3117 reg_parm_seen, pass == 0);
3118
3119 load_register_parameters (args, num_actuals, &call_fusage, flags,
3120 pass == 0, &sibcall_failure);
3121
3122 /* Perform postincrements before actually calling the function. */
3123 emit_queue ();
3124
3125 /* Save a pointer to the last insn before the call, so that we can
3126 later safely search backwards to find the CALL_INSN. */
3127 before_call = get_last_insn ();
3128
3129 /* Set up next argument register. For sibling calls on machines
3130 with register windows this should be the incoming register. */
3131#ifdef FUNCTION_INCOMING_ARG
3132 if (pass == 0)
3133 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3134 void_type_node, 1);
3135 else
3136#endif
3137 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3138 void_type_node, 1);
3139
3140 /* All arguments and registers used for the call must be set up by
3141 now! */
3142
3143 /* Stack must be properly aligned now. */
3144 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3145 abort ();
3146
3147 /* Generate the actual call instruction. */
3148 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3149 adjusted_args_size.constant, struct_value_size,
3150 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3151 flags, & args_so_far);
3152
3153 /* If call is cse'able, make appropriate pair of reg-notes around it.
3154 Test valreg so we don't crash; may safely ignore `const'
3155 if return type is void. Disable for PARALLEL return values, because
3156 we have no way to move such values into a pseudo register. */
3157 if (pass && (flags & ECF_LIBCALL_BLOCK))
3158 {
3159 rtx insns;
3160 rtx insn;
3161 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
3162
3163 insns = get_insns ();
3164
3165 /* Expansion of block moves possibly introduced a loop that may
3166 not appear inside libcall block. */
3167 for (insn = insns; insn; insn = NEXT_INSN (insn))
3168 if (GET_CODE (insn) == JUMP_INSN)
3169 failed = true;
3170
3171 if (failed)
3172 {
3173 end_sequence ();
3174 emit_insn (insns);
3175 }
3176 else
3177 {
3178 rtx note = 0;
3179 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3180
3181 /* Mark the return value as a pointer if needed. */
3182 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3183 mark_reg_pointer (temp,
3184 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3185
3186 end_sequence ();
3187 if (flag_unsafe_math_optimizations
3188 && fndecl
3189 && DECL_BUILT_IN (fndecl)
3190 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
3191 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
3192 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
3193 note = gen_rtx_fmt_e (SQRT,
3194 GET_MODE (temp),
3195 args[0].initial_value);
3196 else
3197 {
3198 /* Construct an "equal form" for the value which
3199 mentions all the arguments in order as well as
3200 the function name. */
3201 for (i = 0; i < num_actuals; i++)
3202 note = gen_rtx_EXPR_LIST (VOIDmode,
3203 args[i].initial_value, note);
3204 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3205
3206 if (flags & ECF_PURE)
3207 note = gen_rtx_EXPR_LIST (VOIDmode,
3208 gen_rtx_USE (VOIDmode,
3209 gen_rtx_MEM (BLKmode,
3210 gen_rtx_SCRATCH (VOIDmode))),
3211 note);
3212 }
3213 emit_libcall_block (insns, temp, valreg, note);
3214
3215 valreg = temp;
3216 }
3217 }
3218 else if (pass && (flags & ECF_MALLOC))
3219 {
3220 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3221 rtx last, insns;
3222
3223 /* The return value from a malloc-like function is a pointer. */
3224 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3225 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3226
3227 emit_move_insn (temp, valreg);
3228
3229 /* The return value from a malloc-like function can not alias
3230 anything else. */
3231 last = get_last_insn ();
3232 REG_NOTES (last) =
3233 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3234
3235 /* Write out the sequence. */
3236 insns = get_insns ();
3237 end_sequence ();
3238 emit_insn (insns);
3239 valreg = temp;
3240 }
3241
3242 /* For calls to `setjmp', etc., inform flow.c it should complain
3243 if nonvolatile values are live. For functions that cannot return,
3244 inform flow that control does not fall through. */
3245
3246 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3247 {
3248 /* The barrier must be emitted
3249 immediately after the CALL_INSN. Some ports emit more
3250 than just a CALL_INSN above, so we must search for it here. */
3251
3252 rtx last = get_last_insn ();
3253 while (GET_CODE (last) != CALL_INSN)
3254 {
3255 last = PREV_INSN (last);
3256 /* There was no CALL_INSN? */
3257 if (last == before_call)
3258 abort ();
3259 }
3260
3261 emit_barrier_after (last);
3262
3263 /* Stack adjustments after a noreturn call are dead code.
3264 However when NO_DEFER_POP is in effect, we must preserve
3265 stack_pointer_delta. */
3266 if (inhibit_defer_pop == 0)
3267 {
3268 stack_pointer_delta = old_stack_allocated;
3269 pending_stack_adjust = 0;
3270 }
3271 }
3272
3273 if (flags & ECF_LONGJMP)
3274 current_function_calls_longjmp = 1;
3275
3276 /* If value type not void, return an rtx for the value. */
3277
3278 /* If there are cleanups to be called, don't use a hard reg as target.
3279 We need to double check this and see if it matters anymore. */
3280 if (any_pending_cleanups ())
3281 {
3282 if (target && REG_P (target)
3283 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3284 target = 0;
3285 sibcall_failure = 1;
3286 }
3287
3288 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3289 || ignore)
3290 target = const0_rtx;
3291 else if (structure_value_addr)
3292 {
3293 if (target == 0 || GET_CODE (target) != MEM)
3294 {
3295 target
3296 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3297 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3298 structure_value_addr));
3299 set_mem_attributes (target, exp, 1);
3300 }
3301 }
3302 else if (pcc_struct_value)
3303 {
3304 /* This is the special C++ case where we need to
3305 know what the true target was. We take care to
3306 never use this value more than once in one expression. */
3307 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3308 copy_to_reg (valreg));
3309 set_mem_attributes (target, exp, 1);
3310 }
3311 /* Handle calls that return values in multiple non-contiguous locations.
3312 The Irix 6 ABI has examples of this. */
3313 else if (GET_CODE (valreg) == PARALLEL)
3314 {
3315 /* Second condition is added because "target" is freed at the
3316 the end of "pass0" for -O2 when call is made to
3317 expand_end_target_temps (). Its "in_use" flag has been set
3318 to false, so allocate a new temp. */
3319 if (target == 0 || (pass == 1 && target == temp_target))
3320 {
3321 /* This will only be assigned once, so it can be readonly. */
3322 tree nt = build_qualified_type (TREE_TYPE (exp),
3323 (TYPE_QUALS (TREE_TYPE (exp))
3324 | TYPE_QUAL_CONST));
3325
3326 target = assign_temp (nt, 0, 1, 1);
3327 temp_target = target;
3328 preserve_temp_slots (target);
3329 }
3330
3331 if (! rtx_equal_p (target, valreg))
3332 emit_group_store (target, valreg, TREE_TYPE (exp),
3333 int_size_in_bytes (TREE_TYPE (exp)));
3334
3335 /* We can not support sibling calls for this case. */
3336 sibcall_failure = 1;
3337 }
3338 else if (target
3339 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3340 && GET_MODE (target) == GET_MODE (valreg))
3341 {
3342 /* TARGET and VALREG cannot be equal at this point because the
3343 latter would not have REG_FUNCTION_VALUE_P true, while the
3344 former would if it were referring to the same register.
3345
3346 If they refer to the same register, this move will be a no-op,
3347 except when function inlining is being done. */
3348 emit_move_insn (target, valreg);
3349
3350 /* If we are setting a MEM, this code must be executed. Since it is
3351 emitted after the call insn, sibcall optimization cannot be
3352 performed in that case. */
3353 if (GET_CODE (target) == MEM)
3354 sibcall_failure = 1;
3355 }
3356 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3357 {
3358 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3359
3360 /* We can not support sibling calls for this case. */
3361 sibcall_failure = 1;
3362 }
3363 else
3364 {
3365 if (shift_returned_value (TREE_TYPE (exp), &valreg))
3366 sibcall_failure = 1;
3367
3368 target = copy_to_reg (valreg);
3369 }
3370
3371 if (targetm.calls.promote_function_return(funtype))
3372 {
3373 /* If we promoted this return value, make the proper SUBREG. TARGET
3374 might be const0_rtx here, so be careful. */
3375 if (GET_CODE (target) == REG
3376 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3377 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3378 {
3379 tree type = TREE_TYPE (exp);
3380 int unsignedp = TREE_UNSIGNED (type);
3381 int offset = 0;
3382
3383 /* If we don't promote as expected, something is wrong. */
3384 if (GET_MODE (target)
3385 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3386 abort ();
3387
3388 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3389 && GET_MODE_SIZE (GET_MODE (target))
3390 > GET_MODE_SIZE (TYPE_MODE (type)))
3391 {
3392 offset = GET_MODE_SIZE (GET_MODE (target))
3393 - GET_MODE_SIZE (TYPE_MODE (type));
3394 if (! BYTES_BIG_ENDIAN)
3395 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3396 else if (! WORDS_BIG_ENDIAN)
3397 offset %= UNITS_PER_WORD;
3398 }
3399 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3400 SUBREG_PROMOTED_VAR_P (target) = 1;
3401 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3402 }
3403 }
3404
3405 /* If size of args is variable or this was a constructor call for a stack
3406 argument, restore saved stack-pointer value. */
3407
3408 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3409 {
3410 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3411 stack_pointer_delta = old_stack_pointer_delta;
3412 pending_stack_adjust = old_pending_adj;
3413 stack_arg_under_construction = old_stack_arg_under_construction;
3414 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3415 stack_usage_map = initial_stack_usage_map;
3416 sibcall_failure = 1;
3417 }
3418 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3419 {
3420#ifdef REG_PARM_STACK_SPACE
3421 if (save_area)
3422 restore_fixed_argument_area (save_area, argblock,
3423 high_to_save, low_to_save);
3424#endif
3425
3426 /* If we saved any argument areas, restore them. */
3427 for (i = 0; i < num_actuals; i++)
3428 if (args[i].save_area)
3429 {
3430 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3431 rtx stack_area
3432 = gen_rtx_MEM (save_mode,
3433 memory_address (save_mode,
3434 XEXP (args[i].stack_slot, 0)));
3435
3436 if (save_mode != BLKmode)
3437 emit_move_insn (stack_area, args[i].save_area);
3438 else
3439 emit_block_move (stack_area, args[i].save_area,
3440 GEN_INT (args[i].locate.size.constant),
3441 BLOCK_OP_CALL_PARM);
3442 }
3443
3444 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3445 stack_usage_map = initial_stack_usage_map;
3446 }
3447
3448 /* If this was alloca, record the new stack level for nonlocal gotos.
3449 Check for the handler slots since we might not have a save area
3450 for non-local gotos. */
3451
3452 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3453 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3454
3455 /* Free up storage we no longer need. */
3456 for (i = 0; i < num_actuals; ++i)
3457 if (args[i].aligned_regs)
3458 free (args[i].aligned_regs);
3459
3460 if (pass == 0)
3461 {
3462 /* Undo the fake expand_start_target_temps we did earlier. If
3463 there had been any cleanups created, we've already set
3464 sibcall_failure. */
3465 expand_end_target_temps ();
3466 }
3467
3468 /* If this function is returning into a memory location marked as
3469 readonly, it means it is initializing that location. We normally treat
3470 functions as not clobbering such locations, so we need to specify that
3471 this one does. We do this by adding the appropriate CLOBBER to the
3472 CALL_INSN function usage list. This cannot be done by emitting a
3473 standalone CLOBBER after the call because the latter would be ignored
3474 by at least the delay slot scheduling pass. We do this now instead of
3475 adding to call_fusage before the call to emit_call_1 because TARGET
3476 may be modified in the meantime. */
3477 if (structure_value_addr != 0 && target != 0
3478 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3479 add_function_usage_to
3480 (last_call_insn (),
3481 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3482 NULL_RTX));
3483
3484 insns = get_insns ();
3485 end_sequence ();
3486
3487 if (pass == 0)
3488 {
3489 tail_call_insns = insns;
3490
3491 /* Restore the pending stack adjustment now that we have
3492 finished generating the sibling call sequence. */
3493
3494 pending_stack_adjust = save_pending_stack_adjust;
3495 stack_pointer_delta = save_stack_pointer_delta;
3496
3497 /* Prepare arg structure for next iteration. */
3498 for (i = 0; i < num_actuals; i++)
3499 {
3500 args[i].value = 0;
3501 args[i].aligned_regs = 0;
3502 args[i].stack = 0;
3503 }
3504
3505 sbitmap_free (stored_args_map);
3506 }
3507 else
3508 {
3509 normal_call_insns = insns;
3510
3511 /* Verify that we've deallocated all the stack we used. */
3512 if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3513 && old_stack_allocated != stack_pointer_delta
3514 - pending_stack_adjust)
3515 abort ();
3516 }
3517
3518 /* If something prevents making this a sibling call,
3519 zero out the sequence. */
3520 if (sibcall_failure)
3521 tail_call_insns = NULL_RTX;
3522 }
3523
3524 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3525 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3526 can happen if the arguments to this function call an inline
3527 function who's expansion contains another CALL_PLACEHOLDER.
3528
3529 If there are any C_Ps in any of these sequences, replace them
3530 with their normal call. */
3531
3532 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3533 if (GET_CODE (insn) == CALL_INSN
3534 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3535 replace_call_placeholder (insn, sibcall_use_normal);
3536
3537 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3538 if (GET_CODE (insn) == CALL_INSN
3539 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3540 replace_call_placeholder (insn, sibcall_use_normal);
3541
3542 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3543 if (GET_CODE (insn) == CALL_INSN
3544 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3545 replace_call_placeholder (insn, sibcall_use_normal);
3546
3547 /* If this was a potential tail recursion site, then emit a
3548 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3549 One of them will be selected later. */
3550 if (tail_recursion_insns || tail_call_insns)
3551 {
3552 /* The tail recursion label must be kept around. We could expose
3553 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3554 and makes determining true tail recursion sites difficult.
3555
3556 So we set LABEL_PRESERVE_P here, then clear it when we select
3557 one of the call sequences after rtl generation is complete. */
3558 if (tail_recursion_insns)
3559 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3560 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3561 tail_call_insns,
3562 tail_recursion_insns,
3563 tail_recursion_label));
3564 }
3565 else
3566 emit_insn (normal_call_insns);
3567
3568 currently_expanding_call--;
3569
3570 /* If this function returns with the stack pointer depressed, ensure
3571 this block saves and restores the stack pointer, show it was
3572 changed, and adjust for any outgoing arg space. */
3573 if (flags & ECF_SP_DEPRESSED)
3574 {
3575 clear_pending_stack_adjust ();
3576 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3577 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3578 save_stack_pointer ();
3579 }
3580
3581 return target;
3582}
3583
3584/* Traverse an argument list in VALUES and expand all complex
3585 arguments into their components. */
3586tree
3587split_complex_values (tree values)
3588{
3589 tree p;
3590
3591 /* Before allocating memory, check for the common case of no complex. */
3592 for (p = values; p; p = TREE_CHAIN (p))
3593 {
3594 tree type = TREE_TYPE (TREE_VALUE (p));
3595 if (type && TREE_CODE (type) == COMPLEX_TYPE
3596 && targetm.calls.split_complex_arg (type))
3597 goto found;
3598 }
3599 return values;
3600
3601 found:
3602 values = copy_list (values);
3603
3604 for (p = values; p; p = TREE_CHAIN (p))
3605 {
3606 tree complex_value = TREE_VALUE (p);
3607 tree complex_type;
3608
3609 complex_type = TREE_TYPE (complex_value);
3610 if (!complex_type)
3611 continue;
3612
3613 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3614 && targetm.calls.split_complex_arg (complex_type))
3615 {
3616 tree subtype;
3617 tree real, imag, next;
3618
3619 subtype = TREE_TYPE (complex_type);
3620 complex_value = save_expr (complex_value);
3621 real = build1 (REALPART_EXPR, subtype, complex_value);
3622 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3623
3624 TREE_VALUE (p) = real;
3625 next = TREE_CHAIN (p);
3626 imag = build_tree_list (NULL_TREE, imag);
3627 TREE_CHAIN (p) = imag;
3628 TREE_CHAIN (imag) = next;
3629
3630 /* Skip the newly created node. */
3631 p = TREE_CHAIN (p);
3632 }
3633 }
3634
3635 return values;
3636}
3637
3638/* Traverse a list of TYPES and expand all complex types into their
3639 components. */
3640tree
3641split_complex_types (tree types)
3642{
3643 tree p;
3644
3645 /* Before allocating memory, check for the common case of no complex. */
3646 for (p = types; p; p = TREE_CHAIN (p))
3647 {
3648 tree type = TREE_VALUE (p);
3649 if (TREE_CODE (type) == COMPLEX_TYPE
3650 && targetm.calls.split_complex_arg (type))
3651 goto found;
3652 }
3653 return types;
3654
3655 found:
3656 types = copy_list (types);
3657
3658 for (p = types; p; p = TREE_CHAIN (p))
3659 {
3660 tree complex_type = TREE_VALUE (p);
3661
3662 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3663 && targetm.calls.split_complex_arg (complex_type))
3664 {
3665 tree next, imag;
3666
3667 /* Rewrite complex type with component type. */
3668 TREE_VALUE (p) = TREE_TYPE (complex_type);
3669 next = TREE_CHAIN (p);
3670
3671 /* Add another component type for the imaginary part. */
3672 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3673 TREE_CHAIN (p) = imag;
3674 TREE_CHAIN (imag) = next;
3675
3676 /* Skip the newly created node. */
3677 p = TREE_CHAIN (p);
3678 }
3679 }
3680
3681 return types;
3682}
3683\f
3684/* Output a library call to function FUN (a SYMBOL_REF rtx).
3685 The RETVAL parameter specifies whether return value needs to be saved, other
3686 parameters are documented in the emit_library_call function below. */
3687
3688static rtx
3689emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3690 enum libcall_type fn_type,
3691 enum machine_mode outmode, int nargs, va_list p)
3692{
3693 /* Total size in bytes of all the stack-parms scanned so far. */
3694 struct args_size args_size;
3695 /* Size of arguments before any adjustments (such as rounding). */
3696 struct args_size original_args_size;
3697 int argnum;
3698 rtx fun;
3699 int inc;
3700 int count;
3701 rtx argblock = 0;
3702 CUMULATIVE_ARGS args_so_far;
3703 struct arg
3704 {
3705 rtx value;
3706 enum machine_mode mode;
3707 rtx reg;
3708 int partial;
3709 struct locate_and_pad_arg_data locate;
3710 rtx save_area;
3711 };
3712 struct arg *argvec;
3713 int old_inhibit_defer_pop = inhibit_defer_pop;
3714 rtx call_fusage = 0;
3715 rtx mem_value = 0;
3716 rtx valreg;
3717 int pcc_struct_value = 0;
3718 int struct_value_size = 0;
3719 int flags;
3720 int reg_parm_stack_space = 0;
3721 int needed;
3722 rtx before_call;
3723 tree tfom; /* type_for_mode (outmode, 0) */
3724
3725#ifdef REG_PARM_STACK_SPACE
3726 /* Define the boundary of the register parm stack space that needs to be
3727 save, if any. */
3728 int low_to_save, high_to_save;
3729 rtx save_area = 0; /* Place that it is saved. */
3730#endif
3731
3732 /* Size of the stack reserved for parameter registers. */
3733 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3734 char *initial_stack_usage_map = stack_usage_map;
3735
3736 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3737
3738#ifdef REG_PARM_STACK_SPACE
3739#ifdef MAYBE_REG_PARM_STACK_SPACE
3740 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3741#else
3742 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3743#endif
3744#endif
3745
3746 /* By default, library functions can not throw. */
3747 flags = ECF_NOTHROW;
3748
3749 switch (fn_type)
3750 {
3751 case LCT_NORMAL:
3752 break;
3753 case LCT_CONST:
3754 flags |= ECF_CONST;
3755 break;
3756 case LCT_PURE:
3757 flags |= ECF_PURE;
3758 break;
3759 case LCT_CONST_MAKE_BLOCK:
3760 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3761 break;
3762 case LCT_PURE_MAKE_BLOCK:
3763 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3764 break;
3765 case LCT_NORETURN:
3766 flags |= ECF_NORETURN;
3767 break;
3768 case LCT_THROW:
3769 flags = ECF_NORETURN;
3770 break;
3771 case LCT_ALWAYS_RETURN:
3772 flags = ECF_ALWAYS_RETURN;
3773 break;
3774 case LCT_RETURNS_TWICE:
3775 flags = ECF_RETURNS_TWICE;
3776 break;
3777 }
3778 fun = orgfun;
3779
3780 /* Ensure current function's preferred stack boundary is at least
3781 what we need. */
3782 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3783 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3784
3785 /* If this kind of value comes back in memory,
3786 decide where in memory it should come back. */
3787 if (outmode != VOIDmode)
3788 {
3789 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3790 if (aggregate_value_p (tfom, 0))
3791 {
3792#ifdef PCC_STATIC_STRUCT_RETURN
3793 rtx pointer_reg
3794 = hard_function_value (build_pointer_type (tfom), 0, 0);
3795 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3796 pcc_struct_value = 1;
3797 if (value == 0)
3798 value = gen_reg_rtx (outmode);
3799#else /* not PCC_STATIC_STRUCT_RETURN */
3800 struct_value_size = GET_MODE_SIZE (outmode);
3801 if (value != 0 && GET_CODE (value) == MEM)
3802 mem_value = value;
3803 else
3804 mem_value = assign_temp (tfom, 0, 1, 1);
3805#endif
3806 /* This call returns a big structure. */
3807 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3808 }
3809 }
3810 else
3811 tfom = void_type_node;
3812
3813 /* ??? Unfinished: must pass the memory address as an argument. */
3814
3815 /* Copy all the libcall-arguments out of the varargs data
3816 and into a vector ARGVEC.
3817
3818 Compute how to pass each argument. We only support a very small subset
3819 of the full argument passing conventions to limit complexity here since
3820 library functions shouldn't have many args. */
3821
3822 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3823 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3824
3825#ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3826 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3827#else
3828 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3829#endif
3830
3831 args_size.constant = 0;
3832 args_size.var = 0;
3833
3834 count = 0;
3835
3836 /* Now we are about to start emitting insns that can be deleted
3837 if a libcall is deleted. */
3838 if (flags & ECF_LIBCALL_BLOCK)
3839 start_sequence ();
3840
3841 push_temp_slots ();
3842
3843 /* If there's a structure value address to be passed,
3844 either pass it in the special place, or pass it as an extra argument. */
3845 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3846 {
3847 rtx addr = XEXP (mem_value, 0);
3848 nargs++;
3849