comparison gcc/calls.c @ 0:a06113de4d67

first commit
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
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children caeb520cebed 855418dad1a3
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-1:000000000000 0:a06113de4d67
1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
4 Free Software Foundation, Inc.
5
6 This file is part of GCC.
7
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
12
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
17
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
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 "gimple.h"
29 #include "flags.h"
30 #include "expr.h"
31 #include "optabs.h"
32 #include "libfuncs.h"
33 #include "function.h"
34 #include "regs.h"
35 #include "toplev.h"
36 #include "output.h"
37 #include "tm_p.h"
38 #include "timevar.h"
39 #include "sbitmap.h"
40 #include "langhooks.h"
41 #include "target.h"
42 #include "cgraph.h"
43 #include "except.h"
44 #include "dbgcnt.h"
45 #include "tree-flow.h"
46
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
49
50 /* Data structure and subroutines used within expand_call. */
51
52 struct arg_data
53 {
54 /* Tree node for this argument. */
55 tree tree_value;
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
59 rtx value;
60 /* Initially-compute RTL value for argument; only for const functions. */
61 rtx initial_value;
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
64 registers. */
65 rtx reg;
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
68 register windows. */
69 rtx tail_call_reg;
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
72 rtx parallel_value;
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
75 int unsignedp;
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
78 int partial;
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
83 int pass_on_stack;
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
88 rtx stack;
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
92 rtx stack_slot;
93 /* Place that this stack area has been saved, if needed. */
94 rtx save_area;
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
99 rtx *aligned_regs;
100 int n_aligned_regs;
101 };
102
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
108
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
111
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
118
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
125
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
128 CUMULATIVE_ARGS *);
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
133 struct args_size *);
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
138 tree, tree,
139 tree, tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
141 bool *, bool);
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
145 int, int *);
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
151
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
153 unsigned int);
154 static tree split_complex_types (tree);
155
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
159 #endif
160
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
164
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
167
168 rtx
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
171 {
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
180 else if (! sibcallp)
181 {
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
185 #endif
186 }
187
188 if (static_chain_value != 0)
189 {
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
192
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
195 }
196
197 return funexp;
198 }
199
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
203
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
206
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
212
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
217 code if necessary.
218
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
221
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
229
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
232
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
236
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
239
240 static void
241 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
249 {
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
251 rtx call_insn;
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
257 #endif
258
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
261 #endif
262
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
268
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
273 {
274 rtx n_pop = GEN_INT (n_popped);
275 rtx pat;
276
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
279
280 if (valreg)
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
284 n_pop);
285 else
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
288
289 emit_call_insn (pat);
290 already_popped = 1;
291 }
292 else
293 #endif
294
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
302 && n_popped > 0)
303 #else
304 if (HAVE_call_pop && HAVE_call_value_pop)
305 #endif
306 {
307 rtx n_pop = GEN_INT (n_popped);
308 rtx pat;
309
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
312
313 if (valreg)
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
317 else
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
320
321 emit_call_insn (pat);
322 already_popped = 1;
323 }
324 else
325 #endif
326
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
330 {
331 if (valreg)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
336 else
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
340 }
341 else
342 #endif
343
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
346 {
347 if (valreg)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
351 NULL_RTX));
352 else
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
356 }
357 else
358 #endif
359 gcc_unreachable ();
360
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
363
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
366
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
370
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
374
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
378
379 /* If this call can't throw, attach a REG_EH_REGION reg note to that
380 effect. */
381 if (ecf_flags & ECF_NOTHROW)
382 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
383 else
384 {
385 int rn = lookup_expr_eh_region (fntree);
386
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
389 if (rn > 0)
390 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
391 }
392
393 if (ecf_flags & ECF_NORETURN)
394 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
395
396 if (ecf_flags & ECF_RETURNS_TWICE)
397 {
398 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
399 cfun->calls_setjmp = 1;
400 }
401
402 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
403
404 /* Restore this now, so that we do defer pops for this call's args
405 if the context of the call as a whole permits. */
406 inhibit_defer_pop = old_inhibit_defer_pop;
407
408 if (n_popped > 0)
409 {
410 if (!already_popped)
411 CALL_INSN_FUNCTION_USAGE (call_insn)
412 = gen_rtx_EXPR_LIST (VOIDmode,
413 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
414 CALL_INSN_FUNCTION_USAGE (call_insn));
415 rounded_stack_size -= n_popped;
416 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
417 stack_pointer_delta -= n_popped;
418
419 /* If popup is needed, stack realign must use DRAP */
420 if (SUPPORTS_STACK_ALIGNMENT)
421 crtl->need_drap = true;
422 }
423
424 if (!ACCUMULATE_OUTGOING_ARGS)
425 {
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
429
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
432
433 if (rounded_stack_size != 0)
434 {
435 if (ecf_flags & ECF_NORETURN)
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
441 else
442 adjust_stack (rounded_stack_size_rtx);
443 }
444 }
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
450
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
453
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
455 such machines. */
456 else if (n_popped)
457 anti_adjust_stack (GEN_INT (n_popped));
458 }
459
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
462
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
465
466 Similarly set NORETURN if the function is in the longjmp family.
467
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
470
471 static int
472 special_function_p (const_tree fndecl, int flags)
473 {
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
478 think they are.
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
482 wish. */
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
486 {
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
489
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
494 && name[0] == 'a'
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
497 && name[0] == '_'
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
500
501 /* Disregard prefix _, __, __x or __builtin_. */
502 if (name[0] == '_')
503 {
504 if (name[1] == '_'
505 && name[2] == 'b'
506 && !strncmp (name + 3, "uiltin_", 7))
507 tname += 10;
508 else if (name[1] == '_' && name[2] == 'x')
509 tname += 3;
510 else if (name[1] == '_')
511 tname += 2;
512 else
513 tname += 1;
514 }
515
516 if (tname[0] == 's')
517 {
518 if ((tname[1] == 'e'
519 && (! strcmp (tname, "setjmp")
520 || ! strcmp (tname, "setjmp_syscall")))
521 || (tname[1] == 'i'
522 && ! strcmp (tname, "sigsetjmp"))
523 || (tname[1] == 'a'
524 && ! strcmp (tname, "savectx")))
525 flags |= ECF_RETURNS_TWICE;
526
527 if (tname[1] == 'i'
528 && ! strcmp (tname, "siglongjmp"))
529 flags |= ECF_NORETURN;
530 }
531 else if ((tname[0] == 'q' && tname[1] == 's'
532 && ! strcmp (tname, "qsetjmp"))
533 || (tname[0] == 'v' && tname[1] == 'f'
534 && ! strcmp (tname, "vfork"))
535 || (tname[0] == 'g' && tname[1] == 'e'
536 && !strcmp (tname, "getcontext")))
537 flags |= ECF_RETURNS_TWICE;
538
539 else if (tname[0] == 'l' && tname[1] == 'o'
540 && ! strcmp (tname, "longjmp"))
541 flags |= ECF_NORETURN;
542 }
543
544 return flags;
545 }
546
547 /* Return nonzero when FNDECL represents a call to setjmp. */
548
549 int
550 setjmp_call_p (const_tree fndecl)
551 {
552 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
553 }
554
555
556 /* Return true if STMT is an alloca call. */
557
558 bool
559 gimple_alloca_call_p (const_gimple stmt)
560 {
561 tree fndecl;
562
563 if (!is_gimple_call (stmt))
564 return false;
565
566 fndecl = gimple_call_fndecl (stmt);
567 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
568 return true;
569
570 return false;
571 }
572
573 /* Return true when exp contains alloca call. */
574
575 bool
576 alloca_call_p (const_tree exp)
577 {
578 if (TREE_CODE (exp) == CALL_EXPR
579 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
580 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
581 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
582 & ECF_MAY_BE_ALLOCA))
583 return true;
584 return false;
585 }
586
587 /* Detect flags (function attributes) from the function decl or type node. */
588
589 int
590 flags_from_decl_or_type (const_tree exp)
591 {
592 int flags = 0;
593 const_tree type = exp;
594
595 if (DECL_P (exp))
596 {
597 type = TREE_TYPE (exp);
598
599 /* The function exp may have the `malloc' attribute. */
600 if (DECL_IS_MALLOC (exp))
601 flags |= ECF_MALLOC;
602
603 /* The function exp may have the `returns_twice' attribute. */
604 if (DECL_IS_RETURNS_TWICE (exp))
605 flags |= ECF_RETURNS_TWICE;
606
607 /* Process the pure and const attributes. */
608 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
609 flags |= ECF_CONST;
610 if (DECL_PURE_P (exp))
611 flags |= ECF_PURE;
612 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
613 flags |= ECF_LOOPING_CONST_OR_PURE;
614
615 if (DECL_IS_NOVOPS (exp))
616 flags |= ECF_NOVOPS;
617
618 if (TREE_NOTHROW (exp))
619 flags |= ECF_NOTHROW;
620
621 flags = special_function_p (exp, flags);
622 }
623 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
624 flags |= ECF_CONST;
625
626 if (TREE_THIS_VOLATILE (exp))
627 flags |= ECF_NORETURN;
628
629 return flags;
630 }
631
632 /* Detect flags from a CALL_EXPR. */
633
634 int
635 call_expr_flags (const_tree t)
636 {
637 int flags;
638 tree decl = get_callee_fndecl (t);
639
640 if (decl)
641 flags = flags_from_decl_or_type (decl);
642 else
643 {
644 t = TREE_TYPE (CALL_EXPR_FN (t));
645 if (t && TREE_CODE (t) == POINTER_TYPE)
646 flags = flags_from_decl_or_type (TREE_TYPE (t));
647 else
648 flags = 0;
649 }
650
651 return flags;
652 }
653
654 /* Precompute all register parameters as described by ARGS, storing values
655 into fields within the ARGS array.
656
657 NUM_ACTUALS indicates the total number elements in the ARGS array.
658
659 Set REG_PARM_SEEN if we encounter a register parameter. */
660
661 static void
662 precompute_register_parameters (int num_actuals, struct arg_data *args,
663 int *reg_parm_seen)
664 {
665 int i;
666
667 *reg_parm_seen = 0;
668
669 for (i = 0; i < num_actuals; i++)
670 if (args[i].reg != 0 && ! args[i].pass_on_stack)
671 {
672 *reg_parm_seen = 1;
673
674 if (args[i].value == 0)
675 {
676 push_temp_slots ();
677 args[i].value = expand_normal (args[i].tree_value);
678 preserve_temp_slots (args[i].value);
679 pop_temp_slots ();
680 }
681
682 /* If the value is a non-legitimate constant, force it into a
683 pseudo now. TLS symbols sometimes need a call to resolve. */
684 if (CONSTANT_P (args[i].value)
685 && !LEGITIMATE_CONSTANT_P (args[i].value))
686 args[i].value = force_reg (args[i].mode, args[i].value);
687
688 /* If we are to promote the function arg to a wider mode,
689 do it now. */
690
691 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
692 args[i].value
693 = convert_modes (args[i].mode,
694 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
695 args[i].value, args[i].unsignedp);
696
697 /* If we're going to have to load the value by parts, pull the
698 parts into pseudos. The part extraction process can involve
699 non-trivial computation. */
700 if (GET_CODE (args[i].reg) == PARALLEL)
701 {
702 tree type = TREE_TYPE (args[i].tree_value);
703 args[i].parallel_value
704 = emit_group_load_into_temps (args[i].reg, args[i].value,
705 type, int_size_in_bytes (type));
706 }
707
708 /* If the value is expensive, and we are inside an appropriately
709 short loop, put the value into a pseudo and then put the pseudo
710 into the hard reg.
711
712 For small register classes, also do this if this call uses
713 register parameters. This is to avoid reload conflicts while
714 loading the parameters registers. */
715
716 else if ((! (REG_P (args[i].value)
717 || (GET_CODE (args[i].value) == SUBREG
718 && REG_P (SUBREG_REG (args[i].value)))))
719 && args[i].mode != BLKmode
720 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
721 > COSTS_N_INSNS (1)
722 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
723 || optimize))
724 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
725 }
726 }
727
728 #ifdef REG_PARM_STACK_SPACE
729
730 /* The argument list is the property of the called routine and it
731 may clobber it. If the fixed area has been used for previous
732 parameters, we must save and restore it. */
733
734 static rtx
735 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
736 {
737 int low;
738 int high;
739
740 /* Compute the boundary of the area that needs to be saved, if any. */
741 high = reg_parm_stack_space;
742 #ifdef ARGS_GROW_DOWNWARD
743 high += 1;
744 #endif
745 if (high > highest_outgoing_arg_in_use)
746 high = highest_outgoing_arg_in_use;
747
748 for (low = 0; low < high; low++)
749 if (stack_usage_map[low] != 0)
750 {
751 int num_to_save;
752 enum machine_mode save_mode;
753 int delta;
754 rtx stack_area;
755 rtx save_area;
756
757 while (stack_usage_map[--high] == 0)
758 ;
759
760 *low_to_save = low;
761 *high_to_save = high;
762
763 num_to_save = high - low + 1;
764 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
765
766 /* If we don't have the required alignment, must do this
767 in BLKmode. */
768 if ((low & (MIN (GET_MODE_SIZE (save_mode),
769 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
770 save_mode = BLKmode;
771
772 #ifdef ARGS_GROW_DOWNWARD
773 delta = -high;
774 #else
775 delta = low;
776 #endif
777 stack_area = gen_rtx_MEM (save_mode,
778 memory_address (save_mode,
779 plus_constant (argblock,
780 delta)));
781
782 set_mem_align (stack_area, PARM_BOUNDARY);
783 if (save_mode == BLKmode)
784 {
785 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
786 emit_block_move (validize_mem (save_area), stack_area,
787 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
788 }
789 else
790 {
791 save_area = gen_reg_rtx (save_mode);
792 emit_move_insn (save_area, stack_area);
793 }
794
795 return save_area;
796 }
797
798 return NULL_RTX;
799 }
800
801 static void
802 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
803 {
804 enum machine_mode save_mode = GET_MODE (save_area);
805 int delta;
806 rtx stack_area;
807
808 #ifdef ARGS_GROW_DOWNWARD
809 delta = -high_to_save;
810 #else
811 delta = low_to_save;
812 #endif
813 stack_area = gen_rtx_MEM (save_mode,
814 memory_address (save_mode,
815 plus_constant (argblock, delta)));
816 set_mem_align (stack_area, PARM_BOUNDARY);
817
818 if (save_mode != BLKmode)
819 emit_move_insn (stack_area, save_area);
820 else
821 emit_block_move (stack_area, validize_mem (save_area),
822 GEN_INT (high_to_save - low_to_save + 1),
823 BLOCK_OP_CALL_PARM);
824 }
825 #endif /* REG_PARM_STACK_SPACE */
826
827 /* If any elements in ARGS refer to parameters that are to be passed in
828 registers, but not in memory, and whose alignment does not permit a
829 direct copy into registers. Copy the values into a group of pseudos
830 which we will later copy into the appropriate hard registers.
831
832 Pseudos for each unaligned argument will be stored into the array
833 args[argnum].aligned_regs. The caller is responsible for deallocating
834 the aligned_regs array if it is nonzero. */
835
836 static void
837 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
838 {
839 int i, j;
840
841 for (i = 0; i < num_actuals; i++)
842 if (args[i].reg != 0 && ! args[i].pass_on_stack
843 && args[i].mode == BLKmode
844 && MEM_P (args[i].value)
845 && (MEM_ALIGN (args[i].value)
846 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
847 {
848 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
849 int endian_correction = 0;
850
851 if (args[i].partial)
852 {
853 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
854 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
855 }
856 else
857 {
858 args[i].n_aligned_regs
859 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
860 }
861
862 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
863
864 /* Structures smaller than a word are normally aligned to the
865 least significant byte. On a BYTES_BIG_ENDIAN machine,
866 this means we must skip the empty high order bytes when
867 calculating the bit offset. */
868 if (bytes < UNITS_PER_WORD
869 #ifdef BLOCK_REG_PADDING
870 && (BLOCK_REG_PADDING (args[i].mode,
871 TREE_TYPE (args[i].tree_value), 1)
872 == downward)
873 #else
874 && BYTES_BIG_ENDIAN
875 #endif
876 )
877 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
878
879 for (j = 0; j < args[i].n_aligned_regs; j++)
880 {
881 rtx reg = gen_reg_rtx (word_mode);
882 rtx word = operand_subword_force (args[i].value, j, BLKmode);
883 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
884
885 args[i].aligned_regs[j] = reg;
886 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
887 word_mode, word_mode);
888
889 /* There is no need to restrict this code to loading items
890 in TYPE_ALIGN sized hunks. The bitfield instructions can
891 load up entire word sized registers efficiently.
892
893 ??? This may not be needed anymore.
894 We use to emit a clobber here but that doesn't let later
895 passes optimize the instructions we emit. By storing 0 into
896 the register later passes know the first AND to zero out the
897 bitfield being set in the register is unnecessary. The store
898 of 0 will be deleted as will at least the first AND. */
899
900 emit_move_insn (reg, const0_rtx);
901
902 bytes -= bitsize / BITS_PER_UNIT;
903 store_bit_field (reg, bitsize, endian_correction, word_mode,
904 word);
905 }
906 }
907 }
908
909 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
910 CALL_EXPR EXP.
911
912 NUM_ACTUALS is the total number of parameters.
913
914 N_NAMED_ARGS is the total number of named arguments.
915
916 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
917 value, or null.
918
919 FNDECL is the tree code for the target of this call (if known)
920
921 ARGS_SO_FAR holds state needed by the target to know where to place
922 the next argument.
923
924 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
925 for arguments which are passed in registers.
926
927 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
928 and may be modified by this routine.
929
930 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
931 flags which may may be modified by this routine.
932
933 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
934 that requires allocation of stack space.
935
936 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
937 the thunked-to function. */
938
939 static void
940 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
941 struct arg_data *args,
942 struct args_size *args_size,
943 int n_named_args ATTRIBUTE_UNUSED,
944 tree exp, tree struct_value_addr_value,
945 tree fndecl, tree fntype,
946 CUMULATIVE_ARGS *args_so_far,
947 int reg_parm_stack_space,
948 rtx *old_stack_level, int *old_pending_adj,
949 int *must_preallocate, int *ecf_flags,
950 bool *may_tailcall, bool call_from_thunk_p)
951 {
952 /* 1 if scanning parms front to back, -1 if scanning back to front. */
953 int inc;
954
955 /* Count arg position in order args appear. */
956 int argpos;
957
958 int i;
959
960 args_size->constant = 0;
961 args_size->var = 0;
962
963 /* In this loop, we consider args in the order they are written.
964 We fill up ARGS from the front or from the back if necessary
965 so that in any case the first arg to be pushed ends up at the front. */
966
967 if (PUSH_ARGS_REVERSED)
968 {
969 i = num_actuals - 1, inc = -1;
970 /* In this case, must reverse order of args
971 so that we compute and push the last arg first. */
972 }
973 else
974 {
975 i = 0, inc = 1;
976 }
977
978 /* First fill in the actual arguments in the ARGS array, splitting
979 complex arguments if necessary. */
980 {
981 int j = i;
982 call_expr_arg_iterator iter;
983 tree arg;
984
985 if (struct_value_addr_value)
986 {
987 args[j].tree_value = struct_value_addr_value;
988 j += inc;
989 }
990 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
991 {
992 tree argtype = TREE_TYPE (arg);
993 if (targetm.calls.split_complex_arg
994 && argtype
995 && TREE_CODE (argtype) == COMPLEX_TYPE
996 && targetm.calls.split_complex_arg (argtype))
997 {
998 tree subtype = TREE_TYPE (argtype);
999 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1000 j += inc;
1001 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1002 }
1003 else
1004 args[j].tree_value = arg;
1005 j += inc;
1006 }
1007 }
1008
1009 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1010 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1011 {
1012 tree type = TREE_TYPE (args[i].tree_value);
1013 int unsignedp;
1014 enum machine_mode mode;
1015
1016 /* Replace erroneous argument with constant zero. */
1017 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1018 args[i].tree_value = integer_zero_node, type = integer_type_node;
1019
1020 /* If TYPE is a transparent union, pass things the way we would
1021 pass the first field of the union. We have already verified that
1022 the modes are the same. */
1023 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1024 type = TREE_TYPE (TYPE_FIELDS (type));
1025
1026 /* Decide where to pass this arg.
1027
1028 args[i].reg is nonzero if all or part is passed in registers.
1029
1030 args[i].partial is nonzero if part but not all is passed in registers,
1031 and the exact value says how many bytes are passed in registers.
1032
1033 args[i].pass_on_stack is nonzero if the argument must at least be
1034 computed on the stack. It may then be loaded back into registers
1035 if args[i].reg is nonzero.
1036
1037 These decisions are driven by the FUNCTION_... macros and must agree
1038 with those made by function.c. */
1039
1040 /* See if this argument should be passed by invisible reference. */
1041 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1042 type, argpos < n_named_args))
1043 {
1044 bool callee_copies;
1045 tree base;
1046
1047 callee_copies
1048 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1049 type, argpos < n_named_args);
1050
1051 /* If we're compiling a thunk, pass through invisible references
1052 instead of making a copy. */
1053 if (call_from_thunk_p
1054 || (callee_copies
1055 && !TREE_ADDRESSABLE (type)
1056 && (base = get_base_address (args[i].tree_value))
1057 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1058 {
1059 /* We can't use sibcalls if a callee-copied argument is
1060 stored in the current function's frame. */
1061 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1062 *may_tailcall = false;
1063
1064 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1065 type = TREE_TYPE (args[i].tree_value);
1066
1067 if (*ecf_flags & ECF_CONST)
1068 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1069 }
1070 else
1071 {
1072 /* We make a copy of the object and pass the address to the
1073 function being called. */
1074 rtx copy;
1075
1076 if (!COMPLETE_TYPE_P (type)
1077 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1078 || (flag_stack_check == GENERIC_STACK_CHECK
1079 && compare_tree_int (TYPE_SIZE_UNIT (type),
1080 STACK_CHECK_MAX_VAR_SIZE) > 0))
1081 {
1082 /* This is a variable-sized object. Make space on the stack
1083 for it. */
1084 rtx size_rtx = expr_size (args[i].tree_value);
1085
1086 if (*old_stack_level == 0)
1087 {
1088 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1089 *old_pending_adj = pending_stack_adjust;
1090 pending_stack_adjust = 0;
1091 }
1092
1093 copy = gen_rtx_MEM (BLKmode,
1094 allocate_dynamic_stack_space
1095 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1096 set_mem_attributes (copy, type, 1);
1097 }
1098 else
1099 copy = assign_temp (type, 0, 1, 0);
1100
1101 store_expr (args[i].tree_value, copy, 0, false);
1102
1103 /* Just change the const function to pure and then let
1104 the next test clear the pure based on
1105 callee_copies. */
1106 if (*ecf_flags & ECF_CONST)
1107 {
1108 *ecf_flags &= ~ECF_CONST;
1109 *ecf_flags |= ECF_PURE;
1110 }
1111
1112 if (!callee_copies && *ecf_flags & ECF_PURE)
1113 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1114
1115 args[i].tree_value
1116 = build_fold_addr_expr (make_tree (type, copy));
1117 type = TREE_TYPE (args[i].tree_value);
1118 *may_tailcall = false;
1119 }
1120 }
1121
1122 mode = TYPE_MODE (type);
1123 unsignedp = TYPE_UNSIGNED (type);
1124
1125 if (targetm.calls.promote_function_args (fndecl
1126 ? TREE_TYPE (fndecl)
1127 : fntype))
1128 mode = promote_mode (type, mode, &unsignedp, 1);
1129
1130 args[i].unsignedp = unsignedp;
1131 args[i].mode = mode;
1132
1133 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1134 argpos < n_named_args);
1135 #ifdef FUNCTION_INCOMING_ARG
1136 /* If this is a sibling call and the machine has register windows, the
1137 register window has to be unwinded before calling the routine, so
1138 arguments have to go into the incoming registers. */
1139 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1140 argpos < n_named_args);
1141 #else
1142 args[i].tail_call_reg = args[i].reg;
1143 #endif
1144
1145 if (args[i].reg)
1146 args[i].partial
1147 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1148 argpos < n_named_args);
1149
1150 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1151
1152 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1153 it means that we are to pass this arg in the register(s) designated
1154 by the PARALLEL, but also to pass it in the stack. */
1155 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1156 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1157 args[i].pass_on_stack = 1;
1158
1159 /* If this is an addressable type, we must preallocate the stack
1160 since we must evaluate the object into its final location.
1161
1162 If this is to be passed in both registers and the stack, it is simpler
1163 to preallocate. */
1164 if (TREE_ADDRESSABLE (type)
1165 || (args[i].pass_on_stack && args[i].reg != 0))
1166 *must_preallocate = 1;
1167
1168 /* Compute the stack-size of this argument. */
1169 if (args[i].reg == 0 || args[i].partial != 0
1170 || reg_parm_stack_space > 0
1171 || args[i].pass_on_stack)
1172 locate_and_pad_parm (mode, type,
1173 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1174 1,
1175 #else
1176 args[i].reg != 0,
1177 #endif
1178 args[i].pass_on_stack ? 0 : args[i].partial,
1179 fndecl, args_size, &args[i].locate);
1180 #ifdef BLOCK_REG_PADDING
1181 else
1182 /* The argument is passed entirely in registers. See at which
1183 end it should be padded. */
1184 args[i].locate.where_pad =
1185 BLOCK_REG_PADDING (mode, type,
1186 int_size_in_bytes (type) <= UNITS_PER_WORD);
1187 #endif
1188
1189 /* Update ARGS_SIZE, the total stack space for args so far. */
1190
1191 args_size->constant += args[i].locate.size.constant;
1192 if (args[i].locate.size.var)
1193 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1194
1195 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1196 have been used, etc. */
1197
1198 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1199 argpos < n_named_args);
1200 }
1201 }
1202
1203 /* Update ARGS_SIZE to contain the total size for the argument block.
1204 Return the original constant component of the argument block's size.
1205
1206 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1207 for arguments passed in registers. */
1208
1209 static int
1210 compute_argument_block_size (int reg_parm_stack_space,
1211 struct args_size *args_size,
1212 tree fndecl ATTRIBUTE_UNUSED,
1213 tree fntype ATTRIBUTE_UNUSED,
1214 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1215 {
1216 int unadjusted_args_size = args_size->constant;
1217
1218 /* For accumulate outgoing args mode we don't need to align, since the frame
1219 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1220 backends from generating misaligned frame sizes. */
1221 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1222 preferred_stack_boundary = STACK_BOUNDARY;
1223
1224 /* Compute the actual size of the argument block required. The variable
1225 and constant sizes must be combined, the size may have to be rounded,
1226 and there may be a minimum required size. */
1227
1228 if (args_size->var)
1229 {
1230 args_size->var = ARGS_SIZE_TREE (*args_size);
1231 args_size->constant = 0;
1232
1233 preferred_stack_boundary /= BITS_PER_UNIT;
1234 if (preferred_stack_boundary > 1)
1235 {
1236 /* We don't handle this case yet. To handle it correctly we have
1237 to add the delta, round and subtract the delta.
1238 Currently no machine description requires this support. */
1239 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1240 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1241 }
1242
1243 if (reg_parm_stack_space > 0)
1244 {
1245 args_size->var
1246 = size_binop (MAX_EXPR, args_size->var,
1247 ssize_int (reg_parm_stack_space));
1248
1249 /* The area corresponding to register parameters is not to count in
1250 the size of the block we need. So make the adjustment. */
1251 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1252 args_size->var
1253 = size_binop (MINUS_EXPR, args_size->var,
1254 ssize_int (reg_parm_stack_space));
1255 }
1256 }
1257 else
1258 {
1259 preferred_stack_boundary /= BITS_PER_UNIT;
1260 if (preferred_stack_boundary < 1)
1261 preferred_stack_boundary = 1;
1262 args_size->constant = (((args_size->constant
1263 + stack_pointer_delta
1264 + preferred_stack_boundary - 1)
1265 / preferred_stack_boundary
1266 * preferred_stack_boundary)
1267 - stack_pointer_delta);
1268
1269 args_size->constant = MAX (args_size->constant,
1270 reg_parm_stack_space);
1271
1272 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1273 args_size->constant -= reg_parm_stack_space;
1274 }
1275 return unadjusted_args_size;
1276 }
1277
1278 /* Precompute parameters as needed for a function call.
1279
1280 FLAGS is mask of ECF_* constants.
1281
1282 NUM_ACTUALS is the number of arguments.
1283
1284 ARGS is an array containing information for each argument; this
1285 routine fills in the INITIAL_VALUE and VALUE fields for each
1286 precomputed argument. */
1287
1288 static void
1289 precompute_arguments (int num_actuals, struct arg_data *args)
1290 {
1291 int i;
1292
1293 /* If this is a libcall, then precompute all arguments so that we do not
1294 get extraneous instructions emitted as part of the libcall sequence. */
1295
1296 /* If we preallocated the stack space, and some arguments must be passed
1297 on the stack, then we must precompute any parameter which contains a
1298 function call which will store arguments on the stack.
1299 Otherwise, evaluating the parameter may clobber previous parameters
1300 which have already been stored into the stack. (we have code to avoid
1301 such case by saving the outgoing stack arguments, but it results in
1302 worse code) */
1303 if (!ACCUMULATE_OUTGOING_ARGS)
1304 return;
1305
1306 for (i = 0; i < num_actuals; i++)
1307 {
1308 enum machine_mode mode;
1309
1310 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1311 continue;
1312
1313 /* If this is an addressable type, we cannot pre-evaluate it. */
1314 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1315
1316 args[i].initial_value = args[i].value
1317 = expand_normal (args[i].tree_value);
1318
1319 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1320 if (mode != args[i].mode)
1321 {
1322 args[i].value
1323 = convert_modes (args[i].mode, mode,
1324 args[i].value, args[i].unsignedp);
1325 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1326 /* CSE will replace this only if it contains args[i].value
1327 pseudo, so convert it down to the declared mode using
1328 a SUBREG. */
1329 if (REG_P (args[i].value)
1330 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1331 {
1332 args[i].initial_value
1333 = gen_lowpart_SUBREG (mode, args[i].value);
1334 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1335 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1336 args[i].unsignedp);
1337 }
1338 #endif
1339 }
1340 }
1341 }
1342
1343 /* Given the current state of MUST_PREALLOCATE and information about
1344 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1345 compute and return the final value for MUST_PREALLOCATE. */
1346
1347 static int
1348 finalize_must_preallocate (int must_preallocate, int num_actuals,
1349 struct arg_data *args, struct args_size *args_size)
1350 {
1351 /* See if we have or want to preallocate stack space.
1352
1353 If we would have to push a partially-in-regs parm
1354 before other stack parms, preallocate stack space instead.
1355
1356 If the size of some parm is not a multiple of the required stack
1357 alignment, we must preallocate.
1358
1359 If the total size of arguments that would otherwise create a copy in
1360 a temporary (such as a CALL) is more than half the total argument list
1361 size, preallocation is faster.
1362
1363 Another reason to preallocate is if we have a machine (like the m88k)
1364 where stack alignment is required to be maintained between every
1365 pair of insns, not just when the call is made. However, we assume here
1366 that such machines either do not have push insns (and hence preallocation
1367 would occur anyway) or the problem is taken care of with
1368 PUSH_ROUNDING. */
1369
1370 if (! must_preallocate)
1371 {
1372 int partial_seen = 0;
1373 int copy_to_evaluate_size = 0;
1374 int i;
1375
1376 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1377 {
1378 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1379 partial_seen = 1;
1380 else if (partial_seen && args[i].reg == 0)
1381 must_preallocate = 1;
1382
1383 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1384 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1385 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1386 || TREE_CODE (args[i].tree_value) == COND_EXPR
1387 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1388 copy_to_evaluate_size
1389 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1390 }
1391
1392 if (copy_to_evaluate_size * 2 >= args_size->constant
1393 && args_size->constant > 0)
1394 must_preallocate = 1;
1395 }
1396 return must_preallocate;
1397 }
1398
1399 /* If we preallocated stack space, compute the address of each argument
1400 and store it into the ARGS array.
1401
1402 We need not ensure it is a valid memory address here; it will be
1403 validized when it is used.
1404
1405 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1406
1407 static void
1408 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1409 {
1410 if (argblock)
1411 {
1412 rtx arg_reg = argblock;
1413 int i, arg_offset = 0;
1414
1415 if (GET_CODE (argblock) == PLUS)
1416 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1417
1418 for (i = 0; i < num_actuals; i++)
1419 {
1420 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1421 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1422 rtx addr;
1423 unsigned int align, boundary;
1424 unsigned int units_on_stack = 0;
1425 enum machine_mode partial_mode = VOIDmode;
1426
1427 /* Skip this parm if it will not be passed on the stack. */
1428 if (! args[i].pass_on_stack
1429 && args[i].reg != 0
1430 && args[i].partial == 0)
1431 continue;
1432
1433 if (GET_CODE (offset) == CONST_INT)
1434 addr = plus_constant (arg_reg, INTVAL (offset));
1435 else
1436 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1437
1438 addr = plus_constant (addr, arg_offset);
1439
1440 if (args[i].partial != 0)
1441 {
1442 /* Only part of the parameter is being passed on the stack.
1443 Generate a simple memory reference of the correct size. */
1444 units_on_stack = args[i].locate.size.constant;
1445 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1446 MODE_INT, 1);
1447 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1448 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1449 }
1450 else
1451 {
1452 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1453 set_mem_attributes (args[i].stack,
1454 TREE_TYPE (args[i].tree_value), 1);
1455 }
1456 align = BITS_PER_UNIT;
1457 boundary = args[i].locate.boundary;
1458 if (args[i].locate.where_pad != downward)
1459 align = boundary;
1460 else if (GET_CODE (offset) == CONST_INT)
1461 {
1462 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1463 align = align & -align;
1464 }
1465 set_mem_align (args[i].stack, align);
1466
1467 if (GET_CODE (slot_offset) == CONST_INT)
1468 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1469 else
1470 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1471
1472 addr = plus_constant (addr, arg_offset);
1473
1474 if (args[i].partial != 0)
1475 {
1476 /* Only part of the parameter is being passed on the stack.
1477 Generate a simple memory reference of the correct size.
1478 */
1479 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1480 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1481 }
1482 else
1483 {
1484 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1485 set_mem_attributes (args[i].stack_slot,
1486 TREE_TYPE (args[i].tree_value), 1);
1487 }
1488 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1489
1490 /* Function incoming arguments may overlap with sibling call
1491 outgoing arguments and we cannot allow reordering of reads
1492 from function arguments with stores to outgoing arguments
1493 of sibling calls. */
1494 set_mem_alias_set (args[i].stack, 0);
1495 set_mem_alias_set (args[i].stack_slot, 0);
1496 }
1497 }
1498 }
1499
1500 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1501 in a call instruction.
1502
1503 FNDECL is the tree node for the target function. For an indirect call
1504 FNDECL will be NULL_TREE.
1505
1506 ADDR is the operand 0 of CALL_EXPR for this call. */
1507
1508 static rtx
1509 rtx_for_function_call (tree fndecl, tree addr)
1510 {
1511 rtx funexp;
1512
1513 /* Get the function to call, in the form of RTL. */
1514 if (fndecl)
1515 {
1516 /* If this is the first use of the function, see if we need to
1517 make an external definition for it. */
1518 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1519 {
1520 assemble_external (fndecl);
1521 TREE_USED (fndecl) = 1;
1522 }
1523
1524 /* Get a SYMBOL_REF rtx for the function address. */
1525 funexp = XEXP (DECL_RTL (fndecl), 0);
1526 }
1527 else
1528 /* Generate an rtx (probably a pseudo-register) for the address. */
1529 {
1530 push_temp_slots ();
1531 funexp = expand_normal (addr);
1532 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1533 }
1534 return funexp;
1535 }
1536
1537 /* Return true if and only if SIZE storage units (usually bytes)
1538 starting from address ADDR overlap with already clobbered argument
1539 area. This function is used to determine if we should give up a
1540 sibcall. */
1541
1542 static bool
1543 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1544 {
1545 HOST_WIDE_INT i;
1546
1547 if (addr == crtl->args.internal_arg_pointer)
1548 i = 0;
1549 else if (GET_CODE (addr) == PLUS
1550 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1551 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1552 i = INTVAL (XEXP (addr, 1));
1553 /* Return true for arg pointer based indexed addressing. */
1554 else if (GET_CODE (addr) == PLUS
1555 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1556 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1557 return true;
1558 else
1559 return false;
1560
1561 #ifdef ARGS_GROW_DOWNWARD
1562 i = -i - size;
1563 #endif
1564 if (size > 0)
1565 {
1566 unsigned HOST_WIDE_INT k;
1567
1568 for (k = 0; k < size; k++)
1569 if (i + k < stored_args_map->n_bits
1570 && TEST_BIT (stored_args_map, i + k))
1571 return true;
1572 }
1573
1574 return false;
1575 }
1576
1577 /* Do the register loads required for any wholly-register parms or any
1578 parms which are passed both on the stack and in a register. Their
1579 expressions were already evaluated.
1580
1581 Mark all register-parms as living through the call, putting these USE
1582 insns in the CALL_INSN_FUNCTION_USAGE field.
1583
1584 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1585 checking, setting *SIBCALL_FAILURE if appropriate. */
1586
1587 static void
1588 load_register_parameters (struct arg_data *args, int num_actuals,
1589 rtx *call_fusage, int flags, int is_sibcall,
1590 int *sibcall_failure)
1591 {
1592 int i, j;
1593
1594 for (i = 0; i < num_actuals; i++)
1595 {
1596 rtx reg = ((flags & ECF_SIBCALL)
1597 ? args[i].tail_call_reg : args[i].reg);
1598 if (reg)
1599 {
1600 int partial = args[i].partial;
1601 int nregs;
1602 int size = 0;
1603 rtx before_arg = get_last_insn ();
1604 /* Set non-negative if we must move a word at a time, even if
1605 just one word (e.g, partial == 4 && mode == DFmode). Set
1606 to -1 if we just use a normal move insn. This value can be
1607 zero if the argument is a zero size structure. */
1608 nregs = -1;
1609 if (GET_CODE (reg) == PARALLEL)
1610 ;
1611 else if (partial)
1612 {
1613 gcc_assert (partial % UNITS_PER_WORD == 0);
1614 nregs = partial / UNITS_PER_WORD;
1615 }
1616 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1617 {
1618 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1619 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1620 }
1621 else
1622 size = GET_MODE_SIZE (args[i].mode);
1623
1624 /* Handle calls that pass values in multiple non-contiguous
1625 locations. The Irix 6 ABI has examples of this. */
1626
1627 if (GET_CODE (reg) == PARALLEL)
1628 emit_group_move (reg, args[i].parallel_value);
1629
1630 /* If simple case, just do move. If normal partial, store_one_arg
1631 has already loaded the register for us. In all other cases,
1632 load the register(s) from memory. */
1633
1634 else if (nregs == -1)
1635 {
1636 emit_move_insn (reg, args[i].value);
1637 #ifdef BLOCK_REG_PADDING
1638 /* Handle case where we have a value that needs shifting
1639 up to the msb. eg. a QImode value and we're padding
1640 upward on a BYTES_BIG_ENDIAN machine. */
1641 if (size < UNITS_PER_WORD
1642 && (args[i].locate.where_pad
1643 == (BYTES_BIG_ENDIAN ? upward : downward)))
1644 {
1645 rtx x;
1646 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1647
1648 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1649 report the whole reg as used. Strictly speaking, the
1650 call only uses SIZE bytes at the msb end, but it doesn't
1651 seem worth generating rtl to say that. */
1652 reg = gen_rtx_REG (word_mode, REGNO (reg));
1653 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1654 build_int_cst (NULL_TREE, shift),
1655 reg, 1);
1656 if (x != reg)
1657 emit_move_insn (reg, x);
1658 }
1659 #endif
1660 }
1661
1662 /* If we have pre-computed the values to put in the registers in
1663 the case of non-aligned structures, copy them in now. */
1664
1665 else if (args[i].n_aligned_regs != 0)
1666 for (j = 0; j < args[i].n_aligned_regs; j++)
1667 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1668 args[i].aligned_regs[j]);
1669
1670 else if (partial == 0 || args[i].pass_on_stack)
1671 {
1672 rtx mem = validize_mem (args[i].value);
1673
1674 /* Check for overlap with already clobbered argument area. */
1675 if (is_sibcall
1676 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1677 size))
1678 *sibcall_failure = 1;
1679
1680 /* Handle a BLKmode that needs shifting. */
1681 if (nregs == 1 && size < UNITS_PER_WORD
1682 #ifdef BLOCK_REG_PADDING
1683 && args[i].locate.where_pad == downward
1684 #else
1685 && BYTES_BIG_ENDIAN
1686 #endif
1687 )
1688 {
1689 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1690 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1691 rtx x = gen_reg_rtx (word_mode);
1692 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1693 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1694 : LSHIFT_EXPR;
1695
1696 emit_move_insn (x, tem);
1697 x = expand_shift (dir, word_mode, x,
1698 build_int_cst (NULL_TREE, shift),
1699 ri, 1);
1700 if (x != ri)
1701 emit_move_insn (ri, x);
1702 }
1703 else
1704 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1705 }
1706
1707 /* When a parameter is a block, and perhaps in other cases, it is
1708 possible that it did a load from an argument slot that was
1709 already clobbered. */
1710 if (is_sibcall
1711 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1712 *sibcall_failure = 1;
1713
1714 /* Handle calls that pass values in multiple non-contiguous
1715 locations. The Irix 6 ABI has examples of this. */
1716 if (GET_CODE (reg) == PARALLEL)
1717 use_group_regs (call_fusage, reg);
1718 else if (nregs == -1)
1719 use_reg (call_fusage, reg);
1720 else if (nregs > 0)
1721 use_regs (call_fusage, REGNO (reg), nregs);
1722 }
1723 }
1724 }
1725
1726 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1727 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1728 bytes, then we would need to push some additional bytes to pad the
1729 arguments. So, we compute an adjust to the stack pointer for an
1730 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1731 bytes. Then, when the arguments are pushed the stack will be perfectly
1732 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1733 be popped after the call. Returns the adjustment. */
1734
1735 static int
1736 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1737 struct args_size *args_size,
1738 unsigned int preferred_unit_stack_boundary)
1739 {
1740 /* The number of bytes to pop so that the stack will be
1741 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1742 HOST_WIDE_INT adjustment;
1743 /* The alignment of the stack after the arguments are pushed, if we
1744 just pushed the arguments without adjust the stack here. */
1745 unsigned HOST_WIDE_INT unadjusted_alignment;
1746
1747 unadjusted_alignment
1748 = ((stack_pointer_delta + unadjusted_args_size)
1749 % preferred_unit_stack_boundary);
1750
1751 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1752 as possible -- leaving just enough left to cancel out the
1753 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1754 PENDING_STACK_ADJUST is non-negative, and congruent to
1755 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1756
1757 /* Begin by trying to pop all the bytes. */
1758 unadjusted_alignment
1759 = (unadjusted_alignment
1760 - (pending_stack_adjust % preferred_unit_stack_boundary));
1761 adjustment = pending_stack_adjust;
1762 /* Push enough additional bytes that the stack will be aligned
1763 after the arguments are pushed. */
1764 if (preferred_unit_stack_boundary > 1)
1765 {
1766 if (unadjusted_alignment > 0)
1767 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1768 else
1769 adjustment += unadjusted_alignment;
1770 }
1771
1772 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1773 bytes after the call. The right number is the entire
1774 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1775 by the arguments in the first place. */
1776 args_size->constant
1777 = pending_stack_adjust - adjustment + unadjusted_args_size;
1778
1779 return adjustment;
1780 }
1781
1782 /* Scan X expression if it does not dereference any argument slots
1783 we already clobbered by tail call arguments (as noted in stored_args_map
1784 bitmap).
1785 Return nonzero if X expression dereferences such argument slots,
1786 zero otherwise. */
1787
1788 static int
1789 check_sibcall_argument_overlap_1 (rtx x)
1790 {
1791 RTX_CODE code;
1792 int i, j;
1793 const char *fmt;
1794
1795 if (x == NULL_RTX)
1796 return 0;
1797
1798 code = GET_CODE (x);
1799
1800 if (code == MEM)
1801 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1802 GET_MODE_SIZE (GET_MODE (x)));
1803
1804 /* Scan all subexpressions. */
1805 fmt = GET_RTX_FORMAT (code);
1806 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1807 {
1808 if (*fmt == 'e')
1809 {
1810 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1811 return 1;
1812 }
1813 else if (*fmt == 'E')
1814 {
1815 for (j = 0; j < XVECLEN (x, i); j++)
1816 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1817 return 1;
1818 }
1819 }
1820 return 0;
1821 }
1822
1823 /* Scan sequence after INSN if it does not dereference any argument slots
1824 we already clobbered by tail call arguments (as noted in stored_args_map
1825 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1826 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1827 should be 0). Return nonzero if sequence after INSN dereferences such argument
1828 slots, zero otherwise. */
1829
1830 static int
1831 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1832 {
1833 int low, high;
1834
1835 if (insn == NULL_RTX)
1836 insn = get_insns ();
1837 else
1838 insn = NEXT_INSN (insn);
1839
1840 for (; insn; insn = NEXT_INSN (insn))
1841 if (INSN_P (insn)
1842 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1843 break;
1844
1845 if (mark_stored_args_map)
1846 {
1847 #ifdef ARGS_GROW_DOWNWARD
1848 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1849 #else
1850 low = arg->locate.slot_offset.constant;
1851 #endif
1852
1853 for (high = low + arg->locate.size.constant; low < high; low++)
1854 SET_BIT (stored_args_map, low);
1855 }
1856 return insn != NULL_RTX;
1857 }
1858
1859 /* Given that a function returns a value of mode MODE at the most
1860 significant end of hard register VALUE, shift VALUE left or right
1861 as specified by LEFT_P. Return true if some action was needed. */
1862
1863 bool
1864 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1865 {
1866 HOST_WIDE_INT shift;
1867
1868 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1869 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1870 if (shift == 0)
1871 return false;
1872
1873 /* Use ashr rather than lshr for right shifts. This is for the benefit
1874 of the MIPS port, which requires SImode values to be sign-extended
1875 when stored in 64-bit registers. */
1876 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1877 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1878 gcc_unreachable ();
1879 return true;
1880 }
1881
1882 /* If X is a likely-spilled register value, copy it to a pseudo
1883 register and return that register. Return X otherwise. */
1884
1885 static rtx
1886 avoid_likely_spilled_reg (rtx x)
1887 {
1888 rtx new_rtx;
1889
1890 if (REG_P (x)
1891 && HARD_REGISTER_P (x)
1892 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1893 {
1894 /* Make sure that we generate a REG rather than a CONCAT.
1895 Moves into CONCATs can need nontrivial instructions,
1896 and the whole point of this function is to avoid
1897 using the hard register directly in such a situation. */
1898 generating_concat_p = 0;
1899 new_rtx = gen_reg_rtx (GET_MODE (x));
1900 generating_concat_p = 1;
1901 emit_move_insn (new_rtx, x);
1902 return new_rtx;
1903 }
1904 return x;
1905 }
1906
1907 /* Generate all the code for a CALL_EXPR exp
1908 and return an rtx for its value.
1909 Store the value in TARGET (specified as an rtx) if convenient.
1910 If the value is stored in TARGET then TARGET is returned.
1911 If IGNORE is nonzero, then we ignore the value of the function call. */
1912
1913 rtx
1914 expand_call (tree exp, rtx target, int ignore)
1915 {
1916 /* Nonzero if we are currently expanding a call. */
1917 static int currently_expanding_call = 0;
1918
1919 /* RTX for the function to be called. */
1920 rtx funexp;
1921 /* Sequence of insns to perform a normal "call". */
1922 rtx normal_call_insns = NULL_RTX;
1923 /* Sequence of insns to perform a tail "call". */
1924 rtx tail_call_insns = NULL_RTX;
1925 /* Data type of the function. */
1926 tree funtype;
1927 tree type_arg_types;
1928 /* Declaration of the function being called,
1929 or 0 if the function is computed (not known by name). */
1930 tree fndecl = 0;
1931 /* The type of the function being called. */
1932 tree fntype;
1933 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1934 int pass;
1935
1936 /* Register in which non-BLKmode value will be returned,
1937 or 0 if no value or if value is BLKmode. */
1938 rtx valreg;
1939 /* Address where we should return a BLKmode value;
1940 0 if value not BLKmode. */
1941 rtx structure_value_addr = 0;
1942 /* Nonzero if that address is being passed by treating it as
1943 an extra, implicit first parameter. Otherwise,
1944 it is passed by being copied directly into struct_value_rtx. */
1945 int structure_value_addr_parm = 0;
1946 /* Holds the value of implicit argument for the struct value. */
1947 tree structure_value_addr_value = NULL_TREE;
1948 /* Size of aggregate value wanted, or zero if none wanted
1949 or if we are using the non-reentrant PCC calling convention
1950 or expecting the value in registers. */
1951 HOST_WIDE_INT struct_value_size = 0;
1952 /* Nonzero if called function returns an aggregate in memory PCC style,
1953 by returning the address of where to find it. */
1954 int pcc_struct_value = 0;
1955 rtx struct_value = 0;
1956
1957 /* Number of actual parameters in this call, including struct value addr. */
1958 int num_actuals;
1959 /* Number of named args. Args after this are anonymous ones
1960 and they must all go on the stack. */
1961 int n_named_args;
1962 /* Number of complex actual arguments that need to be split. */
1963 int num_complex_actuals = 0;
1964
1965 /* Vector of information about each argument.
1966 Arguments are numbered in the order they will be pushed,
1967 not the order they are written. */
1968 struct arg_data *args;
1969
1970 /* Total size in bytes of all the stack-parms scanned so far. */
1971 struct args_size args_size;
1972 struct args_size adjusted_args_size;
1973 /* Size of arguments before any adjustments (such as rounding). */
1974 int unadjusted_args_size;
1975 /* Data on reg parms scanned so far. */
1976 CUMULATIVE_ARGS args_so_far;
1977 /* Nonzero if a reg parm has been scanned. */
1978 int reg_parm_seen;
1979 /* Nonzero if this is an indirect function call. */
1980
1981 /* Nonzero if we must avoid push-insns in the args for this call.
1982 If stack space is allocated for register parameters, but not by the
1983 caller, then it is preallocated in the fixed part of the stack frame.
1984 So the entire argument block must then be preallocated (i.e., we
1985 ignore PUSH_ROUNDING in that case). */
1986
1987 int must_preallocate = !PUSH_ARGS;
1988
1989 /* Size of the stack reserved for parameter registers. */
1990 int reg_parm_stack_space = 0;
1991
1992 /* Address of space preallocated for stack parms
1993 (on machines that lack push insns), or 0 if space not preallocated. */
1994 rtx argblock = 0;
1995
1996 /* Mask of ECF_ flags. */
1997 int flags = 0;
1998 #ifdef REG_PARM_STACK_SPACE
1999 /* Define the boundary of the register parm stack space that needs to be
2000 saved, if any. */
2001 int low_to_save, high_to_save;
2002 rtx save_area = 0; /* Place that it is saved */
2003 #endif
2004
2005 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2006 char *initial_stack_usage_map = stack_usage_map;
2007 char *stack_usage_map_buf = NULL;
2008
2009 int old_stack_allocated;
2010
2011 /* State variables to track stack modifications. */
2012 rtx old_stack_level = 0;
2013 int old_stack_arg_under_construction = 0;
2014 int old_pending_adj = 0;
2015 int old_inhibit_defer_pop = inhibit_defer_pop;
2016
2017 /* Some stack pointer alterations we make are performed via
2018 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2019 which we then also need to save/restore along the way. */
2020 int old_stack_pointer_delta = 0;
2021
2022 rtx call_fusage;
2023 tree p = CALL_EXPR_FN (exp);
2024 tree addr = CALL_EXPR_FN (exp);
2025 int i;
2026 /* The alignment of the stack, in bits. */
2027 unsigned HOST_WIDE_INT preferred_stack_boundary;
2028 /* The alignment of the stack, in bytes. */
2029 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2030 /* The static chain value to use for this call. */
2031 rtx static_chain_value;
2032 /* See if this is "nothrow" function call. */
2033 if (TREE_NOTHROW (exp))
2034 flags |= ECF_NOTHROW;
2035
2036 /* See if we can find a DECL-node for the actual function, and get the
2037 function attributes (flags) from the function decl or type node. */
2038 fndecl = get_callee_fndecl (exp);
2039 if (fndecl)
2040 {
2041 fntype = TREE_TYPE (fndecl);
2042 flags |= flags_from_decl_or_type (fndecl);
2043 }
2044 else
2045 {
2046 fntype = TREE_TYPE (TREE_TYPE (p));
2047 flags |= flags_from_decl_or_type (fntype);
2048 }
2049
2050 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2051
2052 /* Warn if this value is an aggregate type,
2053 regardless of which calling convention we are using for it. */
2054 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2055 warning (OPT_Waggregate_return, "function call has aggregate value");
2056
2057 /* If the result of a non looping pure or const function call is
2058 ignored (or void), and none of its arguments are volatile, we can
2059 avoid expanding the call and just evaluate the arguments for
2060 side-effects. */
2061 if ((flags & (ECF_CONST | ECF_PURE))
2062 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2063 && (ignore || target == const0_rtx
2064 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2065 {
2066 bool volatilep = false;
2067 tree arg;
2068 call_expr_arg_iterator iter;
2069
2070 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2071 if (TREE_THIS_VOLATILE (arg))
2072 {
2073 volatilep = true;
2074 break;
2075 }
2076
2077 if (! volatilep)
2078 {
2079 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2080 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2081 return const0_rtx;
2082 }
2083 }
2084
2085 #ifdef REG_PARM_STACK_SPACE
2086 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2087 #endif
2088
2089 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2090 && reg_parm_stack_space > 0 && PUSH_ARGS)
2091 must_preallocate = 1;
2092
2093 /* Set up a place to return a structure. */
2094
2095 /* Cater to broken compilers. */
2096 if (aggregate_value_p (exp, (!fndecl ? fntype : fndecl)))
2097 {
2098 /* This call returns a big structure. */
2099 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2100
2101 #ifdef PCC_STATIC_STRUCT_RETURN
2102 {
2103 pcc_struct_value = 1;
2104 }
2105 #else /* not PCC_STATIC_STRUCT_RETURN */
2106 {
2107 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2108
2109 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2110 structure_value_addr = XEXP (target, 0);
2111 else
2112 {
2113 /* For variable-sized objects, we must be called with a target
2114 specified. If we were to allocate space on the stack here,
2115 we would have no way of knowing when to free it. */
2116 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2117
2118 mark_temp_addr_taken (d);
2119 structure_value_addr = XEXP (d, 0);
2120 target = 0;
2121 }
2122 }
2123 #endif /* not PCC_STATIC_STRUCT_RETURN */
2124 }
2125
2126 /* Figure out the amount to which the stack should be aligned. */
2127 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2128 if (fndecl)
2129 {
2130 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2131 /* Without automatic stack alignment, we can't increase preferred
2132 stack boundary. With automatic stack alignment, it is
2133 unnecessary since unless we can guarantee that all callers will
2134 align the outgoing stack properly, callee has to align its
2135 stack anyway. */
2136 if (i
2137 && i->preferred_incoming_stack_boundary
2138 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2139 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2140 }
2141
2142 /* Operand 0 is a pointer-to-function; get the type of the function. */
2143 funtype = TREE_TYPE (addr);
2144 gcc_assert (POINTER_TYPE_P (funtype));
2145 funtype = TREE_TYPE (funtype);
2146
2147 /* Count whether there are actual complex arguments that need to be split
2148 into their real and imaginary parts. Munge the type_arg_types
2149 appropriately here as well. */
2150 if (targetm.calls.split_complex_arg)
2151 {
2152 call_expr_arg_iterator iter;
2153 tree arg;
2154 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2155 {
2156 tree type = TREE_TYPE (arg);
2157 if (type && TREE_CODE (type) == COMPLEX_TYPE
2158 && targetm.calls.split_complex_arg (type))
2159 num_complex_actuals++;
2160 }
2161 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2162 }
2163 else
2164 type_arg_types = TYPE_ARG_TYPES (funtype);
2165
2166 if (flags & ECF_MAY_BE_ALLOCA)
2167 cfun->calls_alloca = 1;
2168
2169 /* If struct_value_rtx is 0, it means pass the address
2170 as if it were an extra parameter. Put the argument expression
2171 in structure_value_addr_value. */
2172 if (structure_value_addr && struct_value == 0)
2173 {
2174 /* If structure_value_addr is a REG other than
2175 virtual_outgoing_args_rtx, we can use always use it. If it
2176 is not a REG, we must always copy it into a register.
2177 If it is virtual_outgoing_args_rtx, we must copy it to another
2178 register in some cases. */
2179 rtx temp = (!REG_P (structure_value_addr)
2180 || (ACCUMULATE_OUTGOING_ARGS
2181 && stack_arg_under_construction
2182 && structure_value_addr == virtual_outgoing_args_rtx)
2183 ? copy_addr_to_reg (convert_memory_address
2184 (Pmode, structure_value_addr))
2185 : structure_value_addr);
2186
2187 structure_value_addr_value =
2188 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2189 structure_value_addr_parm = 1;
2190 }
2191
2192 /* Count the arguments and set NUM_ACTUALS. */
2193 num_actuals =
2194 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2195
2196 /* Compute number of named args.
2197 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2198
2199 if (type_arg_types != 0)
2200 n_named_args
2201 = (list_length (type_arg_types)
2202 /* Count the struct value address, if it is passed as a parm. */
2203 + structure_value_addr_parm);
2204 else
2205 /* If we know nothing, treat all args as named. */
2206 n_named_args = num_actuals;
2207
2208 /* Start updating where the next arg would go.
2209
2210 On some machines (such as the PA) indirect calls have a different
2211 calling convention than normal calls. The fourth argument in
2212 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2213 or not. */
2214 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2215
2216 /* Now possibly adjust the number of named args.
2217 Normally, don't include the last named arg if anonymous args follow.
2218 We do include the last named arg if
2219 targetm.calls.strict_argument_naming() returns nonzero.
2220 (If no anonymous args follow, the result of list_length is actually
2221 one too large. This is harmless.)
2222
2223 If targetm.calls.pretend_outgoing_varargs_named() returns
2224 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2225 this machine will be able to place unnamed args that were passed
2226 in registers into the stack. So treat all args as named. This
2227 allows the insns emitting for a specific argument list to be
2228 independent of the function declaration.
2229
2230 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2231 we do not have any reliable way to pass unnamed args in
2232 registers, so we must force them into memory. */
2233
2234 if (type_arg_types != 0
2235 && targetm.calls.strict_argument_naming (&args_so_far))
2236 ;
2237 else if (type_arg_types != 0
2238 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2239 /* Don't include the last named arg. */
2240 --n_named_args;
2241 else
2242 /* Treat all args as named. */
2243 n_named_args = num_actuals;
2244
2245 /* Make a vector to hold all the information about each arg. */
2246 args = XALLOCAVEC (struct arg_data, num_actuals);
2247 memset (args, 0, num_actuals * sizeof (struct arg_data));
2248
2249 /* Build up entries in the ARGS array, compute the size of the
2250 arguments into ARGS_SIZE, etc. */
2251 initialize_argument_information (num_actuals, args, &args_size,
2252 n_named_args, exp,
2253 structure_value_addr_value, fndecl, fntype,
2254 &args_so_far, reg_parm_stack_space,
2255 &old_stack_level, &old_pending_adj,
2256 &must_preallocate, &flags,
2257 &try_tail_call, CALL_FROM_THUNK_P (exp));
2258
2259 if (args_size.var)
2260 must_preallocate = 1;
2261
2262 /* Now make final decision about preallocating stack space. */
2263 must_preallocate = finalize_must_preallocate (must_preallocate,
2264 num_actuals, args,
2265 &args_size);
2266
2267 /* If the structure value address will reference the stack pointer, we
2268 must stabilize it. We don't need to do this if we know that we are
2269 not going to adjust the stack pointer in processing this call. */
2270
2271 if (structure_value_addr
2272 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2273 || reg_mentioned_p (virtual_outgoing_args_rtx,
2274 structure_value_addr))
2275 && (args_size.var
2276 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2277 structure_value_addr = copy_to_reg (structure_value_addr);
2278
2279 /* Tail calls can make things harder to debug, and we've traditionally
2280 pushed these optimizations into -O2. Don't try if we're already
2281 expanding a call, as that means we're an argument. Don't try if
2282 there's cleanups, as we know there's code to follow the call. */
2283
2284 if (currently_expanding_call++ != 0
2285 || !flag_optimize_sibling_calls
2286 || args_size.var
2287 || lookup_expr_eh_region (exp) >= 0
2288 || dbg_cnt (tail_call) == false)
2289 try_tail_call = 0;
2290
2291 /* Rest of purposes for tail call optimizations to fail. */
2292 if (
2293 #ifdef HAVE_sibcall_epilogue
2294 !HAVE_sibcall_epilogue
2295 #else
2296 1
2297 #endif
2298 || !try_tail_call
2299 /* Doing sibling call optimization needs some work, since
2300 structure_value_addr can be allocated on the stack.
2301 It does not seem worth the effort since few optimizable
2302 sibling calls will return a structure. */
2303 || structure_value_addr != NULL_RTX
2304 #ifdef REG_PARM_STACK_SPACE
2305 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2306 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2307 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2308 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2309 #endif
2310 /* Check whether the target is able to optimize the call
2311 into a sibcall. */
2312 || !targetm.function_ok_for_sibcall (fndecl, exp)
2313 /* Functions that do not return exactly once may not be sibcall
2314 optimized. */
2315 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2316 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2317 /* If the called function is nested in the current one, it might access
2318 some of the caller's arguments, but could clobber them beforehand if
2319 the argument areas are shared. */
2320 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2321 /* If this function requires more stack slots than the current
2322 function, we cannot change it into a sibling call.
2323 crtl->args.pretend_args_size is not part of the
2324 stack allocated by our caller. */
2325 || args_size.constant > (crtl->args.size
2326 - crtl->args.pretend_args_size)
2327 /* If the callee pops its own arguments, then it must pop exactly
2328 the same number of arguments as the current function. */
2329 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2330 != RETURN_POPS_ARGS (current_function_decl,
2331 TREE_TYPE (current_function_decl),
2332 crtl->args.size))
2333 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2334 try_tail_call = 0;
2335
2336 /* Check if caller and callee disagree in promotion of function
2337 return value. */
2338 if (try_tail_call)
2339 {
2340 enum machine_mode caller_mode, caller_promoted_mode;
2341 enum machine_mode callee_mode, callee_promoted_mode;
2342 int caller_unsignedp, callee_unsignedp;
2343 tree caller_res = DECL_RESULT (current_function_decl);
2344
2345 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2346 caller_mode = caller_promoted_mode = DECL_MODE (caller_res);
2347 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2348 callee_mode = callee_promoted_mode = TYPE_MODE (TREE_TYPE (funtype));
2349 if (targetm.calls.promote_function_return (TREE_TYPE (current_function_decl)))
2350 caller_promoted_mode
2351 = promote_mode (TREE_TYPE (caller_res), caller_mode,
2352 &caller_unsignedp, 1);
2353 if (targetm.calls.promote_function_return (funtype))
2354 callee_promoted_mode
2355 = promote_mode (TREE_TYPE (funtype), callee_mode,
2356 &callee_unsignedp, 1);
2357 if (caller_mode != VOIDmode
2358 && (caller_promoted_mode != callee_promoted_mode
2359 || ((caller_mode != caller_promoted_mode
2360 || callee_mode != callee_promoted_mode)
2361 && (caller_unsignedp != callee_unsignedp
2362 || GET_MODE_BITSIZE (caller_mode)
2363 < GET_MODE_BITSIZE (callee_mode)))))
2364 try_tail_call = 0;
2365 }
2366
2367 /* Ensure current function's preferred stack boundary is at least
2368 what we need. Stack alignment may also increase preferred stack
2369 boundary. */
2370 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2371 crtl->preferred_stack_boundary = preferred_stack_boundary;
2372 else
2373 preferred_stack_boundary = crtl->preferred_stack_boundary;
2374
2375 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2376
2377 /* We want to make two insn chains; one for a sibling call, the other
2378 for a normal call. We will select one of the two chains after
2379 initial RTL generation is complete. */
2380 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2381 {
2382 int sibcall_failure = 0;
2383 /* We want to emit any pending stack adjustments before the tail
2384 recursion "call". That way we know any adjustment after the tail
2385 recursion call can be ignored if we indeed use the tail
2386 call expansion. */
2387 int save_pending_stack_adjust = 0;
2388 int save_stack_pointer_delta = 0;
2389 rtx insns;
2390 rtx before_call, next_arg_reg, after_args;
2391
2392 if (pass == 0)
2393 {
2394 /* State variables we need to save and restore between
2395 iterations. */
2396 save_pending_stack_adjust = pending_stack_adjust;
2397 save_stack_pointer_delta = stack_pointer_delta;
2398 }
2399 if (pass)
2400 flags &= ~ECF_SIBCALL;
2401 else
2402 flags |= ECF_SIBCALL;
2403
2404 /* Other state variables that we must reinitialize each time
2405 through the loop (that are not initialized by the loop itself). */
2406 argblock = 0;
2407 call_fusage = 0;
2408
2409 /* Start a new sequence for the normal call case.
2410
2411 From this point on, if the sibling call fails, we want to set
2412 sibcall_failure instead of continuing the loop. */
2413 start_sequence ();
2414
2415 /* Don't let pending stack adjusts add up to too much.
2416 Also, do all pending adjustments now if there is any chance
2417 this might be a call to alloca or if we are expanding a sibling
2418 call sequence.
2419 Also do the adjustments before a throwing call, otherwise
2420 exception handling can fail; PR 19225. */
2421 if (pending_stack_adjust >= 32
2422 || (pending_stack_adjust > 0
2423 && (flags & ECF_MAY_BE_ALLOCA))
2424 || (pending_stack_adjust > 0
2425 && flag_exceptions && !(flags & ECF_NOTHROW))
2426 || pass == 0)
2427 do_pending_stack_adjust ();
2428
2429 /* Precompute any arguments as needed. */
2430 if (pass)
2431 precompute_arguments (num_actuals, args);
2432
2433 /* Now we are about to start emitting insns that can be deleted
2434 if a libcall is deleted. */
2435 if (pass && (flags & ECF_MALLOC))
2436 start_sequence ();
2437
2438 if (pass == 0 && crtl->stack_protect_guard)
2439 stack_protect_epilogue ();
2440
2441 adjusted_args_size = args_size;
2442 /* Compute the actual size of the argument block required. The variable
2443 and constant sizes must be combined, the size may have to be rounded,
2444 and there may be a minimum required size. When generating a sibcall
2445 pattern, do not round up, since we'll be re-using whatever space our
2446 caller provided. */
2447 unadjusted_args_size
2448 = compute_argument_block_size (reg_parm_stack_space,
2449 &adjusted_args_size,
2450 fndecl, fntype,
2451 (pass == 0 ? 0
2452 : preferred_stack_boundary));
2453
2454 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2455
2456 /* The argument block when performing a sibling call is the
2457 incoming argument block. */
2458 if (pass == 0)
2459 {
2460 argblock = crtl->args.internal_arg_pointer;
2461 argblock
2462 #ifdef STACK_GROWS_DOWNWARD
2463 = plus_constant (argblock, crtl->args.pretend_args_size);
2464 #else
2465 = plus_constant (argblock, -crtl->args.pretend_args_size);
2466 #endif
2467 stored_args_map = sbitmap_alloc (args_size.constant);
2468 sbitmap_zero (stored_args_map);
2469 }
2470
2471 /* If we have no actual push instructions, or shouldn't use them,
2472 make space for all args right now. */
2473 else if (adjusted_args_size.var != 0)
2474 {
2475 if (old_stack_level == 0)
2476 {
2477 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2478 old_stack_pointer_delta = stack_pointer_delta;
2479 old_pending_adj = pending_stack_adjust;
2480 pending_stack_adjust = 0;
2481 /* stack_arg_under_construction says whether a stack arg is
2482 being constructed at the old stack level. Pushing the stack
2483 gets a clean outgoing argument block. */
2484 old_stack_arg_under_construction = stack_arg_under_construction;
2485 stack_arg_under_construction = 0;
2486 }
2487 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2488 }
2489 else
2490 {
2491 /* Note that we must go through the motions of allocating an argument
2492 block even if the size is zero because we may be storing args
2493 in the area reserved for register arguments, which may be part of
2494 the stack frame. */
2495
2496 int needed = adjusted_args_size.constant;
2497
2498 /* Store the maximum argument space used. It will be pushed by
2499 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2500 checking). */
2501
2502 if (needed > crtl->outgoing_args_size)
2503 crtl->outgoing_args_size = needed;
2504
2505 if (must_preallocate)
2506 {
2507 if (ACCUMULATE_OUTGOING_ARGS)
2508 {
2509 /* Since the stack pointer will never be pushed, it is
2510 possible for the evaluation of a parm to clobber
2511 something we have already written to the stack.
2512 Since most function calls on RISC machines do not use
2513 the stack, this is uncommon, but must work correctly.
2514
2515 Therefore, we save any area of the stack that was already
2516 written and that we are using. Here we set up to do this
2517 by making a new stack usage map from the old one. The
2518 actual save will be done by store_one_arg.
2519
2520 Another approach might be to try to reorder the argument
2521 evaluations to avoid this conflicting stack usage. */
2522
2523 /* Since we will be writing into the entire argument area,
2524 the map must be allocated for its entire size, not just
2525 the part that is the responsibility of the caller. */
2526 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2527 needed += reg_parm_stack_space;
2528
2529 #ifdef ARGS_GROW_DOWNWARD
2530 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2531 needed + 1);
2532 #else
2533 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2534 needed);
2535 #endif
2536 if (stack_usage_map_buf)
2537 free (stack_usage_map_buf);
2538 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2539 stack_usage_map = stack_usage_map_buf;
2540
2541 if (initial_highest_arg_in_use)
2542 memcpy (stack_usage_map, initial_stack_usage_map,
2543 initial_highest_arg_in_use);
2544
2545 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2546 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2547 (highest_outgoing_arg_in_use
2548 - initial_highest_arg_in_use));
2549 needed = 0;
2550
2551 /* The address of the outgoing argument list must not be
2552 copied to a register here, because argblock would be left
2553 pointing to the wrong place after the call to
2554 allocate_dynamic_stack_space below. */
2555
2556 argblock = virtual_outgoing_args_rtx;
2557 }
2558 else
2559 {
2560 if (inhibit_defer_pop == 0)
2561 {
2562 /* Try to reuse some or all of the pending_stack_adjust
2563 to get this space. */
2564 needed
2565 = (combine_pending_stack_adjustment_and_call
2566 (unadjusted_args_size,
2567 &adjusted_args_size,
2568 preferred_unit_stack_boundary));
2569
2570 /* combine_pending_stack_adjustment_and_call computes
2571 an adjustment before the arguments are allocated.
2572 Account for them and see whether or not the stack
2573 needs to go up or down. */
2574 needed = unadjusted_args_size - needed;
2575
2576 if (needed < 0)
2577 {
2578 /* We're releasing stack space. */
2579 /* ??? We can avoid any adjustment at all if we're
2580 already aligned. FIXME. */
2581 pending_stack_adjust = -needed;
2582 do_pending_stack_adjust ();
2583 needed = 0;
2584 }
2585 else
2586 /* We need to allocate space. We'll do that in
2587 push_block below. */
2588 pending_stack_adjust = 0;
2589 }
2590
2591 /* Special case this because overhead of `push_block' in
2592 this case is non-trivial. */
2593 if (needed == 0)
2594 argblock = virtual_outgoing_args_rtx;
2595 else
2596 {
2597 argblock = push_block (GEN_INT (needed), 0, 0);
2598 #ifdef ARGS_GROW_DOWNWARD
2599 argblock = plus_constant (argblock, needed);
2600 #endif
2601 }
2602
2603 /* We only really need to call `copy_to_reg' in the case
2604 where push insns are going to be used to pass ARGBLOCK
2605 to a function call in ARGS. In that case, the stack
2606 pointer changes value from the allocation point to the
2607 call point, and hence the value of
2608 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2609 as well always do it. */
2610 argblock = copy_to_reg (argblock);
2611 }
2612 }
2613 }
2614
2615 if (ACCUMULATE_OUTGOING_ARGS)
2616 {
2617 /* The save/restore code in store_one_arg handles all
2618 cases except one: a constructor call (including a C
2619 function returning a BLKmode struct) to initialize
2620 an argument. */
2621 if (stack_arg_under_construction)
2622 {
2623 rtx push_size
2624 = GEN_INT (adjusted_args_size.constant
2625 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2626 : TREE_TYPE (fndecl))) ? 0
2627 : reg_parm_stack_space));
2628 if (old_stack_level == 0)
2629 {
2630 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2631 NULL_RTX);
2632 old_stack_pointer_delta = stack_pointer_delta;
2633 old_pending_adj = pending_stack_adjust;
2634 pending_stack_adjust = 0;
2635 /* stack_arg_under_construction says whether a stack
2636 arg is being constructed at the old stack level.
2637 Pushing the stack gets a clean outgoing argument
2638 block. */
2639 old_stack_arg_under_construction
2640 = stack_arg_under_construction;
2641 stack_arg_under_construction = 0;
2642 /* Make a new map for the new argument list. */
2643 if (stack_usage_map_buf)
2644 free (stack_usage_map_buf);
2645 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2646 stack_usage_map = stack_usage_map_buf;
2647 highest_outgoing_arg_in_use = 0;
2648 }
2649 allocate_dynamic_stack_space (push_size, NULL_RTX,
2650 BITS_PER_UNIT);
2651 }
2652
2653 /* If argument evaluation might modify the stack pointer,
2654 copy the address of the argument list to a register. */
2655 for (i = 0; i < num_actuals; i++)
2656 if (args[i].pass_on_stack)
2657 {
2658 argblock = copy_addr_to_reg (argblock);
2659 break;
2660 }
2661 }
2662
2663 compute_argument_addresses (args, argblock, num_actuals);
2664
2665 /* If we push args individually in reverse order, perform stack alignment
2666 before the first push (the last arg). */
2667 if (PUSH_ARGS_REVERSED && argblock == 0
2668 && adjusted_args_size.constant != unadjusted_args_size)
2669 {
2670 /* When the stack adjustment is pending, we get better code
2671 by combining the adjustments. */
2672 if (pending_stack_adjust
2673 && ! inhibit_defer_pop)
2674 {
2675 pending_stack_adjust
2676 = (combine_pending_stack_adjustment_and_call
2677 (unadjusted_args_size,
2678 &adjusted_args_size,
2679 preferred_unit_stack_boundary));
2680 do_pending_stack_adjust ();
2681 }
2682 else if (argblock == 0)
2683 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2684 - unadjusted_args_size));
2685 }
2686 /* Now that the stack is properly aligned, pops can't safely
2687 be deferred during the evaluation of the arguments. */
2688 NO_DEFER_POP;
2689
2690 funexp = rtx_for_function_call (fndecl, addr);
2691
2692 /* Figure out the register where the value, if any, will come back. */
2693 valreg = 0;
2694 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2695 && ! structure_value_addr)
2696 {
2697 if (pcc_struct_value)
2698 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2699 fndecl, NULL, (pass == 0));
2700 else
2701 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2702 (pass == 0));
2703
2704 /* If VALREG is a PARALLEL whose first member has a zero
2705 offset, use that. This is for targets such as m68k that
2706 return the same value in multiple places. */
2707 if (GET_CODE (valreg) == PARALLEL)
2708 {
2709 rtx elem = XVECEXP (valreg, 0, 0);
2710 rtx where = XEXP (elem, 0);
2711 rtx offset = XEXP (elem, 1);
2712 if (offset == const0_rtx
2713 && GET_MODE (where) == GET_MODE (valreg))
2714 valreg = where;
2715 }
2716 }
2717
2718 /* Precompute all register parameters. It isn't safe to compute anything
2719 once we have started filling any specific hard regs. */
2720 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2721
2722 if (CALL_EXPR_STATIC_CHAIN (exp))
2723 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2724 else
2725 static_chain_value = 0;
2726
2727 #ifdef REG_PARM_STACK_SPACE
2728 /* Save the fixed argument area if it's part of the caller's frame and
2729 is clobbered by argument setup for this call. */
2730 if (ACCUMULATE_OUTGOING_ARGS && pass)
2731 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2732 &low_to_save, &high_to_save);
2733 #endif
2734
2735 /* Now store (and compute if necessary) all non-register parms.
2736 These come before register parms, since they can require block-moves,
2737 which could clobber the registers used for register parms.
2738 Parms which have partial registers are not stored here,
2739 but we do preallocate space here if they want that. */
2740
2741 for (i = 0; i < num_actuals; i++)
2742 {
2743 if (args[i].reg == 0 || args[i].pass_on_stack)
2744 {
2745 rtx before_arg = get_last_insn ();
2746
2747 if (store_one_arg (&args[i], argblock, flags,
2748 adjusted_args_size.var != 0,
2749 reg_parm_stack_space)
2750 || (pass == 0
2751 && check_sibcall_argument_overlap (before_arg,
2752 &args[i], 1)))
2753 sibcall_failure = 1;
2754 }
2755
2756 if (((flags & ECF_CONST)
2757 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
2758 && args[i].stack)
2759 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2760 gen_rtx_USE (VOIDmode,
2761 args[i].stack),
2762 call_fusage);
2763 }
2764
2765 /* If we have a parm that is passed in registers but not in memory
2766 and whose alignment does not permit a direct copy into registers,
2767 make a group of pseudos that correspond to each register that we
2768 will later fill. */
2769 if (STRICT_ALIGNMENT)
2770 store_unaligned_arguments_into_pseudos (args, num_actuals);
2771
2772 /* Now store any partially-in-registers parm.
2773 This is the last place a block-move can happen. */
2774 if (reg_parm_seen)
2775 for (i = 0; i < num_actuals; i++)
2776 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2777 {
2778 rtx before_arg = get_last_insn ();
2779
2780 if (store_one_arg (&args[i], argblock, flags,
2781 adjusted_args_size.var != 0,
2782 reg_parm_stack_space)
2783 || (pass == 0
2784 && check_sibcall_argument_overlap (before_arg,
2785 &args[i], 1)))
2786 sibcall_failure = 1;
2787 }
2788
2789 /* If we pushed args in forward order, perform stack alignment
2790 after pushing the last arg. */
2791 if (!PUSH_ARGS_REVERSED && argblock == 0)
2792 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2793 - unadjusted_args_size));
2794
2795 /* If register arguments require space on the stack and stack space
2796 was not preallocated, allocate stack space here for arguments
2797 passed in registers. */
2798 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2799 && !ACCUMULATE_OUTGOING_ARGS
2800 && must_preallocate == 0 && reg_parm_stack_space > 0)
2801 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2802
2803 /* Pass the function the address in which to return a
2804 structure value. */
2805 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2806 {
2807 structure_value_addr
2808 = convert_memory_address (Pmode, structure_value_addr);
2809 emit_move_insn (struct_value,
2810 force_reg (Pmode,
2811 force_operand (structure_value_addr,
2812 NULL_RTX)));
2813
2814 if (REG_P (struct_value))
2815 use_reg (&call_fusage, struct_value);
2816 }
2817
2818 after_args = get_last_insn ();
2819 funexp = prepare_call_address (funexp, static_chain_value,
2820 &call_fusage, reg_parm_seen, pass == 0);
2821
2822 load_register_parameters (args, num_actuals, &call_fusage, flags,
2823 pass == 0, &sibcall_failure);
2824
2825 /* Save a pointer to the last insn before the call, so that we can
2826 later safely search backwards to find the CALL_INSN. */
2827 before_call = get_last_insn ();
2828
2829 /* Set up next argument register. For sibling calls on machines
2830 with register windows this should be the incoming register. */
2831 #ifdef FUNCTION_INCOMING_ARG
2832 if (pass == 0)
2833 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2834 void_type_node, 1);
2835 else
2836 #endif
2837 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2838 void_type_node, 1);
2839
2840 /* All arguments and registers used for the call must be set up by
2841 now! */
2842
2843 /* Stack must be properly aligned now. */
2844 gcc_assert (!pass
2845 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2846
2847 /* Generate the actual call instruction. */
2848 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2849 adjusted_args_size.constant, struct_value_size,
2850 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2851 flags, & args_so_far);
2852
2853 /* If the call setup or the call itself overlaps with anything
2854 of the argument setup we probably clobbered our call address.
2855 In that case we can't do sibcalls. */
2856 if (pass == 0
2857 && check_sibcall_argument_overlap (after_args, 0, 0))
2858 sibcall_failure = 1;
2859
2860 /* If a non-BLKmode value is returned at the most significant end
2861 of a register, shift the register right by the appropriate amount
2862 and update VALREG accordingly. BLKmode values are handled by the
2863 group load/store machinery below. */
2864 if (!structure_value_addr
2865 && !pcc_struct_value
2866 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2867 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2868 {
2869 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2870 sibcall_failure = 1;
2871 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2872 }
2873
2874 if (pass && (flags & ECF_MALLOC))
2875 {
2876 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2877 rtx last, insns;
2878
2879 /* The return value from a malloc-like function is a pointer. */
2880 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2881 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2882
2883 emit_move_insn (temp, valreg);
2884
2885 /* The return value from a malloc-like function can not alias
2886 anything else. */
2887 last = get_last_insn ();
2888 add_reg_note (last, REG_NOALIAS, temp);
2889
2890 /* Write out the sequence. */
2891 insns = get_insns ();
2892 end_sequence ();
2893 emit_insn (insns);
2894 valreg = temp;
2895 }
2896
2897 /* For calls to `setjmp', etc., inform
2898 function.c:setjmp_warnings that it should complain if
2899 nonvolatile values are live. For functions that cannot
2900 return, inform flow that control does not fall through. */
2901
2902 if ((flags & ECF_NORETURN) || pass == 0)
2903 {
2904 /* The barrier must be emitted
2905 immediately after the CALL_INSN. Some ports emit more
2906 than just a CALL_INSN above, so we must search for it here. */
2907
2908 rtx last = get_last_insn ();
2909 while (!CALL_P (last))
2910 {
2911 last = PREV_INSN (last);
2912 /* There was no CALL_INSN? */
2913 gcc_assert (last != before_call);
2914 }
2915
2916 emit_barrier_after (last);
2917
2918 /* Stack adjustments after a noreturn call are dead code.
2919 However when NO_DEFER_POP is in effect, we must preserve
2920 stack_pointer_delta. */
2921 if (inhibit_defer_pop == 0)
2922 {
2923 stack_pointer_delta = old_stack_allocated;
2924 pending_stack_adjust = 0;
2925 }
2926 }
2927
2928 /* If value type not void, return an rtx for the value. */
2929
2930 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2931 || ignore)
2932 target = const0_rtx;
2933 else if (structure_value_addr)
2934 {
2935 if (target == 0 || !MEM_P (target))
2936 {
2937 target
2938 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2939 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2940 structure_value_addr));
2941 set_mem_attributes (target, exp, 1);
2942 }
2943 }
2944 else if (pcc_struct_value)
2945 {
2946 /* This is the special C++ case where we need to
2947 know what the true target was. We take care to
2948 never use this value more than once in one expression. */
2949 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2950 copy_to_reg (valreg));
2951 set_mem_attributes (target, exp, 1);
2952 }
2953 /* Handle calls that return values in multiple non-contiguous locations.
2954 The Irix 6 ABI has examples of this. */
2955 else if (GET_CODE (valreg) == PARALLEL)
2956 {
2957 if (target == 0)
2958 {
2959 /* This will only be assigned once, so it can be readonly. */
2960 tree nt = build_qualified_type (TREE_TYPE (exp),
2961 (TYPE_QUALS (TREE_TYPE (exp))
2962 | TYPE_QUAL_CONST));
2963
2964 target = assign_temp (nt, 0, 1, 1);
2965 }
2966
2967 if (! rtx_equal_p (target, valreg))
2968 emit_group_store (target, valreg, TREE_TYPE (exp),
2969 int_size_in_bytes (TREE_TYPE (exp)));
2970
2971 /* We can not support sibling calls for this case. */
2972 sibcall_failure = 1;
2973 }
2974 else if (target
2975 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2976 && GET_MODE (target) == GET_MODE (valreg))
2977 {
2978 bool may_overlap = false;
2979
2980 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2981 reg to a plain register. */
2982 if (!REG_P (target) || HARD_REGISTER_P (target))
2983 valreg = avoid_likely_spilled_reg (valreg);
2984
2985 /* If TARGET is a MEM in the argument area, and we have
2986 saved part of the argument area, then we can't store
2987 directly into TARGET as it may get overwritten when we
2988 restore the argument save area below. Don't work too
2989 hard though and simply force TARGET to a register if it
2990 is a MEM; the optimizer is quite likely to sort it out. */
2991 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2992 for (i = 0; i < num_actuals; i++)
2993 if (args[i].save_area)
2994 {
2995 may_overlap = true;
2996 break;
2997 }
2998
2999 if (may_overlap)
3000 target = copy_to_reg (valreg);
3001 else
3002 {
3003 /* TARGET and VALREG cannot be equal at this point
3004 because the latter would not have
3005 REG_FUNCTION_VALUE_P true, while the former would if
3006 it were referring to the same register.
3007
3008 If they refer to the same register, this move will be
3009 a no-op, except when function inlining is being
3010 done. */
3011 emit_move_insn (target, valreg);
3012
3013 /* If we are setting a MEM, this code must be executed.
3014 Since it is emitted after the call insn, sibcall
3015 optimization cannot be performed in that case. */
3016 if (MEM_P (target))
3017 sibcall_failure = 1;
3018 }
3019 }
3020 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3021 {
3022 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3023
3024 /* We can not support sibling calls for this case. */
3025 sibcall_failure = 1;
3026 }
3027 else
3028 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3029
3030 if (targetm.calls.promote_function_return(funtype))
3031 {
3032 /* If we promoted this return value, make the proper SUBREG.
3033 TARGET might be const0_rtx here, so be careful. */
3034 if (REG_P (target)
3035 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3036 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3037 {
3038 tree type = TREE_TYPE (exp);
3039 int unsignedp = TYPE_UNSIGNED (type);
3040 int offset = 0;
3041 enum machine_mode pmode;
3042
3043 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
3044 /* If we don't promote as expected, something is wrong. */
3045 gcc_assert (GET_MODE (target) == pmode);
3046
3047 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3048 && (GET_MODE_SIZE (GET_MODE (target))
3049 > GET_MODE_SIZE (TYPE_MODE (type))))
3050 {
3051 offset = GET_MODE_SIZE (GET_MODE (target))
3052 - GET_MODE_SIZE (TYPE_MODE (type));
3053 if (! BYTES_BIG_ENDIAN)
3054 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3055 else if (! WORDS_BIG_ENDIAN)
3056 offset %= UNITS_PER_WORD;
3057 }
3058 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3059 SUBREG_PROMOTED_VAR_P (target) = 1;
3060 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3061 }
3062 }
3063
3064 /* If size of args is variable or this was a constructor call for a stack
3065 argument, restore saved stack-pointer value. */
3066
3067 if (old_stack_level)
3068 {
3069 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3070 stack_pointer_delta = old_stack_pointer_delta;
3071 pending_stack_adjust = old_pending_adj;
3072 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3073 stack_arg_under_construction = old_stack_arg_under_construction;
3074 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3075 stack_usage_map = initial_stack_usage_map;
3076 sibcall_failure = 1;
3077 }
3078 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3079 {
3080 #ifdef REG_PARM_STACK_SPACE
3081 if (save_area)
3082 restore_fixed_argument_area (save_area, argblock,
3083 high_to_save, low_to_save);
3084 #endif
3085
3086 /* If we saved any argument areas, restore them. */
3087 for (i = 0; i < num_actuals; i++)
3088 if (args[i].save_area)
3089 {
3090 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3091 rtx stack_area
3092 = gen_rtx_MEM (save_mode,
3093 memory_address (save_mode,
3094 XEXP (args[i].stack_slot, 0)));
3095
3096 if (save_mode != BLKmode)
3097 emit_move_insn (stack_area, args[i].save_area);
3098 else
3099 emit_block_move (stack_area, args[i].save_area,
3100 GEN_INT (args[i].locate.size.constant),
3101 BLOCK_OP_CALL_PARM);
3102 }
3103
3104 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3105 stack_usage_map = initial_stack_usage_map;
3106 }
3107
3108 /* If this was alloca, record the new stack level for nonlocal gotos.
3109 Check for the handler slots since we might not have a save area
3110 for non-local gotos. */
3111
3112 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3113 update_nonlocal_goto_save_area ();
3114
3115 /* Free up storage we no longer need. */
3116 for (i = 0; i < num_actuals; ++i)
3117 if (args[i].aligned_regs)
3118 free (args[i].aligned_regs);
3119
3120 insns = get_insns ();
3121 end_sequence ();
3122
3123 if (pass == 0)
3124 {
3125 tail_call_insns = insns;
3126
3127 /* Restore the pending stack adjustment now that we have
3128 finished generating the sibling call sequence. */
3129
3130 pending_stack_adjust = save_pending_stack_adjust;
3131 stack_pointer_delta = save_stack_pointer_delta;
3132
3133 /* Prepare arg structure for next iteration. */
3134 for (i = 0; i < num_actuals; i++)
3135 {
3136 args[i].value = 0;
3137 args[i].aligned_regs = 0;
3138 args[i].stack = 0;
3139 }
3140
3141 sbitmap_free (stored_args_map);
3142 }
3143 else
3144 {
3145 normal_call_insns = insns;
3146
3147 /* Verify that we've deallocated all the stack we used. */
3148 gcc_assert ((flags & ECF_NORETURN)
3149 || (old_stack_allocated
3150 == stack_pointer_delta - pending_stack_adjust));
3151 }
3152
3153 /* If something prevents making this a sibling call,
3154 zero out the sequence. */
3155 if (sibcall_failure)
3156 tail_call_insns = NULL_RTX;
3157 else
3158 break;
3159 }
3160
3161 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3162 arguments too, as argument area is now clobbered by the call. */
3163 if (tail_call_insns)
3164 {
3165 emit_insn (tail_call_insns);
3166 crtl->tail_call_emit = true;
3167 }
3168 else
3169 emit_insn (normal_call_insns);
3170
3171 currently_expanding_call--;
3172
3173 if (stack_usage_map_buf)
3174 free (stack_usage_map_buf);
3175
3176 return target;
3177 }
3178
3179 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3180 this function's incoming arguments.
3181
3182 At the start of RTL generation we know the only REG_EQUIV notes
3183 in the rtl chain are those for incoming arguments, so we can look
3184 for REG_EQUIV notes between the start of the function and the
3185 NOTE_INSN_FUNCTION_BEG.
3186
3187 This is (slight) overkill. We could keep track of the highest
3188 argument we clobber and be more selective in removing notes, but it
3189 does not seem to be worth the effort. */
3190
3191 void
3192 fixup_tail_calls (void)
3193 {
3194 rtx insn;
3195
3196 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3197 {
3198 rtx note;
3199
3200 /* There are never REG_EQUIV notes for the incoming arguments
3201 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3202 if (NOTE_P (insn)
3203 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3204 break;
3205
3206 note = find_reg_note (insn, REG_EQUIV, 0);
3207 if (note)
3208 remove_note (insn, note);
3209 note = find_reg_note (insn, REG_EQUIV, 0);
3210 gcc_assert (!note);
3211 }
3212 }
3213
3214 /* Traverse a list of TYPES and expand all complex types into their
3215 components. */
3216 static tree
3217 split_complex_types (tree types)
3218 {
3219 tree p;
3220
3221 /* Before allocating memory, check for the common case of no complex. */
3222 for (p = types; p; p = TREE_CHAIN (p))
3223 {
3224 tree type = TREE_VALUE (p);
3225 if (TREE_CODE (type) == COMPLEX_TYPE
3226 && targetm.calls.split_complex_arg (type))
3227 goto found;
3228 }
3229 return types;
3230
3231 found:
3232 types = copy_list (types);
3233
3234 for (p = types; p; p = TREE_CHAIN (p))
3235 {
3236 tree complex_type = TREE_VALUE (p);
3237
3238 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3239 && targetm.calls.split_complex_arg (complex_type))
3240 {
3241 tree next, imag;
3242
3243 /* Rewrite complex type with component type. */
3244 TREE_VALUE (p) = TREE_TYPE (complex_type);
3245 next = TREE_CHAIN (p);
3246
3247 /* Add another component type for the imaginary part. */
3248 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3249 TREE_CHAIN (p) = imag;
3250 TREE_CHAIN (imag) = next;
3251
3252 /* Skip the newly created node. */
3253 p = TREE_CHAIN (p);
3254 }
3255 }
3256
3257 return types;
3258 }
3259
3260 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3261 The RETVAL parameter specifies whether return value needs to be saved, other
3262 parameters are documented in the emit_library_call function below. */
3263
3264 static rtx
3265 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3266 enum libcall_type fn_type,
3267 enum machine_mode outmode, int nargs, va_list p)
3268 {
3269 /* Total size in bytes of all the stack-parms scanned so far. */
3270 struct args_size args_size;
3271 /* Size of arguments before any adjustments (such as rounding). */
3272 struct args_size original_args_size;
3273 int argnum;
3274 rtx fun;
3275 /* Todo, choose the correct decl type of orgfun. Sadly this information
3276 isn't present here, so we default to native calling abi here. */
3277 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3278 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3279 int inc;
3280 int count;
3281 rtx argblock = 0;
3282 CUMULATIVE_ARGS args_so_far;
3283 struct arg
3284 {
3285 rtx value;
3286 enum machine_mode mode;
3287 rtx reg;
3288 int partial;
3289 struct locate_and_pad_arg_data locate;
3290 rtx save_area;
3291 };
3292 struct arg *argvec;
3293 int old_inhibit_defer_pop = inhibit_defer_pop;
3294 rtx call_fusage = 0;
3295 rtx mem_value = 0;
3296 rtx valreg;
3297 int pcc_struct_value = 0;
3298 int struct_value_size = 0;
3299 int flags;
3300 int reg_parm_stack_space = 0;
3301 int needed;
3302 rtx before_call;
3303 tree tfom; /* type_for_mode (outmode, 0) */
3304
3305 #ifdef REG_PARM_STACK_SPACE
3306 /* Define the boundary of the register parm stack space that needs to be
3307 save, if any. */
3308 int low_to_save = 0, high_to_save = 0;
3309 rtx save_area = 0; /* Place that it is saved. */
3310 #endif
3311
3312 /* Size of the stack reserved for parameter registers. */
3313 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3314 char *initial_stack_usage_map = stack_usage_map;
3315 char *stack_usage_map_buf = NULL;
3316
3317 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3318
3319 #ifdef REG_PARM_STACK_SPACE
3320 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3321 #endif
3322
3323 /* By default, library functions can not throw. */
3324 flags = ECF_NOTHROW;
3325
3326 switch (fn_type)
3327 {
3328 case LCT_NORMAL:
3329 break;
3330 case LCT_CONST:
3331 flags |= ECF_CONST;
3332 break;
3333 case LCT_PURE:
3334 flags |= ECF_PURE;
3335 break;
3336 case LCT_NORETURN:
3337 flags |= ECF_NORETURN;
3338 break;
3339 case LCT_THROW:
3340 flags = ECF_NORETURN;
3341 break;
3342 case LCT_RETURNS_TWICE:
3343 flags = ECF_RETURNS_TWICE;
3344 break;
3345 }
3346 fun = orgfun;
3347
3348 /* Ensure current function's preferred stack boundary is at least
3349 what we need. */
3350 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3351 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3352
3353 /* If this kind of value comes back in memory,
3354 decide where in memory it should come back. */
3355 if (outmode != VOIDmode)
3356 {
3357 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3358 if (aggregate_value_p (tfom, 0))
3359 {
3360 #ifdef PCC_STATIC_STRUCT_RETURN
3361 rtx pointer_reg
3362 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3363 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3364 pcc_struct_value = 1;
3365 if (value == 0)
3366 value = gen_reg_rtx (outmode);
3367 #else /* not PCC_STATIC_STRUCT_RETURN */
3368 struct_value_size = GET_MODE_SIZE (outmode);
3369 if (value != 0 && MEM_P (value))
3370 mem_value = value;
3371 else
3372 mem_value = assign_temp (tfom, 0, 1, 1);
3373 #endif
3374 /* This call returns a big structure. */
3375 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3376 }
3377 }
3378 else
3379 tfom = void_type_node;
3380
3381 /* ??? Unfinished: must pass the memory address as an argument. */
3382
3383 /* Copy all the libcall-arguments out of the varargs data
3384 and into a vector ARGVEC.
3385
3386 Compute how to pass each argument. We only support a very small subset
3387 of the full argument passing conventions to limit complexity here since
3388 library functions shouldn't have many args. */
3389
3390 argvec = XALLOCAVEC (struct arg, nargs + 1);
3391 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3392
3393 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3394 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3395 #else
3396 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3397 #endif
3398
3399 args_size.constant = 0;
3400 args_size.var = 0;
3401
3402 count = 0;
3403
3404 push_temp_slots ();
3405
3406 /* If there's a structure value address to be passed,
3407 either pass it in the special place, or pass it as an extra argument. */
3408 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3409 {
3410 rtx addr = XEXP (mem_value, 0);
3411
3412 nargs++;
3413
3414 /* Make sure it is a reasonable operand for a move or push insn. */
3415 if (!REG_P (addr) && !MEM_P (addr)
3416 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3417 addr = force_operand (addr, NULL_RTX);
3418
3419 argvec[count].value = addr;
3420 argvec[count].mode = Pmode;
3421 argvec[count].partial = 0;
3422
3423 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3424 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3425 NULL_TREE, 1) == 0);
3426
3427 locate_and_pad_parm (Pmode, NULL_TREE,
3428 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3429 1,
3430 #else
3431 argvec[count].reg != 0,
3432 #endif
3433 0, NULL_TREE, &args_size, &argvec[count].locate);
3434
3435 if (argvec[count].reg == 0 || argvec[count].partial != 0
3436 || reg_parm_stack_space > 0)
3437 args_size.constant += argvec[count].locate.size.constant;
3438
3439 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3440
3441 count++;
3442 }
3443
3444 for (; count < nargs; count++)
3445 {
3446 rtx val = va_arg (p, rtx);
3447 enum machine_mode mode = va_arg (p, enum machine_mode);
3448
3449 /* We cannot convert the arg value to the mode the library wants here;
3450 must do it earlier where we know the signedness of the arg. */
3451 gcc_assert (mode != BLKmode
3452 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3453
3454 /* Make sure it is a reasonable operand for a move or push insn. */
3455 if (!REG_P (val) && !MEM_P (val)
3456 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3457 val = force_operand (val, NULL_RTX);
3458
3459 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3460 {
3461 rtx slot;
3462 int must_copy
3463 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3464
3465 /* If this was a CONST function, it is now PURE since it now
3466 reads memory. */
3467 if (flags & ECF_CONST)
3468 {
3469 flags &= ~ECF_CONST;
3470 flags |= ECF_PURE;
3471 }
3472
3473 if (MEM_P (val) && !must_copy)
3474 slot = val;
3475 else
3476 {
3477 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3478 0, 1, 1);
3479 emit_move_insn (slot, val);
3480 }
3481
3482 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3483 gen_rtx_USE (VOIDmode, slot),
3484 call_fusage);
3485 if (must_copy)
3486 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3487 gen_rtx_CLOBBER (VOIDmode,
3488 slot),
3489 call_fusage);
3490
3491 mode = Pmode;
3492 val = force_operand (XEXP (slot, 0), NULL_RTX);
3493 }
3494
3495 argvec[count].value = val;
3496 argvec[count].mode = mode;
3497
3498 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3499
3500 argvec[count].partial
3501 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3502
3503 locate_and_pad_parm (mode, NULL_TREE,
3504 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3505 1,
3506 #else
3507 argvec[count].reg != 0,
3508 #endif
3509 argvec[count].partial,
3510 NULL_TREE, &args_size, &argvec[count].locate);
3511
3512 gcc_assert (!argvec[count].locate.size.var);
3513
3514 if (argvec[count].reg == 0 || argvec[count].partial != 0
3515 || reg_parm_stack_space > 0)
3516 args_size.constant += argvec[count].locate.size.constant;
3517
3518 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3519 }
3520
3521 /* If this machine requires an external definition for library
3522 functions, write one out. */
3523 assemble_external_libcall (fun);
3524
3525 original_args_size = args_size;
3526 args_size.constant = (((args_size.constant
3527 + stack_pointer_delta
3528 + STACK_BYTES - 1)
3529 / STACK_BYTES
3530 * STACK_BYTES)
3531 - stack_pointer_delta);
3532
3533 args_size.constant = MAX (args_size.constant,
3534 reg_parm_stack_space);
3535
3536 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3537 args_size.constant -= reg_parm_stack_space;
3538
3539 if (args_size.constant > crtl->outgoing_args_size)
3540 crtl->outgoing_args_size = args_size.constant;
3541
3542 if (ACCUMULATE_OUTGOING_ARGS)
3543 {
3544 /* Since the stack pointer will never be pushed, it is possible for
3545 the evaluation of a parm to clobber something we have already
3546 written to the stack. Since most function calls on RISC machines
3547 do not use the stack, this is uncommon, but must work correctly.
3548
3549 Therefore, we save any area of the stack that was already written
3550 and that we are using. Here we set up to do this by making a new
3551 stack usage map from the old one.
3552
3553 Another approach might be to try to reorder the argument
3554 evaluations to avoid this conflicting stack usage. */
3555
3556 needed = args_size.constant;
3557
3558 /* Since we will be writing into the entire argument area, the
3559 map must be allocated for its entire size, not just the part that
3560 is the responsibility of the caller. */
3561 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3562 needed += reg_parm_stack_space;
3563
3564 #ifdef ARGS_GROW_DOWNWARD
3565 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3566 needed + 1);
3567 #else
3568 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3569 needed);
3570 #endif
3571 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3572 stack_usage_map = stack_usage_map_buf;
3573
3574 if (initial_highest_arg_in_use)
3575 memcpy (stack_usage_map, initial_stack_usage_map,
3576 initial_highest_arg_in_use);
3577
3578 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3579 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3580 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3581 needed = 0;
3582
3583 /* We must be careful to use virtual regs before they're instantiated,
3584 and real regs afterwards. Loop optimization, for example, can create
3585 new libcalls after we've instantiated the virtual regs, and if we
3586 use virtuals anyway, they won't match the rtl patterns. */
3587
3588 if (virtuals_instantiated)
3589 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3590 else
3591 argblock = virtual_outgoing_args_rtx;
3592 }
3593 else
3594 {
3595 if (!PUSH_ARGS)
3596 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3597 }
3598
3599 /* If we push args individually in reverse order, perform stack alignment
3600 before the first push (the last arg). */
3601 if (argblock == 0 && PUSH_ARGS_REVERSED)
3602 anti_adjust_stack (GEN_INT (args_size.constant
3603 - original_args_size.constant));
3604
3605 if (PUSH_ARGS_REVERSED)
3606 {
3607 inc = -1;
3608 argnum = nargs - 1;
3609 }
3610 else
3611 {
3612 inc = 1;
3613 argnum = 0;
3614 }
3615
3616 #ifdef REG_PARM_STACK_SPACE
3617 if (ACCUMULATE_OUTGOING_ARGS)
3618 {
3619 /* The argument list is the property of the called routine and it
3620 may clobber it. If the fixed area has been used for previous
3621 parameters, we must save and restore it. */
3622 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3623 &low_to_save, &high_to_save);
3624 }
3625 #endif
3626
3627 /* Push the args that need to be pushed. */
3628
3629 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3630 are to be pushed. */
3631 for (count = 0; count < nargs; count++, argnum += inc)
3632 {
3633 enum machine_mode mode = argvec[argnum].mode;
3634 rtx val = argvec[argnum].value;
3635 rtx reg = argvec[argnum].reg;
3636 int partial = argvec[argnum].partial;
3637 int lower_bound = 0, upper_bound = 0, i;
3638
3639 if (! (reg != 0 && partial == 0))
3640 {
3641 if (ACCUMULATE_OUTGOING_ARGS)
3642 {
3643 /* If this is being stored into a pre-allocated, fixed-size,
3644 stack area, save any previous data at that location. */
3645
3646 #ifdef ARGS_GROW_DOWNWARD
3647 /* stack_slot is negative, but we want to index stack_usage_map
3648 with positive values. */
3649 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3650 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3651 #else
3652 lower_bound = argvec[argnum].locate.slot_offset.constant;
3653 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3654 #endif
3655
3656 i = lower_bound;
3657 /* Don't worry about things in the fixed argument area;
3658 it has already been saved. */
3659 if (i < reg_parm_stack_space)
3660 i = reg_parm_stack_space;
3661 while (i < upper_bound && stack_usage_map[i] == 0)
3662 i++;
3663
3664 if (i < upper_bound)
3665 {
3666 /* We need to make a save area. */
3667 unsigned int size
3668 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3669 enum machine_mode save_mode
3670 = mode_for_size (size, MODE_INT, 1);
3671 rtx adr
3672 = plus_constant (argblock,
3673 argvec[argnum].locate.offset.constant);
3674 rtx stack_area
3675 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3676
3677 if (save_mode == BLKmode)
3678 {
3679 argvec[argnum].save_area
3680 = assign_stack_temp (BLKmode,
3681 argvec[argnum].locate.size.constant,
3682 0);
3683
3684 emit_block_move (validize_mem (argvec[argnum].save_area),
3685 stack_area,
3686 GEN_INT (argvec[argnum].locate.size.constant),
3687 BLOCK_OP_CALL_PARM);
3688 }
3689 else
3690 {
3691 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3692
3693 emit_move_insn (argvec[argnum].save_area, stack_area);
3694 }
3695 }
3696 }
3697
3698 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3699 partial, reg, 0, argblock,
3700 GEN_INT (argvec[argnum].locate.offset.constant),
3701 reg_parm_stack_space,
3702 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3703
3704 /* Now mark the segment we just used. */
3705 if (ACCUMULATE_OUTGOING_ARGS)
3706 for (i = lower_bound; i < upper_bound; i++)
3707 stack_usage_map[i] = 1;
3708
3709 NO_DEFER_POP;
3710
3711 if ((flags & ECF_CONST)
3712 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
3713 {
3714 rtx use;
3715
3716 /* Indicate argument access so that alias.c knows that these
3717 values are live. */
3718 if (argblock)
3719 use = plus_constant (argblock,
3720 argvec[argnum].locate.offset.constant);
3721 else
3722 /* When arguments are pushed, trying to tell alias.c where
3723 exactly this argument is won't work, because the
3724 auto-increment causes confusion. So we merely indicate
3725 that we access something with a known mode somewhere on
3726 the stack. */
3727 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3728 gen_rtx_SCRATCH (Pmode));
3729 use = gen_rtx_MEM (argvec[argnum].mode, use);
3730 use = gen_rtx_USE (VOIDmode, use);
3731 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3732 }
3733 }
3734 }
3735
3736 /* If we pushed args in forward order, perform stack alignment
3737 after pushing the last arg. */
3738 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3739 anti_adjust_stack (GEN_INT (args_size.constant
3740 - original_args_size.constant));
3741
3742 if (PUSH_ARGS_REVERSED)
3743 argnum = nargs - 1;
3744 else
3745 argnum = 0;
3746
3747 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3748
3749 /* Now load any reg parms into their regs. */
3750
3751 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3752 are to be pushed. */
3753 for (count = 0; count < nargs; count++, argnum += inc)
3754 {
3755 enum machine_mode mode = argvec[argnum].mode;
3756 rtx val = argvec[argnum].value;
3757 rtx reg = argvec[argnum].reg;
3758 int partial = argvec[argnum].partial;
3759
3760 /* Handle calls that pass values in multiple non-contiguous
3761 locations. The PA64 has examples of this for library calls. */
3762 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3763 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3764 else if (reg != 0 && partial == 0)
3765 emit_move_insn (reg, val);
3766
3767 NO_DEFER_POP;
3768 }
3769
3770 /* Any regs containing parms remain in use through the call. */
3771 for (count = 0; count < nargs; count++)
3772 {
3773 rtx reg = argvec[count].reg;
3774 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3775 use_group_regs (&call_fusage, reg);
3776 else if (reg != 0)
3777 {
3778 int partial = argvec[count].partial;
3779 if (partial)
3780 {
3781 int nregs;
3782 gcc_assert (partial % UNITS_PER_WORD == 0);
3783 nregs = partial / UNITS_PER_WORD;
3784 use_regs (&call_fusage, REGNO (reg), nregs);
3785 }
3786 else
3787 use_reg (&call_fusage, reg);
3788 }
3789 }
3790
3791 /* Pass the function the address in which to return a structure value. */
3792 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3793 {
3794 emit_move_insn (struct_value,
3795 force_reg (Pmode,
3796 force_operand (XEXP (mem_value, 0),
3797 NULL_RTX)));
3798 if (REG_P (struct_value))
3799 use_reg (&call_fusage, struct_value);
3800 }
3801
3802 /* Don't allow popping to be deferred, since then
3803 cse'ing of library calls could delete a call and leave the pop. */
3804 NO_DEFER_POP;
3805 valreg = (mem_value == 0 && outmode != VOIDmode
3806 ? hard_libcall_value (outmode) : NULL_RTX);
3807
3808 /* Stack must be properly aligned now. */
3809 gcc_assert (!(stack_pointer_delta
3810 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3811
3812 before_call = get_last_insn ();
3813
3814 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3815 will set inhibit_defer_pop to that value. */
3816 /* The return type is needed to decide how many bytes the function pops.
3817 Signedness plays no role in that, so for simplicity, we pretend it's
3818 always signed. We also assume that the list of arguments passed has
3819 no impact, so we pretend it is unknown. */
3820
3821 emit_call_1 (fun, NULL,
3822 get_identifier (XSTR (orgfun, 0)),
3823 build_function_type (tfom, NULL_TREE),
3824 original_args_size.constant, args_size.constant,
3825 struct_value_size,
3826 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3827 valreg,
3828 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3829
3830 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3831 that it should complain if nonvolatile values are live. For
3832 functions that cannot return, inform flow that control does not
3833 fall through. */
3834
3835 if (flags & ECF_NORETURN)
3836 {
3837 /* The barrier note must be emitted
3838 immediately after the CALL_INSN. Some ports emit more than
3839 just a CALL_INSN above, so we must search for it here. */
3840
3841 rtx last = get_last_insn ();
3842 while (!CALL_P (last))
3843 {
3844 last = PREV_INSN (last);
3845 /* There was no CALL_INSN? */
3846 gcc_assert (last != before_call);
3847 }
3848
3849 emit_barrier_after (last);
3850 }
3851
3852 /* Now restore inhibit_defer_pop to its actual original value. */
3853 OK_DEFER_POP;
3854
3855 pop_temp_slots ();
3856
3857 /* Copy the value to the right place. */
3858 if (outmode != VOIDmode && retval)
3859 {
3860 if (mem_value)
3861 {
3862 if (value == 0)
3863 value = mem_value;
3864 if (value != mem_value)
3865 emit_move_insn (value, mem_value);
3866 }
3867 else if (GET_CODE (valreg) == PARALLEL)
3868 {
3869 if (value == 0)
3870 value = gen_reg_rtx (outmode);
3871 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3872 }
3873 else
3874 {
3875 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3876 if (GET_MODE (valreg) != outmode)
3877 {
3878 int unsignedp = TYPE_UNSIGNED (tfom);
3879
3880 gcc_assert (targetm.calls.promote_function_return (tfom));
3881 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3882 == GET_MODE (valreg));
3883
3884 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3885 }
3886
3887 if (value != 0)
3888 emit_move_insn (value, valreg);
3889 else
3890 value = valreg;
3891 }
3892 }
3893
3894 if (ACCUMULATE_OUTGOING_ARGS)
3895 {
3896 #ifdef REG_PARM_STACK_SPACE
3897 if (save_area)
3898 restore_fixed_argument_area (save_area, argblock,
3899 high_to_save, low_to_save);
3900 #endif
3901
3902 /* If we saved any argument areas, restore them. */
3903 for (count = 0; count < nargs; count++)
3904 if (argvec[count].save_area)
3905 {
3906 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3907 rtx adr = plus_constant (argblock,
3908 argvec[count].locate.offset.constant);
3909 rtx stack_area = gen_rtx_MEM (save_mode,
3910 memory_address (save_mode, adr));
3911
3912 if (save_mode == BLKmode)
3913 emit_block_move (stack_area,
3914 validize_mem (argvec[count].save_area),
3915 GEN_INT (argvec[count].locate.size.constant),
3916 BLOCK_OP_CALL_PARM);
3917 else
3918 emit_move_insn (stack_area, argvec[count].save_area);
3919 }
3920
3921 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3922 stack_usage_map = initial_stack_usage_map;
3923 }
3924
3925 if (stack_usage_map_buf)
3926 free (stack_usage_map_buf);
3927
3928 return value;
3929
3930 }
3931
3932 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3933 (emitting the queue unless NO_QUEUE is nonzero),
3934 for a value of mode OUTMODE,
3935 with NARGS different arguments, passed as alternating rtx values
3936 and machine_modes to convert them to.
3937
3938 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3939 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3940 other types of library calls. */
3941
3942 void
3943 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3944 enum machine_mode outmode, int nargs, ...)
3945 {
3946 va_list p;
3947
3948 va_start (p, nargs);
3949 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3950 va_end (p);
3951 }
3952
3953 /* Like emit_library_call except that an extra argument, VALUE,
3954 comes second and says where to store the result.
3955 (If VALUE is zero, this function chooses a convenient way
3956 to return the value.
3957
3958 This function returns an rtx for where the value is to be found.
3959 If VALUE is nonzero, VALUE is returned. */
3960
3961 rtx
3962 emit_library_call_value (rtx orgfun, rtx value,
3963 enum libcall_type fn_type,
3964 enum machine_mode outmode, int nargs, ...)
3965 {
3966 rtx result;
3967 va_list p;
3968
3969 va_start (p, nargs);
3970 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3971 nargs, p);
3972 va_end (p);
3973
3974 return result;
3975 }
3976
3977 /* Store a single argument for a function call
3978 into the register or memory area where it must be passed.
3979 *ARG describes the argument value and where to pass it.
3980
3981 ARGBLOCK is the address of the stack-block for all the arguments,
3982 or 0 on a machine where arguments are pushed individually.
3983
3984 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3985 so must be careful about how the stack is used.
3986
3987 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3988 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3989 that we need not worry about saving and restoring the stack.
3990
3991 FNDECL is the declaration of the function we are calling.
3992
3993 Return nonzero if this arg should cause sibcall failure,
3994 zero otherwise. */
3995
3996 static int
3997 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3998 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3999 {
4000 tree pval = arg->tree_value;
4001 rtx reg = 0;
4002 int partial = 0;
4003 int used = 0;
4004 int i, lower_bound = 0, upper_bound = 0;
4005 int sibcall_failure = 0;
4006
4007 if (TREE_CODE (pval) == ERROR_MARK)
4008 return 1;
4009
4010 /* Push a new temporary level for any temporaries we make for
4011 this argument. */
4012 push_temp_slots ();
4013
4014 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4015 {
4016 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4017 save any previous data at that location. */
4018 if (argblock && ! variable_size && arg->stack)
4019 {
4020 #ifdef ARGS_GROW_DOWNWARD
4021 /* stack_slot is negative, but we want to index stack_usage_map
4022 with positive values. */
4023 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4024 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4025 else
4026 upper_bound = 0;
4027
4028 lower_bound = upper_bound - arg->locate.size.constant;
4029 #else
4030 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4031 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4032 else
4033 lower_bound = 0;
4034
4035 upper_bound = lower_bound + arg->locate.size.constant;
4036 #endif
4037
4038 i = lower_bound;
4039 /* Don't worry about things in the fixed argument area;
4040 it has already been saved. */
4041 if (i < reg_parm_stack_space)
4042 i = reg_parm_stack_space;
4043 while (i < upper_bound && stack_usage_map[i] == 0)
4044 i++;
4045
4046 if (i < upper_bound)
4047 {
4048 /* We need to make a save area. */
4049 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4050 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4051 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4052 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4053
4054 if (save_mode == BLKmode)
4055 {
4056 tree ot = TREE_TYPE (arg->tree_value);
4057 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4058 | TYPE_QUAL_CONST));
4059
4060 arg->save_area = assign_temp (nt, 0, 1, 1);
4061 preserve_temp_slots (arg->save_area);
4062 emit_block_move (validize_mem (arg->save_area), stack_area,
4063 GEN_INT (arg->locate.size.constant),
4064 BLOCK_OP_CALL_PARM);
4065 }
4066 else
4067 {
4068 arg->save_area = gen_reg_rtx (save_mode);
4069 emit_move_insn (arg->save_area, stack_area);
4070 }
4071 }
4072 }
4073 }
4074
4075 /* If this isn't going to be placed on both the stack and in registers,
4076 set up the register and number of words. */
4077 if (! arg->pass_on_stack)
4078 {
4079 if (flags & ECF_SIBCALL)
4080 reg = arg->tail_call_reg;
4081 else
4082 reg = arg->reg;
4083 partial = arg->partial;
4084 }
4085
4086 /* Being passed entirely in a register. We shouldn't be called in
4087 this case. */
4088 gcc_assert (reg == 0 || partial != 0);
4089
4090 /* If this arg needs special alignment, don't load the registers
4091 here. */
4092 if (arg->n_aligned_regs != 0)
4093 reg = 0;
4094
4095 /* If this is being passed partially in a register, we can't evaluate
4096 it directly into its stack slot. Otherwise, we can. */
4097 if (arg->value == 0)
4098 {
4099 /* stack_arg_under_construction is nonzero if a function argument is
4100 being evaluated directly into the outgoing argument list and
4101 expand_call must take special action to preserve the argument list
4102 if it is called recursively.
4103
4104 For scalar function arguments stack_usage_map is sufficient to
4105 determine which stack slots must be saved and restored. Scalar
4106 arguments in general have pass_on_stack == 0.
4107
4108 If this argument is initialized by a function which takes the
4109 address of the argument (a C++ constructor or a C function
4110 returning a BLKmode structure), then stack_usage_map is
4111 insufficient and expand_call must push the stack around the
4112 function call. Such arguments have pass_on_stack == 1.
4113
4114 Note that it is always safe to set stack_arg_under_construction,
4115 but this generates suboptimal code if set when not needed. */
4116
4117 if (arg->pass_on_stack)
4118 stack_arg_under_construction++;
4119
4120 arg->value = expand_expr (pval,
4121 (partial
4122 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4123 ? NULL_RTX : arg->stack,
4124 VOIDmode, EXPAND_STACK_PARM);
4125
4126 /* If we are promoting object (or for any other reason) the mode
4127 doesn't agree, convert the mode. */
4128
4129 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4130 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4131 arg->value, arg->unsignedp);
4132
4133 if (arg->pass_on_stack)
4134 stack_arg_under_construction--;
4135 }
4136
4137 /* Check for overlap with already clobbered argument area. */
4138 if ((flags & ECF_SIBCALL)
4139 && MEM_P (arg->value)
4140 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4141 arg->locate.size.constant))
4142 sibcall_failure = 1;
4143
4144 /* Don't allow anything left on stack from computation
4145 of argument to alloca. */
4146 if (flags & ECF_MAY_BE_ALLOCA)
4147 do_pending_stack_adjust ();
4148
4149 if (arg->value == arg->stack)
4150 /* If the value is already in the stack slot, we are done. */
4151 ;
4152 else if (arg->mode != BLKmode)
4153 {
4154 int size;
4155 unsigned int parm_align;
4156
4157 /* Argument is a scalar, not entirely passed in registers.
4158 (If part is passed in registers, arg->partial says how much
4159 and emit_push_insn will take care of putting it there.)
4160
4161 Push it, and if its size is less than the
4162 amount of space allocated to it,
4163 also bump stack pointer by the additional space.
4164 Note that in C the default argument promotions
4165 will prevent such mismatches. */
4166
4167 size = GET_MODE_SIZE (arg->mode);
4168 /* Compute how much space the push instruction will push.
4169 On many machines, pushing a byte will advance the stack
4170 pointer by a halfword. */
4171 #ifdef PUSH_ROUNDING
4172 size = PUSH_ROUNDING (size);
4173 #endif
4174 used = size;
4175
4176 /* Compute how much space the argument should get:
4177 round up to a multiple of the alignment for arguments. */
4178 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4179 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4180 / (PARM_BOUNDARY / BITS_PER_UNIT))
4181 * (PARM_BOUNDARY / BITS_PER_UNIT));
4182
4183 /* Compute the alignment of the pushed argument. */
4184 parm_align = arg->locate.boundary;
4185 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4186 {
4187 int pad = used - size;
4188 if (pad)
4189 {
4190 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4191 parm_align = MIN (parm_align, pad_align);
4192 }
4193 }
4194
4195 /* This isn't already where we want it on the stack, so put it there.
4196 This can either be done with push or copy insns. */
4197 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4198 parm_align, partial, reg, used - size, argblock,
4199 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4200 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4201
4202 /* Unless this is a partially-in-register argument, the argument is now
4203 in the stack. */
4204 if (partial == 0)
4205 arg->value = arg->stack;
4206 }
4207 else
4208 {
4209 /* BLKmode, at least partly to be pushed. */
4210
4211 unsigned int parm_align;
4212 int excess;
4213 rtx size_rtx;
4214
4215 /* Pushing a nonscalar.
4216 If part is passed in registers, PARTIAL says how much
4217 and emit_push_insn will take care of putting it there. */
4218
4219 /* Round its size up to a multiple
4220 of the allocation unit for arguments. */
4221
4222 if (arg->locate.size.var != 0)
4223 {
4224 excess = 0;
4225 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4226 }
4227 else
4228 {
4229 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4230 for BLKmode is careful to avoid it. */
4231 excess = (arg->locate.size.constant
4232 - int_size_in_bytes (TREE_TYPE (pval))
4233 + partial);
4234 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4235 NULL_RTX, TYPE_MODE (sizetype), 0);
4236 }
4237
4238 parm_align = arg->locate.boundary;
4239
4240 /* When an argument is padded down, the block is aligned to
4241 PARM_BOUNDARY, but the actual argument isn't. */
4242 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4243 {
4244 if (arg->locate.size.var)
4245 parm_align = BITS_PER_UNIT;
4246 else if (excess)
4247 {
4248 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4249 parm_align = MIN (parm_align, excess_align);
4250 }
4251 }
4252
4253 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4254 {
4255 /* emit_push_insn might not work properly if arg->value and
4256 argblock + arg->locate.offset areas overlap. */
4257 rtx x = arg->value;
4258 int i = 0;
4259
4260 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4261 || (GET_CODE (XEXP (x, 0)) == PLUS
4262 && XEXP (XEXP (x, 0), 0) ==
4263 crtl->args.internal_arg_pointer
4264 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4265 {
4266 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4267 i = INTVAL (XEXP (XEXP (x, 0), 1));
4268
4269 /* expand_call should ensure this. */
4270 gcc_assert (!arg->locate.offset.var
4271 && arg->locate.size.var == 0
4272 && GET_CODE (size_rtx) == CONST_INT);
4273
4274 if (arg->locate.offset.constant > i)
4275 {
4276 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4277 sibcall_failure = 1;
4278 }
4279 else if (arg->locate.offset.constant < i)
4280 {
4281 /* Use arg->locate.size.constant instead of size_rtx
4282 because we only care about the part of the argument
4283 on the stack. */
4284 if (i < (arg->locate.offset.constant
4285 + arg->locate.size.constant))
4286 sibcall_failure = 1;
4287 }
4288 else
4289 {
4290 /* Even though they appear to be at the same location,
4291 if part of the outgoing argument is in registers,
4292 they aren't really at the same location. Check for
4293 this by making sure that the incoming size is the
4294 same as the outgoing size. */
4295 if (arg->locate.size.constant != INTVAL (size_rtx))
4296 sibcall_failure = 1;
4297 }
4298 }
4299 }
4300
4301 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4302 parm_align, partial, reg, excess, argblock,
4303 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4304 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4305
4306 /* Unless this is a partially-in-register argument, the argument is now
4307 in the stack.
4308
4309 ??? Unlike the case above, in which we want the actual
4310 address of the data, so that we can load it directly into a
4311 register, here we want the address of the stack slot, so that
4312 it's properly aligned for word-by-word copying or something
4313 like that. It's not clear that this is always correct. */
4314 if (partial == 0)
4315 arg->value = arg->stack_slot;
4316 }
4317
4318 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4319 {
4320 tree type = TREE_TYPE (arg->tree_value);
4321 arg->parallel_value
4322 = emit_group_load_into_temps (arg->reg, arg->value, type,
4323 int_size_in_bytes (type));
4324 }
4325
4326 /* Mark all slots this store used. */
4327 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4328 && argblock && ! variable_size && arg->stack)
4329 for (i = lower_bound; i < upper_bound; i++)
4330 stack_usage_map[i] = 1;
4331
4332 /* Once we have pushed something, pops can't safely
4333 be deferred during the rest of the arguments. */
4334 NO_DEFER_POP;
4335
4336 /* Free any temporary slots made in processing this argument. Show
4337 that we might have taken the address of something and pushed that
4338 as an operand. */
4339 preserve_temp_slots (NULL_RTX);
4340 free_temp_slots ();
4341 pop_temp_slots ();
4342
4343 return sibcall_failure;
4344 }
4345
4346 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4347
4348 bool
4349 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4350 const_tree type)
4351 {
4352 if (!type)
4353 return false;
4354
4355 /* If the type has variable size... */
4356 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4357 return true;
4358
4359 /* If the type is marked as addressable (it is required
4360 to be constructed into the stack)... */
4361 if (TREE_ADDRESSABLE (type))
4362 return true;
4363
4364 return false;
4365 }
4366
4367 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4368 takes trailing padding of a structure into account. */
4369 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4370
4371 bool
4372 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4373 {
4374 if (!type)
4375 return false;
4376
4377 /* If the type has variable size... */
4378 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4379 return true;
4380
4381 /* If the type is marked as addressable (it is required
4382 to be constructed into the stack)... */
4383 if (TREE_ADDRESSABLE (type))
4384 return true;
4385
4386 /* If the padding and mode of the type is such that a copy into
4387 a register would put it into the wrong part of the register. */
4388 if (mode == BLKmode
4389 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4390 && (FUNCTION_ARG_PADDING (mode, type)
4391 == (BYTES_BIG_ENDIAN ? upward : downward)))
4392 return true;
4393
4394 return false;
4395 }