2012-12-01 Alessandro Fanfarillo <alessandro.fanfarillo@gmail.com>
[official-gcc.git] / gcc / calls.c
blob574c247f0e50257fa3640db70c6f1b89f2bf6e71
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, 2010,
4 2011, 2012 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 3, or (at your option) any later
11 version.
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
16 for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 #include "config.h"
23 #include "system.h"
24 #include "coretypes.h"
25 #include "tm.h"
26 #include "rtl.h"
27 #include "tree.h"
28 #include "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 "diagnostic-core.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"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
52 struct arg_data
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 TARGET_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;
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;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
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;
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;
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_t);
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_t, 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);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
153 unsigned int);
154 static tree split_complex_types (tree);
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
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.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (tree fndecl, rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
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 = ((reg_parm_seen
178 && targetm.small_register_classes_for_mode_p (FUNCTION_MODE))
179 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
180 : memory_address (FUNCTION_MODE, funexp));
181 else if (! sibcallp)
183 #ifndef NO_FUNCTION_CSE
184 if (optimize && ! flag_no_function_cse)
185 funexp = force_reg (Pmode, funexp);
186 #endif
189 if (static_chain_value != 0)
191 rtx chain;
193 gcc_assert (fndecl);
194 chain = targetm.calls.static_chain (fndecl, false);
195 static_chain_value = convert_memory_address (Pmode, static_chain_value);
197 emit_move_insn (chain, static_chain_value);
198 if (REG_P (chain))
199 use_reg (call_fusage, chain);
202 return funexp;
205 /* Generate instructions to call function FUNEXP,
206 and optionally pop the results.
207 The CALL_INSN is the first insn generated.
209 FNDECL is the declaration node of the function. This is given to the
210 hook TARGET_RETURN_POPS_ARGS to determine whether this function pops
211 its own args.
213 FUNTYPE is the data type of the function. This is given to the hook
214 TARGET_RETURN_POPS_ARGS to determine whether this function pops its
215 own args. We used to allow an identifier for library functions, but
216 that doesn't work when the return type is an aggregate type and the
217 calling convention says that the pointer to this aggregate is to be
218 popped by the callee.
220 STACK_SIZE is the number of bytes of arguments on the stack,
221 ROUNDED_STACK_SIZE is that number rounded up to
222 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
223 both to put into the call insn and to generate explicit popping
224 code if necessary.
226 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
227 It is zero if this call doesn't want a structure value.
229 NEXT_ARG_REG is the rtx that results from executing
230 targetm.calls.function_arg (&args_so_far, VOIDmode, void_type_node, true)
231 just after all the args have had their registers assigned.
232 This could be whatever you like, but normally it is the first
233 arg-register beyond those used for args in this call,
234 or 0 if all the arg-registers are used in this call.
235 It is passed on to `gen_call' so you can put this info in the call insn.
237 VALREG is a hard register in which a value is returned,
238 or 0 if the call does not return a value.
240 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
241 the args to this call were processed.
242 We restore `inhibit_defer_pop' to that value.
244 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
245 denote registers used by the called function. */
247 static void
248 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
249 tree funtype ATTRIBUTE_UNUSED,
250 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
251 HOST_WIDE_INT rounded_stack_size,
252 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
253 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
254 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
255 cumulative_args_t args_so_far ATTRIBUTE_UNUSED)
257 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
258 rtx call_insn, call, funmem;
259 int already_popped = 0;
260 HOST_WIDE_INT n_popped
261 = targetm.calls.return_pops_args (fndecl, funtype, stack_size);
263 #ifdef CALL_POPS_ARGS
264 n_popped += CALL_POPS_ARGS (*get_cumulative_args (args_so_far));
265 #endif
267 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
268 and we don't want to load it into a register as an optimization,
269 because prepare_call_address already did it if it should be done. */
270 if (GET_CODE (funexp) != SYMBOL_REF)
271 funexp = memory_address (FUNCTION_MODE, funexp);
273 funmem = gen_rtx_MEM (FUNCTION_MODE, funexp);
274 if (fndecl && TREE_CODE (fndecl) == FUNCTION_DECL)
276 tree t = fndecl;
278 /* Although a built-in FUNCTION_DECL and its non-__builtin
279 counterpart compare equal and get a shared mem_attrs, they
280 produce different dump output in compare-debug compilations,
281 if an entry gets garbage collected in one compilation, then
282 adds a different (but equivalent) entry, while the other
283 doesn't run the garbage collector at the same spot and then
284 shares the mem_attr with the equivalent entry. */
285 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL)
287 tree t2 = builtin_decl_explicit (DECL_FUNCTION_CODE (t));
288 if (t2)
289 t = t2;
292 set_mem_expr (funmem, t);
294 else if (fntree)
295 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
297 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
298 if ((ecf_flags & ECF_SIBCALL)
299 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
300 && (n_popped > 0 || stack_size == 0))
302 rtx n_pop = GEN_INT (n_popped);
303 rtx pat;
305 /* If this subroutine pops its own args, record that in the call insn
306 if possible, for the sake of frame pointer elimination. */
308 if (valreg)
309 pat = GEN_SIBCALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
310 next_arg_reg, n_pop);
311 else
312 pat = GEN_SIBCALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
313 n_pop);
315 emit_call_insn (pat);
316 already_popped = 1;
318 else
319 #endif
321 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
322 /* If the target has "call" or "call_value" insns, then prefer them
323 if no arguments are actually popped. If the target does not have
324 "call" or "call_value" insns, then we must use the popping versions
325 even if the call has no arguments to pop. */
326 #if defined (HAVE_call) && defined (HAVE_call_value)
327 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
328 && n_popped > 0)
329 #else
330 if (HAVE_call_pop && HAVE_call_value_pop)
331 #endif
333 rtx n_pop = GEN_INT (n_popped);
334 rtx pat;
336 /* If this subroutine pops its own args, record that in the call insn
337 if possible, for the sake of frame pointer elimination. */
339 if (valreg)
340 pat = GEN_CALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
341 next_arg_reg, n_pop);
342 else
343 pat = GEN_CALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
344 n_pop);
346 emit_call_insn (pat);
347 already_popped = 1;
349 else
350 #endif
352 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
353 if ((ecf_flags & ECF_SIBCALL)
354 && HAVE_sibcall && HAVE_sibcall_value)
356 if (valreg)
357 emit_call_insn (GEN_SIBCALL_VALUE (valreg, funmem,
358 rounded_stack_size_rtx,
359 next_arg_reg, NULL_RTX));
360 else
361 emit_call_insn (GEN_SIBCALL (funmem, rounded_stack_size_rtx,
362 next_arg_reg,
363 GEN_INT (struct_value_size)));
365 else
366 #endif
368 #if defined (HAVE_call) && defined (HAVE_call_value)
369 if (HAVE_call && HAVE_call_value)
371 if (valreg)
372 emit_call_insn (GEN_CALL_VALUE (valreg, funmem, rounded_stack_size_rtx,
373 next_arg_reg, NULL_RTX));
374 else
375 emit_call_insn (GEN_CALL (funmem, rounded_stack_size_rtx, next_arg_reg,
376 GEN_INT (struct_value_size)));
378 else
379 #endif
380 gcc_unreachable ();
382 /* Find the call we just emitted. */
383 call_insn = last_call_insn ();
385 /* Some target create a fresh MEM instead of reusing the one provided
386 above. Set its MEM_EXPR. */
387 call = get_call_rtx_from (call_insn);
388 if (call
389 && MEM_EXPR (XEXP (call, 0)) == NULL_TREE
390 && MEM_EXPR (funmem) != NULL_TREE)
391 set_mem_expr (XEXP (call, 0), MEM_EXPR (funmem));
393 /* Put the register usage information there. */
394 add_function_usage_to (call_insn, call_fusage);
396 /* If this is a const call, then set the insn's unchanging bit. */
397 if (ecf_flags & ECF_CONST)
398 RTL_CONST_CALL_P (call_insn) = 1;
400 /* If this is a pure call, then set the insn's unchanging bit. */
401 if (ecf_flags & ECF_PURE)
402 RTL_PURE_CALL_P (call_insn) = 1;
404 /* If this is a const call, then set the insn's unchanging bit. */
405 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
406 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
408 /* Create a nothrow REG_EH_REGION note, if needed. */
409 make_reg_eh_region_note (call_insn, ecf_flags, 0);
411 if (ecf_flags & ECF_NORETURN)
412 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
414 if (ecf_flags & ECF_RETURNS_TWICE)
416 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
417 cfun->calls_setjmp = 1;
420 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
422 /* Restore this now, so that we do defer pops for this call's args
423 if the context of the call as a whole permits. */
424 inhibit_defer_pop = old_inhibit_defer_pop;
426 if (n_popped > 0)
428 if (!already_popped)
429 CALL_INSN_FUNCTION_USAGE (call_insn)
430 = gen_rtx_EXPR_LIST (VOIDmode,
431 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
432 CALL_INSN_FUNCTION_USAGE (call_insn));
433 rounded_stack_size -= n_popped;
434 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
435 stack_pointer_delta -= n_popped;
437 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
439 /* If popup is needed, stack realign must use DRAP */
440 if (SUPPORTS_STACK_ALIGNMENT)
441 crtl->need_drap = true;
443 /* For noreturn calls when not accumulating outgoing args force
444 REG_ARGS_SIZE note to prevent crossjumping of calls with different
445 args sizes. */
446 else if (!ACCUMULATE_OUTGOING_ARGS && (ecf_flags & ECF_NORETURN) != 0)
447 add_reg_note (call_insn, REG_ARGS_SIZE, GEN_INT (stack_pointer_delta));
449 if (!ACCUMULATE_OUTGOING_ARGS)
451 /* If returning from the subroutine does not automatically pop the args,
452 we need an instruction to pop them sooner or later.
453 Perhaps do it now; perhaps just record how much space to pop later.
455 If returning from the subroutine does pop the args, indicate that the
456 stack pointer will be changed. */
458 if (rounded_stack_size != 0)
460 if (ecf_flags & ECF_NORETURN)
461 /* Just pretend we did the pop. */
462 stack_pointer_delta -= rounded_stack_size;
463 else if (flag_defer_pop && inhibit_defer_pop == 0
464 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
465 pending_stack_adjust += rounded_stack_size;
466 else
467 adjust_stack (rounded_stack_size_rtx);
470 /* When we accumulate outgoing args, we must avoid any stack manipulations.
471 Restore the stack pointer to its original value now. Usually
472 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
473 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
474 popping variants of functions exist as well.
476 ??? We may optimize similar to defer_pop above, but it is
477 probably not worthwhile.
479 ??? It will be worthwhile to enable combine_stack_adjustments even for
480 such machines. */
481 else if (n_popped)
482 anti_adjust_stack (GEN_INT (n_popped));
485 /* Determine if the function identified by NAME and FNDECL is one with
486 special properties we wish to know about.
488 For example, if the function might return more than one time (setjmp), then
489 set RETURNS_TWICE to a nonzero value.
491 Similarly set NORETURN if the function is in the longjmp family.
493 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
494 space from the stack such as alloca. */
496 static int
497 special_function_p (const_tree fndecl, int flags)
499 if (fndecl && DECL_NAME (fndecl)
500 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
501 /* Exclude functions not at the file scope, or not `extern',
502 since they are not the magic functions we would otherwise
503 think they are.
504 FIXME: this should be handled with attributes, not with this
505 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
506 because you can declare fork() inside a function if you
507 wish. */
508 && (DECL_CONTEXT (fndecl) == NULL_TREE
509 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
510 && TREE_PUBLIC (fndecl))
512 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
513 const char *tname = name;
515 /* We assume that alloca will always be called by name. It
516 makes no sense to pass it as a pointer-to-function to
517 anything that does not understand its behavior. */
518 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
519 && name[0] == 'a'
520 && ! strcmp (name, "alloca"))
521 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
522 && name[0] == '_'
523 && ! strcmp (name, "__builtin_alloca"))))
524 flags |= ECF_MAY_BE_ALLOCA;
526 /* Disregard prefix _, __, __x or __builtin_. */
527 if (name[0] == '_')
529 if (name[1] == '_'
530 && name[2] == 'b'
531 && !strncmp (name + 3, "uiltin_", 7))
532 tname += 10;
533 else if (name[1] == '_' && name[2] == 'x')
534 tname += 3;
535 else if (name[1] == '_')
536 tname += 2;
537 else
538 tname += 1;
541 if (tname[0] == 's')
543 if ((tname[1] == 'e'
544 && (! strcmp (tname, "setjmp")
545 || ! strcmp (tname, "setjmp_syscall")))
546 || (tname[1] == 'i'
547 && ! strcmp (tname, "sigsetjmp"))
548 || (tname[1] == 'a'
549 && ! strcmp (tname, "savectx")))
550 flags |= ECF_RETURNS_TWICE;
552 if (tname[1] == 'i'
553 && ! strcmp (tname, "siglongjmp"))
554 flags |= ECF_NORETURN;
556 else if ((tname[0] == 'q' && tname[1] == 's'
557 && ! strcmp (tname, "qsetjmp"))
558 || (tname[0] == 'v' && tname[1] == 'f'
559 && ! strcmp (tname, "vfork"))
560 || (tname[0] == 'g' && tname[1] == 'e'
561 && !strcmp (tname, "getcontext")))
562 flags |= ECF_RETURNS_TWICE;
564 else if (tname[0] == 'l' && tname[1] == 'o'
565 && ! strcmp (tname, "longjmp"))
566 flags |= ECF_NORETURN;
569 return flags;
572 /* Similar to special_function_p; return a set of ERF_ flags for the
573 function FNDECL. */
574 static int
575 decl_return_flags (tree fndecl)
577 tree attr;
578 tree type = TREE_TYPE (fndecl);
579 if (!type)
580 return 0;
582 attr = lookup_attribute ("fn spec", TYPE_ATTRIBUTES (type));
583 if (!attr)
584 return 0;
586 attr = TREE_VALUE (TREE_VALUE (attr));
587 if (!attr || TREE_STRING_LENGTH (attr) < 1)
588 return 0;
590 switch (TREE_STRING_POINTER (attr)[0])
592 case '1':
593 case '2':
594 case '3':
595 case '4':
596 return ERF_RETURNS_ARG | (TREE_STRING_POINTER (attr)[0] - '1');
598 case 'm':
599 return ERF_NOALIAS;
601 case '.':
602 default:
603 return 0;
607 /* Return nonzero when FNDECL represents a call to setjmp. */
610 setjmp_call_p (const_tree fndecl)
612 if (DECL_IS_RETURNS_TWICE (fndecl))
613 return ECF_RETURNS_TWICE;
614 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
618 /* Return true if STMT is an alloca call. */
620 bool
621 gimple_alloca_call_p (const_gimple stmt)
623 tree fndecl;
625 if (!is_gimple_call (stmt))
626 return false;
628 fndecl = gimple_call_fndecl (stmt);
629 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
630 return true;
632 return false;
635 /* Return true when exp contains alloca call. */
637 bool
638 alloca_call_p (const_tree exp)
640 if (TREE_CODE (exp) == CALL_EXPR
641 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
642 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
643 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
644 & ECF_MAY_BE_ALLOCA))
645 return true;
646 return false;
649 /* Return TRUE if FNDECL is either a TM builtin or a TM cloned
650 function. Return FALSE otherwise. */
652 static bool
653 is_tm_builtin (const_tree fndecl)
655 if (fndecl == NULL)
656 return false;
658 if (decl_is_tm_clone (fndecl))
659 return true;
661 if (DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL)
663 switch (DECL_FUNCTION_CODE (fndecl))
665 case BUILT_IN_TM_COMMIT:
666 case BUILT_IN_TM_COMMIT_EH:
667 case BUILT_IN_TM_ABORT:
668 case BUILT_IN_TM_IRREVOCABLE:
669 case BUILT_IN_TM_GETTMCLONE_IRR:
670 case BUILT_IN_TM_MEMCPY:
671 case BUILT_IN_TM_MEMMOVE:
672 case BUILT_IN_TM_MEMSET:
673 CASE_BUILT_IN_TM_STORE (1):
674 CASE_BUILT_IN_TM_STORE (2):
675 CASE_BUILT_IN_TM_STORE (4):
676 CASE_BUILT_IN_TM_STORE (8):
677 CASE_BUILT_IN_TM_STORE (FLOAT):
678 CASE_BUILT_IN_TM_STORE (DOUBLE):
679 CASE_BUILT_IN_TM_STORE (LDOUBLE):
680 CASE_BUILT_IN_TM_STORE (M64):
681 CASE_BUILT_IN_TM_STORE (M128):
682 CASE_BUILT_IN_TM_STORE (M256):
683 CASE_BUILT_IN_TM_LOAD (1):
684 CASE_BUILT_IN_TM_LOAD (2):
685 CASE_BUILT_IN_TM_LOAD (4):
686 CASE_BUILT_IN_TM_LOAD (8):
687 CASE_BUILT_IN_TM_LOAD (FLOAT):
688 CASE_BUILT_IN_TM_LOAD (DOUBLE):
689 CASE_BUILT_IN_TM_LOAD (LDOUBLE):
690 CASE_BUILT_IN_TM_LOAD (M64):
691 CASE_BUILT_IN_TM_LOAD (M128):
692 CASE_BUILT_IN_TM_LOAD (M256):
693 case BUILT_IN_TM_LOG:
694 case BUILT_IN_TM_LOG_1:
695 case BUILT_IN_TM_LOG_2:
696 case BUILT_IN_TM_LOG_4:
697 case BUILT_IN_TM_LOG_8:
698 case BUILT_IN_TM_LOG_FLOAT:
699 case BUILT_IN_TM_LOG_DOUBLE:
700 case BUILT_IN_TM_LOG_LDOUBLE:
701 case BUILT_IN_TM_LOG_M64:
702 case BUILT_IN_TM_LOG_M128:
703 case BUILT_IN_TM_LOG_M256:
704 return true;
705 default:
706 break;
709 return false;
712 /* Detect flags (function attributes) from the function decl or type node. */
715 flags_from_decl_or_type (const_tree exp)
717 int flags = 0;
719 if (DECL_P (exp))
721 /* The function exp may have the `malloc' attribute. */
722 if (DECL_IS_MALLOC (exp))
723 flags |= ECF_MALLOC;
725 /* The function exp may have the `returns_twice' attribute. */
726 if (DECL_IS_RETURNS_TWICE (exp))
727 flags |= ECF_RETURNS_TWICE;
729 /* Process the pure and const attributes. */
730 if (TREE_READONLY (exp))
731 flags |= ECF_CONST;
732 if (DECL_PURE_P (exp))
733 flags |= ECF_PURE;
734 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
735 flags |= ECF_LOOPING_CONST_OR_PURE;
737 if (DECL_IS_NOVOPS (exp))
738 flags |= ECF_NOVOPS;
739 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
740 flags |= ECF_LEAF;
742 if (TREE_NOTHROW (exp))
743 flags |= ECF_NOTHROW;
745 if (flag_tm)
747 if (is_tm_builtin (exp))
748 flags |= ECF_TM_BUILTIN;
749 else if ((flags & (ECF_CONST|ECF_NOVOPS)) != 0
750 || lookup_attribute ("transaction_pure",
751 TYPE_ATTRIBUTES (TREE_TYPE (exp))))
752 flags |= ECF_TM_PURE;
755 flags = special_function_p (exp, flags);
757 else if (TYPE_P (exp))
759 if (TYPE_READONLY (exp))
760 flags |= ECF_CONST;
762 if (flag_tm
763 && ((flags & ECF_CONST) != 0
764 || lookup_attribute ("transaction_pure", TYPE_ATTRIBUTES (exp))))
765 flags |= ECF_TM_PURE;
768 if (TREE_THIS_VOLATILE (exp))
770 flags |= ECF_NORETURN;
771 if (flags & (ECF_CONST|ECF_PURE))
772 flags |= ECF_LOOPING_CONST_OR_PURE;
775 return flags;
778 /* Detect flags from a CALL_EXPR. */
781 call_expr_flags (const_tree t)
783 int flags;
784 tree decl = get_callee_fndecl (t);
786 if (decl)
787 flags = flags_from_decl_or_type (decl);
788 else
790 t = TREE_TYPE (CALL_EXPR_FN (t));
791 if (t && TREE_CODE (t) == POINTER_TYPE)
792 flags = flags_from_decl_or_type (TREE_TYPE (t));
793 else
794 flags = 0;
797 return flags;
800 /* Precompute all register parameters as described by ARGS, storing values
801 into fields within the ARGS array.
803 NUM_ACTUALS indicates the total number elements in the ARGS array.
805 Set REG_PARM_SEEN if we encounter a register parameter. */
807 static void
808 precompute_register_parameters (int num_actuals, struct arg_data *args,
809 int *reg_parm_seen)
811 int i;
813 *reg_parm_seen = 0;
815 for (i = 0; i < num_actuals; i++)
816 if (args[i].reg != 0 && ! args[i].pass_on_stack)
818 *reg_parm_seen = 1;
820 if (args[i].value == 0)
822 push_temp_slots ();
823 args[i].value = expand_normal (args[i].tree_value);
824 preserve_temp_slots (args[i].value);
825 pop_temp_slots ();
828 /* If we are to promote the function arg to a wider mode,
829 do it now. */
831 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
832 args[i].value
833 = convert_modes (args[i].mode,
834 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
835 args[i].value, args[i].unsignedp);
837 /* If the value is a non-legitimate constant, force it into a
838 pseudo now. TLS symbols sometimes need a call to resolve. */
839 if (CONSTANT_P (args[i].value)
840 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
841 args[i].value = force_reg (args[i].mode, args[i].value);
843 /* If we're going to have to load the value by parts, pull the
844 parts into pseudos. The part extraction process can involve
845 non-trivial computation. */
846 if (GET_CODE (args[i].reg) == PARALLEL)
848 tree type = TREE_TYPE (args[i].tree_value);
849 args[i].parallel_value
850 = emit_group_load_into_temps (args[i].reg, args[i].value,
851 type, int_size_in_bytes (type));
854 /* If the value is expensive, and we are inside an appropriately
855 short loop, put the value into a pseudo and then put the pseudo
856 into the hard reg.
858 For small register classes, also do this if this call uses
859 register parameters. This is to avoid reload conflicts while
860 loading the parameters registers. */
862 else if ((! (REG_P (args[i].value)
863 || (GET_CODE (args[i].value) == SUBREG
864 && REG_P (SUBREG_REG (args[i].value)))))
865 && args[i].mode != BLKmode
866 && set_src_cost (args[i].value, optimize_insn_for_speed_p ())
867 > COSTS_N_INSNS (1)
868 && ((*reg_parm_seen
869 && targetm.small_register_classes_for_mode_p (args[i].mode))
870 || optimize))
871 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
875 #ifdef REG_PARM_STACK_SPACE
877 /* The argument list is the property of the called routine and it
878 may clobber it. If the fixed area has been used for previous
879 parameters, we must save and restore it. */
881 static rtx
882 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
884 int low;
885 int high;
887 /* Compute the boundary of the area that needs to be saved, if any. */
888 high = reg_parm_stack_space;
889 #ifdef ARGS_GROW_DOWNWARD
890 high += 1;
891 #endif
892 if (high > highest_outgoing_arg_in_use)
893 high = highest_outgoing_arg_in_use;
895 for (low = 0; low < high; low++)
896 if (stack_usage_map[low] != 0)
898 int num_to_save;
899 enum machine_mode save_mode;
900 int delta;
901 rtx addr;
902 rtx stack_area;
903 rtx save_area;
905 while (stack_usage_map[--high] == 0)
908 *low_to_save = low;
909 *high_to_save = high;
911 num_to_save = high - low + 1;
912 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
914 /* If we don't have the required alignment, must do this
915 in BLKmode. */
916 if ((low & (MIN (GET_MODE_SIZE (save_mode),
917 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
918 save_mode = BLKmode;
920 #ifdef ARGS_GROW_DOWNWARD
921 delta = -high;
922 #else
923 delta = low;
924 #endif
925 addr = plus_constant (Pmode, argblock, delta);
926 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
928 set_mem_align (stack_area, PARM_BOUNDARY);
929 if (save_mode == BLKmode)
931 save_area = assign_stack_temp (BLKmode, num_to_save);
932 emit_block_move (validize_mem (save_area), stack_area,
933 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
935 else
937 save_area = gen_reg_rtx (save_mode);
938 emit_move_insn (save_area, stack_area);
941 return save_area;
944 return NULL_RTX;
947 static void
948 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
950 enum machine_mode save_mode = GET_MODE (save_area);
951 int delta;
952 rtx addr, stack_area;
954 #ifdef ARGS_GROW_DOWNWARD
955 delta = -high_to_save;
956 #else
957 delta = low_to_save;
958 #endif
959 addr = plus_constant (Pmode, argblock, delta);
960 stack_area = gen_rtx_MEM (save_mode, memory_address (save_mode, addr));
961 set_mem_align (stack_area, PARM_BOUNDARY);
963 if (save_mode != BLKmode)
964 emit_move_insn (stack_area, save_area);
965 else
966 emit_block_move (stack_area, validize_mem (save_area),
967 GEN_INT (high_to_save - low_to_save + 1),
968 BLOCK_OP_CALL_PARM);
970 #endif /* REG_PARM_STACK_SPACE */
972 /* If any elements in ARGS refer to parameters that are to be passed in
973 registers, but not in memory, and whose alignment does not permit a
974 direct copy into registers. Copy the values into a group of pseudos
975 which we will later copy into the appropriate hard registers.
977 Pseudos for each unaligned argument will be stored into the array
978 args[argnum].aligned_regs. The caller is responsible for deallocating
979 the aligned_regs array if it is nonzero. */
981 static void
982 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
984 int i, j;
986 for (i = 0; i < num_actuals; i++)
987 if (args[i].reg != 0 && ! args[i].pass_on_stack
988 && args[i].mode == BLKmode
989 && MEM_P (args[i].value)
990 && (MEM_ALIGN (args[i].value)
991 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
993 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
994 int endian_correction = 0;
996 if (args[i].partial)
998 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
999 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
1001 else
1003 args[i].n_aligned_regs
1004 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
1007 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
1009 /* Structures smaller than a word are normally aligned to the
1010 least significant byte. On a BYTES_BIG_ENDIAN machine,
1011 this means we must skip the empty high order bytes when
1012 calculating the bit offset. */
1013 if (bytes < UNITS_PER_WORD
1014 #ifdef BLOCK_REG_PADDING
1015 && (BLOCK_REG_PADDING (args[i].mode,
1016 TREE_TYPE (args[i].tree_value), 1)
1017 == downward)
1018 #else
1019 && BYTES_BIG_ENDIAN
1020 #endif
1022 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
1024 for (j = 0; j < args[i].n_aligned_regs; j++)
1026 rtx reg = gen_reg_rtx (word_mode);
1027 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1028 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1030 args[i].aligned_regs[j] = reg;
1031 word = extract_bit_field (word, bitsize, 0, 1, false, NULL_RTX,
1032 word_mode, word_mode);
1034 /* There is no need to restrict this code to loading items
1035 in TYPE_ALIGN sized hunks. The bitfield instructions can
1036 load up entire word sized registers efficiently.
1038 ??? This may not be needed anymore.
1039 We use to emit a clobber here but that doesn't let later
1040 passes optimize the instructions we emit. By storing 0 into
1041 the register later passes know the first AND to zero out the
1042 bitfield being set in the register is unnecessary. The store
1043 of 0 will be deleted as will at least the first AND. */
1045 emit_move_insn (reg, const0_rtx);
1047 bytes -= bitsize / BITS_PER_UNIT;
1048 store_bit_field (reg, bitsize, endian_correction, 0, 0,
1049 word_mode, word);
1054 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1055 CALL_EXPR EXP.
1057 NUM_ACTUALS is the total number of parameters.
1059 N_NAMED_ARGS is the total number of named arguments.
1061 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
1062 value, or null.
1064 FNDECL is the tree code for the target of this call (if known)
1066 ARGS_SO_FAR holds state needed by the target to know where to place
1067 the next argument.
1069 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1070 for arguments which are passed in registers.
1072 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1073 and may be modified by this routine.
1075 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1076 flags which may may be modified by this routine.
1078 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1079 that requires allocation of stack space.
1081 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1082 the thunked-to function. */
1084 static void
1085 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1086 struct arg_data *args,
1087 struct args_size *args_size,
1088 int n_named_args ATTRIBUTE_UNUSED,
1089 tree exp, tree struct_value_addr_value,
1090 tree fndecl, tree fntype,
1091 cumulative_args_t args_so_far,
1092 int reg_parm_stack_space,
1093 rtx *old_stack_level, int *old_pending_adj,
1094 int *must_preallocate, int *ecf_flags,
1095 bool *may_tailcall, bool call_from_thunk_p)
1097 CUMULATIVE_ARGS *args_so_far_pnt = get_cumulative_args (args_so_far);
1098 location_t loc = EXPR_LOCATION (exp);
1099 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1100 int inc;
1102 /* Count arg position in order args appear. */
1103 int argpos;
1105 int i;
1107 args_size->constant = 0;
1108 args_size->var = 0;
1110 /* In this loop, we consider args in the order they are written.
1111 We fill up ARGS from the front or from the back if necessary
1112 so that in any case the first arg to be pushed ends up at the front. */
1114 if (PUSH_ARGS_REVERSED)
1116 i = num_actuals - 1, inc = -1;
1117 /* In this case, must reverse order of args
1118 so that we compute and push the last arg first. */
1120 else
1122 i = 0, inc = 1;
1125 /* First fill in the actual arguments in the ARGS array, splitting
1126 complex arguments if necessary. */
1128 int j = i;
1129 call_expr_arg_iterator iter;
1130 tree arg;
1132 if (struct_value_addr_value)
1134 args[j].tree_value = struct_value_addr_value;
1135 j += inc;
1137 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1139 tree argtype = TREE_TYPE (arg);
1140 if (targetm.calls.split_complex_arg
1141 && argtype
1142 && TREE_CODE (argtype) == COMPLEX_TYPE
1143 && targetm.calls.split_complex_arg (argtype))
1145 tree subtype = TREE_TYPE (argtype);
1146 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1147 j += inc;
1148 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1150 else
1151 args[j].tree_value = arg;
1152 j += inc;
1156 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1157 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1159 tree type = TREE_TYPE (args[i].tree_value);
1160 int unsignedp;
1161 enum machine_mode mode;
1163 /* Replace erroneous argument with constant zero. */
1164 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1165 args[i].tree_value = integer_zero_node, type = integer_type_node;
1167 /* If TYPE is a transparent union or record, pass things the way
1168 we would pass the first field of the union or record. We have
1169 already verified that the modes are the same. */
1170 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1171 && TYPE_TRANSPARENT_AGGR (type))
1172 type = TREE_TYPE (first_field (type));
1174 /* Decide where to pass this arg.
1176 args[i].reg is nonzero if all or part is passed in registers.
1178 args[i].partial is nonzero if part but not all is passed in registers,
1179 and the exact value says how many bytes are passed in registers.
1181 args[i].pass_on_stack is nonzero if the argument must at least be
1182 computed on the stack. It may then be loaded back into registers
1183 if args[i].reg is nonzero.
1185 These decisions are driven by the FUNCTION_... macros and must agree
1186 with those made by function.c. */
1188 /* See if this argument should be passed by invisible reference. */
1189 if (pass_by_reference (args_so_far_pnt, TYPE_MODE (type),
1190 type, argpos < n_named_args))
1192 bool callee_copies;
1193 tree base = NULL_TREE;
1195 callee_copies
1196 = reference_callee_copied (args_so_far_pnt, TYPE_MODE (type),
1197 type, argpos < n_named_args);
1199 /* If we're compiling a thunk, pass through invisible references
1200 instead of making a copy. */
1201 if (call_from_thunk_p
1202 || (callee_copies
1203 && !TREE_ADDRESSABLE (type)
1204 && (base = get_base_address (args[i].tree_value))
1205 && TREE_CODE (base) != SSA_NAME
1206 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1208 mark_addressable (args[i].tree_value);
1210 /* We can't use sibcalls if a callee-copied argument is
1211 stored in the current function's frame. */
1212 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1213 *may_tailcall = false;
1215 args[i].tree_value = build_fold_addr_expr_loc (loc,
1216 args[i].tree_value);
1217 type = TREE_TYPE (args[i].tree_value);
1219 if (*ecf_flags & ECF_CONST)
1220 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1222 else
1224 /* We make a copy of the object and pass the address to the
1225 function being called. */
1226 rtx copy;
1228 if (!COMPLETE_TYPE_P (type)
1229 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1230 || (flag_stack_check == GENERIC_STACK_CHECK
1231 && compare_tree_int (TYPE_SIZE_UNIT (type),
1232 STACK_CHECK_MAX_VAR_SIZE) > 0))
1234 /* This is a variable-sized object. Make space on the stack
1235 for it. */
1236 rtx size_rtx = expr_size (args[i].tree_value);
1238 if (*old_stack_level == 0)
1240 emit_stack_save (SAVE_BLOCK, old_stack_level);
1241 *old_pending_adj = pending_stack_adjust;
1242 pending_stack_adjust = 0;
1245 /* We can pass TRUE as the 4th argument because we just
1246 saved the stack pointer and will restore it right after
1247 the call. */
1248 copy = allocate_dynamic_stack_space (size_rtx,
1249 TYPE_ALIGN (type),
1250 TYPE_ALIGN (type),
1251 true);
1252 copy = gen_rtx_MEM (BLKmode, copy);
1253 set_mem_attributes (copy, type, 1);
1255 else
1256 copy = assign_temp (type, 1, 0);
1258 store_expr (args[i].tree_value, copy, 0, false);
1260 /* Just change the const function to pure and then let
1261 the next test clear the pure based on
1262 callee_copies. */
1263 if (*ecf_flags & ECF_CONST)
1265 *ecf_flags &= ~ECF_CONST;
1266 *ecf_flags |= ECF_PURE;
1269 if (!callee_copies && *ecf_flags & ECF_PURE)
1270 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1272 args[i].tree_value
1273 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1274 type = TREE_TYPE (args[i].tree_value);
1275 *may_tailcall = false;
1279 unsignedp = TYPE_UNSIGNED (type);
1280 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1281 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1283 args[i].unsignedp = unsignedp;
1284 args[i].mode = mode;
1286 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
1287 argpos < n_named_args);
1289 /* If this is a sibling call and the machine has register windows, the
1290 register window has to be unwinded before calling the routine, so
1291 arguments have to go into the incoming registers. */
1292 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
1293 args[i].tail_call_reg
1294 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
1295 argpos < n_named_args);
1296 else
1297 args[i].tail_call_reg = args[i].reg;
1299 if (args[i].reg)
1300 args[i].partial
1301 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1302 argpos < n_named_args);
1304 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1306 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1307 it means that we are to pass this arg in the register(s) designated
1308 by the PARALLEL, but also to pass it in the stack. */
1309 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1310 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1311 args[i].pass_on_stack = 1;
1313 /* If this is an addressable type, we must preallocate the stack
1314 since we must evaluate the object into its final location.
1316 If this is to be passed in both registers and the stack, it is simpler
1317 to preallocate. */
1318 if (TREE_ADDRESSABLE (type)
1319 || (args[i].pass_on_stack && args[i].reg != 0))
1320 *must_preallocate = 1;
1322 /* Compute the stack-size of this argument. */
1323 if (args[i].reg == 0 || args[i].partial != 0
1324 || reg_parm_stack_space > 0
1325 || args[i].pass_on_stack)
1326 locate_and_pad_parm (mode, type,
1327 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1329 #else
1330 args[i].reg != 0,
1331 #endif
1332 args[i].pass_on_stack ? 0 : args[i].partial,
1333 fndecl, args_size, &args[i].locate);
1334 #ifdef BLOCK_REG_PADDING
1335 else
1336 /* The argument is passed entirely in registers. See at which
1337 end it should be padded. */
1338 args[i].locate.where_pad =
1339 BLOCK_REG_PADDING (mode, type,
1340 int_size_in_bytes (type) <= UNITS_PER_WORD);
1341 #endif
1343 /* Update ARGS_SIZE, the total stack space for args so far. */
1345 args_size->constant += args[i].locate.size.constant;
1346 if (args[i].locate.size.var)
1347 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1349 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1350 have been used, etc. */
1352 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
1353 type, argpos < n_named_args);
1357 /* Update ARGS_SIZE to contain the total size for the argument block.
1358 Return the original constant component of the argument block's size.
1360 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1361 for arguments passed in registers. */
1363 static int
1364 compute_argument_block_size (int reg_parm_stack_space,
1365 struct args_size *args_size,
1366 tree fndecl ATTRIBUTE_UNUSED,
1367 tree fntype ATTRIBUTE_UNUSED,
1368 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1370 int unadjusted_args_size = args_size->constant;
1372 /* For accumulate outgoing args mode we don't need to align, since the frame
1373 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1374 backends from generating misaligned frame sizes. */
1375 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1376 preferred_stack_boundary = STACK_BOUNDARY;
1378 /* Compute the actual size of the argument block required. The variable
1379 and constant sizes must be combined, the size may have to be rounded,
1380 and there may be a minimum required size. */
1382 if (args_size->var)
1384 args_size->var = ARGS_SIZE_TREE (*args_size);
1385 args_size->constant = 0;
1387 preferred_stack_boundary /= BITS_PER_UNIT;
1388 if (preferred_stack_boundary > 1)
1390 /* We don't handle this case yet. To handle it correctly we have
1391 to add the delta, round and subtract the delta.
1392 Currently no machine description requires this support. */
1393 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1394 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1397 if (reg_parm_stack_space > 0)
1399 args_size->var
1400 = size_binop (MAX_EXPR, args_size->var,
1401 ssize_int (reg_parm_stack_space));
1403 /* The area corresponding to register parameters is not to count in
1404 the size of the block we need. So make the adjustment. */
1405 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1406 args_size->var
1407 = size_binop (MINUS_EXPR, args_size->var,
1408 ssize_int (reg_parm_stack_space));
1411 else
1413 preferred_stack_boundary /= BITS_PER_UNIT;
1414 if (preferred_stack_boundary < 1)
1415 preferred_stack_boundary = 1;
1416 args_size->constant = (((args_size->constant
1417 + stack_pointer_delta
1418 + preferred_stack_boundary - 1)
1419 / preferred_stack_boundary
1420 * preferred_stack_boundary)
1421 - stack_pointer_delta);
1423 args_size->constant = MAX (args_size->constant,
1424 reg_parm_stack_space);
1426 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1427 args_size->constant -= reg_parm_stack_space;
1429 return unadjusted_args_size;
1432 /* Precompute parameters as needed for a function call.
1434 FLAGS is mask of ECF_* constants.
1436 NUM_ACTUALS is the number of arguments.
1438 ARGS is an array containing information for each argument; this
1439 routine fills in the INITIAL_VALUE and VALUE fields for each
1440 precomputed argument. */
1442 static void
1443 precompute_arguments (int num_actuals, struct arg_data *args)
1445 int i;
1447 /* If this is a libcall, then precompute all arguments so that we do not
1448 get extraneous instructions emitted as part of the libcall sequence. */
1450 /* If we preallocated the stack space, and some arguments must be passed
1451 on the stack, then we must precompute any parameter which contains a
1452 function call which will store arguments on the stack.
1453 Otherwise, evaluating the parameter may clobber previous parameters
1454 which have already been stored into the stack. (we have code to avoid
1455 such case by saving the outgoing stack arguments, but it results in
1456 worse code) */
1457 if (!ACCUMULATE_OUTGOING_ARGS)
1458 return;
1460 for (i = 0; i < num_actuals; i++)
1462 tree type;
1463 enum machine_mode mode;
1465 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1466 continue;
1468 /* If this is an addressable type, we cannot pre-evaluate it. */
1469 type = TREE_TYPE (args[i].tree_value);
1470 gcc_assert (!TREE_ADDRESSABLE (type));
1472 args[i].initial_value = args[i].value
1473 = expand_normal (args[i].tree_value);
1475 mode = TYPE_MODE (type);
1476 if (mode != args[i].mode)
1478 int unsignedp = args[i].unsignedp;
1479 args[i].value
1480 = convert_modes (args[i].mode, mode,
1481 args[i].value, args[i].unsignedp);
1483 /* CSE will replace this only if it contains args[i].value
1484 pseudo, so convert it down to the declared mode using
1485 a SUBREG. */
1486 if (REG_P (args[i].value)
1487 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1488 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1490 args[i].initial_value
1491 = gen_lowpart_SUBREG (mode, args[i].value);
1492 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1493 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1494 args[i].unsignedp);
1500 /* Given the current state of MUST_PREALLOCATE and information about
1501 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1502 compute and return the final value for MUST_PREALLOCATE. */
1504 static int
1505 finalize_must_preallocate (int must_preallocate, int num_actuals,
1506 struct arg_data *args, struct args_size *args_size)
1508 /* See if we have or want to preallocate stack space.
1510 If we would have to push a partially-in-regs parm
1511 before other stack parms, preallocate stack space instead.
1513 If the size of some parm is not a multiple of the required stack
1514 alignment, we must preallocate.
1516 If the total size of arguments that would otherwise create a copy in
1517 a temporary (such as a CALL) is more than half the total argument list
1518 size, preallocation is faster.
1520 Another reason to preallocate is if we have a machine (like the m88k)
1521 where stack alignment is required to be maintained between every
1522 pair of insns, not just when the call is made. However, we assume here
1523 that such machines either do not have push insns (and hence preallocation
1524 would occur anyway) or the problem is taken care of with
1525 PUSH_ROUNDING. */
1527 if (! must_preallocate)
1529 int partial_seen = 0;
1530 int copy_to_evaluate_size = 0;
1531 int i;
1533 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1535 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1536 partial_seen = 1;
1537 else if (partial_seen && args[i].reg == 0)
1538 must_preallocate = 1;
1540 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1541 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1542 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1543 || TREE_CODE (args[i].tree_value) == COND_EXPR
1544 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1545 copy_to_evaluate_size
1546 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1549 if (copy_to_evaluate_size * 2 >= args_size->constant
1550 && args_size->constant > 0)
1551 must_preallocate = 1;
1553 return must_preallocate;
1556 /* If we preallocated stack space, compute the address of each argument
1557 and store it into the ARGS array.
1559 We need not ensure it is a valid memory address here; it will be
1560 validized when it is used.
1562 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1564 static void
1565 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1567 if (argblock)
1569 rtx arg_reg = argblock;
1570 int i, arg_offset = 0;
1572 if (GET_CODE (argblock) == PLUS)
1573 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1575 for (i = 0; i < num_actuals; i++)
1577 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1578 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1579 rtx addr;
1580 unsigned int align, boundary;
1581 unsigned int units_on_stack = 0;
1582 enum machine_mode partial_mode = VOIDmode;
1584 /* Skip this parm if it will not be passed on the stack. */
1585 if (! args[i].pass_on_stack
1586 && args[i].reg != 0
1587 && args[i].partial == 0)
1588 continue;
1590 if (CONST_INT_P (offset))
1591 addr = plus_constant (Pmode, arg_reg, INTVAL (offset));
1592 else
1593 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1595 addr = plus_constant (Pmode, addr, arg_offset);
1597 if (args[i].partial != 0)
1599 /* Only part of the parameter is being passed on the stack.
1600 Generate a simple memory reference of the correct size. */
1601 units_on_stack = args[i].locate.size.constant;
1602 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1603 MODE_INT, 1);
1604 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1605 set_mem_size (args[i].stack, units_on_stack);
1607 else
1609 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1610 set_mem_attributes (args[i].stack,
1611 TREE_TYPE (args[i].tree_value), 1);
1613 align = BITS_PER_UNIT;
1614 boundary = args[i].locate.boundary;
1615 if (args[i].locate.where_pad != downward)
1616 align = boundary;
1617 else if (CONST_INT_P (offset))
1619 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1620 align = align & -align;
1622 set_mem_align (args[i].stack, align);
1624 if (CONST_INT_P (slot_offset))
1625 addr = plus_constant (Pmode, arg_reg, INTVAL (slot_offset));
1626 else
1627 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1629 addr = plus_constant (Pmode, addr, arg_offset);
1631 if (args[i].partial != 0)
1633 /* Only part of the parameter is being passed on the stack.
1634 Generate a simple memory reference of the correct size.
1636 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1637 set_mem_size (args[i].stack_slot, units_on_stack);
1639 else
1641 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1642 set_mem_attributes (args[i].stack_slot,
1643 TREE_TYPE (args[i].tree_value), 1);
1645 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1647 /* Function incoming arguments may overlap with sibling call
1648 outgoing arguments and we cannot allow reordering of reads
1649 from function arguments with stores to outgoing arguments
1650 of sibling calls. */
1651 set_mem_alias_set (args[i].stack, 0);
1652 set_mem_alias_set (args[i].stack_slot, 0);
1657 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1658 in a call instruction.
1660 FNDECL is the tree node for the target function. For an indirect call
1661 FNDECL will be NULL_TREE.
1663 ADDR is the operand 0 of CALL_EXPR for this call. */
1665 static rtx
1666 rtx_for_function_call (tree fndecl, tree addr)
1668 rtx funexp;
1670 /* Get the function to call, in the form of RTL. */
1671 if (fndecl)
1673 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1674 TREE_USED (fndecl) = 1;
1676 /* Get a SYMBOL_REF rtx for the function address. */
1677 funexp = XEXP (DECL_RTL (fndecl), 0);
1679 else
1680 /* Generate an rtx (probably a pseudo-register) for the address. */
1682 push_temp_slots ();
1683 funexp = expand_normal (addr);
1684 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1686 return funexp;
1689 /* Internal state for internal_arg_pointer_based_exp and its helpers. */
1690 static struct
1692 /* Last insn that has been scanned by internal_arg_pointer_based_exp_scan,
1693 or NULL_RTX if none has been scanned yet. */
1694 rtx scan_start;
1695 /* Vector indexed by REGNO - FIRST_PSEUDO_REGISTER, recording if a pseudo is
1696 based on crtl->args.internal_arg_pointer. The element is NULL_RTX if the
1697 pseudo isn't based on it, a CONST_INT offset if the pseudo is based on it
1698 with fixed offset, or PC if this is with variable or unknown offset. */
1699 vec<rtx> cache;
1700 } internal_arg_pointer_exp_state;
1702 static rtx internal_arg_pointer_based_exp (rtx, bool);
1704 /* Helper function for internal_arg_pointer_based_exp. Scan insns in
1705 the tail call sequence, starting with first insn that hasn't been
1706 scanned yet, and note for each pseudo on the LHS whether it is based
1707 on crtl->args.internal_arg_pointer or not, and what offset from that
1708 that pointer it has. */
1710 static void
1711 internal_arg_pointer_based_exp_scan (void)
1713 rtx insn, scan_start = internal_arg_pointer_exp_state.scan_start;
1715 if (scan_start == NULL_RTX)
1716 insn = get_insns ();
1717 else
1718 insn = NEXT_INSN (scan_start);
1720 while (insn)
1722 rtx set = single_set (insn);
1723 if (set && REG_P (SET_DEST (set)) && !HARD_REGISTER_P (SET_DEST (set)))
1725 rtx val = NULL_RTX;
1726 unsigned int idx = REGNO (SET_DEST (set)) - FIRST_PSEUDO_REGISTER;
1727 /* Punt on pseudos set multiple times. */
1728 if (idx < internal_arg_pointer_exp_state.cache.length ()
1729 && (internal_arg_pointer_exp_state.cache[idx]
1730 != NULL_RTX))
1731 val = pc_rtx;
1732 else
1733 val = internal_arg_pointer_based_exp (SET_SRC (set), false);
1734 if (val != NULL_RTX)
1736 if (idx >= internal_arg_pointer_exp_state.cache.length ())
1737 internal_arg_pointer_exp_state.cache.safe_grow_cleared(idx + 1);
1738 internal_arg_pointer_exp_state.cache[idx] = val;
1741 if (NEXT_INSN (insn) == NULL_RTX)
1742 scan_start = insn;
1743 insn = NEXT_INSN (insn);
1746 internal_arg_pointer_exp_state.scan_start = scan_start;
1749 /* Helper function for internal_arg_pointer_based_exp, called through
1750 for_each_rtx. Return 1 if *LOC is a register based on
1751 crtl->args.internal_arg_pointer. Return -1 if *LOC is not based on it
1752 and the subexpressions need not be examined. Otherwise return 0. */
1754 static int
1755 internal_arg_pointer_based_exp_1 (rtx *loc, void *data ATTRIBUTE_UNUSED)
1757 if (REG_P (*loc) && internal_arg_pointer_based_exp (*loc, false) != NULL_RTX)
1758 return 1;
1759 if (MEM_P (*loc))
1760 return -1;
1761 return 0;
1764 /* Compute whether RTL is based on crtl->args.internal_arg_pointer. Return
1765 NULL_RTX if RTL isn't based on it, a CONST_INT offset if RTL is based on
1766 it with fixed offset, or PC if this is with variable or unknown offset.
1767 TOPLEVEL is true if the function is invoked at the topmost level. */
1769 static rtx
1770 internal_arg_pointer_based_exp (rtx rtl, bool toplevel)
1772 if (CONSTANT_P (rtl))
1773 return NULL_RTX;
1775 if (rtl == crtl->args.internal_arg_pointer)
1776 return const0_rtx;
1778 if (REG_P (rtl) && HARD_REGISTER_P (rtl))
1779 return NULL_RTX;
1781 if (GET_CODE (rtl) == PLUS && CONST_INT_P (XEXP (rtl, 1)))
1783 rtx val = internal_arg_pointer_based_exp (XEXP (rtl, 0), toplevel);
1784 if (val == NULL_RTX || val == pc_rtx)
1785 return val;
1786 return plus_constant (Pmode, val, INTVAL (XEXP (rtl, 1)));
1789 /* When called at the topmost level, scan pseudo assignments in between the
1790 last scanned instruction in the tail call sequence and the latest insn
1791 in that sequence. */
1792 if (toplevel)
1793 internal_arg_pointer_based_exp_scan ();
1795 if (REG_P (rtl))
1797 unsigned int idx = REGNO (rtl) - FIRST_PSEUDO_REGISTER;
1798 if (idx < internal_arg_pointer_exp_state.cache.length ())
1799 return internal_arg_pointer_exp_state.cache[idx];
1801 return NULL_RTX;
1804 if (for_each_rtx (&rtl, internal_arg_pointer_based_exp_1, NULL))
1805 return pc_rtx;
1807 return NULL_RTX;
1810 /* Return true if and only if SIZE storage units (usually bytes)
1811 starting from address ADDR overlap with already clobbered argument
1812 area. This function is used to determine if we should give up a
1813 sibcall. */
1815 static bool
1816 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1818 HOST_WIDE_INT i;
1819 rtx val;
1821 if (bitmap_empty_p (stored_args_map))
1822 return false;
1823 val = internal_arg_pointer_based_exp (addr, true);
1824 if (val == NULL_RTX)
1825 return false;
1826 else if (val == pc_rtx)
1827 return true;
1828 else
1829 i = INTVAL (val);
1830 #ifdef STACK_GROWS_DOWNWARD
1831 i -= crtl->args.pretend_args_size;
1832 #else
1833 i += crtl->args.pretend_args_size;
1834 #endif
1836 #ifdef ARGS_GROW_DOWNWARD
1837 i = -i - size;
1838 #endif
1839 if (size > 0)
1841 unsigned HOST_WIDE_INT k;
1843 for (k = 0; k < size; k++)
1844 if (i + k < SBITMAP_SIZE (stored_args_map)
1845 && bitmap_bit_p (stored_args_map, i + k))
1846 return true;
1849 return false;
1852 /* Do the register loads required for any wholly-register parms or any
1853 parms which are passed both on the stack and in a register. Their
1854 expressions were already evaluated.
1856 Mark all register-parms as living through the call, putting these USE
1857 insns in the CALL_INSN_FUNCTION_USAGE field.
1859 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1860 checking, setting *SIBCALL_FAILURE if appropriate. */
1862 static void
1863 load_register_parameters (struct arg_data *args, int num_actuals,
1864 rtx *call_fusage, int flags, int is_sibcall,
1865 int *sibcall_failure)
1867 int i, j;
1869 for (i = 0; i < num_actuals; i++)
1871 rtx reg = ((flags & ECF_SIBCALL)
1872 ? args[i].tail_call_reg : args[i].reg);
1873 if (reg)
1875 int partial = args[i].partial;
1876 int nregs;
1877 int size = 0;
1878 rtx before_arg = get_last_insn ();
1879 /* Set non-negative if we must move a word at a time, even if
1880 just one word (e.g, partial == 4 && mode == DFmode). Set
1881 to -1 if we just use a normal move insn. This value can be
1882 zero if the argument is a zero size structure. */
1883 nregs = -1;
1884 if (GET_CODE (reg) == PARALLEL)
1886 else if (partial)
1888 gcc_assert (partial % UNITS_PER_WORD == 0);
1889 nregs = partial / UNITS_PER_WORD;
1891 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1893 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1894 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1896 else
1897 size = GET_MODE_SIZE (args[i].mode);
1899 /* Handle calls that pass values in multiple non-contiguous
1900 locations. The Irix 6 ABI has examples of this. */
1902 if (GET_CODE (reg) == PARALLEL)
1903 emit_group_move (reg, args[i].parallel_value);
1905 /* If simple case, just do move. If normal partial, store_one_arg
1906 has already loaded the register for us. In all other cases,
1907 load the register(s) from memory. */
1909 else if (nregs == -1)
1911 emit_move_insn (reg, args[i].value);
1912 #ifdef BLOCK_REG_PADDING
1913 /* Handle case where we have a value that needs shifting
1914 up to the msb. eg. a QImode value and we're padding
1915 upward on a BYTES_BIG_ENDIAN machine. */
1916 if (size < UNITS_PER_WORD
1917 && (args[i].locate.where_pad
1918 == (BYTES_BIG_ENDIAN ? upward : downward)))
1920 rtx x;
1921 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1923 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1924 report the whole reg as used. Strictly speaking, the
1925 call only uses SIZE bytes at the msb end, but it doesn't
1926 seem worth generating rtl to say that. */
1927 reg = gen_rtx_REG (word_mode, REGNO (reg));
1928 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
1929 if (x != reg)
1930 emit_move_insn (reg, x);
1932 #endif
1935 /* If we have pre-computed the values to put in the registers in
1936 the case of non-aligned structures, copy them in now. */
1938 else if (args[i].n_aligned_regs != 0)
1939 for (j = 0; j < args[i].n_aligned_regs; j++)
1940 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1941 args[i].aligned_regs[j]);
1943 else if (partial == 0 || args[i].pass_on_stack)
1945 rtx mem = validize_mem (args[i].value);
1947 /* Check for overlap with already clobbered argument area,
1948 providing that this has non-zero size. */
1949 if (is_sibcall
1950 && (size == 0
1951 || mem_overlaps_already_clobbered_arg_p
1952 (XEXP (args[i].value, 0), size)))
1953 *sibcall_failure = 1;
1955 /* Handle a BLKmode that needs shifting. */
1956 if (nregs == 1 && size < UNITS_PER_WORD
1957 #ifdef BLOCK_REG_PADDING
1958 && args[i].locate.where_pad == downward
1959 #else
1960 && BYTES_BIG_ENDIAN
1961 #endif
1964 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1965 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1966 rtx x = gen_reg_rtx (word_mode);
1967 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1968 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1969 : LSHIFT_EXPR;
1971 emit_move_insn (x, tem);
1972 x = expand_shift (dir, word_mode, x, shift, ri, 1);
1973 if (x != ri)
1974 emit_move_insn (ri, x);
1976 else
1977 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1980 /* When a parameter is a block, and perhaps in other cases, it is
1981 possible that it did a load from an argument slot that was
1982 already clobbered. */
1983 if (is_sibcall
1984 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1985 *sibcall_failure = 1;
1987 /* Handle calls that pass values in multiple non-contiguous
1988 locations. The Irix 6 ABI has examples of this. */
1989 if (GET_CODE (reg) == PARALLEL)
1990 use_group_regs (call_fusage, reg);
1991 else if (nregs == -1)
1992 use_reg_mode (call_fusage, reg,
1993 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1994 else if (nregs > 0)
1995 use_regs (call_fusage, REGNO (reg), nregs);
2000 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
2001 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
2002 bytes, then we would need to push some additional bytes to pad the
2003 arguments. So, we compute an adjust to the stack pointer for an
2004 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
2005 bytes. Then, when the arguments are pushed the stack will be perfectly
2006 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
2007 be popped after the call. Returns the adjustment. */
2009 static int
2010 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
2011 struct args_size *args_size,
2012 unsigned int preferred_unit_stack_boundary)
2014 /* The number of bytes to pop so that the stack will be
2015 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
2016 HOST_WIDE_INT adjustment;
2017 /* The alignment of the stack after the arguments are pushed, if we
2018 just pushed the arguments without adjust the stack here. */
2019 unsigned HOST_WIDE_INT unadjusted_alignment;
2021 unadjusted_alignment
2022 = ((stack_pointer_delta + unadjusted_args_size)
2023 % preferred_unit_stack_boundary);
2025 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
2026 as possible -- leaving just enough left to cancel out the
2027 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
2028 PENDING_STACK_ADJUST is non-negative, and congruent to
2029 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
2031 /* Begin by trying to pop all the bytes. */
2032 unadjusted_alignment
2033 = (unadjusted_alignment
2034 - (pending_stack_adjust % preferred_unit_stack_boundary));
2035 adjustment = pending_stack_adjust;
2036 /* Push enough additional bytes that the stack will be aligned
2037 after the arguments are pushed. */
2038 if (preferred_unit_stack_boundary > 1)
2040 if (unadjusted_alignment > 0)
2041 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
2042 else
2043 adjustment += unadjusted_alignment;
2046 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
2047 bytes after the call. The right number is the entire
2048 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
2049 by the arguments in the first place. */
2050 args_size->constant
2051 = pending_stack_adjust - adjustment + unadjusted_args_size;
2053 return adjustment;
2056 /* Scan X expression if it does not dereference any argument slots
2057 we already clobbered by tail call arguments (as noted in stored_args_map
2058 bitmap).
2059 Return nonzero if X expression dereferences such argument slots,
2060 zero otherwise. */
2062 static int
2063 check_sibcall_argument_overlap_1 (rtx x)
2065 RTX_CODE code;
2066 int i, j;
2067 const char *fmt;
2069 if (x == NULL_RTX)
2070 return 0;
2072 code = GET_CODE (x);
2074 /* We need not check the operands of the CALL expression itself. */
2075 if (code == CALL)
2076 return 0;
2078 if (code == MEM)
2079 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
2080 GET_MODE_SIZE (GET_MODE (x)));
2082 /* Scan all subexpressions. */
2083 fmt = GET_RTX_FORMAT (code);
2084 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2086 if (*fmt == 'e')
2088 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2089 return 1;
2091 else if (*fmt == 'E')
2093 for (j = 0; j < XVECLEN (x, i); j++)
2094 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2095 return 1;
2098 return 0;
2101 /* Scan sequence after INSN if it does not dereference any argument slots
2102 we already clobbered by tail call arguments (as noted in stored_args_map
2103 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2104 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2105 should be 0). Return nonzero if sequence after INSN dereferences such argument
2106 slots, zero otherwise. */
2108 static int
2109 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
2111 int low, high;
2113 if (insn == NULL_RTX)
2114 insn = get_insns ();
2115 else
2116 insn = NEXT_INSN (insn);
2118 for (; insn; insn = NEXT_INSN (insn))
2119 if (INSN_P (insn)
2120 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2121 break;
2123 if (mark_stored_args_map)
2125 #ifdef ARGS_GROW_DOWNWARD
2126 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2127 #else
2128 low = arg->locate.slot_offset.constant;
2129 #endif
2131 for (high = low + arg->locate.size.constant; low < high; low++)
2132 bitmap_set_bit (stored_args_map, low);
2134 return insn != NULL_RTX;
2137 /* Given that a function returns a value of mode MODE at the most
2138 significant end of hard register VALUE, shift VALUE left or right
2139 as specified by LEFT_P. Return true if some action was needed. */
2141 bool
2142 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
2144 HOST_WIDE_INT shift;
2146 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
2147 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
2148 if (shift == 0)
2149 return false;
2151 /* Use ashr rather than lshr for right shifts. This is for the benefit
2152 of the MIPS port, which requires SImode values to be sign-extended
2153 when stored in 64-bit registers. */
2154 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
2155 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
2156 gcc_unreachable ();
2157 return true;
2160 /* If X is a likely-spilled register value, copy it to a pseudo
2161 register and return that register. Return X otherwise. */
2163 static rtx
2164 avoid_likely_spilled_reg (rtx x)
2166 rtx new_rtx;
2168 if (REG_P (x)
2169 && HARD_REGISTER_P (x)
2170 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
2172 /* Make sure that we generate a REG rather than a CONCAT.
2173 Moves into CONCATs can need nontrivial instructions,
2174 and the whole point of this function is to avoid
2175 using the hard register directly in such a situation. */
2176 generating_concat_p = 0;
2177 new_rtx = gen_reg_rtx (GET_MODE (x));
2178 generating_concat_p = 1;
2179 emit_move_insn (new_rtx, x);
2180 return new_rtx;
2182 return x;
2185 /* Generate all the code for a CALL_EXPR exp
2186 and return an rtx for its value.
2187 Store the value in TARGET (specified as an rtx) if convenient.
2188 If the value is stored in TARGET then TARGET is returned.
2189 If IGNORE is nonzero, then we ignore the value of the function call. */
2192 expand_call (tree exp, rtx target, int ignore)
2194 /* Nonzero if we are currently expanding a call. */
2195 static int currently_expanding_call = 0;
2197 /* RTX for the function to be called. */
2198 rtx funexp;
2199 /* Sequence of insns to perform a normal "call". */
2200 rtx normal_call_insns = NULL_RTX;
2201 /* Sequence of insns to perform a tail "call". */
2202 rtx tail_call_insns = NULL_RTX;
2203 /* Data type of the function. */
2204 tree funtype;
2205 tree type_arg_types;
2206 tree rettype;
2207 /* Declaration of the function being called,
2208 or 0 if the function is computed (not known by name). */
2209 tree fndecl = 0;
2210 /* The type of the function being called. */
2211 tree fntype;
2212 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
2213 int pass;
2215 /* Register in which non-BLKmode value will be returned,
2216 or 0 if no value or if value is BLKmode. */
2217 rtx valreg;
2218 /* Address where we should return a BLKmode value;
2219 0 if value not BLKmode. */
2220 rtx structure_value_addr = 0;
2221 /* Nonzero if that address is being passed by treating it as
2222 an extra, implicit first parameter. Otherwise,
2223 it is passed by being copied directly into struct_value_rtx. */
2224 int structure_value_addr_parm = 0;
2225 /* Holds the value of implicit argument for the struct value. */
2226 tree structure_value_addr_value = NULL_TREE;
2227 /* Size of aggregate value wanted, or zero if none wanted
2228 or if we are using the non-reentrant PCC calling convention
2229 or expecting the value in registers. */
2230 HOST_WIDE_INT struct_value_size = 0;
2231 /* Nonzero if called function returns an aggregate in memory PCC style,
2232 by returning the address of where to find it. */
2233 int pcc_struct_value = 0;
2234 rtx struct_value = 0;
2236 /* Number of actual parameters in this call, including struct value addr. */
2237 int num_actuals;
2238 /* Number of named args. Args after this are anonymous ones
2239 and they must all go on the stack. */
2240 int n_named_args;
2241 /* Number of complex actual arguments that need to be split. */
2242 int num_complex_actuals = 0;
2244 /* Vector of information about each argument.
2245 Arguments are numbered in the order they will be pushed,
2246 not the order they are written. */
2247 struct arg_data *args;
2249 /* Total size in bytes of all the stack-parms scanned so far. */
2250 struct args_size args_size;
2251 struct args_size adjusted_args_size;
2252 /* Size of arguments before any adjustments (such as rounding). */
2253 int unadjusted_args_size;
2254 /* Data on reg parms scanned so far. */
2255 CUMULATIVE_ARGS args_so_far_v;
2256 cumulative_args_t args_so_far;
2257 /* Nonzero if a reg parm has been scanned. */
2258 int reg_parm_seen;
2259 /* Nonzero if this is an indirect function call. */
2261 /* Nonzero if we must avoid push-insns in the args for this call.
2262 If stack space is allocated for register parameters, but not by the
2263 caller, then it is preallocated in the fixed part of the stack frame.
2264 So the entire argument block must then be preallocated (i.e., we
2265 ignore PUSH_ROUNDING in that case). */
2267 int must_preallocate = !PUSH_ARGS;
2269 /* Size of the stack reserved for parameter registers. */
2270 int reg_parm_stack_space = 0;
2272 /* Address of space preallocated for stack parms
2273 (on machines that lack push insns), or 0 if space not preallocated. */
2274 rtx argblock = 0;
2276 /* Mask of ECF_ and ERF_ flags. */
2277 int flags = 0;
2278 int return_flags = 0;
2279 #ifdef REG_PARM_STACK_SPACE
2280 /* Define the boundary of the register parm stack space that needs to be
2281 saved, if any. */
2282 int low_to_save, high_to_save;
2283 rtx save_area = 0; /* Place that it is saved */
2284 #endif
2286 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2287 char *initial_stack_usage_map = stack_usage_map;
2288 char *stack_usage_map_buf = NULL;
2290 int old_stack_allocated;
2292 /* State variables to track stack modifications. */
2293 rtx old_stack_level = 0;
2294 int old_stack_arg_under_construction = 0;
2295 int old_pending_adj = 0;
2296 int old_inhibit_defer_pop = inhibit_defer_pop;
2298 /* Some stack pointer alterations we make are performed via
2299 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2300 which we then also need to save/restore along the way. */
2301 int old_stack_pointer_delta = 0;
2303 rtx call_fusage;
2304 tree addr = CALL_EXPR_FN (exp);
2305 int i;
2306 /* The alignment of the stack, in bits. */
2307 unsigned HOST_WIDE_INT preferred_stack_boundary;
2308 /* The alignment of the stack, in bytes. */
2309 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2310 /* The static chain value to use for this call. */
2311 rtx static_chain_value;
2312 /* See if this is "nothrow" function call. */
2313 if (TREE_NOTHROW (exp))
2314 flags |= ECF_NOTHROW;
2316 /* See if we can find a DECL-node for the actual function, and get the
2317 function attributes (flags) from the function decl or type node. */
2318 fndecl = get_callee_fndecl (exp);
2319 if (fndecl)
2321 fntype = TREE_TYPE (fndecl);
2322 flags |= flags_from_decl_or_type (fndecl);
2323 return_flags |= decl_return_flags (fndecl);
2325 else
2327 fntype = TREE_TYPE (TREE_TYPE (addr));
2328 flags |= flags_from_decl_or_type (fntype);
2330 rettype = TREE_TYPE (exp);
2332 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2334 /* Warn if this value is an aggregate type,
2335 regardless of which calling convention we are using for it. */
2336 if (AGGREGATE_TYPE_P (rettype))
2337 warning (OPT_Waggregate_return, "function call has aggregate value");
2339 /* If the result of a non looping pure or const function call is
2340 ignored (or void), and none of its arguments are volatile, we can
2341 avoid expanding the call and just evaluate the arguments for
2342 side-effects. */
2343 if ((flags & (ECF_CONST | ECF_PURE))
2344 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2345 && (ignore || target == const0_rtx
2346 || TYPE_MODE (rettype) == VOIDmode))
2348 bool volatilep = false;
2349 tree arg;
2350 call_expr_arg_iterator iter;
2352 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2353 if (TREE_THIS_VOLATILE (arg))
2355 volatilep = true;
2356 break;
2359 if (! volatilep)
2361 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2362 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2363 return const0_rtx;
2367 #ifdef REG_PARM_STACK_SPACE
2368 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2369 #endif
2371 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2372 && reg_parm_stack_space > 0 && PUSH_ARGS)
2373 must_preallocate = 1;
2375 /* Set up a place to return a structure. */
2377 /* Cater to broken compilers. */
2378 if (aggregate_value_p (exp, fntype))
2380 /* This call returns a big structure. */
2381 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2383 #ifdef PCC_STATIC_STRUCT_RETURN
2385 pcc_struct_value = 1;
2387 #else /* not PCC_STATIC_STRUCT_RETURN */
2389 struct_value_size = int_size_in_bytes (rettype);
2391 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2392 structure_value_addr = XEXP (target, 0);
2393 else
2395 /* For variable-sized objects, we must be called with a target
2396 specified. If we were to allocate space on the stack here,
2397 we would have no way of knowing when to free it. */
2398 rtx d = assign_temp (rettype, 1, 1);
2399 structure_value_addr = XEXP (d, 0);
2400 target = 0;
2403 #endif /* not PCC_STATIC_STRUCT_RETURN */
2406 /* Figure out the amount to which the stack should be aligned. */
2407 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2408 if (fndecl)
2410 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2411 /* Without automatic stack alignment, we can't increase preferred
2412 stack boundary. With automatic stack alignment, it is
2413 unnecessary since unless we can guarantee that all callers will
2414 align the outgoing stack properly, callee has to align its
2415 stack anyway. */
2416 if (i
2417 && i->preferred_incoming_stack_boundary
2418 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2419 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2422 /* Operand 0 is a pointer-to-function; get the type of the function. */
2423 funtype = TREE_TYPE (addr);
2424 gcc_assert (POINTER_TYPE_P (funtype));
2425 funtype = TREE_TYPE (funtype);
2427 /* Count whether there are actual complex arguments that need to be split
2428 into their real and imaginary parts. Munge the type_arg_types
2429 appropriately here as well. */
2430 if (targetm.calls.split_complex_arg)
2432 call_expr_arg_iterator iter;
2433 tree arg;
2434 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2436 tree type = TREE_TYPE (arg);
2437 if (type && TREE_CODE (type) == COMPLEX_TYPE
2438 && targetm.calls.split_complex_arg (type))
2439 num_complex_actuals++;
2441 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2443 else
2444 type_arg_types = TYPE_ARG_TYPES (funtype);
2446 if (flags & ECF_MAY_BE_ALLOCA)
2447 cfun->calls_alloca = 1;
2449 /* If struct_value_rtx is 0, it means pass the address
2450 as if it were an extra parameter. Put the argument expression
2451 in structure_value_addr_value. */
2452 if (structure_value_addr && struct_value == 0)
2454 /* If structure_value_addr is a REG other than
2455 virtual_outgoing_args_rtx, we can use always use it. If it
2456 is not a REG, we must always copy it into a register.
2457 If it is virtual_outgoing_args_rtx, we must copy it to another
2458 register in some cases. */
2459 rtx temp = (!REG_P (structure_value_addr)
2460 || (ACCUMULATE_OUTGOING_ARGS
2461 && stack_arg_under_construction
2462 && structure_value_addr == virtual_outgoing_args_rtx)
2463 ? copy_addr_to_reg (convert_memory_address
2464 (Pmode, structure_value_addr))
2465 : structure_value_addr);
2467 structure_value_addr_value =
2468 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2469 structure_value_addr_parm = 1;
2472 /* Count the arguments and set NUM_ACTUALS. */
2473 num_actuals =
2474 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2476 /* Compute number of named args.
2477 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2479 if (type_arg_types != 0)
2480 n_named_args
2481 = (list_length (type_arg_types)
2482 /* Count the struct value address, if it is passed as a parm. */
2483 + structure_value_addr_parm);
2484 else
2485 /* If we know nothing, treat all args as named. */
2486 n_named_args = num_actuals;
2488 /* Start updating where the next arg would go.
2490 On some machines (such as the PA) indirect calls have a different
2491 calling convention than normal calls. The fourth argument in
2492 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2493 or not. */
2494 INIT_CUMULATIVE_ARGS (args_so_far_v, funtype, NULL_RTX, fndecl, n_named_args);
2495 args_so_far = pack_cumulative_args (&args_so_far_v);
2497 /* Now possibly adjust the number of named args.
2498 Normally, don't include the last named arg if anonymous args follow.
2499 We do include the last named arg if
2500 targetm.calls.strict_argument_naming() returns nonzero.
2501 (If no anonymous args follow, the result of list_length is actually
2502 one too large. This is harmless.)
2504 If targetm.calls.pretend_outgoing_varargs_named() returns
2505 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2506 this machine will be able to place unnamed args that were passed
2507 in registers into the stack. So treat all args as named. This
2508 allows the insns emitting for a specific argument list to be
2509 independent of the function declaration.
2511 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2512 we do not have any reliable way to pass unnamed args in
2513 registers, so we must force them into memory. */
2515 if (type_arg_types != 0
2516 && targetm.calls.strict_argument_naming (args_so_far))
2518 else if (type_arg_types != 0
2519 && ! targetm.calls.pretend_outgoing_varargs_named (args_so_far))
2520 /* Don't include the last named arg. */
2521 --n_named_args;
2522 else
2523 /* Treat all args as named. */
2524 n_named_args = num_actuals;
2526 /* Make a vector to hold all the information about each arg. */
2527 args = XALLOCAVEC (struct arg_data, num_actuals);
2528 memset (args, 0, num_actuals * sizeof (struct arg_data));
2530 /* Build up entries in the ARGS array, compute the size of the
2531 arguments into ARGS_SIZE, etc. */
2532 initialize_argument_information (num_actuals, args, &args_size,
2533 n_named_args, exp,
2534 structure_value_addr_value, fndecl, fntype,
2535 args_so_far, reg_parm_stack_space,
2536 &old_stack_level, &old_pending_adj,
2537 &must_preallocate, &flags,
2538 &try_tail_call, CALL_FROM_THUNK_P (exp));
2540 if (args_size.var)
2541 must_preallocate = 1;
2543 /* Now make final decision about preallocating stack space. */
2544 must_preallocate = finalize_must_preallocate (must_preallocate,
2545 num_actuals, args,
2546 &args_size);
2548 /* If the structure value address will reference the stack pointer, we
2549 must stabilize it. We don't need to do this if we know that we are
2550 not going to adjust the stack pointer in processing this call. */
2552 if (structure_value_addr
2553 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2554 || reg_mentioned_p (virtual_outgoing_args_rtx,
2555 structure_value_addr))
2556 && (args_size.var
2557 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2558 structure_value_addr = copy_to_reg (structure_value_addr);
2560 /* Tail calls can make things harder to debug, and we've traditionally
2561 pushed these optimizations into -O2. Don't try if we're already
2562 expanding a call, as that means we're an argument. Don't try if
2563 there's cleanups, as we know there's code to follow the call. */
2565 if (currently_expanding_call++ != 0
2566 || !flag_optimize_sibling_calls
2567 || args_size.var
2568 || dbg_cnt (tail_call) == false)
2569 try_tail_call = 0;
2571 /* Rest of purposes for tail call optimizations to fail. */
2572 if (
2573 #ifdef HAVE_sibcall_epilogue
2574 !HAVE_sibcall_epilogue
2575 #else
2577 #endif
2578 || !try_tail_call
2579 /* Doing sibling call optimization needs some work, since
2580 structure_value_addr can be allocated on the stack.
2581 It does not seem worth the effort since few optimizable
2582 sibling calls will return a structure. */
2583 || structure_value_addr != NULL_RTX
2584 #ifdef REG_PARM_STACK_SPACE
2585 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2586 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2587 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2588 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2589 #endif
2590 /* Check whether the target is able to optimize the call
2591 into a sibcall. */
2592 || !targetm.function_ok_for_sibcall (fndecl, exp)
2593 /* Functions that do not return exactly once may not be sibcall
2594 optimized. */
2595 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2596 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2597 /* If the called function is nested in the current one, it might access
2598 some of the caller's arguments, but could clobber them beforehand if
2599 the argument areas are shared. */
2600 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2601 /* If this function requires more stack slots than the current
2602 function, we cannot change it into a sibling call.
2603 crtl->args.pretend_args_size is not part of the
2604 stack allocated by our caller. */
2605 || args_size.constant > (crtl->args.size
2606 - crtl->args.pretend_args_size)
2607 /* If the callee pops its own arguments, then it must pop exactly
2608 the same number of arguments as the current function. */
2609 || (targetm.calls.return_pops_args (fndecl, funtype, args_size.constant)
2610 != targetm.calls.return_pops_args (current_function_decl,
2611 TREE_TYPE (current_function_decl),
2612 crtl->args.size))
2613 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2614 try_tail_call = 0;
2616 /* Check if caller and callee disagree in promotion of function
2617 return value. */
2618 if (try_tail_call)
2620 enum machine_mode caller_mode, caller_promoted_mode;
2621 enum machine_mode callee_mode, callee_promoted_mode;
2622 int caller_unsignedp, callee_unsignedp;
2623 tree caller_res = DECL_RESULT (current_function_decl);
2625 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2626 caller_mode = DECL_MODE (caller_res);
2627 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2628 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2629 caller_promoted_mode
2630 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2631 &caller_unsignedp,
2632 TREE_TYPE (current_function_decl), 1);
2633 callee_promoted_mode
2634 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2635 &callee_unsignedp,
2636 funtype, 1);
2637 if (caller_mode != VOIDmode
2638 && (caller_promoted_mode != callee_promoted_mode
2639 || ((caller_mode != caller_promoted_mode
2640 || callee_mode != callee_promoted_mode)
2641 && (caller_unsignedp != callee_unsignedp
2642 || GET_MODE_BITSIZE (caller_mode)
2643 < GET_MODE_BITSIZE (callee_mode)))))
2644 try_tail_call = 0;
2647 /* Ensure current function's preferred stack boundary is at least
2648 what we need. Stack alignment may also increase preferred stack
2649 boundary. */
2650 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2651 crtl->preferred_stack_boundary = preferred_stack_boundary;
2652 else
2653 preferred_stack_boundary = crtl->preferred_stack_boundary;
2655 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2657 /* We want to make two insn chains; one for a sibling call, the other
2658 for a normal call. We will select one of the two chains after
2659 initial RTL generation is complete. */
2660 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2662 int sibcall_failure = 0;
2663 /* We want to emit any pending stack adjustments before the tail
2664 recursion "call". That way we know any adjustment after the tail
2665 recursion call can be ignored if we indeed use the tail
2666 call expansion. */
2667 int save_pending_stack_adjust = 0;
2668 int save_stack_pointer_delta = 0;
2669 rtx insns;
2670 rtx before_call, next_arg_reg, after_args;
2672 if (pass == 0)
2674 /* State variables we need to save and restore between
2675 iterations. */
2676 save_pending_stack_adjust = pending_stack_adjust;
2677 save_stack_pointer_delta = stack_pointer_delta;
2679 if (pass)
2680 flags &= ~ECF_SIBCALL;
2681 else
2682 flags |= ECF_SIBCALL;
2684 /* Other state variables that we must reinitialize each time
2685 through the loop (that are not initialized by the loop itself). */
2686 argblock = 0;
2687 call_fusage = 0;
2689 /* Start a new sequence for the normal call case.
2691 From this point on, if the sibling call fails, we want to set
2692 sibcall_failure instead of continuing the loop. */
2693 start_sequence ();
2695 /* Don't let pending stack adjusts add up to too much.
2696 Also, do all pending adjustments now if there is any chance
2697 this might be a call to alloca or if we are expanding a sibling
2698 call sequence.
2699 Also do the adjustments before a throwing call, otherwise
2700 exception handling can fail; PR 19225. */
2701 if (pending_stack_adjust >= 32
2702 || (pending_stack_adjust > 0
2703 && (flags & ECF_MAY_BE_ALLOCA))
2704 || (pending_stack_adjust > 0
2705 && flag_exceptions && !(flags & ECF_NOTHROW))
2706 || pass == 0)
2707 do_pending_stack_adjust ();
2709 /* Precompute any arguments as needed. */
2710 if (pass)
2711 precompute_arguments (num_actuals, args);
2713 /* Now we are about to start emitting insns that can be deleted
2714 if a libcall is deleted. */
2715 if (pass && (flags & ECF_MALLOC))
2716 start_sequence ();
2718 if (pass == 0 && crtl->stack_protect_guard)
2719 stack_protect_epilogue ();
2721 adjusted_args_size = args_size;
2722 /* Compute the actual size of the argument block required. The variable
2723 and constant sizes must be combined, the size may have to be rounded,
2724 and there may be a minimum required size. When generating a sibcall
2725 pattern, do not round up, since we'll be re-using whatever space our
2726 caller provided. */
2727 unadjusted_args_size
2728 = compute_argument_block_size (reg_parm_stack_space,
2729 &adjusted_args_size,
2730 fndecl, fntype,
2731 (pass == 0 ? 0
2732 : preferred_stack_boundary));
2734 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2736 /* The argument block when performing a sibling call is the
2737 incoming argument block. */
2738 if (pass == 0)
2740 argblock = crtl->args.internal_arg_pointer;
2741 argblock
2742 #ifdef STACK_GROWS_DOWNWARD
2743 = plus_constant (Pmode, argblock, crtl->args.pretend_args_size);
2744 #else
2745 = plus_constant (Pmode, argblock, -crtl->args.pretend_args_size);
2746 #endif
2747 stored_args_map = sbitmap_alloc (args_size.constant);
2748 bitmap_clear (stored_args_map);
2751 /* If we have no actual push instructions, or shouldn't use them,
2752 make space for all args right now. */
2753 else if (adjusted_args_size.var != 0)
2755 if (old_stack_level == 0)
2757 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2758 old_stack_pointer_delta = stack_pointer_delta;
2759 old_pending_adj = pending_stack_adjust;
2760 pending_stack_adjust = 0;
2761 /* stack_arg_under_construction says whether a stack arg is
2762 being constructed at the old stack level. Pushing the stack
2763 gets a clean outgoing argument block. */
2764 old_stack_arg_under_construction = stack_arg_under_construction;
2765 stack_arg_under_construction = 0;
2767 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2768 if (flag_stack_usage_info)
2769 current_function_has_unbounded_dynamic_stack_size = 1;
2771 else
2773 /* Note that we must go through the motions of allocating an argument
2774 block even if the size is zero because we may be storing args
2775 in the area reserved for register arguments, which may be part of
2776 the stack frame. */
2778 int needed = adjusted_args_size.constant;
2780 /* Store the maximum argument space used. It will be pushed by
2781 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2782 checking). */
2784 if (needed > crtl->outgoing_args_size)
2785 crtl->outgoing_args_size = needed;
2787 if (must_preallocate)
2789 if (ACCUMULATE_OUTGOING_ARGS)
2791 /* Since the stack pointer will never be pushed, it is
2792 possible for the evaluation of a parm to clobber
2793 something we have already written to the stack.
2794 Since most function calls on RISC machines do not use
2795 the stack, this is uncommon, but must work correctly.
2797 Therefore, we save any area of the stack that was already
2798 written and that we are using. Here we set up to do this
2799 by making a new stack usage map from the old one. The
2800 actual save will be done by store_one_arg.
2802 Another approach might be to try to reorder the argument
2803 evaluations to avoid this conflicting stack usage. */
2805 /* Since we will be writing into the entire argument area,
2806 the map must be allocated for its entire size, not just
2807 the part that is the responsibility of the caller. */
2808 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2809 needed += reg_parm_stack_space;
2811 #ifdef ARGS_GROW_DOWNWARD
2812 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2813 needed + 1);
2814 #else
2815 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2816 needed);
2817 #endif
2818 free (stack_usage_map_buf);
2819 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2820 stack_usage_map = stack_usage_map_buf;
2822 if (initial_highest_arg_in_use)
2823 memcpy (stack_usage_map, initial_stack_usage_map,
2824 initial_highest_arg_in_use);
2826 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2827 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2828 (highest_outgoing_arg_in_use
2829 - initial_highest_arg_in_use));
2830 needed = 0;
2832 /* The address of the outgoing argument list must not be
2833 copied to a register here, because argblock would be left
2834 pointing to the wrong place after the call to
2835 allocate_dynamic_stack_space below. */
2837 argblock = virtual_outgoing_args_rtx;
2839 else
2841 if (inhibit_defer_pop == 0)
2843 /* Try to reuse some or all of the pending_stack_adjust
2844 to get this space. */
2845 needed
2846 = (combine_pending_stack_adjustment_and_call
2847 (unadjusted_args_size,
2848 &adjusted_args_size,
2849 preferred_unit_stack_boundary));
2851 /* combine_pending_stack_adjustment_and_call computes
2852 an adjustment before the arguments are allocated.
2853 Account for them and see whether or not the stack
2854 needs to go up or down. */
2855 needed = unadjusted_args_size - needed;
2857 if (needed < 0)
2859 /* We're releasing stack space. */
2860 /* ??? We can avoid any adjustment at all if we're
2861 already aligned. FIXME. */
2862 pending_stack_adjust = -needed;
2863 do_pending_stack_adjust ();
2864 needed = 0;
2866 else
2867 /* We need to allocate space. We'll do that in
2868 push_block below. */
2869 pending_stack_adjust = 0;
2872 /* Special case this because overhead of `push_block' in
2873 this case is non-trivial. */
2874 if (needed == 0)
2875 argblock = virtual_outgoing_args_rtx;
2876 else
2878 argblock = push_block (GEN_INT (needed), 0, 0);
2879 #ifdef ARGS_GROW_DOWNWARD
2880 argblock = plus_constant (Pmode, argblock, needed);
2881 #endif
2884 /* We only really need to call `copy_to_reg' in the case
2885 where push insns are going to be used to pass ARGBLOCK
2886 to a function call in ARGS. In that case, the stack
2887 pointer changes value from the allocation point to the
2888 call point, and hence the value of
2889 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2890 as well always do it. */
2891 argblock = copy_to_reg (argblock);
2896 if (ACCUMULATE_OUTGOING_ARGS)
2898 /* The save/restore code in store_one_arg handles all
2899 cases except one: a constructor call (including a C
2900 function returning a BLKmode struct) to initialize
2901 an argument. */
2902 if (stack_arg_under_construction)
2904 rtx push_size
2905 = GEN_INT (adjusted_args_size.constant
2906 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2907 : TREE_TYPE (fndecl))) ? 0
2908 : reg_parm_stack_space));
2909 if (old_stack_level == 0)
2911 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2912 old_stack_pointer_delta = stack_pointer_delta;
2913 old_pending_adj = pending_stack_adjust;
2914 pending_stack_adjust = 0;
2915 /* stack_arg_under_construction says whether a stack
2916 arg is being constructed at the old stack level.
2917 Pushing the stack gets a clean outgoing argument
2918 block. */
2919 old_stack_arg_under_construction
2920 = stack_arg_under_construction;
2921 stack_arg_under_construction = 0;
2922 /* Make a new map for the new argument list. */
2923 free (stack_usage_map_buf);
2924 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2925 stack_usage_map = stack_usage_map_buf;
2926 highest_outgoing_arg_in_use = 0;
2928 /* We can pass TRUE as the 4th argument because we just
2929 saved the stack pointer and will restore it right after
2930 the call. */
2931 allocate_dynamic_stack_space (push_size, 0,
2932 BIGGEST_ALIGNMENT, true);
2935 /* If argument evaluation might modify the stack pointer,
2936 copy the address of the argument list to a register. */
2937 for (i = 0; i < num_actuals; i++)
2938 if (args[i].pass_on_stack)
2940 argblock = copy_addr_to_reg (argblock);
2941 break;
2945 compute_argument_addresses (args, argblock, num_actuals);
2947 /* If we push args individually in reverse order, perform stack alignment
2948 before the first push (the last arg). */
2949 if (PUSH_ARGS_REVERSED && argblock == 0
2950 && adjusted_args_size.constant != unadjusted_args_size)
2952 /* When the stack adjustment is pending, we get better code
2953 by combining the adjustments. */
2954 if (pending_stack_adjust
2955 && ! inhibit_defer_pop)
2957 pending_stack_adjust
2958 = (combine_pending_stack_adjustment_and_call
2959 (unadjusted_args_size,
2960 &adjusted_args_size,
2961 preferred_unit_stack_boundary));
2962 do_pending_stack_adjust ();
2964 else if (argblock == 0)
2965 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2966 - unadjusted_args_size));
2968 /* Now that the stack is properly aligned, pops can't safely
2969 be deferred during the evaluation of the arguments. */
2970 NO_DEFER_POP;
2972 /* Record the maximum pushed stack space size. We need to delay
2973 doing it this far to take into account the optimization done
2974 by combine_pending_stack_adjustment_and_call. */
2975 if (flag_stack_usage_info
2976 && !ACCUMULATE_OUTGOING_ARGS
2977 && pass
2978 && adjusted_args_size.var == 0)
2980 int pushed = adjusted_args_size.constant + pending_stack_adjust;
2981 if (pushed > current_function_pushed_stack_size)
2982 current_function_pushed_stack_size = pushed;
2985 funexp = rtx_for_function_call (fndecl, addr);
2987 /* Figure out the register where the value, if any, will come back. */
2988 valreg = 0;
2989 if (TYPE_MODE (rettype) != VOIDmode
2990 && ! structure_value_addr)
2992 if (pcc_struct_value)
2993 valreg = hard_function_value (build_pointer_type (rettype),
2994 fndecl, NULL, (pass == 0));
2995 else
2996 valreg = hard_function_value (rettype, fndecl, fntype,
2997 (pass == 0));
2999 /* If VALREG is a PARALLEL whose first member has a zero
3000 offset, use that. This is for targets such as m68k that
3001 return the same value in multiple places. */
3002 if (GET_CODE (valreg) == PARALLEL)
3004 rtx elem = XVECEXP (valreg, 0, 0);
3005 rtx where = XEXP (elem, 0);
3006 rtx offset = XEXP (elem, 1);
3007 if (offset == const0_rtx
3008 && GET_MODE (where) == GET_MODE (valreg))
3009 valreg = where;
3013 /* Precompute all register parameters. It isn't safe to compute anything
3014 once we have started filling any specific hard regs. */
3015 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
3017 if (CALL_EXPR_STATIC_CHAIN (exp))
3018 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
3019 else
3020 static_chain_value = 0;
3022 #ifdef REG_PARM_STACK_SPACE
3023 /* Save the fixed argument area if it's part of the caller's frame and
3024 is clobbered by argument setup for this call. */
3025 if (ACCUMULATE_OUTGOING_ARGS && pass)
3026 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3027 &low_to_save, &high_to_save);
3028 #endif
3030 /* Now store (and compute if necessary) all non-register parms.
3031 These come before register parms, since they can require block-moves,
3032 which could clobber the registers used for register parms.
3033 Parms which have partial registers are not stored here,
3034 but we do preallocate space here if they want that. */
3036 for (i = 0; i < num_actuals; i++)
3038 if (args[i].reg == 0 || args[i].pass_on_stack)
3040 rtx before_arg = get_last_insn ();
3042 if (store_one_arg (&args[i], argblock, flags,
3043 adjusted_args_size.var != 0,
3044 reg_parm_stack_space)
3045 || (pass == 0
3046 && check_sibcall_argument_overlap (before_arg,
3047 &args[i], 1)))
3048 sibcall_failure = 1;
3051 if (args[i].stack)
3052 call_fusage
3053 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
3054 gen_rtx_USE (VOIDmode, args[i].stack),
3055 call_fusage);
3058 /* If we have a parm that is passed in registers but not in memory
3059 and whose alignment does not permit a direct copy into registers,
3060 make a group of pseudos that correspond to each register that we
3061 will later fill. */
3062 if (STRICT_ALIGNMENT)
3063 store_unaligned_arguments_into_pseudos (args, num_actuals);
3065 /* Now store any partially-in-registers parm.
3066 This is the last place a block-move can happen. */
3067 if (reg_parm_seen)
3068 for (i = 0; i < num_actuals; i++)
3069 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3071 rtx before_arg = get_last_insn ();
3073 if (store_one_arg (&args[i], argblock, flags,
3074 adjusted_args_size.var != 0,
3075 reg_parm_stack_space)
3076 || (pass == 0
3077 && check_sibcall_argument_overlap (before_arg,
3078 &args[i], 1)))
3079 sibcall_failure = 1;
3082 /* If we pushed args in forward order, perform stack alignment
3083 after pushing the last arg. */
3084 if (!PUSH_ARGS_REVERSED && argblock == 0)
3085 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3086 - unadjusted_args_size));
3088 /* If register arguments require space on the stack and stack space
3089 was not preallocated, allocate stack space here for arguments
3090 passed in registers. */
3091 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
3092 && !ACCUMULATE_OUTGOING_ARGS
3093 && must_preallocate == 0 && reg_parm_stack_space > 0)
3094 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3096 /* Pass the function the address in which to return a
3097 structure value. */
3098 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3100 structure_value_addr
3101 = convert_memory_address (Pmode, structure_value_addr);
3102 emit_move_insn (struct_value,
3103 force_reg (Pmode,
3104 force_operand (structure_value_addr,
3105 NULL_RTX)));
3107 if (REG_P (struct_value))
3108 use_reg (&call_fusage, struct_value);
3111 after_args = get_last_insn ();
3112 funexp = prepare_call_address (fndecl, funexp, static_chain_value,
3113 &call_fusage, reg_parm_seen, pass == 0);
3115 load_register_parameters (args, num_actuals, &call_fusage, flags,
3116 pass == 0, &sibcall_failure);
3118 /* Save a pointer to the last insn before the call, so that we can
3119 later safely search backwards to find the CALL_INSN. */
3120 before_call = get_last_insn ();
3122 /* Set up next argument register. For sibling calls on machines
3123 with register windows this should be the incoming register. */
3124 if (pass == 0)
3125 next_arg_reg = targetm.calls.function_incoming_arg (args_so_far,
3126 VOIDmode,
3127 void_type_node,
3128 true);
3129 else
3130 next_arg_reg = targetm.calls.function_arg (args_so_far,
3131 VOIDmode, void_type_node,
3132 true);
3134 if (pass == 1 && (return_flags & ERF_RETURNS_ARG))
3136 int arg_nr = return_flags & ERF_RETURN_ARG_MASK;
3137 if (PUSH_ARGS_REVERSED)
3138 arg_nr = num_actuals - arg_nr - 1;
3139 if (args[arg_nr].reg
3140 && valreg
3141 && REG_P (valreg)
3142 && GET_MODE (args[arg_nr].reg) == GET_MODE (valreg))
3143 call_fusage
3144 = gen_rtx_EXPR_LIST (TYPE_MODE (TREE_TYPE (args[arg_nr].tree_value)),
3145 gen_rtx_SET (VOIDmode, valreg, args[arg_nr].reg),
3146 call_fusage);
3148 /* All arguments and registers used for the call must be set up by
3149 now! */
3151 /* Stack must be properly aligned now. */
3152 gcc_assert (!pass
3153 || !(stack_pointer_delta % preferred_unit_stack_boundary));
3155 /* Generate the actual call instruction. */
3156 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
3157 adjusted_args_size.constant, struct_value_size,
3158 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3159 flags, args_so_far);
3161 /* If the call setup or the call itself overlaps with anything
3162 of the argument setup we probably clobbered our call address.
3163 In that case we can't do sibcalls. */
3164 if (pass == 0
3165 && check_sibcall_argument_overlap (after_args, 0, 0))
3166 sibcall_failure = 1;
3168 /* If a non-BLKmode value is returned at the most significant end
3169 of a register, shift the register right by the appropriate amount
3170 and update VALREG accordingly. BLKmode values are handled by the
3171 group load/store machinery below. */
3172 if (!structure_value_addr
3173 && !pcc_struct_value
3174 && TYPE_MODE (rettype) != BLKmode
3175 && targetm.calls.return_in_msb (rettype))
3177 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
3178 sibcall_failure = 1;
3179 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
3182 if (pass && (flags & ECF_MALLOC))
3184 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3185 rtx last, insns;
3187 /* The return value from a malloc-like function is a pointer. */
3188 if (TREE_CODE (rettype) == POINTER_TYPE)
3189 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3191 emit_move_insn (temp, valreg);
3193 /* The return value from a malloc-like function can not alias
3194 anything else. */
3195 last = get_last_insn ();
3196 add_reg_note (last, REG_NOALIAS, temp);
3198 /* Write out the sequence. */
3199 insns = get_insns ();
3200 end_sequence ();
3201 emit_insn (insns);
3202 valreg = temp;
3205 /* For calls to `setjmp', etc., inform
3206 function.c:setjmp_warnings that it should complain if
3207 nonvolatile values are live. For functions that cannot
3208 return, inform flow that control does not fall through. */
3210 if ((flags & ECF_NORETURN) || pass == 0)
3212 /* The barrier must be emitted
3213 immediately after the CALL_INSN. Some ports emit more
3214 than just a CALL_INSN above, so we must search for it here. */
3216 rtx last = get_last_insn ();
3217 while (!CALL_P (last))
3219 last = PREV_INSN (last);
3220 /* There was no CALL_INSN? */
3221 gcc_assert (last != before_call);
3224 emit_barrier_after (last);
3226 /* Stack adjustments after a noreturn call are dead code.
3227 However when NO_DEFER_POP is in effect, we must preserve
3228 stack_pointer_delta. */
3229 if (inhibit_defer_pop == 0)
3231 stack_pointer_delta = old_stack_allocated;
3232 pending_stack_adjust = 0;
3236 /* If value type not void, return an rtx for the value. */
3238 if (TYPE_MODE (rettype) == VOIDmode
3239 || ignore)
3240 target = const0_rtx;
3241 else if (structure_value_addr)
3243 if (target == 0 || !MEM_P (target))
3245 target
3246 = gen_rtx_MEM (TYPE_MODE (rettype),
3247 memory_address (TYPE_MODE (rettype),
3248 structure_value_addr));
3249 set_mem_attributes (target, rettype, 1);
3252 else if (pcc_struct_value)
3254 /* This is the special C++ case where we need to
3255 know what the true target was. We take care to
3256 never use this value more than once in one expression. */
3257 target = gen_rtx_MEM (TYPE_MODE (rettype),
3258 copy_to_reg (valreg));
3259 set_mem_attributes (target, rettype, 1);
3261 /* Handle calls that return values in multiple non-contiguous locations.
3262 The Irix 6 ABI has examples of this. */
3263 else if (GET_CODE (valreg) == PARALLEL)
3265 if (target == 0)
3266 target = emit_group_move_into_temps (valreg);
3267 else if (rtx_equal_p (target, valreg))
3269 else if (GET_CODE (target) == PARALLEL)
3270 /* Handle the result of a emit_group_move_into_temps
3271 call in the previous pass. */
3272 emit_group_move (target, valreg);
3273 else
3274 emit_group_store (target, valreg, rettype,
3275 int_size_in_bytes (rettype));
3277 else if (target
3278 && GET_MODE (target) == TYPE_MODE (rettype)
3279 && GET_MODE (target) == GET_MODE (valreg))
3281 bool may_overlap = false;
3283 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3284 reg to a plain register. */
3285 if (!REG_P (target) || HARD_REGISTER_P (target))
3286 valreg = avoid_likely_spilled_reg (valreg);
3288 /* If TARGET is a MEM in the argument area, and we have
3289 saved part of the argument area, then we can't store
3290 directly into TARGET as it may get overwritten when we
3291 restore the argument save area below. Don't work too
3292 hard though and simply force TARGET to a register if it
3293 is a MEM; the optimizer is quite likely to sort it out. */
3294 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
3295 for (i = 0; i < num_actuals; i++)
3296 if (args[i].save_area)
3298 may_overlap = true;
3299 break;
3302 if (may_overlap)
3303 target = copy_to_reg (valreg);
3304 else
3306 /* TARGET and VALREG cannot be equal at this point
3307 because the latter would not have
3308 REG_FUNCTION_VALUE_P true, while the former would if
3309 it were referring to the same register.
3311 If they refer to the same register, this move will be
3312 a no-op, except when function inlining is being
3313 done. */
3314 emit_move_insn (target, valreg);
3316 /* If we are setting a MEM, this code must be executed.
3317 Since it is emitted after the call insn, sibcall
3318 optimization cannot be performed in that case. */
3319 if (MEM_P (target))
3320 sibcall_failure = 1;
3323 else
3324 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3326 /* If we promoted this return value, make the proper SUBREG.
3327 TARGET might be const0_rtx here, so be careful. */
3328 if (REG_P (target)
3329 && TYPE_MODE (rettype) != BLKmode
3330 && GET_MODE (target) != TYPE_MODE (rettype))
3332 tree type = rettype;
3333 int unsignedp = TYPE_UNSIGNED (type);
3334 int offset = 0;
3335 enum machine_mode pmode;
3337 /* Ensure we promote as expected, and get the new unsignedness. */
3338 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3339 funtype, 1);
3340 gcc_assert (GET_MODE (target) == pmode);
3342 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3343 && (GET_MODE_SIZE (GET_MODE (target))
3344 > GET_MODE_SIZE (TYPE_MODE (type))))
3346 offset = GET_MODE_SIZE (GET_MODE (target))
3347 - GET_MODE_SIZE (TYPE_MODE (type));
3348 if (! BYTES_BIG_ENDIAN)
3349 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3350 else if (! WORDS_BIG_ENDIAN)
3351 offset %= UNITS_PER_WORD;
3354 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3355 SUBREG_PROMOTED_VAR_P (target) = 1;
3356 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3359 /* If size of args is variable or this was a constructor call for a stack
3360 argument, restore saved stack-pointer value. */
3362 if (old_stack_level)
3364 rtx prev = get_last_insn ();
3366 emit_stack_restore (SAVE_BLOCK, old_stack_level);
3367 stack_pointer_delta = old_stack_pointer_delta;
3369 fixup_args_size_notes (prev, get_last_insn (), stack_pointer_delta);
3371 pending_stack_adjust = old_pending_adj;
3372 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3373 stack_arg_under_construction = old_stack_arg_under_construction;
3374 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3375 stack_usage_map = initial_stack_usage_map;
3376 sibcall_failure = 1;
3378 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3380 #ifdef REG_PARM_STACK_SPACE
3381 if (save_area)
3382 restore_fixed_argument_area (save_area, argblock,
3383 high_to_save, low_to_save);
3384 #endif
3386 /* If we saved any argument areas, restore them. */
3387 for (i = 0; i < num_actuals; i++)
3388 if (args[i].save_area)
3390 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3391 rtx stack_area
3392 = gen_rtx_MEM (save_mode,
3393 memory_address (save_mode,
3394 XEXP (args[i].stack_slot, 0)));
3396 if (save_mode != BLKmode)
3397 emit_move_insn (stack_area, args[i].save_area);
3398 else
3399 emit_block_move (stack_area, args[i].save_area,
3400 GEN_INT (args[i].locate.size.constant),
3401 BLOCK_OP_CALL_PARM);
3404 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3405 stack_usage_map = initial_stack_usage_map;
3408 /* If this was alloca, record the new stack level for nonlocal gotos.
3409 Check for the handler slots since we might not have a save area
3410 for non-local gotos. */
3412 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3413 update_nonlocal_goto_save_area ();
3415 /* Free up storage we no longer need. */
3416 for (i = 0; i < num_actuals; ++i)
3417 free (args[i].aligned_regs);
3419 insns = get_insns ();
3420 end_sequence ();
3422 if (pass == 0)
3424 tail_call_insns = insns;
3426 /* Restore the pending stack adjustment now that we have
3427 finished generating the sibling call sequence. */
3429 pending_stack_adjust = save_pending_stack_adjust;
3430 stack_pointer_delta = save_stack_pointer_delta;
3432 /* Prepare arg structure for next iteration. */
3433 for (i = 0; i < num_actuals; i++)
3435 args[i].value = 0;
3436 args[i].aligned_regs = 0;
3437 args[i].stack = 0;
3440 sbitmap_free (stored_args_map);
3441 internal_arg_pointer_exp_state.scan_start = NULL_RTX;
3442 internal_arg_pointer_exp_state.cache.release ();
3444 else
3446 normal_call_insns = insns;
3448 /* Verify that we've deallocated all the stack we used. */
3449 gcc_assert ((flags & ECF_NORETURN)
3450 || (old_stack_allocated
3451 == stack_pointer_delta - pending_stack_adjust));
3454 /* If something prevents making this a sibling call,
3455 zero out the sequence. */
3456 if (sibcall_failure)
3457 tail_call_insns = NULL_RTX;
3458 else
3459 break;
3462 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3463 arguments too, as argument area is now clobbered by the call. */
3464 if (tail_call_insns)
3466 emit_insn (tail_call_insns);
3467 crtl->tail_call_emit = true;
3469 else
3470 emit_insn (normal_call_insns);
3472 currently_expanding_call--;
3474 free (stack_usage_map_buf);
3476 return target;
3479 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3480 this function's incoming arguments.
3482 At the start of RTL generation we know the only REG_EQUIV notes
3483 in the rtl chain are those for incoming arguments, so we can look
3484 for REG_EQUIV notes between the start of the function and the
3485 NOTE_INSN_FUNCTION_BEG.
3487 This is (slight) overkill. We could keep track of the highest
3488 argument we clobber and be more selective in removing notes, but it
3489 does not seem to be worth the effort. */
3491 void
3492 fixup_tail_calls (void)
3494 rtx insn;
3496 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3498 rtx note;
3500 /* There are never REG_EQUIV notes for the incoming arguments
3501 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3502 if (NOTE_P (insn)
3503 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3504 break;
3506 note = find_reg_note (insn, REG_EQUIV, 0);
3507 if (note)
3508 remove_note (insn, note);
3509 note = find_reg_note (insn, REG_EQUIV, 0);
3510 gcc_assert (!note);
3514 /* Traverse a list of TYPES and expand all complex types into their
3515 components. */
3516 static tree
3517 split_complex_types (tree types)
3519 tree p;
3521 /* Before allocating memory, check for the common case of no complex. */
3522 for (p = types; p; p = TREE_CHAIN (p))
3524 tree type = TREE_VALUE (p);
3525 if (TREE_CODE (type) == COMPLEX_TYPE
3526 && targetm.calls.split_complex_arg (type))
3527 goto found;
3529 return types;
3531 found:
3532 types = copy_list (types);
3534 for (p = types; p; p = TREE_CHAIN (p))
3536 tree complex_type = TREE_VALUE (p);
3538 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3539 && targetm.calls.split_complex_arg (complex_type))
3541 tree next, imag;
3543 /* Rewrite complex type with component type. */
3544 TREE_VALUE (p) = TREE_TYPE (complex_type);
3545 next = TREE_CHAIN (p);
3547 /* Add another component type for the imaginary part. */
3548 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3549 TREE_CHAIN (p) = imag;
3550 TREE_CHAIN (imag) = next;
3552 /* Skip the newly created node. */
3553 p = TREE_CHAIN (p);
3557 return types;
3560 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3561 The RETVAL parameter specifies whether return value needs to be saved, other
3562 parameters are documented in the emit_library_call function below. */
3564 static rtx
3565 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3566 enum libcall_type fn_type,
3567 enum machine_mode outmode, int nargs, va_list p)
3569 /* Total size in bytes of all the stack-parms scanned so far. */
3570 struct args_size args_size;
3571 /* Size of arguments before any adjustments (such as rounding). */
3572 struct args_size original_args_size;
3573 int argnum;
3574 rtx fun;
3575 /* Todo, choose the correct decl type of orgfun. Sadly this information
3576 isn't present here, so we default to native calling abi here. */
3577 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3578 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3579 int inc;
3580 int count;
3581 rtx argblock = 0;
3582 CUMULATIVE_ARGS args_so_far_v;
3583 cumulative_args_t args_so_far;
3584 struct arg
3586 rtx value;
3587 enum machine_mode mode;
3588 rtx reg;
3589 int partial;
3590 struct locate_and_pad_arg_data locate;
3591 rtx save_area;
3593 struct arg *argvec;
3594 int old_inhibit_defer_pop = inhibit_defer_pop;
3595 rtx call_fusage = 0;
3596 rtx mem_value = 0;
3597 rtx valreg;
3598 int pcc_struct_value = 0;
3599 int struct_value_size = 0;
3600 int flags;
3601 int reg_parm_stack_space = 0;
3602 int needed;
3603 rtx before_call;
3604 tree tfom; /* type_for_mode (outmode, 0) */
3606 #ifdef REG_PARM_STACK_SPACE
3607 /* Define the boundary of the register parm stack space that needs to be
3608 save, if any. */
3609 int low_to_save = 0, high_to_save = 0;
3610 rtx save_area = 0; /* Place that it is saved. */
3611 #endif
3613 /* Size of the stack reserved for parameter registers. */
3614 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3615 char *initial_stack_usage_map = stack_usage_map;
3616 char *stack_usage_map_buf = NULL;
3618 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3620 #ifdef REG_PARM_STACK_SPACE
3621 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3622 #endif
3624 /* By default, library functions can not throw. */
3625 flags = ECF_NOTHROW;
3627 switch (fn_type)
3629 case LCT_NORMAL:
3630 break;
3631 case LCT_CONST:
3632 flags |= ECF_CONST;
3633 break;
3634 case LCT_PURE:
3635 flags |= ECF_PURE;
3636 break;
3637 case LCT_NORETURN:
3638 flags |= ECF_NORETURN;
3639 break;
3640 case LCT_THROW:
3641 flags = ECF_NORETURN;
3642 break;
3643 case LCT_RETURNS_TWICE:
3644 flags = ECF_RETURNS_TWICE;
3645 break;
3647 fun = orgfun;
3649 /* Ensure current function's preferred stack boundary is at least
3650 what we need. */
3651 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3652 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3654 /* If this kind of value comes back in memory,
3655 decide where in memory it should come back. */
3656 if (outmode != VOIDmode)
3658 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3659 if (aggregate_value_p (tfom, 0))
3661 #ifdef PCC_STATIC_STRUCT_RETURN
3662 rtx pointer_reg
3663 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3664 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3665 pcc_struct_value = 1;
3666 if (value == 0)
3667 value = gen_reg_rtx (outmode);
3668 #else /* not PCC_STATIC_STRUCT_RETURN */
3669 struct_value_size = GET_MODE_SIZE (outmode);
3670 if (value != 0 && MEM_P (value))
3671 mem_value = value;
3672 else
3673 mem_value = assign_temp (tfom, 1, 1);
3674 #endif
3675 /* This call returns a big structure. */
3676 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3679 else
3680 tfom = void_type_node;
3682 /* ??? Unfinished: must pass the memory address as an argument. */
3684 /* Copy all the libcall-arguments out of the varargs data
3685 and into a vector ARGVEC.
3687 Compute how to pass each argument. We only support a very small subset
3688 of the full argument passing conventions to limit complexity here since
3689 library functions shouldn't have many args. */
3691 argvec = XALLOCAVEC (struct arg, nargs + 1);
3692 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3694 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3695 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far_v, outmode, fun);
3696 #else
3697 INIT_CUMULATIVE_ARGS (args_so_far_v, NULL_TREE, fun, 0, nargs);
3698 #endif
3699 args_so_far = pack_cumulative_args (&args_so_far_v);
3701 args_size.constant = 0;
3702 args_size.var = 0;
3704 count = 0;
3706 push_temp_slots ();
3708 /* If there's a structure value address to be passed,
3709 either pass it in the special place, or pass it as an extra argument. */
3710 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3712 rtx addr = XEXP (mem_value, 0);
3714 nargs++;
3716 /* Make sure it is a reasonable operand for a move or push insn. */
3717 if (!REG_P (addr) && !MEM_P (addr)
3718 && !(CONSTANT_P (addr)
3719 && targetm.legitimate_constant_p (Pmode, addr)))
3720 addr = force_operand (addr, NULL_RTX);
3722 argvec[count].value = addr;
3723 argvec[count].mode = Pmode;
3724 argvec[count].partial = 0;
3726 argvec[count].reg = targetm.calls.function_arg (args_so_far,
3727 Pmode, NULL_TREE, true);
3728 gcc_assert (targetm.calls.arg_partial_bytes (args_so_far, Pmode,
3729 NULL_TREE, 1) == 0);
3731 locate_and_pad_parm (Pmode, NULL_TREE,
3732 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3734 #else
3735 argvec[count].reg != 0,
3736 #endif
3737 0, NULL_TREE, &args_size, &argvec[count].locate);
3739 if (argvec[count].reg == 0 || argvec[count].partial != 0
3740 || reg_parm_stack_space > 0)
3741 args_size.constant += argvec[count].locate.size.constant;
3743 targetm.calls.function_arg_advance (args_so_far, Pmode, (tree) 0, true);
3745 count++;
3748 for (; count < nargs; count++)
3750 rtx val = va_arg (p, rtx);
3751 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3752 int unsigned_p = 0;
3754 /* We cannot convert the arg value to the mode the library wants here;
3755 must do it earlier where we know the signedness of the arg. */
3756 gcc_assert (mode != BLKmode
3757 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3759 /* Make sure it is a reasonable operand for a move or push insn. */
3760 if (!REG_P (val) && !MEM_P (val)
3761 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
3762 val = force_operand (val, NULL_RTX);
3764 if (pass_by_reference (&args_so_far_v, mode, NULL_TREE, 1))
3766 rtx slot;
3767 int must_copy
3768 = !reference_callee_copied (&args_so_far_v, mode, NULL_TREE, 1);
3770 /* If this was a CONST function, it is now PURE since it now
3771 reads memory. */
3772 if (flags & ECF_CONST)
3774 flags &= ~ECF_CONST;
3775 flags |= ECF_PURE;
3778 if (MEM_P (val) && !must_copy)
3780 tree val_expr = MEM_EXPR (val);
3781 if (val_expr)
3782 mark_addressable (val_expr);
3783 slot = val;
3785 else
3787 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3788 1, 1);
3789 emit_move_insn (slot, val);
3792 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3793 gen_rtx_USE (VOIDmode, slot),
3794 call_fusage);
3795 if (must_copy)
3796 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3797 gen_rtx_CLOBBER (VOIDmode,
3798 slot),
3799 call_fusage);
3801 mode = Pmode;
3802 val = force_operand (XEXP (slot, 0), NULL_RTX);
3805 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
3806 argvec[count].mode = mode;
3807 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
3808 argvec[count].reg = targetm.calls.function_arg (args_so_far, mode,
3809 NULL_TREE, true);
3811 argvec[count].partial
3812 = targetm.calls.arg_partial_bytes (args_so_far, mode, NULL_TREE, 1);
3814 if (argvec[count].reg == 0
3815 || argvec[count].partial != 0
3816 || reg_parm_stack_space > 0)
3818 locate_and_pad_parm (mode, NULL_TREE,
3819 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3821 #else
3822 argvec[count].reg != 0,
3823 #endif
3824 argvec[count].partial,
3825 NULL_TREE, &args_size, &argvec[count].locate);
3826 args_size.constant += argvec[count].locate.size.constant;
3827 gcc_assert (!argvec[count].locate.size.var);
3829 #ifdef BLOCK_REG_PADDING
3830 else
3831 /* The argument is passed entirely in registers. See at which
3832 end it should be padded. */
3833 argvec[count].locate.where_pad =
3834 BLOCK_REG_PADDING (mode, NULL_TREE,
3835 GET_MODE_SIZE (mode) <= UNITS_PER_WORD);
3836 #endif
3838 targetm.calls.function_arg_advance (args_so_far, mode, (tree) 0, true);
3841 /* If this machine requires an external definition for library
3842 functions, write one out. */
3843 assemble_external_libcall (fun);
3845 original_args_size = args_size;
3846 args_size.constant = (((args_size.constant
3847 + stack_pointer_delta
3848 + STACK_BYTES - 1)
3849 / STACK_BYTES
3850 * STACK_BYTES)
3851 - stack_pointer_delta);
3853 args_size.constant = MAX (args_size.constant,
3854 reg_parm_stack_space);
3856 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3857 args_size.constant -= reg_parm_stack_space;
3859 if (args_size.constant > crtl->outgoing_args_size)
3860 crtl->outgoing_args_size = args_size.constant;
3862 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
3864 int pushed = args_size.constant + pending_stack_adjust;
3865 if (pushed > current_function_pushed_stack_size)
3866 current_function_pushed_stack_size = pushed;
3869 if (ACCUMULATE_OUTGOING_ARGS)
3871 /* Since the stack pointer will never be pushed, it is possible for
3872 the evaluation of a parm to clobber something we have already
3873 written to the stack. Since most function calls on RISC machines
3874 do not use the stack, this is uncommon, but must work correctly.
3876 Therefore, we save any area of the stack that was already written
3877 and that we are using. Here we set up to do this by making a new
3878 stack usage map from the old one.
3880 Another approach might be to try to reorder the argument
3881 evaluations to avoid this conflicting stack usage. */
3883 needed = args_size.constant;
3885 /* Since we will be writing into the entire argument area, the
3886 map must be allocated for its entire size, not just the part that
3887 is the responsibility of the caller. */
3888 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3889 needed += reg_parm_stack_space;
3891 #ifdef ARGS_GROW_DOWNWARD
3892 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3893 needed + 1);
3894 #else
3895 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3896 needed);
3897 #endif
3898 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3899 stack_usage_map = stack_usage_map_buf;
3901 if (initial_highest_arg_in_use)
3902 memcpy (stack_usage_map, initial_stack_usage_map,
3903 initial_highest_arg_in_use);
3905 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3906 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3907 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3908 needed = 0;
3910 /* We must be careful to use virtual regs before they're instantiated,
3911 and real regs afterwards. Loop optimization, for example, can create
3912 new libcalls after we've instantiated the virtual regs, and if we
3913 use virtuals anyway, they won't match the rtl patterns. */
3915 if (virtuals_instantiated)
3916 argblock = plus_constant (Pmode, stack_pointer_rtx,
3917 STACK_POINTER_OFFSET);
3918 else
3919 argblock = virtual_outgoing_args_rtx;
3921 else
3923 if (!PUSH_ARGS)
3924 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3927 /* If we push args individually in reverse order, perform stack alignment
3928 before the first push (the last arg). */
3929 if (argblock == 0 && PUSH_ARGS_REVERSED)
3930 anti_adjust_stack (GEN_INT (args_size.constant
3931 - original_args_size.constant));
3933 if (PUSH_ARGS_REVERSED)
3935 inc = -1;
3936 argnum = nargs - 1;
3938 else
3940 inc = 1;
3941 argnum = 0;
3944 #ifdef REG_PARM_STACK_SPACE
3945 if (ACCUMULATE_OUTGOING_ARGS)
3947 /* The argument list is the property of the called routine and it
3948 may clobber it. If the fixed area has been used for previous
3949 parameters, we must save and restore it. */
3950 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3951 &low_to_save, &high_to_save);
3953 #endif
3955 /* Push the args that need to be pushed. */
3957 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3958 are to be pushed. */
3959 for (count = 0; count < nargs; count++, argnum += inc)
3961 enum machine_mode mode = argvec[argnum].mode;
3962 rtx val = argvec[argnum].value;
3963 rtx reg = argvec[argnum].reg;
3964 int partial = argvec[argnum].partial;
3965 unsigned int parm_align = argvec[argnum].locate.boundary;
3966 int lower_bound = 0, upper_bound = 0, i;
3968 if (! (reg != 0 && partial == 0))
3970 rtx use;
3972 if (ACCUMULATE_OUTGOING_ARGS)
3974 /* If this is being stored into a pre-allocated, fixed-size,
3975 stack area, save any previous data at that location. */
3977 #ifdef ARGS_GROW_DOWNWARD
3978 /* stack_slot is negative, but we want to index stack_usage_map
3979 with positive values. */
3980 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3981 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3982 #else
3983 lower_bound = argvec[argnum].locate.slot_offset.constant;
3984 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3985 #endif
3987 i = lower_bound;
3988 /* Don't worry about things in the fixed argument area;
3989 it has already been saved. */
3990 if (i < reg_parm_stack_space)
3991 i = reg_parm_stack_space;
3992 while (i < upper_bound && stack_usage_map[i] == 0)
3993 i++;
3995 if (i < upper_bound)
3997 /* We need to make a save area. */
3998 unsigned int size
3999 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4000 enum machine_mode save_mode
4001 = mode_for_size (size, MODE_INT, 1);
4002 rtx adr
4003 = plus_constant (Pmode, argblock,
4004 argvec[argnum].locate.offset.constant);
4005 rtx stack_area
4006 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4008 if (save_mode == BLKmode)
4010 argvec[argnum].save_area
4011 = assign_stack_temp (BLKmode,
4012 argvec[argnum].locate.size.constant
4015 emit_block_move (validize_mem (argvec[argnum].save_area),
4016 stack_area,
4017 GEN_INT (argvec[argnum].locate.size.constant),
4018 BLOCK_OP_CALL_PARM);
4020 else
4022 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4024 emit_move_insn (argvec[argnum].save_area, stack_area);
4029 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
4030 partial, reg, 0, argblock,
4031 GEN_INT (argvec[argnum].locate.offset.constant),
4032 reg_parm_stack_space,
4033 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4035 /* Now mark the segment we just used. */
4036 if (ACCUMULATE_OUTGOING_ARGS)
4037 for (i = lower_bound; i < upper_bound; i++)
4038 stack_usage_map[i] = 1;
4040 NO_DEFER_POP;
4042 /* Indicate argument access so that alias.c knows that these
4043 values are live. */
4044 if (argblock)
4045 use = plus_constant (Pmode, argblock,
4046 argvec[argnum].locate.offset.constant);
4047 else
4048 /* When arguments are pushed, trying to tell alias.c where
4049 exactly this argument is won't work, because the
4050 auto-increment causes confusion. So we merely indicate
4051 that we access something with a known mode somewhere on
4052 the stack. */
4053 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
4054 gen_rtx_SCRATCH (Pmode));
4055 use = gen_rtx_MEM (argvec[argnum].mode, use);
4056 use = gen_rtx_USE (VOIDmode, use);
4057 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
4061 /* If we pushed args in forward order, perform stack alignment
4062 after pushing the last arg. */
4063 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4064 anti_adjust_stack (GEN_INT (args_size.constant
4065 - original_args_size.constant));
4067 if (PUSH_ARGS_REVERSED)
4068 argnum = nargs - 1;
4069 else
4070 argnum = 0;
4072 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
4074 /* Now load any reg parms into their regs. */
4076 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4077 are to be pushed. */
4078 for (count = 0; count < nargs; count++, argnum += inc)
4080 enum machine_mode mode = argvec[argnum].mode;
4081 rtx val = argvec[argnum].value;
4082 rtx reg = argvec[argnum].reg;
4083 int partial = argvec[argnum].partial;
4084 #ifdef BLOCK_REG_PADDING
4085 int size = 0;
4086 #endif
4088 /* Handle calls that pass values in multiple non-contiguous
4089 locations. The PA64 has examples of this for library calls. */
4090 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4091 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
4092 else if (reg != 0 && partial == 0)
4094 emit_move_insn (reg, val);
4095 #ifdef BLOCK_REG_PADDING
4096 size = GET_MODE_SIZE (argvec[argnum].mode);
4098 /* Copied from load_register_parameters. */
4100 /* Handle case where we have a value that needs shifting
4101 up to the msb. eg. a QImode value and we're padding
4102 upward on a BYTES_BIG_ENDIAN machine. */
4103 if (size < UNITS_PER_WORD
4104 && (argvec[argnum].locate.where_pad
4105 == (BYTES_BIG_ENDIAN ? upward : downward)))
4107 rtx x;
4108 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
4110 /* Assigning REG here rather than a temp makes CALL_FUSAGE
4111 report the whole reg as used. Strictly speaking, the
4112 call only uses SIZE bytes at the msb end, but it doesn't
4113 seem worth generating rtl to say that. */
4114 reg = gen_rtx_REG (word_mode, REGNO (reg));
4115 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
4116 if (x != reg)
4117 emit_move_insn (reg, x);
4119 #endif
4122 NO_DEFER_POP;
4125 /* Any regs containing parms remain in use through the call. */
4126 for (count = 0; count < nargs; count++)
4128 rtx reg = argvec[count].reg;
4129 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4130 use_group_regs (&call_fusage, reg);
4131 else if (reg != 0)
4133 int partial = argvec[count].partial;
4134 if (partial)
4136 int nregs;
4137 gcc_assert (partial % UNITS_PER_WORD == 0);
4138 nregs = partial / UNITS_PER_WORD;
4139 use_regs (&call_fusage, REGNO (reg), nregs);
4141 else
4142 use_reg (&call_fusage, reg);
4146 /* Pass the function the address in which to return a structure value. */
4147 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4149 emit_move_insn (struct_value,
4150 force_reg (Pmode,
4151 force_operand (XEXP (mem_value, 0),
4152 NULL_RTX)));
4153 if (REG_P (struct_value))
4154 use_reg (&call_fusage, struct_value);
4157 /* Don't allow popping to be deferred, since then
4158 cse'ing of library calls could delete a call and leave the pop. */
4159 NO_DEFER_POP;
4160 valreg = (mem_value == 0 && outmode != VOIDmode
4161 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
4163 /* Stack must be properly aligned now. */
4164 gcc_assert (!(stack_pointer_delta
4165 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
4167 before_call = get_last_insn ();
4169 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4170 will set inhibit_defer_pop to that value. */
4171 /* The return type is needed to decide how many bytes the function pops.
4172 Signedness plays no role in that, so for simplicity, we pretend it's
4173 always signed. We also assume that the list of arguments passed has
4174 no impact, so we pretend it is unknown. */
4176 emit_call_1 (fun, NULL,
4177 get_identifier (XSTR (orgfun, 0)),
4178 build_function_type (tfom, NULL_TREE),
4179 original_args_size.constant, args_size.constant,
4180 struct_value_size,
4181 targetm.calls.function_arg (args_so_far,
4182 VOIDmode, void_type_node, true),
4183 valreg,
4184 old_inhibit_defer_pop + 1, call_fusage, flags, args_so_far);
4186 /* Right-shift returned value if necessary. */
4187 if (!pcc_struct_value
4188 && TYPE_MODE (tfom) != BLKmode
4189 && targetm.calls.return_in_msb (tfom))
4191 shift_return_value (TYPE_MODE (tfom), false, valreg);
4192 valreg = gen_rtx_REG (TYPE_MODE (tfom), REGNO (valreg));
4195 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
4196 that it should complain if nonvolatile values are live. For
4197 functions that cannot return, inform flow that control does not
4198 fall through. */
4199 if (flags & ECF_NORETURN)
4201 /* The barrier note must be emitted
4202 immediately after the CALL_INSN. Some ports emit more than
4203 just a CALL_INSN above, so we must search for it here. */
4204 rtx last = get_last_insn ();
4205 while (!CALL_P (last))
4207 last = PREV_INSN (last);
4208 /* There was no CALL_INSN? */
4209 gcc_assert (last != before_call);
4212 emit_barrier_after (last);
4215 /* Consider that "regular" libcalls, i.e. all of them except for LCT_THROW
4216 and LCT_RETURNS_TWICE, cannot perform non-local gotos. */
4217 if (flags & ECF_NOTHROW)
4219 rtx last = get_last_insn ();
4220 while (!CALL_P (last))
4222 last = PREV_INSN (last);
4223 /* There was no CALL_INSN? */
4224 gcc_assert (last != before_call);
4227 make_reg_eh_region_note_nothrow_nononlocal (last);
4230 /* Now restore inhibit_defer_pop to its actual original value. */
4231 OK_DEFER_POP;
4233 pop_temp_slots ();
4235 /* Copy the value to the right place. */
4236 if (outmode != VOIDmode && retval)
4238 if (mem_value)
4240 if (value == 0)
4241 value = mem_value;
4242 if (value != mem_value)
4243 emit_move_insn (value, mem_value);
4245 else if (GET_CODE (valreg) == PARALLEL)
4247 if (value == 0)
4248 value = gen_reg_rtx (outmode);
4249 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4251 else
4253 /* Convert to the proper mode if a promotion has been active. */
4254 if (GET_MODE (valreg) != outmode)
4256 int unsignedp = TYPE_UNSIGNED (tfom);
4258 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
4259 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
4260 == GET_MODE (valreg));
4261 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
4264 if (value != 0)
4265 emit_move_insn (value, valreg);
4266 else
4267 value = valreg;
4271 if (ACCUMULATE_OUTGOING_ARGS)
4273 #ifdef REG_PARM_STACK_SPACE
4274 if (save_area)
4275 restore_fixed_argument_area (save_area, argblock,
4276 high_to_save, low_to_save);
4277 #endif
4279 /* If we saved any argument areas, restore them. */
4280 for (count = 0; count < nargs; count++)
4281 if (argvec[count].save_area)
4283 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4284 rtx adr = plus_constant (Pmode, argblock,
4285 argvec[count].locate.offset.constant);
4286 rtx stack_area = gen_rtx_MEM (save_mode,
4287 memory_address (save_mode, adr));
4289 if (save_mode == BLKmode)
4290 emit_block_move (stack_area,
4291 validize_mem (argvec[count].save_area),
4292 GEN_INT (argvec[count].locate.size.constant),
4293 BLOCK_OP_CALL_PARM);
4294 else
4295 emit_move_insn (stack_area, argvec[count].save_area);
4298 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4299 stack_usage_map = initial_stack_usage_map;
4302 free (stack_usage_map_buf);
4304 return value;
4308 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4309 (emitting the queue unless NO_QUEUE is nonzero),
4310 for a value of mode OUTMODE,
4311 with NARGS different arguments, passed as alternating rtx values
4312 and machine_modes to convert them to.
4314 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
4315 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
4316 other types of library calls. */
4318 void
4319 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4320 enum machine_mode outmode, int nargs, ...)
4322 va_list p;
4324 va_start (p, nargs);
4325 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4326 va_end (p);
4329 /* Like emit_library_call except that an extra argument, VALUE,
4330 comes second and says where to store the result.
4331 (If VALUE is zero, this function chooses a convenient way
4332 to return the value.
4334 This function returns an rtx for where the value is to be found.
4335 If VALUE is nonzero, VALUE is returned. */
4338 emit_library_call_value (rtx orgfun, rtx value,
4339 enum libcall_type fn_type,
4340 enum machine_mode outmode, int nargs, ...)
4342 rtx result;
4343 va_list p;
4345 va_start (p, nargs);
4346 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4347 nargs, p);
4348 va_end (p);
4350 return result;
4353 /* Store a single argument for a function call
4354 into the register or memory area where it must be passed.
4355 *ARG describes the argument value and where to pass it.
4357 ARGBLOCK is the address of the stack-block for all the arguments,
4358 or 0 on a machine where arguments are pushed individually.
4360 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4361 so must be careful about how the stack is used.
4363 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4364 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4365 that we need not worry about saving and restoring the stack.
4367 FNDECL is the declaration of the function we are calling.
4369 Return nonzero if this arg should cause sibcall failure,
4370 zero otherwise. */
4372 static int
4373 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4374 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4376 tree pval = arg->tree_value;
4377 rtx reg = 0;
4378 int partial = 0;
4379 int used = 0;
4380 int i, lower_bound = 0, upper_bound = 0;
4381 int sibcall_failure = 0;
4383 if (TREE_CODE (pval) == ERROR_MARK)
4384 return 1;
4386 /* Push a new temporary level for any temporaries we make for
4387 this argument. */
4388 push_temp_slots ();
4390 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4392 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4393 save any previous data at that location. */
4394 if (argblock && ! variable_size && arg->stack)
4396 #ifdef ARGS_GROW_DOWNWARD
4397 /* stack_slot is negative, but we want to index stack_usage_map
4398 with positive values. */
4399 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4400 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4401 else
4402 upper_bound = 0;
4404 lower_bound = upper_bound - arg->locate.size.constant;
4405 #else
4406 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4407 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4408 else
4409 lower_bound = 0;
4411 upper_bound = lower_bound + arg->locate.size.constant;
4412 #endif
4414 i = lower_bound;
4415 /* Don't worry about things in the fixed argument area;
4416 it has already been saved. */
4417 if (i < reg_parm_stack_space)
4418 i = reg_parm_stack_space;
4419 while (i < upper_bound && stack_usage_map[i] == 0)
4420 i++;
4422 if (i < upper_bound)
4424 /* We need to make a save area. */
4425 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4426 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4427 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4428 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4430 if (save_mode == BLKmode)
4432 tree ot = TREE_TYPE (arg->tree_value);
4433 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4434 | TYPE_QUAL_CONST));
4436 arg->save_area = assign_temp (nt, 1, 1);
4437 preserve_temp_slots (arg->save_area);
4438 emit_block_move (validize_mem (arg->save_area), stack_area,
4439 GEN_INT (arg->locate.size.constant),
4440 BLOCK_OP_CALL_PARM);
4442 else
4444 arg->save_area = gen_reg_rtx (save_mode);
4445 emit_move_insn (arg->save_area, stack_area);
4451 /* If this isn't going to be placed on both the stack and in registers,
4452 set up the register and number of words. */
4453 if (! arg->pass_on_stack)
4455 if (flags & ECF_SIBCALL)
4456 reg = arg->tail_call_reg;
4457 else
4458 reg = arg->reg;
4459 partial = arg->partial;
4462 /* Being passed entirely in a register. We shouldn't be called in
4463 this case. */
4464 gcc_assert (reg == 0 || partial != 0);
4466 /* If this arg needs special alignment, don't load the registers
4467 here. */
4468 if (arg->n_aligned_regs != 0)
4469 reg = 0;
4471 /* If this is being passed partially in a register, we can't evaluate
4472 it directly into its stack slot. Otherwise, we can. */
4473 if (arg->value == 0)
4475 /* stack_arg_under_construction is nonzero if a function argument is
4476 being evaluated directly into the outgoing argument list and
4477 expand_call must take special action to preserve the argument list
4478 if it is called recursively.
4480 For scalar function arguments stack_usage_map is sufficient to
4481 determine which stack slots must be saved and restored. Scalar
4482 arguments in general have pass_on_stack == 0.
4484 If this argument is initialized by a function which takes the
4485 address of the argument (a C++ constructor or a C function
4486 returning a BLKmode structure), then stack_usage_map is
4487 insufficient and expand_call must push the stack around the
4488 function call. Such arguments have pass_on_stack == 1.
4490 Note that it is always safe to set stack_arg_under_construction,
4491 but this generates suboptimal code if set when not needed. */
4493 if (arg->pass_on_stack)
4494 stack_arg_under_construction++;
4496 arg->value = expand_expr (pval,
4497 (partial
4498 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4499 ? NULL_RTX : arg->stack,
4500 VOIDmode, EXPAND_STACK_PARM);
4502 /* If we are promoting object (or for any other reason) the mode
4503 doesn't agree, convert the mode. */
4505 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4506 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4507 arg->value, arg->unsignedp);
4509 if (arg->pass_on_stack)
4510 stack_arg_under_construction--;
4513 /* Check for overlap with already clobbered argument area. */
4514 if ((flags & ECF_SIBCALL)
4515 && MEM_P (arg->value)
4516 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4517 arg->locate.size.constant))
4518 sibcall_failure = 1;
4520 /* Don't allow anything left on stack from computation
4521 of argument to alloca. */
4522 if (flags & ECF_MAY_BE_ALLOCA)
4523 do_pending_stack_adjust ();
4525 if (arg->value == arg->stack)
4526 /* If the value is already in the stack slot, we are done. */
4528 else if (arg->mode != BLKmode)
4530 int size;
4531 unsigned int parm_align;
4533 /* Argument is a scalar, not entirely passed in registers.
4534 (If part is passed in registers, arg->partial says how much
4535 and emit_push_insn will take care of putting it there.)
4537 Push it, and if its size is less than the
4538 amount of space allocated to it,
4539 also bump stack pointer by the additional space.
4540 Note that in C the default argument promotions
4541 will prevent such mismatches. */
4543 size = GET_MODE_SIZE (arg->mode);
4544 /* Compute how much space the push instruction will push.
4545 On many machines, pushing a byte will advance the stack
4546 pointer by a halfword. */
4547 #ifdef PUSH_ROUNDING
4548 size = PUSH_ROUNDING (size);
4549 #endif
4550 used = size;
4552 /* Compute how much space the argument should get:
4553 round up to a multiple of the alignment for arguments. */
4554 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4555 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4556 / (PARM_BOUNDARY / BITS_PER_UNIT))
4557 * (PARM_BOUNDARY / BITS_PER_UNIT));
4559 /* Compute the alignment of the pushed argument. */
4560 parm_align = arg->locate.boundary;
4561 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4563 int pad = used - size;
4564 if (pad)
4566 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4567 parm_align = MIN (parm_align, pad_align);
4571 /* This isn't already where we want it on the stack, so put it there.
4572 This can either be done with push or copy insns. */
4573 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4574 parm_align, partial, reg, used - size, argblock,
4575 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4576 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4578 /* Unless this is a partially-in-register argument, the argument is now
4579 in the stack. */
4580 if (partial == 0)
4581 arg->value = arg->stack;
4583 else
4585 /* BLKmode, at least partly to be pushed. */
4587 unsigned int parm_align;
4588 int excess;
4589 rtx size_rtx;
4591 /* Pushing a nonscalar.
4592 If part is passed in registers, PARTIAL says how much
4593 and emit_push_insn will take care of putting it there. */
4595 /* Round its size up to a multiple
4596 of the allocation unit for arguments. */
4598 if (arg->locate.size.var != 0)
4600 excess = 0;
4601 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4603 else
4605 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4606 for BLKmode is careful to avoid it. */
4607 excess = (arg->locate.size.constant
4608 - int_size_in_bytes (TREE_TYPE (pval))
4609 + partial);
4610 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4611 NULL_RTX, TYPE_MODE (sizetype),
4612 EXPAND_NORMAL);
4615 parm_align = arg->locate.boundary;
4617 /* When an argument is padded down, the block is aligned to
4618 PARM_BOUNDARY, but the actual argument isn't. */
4619 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4621 if (arg->locate.size.var)
4622 parm_align = BITS_PER_UNIT;
4623 else if (excess)
4625 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4626 parm_align = MIN (parm_align, excess_align);
4630 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4632 /* emit_push_insn might not work properly if arg->value and
4633 argblock + arg->locate.offset areas overlap. */
4634 rtx x = arg->value;
4635 int i = 0;
4637 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4638 || (GET_CODE (XEXP (x, 0)) == PLUS
4639 && XEXP (XEXP (x, 0), 0) ==
4640 crtl->args.internal_arg_pointer
4641 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4643 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4644 i = INTVAL (XEXP (XEXP (x, 0), 1));
4646 /* expand_call should ensure this. */
4647 gcc_assert (!arg->locate.offset.var
4648 && arg->locate.size.var == 0
4649 && CONST_INT_P (size_rtx));
4651 if (arg->locate.offset.constant > i)
4653 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4654 sibcall_failure = 1;
4656 else if (arg->locate.offset.constant < i)
4658 /* Use arg->locate.size.constant instead of size_rtx
4659 because we only care about the part of the argument
4660 on the stack. */
4661 if (i < (arg->locate.offset.constant
4662 + arg->locate.size.constant))
4663 sibcall_failure = 1;
4665 else
4667 /* Even though they appear to be at the same location,
4668 if part of the outgoing argument is in registers,
4669 they aren't really at the same location. Check for
4670 this by making sure that the incoming size is the
4671 same as the outgoing size. */
4672 if (arg->locate.size.constant != INTVAL (size_rtx))
4673 sibcall_failure = 1;
4678 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4679 parm_align, partial, reg, excess, argblock,
4680 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4681 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4683 /* Unless this is a partially-in-register argument, the argument is now
4684 in the stack.
4686 ??? Unlike the case above, in which we want the actual
4687 address of the data, so that we can load it directly into a
4688 register, here we want the address of the stack slot, so that
4689 it's properly aligned for word-by-word copying or something
4690 like that. It's not clear that this is always correct. */
4691 if (partial == 0)
4692 arg->value = arg->stack_slot;
4695 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4697 tree type = TREE_TYPE (arg->tree_value);
4698 arg->parallel_value
4699 = emit_group_load_into_temps (arg->reg, arg->value, type,
4700 int_size_in_bytes (type));
4703 /* Mark all slots this store used. */
4704 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4705 && argblock && ! variable_size && arg->stack)
4706 for (i = lower_bound; i < upper_bound; i++)
4707 stack_usage_map[i] = 1;
4709 /* Once we have pushed something, pops can't safely
4710 be deferred during the rest of the arguments. */
4711 NO_DEFER_POP;
4713 /* Free any temporary slots made in processing this argument. */
4714 pop_temp_slots ();
4716 return sibcall_failure;
4719 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4721 bool
4722 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4723 const_tree type)
4725 if (!type)
4726 return false;
4728 /* If the type has variable size... */
4729 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4730 return true;
4732 /* If the type is marked as addressable (it is required
4733 to be constructed into the stack)... */
4734 if (TREE_ADDRESSABLE (type))
4735 return true;
4737 return false;
4740 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4741 takes trailing padding of a structure into account. */
4742 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4744 bool
4745 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4747 if (!type)
4748 return false;
4750 /* If the type has variable size... */
4751 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4752 return true;
4754 /* If the type is marked as addressable (it is required
4755 to be constructed into the stack)... */
4756 if (TREE_ADDRESSABLE (type))
4757 return true;
4759 /* If the padding and mode of the type is such that a copy into
4760 a register would put it into the wrong part of the register. */
4761 if (mode == BLKmode
4762 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4763 && (FUNCTION_ARG_PADDING (mode, type)
4764 == (BYTES_BIG_ENDIAN ? upward : downward)))
4765 return true;
4767 return false;