20090811-1.c: Skip for incompatible options, do not override other options.
[official-gcc.git] / gcc / calls.c
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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 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 *);
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
133 struct args_size *);
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
138 tree, tree,
139 tree, tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
141 bool *, bool);
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
145 int, int *);
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
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 *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 (* 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;
277 /* Although a built-in FUNCTION_DECL and its non-__builtin
278 counterpart compare equal and get a shared mem_attrs, they
279 produce different dump output in compare-debug compilations,
280 if an entry gets garbage collected in one compilation, then
281 adds a different (but equivalent) entry, while the other
282 doesn't run the garbage collector at the same spot and then
283 shares the mem_attr with the equivalent entry. */
284 if (DECL_BUILT_IN_CLASS (t) == BUILT_IN_NORMAL
285 && built_in_decls[DECL_FUNCTION_CODE (t)])
286 t = built_in_decls[DECL_FUNCTION_CODE (t)];
287 set_mem_expr (funmem, t);
289 else if (fntree)
290 set_mem_expr (funmem, build_simple_mem_ref (CALL_EXPR_FN (fntree)));
292 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
293 if ((ecf_flags & ECF_SIBCALL)
294 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
295 && (n_popped > 0 || stack_size == 0))
297 rtx n_pop = GEN_INT (n_popped);
298 rtx pat;
300 /* If this subroutine pops its own args, record that in the call insn
301 if possible, for the sake of frame pointer elimination. */
303 if (valreg)
304 pat = GEN_SIBCALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
305 next_arg_reg, n_pop);
306 else
307 pat = GEN_SIBCALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
308 n_pop);
310 emit_call_insn (pat);
311 already_popped = 1;
313 else
314 #endif
316 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
317 /* If the target has "call" or "call_value" insns, then prefer them
318 if no arguments are actually popped. If the target does not have
319 "call" or "call_value" insns, then we must use the popping versions
320 even if the call has no arguments to pop. */
321 #if defined (HAVE_call) && defined (HAVE_call_value)
322 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
323 && n_popped > 0)
324 #else
325 if (HAVE_call_pop && HAVE_call_value_pop)
326 #endif
328 rtx n_pop = GEN_INT (n_popped);
329 rtx pat;
331 /* If this subroutine pops its own args, record that in the call insn
332 if possible, for the sake of frame pointer elimination. */
334 if (valreg)
335 pat = GEN_CALL_VALUE_POP (valreg, funmem, rounded_stack_size_rtx,
336 next_arg_reg, n_pop);
337 else
338 pat = GEN_CALL_POP (funmem, rounded_stack_size_rtx, next_arg_reg,
339 n_pop);
341 emit_call_insn (pat);
342 already_popped = 1;
344 else
345 #endif
347 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
348 if ((ecf_flags & ECF_SIBCALL)
349 && HAVE_sibcall && HAVE_sibcall_value)
351 if (valreg)
352 emit_call_insn (GEN_SIBCALL_VALUE (valreg, funmem,
353 rounded_stack_size_rtx,
354 next_arg_reg, NULL_RTX));
355 else
356 emit_call_insn (GEN_SIBCALL (funmem, rounded_stack_size_rtx,
357 next_arg_reg,
358 GEN_INT (struct_value_size)));
360 else
361 #endif
363 #if defined (HAVE_call) && defined (HAVE_call_value)
364 if (HAVE_call && HAVE_call_value)
366 if (valreg)
367 emit_call_insn (GEN_CALL_VALUE (valreg, funmem, rounded_stack_size_rtx,
368 next_arg_reg, NULL_RTX));
369 else
370 emit_call_insn (GEN_CALL (funmem, rounded_stack_size_rtx, next_arg_reg,
371 GEN_INT (struct_value_size)));
373 else
374 #endif
375 gcc_unreachable ();
377 /* Find the call we just emitted. */
378 call_insn = last_call_insn ();
380 /* Some target create a fresh MEM instead of reusing the one provided
381 above. Set its MEM_EXPR. */
382 call = PATTERN (call_insn);
383 if (GET_CODE (call) == PARALLEL)
384 call = XVECEXP (call, 0, 0);
385 if (GET_CODE (call) == SET)
386 call = SET_SRC (call);
387 if (GET_CODE (call) == CALL
388 && MEM_P (XEXP (call, 0))
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 /* If popup is needed, stack realign must use DRAP */
438 if (SUPPORTS_STACK_ALIGNMENT)
439 crtl->need_drap = true;
442 if (!ACCUMULATE_OUTGOING_ARGS)
444 /* If returning from the subroutine does not automatically pop the args,
445 we need an instruction to pop them sooner or later.
446 Perhaps do it now; perhaps just record how much space to pop later.
448 If returning from the subroutine does pop the args, indicate that the
449 stack pointer will be changed. */
451 if (rounded_stack_size != 0)
453 if (ecf_flags & ECF_NORETURN)
454 /* Just pretend we did the pop. */
455 stack_pointer_delta -= rounded_stack_size;
456 else if (flag_defer_pop && inhibit_defer_pop == 0
457 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
458 pending_stack_adjust += rounded_stack_size;
459 else
460 adjust_stack (rounded_stack_size_rtx);
463 /* When we accumulate outgoing args, we must avoid any stack manipulations.
464 Restore the stack pointer to its original value now. Usually
465 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
466 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
467 popping variants of functions exist as well.
469 ??? We may optimize similar to defer_pop above, but it is
470 probably not worthwhile.
472 ??? It will be worthwhile to enable combine_stack_adjustments even for
473 such machines. */
474 else if (n_popped)
475 anti_adjust_stack (GEN_INT (n_popped));
478 /* Determine if the function identified by NAME and FNDECL is one with
479 special properties we wish to know about.
481 For example, if the function might return more than one time (setjmp), then
482 set RETURNS_TWICE to a nonzero value.
484 Similarly set NORETURN if the function is in the longjmp family.
486 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
487 space from the stack such as alloca. */
489 static int
490 special_function_p (const_tree fndecl, int flags)
492 if (fndecl && DECL_NAME (fndecl)
493 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
494 /* Exclude functions not at the file scope, or not `extern',
495 since they are not the magic functions we would otherwise
496 think they are.
497 FIXME: this should be handled with attributes, not with this
498 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
499 because you can declare fork() inside a function if you
500 wish. */
501 && (DECL_CONTEXT (fndecl) == NULL_TREE
502 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
503 && TREE_PUBLIC (fndecl))
505 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
506 const char *tname = name;
508 /* We assume that alloca will always be called by name. It
509 makes no sense to pass it as a pointer-to-function to
510 anything that does not understand its behavior. */
511 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
512 && name[0] == 'a'
513 && ! strcmp (name, "alloca"))
514 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
515 && name[0] == '_'
516 && ! strcmp (name, "__builtin_alloca"))))
517 flags |= ECF_MAY_BE_ALLOCA;
519 /* Disregard prefix _, __, __x or __builtin_. */
520 if (name[0] == '_')
522 if (name[1] == '_'
523 && name[2] == 'b'
524 && !strncmp (name + 3, "uiltin_", 7))
525 tname += 10;
526 else if (name[1] == '_' && name[2] == 'x')
527 tname += 3;
528 else if (name[1] == '_')
529 tname += 2;
530 else
531 tname += 1;
534 if (tname[0] == 's')
536 if ((tname[1] == 'e'
537 && (! strcmp (tname, "setjmp")
538 || ! strcmp (tname, "setjmp_syscall")))
539 || (tname[1] == 'i'
540 && ! strcmp (tname, "sigsetjmp"))
541 || (tname[1] == 'a'
542 && ! strcmp (tname, "savectx")))
543 flags |= ECF_RETURNS_TWICE;
545 if (tname[1] == 'i'
546 && ! strcmp (tname, "siglongjmp"))
547 flags |= ECF_NORETURN;
549 else if ((tname[0] == 'q' && tname[1] == 's'
550 && ! strcmp (tname, "qsetjmp"))
551 || (tname[0] == 'v' && tname[1] == 'f'
552 && ! strcmp (tname, "vfork"))
553 || (tname[0] == 'g' && tname[1] == 'e'
554 && !strcmp (tname, "getcontext")))
555 flags |= ECF_RETURNS_TWICE;
557 else if (tname[0] == 'l' && tname[1] == 'o'
558 && ! strcmp (tname, "longjmp"))
559 flags |= ECF_NORETURN;
562 return flags;
565 /* Return nonzero when FNDECL represents a call to setjmp. */
568 setjmp_call_p (const_tree fndecl)
570 if (DECL_IS_RETURNS_TWICE (fndecl))
571 return ECF_RETURNS_TWICE;
572 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
576 /* Return true if STMT is an alloca call. */
578 bool
579 gimple_alloca_call_p (const_gimple stmt)
581 tree fndecl;
583 if (!is_gimple_call (stmt))
584 return false;
586 fndecl = gimple_call_fndecl (stmt);
587 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
588 return true;
590 return false;
593 /* Return true when exp contains alloca call. */
595 bool
596 alloca_call_p (const_tree exp)
598 if (TREE_CODE (exp) == CALL_EXPR
599 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
600 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
601 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
602 & ECF_MAY_BE_ALLOCA))
603 return true;
604 return false;
607 /* Detect flags (function attributes) from the function decl or type node. */
610 flags_from_decl_or_type (const_tree exp)
612 int flags = 0;
614 if (DECL_P (exp))
616 /* The function exp may have the `malloc' attribute. */
617 if (DECL_IS_MALLOC (exp))
618 flags |= ECF_MALLOC;
620 /* The function exp may have the `returns_twice' attribute. */
621 if (DECL_IS_RETURNS_TWICE (exp))
622 flags |= ECF_RETURNS_TWICE;
624 /* Process the pure and const attributes. */
625 if (TREE_READONLY (exp))
626 flags |= ECF_CONST;
627 if (DECL_PURE_P (exp))
628 flags |= ECF_PURE;
629 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
630 flags |= ECF_LOOPING_CONST_OR_PURE;
632 if (DECL_IS_NOVOPS (exp))
633 flags |= ECF_NOVOPS;
634 if (lookup_attribute ("leaf", DECL_ATTRIBUTES (exp)))
635 flags |= ECF_LEAF;
637 if (TREE_NOTHROW (exp))
638 flags |= ECF_NOTHROW;
640 flags = special_function_p (exp, flags);
642 else if (TYPE_P (exp) && TYPE_READONLY (exp))
643 flags |= ECF_CONST;
645 if (TREE_THIS_VOLATILE (exp))
647 flags |= ECF_NORETURN;
648 if (flags & (ECF_CONST|ECF_PURE))
649 flags |= ECF_LOOPING_CONST_OR_PURE;
652 return flags;
655 /* Detect flags from a CALL_EXPR. */
658 call_expr_flags (const_tree t)
660 int flags;
661 tree decl = get_callee_fndecl (t);
663 if (decl)
664 flags = flags_from_decl_or_type (decl);
665 else
667 t = TREE_TYPE (CALL_EXPR_FN (t));
668 if (t && TREE_CODE (t) == POINTER_TYPE)
669 flags = flags_from_decl_or_type (TREE_TYPE (t));
670 else
671 flags = 0;
674 return flags;
677 /* Precompute all register parameters as described by ARGS, storing values
678 into fields within the ARGS array.
680 NUM_ACTUALS indicates the total number elements in the ARGS array.
682 Set REG_PARM_SEEN if we encounter a register parameter. */
684 static void
685 precompute_register_parameters (int num_actuals, struct arg_data *args,
686 int *reg_parm_seen)
688 int i;
690 *reg_parm_seen = 0;
692 for (i = 0; i < num_actuals; i++)
693 if (args[i].reg != 0 && ! args[i].pass_on_stack)
695 *reg_parm_seen = 1;
697 if (args[i].value == 0)
699 push_temp_slots ();
700 args[i].value = expand_normal (args[i].tree_value);
701 preserve_temp_slots (args[i].value);
702 pop_temp_slots ();
705 /* If the value is a non-legitimate constant, force it into a
706 pseudo now. TLS symbols sometimes need a call to resolve. */
707 if (CONSTANT_P (args[i].value)
708 && !targetm.legitimate_constant_p (args[i].mode, args[i].value))
709 args[i].value = force_reg (args[i].mode, args[i].value);
711 /* If we are to promote the function arg to a wider mode,
712 do it now. */
714 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
715 args[i].value
716 = convert_modes (args[i].mode,
717 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
718 args[i].value, args[i].unsignedp);
720 /* If we're going to have to load the value by parts, pull the
721 parts into pseudos. The part extraction process can involve
722 non-trivial computation. */
723 if (GET_CODE (args[i].reg) == PARALLEL)
725 tree type = TREE_TYPE (args[i].tree_value);
726 args[i].parallel_value
727 = emit_group_load_into_temps (args[i].reg, args[i].value,
728 type, int_size_in_bytes (type));
731 /* If the value is expensive, and we are inside an appropriately
732 short loop, put the value into a pseudo and then put the pseudo
733 into the hard reg.
735 For small register classes, also do this if this call uses
736 register parameters. This is to avoid reload conflicts while
737 loading the parameters registers. */
739 else if ((! (REG_P (args[i].value)
740 || (GET_CODE (args[i].value) == SUBREG
741 && REG_P (SUBREG_REG (args[i].value)))))
742 && args[i].mode != BLKmode
743 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
744 > COSTS_N_INSNS (1)
745 && ((*reg_parm_seen
746 && targetm.small_register_classes_for_mode_p (args[i].mode))
747 || optimize))
748 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
752 #ifdef REG_PARM_STACK_SPACE
754 /* The argument list is the property of the called routine and it
755 may clobber it. If the fixed area has been used for previous
756 parameters, we must save and restore it. */
758 static rtx
759 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
761 int low;
762 int high;
764 /* Compute the boundary of the area that needs to be saved, if any. */
765 high = reg_parm_stack_space;
766 #ifdef ARGS_GROW_DOWNWARD
767 high += 1;
768 #endif
769 if (high > highest_outgoing_arg_in_use)
770 high = highest_outgoing_arg_in_use;
772 for (low = 0; low < high; low++)
773 if (stack_usage_map[low] != 0)
775 int num_to_save;
776 enum machine_mode save_mode;
777 int delta;
778 rtx stack_area;
779 rtx save_area;
781 while (stack_usage_map[--high] == 0)
784 *low_to_save = low;
785 *high_to_save = high;
787 num_to_save = high - low + 1;
788 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
790 /* If we don't have the required alignment, must do this
791 in BLKmode. */
792 if ((low & (MIN (GET_MODE_SIZE (save_mode),
793 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
794 save_mode = BLKmode;
796 #ifdef ARGS_GROW_DOWNWARD
797 delta = -high;
798 #else
799 delta = low;
800 #endif
801 stack_area = gen_rtx_MEM (save_mode,
802 memory_address (save_mode,
803 plus_constant (argblock,
804 delta)));
806 set_mem_align (stack_area, PARM_BOUNDARY);
807 if (save_mode == BLKmode)
809 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
810 emit_block_move (validize_mem (save_area), stack_area,
811 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
813 else
815 save_area = gen_reg_rtx (save_mode);
816 emit_move_insn (save_area, stack_area);
819 return save_area;
822 return NULL_RTX;
825 static void
826 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
828 enum machine_mode save_mode = GET_MODE (save_area);
829 int delta;
830 rtx stack_area;
832 #ifdef ARGS_GROW_DOWNWARD
833 delta = -high_to_save;
834 #else
835 delta = low_to_save;
836 #endif
837 stack_area = gen_rtx_MEM (save_mode,
838 memory_address (save_mode,
839 plus_constant (argblock, delta)));
840 set_mem_align (stack_area, PARM_BOUNDARY);
842 if (save_mode != BLKmode)
843 emit_move_insn (stack_area, save_area);
844 else
845 emit_block_move (stack_area, validize_mem (save_area),
846 GEN_INT (high_to_save - low_to_save + 1),
847 BLOCK_OP_CALL_PARM);
849 #endif /* REG_PARM_STACK_SPACE */
851 /* If any elements in ARGS refer to parameters that are to be passed in
852 registers, but not in memory, and whose alignment does not permit a
853 direct copy into registers. Copy the values into a group of pseudos
854 which we will later copy into the appropriate hard registers.
856 Pseudos for each unaligned argument will be stored into the array
857 args[argnum].aligned_regs. The caller is responsible for deallocating
858 the aligned_regs array if it is nonzero. */
860 static void
861 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
863 int i, j;
865 for (i = 0; i < num_actuals; i++)
866 if (args[i].reg != 0 && ! args[i].pass_on_stack
867 && args[i].mode == BLKmode
868 && MEM_P (args[i].value)
869 && (MEM_ALIGN (args[i].value)
870 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
872 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
873 int endian_correction = 0;
875 if (args[i].partial)
877 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
878 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
880 else
882 args[i].n_aligned_regs
883 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
886 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
888 /* Structures smaller than a word are normally aligned to the
889 least significant byte. On a BYTES_BIG_ENDIAN machine,
890 this means we must skip the empty high order bytes when
891 calculating the bit offset. */
892 if (bytes < UNITS_PER_WORD
893 #ifdef BLOCK_REG_PADDING
894 && (BLOCK_REG_PADDING (args[i].mode,
895 TREE_TYPE (args[i].tree_value), 1)
896 == downward)
897 #else
898 && BYTES_BIG_ENDIAN
899 #endif
901 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
903 for (j = 0; j < args[i].n_aligned_regs; j++)
905 rtx reg = gen_reg_rtx (word_mode);
906 rtx word = operand_subword_force (args[i].value, j, BLKmode);
907 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
909 args[i].aligned_regs[j] = reg;
910 word = extract_bit_field (word, bitsize, 0, 1, false, NULL_RTX,
911 word_mode, word_mode);
913 /* There is no need to restrict this code to loading items
914 in TYPE_ALIGN sized hunks. The bitfield instructions can
915 load up entire word sized registers efficiently.
917 ??? This may not be needed anymore.
918 We use to emit a clobber here but that doesn't let later
919 passes optimize the instructions we emit. By storing 0 into
920 the register later passes know the first AND to zero out the
921 bitfield being set in the register is unnecessary. The store
922 of 0 will be deleted as will at least the first AND. */
924 emit_move_insn (reg, const0_rtx);
926 bytes -= bitsize / BITS_PER_UNIT;
927 store_bit_field (reg, bitsize, endian_correction, word_mode,
928 word);
933 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
934 CALL_EXPR EXP.
936 NUM_ACTUALS is the total number of parameters.
938 N_NAMED_ARGS is the total number of named arguments.
940 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
941 value, or null.
943 FNDECL is the tree code for the target of this call (if known)
945 ARGS_SO_FAR holds state needed by the target to know where to place
946 the next argument.
948 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
949 for arguments which are passed in registers.
951 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
952 and may be modified by this routine.
954 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
955 flags which may may be modified by this routine.
957 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
958 that requires allocation of stack space.
960 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
961 the thunked-to function. */
963 static void
964 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
965 struct arg_data *args,
966 struct args_size *args_size,
967 int n_named_args ATTRIBUTE_UNUSED,
968 tree exp, tree struct_value_addr_value,
969 tree fndecl, tree fntype,
970 CUMULATIVE_ARGS *args_so_far,
971 int reg_parm_stack_space,
972 rtx *old_stack_level, int *old_pending_adj,
973 int *must_preallocate, int *ecf_flags,
974 bool *may_tailcall, bool call_from_thunk_p)
976 location_t loc = EXPR_LOCATION (exp);
977 /* 1 if scanning parms front to back, -1 if scanning back to front. */
978 int inc;
980 /* Count arg position in order args appear. */
981 int argpos;
983 int i;
985 args_size->constant = 0;
986 args_size->var = 0;
988 /* In this loop, we consider args in the order they are written.
989 We fill up ARGS from the front or from the back if necessary
990 so that in any case the first arg to be pushed ends up at the front. */
992 if (PUSH_ARGS_REVERSED)
994 i = num_actuals - 1, inc = -1;
995 /* In this case, must reverse order of args
996 so that we compute and push the last arg first. */
998 else
1000 i = 0, inc = 1;
1003 /* First fill in the actual arguments in the ARGS array, splitting
1004 complex arguments if necessary. */
1006 int j = i;
1007 call_expr_arg_iterator iter;
1008 tree arg;
1010 if (struct_value_addr_value)
1012 args[j].tree_value = struct_value_addr_value;
1013 j += inc;
1015 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
1017 tree argtype = TREE_TYPE (arg);
1018 if (targetm.calls.split_complex_arg
1019 && argtype
1020 && TREE_CODE (argtype) == COMPLEX_TYPE
1021 && targetm.calls.split_complex_arg (argtype))
1023 tree subtype = TREE_TYPE (argtype);
1024 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
1025 j += inc;
1026 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
1028 else
1029 args[j].tree_value = arg;
1030 j += inc;
1034 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1035 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1037 tree type = TREE_TYPE (args[i].tree_value);
1038 int unsignedp;
1039 enum machine_mode mode;
1041 /* Replace erroneous argument with constant zero. */
1042 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1043 args[i].tree_value = integer_zero_node, type = integer_type_node;
1045 /* If TYPE is a transparent union or record, pass things the way
1046 we would pass the first field of the union or record. We have
1047 already verified that the modes are the same. */
1048 if ((TREE_CODE (type) == UNION_TYPE || TREE_CODE (type) == RECORD_TYPE)
1049 && TYPE_TRANSPARENT_AGGR (type))
1050 type = TREE_TYPE (first_field (type));
1052 /* Decide where to pass this arg.
1054 args[i].reg is nonzero if all or part is passed in registers.
1056 args[i].partial is nonzero if part but not all is passed in registers,
1057 and the exact value says how many bytes are passed in registers.
1059 args[i].pass_on_stack is nonzero if the argument must at least be
1060 computed on the stack. It may then be loaded back into registers
1061 if args[i].reg is nonzero.
1063 These decisions are driven by the FUNCTION_... macros and must agree
1064 with those made by function.c. */
1066 /* See if this argument should be passed by invisible reference. */
1067 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1068 type, argpos < n_named_args))
1070 bool callee_copies;
1071 tree base;
1073 callee_copies
1074 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1075 type, argpos < n_named_args);
1077 /* If we're compiling a thunk, pass through invisible references
1078 instead of making a copy. */
1079 if (call_from_thunk_p
1080 || (callee_copies
1081 && !TREE_ADDRESSABLE (type)
1082 && (base = get_base_address (args[i].tree_value))
1083 && TREE_CODE (base) != SSA_NAME
1084 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1086 /* We can't use sibcalls if a callee-copied argument is
1087 stored in the current function's frame. */
1088 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1089 *may_tailcall = false;
1091 args[i].tree_value = build_fold_addr_expr_loc (loc,
1092 args[i].tree_value);
1093 type = TREE_TYPE (args[i].tree_value);
1095 if (*ecf_flags & ECF_CONST)
1096 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1098 else
1100 /* We make a copy of the object and pass the address to the
1101 function being called. */
1102 rtx copy;
1104 if (!COMPLETE_TYPE_P (type)
1105 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1106 || (flag_stack_check == GENERIC_STACK_CHECK
1107 && compare_tree_int (TYPE_SIZE_UNIT (type),
1108 STACK_CHECK_MAX_VAR_SIZE) > 0))
1110 /* This is a variable-sized object. Make space on the stack
1111 for it. */
1112 rtx size_rtx = expr_size (args[i].tree_value);
1114 if (*old_stack_level == 0)
1116 emit_stack_save (SAVE_BLOCK, old_stack_level);
1117 *old_pending_adj = pending_stack_adjust;
1118 pending_stack_adjust = 0;
1121 /* We can pass TRUE as the 4th argument because we just
1122 saved the stack pointer and will restore it right after
1123 the call. */
1124 copy = allocate_dynamic_stack_space (size_rtx,
1125 TYPE_ALIGN (type),
1126 TYPE_ALIGN (type),
1127 true);
1128 copy = gen_rtx_MEM (BLKmode, copy);
1129 set_mem_attributes (copy, type, 1);
1131 else
1132 copy = assign_temp (type, 0, 1, 0);
1134 store_expr (args[i].tree_value, copy, 0, false);
1136 /* Just change the const function to pure and then let
1137 the next test clear the pure based on
1138 callee_copies. */
1139 if (*ecf_flags & ECF_CONST)
1141 *ecf_flags &= ~ECF_CONST;
1142 *ecf_flags |= ECF_PURE;
1145 if (!callee_copies && *ecf_flags & ECF_PURE)
1146 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1148 args[i].tree_value
1149 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1150 type = TREE_TYPE (args[i].tree_value);
1151 *may_tailcall = false;
1155 unsignedp = TYPE_UNSIGNED (type);
1156 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1157 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1159 args[i].unsignedp = unsignedp;
1160 args[i].mode = mode;
1162 args[i].reg = targetm.calls.function_arg (args_so_far, mode, type,
1163 argpos < n_named_args);
1165 /* If this is a sibling call and the machine has register windows, the
1166 register window has to be unwinded before calling the routine, so
1167 arguments have to go into the incoming registers. */
1168 if (targetm.calls.function_incoming_arg != targetm.calls.function_arg)
1169 args[i].tail_call_reg
1170 = targetm.calls.function_incoming_arg (args_so_far, mode, type,
1171 argpos < n_named_args);
1172 else
1173 args[i].tail_call_reg = args[i].reg;
1175 if (args[i].reg)
1176 args[i].partial
1177 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1178 argpos < n_named_args);
1180 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1182 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1183 it means that we are to pass this arg in the register(s) designated
1184 by the PARALLEL, but also to pass it in the stack. */
1185 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1186 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1187 args[i].pass_on_stack = 1;
1189 /* If this is an addressable type, we must preallocate the stack
1190 since we must evaluate the object into its final location.
1192 If this is to be passed in both registers and the stack, it is simpler
1193 to preallocate. */
1194 if (TREE_ADDRESSABLE (type)
1195 || (args[i].pass_on_stack && args[i].reg != 0))
1196 *must_preallocate = 1;
1198 /* Compute the stack-size of this argument. */
1199 if (args[i].reg == 0 || args[i].partial != 0
1200 || reg_parm_stack_space > 0
1201 || args[i].pass_on_stack)
1202 locate_and_pad_parm (mode, type,
1203 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1205 #else
1206 args[i].reg != 0,
1207 #endif
1208 args[i].pass_on_stack ? 0 : args[i].partial,
1209 fndecl, args_size, &args[i].locate);
1210 #ifdef BLOCK_REG_PADDING
1211 else
1212 /* The argument is passed entirely in registers. See at which
1213 end it should be padded. */
1214 args[i].locate.where_pad =
1215 BLOCK_REG_PADDING (mode, type,
1216 int_size_in_bytes (type) <= UNITS_PER_WORD);
1217 #endif
1219 /* Update ARGS_SIZE, the total stack space for args so far. */
1221 args_size->constant += args[i].locate.size.constant;
1222 if (args[i].locate.size.var)
1223 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1225 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1226 have been used, etc. */
1228 targetm.calls.function_arg_advance (args_so_far, TYPE_MODE (type),
1229 type, argpos < n_named_args);
1233 /* Update ARGS_SIZE to contain the total size for the argument block.
1234 Return the original constant component of the argument block's size.
1236 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1237 for arguments passed in registers. */
1239 static int
1240 compute_argument_block_size (int reg_parm_stack_space,
1241 struct args_size *args_size,
1242 tree fndecl ATTRIBUTE_UNUSED,
1243 tree fntype ATTRIBUTE_UNUSED,
1244 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1246 int unadjusted_args_size = args_size->constant;
1248 /* For accumulate outgoing args mode we don't need to align, since the frame
1249 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1250 backends from generating misaligned frame sizes. */
1251 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1252 preferred_stack_boundary = STACK_BOUNDARY;
1254 /* Compute the actual size of the argument block required. The variable
1255 and constant sizes must be combined, the size may have to be rounded,
1256 and there may be a minimum required size. */
1258 if (args_size->var)
1260 args_size->var = ARGS_SIZE_TREE (*args_size);
1261 args_size->constant = 0;
1263 preferred_stack_boundary /= BITS_PER_UNIT;
1264 if (preferred_stack_boundary > 1)
1266 /* We don't handle this case yet. To handle it correctly we have
1267 to add the delta, round and subtract the delta.
1268 Currently no machine description requires this support. */
1269 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1270 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1273 if (reg_parm_stack_space > 0)
1275 args_size->var
1276 = size_binop (MAX_EXPR, args_size->var,
1277 ssize_int (reg_parm_stack_space));
1279 /* The area corresponding to register parameters is not to count in
1280 the size of the block we need. So make the adjustment. */
1281 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1282 args_size->var
1283 = size_binop (MINUS_EXPR, args_size->var,
1284 ssize_int (reg_parm_stack_space));
1287 else
1289 preferred_stack_boundary /= BITS_PER_UNIT;
1290 if (preferred_stack_boundary < 1)
1291 preferred_stack_boundary = 1;
1292 args_size->constant = (((args_size->constant
1293 + stack_pointer_delta
1294 + preferred_stack_boundary - 1)
1295 / preferred_stack_boundary
1296 * preferred_stack_boundary)
1297 - stack_pointer_delta);
1299 args_size->constant = MAX (args_size->constant,
1300 reg_parm_stack_space);
1302 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1303 args_size->constant -= reg_parm_stack_space;
1305 return unadjusted_args_size;
1308 /* Precompute parameters as needed for a function call.
1310 FLAGS is mask of ECF_* constants.
1312 NUM_ACTUALS is the number of arguments.
1314 ARGS is an array containing information for each argument; this
1315 routine fills in the INITIAL_VALUE and VALUE fields for each
1316 precomputed argument. */
1318 static void
1319 precompute_arguments (int num_actuals, struct arg_data *args)
1321 int i;
1323 /* If this is a libcall, then precompute all arguments so that we do not
1324 get extraneous instructions emitted as part of the libcall sequence. */
1326 /* If we preallocated the stack space, and some arguments must be passed
1327 on the stack, then we must precompute any parameter which contains a
1328 function call which will store arguments on the stack.
1329 Otherwise, evaluating the parameter may clobber previous parameters
1330 which have already been stored into the stack. (we have code to avoid
1331 such case by saving the outgoing stack arguments, but it results in
1332 worse code) */
1333 if (!ACCUMULATE_OUTGOING_ARGS)
1334 return;
1336 for (i = 0; i < num_actuals; i++)
1338 tree type;
1339 enum machine_mode mode;
1341 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1342 continue;
1344 /* If this is an addressable type, we cannot pre-evaluate it. */
1345 type = TREE_TYPE (args[i].tree_value);
1346 gcc_assert (!TREE_ADDRESSABLE (type));
1348 args[i].initial_value = args[i].value
1349 = expand_normal (args[i].tree_value);
1351 mode = TYPE_MODE (type);
1352 if (mode != args[i].mode)
1354 int unsignedp = args[i].unsignedp;
1355 args[i].value
1356 = convert_modes (args[i].mode, mode,
1357 args[i].value, args[i].unsignedp);
1359 /* CSE will replace this only if it contains args[i].value
1360 pseudo, so convert it down to the declared mode using
1361 a SUBREG. */
1362 if (REG_P (args[i].value)
1363 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1364 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1366 args[i].initial_value
1367 = gen_lowpart_SUBREG (mode, args[i].value);
1368 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1369 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1370 args[i].unsignedp);
1376 /* Given the current state of MUST_PREALLOCATE and information about
1377 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1378 compute and return the final value for MUST_PREALLOCATE. */
1380 static int
1381 finalize_must_preallocate (int must_preallocate, int num_actuals,
1382 struct arg_data *args, struct args_size *args_size)
1384 /* See if we have or want to preallocate stack space.
1386 If we would have to push a partially-in-regs parm
1387 before other stack parms, preallocate stack space instead.
1389 If the size of some parm is not a multiple of the required stack
1390 alignment, we must preallocate.
1392 If the total size of arguments that would otherwise create a copy in
1393 a temporary (such as a CALL) is more than half the total argument list
1394 size, preallocation is faster.
1396 Another reason to preallocate is if we have a machine (like the m88k)
1397 where stack alignment is required to be maintained between every
1398 pair of insns, not just when the call is made. However, we assume here
1399 that such machines either do not have push insns (and hence preallocation
1400 would occur anyway) or the problem is taken care of with
1401 PUSH_ROUNDING. */
1403 if (! must_preallocate)
1405 int partial_seen = 0;
1406 int copy_to_evaluate_size = 0;
1407 int i;
1409 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1411 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1412 partial_seen = 1;
1413 else if (partial_seen && args[i].reg == 0)
1414 must_preallocate = 1;
1416 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1417 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1418 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1419 || TREE_CODE (args[i].tree_value) == COND_EXPR
1420 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1421 copy_to_evaluate_size
1422 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1425 if (copy_to_evaluate_size * 2 >= args_size->constant
1426 && args_size->constant > 0)
1427 must_preallocate = 1;
1429 return must_preallocate;
1432 /* If we preallocated stack space, compute the address of each argument
1433 and store it into the ARGS array.
1435 We need not ensure it is a valid memory address here; it will be
1436 validized when it is used.
1438 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1440 static void
1441 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1443 if (argblock)
1445 rtx arg_reg = argblock;
1446 int i, arg_offset = 0;
1448 if (GET_CODE (argblock) == PLUS)
1449 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1451 for (i = 0; i < num_actuals; i++)
1453 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1454 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1455 rtx addr;
1456 unsigned int align, boundary;
1457 unsigned int units_on_stack = 0;
1458 enum machine_mode partial_mode = VOIDmode;
1460 /* Skip this parm if it will not be passed on the stack. */
1461 if (! args[i].pass_on_stack
1462 && args[i].reg != 0
1463 && args[i].partial == 0)
1464 continue;
1466 if (CONST_INT_P (offset))
1467 addr = plus_constant (arg_reg, INTVAL (offset));
1468 else
1469 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1471 addr = plus_constant (addr, arg_offset);
1473 if (args[i].partial != 0)
1475 /* Only part of the parameter is being passed on the stack.
1476 Generate a simple memory reference of the correct size. */
1477 units_on_stack = args[i].locate.size.constant;
1478 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1479 MODE_INT, 1);
1480 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1481 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1483 else
1485 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1486 set_mem_attributes (args[i].stack,
1487 TREE_TYPE (args[i].tree_value), 1);
1489 align = BITS_PER_UNIT;
1490 boundary = args[i].locate.boundary;
1491 if (args[i].locate.where_pad != downward)
1492 align = boundary;
1493 else if (CONST_INT_P (offset))
1495 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1496 align = align & -align;
1498 set_mem_align (args[i].stack, align);
1500 if (CONST_INT_P (slot_offset))
1501 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1502 else
1503 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1505 addr = plus_constant (addr, arg_offset);
1507 if (args[i].partial != 0)
1509 /* Only part of the parameter is being passed on the stack.
1510 Generate a simple memory reference of the correct size.
1512 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1513 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1515 else
1517 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1518 set_mem_attributes (args[i].stack_slot,
1519 TREE_TYPE (args[i].tree_value), 1);
1521 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1523 /* Function incoming arguments may overlap with sibling call
1524 outgoing arguments and we cannot allow reordering of reads
1525 from function arguments with stores to outgoing arguments
1526 of sibling calls. */
1527 set_mem_alias_set (args[i].stack, 0);
1528 set_mem_alias_set (args[i].stack_slot, 0);
1533 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1534 in a call instruction.
1536 FNDECL is the tree node for the target function. For an indirect call
1537 FNDECL will be NULL_TREE.
1539 ADDR is the operand 0 of CALL_EXPR for this call. */
1541 static rtx
1542 rtx_for_function_call (tree fndecl, tree addr)
1544 rtx funexp;
1546 /* Get the function to call, in the form of RTL. */
1547 if (fndecl)
1549 /* If this is the first use of the function, see if we need to
1550 make an external definition for it. */
1551 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1553 assemble_external (fndecl);
1554 TREE_USED (fndecl) = 1;
1557 /* Get a SYMBOL_REF rtx for the function address. */
1558 funexp = XEXP (DECL_RTL (fndecl), 0);
1560 else
1561 /* Generate an rtx (probably a pseudo-register) for the address. */
1563 push_temp_slots ();
1564 funexp = expand_normal (addr);
1565 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1567 return funexp;
1570 /* Return true if and only if SIZE storage units (usually bytes)
1571 starting from address ADDR overlap with already clobbered argument
1572 area. This function is used to determine if we should give up a
1573 sibcall. */
1575 static bool
1576 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1578 HOST_WIDE_INT i;
1580 if (addr == crtl->args.internal_arg_pointer)
1581 i = 0;
1582 else if (GET_CODE (addr) == PLUS
1583 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1584 && CONST_INT_P (XEXP (addr, 1)))
1585 i = INTVAL (XEXP (addr, 1));
1586 /* Return true for arg pointer based indexed addressing. */
1587 else if (GET_CODE (addr) == PLUS
1588 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1589 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1590 return true;
1591 else
1592 return false;
1594 #ifdef ARGS_GROW_DOWNWARD
1595 i = -i - size;
1596 #endif
1597 if (size > 0)
1599 unsigned HOST_WIDE_INT k;
1601 for (k = 0; k < size; k++)
1602 if (i + k < stored_args_map->n_bits
1603 && TEST_BIT (stored_args_map, i + k))
1604 return true;
1607 return false;
1610 /* Do the register loads required for any wholly-register parms or any
1611 parms which are passed both on the stack and in a register. Their
1612 expressions were already evaluated.
1614 Mark all register-parms as living through the call, putting these USE
1615 insns in the CALL_INSN_FUNCTION_USAGE field.
1617 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1618 checking, setting *SIBCALL_FAILURE if appropriate. */
1620 static void
1621 load_register_parameters (struct arg_data *args, int num_actuals,
1622 rtx *call_fusage, int flags, int is_sibcall,
1623 int *sibcall_failure)
1625 int i, j;
1627 for (i = 0; i < num_actuals; i++)
1629 rtx reg = ((flags & ECF_SIBCALL)
1630 ? args[i].tail_call_reg : args[i].reg);
1631 if (reg)
1633 int partial = args[i].partial;
1634 int nregs;
1635 int size = 0;
1636 rtx before_arg = get_last_insn ();
1637 /* Set non-negative if we must move a word at a time, even if
1638 just one word (e.g, partial == 4 && mode == DFmode). Set
1639 to -1 if we just use a normal move insn. This value can be
1640 zero if the argument is a zero size structure. */
1641 nregs = -1;
1642 if (GET_CODE (reg) == PARALLEL)
1644 else if (partial)
1646 gcc_assert (partial % UNITS_PER_WORD == 0);
1647 nregs = partial / UNITS_PER_WORD;
1649 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1651 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1652 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1654 else
1655 size = GET_MODE_SIZE (args[i].mode);
1657 /* Handle calls that pass values in multiple non-contiguous
1658 locations. The Irix 6 ABI has examples of this. */
1660 if (GET_CODE (reg) == PARALLEL)
1661 emit_group_move (reg, args[i].parallel_value);
1663 /* If simple case, just do move. If normal partial, store_one_arg
1664 has already loaded the register for us. In all other cases,
1665 load the register(s) from memory. */
1667 else if (nregs == -1)
1669 emit_move_insn (reg, args[i].value);
1670 #ifdef BLOCK_REG_PADDING
1671 /* Handle case where we have a value that needs shifting
1672 up to the msb. eg. a QImode value and we're padding
1673 upward on a BYTES_BIG_ENDIAN machine. */
1674 if (size < UNITS_PER_WORD
1675 && (args[i].locate.where_pad
1676 == (BYTES_BIG_ENDIAN ? upward : downward)))
1678 rtx x;
1679 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1681 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1682 report the whole reg as used. Strictly speaking, the
1683 call only uses SIZE bytes at the msb end, but it doesn't
1684 seem worth generating rtl to say that. */
1685 reg = gen_rtx_REG (word_mode, REGNO (reg));
1686 x = expand_shift (LSHIFT_EXPR, word_mode, reg, shift, reg, 1);
1687 if (x != reg)
1688 emit_move_insn (reg, x);
1690 #endif
1693 /* If we have pre-computed the values to put in the registers in
1694 the case of non-aligned structures, copy them in now. */
1696 else if (args[i].n_aligned_regs != 0)
1697 for (j = 0; j < args[i].n_aligned_regs; j++)
1698 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1699 args[i].aligned_regs[j]);
1701 else if (partial == 0 || args[i].pass_on_stack)
1703 rtx mem = validize_mem (args[i].value);
1705 /* Check for overlap with already clobbered argument area,
1706 providing that this has non-zero size. */
1707 if (is_sibcall
1708 && (size == 0
1709 || mem_overlaps_already_clobbered_arg_p
1710 (XEXP (args[i].value, 0), size)))
1711 *sibcall_failure = 1;
1713 /* Handle a BLKmode that needs shifting. */
1714 if (nregs == 1 && size < UNITS_PER_WORD
1715 #ifdef BLOCK_REG_PADDING
1716 && args[i].locate.where_pad == downward
1717 #else
1718 && BYTES_BIG_ENDIAN
1719 #endif
1722 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1723 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1724 rtx x = gen_reg_rtx (word_mode);
1725 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1726 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1727 : LSHIFT_EXPR;
1729 emit_move_insn (x, tem);
1730 x = expand_shift (dir, word_mode, x, shift, ri, 1);
1731 if (x != ri)
1732 emit_move_insn (ri, x);
1734 else
1735 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1738 /* When a parameter is a block, and perhaps in other cases, it is
1739 possible that it did a load from an argument slot that was
1740 already clobbered. */
1741 if (is_sibcall
1742 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1743 *sibcall_failure = 1;
1745 /* Handle calls that pass values in multiple non-contiguous
1746 locations. The Irix 6 ABI has examples of this. */
1747 if (GET_CODE (reg) == PARALLEL)
1748 use_group_regs (call_fusage, reg);
1749 else if (nregs == -1)
1750 use_reg (call_fusage, reg);
1751 else if (nregs > 0)
1752 use_regs (call_fusage, REGNO (reg), nregs);
1757 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1758 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1759 bytes, then we would need to push some additional bytes to pad the
1760 arguments. So, we compute an adjust to the stack pointer for an
1761 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1762 bytes. Then, when the arguments are pushed the stack will be perfectly
1763 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1764 be popped after the call. Returns the adjustment. */
1766 static int
1767 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1768 struct args_size *args_size,
1769 unsigned int preferred_unit_stack_boundary)
1771 /* The number of bytes to pop so that the stack will be
1772 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1773 HOST_WIDE_INT adjustment;
1774 /* The alignment of the stack after the arguments are pushed, if we
1775 just pushed the arguments without adjust the stack here. */
1776 unsigned HOST_WIDE_INT unadjusted_alignment;
1778 unadjusted_alignment
1779 = ((stack_pointer_delta + unadjusted_args_size)
1780 % preferred_unit_stack_boundary);
1782 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1783 as possible -- leaving just enough left to cancel out the
1784 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1785 PENDING_STACK_ADJUST is non-negative, and congruent to
1786 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1788 /* Begin by trying to pop all the bytes. */
1789 unadjusted_alignment
1790 = (unadjusted_alignment
1791 - (pending_stack_adjust % preferred_unit_stack_boundary));
1792 adjustment = pending_stack_adjust;
1793 /* Push enough additional bytes that the stack will be aligned
1794 after the arguments are pushed. */
1795 if (preferred_unit_stack_boundary > 1)
1797 if (unadjusted_alignment > 0)
1798 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1799 else
1800 adjustment += unadjusted_alignment;
1803 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1804 bytes after the call. The right number is the entire
1805 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1806 by the arguments in the first place. */
1807 args_size->constant
1808 = pending_stack_adjust - adjustment + unadjusted_args_size;
1810 return adjustment;
1813 /* Scan X expression if it does not dereference any argument slots
1814 we already clobbered by tail call arguments (as noted in stored_args_map
1815 bitmap).
1816 Return nonzero if X expression dereferences such argument slots,
1817 zero otherwise. */
1819 static int
1820 check_sibcall_argument_overlap_1 (rtx x)
1822 RTX_CODE code;
1823 int i, j;
1824 const char *fmt;
1826 if (x == NULL_RTX)
1827 return 0;
1829 code = GET_CODE (x);
1831 if (code == MEM)
1832 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1833 GET_MODE_SIZE (GET_MODE (x)));
1835 /* Scan all subexpressions. */
1836 fmt = GET_RTX_FORMAT (code);
1837 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1839 if (*fmt == 'e')
1841 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1842 return 1;
1844 else if (*fmt == 'E')
1846 for (j = 0; j < XVECLEN (x, i); j++)
1847 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1848 return 1;
1851 return 0;
1854 /* Scan sequence after INSN if it does not dereference any argument slots
1855 we already clobbered by tail call arguments (as noted in stored_args_map
1856 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1857 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1858 should be 0). Return nonzero if sequence after INSN dereferences such argument
1859 slots, zero otherwise. */
1861 static int
1862 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1864 int low, high;
1866 if (insn == NULL_RTX)
1867 insn = get_insns ();
1868 else
1869 insn = NEXT_INSN (insn);
1871 for (; insn; insn = NEXT_INSN (insn))
1872 if (INSN_P (insn)
1873 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1874 break;
1876 if (mark_stored_args_map)
1878 #ifdef ARGS_GROW_DOWNWARD
1879 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1880 #else
1881 low = arg->locate.slot_offset.constant;
1882 #endif
1884 for (high = low + arg->locate.size.constant; low < high; low++)
1885 SET_BIT (stored_args_map, low);
1887 return insn != NULL_RTX;
1890 /* Given that a function returns a value of mode MODE at the most
1891 significant end of hard register VALUE, shift VALUE left or right
1892 as specified by LEFT_P. Return true if some action was needed. */
1894 bool
1895 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1897 HOST_WIDE_INT shift;
1899 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1900 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1901 if (shift == 0)
1902 return false;
1904 /* Use ashr rather than lshr for right shifts. This is for the benefit
1905 of the MIPS port, which requires SImode values to be sign-extended
1906 when stored in 64-bit registers. */
1907 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1908 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1909 gcc_unreachable ();
1910 return true;
1913 /* If X is a likely-spilled register value, copy it to a pseudo
1914 register and return that register. Return X otherwise. */
1916 static rtx
1917 avoid_likely_spilled_reg (rtx x)
1919 rtx new_rtx;
1921 if (REG_P (x)
1922 && HARD_REGISTER_P (x)
1923 && targetm.class_likely_spilled_p (REGNO_REG_CLASS (REGNO (x))))
1925 /* Make sure that we generate a REG rather than a CONCAT.
1926 Moves into CONCATs can need nontrivial instructions,
1927 and the whole point of this function is to avoid
1928 using the hard register directly in such a situation. */
1929 generating_concat_p = 0;
1930 new_rtx = gen_reg_rtx (GET_MODE (x));
1931 generating_concat_p = 1;
1932 emit_move_insn (new_rtx, x);
1933 return new_rtx;
1935 return x;
1938 /* Generate all the code for a CALL_EXPR exp
1939 and return an rtx for its value.
1940 Store the value in TARGET (specified as an rtx) if convenient.
1941 If the value is stored in TARGET then TARGET is returned.
1942 If IGNORE is nonzero, then we ignore the value of the function call. */
1945 expand_call (tree exp, rtx target, int ignore)
1947 /* Nonzero if we are currently expanding a call. */
1948 static int currently_expanding_call = 0;
1950 /* RTX for the function to be called. */
1951 rtx funexp;
1952 /* Sequence of insns to perform a normal "call". */
1953 rtx normal_call_insns = NULL_RTX;
1954 /* Sequence of insns to perform a tail "call". */
1955 rtx tail_call_insns = NULL_RTX;
1956 /* Data type of the function. */
1957 tree funtype;
1958 tree type_arg_types;
1959 tree rettype;
1960 /* Declaration of the function being called,
1961 or 0 if the function is computed (not known by name). */
1962 tree fndecl = 0;
1963 /* The type of the function being called. */
1964 tree fntype;
1965 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1966 int pass;
1968 /* Register in which non-BLKmode value will be returned,
1969 or 0 if no value or if value is BLKmode. */
1970 rtx valreg;
1971 /* Address where we should return a BLKmode value;
1972 0 if value not BLKmode. */
1973 rtx structure_value_addr = 0;
1974 /* Nonzero if that address is being passed by treating it as
1975 an extra, implicit first parameter. Otherwise,
1976 it is passed by being copied directly into struct_value_rtx. */
1977 int structure_value_addr_parm = 0;
1978 /* Holds the value of implicit argument for the struct value. */
1979 tree structure_value_addr_value = NULL_TREE;
1980 /* Size of aggregate value wanted, or zero if none wanted
1981 or if we are using the non-reentrant PCC calling convention
1982 or expecting the value in registers. */
1983 HOST_WIDE_INT struct_value_size = 0;
1984 /* Nonzero if called function returns an aggregate in memory PCC style,
1985 by returning the address of where to find it. */
1986 int pcc_struct_value = 0;
1987 rtx struct_value = 0;
1989 /* Number of actual parameters in this call, including struct value addr. */
1990 int num_actuals;
1991 /* Number of named args. Args after this are anonymous ones
1992 and they must all go on the stack. */
1993 int n_named_args;
1994 /* Number of complex actual arguments that need to be split. */
1995 int num_complex_actuals = 0;
1997 /* Vector of information about each argument.
1998 Arguments are numbered in the order they will be pushed,
1999 not the order they are written. */
2000 struct arg_data *args;
2002 /* Total size in bytes of all the stack-parms scanned so far. */
2003 struct args_size args_size;
2004 struct args_size adjusted_args_size;
2005 /* Size of arguments before any adjustments (such as rounding). */
2006 int unadjusted_args_size;
2007 /* Data on reg parms scanned so far. */
2008 CUMULATIVE_ARGS args_so_far;
2009 /* Nonzero if a reg parm has been scanned. */
2010 int reg_parm_seen;
2011 /* Nonzero if this is an indirect function call. */
2013 /* Nonzero if we must avoid push-insns in the args for this call.
2014 If stack space is allocated for register parameters, but not by the
2015 caller, then it is preallocated in the fixed part of the stack frame.
2016 So the entire argument block must then be preallocated (i.e., we
2017 ignore PUSH_ROUNDING in that case). */
2019 int must_preallocate = !PUSH_ARGS;
2021 /* Size of the stack reserved for parameter registers. */
2022 int reg_parm_stack_space = 0;
2024 /* Address of space preallocated for stack parms
2025 (on machines that lack push insns), or 0 if space not preallocated. */
2026 rtx argblock = 0;
2028 /* Mask of ECF_ flags. */
2029 int flags = 0;
2030 #ifdef REG_PARM_STACK_SPACE
2031 /* Define the boundary of the register parm stack space that needs to be
2032 saved, if any. */
2033 int low_to_save, high_to_save;
2034 rtx save_area = 0; /* Place that it is saved */
2035 #endif
2037 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2038 char *initial_stack_usage_map = stack_usage_map;
2039 char *stack_usage_map_buf = NULL;
2041 int old_stack_allocated;
2043 /* State variables to track stack modifications. */
2044 rtx old_stack_level = 0;
2045 int old_stack_arg_under_construction = 0;
2046 int old_pending_adj = 0;
2047 int old_inhibit_defer_pop = inhibit_defer_pop;
2049 /* Some stack pointer alterations we make are performed via
2050 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2051 which we then also need to save/restore along the way. */
2052 int old_stack_pointer_delta = 0;
2054 rtx call_fusage;
2055 tree addr = CALL_EXPR_FN (exp);
2056 int i;
2057 /* The alignment of the stack, in bits. */
2058 unsigned HOST_WIDE_INT preferred_stack_boundary;
2059 /* The alignment of the stack, in bytes. */
2060 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2061 /* The static chain value to use for this call. */
2062 rtx static_chain_value;
2063 /* See if this is "nothrow" function call. */
2064 if (TREE_NOTHROW (exp))
2065 flags |= ECF_NOTHROW;
2067 /* See if we can find a DECL-node for the actual function, and get the
2068 function attributes (flags) from the function decl or type node. */
2069 fndecl = get_callee_fndecl (exp);
2070 if (fndecl)
2072 fntype = TREE_TYPE (fndecl);
2073 flags |= flags_from_decl_or_type (fndecl);
2075 else
2077 fntype = TREE_TYPE (TREE_TYPE (addr));
2078 flags |= flags_from_decl_or_type (fntype);
2080 rettype = TREE_TYPE (exp);
2082 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2084 /* Warn if this value is an aggregate type,
2085 regardless of which calling convention we are using for it. */
2086 if (AGGREGATE_TYPE_P (rettype))
2087 warning (OPT_Waggregate_return, "function call has aggregate value");
2089 /* If the result of a non looping pure or const function call is
2090 ignored (or void), and none of its arguments are volatile, we can
2091 avoid expanding the call and just evaluate the arguments for
2092 side-effects. */
2093 if ((flags & (ECF_CONST | ECF_PURE))
2094 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2095 && (ignore || target == const0_rtx
2096 || TYPE_MODE (rettype) == VOIDmode))
2098 bool volatilep = false;
2099 tree arg;
2100 call_expr_arg_iterator iter;
2102 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2103 if (TREE_THIS_VOLATILE (arg))
2105 volatilep = true;
2106 break;
2109 if (! volatilep)
2111 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2112 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2113 return const0_rtx;
2117 #ifdef REG_PARM_STACK_SPACE
2118 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2119 #endif
2121 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2122 && reg_parm_stack_space > 0 && PUSH_ARGS)
2123 must_preallocate = 1;
2125 /* Set up a place to return a structure. */
2127 /* Cater to broken compilers. */
2128 if (aggregate_value_p (exp, fntype))
2130 /* This call returns a big structure. */
2131 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2133 #ifdef PCC_STATIC_STRUCT_RETURN
2135 pcc_struct_value = 1;
2137 #else /* not PCC_STATIC_STRUCT_RETURN */
2139 struct_value_size = int_size_in_bytes (rettype);
2141 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2142 structure_value_addr = XEXP (target, 0);
2143 else
2145 /* For variable-sized objects, we must be called with a target
2146 specified. If we were to allocate space on the stack here,
2147 we would have no way of knowing when to free it. */
2148 rtx d = assign_temp (rettype, 0, 1, 1);
2150 mark_temp_addr_taken (d);
2151 structure_value_addr = XEXP (d, 0);
2152 target = 0;
2155 #endif /* not PCC_STATIC_STRUCT_RETURN */
2158 /* Figure out the amount to which the stack should be aligned. */
2159 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2160 if (fndecl)
2162 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2163 /* Without automatic stack alignment, we can't increase preferred
2164 stack boundary. With automatic stack alignment, it is
2165 unnecessary since unless we can guarantee that all callers will
2166 align the outgoing stack properly, callee has to align its
2167 stack anyway. */
2168 if (i
2169 && i->preferred_incoming_stack_boundary
2170 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2171 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2174 /* Operand 0 is a pointer-to-function; get the type of the function. */
2175 funtype = TREE_TYPE (addr);
2176 gcc_assert (POINTER_TYPE_P (funtype));
2177 funtype = TREE_TYPE (funtype);
2179 /* Count whether there are actual complex arguments that need to be split
2180 into their real and imaginary parts. Munge the type_arg_types
2181 appropriately here as well. */
2182 if (targetm.calls.split_complex_arg)
2184 call_expr_arg_iterator iter;
2185 tree arg;
2186 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2188 tree type = TREE_TYPE (arg);
2189 if (type && TREE_CODE (type) == COMPLEX_TYPE
2190 && targetm.calls.split_complex_arg (type))
2191 num_complex_actuals++;
2193 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2195 else
2196 type_arg_types = TYPE_ARG_TYPES (funtype);
2198 if (flags & ECF_MAY_BE_ALLOCA)
2199 cfun->calls_alloca = 1;
2201 /* If struct_value_rtx is 0, it means pass the address
2202 as if it were an extra parameter. Put the argument expression
2203 in structure_value_addr_value. */
2204 if (structure_value_addr && struct_value == 0)
2206 /* If structure_value_addr is a REG other than
2207 virtual_outgoing_args_rtx, we can use always use it. If it
2208 is not a REG, we must always copy it into a register.
2209 If it is virtual_outgoing_args_rtx, we must copy it to another
2210 register in some cases. */
2211 rtx temp = (!REG_P (structure_value_addr)
2212 || (ACCUMULATE_OUTGOING_ARGS
2213 && stack_arg_under_construction
2214 && structure_value_addr == virtual_outgoing_args_rtx)
2215 ? copy_addr_to_reg (convert_memory_address
2216 (Pmode, structure_value_addr))
2217 : structure_value_addr);
2219 structure_value_addr_value =
2220 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2221 structure_value_addr_parm = 1;
2224 /* Count the arguments and set NUM_ACTUALS. */
2225 num_actuals =
2226 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2228 /* Compute number of named args.
2229 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2231 if (type_arg_types != 0)
2232 n_named_args
2233 = (list_length (type_arg_types)
2234 /* Count the struct value address, if it is passed as a parm. */
2235 + structure_value_addr_parm);
2236 else
2237 /* If we know nothing, treat all args as named. */
2238 n_named_args = num_actuals;
2240 /* Start updating where the next arg would go.
2242 On some machines (such as the PA) indirect calls have a different
2243 calling convention than normal calls. The fourth argument in
2244 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2245 or not. */
2246 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2248 /* Now possibly adjust the number of named args.
2249 Normally, don't include the last named arg if anonymous args follow.
2250 We do include the last named arg if
2251 targetm.calls.strict_argument_naming() returns nonzero.
2252 (If no anonymous args follow, the result of list_length is actually
2253 one too large. This is harmless.)
2255 If targetm.calls.pretend_outgoing_varargs_named() returns
2256 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2257 this machine will be able to place unnamed args that were passed
2258 in registers into the stack. So treat all args as named. This
2259 allows the insns emitting for a specific argument list to be
2260 independent of the function declaration.
2262 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2263 we do not have any reliable way to pass unnamed args in
2264 registers, so we must force them into memory. */
2266 if (type_arg_types != 0
2267 && targetm.calls.strict_argument_naming (&args_so_far))
2269 else if (type_arg_types != 0
2270 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2271 /* Don't include the last named arg. */
2272 --n_named_args;
2273 else
2274 /* Treat all args as named. */
2275 n_named_args = num_actuals;
2277 /* Make a vector to hold all the information about each arg. */
2278 args = XALLOCAVEC (struct arg_data, num_actuals);
2279 memset (args, 0, num_actuals * sizeof (struct arg_data));
2281 /* Build up entries in the ARGS array, compute the size of the
2282 arguments into ARGS_SIZE, etc. */
2283 initialize_argument_information (num_actuals, args, &args_size,
2284 n_named_args, exp,
2285 structure_value_addr_value, fndecl, fntype,
2286 &args_so_far, reg_parm_stack_space,
2287 &old_stack_level, &old_pending_adj,
2288 &must_preallocate, &flags,
2289 &try_tail_call, CALL_FROM_THUNK_P (exp));
2291 if (args_size.var)
2292 must_preallocate = 1;
2294 /* Now make final decision about preallocating stack space. */
2295 must_preallocate = finalize_must_preallocate (must_preallocate,
2296 num_actuals, args,
2297 &args_size);
2299 /* If the structure value address will reference the stack pointer, we
2300 must stabilize it. We don't need to do this if we know that we are
2301 not going to adjust the stack pointer in processing this call. */
2303 if (structure_value_addr
2304 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2305 || reg_mentioned_p (virtual_outgoing_args_rtx,
2306 structure_value_addr))
2307 && (args_size.var
2308 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2309 structure_value_addr = copy_to_reg (structure_value_addr);
2311 /* Tail calls can make things harder to debug, and we've traditionally
2312 pushed these optimizations into -O2. Don't try if we're already
2313 expanding a call, as that means we're an argument. Don't try if
2314 there's cleanups, as we know there's code to follow the call. */
2316 if (currently_expanding_call++ != 0
2317 || !flag_optimize_sibling_calls
2318 || args_size.var
2319 || dbg_cnt (tail_call) == false)
2320 try_tail_call = 0;
2322 /* Rest of purposes for tail call optimizations to fail. */
2323 if (
2324 #ifdef HAVE_sibcall_epilogue
2325 !HAVE_sibcall_epilogue
2326 #else
2328 #endif
2329 || !try_tail_call
2330 /* Doing sibling call optimization needs some work, since
2331 structure_value_addr can be allocated on the stack.
2332 It does not seem worth the effort since few optimizable
2333 sibling calls will return a structure. */
2334 || structure_value_addr != NULL_RTX
2335 #ifdef REG_PARM_STACK_SPACE
2336 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2337 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2338 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2339 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2340 #endif
2341 /* Check whether the target is able to optimize the call
2342 into a sibcall. */
2343 || !targetm.function_ok_for_sibcall (fndecl, exp)
2344 /* Functions that do not return exactly once may not be sibcall
2345 optimized. */
2346 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2347 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2348 /* If the called function is nested in the current one, it might access
2349 some of the caller's arguments, but could clobber them beforehand if
2350 the argument areas are shared. */
2351 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2352 /* If this function requires more stack slots than the current
2353 function, we cannot change it into a sibling call.
2354 crtl->args.pretend_args_size is not part of the
2355 stack allocated by our caller. */
2356 || args_size.constant > (crtl->args.size
2357 - crtl->args.pretend_args_size)
2358 /* If the callee pops its own arguments, then it must pop exactly
2359 the same number of arguments as the current function. */
2360 || (targetm.calls.return_pops_args (fndecl, funtype, args_size.constant)
2361 != targetm.calls.return_pops_args (current_function_decl,
2362 TREE_TYPE (current_function_decl),
2363 crtl->args.size))
2364 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2365 try_tail_call = 0;
2367 /* Check if caller and callee disagree in promotion of function
2368 return value. */
2369 if (try_tail_call)
2371 enum machine_mode caller_mode, caller_promoted_mode;
2372 enum machine_mode callee_mode, callee_promoted_mode;
2373 int caller_unsignedp, callee_unsignedp;
2374 tree caller_res = DECL_RESULT (current_function_decl);
2376 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2377 caller_mode = DECL_MODE (caller_res);
2378 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2379 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2380 caller_promoted_mode
2381 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2382 &caller_unsignedp,
2383 TREE_TYPE (current_function_decl), 1);
2384 callee_promoted_mode
2385 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2386 &callee_unsignedp,
2387 funtype, 1);
2388 if (caller_mode != VOIDmode
2389 && (caller_promoted_mode != callee_promoted_mode
2390 || ((caller_mode != caller_promoted_mode
2391 || callee_mode != callee_promoted_mode)
2392 && (caller_unsignedp != callee_unsignedp
2393 || GET_MODE_BITSIZE (caller_mode)
2394 < GET_MODE_BITSIZE (callee_mode)))))
2395 try_tail_call = 0;
2398 /* Ensure current function's preferred stack boundary is at least
2399 what we need. Stack alignment may also increase preferred stack
2400 boundary. */
2401 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2402 crtl->preferred_stack_boundary = preferred_stack_boundary;
2403 else
2404 preferred_stack_boundary = crtl->preferred_stack_boundary;
2406 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2408 /* We want to make two insn chains; one for a sibling call, the other
2409 for a normal call. We will select one of the two chains after
2410 initial RTL generation is complete. */
2411 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2413 int sibcall_failure = 0;
2414 /* We want to emit any pending stack adjustments before the tail
2415 recursion "call". That way we know any adjustment after the tail
2416 recursion call can be ignored if we indeed use the tail
2417 call expansion. */
2418 int save_pending_stack_adjust = 0;
2419 int save_stack_pointer_delta = 0;
2420 rtx insns;
2421 rtx before_call, next_arg_reg, after_args;
2423 if (pass == 0)
2425 /* State variables we need to save and restore between
2426 iterations. */
2427 save_pending_stack_adjust = pending_stack_adjust;
2428 save_stack_pointer_delta = stack_pointer_delta;
2430 if (pass)
2431 flags &= ~ECF_SIBCALL;
2432 else
2433 flags |= ECF_SIBCALL;
2435 /* Other state variables that we must reinitialize each time
2436 through the loop (that are not initialized by the loop itself). */
2437 argblock = 0;
2438 call_fusage = 0;
2440 /* Start a new sequence for the normal call case.
2442 From this point on, if the sibling call fails, we want to set
2443 sibcall_failure instead of continuing the loop. */
2444 start_sequence ();
2446 /* Don't let pending stack adjusts add up to too much.
2447 Also, do all pending adjustments now if there is any chance
2448 this might be a call to alloca or if we are expanding a sibling
2449 call sequence.
2450 Also do the adjustments before a throwing call, otherwise
2451 exception handling can fail; PR 19225. */
2452 if (pending_stack_adjust >= 32
2453 || (pending_stack_adjust > 0
2454 && (flags & ECF_MAY_BE_ALLOCA))
2455 || (pending_stack_adjust > 0
2456 && flag_exceptions && !(flags & ECF_NOTHROW))
2457 || pass == 0)
2458 do_pending_stack_adjust ();
2460 /* Precompute any arguments as needed. */
2461 if (pass)
2462 precompute_arguments (num_actuals, args);
2464 /* Now we are about to start emitting insns that can be deleted
2465 if a libcall is deleted. */
2466 if (pass && (flags & ECF_MALLOC))
2467 start_sequence ();
2469 if (pass == 0 && crtl->stack_protect_guard)
2470 stack_protect_epilogue ();
2472 adjusted_args_size = args_size;
2473 /* Compute the actual size of the argument block required. The variable
2474 and constant sizes must be combined, the size may have to be rounded,
2475 and there may be a minimum required size. When generating a sibcall
2476 pattern, do not round up, since we'll be re-using whatever space our
2477 caller provided. */
2478 unadjusted_args_size
2479 = compute_argument_block_size (reg_parm_stack_space,
2480 &adjusted_args_size,
2481 fndecl, fntype,
2482 (pass == 0 ? 0
2483 : preferred_stack_boundary));
2485 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2487 /* The argument block when performing a sibling call is the
2488 incoming argument block. */
2489 if (pass == 0)
2491 argblock = crtl->args.internal_arg_pointer;
2492 argblock
2493 #ifdef STACK_GROWS_DOWNWARD
2494 = plus_constant (argblock, crtl->args.pretend_args_size);
2495 #else
2496 = plus_constant (argblock, -crtl->args.pretend_args_size);
2497 #endif
2498 stored_args_map = sbitmap_alloc (args_size.constant);
2499 sbitmap_zero (stored_args_map);
2502 /* If we have no actual push instructions, or shouldn't use them,
2503 make space for all args right now. */
2504 else if (adjusted_args_size.var != 0)
2506 if (old_stack_level == 0)
2508 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2509 old_stack_pointer_delta = stack_pointer_delta;
2510 old_pending_adj = pending_stack_adjust;
2511 pending_stack_adjust = 0;
2512 /* stack_arg_under_construction says whether a stack arg is
2513 being constructed at the old stack level. Pushing the stack
2514 gets a clean outgoing argument block. */
2515 old_stack_arg_under_construction = stack_arg_under_construction;
2516 stack_arg_under_construction = 0;
2518 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2519 if (flag_stack_usage_info)
2520 current_function_has_unbounded_dynamic_stack_size = 1;
2522 else
2524 /* Note that we must go through the motions of allocating an argument
2525 block even if the size is zero because we may be storing args
2526 in the area reserved for register arguments, which may be part of
2527 the stack frame. */
2529 int needed = adjusted_args_size.constant;
2531 /* Store the maximum argument space used. It will be pushed by
2532 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2533 checking). */
2535 if (needed > crtl->outgoing_args_size)
2536 crtl->outgoing_args_size = needed;
2538 if (must_preallocate)
2540 if (ACCUMULATE_OUTGOING_ARGS)
2542 /* Since the stack pointer will never be pushed, it is
2543 possible for the evaluation of a parm to clobber
2544 something we have already written to the stack.
2545 Since most function calls on RISC machines do not use
2546 the stack, this is uncommon, but must work correctly.
2548 Therefore, we save any area of the stack that was already
2549 written and that we are using. Here we set up to do this
2550 by making a new stack usage map from the old one. The
2551 actual save will be done by store_one_arg.
2553 Another approach might be to try to reorder the argument
2554 evaluations to avoid this conflicting stack usage. */
2556 /* Since we will be writing into the entire argument area,
2557 the map must be allocated for its entire size, not just
2558 the part that is the responsibility of the caller. */
2559 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2560 needed += reg_parm_stack_space;
2562 #ifdef ARGS_GROW_DOWNWARD
2563 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2564 needed + 1);
2565 #else
2566 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2567 needed);
2568 #endif
2569 free (stack_usage_map_buf);
2570 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2571 stack_usage_map = stack_usage_map_buf;
2573 if (initial_highest_arg_in_use)
2574 memcpy (stack_usage_map, initial_stack_usage_map,
2575 initial_highest_arg_in_use);
2577 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2578 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2579 (highest_outgoing_arg_in_use
2580 - initial_highest_arg_in_use));
2581 needed = 0;
2583 /* The address of the outgoing argument list must not be
2584 copied to a register here, because argblock would be left
2585 pointing to the wrong place after the call to
2586 allocate_dynamic_stack_space below. */
2588 argblock = virtual_outgoing_args_rtx;
2590 else
2592 if (inhibit_defer_pop == 0)
2594 /* Try to reuse some or all of the pending_stack_adjust
2595 to get this space. */
2596 needed
2597 = (combine_pending_stack_adjustment_and_call
2598 (unadjusted_args_size,
2599 &adjusted_args_size,
2600 preferred_unit_stack_boundary));
2602 /* combine_pending_stack_adjustment_and_call computes
2603 an adjustment before the arguments are allocated.
2604 Account for them and see whether or not the stack
2605 needs to go up or down. */
2606 needed = unadjusted_args_size - needed;
2608 if (needed < 0)
2610 /* We're releasing stack space. */
2611 /* ??? We can avoid any adjustment at all if we're
2612 already aligned. FIXME. */
2613 pending_stack_adjust = -needed;
2614 do_pending_stack_adjust ();
2615 needed = 0;
2617 else
2618 /* We need to allocate space. We'll do that in
2619 push_block below. */
2620 pending_stack_adjust = 0;
2623 /* Special case this because overhead of `push_block' in
2624 this case is non-trivial. */
2625 if (needed == 0)
2626 argblock = virtual_outgoing_args_rtx;
2627 else
2629 argblock = push_block (GEN_INT (needed), 0, 0);
2630 #ifdef ARGS_GROW_DOWNWARD
2631 argblock = plus_constant (argblock, needed);
2632 #endif
2635 /* We only really need to call `copy_to_reg' in the case
2636 where push insns are going to be used to pass ARGBLOCK
2637 to a function call in ARGS. In that case, the stack
2638 pointer changes value from the allocation point to the
2639 call point, and hence the value of
2640 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2641 as well always do it. */
2642 argblock = copy_to_reg (argblock);
2647 if (ACCUMULATE_OUTGOING_ARGS)
2649 /* The save/restore code in store_one_arg handles all
2650 cases except one: a constructor call (including a C
2651 function returning a BLKmode struct) to initialize
2652 an argument. */
2653 if (stack_arg_under_construction)
2655 rtx push_size
2656 = GEN_INT (adjusted_args_size.constant
2657 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2658 : TREE_TYPE (fndecl))) ? 0
2659 : reg_parm_stack_space));
2660 if (old_stack_level == 0)
2662 emit_stack_save (SAVE_BLOCK, &old_stack_level);
2663 old_stack_pointer_delta = stack_pointer_delta;
2664 old_pending_adj = pending_stack_adjust;
2665 pending_stack_adjust = 0;
2666 /* stack_arg_under_construction says whether a stack
2667 arg is being constructed at the old stack level.
2668 Pushing the stack gets a clean outgoing argument
2669 block. */
2670 old_stack_arg_under_construction
2671 = stack_arg_under_construction;
2672 stack_arg_under_construction = 0;
2673 /* Make a new map for the new argument list. */
2674 free (stack_usage_map_buf);
2675 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2676 stack_usage_map = stack_usage_map_buf;
2677 highest_outgoing_arg_in_use = 0;
2679 /* We can pass TRUE as the 4th argument because we just
2680 saved the stack pointer and will restore it right after
2681 the call. */
2682 allocate_dynamic_stack_space (push_size, 0,
2683 BIGGEST_ALIGNMENT, true);
2686 /* If argument evaluation might modify the stack pointer,
2687 copy the address of the argument list to a register. */
2688 for (i = 0; i < num_actuals; i++)
2689 if (args[i].pass_on_stack)
2691 argblock = copy_addr_to_reg (argblock);
2692 break;
2696 compute_argument_addresses (args, argblock, num_actuals);
2698 /* If we push args individually in reverse order, perform stack alignment
2699 before the first push (the last arg). */
2700 if (PUSH_ARGS_REVERSED && argblock == 0
2701 && adjusted_args_size.constant != unadjusted_args_size)
2703 /* When the stack adjustment is pending, we get better code
2704 by combining the adjustments. */
2705 if (pending_stack_adjust
2706 && ! inhibit_defer_pop)
2708 pending_stack_adjust
2709 = (combine_pending_stack_adjustment_and_call
2710 (unadjusted_args_size,
2711 &adjusted_args_size,
2712 preferred_unit_stack_boundary));
2713 do_pending_stack_adjust ();
2715 else if (argblock == 0)
2716 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2717 - unadjusted_args_size));
2719 /* Now that the stack is properly aligned, pops can't safely
2720 be deferred during the evaluation of the arguments. */
2721 NO_DEFER_POP;
2723 /* Record the maximum pushed stack space size. We need to delay
2724 doing it this far to take into account the optimization done
2725 by combine_pending_stack_adjustment_and_call. */
2726 if (flag_stack_usage_info
2727 && !ACCUMULATE_OUTGOING_ARGS
2728 && pass
2729 && adjusted_args_size.var == 0)
2731 int pushed = adjusted_args_size.constant + pending_stack_adjust;
2732 if (pushed > current_function_pushed_stack_size)
2733 current_function_pushed_stack_size = pushed;
2736 funexp = rtx_for_function_call (fndecl, addr);
2738 /* Figure out the register where the value, if any, will come back. */
2739 valreg = 0;
2740 if (TYPE_MODE (rettype) != VOIDmode
2741 && ! structure_value_addr)
2743 if (pcc_struct_value)
2744 valreg = hard_function_value (build_pointer_type (rettype),
2745 fndecl, NULL, (pass == 0));
2746 else
2747 valreg = hard_function_value (rettype, fndecl, fntype,
2748 (pass == 0));
2750 /* If VALREG is a PARALLEL whose first member has a zero
2751 offset, use that. This is for targets such as m68k that
2752 return the same value in multiple places. */
2753 if (GET_CODE (valreg) == PARALLEL)
2755 rtx elem = XVECEXP (valreg, 0, 0);
2756 rtx where = XEXP (elem, 0);
2757 rtx offset = XEXP (elem, 1);
2758 if (offset == const0_rtx
2759 && GET_MODE (where) == GET_MODE (valreg))
2760 valreg = where;
2764 /* Precompute all register parameters. It isn't safe to compute anything
2765 once we have started filling any specific hard regs. */
2766 precompute_register_parameters (num_actuals, args, &reg_parm_seen);
2768 if (CALL_EXPR_STATIC_CHAIN (exp))
2769 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2770 else
2771 static_chain_value = 0;
2773 #ifdef REG_PARM_STACK_SPACE
2774 /* Save the fixed argument area if it's part of the caller's frame and
2775 is clobbered by argument setup for this call. */
2776 if (ACCUMULATE_OUTGOING_ARGS && pass)
2777 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2778 &low_to_save, &high_to_save);
2779 #endif
2781 /* Now store (and compute if necessary) all non-register parms.
2782 These come before register parms, since they can require block-moves,
2783 which could clobber the registers used for register parms.
2784 Parms which have partial registers are not stored here,
2785 but we do preallocate space here if they want that. */
2787 for (i = 0; i < num_actuals; i++)
2789 if (args[i].reg == 0 || args[i].pass_on_stack)
2791 rtx before_arg = get_last_insn ();
2793 if (store_one_arg (&args[i], argblock, flags,
2794 adjusted_args_size.var != 0,
2795 reg_parm_stack_space)
2796 || (pass == 0
2797 && check_sibcall_argument_overlap (before_arg,
2798 &args[i], 1)))
2799 sibcall_failure = 1;
2802 if (args[i].stack)
2803 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2804 gen_rtx_USE (VOIDmode,
2805 args[i].stack),
2806 call_fusage);
2809 /* If we have a parm that is passed in registers but not in memory
2810 and whose alignment does not permit a direct copy into registers,
2811 make a group of pseudos that correspond to each register that we
2812 will later fill. */
2813 if (STRICT_ALIGNMENT)
2814 store_unaligned_arguments_into_pseudos (args, num_actuals);
2816 /* Now store any partially-in-registers parm.
2817 This is the last place a block-move can happen. */
2818 if (reg_parm_seen)
2819 for (i = 0; i < num_actuals; i++)
2820 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2822 rtx before_arg = get_last_insn ();
2824 if (store_one_arg (&args[i], argblock, flags,
2825 adjusted_args_size.var != 0,
2826 reg_parm_stack_space)
2827 || (pass == 0
2828 && check_sibcall_argument_overlap (before_arg,
2829 &args[i], 1)))
2830 sibcall_failure = 1;
2833 /* If we pushed args in forward order, perform stack alignment
2834 after pushing the last arg. */
2835 if (!PUSH_ARGS_REVERSED && argblock == 0)
2836 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2837 - unadjusted_args_size));
2839 /* If register arguments require space on the stack and stack space
2840 was not preallocated, allocate stack space here for arguments
2841 passed in registers. */
2842 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2843 && !ACCUMULATE_OUTGOING_ARGS
2844 && must_preallocate == 0 && reg_parm_stack_space > 0)
2845 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2847 /* Pass the function the address in which to return a
2848 structure value. */
2849 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2851 structure_value_addr
2852 = convert_memory_address (Pmode, structure_value_addr);
2853 emit_move_insn (struct_value,
2854 force_reg (Pmode,
2855 force_operand (structure_value_addr,
2856 NULL_RTX)));
2858 if (REG_P (struct_value))
2859 use_reg (&call_fusage, struct_value);
2862 after_args = get_last_insn ();
2863 funexp = prepare_call_address (fndecl, funexp, static_chain_value,
2864 &call_fusage, reg_parm_seen, pass == 0);
2866 load_register_parameters (args, num_actuals, &call_fusage, flags,
2867 pass == 0, &sibcall_failure);
2869 /* Save a pointer to the last insn before the call, so that we can
2870 later safely search backwards to find the CALL_INSN. */
2871 before_call = get_last_insn ();
2873 /* Set up next argument register. For sibling calls on machines
2874 with register windows this should be the incoming register. */
2875 if (pass == 0)
2876 next_arg_reg = targetm.calls.function_incoming_arg (&args_so_far,
2877 VOIDmode,
2878 void_type_node,
2879 true);
2880 else
2881 next_arg_reg = targetm.calls.function_arg (&args_so_far,
2882 VOIDmode, void_type_node,
2883 true);
2885 /* All arguments and registers used for the call must be set up by
2886 now! */
2888 /* Stack must be properly aligned now. */
2889 gcc_assert (!pass
2890 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2892 /* Generate the actual call instruction. */
2893 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2894 adjusted_args_size.constant, struct_value_size,
2895 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2896 flags, & args_so_far);
2898 /* If the call setup or the call itself overlaps with anything
2899 of the argument setup we probably clobbered our call address.
2900 In that case we can't do sibcalls. */
2901 if (pass == 0
2902 && check_sibcall_argument_overlap (after_args, 0, 0))
2903 sibcall_failure = 1;
2905 /* If a non-BLKmode value is returned at the most significant end
2906 of a register, shift the register right by the appropriate amount
2907 and update VALREG accordingly. BLKmode values are handled by the
2908 group load/store machinery below. */
2909 if (!structure_value_addr
2910 && !pcc_struct_value
2911 && TYPE_MODE (rettype) != BLKmode
2912 && targetm.calls.return_in_msb (rettype))
2914 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
2915 sibcall_failure = 1;
2916 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
2919 if (pass && (flags & ECF_MALLOC))
2921 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2922 rtx last, insns;
2924 /* The return value from a malloc-like function is a pointer. */
2925 if (TREE_CODE (rettype) == POINTER_TYPE)
2926 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2928 emit_move_insn (temp, valreg);
2930 /* The return value from a malloc-like function can not alias
2931 anything else. */
2932 last = get_last_insn ();
2933 add_reg_note (last, REG_NOALIAS, temp);
2935 /* Write out the sequence. */
2936 insns = get_insns ();
2937 end_sequence ();
2938 emit_insn (insns);
2939 valreg = temp;
2942 /* For calls to `setjmp', etc., inform
2943 function.c:setjmp_warnings that it should complain if
2944 nonvolatile values are live. For functions that cannot
2945 return, inform flow that control does not fall through. */
2947 if ((flags & ECF_NORETURN) || pass == 0)
2949 /* The barrier must be emitted
2950 immediately after the CALL_INSN. Some ports emit more
2951 than just a CALL_INSN above, so we must search for it here. */
2953 rtx last = get_last_insn ();
2954 while (!CALL_P (last))
2956 last = PREV_INSN (last);
2957 /* There was no CALL_INSN? */
2958 gcc_assert (last != before_call);
2961 emit_barrier_after (last);
2963 /* Stack adjustments after a noreturn call are dead code.
2964 However when NO_DEFER_POP is in effect, we must preserve
2965 stack_pointer_delta. */
2966 if (inhibit_defer_pop == 0)
2968 stack_pointer_delta = old_stack_allocated;
2969 pending_stack_adjust = 0;
2973 /* If value type not void, return an rtx for the value. */
2975 if (TYPE_MODE (rettype) == VOIDmode
2976 || ignore)
2977 target = const0_rtx;
2978 else if (structure_value_addr)
2980 if (target == 0 || !MEM_P (target))
2982 target
2983 = gen_rtx_MEM (TYPE_MODE (rettype),
2984 memory_address (TYPE_MODE (rettype),
2985 structure_value_addr));
2986 set_mem_attributes (target, rettype, 1);
2989 else if (pcc_struct_value)
2991 /* This is the special C++ case where we need to
2992 know what the true target was. We take care to
2993 never use this value more than once in one expression. */
2994 target = gen_rtx_MEM (TYPE_MODE (rettype),
2995 copy_to_reg (valreg));
2996 set_mem_attributes (target, rettype, 1);
2998 /* Handle calls that return values in multiple non-contiguous locations.
2999 The Irix 6 ABI has examples of this. */
3000 else if (GET_CODE (valreg) == PARALLEL)
3002 if (target == 0)
3004 /* This will only be assigned once, so it can be readonly. */
3005 tree nt = build_qualified_type (rettype,
3006 (TYPE_QUALS (rettype)
3007 | TYPE_QUAL_CONST));
3009 target = assign_temp (nt, 0, 1, 1);
3012 if (! rtx_equal_p (target, valreg))
3013 emit_group_store (target, valreg, rettype,
3014 int_size_in_bytes (rettype));
3016 /* We can not support sibling calls for this case. */
3017 sibcall_failure = 1;
3019 else if (target
3020 && GET_MODE (target) == TYPE_MODE (rettype)
3021 && GET_MODE (target) == GET_MODE (valreg))
3023 bool may_overlap = false;
3025 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
3026 reg to a plain register. */
3027 if (!REG_P (target) || HARD_REGISTER_P (target))
3028 valreg = avoid_likely_spilled_reg (valreg);
3030 /* If TARGET is a MEM in the argument area, and we have
3031 saved part of the argument area, then we can't store
3032 directly into TARGET as it may get overwritten when we
3033 restore the argument save area below. Don't work too
3034 hard though and simply force TARGET to a register if it
3035 is a MEM; the optimizer is quite likely to sort it out. */
3036 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
3037 for (i = 0; i < num_actuals; i++)
3038 if (args[i].save_area)
3040 may_overlap = true;
3041 break;
3044 if (may_overlap)
3045 target = copy_to_reg (valreg);
3046 else
3048 /* TARGET and VALREG cannot be equal at this point
3049 because the latter would not have
3050 REG_FUNCTION_VALUE_P true, while the former would if
3051 it were referring to the same register.
3053 If they refer to the same register, this move will be
3054 a no-op, except when function inlining is being
3055 done. */
3056 emit_move_insn (target, valreg);
3058 /* If we are setting a MEM, this code must be executed.
3059 Since it is emitted after the call insn, sibcall
3060 optimization cannot be performed in that case. */
3061 if (MEM_P (target))
3062 sibcall_failure = 1;
3065 else if (TYPE_MODE (rettype) == BLKmode)
3067 rtx val = valreg;
3068 if (GET_MODE (val) != BLKmode)
3069 val = avoid_likely_spilled_reg (val);
3070 target = copy_blkmode_from_reg (target, val, rettype);
3072 /* We can not support sibling calls for this case. */
3073 sibcall_failure = 1;
3075 else
3076 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3078 /* If we promoted this return value, make the proper SUBREG.
3079 TARGET might be const0_rtx here, so be careful. */
3080 if (REG_P (target)
3081 && TYPE_MODE (rettype) != BLKmode
3082 && GET_MODE (target) != TYPE_MODE (rettype))
3084 tree type = rettype;
3085 int unsignedp = TYPE_UNSIGNED (type);
3086 int offset = 0;
3087 enum machine_mode pmode;
3089 /* Ensure we promote as expected, and get the new unsignedness. */
3090 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3091 funtype, 1);
3092 gcc_assert (GET_MODE (target) == pmode);
3094 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3095 && (GET_MODE_SIZE (GET_MODE (target))
3096 > GET_MODE_SIZE (TYPE_MODE (type))))
3098 offset = GET_MODE_SIZE (GET_MODE (target))
3099 - GET_MODE_SIZE (TYPE_MODE (type));
3100 if (! BYTES_BIG_ENDIAN)
3101 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3102 else if (! WORDS_BIG_ENDIAN)
3103 offset %= UNITS_PER_WORD;
3106 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3107 SUBREG_PROMOTED_VAR_P (target) = 1;
3108 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3111 /* If size of args is variable or this was a constructor call for a stack
3112 argument, restore saved stack-pointer value. */
3114 if (old_stack_level)
3116 emit_stack_restore (SAVE_BLOCK, old_stack_level);
3117 stack_pointer_delta = old_stack_pointer_delta;
3118 pending_stack_adjust = old_pending_adj;
3119 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3120 stack_arg_under_construction = old_stack_arg_under_construction;
3121 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3122 stack_usage_map = initial_stack_usage_map;
3123 sibcall_failure = 1;
3125 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3127 #ifdef REG_PARM_STACK_SPACE
3128 if (save_area)
3129 restore_fixed_argument_area (save_area, argblock,
3130 high_to_save, low_to_save);
3131 #endif
3133 /* If we saved any argument areas, restore them. */
3134 for (i = 0; i < num_actuals; i++)
3135 if (args[i].save_area)
3137 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3138 rtx stack_area
3139 = gen_rtx_MEM (save_mode,
3140 memory_address (save_mode,
3141 XEXP (args[i].stack_slot, 0)));
3143 if (save_mode != BLKmode)
3144 emit_move_insn (stack_area, args[i].save_area);
3145 else
3146 emit_block_move (stack_area, args[i].save_area,
3147 GEN_INT (args[i].locate.size.constant),
3148 BLOCK_OP_CALL_PARM);
3151 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3152 stack_usage_map = initial_stack_usage_map;
3155 /* If this was alloca, record the new stack level for nonlocal gotos.
3156 Check for the handler slots since we might not have a save area
3157 for non-local gotos. */
3159 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3160 update_nonlocal_goto_save_area ();
3162 /* Free up storage we no longer need. */
3163 for (i = 0; i < num_actuals; ++i)
3164 free (args[i].aligned_regs);
3166 insns = get_insns ();
3167 end_sequence ();
3169 if (pass == 0)
3171 tail_call_insns = insns;
3173 /* Restore the pending stack adjustment now that we have
3174 finished generating the sibling call sequence. */
3176 pending_stack_adjust = save_pending_stack_adjust;
3177 stack_pointer_delta = save_stack_pointer_delta;
3179 /* Prepare arg structure for next iteration. */
3180 for (i = 0; i < num_actuals; i++)
3182 args[i].value = 0;
3183 args[i].aligned_regs = 0;
3184 args[i].stack = 0;
3187 sbitmap_free (stored_args_map);
3189 else
3191 normal_call_insns = insns;
3193 /* Verify that we've deallocated all the stack we used. */
3194 gcc_assert ((flags & ECF_NORETURN)
3195 || (old_stack_allocated
3196 == stack_pointer_delta - pending_stack_adjust));
3199 /* If something prevents making this a sibling call,
3200 zero out the sequence. */
3201 if (sibcall_failure)
3202 tail_call_insns = NULL_RTX;
3203 else
3204 break;
3207 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3208 arguments too, as argument area is now clobbered by the call. */
3209 if (tail_call_insns)
3211 emit_insn (tail_call_insns);
3212 crtl->tail_call_emit = true;
3214 else
3215 emit_insn (normal_call_insns);
3217 currently_expanding_call--;
3219 free (stack_usage_map_buf);
3221 return target;
3224 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3225 this function's incoming arguments.
3227 At the start of RTL generation we know the only REG_EQUIV notes
3228 in the rtl chain are those for incoming arguments, so we can look
3229 for REG_EQUIV notes between the start of the function and the
3230 NOTE_INSN_FUNCTION_BEG.
3232 This is (slight) overkill. We could keep track of the highest
3233 argument we clobber and be more selective in removing notes, but it
3234 does not seem to be worth the effort. */
3236 void
3237 fixup_tail_calls (void)
3239 rtx insn;
3241 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3243 rtx note;
3245 /* There are never REG_EQUIV notes for the incoming arguments
3246 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3247 if (NOTE_P (insn)
3248 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3249 break;
3251 note = find_reg_note (insn, REG_EQUIV, 0);
3252 if (note)
3253 remove_note (insn, note);
3254 note = find_reg_note (insn, REG_EQUIV, 0);
3255 gcc_assert (!note);
3259 /* Traverse a list of TYPES and expand all complex types into their
3260 components. */
3261 static tree
3262 split_complex_types (tree types)
3264 tree p;
3266 /* Before allocating memory, check for the common case of no complex. */
3267 for (p = types; p; p = TREE_CHAIN (p))
3269 tree type = TREE_VALUE (p);
3270 if (TREE_CODE (type) == COMPLEX_TYPE
3271 && targetm.calls.split_complex_arg (type))
3272 goto found;
3274 return types;
3276 found:
3277 types = copy_list (types);
3279 for (p = types; p; p = TREE_CHAIN (p))
3281 tree complex_type = TREE_VALUE (p);
3283 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3284 && targetm.calls.split_complex_arg (complex_type))
3286 tree next, imag;
3288 /* Rewrite complex type with component type. */
3289 TREE_VALUE (p) = TREE_TYPE (complex_type);
3290 next = TREE_CHAIN (p);
3292 /* Add another component type for the imaginary part. */
3293 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3294 TREE_CHAIN (p) = imag;
3295 TREE_CHAIN (imag) = next;
3297 /* Skip the newly created node. */
3298 p = TREE_CHAIN (p);
3302 return types;
3305 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3306 The RETVAL parameter specifies whether return value needs to be saved, other
3307 parameters are documented in the emit_library_call function below. */
3309 static rtx
3310 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3311 enum libcall_type fn_type,
3312 enum machine_mode outmode, int nargs, va_list p)
3314 /* Total size in bytes of all the stack-parms scanned so far. */
3315 struct args_size args_size;
3316 /* Size of arguments before any adjustments (such as rounding). */
3317 struct args_size original_args_size;
3318 int argnum;
3319 rtx fun;
3320 /* Todo, choose the correct decl type of orgfun. Sadly this information
3321 isn't present here, so we default to native calling abi here. */
3322 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3323 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3324 int inc;
3325 int count;
3326 rtx argblock = 0;
3327 CUMULATIVE_ARGS args_so_far;
3328 struct arg
3330 rtx value;
3331 enum machine_mode mode;
3332 rtx reg;
3333 int partial;
3334 struct locate_and_pad_arg_data locate;
3335 rtx save_area;
3337 struct arg *argvec;
3338 int old_inhibit_defer_pop = inhibit_defer_pop;
3339 rtx call_fusage = 0;
3340 rtx mem_value = 0;
3341 rtx valreg;
3342 int pcc_struct_value = 0;
3343 int struct_value_size = 0;
3344 int flags;
3345 int reg_parm_stack_space = 0;
3346 int needed;
3347 rtx before_call;
3348 tree tfom; /* type_for_mode (outmode, 0) */
3350 #ifdef REG_PARM_STACK_SPACE
3351 /* Define the boundary of the register parm stack space that needs to be
3352 save, if any. */
3353 int low_to_save = 0, high_to_save = 0;
3354 rtx save_area = 0; /* Place that it is saved. */
3355 #endif
3357 /* Size of the stack reserved for parameter registers. */
3358 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3359 char *initial_stack_usage_map = stack_usage_map;
3360 char *stack_usage_map_buf = NULL;
3362 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3364 #ifdef REG_PARM_STACK_SPACE
3365 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3366 #endif
3368 /* By default, library functions can not throw. */
3369 flags = ECF_NOTHROW;
3371 switch (fn_type)
3373 case LCT_NORMAL:
3374 break;
3375 case LCT_CONST:
3376 flags |= ECF_CONST;
3377 break;
3378 case LCT_PURE:
3379 flags |= ECF_PURE;
3380 break;
3381 case LCT_NORETURN:
3382 flags |= ECF_NORETURN;
3383 break;
3384 case LCT_THROW:
3385 flags = ECF_NORETURN;
3386 break;
3387 case LCT_RETURNS_TWICE:
3388 flags = ECF_RETURNS_TWICE;
3389 break;
3391 fun = orgfun;
3393 /* Ensure current function's preferred stack boundary is at least
3394 what we need. */
3395 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3396 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3398 /* If this kind of value comes back in memory,
3399 decide where in memory it should come back. */
3400 if (outmode != VOIDmode)
3402 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3403 if (aggregate_value_p (tfom, 0))
3405 #ifdef PCC_STATIC_STRUCT_RETURN
3406 rtx pointer_reg
3407 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3408 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3409 pcc_struct_value = 1;
3410 if (value == 0)
3411 value = gen_reg_rtx (outmode);
3412 #else /* not PCC_STATIC_STRUCT_RETURN */
3413 struct_value_size = GET_MODE_SIZE (outmode);
3414 if (value != 0 && MEM_P (value))
3415 mem_value = value;
3416 else
3417 mem_value = assign_temp (tfom, 0, 1, 1);
3418 #endif
3419 /* This call returns a big structure. */
3420 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3423 else
3424 tfom = void_type_node;
3426 /* ??? Unfinished: must pass the memory address as an argument. */
3428 /* Copy all the libcall-arguments out of the varargs data
3429 and into a vector ARGVEC.
3431 Compute how to pass each argument. We only support a very small subset
3432 of the full argument passing conventions to limit complexity here since
3433 library functions shouldn't have many args. */
3435 argvec = XALLOCAVEC (struct arg, nargs + 1);
3436 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3438 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3439 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3440 #else
3441 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3442 #endif
3444 args_size.constant = 0;
3445 args_size.var = 0;
3447 count = 0;
3449 push_temp_slots ();
3451 /* If there's a structure value address to be passed,
3452 either pass it in the special place, or pass it as an extra argument. */
3453 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3455 rtx addr = XEXP (mem_value, 0);
3457 nargs++;
3459 /* Make sure it is a reasonable operand for a move or push insn. */
3460 if (!REG_P (addr) && !MEM_P (addr)
3461 && !(CONSTANT_P (addr)
3462 && targetm.legitimate_constant_p (Pmode, addr)))
3463 addr = force_operand (addr, NULL_RTX);
3465 argvec[count].value = addr;
3466 argvec[count].mode = Pmode;
3467 argvec[count].partial = 0;
3469 argvec[count].reg = targetm.calls.function_arg (&args_so_far,
3470 Pmode, NULL_TREE, true);
3471 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3472 NULL_TREE, 1) == 0);
3474 locate_and_pad_parm (Pmode, NULL_TREE,
3475 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3477 #else
3478 argvec[count].reg != 0,
3479 #endif
3480 0, NULL_TREE, &args_size, &argvec[count].locate);
3482 if (argvec[count].reg == 0 || argvec[count].partial != 0
3483 || reg_parm_stack_space > 0)
3484 args_size.constant += argvec[count].locate.size.constant;
3486 targetm.calls.function_arg_advance (&args_so_far, Pmode, (tree) 0, true);
3488 count++;
3491 for (; count < nargs; count++)
3493 rtx val = va_arg (p, rtx);
3494 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3495 int unsigned_p = 0;
3497 /* We cannot convert the arg value to the mode the library wants here;
3498 must do it earlier where we know the signedness of the arg. */
3499 gcc_assert (mode != BLKmode
3500 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3502 /* Make sure it is a reasonable operand for a move or push insn. */
3503 if (!REG_P (val) && !MEM_P (val)
3504 && !(CONSTANT_P (val) && targetm.legitimate_constant_p (mode, val)))
3505 val = force_operand (val, NULL_RTX);
3507 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3509 rtx slot;
3510 int must_copy
3511 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3513 /* If this was a CONST function, it is now PURE since it now
3514 reads memory. */
3515 if (flags & ECF_CONST)
3517 flags &= ~ECF_CONST;
3518 flags |= ECF_PURE;
3521 if (MEM_P (val) && !must_copy)
3522 slot = val;
3523 else
3525 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3526 0, 1, 1);
3527 emit_move_insn (slot, val);
3530 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3531 gen_rtx_USE (VOIDmode, slot),
3532 call_fusage);
3533 if (must_copy)
3534 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3535 gen_rtx_CLOBBER (VOIDmode,
3536 slot),
3537 call_fusage);
3539 mode = Pmode;
3540 val = force_operand (XEXP (slot, 0), NULL_RTX);
3543 mode = promote_function_mode (NULL_TREE, mode, &unsigned_p, NULL_TREE, 0);
3544 argvec[count].mode = mode;
3545 argvec[count].value = convert_modes (mode, GET_MODE (val), val, unsigned_p);
3546 argvec[count].reg = targetm.calls.function_arg (&args_so_far, mode,
3547 NULL_TREE, true);
3549 argvec[count].partial
3550 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3552 locate_and_pad_parm (mode, NULL_TREE,
3553 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3555 #else
3556 argvec[count].reg != 0,
3557 #endif
3558 argvec[count].partial,
3559 NULL_TREE, &args_size, &argvec[count].locate);
3561 gcc_assert (!argvec[count].locate.size.var);
3563 if (argvec[count].reg == 0 || argvec[count].partial != 0
3564 || reg_parm_stack_space > 0)
3565 args_size.constant += argvec[count].locate.size.constant;
3567 targetm.calls.function_arg_advance (&args_so_far, mode, (tree) 0, true);
3570 /* If this machine requires an external definition for library
3571 functions, write one out. */
3572 assemble_external_libcall (fun);
3574 original_args_size = args_size;
3575 args_size.constant = (((args_size.constant
3576 + stack_pointer_delta
3577 + STACK_BYTES - 1)
3578 / STACK_BYTES
3579 * STACK_BYTES)
3580 - stack_pointer_delta);
3582 args_size.constant = MAX (args_size.constant,
3583 reg_parm_stack_space);
3585 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3586 args_size.constant -= reg_parm_stack_space;
3588 if (args_size.constant > crtl->outgoing_args_size)
3589 crtl->outgoing_args_size = args_size.constant;
3591 if (flag_stack_usage_info && !ACCUMULATE_OUTGOING_ARGS)
3593 int pushed = args_size.constant + pending_stack_adjust;
3594 if (pushed > current_function_pushed_stack_size)
3595 current_function_pushed_stack_size = pushed;
3598 if (ACCUMULATE_OUTGOING_ARGS)
3600 /* Since the stack pointer will never be pushed, it is possible for
3601 the evaluation of a parm to clobber something we have already
3602 written to the stack. Since most function calls on RISC machines
3603 do not use the stack, this is uncommon, but must work correctly.
3605 Therefore, we save any area of the stack that was already written
3606 and that we are using. Here we set up to do this by making a new
3607 stack usage map from the old one.
3609 Another approach might be to try to reorder the argument
3610 evaluations to avoid this conflicting stack usage. */
3612 needed = args_size.constant;
3614 /* Since we will be writing into the entire argument area, the
3615 map must be allocated for its entire size, not just the part that
3616 is the responsibility of the caller. */
3617 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3618 needed += reg_parm_stack_space;
3620 #ifdef ARGS_GROW_DOWNWARD
3621 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3622 needed + 1);
3623 #else
3624 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3625 needed);
3626 #endif
3627 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3628 stack_usage_map = stack_usage_map_buf;
3630 if (initial_highest_arg_in_use)
3631 memcpy (stack_usage_map, initial_stack_usage_map,
3632 initial_highest_arg_in_use);
3634 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3635 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3636 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3637 needed = 0;
3639 /* We must be careful to use virtual regs before they're instantiated,
3640 and real regs afterwards. Loop optimization, for example, can create
3641 new libcalls after we've instantiated the virtual regs, and if we
3642 use virtuals anyway, they won't match the rtl patterns. */
3644 if (virtuals_instantiated)
3645 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3646 else
3647 argblock = virtual_outgoing_args_rtx;
3649 else
3651 if (!PUSH_ARGS)
3652 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3655 /* If we push args individually in reverse order, perform stack alignment
3656 before the first push (the last arg). */
3657 if (argblock == 0 && PUSH_ARGS_REVERSED)
3658 anti_adjust_stack (GEN_INT (args_size.constant
3659 - original_args_size.constant));
3661 if (PUSH_ARGS_REVERSED)
3663 inc = -1;
3664 argnum = nargs - 1;
3666 else
3668 inc = 1;
3669 argnum = 0;
3672 #ifdef REG_PARM_STACK_SPACE
3673 if (ACCUMULATE_OUTGOING_ARGS)
3675 /* The argument list is the property of the called routine and it
3676 may clobber it. If the fixed area has been used for previous
3677 parameters, we must save and restore it. */
3678 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3679 &low_to_save, &high_to_save);
3681 #endif
3683 /* Push the args that need to be pushed. */
3685 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3686 are to be pushed. */
3687 for (count = 0; count < nargs; count++, argnum += inc)
3689 enum machine_mode mode = argvec[argnum].mode;
3690 rtx val = argvec[argnum].value;
3691 rtx reg = argvec[argnum].reg;
3692 int partial = argvec[argnum].partial;
3693 unsigned int parm_align = argvec[argnum].locate.boundary;
3694 int lower_bound = 0, upper_bound = 0, i;
3696 if (! (reg != 0 && partial == 0))
3698 rtx use;
3700 if (ACCUMULATE_OUTGOING_ARGS)
3702 /* If this is being stored into a pre-allocated, fixed-size,
3703 stack area, save any previous data at that location. */
3705 #ifdef ARGS_GROW_DOWNWARD
3706 /* stack_slot is negative, but we want to index stack_usage_map
3707 with positive values. */
3708 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3709 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3710 #else
3711 lower_bound = argvec[argnum].locate.slot_offset.constant;
3712 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3713 #endif
3715 i = lower_bound;
3716 /* Don't worry about things in the fixed argument area;
3717 it has already been saved. */
3718 if (i < reg_parm_stack_space)
3719 i = reg_parm_stack_space;
3720 while (i < upper_bound && stack_usage_map[i] == 0)
3721 i++;
3723 if (i < upper_bound)
3725 /* We need to make a save area. */
3726 unsigned int size
3727 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3728 enum machine_mode save_mode
3729 = mode_for_size (size, MODE_INT, 1);
3730 rtx adr
3731 = plus_constant (argblock,
3732 argvec[argnum].locate.offset.constant);
3733 rtx stack_area
3734 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3736 if (save_mode == BLKmode)
3738 argvec[argnum].save_area
3739 = assign_stack_temp (BLKmode,
3740 argvec[argnum].locate.size.constant,
3743 emit_block_move (validize_mem (argvec[argnum].save_area),
3744 stack_area,
3745 GEN_INT (argvec[argnum].locate.size.constant),
3746 BLOCK_OP_CALL_PARM);
3748 else
3750 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3752 emit_move_insn (argvec[argnum].save_area, stack_area);
3757 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
3758 partial, reg, 0, argblock,
3759 GEN_INT (argvec[argnum].locate.offset.constant),
3760 reg_parm_stack_space,
3761 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3763 /* Now mark the segment we just used. */
3764 if (ACCUMULATE_OUTGOING_ARGS)
3765 for (i = lower_bound; i < upper_bound; i++)
3766 stack_usage_map[i] = 1;
3768 NO_DEFER_POP;
3770 /* Indicate argument access so that alias.c knows that these
3771 values are live. */
3772 if (argblock)
3773 use = plus_constant (argblock,
3774 argvec[argnum].locate.offset.constant);
3775 else
3776 /* When arguments are pushed, trying to tell alias.c where
3777 exactly this argument is won't work, because the
3778 auto-increment causes confusion. So we merely indicate
3779 that we access something with a known mode somewhere on
3780 the stack. */
3781 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3782 gen_rtx_SCRATCH (Pmode));
3783 use = gen_rtx_MEM (argvec[argnum].mode, use);
3784 use = gen_rtx_USE (VOIDmode, use);
3785 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3789 /* If we pushed args in forward order, perform stack alignment
3790 after pushing the last arg. */
3791 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3792 anti_adjust_stack (GEN_INT (args_size.constant
3793 - original_args_size.constant));
3795 if (PUSH_ARGS_REVERSED)
3796 argnum = nargs - 1;
3797 else
3798 argnum = 0;
3800 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
3802 /* Now load any reg parms into their regs. */
3804 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3805 are to be pushed. */
3806 for (count = 0; count < nargs; count++, argnum += inc)
3808 enum machine_mode mode = argvec[argnum].mode;
3809 rtx val = argvec[argnum].value;
3810 rtx reg = argvec[argnum].reg;
3811 int partial = argvec[argnum].partial;
3813 /* Handle calls that pass values in multiple non-contiguous
3814 locations. The PA64 has examples of this for library calls. */
3815 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3816 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3817 else if (reg != 0 && partial == 0)
3818 emit_move_insn (reg, val);
3820 NO_DEFER_POP;
3823 /* Any regs containing parms remain in use through the call. */
3824 for (count = 0; count < nargs; count++)
3826 rtx reg = argvec[count].reg;
3827 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3828 use_group_regs (&call_fusage, reg);
3829 else if (reg != 0)
3831 int partial = argvec[count].partial;
3832 if (partial)
3834 int nregs;
3835 gcc_assert (partial % UNITS_PER_WORD == 0);
3836 nregs = partial / UNITS_PER_WORD;
3837 use_regs (&call_fusage, REGNO (reg), nregs);
3839 else
3840 use_reg (&call_fusage, reg);
3844 /* Pass the function the address in which to return a structure value. */
3845 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3847 emit_move_insn (struct_value,
3848 force_reg (Pmode,
3849 force_operand (XEXP (mem_value, 0),
3850 NULL_RTX)));
3851 if (REG_P (struct_value))
3852 use_reg (&call_fusage, struct_value);
3855 /* Don't allow popping to be deferred, since then
3856 cse'ing of library calls could delete a call and leave the pop. */
3857 NO_DEFER_POP;
3858 valreg = (mem_value == 0 && outmode != VOIDmode
3859 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
3861 /* Stack must be properly aligned now. */
3862 gcc_assert (!(stack_pointer_delta
3863 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3865 before_call = get_last_insn ();
3867 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3868 will set inhibit_defer_pop to that value. */
3869 /* The return type is needed to decide how many bytes the function pops.
3870 Signedness plays no role in that, so for simplicity, we pretend it's
3871 always signed. We also assume that the list of arguments passed has
3872 no impact, so we pretend it is unknown. */
3874 emit_call_1 (fun, NULL,
3875 get_identifier (XSTR (orgfun, 0)),
3876 build_function_type (tfom, NULL_TREE),
3877 original_args_size.constant, args_size.constant,
3878 struct_value_size,
3879 targetm.calls.function_arg (&args_so_far,
3880 VOIDmode, void_type_node, true),
3881 valreg,
3882 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3884 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3885 that it should complain if nonvolatile values are live. For
3886 functions that cannot return, inform flow that control does not
3887 fall through. */
3889 if (flags & ECF_NORETURN)
3891 /* The barrier note must be emitted
3892 immediately after the CALL_INSN. Some ports emit more than
3893 just a CALL_INSN above, so we must search for it here. */
3895 rtx last = get_last_insn ();
3896 while (!CALL_P (last))
3898 last = PREV_INSN (last);
3899 /* There was no CALL_INSN? */
3900 gcc_assert (last != before_call);
3903 emit_barrier_after (last);
3906 /* Now restore inhibit_defer_pop to its actual original value. */
3907 OK_DEFER_POP;
3909 pop_temp_slots ();
3911 /* Copy the value to the right place. */
3912 if (outmode != VOIDmode && retval)
3914 if (mem_value)
3916 if (value == 0)
3917 value = mem_value;
3918 if (value != mem_value)
3919 emit_move_insn (value, mem_value);
3921 else if (GET_CODE (valreg) == PARALLEL)
3923 if (value == 0)
3924 value = gen_reg_rtx (outmode);
3925 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3927 else
3929 /* Convert to the proper mode if a promotion has been active. */
3930 if (GET_MODE (valreg) != outmode)
3932 int unsignedp = TYPE_UNSIGNED (tfom);
3934 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
3935 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
3936 == GET_MODE (valreg));
3937 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3940 if (value != 0)
3941 emit_move_insn (value, valreg);
3942 else
3943 value = valreg;
3947 if (ACCUMULATE_OUTGOING_ARGS)
3949 #ifdef REG_PARM_STACK_SPACE
3950 if (save_area)
3951 restore_fixed_argument_area (save_area, argblock,
3952 high_to_save, low_to_save);
3953 #endif
3955 /* If we saved any argument areas, restore them. */
3956 for (count = 0; count < nargs; count++)
3957 if (argvec[count].save_area)
3959 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3960 rtx adr = plus_constant (argblock,
3961 argvec[count].locate.offset.constant);
3962 rtx stack_area = gen_rtx_MEM (save_mode,
3963 memory_address (save_mode, adr));
3965 if (save_mode == BLKmode)
3966 emit_block_move (stack_area,
3967 validize_mem (argvec[count].save_area),
3968 GEN_INT (argvec[count].locate.size.constant),
3969 BLOCK_OP_CALL_PARM);
3970 else
3971 emit_move_insn (stack_area, argvec[count].save_area);
3974 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3975 stack_usage_map = initial_stack_usage_map;
3978 free (stack_usage_map_buf);
3980 return value;
3984 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3985 (emitting the queue unless NO_QUEUE is nonzero),
3986 for a value of mode OUTMODE,
3987 with NARGS different arguments, passed as alternating rtx values
3988 and machine_modes to convert them to.
3990 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3991 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3992 other types of library calls. */
3994 void
3995 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3996 enum machine_mode outmode, int nargs, ...)
3998 va_list p;
4000 va_start (p, nargs);
4001 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4002 va_end (p);
4005 /* Like emit_library_call except that an extra argument, VALUE,
4006 comes second and says where to store the result.
4007 (If VALUE is zero, this function chooses a convenient way
4008 to return the value.
4010 This function returns an rtx for where the value is to be found.
4011 If VALUE is nonzero, VALUE is returned. */
4014 emit_library_call_value (rtx orgfun, rtx value,
4015 enum libcall_type fn_type,
4016 enum machine_mode outmode, int nargs, ...)
4018 rtx result;
4019 va_list p;
4021 va_start (p, nargs);
4022 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4023 nargs, p);
4024 va_end (p);
4026 return result;
4029 /* Store a single argument for a function call
4030 into the register or memory area where it must be passed.
4031 *ARG describes the argument value and where to pass it.
4033 ARGBLOCK is the address of the stack-block for all the arguments,
4034 or 0 on a machine where arguments are pushed individually.
4036 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4037 so must be careful about how the stack is used.
4039 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4040 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4041 that we need not worry about saving and restoring the stack.
4043 FNDECL is the declaration of the function we are calling.
4045 Return nonzero if this arg should cause sibcall failure,
4046 zero otherwise. */
4048 static int
4049 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4050 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4052 tree pval = arg->tree_value;
4053 rtx reg = 0;
4054 int partial = 0;
4055 int used = 0;
4056 int i, lower_bound = 0, upper_bound = 0;
4057 int sibcall_failure = 0;
4059 if (TREE_CODE (pval) == ERROR_MARK)
4060 return 1;
4062 /* Push a new temporary level for any temporaries we make for
4063 this argument. */
4064 push_temp_slots ();
4066 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4068 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4069 save any previous data at that location. */
4070 if (argblock && ! variable_size && arg->stack)
4072 #ifdef ARGS_GROW_DOWNWARD
4073 /* stack_slot is negative, but we want to index stack_usage_map
4074 with positive values. */
4075 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4076 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4077 else
4078 upper_bound = 0;
4080 lower_bound = upper_bound - arg->locate.size.constant;
4081 #else
4082 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4083 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4084 else
4085 lower_bound = 0;
4087 upper_bound = lower_bound + arg->locate.size.constant;
4088 #endif
4090 i = lower_bound;
4091 /* Don't worry about things in the fixed argument area;
4092 it has already been saved. */
4093 if (i < reg_parm_stack_space)
4094 i = reg_parm_stack_space;
4095 while (i < upper_bound && stack_usage_map[i] == 0)
4096 i++;
4098 if (i < upper_bound)
4100 /* We need to make a save area. */
4101 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4102 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4103 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4104 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4106 if (save_mode == BLKmode)
4108 tree ot = TREE_TYPE (arg->tree_value);
4109 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4110 | TYPE_QUAL_CONST));
4112 arg->save_area = assign_temp (nt, 0, 1, 1);
4113 preserve_temp_slots (arg->save_area);
4114 emit_block_move (validize_mem (arg->save_area), stack_area,
4115 GEN_INT (arg->locate.size.constant),
4116 BLOCK_OP_CALL_PARM);
4118 else
4120 arg->save_area = gen_reg_rtx (save_mode);
4121 emit_move_insn (arg->save_area, stack_area);
4127 /* If this isn't going to be placed on both the stack and in registers,
4128 set up the register and number of words. */
4129 if (! arg->pass_on_stack)
4131 if (flags & ECF_SIBCALL)
4132 reg = arg->tail_call_reg;
4133 else
4134 reg = arg->reg;
4135 partial = arg->partial;
4138 /* Being passed entirely in a register. We shouldn't be called in
4139 this case. */
4140 gcc_assert (reg == 0 || partial != 0);
4142 /* If this arg needs special alignment, don't load the registers
4143 here. */
4144 if (arg->n_aligned_regs != 0)
4145 reg = 0;
4147 /* If this is being passed partially in a register, we can't evaluate
4148 it directly into its stack slot. Otherwise, we can. */
4149 if (arg->value == 0)
4151 /* stack_arg_under_construction is nonzero if a function argument is
4152 being evaluated directly into the outgoing argument list and
4153 expand_call must take special action to preserve the argument list
4154 if it is called recursively.
4156 For scalar function arguments stack_usage_map is sufficient to
4157 determine which stack slots must be saved and restored. Scalar
4158 arguments in general have pass_on_stack == 0.
4160 If this argument is initialized by a function which takes the
4161 address of the argument (a C++ constructor or a C function
4162 returning a BLKmode structure), then stack_usage_map is
4163 insufficient and expand_call must push the stack around the
4164 function call. Such arguments have pass_on_stack == 1.
4166 Note that it is always safe to set stack_arg_under_construction,
4167 but this generates suboptimal code if set when not needed. */
4169 if (arg->pass_on_stack)
4170 stack_arg_under_construction++;
4172 arg->value = expand_expr (pval,
4173 (partial
4174 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4175 ? NULL_RTX : arg->stack,
4176 VOIDmode, EXPAND_STACK_PARM);
4178 /* If we are promoting object (or for any other reason) the mode
4179 doesn't agree, convert the mode. */
4181 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4182 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4183 arg->value, arg->unsignedp);
4185 if (arg->pass_on_stack)
4186 stack_arg_under_construction--;
4189 /* Check for overlap with already clobbered argument area. */
4190 if ((flags & ECF_SIBCALL)
4191 && MEM_P (arg->value)
4192 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4193 arg->locate.size.constant))
4194 sibcall_failure = 1;
4196 /* Don't allow anything left on stack from computation
4197 of argument to alloca. */
4198 if (flags & ECF_MAY_BE_ALLOCA)
4199 do_pending_stack_adjust ();
4201 if (arg->value == arg->stack)
4202 /* If the value is already in the stack slot, we are done. */
4204 else if (arg->mode != BLKmode)
4206 int size;
4207 unsigned int parm_align;
4209 /* Argument is a scalar, not entirely passed in registers.
4210 (If part is passed in registers, arg->partial says how much
4211 and emit_push_insn will take care of putting it there.)
4213 Push it, and if its size is less than the
4214 amount of space allocated to it,
4215 also bump stack pointer by the additional space.
4216 Note that in C the default argument promotions
4217 will prevent such mismatches. */
4219 size = GET_MODE_SIZE (arg->mode);
4220 /* Compute how much space the push instruction will push.
4221 On many machines, pushing a byte will advance the stack
4222 pointer by a halfword. */
4223 #ifdef PUSH_ROUNDING
4224 size = PUSH_ROUNDING (size);
4225 #endif
4226 used = size;
4228 /* Compute how much space the argument should get:
4229 round up to a multiple of the alignment for arguments. */
4230 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4231 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4232 / (PARM_BOUNDARY / BITS_PER_UNIT))
4233 * (PARM_BOUNDARY / BITS_PER_UNIT));
4235 /* Compute the alignment of the pushed argument. */
4236 parm_align = arg->locate.boundary;
4237 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4239 int pad = used - size;
4240 if (pad)
4242 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4243 parm_align = MIN (parm_align, pad_align);
4247 /* This isn't already where we want it on the stack, so put it there.
4248 This can either be done with push or copy insns. */
4249 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4250 parm_align, partial, reg, used - size, argblock,
4251 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4252 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4254 /* Unless this is a partially-in-register argument, the argument is now
4255 in the stack. */
4256 if (partial == 0)
4257 arg->value = arg->stack;
4259 else
4261 /* BLKmode, at least partly to be pushed. */
4263 unsigned int parm_align;
4264 int excess;
4265 rtx size_rtx;
4267 /* Pushing a nonscalar.
4268 If part is passed in registers, PARTIAL says how much
4269 and emit_push_insn will take care of putting it there. */
4271 /* Round its size up to a multiple
4272 of the allocation unit for arguments. */
4274 if (arg->locate.size.var != 0)
4276 excess = 0;
4277 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4279 else
4281 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4282 for BLKmode is careful to avoid it. */
4283 excess = (arg->locate.size.constant
4284 - int_size_in_bytes (TREE_TYPE (pval))
4285 + partial);
4286 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4287 NULL_RTX, TYPE_MODE (sizetype),
4288 EXPAND_NORMAL);
4291 parm_align = arg->locate.boundary;
4293 /* When an argument is padded down, the block is aligned to
4294 PARM_BOUNDARY, but the actual argument isn't. */
4295 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4297 if (arg->locate.size.var)
4298 parm_align = BITS_PER_UNIT;
4299 else if (excess)
4301 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4302 parm_align = MIN (parm_align, excess_align);
4306 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4308 /* emit_push_insn might not work properly if arg->value and
4309 argblock + arg->locate.offset areas overlap. */
4310 rtx x = arg->value;
4311 int i = 0;
4313 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4314 || (GET_CODE (XEXP (x, 0)) == PLUS
4315 && XEXP (XEXP (x, 0), 0) ==
4316 crtl->args.internal_arg_pointer
4317 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4319 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4320 i = INTVAL (XEXP (XEXP (x, 0), 1));
4322 /* expand_call should ensure this. */
4323 gcc_assert (!arg->locate.offset.var
4324 && arg->locate.size.var == 0
4325 && CONST_INT_P (size_rtx));
4327 if (arg->locate.offset.constant > i)
4329 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4330 sibcall_failure = 1;
4332 else if (arg->locate.offset.constant < i)
4334 /* Use arg->locate.size.constant instead of size_rtx
4335 because we only care about the part of the argument
4336 on the stack. */
4337 if (i < (arg->locate.offset.constant
4338 + arg->locate.size.constant))
4339 sibcall_failure = 1;
4341 else
4343 /* Even though they appear to be at the same location,
4344 if part of the outgoing argument is in registers,
4345 they aren't really at the same location. Check for
4346 this by making sure that the incoming size is the
4347 same as the outgoing size. */
4348 if (arg->locate.size.constant != INTVAL (size_rtx))
4349 sibcall_failure = 1;
4354 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4355 parm_align, partial, reg, excess, argblock,
4356 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4357 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4359 /* Unless this is a partially-in-register argument, the argument is now
4360 in the stack.
4362 ??? Unlike the case above, in which we want the actual
4363 address of the data, so that we can load it directly into a
4364 register, here we want the address of the stack slot, so that
4365 it's properly aligned for word-by-word copying or something
4366 like that. It's not clear that this is always correct. */
4367 if (partial == 0)
4368 arg->value = arg->stack_slot;
4371 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4373 tree type = TREE_TYPE (arg->tree_value);
4374 arg->parallel_value
4375 = emit_group_load_into_temps (arg->reg, arg->value, type,
4376 int_size_in_bytes (type));
4379 /* Mark all slots this store used. */
4380 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4381 && argblock && ! variable_size && arg->stack)
4382 for (i = lower_bound; i < upper_bound; i++)
4383 stack_usage_map[i] = 1;
4385 /* Once we have pushed something, pops can't safely
4386 be deferred during the rest of the arguments. */
4387 NO_DEFER_POP;
4389 /* Free any temporary slots made in processing this argument. Show
4390 that we might have taken the address of something and pushed that
4391 as an operand. */
4392 preserve_temp_slots (NULL_RTX);
4393 free_temp_slots ();
4394 pop_temp_slots ();
4396 return sibcall_failure;
4399 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4401 bool
4402 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4403 const_tree type)
4405 if (!type)
4406 return false;
4408 /* If the type has variable size... */
4409 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4410 return true;
4412 /* If the type is marked as addressable (it is required
4413 to be constructed into the stack)... */
4414 if (TREE_ADDRESSABLE (type))
4415 return true;
4417 return false;
4420 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4421 takes trailing padding of a structure into account. */
4422 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4424 bool
4425 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4427 if (!type)
4428 return false;
4430 /* If the type has variable size... */
4431 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4432 return true;
4434 /* If the type is marked as addressable (it is required
4435 to be constructed into the stack)... */
4436 if (TREE_ADDRESSABLE (type))
4437 return true;
4439 /* If the padding and mode of the type is such that a copy into
4440 a register would put it into the wrong part of the register. */
4441 if (mode == BLKmode
4442 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4443 && (FUNCTION_ARG_PADDING (mode, type)
4444 == (BYTES_BIG_ENDIAN ? upward : downward)))
4445 return true;
4447 return false;