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 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
38 #include "langhooks.h"
41 /* Decide whether a function's arguments should be processed
42 from first to last or from last to first.
44 They should if the stack and args grow in opposite directions, but
45 only if we have push insns. */
49 #ifndef PUSH_ARGS_REVERSED
50 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
51 #define PUSH_ARGS_REVERSED PUSH_ARGS
57 #ifndef PUSH_ARGS_REVERSED
58 #define PUSH_ARGS_REVERSED 0
61 #ifndef STACK_POINTER_OFFSET
62 #define STACK_POINTER_OFFSET 0
65 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
66 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
68 /* Data structure and subroutines used within expand_call. */
72 /* Tree node for this argument. */
74 /* Mode for value; TYPE_MODE unless promoted. */
75 enum machine_mode mode;
76 /* Current RTL value for argument, or 0 if it isn't precomputed. */
78 /* Initially-compute RTL value for argument; only for const functions. */
80 /* Register to pass this argument in, 0 if passed on stack, or an
81 PARALLEL if the arg is to be copied into multiple non-contiguous
84 /* Register to pass this argument in when generating tail call sequence.
85 This is not the same register as for normal calls on machines with
88 /* If REG was promoted from the actual mode of the argument expression,
89 indicates whether the promotion is sign- or zero-extended. */
91 /* Number of registers to use. 0 means put the whole arg in registers.
92 Also 0 if not passed in registers. */
94 /* Nonzero if argument must be passed on stack.
95 Note that some arguments may be passed on the stack
96 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
97 pass_on_stack identifies arguments that *cannot* go in registers. */
99 /* Offset of this argument from beginning of stack-args. */
100 struct args_size offset;
101 /* Similar, but offset to the start of the stack slot. Different from
102 OFFSET if this arg pads downward. */
103 struct args_size slot_offset;
104 /* Size of this argument on the stack, rounded up for any padding it gets,
105 parts of the argument passed in registers do not count.
106 If REG_PARM_STACK_SPACE is defined, then register parms
107 are counted here as well. */
108 struct args_size size;
109 /* Location on the stack at which parameter should be stored. The store
110 has already been done if STACK == VALUE. */
112 /* Location on the stack of the start of this argument slot. This can
113 differ from STACK if this arg pads downward. This location is known
114 to be aligned to FUNCTION_ARG_BOUNDARY. */
116 /* Place that this stack area has been saved, if needed. */
118 /* If an argument's alignment does not permit direct copying into registers,
119 copy in smaller-sized pieces into pseudos. These are stored in a
120 block pointed to by this field. The next field says how many
121 word-sized pseudos we made. */
124 /* The amount that the stack pointer needs to be adjusted to
125 force alignment for the next argument. */
126 struct args_size alignment_pad;
129 /* A vector of one char per byte of stack space. A byte if nonzero if
130 the corresponding stack location has been used.
131 This vector is used to prevent a function call within an argument from
132 clobbering any stack already set up. */
133 static char *stack_usage_map;
135 /* Size of STACK_USAGE_MAP. */
136 static int highest_outgoing_arg_in_use;
138 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
139 stack location's tail call argument has been already stored into the stack.
140 This bitmap is used to prevent sibling call optimization if function tries
141 to use parent's incoming argument slots when they have been already
142 overwritten with tail call arguments. */
143 static sbitmap stored_args_map;
145 /* stack_arg_under_construction is nonzero when an argument may be
146 initialized with a constructor call (including a C function that
147 returns a BLKmode struct) and expand_call must take special action
148 to make sure the object being constructed does not overlap the
149 argument list for the constructor call. */
150 int stack_arg_under_construction;
152 static int calls_function PARAMS ((tree, int));
153 static int calls_function_1 PARAMS ((tree, int));
155 static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
156 HOST_WIDE_INT, HOST_WIDE_INT, rtx,
159 static void precompute_register_parameters PARAMS ((int,
162 static int store_one_arg PARAMS ((struct arg_data *, rtx, int, int,
164 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
166 static int finalize_must_preallocate PARAMS ((int, int,
168 struct args_size *));
169 static void precompute_arguments PARAMS ((int, int,
171 static int compute_argument_block_size PARAMS ((int,
174 static void initialize_argument_information PARAMS ((int,
181 static void compute_argument_addresses PARAMS ((struct arg_data *,
183 static rtx rtx_for_function_call PARAMS ((tree, tree));
184 static void load_register_parameters PARAMS ((struct arg_data *,
186 static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx,
190 static int special_function_p PARAMS ((tree, int));
191 static rtx try_to_integrate PARAMS ((tree, tree, rtx,
193 static int check_sibcall_argument_overlap_1 PARAMS ((rtx));
194 static int check_sibcall_argument_overlap PARAMS ((rtx, struct arg_data *));
196 static int combine_pending_stack_adjustment_and_call
197 PARAMS ((int, struct args_size *, int));
199 #ifdef REG_PARM_STACK_SPACE
200 static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *));
201 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
204 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
207 If WHICH is 0, return 1 if EXP contains a call to any function.
208 Actually, we only need return 1 if evaluating EXP would require pushing
209 arguments on the stack, but that is too difficult to compute, so we just
210 assume any function call might require the stack. */
212 static tree calls_function_save_exprs;
215 calls_function (exp, which)
221 calls_function_save_exprs = 0;
222 val = calls_function_1 (exp, which);
223 calls_function_save_exprs = 0;
227 /* Recursive function to do the work of above function. */
230 calls_function_1 (exp, which)
235 enum tree_code code = TREE_CODE (exp);
236 int class = TREE_CODE_CLASS (code);
237 int length = first_rtl_op (code);
239 /* If this code is language-specific, we don't know what it will do. */
240 if ((int) code >= NUM_TREE_CODES)
248 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
250 && (TYPE_RETURNS_STACK_DEPRESSED
251 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
253 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
254 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
256 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
258 & ECF_MAY_BE_ALLOCA))
267 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
268 if (calls_function_1 (TREE_VALUE (tem), which))
275 if (SAVE_EXPR_RTL (exp) != 0)
277 if (value_member (exp, calls_function_save_exprs))
279 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
280 calls_function_save_exprs);
281 return (TREE_OPERAND (exp, 0) != 0
282 && calls_function_1 (TREE_OPERAND (exp, 0), which));
289 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
290 if (DECL_INITIAL (local) != 0
291 && calls_function_1 (DECL_INITIAL (local), which))
294 for (subblock = BLOCK_SUBBLOCKS (exp);
296 subblock = TREE_CHAIN (subblock))
297 if (calls_function_1 (subblock, which))
303 for (; exp != 0; exp = TREE_CHAIN (exp))
304 if (calls_function_1 (TREE_VALUE (exp), which))
312 /* Only expressions, references, and blocks can contain calls. */
313 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
316 for (i = 0; i < length; i++)
317 if (TREE_OPERAND (exp, i) != 0
318 && calls_function_1 (TREE_OPERAND (exp, i), which))
324 /* Force FUNEXP into a form suitable for the address of a CALL,
325 and return that as an rtx. Also load the static chain register
326 if FNDECL is a nested function.
328 CALL_FUSAGE points to a variable holding the prospective
329 CALL_INSN_FUNCTION_USAGE information. */
332 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen, sibcallp)
339 rtx static_chain_value = 0;
341 funexp = protect_from_queue (funexp, 0);
344 /* Get possible static chain value for nested function in C. */
345 static_chain_value = lookup_static_chain (fndecl);
347 /* Make a valid memory address and copy constants thru pseudo-regs,
348 but not for a constant address if -fno-function-cse. */
349 if (GET_CODE (funexp) != SYMBOL_REF)
350 /* If we are using registers for parameters, force the
351 function address into a register now. */
352 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
353 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
354 : memory_address (FUNCTION_MODE, funexp));
357 #ifndef NO_FUNCTION_CSE
358 if (optimize && ! flag_no_function_cse)
359 #ifdef NO_RECURSIVE_FUNCTION_CSE
360 if (fndecl != current_function_decl)
362 funexp = force_reg (Pmode, funexp);
366 if (static_chain_value != 0)
368 emit_move_insn (static_chain_rtx, static_chain_value);
370 if (GET_CODE (static_chain_rtx) == REG)
371 use_reg (call_fusage, static_chain_rtx);
377 /* Generate instructions to call function FUNEXP,
378 and optionally pop the results.
379 The CALL_INSN is the first insn generated.
381 FNDECL is the declaration node of the function. This is given to the
382 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
384 FUNTYPE is the data type of the function. This is given to the macro
385 RETURN_POPS_ARGS to determine whether this function pops its own args.
386 We used to allow an identifier for library functions, but that doesn't
387 work when the return type is an aggregate type and the calling convention
388 says that the pointer to this aggregate is to be popped by the callee.
390 STACK_SIZE is the number of bytes of arguments on the stack,
391 ROUNDED_STACK_SIZE is that number rounded up to
392 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
393 both to put into the call insn and to generate explicit popping
396 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
397 It is zero if this call doesn't want a structure value.
399 NEXT_ARG_REG is the rtx that results from executing
400 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
401 just after all the args have had their registers assigned.
402 This could be whatever you like, but normally it is the first
403 arg-register beyond those used for args in this call,
404 or 0 if all the arg-registers are used in this call.
405 It is passed on to `gen_call' so you can put this info in the call insn.
407 VALREG is a hard register in which a value is returned,
408 or 0 if the call does not return a value.
410 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
411 the args to this call were processed.
412 We restore `inhibit_defer_pop' to that value.
414 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
415 denote registers used by the called function. */
418 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
419 struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
420 call_fusage, ecf_flags, args_so_far)
422 tree fndecl ATTRIBUTE_UNUSED;
423 tree funtype ATTRIBUTE_UNUSED;
424 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
425 HOST_WIDE_INT rounded_stack_size;
426 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
427 rtx next_arg_reg ATTRIBUTE_UNUSED;
429 int old_inhibit_defer_pop;
432 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED;
434 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
436 int already_popped = 0;
437 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
438 #if defined (HAVE_call) && defined (HAVE_call_value)
439 rtx struct_value_size_rtx;
440 struct_value_size_rtx = GEN_INT (struct_value_size);
443 #ifdef CALL_POPS_ARGS
444 n_popped += CALL_POPS_ARGS (* args_so_far);
447 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
448 and we don't want to load it into a register as an optimization,
449 because prepare_call_address already did it if it should be done. */
450 if (GET_CODE (funexp) != SYMBOL_REF)
451 funexp = memory_address (FUNCTION_MODE, funexp);
453 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
454 if ((ecf_flags & ECF_SIBCALL)
455 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
456 && (n_popped > 0 || stack_size == 0))
458 rtx n_pop = GEN_INT (n_popped);
461 /* If this subroutine pops its own args, record that in the call insn
462 if possible, for the sake of frame pointer elimination. */
465 pat = GEN_SIBCALL_VALUE_POP (valreg,
466 gen_rtx_MEM (FUNCTION_MODE, funexp),
467 rounded_stack_size_rtx, next_arg_reg,
470 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
471 rounded_stack_size_rtx, next_arg_reg, n_pop);
473 emit_call_insn (pat);
479 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
480 /* If the target has "call" or "call_value" insns, then prefer them
481 if no arguments are actually popped. If the target does not have
482 "call" or "call_value" insns, then we must use the popping versions
483 even if the call has no arguments to pop. */
484 #if defined (HAVE_call) && defined (HAVE_call_value)
485 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
486 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
488 if (HAVE_call_pop && HAVE_call_value_pop)
491 rtx n_pop = GEN_INT (n_popped);
494 /* If this subroutine pops its own args, record that in the call insn
495 if possible, for the sake of frame pointer elimination. */
498 pat = GEN_CALL_VALUE_POP (valreg,
499 gen_rtx_MEM (FUNCTION_MODE, funexp),
500 rounded_stack_size_rtx, next_arg_reg, n_pop);
502 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
503 rounded_stack_size_rtx, next_arg_reg, n_pop);
505 emit_call_insn (pat);
511 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
512 if ((ecf_flags & ECF_SIBCALL)
513 && HAVE_sibcall && HAVE_sibcall_value)
516 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
517 gen_rtx_MEM (FUNCTION_MODE, funexp),
518 rounded_stack_size_rtx,
519 next_arg_reg, NULL_RTX));
521 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
522 rounded_stack_size_rtx, next_arg_reg,
523 struct_value_size_rtx));
528 #if defined (HAVE_call) && defined (HAVE_call_value)
529 if (HAVE_call && HAVE_call_value)
532 emit_call_insn (GEN_CALL_VALUE (valreg,
533 gen_rtx_MEM (FUNCTION_MODE, funexp),
534 rounded_stack_size_rtx, next_arg_reg,
537 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
538 rounded_stack_size_rtx, next_arg_reg,
539 struct_value_size_rtx));
545 /* Find the CALL insn we just emitted. */
546 for (call_insn = get_last_insn ();
547 call_insn && GET_CODE (call_insn) != CALL_INSN;
548 call_insn = PREV_INSN (call_insn))
554 /* Mark memory as used for "pure" function call. */
555 if (ecf_flags & ECF_PURE)
559 gen_rtx_USE (VOIDmode,
560 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
563 /* Put the register usage information on the CALL. If there is already
564 some usage information, put ours at the end. */
565 if (CALL_INSN_FUNCTION_USAGE (call_insn))
569 for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0;
570 link = XEXP (link, 1))
573 XEXP (link, 1) = call_fusage;
576 CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage;
578 /* If this is a const call, then set the insn's unchanging bit. */
579 if (ecf_flags & (ECF_CONST | ECF_PURE))
580 CONST_OR_PURE_CALL_P (call_insn) = 1;
582 /* If this call can't throw, attach a REG_EH_REGION reg note to that
584 if (ecf_flags & ECF_NOTHROW)
585 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
586 REG_NOTES (call_insn));
588 if (ecf_flags & ECF_NORETURN)
589 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
590 REG_NOTES (call_insn));
591 if (ecf_flags & ECF_ALWAYS_RETURN)
592 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
593 REG_NOTES (call_insn));
595 if (ecf_flags & ECF_RETURNS_TWICE)
597 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
598 REG_NOTES (call_insn));
599 current_function_calls_setjmp = 1;
602 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
604 /* Restore this now, so that we do defer pops for this call's args
605 if the context of the call as a whole permits. */
606 inhibit_defer_pop = old_inhibit_defer_pop;
611 CALL_INSN_FUNCTION_USAGE (call_insn)
612 = gen_rtx_EXPR_LIST (VOIDmode,
613 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
614 CALL_INSN_FUNCTION_USAGE (call_insn));
615 rounded_stack_size -= n_popped;
616 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
617 stack_pointer_delta -= n_popped;
620 if (!ACCUMULATE_OUTGOING_ARGS)
622 /* If returning from the subroutine does not automatically pop the args,
623 we need an instruction to pop them sooner or later.
624 Perhaps do it now; perhaps just record how much space to pop later.
626 If returning from the subroutine does pop the args, indicate that the
627 stack pointer will be changed. */
629 if (rounded_stack_size != 0)
631 if (ecf_flags & ECF_SP_DEPRESSED)
632 /* Just pretend we did the pop. */
633 stack_pointer_delta -= rounded_stack_size;
634 else if (flag_defer_pop && inhibit_defer_pop == 0
635 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
636 pending_stack_adjust += rounded_stack_size;
638 adjust_stack (rounded_stack_size_rtx);
641 /* When we accumulate outgoing args, we must avoid any stack manipulations.
642 Restore the stack pointer to its original value now. Usually
643 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
644 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
645 popping variants of functions exist as well.
647 ??? We may optimize similar to defer_pop above, but it is
648 probably not worthwhile.
650 ??? It will be worthwhile to enable combine_stack_adjustments even for
653 anti_adjust_stack (GEN_INT (n_popped));
656 /* Determine if the function identified by NAME and FNDECL is one with
657 special properties we wish to know about.
659 For example, if the function might return more than one time (setjmp), then
660 set RETURNS_TWICE to a nonzero value.
662 Similarly set LONGJMP for if the function is in the longjmp family.
664 Set MALLOC for any of the standard memory allocation functions which
665 allocate from the heap.
667 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
668 space from the stack such as alloca. */
671 special_function_p (fndecl, flags)
675 if (! (flags & ECF_MALLOC)
676 && fndecl && DECL_NAME (fndecl)
677 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
678 /* Exclude functions not at the file scope, or not `extern',
679 since they are not the magic functions we would otherwise
681 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
683 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
684 const char *tname = name;
686 /* We assume that alloca will always be called by name. It
687 makes no sense to pass it as a pointer-to-function to
688 anything that does not understand its behavior. */
689 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
691 && ! strcmp (name, "alloca"))
692 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
694 && ! strcmp (name, "__builtin_alloca"))))
695 flags |= ECF_MAY_BE_ALLOCA;
697 /* Disregard prefix _, __ or __x. */
700 if (name[1] == '_' && name[2] == 'x')
702 else if (name[1] == '_')
711 && (! strcmp (tname, "setjmp")
712 || ! strcmp (tname, "setjmp_syscall")))
714 && ! strcmp (tname, "sigsetjmp"))
716 && ! strcmp (tname, "savectx")))
717 flags |= ECF_RETURNS_TWICE;
720 && ! strcmp (tname, "siglongjmp"))
721 flags |= ECF_LONGJMP;
723 else if ((tname[0] == 'q' && tname[1] == 's'
724 && ! strcmp (tname, "qsetjmp"))
725 || (tname[0] == 'v' && tname[1] == 'f'
726 && ! strcmp (tname, "vfork")))
727 flags |= ECF_RETURNS_TWICE;
729 else if (tname[0] == 'l' && tname[1] == 'o'
730 && ! strcmp (tname, "longjmp"))
731 flags |= ECF_LONGJMP;
733 else if ((tname[0] == 'f' && tname[1] == 'o'
734 && ! strcmp (tname, "fork"))
735 /* Linux specific: __clone. check NAME to insist on the
736 leading underscores, to avoid polluting the ISO / POSIX
738 || (name[0] == '_' && name[1] == '_'
739 && ! strcmp (tname, "clone"))
740 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
741 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
743 || ((tname[5] == 'p' || tname[5] == 'e')
744 && tname[6] == '\0'))))
745 flags |= ECF_FORK_OR_EXEC;
747 /* Do not add any more malloc-like functions to this list,
748 instead mark them as malloc functions using the malloc attribute.
749 Note, realloc is not suitable for attribute malloc since
750 it may return the same address across multiple calls.
751 C++ operator new is not suitable because it is not required
752 to return a unique pointer; indeed, the standard placement new
753 just returns its argument. */
754 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
755 && (! strcmp (tname, "malloc")
756 || ! strcmp (tname, "calloc")
757 || ! strcmp (tname, "strdup")))
763 /* Return nonzero when tree represent call to longjmp. */
766 setjmp_call_p (fndecl)
769 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
772 /* Return true when exp contains alloca call. */
777 if (TREE_CODE (exp) == CALL_EXPR
778 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
779 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
781 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
782 0) & ECF_MAY_BE_ALLOCA))
787 /* Detect flags (function attributes) from the function decl or type node. */
790 flags_from_decl_or_type (exp)
795 /* ??? We can't set IS_MALLOC for function types? */
798 type = TREE_TYPE (exp);
800 /* The function exp may have the `malloc' attribute. */
801 if (DECL_P (exp) && DECL_IS_MALLOC (exp))
804 /* The function exp may have the `pure' attribute. */
805 if (DECL_P (exp) && DECL_IS_PURE (exp))
806 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
808 if (TREE_NOTHROW (exp))
809 flags |= ECF_NOTHROW;
812 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
813 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
815 if (TREE_THIS_VOLATILE (exp))
816 flags |= ECF_NORETURN;
818 /* Mark if the function returns with the stack pointer depressed. We
819 cannot consider it pure or constant in that case. */
820 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
822 flags |= ECF_SP_DEPRESSED;
823 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
829 /* Precompute all register parameters as described by ARGS, storing values
830 into fields within the ARGS array.
832 NUM_ACTUALS indicates the total number elements in the ARGS array.
834 Set REG_PARM_SEEN if we encounter a register parameter. */
837 precompute_register_parameters (num_actuals, args, reg_parm_seen)
839 struct arg_data *args;
846 for (i = 0; i < num_actuals; i++)
847 if (args[i].reg != 0 && ! args[i].pass_on_stack)
851 if (args[i].value == 0)
854 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
856 preserve_temp_slots (args[i].value);
859 /* ANSI doesn't require a sequence point here,
860 but PCC has one, so this will avoid some problems. */
864 /* If the value is a non-legitimate constant, force it into a
865 pseudo now. TLS symbols sometimes need a call to resolve. */
866 if (CONSTANT_P (args[i].value)
867 && !LEGITIMATE_CONSTANT_P (args[i].value))
868 args[i].value = force_reg (args[i].mode, args[i].value);
870 /* If we are to promote the function arg to a wider mode,
873 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
875 = convert_modes (args[i].mode,
876 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
877 args[i].value, args[i].unsignedp);
879 /* If the value is expensive, and we are inside an appropriately
880 short loop, put the value into a pseudo and then put the pseudo
883 For small register classes, also do this if this call uses
884 register parameters. This is to avoid reload conflicts while
885 loading the parameters registers. */
887 if ((! (GET_CODE (args[i].value) == REG
888 || (GET_CODE (args[i].value) == SUBREG
889 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
890 && args[i].mode != BLKmode
891 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
892 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
893 || preserve_subexpressions_p ()))
894 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
898 #ifdef REG_PARM_STACK_SPACE
900 /* The argument list is the property of the called routine and it
901 may clobber it. If the fixed area has been used for previous
902 parameters, we must save and restore it. */
905 save_fixed_argument_area (reg_parm_stack_space, argblock,
906 low_to_save, high_to_save)
907 int reg_parm_stack_space;
913 rtx save_area = NULL_RTX;
915 /* Compute the boundary of the that needs to be saved, if any. */
916 #ifdef ARGS_GROW_DOWNWARD
917 for (i = 0; i < reg_parm_stack_space + 1; i++)
919 for (i = 0; i < reg_parm_stack_space; i++)
922 if (i >= highest_outgoing_arg_in_use
923 || stack_usage_map[i] == 0)
926 if (*low_to_save == -1)
932 if (*low_to_save >= 0)
934 int num_to_save = *high_to_save - *low_to_save + 1;
935 enum machine_mode save_mode
936 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
939 /* If we don't have the required alignment, must do this in BLKmode. */
940 if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode),
941 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
944 #ifdef ARGS_GROW_DOWNWARD
946 = gen_rtx_MEM (save_mode,
947 memory_address (save_mode,
948 plus_constant (argblock,
951 stack_area = gen_rtx_MEM (save_mode,
952 memory_address (save_mode,
953 plus_constant (argblock,
957 set_mem_align (stack_area, PARM_BOUNDARY);
958 if (save_mode == BLKmode)
960 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
961 emit_block_move (validize_mem (save_area), stack_area,
962 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
966 save_area = gen_reg_rtx (save_mode);
967 emit_move_insn (save_area, stack_area);
975 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
981 enum machine_mode save_mode = GET_MODE (save_area);
982 #ifdef ARGS_GROW_DOWNWARD
984 = gen_rtx_MEM (save_mode,
985 memory_address (save_mode,
986 plus_constant (argblock,
990 = gen_rtx_MEM (save_mode,
991 memory_address (save_mode,
992 plus_constant (argblock,
996 if (save_mode != BLKmode)
997 emit_move_insn (stack_area, save_area);
999 emit_block_move (stack_area, validize_mem (save_area),
1000 GEN_INT (high_to_save - low_to_save + 1),
1001 BLOCK_OP_CALL_PARM);
1003 #endif /* REG_PARM_STACK_SPACE */
1005 /* If any elements in ARGS refer to parameters that are to be passed in
1006 registers, but not in memory, and whose alignment does not permit a
1007 direct copy into registers. Copy the values into a group of pseudos
1008 which we will later copy into the appropriate hard registers.
1010 Pseudos for each unaligned argument will be stored into the array
1011 args[argnum].aligned_regs. The caller is responsible for deallocating
1012 the aligned_regs array if it is nonzero. */
1015 store_unaligned_arguments_into_pseudos (args, num_actuals)
1016 struct arg_data *args;
1021 for (i = 0; i < num_actuals; i++)
1022 if (args[i].reg != 0 && ! args[i].pass_on_stack
1023 && args[i].mode == BLKmode
1024 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
1025 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1027 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1028 int big_endian_correction = 0;
1030 args[i].n_aligned_regs
1031 = args[i].partial ? args[i].partial
1032 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1034 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
1035 * args[i].n_aligned_regs);
1037 /* Structures smaller than a word are aligned to the least
1038 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
1039 this means we must skip the empty high order bytes when
1040 calculating the bit offset. */
1041 if (BYTES_BIG_ENDIAN
1042 && bytes < UNITS_PER_WORD)
1043 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
1045 for (j = 0; j < args[i].n_aligned_regs; j++)
1047 rtx reg = gen_reg_rtx (word_mode);
1048 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1049 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1051 args[i].aligned_regs[j] = reg;
1053 /* There is no need to restrict this code to loading items
1054 in TYPE_ALIGN sized hunks. The bitfield instructions can
1055 load up entire word sized registers efficiently.
1057 ??? This may not be needed anymore.
1058 We use to emit a clobber here but that doesn't let later
1059 passes optimize the instructions we emit. By storing 0 into
1060 the register later passes know the first AND to zero out the
1061 bitfield being set in the register is unnecessary. The store
1062 of 0 will be deleted as will at least the first AND. */
1064 emit_move_insn (reg, const0_rtx);
1066 bytes -= bitsize / BITS_PER_UNIT;
1067 store_bit_field (reg, bitsize, big_endian_correction, word_mode,
1068 extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1069 word_mode, word_mode,
1076 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1079 NUM_ACTUALS is the total number of parameters.
1081 N_NAMED_ARGS is the total number of named arguments.
1083 FNDECL is the tree code for the target of this call (if known)
1085 ARGS_SO_FAR holds state needed by the target to know where to place
1088 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1089 for arguments which are passed in registers.
1091 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1092 and may be modified by this routine.
1094 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1095 flags which may may be modified by this routine. */
1098 initialize_argument_information (num_actuals, args, args_size, n_named_args,
1099 actparms, fndecl, args_so_far,
1100 reg_parm_stack_space, old_stack_level,
1101 old_pending_adj, must_preallocate,
1103 int num_actuals ATTRIBUTE_UNUSED;
1104 struct arg_data *args;
1105 struct args_size *args_size;
1106 int n_named_args ATTRIBUTE_UNUSED;
1109 CUMULATIVE_ARGS *args_so_far;
1110 int reg_parm_stack_space;
1111 rtx *old_stack_level;
1112 int *old_pending_adj;
1113 int *must_preallocate;
1116 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1119 /* Count arg position in order args appear. */
1122 struct args_size alignment_pad;
1126 args_size->constant = 0;
1129 /* In this loop, we consider args in the order they are written.
1130 We fill up ARGS from the front or from the back if necessary
1131 so that in any case the first arg to be pushed ends up at the front. */
1133 if (PUSH_ARGS_REVERSED)
1135 i = num_actuals - 1, inc = -1;
1136 /* In this case, must reverse order of args
1137 so that we compute and push the last arg first. */
1144 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1145 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1147 tree type = TREE_TYPE (TREE_VALUE (p));
1149 enum machine_mode mode;
1151 args[i].tree_value = TREE_VALUE (p);
1153 /* Replace erroneous argument with constant zero. */
1154 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1155 args[i].tree_value = integer_zero_node, type = integer_type_node;
1157 /* If TYPE is a transparent union, pass things the way we would
1158 pass the first field of the union. We have already verified that
1159 the modes are the same. */
1160 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1161 type = TREE_TYPE (TYPE_FIELDS (type));
1163 /* Decide where to pass this arg.
1165 args[i].reg is nonzero if all or part is passed in registers.
1167 args[i].partial is nonzero if part but not all is passed in registers,
1168 and the exact value says how many words are passed in registers.
1170 args[i].pass_on_stack is nonzero if the argument must at least be
1171 computed on the stack. It may then be loaded back into registers
1172 if args[i].reg is nonzero.
1174 These decisions are driven by the FUNCTION_... macros and must agree
1175 with those made by function.c. */
1177 /* See if this argument should be passed by invisible reference. */
1178 if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1179 && contains_placeholder_p (TYPE_SIZE (type)))
1180 || TREE_ADDRESSABLE (type)
1181 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1182 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1183 type, argpos < n_named_args)
1187 /* If we're compiling a thunk, pass through invisible
1188 references instead of making a copy. */
1189 if (current_function_is_thunk
1190 #ifdef FUNCTION_ARG_CALLEE_COPIES
1191 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1192 type, argpos < n_named_args)
1193 /* If it's in a register, we must make a copy of it too. */
1194 /* ??? Is this a sufficient test? Is there a better one? */
1195 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1196 && REG_P (DECL_RTL (args[i].tree_value)))
1197 && ! TREE_ADDRESSABLE (type))
1201 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1202 new object from the argument. If we are passing by
1203 invisible reference, the callee will do that for us, so we
1204 can strip off the TARGET_EXPR. This is not always safe,
1205 but it is safe in the only case where this is a useful
1206 optimization; namely, when the argument is a plain object.
1207 In that case, the frontend is just asking the backend to
1208 make a bitwise copy of the argument. */
1210 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1211 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1212 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1213 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1215 args[i].tree_value = build1 (ADDR_EXPR,
1216 build_pointer_type (type),
1217 args[i].tree_value);
1218 type = build_pointer_type (type);
1220 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1222 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1223 We implement this by passing the address of the temporary
1224 rather than expanding it into another allocated slot. */
1225 args[i].tree_value = build1 (ADDR_EXPR,
1226 build_pointer_type (type),
1227 args[i].tree_value);
1228 type = build_pointer_type (type);
1232 /* We make a copy of the object and pass the address to the
1233 function being called. */
1236 if (!COMPLETE_TYPE_P (type)
1237 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1238 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1239 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1240 STACK_CHECK_MAX_VAR_SIZE))))
1242 /* This is a variable-sized object. Make space on the stack
1244 rtx size_rtx = expr_size (TREE_VALUE (p));
1246 if (*old_stack_level == 0)
1248 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1249 *old_pending_adj = pending_stack_adjust;
1250 pending_stack_adjust = 0;
1253 copy = gen_rtx_MEM (BLKmode,
1254 allocate_dynamic_stack_space
1255 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1256 set_mem_attributes (copy, type, 1);
1259 copy = assign_temp (type, 0, 1, 0);
1261 store_expr (args[i].tree_value, copy, 0);
1262 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1264 args[i].tree_value = build1 (ADDR_EXPR,
1265 build_pointer_type (type),
1266 make_tree (type, copy));
1267 type = build_pointer_type (type);
1271 mode = TYPE_MODE (type);
1272 unsignedp = TREE_UNSIGNED (type);
1274 #ifdef PROMOTE_FUNCTION_ARGS
1275 mode = promote_mode (type, mode, &unsignedp, 1);
1278 args[i].unsignedp = unsignedp;
1279 args[i].mode = mode;
1281 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1282 argpos < n_named_args);
1283 #ifdef FUNCTION_INCOMING_ARG
1284 /* If this is a sibling call and the machine has register windows, the
1285 register window has to be unwinded before calling the routine, so
1286 arguments have to go into the incoming registers. */
1287 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1288 argpos < n_named_args);
1290 args[i].tail_call_reg = args[i].reg;
1293 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1296 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1297 argpos < n_named_args);
1300 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1302 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1303 it means that we are to pass this arg in the register(s) designated
1304 by the PARALLEL, but also to pass it in the stack. */
1305 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1306 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1307 args[i].pass_on_stack = 1;
1309 /* If this is an addressable type, we must preallocate the stack
1310 since we must evaluate the object into its final location.
1312 If this is to be passed in both registers and the stack, it is simpler
1314 if (TREE_ADDRESSABLE (type)
1315 || (args[i].pass_on_stack && args[i].reg != 0))
1316 *must_preallocate = 1;
1318 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1319 we cannot consider this function call constant. */
1320 if (TREE_ADDRESSABLE (type))
1321 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1323 /* Compute the stack-size of this argument. */
1324 if (args[i].reg == 0 || args[i].partial != 0
1325 || reg_parm_stack_space > 0
1326 || args[i].pass_on_stack)
1327 locate_and_pad_parm (mode, type,
1328 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1333 fndecl, args_size, &args[i].offset,
1334 &args[i].size, &alignment_pad);
1336 #ifndef ARGS_GROW_DOWNWARD
1337 args[i].slot_offset = *args_size;
1340 args[i].alignment_pad = alignment_pad;
1342 /* If a part of the arg was put into registers,
1343 don't include that part in the amount pushed. */
1344 if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack)
1345 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1346 / (PARM_BOUNDARY / BITS_PER_UNIT)
1347 * (PARM_BOUNDARY / BITS_PER_UNIT));
1349 /* Update ARGS_SIZE, the total stack space for args so far. */
1351 args_size->constant += args[i].size.constant;
1352 if (args[i].size.var)
1354 ADD_PARM_SIZE (*args_size, args[i].size.var);
1357 /* Since the slot offset points to the bottom of the slot,
1358 we must record it after incrementing if the args grow down. */
1359 #ifdef ARGS_GROW_DOWNWARD
1360 args[i].slot_offset = *args_size;
1362 args[i].slot_offset.constant = -args_size->constant;
1364 SUB_PARM_SIZE (args[i].slot_offset, args_size->var);
1367 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1368 have been used, etc. */
1370 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1371 argpos < n_named_args);
1375 /* Update ARGS_SIZE to contain the total size for the argument block.
1376 Return the original constant component of the argument block's size.
1378 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1379 for arguments passed in registers. */
1382 compute_argument_block_size (reg_parm_stack_space, args_size,
1383 preferred_stack_boundary)
1384 int reg_parm_stack_space;
1385 struct args_size *args_size;
1386 int preferred_stack_boundary ATTRIBUTE_UNUSED;
1388 int unadjusted_args_size = args_size->constant;
1390 /* For accumulate outgoing args mode we don't need to align, since the frame
1391 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1392 backends from generating misaligned frame sizes. */
1393 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1394 preferred_stack_boundary = STACK_BOUNDARY;
1396 /* Compute the actual size of the argument block required. The variable
1397 and constant sizes must be combined, the size may have to be rounded,
1398 and there may be a minimum required size. */
1402 args_size->var = ARGS_SIZE_TREE (*args_size);
1403 args_size->constant = 0;
1405 preferred_stack_boundary /= BITS_PER_UNIT;
1406 if (preferred_stack_boundary > 1)
1408 /* We don't handle this case yet. To handle it correctly we have
1409 to add the delta, round and subtract the delta.
1410 Currently no machine description requires this support. */
1411 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1413 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1416 if (reg_parm_stack_space > 0)
1419 = size_binop (MAX_EXPR, args_size->var,
1420 ssize_int (reg_parm_stack_space));
1422 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1423 /* The area corresponding to register parameters is not to count in
1424 the size of the block we need. So make the adjustment. */
1426 = size_binop (MINUS_EXPR, args_size->var,
1427 ssize_int (reg_parm_stack_space));
1433 preferred_stack_boundary /= BITS_PER_UNIT;
1434 if (preferred_stack_boundary < 1)
1435 preferred_stack_boundary = 1;
1436 args_size->constant = (((args_size->constant
1437 + stack_pointer_delta
1438 + preferred_stack_boundary - 1)
1439 / preferred_stack_boundary
1440 * preferred_stack_boundary)
1441 - stack_pointer_delta);
1443 args_size->constant = MAX (args_size->constant,
1444 reg_parm_stack_space);
1446 #ifdef MAYBE_REG_PARM_STACK_SPACE
1447 if (reg_parm_stack_space == 0)
1448 args_size->constant = 0;
1451 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1452 args_size->constant -= reg_parm_stack_space;
1455 return unadjusted_args_size;
1458 /* Precompute parameters as needed for a function call.
1460 FLAGS is mask of ECF_* constants.
1462 NUM_ACTUALS is the number of arguments.
1464 ARGS is an array containing information for each argument; this
1465 routine fills in the INITIAL_VALUE and VALUE fields for each
1466 precomputed argument. */
1469 precompute_arguments (flags, num_actuals, args)
1472 struct arg_data *args;
1476 /* If this function call is cse'able, precompute all the parameters.
1477 Note that if the parameter is constructed into a temporary, this will
1478 cause an additional copy because the parameter will be constructed
1479 into a temporary location and then copied into the outgoing arguments.
1480 If a parameter contains a call to alloca and this function uses the
1481 stack, precompute the parameter. */
1483 /* If we preallocated the stack space, and some arguments must be passed
1484 on the stack, then we must precompute any parameter which contains a
1485 function call which will store arguments on the stack.
1486 Otherwise, evaluating the parameter may clobber previous parameters
1487 which have already been stored into the stack. (we have code to avoid
1488 such case by saving the outgoing stack arguments, but it results in
1491 for (i = 0; i < num_actuals; i++)
1492 if ((flags & ECF_LIBCALL_BLOCK)
1493 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1495 enum machine_mode mode;
1497 /* If this is an addressable type, we cannot pre-evaluate it. */
1498 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1502 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1504 /* ANSI doesn't require a sequence point here,
1505 but PCC has one, so this will avoid some problems. */
1508 args[i].initial_value = args[i].value
1509 = protect_from_queue (args[i].value, 0);
1511 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1512 if (mode != args[i].mode)
1515 = convert_modes (args[i].mode, mode,
1516 args[i].value, args[i].unsignedp);
1517 #ifdef PROMOTE_FOR_CALL_ONLY
1518 /* CSE will replace this only if it contains args[i].value
1519 pseudo, so convert it down to the declared mode using
1521 if (GET_CODE (args[i].value) == REG
1522 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1524 args[i].initial_value
1525 = gen_lowpart_SUBREG (mode, args[i].value);
1526 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1527 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1535 /* Given the current state of MUST_PREALLOCATE and information about
1536 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1537 compute and return the final value for MUST_PREALLOCATE. */
1540 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1541 int must_preallocate;
1543 struct arg_data *args;
1544 struct args_size *args_size;
1546 /* See if we have or want to preallocate stack space.
1548 If we would have to push a partially-in-regs parm
1549 before other stack parms, preallocate stack space instead.
1551 If the size of some parm is not a multiple of the required stack
1552 alignment, we must preallocate.
1554 If the total size of arguments that would otherwise create a copy in
1555 a temporary (such as a CALL) is more than half the total argument list
1556 size, preallocation is faster.
1558 Another reason to preallocate is if we have a machine (like the m88k)
1559 where stack alignment is required to be maintained between every
1560 pair of insns, not just when the call is made. However, we assume here
1561 that such machines either do not have push insns (and hence preallocation
1562 would occur anyway) or the problem is taken care of with
1565 if (! must_preallocate)
1567 int partial_seen = 0;
1568 int copy_to_evaluate_size = 0;
1571 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1573 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1575 else if (partial_seen && args[i].reg == 0)
1576 must_preallocate = 1;
1578 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1579 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1580 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1581 || TREE_CODE (args[i].tree_value) == COND_EXPR
1582 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1583 copy_to_evaluate_size
1584 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1587 if (copy_to_evaluate_size * 2 >= args_size->constant
1588 && args_size->constant > 0)
1589 must_preallocate = 1;
1591 return must_preallocate;
1594 /* If we preallocated stack space, compute the address of each argument
1595 and store it into the ARGS array.
1597 We need not ensure it is a valid memory address here; it will be
1598 validized when it is used.
1600 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1603 compute_argument_addresses (args, argblock, num_actuals)
1604 struct arg_data *args;
1610 rtx arg_reg = argblock;
1611 int i, arg_offset = 0;
1613 if (GET_CODE (argblock) == PLUS)
1614 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1616 for (i = 0; i < num_actuals; i++)
1618 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1619 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1622 /* Skip this parm if it will not be passed on the stack. */
1623 if (! args[i].pass_on_stack && args[i].reg != 0)
1626 if (GET_CODE (offset) == CONST_INT)
1627 addr = plus_constant (arg_reg, INTVAL (offset));
1629 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1631 addr = plus_constant (addr, arg_offset);
1632 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1633 set_mem_attributes (args[i].stack,
1634 TREE_TYPE (args[i].tree_value), 1);
1636 if (GET_CODE (slot_offset) == CONST_INT)
1637 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1639 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1641 addr = plus_constant (addr, arg_offset);
1642 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1643 set_mem_attributes (args[i].stack_slot,
1644 TREE_TYPE (args[i].tree_value), 1);
1646 /* Function incoming arguments may overlap with sibling call
1647 outgoing arguments and we cannot allow reordering of reads
1648 from function arguments with stores to outgoing arguments
1649 of sibling calls. */
1650 set_mem_alias_set (args[i].stack, 0);
1651 set_mem_alias_set (args[i].stack_slot, 0);
1656 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1657 in a call instruction.
1659 FNDECL is the tree node for the target function. For an indirect call
1660 FNDECL will be NULL_TREE.
1662 EXP is the CALL_EXPR for this call. */
1665 rtx_for_function_call (fndecl, exp)
1671 /* Get the function to call, in the form of RTL. */
1674 /* If this is the first use of the function, see if we need to
1675 make an external definition for it. */
1676 if (! TREE_USED (fndecl))
1678 assemble_external (fndecl);
1679 TREE_USED (fndecl) = 1;
1682 /* Get a SYMBOL_REF rtx for the function address. */
1683 funexp = XEXP (DECL_RTL (fndecl), 0);
1686 /* Generate an rtx (probably a pseudo-register) for the address. */
1689 funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1690 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1696 /* Do the register loads required for any wholly-register parms or any
1697 parms which are passed both on the stack and in a register. Their
1698 expressions were already evaluated.
1700 Mark all register-parms as living through the call, putting these USE
1701 insns in the CALL_INSN_FUNCTION_USAGE field. */
1704 load_register_parameters (args, num_actuals, call_fusage, flags)
1705 struct arg_data *args;
1712 #ifdef LOAD_ARGS_REVERSED
1713 for (i = num_actuals - 1; i >= 0; i--)
1715 for (i = 0; i < num_actuals; i++)
1718 rtx reg = ((flags & ECF_SIBCALL)
1719 ? args[i].tail_call_reg : args[i].reg);
1720 int partial = args[i].partial;
1725 /* Set to non-negative if must move a word at a time, even if just
1726 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1727 we just use a normal move insn. This value can be zero if the
1728 argument is a zero size structure with no fields. */
1729 nregs = (partial ? partial
1730 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1731 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1732 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1735 /* Handle calls that pass values in multiple non-contiguous
1736 locations. The Irix 6 ABI has examples of this. */
1738 if (GET_CODE (reg) == PARALLEL)
1739 emit_group_load (reg, args[i].value,
1740 int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1742 /* If simple case, just do move. If normal partial, store_one_arg
1743 has already loaded the register for us. In all other cases,
1744 load the register(s) from memory. */
1746 else if (nregs == -1)
1747 emit_move_insn (reg, args[i].value);
1749 /* If we have pre-computed the values to put in the registers in
1750 the case of non-aligned structures, copy them in now. */
1752 else if (args[i].n_aligned_regs != 0)
1753 for (j = 0; j < args[i].n_aligned_regs; j++)
1754 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1755 args[i].aligned_regs[j]);
1757 else if (partial == 0 || args[i].pass_on_stack)
1758 move_block_to_reg (REGNO (reg),
1759 validize_mem (args[i].value), nregs,
1762 /* Handle calls that pass values in multiple non-contiguous
1763 locations. The Irix 6 ABI has examples of this. */
1764 if (GET_CODE (reg) == PARALLEL)
1765 use_group_regs (call_fusage, reg);
1766 else if (nregs == -1)
1767 use_reg (call_fusage, reg);
1769 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1774 /* Try to integrate function. See expand_inline_function for documentation
1775 about the parameters. */
1778 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1784 rtx structure_value_addr;
1789 rtx old_stack_level = 0;
1790 int reg_parm_stack_space = 0;
1792 #ifdef REG_PARM_STACK_SPACE
1793 #ifdef MAYBE_REG_PARM_STACK_SPACE
1794 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1796 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1800 before_call = get_last_insn ();
1802 timevar_push (TV_INTEGRATION);
1804 temp = expand_inline_function (fndecl, actparms, target,
1806 structure_value_addr);
1808 timevar_pop (TV_INTEGRATION);
1810 /* If inlining succeeded, return. */
1811 if (temp != (rtx) (size_t) - 1)
1813 if (ACCUMULATE_OUTGOING_ARGS)
1815 /* If the outgoing argument list must be preserved, push
1816 the stack before executing the inlined function if it
1819 for (i = reg_parm_stack_space - 1; i >= 0; i--)
1820 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
1823 if (stack_arg_under_construction || i >= 0)
1826 = before_call ? NEXT_INSN (before_call) : get_insns ();
1827 rtx insn = NULL_RTX, seq;
1829 /* Look for a call in the inline function code.
1830 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1831 nonzero then there is a call and it is not necessary
1832 to scan the insns. */
1834 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1835 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1836 if (GET_CODE (insn) == CALL_INSN)
1841 /* Reserve enough stack space so that the largest
1842 argument list of any function call in the inline
1843 function does not overlap the argument list being
1844 evaluated. This is usually an overestimate because
1845 allocate_dynamic_stack_space reserves space for an
1846 outgoing argument list in addition to the requested
1847 space, but there is no way to ask for stack space such
1848 that an argument list of a certain length can be
1851 Add the stack space reserved for register arguments, if
1852 any, in the inline function. What is really needed is the
1853 largest value of reg_parm_stack_space in the inline
1854 function, but that is not available. Using the current
1855 value of reg_parm_stack_space is wrong, but gives
1856 correct results on all supported machines. */
1858 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1859 + reg_parm_stack_space);
1862 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1863 allocate_dynamic_stack_space (GEN_INT (adjust),
1864 NULL_RTX, BITS_PER_UNIT);
1867 emit_insn_before (seq, first_insn);
1868 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1873 /* If the result is equivalent to TARGET, return TARGET to simplify
1874 checks in store_expr. They can be equivalent but not equal in the
1875 case of a function that returns BLKmode. */
1876 if (temp != target && rtx_equal_p (temp, target))
1881 /* If inlining failed, mark FNDECL as needing to be compiled
1882 separately after all. If function was declared inline,
1884 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1885 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1887 warning_with_decl (fndecl, "inlining failed in call to `%s'");
1888 warning ("called from here");
1890 (*lang_hooks.mark_addressable) (fndecl);
1891 return (rtx) (size_t) - 1;
1894 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1895 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1896 bytes, then we would need to push some additional bytes to pad the
1897 arguments. So, we compute an adjust to the stack pointer for an
1898 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1899 bytes. Then, when the arguments are pushed the stack will be perfectly
1900 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1901 be popped after the call. Returns the adjustment. */
1904 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1906 preferred_unit_stack_boundary)
1907 int unadjusted_args_size;
1908 struct args_size *args_size;
1909 int preferred_unit_stack_boundary;
1911 /* The number of bytes to pop so that the stack will be
1912 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1913 HOST_WIDE_INT adjustment;
1914 /* The alignment of the stack after the arguments are pushed, if we
1915 just pushed the arguments without adjust the stack here. */
1916 HOST_WIDE_INT unadjusted_alignment;
1918 unadjusted_alignment
1919 = ((stack_pointer_delta + unadjusted_args_size)
1920 % preferred_unit_stack_boundary);
1922 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1923 as possible -- leaving just enough left to cancel out the
1924 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1925 PENDING_STACK_ADJUST is non-negative, and congruent to
1926 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1928 /* Begin by trying to pop all the bytes. */
1929 unadjusted_alignment
1930 = (unadjusted_alignment
1931 - (pending_stack_adjust % preferred_unit_stack_boundary));
1932 adjustment = pending_stack_adjust;
1933 /* Push enough additional bytes that the stack will be aligned
1934 after the arguments are pushed. */
1935 if (preferred_unit_stack_boundary > 1)
1937 if (unadjusted_alignment > 0)
1938 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1940 adjustment += unadjusted_alignment;
1943 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1944 bytes after the call. The right number is the entire
1945 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1946 by the arguments in the first place. */
1948 = pending_stack_adjust - adjustment + unadjusted_args_size;
1953 /* Scan X expression if it does not dereference any argument slots
1954 we already clobbered by tail call arguments (as noted in stored_args_map
1956 Return nonzero if X expression dereferences such argument slots,
1960 check_sibcall_argument_overlap_1 (x)
1971 code = GET_CODE (x);
1975 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1977 else if (GET_CODE (XEXP (x, 0)) == PLUS
1978 && XEXP (XEXP (x, 0), 0) ==
1979 current_function_internal_arg_pointer
1980 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1981 i = INTVAL (XEXP (XEXP (x, 0), 1));
1985 #ifdef ARGS_GROW_DOWNWARD
1986 i = -i - GET_MODE_SIZE (GET_MODE (x));
1989 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1990 if (i + k < stored_args_map->n_bits
1991 && TEST_BIT (stored_args_map, i + k))
1997 /* Scan all subexpressions. */
1998 fmt = GET_RTX_FORMAT (code);
1999 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
2003 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
2006 else if (*fmt == 'E')
2008 for (j = 0; j < XVECLEN (x, i); j++)
2009 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
2016 /* Scan sequence after INSN if it does not dereference any argument slots
2017 we already clobbered by tail call arguments (as noted in stored_args_map
2018 bitmap). Add stack slots for ARG to stored_args_map bitmap afterwards.
2019 Return nonzero if sequence after INSN dereferences such argument slots,
2023 check_sibcall_argument_overlap (insn, arg)
2025 struct arg_data *arg;
2029 if (insn == NULL_RTX)
2030 insn = get_insns ();
2032 insn = NEXT_INSN (insn);
2034 for (; insn; insn = NEXT_INSN (insn))
2036 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2039 #ifdef ARGS_GROW_DOWNWARD
2040 low = -arg->slot_offset.constant - arg->size.constant;
2042 low = arg->slot_offset.constant;
2045 for (high = low + arg->size.constant; low < high; low++)
2046 SET_BIT (stored_args_map, low);
2047 return insn != NULL_RTX;
2050 /* Generate all the code for a function call
2051 and return an rtx for its value.
2052 Store the value in TARGET (specified as an rtx) if convenient.
2053 If the value is stored in TARGET then TARGET is returned.
2054 If IGNORE is nonzero, then we ignore the value of the function call. */
2057 expand_call (exp, target, ignore)
2062 /* Nonzero if we are currently expanding a call. */
2063 static int currently_expanding_call = 0;
2065 /* List of actual parameters. */
2066 tree actparms = TREE_OPERAND (exp, 1);
2067 /* RTX for the function to be called. */
2069 /* Sequence of insns to perform a tail recursive "call". */
2070 rtx tail_recursion_insns = NULL_RTX;
2071 /* Sequence of insns to perform a normal "call". */
2072 rtx normal_call_insns = NULL_RTX;
2073 /* Sequence of insns to perform a tail recursive "call". */
2074 rtx tail_call_insns = NULL_RTX;
2075 /* Data type of the function. */
2077 /* Declaration of the function being called,
2078 or 0 if the function is computed (not known by name). */
2081 int try_tail_call = 1;
2082 int try_tail_recursion = 1;
2085 /* Register in which non-BLKmode value will be returned,
2086 or 0 if no value or if value is BLKmode. */
2088 /* Address where we should return a BLKmode value;
2089 0 if value not BLKmode. */
2090 rtx structure_value_addr = 0;
2091 /* Nonzero if that address is being passed by treating it as
2092 an extra, implicit first parameter. Otherwise,
2093 it is passed by being copied directly into struct_value_rtx. */
2094 int structure_value_addr_parm = 0;
2095 /* Size of aggregate value wanted, or zero if none wanted
2096 or if we are using the non-reentrant PCC calling convention
2097 or expecting the value in registers. */
2098 HOST_WIDE_INT struct_value_size = 0;
2099 /* Nonzero if called function returns an aggregate in memory PCC style,
2100 by returning the address of where to find it. */
2101 int pcc_struct_value = 0;
2103 /* Number of actual parameters in this call, including struct value addr. */
2105 /* Number of named args. Args after this are anonymous ones
2106 and they must all go on the stack. */
2109 /* Vector of information about each argument.
2110 Arguments are numbered in the order they will be pushed,
2111 not the order they are written. */
2112 struct arg_data *args;
2114 /* Total size in bytes of all the stack-parms scanned so far. */
2115 struct args_size args_size;
2116 struct args_size adjusted_args_size;
2117 /* Size of arguments before any adjustments (such as rounding). */
2118 int unadjusted_args_size;
2119 /* Data on reg parms scanned so far. */
2120 CUMULATIVE_ARGS args_so_far;
2121 /* Nonzero if a reg parm has been scanned. */
2123 /* Nonzero if this is an indirect function call. */
2125 /* Nonzero if we must avoid push-insns in the args for this call.
2126 If stack space is allocated for register parameters, but not by the
2127 caller, then it is preallocated in the fixed part of the stack frame.
2128 So the entire argument block must then be preallocated (i.e., we
2129 ignore PUSH_ROUNDING in that case). */
2131 int must_preallocate = !PUSH_ARGS;
2133 /* Size of the stack reserved for parameter registers. */
2134 int reg_parm_stack_space = 0;
2136 /* Address of space preallocated for stack parms
2137 (on machines that lack push insns), or 0 if space not preallocated. */
2140 /* Mask of ECF_ flags. */
2142 /* Nonzero if this is a call to an inline function. */
2143 int is_integrable = 0;
2144 #ifdef REG_PARM_STACK_SPACE
2145 /* Define the boundary of the register parm stack space that needs to be
2147 int low_to_save = -1, high_to_save;
2148 rtx save_area = 0; /* Place that it is saved */
2151 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2152 char *initial_stack_usage_map = stack_usage_map;
2153 int old_stack_arg_under_construction = 0;
2155 rtx old_stack_level = 0;
2156 int old_pending_adj = 0;
2157 int old_inhibit_defer_pop = inhibit_defer_pop;
2158 int old_stack_allocated;
2160 tree p = TREE_OPERAND (exp, 0);
2162 /* The alignment of the stack, in bits. */
2163 HOST_WIDE_INT preferred_stack_boundary;
2164 /* The alignment of the stack, in bytes. */
2165 HOST_WIDE_INT preferred_unit_stack_boundary;
2167 /* See if this is "nothrow" function call. */
2168 if (TREE_NOTHROW (exp))
2169 flags |= ECF_NOTHROW;
2171 /* See if we can find a DECL-node for the actual function.
2172 As a result, decide whether this is a call to an integrable function. */
2174 fndecl = get_callee_fndecl (exp);
2178 && fndecl != current_function_decl
2179 && DECL_INLINE (fndecl)
2180 && DECL_SAVED_INSNS (fndecl)
2181 && DECL_SAVED_INSNS (fndecl)->inlinable)
2183 else if (! TREE_ADDRESSABLE (fndecl))
2185 /* In case this function later becomes inlinable,
2186 record that there was already a non-inline call to it.
2188 Use abstraction instead of setting TREE_ADDRESSABLE
2190 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2193 warning_with_decl (fndecl, "can't inline call to `%s'");
2194 warning ("called from here");
2196 (*lang_hooks.mark_addressable) (fndecl);
2199 flags |= flags_from_decl_or_type (fndecl);
2202 /* If we don't have specific function to call, see if we have a
2203 attributes set in the type. */
2205 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2207 #ifdef REG_PARM_STACK_SPACE
2208 #ifdef MAYBE_REG_PARM_STACK_SPACE
2209 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2211 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2215 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2216 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2217 must_preallocate = 1;
2220 /* Warn if this value is an aggregate type,
2221 regardless of which calling convention we are using for it. */
2222 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2223 warning ("function call has aggregate value");
2225 /* Set up a place to return a structure. */
2227 /* Cater to broken compilers. */
2228 if (aggregate_value_p (exp))
2230 /* This call returns a big structure. */
2231 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2233 #ifdef PCC_STATIC_STRUCT_RETURN
2235 pcc_struct_value = 1;
2236 /* Easier than making that case work right. */
2239 /* In case this is a static function, note that it has been
2241 if (! TREE_ADDRESSABLE (fndecl))
2242 (*lang_hooks.mark_addressable) (fndecl);
2246 #else /* not PCC_STATIC_STRUCT_RETURN */
2248 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2250 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2251 /* The structure value address arg is already in actparms. */
2252 structure_value_addr_parm = 1;
2253 else if (target && GET_CODE (target) == MEM)
2254 structure_value_addr = XEXP (target, 0);
2257 /* For variable-sized objects, we must be called with a target
2258 specified. If we were to allocate space on the stack here,
2259 we would have no way of knowing when to free it. */
2260 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2262 mark_temp_addr_taken (d);
2263 structure_value_addr = XEXP (d, 0);
2267 #endif /* not PCC_STATIC_STRUCT_RETURN */
2270 /* If called function is inline, try to integrate it. */
2274 rtx temp = try_to_integrate (fndecl, actparms, target,
2275 ignore, TREE_TYPE (exp),
2276 structure_value_addr);
2277 if (temp != (rtx) (size_t) - 1)
2281 /* Figure out the amount to which the stack should be aligned. */
2282 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2284 /* Operand 0 is a pointer-to-function; get the type of the function. */
2285 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
2286 if (! POINTER_TYPE_P (funtype))
2288 funtype = TREE_TYPE (funtype);
2290 /* See if this is a call to a function that can return more than once
2291 or a call to longjmp or malloc. */
2292 flags |= special_function_p (fndecl, flags);
2294 if (flags & ECF_MAY_BE_ALLOCA)
2295 current_function_calls_alloca = 1;
2297 /* If struct_value_rtx is 0, it means pass the address
2298 as if it were an extra parameter. */
2299 if (structure_value_addr && struct_value_rtx == 0)
2301 /* If structure_value_addr is a REG other than
2302 virtual_outgoing_args_rtx, we can use always use it. If it
2303 is not a REG, we must always copy it into a register.
2304 If it is virtual_outgoing_args_rtx, we must copy it to another
2305 register in some cases. */
2306 rtx temp = (GET_CODE (structure_value_addr) != REG
2307 || (ACCUMULATE_OUTGOING_ARGS
2308 && stack_arg_under_construction
2309 && structure_value_addr == virtual_outgoing_args_rtx)
2310 ? copy_addr_to_reg (structure_value_addr)
2311 : structure_value_addr);
2314 = tree_cons (error_mark_node,
2315 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2318 structure_value_addr_parm = 1;
2321 /* Count the arguments and set NUM_ACTUALS. */
2322 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2325 /* Compute number of named args.
2326 Normally, don't include the last named arg if anonymous args follow.
2327 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2328 (If no anonymous args follow, the result of list_length is actually
2329 one too large. This is harmless.)
2331 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2332 zero, this machine will be able to place unnamed args that were
2333 passed in registers into the stack. So treat all args as named.
2334 This allows the insns emitting for a specific argument list to be
2335 independent of the function declaration.
2337 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2338 reliable way to pass unnamed args in registers, so we must force
2339 them into memory. */
2341 if ((STRICT_ARGUMENT_NAMING
2342 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2343 && TYPE_ARG_TYPES (funtype) != 0)
2345 = (list_length (TYPE_ARG_TYPES (funtype))
2346 /* Don't include the last named arg. */
2347 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2348 /* Count the struct value address, if it is passed as a parm. */
2349 + structure_value_addr_parm);
2351 /* If we know nothing, treat all args as named. */
2352 n_named_args = num_actuals;
2354 /* Start updating where the next arg would go.
2356 On some machines (such as the PA) indirect calls have a different
2357 calling convention than normal calls. The last argument in
2358 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2360 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0));
2362 /* Make a vector to hold all the information about each arg. */
2363 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2364 memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2366 /* Build up entries in the ARGS array, compute the size of the
2367 arguments into ARGS_SIZE, etc. */
2368 initialize_argument_information (num_actuals, args, &args_size,
2369 n_named_args, actparms, fndecl,
2370 &args_so_far, reg_parm_stack_space,
2371 &old_stack_level, &old_pending_adj,
2372 &must_preallocate, &flags);
2376 /* If this function requires a variable-sized argument list, don't
2377 try to make a cse'able block for this call. We may be able to
2378 do this eventually, but it is too complicated to keep track of
2379 what insns go in the cse'able block and which don't. */
2381 flags &= ~ECF_LIBCALL_BLOCK;
2382 must_preallocate = 1;
2385 /* Now make final decision about preallocating stack space. */
2386 must_preallocate = finalize_must_preallocate (must_preallocate,
2390 /* If the structure value address will reference the stack pointer, we
2391 must stabilize it. We don't need to do this if we know that we are
2392 not going to adjust the stack pointer in processing this call. */
2394 if (structure_value_addr
2395 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2396 || reg_mentioned_p (virtual_outgoing_args_rtx,
2397 structure_value_addr))
2399 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2400 structure_value_addr = copy_to_reg (structure_value_addr);
2402 /* Tail calls can make things harder to debug, and we're traditionally
2403 pushed these optimizations into -O2. Don't try if we're already
2404 expanding a call, as that means we're an argument. Don't try if
2405 there's cleanups, as we know there's code to follow the call.
2407 If rtx_equal_function_value_matters is false, that means we've
2408 finished with regular parsing. Which means that some of the
2409 machinery we use to generate tail-calls is no longer in place.
2410 This is most often true of sjlj-exceptions, which we couldn't
2411 tail-call to anyway. */
2413 if (currently_expanding_call++ != 0
2414 || !flag_optimize_sibling_calls
2415 || !rtx_equal_function_value_matters
2416 || any_pending_cleanups (1)
2418 try_tail_call = try_tail_recursion = 0;
2420 /* Tail recursion fails, when we are not dealing with recursive calls. */
2421 if (!try_tail_recursion
2422 || TREE_CODE (TREE_OPERAND (exp, 0)) != ADDR_EXPR
2423 || TREE_OPERAND (TREE_OPERAND (exp, 0), 0) != current_function_decl)
2424 try_tail_recursion = 0;
2426 /* Rest of purposes for tail call optimizations to fail. */
2428 #ifdef HAVE_sibcall_epilogue
2429 !HAVE_sibcall_epilogue
2434 /* Doing sibling call optimization needs some work, since
2435 structure_value_addr can be allocated on the stack.
2436 It does not seem worth the effort since few optimizable
2437 sibling calls will return a structure. */
2438 || structure_value_addr != NULL_RTX
2439 /* Check whether the target is able to optimize the call
2441 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2442 /* Functions that do not return exactly once may not be sibcall
2444 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2445 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
2446 /* If this function requires more stack slots than the current
2447 function, we cannot change it into a sibling call. */
2448 || args_size.constant > current_function_args_size
2449 /* If the callee pops its own arguments, then it must pop exactly
2450 the same number of arguments as the current function. */
2451 || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2452 != RETURN_POPS_ARGS (current_function_decl,
2453 TREE_TYPE (current_function_decl),
2454 current_function_args_size))
2457 if (try_tail_call || try_tail_recursion)
2460 actparms = NULL_TREE;
2461 /* Ok, we're going to give the tail call the old college try.
2462 This means we're going to evaluate the function arguments
2463 up to three times. There are two degrees of badness we can
2464 encounter, those that can be unsaved and those that can't.
2465 (See unsafe_for_reeval commentary for details.)
2467 Generate a new argument list. Pass safe arguments through
2468 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2469 For hard badness, evaluate them now and put their resulting
2470 rtx in a temporary VAR_DECL.
2472 initialize_argument_information has ordered the array for the
2473 order to be pushed, and we must remember this when reconstructing
2474 the original argument order. */
2476 if (PUSH_ARGS_REVERSED)
2485 i = num_actuals - 1;
2489 for (; i != end; i += inc)
2491 switch (unsafe_for_reeval (args[i].tree_value))
2496 case 1: /* Mildly unsafe. */
2497 args[i].tree_value = unsave_expr (args[i].tree_value);
2500 case 2: /* Wildly unsafe. */
2502 tree var = build_decl (VAR_DECL, NULL_TREE,
2503 TREE_TYPE (args[i].tree_value));
2505 expand_expr (args[i].tree_value, NULL_RTX,
2506 VOIDmode, EXPAND_NORMAL));
2507 args[i].tree_value = var;
2514 /* We need to build actparms for optimize_tail_recursion. We can
2515 safely trash away TREE_PURPOSE, since it is unused by this
2517 if (try_tail_recursion)
2518 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2520 /* Expanding one of those dangerous arguments could have added
2521 cleanups, but otherwise give it a whirl. */
2522 if (any_pending_cleanups (1))
2523 try_tail_call = try_tail_recursion = 0;
2526 /* Generate a tail recursion sequence when calling ourselves. */
2528 if (try_tail_recursion)
2530 /* We want to emit any pending stack adjustments before the tail
2531 recursion "call". That way we know any adjustment after the tail
2532 recursion call can be ignored if we indeed use the tail recursion
2534 int save_pending_stack_adjust = pending_stack_adjust;
2535 int save_stack_pointer_delta = stack_pointer_delta;
2537 /* Emit any queued insns now; otherwise they would end up in
2538 only one of the alternates. */
2541 /* Use a new sequence to hold any RTL we generate. We do not even
2542 know if we will use this RTL yet. The final decision can not be
2543 made until after RTL generation for the entire function is
2546 /* If expanding any of the arguments creates cleanups, we can't
2547 do a tailcall. So, we'll need to pop the pending cleanups
2548 list. If, however, all goes well, and there are no cleanups
2549 then the call to expand_start_target_temps will have no
2551 expand_start_target_temps ();
2552 if (optimize_tail_recursion (actparms, get_last_insn ()))
2554 if (any_pending_cleanups (1))
2555 try_tail_call = try_tail_recursion = 0;
2557 tail_recursion_insns = get_insns ();
2559 expand_end_target_temps ();
2562 /* Restore the original pending stack adjustment for the sibling and
2563 normal call cases below. */
2564 pending_stack_adjust = save_pending_stack_adjust;
2565 stack_pointer_delta = save_stack_pointer_delta;
2568 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2570 /* A fork duplicates the profile information, and an exec discards
2571 it. We can't rely on fork/exec to be paired. So write out the
2572 profile information we have gathered so far, and clear it. */
2573 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2574 is subject to race conditions, just as with multithreaded
2577 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__gcov_flush"),
2582 /* Ensure current function's preferred stack boundary is at least
2583 what we need. We don't have to increase alignment for recursive
2585 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2586 && fndecl != current_function_decl)
2587 cfun->preferred_stack_boundary = preferred_stack_boundary;
2589 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2591 function_call_count++;
2593 /* We want to make two insn chains; one for a sibling call, the other
2594 for a normal call. We will select one of the two chains after
2595 initial RTL generation is complete. */
2596 for (pass = 0; pass < 2; pass++)
2598 int sibcall_failure = 0;
2599 /* We want to emit any pending stack adjustments before the tail
2600 recursion "call". That way we know any adjustment after the tail
2601 recursion call can be ignored if we indeed use the tail recursion
2603 int save_pending_stack_adjust = 0;
2604 int save_stack_pointer_delta = 0;
2606 rtx before_call, next_arg_reg;
2610 if (! try_tail_call)
2613 /* Emit any queued insns now; otherwise they would end up in
2614 only one of the alternates. */
2617 /* State variables we need to save and restore between
2619 save_pending_stack_adjust = pending_stack_adjust;
2620 save_stack_pointer_delta = stack_pointer_delta;
2623 flags &= ~ECF_SIBCALL;
2625 flags |= ECF_SIBCALL;
2627 /* Other state variables that we must reinitialize each time
2628 through the loop (that are not initialized by the loop itself). */
2632 /* Start a new sequence for the normal call case.
2634 From this point on, if the sibling call fails, we want to set
2635 sibcall_failure instead of continuing the loop. */
2640 /* We know at this point that there are not currently any
2641 pending cleanups. If, however, in the process of evaluating
2642 the arguments we were to create some, we'll need to be
2643 able to get rid of them. */
2644 expand_start_target_temps ();
2647 /* Don't let pending stack adjusts add up to too much.
2648 Also, do all pending adjustments now if there is any chance
2649 this might be a call to alloca or if we are expanding a sibling
2650 call sequence or if we are calling a function that is to return
2651 with stack pointer depressed. */
2652 if (pending_stack_adjust >= 32
2653 || (pending_stack_adjust > 0
2654 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2656 do_pending_stack_adjust ();
2658 /* When calling a const function, we must pop the stack args right away,
2659 so that the pop is deleted or moved with the call. */
2660 if (pass && (flags & ECF_LIBCALL_BLOCK))
2663 #ifdef FINAL_REG_PARM_STACK_SPACE
2664 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2667 /* Precompute any arguments as needed. */
2669 precompute_arguments (flags, num_actuals, args);
2671 /* Now we are about to start emitting insns that can be deleted
2672 if a libcall is deleted. */
2673 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2676 adjusted_args_size = args_size;
2677 /* Compute the actual size of the argument block required. The variable
2678 and constant sizes must be combined, the size may have to be rounded,
2679 and there may be a minimum required size. When generating a sibcall
2680 pattern, do not round up, since we'll be re-using whatever space our
2682 unadjusted_args_size
2683 = compute_argument_block_size (reg_parm_stack_space,
2684 &adjusted_args_size,
2686 : preferred_stack_boundary));
2688 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2690 /* The argument block when performing a sibling call is the
2691 incoming argument block. */
2694 argblock = virtual_incoming_args_rtx;
2696 #ifdef STACK_GROWS_DOWNWARD
2697 = plus_constant (argblock, current_function_pretend_args_size);
2699 = plus_constant (argblock, -current_function_pretend_args_size);
2701 stored_args_map = sbitmap_alloc (args_size.constant);
2702 sbitmap_zero (stored_args_map);
2705 /* If we have no actual push instructions, or shouldn't use them,
2706 make space for all args right now. */
2707 else if (adjusted_args_size.var != 0)
2709 if (old_stack_level == 0)
2711 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2712 old_pending_adj = pending_stack_adjust;
2713 pending_stack_adjust = 0;
2714 /* stack_arg_under_construction says whether a stack arg is
2715 being constructed at the old stack level. Pushing the stack
2716 gets a clean outgoing argument block. */
2717 old_stack_arg_under_construction = stack_arg_under_construction;
2718 stack_arg_under_construction = 0;
2720 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2724 /* Note that we must go through the motions of allocating an argument
2725 block even if the size is zero because we may be storing args
2726 in the area reserved for register arguments, which may be part of
2729 int needed = adjusted_args_size.constant;
2731 /* Store the maximum argument space used. It will be pushed by
2732 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2735 if (needed > current_function_outgoing_args_size)
2736 current_function_outgoing_args_size = needed;
2738 if (must_preallocate)
2740 if (ACCUMULATE_OUTGOING_ARGS)
2742 /* Since the stack pointer will never be pushed, it is
2743 possible for the evaluation of a parm to clobber
2744 something we have already written to the stack.
2745 Since most function calls on RISC machines do not use
2746 the stack, this is uncommon, but must work correctly.
2748 Therefore, we save any area of the stack that was already
2749 written and that we are using. Here we set up to do this
2750 by making a new stack usage map from the old one. The
2751 actual save will be done by store_one_arg.
2753 Another approach might be to try to reorder the argument
2754 evaluations to avoid this conflicting stack usage. */
2756 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2757 /* Since we will be writing into the entire argument area,
2758 the map must be allocated for its entire size, not just
2759 the part that is the responsibility of the caller. */
2760 needed += reg_parm_stack_space;
2763 #ifdef ARGS_GROW_DOWNWARD
2764 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2767 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2771 = (char *) alloca (highest_outgoing_arg_in_use);
2773 if (initial_highest_arg_in_use)
2774 memcpy (stack_usage_map, initial_stack_usage_map,
2775 initial_highest_arg_in_use);
2777 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2778 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2779 (highest_outgoing_arg_in_use
2780 - initial_highest_arg_in_use));
2783 /* The address of the outgoing argument list must not be
2784 copied to a register here, because argblock would be left
2785 pointing to the wrong place after the call to
2786 allocate_dynamic_stack_space below. */
2788 argblock = virtual_outgoing_args_rtx;
2792 if (inhibit_defer_pop == 0)
2794 /* Try to reuse some or all of the pending_stack_adjust
2795 to get this space. */
2797 = (combine_pending_stack_adjustment_and_call
2798 (unadjusted_args_size,
2799 &adjusted_args_size,
2800 preferred_unit_stack_boundary));
2802 /* combine_pending_stack_adjustment_and_call computes
2803 an adjustment before the arguments are allocated.
2804 Account for them and see whether or not the stack
2805 needs to go up or down. */
2806 needed = unadjusted_args_size - needed;
2810 /* We're releasing stack space. */
2811 /* ??? We can avoid any adjustment at all if we're
2812 already aligned. FIXME. */
2813 pending_stack_adjust = -needed;
2814 do_pending_stack_adjust ();
2818 /* We need to allocate space. We'll do that in
2819 push_block below. */
2820 pending_stack_adjust = 0;
2823 /* Special case this because overhead of `push_block' in
2824 this case is non-trivial. */
2826 argblock = virtual_outgoing_args_rtx;
2828 argblock = push_block (GEN_INT (needed), 0, 0);
2830 /* We only really need to call `copy_to_reg' in the case
2831 where push insns are going to be used to pass ARGBLOCK
2832 to a function call in ARGS. In that case, the stack
2833 pointer changes value from the allocation point to the
2834 call point, and hence the value of
2835 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2836 as well always do it. */
2837 argblock = copy_to_reg (argblock);
2839 /* The save/restore code in store_one_arg handles all
2840 cases except one: a constructor call (including a C
2841 function returning a BLKmode struct) to initialize
2843 if (stack_arg_under_construction)
2845 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2846 rtx push_size = GEN_INT (reg_parm_stack_space
2847 + adjusted_args_size.constant);
2849 rtx push_size = GEN_INT (adjusted_args_size.constant);
2851 if (old_stack_level == 0)
2853 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2855 old_pending_adj = pending_stack_adjust;
2856 pending_stack_adjust = 0;
2857 /* stack_arg_under_construction says whether a stack
2858 arg is being constructed at the old stack level.
2859 Pushing the stack gets a clean outgoing argument
2861 old_stack_arg_under_construction
2862 = stack_arg_under_construction;
2863 stack_arg_under_construction = 0;
2864 /* Make a new map for the new argument list. */
2865 stack_usage_map = (char *)
2866 alloca (highest_outgoing_arg_in_use);
2867 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2868 highest_outgoing_arg_in_use = 0;
2870 allocate_dynamic_stack_space (push_size, NULL_RTX,
2873 /* If argument evaluation might modify the stack pointer,
2874 copy the address of the argument list to a register. */
2875 for (i = 0; i < num_actuals; i++)
2876 if (args[i].pass_on_stack)
2878 argblock = copy_addr_to_reg (argblock);
2885 compute_argument_addresses (args, argblock, num_actuals);
2887 /* If we push args individually in reverse order, perform stack alignment
2888 before the first push (the last arg). */
2889 if (PUSH_ARGS_REVERSED && argblock == 0
2890 && adjusted_args_size.constant != unadjusted_args_size)
2892 /* When the stack adjustment is pending, we get better code
2893 by combining the adjustments. */
2894 if (pending_stack_adjust
2895 && ! (flags & ECF_LIBCALL_BLOCK)
2896 && ! inhibit_defer_pop)
2898 pending_stack_adjust
2899 = (combine_pending_stack_adjustment_and_call
2900 (unadjusted_args_size,
2901 &adjusted_args_size,
2902 preferred_unit_stack_boundary));
2903 do_pending_stack_adjust ();
2905 else if (argblock == 0)
2906 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2907 - unadjusted_args_size));
2909 /* Now that the stack is properly aligned, pops can't safely
2910 be deferred during the evaluation of the arguments. */
2913 funexp = rtx_for_function_call (fndecl, exp);
2915 /* Figure out the register where the value, if any, will come back. */
2917 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2918 && ! structure_value_addr)
2920 if (pcc_struct_value)
2921 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2922 fndecl, (pass == 0));
2924 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2927 /* Precompute all register parameters. It isn't safe to compute anything
2928 once we have started filling any specific hard regs. */
2929 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2931 #ifdef REG_PARM_STACK_SPACE
2932 /* Save the fixed argument area if it's part of the caller's frame and
2933 is clobbered by argument setup for this call. */
2934 if (ACCUMULATE_OUTGOING_ARGS && pass)
2935 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2936 &low_to_save, &high_to_save);
2939 /* Now store (and compute if necessary) all non-register parms.
2940 These come before register parms, since they can require block-moves,
2941 which could clobber the registers used for register parms.
2942 Parms which have partial registers are not stored here,
2943 but we do preallocate space here if they want that. */
2945 for (i = 0; i < num_actuals; i++)
2946 if (args[i].reg == 0 || args[i].pass_on_stack)
2948 rtx before_arg = get_last_insn ();
2950 if (store_one_arg (&args[i], argblock, flags,
2951 adjusted_args_size.var != 0,
2952 reg_parm_stack_space)
2954 && check_sibcall_argument_overlap (before_arg,
2956 sibcall_failure = 1;
2959 /* If we have a parm that is passed in registers but not in memory
2960 and whose alignment does not permit a direct copy into registers,
2961 make a group of pseudos that correspond to each register that we
2963 if (STRICT_ALIGNMENT)
2964 store_unaligned_arguments_into_pseudos (args, num_actuals);
2966 /* Now store any partially-in-registers parm.
2967 This is the last place a block-move can happen. */
2969 for (i = 0; i < num_actuals; i++)
2970 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2972 rtx before_arg = get_last_insn ();
2974 if (store_one_arg (&args[i], argblock, flags,
2975 adjusted_args_size.var != 0,
2976 reg_parm_stack_space)
2978 && check_sibcall_argument_overlap (before_arg,
2980 sibcall_failure = 1;
2983 /* If we pushed args in forward order, perform stack alignment
2984 after pushing the last arg. */
2985 if (!PUSH_ARGS_REVERSED && argblock == 0)
2986 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2987 - unadjusted_args_size));
2989 /* If register arguments require space on the stack and stack space
2990 was not preallocated, allocate stack space here for arguments
2991 passed in registers. */
2992 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2993 if (!ACCUMULATE_OUTGOING_ARGS
2994 && must_preallocate == 0 && reg_parm_stack_space > 0)
2995 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2998 /* Pass the function the address in which to return a
3000 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3002 emit_move_insn (struct_value_rtx,
3004 force_operand (structure_value_addr,
3007 if (GET_CODE (struct_value_rtx) == REG)
3008 use_reg (&call_fusage, struct_value_rtx);
3011 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3012 reg_parm_seen, pass == 0);
3014 load_register_parameters (args, num_actuals, &call_fusage, flags);
3016 /* Perform postincrements before actually calling the function. */
3019 /* Save a pointer to the last insn before the call, so that we can
3020 later safely search backwards to find the CALL_INSN. */
3021 before_call = get_last_insn ();
3023 /* Set up next argument register. For sibling calls on machines
3024 with register windows this should be the incoming register. */
3025 #ifdef FUNCTION_INCOMING_ARG
3027 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3031 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3034 /* All arguments and registers used for the call must be set up by
3037 /* Stack must be properly aligned now. */
3038 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3041 /* Generate the actual call instruction. */
3042 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3043 adjusted_args_size.constant, struct_value_size,
3044 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3045 flags, & args_so_far);
3047 /* Verify that we've deallocated all the stack we used. */
3049 && old_stack_allocated != stack_pointer_delta - pending_stack_adjust)
3052 /* If call is cse'able, make appropriate pair of reg-notes around it.
3053 Test valreg so we don't crash; may safely ignore `const'
3054 if return type is void. Disable for PARALLEL return values, because
3055 we have no way to move such values into a pseudo register. */
3056 if (pass && (flags & ECF_LIBCALL_BLOCK))
3060 if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3062 insns = get_insns ();
3069 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3071 /* Mark the return value as a pointer if needed. */
3072 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3073 mark_reg_pointer (temp,
3074 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3076 /* Construct an "equal form" for the value which mentions all the
3077 arguments in order as well as the function name. */
3078 for (i = 0; i < num_actuals; i++)
3079 note = gen_rtx_EXPR_LIST (VOIDmode,
3080 args[i].initial_value, note);
3081 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3083 insns = get_insns ();
3086 if (flags & ECF_PURE)
3087 note = gen_rtx_EXPR_LIST (VOIDmode,
3088 gen_rtx_USE (VOIDmode,
3089 gen_rtx_MEM (BLKmode,
3090 gen_rtx_SCRATCH (VOIDmode))),
3093 emit_libcall_block (insns, temp, valreg, note);
3098 else if (pass && (flags & ECF_MALLOC))
3100 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3103 /* The return value from a malloc-like function is a pointer. */
3104 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3105 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3107 emit_move_insn (temp, valreg);
3109 /* The return value from a malloc-like function can not alias
3111 last = get_last_insn ();
3113 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3115 /* Write out the sequence. */
3116 insns = get_insns ();
3122 /* For calls to `setjmp', etc., inform flow.c it should complain
3123 if nonvolatile values are live. For functions that cannot return,
3124 inform flow that control does not fall through. */
3126 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3128 /* The barrier must be emitted
3129 immediately after the CALL_INSN. Some ports emit more
3130 than just a CALL_INSN above, so we must search for it here. */
3132 rtx last = get_last_insn ();
3133 while (GET_CODE (last) != CALL_INSN)
3135 last = PREV_INSN (last);
3136 /* There was no CALL_INSN? */
3137 if (last == before_call)
3141 emit_barrier_after (last);
3144 if (flags & ECF_LONGJMP)
3145 current_function_calls_longjmp = 1;
3147 /* If this function is returning into a memory location marked as
3148 readonly, it means it is initializing that location. But we normally
3149 treat functions as not clobbering such locations, so we need to
3150 specify that this one does. */
3151 if (target != 0 && GET_CODE (target) == MEM
3152 && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
3153 emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
3155 /* If value type not void, return an rtx for the value. */
3157 /* If there are cleanups to be called, don't use a hard reg as target.
3158 We need to double check this and see if it matters anymore. */
3159 if (any_pending_cleanups (1))
3161 if (target && REG_P (target)
3162 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3164 sibcall_failure = 1;
3167 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3169 target = const0_rtx;
3170 else if (structure_value_addr)
3172 if (target == 0 || GET_CODE (target) != MEM)
3175 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3176 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3177 structure_value_addr));
3178 set_mem_attributes (target, exp, 1);
3181 else if (pcc_struct_value)
3183 /* This is the special C++ case where we need to
3184 know what the true target was. We take care to
3185 never use this value more than once in one expression. */
3186 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3187 copy_to_reg (valreg));
3188 set_mem_attributes (target, exp, 1);
3190 /* Handle calls that return values in multiple non-contiguous locations.
3191 The Irix 6 ABI has examples of this. */
3192 else if (GET_CODE (valreg) == PARALLEL)
3196 /* This will only be assigned once, so it can be readonly. */
3197 tree nt = build_qualified_type (TREE_TYPE (exp),
3198 (TYPE_QUALS (TREE_TYPE (exp))
3199 | TYPE_QUAL_CONST));
3201 target = assign_temp (nt, 0, 1, 1);
3202 preserve_temp_slots (target);
3205 if (! rtx_equal_p (target, valreg))
3206 emit_group_store (target, valreg,
3207 int_size_in_bytes (TREE_TYPE (exp)));
3209 /* We can not support sibling calls for this case. */
3210 sibcall_failure = 1;
3213 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3214 && GET_MODE (target) == GET_MODE (valreg))
3216 /* TARGET and VALREG cannot be equal at this point because the
3217 latter would not have REG_FUNCTION_VALUE_P true, while the
3218 former would if it were referring to the same register.
3220 If they refer to the same register, this move will be a no-op,
3221 except when function inlining is being done. */
3222 emit_move_insn (target, valreg);
3224 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3226 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3228 /* We can not support sibling calls for this case. */
3229 sibcall_failure = 1;
3232 target = copy_to_reg (valreg);
3234 #ifdef PROMOTE_FUNCTION_RETURN
3235 /* If we promoted this return value, make the proper SUBREG. TARGET
3236 might be const0_rtx here, so be careful. */
3237 if (GET_CODE (target) == REG
3238 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3239 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3241 tree type = TREE_TYPE (exp);
3242 int unsignedp = TREE_UNSIGNED (type);
3245 /* If we don't promote as expected, something is wrong. */
3246 if (GET_MODE (target)
3247 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3250 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3251 && GET_MODE_SIZE (GET_MODE (target))
3252 > GET_MODE_SIZE (TYPE_MODE (type)))
3254 offset = GET_MODE_SIZE (GET_MODE (target))
3255 - GET_MODE_SIZE (TYPE_MODE (type));
3256 if (! BYTES_BIG_ENDIAN)
3257 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3258 else if (! WORDS_BIG_ENDIAN)
3259 offset %= UNITS_PER_WORD;
3261 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3262 SUBREG_PROMOTED_VAR_P (target) = 1;
3263 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3267 /* If size of args is variable or this was a constructor call for a stack
3268 argument, restore saved stack-pointer value. */
3270 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3272 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3273 pending_stack_adjust = old_pending_adj;
3274 stack_arg_under_construction = old_stack_arg_under_construction;
3275 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3276 stack_usage_map = initial_stack_usage_map;
3277 sibcall_failure = 1;
3279 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3281 #ifdef REG_PARM_STACK_SPACE
3284 restore_fixed_argument_area (save_area, argblock,
3285 high_to_save, low_to_save);
3289 /* If we saved any argument areas, restore them. */
3290 for (i = 0; i < num_actuals; i++)
3291 if (args[i].save_area)
3293 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3295 = gen_rtx_MEM (save_mode,
3296 memory_address (save_mode,
3297 XEXP (args[i].stack_slot, 0)));
3299 if (save_mode != BLKmode)
3300 emit_move_insn (stack_area, args[i].save_area);
3302 emit_block_move (stack_area, args[i].save_area,
3303 GEN_INT (args[i].size.constant),
3304 BLOCK_OP_CALL_PARM);
3307 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3308 stack_usage_map = initial_stack_usage_map;
3311 /* If this was alloca, record the new stack level for nonlocal gotos.
3312 Check for the handler slots since we might not have a save area
3313 for non-local gotos. */
3315 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3316 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3318 /* Free up storage we no longer need. */
3319 for (i = 0; i < num_actuals; ++i)
3320 if (args[i].aligned_regs)
3321 free (args[i].aligned_regs);
3325 /* Undo the fake expand_start_target_temps we did earlier. If
3326 there had been any cleanups created, we've already set
3328 expand_end_target_temps ();
3331 insns = get_insns ();
3336 tail_call_insns = insns;
3338 /* Restore the pending stack adjustment now that we have
3339 finished generating the sibling call sequence. */
3341 pending_stack_adjust = save_pending_stack_adjust;
3342 stack_pointer_delta = save_stack_pointer_delta;
3344 /* Prepare arg structure for next iteration. */
3345 for (i = 0; i < num_actuals; i++)
3348 args[i].aligned_regs = 0;
3352 sbitmap_free (stored_args_map);
3355 normal_call_insns = insns;
3357 /* If something prevents making this a sibling call,
3358 zero out the sequence. */
3359 if (sibcall_failure)
3360 tail_call_insns = NULL_RTX;
3363 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3364 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3365 can happen if the arguments to this function call an inline
3366 function who's expansion contains another CALL_PLACEHOLDER.
3368 If there are any C_Ps in any of these sequences, replace them
3369 with their normal call. */
3371 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3372 if (GET_CODE (insn) == CALL_INSN
3373 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3374 replace_call_placeholder (insn, sibcall_use_normal);
3376 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3377 if (GET_CODE (insn) == CALL_INSN
3378 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3379 replace_call_placeholder (insn, sibcall_use_normal);
3381 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3382 if (GET_CODE (insn) == CALL_INSN
3383 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3384 replace_call_placeholder (insn, sibcall_use_normal);
3386 /* If this was a potential tail recursion site, then emit a
3387 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3388 One of them will be selected later. */
3389 if (tail_recursion_insns || tail_call_insns)
3391 /* The tail recursion label must be kept around. We could expose
3392 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3393 and makes determining true tail recursion sites difficult.
3395 So we set LABEL_PRESERVE_P here, then clear it when we select
3396 one of the call sequences after rtl generation is complete. */
3397 if (tail_recursion_insns)
3398 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3399 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3401 tail_recursion_insns,
3402 tail_recursion_label));
3405 emit_insn (normal_call_insns);
3407 currently_expanding_call--;
3409 /* If this function returns with the stack pointer depressed, ensure
3410 this block saves and restores the stack pointer, show it was
3411 changed, and adjust for any outgoing arg space. */
3412 if (flags & ECF_SP_DEPRESSED)
3414 clear_pending_stack_adjust ();
3415 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3416 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3417 save_stack_pointer ();
3423 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3424 The RETVAL parameter specifies whether return value needs to be saved, other
3425 parameters are documented in the emit_library_call function below. */
3428 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3432 enum libcall_type fn_type;
3433 enum machine_mode outmode;
3437 /* Total size in bytes of all the stack-parms scanned so far. */
3438 struct args_size args_size;
3439 /* Size of arguments before any adjustments (such as rounding). */
3440 struct args_size original_args_size;
3445 struct args_size alignment_pad;
3447 CUMULATIVE_ARGS args_so_far;
3451 enum machine_mode mode;
3454 struct args_size offset;
3455 struct args_size size;
3459 int old_inhibit_defer_pop = inhibit_defer_pop;
3460 rtx call_fusage = 0;
3463 int pcc_struct_value = 0;
3464 int struct_value_size = 0;
3466 int reg_parm_stack_space = 0;
3469 tree tfom; /* type_for_mode (outmode, 0) */
3471 #ifdef REG_PARM_STACK_SPACE
3472 /* Define the boundary of the register parm stack space that needs to be
3474 int low_to_save = -1, high_to_save = 0;
3475 rtx save_area = 0; /* Place that it is saved. */
3478 /* Size of the stack reserved for parameter registers. */
3479 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3480 char *initial_stack_usage_map = stack_usage_map;
3482 #ifdef REG_PARM_STACK_SPACE
3483 #ifdef MAYBE_REG_PARM_STACK_SPACE
3484 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3486 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3490 /* By default, library functions can not throw. */
3491 flags = ECF_NOTHROW;
3503 case LCT_CONST_MAKE_BLOCK:
3504 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3506 case LCT_PURE_MAKE_BLOCK:
3507 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3510 flags |= ECF_NORETURN;
3513 flags = ECF_NORETURN;
3515 case LCT_ALWAYS_RETURN:
3516 flags = ECF_ALWAYS_RETURN;
3518 case LCT_RETURNS_TWICE:
3519 flags = ECF_RETURNS_TWICE;
3524 /* Ensure current function's preferred stack boundary is at least
3526 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3527 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3529 /* If this kind of value comes back in memory,
3530 decide where in memory it should come back. */
3531 if (outmode != VOIDmode)
3533 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3534 if (aggregate_value_p (tfom))
3536 #ifdef PCC_STATIC_STRUCT_RETURN
3538 = hard_function_value (build_pointer_type (tfom), 0, 0);
3539 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3540 pcc_struct_value = 1;
3542 value = gen_reg_rtx (outmode);
3543 #else /* not PCC_STATIC_STRUCT_RETURN */
3544 struct_value_size = GET_MODE_SIZE (outmode);
3545 if (value != 0 && GET_CODE (value) == MEM)
3548 mem_value = assign_temp (tfom, 0, 1, 1);
3550 /* This call returns a big structure. */
3551 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3555 tfom = void_type_node;
3557 /* ??? Unfinished: must pass the memory address as an argument. */
3559 /* Copy all the libcall-arguments out of the varargs data
3560 and into a vector ARGVEC.
3562 Compute how to pass each argument. We only support a very small subset
3563 of the full argument passing conventions to limit complexity here since
3564 library functions shouldn't have many args. */
3566 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3567 memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3569 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3570 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3572 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3575 args_size.constant = 0;
3580 /* Now we are about to start emitting insns that can be deleted
3581 if a libcall is deleted. */
3582 if (flags & ECF_LIBCALL_BLOCK)
3587 /* If there's a structure value address to be passed,
3588 either pass it in the special place, or pass it as an extra argument. */
3589 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3591 rtx addr = XEXP (mem_value, 0);
3594 /* Make sure it is a reasonable operand for a move or push insn. */
3595 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3596 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3597 addr = force_operand (addr, NULL_RTX);
3599 argvec[count].value = addr;
3600 argvec[count].mode = Pmode;
3601 argvec[count].partial = 0;
3603 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3604 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3605 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3609 locate_and_pad_parm (Pmode, NULL_TREE,
3610 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3613 argvec[count].reg != 0,
3615 NULL_TREE, &args_size, &argvec[count].offset,
3616 &argvec[count].size, &alignment_pad);
3618 if (argvec[count].reg == 0 || argvec[count].partial != 0
3619 || reg_parm_stack_space > 0)
3620 args_size.constant += argvec[count].size.constant;
3622 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3627 for (; count < nargs; count++)
3629 rtx val = va_arg (p, rtx);
3630 enum machine_mode mode = va_arg (p, enum machine_mode);
3632 /* We cannot convert the arg value to the mode the library wants here;
3633 must do it earlier where we know the signedness of the arg. */
3635 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3638 /* On some machines, there's no way to pass a float to a library fcn.
3639 Pass it as a double instead. */
3640 #ifdef LIBGCC_NEEDS_DOUBLE
3641 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3642 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3645 /* There's no need to call protect_from_queue, because
3646 either emit_move_insn or emit_push_insn will do that. */
3648 /* Make sure it is a reasonable operand for a move or push insn. */
3649 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3650 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3651 val = force_operand (val, NULL_RTX);
3653 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3654 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3658 #ifdef FUNCTION_ARG_CALLEE_COPIES
3659 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3664 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3665 functions, so we have to pretend this isn't such a function. */
3666 if (flags & ECF_LIBCALL_BLOCK)
3668 rtx insns = get_insns ();
3672 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3674 /* If this was a CONST function, it is now PURE since
3675 it now reads memory. */
3676 if (flags & ECF_CONST)
3678 flags &= ~ECF_CONST;
3682 if (GET_MODE (val) == MEM && ! must_copy)
3686 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3688 emit_move_insn (slot, val);
3692 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3694 slot = gen_rtx_MEM (mode,
3695 expand_expr (build1 (ADDR_EXPR,
3698 make_tree (type, val)),
3699 NULL_RTX, VOIDmode, 0));
3702 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3703 gen_rtx_USE (VOIDmode, slot),
3706 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3707 gen_rtx_CLOBBER (VOIDmode,
3712 val = force_operand (XEXP (slot, 0), NULL_RTX);
3716 argvec[count].value = val;
3717 argvec[count].mode = mode;
3719 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3721 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3722 argvec[count].partial
3723 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3725 argvec[count].partial = 0;
3728 locate_and_pad_parm (mode, NULL_TREE,
3729 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3732 argvec[count].reg != 0,
3734 NULL_TREE, &args_size, &argvec[count].offset,
3735 &argvec[count].size, &alignment_pad);
3737 if (argvec[count].size.var)
3740 if (reg_parm_stack_space == 0 && argvec[count].partial)
3741 argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3743 if (argvec[count].reg == 0 || argvec[count].partial != 0
3744 || reg_parm_stack_space > 0)
3745 args_size.constant += argvec[count].size.constant;
3747 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3750 #ifdef FINAL_REG_PARM_STACK_SPACE
3751 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3754 /* If this machine requires an external definition for library
3755 functions, write one out. */
3756 assemble_external_libcall (fun);
3758 original_args_size = args_size;
3759 args_size.constant = (((args_size.constant
3760 + stack_pointer_delta
3764 - stack_pointer_delta);
3766 args_size.constant = MAX (args_size.constant,
3767 reg_parm_stack_space);
3769 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3770 args_size.constant -= reg_parm_stack_space;
3773 if (args_size.constant > current_function_outgoing_args_size)
3774 current_function_outgoing_args_size = args_size.constant;
3776 if (ACCUMULATE_OUTGOING_ARGS)
3778 /* Since the stack pointer will never be pushed, it is possible for
3779 the evaluation of a parm to clobber something we have already
3780 written to the stack. Since most function calls on RISC machines
3781 do not use the stack, this is uncommon, but must work correctly.
3783 Therefore, we save any area of the stack that was already written
3784 and that we are using. Here we set up to do this by making a new
3785 stack usage map from the old one.
3787 Another approach might be to try to reorder the argument
3788 evaluations to avoid this conflicting stack usage. */
3790 needed = args_size.constant;
3792 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3793 /* Since we will be writing into the entire argument area, the
3794 map must be allocated for its entire size, not just the part that
3795 is the responsibility of the caller. */
3796 needed += reg_parm_stack_space;
3799 #ifdef ARGS_GROW_DOWNWARD
3800 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3803 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3806 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3808 if (initial_highest_arg_in_use)
3809 memcpy (stack_usage_map, initial_stack_usage_map,
3810 initial_highest_arg_in_use);
3812 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3813 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3814 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3817 /* We must be careful to use virtual regs before they're instantiated,
3818 and real regs afterwards. Loop optimization, for example, can create
3819 new libcalls after we've instantiated the virtual regs, and if we
3820 use virtuals anyway, they won't match the rtl patterns. */
3822 if (virtuals_instantiated)
3823 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3825 argblock = virtual_outgoing_args_rtx;
3830 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3833 /* If we push args individually in reverse order, perform stack alignment
3834 before the first push (the last arg). */
3835 if (argblock == 0 && PUSH_ARGS_REVERSED)
3836 anti_adjust_stack (GEN_INT (args_size.constant
3837 - original_args_size.constant));
3839 if (PUSH_ARGS_REVERSED)
3850 #ifdef REG_PARM_STACK_SPACE
3851 if (ACCUMULATE_OUTGOING_ARGS)
3853 /* The argument list is the property of the called routine and it
3854 may clobber it. If the fixed area has been used for previous
3855 parameters, we must save and restore it.
3857 Here we compute the boundary of the that needs to be saved, if any. */
3859 #ifdef ARGS_GROW_DOWNWARD
3860 for (count = 0; count < reg_parm_stack_space + 1; count++)
3862 for (count = 0; count < reg_parm_stack_space; count++)
3865 if (count >= highest_outgoing_arg_in_use
3866 || stack_usage_map[count] == 0)
3869 if (low_to_save == -1)
3870 low_to_save = count;
3872 high_to_save = count;
3875 if (low_to_save >= 0)
3877 int num_to_save = high_to_save - low_to_save + 1;
3878 enum machine_mode save_mode
3879 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
3882 /* If we don't have the required alignment, must do this in BLKmode. */
3883 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
3884 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
3885 save_mode = BLKmode;
3887 #ifdef ARGS_GROW_DOWNWARD
3888 stack_area = gen_rtx_MEM (save_mode,
3889 memory_address (save_mode,
3890 plus_constant (argblock,
3893 stack_area = gen_rtx_MEM (save_mode,
3894 memory_address (save_mode,
3895 plus_constant (argblock,
3898 if (save_mode == BLKmode)
3900 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
3901 set_mem_align (save_area, PARM_BOUNDARY);
3902 emit_block_move (save_area, stack_area, GEN_INT (num_to_save),
3903 BLOCK_OP_CALL_PARM);
3907 save_area = gen_reg_rtx (save_mode);
3908 emit_move_insn (save_area, stack_area);
3914 /* Push the args that need to be pushed. */
3916 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3917 are to be pushed. */
3918 for (count = 0; count < nargs; count++, argnum += inc)
3920 enum machine_mode mode = argvec[argnum].mode;
3921 rtx val = argvec[argnum].value;
3922 rtx reg = argvec[argnum].reg;
3923 int partial = argvec[argnum].partial;
3924 int lower_bound = 0, upper_bound = 0, i;
3926 if (! (reg != 0 && partial == 0))
3928 if (ACCUMULATE_OUTGOING_ARGS)
3930 /* If this is being stored into a pre-allocated, fixed-size,
3931 stack area, save any previous data at that location. */
3933 #ifdef ARGS_GROW_DOWNWARD
3934 /* stack_slot is negative, but we want to index stack_usage_map
3935 with positive values. */
3936 upper_bound = -argvec[argnum].offset.constant + 1;
3937 lower_bound = upper_bound - argvec[argnum].size.constant;
3939 lower_bound = argvec[argnum].offset.constant;
3940 upper_bound = lower_bound + argvec[argnum].size.constant;
3943 for (i = lower_bound; i < upper_bound; i++)
3944 if (stack_usage_map[i]
3945 /* Don't store things in the fixed argument area at this
3946 point; it has already been saved. */
3947 && i > reg_parm_stack_space)
3950 if (i != upper_bound)
3952 /* We need to make a save area. See what mode we can make
3954 enum machine_mode save_mode
3955 = mode_for_size (argvec[argnum].size.constant
3963 plus_constant (argblock,
3964 argvec[argnum].offset.constant)));
3965 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3967 emit_move_insn (argvec[argnum].save_area, stack_area);
3971 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3972 partial, reg, 0, argblock,
3973 GEN_INT (argvec[argnum].offset.constant),
3974 reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3976 /* Now mark the segment we just used. */
3977 if (ACCUMULATE_OUTGOING_ARGS)
3978 for (i = lower_bound; i < upper_bound; i++)
3979 stack_usage_map[i] = 1;
3985 /* If we pushed args in forward order, perform stack alignment
3986 after pushing the last arg. */
3987 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3988 anti_adjust_stack (GEN_INT (args_size.constant
3989 - original_args_size.constant));
3991 if (PUSH_ARGS_REVERSED)
3996 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
3998 /* Now load any reg parms into their regs. */
4000 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4001 are to be pushed. */
4002 for (count = 0; count < nargs; count++, argnum += inc)
4004 rtx val = argvec[argnum].value;
4005 rtx reg = argvec[argnum].reg;
4006 int partial = argvec[argnum].partial;
4008 /* Handle calls that pass values in multiple non-contiguous
4009 locations. The PA64 has examples of this for library calls. */
4010 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4011 emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
4012 else if (reg != 0 && partial == 0)
4013 emit_move_insn (reg, val);
4018 /* Any regs containing parms remain in use through the call. */
4019 for (count = 0; count < nargs; count++)
4021 rtx reg = argvec[count].reg;
4022 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4023 use_group_regs (&call_fusage, reg);
4025 use_reg (&call_fusage, reg);
4028 /* Pass the function the address in which to return a structure value. */
4029 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4031 emit_move_insn (struct_value_rtx,
4033 force_operand (XEXP (mem_value, 0),
4035 if (GET_CODE (struct_value_rtx) == REG)
4036 use_reg (&call_fusage, struct_value_rtx);
4039 /* Don't allow popping to be deferred, since then
4040 cse'ing of library calls could delete a call and leave the pop. */
4042 valreg = (mem_value == 0 && outmode != VOIDmode
4043 ? hard_libcall_value (outmode) : NULL_RTX);
4045 /* Stack must be properly aligned now. */
4046 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4049 before_call = get_last_insn ();
4051 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4052 will set inhibit_defer_pop to that value. */
4053 /* The return type is needed to decide how many bytes the function pops.
4054 Signedness plays no role in that, so for simplicity, we pretend it's
4055 always signed. We also assume that the list of arguments passed has
4056 no impact, so we pretend it is unknown. */
4059 get_identifier (XSTR (orgfun, 0)),
4060 build_function_type (tfom, NULL_TREE),
4061 original_args_size.constant, args_size.constant,
4063 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4065 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4067 /* For calls to `setjmp', etc., inform flow.c it should complain
4068 if nonvolatile values are live. For functions that cannot return,
4069 inform flow that control does not fall through. */
4071 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4073 /* The barrier note must be emitted
4074 immediately after the CALL_INSN. Some ports emit more than
4075 just a CALL_INSN above, so we must search for it here. */
4077 rtx last = get_last_insn ();
4078 while (GET_CODE (last) != CALL_INSN)
4080 last = PREV_INSN (last);
4081 /* There was no CALL_INSN? */
4082 if (last == before_call)
4086 emit_barrier_after (last);
4089 /* Now restore inhibit_defer_pop to its actual original value. */
4092 /* If call is cse'able, make appropriate pair of reg-notes around it.
4093 Test valreg so we don't crash; may safely ignore `const'
4094 if return type is void. Disable for PARALLEL return values, because
4095 we have no way to move such values into a pseudo register. */
4096 if (flags & ECF_LIBCALL_BLOCK)
4100 if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
4102 insns = get_insns ();
4109 rtx temp = gen_reg_rtx (GET_MODE (valreg));
4112 /* Construct an "equal form" for the value which mentions all the
4113 arguments in order as well as the function name. */
4114 for (i = 0; i < nargs; i++)
4115 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4116 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4118 insns = get_insns ();
4121 if (flags & ECF_PURE)
4122 note = gen_rtx_EXPR_LIST (VOIDmode,
4123 gen_rtx_USE (VOIDmode,
4124 gen_rtx_MEM (BLKmode,
4125 gen_rtx_SCRATCH (VOIDmode))),
4128 emit_libcall_block (insns, temp, valreg, note);
4135 /* Copy the value to the right place. */
4136 if (outmode != VOIDmode && retval)
4142 if (value != mem_value)
4143 emit_move_insn (value, mem_value);
4145 else if (value != 0)
4146 emit_move_insn (value, valreg);
4151 if (ACCUMULATE_OUTGOING_ARGS)
4153 #ifdef REG_PARM_STACK_SPACE
4156 enum machine_mode save_mode = GET_MODE (save_area);
4157 #ifdef ARGS_GROW_DOWNWARD
4159 = gen_rtx_MEM (save_mode,
4160 memory_address (save_mode,
4161 plus_constant (argblock,
4165 = gen_rtx_MEM (save_mode,
4166 memory_address (save_mode,
4167 plus_constant (argblock, low_to_save)));
4170 set_mem_align (stack_area, PARM_BOUNDARY);
4171 if (save_mode != BLKmode)
4172 emit_move_insn (stack_area, save_area);
4174 emit_block_move (stack_area, save_area,
4175 GEN_INT (high_to_save - low_to_save + 1),
4176 BLOCK_OP_CALL_PARM);
4180 /* If we saved any argument areas, restore them. */
4181 for (count = 0; count < nargs; count++)
4182 if (argvec[count].save_area)
4184 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4186 = gen_rtx_MEM (save_mode,
4189 plus_constant (argblock,
4190 argvec[count].offset.constant)));
4192 emit_move_insn (stack_area, argvec[count].save_area);
4195 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4196 stack_usage_map = initial_stack_usage_map;
4203 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4204 (emitting the queue unless NO_QUEUE is nonzero),
4205 for a value of mode OUTMODE,
4206 with NARGS different arguments, passed as alternating rtx values
4207 and machine_modes to convert them to.
4208 The rtx values should have been passed through protect_from_queue already.
4210 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4211 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4212 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4213 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4214 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4215 or other LCT_ value for other types of library calls. */
4218 emit_library_call VPARAMS((rtx orgfun, enum libcall_type fn_type,
4219 enum machine_mode outmode, int nargs, ...))
4222 VA_FIXEDARG (p, rtx, orgfun);
4223 VA_FIXEDARG (p, int, fn_type);
4224 VA_FIXEDARG (p, enum machine_mode, outmode);
4225 VA_FIXEDARG (p, int, nargs);
4227 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4232 /* Like emit_library_call except that an extra argument, VALUE,
4233 comes second and says where to store the result.
4234 (If VALUE is zero, this function chooses a convenient way
4235 to return the value.
4237 This function returns an rtx for where the value is to be found.
4238 If VALUE is nonzero, VALUE is returned. */
4241 emit_library_call_value VPARAMS((rtx orgfun, rtx value,
4242 enum libcall_type fn_type,
4243 enum machine_mode outmode, int nargs, ...))
4248 VA_FIXEDARG (p, rtx, orgfun);
4249 VA_FIXEDARG (p, rtx, value);
4250 VA_FIXEDARG (p, int, fn_type);
4251 VA_FIXEDARG (p, enum machine_mode, outmode);
4252 VA_FIXEDARG (p, int, nargs);
4254 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4262 /* Store a single argument for a function call
4263 into the register or memory area where it must be passed.
4264 *ARG describes the argument value and where to pass it.
4266 ARGBLOCK is the address of the stack-block for all the arguments,
4267 or 0 on a machine where arguments are pushed individually.
4269 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4270 so must be careful about how the stack is used.
4272 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4273 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4274 that we need not worry about saving and restoring the stack.
4276 FNDECL is the declaration of the function we are calling.
4278 Return nonzero if this arg should cause sibcall failure,
4282 store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
4283 struct arg_data *arg;
4286 int variable_size ATTRIBUTE_UNUSED;
4287 int reg_parm_stack_space;
4289 tree pval = arg->tree_value;
4293 int i, lower_bound = 0, upper_bound = 0;
4294 int sibcall_failure = 0;
4296 if (TREE_CODE (pval) == ERROR_MARK)
4299 /* Push a new temporary level for any temporaries we make for
4303 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4305 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4306 save any previous data at that location. */
4307 if (argblock && ! variable_size && arg->stack)
4309 #ifdef ARGS_GROW_DOWNWARD
4310 /* stack_slot is negative, but we want to index stack_usage_map
4311 with positive values. */
4312 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4313 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4317 lower_bound = upper_bound - arg->size.constant;
4319 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4320 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4324 upper_bound = lower_bound + arg->size.constant;
4327 for (i = lower_bound; i < upper_bound; i++)
4328 if (stack_usage_map[i]
4329 /* Don't store things in the fixed argument area at this point;
4330 it has already been saved. */
4331 && i > reg_parm_stack_space)
4334 if (i != upper_bound)
4336 /* We need to make a save area. See what mode we can make it. */
4337 enum machine_mode save_mode
4338 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
4340 = gen_rtx_MEM (save_mode,
4341 memory_address (save_mode,
4342 XEXP (arg->stack_slot, 0)));
4344 if (save_mode == BLKmode)
4346 tree ot = TREE_TYPE (arg->tree_value);
4347 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4348 | TYPE_QUAL_CONST));
4350 arg->save_area = assign_temp (nt, 0, 1, 1);
4351 preserve_temp_slots (arg->save_area);
4352 emit_block_move (validize_mem (arg->save_area), stack_area,
4353 expr_size (arg->tree_value),
4354 BLOCK_OP_CALL_PARM);
4358 arg->save_area = gen_reg_rtx (save_mode);
4359 emit_move_insn (arg->save_area, stack_area);
4363 /* Now that we have saved any slots that will be overwritten by this
4364 store, mark all slots this store will use. We must do this before
4365 we actually expand the argument since the expansion itself may
4366 trigger library calls which might need to use the same stack slot. */
4367 if (argblock && ! variable_size && arg->stack)
4368 for (i = lower_bound; i < upper_bound; i++)
4369 stack_usage_map[i] = 1;
4372 /* If this isn't going to be placed on both the stack and in registers,
4373 set up the register and number of words. */
4374 if (! arg->pass_on_stack)
4376 if (flags & ECF_SIBCALL)
4377 reg = arg->tail_call_reg;
4380 partial = arg->partial;
4383 if (reg != 0 && partial == 0)
4384 /* Being passed entirely in a register. We shouldn't be called in
4388 /* If this arg needs special alignment, don't load the registers
4390 if (arg->n_aligned_regs != 0)
4393 /* If this is being passed partially in a register, we can't evaluate
4394 it directly into its stack slot. Otherwise, we can. */
4395 if (arg->value == 0)
4397 /* stack_arg_under_construction is nonzero if a function argument is
4398 being evaluated directly into the outgoing argument list and
4399 expand_call must take special action to preserve the argument list
4400 if it is called recursively.
4402 For scalar function arguments stack_usage_map is sufficient to
4403 determine which stack slots must be saved and restored. Scalar
4404 arguments in general have pass_on_stack == 0.
4406 If this argument is initialized by a function which takes the
4407 address of the argument (a C++ constructor or a C function
4408 returning a BLKmode structure), then stack_usage_map is
4409 insufficient and expand_call must push the stack around the
4410 function call. Such arguments have pass_on_stack == 1.
4412 Note that it is always safe to set stack_arg_under_construction,
4413 but this generates suboptimal code if set when not needed. */
4415 if (arg->pass_on_stack)
4416 stack_arg_under_construction++;
4418 arg->value = expand_expr (pval,
4420 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4421 ? NULL_RTX : arg->stack,
4424 /* If we are promoting object (or for any other reason) the mode
4425 doesn't agree, convert the mode. */
4427 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4428 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4429 arg->value, arg->unsignedp);
4431 if (arg->pass_on_stack)
4432 stack_arg_under_construction--;
4435 /* Don't allow anything left on stack from computation
4436 of argument to alloca. */
4437 if (flags & ECF_MAY_BE_ALLOCA)
4438 do_pending_stack_adjust ();
4440 if (arg->value == arg->stack)
4441 /* If the value is already in the stack slot, we are done. */
4443 else if (arg->mode != BLKmode)
4447 /* Argument is a scalar, not entirely passed in registers.
4448 (If part is passed in registers, arg->partial says how much
4449 and emit_push_insn will take care of putting it there.)
4451 Push it, and if its size is less than the
4452 amount of space allocated to it,
4453 also bump stack pointer by the additional space.
4454 Note that in C the default argument promotions
4455 will prevent such mismatches. */
4457 size = GET_MODE_SIZE (arg->mode);
4458 /* Compute how much space the push instruction will push.
4459 On many machines, pushing a byte will advance the stack
4460 pointer by a halfword. */
4461 #ifdef PUSH_ROUNDING
4462 size = PUSH_ROUNDING (size);
4466 /* Compute how much space the argument should get:
4467 round up to a multiple of the alignment for arguments. */
4468 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4469 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4470 / (PARM_BOUNDARY / BITS_PER_UNIT))
4471 * (PARM_BOUNDARY / BITS_PER_UNIT));
4473 /* This isn't already where we want it on the stack, so put it there.
4474 This can either be done with push or copy insns. */
4475 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4476 PARM_BOUNDARY, partial, reg, used - size, argblock,
4477 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4478 ARGS_SIZE_RTX (arg->alignment_pad));
4480 /* Unless this is a partially-in-register argument, the argument is now
4483 arg->value = arg->stack;
4487 /* BLKmode, at least partly to be pushed. */
4489 unsigned int parm_align;
4493 /* Pushing a nonscalar.
4494 If part is passed in registers, PARTIAL says how much
4495 and emit_push_insn will take care of putting it there. */
4497 /* Round its size up to a multiple
4498 of the allocation unit for arguments. */
4500 if (arg->size.var != 0)
4503 size_rtx = ARGS_SIZE_RTX (arg->size);
4507 /* PUSH_ROUNDING has no effect on us, because
4508 emit_push_insn for BLKmode is careful to avoid it. */
4509 excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4510 + partial * UNITS_PER_WORD);
4511 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4512 NULL_RTX, TYPE_MODE (sizetype), 0);
4515 /* Some types will require stricter alignment, which will be
4516 provided for elsewhere in argument layout. */
4517 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4519 /* When an argument is padded down, the block is aligned to
4520 PARM_BOUNDARY, but the actual argument isn't. */
4521 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4524 parm_align = BITS_PER_UNIT;
4527 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4528 parm_align = MIN (parm_align, excess_align);
4532 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4534 /* emit_push_insn might not work properly if arg->value and
4535 argblock + arg->offset areas overlap. */
4539 if (XEXP (x, 0) == current_function_internal_arg_pointer
4540 || (GET_CODE (XEXP (x, 0)) == PLUS
4541 && XEXP (XEXP (x, 0), 0) ==
4542 current_function_internal_arg_pointer
4543 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4545 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4546 i = INTVAL (XEXP (XEXP (x, 0), 1));
4548 /* expand_call should ensure this */
4549 if (arg->offset.var || GET_CODE (size_rtx) != CONST_INT)
4552 if (arg->offset.constant > i)
4554 if (arg->offset.constant < i + INTVAL (size_rtx))
4555 sibcall_failure = 1;
4557 else if (arg->offset.constant < i)
4559 if (i < arg->offset.constant + INTVAL (size_rtx))
4560 sibcall_failure = 1;
4565 /* Special handling is required if part of the parameter lies in the
4566 register parameter area. The argument may be copied into the stack
4567 slot using memcpy(), but the original contents of the register
4568 parameter area will be restored after the memcpy() call.
4570 To ensure that the part that lies in the register parameter area
4571 is copied correctly, we emit a separate push for that part. This
4572 push should be small enough to avoid a call to memcpy(). */
4573 #ifndef STACK_PARMS_IN_REG_PARM_AREA
4574 if (arg->reg && arg->pass_on_stack)
4579 if (arg->offset.constant < reg_parm_stack_space && arg->offset.var)
4580 error ("variable offset is passed partially in stack and in reg");
4581 else if (arg->offset.constant < reg_parm_stack_space && arg->size.var)
4582 error ("variable size is passed partially in stack and in reg");
4583 else if (arg->offset.constant < reg_parm_stack_space
4584 && ((arg->offset.constant + arg->size.constant)
4585 > reg_parm_stack_space))
4587 rtx size_rtx1 = GEN_INT (reg_parm_stack_space - arg->offset.constant);
4588 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx1,
4589 parm_align, partial, reg, excess, argblock,
4590 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4591 ARGS_SIZE_RTX (arg->alignment_pad));
4596 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4597 parm_align, partial, reg, excess, argblock,
4598 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4599 ARGS_SIZE_RTX (arg->alignment_pad));
4601 /* Unless this is a partially-in-register argument, the argument is now
4604 ??? Unlike the case above, in which we want the actual
4605 address of the data, so that we can load it directly into a
4606 register, here we want the address of the stack slot, so that
4607 it's properly aligned for word-by-word copying or something
4608 like that. It's not clear that this is always correct. */
4610 arg->value = arg->stack_slot;
4613 /* Once we have pushed something, pops can't safely
4614 be deferred during the rest of the arguments. */
4617 /* ANSI doesn't require a sequence point here,
4618 but PCC has one, so this will avoid some problems. */
4621 /* Free any temporary slots made in processing this argument. Show
4622 that we might have taken the address of something and pushed that
4624 preserve_temp_slots (NULL_RTX);
4628 return sibcall_failure;