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 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
30 #include "insn-flags.h"
35 #if !defined FUNCTION_OK_FOR_SIBCALL
36 #define FUNCTION_OK_FOR_SIBCALL(DECL) 1
39 #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY
40 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
43 /* Decide whether a function's arguments should be processed
44 from first to last or from last to first.
46 They should if the stack and args grow in opposite directions, but
47 only if we have push insns. */
51 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
52 #define PUSH_ARGS_REVERSED /* If it's last to first */
57 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
58 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
60 /* Data structure and subroutines used within expand_call. */
64 /* Tree node for this argument. */
66 /* Mode for value; TYPE_MODE unless promoted. */
67 enum machine_mode mode;
68 /* Current RTL value for argument, or 0 if it isn't precomputed. */
70 /* Initially-compute RTL value for argument; only for const functions. */
72 /* Register to pass this argument in, 0 if passed on stack, or an
73 PARALLEL if the arg is to be copied into multiple non-contiguous
76 /* If REG was promoted from the actual mode of the argument expression,
77 indicates whether the promotion is sign- or zero-extended. */
79 /* Number of registers to use. 0 means put the whole arg in registers.
80 Also 0 if not passed in registers. */
82 /* Non-zero if argument must be passed on stack.
83 Note that some arguments may be passed on the stack
84 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
85 pass_on_stack identifies arguments that *cannot* go in registers. */
87 /* Offset of this argument from beginning of stack-args. */
88 struct args_size offset;
89 /* Similar, but offset to the start of the stack slot. Different from
90 OFFSET if this arg pads downward. */
91 struct args_size slot_offset;
92 /* Size of this argument on the stack, rounded up for any padding it gets,
93 parts of the argument passed in registers do not count.
94 If REG_PARM_STACK_SPACE is defined, then register parms
95 are counted here as well. */
96 struct args_size size;
97 /* Location on the stack at which parameter should be stored. The store
98 has already been done if STACK == VALUE. */
100 /* Location on the stack of the start of this argument slot. This can
101 differ from STACK if this arg pads downward. This location is known
102 to be aligned to FUNCTION_ARG_BOUNDARY. */
104 #ifdef ACCUMULATE_OUTGOING_ARGS
105 /* Place that this stack area has been saved, if needed. */
108 /* If an argument's alignment does not permit direct copying into registers,
109 copy in smaller-sized pieces into pseudos. These are stored in a
110 block pointed to by this field. The next field says how many
111 word-sized pseudos we made. */
114 /* The amount that the stack pointer needs to be adjusted to
115 force alignment for the next argument. */
116 struct args_size alignment_pad;
119 #ifdef ACCUMULATE_OUTGOING_ARGS
120 /* A vector of one char per byte of stack space. A byte if non-zero if
121 the corresponding stack location has been used.
122 This vector is used to prevent a function call within an argument from
123 clobbering any stack already set up. */
124 static char *stack_usage_map;
126 /* Size of STACK_USAGE_MAP. */
127 static int highest_outgoing_arg_in_use;
129 /* stack_arg_under_construction is nonzero when an argument may be
130 initialized with a constructor call (including a C function that
131 returns a BLKmode struct) and expand_call must take special action
132 to make sure the object being constructed does not overlap the
133 argument list for the constructor call. */
134 int stack_arg_under_construction;
137 static int calls_function PARAMS ((tree, int));
138 static int calls_function_1 PARAMS ((tree, int));
140 #define ECF_IS_CONST 1
141 #define ECF_NOTHROW 2
142 #define ECF_SIBCALL 4
143 static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
144 HOST_WIDE_INT, HOST_WIDE_INT, rtx,
145 rtx, int, rtx, int));
146 static void precompute_register_parameters PARAMS ((int,
149 static void store_one_arg PARAMS ((struct arg_data *, rtx, int, int,
151 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
153 static int finalize_must_preallocate PARAMS ((int, int,
155 struct args_size *));
156 static void precompute_arguments PARAMS ((int, int, int,
158 struct args_size *));
159 static int compute_argument_block_size PARAMS ((int,
162 static void initialize_argument_information PARAMS ((int,
169 static void compute_argument_addresses PARAMS ((struct arg_data *,
171 static rtx rtx_for_function_call PARAMS ((tree, tree));
172 static void load_register_parameters PARAMS ((struct arg_data *,
174 static int libfunc_nothrow PARAMS ((rtx));
175 static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx, int,
179 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
180 static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *));
181 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
184 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
187 If WHICH is 0, return 1 if EXP contains a call to any function.
188 Actually, we only need return 1 if evaluating EXP would require pushing
189 arguments on the stack, but that is too difficult to compute, so we just
190 assume any function call might require the stack. */
192 static tree calls_function_save_exprs;
195 calls_function (exp, which)
200 calls_function_save_exprs = 0;
201 val = calls_function_1 (exp, which);
202 calls_function_save_exprs = 0;
207 calls_function_1 (exp, which)
212 enum tree_code code = TREE_CODE (exp);
213 int type = TREE_CODE_CLASS (code);
214 int length = tree_code_length[(int) code];
216 /* If this code is language-specific, we don't know what it will do. */
217 if ((int) code >= NUM_TREE_CODES)
220 /* Only expressions and references can contain calls. */
221 if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r'
230 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
231 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
234 tree fndecl = TREE_OPERAND (TREE_OPERAND (exp, 0), 0);
236 if ((DECL_BUILT_IN (fndecl)
237 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
238 && DECL_FUNCTION_CODE (fndecl) == BUILT_IN_ALLOCA)
239 || (DECL_SAVED_INSNS (fndecl)
240 && DECL_SAVED_INSNS (fndecl)->calls_alloca))
244 /* Third operand is RTL. */
249 if (SAVE_EXPR_RTL (exp) != 0)
251 if (value_member (exp, calls_function_save_exprs))
253 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
254 calls_function_save_exprs);
255 return (TREE_OPERAND (exp, 0) != 0
256 && calls_function_1 (TREE_OPERAND (exp, 0), which));
262 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
263 if (DECL_INITIAL (local) != 0
264 && calls_function_1 (DECL_INITIAL (local), which))
268 register tree subblock;
270 for (subblock = BLOCK_SUBBLOCKS (exp);
272 subblock = TREE_CHAIN (subblock))
273 if (calls_function_1 (subblock, which))
278 case METHOD_CALL_EXPR:
282 case WITH_CLEANUP_EXPR:
293 for (i = 0; i < length; i++)
294 if (TREE_OPERAND (exp, i) != 0
295 && calls_function_1 (TREE_OPERAND (exp, i), which))
301 /* Force FUNEXP into a form suitable for the address of a CALL,
302 and return that as an rtx. Also load the static chain register
303 if FNDECL is a nested function.
305 CALL_FUSAGE points to a variable holding the prospective
306 CALL_INSN_FUNCTION_USAGE information. */
309 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen)
315 rtx static_chain_value = 0;
317 funexp = protect_from_queue (funexp, 0);
320 /* Get possible static chain value for nested function in C. */
321 static_chain_value = lookup_static_chain (fndecl);
323 /* Make a valid memory address and copy constants thru pseudo-regs,
324 but not for a constant address if -fno-function-cse. */
325 if (GET_CODE (funexp) != SYMBOL_REF)
326 /* If we are using registers for parameters, force the
327 function address into a register now. */
328 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
329 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
330 : memory_address (FUNCTION_MODE, funexp));
333 #ifndef NO_FUNCTION_CSE
334 if (optimize && ! flag_no_function_cse)
335 #ifdef NO_RECURSIVE_FUNCTION_CSE
336 if (fndecl != current_function_decl)
338 funexp = force_reg (Pmode, funexp);
342 if (static_chain_value != 0)
344 emit_move_insn (static_chain_rtx, static_chain_value);
346 if (GET_CODE (static_chain_rtx) == REG)
347 use_reg (call_fusage, static_chain_rtx);
353 /* Generate instructions to call function FUNEXP,
354 and optionally pop the results.
355 The CALL_INSN is the first insn generated.
357 FNDECL is the declaration node of the function. This is given to the
358 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
360 FUNTYPE is the data type of the function. This is given to the macro
361 RETURN_POPS_ARGS to determine whether this function pops its own args.
362 We used to allow an identifier for library functions, but that doesn't
363 work when the return type is an aggregate type and the calling convention
364 says that the pointer to this aggregate is to be popped by the callee.
366 STACK_SIZE is the number of bytes of arguments on the stack,
367 ROUNDED_STACK_SIZE is that number rounded up to
368 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
369 both to put into the call insn and to generate explicit popping
372 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
373 It is zero if this call doesn't want a structure value.
375 NEXT_ARG_REG is the rtx that results from executing
376 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
377 just after all the args have had their registers assigned.
378 This could be whatever you like, but normally it is the first
379 arg-register beyond those used for args in this call,
380 or 0 if all the arg-registers are used in this call.
381 It is passed on to `gen_call' so you can put this info in the call insn.
383 VALREG is a hard register in which a value is returned,
384 or 0 if the call does not return a value.
386 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
387 the args to this call were processed.
388 We restore `inhibit_defer_pop' to that value.
390 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
391 denote registers used by the called function.
393 IS_CONST is true if this is a `const' call. */
396 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
397 struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
398 call_fusage, ecf_flags)
400 tree fndecl ATTRIBUTE_UNUSED;
401 tree funtype ATTRIBUTE_UNUSED;
402 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
403 HOST_WIDE_INT rounded_stack_size;
404 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
407 int old_inhibit_defer_pop;
411 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
412 #if defined (HAVE_call) && defined (HAVE_call_value)
413 rtx struct_value_size_rtx = GEN_INT (struct_value_size);
416 #ifndef ACCUMULATE_OUTGOING_ARGS
417 int already_popped = 0;
418 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
421 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
422 and we don't want to load it into a register as an optimization,
423 because prepare_call_address already did it if it should be done. */
424 if (GET_CODE (funexp) != SYMBOL_REF)
425 funexp = memory_address (FUNCTION_MODE, funexp);
427 #ifndef ACCUMULATE_OUTGOING_ARGS
428 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
429 if ((ecf_flags & ECF_SIBCALL)
430 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
431 && (RETURN_POPS_ARGS (fndecl, funtype, stack_size) > 0
434 rtx n_pop = GEN_INT (RETURN_POPS_ARGS (fndecl, funtype, stack_size));
437 /* If this subroutine pops its own args, record that in the call insn
438 if possible, for the sake of frame pointer elimination. */
441 pat = gen_sibcall_value_pop (valreg,
442 gen_rtx_MEM (FUNCTION_MODE, funexp),
443 rounded_stack_size_rtx, next_arg_reg,
446 pat = gen_sibcall_pop (gen_rtx_MEM (FUNCTION_MODE, funexp),
447 rounded_stack_size_rtx, next_arg_reg, n_pop);
449 emit_call_insn (pat);
455 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
456 /* If the target has "call" or "call_value" insns, then prefer them
457 if no arguments are actually popped. If the target does not have
458 "call" or "call_value" insns, then we must use the popping versions
459 even if the call has no arguments to pop. */
460 #if defined (HAVE_call) && defined (HAVE_call_value)
461 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
464 if (HAVE_call_pop && HAVE_call_value_pop)
467 rtx n_pop = GEN_INT (n_popped);
470 /* If this subroutine pops its own args, record that in the call insn
471 if possible, for the sake of frame pointer elimination. */
474 pat = gen_call_value_pop (valreg,
475 gen_rtx_MEM (FUNCTION_MODE, funexp),
476 rounded_stack_size_rtx, next_arg_reg, n_pop);
478 pat = gen_call_pop (gen_rtx_MEM (FUNCTION_MODE, funexp),
479 rounded_stack_size_rtx, next_arg_reg, n_pop);
481 emit_call_insn (pat);
488 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
489 if ((ecf_flags & ECF_SIBCALL)
490 && HAVE_sibcall && HAVE_sibcall_value)
493 emit_call_insn (gen_sibcall_value (valreg,
494 gen_rtx_MEM (FUNCTION_MODE, funexp),
495 rounded_stack_size_rtx,
496 next_arg_reg, NULL_RTX));
498 emit_call_insn (gen_sibcall (gen_rtx_MEM (FUNCTION_MODE, funexp),
499 rounded_stack_size_rtx, next_arg_reg,
500 struct_value_size_rtx));
505 #if defined (HAVE_call) && defined (HAVE_call_value)
506 if (HAVE_call && HAVE_call_value)
509 emit_call_insn (gen_call_value (valreg,
510 gen_rtx_MEM (FUNCTION_MODE, funexp),
511 rounded_stack_size_rtx, next_arg_reg,
514 emit_call_insn (gen_call (gen_rtx_MEM (FUNCTION_MODE, funexp),
515 rounded_stack_size_rtx, next_arg_reg,
516 struct_value_size_rtx));
522 /* Find the CALL insn we just emitted. */
523 for (call_insn = get_last_insn ();
524 call_insn && GET_CODE (call_insn) != CALL_INSN;
525 call_insn = PREV_INSN (call_insn))
531 /* Put the register usage information on the CALL. If there is already
532 some usage information, put ours at the end. */
533 if (CALL_INSN_FUNCTION_USAGE (call_insn))
537 for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0;
538 link = XEXP (link, 1))
541 XEXP (link, 1) = call_fusage;
544 CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage;
546 /* If this is a const call, then set the insn's unchanging bit. */
547 if (ecf_flags & ECF_IS_CONST)
548 CONST_CALL_P (call_insn) = 1;
550 /* If this call can't throw, attach a REG_EH_REGION reg note to that
552 if (ecf_flags & ECF_NOTHROW)
553 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
554 REG_NOTES (call_insn));
556 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
558 /* Restore this now, so that we do defer pops for this call's args
559 if the context of the call as a whole permits. */
560 inhibit_defer_pop = old_inhibit_defer_pop;
562 #ifndef ACCUMULATE_OUTGOING_ARGS
563 /* If returning from the subroutine does not automatically pop the args,
564 we need an instruction to pop them sooner or later.
565 Perhaps do it now; perhaps just record how much space to pop later.
567 If returning from the subroutine does pop the args, indicate that the
568 stack pointer will be changed. */
570 /* The space for the args is no longer waiting for the call; either it
571 was popped by the call, or it'll be popped below. */
572 arg_space_so_far -= rounded_stack_size;
577 CALL_INSN_FUNCTION_USAGE (call_insn)
578 = gen_rtx_EXPR_LIST (VOIDmode,
579 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
580 CALL_INSN_FUNCTION_USAGE (call_insn));
581 rounded_stack_size -= n_popped;
582 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
585 if (rounded_stack_size != 0)
587 if (flag_defer_pop && inhibit_defer_pop == 0
588 && !(ecf_flags & ECF_IS_CONST))
589 pending_stack_adjust += rounded_stack_size;
591 adjust_stack (rounded_stack_size_rtx);
596 /* Determine if the function identified by NAME and FNDECL is one with
597 special properties we wish to know about.
599 For example, if the function might return more than one time (setjmp), then
600 set RETURNS_TWICE to a nonzero value.
602 Similarly set IS_LONGJMP for if the function is in the longjmp family.
604 Set IS_MALLOC for any of the standard memory allocation functions which
605 allocate from the heap.
607 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
608 space from the stack such as alloca. */
611 special_function_p (fndecl, returns_twice, is_longjmp, fork_or_exec,
612 is_malloc, may_be_alloca)
625 /* The function decl may have the `malloc' attribute. */
626 *is_malloc = fndecl && DECL_IS_MALLOC (fndecl);
629 && fndecl && DECL_NAME (fndecl)
630 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
631 /* Exclude functions not at the file scope, or not `extern',
632 since they are not the magic functions we would otherwise
634 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
636 char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
639 /* We assume that alloca will always be called by name. It
640 makes no sense to pass it as a pointer-to-function to
641 anything that does not understand its behavior. */
643 = (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
645 && ! strcmp (name, "alloca"))
646 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
648 && ! strcmp (name, "__builtin_alloca"))));
650 /* Disregard prefix _, __ or __x. */
653 if (name[1] == '_' && name[2] == 'x')
655 else if (name[1] == '_')
665 && (! strcmp (tname, "setjmp")
666 || ! strcmp (tname, "setjmp_syscall")))
668 && ! strcmp (tname, "sigsetjmp"))
670 && ! strcmp (tname, "savectx")));
672 && ! strcmp (tname, "siglongjmp"))
675 else if ((tname[0] == 'q' && tname[1] == 's'
676 && ! strcmp (tname, "qsetjmp"))
677 || (tname[0] == 'v' && tname[1] == 'f'
678 && ! strcmp (tname, "vfork")))
681 else if (tname[0] == 'l' && tname[1] == 'o'
682 && ! strcmp (tname, "longjmp"))
685 else if ((tname[0] == 'f' && tname[1] == 'o'
686 && ! strcmp (tname, "fork"))
687 /* Linux specific: __clone. check NAME to insist on the
688 leading underscores, to avoid polluting the ISO / POSIX
690 || (name[0] == '_' && name[1] == '_'
691 && ! strcmp (tname, "clone"))
692 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
693 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
695 || ((tname[5] == 'p' || tname[5] == 'e')
696 && tname[6] == '\0'))))
699 /* Do not add any more malloc-like functions to this list,
700 instead mark them as malloc functions using the malloc attribute.
701 Note, realloc is not suitable for attribute malloc since
702 it may return the same address across multiple calls.
703 C++ operator new is not suitable because it is not required
704 to return a unique pointer; indeed, the standard placement new
705 just returns its argument. */
706 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
707 && (! strcmp (tname, "malloc")
708 || ! strcmp (tname, "calloc")
709 || ! strcmp (tname, "strdup")))
714 /* Precompute all register parameters as described by ARGS, storing values
715 into fields within the ARGS array.
717 NUM_ACTUALS indicates the total number elements in the ARGS array.
719 Set REG_PARM_SEEN if we encounter a register parameter. */
722 precompute_register_parameters (num_actuals, args, reg_parm_seen)
724 struct arg_data *args;
731 for (i = 0; i < num_actuals; i++)
732 if (args[i].reg != 0 && ! args[i].pass_on_stack)
736 if (args[i].value == 0)
739 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
741 preserve_temp_slots (args[i].value);
744 /* ANSI doesn't require a sequence point here,
745 but PCC has one, so this will avoid some problems. */
749 /* If we are to promote the function arg to a wider mode,
752 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
754 = convert_modes (args[i].mode,
755 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
756 args[i].value, args[i].unsignedp);
758 /* If the value is expensive, and we are inside an appropriately
759 short loop, put the value into a pseudo and then put the pseudo
762 For small register classes, also do this if this call uses
763 register parameters. This is to avoid reload conflicts while
764 loading the parameters registers. */
766 if ((! (GET_CODE (args[i].value) == REG
767 || (GET_CODE (args[i].value) == SUBREG
768 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
769 && args[i].mode != BLKmode
770 && rtx_cost (args[i].value, SET) > 2
771 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
772 || preserve_subexpressions_p ()))
773 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
777 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
779 /* The argument list is the property of the called routine and it
780 may clobber it. If the fixed area has been used for previous
781 parameters, we must save and restore it. */
783 save_fixed_argument_area (reg_parm_stack_space, argblock,
784 low_to_save, high_to_save)
785 int reg_parm_stack_space;
791 rtx save_area = NULL_RTX;
793 /* Compute the boundary of the that needs to be saved, if any. */
794 #ifdef ARGS_GROW_DOWNWARD
795 for (i = 0; i < reg_parm_stack_space + 1; i++)
797 for (i = 0; i < reg_parm_stack_space; i++)
800 if (i >= highest_outgoing_arg_in_use
801 || stack_usage_map[i] == 0)
804 if (*low_to_save == -1)
810 if (*low_to_save >= 0)
812 int num_to_save = *high_to_save - *low_to_save + 1;
813 enum machine_mode save_mode
814 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
817 /* If we don't have the required alignment, must do this in BLKmode. */
818 if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode),
819 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
822 #ifdef ARGS_GROW_DOWNWARD
823 stack_area = gen_rtx_MEM (save_mode,
824 memory_address (save_mode,
825 plus_constant (argblock,
828 stack_area = gen_rtx_MEM (save_mode,
829 memory_address (save_mode,
830 plus_constant (argblock,
833 if (save_mode == BLKmode)
835 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
836 /* Cannot use emit_block_move here because it can be done by a library
837 call which in turn gets into this place again and deadly infinite
838 recursion happens. */
839 move_by_pieces (validize_mem (save_area), stack_area, num_to_save,
840 PARM_BOUNDARY / BITS_PER_UNIT);
844 save_area = gen_reg_rtx (save_mode);
845 emit_move_insn (save_area, stack_area);
852 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
858 enum machine_mode save_mode = GET_MODE (save_area);
859 #ifdef ARGS_GROW_DOWNWARD
861 = gen_rtx_MEM (save_mode,
862 memory_address (save_mode,
863 plus_constant (argblock,
867 = gen_rtx_MEM (save_mode,
868 memory_address (save_mode,
869 plus_constant (argblock,
873 if (save_mode != BLKmode)
874 emit_move_insn (stack_area, save_area);
876 /* Cannot use emit_block_move here because it can be done by a library
877 call which in turn gets into this place again and deadly infinite
878 recursion happens. */
879 move_by_pieces (stack_area, validize_mem (save_area),
880 high_to_save - low_to_save + 1,
881 PARM_BOUNDARY / BITS_PER_UNIT);
885 /* If any elements in ARGS refer to parameters that are to be passed in
886 registers, but not in memory, and whose alignment does not permit a
887 direct copy into registers. Copy the values into a group of pseudos
888 which we will later copy into the appropriate hard registers.
890 Pseudos for each unaligned argument will be stored into the array
891 args[argnum].aligned_regs. The caller is responsible for deallocating
892 the aligned_regs array if it is nonzero. */
895 store_unaligned_arguments_into_pseudos (args, num_actuals)
896 struct arg_data *args;
901 for (i = 0; i < num_actuals; i++)
902 if (args[i].reg != 0 && ! args[i].pass_on_stack
903 && args[i].mode == BLKmode
904 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
905 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
907 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
908 int big_endian_correction = 0;
910 args[i].n_aligned_regs
911 = args[i].partial ? args[i].partial
912 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
914 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
915 * args[i].n_aligned_regs);
917 /* Structures smaller than a word are aligned to the least
918 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
919 this means we must skip the empty high order bytes when
920 calculating the bit offset. */
921 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
922 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
924 for (j = 0; j < args[i].n_aligned_regs; j++)
926 rtx reg = gen_reg_rtx (word_mode);
927 rtx word = operand_subword_force (args[i].value, j, BLKmode);
928 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
929 int bitalign = TYPE_ALIGN (TREE_TYPE (args[i].tree_value));
931 args[i].aligned_regs[j] = reg;
933 /* There is no need to restrict this code to loading items
934 in TYPE_ALIGN sized hunks. The bitfield instructions can
935 load up entire word sized registers efficiently.
937 ??? This may not be needed anymore.
938 We use to emit a clobber here but that doesn't let later
939 passes optimize the instructions we emit. By storing 0 into
940 the register later passes know the first AND to zero out the
941 bitfield being set in the register is unnecessary. The store
942 of 0 will be deleted as will at least the first AND. */
944 emit_move_insn (reg, const0_rtx);
946 bytes -= bitsize / BITS_PER_UNIT;
947 store_bit_field (reg, bitsize, big_endian_correction, word_mode,
948 extract_bit_field (word, bitsize, 0, 1,
951 bitalign / BITS_PER_UNIT,
953 bitalign / BITS_PER_UNIT, BITS_PER_WORD);
958 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
961 NUM_ACTUALS is the total number of parameters.
963 N_NAMED_ARGS is the total number of named arguments.
965 FNDECL is the tree code for the target of this call (if known)
967 ARGS_SO_FAR holds state needed by the target to know where to place
970 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
971 for arguments which are passed in registers.
973 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
974 and may be modified by this routine.
976 OLD_PENDING_ADJ, MUST_PREALLOCATE and IS_CONST are pointers to integer
977 flags which may may be modified by this routine. */
980 initialize_argument_information (num_actuals, args, args_size, n_named_args,
981 actparms, fndecl, args_so_far,
982 reg_parm_stack_space, old_stack_level,
983 old_pending_adj, must_preallocate, is_const,
985 int num_actuals ATTRIBUTE_UNUSED;
986 struct arg_data *args;
987 struct args_size *args_size;
988 int n_named_args ATTRIBUTE_UNUSED;
991 CUMULATIVE_ARGS *args_so_far;
992 int reg_parm_stack_space;
993 rtx *old_stack_level;
994 int *old_pending_adj;
995 int *must_preallocate;
999 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1002 /* Count arg position in order args appear. */
1005 struct args_size alignment_pad;
1009 args_size->constant = 0;
1012 /* In this loop, we consider args in the order they are written.
1013 We fill up ARGS from the front or from the back if necessary
1014 so that in any case the first arg to be pushed ends up at the front. */
1016 #ifdef PUSH_ARGS_REVERSED
1017 i = num_actuals - 1, inc = -1;
1018 /* In this case, must reverse order of args
1019 so that we compute and push the last arg first. */
1024 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1025 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1027 tree type = TREE_TYPE (TREE_VALUE (p));
1029 enum machine_mode mode;
1031 args[i].tree_value = TREE_VALUE (p);
1033 /* Replace erroneous argument with constant zero. */
1034 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1035 args[i].tree_value = integer_zero_node, type = integer_type_node;
1037 /* If TYPE is a transparent union, pass things the way we would
1038 pass the first field of the union. We have already verified that
1039 the modes are the same. */
1040 if (TYPE_TRANSPARENT_UNION (type))
1041 type = TREE_TYPE (TYPE_FIELDS (type));
1043 /* Decide where to pass this arg.
1045 args[i].reg is nonzero if all or part is passed in registers.
1047 args[i].partial is nonzero if part but not all is passed in registers,
1048 and the exact value says how many words are passed in registers.
1050 args[i].pass_on_stack is nonzero if the argument must at least be
1051 computed on the stack. It may then be loaded back into registers
1052 if args[i].reg is nonzero.
1054 These decisions are driven by the FUNCTION_... macros and must agree
1055 with those made by function.c. */
1057 /* See if this argument should be passed by invisible reference. */
1058 if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1059 && contains_placeholder_p (TYPE_SIZE (type)))
1060 || TREE_ADDRESSABLE (type)
1061 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1062 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1063 type, argpos < n_named_args)
1067 /* If we're compiling a thunk, pass through invisible
1068 references instead of making a copy. */
1069 if (current_function_is_thunk
1070 #ifdef FUNCTION_ARG_CALLEE_COPIES
1071 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1072 type, argpos < n_named_args)
1073 /* If it's in a register, we must make a copy of it too. */
1074 /* ??? Is this a sufficient test? Is there a better one? */
1075 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1076 && REG_P (DECL_RTL (args[i].tree_value)))
1077 && ! TREE_ADDRESSABLE (type))
1081 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1082 new object from the argument. If we are passing by
1083 invisible reference, the callee will do that for us, so we
1084 can strip off the TARGET_EXPR. This is not always safe,
1085 but it is safe in the only case where this is a useful
1086 optimization; namely, when the argument is a plain object.
1087 In that case, the frontend is just asking the backend to
1088 make a bitwise copy of the argument. */
1090 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1091 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1092 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1093 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1095 args[i].tree_value = build1 (ADDR_EXPR,
1096 build_pointer_type (type),
1097 args[i].tree_value);
1098 type = build_pointer_type (type);
1102 /* We make a copy of the object and pass the address to the
1103 function being called. */
1106 if (!COMPLETE_TYPE_P (type)
1107 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1108 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1109 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1110 STACK_CHECK_MAX_VAR_SIZE))))
1112 /* This is a variable-sized object. Make space on the stack
1114 rtx size_rtx = expr_size (TREE_VALUE (p));
1116 if (*old_stack_level == 0)
1118 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1119 *old_pending_adj = pending_stack_adjust;
1120 pending_stack_adjust = 0;
1123 copy = gen_rtx_MEM (BLKmode,
1124 allocate_dynamic_stack_space (size_rtx,
1126 TYPE_ALIGN (type)));
1130 int size = int_size_in_bytes (type);
1131 copy = assign_stack_temp (TYPE_MODE (type), size, 0);
1134 MEM_SET_IN_STRUCT_P (copy, AGGREGATE_TYPE_P (type));
1136 store_expr (args[i].tree_value, copy, 0);
1139 args[i].tree_value = build1 (ADDR_EXPR,
1140 build_pointer_type (type),
1141 make_tree (type, copy));
1142 type = build_pointer_type (type);
1146 mode = TYPE_MODE (type);
1147 unsignedp = TREE_UNSIGNED (type);
1149 #ifdef PROMOTE_FUNCTION_ARGS
1150 mode = promote_mode (type, mode, &unsignedp, 1);
1153 args[i].unsignedp = unsignedp;
1154 args[i].mode = mode;
1156 #ifdef FUNCTION_INCOMING_ARG
1157 /* If this is a sibling call and the machine has register windows, the
1158 register window has to be unwinded before calling the routine, so
1159 arguments have to go into the incoming registers. */
1160 if (ecf_flags & ECF_SIBCALL)
1161 args[i].reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1162 argpos < n_named_args);
1165 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1166 argpos < n_named_args);
1168 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1171 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1172 argpos < n_named_args);
1175 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1177 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1178 it means that we are to pass this arg in the register(s) designated
1179 by the PARALLEL, but also to pass it in the stack. */
1180 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1181 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1182 args[i].pass_on_stack = 1;
1184 /* If this is an addressable type, we must preallocate the stack
1185 since we must evaluate the object into its final location.
1187 If this is to be passed in both registers and the stack, it is simpler
1189 if (TREE_ADDRESSABLE (type)
1190 || (args[i].pass_on_stack && args[i].reg != 0))
1191 *must_preallocate = 1;
1193 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1194 we cannot consider this function call constant. */
1195 if (TREE_ADDRESSABLE (type))
1198 /* Compute the stack-size of this argument. */
1199 if (args[i].reg == 0 || args[i].partial != 0
1200 || reg_parm_stack_space > 0
1201 || args[i].pass_on_stack)
1202 locate_and_pad_parm (mode, type,
1203 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1208 fndecl, args_size, &args[i].offset,
1209 &args[i].size, &alignment_pad);
1211 #ifndef ARGS_GROW_DOWNWARD
1212 args[i].slot_offset = *args_size;
1215 args[i].alignment_pad = alignment_pad;
1217 /* If a part of the arg was put into registers,
1218 don't include that part in the amount pushed. */
1219 if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack)
1220 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1221 / (PARM_BOUNDARY / BITS_PER_UNIT)
1222 * (PARM_BOUNDARY / BITS_PER_UNIT));
1224 /* Update ARGS_SIZE, the total stack space for args so far. */
1226 args_size->constant += args[i].size.constant;
1227 if (args[i].size.var)
1229 ADD_PARM_SIZE (*args_size, args[i].size.var);
1232 /* Since the slot offset points to the bottom of the slot,
1233 we must record it after incrementing if the args grow down. */
1234 #ifdef ARGS_GROW_DOWNWARD
1235 args[i].slot_offset = *args_size;
1237 args[i].slot_offset.constant = -args_size->constant;
1239 SUB_PARM_SIZE (args[i].slot_offset, args_size->var);
1242 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1243 have been used, etc. */
1245 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1246 argpos < n_named_args);
1250 /* Update ARGS_SIZE to contain the total size for the argument block.
1251 Return the original constant component of the argument block's size.
1253 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1254 for arguments passed in registers. */
1257 compute_argument_block_size (reg_parm_stack_space, args_size,
1258 preferred_stack_boundary)
1259 int reg_parm_stack_space;
1260 struct args_size *args_size;
1261 int preferred_stack_boundary ATTRIBUTE_UNUSED;
1263 int unadjusted_args_size = args_size->constant;
1265 /* Compute the actual size of the argument block required. The variable
1266 and constant sizes must be combined, the size may have to be rounded,
1267 and there may be a minimum required size. */
1271 args_size->var = ARGS_SIZE_TREE (*args_size);
1272 args_size->constant = 0;
1274 #ifdef PREFERRED_STACK_BOUNDARY
1275 preferred_stack_boundary /= BITS_PER_UNIT;
1276 if (preferred_stack_boundary > 1)
1277 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1280 if (reg_parm_stack_space > 0)
1283 = size_binop (MAX_EXPR, args_size->var,
1284 ssize_int (reg_parm_stack_space));
1286 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1287 /* The area corresponding to register parameters is not to count in
1288 the size of the block we need. So make the adjustment. */
1290 = size_binop (MINUS_EXPR, args_size->var,
1291 ssize_int (reg_parm_stack_space));
1297 #ifdef PREFERRED_STACK_BOUNDARY
1298 preferred_stack_boundary /= BITS_PER_UNIT;
1299 if (preferred_stack_boundary < 1)
1300 preferred_stack_boundary = 1;
1301 args_size->constant = (((args_size->constant
1303 + pending_stack_adjust
1304 + preferred_stack_boundary - 1)
1305 / preferred_stack_boundary
1306 * preferred_stack_boundary)
1308 - pending_stack_adjust);
1311 args_size->constant = MAX (args_size->constant,
1312 reg_parm_stack_space);
1314 #ifdef MAYBE_REG_PARM_STACK_SPACE
1315 if (reg_parm_stack_space == 0)
1316 args_size->constant = 0;
1319 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1320 args_size->constant -= reg_parm_stack_space;
1323 return unadjusted_args_size;
1326 /* Precompute parameters as needed for a function call.
1328 IS_CONST indicates the target function is a pure function.
1330 MUST_PREALLOCATE indicates that we must preallocate stack space for
1331 any stack arguments.
1333 NUM_ACTUALS is the number of arguments.
1335 ARGS is an array containing information for each argument; this routine
1336 fills in the INITIAL_VALUE and VALUE fields for each precomputed argument.
1338 ARGS_SIZE contains information about the size of the arg list. */
1341 precompute_arguments (is_const, must_preallocate, num_actuals, args, args_size)
1343 int must_preallocate;
1345 struct arg_data *args;
1346 struct args_size *args_size;
1350 /* If this function call is cse'able, precompute all the parameters.
1351 Note that if the parameter is constructed into a temporary, this will
1352 cause an additional copy because the parameter will be constructed
1353 into a temporary location and then copied into the outgoing arguments.
1354 If a parameter contains a call to alloca and this function uses the
1355 stack, precompute the parameter. */
1357 /* If we preallocated the stack space, and some arguments must be passed
1358 on the stack, then we must precompute any parameter which contains a
1359 function call which will store arguments on the stack.
1360 Otherwise, evaluating the parameter may clobber previous parameters
1361 which have already been stored into the stack. */
1363 for (i = 0; i < num_actuals; i++)
1365 || ((args_size->var != 0 || args_size->constant != 0)
1366 && calls_function (args[i].tree_value, 1))
1367 || (must_preallocate
1368 && (args_size->var != 0 || args_size->constant != 0)
1369 && calls_function (args[i].tree_value, 0)))
1371 /* If this is an addressable type, we cannot pre-evaluate it. */
1372 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1378 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1380 preserve_temp_slots (args[i].value);
1383 /* ANSI doesn't require a sequence point here,
1384 but PCC has one, so this will avoid some problems. */
1387 args[i].initial_value = args[i].value
1388 = protect_from_queue (args[i].value, 0);
1390 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) != args[i].mode)
1393 = convert_modes (args[i].mode,
1394 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1395 args[i].value, args[i].unsignedp);
1396 #ifdef PROMOTE_FOR_CALL_ONLY
1397 /* CSE will replace this only if it contains args[i].value
1398 pseudo, so convert it down to the declared mode using
1400 if (GET_CODE (args[i].value) == REG
1401 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1403 args[i].initial_value
1404 = gen_rtx_SUBREG (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1406 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1407 SUBREG_PROMOTED_UNSIGNED_P (args[i].initial_value)
1408 = args[i].unsignedp;
1415 /* Given the current state of MUST_PREALLOCATE and information about
1416 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1417 compute and return the final value for MUST_PREALLOCATE. */
1420 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1421 int must_preallocate;
1423 struct arg_data *args;
1424 struct args_size *args_size;
1426 /* See if we have or want to preallocate stack space.
1428 If we would have to push a partially-in-regs parm
1429 before other stack parms, preallocate stack space instead.
1431 If the size of some parm is not a multiple of the required stack
1432 alignment, we must preallocate.
1434 If the total size of arguments that would otherwise create a copy in
1435 a temporary (such as a CALL) is more than half the total argument list
1436 size, preallocation is faster.
1438 Another reason to preallocate is if we have a machine (like the m88k)
1439 where stack alignment is required to be maintained between every
1440 pair of insns, not just when the call is made. However, we assume here
1441 that such machines either do not have push insns (and hence preallocation
1442 would occur anyway) or the problem is taken care of with
1445 if (! must_preallocate)
1447 int partial_seen = 0;
1448 int copy_to_evaluate_size = 0;
1451 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1453 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1455 else if (partial_seen && args[i].reg == 0)
1456 must_preallocate = 1;
1458 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1459 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1460 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1461 || TREE_CODE (args[i].tree_value) == COND_EXPR
1462 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1463 copy_to_evaluate_size
1464 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1467 if (copy_to_evaluate_size * 2 >= args_size->constant
1468 && args_size->constant > 0)
1469 must_preallocate = 1;
1471 return must_preallocate;
1474 /* If we preallocated stack space, compute the address of each argument
1475 and store it into the ARGS array.
1477 We need not ensure it is a valid memory address here; it will be
1478 validized when it is used.
1480 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1483 compute_argument_addresses (args, argblock, num_actuals)
1484 struct arg_data *args;
1490 rtx arg_reg = argblock;
1491 int i, arg_offset = 0;
1493 if (GET_CODE (argblock) == PLUS)
1494 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1496 for (i = 0; i < num_actuals; i++)
1498 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1499 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1502 /* Skip this parm if it will not be passed on the stack. */
1503 if (! args[i].pass_on_stack && args[i].reg != 0)
1506 if (GET_CODE (offset) == CONST_INT)
1507 addr = plus_constant (arg_reg, INTVAL (offset));
1509 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1511 addr = plus_constant (addr, arg_offset);
1512 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1515 AGGREGATE_TYPE_P (TREE_TYPE (args[i].tree_value)));
1517 if (GET_CODE (slot_offset) == CONST_INT)
1518 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1520 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1522 addr = plus_constant (addr, arg_offset);
1523 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1528 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1529 in a call instruction.
1531 FNDECL is the tree node for the target function. For an indirect call
1532 FNDECL will be NULL_TREE.
1534 EXP is the CALL_EXPR for this call. */
1537 rtx_for_function_call (fndecl, exp)
1543 /* Get the function to call, in the form of RTL. */
1546 /* If this is the first use of the function, see if we need to
1547 make an external definition for it. */
1548 if (! TREE_USED (fndecl))
1550 assemble_external (fndecl);
1551 TREE_USED (fndecl) = 1;
1554 /* Get a SYMBOL_REF rtx for the function address. */
1555 funexp = XEXP (DECL_RTL (fndecl), 0);
1558 /* Generate an rtx (probably a pseudo-register) for the address. */
1563 expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1564 pop_temp_slots (); /* FUNEXP can't be BLKmode */
1566 /* Check the function is executable. */
1567 if (current_function_check_memory_usage)
1569 #ifdef POINTERS_EXTEND_UNSIGNED
1570 /* It might be OK to convert funexp in place, but there's
1571 a lot going on between here and when it happens naturally
1572 that this seems safer. */
1573 funaddr = convert_memory_address (Pmode, funexp);
1575 emit_library_call (chkr_check_exec_libfunc, 1,
1584 /* Do the register loads required for any wholly-register parms or any
1585 parms which are passed both on the stack and in a register. Their
1586 expressions were already evaluated.
1588 Mark all register-parms as living through the call, putting these USE
1589 insns in the CALL_INSN_FUNCTION_USAGE field. */
1592 load_register_parameters (args, num_actuals, call_fusage)
1593 struct arg_data *args;
1599 #ifdef LOAD_ARGS_REVERSED
1600 for (i = num_actuals - 1; i >= 0; i--)
1602 for (i = 0; i < num_actuals; i++)
1605 rtx reg = args[i].reg;
1606 int partial = args[i].partial;
1611 /* Set to non-negative if must move a word at a time, even if just
1612 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1613 we just use a normal move insn. This value can be zero if the
1614 argument is a zero size structure with no fields. */
1615 nregs = (partial ? partial
1616 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1617 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1618 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1621 /* Handle calls that pass values in multiple non-contiguous
1622 locations. The Irix 6 ABI has examples of this. */
1624 if (GET_CODE (reg) == PARALLEL)
1626 emit_group_load (reg, args[i].value,
1627 int_size_in_bytes (TREE_TYPE (args[i].tree_value)),
1628 (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
1632 /* If simple case, just do move. If normal partial, store_one_arg
1633 has already loaded the register for us. In all other cases,
1634 load the register(s) from memory. */
1636 else if (nregs == -1)
1637 emit_move_insn (reg, args[i].value);
1639 /* If we have pre-computed the values to put in the registers in
1640 the case of non-aligned structures, copy them in now. */
1642 else if (args[i].n_aligned_regs != 0)
1643 for (j = 0; j < args[i].n_aligned_regs; j++)
1644 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1645 args[i].aligned_regs[j]);
1647 else if (partial == 0 || args[i].pass_on_stack)
1648 move_block_to_reg (REGNO (reg),
1649 validize_mem (args[i].value), nregs,
1652 /* Handle calls that pass values in multiple non-contiguous
1653 locations. The Irix 6 ABI has examples of this. */
1654 if (GET_CODE (reg) == PARALLEL)
1655 use_group_regs (call_fusage, reg);
1656 else if (nregs == -1)
1657 use_reg (call_fusage, reg);
1659 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1664 /* Generate all the code for a function call
1665 and return an rtx for its value.
1666 Store the value in TARGET (specified as an rtx) if convenient.
1667 If the value is stored in TARGET then TARGET is returned.
1668 If IGNORE is nonzero, then we ignore the value of the function call. */
1671 expand_call (exp, target, ignore)
1676 /* Nonzero if we are currently expanding a call. */
1677 static int currently_expanding_call = 0;
1679 /* List of actual parameters. */
1680 tree actparms = TREE_OPERAND (exp, 1);
1681 /* RTX for the function to be called. */
1683 /* Sequence of insns to perform a tail recursive "call". */
1684 rtx tail_recursion_insns = NULL_RTX;
1685 /* Sequence of insns to perform a normal "call". */
1686 rtx normal_call_insns = NULL_RTX;
1687 /* Sequence of insns to perform a tail recursive "call". */
1688 rtx tail_call_insns = NULL_RTX;
1689 /* Data type of the function. */
1691 /* Declaration of the function being called,
1692 or 0 if the function is computed (not known by name). */
1695 #ifdef ACCUMULATE_OUTGOING_ARGS
1699 int safe_for_reeval;
1702 /* Register in which non-BLKmode value will be returned,
1703 or 0 if no value or if value is BLKmode. */
1705 /* Address where we should return a BLKmode value;
1706 0 if value not BLKmode. */
1707 rtx structure_value_addr = 0;
1708 /* Nonzero if that address is being passed by treating it as
1709 an extra, implicit first parameter. Otherwise,
1710 it is passed by being copied directly into struct_value_rtx. */
1711 int structure_value_addr_parm = 0;
1712 /* Size of aggregate value wanted, or zero if none wanted
1713 or if we are using the non-reentrant PCC calling convention
1714 or expecting the value in registers. */
1715 HOST_WIDE_INT struct_value_size = 0;
1716 /* Nonzero if called function returns an aggregate in memory PCC style,
1717 by returning the address of where to find it. */
1718 int pcc_struct_value = 0;
1720 /* Number of actual parameters in this call, including struct value addr. */
1722 /* Number of named args. Args after this are anonymous ones
1723 and they must all go on the stack. */
1726 /* Vector of information about each argument.
1727 Arguments are numbered in the order they will be pushed,
1728 not the order they are written. */
1729 struct arg_data *args;
1731 /* Total size in bytes of all the stack-parms scanned so far. */
1732 struct args_size args_size;
1733 /* Size of arguments before any adjustments (such as rounding). */
1734 int unadjusted_args_size;
1735 /* Data on reg parms scanned so far. */
1736 CUMULATIVE_ARGS args_so_far;
1737 /* Nonzero if a reg parm has been scanned. */
1739 /* Nonzero if this is an indirect function call. */
1741 /* Nonzero if we must avoid push-insns in the args for this call.
1742 If stack space is allocated for register parameters, but not by the
1743 caller, then it is preallocated in the fixed part of the stack frame.
1744 So the entire argument block must then be preallocated (i.e., we
1745 ignore PUSH_ROUNDING in that case). */
1747 #ifdef PUSH_ROUNDING
1748 int must_preallocate = 0;
1750 int must_preallocate = 1;
1753 /* Size of the stack reserved for parameter registers. */
1754 int reg_parm_stack_space = 0;
1756 /* Address of space preallocated for stack parms
1757 (on machines that lack push insns), or 0 if space not preallocated. */
1760 /* Nonzero if it is plausible that this is a call to alloca. */
1762 /* Nonzero if this is a call to malloc or a related function. */
1764 /* Nonzero if this is a call to setjmp or a related function. */
1766 /* Nonzero if this is a call to `longjmp'. */
1768 /* Nonzero if this is a syscall that makes a new process in the image of
1771 /* Nonzero if this is a call to an inline function. */
1772 int is_integrable = 0;
1773 /* Nonzero if this is a call to a `const' function.
1774 Note that only explicitly named functions are handled as `const' here. */
1776 /* Nonzero if this is a call to a `volatile' function. */
1777 int is_volatile = 0;
1778 /* Nonzero if this is a call to a function that won't throw an exception. */
1779 int nothrow = TREE_NOTHROW (exp);
1780 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1781 /* Define the boundary of the register parm stack space that needs to be
1783 int low_to_save = -1, high_to_save;
1784 rtx save_area = 0; /* Place that it is saved */
1787 #ifdef ACCUMULATE_OUTGOING_ARGS
1788 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1789 char *initial_stack_usage_map = stack_usage_map;
1790 int old_stack_arg_under_construction = 0;
1793 rtx old_stack_level = 0;
1794 int old_pending_adj = 0;
1795 int old_inhibit_defer_pop = inhibit_defer_pop;
1799 int preferred_stack_boundary;
1801 /* The value of the function call can be put in a hard register. But
1802 if -fcheck-memory-usage, code which invokes functions (and thus
1803 damages some hard registers) can be inserted before using the value.
1804 So, target is always a pseudo-register in that case. */
1805 if (current_function_check_memory_usage)
1808 /* See if we can find a DECL-node for the actual function.
1809 As a result, decide whether this is a call to an integrable function. */
1811 p = TREE_OPERAND (exp, 0);
1812 if (TREE_CODE (p) == ADDR_EXPR)
1814 fndecl = TREE_OPERAND (p, 0);
1815 if (TREE_CODE (fndecl) != FUNCTION_DECL)
1820 && fndecl != current_function_decl
1821 && DECL_INLINE (fndecl)
1822 && DECL_SAVED_INSNS (fndecl)
1823 && DECL_SAVED_INSNS (fndecl)->inlinable)
1825 else if (! TREE_ADDRESSABLE (fndecl))
1827 /* In case this function later becomes inlinable,
1828 record that there was already a non-inline call to it.
1830 Use abstraction instead of setting TREE_ADDRESSABLE
1832 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1835 warning_with_decl (fndecl, "can't inline call to `%s'");
1836 warning ("called from here");
1838 mark_addressable (fndecl);
1841 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
1842 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
1845 if (TREE_THIS_VOLATILE (fndecl))
1848 if (TREE_NOTHROW (fndecl))
1853 /* If we don't have specific function to call, see if we have a
1854 constant or `noreturn' function from the type. */
1857 is_const = TREE_READONLY (TREE_TYPE (TREE_TYPE (p)));
1858 is_volatile = TREE_THIS_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
1861 #ifdef REG_PARM_STACK_SPACE
1862 #ifdef MAYBE_REG_PARM_STACK_SPACE
1863 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1865 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1869 #if defined(PUSH_ROUNDING) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1870 if (reg_parm_stack_space > 0)
1871 must_preallocate = 1;
1874 /* Warn if this value is an aggregate type,
1875 regardless of which calling convention we are using for it. */
1876 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
1877 warning ("function call has aggregate value");
1879 /* Set up a place to return a structure. */
1881 /* Cater to broken compilers. */
1882 if (aggregate_value_p (exp))
1884 /* This call returns a big structure. */
1887 #ifdef PCC_STATIC_STRUCT_RETURN
1889 pcc_struct_value = 1;
1890 /* Easier than making that case work right. */
1893 /* In case this is a static function, note that it has been
1895 if (! TREE_ADDRESSABLE (fndecl))
1896 mark_addressable (fndecl);
1900 #else /* not PCC_STATIC_STRUCT_RETURN */
1902 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
1904 if (target && GET_CODE (target) == MEM)
1905 structure_value_addr = XEXP (target, 0);
1908 /* Assign a temporary to hold the value. */
1911 /* For variable-sized objects, we must be called with a target
1912 specified. If we were to allocate space on the stack here,
1913 we would have no way of knowing when to free it. */
1915 if (struct_value_size < 0)
1918 /* This DECL is just something to feed to mark_addressable;
1919 it doesn't get pushed. */
1920 d = build_decl (VAR_DECL, NULL_TREE, TREE_TYPE (exp));
1921 DECL_RTL (d) = assign_temp (TREE_TYPE (exp), 1, 0, 1);
1922 mark_addressable (d);
1923 mark_temp_addr_taken (DECL_RTL (d));
1924 structure_value_addr = XEXP (DECL_RTL (d), 0);
1929 #endif /* not PCC_STATIC_STRUCT_RETURN */
1932 /* If called function is inline, try to integrate it. */
1938 #ifdef ACCUMULATE_OUTGOING_ARGS
1939 before_call = get_last_insn ();
1942 temp = expand_inline_function (fndecl, actparms, target,
1943 ignore, TREE_TYPE (exp),
1944 structure_value_addr);
1946 /* If inlining succeeded, return. */
1947 if (temp != (rtx) (HOST_WIDE_INT) -1)
1949 #ifdef ACCUMULATE_OUTGOING_ARGS
1950 /* If the outgoing argument list must be preserved, push
1951 the stack before executing the inlined function if it
1954 for (i = reg_parm_stack_space - 1; i >= 0; i--)
1955 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
1958 if (stack_arg_under_construction || i >= 0)
1961 = before_call ? NEXT_INSN (before_call) : get_insns ();
1962 rtx insn = NULL_RTX, seq;
1964 /* Look for a call in the inline function code.
1965 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1966 nonzero then there is a call and it is not necessary
1967 to scan the insns. */
1969 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1970 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1971 if (GET_CODE (insn) == CALL_INSN)
1976 /* Reserve enough stack space so that the largest
1977 argument list of any function call in the inline
1978 function does not overlap the argument list being
1979 evaluated. This is usually an overestimate because
1980 allocate_dynamic_stack_space reserves space for an
1981 outgoing argument list in addition to the requested
1982 space, but there is no way to ask for stack space such
1983 that an argument list of a certain length can be
1986 Add the stack space reserved for register arguments, if
1987 any, in the inline function. What is really needed is the
1988 largest value of reg_parm_stack_space in the inline
1989 function, but that is not available. Using the current
1990 value of reg_parm_stack_space is wrong, but gives
1991 correct results on all supported machines. */
1993 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1994 + reg_parm_stack_space);
1997 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1998 allocate_dynamic_stack_space (GEN_INT (adjust),
1999 NULL_RTX, BITS_PER_UNIT);
2002 emit_insns_before (seq, first_insn);
2003 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2008 /* If the result is equivalent to TARGET, return TARGET to simplify
2009 checks in store_expr. They can be equivalent but not equal in the
2010 case of a function that returns BLKmode. */
2011 if (temp != target && rtx_equal_p (temp, target))
2016 /* If inlining failed, mark FNDECL as needing to be compiled
2017 separately after all. If function was declared inline,
2019 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2020 && optimize > 0 && ! TREE_ADDRESSABLE (fndecl))
2022 warning_with_decl (fndecl, "inlining failed in call to `%s'");
2023 warning ("called from here");
2025 mark_addressable (fndecl);
2028 currently_expanding_call++;
2030 /* If we're considering tail recursion optimizations, verify that the
2031 arguments are safe for re-evaluation. If we can unsave them, wrap
2032 each argument in an UNSAVE_EXPR. */
2034 safe_for_reeval = 0;
2036 && currently_expanding_call == 1
2037 && stmt_loop_nest_empty ()
2038 && ! any_pending_cleanups (1))
2040 /* Verify that each argument is safe for re-evaluation. */
2041 for (p = actparms; p; p = TREE_CHAIN (p))
2042 if (! safe_for_unsave (TREE_VALUE (p)))
2047 tree new_actparms = NULL_TREE, q;
2049 for (p = actparms; p ; p = TREE_CHAIN (p))
2051 tree np = build_tree_list (TREE_PURPOSE (p),
2052 unsave_expr (TREE_VALUE (p)));
2054 TREE_CHAIN (q) = np;
2060 actparms = new_actparms;
2061 safe_for_reeval = 1;
2065 /* Generate a tail recursion sequence when calling ourselves. */
2068 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
2069 && TREE_OPERAND (TREE_OPERAND (exp, 0), 0) == current_function_decl)
2071 /* We want to emit any pending stack adjustments before the tail
2072 recursion "call". That way we know any adjustment after the tail
2073 recursion call can be ignored if we indeed use the tail recursion
2075 int save_pending_stack_adjust = pending_stack_adjust;
2078 /* Use a new sequence to hold any RTL we generate. We do not even
2079 know if we will use this RTL yet. The final decision can not be
2080 made until after RTL generation for the entire function is
2082 push_to_sequence (0);
2084 /* Emit the pending stack adjustments before we expand any arguments. */
2085 do_pending_stack_adjust ();
2087 optimize_tail_recursion (exp, get_last_insn ());
2089 last = get_last_insn ();
2090 tail_recursion_insns = get_insns ();
2093 /* If the last insn on the tail recursion sequence is not a
2094 BARRIER, then tail recursion optimization failed. */
2095 if (last == NULL_RTX || GET_CODE (last) != BARRIER)
2096 tail_recursion_insns = NULL_RTX;
2098 /* Restore the original pending stack adjustment for the sibling and
2099 normal call cases below. */
2100 pending_stack_adjust = save_pending_stack_adjust;
2103 function_call_count++;
2105 if (fndecl && DECL_NAME (fndecl))
2106 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
2108 #ifdef PREFERRED_STACK_BOUNDARY
2109 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2111 preferred_stack_boundary = STACK_BOUNDARY;
2114 /* Ensure current function's preferred stack boundary is at least
2115 what we need. We don't have to increase alignment for recursive
2117 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2118 && fndecl != current_function_decl)
2119 cfun->preferred_stack_boundary = preferred_stack_boundary;
2121 /* See if this is a call to a function that can return more than once
2122 or a call to longjmp or malloc. */
2123 special_function_p (fndecl, &returns_twice, &is_longjmp, &fork_or_exec,
2124 &is_malloc, &may_be_alloca);
2127 current_function_calls_alloca = 1;
2129 /* Operand 0 is a pointer-to-function; get the type of the function. */
2130 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
2131 if (! POINTER_TYPE_P (funtype))
2133 funtype = TREE_TYPE (funtype);
2135 /* We want to make two insn chains; one for a sibling call, the other
2136 for a normal call. We will select one of the two chains after
2137 initial RTL generation is complete. */
2138 for (pass = 0; pass < 2; pass++)
2140 int sibcall_failure = 0;
2141 /* We want to emit ay pending stack adjustments before the tail
2142 recursion "call". That way we know any adjustment after the tail
2143 recursion call can be ignored if we indeed use the tail recursion
2145 int save_pending_stack_adjust;
2147 rtx before_call, next_arg_reg;
2151 /* Various reasons we can not use a sibling call. */
2152 if (! safe_for_reeval
2153 #ifdef HAVE_sibcall_epilogue
2154 || ! HAVE_sibcall_epilogue
2158 /* The structure value address is used and modified in the
2159 loop below. It does not seem worth the effort to save and
2160 restore it as a state variable since few optimizable
2161 sibling calls will return a structure. */
2162 || structure_value_addr != NULL_RTX
2163 /* If the register holding the address is a callee saved
2164 register, then we lose. We have no way to prevent that,
2165 so we only allow calls to named functions. */
2166 || fndecl == NULL_TREE
2167 || ! FUNCTION_OK_FOR_SIBCALL (fndecl))
2170 /* We know at this point that there are not currently any
2171 pending cleanups. If, however, in the process of evaluating
2172 the arguments we were to create some, we'll need to be
2173 able to get rid of them. */
2174 expand_start_target_temps ();
2176 /* State variables we need to save and restore between
2178 save_pending_stack_adjust = pending_stack_adjust;
2181 /* Other state variables that we must reinitialize each time
2182 through the loop (that are not initialized by the loop itself. */
2186 /* Start a new sequence for the normal call case.
2188 From this point on, if the sibling call fails, we want to set
2189 sibcall_failure instead of continuing the loop. */
2192 /* When calling a const function, we must pop the stack args right away,
2193 so that the pop is deleted or moved with the call. */
2197 /* Don't let pending stack adjusts add up to too much.
2198 Also, do all pending adjustments now if there is any chance
2199 this might be a call to alloca or if we are expanding a sibling
2201 if (pending_stack_adjust >= 32
2202 || (pending_stack_adjust > 0 && may_be_alloca)
2204 do_pending_stack_adjust ();
2206 if (profile_arc_flag && fork_or_exec)
2208 /* A fork duplicates the profile information, and an exec discards
2209 it. We can't rely on fork/exec to be paired. So write out the
2210 profile information we have gathered so far, and clear it. */
2211 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2212 is subject to race conditions, just as with multithreaded
2215 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_fork_func"), 0,
2219 /* Push the temporary stack slot level so that we can free any
2220 temporaries we make. */
2223 /* Start updating where the next arg would go.
2225 On some machines (such as the PA) indirect calls have a different
2226 calling convention than normal calls. The last argument in
2227 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2229 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0));
2231 /* If struct_value_rtx is 0, it means pass the address
2232 as if it were an extra parameter. */
2233 if (structure_value_addr && struct_value_rtx == 0)
2235 /* If structure_value_addr is a REG other than
2236 virtual_outgoing_args_rtx, we can use always use it. If it
2237 is not a REG, we must always copy it into a register.
2238 If it is virtual_outgoing_args_rtx, we must copy it to another
2239 register in some cases. */
2240 rtx temp = (GET_CODE (structure_value_addr) != REG
2241 #ifdef ACCUMULATE_OUTGOING_ARGS
2242 || (stack_arg_under_construction
2243 && structure_value_addr == virtual_outgoing_args_rtx)
2245 ? copy_addr_to_reg (structure_value_addr)
2246 : structure_value_addr);
2249 = tree_cons (error_mark_node,
2250 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2253 structure_value_addr_parm = 1;
2256 /* Count the arguments and set NUM_ACTUALS. */
2257 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
2260 /* Compute number of named args.
2261 Normally, don't include the last named arg if anonymous args follow.
2262 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2263 (If no anonymous args follow, the result of list_length is actually
2264 one too large. This is harmless.)
2266 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2267 zero, this machine will be able to place unnamed args that were
2268 passed in registers into the stack. So treat all args as named.
2269 This allows the insns emitting for a specific argument list to be
2270 independent of the function declaration.
2272 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2273 reliable way to pass unnamed args in registers, so we must force
2274 them into memory. */
2276 if ((STRICT_ARGUMENT_NAMING
2277 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2278 && TYPE_ARG_TYPES (funtype) != 0)
2280 = (list_length (TYPE_ARG_TYPES (funtype))
2281 /* Don't include the last named arg. */
2282 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2283 /* Count the struct value address, if it is passed as a parm. */
2284 + structure_value_addr_parm);
2286 /* If we know nothing, treat all args as named. */
2287 n_named_args = num_actuals;
2289 /* Make a vector to hold all the information about each arg. */
2290 args = (struct arg_data *) alloca (num_actuals
2291 * sizeof (struct arg_data));
2292 bzero ((char *) args, num_actuals * sizeof (struct arg_data));
2294 /* Build up entries inthe ARGS array, compute the size of the arguments
2295 into ARGS_SIZE, etc. */
2296 initialize_argument_information (num_actuals, args, &args_size,
2297 n_named_args, actparms, fndecl,
2298 &args_so_far, reg_parm_stack_space,
2299 &old_stack_level, &old_pending_adj,
2300 &must_preallocate, &is_const,
2301 (pass == 0) ? ECF_SIBCALL : 0);
2303 #ifdef FINAL_REG_PARM_STACK_SPACE
2304 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2310 /* If this function requires a variable-sized argument list, don't
2311 try to make a cse'able block for this call. We may be able to
2312 do this eventually, but it is too complicated to keep track of
2313 what insns go in the cse'able block and which don't.
2315 Also do not make a sibling call. */
2318 must_preallocate = 1;
2319 sibcall_failure = 1;
2322 if (args_size.constant > current_function_args_size)
2324 /* If this function requires more stack slots than the current
2325 function, we cannot change it into a sibling call. */
2326 sibcall_failure = 1;
2329 /* Compute the actual size of the argument block required. The variable
2330 and constant sizes must be combined, the size may have to be rounded,
2331 and there may be a minimum required size. When generating a sibcall
2332 pattern, do not round up, since we'll be re-using whatever space our
2334 unadjusted_args_size
2335 = compute_argument_block_size (reg_parm_stack_space, &args_size,
2337 : preferred_stack_boundary));
2339 /* If the callee pops its own arguments, then it must pop exactly
2340 the same number of arguments as the current function. */
2341 if (RETURN_POPS_ARGS (fndecl, funtype, unadjusted_args_size)
2342 != RETURN_POPS_ARGS (current_function_decl,
2343 TREE_TYPE (current_function_decl),
2344 current_function_args_size))
2345 sibcall_failure = 1;
2347 /* Now make final decision about preallocating stack space. */
2348 must_preallocate = finalize_must_preallocate (must_preallocate,
2352 /* If the structure value address will reference the stack pointer, we
2353 must stabilize it. We don't need to do this if we know that we are
2354 not going to adjust the stack pointer in processing this call. */
2356 if (structure_value_addr
2357 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2358 || reg_mentioned_p (virtual_outgoing_args_rtx,
2359 structure_value_addr))
2361 #ifndef ACCUMULATE_OUTGOING_ARGS
2362 || args_size.constant
2365 structure_value_addr = copy_to_reg (structure_value_addr);
2367 /* Precompute any arguments as needed. */
2368 precompute_arguments (is_const, must_preallocate, num_actuals,
2371 /* Now we are about to start emitting insns that can be deleted
2372 if a libcall is deleted. */
2373 if (is_const || is_malloc)
2376 /* If we have no actual push instructions, or shouldn't use them,
2377 make space for all args right now. */
2379 if (args_size.var != 0)
2381 if (old_stack_level == 0)
2383 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2384 old_pending_adj = pending_stack_adjust;
2385 pending_stack_adjust = 0;
2386 #ifdef ACCUMULATE_OUTGOING_ARGS
2387 /* stack_arg_under_construction says whether a stack arg is
2388 being constructed at the old stack level. Pushing the stack
2389 gets a clean outgoing argument block. */
2390 old_stack_arg_under_construction = stack_arg_under_construction;
2391 stack_arg_under_construction = 0;
2394 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
2398 /* Note that we must go through the motions of allocating an argument
2399 block even if the size is zero because we may be storing args
2400 in the area reserved for register arguments, which may be part of
2403 int needed = args_size.constant;
2405 /* Store the maximum argument space used. It will be pushed by
2406 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2409 if (needed > current_function_outgoing_args_size)
2410 current_function_outgoing_args_size = needed;
2412 if (must_preallocate)
2414 #ifdef ACCUMULATE_OUTGOING_ARGS
2415 /* Since the stack pointer will never be pushed, it is possible
2416 for the evaluation of a parm to clobber something we have
2417 already written to the stack. Since most function calls on
2418 RISC machines do not use the stack, this is uncommon, but
2419 must work correctly.
2421 Therefore, we save any area of the stack that was already
2422 written and that we are using. Here we set up to do this by
2423 making a new stack usage map from the old one. The actual
2424 save will be done by store_one_arg.
2426 Another approach might be to try to reorder the argument
2427 evaluations to avoid this conflicting stack usage. */
2429 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2430 /* Since we will be writing into the entire argument area, the
2431 map must be allocated for its entire size, not just the part
2432 that is the responsibility of the caller. */
2433 needed += reg_parm_stack_space;
2436 #ifdef ARGS_GROW_DOWNWARD
2437 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2440 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2443 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
2445 if (initial_highest_arg_in_use)
2446 bcopy (initial_stack_usage_map, stack_usage_map,
2447 initial_highest_arg_in_use);
2449 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2450 bzero (&stack_usage_map[initial_highest_arg_in_use],
2451 (highest_outgoing_arg_in_use
2452 - initial_highest_arg_in_use));
2455 /* The address of the outgoing argument list must not be copied
2456 to a register here, because argblock would be left pointing
2457 to the wrong place after the call to
2458 allocate_dynamic_stack_space below. */
2460 argblock = virtual_outgoing_args_rtx;
2462 #else /* not ACCUMULATE_OUTGOING_ARGS */
2463 if (inhibit_defer_pop == 0)
2465 /* Try to reuse some or all of the pending_stack_adjust
2466 to get this space. Maybe we can avoid any pushing. */
2467 if (needed > pending_stack_adjust)
2469 needed -= pending_stack_adjust;
2470 pending_stack_adjust = 0;
2474 pending_stack_adjust -= needed;
2478 /* Special case this because overhead of `push_block' in this
2479 case is non-trivial. */
2481 argblock = virtual_outgoing_args_rtx;
2483 argblock = push_block (GEN_INT (needed), 0, 0);
2485 /* We only really need to call `copy_to_reg' in the case where
2486 push insns are going to be used to pass ARGBLOCK to a function
2487 call in ARGS. In that case, the stack pointer changes value
2488 from the allocation point to the call point, and hence
2489 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
2490 But might as well always do it. */
2491 argblock = copy_to_reg (argblock);
2492 #endif /* not ACCUMULATE_OUTGOING_ARGS */
2496 /* The argument block when performing a sibling call is the
2497 incoming argument block. */
2500 rtx temp = plus_constant (arg_pointer_rtx,
2501 FIRST_PARM_OFFSET (current_function_decl));
2502 argblock = force_reg (Pmode, force_operand (temp, NULL_RTX));
2505 #ifdef ACCUMULATE_OUTGOING_ARGS
2506 /* The save/restore code in store_one_arg handles all cases except one:
2507 a constructor call (including a C function returning a BLKmode struct)
2508 to initialize an argument. */
2509 if (stack_arg_under_construction)
2511 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2512 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
2514 rtx push_size = GEN_INT (args_size.constant);
2516 if (old_stack_level == 0)
2518 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2519 old_pending_adj = pending_stack_adjust;
2520 pending_stack_adjust = 0;
2521 /* stack_arg_under_construction says whether a stack arg is
2522 being constructed at the old stack level. Pushing the stack
2523 gets a clean outgoing argument block. */
2524 old_stack_arg_under_construction = stack_arg_under_construction;
2525 stack_arg_under_construction = 0;
2526 /* Make a new map for the new argument list. */
2527 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
2528 bzero (stack_usage_map, highest_outgoing_arg_in_use);
2529 highest_outgoing_arg_in_use = 0;
2531 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
2533 /* If argument evaluation might modify the stack pointer, copy the
2534 address of the argument list to a register. */
2535 for (i = 0; i < num_actuals; i++)
2536 if (args[i].pass_on_stack)
2538 argblock = copy_addr_to_reg (argblock);
2543 compute_argument_addresses (args, argblock, num_actuals);
2545 #ifdef PUSH_ARGS_REVERSED
2546 #ifdef PREFERRED_STACK_BOUNDARY
2547 /* If we push args individually in reverse order, perform stack alignment
2548 before the first push (the last arg). */
2549 if (args_size.constant != unadjusted_args_size)
2551 /* When the stack adjustment is pending, we get better code
2552 by combining the adjustments. */
2553 if (pending_stack_adjust && ! is_const
2554 && ! inhibit_defer_pop)
2556 args_size.constant = (unadjusted_args_size
2557 + ((pending_stack_adjust
2558 + args_size.constant
2560 - unadjusted_args_size)
2561 % (preferred_stack_boundary
2563 pending_stack_adjust -= (args_size.constant
2564 - unadjusted_args_size);
2565 do_pending_stack_adjust ();
2567 else if (argblock == 0)
2568 anti_adjust_stack (GEN_INT (args_size.constant
2569 - unadjusted_args_size));
2570 arg_space_so_far += args_size.constant - unadjusted_args_size;
2572 /* Now that the stack is properly aligned, pops can't safely
2573 be deferred during the evaluation of the arguments. */
2579 /* Don't try to defer pops if preallocating, not even from the first arg,
2580 since ARGBLOCK probably refers to the SP. */
2584 funexp = rtx_for_function_call (fndecl, exp);
2586 /* Figure out the register where the value, if any, will come back. */
2588 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2589 && ! structure_value_addr)
2591 if (pcc_struct_value)
2592 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2593 fndecl, (pass == 0));
2595 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2598 /* Precompute all register parameters. It isn't safe to compute anything
2599 once we have started filling any specific hard regs. */
2600 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2602 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
2603 /* Save the fixed argument area if it's part of the caller's frame and
2604 is clobbered by argument setup for this call. */
2605 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2606 &low_to_save, &high_to_save);
2609 /* Now store (and compute if necessary) all non-register parms.
2610 These come before register parms, since they can require block-moves,
2611 which could clobber the registers used for register parms.
2612 Parms which have partial registers are not stored here,
2613 but we do preallocate space here if they want that. */
2615 for (i = 0; i < num_actuals; i++)
2616 if (args[i].reg == 0 || args[i].pass_on_stack)
2617 store_one_arg (&args[i], argblock, may_be_alloca,
2618 args_size.var != 0, reg_parm_stack_space);
2620 /* If we have a parm that is passed in registers but not in memory
2621 and whose alignment does not permit a direct copy into registers,
2622 make a group of pseudos that correspond to each register that we
2624 if (STRICT_ALIGNMENT)
2625 store_unaligned_arguments_into_pseudos (args, num_actuals);
2627 /* Now store any partially-in-registers parm.
2628 This is the last place a block-move can happen. */
2630 for (i = 0; i < num_actuals; i++)
2631 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2632 store_one_arg (&args[i], argblock, may_be_alloca,
2633 args_size.var != 0, reg_parm_stack_space);
2635 #ifndef PUSH_ARGS_REVERSED
2636 #ifdef PREFERRED_STACK_BOUNDARY
2637 /* If we pushed args in forward order, perform stack alignment
2638 after pushing the last arg. */
2639 /* ??? Fix for arg_space_so_far. */
2641 anti_adjust_stack (GEN_INT (args_size.constant
2642 - unadjusted_args_size));
2646 /* If register arguments require space on the stack and stack space
2647 was not preallocated, allocate stack space here for arguments
2648 passed in registers. */
2649 #if ! defined(ACCUMULATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
2650 if (must_preallocate == 0 && reg_parm_stack_space > 0)
2651 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2654 /* Pass the function the address in which to return a
2656 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2658 emit_move_insn (struct_value_rtx,
2660 force_operand (structure_value_addr,
2663 /* Mark the memory for the aggregate as write-only. */
2664 if (current_function_check_memory_usage)
2665 emit_library_call (chkr_set_right_libfunc, 1,
2667 structure_value_addr, ptr_mode,
2668 GEN_INT (struct_value_size),
2669 TYPE_MODE (sizetype),
2670 GEN_INT (MEMORY_USE_WO),
2671 TYPE_MODE (integer_type_node));
2673 if (GET_CODE (struct_value_rtx) == REG)
2674 use_reg (&call_fusage, struct_value_rtx);
2677 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
2680 load_register_parameters (args, num_actuals, &call_fusage);
2682 /* Perform postincrements before actually calling the function. */
2685 /* Save a pointer to the last insn before the call, so that we can
2686 later safely search backwards to find the CALL_INSN. */
2687 before_call = get_last_insn ();
2689 /* Set up next argument register. For sibling calls on machines
2690 with register windows this should be the incoming register. */
2691 #ifdef FUNCTION_INCOMING_ARG
2693 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2697 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2700 /* All arguments and registers used for the call must be set up by
2703 /* Generate the actual call instruction. */
2704 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
2705 args_size.constant, struct_value_size,
2706 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2707 ((is_const ? ECF_IS_CONST : 0)
2708 | (nothrow ? ECF_NOTHROW : 0)
2709 | (pass == 0 ? ECF_SIBCALL : 0)));
2711 /* If call is cse'able, make appropriate pair of reg-notes around it.
2712 Test valreg so we don't crash; may safely ignore `const'
2713 if return type is void. Disable for PARALLEL return values, because
2714 we have no way to move such values into a pseudo register. */
2715 if (is_const && valreg != 0 && GET_CODE (valreg) != PARALLEL)
2718 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2721 /* Mark the return value as a pointer if needed. */
2722 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2724 tree pointed_to = TREE_TYPE (TREE_TYPE (exp));
2725 mark_reg_pointer (temp, TYPE_ALIGN (pointed_to) / BITS_PER_UNIT);
2728 /* Construct an "equal form" for the value which mentions all the
2729 arguments in order as well as the function name. */
2730 #ifdef PUSH_ARGS_REVERSED
2731 for (i = 0; i < num_actuals; i++)
2732 note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note);
2734 for (i = num_actuals - 1; i >= 0; i--)
2735 note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note);
2737 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2739 insns = get_insns ();
2742 emit_libcall_block (insns, temp, valreg, note);
2748 /* Otherwise, just write out the sequence without a note. */
2749 rtx insns = get_insns ();
2756 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2759 /* The return value from a malloc-like function is a pointer. */
2760 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2761 mark_reg_pointer (temp, BIGGEST_ALIGNMENT / BITS_PER_UNIT);
2763 emit_move_insn (temp, valreg);
2765 /* The return value from a malloc-like function can not alias
2767 last = get_last_insn ();
2769 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2771 /* Write out the sequence. */
2772 insns = get_insns ();
2778 /* For calls to `setjmp', etc., inform flow.c it should complain
2779 if nonvolatile values are live. For functions that cannot return,
2780 inform flow that control does not fall through. */
2782 if (returns_twice || is_volatile || is_longjmp || pass == 0)
2784 /* The barrier or NOTE_INSN_SETJMP note must be emitted
2785 immediately after the CALL_INSN. Some ports emit more
2786 than just a CALL_INSN above, so we must search for it here. */
2788 rtx last = get_last_insn ();
2789 while (GET_CODE (last) != CALL_INSN)
2791 last = PREV_INSN (last);
2792 /* There was no CALL_INSN? */
2793 if (last == before_call)
2799 emit_note_after (NOTE_INSN_SETJMP, last);
2800 current_function_calls_setjmp = 1;
2801 sibcall_failure = 1;
2804 emit_barrier_after (last);
2808 current_function_calls_longjmp = 1, sibcall_failure = 1;
2810 /* If this function is returning into a memory location marked as
2811 readonly, it means it is initializing that location. But we normally
2812 treat functions as not clobbering such locations, so we need to
2813 specify that this one does. */
2814 if (target != 0 && GET_CODE (target) == MEM
2815 && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
2816 emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
2818 /* If value type not void, return an rtx for the value. */
2820 /* If there are cleanups to be called, don't use a hard reg as target.
2821 We need to double check this and see if it matters anymore. */
2822 if (any_pending_cleanups (1)
2823 && target && REG_P (target)
2824 && REGNO (target) < FIRST_PSEUDO_REGISTER)
2825 target = 0, sibcall_failure = 1;
2827 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2830 target = const0_rtx;
2832 else if (structure_value_addr)
2834 if (target == 0 || GET_CODE (target) != MEM)
2836 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2837 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2838 structure_value_addr));
2839 MEM_SET_IN_STRUCT_P (target,
2840 AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2843 else if (pcc_struct_value)
2845 /* This is the special C++ case where we need to
2846 know what the true target was. We take care to
2847 never use this value more than once in one expression. */
2848 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2849 copy_to_reg (valreg));
2850 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2852 /* Handle calls that return values in multiple non-contiguous locations.
2853 The Irix 6 ABI has examples of this. */
2854 else if (GET_CODE (valreg) == PARALLEL)
2856 int bytes = int_size_in_bytes (TREE_TYPE (exp));
2860 target = assign_stack_temp (TYPE_MODE (TREE_TYPE (exp)),
2862 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2863 preserve_temp_slots (target);
2866 if (! rtx_equal_p (target, valreg))
2867 emit_group_store (target, valreg, bytes,
2868 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
2869 /* We can not support sibling calls for this case. */
2870 sibcall_failure = 1;
2873 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2874 && GET_MODE (target) == GET_MODE (valreg))
2876 /* TARGET and VALREG cannot be equal at this point because the
2877 latter would not have REG_FUNCTION_VALUE_P true, while the
2878 former would if it were referring to the same register.
2880 If they refer to the same register, this move will be a no-op,
2881 except when function inlining is being done. */
2882 emit_move_insn (target, valreg);
2884 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2885 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2887 target = copy_to_reg (valreg);
2889 #ifdef PROMOTE_FUNCTION_RETURN
2890 /* If we promoted this return value, make the proper SUBREG. TARGET
2891 might be const0_rtx here, so be careful. */
2892 if (GET_CODE (target) == REG
2893 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2894 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2896 tree type = TREE_TYPE (exp);
2897 int unsignedp = TREE_UNSIGNED (type);
2899 /* If we don't promote as expected, something is wrong. */
2900 if (GET_MODE (target)
2901 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
2904 target = gen_rtx_SUBREG (TYPE_MODE (type), target, 0);
2905 SUBREG_PROMOTED_VAR_P (target) = 1;
2906 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
2910 /* If size of args is variable or this was a constructor call for a stack
2911 argument, restore saved stack-pointer value. */
2913 if (old_stack_level)
2915 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2916 pending_stack_adjust = old_pending_adj;
2917 #ifdef ACCUMULATE_OUTGOING_ARGS
2918 stack_arg_under_construction = old_stack_arg_under_construction;
2919 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2920 stack_usage_map = initial_stack_usage_map;
2922 sibcall_failure = 1;
2924 #ifdef ACCUMULATE_OUTGOING_ARGS
2927 #ifdef REG_PARM_STACK_SPACE
2930 restore_fixed_argument_area (save_area, argblock,
2931 high_to_save, low_to_save);
2932 sibcall_failure = 1;
2936 /* If we saved any argument areas, restore them. */
2937 for (i = 0; i < num_actuals; i++)
2938 if (args[i].save_area)
2940 enum machine_mode save_mode = GET_MODE (args[i].save_area);
2942 = gen_rtx_MEM (save_mode,
2943 memory_address (save_mode,
2944 XEXP (args[i].stack_slot, 0)));
2946 if (save_mode != BLKmode)
2947 emit_move_insn (stack_area, args[i].save_area);
2949 emit_block_move (stack_area,
2950 validize_mem (args[i].save_area),
2951 GEN_INT (args[i].size.constant),
2952 PARM_BOUNDARY / BITS_PER_UNIT);
2953 sibcall_failure = 1;
2956 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2957 stack_usage_map = initial_stack_usage_map;
2961 /* If this was alloca, record the new stack level for nonlocal gotos.
2962 Check for the handler slots since we might not have a save area
2963 for non-local gotos. */
2965 if (may_be_alloca && nonlocal_goto_handler_slots != 0)
2966 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
2970 /* Free up storage we no longer need. */
2971 for (i = 0; i < num_actuals; ++i)
2972 if (args[i].aligned_regs)
2973 free (args[i].aligned_regs);
2977 /* Undo the fake expand_start_target_temps we did earlier. If
2978 there had been any cleanups created, we've already set
2980 expand_end_target_temps ();
2983 insns = get_insns ();
2988 tail_call_insns = insns;
2990 /* If something prevents making this a sibling call,
2991 zero out the sequence. */
2992 if (sibcall_failure)
2993 tail_call_insns = NULL_RTX;
2995 /* Restore the pending stack adjustment now that we have
2996 finished generating the sibling call sequence. */
2997 pending_stack_adjust = save_pending_stack_adjust;
3000 normal_call_insns = insns;
3003 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3004 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3005 can happen if the arguments to this function call an inline
3006 function who's expansion contains another CALL_PLACEHOLDER.
3008 If there are any C_Ps in any of these sequences, replace them
3009 with their normal call. */
3011 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3012 if (GET_CODE (insn) == CALL_INSN
3013 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3014 replace_call_placeholder (insn, sibcall_use_normal);
3016 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3017 if (GET_CODE (insn) == CALL_INSN
3018 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3019 replace_call_placeholder (insn, sibcall_use_normal);
3021 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3022 if (GET_CODE (insn) == CALL_INSN
3023 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3024 replace_call_placeholder (insn, sibcall_use_normal);
3026 /* If this was a potential tail recursion site, then emit a
3027 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3028 One of them will be selected later. */
3029 if (tail_recursion_insns || tail_call_insns)
3031 /* The tail recursion label must be kept around. We could expose
3032 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3033 and makes determining true tail recursion sites difficult.
3035 So we set LABEL_PRESERVE_P here, then clear it when we select
3036 one of the call sequences after rtl generation is complete. */
3037 if (tail_recursion_insns)
3038 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3039 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3041 tail_recursion_insns,
3042 tail_recursion_label));
3045 emit_insns (normal_call_insns);
3047 currently_expanding_call--;
3052 /* Returns nonzero if FUN is the symbol for a library function which can
3056 libfunc_nothrow (fun)
3059 if (fun == throw_libfunc
3060 || fun == rethrow_libfunc
3061 || fun == sjthrow_libfunc
3062 || fun == sjpopnthrow_libfunc)
3068 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3069 The RETVAL parameter specifies whether return value needs to be saved, other
3070 parameters are documented in the emit_library_call function bellow. */
3072 emit_library_call_value_1 (retval, orgfun, value, no_queue, outmode, nargs, p)
3077 enum machine_mode outmode;
3081 /* Total size in bytes of all the stack-parms scanned so far. */
3082 struct args_size args_size;
3083 /* Size of arguments before any adjustments (such as rounding). */
3084 struct args_size original_args_size;
3085 register int argnum;
3089 struct args_size alignment_pad;
3091 CUMULATIVE_ARGS args_so_far;
3092 struct arg { rtx value; enum machine_mode mode; rtx reg; int partial;
3093 struct args_size offset; struct args_size size; rtx save_area; };
3095 int old_inhibit_defer_pop = inhibit_defer_pop;
3096 rtx call_fusage = 0;
3098 int pcc_struct_value = 0;
3099 int struct_value_size = 0;
3101 int reg_parm_stack_space = 0;
3103 #ifdef ACCUMULATE_OUTGOING_ARGS
3107 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
3108 /* Define the boundary of the register parm stack space that needs to be
3110 int low_to_save = -1, high_to_save = 0;
3111 rtx save_area = 0; /* Place that it is saved */
3114 #ifdef ACCUMULATE_OUTGOING_ARGS
3115 /* Size of the stack reserved for parameter registers. */
3116 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3117 char *initial_stack_usage_map = stack_usage_map;
3120 #ifdef REG_PARM_STACK_SPACE
3121 #ifdef MAYBE_REG_PARM_STACK_SPACE
3122 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3124 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3128 is_const = no_queue;
3131 nothrow = libfunc_nothrow (fun);
3133 #ifdef PREFERRED_STACK_BOUNDARY
3134 /* Ensure current function's preferred stack boundary is at least
3136 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3137 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3140 /* If this kind of value comes back in memory,
3141 decide where in memory it should come back. */
3142 if (outmode != VOIDmode && aggregate_value_p (type_for_mode (outmode, 0)))
3144 #ifdef PCC_STATIC_STRUCT_RETURN
3146 = hard_function_value (build_pointer_type (type_for_mode (outmode, 0)),
3148 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3149 pcc_struct_value = 1;
3151 value = gen_reg_rtx (outmode);
3152 #else /* not PCC_STATIC_STRUCT_RETURN */
3153 struct_value_size = GET_MODE_SIZE (outmode);
3154 if (value != 0 && GET_CODE (value) == MEM)
3157 mem_value = assign_stack_temp (outmode, GET_MODE_SIZE (outmode), 0);
3160 /* This call returns a big structure. */
3164 /* ??? Unfinished: must pass the memory address as an argument. */
3166 /* Copy all the libcall-arguments out of the varargs data
3167 and into a vector ARGVEC.
3169 Compute how to pass each argument. We only support a very small subset
3170 of the full argument passing conventions to limit complexity here since
3171 library functions shouldn't have many args. */
3173 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3174 bzero ((char *) argvec, (nargs + 1) * sizeof (struct arg));
3176 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3178 args_size.constant = 0;
3185 /* If there's a structure value address to be passed,
3186 either pass it in the special place, or pass it as an extra argument. */
3187 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3189 rtx addr = XEXP (mem_value, 0);
3192 /* Make sure it is a reasonable operand for a move or push insn. */
3193 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3194 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3195 addr = force_operand (addr, NULL_RTX);
3197 argvec[count].value = addr;
3198 argvec[count].mode = Pmode;
3199 argvec[count].partial = 0;
3201 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3202 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3203 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3207 locate_and_pad_parm (Pmode, NULL_TREE,
3208 argvec[count].reg && argvec[count].partial == 0,
3209 NULL_TREE, &args_size, &argvec[count].offset,
3210 &argvec[count].size, &alignment_pad);
3213 if (argvec[count].reg == 0 || argvec[count].partial != 0
3214 || reg_parm_stack_space > 0)
3215 args_size.constant += argvec[count].size.constant;
3217 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3222 for (; count < nargs; count++)
3224 rtx val = va_arg (p, rtx);
3225 enum machine_mode mode = va_arg (p, enum machine_mode);
3227 /* We cannot convert the arg value to the mode the library wants here;
3228 must do it earlier where we know the signedness of the arg. */
3230 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3233 /* On some machines, there's no way to pass a float to a library fcn.
3234 Pass it as a double instead. */
3235 #ifdef LIBGCC_NEEDS_DOUBLE
3236 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3237 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3240 /* There's no need to call protect_from_queue, because
3241 either emit_move_insn or emit_push_insn will do that. */
3243 /* Make sure it is a reasonable operand for a move or push insn. */
3244 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3245 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3246 val = force_operand (val, NULL_RTX);
3248 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3249 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3251 /* We do not support FUNCTION_ARG_CALLEE_COPIES here since it can
3252 be viewed as just an efficiency improvement. */
3253 rtx slot = assign_stack_temp (mode, GET_MODE_SIZE (mode), 0);
3254 emit_move_insn (slot, val);
3255 val = force_operand (XEXP (slot, 0), NULL_RTX);
3260 argvec[count].value = val;
3261 argvec[count].mode = mode;
3263 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3265 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3266 argvec[count].partial
3267 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3269 argvec[count].partial = 0;
3272 locate_and_pad_parm (mode, NULL_TREE,
3273 argvec[count].reg && argvec[count].partial == 0,
3274 NULL_TREE, &args_size, &argvec[count].offset,
3275 &argvec[count].size, &alignment_pad);
3277 if (argvec[count].size.var)
3280 if (reg_parm_stack_space == 0 && argvec[count].partial)
3281 argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3283 if (argvec[count].reg == 0 || argvec[count].partial != 0
3284 || reg_parm_stack_space > 0)
3285 args_size.constant += argvec[count].size.constant;
3287 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3290 #ifdef FINAL_REG_PARM_STACK_SPACE
3291 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3294 /* If this machine requires an external definition for library
3295 functions, write one out. */
3296 assemble_external_libcall (fun);
3298 original_args_size = args_size;
3299 #ifdef PREFERRED_STACK_BOUNDARY
3300 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
3301 / STACK_BYTES) * STACK_BYTES);
3304 args_size.constant = MAX (args_size.constant,
3305 reg_parm_stack_space);
3307 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3308 args_size.constant -= reg_parm_stack_space;
3311 if (args_size.constant > current_function_outgoing_args_size)
3312 current_function_outgoing_args_size = args_size.constant;
3314 #ifdef ACCUMULATE_OUTGOING_ARGS
3315 /* Since the stack pointer will never be pushed, it is possible for
3316 the evaluation of a parm to clobber something we have already
3317 written to the stack. Since most function calls on RISC machines
3318 do not use the stack, this is uncommon, but must work correctly.
3320 Therefore, we save any area of the stack that was already written
3321 and that we are using. Here we set up to do this by making a new
3322 stack usage map from the old one.
3324 Another approach might be to try to reorder the argument
3325 evaluations to avoid this conflicting stack usage. */
3327 needed = args_size.constant;
3329 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3330 /* Since we will be writing into the entire argument area, the
3331 map must be allocated for its entire size, not just the part that
3332 is the responsibility of the caller. */
3333 needed += reg_parm_stack_space;
3336 #ifdef ARGS_GROW_DOWNWARD
3337 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3340 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3343 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3345 if (initial_highest_arg_in_use)
3346 bcopy (initial_stack_usage_map, stack_usage_map,
3347 initial_highest_arg_in_use);
3349 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3350 bzero (&stack_usage_map[initial_highest_arg_in_use],
3351 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3354 /* The address of the outgoing argument list must not be copied to a
3355 register here, because argblock would be left pointing to the
3356 wrong place after the call to allocate_dynamic_stack_space below.
3359 argblock = virtual_outgoing_args_rtx;
3360 #else /* not ACCUMULATE_OUTGOING_ARGS */
3361 #ifndef PUSH_ROUNDING
3362 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3366 #ifdef PUSH_ARGS_REVERSED
3367 #ifdef PREFERRED_STACK_BOUNDARY
3368 /* If we push args individually in reverse order, perform stack alignment
3369 before the first push (the last arg). */
3371 anti_adjust_stack (GEN_INT (args_size.constant
3372 - original_args_size.constant));
3376 #ifdef PUSH_ARGS_REVERSED
3384 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
3385 /* The argument list is the property of the called routine and it
3386 may clobber it. If the fixed area has been used for previous
3387 parameters, we must save and restore it.
3389 Here we compute the boundary of the that needs to be saved, if any. */
3391 #ifdef ARGS_GROW_DOWNWARD
3392 for (count = 0; count < reg_parm_stack_space + 1; count++)
3394 for (count = 0; count < reg_parm_stack_space; count++)
3397 if (count >= highest_outgoing_arg_in_use
3398 || stack_usage_map[count] == 0)
3401 if (low_to_save == -1)
3402 low_to_save = count;
3404 high_to_save = count;
3407 if (low_to_save >= 0)
3409 int num_to_save = high_to_save - low_to_save + 1;
3410 enum machine_mode save_mode
3411 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
3414 /* If we don't have the required alignment, must do this in BLKmode. */
3415 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
3416 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
3417 save_mode = BLKmode;
3419 #ifdef ARGS_GROW_DOWNWARD
3420 stack_area = gen_rtx_MEM (save_mode,
3421 memory_address (save_mode,
3422 plus_constant (argblock,
3425 stack_area = gen_rtx_MEM (save_mode,
3426 memory_address (save_mode,
3427 plus_constant (argblock,
3430 if (save_mode == BLKmode)
3432 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
3433 emit_block_move (validize_mem (save_area), stack_area,
3434 GEN_INT (num_to_save),
3435 PARM_BOUNDARY / BITS_PER_UNIT);
3439 save_area = gen_reg_rtx (save_mode);
3440 emit_move_insn (save_area, stack_area);
3445 /* Push the args that need to be pushed. */
3447 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3448 are to be pushed. */
3449 for (count = 0; count < nargs; count++, argnum += inc)
3451 register enum machine_mode mode = argvec[argnum].mode;
3452 register rtx val = argvec[argnum].value;
3453 rtx reg = argvec[argnum].reg;
3454 int partial = argvec[argnum].partial;
3455 #ifdef ACCUMULATE_OUTGOING_ARGS
3456 int lower_bound, upper_bound, i;
3459 if (! (reg != 0 && partial == 0))
3461 #ifdef ACCUMULATE_OUTGOING_ARGS
3462 /* If this is being stored into a pre-allocated, fixed-size, stack
3463 area, save any previous data at that location. */
3465 #ifdef ARGS_GROW_DOWNWARD
3466 /* stack_slot is negative, but we want to index stack_usage_map
3467 with positive values. */
3468 upper_bound = -argvec[argnum].offset.constant + 1;
3469 lower_bound = upper_bound - argvec[argnum].size.constant;
3471 lower_bound = argvec[argnum].offset.constant;
3472 upper_bound = lower_bound + argvec[argnum].size.constant;
3475 for (i = lower_bound; i < upper_bound; i++)
3476 if (stack_usage_map[i]
3477 /* Don't store things in the fixed argument area at this point;
3478 it has already been saved. */
3479 && i > reg_parm_stack_space)
3482 if (i != upper_bound)
3484 /* We need to make a save area. See what mode we can make it. */
3485 enum machine_mode save_mode
3486 = mode_for_size (argvec[argnum].size.constant * BITS_PER_UNIT,
3493 plus_constant (argblock,
3494 argvec[argnum].offset.constant)));
3495 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3497 emit_move_insn (argvec[argnum].save_area, stack_area);
3500 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0,
3501 argblock, GEN_INT (argvec[argnum].offset.constant),
3502 reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3504 #ifdef ACCUMULATE_OUTGOING_ARGS
3505 /* Now mark the segment we just used. */
3506 for (i = lower_bound; i < upper_bound; i++)
3507 stack_usage_map[i] = 1;
3514 #ifndef PUSH_ARGS_REVERSED
3515 #ifdef PREFERRED_STACK_BOUNDARY
3516 /* If we pushed args in forward order, perform stack alignment
3517 after pushing the last arg. */
3519 anti_adjust_stack (GEN_INT (args_size.constant
3520 - original_args_size.constant));
3524 #ifdef PUSH_ARGS_REVERSED
3530 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0);
3532 /* Now load any reg parms into their regs. */
3534 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3535 are to be pushed. */
3536 for (count = 0; count < nargs; count++, argnum += inc)
3538 register rtx val = argvec[argnum].value;
3539 rtx reg = argvec[argnum].reg;
3540 int partial = argvec[argnum].partial;
3542 /* Handle calls that pass values in multiple non-contiguous
3543 locations. The PA64 has examples of this for library calls. */
3544 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3545 emit_group_load (reg, val,
3546 GET_MODE_SIZE (GET_MODE (val)),
3547 GET_MODE_ALIGNMENT (GET_MODE (val)));
3548 else if (reg != 0 && partial == 0)
3549 emit_move_insn (reg, val);
3555 /* For version 1.37, try deleting this entirely. */
3560 /* Any regs containing parms remain in use through the call. */
3561 for (count = 0; count < nargs; count++)
3563 rtx reg = argvec[count].reg;
3564 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3565 use_group_regs (&call_fusage, reg);
3567 use_reg (&call_fusage, reg);
3570 /* Pass the function the address in which to return a structure value. */
3571 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
3573 emit_move_insn (struct_value_rtx,
3575 force_operand (XEXP (mem_value, 0),
3577 if (GET_CODE (struct_value_rtx) == REG)
3578 use_reg (&call_fusage, struct_value_rtx);
3581 /* Don't allow popping to be deferred, since then
3582 cse'ing of library calls could delete a call and leave the pop. */
3585 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3586 will set inhibit_defer_pop to that value. */
3587 /* The return type is needed to decide how many bytes the function pops.
3588 Signedness plays no role in that, so for simplicity, we pretend it's
3589 always signed. We also assume that the list of arguments passed has
3590 no impact, so we pretend it is unknown. */
3593 get_identifier (XSTR (orgfun, 0)),
3594 build_function_type (outmode == VOIDmode ? void_type_node
3595 : type_for_mode (outmode, 0), NULL_TREE),
3596 original_args_size.constant, args_size.constant,
3598 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3599 mem_value == 0 && outmode != VOIDmode ? hard_libcall_value (outmode) : NULL_RTX,
3600 old_inhibit_defer_pop + 1, call_fusage,
3601 ((is_const ? ECF_IS_CONST : 0)
3602 | (nothrow ? ECF_NOTHROW : 0)));
3604 /* Now restore inhibit_defer_pop to its actual original value. */
3609 /* Copy the value to the right place. */
3610 if (outmode != VOIDmode && retval)
3616 if (value != mem_value)
3617 emit_move_insn (value, mem_value);
3619 else if (value != 0)
3620 emit_move_insn (value, hard_libcall_value (outmode));
3622 value = hard_libcall_value (outmode);
3625 #ifdef ACCUMULATE_OUTGOING_ARGS
3626 #ifdef REG_PARM_STACK_SPACE
3629 enum machine_mode save_mode = GET_MODE (save_area);
3630 #ifdef ARGS_GROW_DOWNWARD
3632 = gen_rtx_MEM (save_mode,
3633 memory_address (save_mode,
3634 plus_constant (argblock,
3638 = gen_rtx_MEM (save_mode,
3639 memory_address (save_mode,
3640 plus_constant (argblock, low_to_save)));
3642 if (save_mode != BLKmode)
3643 emit_move_insn (stack_area, save_area);
3645 emit_block_move (stack_area, validize_mem (save_area),
3646 GEN_INT (high_to_save - low_to_save + 1),
3647 PARM_BOUNDARY / BITS_PER_UNIT);
3651 /* If we saved any argument areas, restore them. */
3652 for (count = 0; count < nargs; count++)
3653 if (argvec[count].save_area)
3655 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3657 = gen_rtx_MEM (save_mode,
3660 plus_constant (argblock,
3661 argvec[count].offset.constant)));
3663 emit_move_insn (stack_area, argvec[count].save_area);
3666 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3667 stack_usage_map = initial_stack_usage_map;
3674 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3675 (emitting the queue unless NO_QUEUE is nonzero),
3676 for a value of mode OUTMODE,
3677 with NARGS different arguments, passed as alternating rtx values
3678 and machine_modes to convert them to.
3679 The rtx values should have been passed through protect_from_queue already.
3681 NO_QUEUE will be true if and only if the library call is a `const' call
3682 which will be enclosed in REG_LIBCALL/REG_RETVAL notes; it is equivalent
3683 to the variable is_const in expand_call.
3685 NO_QUEUE must be true for const calls, because if it isn't, then
3686 any pending increment will be emitted between REG_LIBCALL/REG_RETVAL notes,
3687 and will be lost if the libcall sequence is optimized away.
3689 NO_QUEUE must be false for non-const calls, because if it isn't, the
3690 call insn will have its CONST_CALL_P bit set, and it will be incorrectly
3691 optimized. For instance, the instruction scheduler may incorrectly
3692 move memory references across the non-const call. */
3695 emit_library_call VPARAMS((rtx orgfun, int no_queue, enum machine_mode outmode,
3698 #ifndef ANSI_PROTOTYPES
3701 enum machine_mode outmode;
3706 VA_START (p, nargs);
3708 #ifndef ANSI_PROTOTYPES
3709 orgfun = va_arg (p, rtx);
3710 no_queue = va_arg (p, int);
3711 outmode = va_arg (p, enum machine_mode);
3712 nargs = va_arg (p, int);
3715 emit_library_call_value_1 (0, orgfun, NULL_RTX, no_queue, outmode, nargs, p);
3720 /* Like emit_library_call except that an extra argument, VALUE,
3721 comes second and says where to store the result.
3722 (If VALUE is zero, this function chooses a convenient way
3723 to return the value.
3725 This function returns an rtx for where the value is to be found.
3726 If VALUE is nonzero, VALUE is returned. */
3729 emit_library_call_value VPARAMS((rtx orgfun, rtx value, int no_queue,
3730 enum machine_mode outmode, int nargs, ...))
3732 #ifndef ANSI_PROTOTYPES
3736 enum machine_mode outmode;
3741 VA_START (p, nargs);
3743 #ifndef ANSI_PROTOTYPES
3744 orgfun = va_arg (p, rtx);
3745 value = va_arg (p, rtx);
3746 no_queue = va_arg (p, int);
3747 outmode = va_arg (p, enum machine_mode);
3748 nargs = va_arg (p, int);
3751 value = emit_library_call_value_1 (1, orgfun, value, no_queue, outmode, nargs, p);
3759 /* Return an rtx which represents a suitable home on the stack
3760 given TYPE, the type of the argument looking for a home.
3761 This is called only for BLKmode arguments.
3763 SIZE is the size needed for this target.
3764 ARGS_ADDR is the address of the bottom of the argument block for this call.
3765 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
3766 if this machine uses push insns. */
3769 target_for_arg (type, size, args_addr, offset)
3773 struct args_size offset;
3776 rtx offset_rtx = ARGS_SIZE_RTX (offset);
3778 /* We do not call memory_address if possible,
3779 because we want to address as close to the stack
3780 as possible. For non-variable sized arguments,
3781 this will be stack-pointer relative addressing. */
3782 if (GET_CODE (offset_rtx) == CONST_INT)
3783 target = plus_constant (args_addr, INTVAL (offset_rtx));
3786 /* I have no idea how to guarantee that this
3787 will work in the presence of register parameters. */
3788 target = gen_rtx_PLUS (Pmode, args_addr, offset_rtx);
3789 target = memory_address (QImode, target);
3792 return gen_rtx_MEM (BLKmode, target);
3796 /* Store a single argument for a function call
3797 into the register or memory area where it must be passed.
3798 *ARG describes the argument value and where to pass it.
3800 ARGBLOCK is the address of the stack-block for all the arguments,
3801 or 0 on a machine where arguments are pushed individually.
3803 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3804 so must be careful about how the stack is used.
3806 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3807 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3808 that we need not worry about saving and restoring the stack.
3810 FNDECL is the declaration of the function we are calling. */
3813 store_one_arg (arg, argblock, may_be_alloca, variable_size,
3814 reg_parm_stack_space)
3815 struct arg_data *arg;
3818 int variable_size ATTRIBUTE_UNUSED;
3819 int reg_parm_stack_space;
3821 register tree pval = arg->tree_value;
3825 #ifdef ACCUMULATE_OUTGOING_ARGS
3826 int i, lower_bound = 0, upper_bound = 0;
3829 if (TREE_CODE (pval) == ERROR_MARK)
3832 /* Push a new temporary level for any temporaries we make for
3836 #ifdef ACCUMULATE_OUTGOING_ARGS
3837 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3838 save any previous data at that location. */
3839 if (argblock && ! variable_size && arg->stack)
3841 #ifdef ARGS_GROW_DOWNWARD
3842 /* stack_slot is negative, but we want to index stack_usage_map
3843 with positive values. */
3844 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3845 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3849 lower_bound = upper_bound - arg->size.constant;
3851 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3852 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3856 upper_bound = lower_bound + arg->size.constant;
3859 for (i = lower_bound; i < upper_bound; i++)
3860 if (stack_usage_map[i]
3861 /* Don't store things in the fixed argument area at this point;
3862 it has already been saved. */
3863 && i > reg_parm_stack_space)
3866 if (i != upper_bound)
3868 /* We need to make a save area. See what mode we can make it. */
3869 enum machine_mode save_mode
3870 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
3872 = gen_rtx_MEM (save_mode,
3873 memory_address (save_mode,
3874 XEXP (arg->stack_slot, 0)));
3876 if (save_mode == BLKmode)
3878 arg->save_area = assign_stack_temp (BLKmode,
3879 arg->size.constant, 0);
3880 MEM_SET_IN_STRUCT_P (arg->save_area,
3881 AGGREGATE_TYPE_P (TREE_TYPE
3882 (arg->tree_value)));
3883 preserve_temp_slots (arg->save_area);
3884 emit_block_move (validize_mem (arg->save_area), stack_area,
3885 GEN_INT (arg->size.constant),
3886 PARM_BOUNDARY / BITS_PER_UNIT);
3890 arg->save_area = gen_reg_rtx (save_mode);
3891 emit_move_insn (arg->save_area, stack_area);
3896 /* Now that we have saved any slots that will be overwritten by this
3897 store, mark all slots this store will use. We must do this before
3898 we actually expand the argument since the expansion itself may
3899 trigger library calls which might need to use the same stack slot. */
3900 if (argblock && ! variable_size && arg->stack)
3901 for (i = lower_bound; i < upper_bound; i++)
3902 stack_usage_map[i] = 1;
3905 /* If this isn't going to be placed on both the stack and in registers,
3906 set up the register and number of words. */
3907 if (! arg->pass_on_stack)
3908 reg = arg->reg, partial = arg->partial;
3910 if (reg != 0 && partial == 0)
3911 /* Being passed entirely in a register. We shouldn't be called in
3915 /* If this arg needs special alignment, don't load the registers
3917 if (arg->n_aligned_regs != 0)
3920 /* If this is being passed partially in a register, we can't evaluate
3921 it directly into its stack slot. Otherwise, we can. */
3922 if (arg->value == 0)
3924 #ifdef ACCUMULATE_OUTGOING_ARGS
3925 /* stack_arg_under_construction is nonzero if a function argument is
3926 being evaluated directly into the outgoing argument list and
3927 expand_call must take special action to preserve the argument list
3928 if it is called recursively.
3930 For scalar function arguments stack_usage_map is sufficient to
3931 determine which stack slots must be saved and restored. Scalar
3932 arguments in general have pass_on_stack == 0.
3934 If this argument is initialized by a function which takes the
3935 address of the argument (a C++ constructor or a C function
3936 returning a BLKmode structure), then stack_usage_map is
3937 insufficient and expand_call must push the stack around the
3938 function call. Such arguments have pass_on_stack == 1.
3940 Note that it is always safe to set stack_arg_under_construction,
3941 but this generates suboptimal code if set when not needed. */
3943 if (arg->pass_on_stack)
3944 stack_arg_under_construction++;
3946 arg->value = expand_expr (pval,
3948 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
3949 ? NULL_RTX : arg->stack,
3952 /* If we are promoting object (or for any other reason) the mode
3953 doesn't agree, convert the mode. */
3955 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
3956 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
3957 arg->value, arg->unsignedp);
3959 #ifdef ACCUMULATE_OUTGOING_ARGS
3960 if (arg->pass_on_stack)
3961 stack_arg_under_construction--;
3965 /* Don't allow anything left on stack from computation
3966 of argument to alloca. */
3968 do_pending_stack_adjust ();
3970 if (arg->value == arg->stack)
3972 /* If the value is already in the stack slot, we are done. */
3973 if (current_function_check_memory_usage && GET_CODE (arg->stack) == MEM)
3975 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
3976 XEXP (arg->stack, 0), Pmode,
3977 ARGS_SIZE_RTX (arg->size),
3978 TYPE_MODE (sizetype),
3979 GEN_INT (MEMORY_USE_RW),
3980 TYPE_MODE (integer_type_node));
3983 else if (arg->mode != BLKmode)
3987 /* Argument is a scalar, not entirely passed in registers.
3988 (If part is passed in registers, arg->partial says how much
3989 and emit_push_insn will take care of putting it there.)
3991 Push it, and if its size is less than the
3992 amount of space allocated to it,
3993 also bump stack pointer by the additional space.
3994 Note that in C the default argument promotions
3995 will prevent such mismatches. */
3997 size = GET_MODE_SIZE (arg->mode);
3998 /* Compute how much space the push instruction will push.
3999 On many machines, pushing a byte will advance the stack
4000 pointer by a halfword. */
4001 #ifdef PUSH_ROUNDING
4002 size = PUSH_ROUNDING (size);
4006 /* Compute how much space the argument should get:
4007 round up to a multiple of the alignment for arguments. */
4008 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4009 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4010 / (PARM_BOUNDARY / BITS_PER_UNIT))
4011 * (PARM_BOUNDARY / BITS_PER_UNIT));
4013 /* This isn't already where we want it on the stack, so put it there.
4014 This can either be done with push or copy insns. */
4015 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 0,
4016 partial, reg, used - size, argblock,
4017 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4018 ARGS_SIZE_RTX (arg->alignment_pad));
4020 arg_space_so_far += used;
4024 /* BLKmode, at least partly to be pushed. */
4026 register int excess;
4029 /* Pushing a nonscalar.
4030 If part is passed in registers, PARTIAL says how much
4031 and emit_push_insn will take care of putting it there. */
4033 /* Round its size up to a multiple
4034 of the allocation unit for arguments. */
4036 if (arg->size.var != 0)
4039 size_rtx = ARGS_SIZE_RTX (arg->size);
4043 /* PUSH_ROUNDING has no effect on us, because
4044 emit_push_insn for BLKmode is careful to avoid it. */
4045 excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4046 + partial * UNITS_PER_WORD);
4047 size_rtx = expr_size (pval);
4048 arg_space_so_far += excess + INTVAL (size_rtx);
4051 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4052 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
4053 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset),
4054 reg_parm_stack_space,
4055 ARGS_SIZE_RTX (arg->alignment_pad));
4059 /* Unless this is a partially-in-register argument, the argument is now
4062 ??? Note that this can change arg->value from arg->stack to
4063 arg->stack_slot and it matters when they are not the same.
4064 It isn't totally clear that this is correct in all cases. */
4066 arg->value = arg->stack_slot;
4068 /* Once we have pushed something, pops can't safely
4069 be deferred during the rest of the arguments. */
4072 /* ANSI doesn't require a sequence point here,
4073 but PCC has one, so this will avoid some problems. */
4076 /* Free any temporary slots made in processing this argument. Show
4077 that we might have taken the address of something and pushed that
4079 preserve_temp_slots (NULL_RTX);