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
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 /* Tail calls can make things harder to debug, and we're traditionally
2031 pushed these optimizations into -O2. Don't try if we're already
2032 expanding a call, as that means we're an argument. Similarly, if
2033 there's pending loops or cleanups we know there's code to follow
2037 if (flag_optimize_sibling_calls
2038 && currently_expanding_call == 1
2039 && stmt_loop_nest_empty ()
2040 && ! any_pending_cleanups (1))
2042 tree new_actparms = NULL_TREE;
2044 /* Ok, we're going to give the tail call the old college try.
2045 This means we're going to evaluate the function arguments
2046 up to three times. There are two degrees of badness we can
2047 encounter, those that can be unsaved and those that can't.
2048 (See unsafe_for_reeval commentary for details.)
2050 Generate a new argument list. Pass safe arguments through
2051 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2052 For hard badness, evaluate them now and put their resulting
2053 rtx in a temporary VAR_DECL. */
2055 for (p = actparms; p; p = TREE_CHAIN (p))
2056 switch (unsafe_for_reeval (TREE_VALUE (p)))
2059 new_actparms = tree_cons (TREE_PURPOSE (p), TREE_VALUE (p),
2063 case 1: /* Mildly unsafe. */
2064 new_actparms = tree_cons (TREE_PURPOSE (p),
2065 unsave_expr (TREE_VALUE (p)),
2069 case 2: /* Wildly unsafe. */
2071 tree var = build_decl (VAR_DECL, NULL_TREE,
2072 TREE_TYPE (TREE_VALUE (p)));
2073 DECL_RTL (var) = expand_expr (TREE_VALUE (p), NULL_RTX,
2074 VOIDmode, EXPAND_NORMAL);
2075 new_actparms = tree_cons (TREE_PURPOSE (p), var, new_actparms);
2083 /* We built the new argument chain backwards. */
2084 actparms = nreverse (new_actparms);
2086 /* Expanding one of those dangerous arguments could have added
2087 cleanups, but otherwise give it a whirl. */
2088 try_tail_call = ! any_pending_cleanups (1);
2091 /* Generate a tail recursion sequence when calling ourselves. */
2094 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
2095 && TREE_OPERAND (TREE_OPERAND (exp, 0), 0) == current_function_decl)
2097 /* We want to emit any pending stack adjustments before the tail
2098 recursion "call". That way we know any adjustment after the tail
2099 recursion call can be ignored if we indeed use the tail recursion
2101 int save_pending_stack_adjust = pending_stack_adjust;
2103 /* Use a new sequence to hold any RTL we generate. We do not even
2104 know if we will use this RTL yet. The final decision can not be
2105 made until after RTL generation for the entire function is
2109 /* Emit the pending stack adjustments before we expand any arguments. */
2110 do_pending_stack_adjust ();
2112 if (optimize_tail_recursion (actparms, get_last_insn ()))
2113 tail_recursion_insns = get_insns ();
2116 /* Restore the original pending stack adjustment for the sibling and
2117 normal call cases below. */
2118 pending_stack_adjust = save_pending_stack_adjust;
2121 function_call_count++;
2123 if (fndecl && DECL_NAME (fndecl))
2124 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
2126 #ifdef PREFERRED_STACK_BOUNDARY
2127 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2129 preferred_stack_boundary = STACK_BOUNDARY;
2132 /* Ensure current function's preferred stack boundary is at least
2133 what we need. We don't have to increase alignment for recursive
2135 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2136 && fndecl != current_function_decl)
2137 cfun->preferred_stack_boundary = preferred_stack_boundary;
2139 /* See if this is a call to a function that can return more than once
2140 or a call to longjmp or malloc. */
2141 special_function_p (fndecl, &returns_twice, &is_longjmp, &fork_or_exec,
2142 &is_malloc, &may_be_alloca);
2145 current_function_calls_alloca = 1;
2147 /* Operand 0 is a pointer-to-function; get the type of the function. */
2148 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
2149 if (! POINTER_TYPE_P (funtype))
2151 funtype = TREE_TYPE (funtype);
2153 /* We want to make two insn chains; one for a sibling call, the other
2154 for a normal call. We will select one of the two chains after
2155 initial RTL generation is complete. */
2156 for (pass = 0; pass < 2; pass++)
2158 int sibcall_failure = 0;
2159 /* We want to emit ay pending stack adjustments before the tail
2160 recursion "call". That way we know any adjustment after the tail
2161 recursion call can be ignored if we indeed use the tail recursion
2163 int save_pending_stack_adjust;
2165 rtx before_call, next_arg_reg;
2169 /* Various reasons we can not use a sibling call. */
2171 #ifdef HAVE_sibcall_epilogue
2172 || ! HAVE_sibcall_epilogue
2176 /* The structure value address is used and modified in the
2177 loop below. It does not seem worth the effort to save and
2178 restore it as a state variable since few optimizable
2179 sibling calls will return a structure. */
2180 || structure_value_addr != NULL_RTX
2181 /* If the register holding the address is a callee saved
2182 register, then we lose. We have no way to prevent that,
2183 so we only allow calls to named functions. */
2184 /* ??? This could be done by having the insn constraints
2185 use a register class that is all call-clobbered. Any
2186 reload insns generated to fix things up would appear
2187 before the sibcall_epilogue. */
2188 || fndecl == NULL_TREE
2189 || ! FUNCTION_OK_FOR_SIBCALL (fndecl))
2192 /* We know at this point that there are not currently any
2193 pending cleanups. If, however, in the process of evaluating
2194 the arguments we were to create some, we'll need to be
2195 able to get rid of them. */
2196 expand_start_target_temps ();
2198 /* State variables we need to save and restore between
2200 save_pending_stack_adjust = pending_stack_adjust;
2203 /* Other state variables that we must reinitialize each time
2204 through the loop (that are not initialized by the loop itself. */
2208 /* Start a new sequence for the normal call case.
2210 From this point on, if the sibling call fails, we want to set
2211 sibcall_failure instead of continuing the loop. */
2214 /* When calling a const function, we must pop the stack args right away,
2215 so that the pop is deleted or moved with the call. */
2219 /* Don't let pending stack adjusts add up to too much.
2220 Also, do all pending adjustments now if there is any chance
2221 this might be a call to alloca or if we are expanding a sibling
2223 if (pending_stack_adjust >= 32
2224 || (pending_stack_adjust > 0 && may_be_alloca)
2226 do_pending_stack_adjust ();
2228 if (profile_arc_flag && fork_or_exec)
2230 /* A fork duplicates the profile information, and an exec discards
2231 it. We can't rely on fork/exec to be paired. So write out the
2232 profile information we have gathered so far, and clear it. */
2233 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2234 is subject to race conditions, just as with multithreaded
2237 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_fork_func"), 0,
2241 /* Push the temporary stack slot level so that we can free any
2242 temporaries we make. */
2245 /* Start updating where the next arg would go.
2247 On some machines (such as the PA) indirect calls have a different
2248 calling convention than normal calls. The last argument in
2249 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2251 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0));
2253 /* If struct_value_rtx is 0, it means pass the address
2254 as if it were an extra parameter. */
2255 if (structure_value_addr && struct_value_rtx == 0)
2257 /* If structure_value_addr is a REG other than
2258 virtual_outgoing_args_rtx, we can use always use it. If it
2259 is not a REG, we must always copy it into a register.
2260 If it is virtual_outgoing_args_rtx, we must copy it to another
2261 register in some cases. */
2262 rtx temp = (GET_CODE (structure_value_addr) != REG
2263 #ifdef ACCUMULATE_OUTGOING_ARGS
2264 || (stack_arg_under_construction
2265 && structure_value_addr == virtual_outgoing_args_rtx)
2267 ? copy_addr_to_reg (structure_value_addr)
2268 : structure_value_addr);
2271 = tree_cons (error_mark_node,
2272 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2275 structure_value_addr_parm = 1;
2278 /* Count the arguments and set NUM_ACTUALS. */
2279 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
2282 /* Compute number of named args.
2283 Normally, don't include the last named arg if anonymous args follow.
2284 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2285 (If no anonymous args follow, the result of list_length is actually
2286 one too large. This is harmless.)
2288 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2289 zero, this machine will be able to place unnamed args that were
2290 passed in registers into the stack. So treat all args as named.
2291 This allows the insns emitting for a specific argument list to be
2292 independent of the function declaration.
2294 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2295 reliable way to pass unnamed args in registers, so we must force
2296 them into memory. */
2298 if ((STRICT_ARGUMENT_NAMING
2299 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2300 && TYPE_ARG_TYPES (funtype) != 0)
2302 = (list_length (TYPE_ARG_TYPES (funtype))
2303 /* Don't include the last named arg. */
2304 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2305 /* Count the struct value address, if it is passed as a parm. */
2306 + structure_value_addr_parm);
2308 /* If we know nothing, treat all args as named. */
2309 n_named_args = num_actuals;
2311 /* Make a vector to hold all the information about each arg. */
2312 args = (struct arg_data *) alloca (num_actuals
2313 * sizeof (struct arg_data));
2314 bzero ((char *) args, num_actuals * sizeof (struct arg_data));
2316 /* Build up entries inthe ARGS array, compute the size of the arguments
2317 into ARGS_SIZE, etc. */
2318 initialize_argument_information (num_actuals, args, &args_size,
2319 n_named_args, actparms, fndecl,
2320 &args_so_far, reg_parm_stack_space,
2321 &old_stack_level, &old_pending_adj,
2322 &must_preallocate, &is_const,
2323 (pass == 0) ? ECF_SIBCALL : 0);
2325 #ifdef FINAL_REG_PARM_STACK_SPACE
2326 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2332 /* If this function requires a variable-sized argument list, don't
2333 try to make a cse'able block for this call. We may be able to
2334 do this eventually, but it is too complicated to keep track of
2335 what insns go in the cse'able block and which don't.
2337 Also do not make a sibling call. */
2340 must_preallocate = 1;
2341 sibcall_failure = 1;
2344 if (args_size.constant > current_function_args_size)
2346 /* If this function requires more stack slots than the current
2347 function, we cannot change it into a sibling call. */
2348 sibcall_failure = 1;
2351 /* Compute the actual size of the argument block required. The variable
2352 and constant sizes must be combined, the size may have to be rounded,
2353 and there may be a minimum required size. When generating a sibcall
2354 pattern, do not round up, since we'll be re-using whatever space our
2356 unadjusted_args_size
2357 = compute_argument_block_size (reg_parm_stack_space, &args_size,
2359 : preferred_stack_boundary));
2361 /* If the callee pops its own arguments, then it must pop exactly
2362 the same number of arguments as the current function. */
2363 if (RETURN_POPS_ARGS (fndecl, funtype, unadjusted_args_size)
2364 != RETURN_POPS_ARGS (current_function_decl,
2365 TREE_TYPE (current_function_decl),
2366 current_function_args_size))
2367 sibcall_failure = 1;
2369 /* Now make final decision about preallocating stack space. */
2370 must_preallocate = finalize_must_preallocate (must_preallocate,
2374 /* If the structure value address will reference the stack pointer, we
2375 must stabilize it. We don't need to do this if we know that we are
2376 not going to adjust the stack pointer in processing this call. */
2378 if (structure_value_addr
2379 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2380 || reg_mentioned_p (virtual_outgoing_args_rtx,
2381 structure_value_addr))
2383 #ifndef ACCUMULATE_OUTGOING_ARGS
2384 || args_size.constant
2387 structure_value_addr = copy_to_reg (structure_value_addr);
2389 /* Precompute any arguments as needed. */
2390 precompute_arguments (is_const, must_preallocate, num_actuals,
2393 /* Now we are about to start emitting insns that can be deleted
2394 if a libcall is deleted. */
2395 if (is_const || is_malloc)
2398 /* If we have no actual push instructions, or shouldn't use them,
2399 make space for all args right now. */
2401 if (args_size.var != 0)
2403 if (old_stack_level == 0)
2405 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2406 old_pending_adj = pending_stack_adjust;
2407 pending_stack_adjust = 0;
2408 #ifdef ACCUMULATE_OUTGOING_ARGS
2409 /* stack_arg_under_construction says whether a stack arg is
2410 being constructed at the old stack level. Pushing the stack
2411 gets a clean outgoing argument block. */
2412 old_stack_arg_under_construction = stack_arg_under_construction;
2413 stack_arg_under_construction = 0;
2416 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
2420 /* Note that we must go through the motions of allocating an argument
2421 block even if the size is zero because we may be storing args
2422 in the area reserved for register arguments, which may be part of
2425 int needed = args_size.constant;
2427 /* Store the maximum argument space used. It will be pushed by
2428 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2431 if (needed > current_function_outgoing_args_size)
2432 current_function_outgoing_args_size = needed;
2434 if (must_preallocate)
2436 #ifdef ACCUMULATE_OUTGOING_ARGS
2437 /* Since the stack pointer will never be pushed, it is possible
2438 for the evaluation of a parm to clobber something we have
2439 already written to the stack. Since most function calls on
2440 RISC machines do not use the stack, this is uncommon, but
2441 must work correctly.
2443 Therefore, we save any area of the stack that was already
2444 written and that we are using. Here we set up to do this by
2445 making a new stack usage map from the old one. The actual
2446 save will be done by store_one_arg.
2448 Another approach might be to try to reorder the argument
2449 evaluations to avoid this conflicting stack usage. */
2451 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2452 /* Since we will be writing into the entire argument area, the
2453 map must be allocated for its entire size, not just the part
2454 that is the responsibility of the caller. */
2455 needed += reg_parm_stack_space;
2458 #ifdef ARGS_GROW_DOWNWARD
2459 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2462 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2465 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
2467 if (initial_highest_arg_in_use)
2468 bcopy (initial_stack_usage_map, stack_usage_map,
2469 initial_highest_arg_in_use);
2471 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2472 bzero (&stack_usage_map[initial_highest_arg_in_use],
2473 (highest_outgoing_arg_in_use
2474 - initial_highest_arg_in_use));
2477 /* The address of the outgoing argument list must not be copied
2478 to a register here, because argblock would be left pointing
2479 to the wrong place after the call to
2480 allocate_dynamic_stack_space below. */
2482 argblock = virtual_outgoing_args_rtx;
2484 #else /* not ACCUMULATE_OUTGOING_ARGS */
2485 if (inhibit_defer_pop == 0)
2487 /* Try to reuse some or all of the pending_stack_adjust
2488 to get this space. Maybe we can avoid any pushing. */
2489 if (needed > pending_stack_adjust)
2491 needed -= pending_stack_adjust;
2492 pending_stack_adjust = 0;
2496 pending_stack_adjust -= needed;
2500 /* Special case this because overhead of `push_block' in this
2501 case is non-trivial. */
2503 argblock = virtual_outgoing_args_rtx;
2505 argblock = push_block (GEN_INT (needed), 0, 0);
2507 /* We only really need to call `copy_to_reg' in the case where
2508 push insns are going to be used to pass ARGBLOCK to a function
2509 call in ARGS. In that case, the stack pointer changes value
2510 from the allocation point to the call point, and hence
2511 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
2512 But might as well always do it. */
2513 argblock = copy_to_reg (argblock);
2514 #endif /* not ACCUMULATE_OUTGOING_ARGS */
2518 /* The argument block when performing a sibling call is the
2519 incoming argument block. */
2522 rtx temp = plus_constant (arg_pointer_rtx,
2523 FIRST_PARM_OFFSET (current_function_decl));
2524 argblock = force_reg (Pmode, force_operand (temp, NULL_RTX));
2527 #ifdef ACCUMULATE_OUTGOING_ARGS
2528 /* The save/restore code in store_one_arg handles all cases except one:
2529 a constructor call (including a C function returning a BLKmode struct)
2530 to initialize an argument. */
2531 if (stack_arg_under_construction)
2533 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2534 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
2536 rtx push_size = GEN_INT (args_size.constant);
2538 if (old_stack_level == 0)
2540 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2541 old_pending_adj = pending_stack_adjust;
2542 pending_stack_adjust = 0;
2543 /* stack_arg_under_construction says whether a stack arg is
2544 being constructed at the old stack level. Pushing the stack
2545 gets a clean outgoing argument block. */
2546 old_stack_arg_under_construction = stack_arg_under_construction;
2547 stack_arg_under_construction = 0;
2548 /* Make a new map for the new argument list. */
2549 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
2550 bzero (stack_usage_map, highest_outgoing_arg_in_use);
2551 highest_outgoing_arg_in_use = 0;
2553 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
2555 /* If argument evaluation might modify the stack pointer, copy the
2556 address of the argument list to a register. */
2557 for (i = 0; i < num_actuals; i++)
2558 if (args[i].pass_on_stack)
2560 argblock = copy_addr_to_reg (argblock);
2565 compute_argument_addresses (args, argblock, num_actuals);
2567 #ifdef PUSH_ARGS_REVERSED
2568 #ifdef PREFERRED_STACK_BOUNDARY
2569 /* If we push args individually in reverse order, perform stack alignment
2570 before the first push (the last arg). */
2571 if (args_size.constant != unadjusted_args_size)
2573 /* When the stack adjustment is pending, we get better code
2574 by combining the adjustments. */
2575 if (pending_stack_adjust && ! is_const
2576 && ! inhibit_defer_pop)
2578 args_size.constant = (unadjusted_args_size
2579 + ((pending_stack_adjust
2580 + args_size.constant
2582 - unadjusted_args_size)
2583 % (preferred_stack_boundary
2585 pending_stack_adjust -= (args_size.constant
2586 - unadjusted_args_size);
2587 do_pending_stack_adjust ();
2589 else if (argblock == 0)
2590 anti_adjust_stack (GEN_INT (args_size.constant
2591 - unadjusted_args_size));
2592 arg_space_so_far += args_size.constant - unadjusted_args_size;
2594 /* Now that the stack is properly aligned, pops can't safely
2595 be deferred during the evaluation of the arguments. */
2601 /* Don't try to defer pops if preallocating, not even from the first arg,
2602 since ARGBLOCK probably refers to the SP. */
2606 funexp = rtx_for_function_call (fndecl, exp);
2608 /* Figure out the register where the value, if any, will come back. */
2610 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2611 && ! structure_value_addr)
2613 if (pcc_struct_value)
2614 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2615 fndecl, (pass == 0));
2617 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2620 /* Precompute all register parameters. It isn't safe to compute anything
2621 once we have started filling any specific hard regs. */
2622 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2624 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
2625 /* Save the fixed argument area if it's part of the caller's frame and
2626 is clobbered by argument setup for this call. */
2627 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2628 &low_to_save, &high_to_save);
2631 /* Now store (and compute if necessary) all non-register parms.
2632 These come before register parms, since they can require block-moves,
2633 which could clobber the registers used for register parms.
2634 Parms which have partial registers are not stored here,
2635 but we do preallocate space here if they want that. */
2637 for (i = 0; i < num_actuals; i++)
2638 if (args[i].reg == 0 || args[i].pass_on_stack)
2639 store_one_arg (&args[i], argblock, may_be_alloca,
2640 args_size.var != 0, reg_parm_stack_space);
2642 /* If we have a parm that is passed in registers but not in memory
2643 and whose alignment does not permit a direct copy into registers,
2644 make a group of pseudos that correspond to each register that we
2646 if (STRICT_ALIGNMENT)
2647 store_unaligned_arguments_into_pseudos (args, num_actuals);
2649 /* Now store any partially-in-registers parm.
2650 This is the last place a block-move can happen. */
2652 for (i = 0; i < num_actuals; i++)
2653 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2654 store_one_arg (&args[i], argblock, may_be_alloca,
2655 args_size.var != 0, reg_parm_stack_space);
2657 #ifndef PUSH_ARGS_REVERSED
2658 #ifdef PREFERRED_STACK_BOUNDARY
2659 /* If we pushed args in forward order, perform stack alignment
2660 after pushing the last arg. */
2661 /* ??? Fix for arg_space_so_far. */
2663 anti_adjust_stack (GEN_INT (args_size.constant
2664 - unadjusted_args_size));
2668 /* If register arguments require space on the stack and stack space
2669 was not preallocated, allocate stack space here for arguments
2670 passed in registers. */
2671 #if ! defined(ACCUMULATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
2672 if (must_preallocate == 0 && reg_parm_stack_space > 0)
2673 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2676 /* Pass the function the address in which to return a
2678 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2680 emit_move_insn (struct_value_rtx,
2682 force_operand (structure_value_addr,
2685 /* Mark the memory for the aggregate as write-only. */
2686 if (current_function_check_memory_usage)
2687 emit_library_call (chkr_set_right_libfunc, 1,
2689 structure_value_addr, ptr_mode,
2690 GEN_INT (struct_value_size),
2691 TYPE_MODE (sizetype),
2692 GEN_INT (MEMORY_USE_WO),
2693 TYPE_MODE (integer_type_node));
2695 if (GET_CODE (struct_value_rtx) == REG)
2696 use_reg (&call_fusage, struct_value_rtx);
2699 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
2702 load_register_parameters (args, num_actuals, &call_fusage);
2704 /* Perform postincrements before actually calling the function. */
2707 /* Save a pointer to the last insn before the call, so that we can
2708 later safely search backwards to find the CALL_INSN. */
2709 before_call = get_last_insn ();
2711 /* Set up next argument register. For sibling calls on machines
2712 with register windows this should be the incoming register. */
2713 #ifdef FUNCTION_INCOMING_ARG
2715 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2719 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2722 /* All arguments and registers used for the call must be set up by
2725 /* Generate the actual call instruction. */
2726 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
2727 args_size.constant, struct_value_size,
2728 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2729 ((is_const ? ECF_IS_CONST : 0)
2730 | (nothrow ? ECF_NOTHROW : 0)
2731 | (pass == 0 ? ECF_SIBCALL : 0)));
2733 /* If call is cse'able, make appropriate pair of reg-notes around it.
2734 Test valreg so we don't crash; may safely ignore `const'
2735 if return type is void. Disable for PARALLEL return values, because
2736 we have no way to move such values into a pseudo register. */
2737 if (is_const && valreg != 0 && GET_CODE (valreg) != PARALLEL)
2740 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2743 /* Mark the return value as a pointer if needed. */
2744 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2746 tree pointed_to = TREE_TYPE (TREE_TYPE (exp));
2747 mark_reg_pointer (temp, TYPE_ALIGN (pointed_to) / BITS_PER_UNIT);
2750 /* Construct an "equal form" for the value which mentions all the
2751 arguments in order as well as the function name. */
2752 #ifdef PUSH_ARGS_REVERSED
2753 for (i = 0; i < num_actuals; i++)
2754 note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note);
2756 for (i = num_actuals - 1; i >= 0; i--)
2757 note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note);
2759 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2761 insns = get_insns ();
2764 emit_libcall_block (insns, temp, valreg, note);
2770 /* Otherwise, just write out the sequence without a note. */
2771 rtx insns = get_insns ();
2778 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2781 /* The return value from a malloc-like function is a pointer. */
2782 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2783 mark_reg_pointer (temp, BIGGEST_ALIGNMENT / BITS_PER_UNIT);
2785 emit_move_insn (temp, valreg);
2787 /* The return value from a malloc-like function can not alias
2789 last = get_last_insn ();
2791 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2793 /* Write out the sequence. */
2794 insns = get_insns ();
2800 /* For calls to `setjmp', etc., inform flow.c it should complain
2801 if nonvolatile values are live. For functions that cannot return,
2802 inform flow that control does not fall through. */
2804 if (returns_twice || is_volatile || is_longjmp || pass == 0)
2806 /* The barrier or NOTE_INSN_SETJMP note must be emitted
2807 immediately after the CALL_INSN. Some ports emit more
2808 than just a CALL_INSN above, so we must search for it here. */
2810 rtx last = get_last_insn ();
2811 while (GET_CODE (last) != CALL_INSN)
2813 last = PREV_INSN (last);
2814 /* There was no CALL_INSN? */
2815 if (last == before_call)
2821 emit_note_after (NOTE_INSN_SETJMP, last);
2822 current_function_calls_setjmp = 1;
2823 sibcall_failure = 1;
2826 emit_barrier_after (last);
2830 current_function_calls_longjmp = 1, sibcall_failure = 1;
2832 /* If this function is returning into a memory location marked as
2833 readonly, it means it is initializing that location. But we normally
2834 treat functions as not clobbering such locations, so we need to
2835 specify that this one does. */
2836 if (target != 0 && GET_CODE (target) == MEM
2837 && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
2838 emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
2840 /* If value type not void, return an rtx for the value. */
2842 /* If there are cleanups to be called, don't use a hard reg as target.
2843 We need to double check this and see if it matters anymore. */
2844 if (any_pending_cleanups (1))
2846 if (target && REG_P (target)
2847 && REGNO (target) < FIRST_PSEUDO_REGISTER)
2849 sibcall_failure = 1;
2852 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2855 target = const0_rtx;
2857 else if (structure_value_addr)
2859 if (target == 0 || GET_CODE (target) != MEM)
2861 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2862 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2863 structure_value_addr));
2864 MEM_SET_IN_STRUCT_P (target,
2865 AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2868 else if (pcc_struct_value)
2870 /* This is the special C++ case where we need to
2871 know what the true target was. We take care to
2872 never use this value more than once in one expression. */
2873 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2874 copy_to_reg (valreg));
2875 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2877 /* Handle calls that return values in multiple non-contiguous locations.
2878 The Irix 6 ABI has examples of this. */
2879 else if (GET_CODE (valreg) == PARALLEL)
2881 int bytes = int_size_in_bytes (TREE_TYPE (exp));
2885 target = assign_stack_temp (TYPE_MODE (TREE_TYPE (exp)),
2887 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
2888 preserve_temp_slots (target);
2891 if (! rtx_equal_p (target, valreg))
2892 emit_group_store (target, valreg, bytes,
2893 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
2894 /* We can not support sibling calls for this case. */
2895 sibcall_failure = 1;
2898 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2899 && GET_MODE (target) == GET_MODE (valreg))
2901 /* TARGET and VALREG cannot be equal at this point because the
2902 latter would not have REG_FUNCTION_VALUE_P true, while the
2903 former would if it were referring to the same register.
2905 If they refer to the same register, this move will be a no-op,
2906 except when function inlining is being done. */
2907 emit_move_insn (target, valreg);
2909 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2910 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2912 target = copy_to_reg (valreg);
2914 #ifdef PROMOTE_FUNCTION_RETURN
2915 /* If we promoted this return value, make the proper SUBREG. TARGET
2916 might be const0_rtx here, so be careful. */
2917 if (GET_CODE (target) == REG
2918 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2919 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2921 tree type = TREE_TYPE (exp);
2922 int unsignedp = TREE_UNSIGNED (type);
2924 /* If we don't promote as expected, something is wrong. */
2925 if (GET_MODE (target)
2926 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
2929 target = gen_rtx_SUBREG (TYPE_MODE (type), target, 0);
2930 SUBREG_PROMOTED_VAR_P (target) = 1;
2931 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
2935 /* If size of args is variable or this was a constructor call for a stack
2936 argument, restore saved stack-pointer value. */
2938 if (old_stack_level)
2940 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2941 pending_stack_adjust = old_pending_adj;
2942 #ifdef ACCUMULATE_OUTGOING_ARGS
2943 stack_arg_under_construction = old_stack_arg_under_construction;
2944 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2945 stack_usage_map = initial_stack_usage_map;
2947 sibcall_failure = 1;
2949 #ifdef ACCUMULATE_OUTGOING_ARGS
2952 #ifdef REG_PARM_STACK_SPACE
2955 restore_fixed_argument_area (save_area, argblock,
2956 high_to_save, low_to_save);
2957 sibcall_failure = 1;
2961 /* If we saved any argument areas, restore them. */
2962 for (i = 0; i < num_actuals; i++)
2963 if (args[i].save_area)
2965 enum machine_mode save_mode = GET_MODE (args[i].save_area);
2967 = gen_rtx_MEM (save_mode,
2968 memory_address (save_mode,
2969 XEXP (args[i].stack_slot, 0)));
2971 if (save_mode != BLKmode)
2972 emit_move_insn (stack_area, args[i].save_area);
2974 emit_block_move (stack_area,
2975 validize_mem (args[i].save_area),
2976 GEN_INT (args[i].size.constant),
2977 PARM_BOUNDARY / BITS_PER_UNIT);
2978 sibcall_failure = 1;
2981 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2982 stack_usage_map = initial_stack_usage_map;
2986 /* If this was alloca, record the new stack level for nonlocal gotos.
2987 Check for the handler slots since we might not have a save area
2988 for non-local gotos. */
2990 if (may_be_alloca && nonlocal_goto_handler_slots != 0)
2991 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
2995 /* Free up storage we no longer need. */
2996 for (i = 0; i < num_actuals; ++i)
2997 if (args[i].aligned_regs)
2998 free (args[i].aligned_regs);
3002 /* Undo the fake expand_start_target_temps we did earlier. If
3003 there had been any cleanups created, we've already set
3005 expand_end_target_temps ();
3008 insns = get_insns ();
3013 tail_call_insns = insns;
3015 /* If something prevents making this a sibling call,
3016 zero out the sequence. */
3017 if (sibcall_failure)
3018 tail_call_insns = NULL_RTX;
3020 /* Restore the pending stack adjustment now that we have
3021 finished generating the sibling call sequence. */
3022 pending_stack_adjust = save_pending_stack_adjust;
3025 normal_call_insns = insns;
3028 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3029 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3030 can happen if the arguments to this function call an inline
3031 function who's expansion contains another CALL_PLACEHOLDER.
3033 If there are any C_Ps in any of these sequences, replace them
3034 with their normal call. */
3036 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3037 if (GET_CODE (insn) == CALL_INSN
3038 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3039 replace_call_placeholder (insn, sibcall_use_normal);
3041 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3042 if (GET_CODE (insn) == CALL_INSN
3043 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3044 replace_call_placeholder (insn, sibcall_use_normal);
3046 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3047 if (GET_CODE (insn) == CALL_INSN
3048 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3049 replace_call_placeholder (insn, sibcall_use_normal);
3051 /* If this was a potential tail recursion site, then emit a
3052 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3053 One of them will be selected later. */
3054 if (tail_recursion_insns || tail_call_insns)
3056 /* The tail recursion label must be kept around. We could expose
3057 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3058 and makes determining true tail recursion sites difficult.
3060 So we set LABEL_PRESERVE_P here, then clear it when we select
3061 one of the call sequences after rtl generation is complete. */
3062 if (tail_recursion_insns)
3063 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3064 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3066 tail_recursion_insns,
3067 tail_recursion_label));
3070 emit_insns (normal_call_insns);
3072 currently_expanding_call--;
3077 /* Returns nonzero if FUN is the symbol for a library function which can
3081 libfunc_nothrow (fun)
3084 if (fun == throw_libfunc
3085 || fun == rethrow_libfunc
3086 || fun == sjthrow_libfunc
3087 || fun == sjpopnthrow_libfunc)
3093 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3094 The RETVAL parameter specifies whether return value needs to be saved, other
3095 parameters are documented in the emit_library_call function bellow. */
3097 emit_library_call_value_1 (retval, orgfun, value, no_queue, outmode, nargs, p)
3102 enum machine_mode outmode;
3106 /* Total size in bytes of all the stack-parms scanned so far. */
3107 struct args_size args_size;
3108 /* Size of arguments before any adjustments (such as rounding). */
3109 struct args_size original_args_size;
3110 register int argnum;
3114 struct args_size alignment_pad;
3116 CUMULATIVE_ARGS args_so_far;
3117 struct arg { rtx value; enum machine_mode mode; rtx reg; int partial;
3118 struct args_size offset; struct args_size size; rtx save_area; };
3120 int old_inhibit_defer_pop = inhibit_defer_pop;
3121 rtx call_fusage = 0;
3123 int pcc_struct_value = 0;
3124 int struct_value_size = 0;
3126 int reg_parm_stack_space = 0;
3128 #ifdef ACCUMULATE_OUTGOING_ARGS
3132 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
3133 /* Define the boundary of the register parm stack space that needs to be
3135 int low_to_save = -1, high_to_save = 0;
3136 rtx save_area = 0; /* Place that it is saved */
3139 #ifdef ACCUMULATE_OUTGOING_ARGS
3140 /* Size of the stack reserved for parameter registers. */
3141 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3142 char *initial_stack_usage_map = stack_usage_map;
3145 #ifdef REG_PARM_STACK_SPACE
3146 #ifdef MAYBE_REG_PARM_STACK_SPACE
3147 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3149 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3153 is_const = no_queue;
3156 nothrow = libfunc_nothrow (fun);
3158 #ifdef PREFERRED_STACK_BOUNDARY
3159 /* Ensure current function's preferred stack boundary is at least
3161 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3162 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3165 /* If this kind of value comes back in memory,
3166 decide where in memory it should come back. */
3167 if (outmode != VOIDmode && aggregate_value_p (type_for_mode (outmode, 0)))
3169 #ifdef PCC_STATIC_STRUCT_RETURN
3171 = hard_function_value (build_pointer_type (type_for_mode (outmode, 0)),
3173 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3174 pcc_struct_value = 1;
3176 value = gen_reg_rtx (outmode);
3177 #else /* not PCC_STATIC_STRUCT_RETURN */
3178 struct_value_size = GET_MODE_SIZE (outmode);
3179 if (value != 0 && GET_CODE (value) == MEM)
3182 mem_value = assign_stack_temp (outmode, GET_MODE_SIZE (outmode), 0);
3185 /* This call returns a big structure. */
3189 /* ??? Unfinished: must pass the memory address as an argument. */
3191 /* Copy all the libcall-arguments out of the varargs data
3192 and into a vector ARGVEC.
3194 Compute how to pass each argument. We only support a very small subset
3195 of the full argument passing conventions to limit complexity here since
3196 library functions shouldn't have many args. */
3198 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3199 bzero ((char *) argvec, (nargs + 1) * sizeof (struct arg));
3201 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3203 args_size.constant = 0;
3210 /* If there's a structure value address to be passed,
3211 either pass it in the special place, or pass it as an extra argument. */
3212 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3214 rtx addr = XEXP (mem_value, 0);
3217 /* Make sure it is a reasonable operand for a move or push insn. */
3218 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3219 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3220 addr = force_operand (addr, NULL_RTX);
3222 argvec[count].value = addr;
3223 argvec[count].mode = Pmode;
3224 argvec[count].partial = 0;
3226 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3227 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3228 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3232 locate_and_pad_parm (Pmode, NULL_TREE,
3233 argvec[count].reg && argvec[count].partial == 0,
3234 NULL_TREE, &args_size, &argvec[count].offset,
3235 &argvec[count].size, &alignment_pad);
3238 if (argvec[count].reg == 0 || argvec[count].partial != 0
3239 || reg_parm_stack_space > 0)
3240 args_size.constant += argvec[count].size.constant;
3242 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3247 for (; count < nargs; count++)
3249 rtx val = va_arg (p, rtx);
3250 enum machine_mode mode = va_arg (p, enum machine_mode);
3252 /* We cannot convert the arg value to the mode the library wants here;
3253 must do it earlier where we know the signedness of the arg. */
3255 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3258 /* On some machines, there's no way to pass a float to a library fcn.
3259 Pass it as a double instead. */
3260 #ifdef LIBGCC_NEEDS_DOUBLE
3261 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3262 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3265 /* There's no need to call protect_from_queue, because
3266 either emit_move_insn or emit_push_insn will do that. */
3268 /* Make sure it is a reasonable operand for a move or push insn. */
3269 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3270 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3271 val = force_operand (val, NULL_RTX);
3273 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3274 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3276 /* We do not support FUNCTION_ARG_CALLEE_COPIES here since it can
3277 be viewed as just an efficiency improvement. */
3278 rtx slot = assign_stack_temp (mode, GET_MODE_SIZE (mode), 0);
3279 emit_move_insn (slot, val);
3280 val = force_operand (XEXP (slot, 0), NULL_RTX);
3285 argvec[count].value = val;
3286 argvec[count].mode = mode;
3288 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3290 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3291 argvec[count].partial
3292 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3294 argvec[count].partial = 0;
3297 locate_and_pad_parm (mode, NULL_TREE,
3298 argvec[count].reg && argvec[count].partial == 0,
3299 NULL_TREE, &args_size, &argvec[count].offset,
3300 &argvec[count].size, &alignment_pad);
3302 if (argvec[count].size.var)
3305 if (reg_parm_stack_space == 0 && argvec[count].partial)
3306 argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3308 if (argvec[count].reg == 0 || argvec[count].partial != 0
3309 || reg_parm_stack_space > 0)
3310 args_size.constant += argvec[count].size.constant;
3312 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3315 #ifdef FINAL_REG_PARM_STACK_SPACE
3316 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3319 /* If this machine requires an external definition for library
3320 functions, write one out. */
3321 assemble_external_libcall (fun);
3323 original_args_size = args_size;
3324 #ifdef PREFERRED_STACK_BOUNDARY
3325 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
3326 / STACK_BYTES) * STACK_BYTES);
3329 args_size.constant = MAX (args_size.constant,
3330 reg_parm_stack_space);
3332 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3333 args_size.constant -= reg_parm_stack_space;
3336 if (args_size.constant > current_function_outgoing_args_size)
3337 current_function_outgoing_args_size = args_size.constant;
3339 #ifdef ACCUMULATE_OUTGOING_ARGS
3340 /* Since the stack pointer will never be pushed, it is possible for
3341 the evaluation of a parm to clobber something we have already
3342 written to the stack. Since most function calls on RISC machines
3343 do not use the stack, this is uncommon, but must work correctly.
3345 Therefore, we save any area of the stack that was already written
3346 and that we are using. Here we set up to do this by making a new
3347 stack usage map from the old one.
3349 Another approach might be to try to reorder the argument
3350 evaluations to avoid this conflicting stack usage. */
3352 needed = args_size.constant;
3354 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3355 /* Since we will be writing into the entire argument area, the
3356 map must be allocated for its entire size, not just the part that
3357 is the responsibility of the caller. */
3358 needed += reg_parm_stack_space;
3361 #ifdef ARGS_GROW_DOWNWARD
3362 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3365 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3368 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3370 if (initial_highest_arg_in_use)
3371 bcopy (initial_stack_usage_map, stack_usage_map,
3372 initial_highest_arg_in_use);
3374 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3375 bzero (&stack_usage_map[initial_highest_arg_in_use],
3376 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3379 /* The address of the outgoing argument list must not be copied to a
3380 register here, because argblock would be left pointing to the
3381 wrong place after the call to allocate_dynamic_stack_space below.
3384 argblock = virtual_outgoing_args_rtx;
3385 #else /* not ACCUMULATE_OUTGOING_ARGS */
3386 #ifndef PUSH_ROUNDING
3387 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3391 #ifdef PUSH_ARGS_REVERSED
3392 #ifdef PREFERRED_STACK_BOUNDARY
3393 /* If we push args individually in reverse order, perform stack alignment
3394 before the first push (the last arg). */
3396 anti_adjust_stack (GEN_INT (args_size.constant
3397 - original_args_size.constant));
3401 #ifdef PUSH_ARGS_REVERSED
3409 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
3410 /* The argument list is the property of the called routine and it
3411 may clobber it. If the fixed area has been used for previous
3412 parameters, we must save and restore it.
3414 Here we compute the boundary of the that needs to be saved, if any. */
3416 #ifdef ARGS_GROW_DOWNWARD
3417 for (count = 0; count < reg_parm_stack_space + 1; count++)
3419 for (count = 0; count < reg_parm_stack_space; count++)
3422 if (count >= highest_outgoing_arg_in_use
3423 || stack_usage_map[count] == 0)
3426 if (low_to_save == -1)
3427 low_to_save = count;
3429 high_to_save = count;
3432 if (low_to_save >= 0)
3434 int num_to_save = high_to_save - low_to_save + 1;
3435 enum machine_mode save_mode
3436 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
3439 /* If we don't have the required alignment, must do this in BLKmode. */
3440 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
3441 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
3442 save_mode = BLKmode;
3444 #ifdef ARGS_GROW_DOWNWARD
3445 stack_area = gen_rtx_MEM (save_mode,
3446 memory_address (save_mode,
3447 plus_constant (argblock,
3450 stack_area = gen_rtx_MEM (save_mode,
3451 memory_address (save_mode,
3452 plus_constant (argblock,
3455 if (save_mode == BLKmode)
3457 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
3458 emit_block_move (validize_mem (save_area), stack_area,
3459 GEN_INT (num_to_save),
3460 PARM_BOUNDARY / BITS_PER_UNIT);
3464 save_area = gen_reg_rtx (save_mode);
3465 emit_move_insn (save_area, stack_area);
3470 /* Push the args that need to be pushed. */
3472 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3473 are to be pushed. */
3474 for (count = 0; count < nargs; count++, argnum += inc)
3476 register enum machine_mode mode = argvec[argnum].mode;
3477 register rtx val = argvec[argnum].value;
3478 rtx reg = argvec[argnum].reg;
3479 int partial = argvec[argnum].partial;
3480 #ifdef ACCUMULATE_OUTGOING_ARGS
3481 int lower_bound, upper_bound, i;
3484 if (! (reg != 0 && partial == 0))
3486 #ifdef ACCUMULATE_OUTGOING_ARGS
3487 /* If this is being stored into a pre-allocated, fixed-size, stack
3488 area, save any previous data at that location. */
3490 #ifdef ARGS_GROW_DOWNWARD
3491 /* stack_slot is negative, but we want to index stack_usage_map
3492 with positive values. */
3493 upper_bound = -argvec[argnum].offset.constant + 1;
3494 lower_bound = upper_bound - argvec[argnum].size.constant;
3496 lower_bound = argvec[argnum].offset.constant;
3497 upper_bound = lower_bound + argvec[argnum].size.constant;
3500 for (i = lower_bound; i < upper_bound; i++)
3501 if (stack_usage_map[i]
3502 /* Don't store things in the fixed argument area at this point;
3503 it has already been saved. */
3504 && i > reg_parm_stack_space)
3507 if (i != upper_bound)
3509 /* We need to make a save area. See what mode we can make it. */
3510 enum machine_mode save_mode
3511 = mode_for_size (argvec[argnum].size.constant * BITS_PER_UNIT,
3518 plus_constant (argblock,
3519 argvec[argnum].offset.constant)));
3520 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3522 emit_move_insn (argvec[argnum].save_area, stack_area);
3525 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0,
3526 argblock, GEN_INT (argvec[argnum].offset.constant),
3527 reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3529 #ifdef ACCUMULATE_OUTGOING_ARGS
3530 /* Now mark the segment we just used. */
3531 for (i = lower_bound; i < upper_bound; i++)
3532 stack_usage_map[i] = 1;
3539 #ifndef PUSH_ARGS_REVERSED
3540 #ifdef PREFERRED_STACK_BOUNDARY
3541 /* If we pushed args in forward order, perform stack alignment
3542 after pushing the last arg. */
3544 anti_adjust_stack (GEN_INT (args_size.constant
3545 - original_args_size.constant));
3549 #ifdef PUSH_ARGS_REVERSED
3555 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0);
3557 /* Now load any reg parms into their regs. */
3559 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3560 are to be pushed. */
3561 for (count = 0; count < nargs; count++, argnum += inc)
3563 register rtx val = argvec[argnum].value;
3564 rtx reg = argvec[argnum].reg;
3565 int partial = argvec[argnum].partial;
3567 /* Handle calls that pass values in multiple non-contiguous
3568 locations. The PA64 has examples of this for library calls. */
3569 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3570 emit_group_load (reg, val,
3571 GET_MODE_SIZE (GET_MODE (val)),
3572 GET_MODE_ALIGNMENT (GET_MODE (val)));
3573 else if (reg != 0 && partial == 0)
3574 emit_move_insn (reg, val);
3580 /* For version 1.37, try deleting this entirely. */
3585 /* Any regs containing parms remain in use through the call. */
3586 for (count = 0; count < nargs; count++)
3588 rtx reg = argvec[count].reg;
3589 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3590 use_group_regs (&call_fusage, reg);
3592 use_reg (&call_fusage, reg);
3595 /* Pass the function the address in which to return a structure value. */
3596 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
3598 emit_move_insn (struct_value_rtx,
3600 force_operand (XEXP (mem_value, 0),
3602 if (GET_CODE (struct_value_rtx) == REG)
3603 use_reg (&call_fusage, struct_value_rtx);
3606 /* Don't allow popping to be deferred, since then
3607 cse'ing of library calls could delete a call and leave the pop. */
3610 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3611 will set inhibit_defer_pop to that value. */
3612 /* The return type is needed to decide how many bytes the function pops.
3613 Signedness plays no role in that, so for simplicity, we pretend it's
3614 always signed. We also assume that the list of arguments passed has
3615 no impact, so we pretend it is unknown. */
3618 get_identifier (XSTR (orgfun, 0)),
3619 build_function_type (outmode == VOIDmode ? void_type_node
3620 : type_for_mode (outmode, 0), NULL_TREE),
3621 original_args_size.constant, args_size.constant,
3623 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3624 mem_value == 0 && outmode != VOIDmode ? hard_libcall_value (outmode) : NULL_RTX,
3625 old_inhibit_defer_pop + 1, call_fusage,
3626 ((is_const ? ECF_IS_CONST : 0)
3627 | (nothrow ? ECF_NOTHROW : 0)));
3629 /* Now restore inhibit_defer_pop to its actual original value. */
3634 /* Copy the value to the right place. */
3635 if (outmode != VOIDmode && retval)
3641 if (value != mem_value)
3642 emit_move_insn (value, mem_value);
3644 else if (value != 0)
3645 emit_move_insn (value, hard_libcall_value (outmode));
3647 value = hard_libcall_value (outmode);
3650 #ifdef ACCUMULATE_OUTGOING_ARGS
3651 #ifdef REG_PARM_STACK_SPACE
3654 enum machine_mode save_mode = GET_MODE (save_area);
3655 #ifdef ARGS_GROW_DOWNWARD
3657 = gen_rtx_MEM (save_mode,
3658 memory_address (save_mode,
3659 plus_constant (argblock,
3663 = gen_rtx_MEM (save_mode,
3664 memory_address (save_mode,
3665 plus_constant (argblock, low_to_save)));
3667 if (save_mode != BLKmode)
3668 emit_move_insn (stack_area, save_area);
3670 emit_block_move (stack_area, validize_mem (save_area),
3671 GEN_INT (high_to_save - low_to_save + 1),
3672 PARM_BOUNDARY / BITS_PER_UNIT);
3676 /* If we saved any argument areas, restore them. */
3677 for (count = 0; count < nargs; count++)
3678 if (argvec[count].save_area)
3680 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3682 = gen_rtx_MEM (save_mode,
3685 plus_constant (argblock,
3686 argvec[count].offset.constant)));
3688 emit_move_insn (stack_area, argvec[count].save_area);
3691 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3692 stack_usage_map = initial_stack_usage_map;
3699 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3700 (emitting the queue unless NO_QUEUE is nonzero),
3701 for a value of mode OUTMODE,
3702 with NARGS different arguments, passed as alternating rtx values
3703 and machine_modes to convert them to.
3704 The rtx values should have been passed through protect_from_queue already.
3706 NO_QUEUE will be true if and only if the library call is a `const' call
3707 which will be enclosed in REG_LIBCALL/REG_RETVAL notes; it is equivalent
3708 to the variable is_const in expand_call.
3710 NO_QUEUE must be true for const calls, because if it isn't, then
3711 any pending increment will be emitted between REG_LIBCALL/REG_RETVAL notes,
3712 and will be lost if the libcall sequence is optimized away.
3714 NO_QUEUE must be false for non-const calls, because if it isn't, the
3715 call insn will have its CONST_CALL_P bit set, and it will be incorrectly
3716 optimized. For instance, the instruction scheduler may incorrectly
3717 move memory references across the non-const call. */
3720 emit_library_call VPARAMS((rtx orgfun, int no_queue, enum machine_mode outmode,
3723 #ifndef ANSI_PROTOTYPES
3726 enum machine_mode outmode;
3731 VA_START (p, nargs);
3733 #ifndef ANSI_PROTOTYPES
3734 orgfun = va_arg (p, rtx);
3735 no_queue = va_arg (p, int);
3736 outmode = va_arg (p, enum machine_mode);
3737 nargs = va_arg (p, int);
3740 emit_library_call_value_1 (0, orgfun, NULL_RTX, no_queue, outmode, nargs, p);
3745 /* Like emit_library_call except that an extra argument, VALUE,
3746 comes second and says where to store the result.
3747 (If VALUE is zero, this function chooses a convenient way
3748 to return the value.
3750 This function returns an rtx for where the value is to be found.
3751 If VALUE is nonzero, VALUE is returned. */
3754 emit_library_call_value VPARAMS((rtx orgfun, rtx value, int no_queue,
3755 enum machine_mode outmode, int nargs, ...))
3757 #ifndef ANSI_PROTOTYPES
3761 enum machine_mode outmode;
3766 VA_START (p, nargs);
3768 #ifndef ANSI_PROTOTYPES
3769 orgfun = va_arg (p, rtx);
3770 value = va_arg (p, rtx);
3771 no_queue = va_arg (p, int);
3772 outmode = va_arg (p, enum machine_mode);
3773 nargs = va_arg (p, int);
3776 value = emit_library_call_value_1 (1, orgfun, value, no_queue, outmode, nargs, p);
3784 /* Return an rtx which represents a suitable home on the stack
3785 given TYPE, the type of the argument looking for a home.
3786 This is called only for BLKmode arguments.
3788 SIZE is the size needed for this target.
3789 ARGS_ADDR is the address of the bottom of the argument block for this call.
3790 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
3791 if this machine uses push insns. */
3794 target_for_arg (type, size, args_addr, offset)
3798 struct args_size offset;
3801 rtx offset_rtx = ARGS_SIZE_RTX (offset);
3803 /* We do not call memory_address if possible,
3804 because we want to address as close to the stack
3805 as possible. For non-variable sized arguments,
3806 this will be stack-pointer relative addressing. */
3807 if (GET_CODE (offset_rtx) == CONST_INT)
3808 target = plus_constant (args_addr, INTVAL (offset_rtx));
3811 /* I have no idea how to guarantee that this
3812 will work in the presence of register parameters. */
3813 target = gen_rtx_PLUS (Pmode, args_addr, offset_rtx);
3814 target = memory_address (QImode, target);
3817 return gen_rtx_MEM (BLKmode, target);
3821 /* Store a single argument for a function call
3822 into the register or memory area where it must be passed.
3823 *ARG describes the argument value and where to pass it.
3825 ARGBLOCK is the address of the stack-block for all the arguments,
3826 or 0 on a machine where arguments are pushed individually.
3828 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3829 so must be careful about how the stack is used.
3831 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3832 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3833 that we need not worry about saving and restoring the stack.
3835 FNDECL is the declaration of the function we are calling. */
3838 store_one_arg (arg, argblock, may_be_alloca, variable_size,
3839 reg_parm_stack_space)
3840 struct arg_data *arg;
3843 int variable_size ATTRIBUTE_UNUSED;
3844 int reg_parm_stack_space;
3846 register tree pval = arg->tree_value;
3850 #ifdef ACCUMULATE_OUTGOING_ARGS
3851 int i, lower_bound = 0, upper_bound = 0;
3854 if (TREE_CODE (pval) == ERROR_MARK)
3857 /* Push a new temporary level for any temporaries we make for
3861 #ifdef ACCUMULATE_OUTGOING_ARGS
3862 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3863 save any previous data at that location. */
3864 if (argblock && ! variable_size && arg->stack)
3866 #ifdef ARGS_GROW_DOWNWARD
3867 /* stack_slot is negative, but we want to index stack_usage_map
3868 with positive values. */
3869 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3870 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3874 lower_bound = upper_bound - arg->size.constant;
3876 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3877 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3881 upper_bound = lower_bound + arg->size.constant;
3884 for (i = lower_bound; i < upper_bound; i++)
3885 if (stack_usage_map[i]
3886 /* Don't store things in the fixed argument area at this point;
3887 it has already been saved. */
3888 && i > reg_parm_stack_space)
3891 if (i != upper_bound)
3893 /* We need to make a save area. See what mode we can make it. */
3894 enum machine_mode save_mode
3895 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
3897 = gen_rtx_MEM (save_mode,
3898 memory_address (save_mode,
3899 XEXP (arg->stack_slot, 0)));
3901 if (save_mode == BLKmode)
3903 arg->save_area = assign_stack_temp (BLKmode,
3904 arg->size.constant, 0);
3905 MEM_SET_IN_STRUCT_P (arg->save_area,
3906 AGGREGATE_TYPE_P (TREE_TYPE
3907 (arg->tree_value)));
3908 preserve_temp_slots (arg->save_area);
3909 emit_block_move (validize_mem (arg->save_area), stack_area,
3910 GEN_INT (arg->size.constant),
3911 PARM_BOUNDARY / BITS_PER_UNIT);
3915 arg->save_area = gen_reg_rtx (save_mode);
3916 emit_move_insn (arg->save_area, stack_area);
3921 /* Now that we have saved any slots that will be overwritten by this
3922 store, mark all slots this store will use. We must do this before
3923 we actually expand the argument since the expansion itself may
3924 trigger library calls which might need to use the same stack slot. */
3925 if (argblock && ! variable_size && arg->stack)
3926 for (i = lower_bound; i < upper_bound; i++)
3927 stack_usage_map[i] = 1;
3930 /* If this isn't going to be placed on both the stack and in registers,
3931 set up the register and number of words. */
3932 if (! arg->pass_on_stack)
3933 reg = arg->reg, partial = arg->partial;
3935 if (reg != 0 && partial == 0)
3936 /* Being passed entirely in a register. We shouldn't be called in
3940 /* If this arg needs special alignment, don't load the registers
3942 if (arg->n_aligned_regs != 0)
3945 /* If this is being passed partially in a register, we can't evaluate
3946 it directly into its stack slot. Otherwise, we can. */
3947 if (arg->value == 0)
3949 #ifdef ACCUMULATE_OUTGOING_ARGS
3950 /* stack_arg_under_construction is nonzero if a function argument is
3951 being evaluated directly into the outgoing argument list and
3952 expand_call must take special action to preserve the argument list
3953 if it is called recursively.
3955 For scalar function arguments stack_usage_map is sufficient to
3956 determine which stack slots must be saved and restored. Scalar
3957 arguments in general have pass_on_stack == 0.
3959 If this argument is initialized by a function which takes the
3960 address of the argument (a C++ constructor or a C function
3961 returning a BLKmode structure), then stack_usage_map is
3962 insufficient and expand_call must push the stack around the
3963 function call. Such arguments have pass_on_stack == 1.
3965 Note that it is always safe to set stack_arg_under_construction,
3966 but this generates suboptimal code if set when not needed. */
3968 if (arg->pass_on_stack)
3969 stack_arg_under_construction++;
3971 arg->value = expand_expr (pval,
3973 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
3974 ? NULL_RTX : arg->stack,
3977 /* If we are promoting object (or for any other reason) the mode
3978 doesn't agree, convert the mode. */
3980 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
3981 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
3982 arg->value, arg->unsignedp);
3984 #ifdef ACCUMULATE_OUTGOING_ARGS
3985 if (arg->pass_on_stack)
3986 stack_arg_under_construction--;
3990 /* Don't allow anything left on stack from computation
3991 of argument to alloca. */
3993 do_pending_stack_adjust ();
3995 if (arg->value == arg->stack)
3997 /* If the value is already in the stack slot, we are done. */
3998 if (current_function_check_memory_usage && GET_CODE (arg->stack) == MEM)
4000 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
4001 XEXP (arg->stack, 0), Pmode,
4002 ARGS_SIZE_RTX (arg->size),
4003 TYPE_MODE (sizetype),
4004 GEN_INT (MEMORY_USE_RW),
4005 TYPE_MODE (integer_type_node));
4008 else if (arg->mode != BLKmode)
4012 /* Argument is a scalar, not entirely passed in registers.
4013 (If part is passed in registers, arg->partial says how much
4014 and emit_push_insn will take care of putting it there.)
4016 Push it, and if its size is less than the
4017 amount of space allocated to it,
4018 also bump stack pointer by the additional space.
4019 Note that in C the default argument promotions
4020 will prevent such mismatches. */
4022 size = GET_MODE_SIZE (arg->mode);
4023 /* Compute how much space the push instruction will push.
4024 On many machines, pushing a byte will advance the stack
4025 pointer by a halfword. */
4026 #ifdef PUSH_ROUNDING
4027 size = PUSH_ROUNDING (size);
4031 /* Compute how much space the argument should get:
4032 round up to a multiple of the alignment for arguments. */
4033 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4034 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4035 / (PARM_BOUNDARY / BITS_PER_UNIT))
4036 * (PARM_BOUNDARY / BITS_PER_UNIT));
4038 /* This isn't already where we want it on the stack, so put it there.
4039 This can either be done with push or copy insns. */
4040 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 0,
4041 partial, reg, used - size, argblock,
4042 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4043 ARGS_SIZE_RTX (arg->alignment_pad));
4045 arg_space_so_far += used;
4049 /* BLKmode, at least partly to be pushed. */
4051 register int excess;
4054 /* Pushing a nonscalar.
4055 If part is passed in registers, PARTIAL says how much
4056 and emit_push_insn will take care of putting it there. */
4058 /* Round its size up to a multiple
4059 of the allocation unit for arguments. */
4061 if (arg->size.var != 0)
4064 size_rtx = ARGS_SIZE_RTX (arg->size);
4068 /* PUSH_ROUNDING has no effect on us, because
4069 emit_push_insn for BLKmode is careful to avoid it. */
4070 excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4071 + partial * UNITS_PER_WORD);
4072 size_rtx = expr_size (pval);
4073 arg_space_so_far += excess + INTVAL (size_rtx);
4076 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4077 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
4078 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset),
4079 reg_parm_stack_space,
4080 ARGS_SIZE_RTX (arg->alignment_pad));
4084 /* Unless this is a partially-in-register argument, the argument is now
4087 ??? Note that this can change arg->value from arg->stack to
4088 arg->stack_slot and it matters when they are not the same.
4089 It isn't totally clear that this is correct in all cases. */
4091 arg->value = arg->stack_slot;
4093 /* Once we have pushed something, pops can't safely
4094 be deferred during the rest of the arguments. */
4097 /* ANSI doesn't require a sequence point here,
4098 but PCC has one, so this will avoid some problems. */
4101 /* Free any temporary slots made in processing this argument. Show
4102 that we might have taken the address of something and pushed that
4104 preserve_temp_slots (NULL_RTX);