1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
3 1999, 2000, 2001 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
38 #include "langhooks.h"
41 /* Decide whether a function's arguments should be processed
42 from first to last or from last to first.
44 They should if the stack and args grow in opposite directions, but
45 only if we have push insns. */
49 #ifndef PUSH_ARGS_REVERSED
50 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
51 #define PUSH_ARGS_REVERSED PUSH_ARGS
57 #ifndef PUSH_ARGS_REVERSED
58 #define PUSH_ARGS_REVERSED 0
61 #ifndef STACK_POINTER_OFFSET
62 #define STACK_POINTER_OFFSET 0
65 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
66 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
68 /* Data structure and subroutines used within expand_call. */
72 /* Tree node for this argument. */
74 /* Mode for value; TYPE_MODE unless promoted. */
75 enum machine_mode mode
;
76 /* Current RTL value for argument, or 0 if it isn't precomputed. */
78 /* Initially-compute RTL value for argument; only for const functions. */
80 /* Register to pass this argument in, 0 if passed on stack, or an
81 PARALLEL if the arg is to be copied into multiple non-contiguous
84 /* Register to pass this argument in when generating tail call sequence.
85 This is not the same register as for normal calls on machines with
88 /* If REG was promoted from the actual mode of the argument expression,
89 indicates whether the promotion is sign- or zero-extended. */
91 /* Number of registers to use. 0 means put the whole arg in registers.
92 Also 0 if not passed in registers. */
94 /* Nonzero if argument must be passed on stack.
95 Note that some arguments may be passed on the stack
96 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
97 pass_on_stack identifies arguments that *cannot* go in registers. */
99 /* Offset of this argument from beginning of stack-args. */
100 struct args_size offset
;
101 /* Similar, but offset to the start of the stack slot. Different from
102 OFFSET if this arg pads downward. */
103 struct args_size slot_offset
;
104 /* Size of this argument on the stack, rounded up for any padding it gets,
105 parts of the argument passed in registers do not count.
106 If REG_PARM_STACK_SPACE is defined, then register parms
107 are counted here as well. */
108 struct args_size size
;
109 /* Location on the stack at which parameter should be stored. The store
110 has already been done if STACK == VALUE. */
112 /* Location on the stack of the start of this argument slot. This can
113 differ from STACK if this arg pads downward. This location is known
114 to be aligned to FUNCTION_ARG_BOUNDARY. */
116 /* Place that this stack area has been saved, if needed. */
118 /* If an argument's alignment does not permit direct copying into registers,
119 copy in smaller-sized pieces into pseudos. These are stored in a
120 block pointed to by this field. The next field says how many
121 word-sized pseudos we made. */
124 /* The amount that the stack pointer needs to be adjusted to
125 force alignment for the next argument. */
126 struct args_size alignment_pad
;
129 /* A vector of one char per byte of stack space. A byte if nonzero if
130 the corresponding stack location has been used.
131 This vector is used to prevent a function call within an argument from
132 clobbering any stack already set up. */
133 static char *stack_usage_map
;
135 /* Size of STACK_USAGE_MAP. */
136 static int highest_outgoing_arg_in_use
;
138 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
139 stack location's tail call argument has been already stored into the stack.
140 This bitmap is used to prevent sibling call optimization if function tries
141 to use parent's incoming argument slots when they have been already
142 overwritten with tail call arguments. */
143 static sbitmap stored_args_map
;
145 /* stack_arg_under_construction is nonzero when an argument may be
146 initialized with a constructor call (including a C function that
147 returns a BLKmode struct) and expand_call must take special action
148 to make sure the object being constructed does not overlap the
149 argument list for the constructor call. */
150 int stack_arg_under_construction
;
152 static int calls_function
PARAMS ((tree
, int));
153 static int calls_function_1
PARAMS ((tree
, int));
155 static void emit_call_1
PARAMS ((rtx
, tree
, tree
, HOST_WIDE_INT
,
156 HOST_WIDE_INT
, HOST_WIDE_INT
, rtx
,
159 static void precompute_register_parameters
PARAMS ((int,
162 static int store_one_arg
PARAMS ((struct arg_data
*, rtx
, int, int,
164 static void store_unaligned_arguments_into_pseudos
PARAMS ((struct arg_data
*,
166 static int finalize_must_preallocate
PARAMS ((int, int,
168 struct args_size
*));
169 static void precompute_arguments
PARAMS ((int, int,
171 static int compute_argument_block_size
PARAMS ((int,
174 static void initialize_argument_information
PARAMS ((int,
181 static void compute_argument_addresses
PARAMS ((struct arg_data
*,
183 static rtx rtx_for_function_call
PARAMS ((tree
, tree
));
184 static void load_register_parameters
PARAMS ((struct arg_data
*,
187 static rtx emit_library_call_value_1
PARAMS ((int, rtx
, rtx
,
191 static int special_function_p
PARAMS ((tree
, int));
192 static rtx try_to_integrate
PARAMS ((tree
, tree
, rtx
,
194 static int check_sibcall_argument_overlap_1
PARAMS ((rtx
));
195 static int check_sibcall_argument_overlap
PARAMS ((rtx
, struct arg_data
*,
198 static int combine_pending_stack_adjustment_and_call
199 PARAMS ((int, struct args_size
*, int));
200 static tree fix_unsafe_tree
PARAMS ((tree
));
202 #ifdef REG_PARM_STACK_SPACE
203 static rtx save_fixed_argument_area
PARAMS ((int, rtx
, int *, int *));
204 static void restore_fixed_argument_area
PARAMS ((rtx
, rtx
, int, int));
207 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
210 If WHICH is 0, return 1 if EXP contains a call to any function.
211 Actually, we only need return 1 if evaluating EXP would require pushing
212 arguments on the stack, but that is too difficult to compute, so we just
213 assume any function call might require the stack. */
215 static tree calls_function_save_exprs
;
218 calls_function (exp
, which
)
224 calls_function_save_exprs
= 0;
225 val
= calls_function_1 (exp
, which
);
226 calls_function_save_exprs
= 0;
230 /* Recursive function to do the work of above function. */
233 calls_function_1 (exp
, which
)
238 enum tree_code code
= TREE_CODE (exp
);
239 int class = TREE_CODE_CLASS (code
);
240 int length
= first_rtl_op (code
);
242 /* If this code is language-specific, we don't know what it will do. */
243 if ((int) code
>= NUM_TREE_CODES
)
251 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))
253 && (TYPE_RETURNS_STACK_DEPRESSED
254 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))))
256 else if (TREE_CODE (TREE_OPERAND (exp
, 0)) == ADDR_EXPR
257 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
259 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0),
261 & ECF_MAY_BE_ALLOCA
))
270 for (tem
= CONSTRUCTOR_ELTS (exp
); tem
!= 0; tem
= TREE_CHAIN (tem
))
271 if (calls_function_1 (TREE_VALUE (tem
), which
))
278 if (SAVE_EXPR_RTL (exp
) != 0)
280 if (value_member (exp
, calls_function_save_exprs
))
282 calls_function_save_exprs
= tree_cons (NULL_TREE
, exp
,
283 calls_function_save_exprs
);
284 return (TREE_OPERAND (exp
, 0) != 0
285 && calls_function_1 (TREE_OPERAND (exp
, 0), which
));
292 for (local
= BLOCK_VARS (exp
); local
; local
= TREE_CHAIN (local
))
293 if (DECL_INITIAL (local
) != 0
294 && calls_function_1 (DECL_INITIAL (local
), which
))
297 for (subblock
= BLOCK_SUBBLOCKS (exp
);
299 subblock
= TREE_CHAIN (subblock
))
300 if (calls_function_1 (subblock
, which
))
306 for (; exp
!= 0; exp
= TREE_CHAIN (exp
))
307 if (calls_function_1 (TREE_VALUE (exp
), which
))
315 /* Only expressions, references, and blocks can contain calls. */
316 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
319 for (i
= 0; i
< length
; i
++)
320 if (TREE_OPERAND (exp
, i
) != 0
321 && calls_function_1 (TREE_OPERAND (exp
, i
), which
))
327 /* Force FUNEXP into a form suitable for the address of a CALL,
328 and return that as an rtx. Also load the static chain register
329 if FNDECL is a nested function.
331 CALL_FUSAGE points to a variable holding the prospective
332 CALL_INSN_FUNCTION_USAGE information. */
335 prepare_call_address (funexp
, fndecl
, call_fusage
, reg_parm_seen
, sibcallp
)
342 rtx static_chain_value
= 0;
344 funexp
= protect_from_queue (funexp
, 0);
347 /* Get possible static chain value for nested function in C. */
348 static_chain_value
= lookup_static_chain (fndecl
);
350 /* Make a valid memory address and copy constants thru pseudo-regs,
351 but not for a constant address if -fno-function-cse. */
352 if (GET_CODE (funexp
) != SYMBOL_REF
)
353 /* If we are using registers for parameters, force the
354 function address into a register now. */
355 funexp
= ((SMALL_REGISTER_CLASSES
&& reg_parm_seen
)
356 ? force_not_mem (memory_address (FUNCTION_MODE
, funexp
))
357 : memory_address (FUNCTION_MODE
, funexp
));
360 #ifndef NO_FUNCTION_CSE
361 if (optimize
&& ! flag_no_function_cse
)
362 #ifdef NO_RECURSIVE_FUNCTION_CSE
363 if (fndecl
!= current_function_decl
)
365 funexp
= force_reg (Pmode
, funexp
);
369 if (static_chain_value
!= 0)
371 emit_move_insn (static_chain_rtx
, static_chain_value
);
373 if (GET_CODE (static_chain_rtx
) == REG
)
374 use_reg (call_fusage
, static_chain_rtx
);
380 /* Generate instructions to call function FUNEXP,
381 and optionally pop the results.
382 The CALL_INSN is the first insn generated.
384 FNDECL is the declaration node of the function. This is given to the
385 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
387 FUNTYPE is the data type of the function. This is given to the macro
388 RETURN_POPS_ARGS to determine whether this function pops its own args.
389 We used to allow an identifier for library functions, but that doesn't
390 work when the return type is an aggregate type and the calling convention
391 says that the pointer to this aggregate is to be popped by the callee.
393 STACK_SIZE is the number of bytes of arguments on the stack,
394 ROUNDED_STACK_SIZE is that number rounded up to
395 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
396 both to put into the call insn and to generate explicit popping
399 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
400 It is zero if this call doesn't want a structure value.
402 NEXT_ARG_REG is the rtx that results from executing
403 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
404 just after all the args have had their registers assigned.
405 This could be whatever you like, but normally it is the first
406 arg-register beyond those used for args in this call,
407 or 0 if all the arg-registers are used in this call.
408 It is passed on to `gen_call' so you can put this info in the call insn.
410 VALREG is a hard register in which a value is returned,
411 or 0 if the call does not return a value.
413 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
414 the args to this call were processed.
415 We restore `inhibit_defer_pop' to that value.
417 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
418 denote registers used by the called function. */
421 emit_call_1 (funexp
, fndecl
, funtype
, stack_size
, rounded_stack_size
,
422 struct_value_size
, next_arg_reg
, valreg
, old_inhibit_defer_pop
,
423 call_fusage
, ecf_flags
, args_so_far
)
425 tree fndecl ATTRIBUTE_UNUSED
;
426 tree funtype ATTRIBUTE_UNUSED
;
427 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED
;
428 HOST_WIDE_INT rounded_stack_size
;
429 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED
;
430 rtx next_arg_reg ATTRIBUTE_UNUSED
;
432 int old_inhibit_defer_pop
;
435 CUMULATIVE_ARGS
*args_so_far ATTRIBUTE_UNUSED
;
437 rtx rounded_stack_size_rtx
= GEN_INT (rounded_stack_size
);
439 int already_popped
= 0;
440 HOST_WIDE_INT n_popped
= RETURN_POPS_ARGS (fndecl
, funtype
, stack_size
);
441 #if defined (HAVE_call) && defined (HAVE_call_value)
442 rtx struct_value_size_rtx
;
443 struct_value_size_rtx
= GEN_INT (struct_value_size
);
446 #ifdef CALL_POPS_ARGS
447 n_popped
+= CALL_POPS_ARGS (* args_so_far
);
450 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
451 and we don't want to load it into a register as an optimization,
452 because prepare_call_address already did it if it should be done. */
453 if (GET_CODE (funexp
) != SYMBOL_REF
)
454 funexp
= memory_address (FUNCTION_MODE
, funexp
);
456 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
457 if ((ecf_flags
& ECF_SIBCALL
)
458 && HAVE_sibcall_pop
&& HAVE_sibcall_value_pop
459 && (n_popped
> 0 || stack_size
== 0))
461 rtx n_pop
= GEN_INT (n_popped
);
464 /* If this subroutine pops its own args, record that in the call insn
465 if possible, for the sake of frame pointer elimination. */
468 pat
= GEN_SIBCALL_VALUE_POP (valreg
,
469 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
470 rounded_stack_size_rtx
, next_arg_reg
,
473 pat
= GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
474 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
476 emit_call_insn (pat
);
482 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
483 /* If the target has "call" or "call_value" insns, then prefer them
484 if no arguments are actually popped. If the target does not have
485 "call" or "call_value" insns, then we must use the popping versions
486 even if the call has no arguments to pop. */
487 #if defined (HAVE_call) && defined (HAVE_call_value)
488 if (HAVE_call
&& HAVE_call_value
&& HAVE_call_pop
&& HAVE_call_value_pop
489 && n_popped
> 0 && ! (ecf_flags
& ECF_SP_DEPRESSED
))
491 if (HAVE_call_pop
&& HAVE_call_value_pop
)
494 rtx n_pop
= GEN_INT (n_popped
);
497 /* If this subroutine pops its own args, record that in the call insn
498 if possible, for the sake of frame pointer elimination. */
501 pat
= GEN_CALL_VALUE_POP (valreg
,
502 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
503 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
505 pat
= GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
506 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
508 emit_call_insn (pat
);
514 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
515 if ((ecf_flags
& ECF_SIBCALL
)
516 && HAVE_sibcall
&& HAVE_sibcall_value
)
519 emit_call_insn (GEN_SIBCALL_VALUE (valreg
,
520 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
521 rounded_stack_size_rtx
,
522 next_arg_reg
, NULL_RTX
));
524 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
525 rounded_stack_size_rtx
, next_arg_reg
,
526 struct_value_size_rtx
));
531 #if defined (HAVE_call) && defined (HAVE_call_value)
532 if (HAVE_call
&& HAVE_call_value
)
535 emit_call_insn (GEN_CALL_VALUE (valreg
,
536 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
537 rounded_stack_size_rtx
, next_arg_reg
,
540 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
541 rounded_stack_size_rtx
, next_arg_reg
,
542 struct_value_size_rtx
));
548 /* Find the CALL insn we just emitted. */
549 for (call_insn
= get_last_insn ();
550 call_insn
&& GET_CODE (call_insn
) != CALL_INSN
;
551 call_insn
= PREV_INSN (call_insn
))
557 /* Mark memory as used for "pure" function call. */
558 if (ecf_flags
& ECF_PURE
)
562 gen_rtx_USE (VOIDmode
,
563 gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
))),
566 /* Put the register usage information on the CALL. If there is already
567 some usage information, put ours at the end. */
568 if (CALL_INSN_FUNCTION_USAGE (call_insn
))
572 for (link
= CALL_INSN_FUNCTION_USAGE (call_insn
); XEXP (link
, 1) != 0;
573 link
= XEXP (link
, 1))
576 XEXP (link
, 1) = call_fusage
;
579 CALL_INSN_FUNCTION_USAGE (call_insn
) = call_fusage
;
581 /* If this is a const call, then set the insn's unchanging bit. */
582 if (ecf_flags
& (ECF_CONST
| ECF_PURE
))
583 CONST_OR_PURE_CALL_P (call_insn
) = 1;
585 /* If this call can't throw, attach a REG_EH_REGION reg note to that
587 if (ecf_flags
& ECF_NOTHROW
)
588 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_EH_REGION
, const0_rtx
,
589 REG_NOTES (call_insn
));
591 if (ecf_flags
& ECF_NORETURN
)
592 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_NORETURN
, const0_rtx
,
593 REG_NOTES (call_insn
));
594 if (ecf_flags
& ECF_ALWAYS_RETURN
)
595 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN
, const0_rtx
,
596 REG_NOTES (call_insn
));
598 if (ecf_flags
& ECF_RETURNS_TWICE
)
600 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_SETJMP
, const0_rtx
,
601 REG_NOTES (call_insn
));
602 current_function_calls_setjmp
= 1;
605 SIBLING_CALL_P (call_insn
) = ((ecf_flags
& ECF_SIBCALL
) != 0);
607 /* Restore this now, so that we do defer pops for this call's args
608 if the context of the call as a whole permits. */
609 inhibit_defer_pop
= old_inhibit_defer_pop
;
614 CALL_INSN_FUNCTION_USAGE (call_insn
)
615 = gen_rtx_EXPR_LIST (VOIDmode
,
616 gen_rtx_CLOBBER (VOIDmode
, stack_pointer_rtx
),
617 CALL_INSN_FUNCTION_USAGE (call_insn
));
618 rounded_stack_size
-= n_popped
;
619 rounded_stack_size_rtx
= GEN_INT (rounded_stack_size
);
620 stack_pointer_delta
-= n_popped
;
623 if (!ACCUMULATE_OUTGOING_ARGS
)
625 /* If returning from the subroutine does not automatically pop the args,
626 we need an instruction to pop them sooner or later.
627 Perhaps do it now; perhaps just record how much space to pop later.
629 If returning from the subroutine does pop the args, indicate that the
630 stack pointer will be changed. */
632 if (rounded_stack_size
!= 0)
634 if (ecf_flags
& ECF_SP_DEPRESSED
)
635 /* Just pretend we did the pop. */
636 stack_pointer_delta
-= rounded_stack_size
;
637 else if (flag_defer_pop
&& inhibit_defer_pop
== 0
638 && ! (ecf_flags
& (ECF_CONST
| ECF_PURE
)))
639 pending_stack_adjust
+= rounded_stack_size
;
641 adjust_stack (rounded_stack_size_rtx
);
644 /* When we accumulate outgoing args, we must avoid any stack manipulations.
645 Restore the stack pointer to its original value now. Usually
646 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
647 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
648 popping variants of functions exist as well.
650 ??? We may optimize similar to defer_pop above, but it is
651 probably not worthwhile.
653 ??? It will be worthwhile to enable combine_stack_adjustments even for
656 anti_adjust_stack (GEN_INT (n_popped
));
659 /* Determine if the function identified by NAME and FNDECL is one with
660 special properties we wish to know about.
662 For example, if the function might return more than one time (setjmp), then
663 set RETURNS_TWICE to a nonzero value.
665 Similarly set LONGJMP for if the function is in the longjmp family.
667 Set MALLOC for any of the standard memory allocation functions which
668 allocate from the heap.
670 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
671 space from the stack such as alloca. */
674 special_function_p (fndecl
, flags
)
678 if (! (flags
& ECF_MALLOC
)
679 && fndecl
&& DECL_NAME (fndecl
)
680 && IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) <= 17
681 /* Exclude functions not at the file scope, or not `extern',
682 since they are not the magic functions we would otherwise
684 && DECL_CONTEXT (fndecl
) == NULL_TREE
&& TREE_PUBLIC (fndecl
))
686 const char *name
= IDENTIFIER_POINTER (DECL_NAME (fndecl
));
687 const char *tname
= name
;
689 /* We assume that alloca will always be called by name. It
690 makes no sense to pass it as a pointer-to-function to
691 anything that does not understand its behavior. */
692 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 6
694 && ! strcmp (name
, "alloca"))
695 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 16
697 && ! strcmp (name
, "__builtin_alloca"))))
698 flags
|= ECF_MAY_BE_ALLOCA
;
700 /* Disregard prefix _, __ or __x. */
703 if (name
[1] == '_' && name
[2] == 'x')
705 else if (name
[1] == '_')
714 && (! strcmp (tname
, "setjmp")
715 || ! strcmp (tname
, "setjmp_syscall")))
717 && ! strcmp (tname
, "sigsetjmp"))
719 && ! strcmp (tname
, "savectx")))
720 flags
|= ECF_RETURNS_TWICE
;
723 && ! strcmp (tname
, "siglongjmp"))
724 flags
|= ECF_LONGJMP
;
726 else if ((tname
[0] == 'q' && tname
[1] == 's'
727 && ! strcmp (tname
, "qsetjmp"))
728 || (tname
[0] == 'v' && tname
[1] == 'f'
729 && ! strcmp (tname
, "vfork")))
730 flags
|= ECF_RETURNS_TWICE
;
732 else if (tname
[0] == 'l' && tname
[1] == 'o'
733 && ! strcmp (tname
, "longjmp"))
734 flags
|= ECF_LONGJMP
;
736 else if ((tname
[0] == 'f' && tname
[1] == 'o'
737 && ! strcmp (tname
, "fork"))
738 /* Linux specific: __clone. check NAME to insist on the
739 leading underscores, to avoid polluting the ISO / POSIX
741 || (name
[0] == '_' && name
[1] == '_'
742 && ! strcmp (tname
, "clone"))
743 || (tname
[0] == 'e' && tname
[1] == 'x' && tname
[2] == 'e'
744 && tname
[3] == 'c' && (tname
[4] == 'l' || tname
[4] == 'v')
746 || ((tname
[5] == 'p' || tname
[5] == 'e')
747 && tname
[6] == '\0'))))
748 flags
|= ECF_FORK_OR_EXEC
;
750 /* Do not add any more malloc-like functions to this list,
751 instead mark them as malloc functions using the malloc attribute.
752 Note, realloc is not suitable for attribute malloc since
753 it may return the same address across multiple calls.
754 C++ operator new is not suitable because it is not required
755 to return a unique pointer; indeed, the standard placement new
756 just returns its argument. */
757 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl
))) == Pmode
758 && (! strcmp (tname
, "malloc")
759 || ! strcmp (tname
, "calloc")
760 || ! strcmp (tname
, "strdup")))
766 /* Return nonzero when tree represent call to longjmp. */
769 setjmp_call_p (fndecl
)
772 return special_function_p (fndecl
, 0) & ECF_RETURNS_TWICE
;
775 /* Return true when exp contains alloca call. */
780 if (TREE_CODE (exp
) == CALL_EXPR
781 && TREE_CODE (TREE_OPERAND (exp
, 0)) == ADDR_EXPR
782 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
784 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0),
785 0) & ECF_MAY_BE_ALLOCA
))
790 /* Detect flags (function attributes) from the function decl or type node. */
793 flags_from_decl_or_type (exp
)
798 /* ??? We can't set IS_MALLOC for function types? */
801 type
= TREE_TYPE (exp
);
803 /* The function exp may have the `malloc' attribute. */
804 if (DECL_P (exp
) && DECL_IS_MALLOC (exp
))
807 /* The function exp may have the `pure' attribute. */
808 if (DECL_P (exp
) && DECL_IS_PURE (exp
))
809 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
811 if (TREE_NOTHROW (exp
))
812 flags
|= ECF_NOTHROW
;
815 if (TREE_READONLY (exp
) && ! TREE_THIS_VOLATILE (exp
))
816 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
818 if (TREE_THIS_VOLATILE (exp
))
819 flags
|= ECF_NORETURN
;
821 /* Mark if the function returns with the stack pointer depressed. We
822 cannot consider it pure or constant in that case. */
823 if (TREE_CODE (type
) == FUNCTION_TYPE
&& TYPE_RETURNS_STACK_DEPRESSED (type
))
825 flags
|= ECF_SP_DEPRESSED
;
826 flags
&= ~(ECF_PURE
| ECF_CONST
| ECF_LIBCALL_BLOCK
);
832 /* Precompute all register parameters as described by ARGS, storing values
833 into fields within the ARGS array.
835 NUM_ACTUALS indicates the total number elements in the ARGS array.
837 Set REG_PARM_SEEN if we encounter a register parameter. */
840 precompute_register_parameters (num_actuals
, args
, reg_parm_seen
)
842 struct arg_data
*args
;
849 for (i
= 0; i
< num_actuals
; i
++)
850 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
)
854 if (args
[i
].value
== 0)
857 args
[i
].value
= expand_expr (args
[i
].tree_value
, NULL_RTX
,
859 preserve_temp_slots (args
[i
].value
);
862 /* ANSI doesn't require a sequence point here,
863 but PCC has one, so this will avoid some problems. */
867 /* If the value is a non-legitimate constant, force it into a
868 pseudo now. TLS symbols sometimes need a call to resolve. */
869 if (CONSTANT_P (args
[i
].value
)
870 && !LEGITIMATE_CONSTANT_P (args
[i
].value
))
871 args
[i
].value
= force_reg (args
[i
].mode
, args
[i
].value
);
873 /* If we are to promote the function arg to a wider mode,
876 if (args
[i
].mode
!= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)))
878 = convert_modes (args
[i
].mode
,
879 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
880 args
[i
].value
, args
[i
].unsignedp
);
882 /* If the value is expensive, and we are inside an appropriately
883 short loop, put the value into a pseudo and then put the pseudo
886 For small register classes, also do this if this call uses
887 register parameters. This is to avoid reload conflicts while
888 loading the parameters registers. */
890 if ((! (GET_CODE (args
[i
].value
) == REG
891 || (GET_CODE (args
[i
].value
) == SUBREG
892 && GET_CODE (SUBREG_REG (args
[i
].value
)) == REG
)))
893 && args
[i
].mode
!= BLKmode
894 && rtx_cost (args
[i
].value
, SET
) > COSTS_N_INSNS (1)
895 && ((SMALL_REGISTER_CLASSES
&& *reg_parm_seen
)
896 || preserve_subexpressions_p ()))
897 args
[i
].value
= copy_to_mode_reg (args
[i
].mode
, args
[i
].value
);
901 #ifdef REG_PARM_STACK_SPACE
903 /* The argument list is the property of the called routine and it
904 may clobber it. If the fixed area has been used for previous
905 parameters, we must save and restore it. */
908 save_fixed_argument_area (reg_parm_stack_space
, argblock
,
909 low_to_save
, high_to_save
)
910 int reg_parm_stack_space
;
916 rtx save_area
= NULL_RTX
;
918 /* Compute the boundary of the that needs to be saved, if any. */
919 #ifdef ARGS_GROW_DOWNWARD
920 for (i
= 0; i
< reg_parm_stack_space
+ 1; i
++)
922 for (i
= 0; i
< reg_parm_stack_space
; i
++)
925 if (i
>= highest_outgoing_arg_in_use
926 || stack_usage_map
[i
] == 0)
929 if (*low_to_save
== -1)
935 if (*low_to_save
>= 0)
937 int num_to_save
= *high_to_save
- *low_to_save
+ 1;
938 enum machine_mode save_mode
939 = mode_for_size (num_to_save
* BITS_PER_UNIT
, MODE_INT
, 1);
942 /* If we don't have the required alignment, must do this in BLKmode. */
943 if ((*low_to_save
& (MIN (GET_MODE_SIZE (save_mode
),
944 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)))
947 #ifdef ARGS_GROW_DOWNWARD
949 = gen_rtx_MEM (save_mode
,
950 memory_address (save_mode
,
951 plus_constant (argblock
,
954 stack_area
= gen_rtx_MEM (save_mode
,
955 memory_address (save_mode
,
956 plus_constant (argblock
,
960 set_mem_align (stack_area
, PARM_BOUNDARY
);
961 if (save_mode
== BLKmode
)
963 save_area
= assign_stack_temp (BLKmode
, num_to_save
, 0);
964 emit_block_move (validize_mem (save_area
), stack_area
,
965 GEN_INT (num_to_save
), BLOCK_OP_CALL_PARM
);
969 save_area
= gen_reg_rtx (save_mode
);
970 emit_move_insn (save_area
, stack_area
);
978 restore_fixed_argument_area (save_area
, argblock
, high_to_save
, low_to_save
)
984 enum machine_mode save_mode
= GET_MODE (save_area
);
985 #ifdef ARGS_GROW_DOWNWARD
987 = gen_rtx_MEM (save_mode
,
988 memory_address (save_mode
,
989 plus_constant (argblock
,
993 = gen_rtx_MEM (save_mode
,
994 memory_address (save_mode
,
995 plus_constant (argblock
,
999 if (save_mode
!= BLKmode
)
1000 emit_move_insn (stack_area
, save_area
);
1002 emit_block_move (stack_area
, validize_mem (save_area
),
1003 GEN_INT (high_to_save
- low_to_save
+ 1),
1004 BLOCK_OP_CALL_PARM
);
1006 #endif /* REG_PARM_STACK_SPACE */
1008 /* If any elements in ARGS refer to parameters that are to be passed in
1009 registers, but not in memory, and whose alignment does not permit a
1010 direct copy into registers. Copy the values into a group of pseudos
1011 which we will later copy into the appropriate hard registers.
1013 Pseudos for each unaligned argument will be stored into the array
1014 args[argnum].aligned_regs. The caller is responsible for deallocating
1015 the aligned_regs array if it is nonzero. */
1018 store_unaligned_arguments_into_pseudos (args
, num_actuals
)
1019 struct arg_data
*args
;
1024 for (i
= 0; i
< num_actuals
; i
++)
1025 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
1026 && args
[i
].mode
== BLKmode
1027 && (TYPE_ALIGN (TREE_TYPE (args
[i
].tree_value
))
1028 < (unsigned int) MIN (BIGGEST_ALIGNMENT
, BITS_PER_WORD
)))
1030 int bytes
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1031 int big_endian_correction
= 0;
1033 args
[i
].n_aligned_regs
1034 = args
[i
].partial
? args
[i
].partial
1035 : (bytes
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
1037 args
[i
].aligned_regs
= (rtx
*) xmalloc (sizeof (rtx
)
1038 * args
[i
].n_aligned_regs
);
1040 /* Structures smaller than a word are aligned to the least
1041 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
1042 this means we must skip the empty high order bytes when
1043 calculating the bit offset. */
1044 if (BYTES_BIG_ENDIAN
1045 && bytes
< UNITS_PER_WORD
)
1046 big_endian_correction
= (BITS_PER_WORD
- (bytes
* BITS_PER_UNIT
));
1048 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1050 rtx reg
= gen_reg_rtx (word_mode
);
1051 rtx word
= operand_subword_force (args
[i
].value
, j
, BLKmode
);
1052 int bitsize
= MIN (bytes
* BITS_PER_UNIT
, BITS_PER_WORD
);
1054 args
[i
].aligned_regs
[j
] = reg
;
1056 /* There is no need to restrict this code to loading items
1057 in TYPE_ALIGN sized hunks. The bitfield instructions can
1058 load up entire word sized registers efficiently.
1060 ??? This may not be needed anymore.
1061 We use to emit a clobber here but that doesn't let later
1062 passes optimize the instructions we emit. By storing 0 into
1063 the register later passes know the first AND to zero out the
1064 bitfield being set in the register is unnecessary. The store
1065 of 0 will be deleted as will at least the first AND. */
1067 emit_move_insn (reg
, const0_rtx
);
1069 bytes
-= bitsize
/ BITS_PER_UNIT
;
1070 store_bit_field (reg
, bitsize
, big_endian_correction
, word_mode
,
1071 extract_bit_field (word
, bitsize
, 0, 1, NULL_RTX
,
1072 word_mode
, word_mode
,
1079 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1082 NUM_ACTUALS is the total number of parameters.
1084 N_NAMED_ARGS is the total number of named arguments.
1086 FNDECL is the tree code for the target of this call (if known)
1088 ARGS_SO_FAR holds state needed by the target to know where to place
1091 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1092 for arguments which are passed in registers.
1094 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1095 and may be modified by this routine.
1097 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1098 flags which may may be modified by this routine. */
1101 initialize_argument_information (num_actuals
, args
, args_size
, n_named_args
,
1102 actparms
, fndecl
, args_so_far
,
1103 reg_parm_stack_space
, old_stack_level
,
1104 old_pending_adj
, must_preallocate
,
1106 int num_actuals ATTRIBUTE_UNUSED
;
1107 struct arg_data
*args
;
1108 struct args_size
*args_size
;
1109 int n_named_args ATTRIBUTE_UNUSED
;
1112 CUMULATIVE_ARGS
*args_so_far
;
1113 int reg_parm_stack_space
;
1114 rtx
*old_stack_level
;
1115 int *old_pending_adj
;
1116 int *must_preallocate
;
1119 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1122 /* Count arg position in order args appear. */
1125 struct args_size alignment_pad
;
1129 args_size
->constant
= 0;
1132 /* In this loop, we consider args in the order they are written.
1133 We fill up ARGS from the front or from the back if necessary
1134 so that in any case the first arg to be pushed ends up at the front. */
1136 if (PUSH_ARGS_REVERSED
)
1138 i
= num_actuals
- 1, inc
= -1;
1139 /* In this case, must reverse order of args
1140 so that we compute and push the last arg first. */
1147 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1148 for (p
= actparms
, argpos
= 0; p
; p
= TREE_CHAIN (p
), i
+= inc
, argpos
++)
1150 tree type
= TREE_TYPE (TREE_VALUE (p
));
1152 enum machine_mode mode
;
1154 args
[i
].tree_value
= TREE_VALUE (p
);
1156 /* Replace erroneous argument with constant zero. */
1157 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
1158 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
1160 /* If TYPE is a transparent union, pass things the way we would
1161 pass the first field of the union. We have already verified that
1162 the modes are the same. */
1163 if (TREE_CODE (type
) == UNION_TYPE
&& TYPE_TRANSPARENT_UNION (type
))
1164 type
= TREE_TYPE (TYPE_FIELDS (type
));
1166 /* Decide where to pass this arg.
1168 args[i].reg is nonzero if all or part is passed in registers.
1170 args[i].partial is nonzero if part but not all is passed in registers,
1171 and the exact value says how many words are passed in registers.
1173 args[i].pass_on_stack is nonzero if the argument must at least be
1174 computed on the stack. It may then be loaded back into registers
1175 if args[i].reg is nonzero.
1177 These decisions are driven by the FUNCTION_... macros and must agree
1178 with those made by function.c. */
1180 /* See if this argument should be passed by invisible reference. */
1181 if ((TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1182 && contains_placeholder_p (TYPE_SIZE (type
)))
1183 || TREE_ADDRESSABLE (type
)
1184 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1185 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far
, TYPE_MODE (type
),
1186 type
, argpos
< n_named_args
)
1190 /* If we're compiling a thunk, pass through invisible
1191 references instead of making a copy. */
1192 if (current_function_is_thunk
1193 #ifdef FUNCTION_ARG_CALLEE_COPIES
1194 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far
, TYPE_MODE (type
),
1195 type
, argpos
< n_named_args
)
1196 /* If it's in a register, we must make a copy of it too. */
1197 /* ??? Is this a sufficient test? Is there a better one? */
1198 && !(TREE_CODE (args
[i
].tree_value
) == VAR_DECL
1199 && REG_P (DECL_RTL (args
[i
].tree_value
)))
1200 && ! TREE_ADDRESSABLE (type
))
1204 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1205 new object from the argument. If we are passing by
1206 invisible reference, the callee will do that for us, so we
1207 can strip off the TARGET_EXPR. This is not always safe,
1208 but it is safe in the only case where this is a useful
1209 optimization; namely, when the argument is a plain object.
1210 In that case, the frontend is just asking the backend to
1211 make a bitwise copy of the argument. */
1213 if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1214 && (DECL_P (TREE_OPERAND (args
[i
].tree_value
, 1)))
1215 && ! REG_P (DECL_RTL (TREE_OPERAND (args
[i
].tree_value
, 1))))
1216 args
[i
].tree_value
= TREE_OPERAND (args
[i
].tree_value
, 1);
1218 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1219 build_pointer_type (type
),
1220 args
[i
].tree_value
);
1221 type
= build_pointer_type (type
);
1223 else if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
)
1225 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1226 We implement this by passing the address of the temporary
1227 rather than expanding it into another allocated slot. */
1228 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1229 build_pointer_type (type
),
1230 args
[i
].tree_value
);
1231 type
= build_pointer_type (type
);
1235 /* We make a copy of the object and pass the address to the
1236 function being called. */
1239 if (!COMPLETE_TYPE_P (type
)
1240 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1241 || (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1242 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type
),
1243 STACK_CHECK_MAX_VAR_SIZE
))))
1245 /* This is a variable-sized object. Make space on the stack
1247 rtx size_rtx
= expr_size (TREE_VALUE (p
));
1249 if (*old_stack_level
== 0)
1251 emit_stack_save (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1252 *old_pending_adj
= pending_stack_adjust
;
1253 pending_stack_adjust
= 0;
1256 copy
= gen_rtx_MEM (BLKmode
,
1257 allocate_dynamic_stack_space
1258 (size_rtx
, NULL_RTX
, TYPE_ALIGN (type
)));
1259 set_mem_attributes (copy
, type
, 1);
1262 copy
= assign_temp (type
, 0, 1, 0);
1264 store_expr (args
[i
].tree_value
, copy
, 0);
1265 *ecf_flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
1267 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1268 build_pointer_type (type
),
1269 make_tree (type
, copy
));
1270 type
= build_pointer_type (type
);
1274 mode
= TYPE_MODE (type
);
1275 unsignedp
= TREE_UNSIGNED (type
);
1277 #ifdef PROMOTE_FUNCTION_ARGS
1278 mode
= promote_mode (type
, mode
, &unsignedp
, 1);
1281 args
[i
].unsignedp
= unsignedp
;
1282 args
[i
].mode
= mode
;
1284 args
[i
].reg
= FUNCTION_ARG (*args_so_far
, mode
, type
,
1285 argpos
< n_named_args
);
1286 #ifdef FUNCTION_INCOMING_ARG
1287 /* If this is a sibling call and the machine has register windows, the
1288 register window has to be unwinded before calling the routine, so
1289 arguments have to go into the incoming registers. */
1290 args
[i
].tail_call_reg
= FUNCTION_INCOMING_ARG (*args_so_far
, mode
, type
,
1291 argpos
< n_named_args
);
1293 args
[i
].tail_call_reg
= args
[i
].reg
;
1296 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1299 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far
, mode
, type
,
1300 argpos
< n_named_args
);
1303 args
[i
].pass_on_stack
= MUST_PASS_IN_STACK (mode
, type
);
1305 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1306 it means that we are to pass this arg in the register(s) designated
1307 by the PARALLEL, but also to pass it in the stack. */
1308 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
1309 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
1310 args
[i
].pass_on_stack
= 1;
1312 /* If this is an addressable type, we must preallocate the stack
1313 since we must evaluate the object into its final location.
1315 If this is to be passed in both registers and the stack, it is simpler
1317 if (TREE_ADDRESSABLE (type
)
1318 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
1319 *must_preallocate
= 1;
1321 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1322 we cannot consider this function call constant. */
1323 if (TREE_ADDRESSABLE (type
))
1324 *ecf_flags
&= ~ECF_LIBCALL_BLOCK
;
1326 /* Compute the stack-size of this argument. */
1327 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
1328 || reg_parm_stack_space
> 0
1329 || args
[i
].pass_on_stack
)
1330 locate_and_pad_parm (mode
, type
,
1331 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1336 fndecl
, args_size
, &args
[i
].offset
,
1337 &args
[i
].size
, &alignment_pad
);
1339 #ifndef ARGS_GROW_DOWNWARD
1340 args
[i
].slot_offset
= *args_size
;
1343 args
[i
].alignment_pad
= alignment_pad
;
1345 /* If a part of the arg was put into registers,
1346 don't include that part in the amount pushed. */
1347 if (reg_parm_stack_space
== 0 && ! args
[i
].pass_on_stack
)
1348 args
[i
].size
.constant
-= ((args
[i
].partial
* UNITS_PER_WORD
)
1349 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
1350 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
1352 /* Update ARGS_SIZE, the total stack space for args so far. */
1354 args_size
->constant
+= args
[i
].size
.constant
;
1355 if (args
[i
].size
.var
)
1357 ADD_PARM_SIZE (*args_size
, args
[i
].size
.var
);
1360 /* Since the slot offset points to the bottom of the slot,
1361 we must record it after incrementing if the args grow down. */
1362 #ifdef ARGS_GROW_DOWNWARD
1363 args
[i
].slot_offset
= *args_size
;
1365 args
[i
].slot_offset
.constant
= -args_size
->constant
;
1367 SUB_PARM_SIZE (args
[i
].slot_offset
, args_size
->var
);
1370 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1371 have been used, etc. */
1373 FUNCTION_ARG_ADVANCE (*args_so_far
, TYPE_MODE (type
), type
,
1374 argpos
< n_named_args
);
1378 /* Update ARGS_SIZE to contain the total size for the argument block.
1379 Return the original constant component of the argument block's size.
1381 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1382 for arguments passed in registers. */
1385 compute_argument_block_size (reg_parm_stack_space
, args_size
,
1386 preferred_stack_boundary
)
1387 int reg_parm_stack_space
;
1388 struct args_size
*args_size
;
1389 int preferred_stack_boundary ATTRIBUTE_UNUSED
;
1391 int unadjusted_args_size
= args_size
->constant
;
1393 /* For accumulate outgoing args mode we don't need to align, since the frame
1394 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1395 backends from generating misaligned frame sizes. */
1396 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
1397 preferred_stack_boundary
= STACK_BOUNDARY
;
1399 /* Compute the actual size of the argument block required. The variable
1400 and constant sizes must be combined, the size may have to be rounded,
1401 and there may be a minimum required size. */
1405 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
1406 args_size
->constant
= 0;
1408 preferred_stack_boundary
/= BITS_PER_UNIT
;
1409 if (preferred_stack_boundary
> 1)
1411 /* We don't handle this case yet. To handle it correctly we have
1412 to add the delta, round and subtract the delta.
1413 Currently no machine description requires this support. */
1414 if (stack_pointer_delta
& (preferred_stack_boundary
- 1))
1416 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
1419 if (reg_parm_stack_space
> 0)
1422 = size_binop (MAX_EXPR
, args_size
->var
,
1423 ssize_int (reg_parm_stack_space
));
1425 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1426 /* The area corresponding to register parameters is not to count in
1427 the size of the block we need. So make the adjustment. */
1429 = size_binop (MINUS_EXPR
, args_size
->var
,
1430 ssize_int (reg_parm_stack_space
));
1436 preferred_stack_boundary
/= BITS_PER_UNIT
;
1437 if (preferred_stack_boundary
< 1)
1438 preferred_stack_boundary
= 1;
1439 args_size
->constant
= (((args_size
->constant
1440 + stack_pointer_delta
1441 + preferred_stack_boundary
- 1)
1442 / preferred_stack_boundary
1443 * preferred_stack_boundary
)
1444 - stack_pointer_delta
);
1446 args_size
->constant
= MAX (args_size
->constant
,
1447 reg_parm_stack_space
);
1449 #ifdef MAYBE_REG_PARM_STACK_SPACE
1450 if (reg_parm_stack_space
== 0)
1451 args_size
->constant
= 0;
1454 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1455 args_size
->constant
-= reg_parm_stack_space
;
1458 return unadjusted_args_size
;
1461 /* Precompute parameters as needed for a function call.
1463 FLAGS is mask of ECF_* constants.
1465 NUM_ACTUALS is the number of arguments.
1467 ARGS is an array containing information for each argument; this
1468 routine fills in the INITIAL_VALUE and VALUE fields for each
1469 precomputed argument. */
1472 precompute_arguments (flags
, num_actuals
, args
)
1475 struct arg_data
*args
;
1479 /* If this function call is cse'able, precompute all the parameters.
1480 Note that if the parameter is constructed into a temporary, this will
1481 cause an additional copy because the parameter will be constructed
1482 into a temporary location and then copied into the outgoing arguments.
1483 If a parameter contains a call to alloca and this function uses the
1484 stack, precompute the parameter. */
1486 /* If we preallocated the stack space, and some arguments must be passed
1487 on the stack, then we must precompute any parameter which contains a
1488 function call which will store arguments on the stack.
1489 Otherwise, evaluating the parameter may clobber previous parameters
1490 which have already been stored into the stack. (we have code to avoid
1491 such case by saving the outgoing stack arguments, but it results in
1494 for (i
= 0; i
< num_actuals
; i
++)
1495 if ((flags
& ECF_LIBCALL_BLOCK
)
1496 || calls_function (args
[i
].tree_value
, !ACCUMULATE_OUTGOING_ARGS
))
1498 enum machine_mode mode
;
1500 /* If this is an addressable type, we cannot pre-evaluate it. */
1501 if (TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
)))
1505 = expand_expr (args
[i
].tree_value
, NULL_RTX
, VOIDmode
, 0);
1507 /* ANSI doesn't require a sequence point here,
1508 but PCC has one, so this will avoid some problems. */
1511 args
[i
].initial_value
= args
[i
].value
1512 = protect_from_queue (args
[i
].value
, 0);
1514 mode
= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
));
1515 if (mode
!= args
[i
].mode
)
1518 = convert_modes (args
[i
].mode
, mode
,
1519 args
[i
].value
, args
[i
].unsignedp
);
1520 #ifdef PROMOTE_FOR_CALL_ONLY
1521 /* CSE will replace this only if it contains args[i].value
1522 pseudo, so convert it down to the declared mode using
1524 if (GET_CODE (args
[i
].value
) == REG
1525 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
)
1527 args
[i
].initial_value
1528 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
1529 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
1530 SUBREG_PROMOTED_UNSIGNED_SET (args
[i
].initial_value
,
1538 /* Given the current state of MUST_PREALLOCATE and information about
1539 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1540 compute and return the final value for MUST_PREALLOCATE. */
1543 finalize_must_preallocate (must_preallocate
, num_actuals
, args
, args_size
)
1544 int must_preallocate
;
1546 struct arg_data
*args
;
1547 struct args_size
*args_size
;
1549 /* See if we have or want to preallocate stack space.
1551 If we would have to push a partially-in-regs parm
1552 before other stack parms, preallocate stack space instead.
1554 If the size of some parm is not a multiple of the required stack
1555 alignment, we must preallocate.
1557 If the total size of arguments that would otherwise create a copy in
1558 a temporary (such as a CALL) is more than half the total argument list
1559 size, preallocation is faster.
1561 Another reason to preallocate is if we have a machine (like the m88k)
1562 where stack alignment is required to be maintained between every
1563 pair of insns, not just when the call is made. However, we assume here
1564 that such machines either do not have push insns (and hence preallocation
1565 would occur anyway) or the problem is taken care of with
1568 if (! must_preallocate
)
1570 int partial_seen
= 0;
1571 int copy_to_evaluate_size
= 0;
1574 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
1576 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
1578 else if (partial_seen
&& args
[i
].reg
== 0)
1579 must_preallocate
= 1;
1581 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1582 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
1583 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1584 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
1585 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
1586 copy_to_evaluate_size
1587 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1590 if (copy_to_evaluate_size
* 2 >= args_size
->constant
1591 && args_size
->constant
> 0)
1592 must_preallocate
= 1;
1594 return must_preallocate
;
1597 /* If we preallocated stack space, compute the address of each argument
1598 and store it into the ARGS array.
1600 We need not ensure it is a valid memory address here; it will be
1601 validized when it is used.
1603 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1606 compute_argument_addresses (args
, argblock
, num_actuals
)
1607 struct arg_data
*args
;
1613 rtx arg_reg
= argblock
;
1614 int i
, arg_offset
= 0;
1616 if (GET_CODE (argblock
) == PLUS
)
1617 arg_reg
= XEXP (argblock
, 0), arg_offset
= INTVAL (XEXP (argblock
, 1));
1619 for (i
= 0; i
< num_actuals
; i
++)
1621 rtx offset
= ARGS_SIZE_RTX (args
[i
].offset
);
1622 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].slot_offset
);
1625 /* Skip this parm if it will not be passed on the stack. */
1626 if (! args
[i
].pass_on_stack
&& args
[i
].reg
!= 0)
1629 if (GET_CODE (offset
) == CONST_INT
)
1630 addr
= plus_constant (arg_reg
, INTVAL (offset
));
1632 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, offset
);
1634 addr
= plus_constant (addr
, arg_offset
);
1635 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
1636 set_mem_attributes (args
[i
].stack
,
1637 TREE_TYPE (args
[i
].tree_value
), 1);
1639 if (GET_CODE (slot_offset
) == CONST_INT
)
1640 addr
= plus_constant (arg_reg
, INTVAL (slot_offset
));
1642 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, slot_offset
);
1644 addr
= plus_constant (addr
, arg_offset
);
1645 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
1646 set_mem_attributes (args
[i
].stack_slot
,
1647 TREE_TYPE (args
[i
].tree_value
), 1);
1649 /* Function incoming arguments may overlap with sibling call
1650 outgoing arguments and we cannot allow reordering of reads
1651 from function arguments with stores to outgoing arguments
1652 of sibling calls. */
1653 set_mem_alias_set (args
[i
].stack
, 0);
1654 set_mem_alias_set (args
[i
].stack_slot
, 0);
1659 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1660 in a call instruction.
1662 FNDECL is the tree node for the target function. For an indirect call
1663 FNDECL will be NULL_TREE.
1665 EXP is the CALL_EXPR for this call. */
1668 rtx_for_function_call (fndecl
, exp
)
1674 /* Get the function to call, in the form of RTL. */
1677 /* If this is the first use of the function, see if we need to
1678 make an external definition for it. */
1679 if (! TREE_USED (fndecl
))
1681 assemble_external (fndecl
);
1682 TREE_USED (fndecl
) = 1;
1685 /* Get a SYMBOL_REF rtx for the function address. */
1686 funexp
= XEXP (DECL_RTL (fndecl
), 0);
1689 /* Generate an rtx (probably a pseudo-register) for the address. */
1692 funexp
= expand_expr (TREE_OPERAND (exp
, 0), NULL_RTX
, VOIDmode
, 0);
1693 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1699 /* Do the register loads required for any wholly-register parms or any
1700 parms which are passed both on the stack and in a register. Their
1701 expressions were already evaluated.
1703 Mark all register-parms as living through the call, putting these USE
1704 insns in the CALL_INSN_FUNCTION_USAGE field.
1706 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1707 checking, setting *SIBCALL_FAILURE if appropriate. */
1710 load_register_parameters (args
, num_actuals
, call_fusage
, flags
,
1711 is_sibcall
, sibcall_failure
)
1712 struct arg_data
*args
;
1717 int *sibcall_failure
;
1721 #ifdef LOAD_ARGS_REVERSED
1722 for (i
= num_actuals
- 1; i
>= 0; i
--)
1724 for (i
= 0; i
< num_actuals
; i
++)
1727 rtx reg
= ((flags
& ECF_SIBCALL
)
1728 ? args
[i
].tail_call_reg
: args
[i
].reg
);
1729 int partial
= args
[i
].partial
;
1734 rtx before_arg
= get_last_insn ();
1735 /* Set to non-negative if must move a word at a time, even if just
1736 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1737 we just use a normal move insn. This value can be zero if the
1738 argument is a zero size structure with no fields. */
1739 nregs
= (partial
? partial
1740 : (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1741 ? ((int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
))
1742 + (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
)
1745 /* Handle calls that pass values in multiple non-contiguous
1746 locations. The Irix 6 ABI has examples of this. */
1748 if (GET_CODE (reg
) == PARALLEL
)
1749 emit_group_load (reg
, args
[i
].value
,
1750 int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
)));
1752 /* If simple case, just do move. If normal partial, store_one_arg
1753 has already loaded the register for us. In all other cases,
1754 load the register(s) from memory. */
1756 else if (nregs
== -1)
1757 emit_move_insn (reg
, args
[i
].value
);
1759 /* If we have pre-computed the values to put in the registers in
1760 the case of non-aligned structures, copy them in now. */
1762 else if (args
[i
].n_aligned_regs
!= 0)
1763 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1764 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
1765 args
[i
].aligned_regs
[j
]);
1767 else if (partial
== 0 || args
[i
].pass_on_stack
)
1768 move_block_to_reg (REGNO (reg
),
1769 validize_mem (args
[i
].value
), nregs
,
1772 /* When a parameter is a block, and perhaps in other cases, it is
1773 possible that it did a load from an argument slot that was
1774 already clobbered. */
1776 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
1777 *sibcall_failure
= 1;
1779 /* Handle calls that pass values in multiple non-contiguous
1780 locations. The Irix 6 ABI has examples of this. */
1781 if (GET_CODE (reg
) == PARALLEL
)
1782 use_group_regs (call_fusage
, reg
);
1783 else if (nregs
== -1)
1784 use_reg (call_fusage
, reg
);
1786 use_regs (call_fusage
, REGNO (reg
), nregs
== 0 ? 1 : nregs
);
1791 /* Try to integrate function. See expand_inline_function for documentation
1792 about the parameters. */
1795 try_to_integrate (fndecl
, actparms
, target
, ignore
, type
, structure_value_addr
)
1801 rtx structure_value_addr
;
1806 rtx old_stack_level
= 0;
1807 int reg_parm_stack_space
= 0;
1809 #ifdef REG_PARM_STACK_SPACE
1810 #ifdef MAYBE_REG_PARM_STACK_SPACE
1811 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
1813 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
1817 before_call
= get_last_insn ();
1819 timevar_push (TV_INTEGRATION
);
1821 temp
= expand_inline_function (fndecl
, actparms
, target
,
1823 structure_value_addr
);
1825 timevar_pop (TV_INTEGRATION
);
1827 /* If inlining succeeded, return. */
1828 if (temp
!= (rtx
) (size_t) - 1)
1830 if (ACCUMULATE_OUTGOING_ARGS
)
1832 /* If the outgoing argument list must be preserved, push
1833 the stack before executing the inlined function if it
1836 for (i
= reg_parm_stack_space
- 1; i
>= 0; i
--)
1837 if (i
< highest_outgoing_arg_in_use
&& stack_usage_map
[i
] != 0)
1840 if (stack_arg_under_construction
|| i
>= 0)
1843 = before_call
? NEXT_INSN (before_call
) : get_insns ();
1844 rtx insn
= NULL_RTX
, seq
;
1846 /* Look for a call in the inline function code.
1847 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1848 nonzero then there is a call and it is not necessary
1849 to scan the insns. */
1851 if (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
== 0)
1852 for (insn
= first_insn
; insn
; insn
= NEXT_INSN (insn
))
1853 if (GET_CODE (insn
) == CALL_INSN
)
1858 /* Reserve enough stack space so that the largest
1859 argument list of any function call in the inline
1860 function does not overlap the argument list being
1861 evaluated. This is usually an overestimate because
1862 allocate_dynamic_stack_space reserves space for an
1863 outgoing argument list in addition to the requested
1864 space, but there is no way to ask for stack space such
1865 that an argument list of a certain length can be
1868 Add the stack space reserved for register arguments, if
1869 any, in the inline function. What is really needed is the
1870 largest value of reg_parm_stack_space in the inline
1871 function, but that is not available. Using the current
1872 value of reg_parm_stack_space is wrong, but gives
1873 correct results on all supported machines. */
1875 int adjust
= (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
1876 + reg_parm_stack_space
);
1879 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
1880 allocate_dynamic_stack_space (GEN_INT (adjust
),
1881 NULL_RTX
, BITS_PER_UNIT
);
1884 emit_insn_before (seq
, first_insn
);
1885 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1890 /* If the result is equivalent to TARGET, return TARGET to simplify
1891 checks in store_expr. They can be equivalent but not equal in the
1892 case of a function that returns BLKmode. */
1893 if (temp
!= target
&& rtx_equal_p (temp
, target
))
1898 /* If inlining failed, mark FNDECL as needing to be compiled
1899 separately after all. If function was declared inline,
1901 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
1902 && optimize
> 0 && !TREE_ADDRESSABLE (fndecl
))
1904 warning_with_decl (fndecl
, "inlining failed in call to `%s'");
1905 warning ("called from here");
1907 (*lang_hooks
.mark_addressable
) (fndecl
);
1908 return (rtx
) (size_t) - 1;
1911 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1912 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1913 bytes, then we would need to push some additional bytes to pad the
1914 arguments. So, we compute an adjust to the stack pointer for an
1915 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1916 bytes. Then, when the arguments are pushed the stack will be perfectly
1917 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1918 be popped after the call. Returns the adjustment. */
1921 combine_pending_stack_adjustment_and_call (unadjusted_args_size
,
1923 preferred_unit_stack_boundary
)
1924 int unadjusted_args_size
;
1925 struct args_size
*args_size
;
1926 int preferred_unit_stack_boundary
;
1928 /* The number of bytes to pop so that the stack will be
1929 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1930 HOST_WIDE_INT adjustment
;
1931 /* The alignment of the stack after the arguments are pushed, if we
1932 just pushed the arguments without adjust the stack here. */
1933 HOST_WIDE_INT unadjusted_alignment
;
1935 unadjusted_alignment
1936 = ((stack_pointer_delta
+ unadjusted_args_size
)
1937 % preferred_unit_stack_boundary
);
1939 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1940 as possible -- leaving just enough left to cancel out the
1941 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1942 PENDING_STACK_ADJUST is non-negative, and congruent to
1943 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1945 /* Begin by trying to pop all the bytes. */
1946 unadjusted_alignment
1947 = (unadjusted_alignment
1948 - (pending_stack_adjust
% preferred_unit_stack_boundary
));
1949 adjustment
= pending_stack_adjust
;
1950 /* Push enough additional bytes that the stack will be aligned
1951 after the arguments are pushed. */
1952 if (preferred_unit_stack_boundary
> 1)
1954 if (unadjusted_alignment
> 0)
1955 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
1957 adjustment
+= unadjusted_alignment
;
1960 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1961 bytes after the call. The right number is the entire
1962 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1963 by the arguments in the first place. */
1965 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
1970 /* Scan X expression if it does not dereference any argument slots
1971 we already clobbered by tail call arguments (as noted in stored_args_map
1973 Return nonzero if X expression dereferences such argument slots,
1977 check_sibcall_argument_overlap_1 (x
)
1988 code
= GET_CODE (x
);
1992 if (XEXP (x
, 0) == current_function_internal_arg_pointer
)
1994 else if (GET_CODE (XEXP (x
, 0)) == PLUS
1995 && XEXP (XEXP (x
, 0), 0) ==
1996 current_function_internal_arg_pointer
1997 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
)
1998 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
2002 #ifdef ARGS_GROW_DOWNWARD
2003 i
= -i
- GET_MODE_SIZE (GET_MODE (x
));
2006 for (k
= 0; k
< GET_MODE_SIZE (GET_MODE (x
)); k
++)
2007 if (i
+ k
< stored_args_map
->n_bits
2008 && TEST_BIT (stored_args_map
, i
+ k
))
2014 /* Scan all subexpressions. */
2015 fmt
= GET_RTX_FORMAT (code
);
2016 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2020 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
2023 else if (*fmt
== 'E')
2025 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2026 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
2033 /* Scan sequence after INSN if it does not dereference any argument slots
2034 we already clobbered by tail call arguments (as noted in stored_args_map
2035 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2036 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2037 should be 0). Return nonzero if sequence after INSN dereferences such argument
2038 slots, zero otherwise. */
2041 check_sibcall_argument_overlap (insn
, arg
, mark_stored_args_map
)
2043 struct arg_data
*arg
;
2044 int mark_stored_args_map
;
2048 if (insn
== NULL_RTX
)
2049 insn
= get_insns ();
2051 insn
= NEXT_INSN (insn
);
2053 for (; insn
; insn
= NEXT_INSN (insn
))
2055 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
2058 if (mark_stored_args_map
)
2060 #ifdef ARGS_GROW_DOWNWARD
2061 low
= -arg
->slot_offset
.constant
- arg
->size
.constant
;
2063 low
= arg
->slot_offset
.constant
;
2066 for (high
= low
+ arg
->size
.constant
; low
< high
; low
++)
2067 SET_BIT (stored_args_map
, low
);
2069 return insn
!= NULL_RTX
;
2076 switch (unsafe_for_reeval (t
))
2081 case 1: /* Mildly unsafe. */
2082 t
= unsave_expr (t
);
2085 case 2: /* Wildly unsafe. */
2087 tree var
= build_decl (VAR_DECL
, NULL_TREE
,
2090 expand_expr (t
, NULL_RTX
, VOIDmode
, EXPAND_NORMAL
));
2101 /* Generate all the code for a function call
2102 and return an rtx for its value.
2103 Store the value in TARGET (specified as an rtx) if convenient.
2104 If the value is stored in TARGET then TARGET is returned.
2105 If IGNORE is nonzero, then we ignore the value of the function call. */
2108 expand_call (exp
, target
, ignore
)
2113 /* Nonzero if we are currently expanding a call. */
2114 static int currently_expanding_call
= 0;
2116 /* List of actual parameters. */
2117 tree actparms
= TREE_OPERAND (exp
, 1);
2118 /* RTX for the function to be called. */
2120 /* Sequence of insns to perform a tail recursive "call". */
2121 rtx tail_recursion_insns
= NULL_RTX
;
2122 /* Sequence of insns to perform a normal "call". */
2123 rtx normal_call_insns
= NULL_RTX
;
2124 /* Sequence of insns to perform a tail recursive "call". */
2125 rtx tail_call_insns
= NULL_RTX
;
2126 /* Data type of the function. */
2128 /* Declaration of the function being called,
2129 or 0 if the function is computed (not known by name). */
2132 int try_tail_call
= 1;
2133 int try_tail_recursion
= 1;
2136 /* Register in which non-BLKmode value will be returned,
2137 or 0 if no value or if value is BLKmode. */
2139 /* Address where we should return a BLKmode value;
2140 0 if value not BLKmode. */
2141 rtx structure_value_addr
= 0;
2142 /* Nonzero if that address is being passed by treating it as
2143 an extra, implicit first parameter. Otherwise,
2144 it is passed by being copied directly into struct_value_rtx. */
2145 int structure_value_addr_parm
= 0;
2146 /* Size of aggregate value wanted, or zero if none wanted
2147 or if we are using the non-reentrant PCC calling convention
2148 or expecting the value in registers. */
2149 HOST_WIDE_INT struct_value_size
= 0;
2150 /* Nonzero if called function returns an aggregate in memory PCC style,
2151 by returning the address of where to find it. */
2152 int pcc_struct_value
= 0;
2154 /* Number of actual parameters in this call, including struct value addr. */
2156 /* Number of named args. Args after this are anonymous ones
2157 and they must all go on the stack. */
2160 /* Vector of information about each argument.
2161 Arguments are numbered in the order they will be pushed,
2162 not the order they are written. */
2163 struct arg_data
*args
;
2165 /* Total size in bytes of all the stack-parms scanned so far. */
2166 struct args_size args_size
;
2167 struct args_size adjusted_args_size
;
2168 /* Size of arguments before any adjustments (such as rounding). */
2169 int unadjusted_args_size
;
2170 /* Data on reg parms scanned so far. */
2171 CUMULATIVE_ARGS args_so_far
;
2172 /* Nonzero if a reg parm has been scanned. */
2174 /* Nonzero if this is an indirect function call. */
2176 /* Nonzero if we must avoid push-insns in the args for this call.
2177 If stack space is allocated for register parameters, but not by the
2178 caller, then it is preallocated in the fixed part of the stack frame.
2179 So the entire argument block must then be preallocated (i.e., we
2180 ignore PUSH_ROUNDING in that case). */
2182 int must_preallocate
= !PUSH_ARGS
;
2184 /* Size of the stack reserved for parameter registers. */
2185 int reg_parm_stack_space
= 0;
2187 /* Address of space preallocated for stack parms
2188 (on machines that lack push insns), or 0 if space not preallocated. */
2191 /* Mask of ECF_ flags. */
2193 /* Nonzero if this is a call to an inline function. */
2194 int is_integrable
= 0;
2195 #ifdef REG_PARM_STACK_SPACE
2196 /* Define the boundary of the register parm stack space that needs to be
2198 int low_to_save
= -1, high_to_save
;
2199 rtx save_area
= 0; /* Place that it is saved */
2202 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
2203 char *initial_stack_usage_map
= stack_usage_map
;
2204 int old_stack_arg_under_construction
= 0;
2206 rtx old_stack_level
= 0;
2207 int old_pending_adj
= 0;
2208 int old_inhibit_defer_pop
= inhibit_defer_pop
;
2209 int old_stack_allocated
;
2211 tree p
= TREE_OPERAND (exp
, 0);
2213 /* The alignment of the stack, in bits. */
2214 HOST_WIDE_INT preferred_stack_boundary
;
2215 /* The alignment of the stack, in bytes. */
2216 HOST_WIDE_INT preferred_unit_stack_boundary
;
2218 /* See if this is "nothrow" function call. */
2219 if (TREE_NOTHROW (exp
))
2220 flags
|= ECF_NOTHROW
;
2222 /* See if we can find a DECL-node for the actual function.
2223 As a result, decide whether this is a call to an integrable function. */
2225 fndecl
= get_callee_fndecl (exp
);
2229 && fndecl
!= current_function_decl
2230 && DECL_INLINE (fndecl
)
2231 && DECL_SAVED_INSNS (fndecl
)
2232 && DECL_SAVED_INSNS (fndecl
)->inlinable
)
2234 else if (! TREE_ADDRESSABLE (fndecl
))
2236 /* In case this function later becomes inlinable,
2237 record that there was already a non-inline call to it.
2239 Use abstraction instead of setting TREE_ADDRESSABLE
2241 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
2244 warning_with_decl (fndecl
, "can't inline call to `%s'");
2245 warning ("called from here");
2247 (*lang_hooks
.mark_addressable
) (fndecl
);
2250 flags
|= flags_from_decl_or_type (fndecl
);
2253 /* If we don't have specific function to call, see if we have a
2254 attributes set in the type. */
2256 flags
|= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p
)));
2258 #ifdef REG_PARM_STACK_SPACE
2259 #ifdef MAYBE_REG_PARM_STACK_SPACE
2260 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
2262 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
2266 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2267 if (reg_parm_stack_space
> 0 && PUSH_ARGS
)
2268 must_preallocate
= 1;
2271 /* Warn if this value is an aggregate type,
2272 regardless of which calling convention we are using for it. */
2273 if (warn_aggregate_return
&& AGGREGATE_TYPE_P (TREE_TYPE (exp
)))
2274 warning ("function call has aggregate value");
2276 /* Set up a place to return a structure. */
2278 /* Cater to broken compilers. */
2279 if (aggregate_value_p (exp
))
2281 /* This call returns a big structure. */
2282 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
2284 #ifdef PCC_STATIC_STRUCT_RETURN
2286 pcc_struct_value
= 1;
2287 /* Easier than making that case work right. */
2290 /* In case this is a static function, note that it has been
2292 if (! TREE_ADDRESSABLE (fndecl
))
2293 (*lang_hooks
.mark_addressable
) (fndecl
);
2297 #else /* not PCC_STATIC_STRUCT_RETURN */
2299 struct_value_size
= int_size_in_bytes (TREE_TYPE (exp
));
2301 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp
))
2303 /* The structure value address arg is already in actparms.
2304 Pull it out. It might be nice to just leave it there, but
2305 we need to set structure_value_addr. */
2306 tree return_arg
= TREE_VALUE (actparms
);
2307 actparms
= TREE_CHAIN (actparms
);
2308 structure_value_addr
= expand_expr (return_arg
, NULL_RTX
,
2309 VOIDmode
, EXPAND_NORMAL
);
2311 else if (target
&& GET_CODE (target
) == MEM
)
2312 structure_value_addr
= XEXP (target
, 0);
2315 /* For variable-sized objects, we must be called with a target
2316 specified. If we were to allocate space on the stack here,
2317 we would have no way of knowing when to free it. */
2318 rtx d
= assign_temp (TREE_TYPE (exp
), 1, 1, 1);
2320 mark_temp_addr_taken (d
);
2321 structure_value_addr
= XEXP (d
, 0);
2325 #endif /* not PCC_STATIC_STRUCT_RETURN */
2328 /* If called function is inline, try to integrate it. */
2332 rtx temp
= try_to_integrate (fndecl
, actparms
, target
,
2333 ignore
, TREE_TYPE (exp
),
2334 structure_value_addr
);
2335 if (temp
!= (rtx
) (size_t) - 1)
2339 /* Figure out the amount to which the stack should be aligned. */
2340 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
2342 /* Operand 0 is a pointer-to-function; get the type of the function. */
2343 funtype
= TREE_TYPE (TREE_OPERAND (exp
, 0));
2344 if (! POINTER_TYPE_P (funtype
))
2346 funtype
= TREE_TYPE (funtype
);
2348 /* See if this is a call to a function that can return more than once
2349 or a call to longjmp or malloc. */
2350 flags
|= special_function_p (fndecl
, flags
);
2352 if (flags
& ECF_MAY_BE_ALLOCA
)
2353 current_function_calls_alloca
= 1;
2355 /* If struct_value_rtx is 0, it means pass the address
2356 as if it were an extra parameter. */
2357 if (structure_value_addr
&& struct_value_rtx
== 0)
2359 /* If structure_value_addr is a REG other than
2360 virtual_outgoing_args_rtx, we can use always use it. If it
2361 is not a REG, we must always copy it into a register.
2362 If it is virtual_outgoing_args_rtx, we must copy it to another
2363 register in some cases. */
2364 rtx temp
= (GET_CODE (structure_value_addr
) != REG
2365 || (ACCUMULATE_OUTGOING_ARGS
2366 && stack_arg_under_construction
2367 && structure_value_addr
== virtual_outgoing_args_rtx
)
2368 ? copy_addr_to_reg (structure_value_addr
)
2369 : structure_value_addr
);
2372 = tree_cons (error_mark_node
,
2373 make_tree (build_pointer_type (TREE_TYPE (funtype
)),
2376 structure_value_addr_parm
= 1;
2379 /* Count the arguments and set NUM_ACTUALS. */
2380 for (p
= actparms
, num_actuals
= 0; p
; p
= TREE_CHAIN (p
))
2383 /* Compute number of named args.
2384 Normally, don't include the last named arg if anonymous args follow.
2385 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2386 (If no anonymous args follow, the result of list_length is actually
2387 one too large. This is harmless.)
2389 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2390 zero, this machine will be able to place unnamed args that were
2391 passed in registers into the stack. So treat all args as named.
2392 This allows the insns emitting for a specific argument list to be
2393 independent of the function declaration.
2395 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2396 reliable way to pass unnamed args in registers, so we must force
2397 them into memory. */
2399 if ((STRICT_ARGUMENT_NAMING
2400 || ! PRETEND_OUTGOING_VARARGS_NAMED
)
2401 && TYPE_ARG_TYPES (funtype
) != 0)
2403 = (list_length (TYPE_ARG_TYPES (funtype
))
2404 /* Don't include the last named arg. */
2405 - (STRICT_ARGUMENT_NAMING
? 0 : 1)
2406 /* Count the struct value address, if it is passed as a parm. */
2407 + structure_value_addr_parm
);
2409 /* If we know nothing, treat all args as named. */
2410 n_named_args
= num_actuals
;
2412 /* Start updating where the next arg would go.
2414 On some machines (such as the PA) indirect calls have a different
2415 calling convention than normal calls. The last argument in
2416 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2418 INIT_CUMULATIVE_ARGS (args_so_far
, funtype
, NULL_RTX
, (fndecl
== 0));
2420 /* Make a vector to hold all the information about each arg. */
2421 args
= (struct arg_data
*) alloca (num_actuals
* sizeof (struct arg_data
));
2422 memset ((char *) args
, 0, num_actuals
* sizeof (struct arg_data
));
2424 /* Build up entries in the ARGS array, compute the size of the
2425 arguments into ARGS_SIZE, etc. */
2426 initialize_argument_information (num_actuals
, args
, &args_size
,
2427 n_named_args
, actparms
, fndecl
,
2428 &args_so_far
, reg_parm_stack_space
,
2429 &old_stack_level
, &old_pending_adj
,
2430 &must_preallocate
, &flags
);
2434 /* If this function requires a variable-sized argument list, don't
2435 try to make a cse'able block for this call. We may be able to
2436 do this eventually, but it is too complicated to keep track of
2437 what insns go in the cse'able block and which don't. */
2439 flags
&= ~ECF_LIBCALL_BLOCK
;
2440 must_preallocate
= 1;
2443 /* Now make final decision about preallocating stack space. */
2444 must_preallocate
= finalize_must_preallocate (must_preallocate
,
2448 /* If the structure value address will reference the stack pointer, we
2449 must stabilize it. We don't need to do this if we know that we are
2450 not going to adjust the stack pointer in processing this call. */
2452 if (structure_value_addr
2453 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
2454 || reg_mentioned_p (virtual_outgoing_args_rtx
,
2455 structure_value_addr
))
2457 || (!ACCUMULATE_OUTGOING_ARGS
&& args_size
.constant
)))
2458 structure_value_addr
= copy_to_reg (structure_value_addr
);
2460 /* Tail calls can make things harder to debug, and we're traditionally
2461 pushed these optimizations into -O2. Don't try if we're already
2462 expanding a call, as that means we're an argument. Don't try if
2463 there's cleanups, as we know there's code to follow the call.
2465 If rtx_equal_function_value_matters is false, that means we've
2466 finished with regular parsing. Which means that some of the
2467 machinery we use to generate tail-calls is no longer in place.
2468 This is most often true of sjlj-exceptions, which we couldn't
2469 tail-call to anyway. */
2471 if (currently_expanding_call
++ != 0
2472 || !flag_optimize_sibling_calls
2473 || !rtx_equal_function_value_matters
2474 || any_pending_cleanups (1)
2476 try_tail_call
= try_tail_recursion
= 0;
2478 /* Tail recursion fails, when we are not dealing with recursive calls. */
2479 if (!try_tail_recursion
2480 || TREE_CODE (TREE_OPERAND (exp
, 0)) != ADDR_EXPR
2481 || TREE_OPERAND (TREE_OPERAND (exp
, 0), 0) != current_function_decl
)
2482 try_tail_recursion
= 0;
2484 /* Rest of purposes for tail call optimizations to fail. */
2486 #ifdef HAVE_sibcall_epilogue
2487 !HAVE_sibcall_epilogue
2492 /* Doing sibling call optimization needs some work, since
2493 structure_value_addr can be allocated on the stack.
2494 It does not seem worth the effort since few optimizable
2495 sibling calls will return a structure. */
2496 || structure_value_addr
!= NULL_RTX
2497 /* Check whether the target is able to optimize the call
2499 || !(*targetm
.function_ok_for_sibcall
) (fndecl
, exp
)
2500 /* Functions that do not return exactly once may not be sibcall
2502 || (flags
& (ECF_RETURNS_TWICE
| ECF_LONGJMP
| ECF_NORETURN
))
2503 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))
2504 /* If this function requires more stack slots than the current
2505 function, we cannot change it into a sibling call. */
2506 || args_size
.constant
> current_function_args_size
2507 /* If the callee pops its own arguments, then it must pop exactly
2508 the same number of arguments as the current function. */
2509 || RETURN_POPS_ARGS (fndecl
, funtype
, args_size
.constant
)
2510 != RETURN_POPS_ARGS (current_function_decl
,
2511 TREE_TYPE (current_function_decl
),
2512 current_function_args_size
))
2515 if (try_tail_call
|| try_tail_recursion
)
2518 actparms
= NULL_TREE
;
2519 /* Ok, we're going to give the tail call the old college try.
2520 This means we're going to evaluate the function arguments
2521 up to three times. There are two degrees of badness we can
2522 encounter, those that can be unsaved and those that can't.
2523 (See unsafe_for_reeval commentary for details.)
2525 Generate a new argument list. Pass safe arguments through
2526 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2527 For hard badness, evaluate them now and put their resulting
2528 rtx in a temporary VAR_DECL.
2530 initialize_argument_information has ordered the array for the
2531 order to be pushed, and we must remember this when reconstructing
2532 the original argument order. */
2534 if (PUSH_ARGS_REVERSED
)
2543 i
= num_actuals
- 1;
2547 for (; i
!= end
; i
+= inc
)
2549 args
[i
].tree_value
= fix_unsafe_tree (args
[i
].tree_value
);
2550 /* We need to build actparms for optimize_tail_recursion. We can
2551 safely trash away TREE_PURPOSE, since it is unused by this
2553 if (try_tail_recursion
)
2554 actparms
= tree_cons (NULL_TREE
, args
[i
].tree_value
, actparms
);
2556 /* Do the same for the function address if it is an expression. */
2558 TREE_OPERAND (exp
, 0) = fix_unsafe_tree (TREE_OPERAND (exp
, 0));
2559 /* Expanding one of those dangerous arguments could have added
2560 cleanups, but otherwise give it a whirl. */
2561 if (any_pending_cleanups (1))
2562 try_tail_call
= try_tail_recursion
= 0;
2565 /* Generate a tail recursion sequence when calling ourselves. */
2567 if (try_tail_recursion
)
2569 /* We want to emit any pending stack adjustments before the tail
2570 recursion "call". That way we know any adjustment after the tail
2571 recursion call can be ignored if we indeed use the tail recursion
2573 int save_pending_stack_adjust
= pending_stack_adjust
;
2574 int save_stack_pointer_delta
= stack_pointer_delta
;
2576 /* Emit any queued insns now; otherwise they would end up in
2577 only one of the alternates. */
2580 /* Use a new sequence to hold any RTL we generate. We do not even
2581 know if we will use this RTL yet. The final decision can not be
2582 made until after RTL generation for the entire function is
2585 /* If expanding any of the arguments creates cleanups, we can't
2586 do a tailcall. So, we'll need to pop the pending cleanups
2587 list. If, however, all goes well, and there are no cleanups
2588 then the call to expand_start_target_temps will have no
2590 expand_start_target_temps ();
2591 if (optimize_tail_recursion (actparms
, get_last_insn ()))
2593 if (any_pending_cleanups (1))
2594 try_tail_call
= try_tail_recursion
= 0;
2596 tail_recursion_insns
= get_insns ();
2598 expand_end_target_temps ();
2601 /* Restore the original pending stack adjustment for the sibling and
2602 normal call cases below. */
2603 pending_stack_adjust
= save_pending_stack_adjust
;
2604 stack_pointer_delta
= save_stack_pointer_delta
;
2607 if (profile_arc_flag
&& (flags
& ECF_FORK_OR_EXEC
))
2609 /* A fork duplicates the profile information, and an exec discards
2610 it. We can't rely on fork/exec to be paired. So write out the
2611 profile information we have gathered so far, and clear it. */
2612 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2613 is subject to race conditions, just as with multithreaded
2616 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "__gcov_flush"),
2621 /* Ensure current function's preferred stack boundary is at least
2622 what we need. We don't have to increase alignment for recursive
2624 if (cfun
->preferred_stack_boundary
< preferred_stack_boundary
2625 && fndecl
!= current_function_decl
)
2626 cfun
->preferred_stack_boundary
= preferred_stack_boundary
;
2628 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
2630 function_call_count
++;
2632 /* We want to make two insn chains; one for a sibling call, the other
2633 for a normal call. We will select one of the two chains after
2634 initial RTL generation is complete. */
2635 for (pass
= 0; pass
< 2; pass
++)
2637 int sibcall_failure
= 0;
2638 /* We want to emit any pending stack adjustments before the tail
2639 recursion "call". That way we know any adjustment after the tail
2640 recursion call can be ignored if we indeed use the tail recursion
2642 int save_pending_stack_adjust
= 0;
2643 int save_stack_pointer_delta
= 0;
2645 rtx before_call
, next_arg_reg
;
2649 if (! try_tail_call
)
2652 /* Emit any queued insns now; otherwise they would end up in
2653 only one of the alternates. */
2656 /* State variables we need to save and restore between
2658 save_pending_stack_adjust
= pending_stack_adjust
;
2659 save_stack_pointer_delta
= stack_pointer_delta
;
2662 flags
&= ~ECF_SIBCALL
;
2664 flags
|= ECF_SIBCALL
;
2666 /* Other state variables that we must reinitialize each time
2667 through the loop (that are not initialized by the loop itself). */
2671 /* Start a new sequence for the normal call case.
2673 From this point on, if the sibling call fails, we want to set
2674 sibcall_failure instead of continuing the loop. */
2679 /* We know at this point that there are not currently any
2680 pending cleanups. If, however, in the process of evaluating
2681 the arguments we were to create some, we'll need to be
2682 able to get rid of them. */
2683 expand_start_target_temps ();
2686 /* Don't let pending stack adjusts add up to too much.
2687 Also, do all pending adjustments now if there is any chance
2688 this might be a call to alloca or if we are expanding a sibling
2689 call sequence or if we are calling a function that is to return
2690 with stack pointer depressed. */
2691 if (pending_stack_adjust
>= 32
2692 || (pending_stack_adjust
> 0
2693 && (flags
& (ECF_MAY_BE_ALLOCA
| ECF_SP_DEPRESSED
)))
2695 do_pending_stack_adjust ();
2697 /* When calling a const function, we must pop the stack args right away,
2698 so that the pop is deleted or moved with the call. */
2699 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
2702 #ifdef FINAL_REG_PARM_STACK_SPACE
2703 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
2706 /* Precompute any arguments as needed. */
2708 precompute_arguments (flags
, num_actuals
, args
);
2710 /* Now we are about to start emitting insns that can be deleted
2711 if a libcall is deleted. */
2712 if (pass
&& (flags
& (ECF_LIBCALL_BLOCK
| ECF_MALLOC
)))
2715 adjusted_args_size
= args_size
;
2716 /* Compute the actual size of the argument block required. The variable
2717 and constant sizes must be combined, the size may have to be rounded,
2718 and there may be a minimum required size. When generating a sibcall
2719 pattern, do not round up, since we'll be re-using whatever space our
2721 unadjusted_args_size
2722 = compute_argument_block_size (reg_parm_stack_space
,
2723 &adjusted_args_size
,
2725 : preferred_stack_boundary
));
2727 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
2729 /* The argument block when performing a sibling call is the
2730 incoming argument block. */
2733 argblock
= virtual_incoming_args_rtx
;
2735 #ifdef STACK_GROWS_DOWNWARD
2736 = plus_constant (argblock
, current_function_pretend_args_size
);
2738 = plus_constant (argblock
, -current_function_pretend_args_size
);
2740 stored_args_map
= sbitmap_alloc (args_size
.constant
);
2741 sbitmap_zero (stored_args_map
);
2744 /* If we have no actual push instructions, or shouldn't use them,
2745 make space for all args right now. */
2746 else if (adjusted_args_size
.var
!= 0)
2748 if (old_stack_level
== 0)
2750 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
2751 old_pending_adj
= pending_stack_adjust
;
2752 pending_stack_adjust
= 0;
2753 /* stack_arg_under_construction says whether a stack arg is
2754 being constructed at the old stack level. Pushing the stack
2755 gets a clean outgoing argument block. */
2756 old_stack_arg_under_construction
= stack_arg_under_construction
;
2757 stack_arg_under_construction
= 0;
2759 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
2763 /* Note that we must go through the motions of allocating an argument
2764 block even if the size is zero because we may be storing args
2765 in the area reserved for register arguments, which may be part of
2768 int needed
= adjusted_args_size
.constant
;
2770 /* Store the maximum argument space used. It will be pushed by
2771 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2774 if (needed
> current_function_outgoing_args_size
)
2775 current_function_outgoing_args_size
= needed
;
2777 if (must_preallocate
)
2779 if (ACCUMULATE_OUTGOING_ARGS
)
2781 /* Since the stack pointer will never be pushed, it is
2782 possible for the evaluation of a parm to clobber
2783 something we have already written to the stack.
2784 Since most function calls on RISC machines do not use
2785 the stack, this is uncommon, but must work correctly.
2787 Therefore, we save any area of the stack that was already
2788 written and that we are using. Here we set up to do this
2789 by making a new stack usage map from the old one. The
2790 actual save will be done by store_one_arg.
2792 Another approach might be to try to reorder the argument
2793 evaluations to avoid this conflicting stack usage. */
2795 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2796 /* Since we will be writing into the entire argument area,
2797 the map must be allocated for its entire size, not just
2798 the part that is the responsibility of the caller. */
2799 needed
+= reg_parm_stack_space
;
2802 #ifdef ARGS_GROW_DOWNWARD
2803 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2806 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2810 = (char *) alloca (highest_outgoing_arg_in_use
);
2812 if (initial_highest_arg_in_use
)
2813 memcpy (stack_usage_map
, initial_stack_usage_map
,
2814 initial_highest_arg_in_use
);
2816 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
2817 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
2818 (highest_outgoing_arg_in_use
2819 - initial_highest_arg_in_use
));
2822 /* The address of the outgoing argument list must not be
2823 copied to a register here, because argblock would be left
2824 pointing to the wrong place after the call to
2825 allocate_dynamic_stack_space below. */
2827 argblock
= virtual_outgoing_args_rtx
;
2831 if (inhibit_defer_pop
== 0)
2833 /* Try to reuse some or all of the pending_stack_adjust
2834 to get this space. */
2836 = (combine_pending_stack_adjustment_and_call
2837 (unadjusted_args_size
,
2838 &adjusted_args_size
,
2839 preferred_unit_stack_boundary
));
2841 /* combine_pending_stack_adjustment_and_call computes
2842 an adjustment before the arguments are allocated.
2843 Account for them and see whether or not the stack
2844 needs to go up or down. */
2845 needed
= unadjusted_args_size
- needed
;
2849 /* We're releasing stack space. */
2850 /* ??? We can avoid any adjustment at all if we're
2851 already aligned. FIXME. */
2852 pending_stack_adjust
= -needed
;
2853 do_pending_stack_adjust ();
2857 /* We need to allocate space. We'll do that in
2858 push_block below. */
2859 pending_stack_adjust
= 0;
2862 /* Special case this because overhead of `push_block' in
2863 this case is non-trivial. */
2865 argblock
= virtual_outgoing_args_rtx
;
2867 argblock
= push_block (GEN_INT (needed
), 0, 0);
2869 /* We only really need to call `copy_to_reg' in the case
2870 where push insns are going to be used to pass ARGBLOCK
2871 to a function call in ARGS. In that case, the stack
2872 pointer changes value from the allocation point to the
2873 call point, and hence the value of
2874 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2875 as well always do it. */
2876 argblock
= copy_to_reg (argblock
);
2878 /* The save/restore code in store_one_arg handles all
2879 cases except one: a constructor call (including a C
2880 function returning a BLKmode struct) to initialize
2882 if (stack_arg_under_construction
)
2884 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2885 rtx push_size
= GEN_INT (reg_parm_stack_space
2886 + adjusted_args_size
.constant
);
2888 rtx push_size
= GEN_INT (adjusted_args_size
.constant
);
2890 if (old_stack_level
== 0)
2892 emit_stack_save (SAVE_BLOCK
, &old_stack_level
,
2894 old_pending_adj
= pending_stack_adjust
;
2895 pending_stack_adjust
= 0;
2896 /* stack_arg_under_construction says whether a stack
2897 arg is being constructed at the old stack level.
2898 Pushing the stack gets a clean outgoing argument
2900 old_stack_arg_under_construction
2901 = stack_arg_under_construction
;
2902 stack_arg_under_construction
= 0;
2903 /* Make a new map for the new argument list. */
2904 stack_usage_map
= (char *)
2905 alloca (highest_outgoing_arg_in_use
);
2906 memset (stack_usage_map
, 0, highest_outgoing_arg_in_use
);
2907 highest_outgoing_arg_in_use
= 0;
2909 allocate_dynamic_stack_space (push_size
, NULL_RTX
,
2912 /* If argument evaluation might modify the stack pointer,
2913 copy the address of the argument list to a register. */
2914 for (i
= 0; i
< num_actuals
; i
++)
2915 if (args
[i
].pass_on_stack
)
2917 argblock
= copy_addr_to_reg (argblock
);
2924 compute_argument_addresses (args
, argblock
, num_actuals
);
2926 /* If we push args individually in reverse order, perform stack alignment
2927 before the first push (the last arg). */
2928 if (PUSH_ARGS_REVERSED
&& argblock
== 0
2929 && adjusted_args_size
.constant
!= unadjusted_args_size
)
2931 /* When the stack adjustment is pending, we get better code
2932 by combining the adjustments. */
2933 if (pending_stack_adjust
2934 && ! (flags
& ECF_LIBCALL_BLOCK
)
2935 && ! inhibit_defer_pop
)
2937 pending_stack_adjust
2938 = (combine_pending_stack_adjustment_and_call
2939 (unadjusted_args_size
,
2940 &adjusted_args_size
,
2941 preferred_unit_stack_boundary
));
2942 do_pending_stack_adjust ();
2944 else if (argblock
== 0)
2945 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
2946 - unadjusted_args_size
));
2948 /* Now that the stack is properly aligned, pops can't safely
2949 be deferred during the evaluation of the arguments. */
2952 funexp
= rtx_for_function_call (fndecl
, exp
);
2954 /* Figure out the register where the value, if any, will come back. */
2956 if (TYPE_MODE (TREE_TYPE (exp
)) != VOIDmode
2957 && ! structure_value_addr
)
2959 if (pcc_struct_value
)
2960 valreg
= hard_function_value (build_pointer_type (TREE_TYPE (exp
)),
2961 fndecl
, (pass
== 0));
2963 valreg
= hard_function_value (TREE_TYPE (exp
), fndecl
, (pass
== 0));
2966 /* Precompute all register parameters. It isn't safe to compute anything
2967 once we have started filling any specific hard regs. */
2968 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
2970 #ifdef REG_PARM_STACK_SPACE
2971 /* Save the fixed argument area if it's part of the caller's frame and
2972 is clobbered by argument setup for this call. */
2973 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
2974 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
2975 &low_to_save
, &high_to_save
);
2978 /* Now store (and compute if necessary) all non-register parms.
2979 These come before register parms, since they can require block-moves,
2980 which could clobber the registers used for register parms.
2981 Parms which have partial registers are not stored here,
2982 but we do preallocate space here if they want that. */
2984 for (i
= 0; i
< num_actuals
; i
++)
2985 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
2987 rtx before_arg
= get_last_insn ();
2989 if (store_one_arg (&args
[i
], argblock
, flags
,
2990 adjusted_args_size
.var
!= 0,
2991 reg_parm_stack_space
)
2993 && check_sibcall_argument_overlap (before_arg
,
2995 sibcall_failure
= 1;
2998 /* If we have a parm that is passed in registers but not in memory
2999 and whose alignment does not permit a direct copy into registers,
3000 make a group of pseudos that correspond to each register that we
3002 if (STRICT_ALIGNMENT
)
3003 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
3005 /* Now store any partially-in-registers parm.
3006 This is the last place a block-move can happen. */
3008 for (i
= 0; i
< num_actuals
; i
++)
3009 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
3011 rtx before_arg
= get_last_insn ();
3013 if (store_one_arg (&args
[i
], argblock
, flags
,
3014 adjusted_args_size
.var
!= 0,
3015 reg_parm_stack_space
)
3017 && check_sibcall_argument_overlap (before_arg
,
3019 sibcall_failure
= 1;
3022 /* If we pushed args in forward order, perform stack alignment
3023 after pushing the last arg. */
3024 if (!PUSH_ARGS_REVERSED
&& argblock
== 0)
3025 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
3026 - unadjusted_args_size
));
3028 /* If register arguments require space on the stack and stack space
3029 was not preallocated, allocate stack space here for arguments
3030 passed in registers. */
3031 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3032 if (!ACCUMULATE_OUTGOING_ARGS
3033 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
3034 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
3037 /* Pass the function the address in which to return a
3039 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
3041 emit_move_insn (struct_value_rtx
,
3043 force_operand (structure_value_addr
,
3046 if (GET_CODE (struct_value_rtx
) == REG
)
3047 use_reg (&call_fusage
, struct_value_rtx
);
3050 funexp
= prepare_call_address (funexp
, fndecl
, &call_fusage
,
3051 reg_parm_seen
, pass
== 0);
3053 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
3054 pass
== 0, &sibcall_failure
);
3056 /* Perform postincrements before actually calling the function. */
3059 /* Save a pointer to the last insn before the call, so that we can
3060 later safely search backwards to find the CALL_INSN. */
3061 before_call
= get_last_insn ();
3063 /* Set up next argument register. For sibling calls on machines
3064 with register windows this should be the incoming register. */
3065 #ifdef FUNCTION_INCOMING_ARG
3067 next_arg_reg
= FUNCTION_INCOMING_ARG (args_so_far
, VOIDmode
,
3071 next_arg_reg
= FUNCTION_ARG (args_so_far
, VOIDmode
,
3074 /* All arguments and registers used for the call must be set up by
3077 /* Stack must be properly aligned now. */
3078 if (pass
&& stack_pointer_delta
% preferred_unit_stack_boundary
)
3081 /* Generate the actual call instruction. */
3082 emit_call_1 (funexp
, fndecl
, funtype
, unadjusted_args_size
,
3083 adjusted_args_size
.constant
, struct_value_size
,
3084 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
3085 flags
, & args_so_far
);
3087 /* Verify that we've deallocated all the stack we used. */
3089 && old_stack_allocated
!= stack_pointer_delta
- pending_stack_adjust
)
3092 /* If call is cse'able, make appropriate pair of reg-notes around it.
3093 Test valreg so we don't crash; may safely ignore `const'
3094 if return type is void. Disable for PARALLEL return values, because
3095 we have no way to move such values into a pseudo register. */
3096 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
3100 if (valreg
== 0 || GET_CODE (valreg
) == PARALLEL
)
3102 insns
= get_insns ();
3109 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3111 /* Mark the return value as a pointer if needed. */
3112 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3113 mark_reg_pointer (temp
,
3114 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp
))));
3116 /* Construct an "equal form" for the value which mentions all the
3117 arguments in order as well as the function name. */
3118 for (i
= 0; i
< num_actuals
; i
++)
3119 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3120 args
[i
].initial_value
, note
);
3121 note
= gen_rtx_EXPR_LIST (VOIDmode
, funexp
, note
);
3123 insns
= get_insns ();
3126 if (flags
& ECF_PURE
)
3127 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3128 gen_rtx_USE (VOIDmode
,
3129 gen_rtx_MEM (BLKmode
,
3130 gen_rtx_SCRATCH (VOIDmode
))),
3133 emit_libcall_block (insns
, temp
, valreg
, note
);
3138 else if (pass
&& (flags
& ECF_MALLOC
))
3140 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3143 /* The return value from a malloc-like function is a pointer. */
3144 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3145 mark_reg_pointer (temp
, BIGGEST_ALIGNMENT
);
3147 emit_move_insn (temp
, valreg
);
3149 /* The return value from a malloc-like function can not alias
3151 last
= get_last_insn ();
3153 gen_rtx_EXPR_LIST (REG_NOALIAS
, temp
, REG_NOTES (last
));
3155 /* Write out the sequence. */
3156 insns
= get_insns ();
3162 /* For calls to `setjmp', etc., inform flow.c it should complain
3163 if nonvolatile values are live. For functions that cannot return,
3164 inform flow that control does not fall through. */
3166 if ((flags
& (ECF_NORETURN
| ECF_LONGJMP
)) || pass
== 0)
3168 /* The barrier must be emitted
3169 immediately after the CALL_INSN. Some ports emit more
3170 than just a CALL_INSN above, so we must search for it here. */
3172 rtx last
= get_last_insn ();
3173 while (GET_CODE (last
) != CALL_INSN
)
3175 last
= PREV_INSN (last
);
3176 /* There was no CALL_INSN? */
3177 if (last
== before_call
)
3181 emit_barrier_after (last
);
3184 if (flags
& ECF_LONGJMP
)
3185 current_function_calls_longjmp
= 1;
3187 /* If this function is returning into a memory location marked as
3188 readonly, it means it is initializing that location. But we normally
3189 treat functions as not clobbering such locations, so we need to
3190 specify that this one does. */
3191 if (target
!= 0 && GET_CODE (target
) == MEM
3192 && structure_value_addr
!= 0 && RTX_UNCHANGING_P (target
))
3193 emit_insn (gen_rtx_CLOBBER (VOIDmode
, target
));
3195 /* If value type not void, return an rtx for the value. */
3197 /* If there are cleanups to be called, don't use a hard reg as target.
3198 We need to double check this and see if it matters anymore. */
3199 if (any_pending_cleanups (1))
3201 if (target
&& REG_P (target
)
3202 && REGNO (target
) < FIRST_PSEUDO_REGISTER
)
3204 sibcall_failure
= 1;
3207 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
3209 target
= const0_rtx
;
3210 else if (structure_value_addr
)
3212 if (target
== 0 || GET_CODE (target
) != MEM
)
3215 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3216 memory_address (TYPE_MODE (TREE_TYPE (exp
)),
3217 structure_value_addr
));
3218 set_mem_attributes (target
, exp
, 1);
3221 else if (pcc_struct_value
)
3223 /* This is the special C++ case where we need to
3224 know what the true target was. We take care to
3225 never use this value more than once in one expression. */
3226 target
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3227 copy_to_reg (valreg
));
3228 set_mem_attributes (target
, exp
, 1);
3230 /* Handle calls that return values in multiple non-contiguous locations.
3231 The Irix 6 ABI has examples of this. */
3232 else if (GET_CODE (valreg
) == PARALLEL
)
3236 /* This will only be assigned once, so it can be readonly. */
3237 tree nt
= build_qualified_type (TREE_TYPE (exp
),
3238 (TYPE_QUALS (TREE_TYPE (exp
))
3239 | TYPE_QUAL_CONST
));
3241 target
= assign_temp (nt
, 0, 1, 1);
3242 preserve_temp_slots (target
);
3245 if (! rtx_equal_p (target
, valreg
))
3246 emit_group_store (target
, valreg
,
3247 int_size_in_bytes (TREE_TYPE (exp
)));
3249 /* We can not support sibling calls for this case. */
3250 sibcall_failure
= 1;
3253 && GET_MODE (target
) == TYPE_MODE (TREE_TYPE (exp
))
3254 && GET_MODE (target
) == GET_MODE (valreg
))
3256 /* TARGET and VALREG cannot be equal at this point because the
3257 latter would not have REG_FUNCTION_VALUE_P true, while the
3258 former would if it were referring to the same register.
3260 If they refer to the same register, this move will be a no-op,
3261 except when function inlining is being done. */
3262 emit_move_insn (target
, valreg
);
3264 else if (TYPE_MODE (TREE_TYPE (exp
)) == BLKmode
)
3266 target
= copy_blkmode_from_reg (target
, valreg
, TREE_TYPE (exp
));
3268 /* We can not support sibling calls for this case. */
3269 sibcall_failure
= 1;
3272 target
= copy_to_reg (valreg
);
3274 #ifdef PROMOTE_FUNCTION_RETURN
3275 /* If we promoted this return value, make the proper SUBREG. TARGET
3276 might be const0_rtx here, so be careful. */
3277 if (GET_CODE (target
) == REG
3278 && TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
3279 && GET_MODE (target
) != TYPE_MODE (TREE_TYPE (exp
)))
3281 tree type
= TREE_TYPE (exp
);
3282 int unsignedp
= TREE_UNSIGNED (type
);
3285 /* If we don't promote as expected, something is wrong. */
3286 if (GET_MODE (target
)
3287 != promote_mode (type
, TYPE_MODE (type
), &unsignedp
, 1))
3290 if ((WORDS_BIG_ENDIAN
|| BYTES_BIG_ENDIAN
)
3291 && GET_MODE_SIZE (GET_MODE (target
))
3292 > GET_MODE_SIZE (TYPE_MODE (type
)))
3294 offset
= GET_MODE_SIZE (GET_MODE (target
))
3295 - GET_MODE_SIZE (TYPE_MODE (type
));
3296 if (! BYTES_BIG_ENDIAN
)
3297 offset
= (offset
/ UNITS_PER_WORD
) * UNITS_PER_WORD
;
3298 else if (! WORDS_BIG_ENDIAN
)
3299 offset
%= UNITS_PER_WORD
;
3301 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
3302 SUBREG_PROMOTED_VAR_P (target
) = 1;
3303 SUBREG_PROMOTED_UNSIGNED_SET (target
, unsignedp
);
3307 /* If size of args is variable or this was a constructor call for a stack
3308 argument, restore saved stack-pointer value. */
3310 if (old_stack_level
&& ! (flags
& ECF_SP_DEPRESSED
))
3312 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
3313 pending_stack_adjust
= old_pending_adj
;
3314 stack_arg_under_construction
= old_stack_arg_under_construction
;
3315 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3316 stack_usage_map
= initial_stack_usage_map
;
3317 sibcall_failure
= 1;
3319 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
3321 #ifdef REG_PARM_STACK_SPACE
3324 restore_fixed_argument_area (save_area
, argblock
,
3325 high_to_save
, low_to_save
);
3329 /* If we saved any argument areas, restore them. */
3330 for (i
= 0; i
< num_actuals
; i
++)
3331 if (args
[i
].save_area
)
3333 enum machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
3335 = gen_rtx_MEM (save_mode
,
3336 memory_address (save_mode
,
3337 XEXP (args
[i
].stack_slot
, 0)));
3339 if (save_mode
!= BLKmode
)
3340 emit_move_insn (stack_area
, args
[i
].save_area
);
3342 emit_block_move (stack_area
, args
[i
].save_area
,
3343 GEN_INT (args
[i
].size
.constant
),
3344 BLOCK_OP_CALL_PARM
);
3347 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3348 stack_usage_map
= initial_stack_usage_map
;
3351 /* If this was alloca, record the new stack level for nonlocal gotos.
3352 Check for the handler slots since we might not have a save area
3353 for non-local gotos. */
3355 if ((flags
& ECF_MAY_BE_ALLOCA
) && nonlocal_goto_handler_slots
!= 0)
3356 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
3358 /* Free up storage we no longer need. */
3359 for (i
= 0; i
< num_actuals
; ++i
)
3360 if (args
[i
].aligned_regs
)
3361 free (args
[i
].aligned_regs
);
3365 /* Undo the fake expand_start_target_temps we did earlier. If
3366 there had been any cleanups created, we've already set
3368 expand_end_target_temps ();
3371 insns
= get_insns ();
3376 tail_call_insns
= insns
;
3378 /* Restore the pending stack adjustment now that we have
3379 finished generating the sibling call sequence. */
3381 pending_stack_adjust
= save_pending_stack_adjust
;
3382 stack_pointer_delta
= save_stack_pointer_delta
;
3384 /* Prepare arg structure for next iteration. */
3385 for (i
= 0; i
< num_actuals
; i
++)
3388 args
[i
].aligned_regs
= 0;
3392 sbitmap_free (stored_args_map
);
3395 normal_call_insns
= insns
;
3397 /* If something prevents making this a sibling call,
3398 zero out the sequence. */
3399 if (sibcall_failure
)
3400 tail_call_insns
= NULL_RTX
;
3403 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3404 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3405 can happen if the arguments to this function call an inline
3406 function who's expansion contains another CALL_PLACEHOLDER.
3408 If there are any C_Ps in any of these sequences, replace them
3409 with their normal call. */
3411 for (insn
= normal_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3412 if (GET_CODE (insn
) == CALL_INSN
3413 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3414 replace_call_placeholder (insn
, sibcall_use_normal
);
3416 for (insn
= tail_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3417 if (GET_CODE (insn
) == CALL_INSN
3418 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3419 replace_call_placeholder (insn
, sibcall_use_normal
);
3421 for (insn
= tail_recursion_insns
; insn
; insn
= NEXT_INSN (insn
))
3422 if (GET_CODE (insn
) == CALL_INSN
3423 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3424 replace_call_placeholder (insn
, sibcall_use_normal
);
3426 /* If this was a potential tail recursion site, then emit a
3427 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3428 One of them will be selected later. */
3429 if (tail_recursion_insns
|| tail_call_insns
)
3431 /* The tail recursion label must be kept around. We could expose
3432 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3433 and makes determining true tail recursion sites difficult.
3435 So we set LABEL_PRESERVE_P here, then clear it when we select
3436 one of the call sequences after rtl generation is complete. */
3437 if (tail_recursion_insns
)
3438 LABEL_PRESERVE_P (tail_recursion_label
) = 1;
3439 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode
, normal_call_insns
,
3441 tail_recursion_insns
,
3442 tail_recursion_label
));
3445 emit_insn (normal_call_insns
);
3447 currently_expanding_call
--;
3449 /* If this function returns with the stack pointer depressed, ensure
3450 this block saves and restores the stack pointer, show it was
3451 changed, and adjust for any outgoing arg space. */
3452 if (flags
& ECF_SP_DEPRESSED
)
3454 clear_pending_stack_adjust ();
3455 emit_insn (gen_rtx (CLOBBER
, VOIDmode
, stack_pointer_rtx
));
3456 emit_move_insn (virtual_stack_dynamic_rtx
, stack_pointer_rtx
);
3457 save_stack_pointer ();
3463 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3464 The RETVAL parameter specifies whether return value needs to be saved, other
3465 parameters are documented in the emit_library_call function below. */
3468 emit_library_call_value_1 (retval
, orgfun
, value
, fn_type
, outmode
, nargs
, p
)
3472 enum libcall_type fn_type
;
3473 enum machine_mode outmode
;
3477 /* Total size in bytes of all the stack-parms scanned so far. */
3478 struct args_size args_size
;
3479 /* Size of arguments before any adjustments (such as rounding). */
3480 struct args_size original_args_size
;
3485 struct args_size alignment_pad
;
3487 CUMULATIVE_ARGS args_so_far
;
3491 enum machine_mode mode
;
3494 struct args_size offset
;
3495 struct args_size size
;
3499 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3500 rtx call_fusage
= 0;
3503 int pcc_struct_value
= 0;
3504 int struct_value_size
= 0;
3506 int reg_parm_stack_space
= 0;
3509 tree tfom
; /* type_for_mode (outmode, 0) */
3511 #ifdef REG_PARM_STACK_SPACE
3512 /* Define the boundary of the register parm stack space that needs to be
3514 int low_to_save
= -1, high_to_save
= 0;
3515 rtx save_area
= 0; /* Place that it is saved. */
3518 /* Size of the stack reserved for parameter registers. */
3519 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3520 char *initial_stack_usage_map
= stack_usage_map
;
3522 #ifdef REG_PARM_STACK_SPACE
3523 #ifdef MAYBE_REG_PARM_STACK_SPACE
3524 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
3526 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
3530 /* By default, library functions can not throw. */
3531 flags
= ECF_NOTHROW
;
3543 case LCT_CONST_MAKE_BLOCK
:
3544 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
3546 case LCT_PURE_MAKE_BLOCK
:
3547 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
3550 flags
|= ECF_NORETURN
;
3553 flags
= ECF_NORETURN
;
3555 case LCT_ALWAYS_RETURN
:
3556 flags
= ECF_ALWAYS_RETURN
;
3558 case LCT_RETURNS_TWICE
:
3559 flags
= ECF_RETURNS_TWICE
;
3564 /* Ensure current function's preferred stack boundary is at least
3566 if (cfun
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
3567 cfun
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3569 /* If this kind of value comes back in memory,
3570 decide where in memory it should come back. */
3571 if (outmode
!= VOIDmode
)
3573 tfom
= (*lang_hooks
.types
.type_for_mode
) (outmode
, 0);
3574 if (aggregate_value_p (tfom
))
3576 #ifdef PCC_STATIC_STRUCT_RETURN
3578 = hard_function_value (build_pointer_type (tfom
), 0, 0);
3579 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
3580 pcc_struct_value
= 1;
3582 value
= gen_reg_rtx (outmode
);
3583 #else /* not PCC_STATIC_STRUCT_RETURN */
3584 struct_value_size
= GET_MODE_SIZE (outmode
);
3585 if (value
!= 0 && GET_CODE (value
) == MEM
)
3588 mem_value
= assign_temp (tfom
, 0, 1, 1);
3590 /* This call returns a big structure. */
3591 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3595 tfom
= void_type_node
;
3597 /* ??? Unfinished: must pass the memory address as an argument. */
3599 /* Copy all the libcall-arguments out of the varargs data
3600 and into a vector ARGVEC.
3602 Compute how to pass each argument. We only support a very small subset
3603 of the full argument passing conventions to limit complexity here since
3604 library functions shouldn't have many args. */
3606 argvec
= (struct arg
*) alloca ((nargs
+ 1) * sizeof (struct arg
));
3607 memset ((char *) argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
3609 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3610 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far
, outmode
, fun
);
3612 INIT_CUMULATIVE_ARGS (args_so_far
, NULL_TREE
, fun
, 0);
3615 args_size
.constant
= 0;
3620 /* Now we are about to start emitting insns that can be deleted
3621 if a libcall is deleted. */
3622 if (flags
& ECF_LIBCALL_BLOCK
)
3627 /* If there's a structure value address to be passed,
3628 either pass it in the special place, or pass it as an extra argument. */
3629 if (mem_value
&& struct_value_rtx
== 0 && ! pcc_struct_value
)
3631 rtx addr
= XEXP (mem_value
, 0);
3634 /* Make sure it is a reasonable operand for a move or push insn. */
3635 if (GET_CODE (addr
) != REG
&& GET_CODE (addr
) != MEM
3636 && ! (CONSTANT_P (addr
) && LEGITIMATE_CONSTANT_P (addr
)))
3637 addr
= force_operand (addr
, NULL_RTX
);
3639 argvec
[count
].value
= addr
;
3640 argvec
[count
].mode
= Pmode
;
3641 argvec
[count
].partial
= 0;
3643 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, Pmode
, NULL_TREE
, 1);
3644 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3645 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, Pmode
, NULL_TREE
, 1))
3649 locate_and_pad_parm (Pmode
, NULL_TREE
,
3650 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3653 argvec
[count
].reg
!= 0,
3655 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3656 &argvec
[count
].size
, &alignment_pad
);
3658 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3659 || reg_parm_stack_space
> 0)
3660 args_size
.constant
+= argvec
[count
].size
.constant
;
3662 FUNCTION_ARG_ADVANCE (args_so_far
, Pmode
, (tree
) 0, 1);
3667 for (; count
< nargs
; count
++)
3669 rtx val
= va_arg (p
, rtx
);
3670 enum machine_mode mode
= va_arg (p
, enum machine_mode
);
3672 /* We cannot convert the arg value to the mode the library wants here;
3673 must do it earlier where we know the signedness of the arg. */
3675 || (GET_MODE (val
) != mode
&& GET_MODE (val
) != VOIDmode
))
3678 /* On some machines, there's no way to pass a float to a library fcn.
3679 Pass it as a double instead. */
3680 #ifdef LIBGCC_NEEDS_DOUBLE
3681 if (LIBGCC_NEEDS_DOUBLE
&& mode
== SFmode
)
3682 val
= convert_modes (DFmode
, SFmode
, val
, 0), mode
= DFmode
;
3685 /* There's no need to call protect_from_queue, because
3686 either emit_move_insn or emit_push_insn will do that. */
3688 /* Make sure it is a reasonable operand for a move or push insn. */
3689 if (GET_CODE (val
) != REG
&& GET_CODE (val
) != MEM
3690 && ! (CONSTANT_P (val
) && LEGITIMATE_CONSTANT_P (val
)))
3691 val
= force_operand (val
, NULL_RTX
);
3693 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3694 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, mode
, NULL_TREE
, 1))
3698 #ifdef FUNCTION_ARG_CALLEE_COPIES
3699 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far
, mode
,
3704 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3705 functions, so we have to pretend this isn't such a function. */
3706 if (flags
& ECF_LIBCALL_BLOCK
)
3708 rtx insns
= get_insns ();
3712 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3714 /* If this was a CONST function, it is now PURE since
3715 it now reads memory. */
3716 if (flags
& ECF_CONST
)
3718 flags
&= ~ECF_CONST
;
3722 if (GET_MODE (val
) == MEM
&& ! must_copy
)
3726 slot
= assign_temp ((*lang_hooks
.types
.type_for_mode
) (mode
, 0),
3728 emit_move_insn (slot
, val
);
3732 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, 0);
3734 slot
= gen_rtx_MEM (mode
,
3735 expand_expr (build1 (ADDR_EXPR
,
3738 make_tree (type
, val
)),
3739 NULL_RTX
, VOIDmode
, 0));
3742 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3743 gen_rtx_USE (VOIDmode
, slot
),
3746 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3747 gen_rtx_CLOBBER (VOIDmode
,
3752 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
3756 argvec
[count
].value
= val
;
3757 argvec
[count
].mode
= mode
;
3759 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, mode
, NULL_TREE
, 1);
3761 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3762 argvec
[count
].partial
3763 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, mode
, NULL_TREE
, 1);
3765 argvec
[count
].partial
= 0;
3768 locate_and_pad_parm (mode
, NULL_TREE
,
3769 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3772 argvec
[count
].reg
!= 0,
3774 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3775 &argvec
[count
].size
, &alignment_pad
);
3777 if (argvec
[count
].size
.var
)
3780 if (reg_parm_stack_space
== 0 && argvec
[count
].partial
)
3781 argvec
[count
].size
.constant
-= argvec
[count
].partial
* UNITS_PER_WORD
;
3783 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3784 || reg_parm_stack_space
> 0)
3785 args_size
.constant
+= argvec
[count
].size
.constant
;
3787 FUNCTION_ARG_ADVANCE (args_so_far
, mode
, (tree
) 0, 1);
3790 #ifdef FINAL_REG_PARM_STACK_SPACE
3791 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
3794 /* If this machine requires an external definition for library
3795 functions, write one out. */
3796 assemble_external_libcall (fun
);
3798 original_args_size
= args_size
;
3799 args_size
.constant
= (((args_size
.constant
3800 + stack_pointer_delta
3804 - stack_pointer_delta
);
3806 args_size
.constant
= MAX (args_size
.constant
,
3807 reg_parm_stack_space
);
3809 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3810 args_size
.constant
-= reg_parm_stack_space
;
3813 if (args_size
.constant
> current_function_outgoing_args_size
)
3814 current_function_outgoing_args_size
= args_size
.constant
;
3816 if (ACCUMULATE_OUTGOING_ARGS
)
3818 /* Since the stack pointer will never be pushed, it is possible for
3819 the evaluation of a parm to clobber something we have already
3820 written to the stack. Since most function calls on RISC machines
3821 do not use the stack, this is uncommon, but must work correctly.
3823 Therefore, we save any area of the stack that was already written
3824 and that we are using. Here we set up to do this by making a new
3825 stack usage map from the old one.
3827 Another approach might be to try to reorder the argument
3828 evaluations to avoid this conflicting stack usage. */
3830 needed
= args_size
.constant
;
3832 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3833 /* Since we will be writing into the entire argument area, the
3834 map must be allocated for its entire size, not just the part that
3835 is the responsibility of the caller. */
3836 needed
+= reg_parm_stack_space
;
3839 #ifdef ARGS_GROW_DOWNWARD
3840 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3843 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3846 stack_usage_map
= (char *) alloca (highest_outgoing_arg_in_use
);
3848 if (initial_highest_arg_in_use
)
3849 memcpy (stack_usage_map
, initial_stack_usage_map
,
3850 initial_highest_arg_in_use
);
3852 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
3853 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
3854 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
3857 /* We must be careful to use virtual regs before they're instantiated,
3858 and real regs afterwards. Loop optimization, for example, can create
3859 new libcalls after we've instantiated the virtual regs, and if we
3860 use virtuals anyway, they won't match the rtl patterns. */
3862 if (virtuals_instantiated
)
3863 argblock
= plus_constant (stack_pointer_rtx
, STACK_POINTER_OFFSET
);
3865 argblock
= virtual_outgoing_args_rtx
;
3870 argblock
= push_block (GEN_INT (args_size
.constant
), 0, 0);
3873 /* If we push args individually in reverse order, perform stack alignment
3874 before the first push (the last arg). */
3875 if (argblock
== 0 && PUSH_ARGS_REVERSED
)
3876 anti_adjust_stack (GEN_INT (args_size
.constant
3877 - original_args_size
.constant
));
3879 if (PUSH_ARGS_REVERSED
)
3890 #ifdef REG_PARM_STACK_SPACE
3891 if (ACCUMULATE_OUTGOING_ARGS
)
3893 /* The argument list is the property of the called routine and it
3894 may clobber it. If the fixed area has been used for previous
3895 parameters, we must save and restore it.
3897 Here we compute the boundary of the that needs to be saved, if any. */
3899 #ifdef ARGS_GROW_DOWNWARD
3900 for (count
= 0; count
< reg_parm_stack_space
+ 1; count
++)
3902 for (count
= 0; count
< reg_parm_stack_space
; count
++)
3905 if (count
>= highest_outgoing_arg_in_use
3906 || stack_usage_map
[count
] == 0)
3909 if (low_to_save
== -1)
3910 low_to_save
= count
;
3912 high_to_save
= count
;
3915 if (low_to_save
>= 0)
3917 int num_to_save
= high_to_save
- low_to_save
+ 1;
3918 enum machine_mode save_mode
3919 = mode_for_size (num_to_save
* BITS_PER_UNIT
, MODE_INT
, 1);
3922 /* If we don't have the required alignment, must do this in BLKmode. */
3923 if ((low_to_save
& (MIN (GET_MODE_SIZE (save_mode
),
3924 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)))
3925 save_mode
= BLKmode
;
3927 #ifdef ARGS_GROW_DOWNWARD
3928 stack_area
= gen_rtx_MEM (save_mode
,
3929 memory_address (save_mode
,
3930 plus_constant (argblock
,
3933 stack_area
= gen_rtx_MEM (save_mode
,
3934 memory_address (save_mode
,
3935 plus_constant (argblock
,
3938 if (save_mode
== BLKmode
)
3940 save_area
= assign_stack_temp (BLKmode
, num_to_save
, 0);
3941 set_mem_align (save_area
, PARM_BOUNDARY
);
3942 emit_block_move (save_area
, stack_area
, GEN_INT (num_to_save
),
3943 BLOCK_OP_CALL_PARM
);
3947 save_area
= gen_reg_rtx (save_mode
);
3948 emit_move_insn (save_area
, stack_area
);
3954 /* Push the args that need to be pushed. */
3956 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3957 are to be pushed. */
3958 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
3960 enum machine_mode mode
= argvec
[argnum
].mode
;
3961 rtx val
= argvec
[argnum
].value
;
3962 rtx reg
= argvec
[argnum
].reg
;
3963 int partial
= argvec
[argnum
].partial
;
3964 int lower_bound
= 0, upper_bound
= 0, i
;
3966 if (! (reg
!= 0 && partial
== 0))
3968 if (ACCUMULATE_OUTGOING_ARGS
)
3970 /* If this is being stored into a pre-allocated, fixed-size,
3971 stack area, save any previous data at that location. */
3973 #ifdef ARGS_GROW_DOWNWARD
3974 /* stack_slot is negative, but we want to index stack_usage_map
3975 with positive values. */
3976 upper_bound
= -argvec
[argnum
].offset
.constant
+ 1;
3977 lower_bound
= upper_bound
- argvec
[argnum
].size
.constant
;
3979 lower_bound
= argvec
[argnum
].offset
.constant
;
3980 upper_bound
= lower_bound
+ argvec
[argnum
].size
.constant
;
3983 for (i
= lower_bound
; i
< upper_bound
; i
++)
3984 if (stack_usage_map
[i
]
3985 /* Don't store things in the fixed argument area at this
3986 point; it has already been saved. */
3987 && i
> reg_parm_stack_space
)
3990 if (i
!= upper_bound
)
3992 /* We need to make a save area. See what mode we can make
3994 enum machine_mode save_mode
3995 = mode_for_size (argvec
[argnum
].size
.constant
4003 plus_constant (argblock
,
4004 argvec
[argnum
].offset
.constant
)));
4005 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
4007 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
4011 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, PARM_BOUNDARY
,
4012 partial
, reg
, 0, argblock
,
4013 GEN_INT (argvec
[argnum
].offset
.constant
),
4014 reg_parm_stack_space
, ARGS_SIZE_RTX (alignment_pad
));
4016 /* Now mark the segment we just used. */
4017 if (ACCUMULATE_OUTGOING_ARGS
)
4018 for (i
= lower_bound
; i
< upper_bound
; i
++)
4019 stack_usage_map
[i
] = 1;
4025 /* If we pushed args in forward order, perform stack alignment
4026 after pushing the last arg. */
4027 if (argblock
== 0 && !PUSH_ARGS_REVERSED
)
4028 anti_adjust_stack (GEN_INT (args_size
.constant
4029 - original_args_size
.constant
));
4031 if (PUSH_ARGS_REVERSED
)
4036 fun
= prepare_call_address (fun
, NULL_TREE
, &call_fusage
, 0, 0);
4038 /* Now load any reg parms into their regs. */
4040 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4041 are to be pushed. */
4042 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
4044 rtx val
= argvec
[argnum
].value
;
4045 rtx reg
= argvec
[argnum
].reg
;
4046 int partial
= argvec
[argnum
].partial
;
4048 /* Handle calls that pass values in multiple non-contiguous
4049 locations. The PA64 has examples of this for library calls. */
4050 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
4051 emit_group_load (reg
, val
, GET_MODE_SIZE (GET_MODE (val
)));
4052 else if (reg
!= 0 && partial
== 0)
4053 emit_move_insn (reg
, val
);
4058 /* Any regs containing parms remain in use through the call. */
4059 for (count
= 0; count
< nargs
; count
++)
4061 rtx reg
= argvec
[count
].reg
;
4062 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
4063 use_group_regs (&call_fusage
, reg
);
4065 use_reg (&call_fusage
, reg
);
4068 /* Pass the function the address in which to return a structure value. */
4069 if (mem_value
!= 0 && struct_value_rtx
!= 0 && ! pcc_struct_value
)
4071 emit_move_insn (struct_value_rtx
,
4073 force_operand (XEXP (mem_value
, 0),
4075 if (GET_CODE (struct_value_rtx
) == REG
)
4076 use_reg (&call_fusage
, struct_value_rtx
);
4079 /* Don't allow popping to be deferred, since then
4080 cse'ing of library calls could delete a call and leave the pop. */
4082 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
4083 ? hard_libcall_value (outmode
) : NULL_RTX
);
4085 /* Stack must be properly aligned now. */
4086 if (stack_pointer_delta
& (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
- 1))
4089 before_call
= get_last_insn ();
4091 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4092 will set inhibit_defer_pop to that value. */
4093 /* The return type is needed to decide how many bytes the function pops.
4094 Signedness plays no role in that, so for simplicity, we pretend it's
4095 always signed. We also assume that the list of arguments passed has
4096 no impact, so we pretend it is unknown. */
4099 get_identifier (XSTR (orgfun
, 0)),
4100 build_function_type (tfom
, NULL_TREE
),
4101 original_args_size
.constant
, args_size
.constant
,
4103 FUNCTION_ARG (args_so_far
, VOIDmode
, void_type_node
, 1),
4105 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, & args_so_far
);
4107 /* For calls to `setjmp', etc., inform flow.c it should complain
4108 if nonvolatile values are live. For functions that cannot return,
4109 inform flow that control does not fall through. */
4111 if (flags
& (ECF_NORETURN
| ECF_LONGJMP
))
4113 /* The barrier note must be emitted
4114 immediately after the CALL_INSN. Some ports emit more than
4115 just a CALL_INSN above, so we must search for it here. */
4117 rtx last
= get_last_insn ();
4118 while (GET_CODE (last
) != CALL_INSN
)
4120 last
= PREV_INSN (last
);
4121 /* There was no CALL_INSN? */
4122 if (last
== before_call
)
4126 emit_barrier_after (last
);
4129 /* Now restore inhibit_defer_pop to its actual original value. */
4132 /* If call is cse'able, make appropriate pair of reg-notes around it.
4133 Test valreg so we don't crash; may safely ignore `const'
4134 if return type is void. Disable for PARALLEL return values, because
4135 we have no way to move such values into a pseudo register. */
4136 if (flags
& ECF_LIBCALL_BLOCK
)
4140 if (valreg
== 0 || GET_CODE (valreg
) == PARALLEL
)
4142 insns
= get_insns ();
4149 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
4152 /* Construct an "equal form" for the value which mentions all the
4153 arguments in order as well as the function name. */
4154 for (i
= 0; i
< nargs
; i
++)
4155 note
= gen_rtx_EXPR_LIST (VOIDmode
, argvec
[i
].value
, note
);
4156 note
= gen_rtx_EXPR_LIST (VOIDmode
, fun
, note
);
4158 insns
= get_insns ();
4161 if (flags
& ECF_PURE
)
4162 note
= gen_rtx_EXPR_LIST (VOIDmode
,
4163 gen_rtx_USE (VOIDmode
,
4164 gen_rtx_MEM (BLKmode
,
4165 gen_rtx_SCRATCH (VOIDmode
))),
4168 emit_libcall_block (insns
, temp
, valreg
, note
);
4175 /* Copy the value to the right place. */
4176 if (outmode
!= VOIDmode
&& retval
)
4182 if (value
!= mem_value
)
4183 emit_move_insn (value
, mem_value
);
4185 else if (value
!= 0)
4186 emit_move_insn (value
, valreg
);
4191 if (ACCUMULATE_OUTGOING_ARGS
)
4193 #ifdef REG_PARM_STACK_SPACE
4196 enum machine_mode save_mode
= GET_MODE (save_area
);
4197 #ifdef ARGS_GROW_DOWNWARD
4199 = gen_rtx_MEM (save_mode
,
4200 memory_address (save_mode
,
4201 plus_constant (argblock
,
4205 = gen_rtx_MEM (save_mode
,
4206 memory_address (save_mode
,
4207 plus_constant (argblock
, low_to_save
)));
4210 set_mem_align (stack_area
, PARM_BOUNDARY
);
4211 if (save_mode
!= BLKmode
)
4212 emit_move_insn (stack_area
, save_area
);
4214 emit_block_move (stack_area
, save_area
,
4215 GEN_INT (high_to_save
- low_to_save
+ 1),
4216 BLOCK_OP_CALL_PARM
);
4220 /* If we saved any argument areas, restore them. */
4221 for (count
= 0; count
< nargs
; count
++)
4222 if (argvec
[count
].save_area
)
4224 enum machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
4226 = gen_rtx_MEM (save_mode
,
4229 plus_constant (argblock
,
4230 argvec
[count
].offset
.constant
)));
4232 emit_move_insn (stack_area
, argvec
[count
].save_area
);
4235 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4236 stack_usage_map
= initial_stack_usage_map
;
4243 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4244 (emitting the queue unless NO_QUEUE is nonzero),
4245 for a value of mode OUTMODE,
4246 with NARGS different arguments, passed as alternating rtx values
4247 and machine_modes to convert them to.
4248 The rtx values should have been passed through protect_from_queue already.
4250 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4251 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4252 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4253 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4254 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4255 or other LCT_ value for other types of library calls. */
4258 emit_library_call
VPARAMS((rtx orgfun
, enum libcall_type fn_type
,
4259 enum machine_mode outmode
, int nargs
, ...))
4262 VA_FIXEDARG (p
, rtx
, orgfun
);
4263 VA_FIXEDARG (p
, int, fn_type
);
4264 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4265 VA_FIXEDARG (p
, int, nargs
);
4267 emit_library_call_value_1 (0, orgfun
, NULL_RTX
, fn_type
, outmode
, nargs
, p
);
4272 /* Like emit_library_call except that an extra argument, VALUE,
4273 comes second and says where to store the result.
4274 (If VALUE is zero, this function chooses a convenient way
4275 to return the value.
4277 This function returns an rtx for where the value is to be found.
4278 If VALUE is nonzero, VALUE is returned. */
4281 emit_library_call_value
VPARAMS((rtx orgfun
, rtx value
,
4282 enum libcall_type fn_type
,
4283 enum machine_mode outmode
, int nargs
, ...))
4288 VA_FIXEDARG (p
, rtx
, orgfun
);
4289 VA_FIXEDARG (p
, rtx
, value
);
4290 VA_FIXEDARG (p
, int, fn_type
);
4291 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4292 VA_FIXEDARG (p
, int, nargs
);
4294 result
= emit_library_call_value_1 (1, orgfun
, value
, fn_type
, outmode
,
4302 /* Store a single argument for a function call
4303 into the register or memory area where it must be passed.
4304 *ARG describes the argument value and where to pass it.
4306 ARGBLOCK is the address of the stack-block for all the arguments,
4307 or 0 on a machine where arguments are pushed individually.
4309 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4310 so must be careful about how the stack is used.
4312 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4313 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4314 that we need not worry about saving and restoring the stack.
4316 FNDECL is the declaration of the function we are calling.
4318 Return nonzero if this arg should cause sibcall failure,
4322 store_one_arg (arg
, argblock
, flags
, variable_size
, reg_parm_stack_space
)
4323 struct arg_data
*arg
;
4326 int variable_size ATTRIBUTE_UNUSED
;
4327 int reg_parm_stack_space
;
4329 tree pval
= arg
->tree_value
;
4333 int i
, lower_bound
= 0, upper_bound
= 0;
4334 int sibcall_failure
= 0;
4336 if (TREE_CODE (pval
) == ERROR_MARK
)
4339 /* Push a new temporary level for any temporaries we make for
4343 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
4345 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4346 save any previous data at that location. */
4347 if (argblock
&& ! variable_size
&& arg
->stack
)
4349 #ifdef ARGS_GROW_DOWNWARD
4350 /* stack_slot is negative, but we want to index stack_usage_map
4351 with positive values. */
4352 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4353 upper_bound
= -INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1)) + 1;
4357 lower_bound
= upper_bound
- arg
->size
.constant
;
4359 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4360 lower_bound
= INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1));
4364 upper_bound
= lower_bound
+ arg
->size
.constant
;
4367 for (i
= lower_bound
; i
< upper_bound
; i
++)
4368 if (stack_usage_map
[i
]
4369 /* Don't store things in the fixed argument area at this point;
4370 it has already been saved. */
4371 && i
> reg_parm_stack_space
)
4374 if (i
!= upper_bound
)
4376 /* We need to make a save area. See what mode we can make it. */
4377 enum machine_mode save_mode
4378 = mode_for_size (arg
->size
.constant
* BITS_PER_UNIT
, MODE_INT
, 1);
4380 = gen_rtx_MEM (save_mode
,
4381 memory_address (save_mode
,
4382 XEXP (arg
->stack_slot
, 0)));
4384 if (save_mode
== BLKmode
)
4386 tree ot
= TREE_TYPE (arg
->tree_value
);
4387 tree nt
= build_qualified_type (ot
, (TYPE_QUALS (ot
)
4388 | TYPE_QUAL_CONST
));
4390 arg
->save_area
= assign_temp (nt
, 0, 1, 1);
4391 preserve_temp_slots (arg
->save_area
);
4392 emit_block_move (validize_mem (arg
->save_area
), stack_area
,
4393 expr_size (arg
->tree_value
),
4394 BLOCK_OP_CALL_PARM
);
4398 arg
->save_area
= gen_reg_rtx (save_mode
);
4399 emit_move_insn (arg
->save_area
, stack_area
);
4403 /* Now that we have saved any slots that will be overwritten by this
4404 store, mark all slots this store will use. We must do this before
4405 we actually expand the argument since the expansion itself may
4406 trigger library calls which might need to use the same stack slot. */
4407 if (argblock
&& ! variable_size
&& arg
->stack
)
4408 for (i
= lower_bound
; i
< upper_bound
; i
++)
4409 stack_usage_map
[i
] = 1;
4412 /* If this isn't going to be placed on both the stack and in registers,
4413 set up the register and number of words. */
4414 if (! arg
->pass_on_stack
)
4416 if (flags
& ECF_SIBCALL
)
4417 reg
= arg
->tail_call_reg
;
4420 partial
= arg
->partial
;
4423 if (reg
!= 0 && partial
== 0)
4424 /* Being passed entirely in a register. We shouldn't be called in
4428 /* If this arg needs special alignment, don't load the registers
4430 if (arg
->n_aligned_regs
!= 0)
4433 /* If this is being passed partially in a register, we can't evaluate
4434 it directly into its stack slot. Otherwise, we can. */
4435 if (arg
->value
== 0)
4437 /* stack_arg_under_construction is nonzero if a function argument is
4438 being evaluated directly into the outgoing argument list and
4439 expand_call must take special action to preserve the argument list
4440 if it is called recursively.
4442 For scalar function arguments stack_usage_map is sufficient to
4443 determine which stack slots must be saved and restored. Scalar
4444 arguments in general have pass_on_stack == 0.
4446 If this argument is initialized by a function which takes the
4447 address of the argument (a C++ constructor or a C function
4448 returning a BLKmode structure), then stack_usage_map is
4449 insufficient and expand_call must push the stack around the
4450 function call. Such arguments have pass_on_stack == 1.
4452 Note that it is always safe to set stack_arg_under_construction,
4453 but this generates suboptimal code if set when not needed. */
4455 if (arg
->pass_on_stack
)
4456 stack_arg_under_construction
++;
4458 arg
->value
= expand_expr (pval
,
4460 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
4461 ? NULL_RTX
: arg
->stack
,
4464 /* If we are promoting object (or for any other reason) the mode
4465 doesn't agree, convert the mode. */
4467 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
4468 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
4469 arg
->value
, arg
->unsignedp
);
4471 if (arg
->pass_on_stack
)
4472 stack_arg_under_construction
--;
4475 /* Don't allow anything left on stack from computation
4476 of argument to alloca. */
4477 if (flags
& ECF_MAY_BE_ALLOCA
)
4478 do_pending_stack_adjust ();
4480 if (arg
->value
== arg
->stack
)
4481 /* If the value is already in the stack slot, we are done. */
4483 else if (arg
->mode
!= BLKmode
)
4487 /* Argument is a scalar, not entirely passed in registers.
4488 (If part is passed in registers, arg->partial says how much
4489 and emit_push_insn will take care of putting it there.)
4491 Push it, and if its size is less than the
4492 amount of space allocated to it,
4493 also bump stack pointer by the additional space.
4494 Note that in C the default argument promotions
4495 will prevent such mismatches. */
4497 size
= GET_MODE_SIZE (arg
->mode
);
4498 /* Compute how much space the push instruction will push.
4499 On many machines, pushing a byte will advance the stack
4500 pointer by a halfword. */
4501 #ifdef PUSH_ROUNDING
4502 size
= PUSH_ROUNDING (size
);
4506 /* Compute how much space the argument should get:
4507 round up to a multiple of the alignment for arguments. */
4508 if (none
!= FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)))
4509 used
= (((size
+ PARM_BOUNDARY
/ BITS_PER_UNIT
- 1)
4510 / (PARM_BOUNDARY
/ BITS_PER_UNIT
))
4511 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
4513 /* This isn't already where we want it on the stack, so put it there.
4514 This can either be done with push or copy insns. */
4515 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), NULL_RTX
,
4516 PARM_BOUNDARY
, partial
, reg
, used
- size
, argblock
,
4517 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4518 ARGS_SIZE_RTX (arg
->alignment_pad
));
4520 /* Unless this is a partially-in-register argument, the argument is now
4523 arg
->value
= arg
->stack
;
4527 /* BLKmode, at least partly to be pushed. */
4529 unsigned int parm_align
;
4533 /* Pushing a nonscalar.
4534 If part is passed in registers, PARTIAL says how much
4535 and emit_push_insn will take care of putting it there. */
4537 /* Round its size up to a multiple
4538 of the allocation unit for arguments. */
4540 if (arg
->size
.var
!= 0)
4543 size_rtx
= ARGS_SIZE_RTX (arg
->size
);
4547 /* PUSH_ROUNDING has no effect on us, because
4548 emit_push_insn for BLKmode is careful to avoid it. */
4549 excess
= (arg
->size
.constant
- int_size_in_bytes (TREE_TYPE (pval
))
4550 + partial
* UNITS_PER_WORD
);
4551 size_rtx
= expand_expr (size_in_bytes (TREE_TYPE (pval
)),
4552 NULL_RTX
, TYPE_MODE (sizetype
), 0);
4555 /* Some types will require stricter alignment, which will be
4556 provided for elsewhere in argument layout. */
4557 parm_align
= MAX (PARM_BOUNDARY
, TYPE_ALIGN (TREE_TYPE (pval
)));
4559 /* When an argument is padded down, the block is aligned to
4560 PARM_BOUNDARY, but the actual argument isn't. */
4561 if (FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)) == downward
)
4564 parm_align
= BITS_PER_UNIT
;
4567 unsigned int excess_align
= (excess
& -excess
) * BITS_PER_UNIT
;
4568 parm_align
= MIN (parm_align
, excess_align
);
4572 if ((flags
& ECF_SIBCALL
) && GET_CODE (arg
->value
) == MEM
)
4574 /* emit_push_insn might not work properly if arg->value and
4575 argblock + arg->offset areas overlap. */
4579 if (XEXP (x
, 0) == current_function_internal_arg_pointer
4580 || (GET_CODE (XEXP (x
, 0)) == PLUS
4581 && XEXP (XEXP (x
, 0), 0) ==
4582 current_function_internal_arg_pointer
4583 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
))
4585 if (XEXP (x
, 0) != current_function_internal_arg_pointer
)
4586 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
4588 /* expand_call should ensure this */
4589 if (arg
->offset
.var
|| GET_CODE (size_rtx
) != CONST_INT
)
4592 if (arg
->offset
.constant
> i
)
4594 if (arg
->offset
.constant
< i
+ INTVAL (size_rtx
))
4595 sibcall_failure
= 1;
4597 else if (arg
->offset
.constant
< i
)
4599 if (i
< arg
->offset
.constant
+ INTVAL (size_rtx
))
4600 sibcall_failure
= 1;
4605 /* Special handling is required if part of the parameter lies in the
4606 register parameter area. The argument may be copied into the stack
4607 slot using memcpy(), but the original contents of the register
4608 parameter area will be restored after the memcpy() call.
4610 To ensure that the part that lies in the register parameter area
4611 is copied correctly, we emit a separate push for that part. This
4612 push should be small enough to avoid a call to memcpy(). */
4613 #ifndef STACK_PARMS_IN_REG_PARM_AREA
4614 if (arg
->reg
&& arg
->pass_on_stack
)
4619 if (arg
->offset
.constant
< reg_parm_stack_space
&& arg
->offset
.var
)
4620 error ("variable offset is passed partially in stack and in reg");
4621 else if (arg
->offset
.constant
< reg_parm_stack_space
&& arg
->size
.var
)
4622 error ("variable size is passed partially in stack and in reg");
4623 else if (arg
->offset
.constant
< reg_parm_stack_space
4624 && ((arg
->offset
.constant
+ arg
->size
.constant
)
4625 > reg_parm_stack_space
))
4627 rtx size_rtx1
= GEN_INT (reg_parm_stack_space
- arg
->offset
.constant
);
4628 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx1
,
4629 parm_align
, partial
, reg
, excess
, argblock
,
4630 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4631 ARGS_SIZE_RTX (arg
->alignment_pad
));
4636 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
4637 parm_align
, partial
, reg
, excess
, argblock
,
4638 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4639 ARGS_SIZE_RTX (arg
->alignment_pad
));
4641 /* Unless this is a partially-in-register argument, the argument is now
4644 ??? Unlike the case above, in which we want the actual
4645 address of the data, so that we can load it directly into a
4646 register, here we want the address of the stack slot, so that
4647 it's properly aligned for word-by-word copying or something
4648 like that. It's not clear that this is always correct. */
4650 arg
->value
= arg
->stack_slot
;
4653 /* Once we have pushed something, pops can't safely
4654 be deferred during the rest of the arguments. */
4657 /* ANSI doesn't require a sequence point here,
4658 but PCC has one, so this will avoid some problems. */
4661 /* Free any temporary slots made in processing this argument. Show
4662 that we might have taken the address of something and pushed that
4664 preserve_temp_slots (NULL_RTX
);
4668 return sibcall_failure
;
4672 /* Nonzero if we do not know how to pass TYPE solely in registers.
4673 We cannot do so in the following cases:
4675 - if the type has variable size
4676 - if the type is marked as addressable (it is required to be constructed
4678 - if the padding and mode of the type is such that a copy into a register
4679 would put it into the wrong part of the register.
4681 Which padding can't be supported depends on the byte endianness.
4683 A value in a register is implicitly padded at the most significant end.
4684 On a big-endian machine, that is the lower end in memory.
4685 So a value padded in memory at the upper end can't go in a register.
4686 For a little-endian machine, the reverse is true. */
4689 default_must_pass_in_stack (mode
, type
)
4690 enum machine_mode mode
;
4696 /* If the type has variable size... */
4697 if (TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
4700 /* If the type is marked as addressable (it is required
4701 to be constructed into the stack)... */
4702 if (TREE_ADDRESSABLE (type
))
4705 /* If the padding and mode of the type is such that a copy into
4706 a register would put it into the wrong part of the register. */
4708 && int_size_in_bytes (type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
4709 && (FUNCTION_ARG_PADDING (mode
, type
)
4710 == (BYTES_BIG_ENDIAN
? upward
: downward
)))