1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
3 1999, 2000, 2001, 2002, 2003 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
;
918 /* Compute the boundary of the area that needs to be saved, if any. */
919 high
= reg_parm_stack_space
;
920 #ifdef ARGS_GROW_DOWNWARD
923 if (high
> highest_outgoing_arg_in_use
)
924 high
= highest_outgoing_arg_in_use
;
926 for (low
= 0; low
< high
; low
++)
927 if (stack_usage_map
[low
] != 0)
930 enum machine_mode save_mode
;
935 while (stack_usage_map
[--high
] == 0)
939 *high_to_save
= high
;
941 num_to_save
= high
- low
+ 1;
942 save_mode
= mode_for_size (num_to_save
* BITS_PER_UNIT
, MODE_INT
, 1);
944 /* If we don't have the required alignment, must do this
946 if ((low
& (MIN (GET_MODE_SIZE (save_mode
),
947 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)))
950 #ifdef ARGS_GROW_DOWNWARD
955 stack_area
= gen_rtx_MEM (save_mode
,
956 memory_address (save_mode
,
957 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
);
980 restore_fixed_argument_area (save_area
, argblock
, high_to_save
, low_to_save
)
986 enum machine_mode save_mode
= GET_MODE (save_area
);
990 #ifdef ARGS_GROW_DOWNWARD
991 delta
= -high_to_save
;
995 stack_area
= gen_rtx_MEM (save_mode
,
996 memory_address (save_mode
,
997 plus_constant (argblock
, delta
)));
998 set_mem_align (stack_area
, PARM_BOUNDARY
);
1000 if (save_mode
!= BLKmode
)
1001 emit_move_insn (stack_area
, save_area
);
1003 emit_block_move (stack_area
, validize_mem (save_area
),
1004 GEN_INT (high_to_save
- low_to_save
+ 1),
1005 BLOCK_OP_CALL_PARM
);
1007 #endif /* REG_PARM_STACK_SPACE */
1009 /* If any elements in ARGS refer to parameters that are to be passed in
1010 registers, but not in memory, and whose alignment does not permit a
1011 direct copy into registers. Copy the values into a group of pseudos
1012 which we will later copy into the appropriate hard registers.
1014 Pseudos for each unaligned argument will be stored into the array
1015 args[argnum].aligned_regs. The caller is responsible for deallocating
1016 the aligned_regs array if it is nonzero. */
1019 store_unaligned_arguments_into_pseudos (args
, num_actuals
)
1020 struct arg_data
*args
;
1025 for (i
= 0; i
< num_actuals
; i
++)
1026 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
1027 && args
[i
].mode
== BLKmode
1028 && (TYPE_ALIGN (TREE_TYPE (args
[i
].tree_value
))
1029 < (unsigned int) MIN (BIGGEST_ALIGNMENT
, BITS_PER_WORD
)))
1031 int bytes
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1032 int big_endian_correction
= 0;
1034 args
[i
].n_aligned_regs
1035 = args
[i
].partial
? args
[i
].partial
1036 : (bytes
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
1038 args
[i
].aligned_regs
= (rtx
*) xmalloc (sizeof (rtx
)
1039 * args
[i
].n_aligned_regs
);
1041 /* Structures smaller than a word are aligned to the least
1042 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
1043 this means we must skip the empty high order bytes when
1044 calculating the bit offset. */
1045 if (BYTES_BIG_ENDIAN
1046 && bytes
< UNITS_PER_WORD
)
1047 big_endian_correction
= (BITS_PER_WORD
- (bytes
* BITS_PER_UNIT
));
1049 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1051 rtx reg
= gen_reg_rtx (word_mode
);
1052 rtx word
= operand_subword_force (args
[i
].value
, j
, BLKmode
);
1053 int bitsize
= MIN (bytes
* BITS_PER_UNIT
, BITS_PER_WORD
);
1055 args
[i
].aligned_regs
[j
] = reg
;
1057 /* There is no need to restrict this code to loading items
1058 in TYPE_ALIGN sized hunks. The bitfield instructions can
1059 load up entire word sized registers efficiently.
1061 ??? This may not be needed anymore.
1062 We use to emit a clobber here but that doesn't let later
1063 passes optimize the instructions we emit. By storing 0 into
1064 the register later passes know the first AND to zero out the
1065 bitfield being set in the register is unnecessary. The store
1066 of 0 will be deleted as will at least the first AND. */
1068 emit_move_insn (reg
, const0_rtx
);
1070 bytes
-= bitsize
/ BITS_PER_UNIT
;
1071 store_bit_field (reg
, bitsize
, big_endian_correction
, word_mode
,
1072 extract_bit_field (word
, bitsize
, 0, 1, NULL_RTX
,
1073 word_mode
, word_mode
,
1080 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1083 NUM_ACTUALS is the total number of parameters.
1085 N_NAMED_ARGS is the total number of named arguments.
1087 FNDECL is the tree code for the target of this call (if known)
1089 ARGS_SO_FAR holds state needed by the target to know where to place
1092 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1093 for arguments which are passed in registers.
1095 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1096 and may be modified by this routine.
1098 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1099 flags which may may be modified by this routine. */
1102 initialize_argument_information (num_actuals
, args
, args_size
, n_named_args
,
1103 actparms
, fndecl
, args_so_far
,
1104 reg_parm_stack_space
, old_stack_level
,
1105 old_pending_adj
, must_preallocate
,
1107 int num_actuals ATTRIBUTE_UNUSED
;
1108 struct arg_data
*args
;
1109 struct args_size
*args_size
;
1110 int n_named_args ATTRIBUTE_UNUSED
;
1113 CUMULATIVE_ARGS
*args_so_far
;
1114 int reg_parm_stack_space
;
1115 rtx
*old_stack_level
;
1116 int *old_pending_adj
;
1117 int *must_preallocate
;
1120 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1123 /* Count arg position in order args appear. */
1126 struct args_size alignment_pad
;
1130 args_size
->constant
= 0;
1133 /* In this loop, we consider args in the order they are written.
1134 We fill up ARGS from the front or from the back if necessary
1135 so that in any case the first arg to be pushed ends up at the front. */
1137 if (PUSH_ARGS_REVERSED
)
1139 i
= num_actuals
- 1, inc
= -1;
1140 /* In this case, must reverse order of args
1141 so that we compute and push the last arg first. */
1148 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1149 for (p
= actparms
, argpos
= 0; p
; p
= TREE_CHAIN (p
), i
+= inc
, argpos
++)
1151 tree type
= TREE_TYPE (TREE_VALUE (p
));
1153 enum machine_mode mode
;
1155 args
[i
].tree_value
= TREE_VALUE (p
);
1157 /* Replace erroneous argument with constant zero. */
1158 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
1159 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
1161 /* If TYPE is a transparent union, pass things the way we would
1162 pass the first field of the union. We have already verified that
1163 the modes are the same. */
1164 if (TREE_CODE (type
) == UNION_TYPE
&& TYPE_TRANSPARENT_UNION (type
))
1165 type
= TREE_TYPE (TYPE_FIELDS (type
));
1167 /* Decide where to pass this arg.
1169 args[i].reg is nonzero if all or part is passed in registers.
1171 args[i].partial is nonzero if part but not all is passed in registers,
1172 and the exact value says how many words are passed in registers.
1174 args[i].pass_on_stack is nonzero if the argument must at least be
1175 computed on the stack. It may then be loaded back into registers
1176 if args[i].reg is nonzero.
1178 These decisions are driven by the FUNCTION_... macros and must agree
1179 with those made by function.c. */
1181 /* See if this argument should be passed by invisible reference. */
1182 if ((TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1183 && contains_placeholder_p (TYPE_SIZE (type
)))
1184 || TREE_ADDRESSABLE (type
)
1185 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1186 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far
, TYPE_MODE (type
),
1187 type
, argpos
< n_named_args
)
1191 /* If we're compiling a thunk, pass through invisible
1192 references instead of making a copy. */
1193 if (current_function_is_thunk
1194 #ifdef FUNCTION_ARG_CALLEE_COPIES
1195 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far
, TYPE_MODE (type
),
1196 type
, argpos
< n_named_args
)
1197 /* If it's in a register, we must make a copy of it too. */
1198 /* ??? Is this a sufficient test? Is there a better one? */
1199 && !(TREE_CODE (args
[i
].tree_value
) == VAR_DECL
1200 && REG_P (DECL_RTL (args
[i
].tree_value
)))
1201 && ! TREE_ADDRESSABLE (type
))
1205 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1206 new object from the argument. If we are passing by
1207 invisible reference, the callee will do that for us, so we
1208 can strip off the TARGET_EXPR. This is not always safe,
1209 but it is safe in the only case where this is a useful
1210 optimization; namely, when the argument is a plain object.
1211 In that case, the frontend is just asking the backend to
1212 make a bitwise copy of the argument. */
1214 if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1215 && (DECL_P (TREE_OPERAND (args
[i
].tree_value
, 1)))
1216 && ! REG_P (DECL_RTL (TREE_OPERAND (args
[i
].tree_value
, 1))))
1217 args
[i
].tree_value
= TREE_OPERAND (args
[i
].tree_value
, 1);
1219 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1220 build_pointer_type (type
),
1221 args
[i
].tree_value
);
1222 type
= build_pointer_type (type
);
1224 else if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
)
1226 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1227 We implement this by passing the address of the temporary
1228 rather than expanding it into another allocated slot. */
1229 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1230 build_pointer_type (type
),
1231 args
[i
].tree_value
);
1232 type
= build_pointer_type (type
);
1236 /* We make a copy of the object and pass the address to the
1237 function being called. */
1240 if (!COMPLETE_TYPE_P (type
)
1241 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1242 || (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1243 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type
),
1244 STACK_CHECK_MAX_VAR_SIZE
))))
1246 /* This is a variable-sized object. Make space on the stack
1248 rtx size_rtx
= expr_size (TREE_VALUE (p
));
1250 if (*old_stack_level
== 0)
1252 emit_stack_save (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1253 *old_pending_adj
= pending_stack_adjust
;
1254 pending_stack_adjust
= 0;
1257 copy
= gen_rtx_MEM (BLKmode
,
1258 allocate_dynamic_stack_space
1259 (size_rtx
, NULL_RTX
, TYPE_ALIGN (type
)));
1260 set_mem_attributes (copy
, type
, 1);
1263 copy
= assign_temp (type
, 0, 1, 0);
1265 store_expr (args
[i
].tree_value
, copy
, 0);
1266 *ecf_flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
1268 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1269 build_pointer_type (type
),
1270 make_tree (type
, copy
));
1271 type
= build_pointer_type (type
);
1275 mode
= TYPE_MODE (type
);
1276 unsignedp
= TREE_UNSIGNED (type
);
1278 #ifdef PROMOTE_FUNCTION_ARGS
1279 mode
= promote_mode (type
, mode
, &unsignedp
, 1);
1282 args
[i
].unsignedp
= unsignedp
;
1283 args
[i
].mode
= mode
;
1285 args
[i
].reg
= FUNCTION_ARG (*args_so_far
, mode
, type
,
1286 argpos
< n_named_args
);
1287 #ifdef FUNCTION_INCOMING_ARG
1288 /* If this is a sibling call and the machine has register windows, the
1289 register window has to be unwinded before calling the routine, so
1290 arguments have to go into the incoming registers. */
1291 args
[i
].tail_call_reg
= FUNCTION_INCOMING_ARG (*args_so_far
, mode
, type
,
1292 argpos
< n_named_args
);
1294 args
[i
].tail_call_reg
= args
[i
].reg
;
1297 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1300 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far
, mode
, type
,
1301 argpos
< n_named_args
);
1304 args
[i
].pass_on_stack
= MUST_PASS_IN_STACK (mode
, type
);
1306 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1307 it means that we are to pass this arg in the register(s) designated
1308 by the PARALLEL, but also to pass it in the stack. */
1309 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
1310 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
1311 args
[i
].pass_on_stack
= 1;
1313 /* If this is an addressable type, we must preallocate the stack
1314 since we must evaluate the object into its final location.
1316 If this is to be passed in both registers and the stack, it is simpler
1318 if (TREE_ADDRESSABLE (type
)
1319 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
1320 *must_preallocate
= 1;
1322 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1323 we cannot consider this function call constant. */
1324 if (TREE_ADDRESSABLE (type
))
1325 *ecf_flags
&= ~ECF_LIBCALL_BLOCK
;
1327 /* Compute the stack-size of this argument. */
1328 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
1329 || reg_parm_stack_space
> 0
1330 || args
[i
].pass_on_stack
)
1331 locate_and_pad_parm (mode
, type
,
1332 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1337 fndecl
, args_size
, &args
[i
].offset
,
1338 &args
[i
].size
, &alignment_pad
);
1340 #ifndef ARGS_GROW_DOWNWARD
1341 args
[i
].slot_offset
= *args_size
;
1344 args
[i
].alignment_pad
= alignment_pad
;
1346 /* If a part of the arg was put into registers,
1347 don't include that part in the amount pushed. */
1348 if (reg_parm_stack_space
== 0 && ! args
[i
].pass_on_stack
)
1349 args
[i
].size
.constant
-= ((args
[i
].partial
* UNITS_PER_WORD
)
1350 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
1351 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
1353 /* Update ARGS_SIZE, the total stack space for args so far. */
1355 args_size
->constant
+= args
[i
].size
.constant
;
1356 if (args
[i
].size
.var
)
1358 ADD_PARM_SIZE (*args_size
, args
[i
].size
.var
);
1361 /* Since the slot offset points to the bottom of the slot,
1362 we must record it after incrementing if the args grow down. */
1363 #ifdef ARGS_GROW_DOWNWARD
1364 args
[i
].slot_offset
= *args_size
;
1366 args
[i
].slot_offset
.constant
= -args_size
->constant
;
1368 SUB_PARM_SIZE (args
[i
].slot_offset
, args_size
->var
);
1371 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1372 have been used, etc. */
1374 FUNCTION_ARG_ADVANCE (*args_so_far
, TYPE_MODE (type
), type
,
1375 argpos
< n_named_args
);
1379 /* Update ARGS_SIZE to contain the total size for the argument block.
1380 Return the original constant component of the argument block's size.
1382 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1383 for arguments passed in registers. */
1386 compute_argument_block_size (reg_parm_stack_space
, args_size
,
1387 preferred_stack_boundary
)
1388 int reg_parm_stack_space
;
1389 struct args_size
*args_size
;
1390 int preferred_stack_boundary ATTRIBUTE_UNUSED
;
1392 int unadjusted_args_size
= args_size
->constant
;
1394 /* For accumulate outgoing args mode we don't need to align, since the frame
1395 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1396 backends from generating misaligned frame sizes. */
1397 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
1398 preferred_stack_boundary
= STACK_BOUNDARY
;
1400 /* Compute the actual size of the argument block required. The variable
1401 and constant sizes must be combined, the size may have to be rounded,
1402 and there may be a minimum required size. */
1406 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
1407 args_size
->constant
= 0;
1409 preferred_stack_boundary
/= BITS_PER_UNIT
;
1410 if (preferred_stack_boundary
> 1)
1412 /* We don't handle this case yet. To handle it correctly we have
1413 to add the delta, round and subtract the delta.
1414 Currently no machine description requires this support. */
1415 if (stack_pointer_delta
& (preferred_stack_boundary
- 1))
1417 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
1420 if (reg_parm_stack_space
> 0)
1423 = size_binop (MAX_EXPR
, args_size
->var
,
1424 ssize_int (reg_parm_stack_space
));
1426 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1427 /* The area corresponding to register parameters is not to count in
1428 the size of the block we need. So make the adjustment. */
1430 = size_binop (MINUS_EXPR
, args_size
->var
,
1431 ssize_int (reg_parm_stack_space
));
1437 preferred_stack_boundary
/= BITS_PER_UNIT
;
1438 if (preferred_stack_boundary
< 1)
1439 preferred_stack_boundary
= 1;
1440 args_size
->constant
= (((args_size
->constant
1441 + stack_pointer_delta
1442 + preferred_stack_boundary
- 1)
1443 / preferred_stack_boundary
1444 * preferred_stack_boundary
)
1445 - stack_pointer_delta
);
1447 args_size
->constant
= MAX (args_size
->constant
,
1448 reg_parm_stack_space
);
1450 #ifdef MAYBE_REG_PARM_STACK_SPACE
1451 if (reg_parm_stack_space
== 0)
1452 args_size
->constant
= 0;
1455 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1456 args_size
->constant
-= reg_parm_stack_space
;
1459 return unadjusted_args_size
;
1462 /* Precompute parameters as needed for a function call.
1464 FLAGS is mask of ECF_* constants.
1466 NUM_ACTUALS is the number of arguments.
1468 ARGS is an array containing information for each argument; this
1469 routine fills in the INITIAL_VALUE and VALUE fields for each
1470 precomputed argument. */
1473 precompute_arguments (flags
, num_actuals
, args
)
1476 struct arg_data
*args
;
1480 /* If this function call is cse'able, precompute all the parameters.
1481 Note that if the parameter is constructed into a temporary, this will
1482 cause an additional copy because the parameter will be constructed
1483 into a temporary location and then copied into the outgoing arguments.
1484 If a parameter contains a call to alloca and this function uses the
1485 stack, precompute the parameter. */
1487 /* If we preallocated the stack space, and some arguments must be passed
1488 on the stack, then we must precompute any parameter which contains a
1489 function call which will store arguments on the stack.
1490 Otherwise, evaluating the parameter may clobber previous parameters
1491 which have already been stored into the stack. (we have code to avoid
1492 such case by saving the outgoing stack arguments, but it results in
1495 for (i
= 0; i
< num_actuals
; i
++)
1496 if ((flags
& ECF_LIBCALL_BLOCK
)
1497 || calls_function (args
[i
].tree_value
, !ACCUMULATE_OUTGOING_ARGS
))
1499 enum machine_mode mode
;
1501 /* If this is an addressable type, we cannot pre-evaluate it. */
1502 if (TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
)))
1506 = expand_expr (args
[i
].tree_value
, NULL_RTX
, VOIDmode
, 0);
1508 /* ANSI doesn't require a sequence point here,
1509 but PCC has one, so this will avoid some problems. */
1512 args
[i
].initial_value
= args
[i
].value
1513 = protect_from_queue (args
[i
].value
, 0);
1515 mode
= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
));
1516 if (mode
!= args
[i
].mode
)
1519 = convert_modes (args
[i
].mode
, mode
,
1520 args
[i
].value
, args
[i
].unsignedp
);
1521 #ifdef PROMOTE_FOR_CALL_ONLY
1522 /* CSE will replace this only if it contains args[i].value
1523 pseudo, so convert it down to the declared mode using
1525 if (GET_CODE (args
[i
].value
) == REG
1526 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
)
1528 args
[i
].initial_value
1529 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
1530 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
1531 SUBREG_PROMOTED_UNSIGNED_SET (args
[i
].initial_value
,
1539 /* Given the current state of MUST_PREALLOCATE and information about
1540 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1541 compute and return the final value for MUST_PREALLOCATE. */
1544 finalize_must_preallocate (must_preallocate
, num_actuals
, args
, args_size
)
1545 int must_preallocate
;
1547 struct arg_data
*args
;
1548 struct args_size
*args_size
;
1550 /* See if we have or want to preallocate stack space.
1552 If we would have to push a partially-in-regs parm
1553 before other stack parms, preallocate stack space instead.
1555 If the size of some parm is not a multiple of the required stack
1556 alignment, we must preallocate.
1558 If the total size of arguments that would otherwise create a copy in
1559 a temporary (such as a CALL) is more than half the total argument list
1560 size, preallocation is faster.
1562 Another reason to preallocate is if we have a machine (like the m88k)
1563 where stack alignment is required to be maintained between every
1564 pair of insns, not just when the call is made. However, we assume here
1565 that such machines either do not have push insns (and hence preallocation
1566 would occur anyway) or the problem is taken care of with
1569 if (! must_preallocate
)
1571 int partial_seen
= 0;
1572 int copy_to_evaluate_size
= 0;
1575 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
1577 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
1579 else if (partial_seen
&& args
[i
].reg
== 0)
1580 must_preallocate
= 1;
1582 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1583 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
1584 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1585 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
1586 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
1587 copy_to_evaluate_size
1588 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1591 if (copy_to_evaluate_size
* 2 >= args_size
->constant
1592 && args_size
->constant
> 0)
1593 must_preallocate
= 1;
1595 return must_preallocate
;
1598 /* If we preallocated stack space, compute the address of each argument
1599 and store it into the ARGS array.
1601 We need not ensure it is a valid memory address here; it will be
1602 validized when it is used.
1604 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1607 compute_argument_addresses (args
, argblock
, num_actuals
)
1608 struct arg_data
*args
;
1614 rtx arg_reg
= argblock
;
1615 int i
, arg_offset
= 0;
1617 if (GET_CODE (argblock
) == PLUS
)
1618 arg_reg
= XEXP (argblock
, 0), arg_offset
= INTVAL (XEXP (argblock
, 1));
1620 for (i
= 0; i
< num_actuals
; i
++)
1622 rtx offset
= ARGS_SIZE_RTX (args
[i
].offset
);
1623 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].slot_offset
);
1626 /* Skip this parm if it will not be passed on the stack. */
1627 if (! args
[i
].pass_on_stack
&& args
[i
].reg
!= 0)
1630 if (GET_CODE (offset
) == CONST_INT
)
1631 addr
= plus_constant (arg_reg
, INTVAL (offset
));
1633 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, offset
);
1635 addr
= plus_constant (addr
, arg_offset
);
1636 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
1637 set_mem_attributes (args
[i
].stack
,
1638 TREE_TYPE (args
[i
].tree_value
), 1);
1640 if (GET_CODE (slot_offset
) == CONST_INT
)
1641 addr
= plus_constant (arg_reg
, INTVAL (slot_offset
));
1643 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, slot_offset
);
1645 addr
= plus_constant (addr
, arg_offset
);
1646 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
1647 set_mem_attributes (args
[i
].stack_slot
,
1648 TREE_TYPE (args
[i
].tree_value
), 1);
1650 /* Function incoming arguments may overlap with sibling call
1651 outgoing arguments and we cannot allow reordering of reads
1652 from function arguments with stores to outgoing arguments
1653 of sibling calls. */
1654 set_mem_alias_set (args
[i
].stack
, 0);
1655 set_mem_alias_set (args
[i
].stack_slot
, 0);
1660 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1661 in a call instruction.
1663 FNDECL is the tree node for the target function. For an indirect call
1664 FNDECL will be NULL_TREE.
1666 EXP is the CALL_EXPR for this call. */
1669 rtx_for_function_call (fndecl
, exp
)
1675 /* Get the function to call, in the form of RTL. */
1678 /* If this is the first use of the function, see if we need to
1679 make an external definition for it. */
1680 if (! TREE_USED (fndecl
))
1682 assemble_external (fndecl
);
1683 TREE_USED (fndecl
) = 1;
1686 /* Get a SYMBOL_REF rtx for the function address. */
1687 funexp
= XEXP (DECL_RTL (fndecl
), 0);
1690 /* Generate an rtx (probably a pseudo-register) for the address. */
1693 funexp
= expand_expr (TREE_OPERAND (exp
, 0), NULL_RTX
, VOIDmode
, 0);
1694 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1700 /* Do the register loads required for any wholly-register parms or any
1701 parms which are passed both on the stack and in a register. Their
1702 expressions were already evaluated.
1704 Mark all register-parms as living through the call, putting these USE
1705 insns in the CALL_INSN_FUNCTION_USAGE field.
1707 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1708 checking, setting *SIBCALL_FAILURE if appropriate. */
1711 load_register_parameters (args
, num_actuals
, call_fusage
, flags
,
1712 is_sibcall
, sibcall_failure
)
1713 struct arg_data
*args
;
1718 int *sibcall_failure
;
1722 #ifdef LOAD_ARGS_REVERSED
1723 for (i
= num_actuals
- 1; i
>= 0; i
--)
1725 for (i
= 0; i
< num_actuals
; i
++)
1728 rtx reg
= ((flags
& ECF_SIBCALL
)
1729 ? args
[i
].tail_call_reg
: args
[i
].reg
);
1730 int partial
= args
[i
].partial
;
1735 rtx before_arg
= get_last_insn ();
1736 /* Set to non-negative if must move a word at a time, even if just
1737 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1738 we just use a normal move insn. This value can be zero if the
1739 argument is a zero size structure with no fields. */
1740 nregs
= (partial
? partial
1741 : (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1742 ? ((int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
))
1743 + (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
)
1746 /* Handle calls that pass values in multiple non-contiguous
1747 locations. The Irix 6 ABI has examples of this. */
1749 if (GET_CODE (reg
) == PARALLEL
)
1750 emit_group_load (reg
, args
[i
].value
,
1751 int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
)));
1753 /* If simple case, just do move. If normal partial, store_one_arg
1754 has already loaded the register for us. In all other cases,
1755 load the register(s) from memory. */
1757 else if (nregs
== -1)
1758 emit_move_insn (reg
, args
[i
].value
);
1760 /* If we have pre-computed the values to put in the registers in
1761 the case of non-aligned structures, copy them in now. */
1763 else if (args
[i
].n_aligned_regs
!= 0)
1764 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1765 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
1766 args
[i
].aligned_regs
[j
]);
1768 else if (partial
== 0 || args
[i
].pass_on_stack
)
1769 move_block_to_reg (REGNO (reg
),
1770 validize_mem (args
[i
].value
), nregs
,
1773 /* When a parameter is a block, and perhaps in other cases, it is
1774 possible that it did a load from an argument slot that was
1775 already clobbered. */
1777 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
1778 *sibcall_failure
= 1;
1780 /* Handle calls that pass values in multiple non-contiguous
1781 locations. The Irix 6 ABI has examples of this. */
1782 if (GET_CODE (reg
) == PARALLEL
)
1783 use_group_regs (call_fusage
, reg
);
1784 else if (nregs
== -1)
1785 use_reg (call_fusage
, reg
);
1787 use_regs (call_fusage
, REGNO (reg
), nregs
== 0 ? 1 : nregs
);
1792 /* Try to integrate function. See expand_inline_function for documentation
1793 about the parameters. */
1796 try_to_integrate (fndecl
, actparms
, target
, ignore
, type
, structure_value_addr
)
1802 rtx structure_value_addr
;
1807 rtx old_stack_level
= 0;
1808 int reg_parm_stack_space
= 0;
1810 #ifdef REG_PARM_STACK_SPACE
1811 #ifdef MAYBE_REG_PARM_STACK_SPACE
1812 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
1814 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
1818 before_call
= get_last_insn ();
1820 timevar_push (TV_INTEGRATION
);
1822 temp
= expand_inline_function (fndecl
, actparms
, target
,
1824 structure_value_addr
);
1826 timevar_pop (TV_INTEGRATION
);
1828 /* If inlining succeeded, return. */
1829 if (temp
!= (rtx
) (size_t) - 1)
1831 if (ACCUMULATE_OUTGOING_ARGS
)
1833 /* If the outgoing argument list must be preserved, push
1834 the stack before executing the inlined function if it
1837 for (i
= reg_parm_stack_space
- 1; i
>= 0; i
--)
1838 if (i
< highest_outgoing_arg_in_use
&& stack_usage_map
[i
] != 0)
1841 if (stack_arg_under_construction
|| i
>= 0)
1844 = before_call
? NEXT_INSN (before_call
) : get_insns ();
1845 rtx insn
= NULL_RTX
, seq
;
1847 /* Look for a call in the inline function code.
1848 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1849 nonzero then there is a call and it is not necessary
1850 to scan the insns. */
1852 if (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
== 0)
1853 for (insn
= first_insn
; insn
; insn
= NEXT_INSN (insn
))
1854 if (GET_CODE (insn
) == CALL_INSN
)
1859 /* Reserve enough stack space so that the largest
1860 argument list of any function call in the inline
1861 function does not overlap the argument list being
1862 evaluated. This is usually an overestimate because
1863 allocate_dynamic_stack_space reserves space for an
1864 outgoing argument list in addition to the requested
1865 space, but there is no way to ask for stack space such
1866 that an argument list of a certain length can be
1869 Add the stack space reserved for register arguments, if
1870 any, in the inline function. What is really needed is the
1871 largest value of reg_parm_stack_space in the inline
1872 function, but that is not available. Using the current
1873 value of reg_parm_stack_space is wrong, but gives
1874 correct results on all supported machines. */
1876 int adjust
= (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
1877 + reg_parm_stack_space
);
1880 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
1881 allocate_dynamic_stack_space (GEN_INT (adjust
),
1882 NULL_RTX
, BITS_PER_UNIT
);
1885 emit_insn_before (seq
, first_insn
);
1886 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1891 /* If the result is equivalent to TARGET, return TARGET to simplify
1892 checks in store_expr. They can be equivalent but not equal in the
1893 case of a function that returns BLKmode. */
1894 if (temp
!= target
&& rtx_equal_p (temp
, target
))
1899 /* If inlining failed, mark FNDECL as needing to be compiled
1900 separately after all. If function was declared inline,
1902 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
1903 && optimize
> 0 && !TREE_ADDRESSABLE (fndecl
))
1905 warning_with_decl (fndecl
, "inlining failed in call to `%s'");
1906 warning ("called from here");
1908 (*lang_hooks
.mark_addressable
) (fndecl
);
1909 return (rtx
) (size_t) - 1;
1912 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1913 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1914 bytes, then we would need to push some additional bytes to pad the
1915 arguments. So, we compute an adjust to the stack pointer for an
1916 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1917 bytes. Then, when the arguments are pushed the stack will be perfectly
1918 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1919 be popped after the call. Returns the adjustment. */
1922 combine_pending_stack_adjustment_and_call (unadjusted_args_size
,
1924 preferred_unit_stack_boundary
)
1925 int unadjusted_args_size
;
1926 struct args_size
*args_size
;
1927 int preferred_unit_stack_boundary
;
1929 /* The number of bytes to pop so that the stack will be
1930 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1931 HOST_WIDE_INT adjustment
;
1932 /* The alignment of the stack after the arguments are pushed, if we
1933 just pushed the arguments without adjust the stack here. */
1934 HOST_WIDE_INT unadjusted_alignment
;
1936 unadjusted_alignment
1937 = ((stack_pointer_delta
+ unadjusted_args_size
)
1938 % preferred_unit_stack_boundary
);
1940 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1941 as possible -- leaving just enough left to cancel out the
1942 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1943 PENDING_STACK_ADJUST is non-negative, and congruent to
1944 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1946 /* Begin by trying to pop all the bytes. */
1947 unadjusted_alignment
1948 = (unadjusted_alignment
1949 - (pending_stack_adjust
% preferred_unit_stack_boundary
));
1950 adjustment
= pending_stack_adjust
;
1951 /* Push enough additional bytes that the stack will be aligned
1952 after the arguments are pushed. */
1953 if (preferred_unit_stack_boundary
> 1)
1955 if (unadjusted_alignment
> 0)
1956 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
1958 adjustment
+= unadjusted_alignment
;
1961 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1962 bytes after the call. The right number is the entire
1963 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1964 by the arguments in the first place. */
1966 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
1971 /* Scan X expression if it does not dereference any argument slots
1972 we already clobbered by tail call arguments (as noted in stored_args_map
1974 Return nonzero if X expression dereferences such argument slots,
1978 check_sibcall_argument_overlap_1 (x
)
1989 code
= GET_CODE (x
);
1993 if (XEXP (x
, 0) == current_function_internal_arg_pointer
)
1995 else if (GET_CODE (XEXP (x
, 0)) == PLUS
1996 && XEXP (XEXP (x
, 0), 0) ==
1997 current_function_internal_arg_pointer
1998 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
)
1999 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
2003 #ifdef ARGS_GROW_DOWNWARD
2004 i
= -i
- GET_MODE_SIZE (GET_MODE (x
));
2007 for (k
= 0; k
< GET_MODE_SIZE (GET_MODE (x
)); k
++)
2008 if (i
+ k
< stored_args_map
->n_bits
2009 && TEST_BIT (stored_args_map
, i
+ k
))
2015 /* Scan all subexpressions. */
2016 fmt
= GET_RTX_FORMAT (code
);
2017 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2021 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
2024 else if (*fmt
== 'E')
2026 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2027 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
2034 /* Scan sequence after INSN if it does not dereference any argument slots
2035 we already clobbered by tail call arguments (as noted in stored_args_map
2036 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2037 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2038 should be 0). Return nonzero if sequence after INSN dereferences such argument
2039 slots, zero otherwise. */
2042 check_sibcall_argument_overlap (insn
, arg
, mark_stored_args_map
)
2044 struct arg_data
*arg
;
2045 int mark_stored_args_map
;
2049 if (insn
== NULL_RTX
)
2050 insn
= get_insns ();
2052 insn
= NEXT_INSN (insn
);
2054 for (; insn
; insn
= NEXT_INSN (insn
))
2056 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
2059 if (mark_stored_args_map
)
2061 #ifdef ARGS_GROW_DOWNWARD
2062 low
= -arg
->slot_offset
.constant
- arg
->size
.constant
;
2064 low
= arg
->slot_offset
.constant
;
2067 for (high
= low
+ arg
->size
.constant
; low
< high
; low
++)
2068 SET_BIT (stored_args_map
, low
);
2070 return insn
!= NULL_RTX
;
2077 switch (unsafe_for_reeval (t
))
2082 case 1: /* Mildly unsafe. */
2083 t
= unsave_expr (t
);
2086 case 2: /* Wildly unsafe. */
2088 tree var
= build_decl (VAR_DECL
, NULL_TREE
,
2091 expand_expr (t
, NULL_RTX
, VOIDmode
, EXPAND_NORMAL
));
2102 /* Generate all the code for a function call
2103 and return an rtx for its value.
2104 Store the value in TARGET (specified as an rtx) if convenient.
2105 If the value is stored in TARGET then TARGET is returned.
2106 If IGNORE is nonzero, then we ignore the value of the function call. */
2109 expand_call (exp
, target
, ignore
)
2114 /* Nonzero if we are currently expanding a call. */
2115 static int currently_expanding_call
= 0;
2117 /* List of actual parameters. */
2118 tree actparms
= TREE_OPERAND (exp
, 1);
2119 /* RTX for the function to be called. */
2121 /* Sequence of insns to perform a tail recursive "call". */
2122 rtx tail_recursion_insns
= NULL_RTX
;
2123 /* Sequence of insns to perform a normal "call". */
2124 rtx normal_call_insns
= NULL_RTX
;
2125 /* Sequence of insns to perform a tail recursive "call". */
2126 rtx tail_call_insns
= NULL_RTX
;
2127 /* Data type of the function. */
2129 /* Declaration of the function being called,
2130 or 0 if the function is computed (not known by name). */
2133 int try_tail_call
= 1;
2134 int try_tail_recursion
= 1;
2137 /* Register in which non-BLKmode value will be returned,
2138 or 0 if no value or if value is BLKmode. */
2140 /* Address where we should return a BLKmode value;
2141 0 if value not BLKmode. */
2142 rtx structure_value_addr
= 0;
2143 /* Nonzero if that address is being passed by treating it as
2144 an extra, implicit first parameter. Otherwise,
2145 it is passed by being copied directly into struct_value_rtx. */
2146 int structure_value_addr_parm
= 0;
2147 /* Size of aggregate value wanted, or zero if none wanted
2148 or if we are using the non-reentrant PCC calling convention
2149 or expecting the value in registers. */
2150 HOST_WIDE_INT struct_value_size
= 0;
2151 /* Nonzero if called function returns an aggregate in memory PCC style,
2152 by returning the address of where to find it. */
2153 int pcc_struct_value
= 0;
2155 /* Number of actual parameters in this call, including struct value addr. */
2157 /* Number of named args. Args after this are anonymous ones
2158 and they must all go on the stack. */
2161 /* Vector of information about each argument.
2162 Arguments are numbered in the order they will be pushed,
2163 not the order they are written. */
2164 struct arg_data
*args
;
2166 /* Total size in bytes of all the stack-parms scanned so far. */
2167 struct args_size args_size
;
2168 struct args_size adjusted_args_size
;
2169 /* Size of arguments before any adjustments (such as rounding). */
2170 int unadjusted_args_size
;
2171 /* Data on reg parms scanned so far. */
2172 CUMULATIVE_ARGS args_so_far
;
2173 /* Nonzero if a reg parm has been scanned. */
2175 /* Nonzero if this is an indirect function call. */
2177 /* Nonzero if we must avoid push-insns in the args for this call.
2178 If stack space is allocated for register parameters, but not by the
2179 caller, then it is preallocated in the fixed part of the stack frame.
2180 So the entire argument block must then be preallocated (i.e., we
2181 ignore PUSH_ROUNDING in that case). */
2183 int must_preallocate
= !PUSH_ARGS
;
2185 /* Size of the stack reserved for parameter registers. */
2186 int reg_parm_stack_space
= 0;
2188 /* Address of space preallocated for stack parms
2189 (on machines that lack push insns), or 0 if space not preallocated. */
2192 /* Mask of ECF_ flags. */
2194 /* Nonzero if this is a call to an inline function. */
2195 int is_integrable
= 0;
2196 #ifdef REG_PARM_STACK_SPACE
2197 /* Define the boundary of the register parm stack space that needs to be
2199 int low_to_save
, high_to_save
;
2200 rtx save_area
= 0; /* Place that it is saved */
2203 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
2204 char *initial_stack_usage_map
= stack_usage_map
;
2205 int old_stack_arg_under_construction
= 0;
2207 rtx old_stack_level
= 0;
2208 int old_pending_adj
= 0;
2209 int old_inhibit_defer_pop
= inhibit_defer_pop
;
2210 int old_stack_allocated
;
2212 tree p
= TREE_OPERAND (exp
, 0);
2214 /* The alignment of the stack, in bits. */
2215 HOST_WIDE_INT preferred_stack_boundary
;
2216 /* The alignment of the stack, in bytes. */
2217 HOST_WIDE_INT preferred_unit_stack_boundary
;
2219 /* See if this is "nothrow" function call. */
2220 if (TREE_NOTHROW (exp
))
2221 flags
|= ECF_NOTHROW
;
2223 /* See if we can find a DECL-node for the actual function.
2224 As a result, decide whether this is a call to an integrable function. */
2226 fndecl
= get_callee_fndecl (exp
);
2230 && fndecl
!= current_function_decl
2231 && DECL_INLINE (fndecl
)
2232 && DECL_SAVED_INSNS (fndecl
)
2233 && DECL_SAVED_INSNS (fndecl
)->inlinable
)
2235 else if (! TREE_ADDRESSABLE (fndecl
))
2237 /* In case this function later becomes inlinable,
2238 record that there was already a non-inline call to it.
2240 Use abstraction instead of setting TREE_ADDRESSABLE
2242 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
2245 warning_with_decl (fndecl
, "can't inline call to `%s'");
2246 warning ("called from here");
2248 (*lang_hooks
.mark_addressable
) (fndecl
);
2251 flags
|= flags_from_decl_or_type (fndecl
);
2254 /* If we don't have specific function to call, see if we have a
2255 attributes set in the type. */
2257 flags
|= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p
)));
2259 #ifdef REG_PARM_STACK_SPACE
2260 #ifdef MAYBE_REG_PARM_STACK_SPACE
2261 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
2263 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
2267 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2268 if (reg_parm_stack_space
> 0 && PUSH_ARGS
)
2269 must_preallocate
= 1;
2272 /* Warn if this value is an aggregate type,
2273 regardless of which calling convention we are using for it. */
2274 if (warn_aggregate_return
&& AGGREGATE_TYPE_P (TREE_TYPE (exp
)))
2275 warning ("function call has aggregate value");
2277 /* Set up a place to return a structure. */
2279 /* Cater to broken compilers. */
2280 if (aggregate_value_p (exp
))
2282 /* This call returns a big structure. */
2283 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
2285 #ifdef PCC_STATIC_STRUCT_RETURN
2287 pcc_struct_value
= 1;
2288 /* Easier than making that case work right. */
2291 /* In case this is a static function, note that it has been
2293 if (! TREE_ADDRESSABLE (fndecl
))
2294 (*lang_hooks
.mark_addressable
) (fndecl
);
2298 #else /* not PCC_STATIC_STRUCT_RETURN */
2300 struct_value_size
= int_size_in_bytes (TREE_TYPE (exp
));
2302 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp
))
2304 /* The structure value address arg is already in actparms.
2305 Pull it out. It might be nice to just leave it there, but
2306 we need to set structure_value_addr. */
2307 tree return_arg
= TREE_VALUE (actparms
);
2308 actparms
= TREE_CHAIN (actparms
);
2309 structure_value_addr
= expand_expr (return_arg
, NULL_RTX
,
2310 VOIDmode
, EXPAND_NORMAL
);
2312 else if (target
&& GET_CODE (target
) == MEM
)
2313 structure_value_addr
= XEXP (target
, 0);
2316 /* For variable-sized objects, we must be called with a target
2317 specified. If we were to allocate space on the stack here,
2318 we would have no way of knowing when to free it. */
2319 rtx d
= assign_temp (TREE_TYPE (exp
), 1, 1, 1);
2321 mark_temp_addr_taken (d
);
2322 structure_value_addr
= XEXP (d
, 0);
2326 #endif /* not PCC_STATIC_STRUCT_RETURN */
2329 /* If called function is inline, try to integrate it. */
2333 rtx temp
= try_to_integrate (fndecl
, actparms
, target
,
2334 ignore
, TREE_TYPE (exp
),
2335 structure_value_addr
);
2336 if (temp
!= (rtx
) (size_t) - 1)
2340 /* Figure out the amount to which the stack should be aligned. */
2341 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
2343 /* Operand 0 is a pointer-to-function; get the type of the function. */
2344 funtype
= TREE_TYPE (TREE_OPERAND (exp
, 0));
2345 if (! POINTER_TYPE_P (funtype
))
2347 funtype
= TREE_TYPE (funtype
);
2349 /* See if this is a call to a function that can return more than once
2350 or a call to longjmp or malloc. */
2351 flags
|= special_function_p (fndecl
, flags
);
2353 if (flags
& ECF_MAY_BE_ALLOCA
)
2354 current_function_calls_alloca
= 1;
2356 /* If struct_value_rtx is 0, it means pass the address
2357 as if it were an extra parameter. */
2358 if (structure_value_addr
&& struct_value_rtx
== 0)
2360 /* If structure_value_addr is a REG other than
2361 virtual_outgoing_args_rtx, we can use always use it. If it
2362 is not a REG, we must always copy it into a register.
2363 If it is virtual_outgoing_args_rtx, we must copy it to another
2364 register in some cases. */
2365 rtx temp
= (GET_CODE (structure_value_addr
) != REG
2366 || (ACCUMULATE_OUTGOING_ARGS
2367 && stack_arg_under_construction
2368 && structure_value_addr
== virtual_outgoing_args_rtx
)
2369 ? copy_addr_to_reg (structure_value_addr
)
2370 : structure_value_addr
);
2373 = tree_cons (error_mark_node
,
2374 make_tree (build_pointer_type (TREE_TYPE (funtype
)),
2377 structure_value_addr_parm
= 1;
2380 /* Count the arguments and set NUM_ACTUALS. */
2381 for (p
= actparms
, num_actuals
= 0; p
; p
= TREE_CHAIN (p
))
2384 /* Compute number of named args.
2385 Normally, don't include the last named arg if anonymous args follow.
2386 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2387 (If no anonymous args follow, the result of list_length is actually
2388 one too large. This is harmless.)
2390 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2391 zero, this machine will be able to place unnamed args that were
2392 passed in registers into the stack. So treat all args as named.
2393 This allows the insns emitting for a specific argument list to be
2394 independent of the function declaration.
2396 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2397 reliable way to pass unnamed args in registers, so we must force
2398 them into memory. */
2400 if ((STRICT_ARGUMENT_NAMING
2401 || ! PRETEND_OUTGOING_VARARGS_NAMED
)
2402 && TYPE_ARG_TYPES (funtype
) != 0)
2404 = (list_length (TYPE_ARG_TYPES (funtype
))
2405 /* Don't include the last named arg. */
2406 - (STRICT_ARGUMENT_NAMING
? 0 : 1)
2407 /* Count the struct value address, if it is passed as a parm. */
2408 + structure_value_addr_parm
);
2410 /* If we know nothing, treat all args as named. */
2411 n_named_args
= num_actuals
;
2413 /* Start updating where the next arg would go.
2415 On some machines (such as the PA) indirect calls have a different
2416 calling convention than normal calls. The last argument in
2417 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2419 INIT_CUMULATIVE_ARGS (args_so_far
, funtype
, NULL_RTX
, (fndecl
== 0));
2421 /* Make a vector to hold all the information about each arg. */
2422 args
= (struct arg_data
*) alloca (num_actuals
* sizeof (struct arg_data
));
2423 memset ((char *) args
, 0, num_actuals
* sizeof (struct arg_data
));
2425 /* Build up entries in the ARGS array, compute the size of the
2426 arguments into ARGS_SIZE, etc. */
2427 initialize_argument_information (num_actuals
, args
, &args_size
,
2428 n_named_args
, actparms
, fndecl
,
2429 &args_so_far
, reg_parm_stack_space
,
2430 &old_stack_level
, &old_pending_adj
,
2431 &must_preallocate
, &flags
);
2435 /* If this function requires a variable-sized argument list, don't
2436 try to make a cse'able block for this call. We may be able to
2437 do this eventually, but it is too complicated to keep track of
2438 what insns go in the cse'able block and which don't. */
2440 flags
&= ~ECF_LIBCALL_BLOCK
;
2441 must_preallocate
= 1;
2444 /* Now make final decision about preallocating stack space. */
2445 must_preallocate
= finalize_must_preallocate (must_preallocate
,
2449 /* If the structure value address will reference the stack pointer, we
2450 must stabilize it. We don't need to do this if we know that we are
2451 not going to adjust the stack pointer in processing this call. */
2453 if (structure_value_addr
2454 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
2455 || reg_mentioned_p (virtual_outgoing_args_rtx
,
2456 structure_value_addr
))
2458 || (!ACCUMULATE_OUTGOING_ARGS
&& args_size
.constant
)))
2459 structure_value_addr
= copy_to_reg (structure_value_addr
);
2461 /* Tail calls can make things harder to debug, and we're traditionally
2462 pushed these optimizations into -O2. Don't try if we're already
2463 expanding a call, as that means we're an argument. Don't try if
2464 there's cleanups, as we know there's code to follow the call.
2466 If rtx_equal_function_value_matters is false, that means we've
2467 finished with regular parsing. Which means that some of the
2468 machinery we use to generate tail-calls is no longer in place.
2469 This is most often true of sjlj-exceptions, which we couldn't
2470 tail-call to anyway. */
2472 if (currently_expanding_call
++ != 0
2473 || !flag_optimize_sibling_calls
2474 || !rtx_equal_function_value_matters
2475 || any_pending_cleanups (1)
2477 try_tail_call
= try_tail_recursion
= 0;
2479 /* Tail recursion fails, when we are not dealing with recursive calls. */
2480 if (!try_tail_recursion
2481 || TREE_CODE (TREE_OPERAND (exp
, 0)) != ADDR_EXPR
2482 || TREE_OPERAND (TREE_OPERAND (exp
, 0), 0) != current_function_decl
)
2483 try_tail_recursion
= 0;
2485 /* Rest of purposes for tail call optimizations to fail. */
2487 #ifdef HAVE_sibcall_epilogue
2488 !HAVE_sibcall_epilogue
2493 /* Doing sibling call optimization needs some work, since
2494 structure_value_addr can be allocated on the stack.
2495 It does not seem worth the effort since few optimizable
2496 sibling calls will return a structure. */
2497 || structure_value_addr
!= NULL_RTX
2498 /* Check whether the target is able to optimize the call
2500 || !(*targetm
.function_ok_for_sibcall
) (fndecl
, exp
)
2501 /* Functions that do not return exactly once may not be sibcall
2503 || (flags
& (ECF_RETURNS_TWICE
| ECF_LONGJMP
| ECF_NORETURN
))
2504 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))
2505 /* If this function requires more stack slots than the current
2506 function, we cannot change it into a sibling call. */
2507 || args_size
.constant
> current_function_args_size
2508 /* If the callee pops its own arguments, then it must pop exactly
2509 the same number of arguments as the current function. */
2510 || RETURN_POPS_ARGS (fndecl
, funtype
, args_size
.constant
)
2511 != RETURN_POPS_ARGS (current_function_decl
,
2512 TREE_TYPE (current_function_decl
),
2513 current_function_args_size
))
2516 if (try_tail_call
|| try_tail_recursion
)
2519 actparms
= NULL_TREE
;
2520 /* Ok, we're going to give the tail call the old college try.
2521 This means we're going to evaluate the function arguments
2522 up to three times. There are two degrees of badness we can
2523 encounter, those that can be unsaved and those that can't.
2524 (See unsafe_for_reeval commentary for details.)
2526 Generate a new argument list. Pass safe arguments through
2527 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2528 For hard badness, evaluate them now and put their resulting
2529 rtx in a temporary VAR_DECL.
2531 initialize_argument_information has ordered the array for the
2532 order to be pushed, and we must remember this when reconstructing
2533 the original argument order. */
2535 if (PUSH_ARGS_REVERSED
)
2544 i
= num_actuals
- 1;
2548 for (; i
!= end
; i
+= inc
)
2550 args
[i
].tree_value
= fix_unsafe_tree (args
[i
].tree_value
);
2551 /* We need to build actparms for optimize_tail_recursion. We can
2552 safely trash away TREE_PURPOSE, since it is unused by this
2554 if (try_tail_recursion
)
2555 actparms
= tree_cons (NULL_TREE
, args
[i
].tree_value
, actparms
);
2557 /* Do the same for the function address if it is an expression. */
2559 TREE_OPERAND (exp
, 0) = fix_unsafe_tree (TREE_OPERAND (exp
, 0));
2560 /* Expanding one of those dangerous arguments could have added
2561 cleanups, but otherwise give it a whirl. */
2562 if (any_pending_cleanups (1))
2563 try_tail_call
= try_tail_recursion
= 0;
2566 /* Generate a tail recursion sequence when calling ourselves. */
2568 if (try_tail_recursion
)
2570 /* We want to emit any pending stack adjustments before the tail
2571 recursion "call". That way we know any adjustment after the tail
2572 recursion call can be ignored if we indeed use the tail recursion
2574 int save_pending_stack_adjust
= pending_stack_adjust
;
2575 int save_stack_pointer_delta
= stack_pointer_delta
;
2577 /* Emit any queued insns now; otherwise they would end up in
2578 only one of the alternates. */
2581 /* Use a new sequence to hold any RTL we generate. We do not even
2582 know if we will use this RTL yet. The final decision can not be
2583 made until after RTL generation for the entire function is
2586 /* If expanding any of the arguments creates cleanups, we can't
2587 do a tailcall. So, we'll need to pop the pending cleanups
2588 list. If, however, all goes well, and there are no cleanups
2589 then the call to expand_start_target_temps will have no
2591 expand_start_target_temps ();
2592 if (optimize_tail_recursion (actparms
, get_last_insn ()))
2594 if (any_pending_cleanups (1))
2595 try_tail_call
= try_tail_recursion
= 0;
2597 tail_recursion_insns
= get_insns ();
2599 expand_end_target_temps ();
2602 /* Restore the original pending stack adjustment for the sibling and
2603 normal call cases below. */
2604 pending_stack_adjust
= save_pending_stack_adjust
;
2605 stack_pointer_delta
= save_stack_pointer_delta
;
2608 if (profile_arc_flag
&& (flags
& ECF_FORK_OR_EXEC
))
2610 /* A fork duplicates the profile information, and an exec discards
2611 it. We can't rely on fork/exec to be paired. So write out the
2612 profile information we have gathered so far, and clear it. */
2613 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2614 is subject to race conditions, just as with multithreaded
2617 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "__gcov_flush"),
2622 /* Ensure current function's preferred stack boundary is at least
2623 what we need. We don't have to increase alignment for recursive
2625 if (cfun
->preferred_stack_boundary
< preferred_stack_boundary
2626 && fndecl
!= current_function_decl
)
2627 cfun
->preferred_stack_boundary
= preferred_stack_boundary
;
2629 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
2631 function_call_count
++;
2633 /* We want to make two insn chains; one for a sibling call, the other
2634 for a normal call. We will select one of the two chains after
2635 initial RTL generation is complete. */
2636 for (pass
= try_tail_call
? 0 : 1; pass
< 2; pass
++)
2638 int sibcall_failure
= 0;
2639 /* We want to emit any pending stack adjustments before the tail
2640 recursion "call". That way we know any adjustment after the tail
2641 recursion call can be ignored if we indeed use the tail recursion
2643 int save_pending_stack_adjust
= 0;
2644 int save_stack_pointer_delta
= 0;
2646 rtx before_call
, next_arg_reg
;
2650 /* Emit any queued insns now; otherwise they would end up in
2651 only one of the alternates. */
2654 /* State variables we need to save and restore between
2656 save_pending_stack_adjust
= pending_stack_adjust
;
2657 save_stack_pointer_delta
= stack_pointer_delta
;
2660 flags
&= ~ECF_SIBCALL
;
2662 flags
|= ECF_SIBCALL
;
2664 /* Other state variables that we must reinitialize each time
2665 through the loop (that are not initialized by the loop itself). */
2669 /* Start a new sequence for the normal call case.
2671 From this point on, if the sibling call fails, we want to set
2672 sibcall_failure instead of continuing the loop. */
2677 /* We know at this point that there are not currently any
2678 pending cleanups. If, however, in the process of evaluating
2679 the arguments we were to create some, we'll need to be
2680 able to get rid of them. */
2681 expand_start_target_temps ();
2684 /* Don't let pending stack adjusts add up to too much.
2685 Also, do all pending adjustments now if there is any chance
2686 this might be a call to alloca or if we are expanding a sibling
2687 call sequence or if we are calling a function that is to return
2688 with stack pointer depressed. */
2689 if (pending_stack_adjust
>= 32
2690 || (pending_stack_adjust
> 0
2691 && (flags
& (ECF_MAY_BE_ALLOCA
| ECF_SP_DEPRESSED
)))
2693 do_pending_stack_adjust ();
2695 /* When calling a const function, we must pop the stack args right away,
2696 so that the pop is deleted or moved with the call. */
2697 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
2700 #ifdef FINAL_REG_PARM_STACK_SPACE
2701 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
2704 /* Precompute any arguments as needed. */
2706 precompute_arguments (flags
, num_actuals
, args
);
2708 /* Now we are about to start emitting insns that can be deleted
2709 if a libcall is deleted. */
2710 if (pass
&& (flags
& (ECF_LIBCALL_BLOCK
| ECF_MALLOC
)))
2713 adjusted_args_size
= args_size
;
2714 /* Compute the actual size of the argument block required. The variable
2715 and constant sizes must be combined, the size may have to be rounded,
2716 and there may be a minimum required size. When generating a sibcall
2717 pattern, do not round up, since we'll be re-using whatever space our
2719 unadjusted_args_size
2720 = compute_argument_block_size (reg_parm_stack_space
,
2721 &adjusted_args_size
,
2723 : preferred_stack_boundary
));
2725 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
2727 /* The argument block when performing a sibling call is the
2728 incoming argument block. */
2731 argblock
= virtual_incoming_args_rtx
;
2733 #ifdef STACK_GROWS_DOWNWARD
2734 = plus_constant (argblock
, current_function_pretend_args_size
);
2736 = plus_constant (argblock
, -current_function_pretend_args_size
);
2738 stored_args_map
= sbitmap_alloc (args_size
.constant
);
2739 sbitmap_zero (stored_args_map
);
2742 /* If we have no actual push instructions, or shouldn't use them,
2743 make space for all args right now. */
2744 else if (adjusted_args_size
.var
!= 0)
2746 if (old_stack_level
== 0)
2748 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
2749 old_pending_adj
= pending_stack_adjust
;
2750 pending_stack_adjust
= 0;
2751 /* stack_arg_under_construction says whether a stack arg is
2752 being constructed at the old stack level. Pushing the stack
2753 gets a clean outgoing argument block. */
2754 old_stack_arg_under_construction
= stack_arg_under_construction
;
2755 stack_arg_under_construction
= 0;
2757 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
2761 /* Note that we must go through the motions of allocating an argument
2762 block even if the size is zero because we may be storing args
2763 in the area reserved for register arguments, which may be part of
2766 int needed
= adjusted_args_size
.constant
;
2768 /* Store the maximum argument space used. It will be pushed by
2769 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2772 if (needed
> current_function_outgoing_args_size
)
2773 current_function_outgoing_args_size
= needed
;
2775 if (must_preallocate
)
2777 if (ACCUMULATE_OUTGOING_ARGS
)
2779 /* Since the stack pointer will never be pushed, it is
2780 possible for the evaluation of a parm to clobber
2781 something we have already written to the stack.
2782 Since most function calls on RISC machines do not use
2783 the stack, this is uncommon, but must work correctly.
2785 Therefore, we save any area of the stack that was already
2786 written and that we are using. Here we set up to do this
2787 by making a new stack usage map from the old one. The
2788 actual save will be done by store_one_arg.
2790 Another approach might be to try to reorder the argument
2791 evaluations to avoid this conflicting stack usage. */
2793 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2794 /* Since we will be writing into the entire argument area,
2795 the map must be allocated for its entire size, not just
2796 the part that is the responsibility of the caller. */
2797 needed
+= reg_parm_stack_space
;
2800 #ifdef ARGS_GROW_DOWNWARD
2801 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2804 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2808 = (char *) alloca (highest_outgoing_arg_in_use
);
2810 if (initial_highest_arg_in_use
)
2811 memcpy (stack_usage_map
, initial_stack_usage_map
,
2812 initial_highest_arg_in_use
);
2814 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
2815 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
2816 (highest_outgoing_arg_in_use
2817 - initial_highest_arg_in_use
));
2820 /* The address of the outgoing argument list must not be
2821 copied to a register here, because argblock would be left
2822 pointing to the wrong place after the call to
2823 allocate_dynamic_stack_space below. */
2825 argblock
= virtual_outgoing_args_rtx
;
2829 if (inhibit_defer_pop
== 0)
2831 /* Try to reuse some or all of the pending_stack_adjust
2832 to get this space. */
2834 = (combine_pending_stack_adjustment_and_call
2835 (unadjusted_args_size
,
2836 &adjusted_args_size
,
2837 preferred_unit_stack_boundary
));
2839 /* combine_pending_stack_adjustment_and_call computes
2840 an adjustment before the arguments are allocated.
2841 Account for them and see whether or not the stack
2842 needs to go up or down. */
2843 needed
= unadjusted_args_size
- needed
;
2847 /* We're releasing stack space. */
2848 /* ??? We can avoid any adjustment at all if we're
2849 already aligned. FIXME. */
2850 pending_stack_adjust
= -needed
;
2851 do_pending_stack_adjust ();
2855 /* We need to allocate space. We'll do that in
2856 push_block below. */
2857 pending_stack_adjust
= 0;
2860 /* Special case this because overhead of `push_block' in
2861 this case is non-trivial. */
2863 argblock
= virtual_outgoing_args_rtx
;
2865 argblock
= push_block (GEN_INT (needed
), 0, 0);
2867 /* We only really need to call `copy_to_reg' in the case
2868 where push insns are going to be used to pass ARGBLOCK
2869 to a function call in ARGS. In that case, the stack
2870 pointer changes value from the allocation point to the
2871 call point, and hence the value of
2872 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2873 as well always do it. */
2874 argblock
= copy_to_reg (argblock
);
2876 /* The save/restore code in store_one_arg handles all
2877 cases except one: a constructor call (including a C
2878 function returning a BLKmode struct) to initialize
2880 if (stack_arg_under_construction
)
2882 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2883 rtx push_size
= GEN_INT (reg_parm_stack_space
2884 + adjusted_args_size
.constant
);
2886 rtx push_size
= GEN_INT (adjusted_args_size
.constant
);
2888 if (old_stack_level
== 0)
2890 emit_stack_save (SAVE_BLOCK
, &old_stack_level
,
2892 old_pending_adj
= pending_stack_adjust
;
2893 pending_stack_adjust
= 0;
2894 /* stack_arg_under_construction says whether a stack
2895 arg is being constructed at the old stack level.
2896 Pushing the stack gets a clean outgoing argument
2898 old_stack_arg_under_construction
2899 = stack_arg_under_construction
;
2900 stack_arg_under_construction
= 0;
2901 /* Make a new map for the new argument list. */
2902 stack_usage_map
= (char *)
2903 alloca (highest_outgoing_arg_in_use
);
2904 memset (stack_usage_map
, 0, highest_outgoing_arg_in_use
);
2905 highest_outgoing_arg_in_use
= 0;
2907 allocate_dynamic_stack_space (push_size
, NULL_RTX
,
2910 /* If argument evaluation might modify the stack pointer,
2911 copy the address of the argument list to a register. */
2912 for (i
= 0; i
< num_actuals
; i
++)
2913 if (args
[i
].pass_on_stack
)
2915 argblock
= copy_addr_to_reg (argblock
);
2922 compute_argument_addresses (args
, argblock
, num_actuals
);
2924 /* If we push args individually in reverse order, perform stack alignment
2925 before the first push (the last arg). */
2926 if (PUSH_ARGS_REVERSED
&& argblock
== 0
2927 && adjusted_args_size
.constant
!= unadjusted_args_size
)
2929 /* When the stack adjustment is pending, we get better code
2930 by combining the adjustments. */
2931 if (pending_stack_adjust
2932 && ! (flags
& ECF_LIBCALL_BLOCK
)
2933 && ! inhibit_defer_pop
)
2935 pending_stack_adjust
2936 = (combine_pending_stack_adjustment_and_call
2937 (unadjusted_args_size
,
2938 &adjusted_args_size
,
2939 preferred_unit_stack_boundary
));
2940 do_pending_stack_adjust ();
2942 else if (argblock
== 0)
2943 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
2944 - unadjusted_args_size
));
2946 /* Now that the stack is properly aligned, pops can't safely
2947 be deferred during the evaluation of the arguments. */
2950 funexp
= rtx_for_function_call (fndecl
, exp
);
2952 /* Figure out the register where the value, if any, will come back. */
2954 if (TYPE_MODE (TREE_TYPE (exp
)) != VOIDmode
2955 && ! structure_value_addr
)
2957 if (pcc_struct_value
)
2958 valreg
= hard_function_value (build_pointer_type (TREE_TYPE (exp
)),
2959 fndecl
, (pass
== 0));
2961 valreg
= hard_function_value (TREE_TYPE (exp
), fndecl
, (pass
== 0));
2964 /* Precompute all register parameters. It isn't safe to compute anything
2965 once we have started filling any specific hard regs. */
2966 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
2968 #ifdef REG_PARM_STACK_SPACE
2969 /* Save the fixed argument area if it's part of the caller's frame and
2970 is clobbered by argument setup for this call. */
2971 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
2972 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
2973 &low_to_save
, &high_to_save
);
2976 /* Now store (and compute if necessary) all non-register parms.
2977 These come before register parms, since they can require block-moves,
2978 which could clobber the registers used for register parms.
2979 Parms which have partial registers are not stored here,
2980 but we do preallocate space here if they want that. */
2982 for (i
= 0; i
< num_actuals
; i
++)
2983 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
2985 rtx before_arg
= get_last_insn ();
2987 if (store_one_arg (&args
[i
], argblock
, flags
,
2988 adjusted_args_size
.var
!= 0,
2989 reg_parm_stack_space
)
2991 && check_sibcall_argument_overlap (before_arg
,
2993 sibcall_failure
= 1;
2996 /* If we have a parm that is passed in registers but not in memory
2997 and whose alignment does not permit a direct copy into registers,
2998 make a group of pseudos that correspond to each register that we
3000 if (STRICT_ALIGNMENT
)
3001 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
3003 /* Now store any partially-in-registers parm.
3004 This is the last place a block-move can happen. */
3006 for (i
= 0; i
< num_actuals
; i
++)
3007 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
3009 rtx before_arg
= get_last_insn ();
3011 if (store_one_arg (&args
[i
], argblock
, flags
,
3012 adjusted_args_size
.var
!= 0,
3013 reg_parm_stack_space
)
3015 && check_sibcall_argument_overlap (before_arg
,
3017 sibcall_failure
= 1;
3020 /* If we pushed args in forward order, perform stack alignment
3021 after pushing the last arg. */
3022 if (!PUSH_ARGS_REVERSED
&& argblock
== 0)
3023 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
3024 - unadjusted_args_size
));
3026 /* If register arguments require space on the stack and stack space
3027 was not preallocated, allocate stack space here for arguments
3028 passed in registers. */
3029 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3030 if (!ACCUMULATE_OUTGOING_ARGS
3031 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
3032 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
3035 /* Pass the function the address in which to return a
3037 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
3039 emit_move_insn (struct_value_rtx
,
3041 force_operand (structure_value_addr
,
3044 if (GET_CODE (struct_value_rtx
) == REG
)
3045 use_reg (&call_fusage
, struct_value_rtx
);
3048 funexp
= prepare_call_address (funexp
, fndecl
, &call_fusage
,
3049 reg_parm_seen
, pass
== 0);
3051 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
3052 pass
== 0, &sibcall_failure
);
3054 /* Perform postincrements before actually calling the function. */
3057 /* Save a pointer to the last insn before the call, so that we can
3058 later safely search backwards to find the CALL_INSN. */
3059 before_call
= get_last_insn ();
3061 /* Set up next argument register. For sibling calls on machines
3062 with register windows this should be the incoming register. */
3063 #ifdef FUNCTION_INCOMING_ARG
3065 next_arg_reg
= FUNCTION_INCOMING_ARG (args_so_far
, VOIDmode
,
3069 next_arg_reg
= FUNCTION_ARG (args_so_far
, VOIDmode
,
3072 /* All arguments and registers used for the call must be set up by
3075 /* Stack must be properly aligned now. */
3076 if (pass
&& stack_pointer_delta
% preferred_unit_stack_boundary
)
3079 /* Generate the actual call instruction. */
3080 emit_call_1 (funexp
, fndecl
, funtype
, unadjusted_args_size
,
3081 adjusted_args_size
.constant
, struct_value_size
,
3082 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
3083 flags
, & args_so_far
);
3085 /* Verify that we've deallocated all the stack we used. */
3087 && old_stack_allocated
!= stack_pointer_delta
- pending_stack_adjust
)
3090 /* If call is cse'able, make appropriate pair of reg-notes around it.
3091 Test valreg so we don't crash; may safely ignore `const'
3092 if return type is void. Disable for PARALLEL return values, because
3093 we have no way to move such values into a pseudo register. */
3094 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
3098 if (valreg
== 0 || GET_CODE (valreg
) == PARALLEL
)
3100 insns
= get_insns ();
3107 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3109 /* Mark the return value as a pointer if needed. */
3110 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3111 mark_reg_pointer (temp
,
3112 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp
))));
3114 /* Construct an "equal form" for the value which mentions all the
3115 arguments in order as well as the function name. */
3116 for (i
= 0; i
< num_actuals
; i
++)
3117 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3118 args
[i
].initial_value
, note
);
3119 note
= gen_rtx_EXPR_LIST (VOIDmode
, funexp
, note
);
3121 insns
= get_insns ();
3124 if (flags
& ECF_PURE
)
3125 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3126 gen_rtx_USE (VOIDmode
,
3127 gen_rtx_MEM (BLKmode
,
3128 gen_rtx_SCRATCH (VOIDmode
))),
3131 emit_libcall_block (insns
, temp
, valreg
, note
);
3136 else if (pass
&& (flags
& ECF_MALLOC
))
3138 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3141 /* The return value from a malloc-like function is a pointer. */
3142 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3143 mark_reg_pointer (temp
, BIGGEST_ALIGNMENT
);
3145 emit_move_insn (temp
, valreg
);
3147 /* The return value from a malloc-like function can not alias
3149 last
= get_last_insn ();
3151 gen_rtx_EXPR_LIST (REG_NOALIAS
, temp
, REG_NOTES (last
));
3153 /* Write out the sequence. */
3154 insns
= get_insns ();
3160 /* For calls to `setjmp', etc., inform flow.c it should complain
3161 if nonvolatile values are live. For functions that cannot return,
3162 inform flow that control does not fall through. */
3164 if ((flags
& (ECF_NORETURN
| ECF_LONGJMP
)) || pass
== 0)
3166 /* The barrier must be emitted
3167 immediately after the CALL_INSN. Some ports emit more
3168 than just a CALL_INSN above, so we must search for it here. */
3170 rtx last
= get_last_insn ();
3171 while (GET_CODE (last
) != CALL_INSN
)
3173 last
= PREV_INSN (last
);
3174 /* There was no CALL_INSN? */
3175 if (last
== before_call
)
3179 emit_barrier_after (last
);
3182 if (flags
& ECF_LONGJMP
)
3183 current_function_calls_longjmp
= 1;
3185 /* If this function is returning into a memory location marked as
3186 readonly, it means it is initializing that location. But we normally
3187 treat functions as not clobbering such locations, so we need to
3188 specify that this one does. */
3189 if (target
!= 0 && GET_CODE (target
) == MEM
3190 && structure_value_addr
!= 0 && RTX_UNCHANGING_P (target
))
3191 emit_insn (gen_rtx_CLOBBER (VOIDmode
, target
));
3193 /* If value type not void, return an rtx for the value. */
3195 /* If there are cleanups to be called, don't use a hard reg as target.
3196 We need to double check this and see if it matters anymore. */
3197 if (any_pending_cleanups (1))
3199 if (target
&& REG_P (target
)
3200 && REGNO (target
) < FIRST_PSEUDO_REGISTER
)
3202 sibcall_failure
= 1;
3205 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
3207 target
= const0_rtx
;
3208 else if (structure_value_addr
)
3210 if (target
== 0 || GET_CODE (target
) != MEM
)
3213 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3214 memory_address (TYPE_MODE (TREE_TYPE (exp
)),
3215 structure_value_addr
));
3216 set_mem_attributes (target
, exp
, 1);
3219 else if (pcc_struct_value
)
3221 /* This is the special C++ case where we need to
3222 know what the true target was. We take care to
3223 never use this value more than once in one expression. */
3224 target
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3225 copy_to_reg (valreg
));
3226 set_mem_attributes (target
, exp
, 1);
3228 /* Handle calls that return values in multiple non-contiguous locations.
3229 The Irix 6 ABI has examples of this. */
3230 else if (GET_CODE (valreg
) == PARALLEL
)
3234 /* This will only be assigned once, so it can be readonly. */
3235 tree nt
= build_qualified_type (TREE_TYPE (exp
),
3236 (TYPE_QUALS (TREE_TYPE (exp
))
3237 | TYPE_QUAL_CONST
));
3239 target
= assign_temp (nt
, 0, 1, 1);
3240 preserve_temp_slots (target
);
3243 if (! rtx_equal_p (target
, valreg
))
3244 emit_group_store (target
, valreg
,
3245 int_size_in_bytes (TREE_TYPE (exp
)));
3247 /* We can not support sibling calls for this case. */
3248 sibcall_failure
= 1;
3251 && GET_MODE (target
) == TYPE_MODE (TREE_TYPE (exp
))
3252 && GET_MODE (target
) == GET_MODE (valreg
))
3254 /* TARGET and VALREG cannot be equal at this point because the
3255 latter would not have REG_FUNCTION_VALUE_P true, while the
3256 former would if it were referring to the same register.
3258 If they refer to the same register, this move will be a no-op,
3259 except when function inlining is being done. */
3260 emit_move_insn (target
, valreg
);
3262 else if (TYPE_MODE (TREE_TYPE (exp
)) == BLKmode
)
3264 target
= copy_blkmode_from_reg (target
, valreg
, TREE_TYPE (exp
));
3266 /* We can not support sibling calls for this case. */
3267 sibcall_failure
= 1;
3270 target
= copy_to_reg (valreg
);
3272 #ifdef PROMOTE_FUNCTION_RETURN
3273 /* If we promoted this return value, make the proper SUBREG. TARGET
3274 might be const0_rtx here, so be careful. */
3275 if (GET_CODE (target
) == REG
3276 && TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
3277 && GET_MODE (target
) != TYPE_MODE (TREE_TYPE (exp
)))
3279 tree type
= TREE_TYPE (exp
);
3280 int unsignedp
= TREE_UNSIGNED (type
);
3283 /* If we don't promote as expected, something is wrong. */
3284 if (GET_MODE (target
)
3285 != promote_mode (type
, TYPE_MODE (type
), &unsignedp
, 1))
3288 if ((WORDS_BIG_ENDIAN
|| BYTES_BIG_ENDIAN
)
3289 && GET_MODE_SIZE (GET_MODE (target
))
3290 > GET_MODE_SIZE (TYPE_MODE (type
)))
3292 offset
= GET_MODE_SIZE (GET_MODE (target
))
3293 - GET_MODE_SIZE (TYPE_MODE (type
));
3294 if (! BYTES_BIG_ENDIAN
)
3295 offset
= (offset
/ UNITS_PER_WORD
) * UNITS_PER_WORD
;
3296 else if (! WORDS_BIG_ENDIAN
)
3297 offset
%= UNITS_PER_WORD
;
3299 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
3300 SUBREG_PROMOTED_VAR_P (target
) = 1;
3301 SUBREG_PROMOTED_UNSIGNED_SET (target
, unsignedp
);
3305 /* If size of args is variable or this was a constructor call for a stack
3306 argument, restore saved stack-pointer value. */
3308 if (old_stack_level
&& ! (flags
& ECF_SP_DEPRESSED
))
3310 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
3311 pending_stack_adjust
= old_pending_adj
;
3312 stack_arg_under_construction
= old_stack_arg_under_construction
;
3313 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3314 stack_usage_map
= initial_stack_usage_map
;
3315 sibcall_failure
= 1;
3317 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
3319 #ifdef REG_PARM_STACK_SPACE
3321 restore_fixed_argument_area (save_area
, argblock
,
3322 high_to_save
, low_to_save
);
3325 /* If we saved any argument areas, restore them. */
3326 for (i
= 0; i
< num_actuals
; i
++)
3327 if (args
[i
].save_area
)
3329 enum machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
3331 = gen_rtx_MEM (save_mode
,
3332 memory_address (save_mode
,
3333 XEXP (args
[i
].stack_slot
, 0)));
3335 if (save_mode
!= BLKmode
)
3336 emit_move_insn (stack_area
, args
[i
].save_area
);
3338 emit_block_move (stack_area
, args
[i
].save_area
,
3339 GEN_INT (args
[i
].size
.constant
),
3340 BLOCK_OP_CALL_PARM
);
3343 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3344 stack_usage_map
= initial_stack_usage_map
;
3347 /* If this was alloca, record the new stack level for nonlocal gotos.
3348 Check for the handler slots since we might not have a save area
3349 for non-local gotos. */
3351 if ((flags
& ECF_MAY_BE_ALLOCA
) && nonlocal_goto_handler_slots
!= 0)
3352 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
3354 /* Free up storage we no longer need. */
3355 for (i
= 0; i
< num_actuals
; ++i
)
3356 if (args
[i
].aligned_regs
)
3357 free (args
[i
].aligned_regs
);
3361 /* Undo the fake expand_start_target_temps we did earlier. If
3362 there had been any cleanups created, we've already set
3364 expand_end_target_temps ();
3367 insns
= get_insns ();
3372 tail_call_insns
= insns
;
3374 /* Restore the pending stack adjustment now that we have
3375 finished generating the sibling call sequence. */
3377 pending_stack_adjust
= save_pending_stack_adjust
;
3378 stack_pointer_delta
= save_stack_pointer_delta
;
3380 /* Prepare arg structure for next iteration. */
3381 for (i
= 0; i
< num_actuals
; i
++)
3384 args
[i
].aligned_regs
= 0;
3388 sbitmap_free (stored_args_map
);
3391 normal_call_insns
= insns
;
3393 /* If something prevents making this a sibling call,
3394 zero out the sequence. */
3395 if (sibcall_failure
)
3396 tail_call_insns
= NULL_RTX
;
3399 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3400 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3401 can happen if the arguments to this function call an inline
3402 function who's expansion contains another CALL_PLACEHOLDER.
3404 If there are any C_Ps in any of these sequences, replace them
3405 with their normal call. */
3407 for (insn
= normal_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3408 if (GET_CODE (insn
) == CALL_INSN
3409 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3410 replace_call_placeholder (insn
, sibcall_use_normal
);
3412 for (insn
= tail_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3413 if (GET_CODE (insn
) == CALL_INSN
3414 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3415 replace_call_placeholder (insn
, sibcall_use_normal
);
3417 for (insn
= tail_recursion_insns
; insn
; insn
= NEXT_INSN (insn
))
3418 if (GET_CODE (insn
) == CALL_INSN
3419 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3420 replace_call_placeholder (insn
, sibcall_use_normal
);
3422 /* If this was a potential tail recursion site, then emit a
3423 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3424 One of them will be selected later. */
3425 if (tail_recursion_insns
|| tail_call_insns
)
3427 /* The tail recursion label must be kept around. We could expose
3428 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3429 and makes determining true tail recursion sites difficult.
3431 So we set LABEL_PRESERVE_P here, then clear it when we select
3432 one of the call sequences after rtl generation is complete. */
3433 if (tail_recursion_insns
)
3434 LABEL_PRESERVE_P (tail_recursion_label
) = 1;
3435 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode
, normal_call_insns
,
3437 tail_recursion_insns
,
3438 tail_recursion_label
));
3441 emit_insn (normal_call_insns
);
3443 currently_expanding_call
--;
3445 /* If this function returns with the stack pointer depressed, ensure
3446 this block saves and restores the stack pointer, show it was
3447 changed, and adjust for any outgoing arg space. */
3448 if (flags
& ECF_SP_DEPRESSED
)
3450 clear_pending_stack_adjust ();
3451 emit_insn (gen_rtx (CLOBBER
, VOIDmode
, stack_pointer_rtx
));
3452 emit_move_insn (virtual_stack_dynamic_rtx
, stack_pointer_rtx
);
3453 save_stack_pointer ();
3459 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3460 The RETVAL parameter specifies whether return value needs to be saved, other
3461 parameters are documented in the emit_library_call function below. */
3464 emit_library_call_value_1 (retval
, orgfun
, value
, fn_type
, outmode
, nargs
, p
)
3468 enum libcall_type fn_type
;
3469 enum machine_mode outmode
;
3473 /* Total size in bytes of all the stack-parms scanned so far. */
3474 struct args_size args_size
;
3475 /* Size of arguments before any adjustments (such as rounding). */
3476 struct args_size original_args_size
;
3481 struct args_size alignment_pad
;
3483 CUMULATIVE_ARGS args_so_far
;
3487 enum machine_mode mode
;
3490 struct args_size offset
;
3491 struct args_size size
;
3495 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3496 rtx call_fusage
= 0;
3499 int pcc_struct_value
= 0;
3500 int struct_value_size
= 0;
3502 int reg_parm_stack_space
= 0;
3505 tree tfom
; /* type_for_mode (outmode, 0) */
3507 #ifdef REG_PARM_STACK_SPACE
3508 /* Define the boundary of the register parm stack space that needs to be
3510 int low_to_save
, high_to_save
;
3511 rtx save_area
= 0; /* Place that it is saved. */
3514 /* Size of the stack reserved for parameter registers. */
3515 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3516 char *initial_stack_usage_map
= stack_usage_map
;
3518 #ifdef REG_PARM_STACK_SPACE
3519 #ifdef MAYBE_REG_PARM_STACK_SPACE
3520 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
3522 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
3526 /* By default, library functions can not throw. */
3527 flags
= ECF_NOTHROW
;
3539 case LCT_CONST_MAKE_BLOCK
:
3540 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
3542 case LCT_PURE_MAKE_BLOCK
:
3543 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
3546 flags
|= ECF_NORETURN
;
3549 flags
= ECF_NORETURN
;
3551 case LCT_ALWAYS_RETURN
:
3552 flags
= ECF_ALWAYS_RETURN
;
3554 case LCT_RETURNS_TWICE
:
3555 flags
= ECF_RETURNS_TWICE
;
3560 /* Ensure current function's preferred stack boundary is at least
3562 if (cfun
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
3563 cfun
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3565 /* If this kind of value comes back in memory,
3566 decide where in memory it should come back. */
3567 if (outmode
!= VOIDmode
)
3569 tfom
= (*lang_hooks
.types
.type_for_mode
) (outmode
, 0);
3570 if (aggregate_value_p (tfom
))
3572 #ifdef PCC_STATIC_STRUCT_RETURN
3574 = hard_function_value (build_pointer_type (tfom
), 0, 0);
3575 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
3576 pcc_struct_value
= 1;
3578 value
= gen_reg_rtx (outmode
);
3579 #else /* not PCC_STATIC_STRUCT_RETURN */
3580 struct_value_size
= GET_MODE_SIZE (outmode
);
3581 if (value
!= 0 && GET_CODE (value
) == MEM
)
3584 mem_value
= assign_temp (tfom
, 0, 1, 1);
3586 /* This call returns a big structure. */
3587 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3591 tfom
= void_type_node
;
3593 /* ??? Unfinished: must pass the memory address as an argument. */
3595 /* Copy all the libcall-arguments out of the varargs data
3596 and into a vector ARGVEC.
3598 Compute how to pass each argument. We only support a very small subset
3599 of the full argument passing conventions to limit complexity here since
3600 library functions shouldn't have many args. */
3602 argvec
= (struct arg
*) alloca ((nargs
+ 1) * sizeof (struct arg
));
3603 memset ((char *) argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
3605 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3606 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far
, outmode
, fun
);
3608 INIT_CUMULATIVE_ARGS (args_so_far
, NULL_TREE
, fun
, 0);
3611 args_size
.constant
= 0;
3616 /* Now we are about to start emitting insns that can be deleted
3617 if a libcall is deleted. */
3618 if (flags
& ECF_LIBCALL_BLOCK
)
3623 /* If there's a structure value address to be passed,
3624 either pass it in the special place, or pass it as an extra argument. */
3625 if (mem_value
&& struct_value_rtx
== 0 && ! pcc_struct_value
)
3627 rtx addr
= XEXP (mem_value
, 0);
3630 /* Make sure it is a reasonable operand for a move or push insn. */
3631 if (GET_CODE (addr
) != REG
&& GET_CODE (addr
) != MEM
3632 && ! (CONSTANT_P (addr
) && LEGITIMATE_CONSTANT_P (addr
)))
3633 addr
= force_operand (addr
, NULL_RTX
);
3635 argvec
[count
].value
= addr
;
3636 argvec
[count
].mode
= Pmode
;
3637 argvec
[count
].partial
= 0;
3639 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, Pmode
, NULL_TREE
, 1);
3640 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3641 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, Pmode
, NULL_TREE
, 1))
3645 locate_and_pad_parm (Pmode
, NULL_TREE
,
3646 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3649 argvec
[count
].reg
!= 0,
3651 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3652 &argvec
[count
].size
, &alignment_pad
);
3654 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3655 || reg_parm_stack_space
> 0)
3656 args_size
.constant
+= argvec
[count
].size
.constant
;
3658 FUNCTION_ARG_ADVANCE (args_so_far
, Pmode
, (tree
) 0, 1);
3663 for (; count
< nargs
; count
++)
3665 rtx val
= va_arg (p
, rtx
);
3666 enum machine_mode mode
= va_arg (p
, enum machine_mode
);
3668 /* We cannot convert the arg value to the mode the library wants here;
3669 must do it earlier where we know the signedness of the arg. */
3671 || (GET_MODE (val
) != mode
&& GET_MODE (val
) != VOIDmode
))
3674 /* On some machines, there's no way to pass a float to a library fcn.
3675 Pass it as a double instead. */
3676 #ifdef LIBGCC_NEEDS_DOUBLE
3677 if (LIBGCC_NEEDS_DOUBLE
&& mode
== SFmode
)
3678 val
= convert_modes (DFmode
, SFmode
, val
, 0), mode
= DFmode
;
3681 /* There's no need to call protect_from_queue, because
3682 either emit_move_insn or emit_push_insn will do that. */
3684 /* Make sure it is a reasonable operand for a move or push insn. */
3685 if (GET_CODE (val
) != REG
&& GET_CODE (val
) != MEM
3686 && ! (CONSTANT_P (val
) && LEGITIMATE_CONSTANT_P (val
)))
3687 val
= force_operand (val
, NULL_RTX
);
3689 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3690 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, mode
, NULL_TREE
, 1))
3694 #ifdef FUNCTION_ARG_CALLEE_COPIES
3695 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far
, mode
,
3700 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3701 functions, so we have to pretend this isn't such a function. */
3702 if (flags
& ECF_LIBCALL_BLOCK
)
3704 rtx insns
= get_insns ();
3708 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3710 /* If this was a CONST function, it is now PURE since
3711 it now reads memory. */
3712 if (flags
& ECF_CONST
)
3714 flags
&= ~ECF_CONST
;
3718 if (GET_MODE (val
) == MEM
&& ! must_copy
)
3722 slot
= assign_temp ((*lang_hooks
.types
.type_for_mode
) (mode
, 0),
3724 emit_move_insn (slot
, val
);
3728 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, 0);
3730 slot
= gen_rtx_MEM (mode
,
3731 expand_expr (build1 (ADDR_EXPR
,
3734 make_tree (type
, val
)),
3735 NULL_RTX
, VOIDmode
, 0));
3738 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3739 gen_rtx_USE (VOIDmode
, slot
),
3742 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3743 gen_rtx_CLOBBER (VOIDmode
,
3748 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
3752 argvec
[count
].value
= val
;
3753 argvec
[count
].mode
= mode
;
3755 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, mode
, NULL_TREE
, 1);
3757 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3758 argvec
[count
].partial
3759 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, mode
, NULL_TREE
, 1);
3761 argvec
[count
].partial
= 0;
3764 locate_and_pad_parm (mode
, NULL_TREE
,
3765 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3768 argvec
[count
].reg
!= 0,
3770 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3771 &argvec
[count
].size
, &alignment_pad
);
3773 if (argvec
[count
].size
.var
)
3776 if (reg_parm_stack_space
== 0 && argvec
[count
].partial
)
3777 argvec
[count
].size
.constant
-= argvec
[count
].partial
* UNITS_PER_WORD
;
3779 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3780 || reg_parm_stack_space
> 0)
3781 args_size
.constant
+= argvec
[count
].size
.constant
;
3783 FUNCTION_ARG_ADVANCE (args_so_far
, mode
, (tree
) 0, 1);
3786 #ifdef FINAL_REG_PARM_STACK_SPACE
3787 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
3790 /* If this machine requires an external definition for library
3791 functions, write one out. */
3792 assemble_external_libcall (fun
);
3794 original_args_size
= args_size
;
3795 args_size
.constant
= (((args_size
.constant
3796 + stack_pointer_delta
3800 - stack_pointer_delta
);
3802 args_size
.constant
= MAX (args_size
.constant
,
3803 reg_parm_stack_space
);
3805 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3806 args_size
.constant
-= reg_parm_stack_space
;
3809 if (args_size
.constant
> current_function_outgoing_args_size
)
3810 current_function_outgoing_args_size
= args_size
.constant
;
3812 if (ACCUMULATE_OUTGOING_ARGS
)
3814 /* Since the stack pointer will never be pushed, it is possible for
3815 the evaluation of a parm to clobber something we have already
3816 written to the stack. Since most function calls on RISC machines
3817 do not use the stack, this is uncommon, but must work correctly.
3819 Therefore, we save any area of the stack that was already written
3820 and that we are using. Here we set up to do this by making a new
3821 stack usage map from the old one.
3823 Another approach might be to try to reorder the argument
3824 evaluations to avoid this conflicting stack usage. */
3826 needed
= args_size
.constant
;
3828 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3829 /* Since we will be writing into the entire argument area, the
3830 map must be allocated for its entire size, not just the part that
3831 is the responsibility of the caller. */
3832 needed
+= reg_parm_stack_space
;
3835 #ifdef ARGS_GROW_DOWNWARD
3836 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3839 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3842 stack_usage_map
= (char *) alloca (highest_outgoing_arg_in_use
);
3844 if (initial_highest_arg_in_use
)
3845 memcpy (stack_usage_map
, initial_stack_usage_map
,
3846 initial_highest_arg_in_use
);
3848 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
3849 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
3850 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
3853 /* We must be careful to use virtual regs before they're instantiated,
3854 and real regs afterwards. Loop optimization, for example, can create
3855 new libcalls after we've instantiated the virtual regs, and if we
3856 use virtuals anyway, they won't match the rtl patterns. */
3858 if (virtuals_instantiated
)
3859 argblock
= plus_constant (stack_pointer_rtx
, STACK_POINTER_OFFSET
);
3861 argblock
= virtual_outgoing_args_rtx
;
3866 argblock
= push_block (GEN_INT (args_size
.constant
), 0, 0);
3869 /* If we push args individually in reverse order, perform stack alignment
3870 before the first push (the last arg). */
3871 if (argblock
== 0 && PUSH_ARGS_REVERSED
)
3872 anti_adjust_stack (GEN_INT (args_size
.constant
3873 - original_args_size
.constant
));
3875 if (PUSH_ARGS_REVERSED
)
3886 #ifdef REG_PARM_STACK_SPACE
3887 if (ACCUMULATE_OUTGOING_ARGS
)
3889 /* The argument list is the property of the called routine and it
3890 may clobber it. If the fixed area has been used for previous
3891 parameters, we must save and restore it. */
3892 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
3893 &low_to_save
, &high_to_save
);
3897 /* Push the args that need to be pushed. */
3899 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3900 are to be pushed. */
3901 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
3903 enum machine_mode mode
= argvec
[argnum
].mode
;
3904 rtx val
= argvec
[argnum
].value
;
3905 rtx reg
= argvec
[argnum
].reg
;
3906 int partial
= argvec
[argnum
].partial
;
3907 int lower_bound
= 0, upper_bound
= 0, i
;
3909 if (! (reg
!= 0 && partial
== 0))
3911 if (ACCUMULATE_OUTGOING_ARGS
)
3913 /* If this is being stored into a pre-allocated, fixed-size,
3914 stack area, save any previous data at that location. */
3916 #ifdef ARGS_GROW_DOWNWARD
3917 /* stack_slot is negative, but we want to index stack_usage_map
3918 with positive values. */
3919 upper_bound
= -argvec
[argnum
].offset
.constant
+ 1;
3920 lower_bound
= upper_bound
- argvec
[argnum
].size
.constant
;
3922 lower_bound
= argvec
[argnum
].offset
.constant
;
3923 upper_bound
= lower_bound
+ argvec
[argnum
].size
.constant
;
3926 for (i
= lower_bound
; i
< upper_bound
; i
++)
3927 if (stack_usage_map
[i
]
3928 /* Don't store things in the fixed argument area at this
3929 point; it has already been saved. */
3930 && i
> reg_parm_stack_space
)
3933 if (i
!= upper_bound
)
3935 /* We need to make a save area. See what mode we can make
3937 enum machine_mode save_mode
3938 = mode_for_size (argvec
[argnum
].size
.constant
3946 plus_constant (argblock
,
3947 argvec
[argnum
].offset
.constant
)));
3948 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
3950 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
3954 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, PARM_BOUNDARY
,
3955 partial
, reg
, 0, argblock
,
3956 GEN_INT (argvec
[argnum
].offset
.constant
),
3957 reg_parm_stack_space
, ARGS_SIZE_RTX (alignment_pad
));
3959 /* Now mark the segment we just used. */
3960 if (ACCUMULATE_OUTGOING_ARGS
)
3961 for (i
= lower_bound
; i
< upper_bound
; i
++)
3962 stack_usage_map
[i
] = 1;
3968 /* If we pushed args in forward order, perform stack alignment
3969 after pushing the last arg. */
3970 if (argblock
== 0 && !PUSH_ARGS_REVERSED
)
3971 anti_adjust_stack (GEN_INT (args_size
.constant
3972 - original_args_size
.constant
));
3974 if (PUSH_ARGS_REVERSED
)
3979 fun
= prepare_call_address (fun
, NULL_TREE
, &call_fusage
, 0, 0);
3981 /* Now load any reg parms into their regs. */
3983 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3984 are to be pushed. */
3985 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
3987 rtx val
= argvec
[argnum
].value
;
3988 rtx reg
= argvec
[argnum
].reg
;
3989 int partial
= argvec
[argnum
].partial
;
3991 /* Handle calls that pass values in multiple non-contiguous
3992 locations. The PA64 has examples of this for library calls. */
3993 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
3994 emit_group_load (reg
, val
, GET_MODE_SIZE (GET_MODE (val
)));
3995 else if (reg
!= 0 && partial
== 0)
3996 emit_move_insn (reg
, val
);
4001 /* Any regs containing parms remain in use through the call. */
4002 for (count
= 0; count
< nargs
; count
++)
4004 rtx reg
= argvec
[count
].reg
;
4005 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
4006 use_group_regs (&call_fusage
, reg
);
4008 use_reg (&call_fusage
, reg
);
4011 /* Pass the function the address in which to return a structure value. */
4012 if (mem_value
!= 0 && struct_value_rtx
!= 0 && ! pcc_struct_value
)
4014 emit_move_insn (struct_value_rtx
,
4016 force_operand (XEXP (mem_value
, 0),
4018 if (GET_CODE (struct_value_rtx
) == REG
)
4019 use_reg (&call_fusage
, struct_value_rtx
);
4022 /* Don't allow popping to be deferred, since then
4023 cse'ing of library calls could delete a call and leave the pop. */
4025 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
4026 ? hard_libcall_value (outmode
) : NULL_RTX
);
4028 /* Stack must be properly aligned now. */
4029 if (stack_pointer_delta
& (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
- 1))
4032 before_call
= get_last_insn ();
4034 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4035 will set inhibit_defer_pop to that value. */
4036 /* The return type is needed to decide how many bytes the function pops.
4037 Signedness plays no role in that, so for simplicity, we pretend it's
4038 always signed. We also assume that the list of arguments passed has
4039 no impact, so we pretend it is unknown. */
4042 get_identifier (XSTR (orgfun
, 0)),
4043 build_function_type (tfom
, NULL_TREE
),
4044 original_args_size
.constant
, args_size
.constant
,
4046 FUNCTION_ARG (args_so_far
, VOIDmode
, void_type_node
, 1),
4048 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, & args_so_far
);
4050 /* For calls to `setjmp', etc., inform flow.c it should complain
4051 if nonvolatile values are live. For functions that cannot return,
4052 inform flow that control does not fall through. */
4054 if (flags
& (ECF_NORETURN
| ECF_LONGJMP
))
4056 /* The barrier note must be emitted
4057 immediately after the CALL_INSN. Some ports emit more than
4058 just a CALL_INSN above, so we must search for it here. */
4060 rtx last
= get_last_insn ();
4061 while (GET_CODE (last
) != CALL_INSN
)
4063 last
= PREV_INSN (last
);
4064 /* There was no CALL_INSN? */
4065 if (last
== before_call
)
4069 emit_barrier_after (last
);
4072 /* Now restore inhibit_defer_pop to its actual original value. */
4075 /* If call is cse'able, make appropriate pair of reg-notes around it.
4076 Test valreg so we don't crash; may safely ignore `const'
4077 if return type is void. Disable for PARALLEL return values, because
4078 we have no way to move such values into a pseudo register. */
4079 if (flags
& ECF_LIBCALL_BLOCK
)
4083 if (valreg
== 0 || GET_CODE (valreg
) == PARALLEL
)
4085 insns
= get_insns ();
4092 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
4095 /* Construct an "equal form" for the value which mentions all the
4096 arguments in order as well as the function name. */
4097 for (i
= 0; i
< nargs
; i
++)
4098 note
= gen_rtx_EXPR_LIST (VOIDmode
, argvec
[i
].value
, note
);
4099 note
= gen_rtx_EXPR_LIST (VOIDmode
, fun
, note
);
4101 insns
= get_insns ();
4104 if (flags
& ECF_PURE
)
4105 note
= gen_rtx_EXPR_LIST (VOIDmode
,
4106 gen_rtx_USE (VOIDmode
,
4107 gen_rtx_MEM (BLKmode
,
4108 gen_rtx_SCRATCH (VOIDmode
))),
4111 emit_libcall_block (insns
, temp
, valreg
, note
);
4118 /* Copy the value to the right place. */
4119 if (outmode
!= VOIDmode
&& retval
)
4125 if (value
!= mem_value
)
4126 emit_move_insn (value
, mem_value
);
4128 else if (value
!= 0)
4129 emit_move_insn (value
, valreg
);
4134 if (ACCUMULATE_OUTGOING_ARGS
)
4136 #ifdef REG_PARM_STACK_SPACE
4138 restore_fixed_argument_area (save_area
, argblock
,
4139 high_to_save
, low_to_save
);
4142 /* If we saved any argument areas, restore them. */
4143 for (count
= 0; count
< nargs
; count
++)
4144 if (argvec
[count
].save_area
)
4146 enum machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
4148 = gen_rtx_MEM (save_mode
,
4151 plus_constant (argblock
,
4152 argvec
[count
].offset
.constant
)));
4154 emit_move_insn (stack_area
, argvec
[count
].save_area
);
4157 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4158 stack_usage_map
= initial_stack_usage_map
;
4165 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4166 (emitting the queue unless NO_QUEUE is nonzero),
4167 for a value of mode OUTMODE,
4168 with NARGS different arguments, passed as alternating rtx values
4169 and machine_modes to convert them to.
4170 The rtx values should have been passed through protect_from_queue already.
4172 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4173 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4174 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4175 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4176 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4177 or other LCT_ value for other types of library calls. */
4180 emit_library_call
VPARAMS((rtx orgfun
, enum libcall_type fn_type
,
4181 enum machine_mode outmode
, int nargs
, ...))
4184 VA_FIXEDARG (p
, rtx
, orgfun
);
4185 VA_FIXEDARG (p
, int, fn_type
);
4186 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4187 VA_FIXEDARG (p
, int, nargs
);
4189 emit_library_call_value_1 (0, orgfun
, NULL_RTX
, fn_type
, outmode
, nargs
, p
);
4194 /* Like emit_library_call except that an extra argument, VALUE,
4195 comes second and says where to store the result.
4196 (If VALUE is zero, this function chooses a convenient way
4197 to return the value.
4199 This function returns an rtx for where the value is to be found.
4200 If VALUE is nonzero, VALUE is returned. */
4203 emit_library_call_value
VPARAMS((rtx orgfun
, rtx value
,
4204 enum libcall_type fn_type
,
4205 enum machine_mode outmode
, int nargs
, ...))
4210 VA_FIXEDARG (p
, rtx
, orgfun
);
4211 VA_FIXEDARG (p
, rtx
, value
);
4212 VA_FIXEDARG (p
, int, fn_type
);
4213 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4214 VA_FIXEDARG (p
, int, nargs
);
4216 result
= emit_library_call_value_1 (1, orgfun
, value
, fn_type
, outmode
,
4224 /* Store a single argument for a function call
4225 into the register or memory area where it must be passed.
4226 *ARG describes the argument value and where to pass it.
4228 ARGBLOCK is the address of the stack-block for all the arguments,
4229 or 0 on a machine where arguments are pushed individually.
4231 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4232 so must be careful about how the stack is used.
4234 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4235 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4236 that we need not worry about saving and restoring the stack.
4238 FNDECL is the declaration of the function we are calling.
4240 Return nonzero if this arg should cause sibcall failure,
4244 store_one_arg (arg
, argblock
, flags
, variable_size
, reg_parm_stack_space
)
4245 struct arg_data
*arg
;
4248 int variable_size ATTRIBUTE_UNUSED
;
4249 int reg_parm_stack_space
;
4251 tree pval
= arg
->tree_value
;
4255 int i
, lower_bound
= 0, upper_bound
= 0;
4256 int sibcall_failure
= 0;
4258 if (TREE_CODE (pval
) == ERROR_MARK
)
4261 /* Push a new temporary level for any temporaries we make for
4265 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
4267 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4268 save any previous data at that location. */
4269 if (argblock
&& ! variable_size
&& arg
->stack
)
4271 #ifdef ARGS_GROW_DOWNWARD
4272 /* stack_slot is negative, but we want to index stack_usage_map
4273 with positive values. */
4274 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4275 upper_bound
= -INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1)) + 1;
4279 lower_bound
= upper_bound
- arg
->size
.constant
;
4281 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4282 lower_bound
= INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1));
4286 upper_bound
= lower_bound
+ arg
->size
.constant
;
4289 for (i
= lower_bound
; i
< upper_bound
; i
++)
4290 if (stack_usage_map
[i
]
4291 /* Don't store things in the fixed argument area at this point;
4292 it has already been saved. */
4293 && i
> reg_parm_stack_space
)
4296 if (i
!= upper_bound
)
4298 /* We need to make a save area. See what mode we can make it. */
4299 enum machine_mode save_mode
4300 = mode_for_size (arg
->size
.constant
* BITS_PER_UNIT
, MODE_INT
, 1);
4302 = gen_rtx_MEM (save_mode
,
4303 memory_address (save_mode
,
4304 XEXP (arg
->stack_slot
, 0)));
4306 if (save_mode
== BLKmode
)
4308 tree ot
= TREE_TYPE (arg
->tree_value
);
4309 tree nt
= build_qualified_type (ot
, (TYPE_QUALS (ot
)
4310 | TYPE_QUAL_CONST
));
4312 arg
->save_area
= assign_temp (nt
, 0, 1, 1);
4313 preserve_temp_slots (arg
->save_area
);
4314 emit_block_move (validize_mem (arg
->save_area
), stack_area
,
4315 expr_size (arg
->tree_value
),
4316 BLOCK_OP_CALL_PARM
);
4320 arg
->save_area
= gen_reg_rtx (save_mode
);
4321 emit_move_insn (arg
->save_area
, stack_area
);
4325 /* Now that we have saved any slots that will be overwritten by this
4326 store, mark all slots this store will use. We must do this before
4327 we actually expand the argument since the expansion itself may
4328 trigger library calls which might need to use the same stack slot. */
4329 if (argblock
&& ! variable_size
&& arg
->stack
)
4330 for (i
= lower_bound
; i
< upper_bound
; i
++)
4331 stack_usage_map
[i
] = 1;
4334 /* If this isn't going to be placed on both the stack and in registers,
4335 set up the register and number of words. */
4336 if (! arg
->pass_on_stack
)
4338 if (flags
& ECF_SIBCALL
)
4339 reg
= arg
->tail_call_reg
;
4342 partial
= arg
->partial
;
4345 if (reg
!= 0 && partial
== 0)
4346 /* Being passed entirely in a register. We shouldn't be called in
4350 /* If this arg needs special alignment, don't load the registers
4352 if (arg
->n_aligned_regs
!= 0)
4355 /* If this is being passed partially in a register, we can't evaluate
4356 it directly into its stack slot. Otherwise, we can. */
4357 if (arg
->value
== 0)
4359 /* stack_arg_under_construction is nonzero if a function argument is
4360 being evaluated directly into the outgoing argument list and
4361 expand_call must take special action to preserve the argument list
4362 if it is called recursively.
4364 For scalar function arguments stack_usage_map is sufficient to
4365 determine which stack slots must be saved and restored. Scalar
4366 arguments in general have pass_on_stack == 0.
4368 If this argument is initialized by a function which takes the
4369 address of the argument (a C++ constructor or a C function
4370 returning a BLKmode structure), then stack_usage_map is
4371 insufficient and expand_call must push the stack around the
4372 function call. Such arguments have pass_on_stack == 1.
4374 Note that it is always safe to set stack_arg_under_construction,
4375 but this generates suboptimal code if set when not needed. */
4377 if (arg
->pass_on_stack
)
4378 stack_arg_under_construction
++;
4380 arg
->value
= expand_expr (pval
,
4382 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
4383 ? NULL_RTX
: arg
->stack
,
4386 /* If we are promoting object (or for any other reason) the mode
4387 doesn't agree, convert the mode. */
4389 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
4390 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
4391 arg
->value
, arg
->unsignedp
);
4393 if (arg
->pass_on_stack
)
4394 stack_arg_under_construction
--;
4397 /* Don't allow anything left on stack from computation
4398 of argument to alloca. */
4399 if (flags
& ECF_MAY_BE_ALLOCA
)
4400 do_pending_stack_adjust ();
4402 if (arg
->value
== arg
->stack
)
4403 /* If the value is already in the stack slot, we are done. */
4405 else if (arg
->mode
!= BLKmode
)
4409 /* Argument is a scalar, not entirely passed in registers.
4410 (If part is passed in registers, arg->partial says how much
4411 and emit_push_insn will take care of putting it there.)
4413 Push it, and if its size is less than the
4414 amount of space allocated to it,
4415 also bump stack pointer by the additional space.
4416 Note that in C the default argument promotions
4417 will prevent such mismatches. */
4419 size
= GET_MODE_SIZE (arg
->mode
);
4420 /* Compute how much space the push instruction will push.
4421 On many machines, pushing a byte will advance the stack
4422 pointer by a halfword. */
4423 #ifdef PUSH_ROUNDING
4424 size
= PUSH_ROUNDING (size
);
4428 /* Compute how much space the argument should get:
4429 round up to a multiple of the alignment for arguments. */
4430 if (none
!= FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)))
4431 used
= (((size
+ PARM_BOUNDARY
/ BITS_PER_UNIT
- 1)
4432 / (PARM_BOUNDARY
/ BITS_PER_UNIT
))
4433 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
4435 /* This isn't already where we want it on the stack, so put it there.
4436 This can either be done with push or copy insns. */
4437 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), NULL_RTX
,
4438 PARM_BOUNDARY
, partial
, reg
, used
- size
, argblock
,
4439 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4440 ARGS_SIZE_RTX (arg
->alignment_pad
));
4442 /* Unless this is a partially-in-register argument, the argument is now
4445 arg
->value
= arg
->stack
;
4449 /* BLKmode, at least partly to be pushed. */
4451 unsigned int parm_align
;
4455 /* Pushing a nonscalar.
4456 If part is passed in registers, PARTIAL says how much
4457 and emit_push_insn will take care of putting it there. */
4459 /* Round its size up to a multiple
4460 of the allocation unit for arguments. */
4462 if (arg
->size
.var
!= 0)
4465 size_rtx
= ARGS_SIZE_RTX (arg
->size
);
4469 /* PUSH_ROUNDING has no effect on us, because
4470 emit_push_insn for BLKmode is careful to avoid it. */
4471 excess
= (arg
->size
.constant
- int_size_in_bytes (TREE_TYPE (pval
))
4472 + partial
* UNITS_PER_WORD
);
4473 size_rtx
= expand_expr (size_in_bytes (TREE_TYPE (pval
)),
4474 NULL_RTX
, TYPE_MODE (sizetype
), 0);
4477 /* Some types will require stricter alignment, which will be
4478 provided for elsewhere in argument layout. */
4479 parm_align
= MAX (PARM_BOUNDARY
, TYPE_ALIGN (TREE_TYPE (pval
)));
4481 /* When an argument is padded down, the block is aligned to
4482 PARM_BOUNDARY, but the actual argument isn't. */
4483 if (FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)) == downward
)
4486 parm_align
= BITS_PER_UNIT
;
4489 unsigned int excess_align
= (excess
& -excess
) * BITS_PER_UNIT
;
4490 parm_align
= MIN (parm_align
, excess_align
);
4494 if ((flags
& ECF_SIBCALL
) && GET_CODE (arg
->value
) == MEM
)
4496 /* emit_push_insn might not work properly if arg->value and
4497 argblock + arg->offset areas overlap. */
4501 if (XEXP (x
, 0) == current_function_internal_arg_pointer
4502 || (GET_CODE (XEXP (x
, 0)) == PLUS
4503 && XEXP (XEXP (x
, 0), 0) ==
4504 current_function_internal_arg_pointer
4505 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
))
4507 if (XEXP (x
, 0) != current_function_internal_arg_pointer
)
4508 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
4510 /* expand_call should ensure this */
4511 if (arg
->offset
.var
|| GET_CODE (size_rtx
) != CONST_INT
)
4514 if (arg
->offset
.constant
> i
)
4516 if (arg
->offset
.constant
< i
+ INTVAL (size_rtx
))
4517 sibcall_failure
= 1;
4519 else if (arg
->offset
.constant
< i
)
4521 if (i
< arg
->offset
.constant
+ INTVAL (size_rtx
))
4522 sibcall_failure
= 1;
4527 /* Special handling is required if part of the parameter lies in the
4528 register parameter area. The argument may be copied into the stack
4529 slot using memcpy(), but the original contents of the register
4530 parameter area will be restored after the memcpy() call.
4532 To ensure that the part that lies in the register parameter area
4533 is copied correctly, we emit a separate push for that part. This
4534 push should be small enough to avoid a call to memcpy(). */
4535 #ifndef STACK_PARMS_IN_REG_PARM_AREA
4536 if (arg
->reg
&& arg
->pass_on_stack
)
4541 if (arg
->offset
.constant
< reg_parm_stack_space
&& arg
->offset
.var
)
4542 error ("variable offset is passed partially in stack and in reg");
4543 else if (arg
->offset
.constant
< reg_parm_stack_space
&& arg
->size
.var
)
4544 error ("variable size is passed partially in stack and in reg");
4545 else if (arg
->offset
.constant
< reg_parm_stack_space
4546 && ((arg
->offset
.constant
+ arg
->size
.constant
)
4547 > reg_parm_stack_space
))
4549 rtx size_rtx1
= GEN_INT (reg_parm_stack_space
- arg
->offset
.constant
);
4550 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx1
,
4551 parm_align
, partial
, reg
, excess
, argblock
,
4552 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4553 ARGS_SIZE_RTX (arg
->alignment_pad
));
4558 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
4559 parm_align
, partial
, reg
, excess
, argblock
,
4560 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4561 ARGS_SIZE_RTX (arg
->alignment_pad
));
4563 /* Unless this is a partially-in-register argument, the argument is now
4566 ??? Unlike the case above, in which we want the actual
4567 address of the data, so that we can load it directly into a
4568 register, here we want the address of the stack slot, so that
4569 it's properly aligned for word-by-word copying or something
4570 like that. It's not clear that this is always correct. */
4572 arg
->value
= arg
->stack_slot
;
4575 /* Once we have pushed something, pops can't safely
4576 be deferred during the rest of the arguments. */
4579 /* ANSI doesn't require a sequence point here,
4580 but PCC has one, so this will avoid some problems. */
4583 /* Free any temporary slots made in processing this argument. Show
4584 that we might have taken the address of something and pushed that
4586 preserve_temp_slots (NULL_RTX
);
4590 return sibcall_failure
;
4594 /* Nonzero if we do not know how to pass TYPE solely in registers.
4595 We cannot do so in the following cases:
4597 - if the type has variable size
4598 - if the type is marked as addressable (it is required to be constructed
4600 - if the padding and mode of the type is such that a copy into a register
4601 would put it into the wrong part of the register.
4603 Which padding can't be supported depends on the byte endianness.
4605 A value in a register is implicitly padded at the most significant end.
4606 On a big-endian machine, that is the lower end in memory.
4607 So a value padded in memory at the upper end can't go in a register.
4608 For a little-endian machine, the reverse is true. */
4611 default_must_pass_in_stack (mode
, type
)
4612 enum machine_mode mode
;
4618 /* If the type has variable size... */
4619 if (TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
4622 /* If the type is marked as addressable (it is required
4623 to be constructed into the stack)... */
4624 if (TREE_ADDRESSABLE (type
))
4627 /* If the padding and mode of the type is such that a copy into
4628 a register would put it into the wrong part of the register. */
4630 && int_size_in_bytes (type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
4631 && (FUNCTION_ARG_PADDING (mode
, type
)
4632 == (BYTES_BIG_ENDIAN
? upward
: downward
)))