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"
42 /* Decide whether a function's arguments should be processed
43 from first to last or from last to first.
45 They should if the stack and args grow in opposite directions, but
46 only if we have push insns. */
50 #ifndef PUSH_ARGS_REVERSED
51 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
52 #define PUSH_ARGS_REVERSED PUSH_ARGS
58 #ifndef PUSH_ARGS_REVERSED
59 #define PUSH_ARGS_REVERSED 0
62 #ifndef STACK_POINTER_OFFSET
63 #define STACK_POINTER_OFFSET 0
66 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
67 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
69 /* Data structure and subroutines used within expand_call. */
73 /* Tree node for this argument. */
75 /* Mode for value; TYPE_MODE unless promoted. */
76 enum machine_mode mode
;
77 /* Current RTL value for argument, or 0 if it isn't precomputed. */
79 /* Initially-compute RTL value for argument; only for const functions. */
81 /* Register to pass this argument in, 0 if passed on stack, or an
82 PARALLEL if the arg is to be copied into multiple non-contiguous
85 /* Register to pass this argument in when generating tail call sequence.
86 This is not the same register as for normal calls on machines with
89 /* If REG was promoted from the actual mode of the argument expression,
90 indicates whether the promotion is sign- or zero-extended. */
92 /* Number of registers to use. 0 means put the whole arg in registers.
93 Also 0 if not passed in registers. */
95 /* Nonzero if argument must be passed on stack.
96 Note that some arguments may be passed on the stack
97 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
98 pass_on_stack identifies arguments that *cannot* go in registers. */
100 /* Offset of this argument from beginning of stack-args. */
101 struct args_size offset
;
102 /* Similar, but offset to the start of the stack slot. Different from
103 OFFSET if this arg pads downward. */
104 struct args_size slot_offset
;
105 /* Size of this argument on the stack, rounded up for any padding it gets,
106 parts of the argument passed in registers do not count.
107 If REG_PARM_STACK_SPACE is defined, then register parms
108 are counted here as well. */
109 struct args_size size
;
110 /* Location on the stack at which parameter should be stored. The store
111 has already been done if STACK == VALUE. */
113 /* Location on the stack of the start of this argument slot. This can
114 differ from STACK if this arg pads downward. This location is known
115 to be aligned to FUNCTION_ARG_BOUNDARY. */
117 /* Place that this stack area has been saved, if needed. */
119 /* If an argument's alignment does not permit direct copying into registers,
120 copy in smaller-sized pieces into pseudos. These are stored in a
121 block pointed to by this field. The next field says how many
122 word-sized pseudos we made. */
125 /* The amount that the stack pointer needs to be adjusted to
126 force alignment for the next argument. */
127 struct args_size alignment_pad
;
130 /* A vector of one char per byte of stack space. A byte if nonzero if
131 the corresponding stack location has been used.
132 This vector is used to prevent a function call within an argument from
133 clobbering any stack already set up. */
134 static char *stack_usage_map
;
136 /* Size of STACK_USAGE_MAP. */
137 static int highest_outgoing_arg_in_use
;
139 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
140 stack location's tail call argument has been already stored into the stack.
141 This bitmap is used to prevent sibling call optimization if function tries
142 to use parent's incoming argument slots when they have been already
143 overwritten with tail call arguments. */
144 static sbitmap stored_args_map
;
146 /* stack_arg_under_construction is nonzero when an argument may be
147 initialized with a constructor call (including a C function that
148 returns a BLKmode struct) and expand_call must take special action
149 to make sure the object being constructed does not overlap the
150 argument list for the constructor call. */
151 int stack_arg_under_construction
;
153 static int calls_function
PARAMS ((tree
, int));
154 static int calls_function_1
PARAMS ((tree
, int));
156 static void emit_call_1
PARAMS ((rtx
, tree
, tree
, HOST_WIDE_INT
,
157 HOST_WIDE_INT
, HOST_WIDE_INT
, rtx
,
160 static void precompute_register_parameters
PARAMS ((int,
163 static int store_one_arg
PARAMS ((struct arg_data
*, rtx
, int, int,
165 static void store_unaligned_arguments_into_pseudos
PARAMS ((struct arg_data
*,
167 static int finalize_must_preallocate
PARAMS ((int, int,
169 struct args_size
*));
170 static void precompute_arguments
PARAMS ((int, int,
172 static int compute_argument_block_size
PARAMS ((int,
175 static void initialize_argument_information
PARAMS ((int,
182 static void compute_argument_addresses
PARAMS ((struct arg_data
*,
184 static rtx rtx_for_function_call
PARAMS ((tree
, tree
));
185 static void load_register_parameters
PARAMS ((struct arg_data
*,
188 static rtx emit_library_call_value_1
PARAMS ((int, rtx
, rtx
,
192 static int special_function_p
PARAMS ((tree
, int));
193 static rtx try_to_integrate
PARAMS ((tree
, tree
, rtx
,
195 static int check_sibcall_argument_overlap_1
PARAMS ((rtx
));
196 static int check_sibcall_argument_overlap
PARAMS ((rtx
, struct arg_data
*,
199 static int combine_pending_stack_adjustment_and_call
200 PARAMS ((int, struct args_size
*, int));
201 static tree fix_unsafe_tree
PARAMS ((tree
));
203 #ifdef REG_PARM_STACK_SPACE
204 static rtx save_fixed_argument_area
PARAMS ((int, rtx
, int *, int *));
205 static void restore_fixed_argument_area
PARAMS ((rtx
, rtx
, int, int));
208 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
211 If WHICH is 0, return 1 if EXP contains a call to any function.
212 Actually, we only need return 1 if evaluating EXP would require pushing
213 arguments on the stack, but that is too difficult to compute, so we just
214 assume any function call might require the stack. */
216 static tree calls_function_save_exprs
;
219 calls_function (exp
, which
)
225 calls_function_save_exprs
= 0;
226 val
= calls_function_1 (exp
, which
);
227 calls_function_save_exprs
= 0;
231 /* Recursive function to do the work of above function. */
234 calls_function_1 (exp
, which
)
239 enum tree_code code
= TREE_CODE (exp
);
240 int class = TREE_CODE_CLASS (code
);
241 int length
= first_rtl_op (code
);
243 /* If this code is language-specific, we don't know what it will do. */
244 if ((int) code
>= NUM_TREE_CODES
)
252 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))
254 && (TYPE_RETURNS_STACK_DEPRESSED
255 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp
, 0))))))
257 else if (TREE_CODE (TREE_OPERAND (exp
, 0)) == ADDR_EXPR
258 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
260 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0),
262 & ECF_MAY_BE_ALLOCA
))
271 for (tem
= CONSTRUCTOR_ELTS (exp
); tem
!= 0; tem
= TREE_CHAIN (tem
))
272 if (calls_function_1 (TREE_VALUE (tem
), which
))
279 if (SAVE_EXPR_RTL (exp
) != 0)
281 if (value_member (exp
, calls_function_save_exprs
))
283 calls_function_save_exprs
= tree_cons (NULL_TREE
, exp
,
284 calls_function_save_exprs
);
285 return (TREE_OPERAND (exp
, 0) != 0
286 && calls_function_1 (TREE_OPERAND (exp
, 0), which
));
293 for (local
= BLOCK_VARS (exp
); local
; local
= TREE_CHAIN (local
))
294 if (DECL_INITIAL (local
) != 0
295 && calls_function_1 (DECL_INITIAL (local
), which
))
298 for (subblock
= BLOCK_SUBBLOCKS (exp
);
300 subblock
= TREE_CHAIN (subblock
))
301 if (calls_function_1 (subblock
, which
))
307 for (; exp
!= 0; exp
= TREE_CHAIN (exp
))
308 if (calls_function_1 (TREE_VALUE (exp
), which
))
316 /* Only expressions, references, and blocks can contain calls. */
317 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
320 for (i
= 0; i
< length
; i
++)
321 if (TREE_OPERAND (exp
, i
) != 0
322 && calls_function_1 (TREE_OPERAND (exp
, i
), which
))
328 /* Force FUNEXP into a form suitable for the address of a CALL,
329 and return that as an rtx. Also load the static chain register
330 if FNDECL is a nested function.
332 CALL_FUSAGE points to a variable holding the prospective
333 CALL_INSN_FUNCTION_USAGE information. */
336 prepare_call_address (funexp
, fndecl
, call_fusage
, reg_parm_seen
, sibcallp
)
343 rtx static_chain_value
= 0;
345 funexp
= protect_from_queue (funexp
, 0);
348 /* Get possible static chain value for nested function in C. */
349 static_chain_value
= lookup_static_chain (fndecl
);
351 /* Make a valid memory address and copy constants thru pseudo-regs,
352 but not for a constant address if -fno-function-cse. */
353 if (GET_CODE (funexp
) != SYMBOL_REF
)
354 /* If we are using registers for parameters, force the
355 function address into a register now. */
356 funexp
= ((SMALL_REGISTER_CLASSES
&& reg_parm_seen
)
357 ? force_not_mem (memory_address (FUNCTION_MODE
, funexp
))
358 : memory_address (FUNCTION_MODE
, funexp
));
361 #ifndef NO_FUNCTION_CSE
362 if (optimize
&& ! flag_no_function_cse
)
363 #ifdef NO_RECURSIVE_FUNCTION_CSE
364 if (fndecl
!= current_function_decl
)
366 funexp
= force_reg (Pmode
, funexp
);
370 if (static_chain_value
!= 0)
372 emit_move_insn (static_chain_rtx
, static_chain_value
);
374 if (GET_CODE (static_chain_rtx
) == REG
)
375 use_reg (call_fusage
, static_chain_rtx
);
381 /* Generate instructions to call function FUNEXP,
382 and optionally pop the results.
383 The CALL_INSN is the first insn generated.
385 FNDECL is the declaration node of the function. This is given to the
386 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
388 FUNTYPE is the data type of the function. This is given to the macro
389 RETURN_POPS_ARGS to determine whether this function pops its own args.
390 We used to allow an identifier for library functions, but that doesn't
391 work when the return type is an aggregate type and the calling convention
392 says that the pointer to this aggregate is to be popped by the callee.
394 STACK_SIZE is the number of bytes of arguments on the stack,
395 ROUNDED_STACK_SIZE is that number rounded up to
396 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
397 both to put into the call insn and to generate explicit popping
400 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
401 It is zero if this call doesn't want a structure value.
403 NEXT_ARG_REG is the rtx that results from executing
404 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
405 just after all the args have had their registers assigned.
406 This could be whatever you like, but normally it is the first
407 arg-register beyond those used for args in this call,
408 or 0 if all the arg-registers are used in this call.
409 It is passed on to `gen_call' so you can put this info in the call insn.
411 VALREG is a hard register in which a value is returned,
412 or 0 if the call does not return a value.
414 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
415 the args to this call were processed.
416 We restore `inhibit_defer_pop' to that value.
418 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
419 denote registers used by the called function. */
422 emit_call_1 (funexp
, fndecl
, funtype
, stack_size
, rounded_stack_size
,
423 struct_value_size
, next_arg_reg
, valreg
, old_inhibit_defer_pop
,
424 call_fusage
, ecf_flags
, args_so_far
)
426 tree fndecl ATTRIBUTE_UNUSED
;
427 tree funtype ATTRIBUTE_UNUSED
;
428 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED
;
429 HOST_WIDE_INT rounded_stack_size
;
430 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED
;
431 rtx next_arg_reg ATTRIBUTE_UNUSED
;
433 int old_inhibit_defer_pop
;
436 CUMULATIVE_ARGS
*args_so_far ATTRIBUTE_UNUSED
;
438 rtx rounded_stack_size_rtx
= GEN_INT (rounded_stack_size
);
440 int already_popped
= 0;
441 HOST_WIDE_INT n_popped
= RETURN_POPS_ARGS (fndecl
, funtype
, stack_size
);
442 #if defined (HAVE_call) && defined (HAVE_call_value)
443 rtx struct_value_size_rtx
;
444 struct_value_size_rtx
= GEN_INT (struct_value_size
);
447 #ifdef CALL_POPS_ARGS
448 n_popped
+= CALL_POPS_ARGS (* args_so_far
);
451 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
452 and we don't want to load it into a register as an optimization,
453 because prepare_call_address already did it if it should be done. */
454 if (GET_CODE (funexp
) != SYMBOL_REF
)
455 funexp
= memory_address (FUNCTION_MODE
, funexp
);
457 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
458 if ((ecf_flags
& ECF_SIBCALL
)
459 && HAVE_sibcall_pop
&& HAVE_sibcall_value_pop
460 && (n_popped
> 0 || stack_size
== 0))
462 rtx n_pop
= GEN_INT (n_popped
);
465 /* If this subroutine pops its own args, record that in the call insn
466 if possible, for the sake of frame pointer elimination. */
469 pat
= GEN_SIBCALL_VALUE_POP (valreg
,
470 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
471 rounded_stack_size_rtx
, next_arg_reg
,
474 pat
= GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
475 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
477 emit_call_insn (pat
);
483 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
484 /* If the target has "call" or "call_value" insns, then prefer them
485 if no arguments are actually popped. If the target does not have
486 "call" or "call_value" insns, then we must use the popping versions
487 even if the call has no arguments to pop. */
488 #if defined (HAVE_call) && defined (HAVE_call_value)
489 if (HAVE_call
&& HAVE_call_value
&& HAVE_call_pop
&& HAVE_call_value_pop
490 && n_popped
> 0 && ! (ecf_flags
& ECF_SP_DEPRESSED
))
492 if (HAVE_call_pop
&& HAVE_call_value_pop
)
495 rtx n_pop
= GEN_INT (n_popped
);
498 /* If this subroutine pops its own args, record that in the call insn
499 if possible, for the sake of frame pointer elimination. */
502 pat
= GEN_CALL_VALUE_POP (valreg
,
503 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
504 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
506 pat
= GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
507 rounded_stack_size_rtx
, next_arg_reg
, n_pop
);
509 emit_call_insn (pat
);
515 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
516 if ((ecf_flags
& ECF_SIBCALL
)
517 && HAVE_sibcall
&& HAVE_sibcall_value
)
520 emit_call_insn (GEN_SIBCALL_VALUE (valreg
,
521 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
522 rounded_stack_size_rtx
,
523 next_arg_reg
, NULL_RTX
));
525 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
526 rounded_stack_size_rtx
, next_arg_reg
,
527 struct_value_size_rtx
));
532 #if defined (HAVE_call) && defined (HAVE_call_value)
533 if (HAVE_call
&& HAVE_call_value
)
536 emit_call_insn (GEN_CALL_VALUE (valreg
,
537 gen_rtx_MEM (FUNCTION_MODE
, funexp
),
538 rounded_stack_size_rtx
, next_arg_reg
,
541 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE
, funexp
),
542 rounded_stack_size_rtx
, next_arg_reg
,
543 struct_value_size_rtx
));
549 /* Find the CALL insn we just emitted. */
550 for (call_insn
= get_last_insn ();
551 call_insn
&& GET_CODE (call_insn
) != CALL_INSN
;
552 call_insn
= PREV_INSN (call_insn
))
558 /* Mark memory as used for "pure" function call. */
559 if (ecf_flags
& ECF_PURE
)
563 gen_rtx_USE (VOIDmode
,
564 gen_rtx_MEM (BLKmode
, gen_rtx_SCRATCH (VOIDmode
))),
567 /* Put the register usage information on the CALL. If there is already
568 some usage information, put ours at the end. */
569 if (CALL_INSN_FUNCTION_USAGE (call_insn
))
573 for (link
= CALL_INSN_FUNCTION_USAGE (call_insn
); XEXP (link
, 1) != 0;
574 link
= XEXP (link
, 1))
577 XEXP (link
, 1) = call_fusage
;
580 CALL_INSN_FUNCTION_USAGE (call_insn
) = call_fusage
;
582 /* If this is a const call, then set the insn's unchanging bit. */
583 if (ecf_flags
& (ECF_CONST
| ECF_PURE
))
584 CONST_OR_PURE_CALL_P (call_insn
) = 1;
586 /* If this call can't throw, attach a REG_EH_REGION reg note to that
588 if (ecf_flags
& ECF_NOTHROW
)
589 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_EH_REGION
, const0_rtx
,
590 REG_NOTES (call_insn
));
592 if (ecf_flags
& ECF_NORETURN
)
593 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_NORETURN
, const0_rtx
,
594 REG_NOTES (call_insn
));
595 if (ecf_flags
& ECF_ALWAYS_RETURN
)
596 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN
, const0_rtx
,
597 REG_NOTES (call_insn
));
599 if (ecf_flags
& ECF_RETURNS_TWICE
)
601 REG_NOTES (call_insn
) = gen_rtx_EXPR_LIST (REG_SETJMP
, const0_rtx
,
602 REG_NOTES (call_insn
));
603 current_function_calls_setjmp
= 1;
606 SIBLING_CALL_P (call_insn
) = ((ecf_flags
& ECF_SIBCALL
) != 0);
608 /* Restore this now, so that we do defer pops for this call's args
609 if the context of the call as a whole permits. */
610 inhibit_defer_pop
= old_inhibit_defer_pop
;
615 CALL_INSN_FUNCTION_USAGE (call_insn
)
616 = gen_rtx_EXPR_LIST (VOIDmode
,
617 gen_rtx_CLOBBER (VOIDmode
, stack_pointer_rtx
),
618 CALL_INSN_FUNCTION_USAGE (call_insn
));
619 rounded_stack_size
-= n_popped
;
620 rounded_stack_size_rtx
= GEN_INT (rounded_stack_size
);
621 stack_pointer_delta
-= n_popped
;
624 if (!ACCUMULATE_OUTGOING_ARGS
)
626 /* If returning from the subroutine does not automatically pop the args,
627 we need an instruction to pop them sooner or later.
628 Perhaps do it now; perhaps just record how much space to pop later.
630 If returning from the subroutine does pop the args, indicate that the
631 stack pointer will be changed. */
633 if (rounded_stack_size
!= 0)
635 if (ecf_flags
& ECF_SP_DEPRESSED
)
636 /* Just pretend we did the pop. */
637 stack_pointer_delta
-= rounded_stack_size
;
638 else if (flag_defer_pop
&& inhibit_defer_pop
== 0
639 && ! (ecf_flags
& (ECF_CONST
| ECF_PURE
)))
640 pending_stack_adjust
+= rounded_stack_size
;
642 adjust_stack (rounded_stack_size_rtx
);
645 /* When we accumulate outgoing args, we must avoid any stack manipulations.
646 Restore the stack pointer to its original value now. Usually
647 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
648 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
649 popping variants of functions exist as well.
651 ??? We may optimize similar to defer_pop above, but it is
652 probably not worthwhile.
654 ??? It will be worthwhile to enable combine_stack_adjustments even for
657 anti_adjust_stack (GEN_INT (n_popped
));
660 /* Determine if the function identified by NAME and FNDECL is one with
661 special properties we wish to know about.
663 For example, if the function might return more than one time (setjmp), then
664 set RETURNS_TWICE to a nonzero value.
666 Similarly set LONGJMP for if the function is in the longjmp family.
668 Set MALLOC for any of the standard memory allocation functions which
669 allocate from the heap.
671 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
672 space from the stack such as alloca. */
675 special_function_p (fndecl
, flags
)
679 if (! (flags
& ECF_MALLOC
)
680 && fndecl
&& DECL_NAME (fndecl
)
681 && IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) <= 17
682 /* Exclude functions not at the file scope, or not `extern',
683 since they are not the magic functions we would otherwise
685 && DECL_CONTEXT (fndecl
) == NULL_TREE
&& TREE_PUBLIC (fndecl
))
687 const char *name
= IDENTIFIER_POINTER (DECL_NAME (fndecl
));
688 const char *tname
= name
;
690 /* We assume that alloca will always be called by name. It
691 makes no sense to pass it as a pointer-to-function to
692 anything that does not understand its behavior. */
693 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 6
695 && ! strcmp (name
, "alloca"))
696 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 16
698 && ! strcmp (name
, "__builtin_alloca"))))
699 flags
|= ECF_MAY_BE_ALLOCA
;
701 /* Disregard prefix _, __ or __x. */
704 if (name
[1] == '_' && name
[2] == 'x')
706 else if (name
[1] == '_')
715 && (! strcmp (tname
, "setjmp")
716 || ! strcmp (tname
, "setjmp_syscall")))
718 && ! strcmp (tname
, "sigsetjmp"))
720 && ! strcmp (tname
, "savectx")))
721 flags
|= ECF_RETURNS_TWICE
;
724 && ! strcmp (tname
, "siglongjmp"))
725 flags
|= ECF_LONGJMP
;
727 else if ((tname
[0] == 'q' && tname
[1] == 's'
728 && ! strcmp (tname
, "qsetjmp"))
729 || (tname
[0] == 'v' && tname
[1] == 'f'
730 && ! strcmp (tname
, "vfork")))
731 flags
|= ECF_RETURNS_TWICE
;
733 else if (tname
[0] == 'l' && tname
[1] == 'o'
734 && ! strcmp (tname
, "longjmp"))
735 flags
|= ECF_LONGJMP
;
737 else if ((tname
[0] == 'f' && tname
[1] == 'o'
738 && ! strcmp (tname
, "fork"))
739 /* Linux specific: __clone. check NAME to insist on the
740 leading underscores, to avoid polluting the ISO / POSIX
742 || (name
[0] == '_' && name
[1] == '_'
743 && ! strcmp (tname
, "clone"))
744 || (tname
[0] == 'e' && tname
[1] == 'x' && tname
[2] == 'e'
745 && tname
[3] == 'c' && (tname
[4] == 'l' || tname
[4] == 'v')
747 || ((tname
[5] == 'p' || tname
[5] == 'e')
748 && tname
[6] == '\0'))))
749 flags
|= ECF_FORK_OR_EXEC
;
751 /* Do not add any more malloc-like functions to this list,
752 instead mark them as malloc functions using the malloc attribute.
753 Note, realloc is not suitable for attribute malloc since
754 it may return the same address across multiple calls.
755 C++ operator new is not suitable because it is not required
756 to return a unique pointer; indeed, the standard placement new
757 just returns its argument. */
758 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl
))) == Pmode
759 && (! strcmp (tname
, "malloc")
760 || ! strcmp (tname
, "calloc")
761 || ! strcmp (tname
, "strdup")))
767 /* Return nonzero when tree represent call to longjmp. */
770 setjmp_call_p (fndecl
)
773 return special_function_p (fndecl
, 0) & ECF_RETURNS_TWICE
;
776 /* Return true when exp contains alloca call. */
781 if (TREE_CODE (exp
) == CALL_EXPR
782 && TREE_CODE (TREE_OPERAND (exp
, 0)) == ADDR_EXPR
783 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
785 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0),
786 0) & ECF_MAY_BE_ALLOCA
))
791 /* Detect flags (function attributes) from the function decl or type node. */
794 flags_from_decl_or_type (exp
)
802 struct cgraph_rtl_info
*i
= cgraph_rtl_info (exp
);
803 type
= TREE_TYPE (exp
);
807 if (i
->pure_function
)
808 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
809 if (i
->const_function
)
810 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
813 /* The function exp may have the `malloc' attribute. */
814 if (DECL_IS_MALLOC (exp
))
817 /* The function exp may have the `pure' attribute. */
818 if (DECL_IS_PURE (exp
))
819 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
821 if (TREE_NOTHROW (exp
))
822 flags
|= ECF_NOTHROW
;
825 if (TREE_READONLY (exp
) && ! TREE_THIS_VOLATILE (exp
))
826 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
828 if (TREE_THIS_VOLATILE (exp
))
829 flags
|= ECF_NORETURN
;
831 /* Mark if the function returns with the stack pointer depressed. We
832 cannot consider it pure or constant in that case. */
833 if (TREE_CODE (type
) == FUNCTION_TYPE
&& TYPE_RETURNS_STACK_DEPRESSED (type
))
835 flags
|= ECF_SP_DEPRESSED
;
836 flags
&= ~(ECF_PURE
| ECF_CONST
| ECF_LIBCALL_BLOCK
);
842 /* Precompute all register parameters as described by ARGS, storing values
843 into fields within the ARGS array.
845 NUM_ACTUALS indicates the total number elements in the ARGS array.
847 Set REG_PARM_SEEN if we encounter a register parameter. */
850 precompute_register_parameters (num_actuals
, args
, reg_parm_seen
)
852 struct arg_data
*args
;
859 for (i
= 0; i
< num_actuals
; i
++)
860 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
)
864 if (args
[i
].value
== 0)
867 args
[i
].value
= expand_expr (args
[i
].tree_value
, NULL_RTX
,
869 preserve_temp_slots (args
[i
].value
);
872 /* ANSI doesn't require a sequence point here,
873 but PCC has one, so this will avoid some problems. */
877 /* If the value is a non-legitimate constant, force it into a
878 pseudo now. TLS symbols sometimes need a call to resolve. */
879 if (CONSTANT_P (args
[i
].value
)
880 && !LEGITIMATE_CONSTANT_P (args
[i
].value
))
881 args
[i
].value
= force_reg (args
[i
].mode
, args
[i
].value
);
883 /* If we are to promote the function arg to a wider mode,
886 if (args
[i
].mode
!= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)))
888 = convert_modes (args
[i
].mode
,
889 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)),
890 args
[i
].value
, args
[i
].unsignedp
);
892 /* If the value is expensive, and we are inside an appropriately
893 short loop, put the value into a pseudo and then put the pseudo
896 For small register classes, also do this if this call uses
897 register parameters. This is to avoid reload conflicts while
898 loading the parameters registers. */
900 if ((! (GET_CODE (args
[i
].value
) == REG
901 || (GET_CODE (args
[i
].value
) == SUBREG
902 && GET_CODE (SUBREG_REG (args
[i
].value
)) == REG
)))
903 && args
[i
].mode
!= BLKmode
904 && rtx_cost (args
[i
].value
, SET
) > COSTS_N_INSNS (1)
905 && ((SMALL_REGISTER_CLASSES
&& *reg_parm_seen
)
906 || preserve_subexpressions_p ()))
907 args
[i
].value
= copy_to_mode_reg (args
[i
].mode
, args
[i
].value
);
911 #ifdef REG_PARM_STACK_SPACE
913 /* The argument list is the property of the called routine and it
914 may clobber it. If the fixed area has been used for previous
915 parameters, we must save and restore it. */
918 save_fixed_argument_area (reg_parm_stack_space
, argblock
,
919 low_to_save
, high_to_save
)
920 int reg_parm_stack_space
;
928 /* Compute the boundary of the area that needs to be saved, if any. */
929 high
= reg_parm_stack_space
;
930 #ifdef ARGS_GROW_DOWNWARD
933 if (high
> highest_outgoing_arg_in_use
)
934 high
= highest_outgoing_arg_in_use
;
936 for (low
= 0; low
< high
; low
++)
937 if (stack_usage_map
[low
] != 0)
940 enum machine_mode save_mode
;
945 while (stack_usage_map
[--high
] == 0)
949 *high_to_save
= high
;
951 num_to_save
= high
- low
+ 1;
952 save_mode
= mode_for_size (num_to_save
* BITS_PER_UNIT
, MODE_INT
, 1);
954 /* If we don't have the required alignment, must do this
956 if ((low
& (MIN (GET_MODE_SIZE (save_mode
),
957 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)))
960 #ifdef ARGS_GROW_DOWNWARD
965 stack_area
= gen_rtx_MEM (save_mode
,
966 memory_address (save_mode
,
967 plus_constant (argblock
,
970 set_mem_align (stack_area
, PARM_BOUNDARY
);
971 if (save_mode
== BLKmode
)
973 save_area
= assign_stack_temp (BLKmode
, num_to_save
, 0);
974 emit_block_move (validize_mem (save_area
), stack_area
,
975 GEN_INT (num_to_save
), BLOCK_OP_CALL_PARM
);
979 save_area
= gen_reg_rtx (save_mode
);
980 emit_move_insn (save_area
, stack_area
);
990 restore_fixed_argument_area (save_area
, argblock
, high_to_save
, low_to_save
)
996 enum machine_mode save_mode
= GET_MODE (save_area
);
1000 #ifdef ARGS_GROW_DOWNWARD
1001 delta
= -high_to_save
;
1003 delta
= low_to_save
;
1005 stack_area
= gen_rtx_MEM (save_mode
,
1006 memory_address (save_mode
,
1007 plus_constant (argblock
, delta
)));
1008 set_mem_align (stack_area
, PARM_BOUNDARY
);
1010 if (save_mode
!= BLKmode
)
1011 emit_move_insn (stack_area
, save_area
);
1013 emit_block_move (stack_area
, validize_mem (save_area
),
1014 GEN_INT (high_to_save
- low_to_save
+ 1),
1015 BLOCK_OP_CALL_PARM
);
1017 #endif /* REG_PARM_STACK_SPACE */
1019 /* If any elements in ARGS refer to parameters that are to be passed in
1020 registers, but not in memory, and whose alignment does not permit a
1021 direct copy into registers. Copy the values into a group of pseudos
1022 which we will later copy into the appropriate hard registers.
1024 Pseudos for each unaligned argument will be stored into the array
1025 args[argnum].aligned_regs. The caller is responsible for deallocating
1026 the aligned_regs array if it is nonzero. */
1029 store_unaligned_arguments_into_pseudos (args
, num_actuals
)
1030 struct arg_data
*args
;
1035 for (i
= 0; i
< num_actuals
; i
++)
1036 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
1037 && args
[i
].mode
== BLKmode
1038 && (TYPE_ALIGN (TREE_TYPE (args
[i
].tree_value
))
1039 < (unsigned int) MIN (BIGGEST_ALIGNMENT
, BITS_PER_WORD
)))
1041 int bytes
= int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1042 int big_endian_correction
= 0;
1044 args
[i
].n_aligned_regs
1045 = args
[i
].partial
? args
[i
].partial
1046 : (bytes
+ (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
;
1048 args
[i
].aligned_regs
= (rtx
*) xmalloc (sizeof (rtx
)
1049 * args
[i
].n_aligned_regs
);
1051 /* Structures smaller than a word are aligned to the least
1052 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
1053 this means we must skip the empty high order bytes when
1054 calculating the bit offset. */
1055 if (BYTES_BIG_ENDIAN
1056 && bytes
< UNITS_PER_WORD
)
1057 big_endian_correction
= (BITS_PER_WORD
- (bytes
* BITS_PER_UNIT
));
1059 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1061 rtx reg
= gen_reg_rtx (word_mode
);
1062 rtx word
= operand_subword_force (args
[i
].value
, j
, BLKmode
);
1063 int bitsize
= MIN (bytes
* BITS_PER_UNIT
, BITS_PER_WORD
);
1065 args
[i
].aligned_regs
[j
] = reg
;
1067 /* There is no need to restrict this code to loading items
1068 in TYPE_ALIGN sized hunks. The bitfield instructions can
1069 load up entire word sized registers efficiently.
1071 ??? This may not be needed anymore.
1072 We use to emit a clobber here but that doesn't let later
1073 passes optimize the instructions we emit. By storing 0 into
1074 the register later passes know the first AND to zero out the
1075 bitfield being set in the register is unnecessary. The store
1076 of 0 will be deleted as will at least the first AND. */
1078 emit_move_insn (reg
, const0_rtx
);
1080 bytes
-= bitsize
/ BITS_PER_UNIT
;
1081 store_bit_field (reg
, bitsize
, big_endian_correction
, word_mode
,
1082 extract_bit_field (word
, bitsize
, 0, 1, NULL_RTX
,
1083 word_mode
, word_mode
,
1090 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1093 NUM_ACTUALS is the total number of parameters.
1095 N_NAMED_ARGS is the total number of named arguments.
1097 FNDECL is the tree code for the target of this call (if known)
1099 ARGS_SO_FAR holds state needed by the target to know where to place
1102 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1103 for arguments which are passed in registers.
1105 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1106 and may be modified by this routine.
1108 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1109 flags which may may be modified by this routine. */
1112 initialize_argument_information (num_actuals
, args
, args_size
, n_named_args
,
1113 actparms
, fndecl
, args_so_far
,
1114 reg_parm_stack_space
, old_stack_level
,
1115 old_pending_adj
, must_preallocate
,
1117 int num_actuals ATTRIBUTE_UNUSED
;
1118 struct arg_data
*args
;
1119 struct args_size
*args_size
;
1120 int n_named_args ATTRIBUTE_UNUSED
;
1123 CUMULATIVE_ARGS
*args_so_far
;
1124 int reg_parm_stack_space
;
1125 rtx
*old_stack_level
;
1126 int *old_pending_adj
;
1127 int *must_preallocate
;
1130 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1133 /* Count arg position in order args appear. */
1136 struct args_size alignment_pad
;
1140 args_size
->constant
= 0;
1143 /* In this loop, we consider args in the order they are written.
1144 We fill up ARGS from the front or from the back if necessary
1145 so that in any case the first arg to be pushed ends up at the front. */
1147 if (PUSH_ARGS_REVERSED
)
1149 i
= num_actuals
- 1, inc
= -1;
1150 /* In this case, must reverse order of args
1151 so that we compute and push the last arg first. */
1158 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1159 for (p
= actparms
, argpos
= 0; p
; p
= TREE_CHAIN (p
), i
+= inc
, argpos
++)
1161 tree type
= TREE_TYPE (TREE_VALUE (p
));
1163 enum machine_mode mode
;
1165 args
[i
].tree_value
= TREE_VALUE (p
);
1167 /* Replace erroneous argument with constant zero. */
1168 if (type
== error_mark_node
|| !COMPLETE_TYPE_P (type
))
1169 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
1171 /* If TYPE is a transparent union, pass things the way we would
1172 pass the first field of the union. We have already verified that
1173 the modes are the same. */
1174 if (TREE_CODE (type
) == UNION_TYPE
&& TYPE_TRANSPARENT_UNION (type
))
1175 type
= TREE_TYPE (TYPE_FIELDS (type
));
1177 /* Decide where to pass this arg.
1179 args[i].reg is nonzero if all or part is passed in registers.
1181 args[i].partial is nonzero if part but not all is passed in registers,
1182 and the exact value says how many words are passed in registers.
1184 args[i].pass_on_stack is nonzero if the argument must at least be
1185 computed on the stack. It may then be loaded back into registers
1186 if args[i].reg is nonzero.
1188 These decisions are driven by the FUNCTION_... macros and must agree
1189 with those made by function.c. */
1191 /* See if this argument should be passed by invisible reference. */
1192 if ((TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1193 && contains_placeholder_p (TYPE_SIZE (type
)))
1194 || TREE_ADDRESSABLE (type
)
1195 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1196 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far
, TYPE_MODE (type
),
1197 type
, argpos
< n_named_args
)
1201 /* If we're compiling a thunk, pass through invisible
1202 references instead of making a copy. */
1203 if (current_function_is_thunk
1204 #ifdef FUNCTION_ARG_CALLEE_COPIES
1205 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far
, TYPE_MODE (type
),
1206 type
, argpos
< n_named_args
)
1207 /* If it's in a register, we must make a copy of it too. */
1208 /* ??? Is this a sufficient test? Is there a better one? */
1209 && !(TREE_CODE (args
[i
].tree_value
) == VAR_DECL
1210 && REG_P (DECL_RTL (args
[i
].tree_value
)))
1211 && ! TREE_ADDRESSABLE (type
))
1215 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1216 new object from the argument. If we are passing by
1217 invisible reference, the callee will do that for us, so we
1218 can strip off the TARGET_EXPR. This is not always safe,
1219 but it is safe in the only case where this is a useful
1220 optimization; namely, when the argument is a plain object.
1221 In that case, the frontend is just asking the backend to
1222 make a bitwise copy of the argument. */
1224 if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1225 && (DECL_P (TREE_OPERAND (args
[i
].tree_value
, 1)))
1226 && ! REG_P (DECL_RTL (TREE_OPERAND (args
[i
].tree_value
, 1))))
1227 args
[i
].tree_value
= TREE_OPERAND (args
[i
].tree_value
, 1);
1229 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1230 build_pointer_type (type
),
1231 args
[i
].tree_value
);
1232 type
= build_pointer_type (type
);
1234 else if (TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
)
1236 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1237 We implement this by passing the address of the temporary
1238 rather than expanding it into another allocated slot. */
1239 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1240 build_pointer_type (type
),
1241 args
[i
].tree_value
);
1242 type
= build_pointer_type (type
);
1246 /* We make a copy of the object and pass the address to the
1247 function being called. */
1250 if (!COMPLETE_TYPE_P (type
)
1251 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
1252 || (flag_stack_check
&& ! STACK_CHECK_BUILTIN
1253 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type
),
1254 STACK_CHECK_MAX_VAR_SIZE
))))
1256 /* This is a variable-sized object. Make space on the stack
1258 rtx size_rtx
= expr_size (TREE_VALUE (p
));
1260 if (*old_stack_level
== 0)
1262 emit_stack_save (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1263 *old_pending_adj
= pending_stack_adjust
;
1264 pending_stack_adjust
= 0;
1267 copy
= gen_rtx_MEM (BLKmode
,
1268 allocate_dynamic_stack_space
1269 (size_rtx
, NULL_RTX
, TYPE_ALIGN (type
)));
1270 set_mem_attributes (copy
, type
, 1);
1273 copy
= assign_temp (type
, 0, 1, 0);
1275 store_expr (args
[i
].tree_value
, copy
, 0);
1276 *ecf_flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
1278 args
[i
].tree_value
= build1 (ADDR_EXPR
,
1279 build_pointer_type (type
),
1280 make_tree (type
, copy
));
1281 type
= build_pointer_type (type
);
1285 mode
= TYPE_MODE (type
);
1286 unsignedp
= TREE_UNSIGNED (type
);
1288 #ifdef PROMOTE_FUNCTION_ARGS
1289 mode
= promote_mode (type
, mode
, &unsignedp
, 1);
1292 args
[i
].unsignedp
= unsignedp
;
1293 args
[i
].mode
= mode
;
1295 args
[i
].reg
= FUNCTION_ARG (*args_so_far
, mode
, type
,
1296 argpos
< n_named_args
);
1297 #ifdef FUNCTION_INCOMING_ARG
1298 /* If this is a sibling call and the machine has register windows, the
1299 register window has to be unwinded before calling the routine, so
1300 arguments have to go into the incoming registers. */
1301 args
[i
].tail_call_reg
= FUNCTION_INCOMING_ARG (*args_so_far
, mode
, type
,
1302 argpos
< n_named_args
);
1304 args
[i
].tail_call_reg
= args
[i
].reg
;
1307 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1310 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far
, mode
, type
,
1311 argpos
< n_named_args
);
1314 args
[i
].pass_on_stack
= MUST_PASS_IN_STACK (mode
, type
);
1316 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1317 it means that we are to pass this arg in the register(s) designated
1318 by the PARALLEL, but also to pass it in the stack. */
1319 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == PARALLEL
1320 && XEXP (XVECEXP (args
[i
].reg
, 0, 0), 0) == 0)
1321 args
[i
].pass_on_stack
= 1;
1323 /* If this is an addressable type, we must preallocate the stack
1324 since we must evaluate the object into its final location.
1326 If this is to be passed in both registers and the stack, it is simpler
1328 if (TREE_ADDRESSABLE (type
)
1329 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
1330 *must_preallocate
= 1;
1332 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1333 we cannot consider this function call constant. */
1334 if (TREE_ADDRESSABLE (type
))
1335 *ecf_flags
&= ~ECF_LIBCALL_BLOCK
;
1337 /* Compute the stack-size of this argument. */
1338 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
1339 || reg_parm_stack_space
> 0
1340 || args
[i
].pass_on_stack
)
1341 locate_and_pad_parm (mode
, type
,
1342 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1347 fndecl
, args_size
, &args
[i
].offset
,
1348 &args
[i
].size
, &alignment_pad
);
1350 #ifndef ARGS_GROW_DOWNWARD
1351 args
[i
].slot_offset
= *args_size
;
1354 args
[i
].alignment_pad
= alignment_pad
;
1356 /* If a part of the arg was put into registers,
1357 don't include that part in the amount pushed. */
1358 if (reg_parm_stack_space
== 0 && ! args
[i
].pass_on_stack
)
1359 args
[i
].size
.constant
-= ((args
[i
].partial
* UNITS_PER_WORD
)
1360 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
1361 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
1363 /* Update ARGS_SIZE, the total stack space for args so far. */
1365 args_size
->constant
+= args
[i
].size
.constant
;
1366 if (args
[i
].size
.var
)
1368 ADD_PARM_SIZE (*args_size
, args
[i
].size
.var
);
1371 /* Since the slot offset points to the bottom of the slot,
1372 we must record it after incrementing if the args grow down. */
1373 #ifdef ARGS_GROW_DOWNWARD
1374 args
[i
].slot_offset
= *args_size
;
1376 args
[i
].slot_offset
.constant
= -args_size
->constant
;
1378 SUB_PARM_SIZE (args
[i
].slot_offset
, args_size
->var
);
1381 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1382 have been used, etc. */
1384 FUNCTION_ARG_ADVANCE (*args_so_far
, TYPE_MODE (type
), type
,
1385 argpos
< n_named_args
);
1389 /* Update ARGS_SIZE to contain the total size for the argument block.
1390 Return the original constant component of the argument block's size.
1392 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1393 for arguments passed in registers. */
1396 compute_argument_block_size (reg_parm_stack_space
, args_size
,
1397 preferred_stack_boundary
)
1398 int reg_parm_stack_space
;
1399 struct args_size
*args_size
;
1400 int preferred_stack_boundary ATTRIBUTE_UNUSED
;
1402 int unadjusted_args_size
= args_size
->constant
;
1404 /* For accumulate outgoing args mode we don't need to align, since the frame
1405 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1406 backends from generating misaligned frame sizes. */
1407 if (ACCUMULATE_OUTGOING_ARGS
&& preferred_stack_boundary
> STACK_BOUNDARY
)
1408 preferred_stack_boundary
= STACK_BOUNDARY
;
1410 /* Compute the actual size of the argument block required. The variable
1411 and constant sizes must be combined, the size may have to be rounded,
1412 and there may be a minimum required size. */
1416 args_size
->var
= ARGS_SIZE_TREE (*args_size
);
1417 args_size
->constant
= 0;
1419 preferred_stack_boundary
/= BITS_PER_UNIT
;
1420 if (preferred_stack_boundary
> 1)
1422 /* We don't handle this case yet. To handle it correctly we have
1423 to add the delta, round and subtract the delta.
1424 Currently no machine description requires this support. */
1425 if (stack_pointer_delta
& (preferred_stack_boundary
- 1))
1427 args_size
->var
= round_up (args_size
->var
, preferred_stack_boundary
);
1430 if (reg_parm_stack_space
> 0)
1433 = size_binop (MAX_EXPR
, args_size
->var
,
1434 ssize_int (reg_parm_stack_space
));
1436 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1437 /* The area corresponding to register parameters is not to count in
1438 the size of the block we need. So make the adjustment. */
1440 = size_binop (MINUS_EXPR
, args_size
->var
,
1441 ssize_int (reg_parm_stack_space
));
1447 preferred_stack_boundary
/= BITS_PER_UNIT
;
1448 if (preferred_stack_boundary
< 1)
1449 preferred_stack_boundary
= 1;
1450 args_size
->constant
= (((args_size
->constant
1451 + stack_pointer_delta
1452 + preferred_stack_boundary
- 1)
1453 / preferred_stack_boundary
1454 * preferred_stack_boundary
)
1455 - stack_pointer_delta
);
1457 args_size
->constant
= MAX (args_size
->constant
,
1458 reg_parm_stack_space
);
1460 #ifdef MAYBE_REG_PARM_STACK_SPACE
1461 if (reg_parm_stack_space
== 0)
1462 args_size
->constant
= 0;
1465 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1466 args_size
->constant
-= reg_parm_stack_space
;
1469 return unadjusted_args_size
;
1472 /* Precompute parameters as needed for a function call.
1474 FLAGS is mask of ECF_* constants.
1476 NUM_ACTUALS is the number of arguments.
1478 ARGS is an array containing information for each argument; this
1479 routine fills in the INITIAL_VALUE and VALUE fields for each
1480 precomputed argument. */
1483 precompute_arguments (flags
, num_actuals
, args
)
1486 struct arg_data
*args
;
1490 /* If this function call is cse'able, precompute all the parameters.
1491 Note that if the parameter is constructed into a temporary, this will
1492 cause an additional copy because the parameter will be constructed
1493 into a temporary location and then copied into the outgoing arguments.
1494 If a parameter contains a call to alloca and this function uses the
1495 stack, precompute the parameter. */
1497 /* If we preallocated the stack space, and some arguments must be passed
1498 on the stack, then we must precompute any parameter which contains a
1499 function call which will store arguments on the stack.
1500 Otherwise, evaluating the parameter may clobber previous parameters
1501 which have already been stored into the stack. (we have code to avoid
1502 such case by saving the outgoing stack arguments, but it results in
1505 for (i
= 0; i
< num_actuals
; i
++)
1506 if ((flags
& ECF_LIBCALL_BLOCK
)
1507 || calls_function (args
[i
].tree_value
, !ACCUMULATE_OUTGOING_ARGS
))
1509 enum machine_mode mode
;
1511 /* If this is an addressable type, we cannot pre-evaluate it. */
1512 if (TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
)))
1516 = expand_expr (args
[i
].tree_value
, NULL_RTX
, VOIDmode
, 0);
1518 /* ANSI doesn't require a sequence point here,
1519 but PCC has one, so this will avoid some problems. */
1522 args
[i
].initial_value
= args
[i
].value
1523 = protect_from_queue (args
[i
].value
, 0);
1525 mode
= TYPE_MODE (TREE_TYPE (args
[i
].tree_value
));
1526 if (mode
!= args
[i
].mode
)
1529 = convert_modes (args
[i
].mode
, mode
,
1530 args
[i
].value
, args
[i
].unsignedp
);
1531 #ifdef PROMOTE_FOR_CALL_ONLY
1532 /* CSE will replace this only if it contains args[i].value
1533 pseudo, so convert it down to the declared mode using
1535 if (GET_CODE (args
[i
].value
) == REG
1536 && GET_MODE_CLASS (args
[i
].mode
) == MODE_INT
)
1538 args
[i
].initial_value
1539 = gen_lowpart_SUBREG (mode
, args
[i
].value
);
1540 SUBREG_PROMOTED_VAR_P (args
[i
].initial_value
) = 1;
1541 SUBREG_PROMOTED_UNSIGNED_SET (args
[i
].initial_value
,
1549 /* Given the current state of MUST_PREALLOCATE and information about
1550 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1551 compute and return the final value for MUST_PREALLOCATE. */
1554 finalize_must_preallocate (must_preallocate
, num_actuals
, args
, args_size
)
1555 int must_preallocate
;
1557 struct arg_data
*args
;
1558 struct args_size
*args_size
;
1560 /* See if we have or want to preallocate stack space.
1562 If we would have to push a partially-in-regs parm
1563 before other stack parms, preallocate stack space instead.
1565 If the size of some parm is not a multiple of the required stack
1566 alignment, we must preallocate.
1568 If the total size of arguments that would otherwise create a copy in
1569 a temporary (such as a CALL) is more than half the total argument list
1570 size, preallocation is faster.
1572 Another reason to preallocate is if we have a machine (like the m88k)
1573 where stack alignment is required to be maintained between every
1574 pair of insns, not just when the call is made. However, we assume here
1575 that such machines either do not have push insns (and hence preallocation
1576 would occur anyway) or the problem is taken care of with
1579 if (! must_preallocate
)
1581 int partial_seen
= 0;
1582 int copy_to_evaluate_size
= 0;
1585 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
1587 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
1589 else if (partial_seen
&& args
[i
].reg
== 0)
1590 must_preallocate
= 1;
1592 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1593 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
1594 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1595 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
1596 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
1597 copy_to_evaluate_size
1598 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1601 if (copy_to_evaluate_size
* 2 >= args_size
->constant
1602 && args_size
->constant
> 0)
1603 must_preallocate
= 1;
1605 return must_preallocate
;
1608 /* If we preallocated stack space, compute the address of each argument
1609 and store it into the ARGS array.
1611 We need not ensure it is a valid memory address here; it will be
1612 validized when it is used.
1614 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1617 compute_argument_addresses (args
, argblock
, num_actuals
)
1618 struct arg_data
*args
;
1624 rtx arg_reg
= argblock
;
1625 int i
, arg_offset
= 0;
1627 if (GET_CODE (argblock
) == PLUS
)
1628 arg_reg
= XEXP (argblock
, 0), arg_offset
= INTVAL (XEXP (argblock
, 1));
1630 for (i
= 0; i
< num_actuals
; i
++)
1632 rtx offset
= ARGS_SIZE_RTX (args
[i
].offset
);
1633 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].slot_offset
);
1636 /* Skip this parm if it will not be passed on the stack. */
1637 if (! args
[i
].pass_on_stack
&& args
[i
].reg
!= 0)
1640 if (GET_CODE (offset
) == CONST_INT
)
1641 addr
= plus_constant (arg_reg
, INTVAL (offset
));
1643 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, offset
);
1645 addr
= plus_constant (addr
, arg_offset
);
1646 args
[i
].stack
= gen_rtx_MEM (args
[i
].mode
, addr
);
1647 set_mem_align (args
[i
].stack
, PARM_BOUNDARY
);
1648 set_mem_attributes (args
[i
].stack
,
1649 TREE_TYPE (args
[i
].tree_value
), 1);
1651 if (GET_CODE (slot_offset
) == CONST_INT
)
1652 addr
= plus_constant (arg_reg
, INTVAL (slot_offset
));
1654 addr
= gen_rtx_PLUS (Pmode
, arg_reg
, slot_offset
);
1656 addr
= plus_constant (addr
, arg_offset
);
1657 args
[i
].stack_slot
= gen_rtx_MEM (args
[i
].mode
, addr
);
1658 set_mem_align (args
[i
].stack_slot
, PARM_BOUNDARY
);
1659 set_mem_attributes (args
[i
].stack_slot
,
1660 TREE_TYPE (args
[i
].tree_value
), 1);
1662 /* Function incoming arguments may overlap with sibling call
1663 outgoing arguments and we cannot allow reordering of reads
1664 from function arguments with stores to outgoing arguments
1665 of sibling calls. */
1666 set_mem_alias_set (args
[i
].stack
, 0);
1667 set_mem_alias_set (args
[i
].stack_slot
, 0);
1672 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1673 in a call instruction.
1675 FNDECL is the tree node for the target function. For an indirect call
1676 FNDECL will be NULL_TREE.
1678 ADDR is the operand 0 of CALL_EXPR for this call. */
1681 rtx_for_function_call (fndecl
, addr
)
1687 /* Get the function to call, in the form of RTL. */
1690 /* If this is the first use of the function, see if we need to
1691 make an external definition for it. */
1692 if (! TREE_USED (fndecl
))
1694 assemble_external (fndecl
);
1695 TREE_USED (fndecl
) = 1;
1698 /* Get a SYMBOL_REF rtx for the function address. */
1699 funexp
= XEXP (DECL_RTL (fndecl
), 0);
1702 /* Generate an rtx (probably a pseudo-register) for the address. */
1705 funexp
= expand_expr (addr
, NULL_RTX
, VOIDmode
, 0);
1706 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1712 /* Do the register loads required for any wholly-register parms or any
1713 parms which are passed both on the stack and in a register. Their
1714 expressions were already evaluated.
1716 Mark all register-parms as living through the call, putting these USE
1717 insns in the CALL_INSN_FUNCTION_USAGE field.
1719 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1720 checking, setting *SIBCALL_FAILURE if appropriate. */
1723 load_register_parameters (args
, num_actuals
, call_fusage
, flags
,
1724 is_sibcall
, sibcall_failure
)
1725 struct arg_data
*args
;
1730 int *sibcall_failure
;
1734 #ifdef LOAD_ARGS_REVERSED
1735 for (i
= num_actuals
- 1; i
>= 0; i
--)
1737 for (i
= 0; i
< num_actuals
; i
++)
1740 rtx reg
= ((flags
& ECF_SIBCALL
)
1741 ? args
[i
].tail_call_reg
: args
[i
].reg
);
1742 int partial
= args
[i
].partial
;
1747 rtx before_arg
= get_last_insn ();
1748 /* Set to non-negative if must move a word at a time, even if just
1749 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1750 we just use a normal move insn. This value can be zero if the
1751 argument is a zero size structure with no fields. */
1752 nregs
= (partial
? partial
1753 : (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1754 ? ((int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
))
1755 + (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
)
1758 /* Handle calls that pass values in multiple non-contiguous
1759 locations. The Irix 6 ABI has examples of this. */
1761 if (GET_CODE (reg
) == PARALLEL
)
1762 emit_group_load (reg
, args
[i
].value
,
1763 int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
)));
1765 /* If simple case, just do move. If normal partial, store_one_arg
1766 has already loaded the register for us. In all other cases,
1767 load the register(s) from memory. */
1769 else if (nregs
== -1)
1770 emit_move_insn (reg
, args
[i
].value
);
1772 /* If we have pre-computed the values to put in the registers in
1773 the case of non-aligned structures, copy them in now. */
1775 else if (args
[i
].n_aligned_regs
!= 0)
1776 for (j
= 0; j
< args
[i
].n_aligned_regs
; j
++)
1777 emit_move_insn (gen_rtx_REG (word_mode
, REGNO (reg
) + j
),
1778 args
[i
].aligned_regs
[j
]);
1780 else if (partial
== 0 || args
[i
].pass_on_stack
)
1781 move_block_to_reg (REGNO (reg
),
1782 validize_mem (args
[i
].value
), nregs
,
1785 /* When a parameter is a block, and perhaps in other cases, it is
1786 possible that it did a load from an argument slot that was
1787 already clobbered. */
1789 && check_sibcall_argument_overlap (before_arg
, &args
[i
], 0))
1790 *sibcall_failure
= 1;
1792 /* Handle calls that pass values in multiple non-contiguous
1793 locations. The Irix 6 ABI has examples of this. */
1794 if (GET_CODE (reg
) == PARALLEL
)
1795 use_group_regs (call_fusage
, reg
);
1796 else if (nregs
== -1)
1797 use_reg (call_fusage
, reg
);
1799 use_regs (call_fusage
, REGNO (reg
), nregs
== 0 ? 1 : nregs
);
1804 /* Try to integrate function. See expand_inline_function for documentation
1805 about the parameters. */
1808 try_to_integrate (fndecl
, actparms
, target
, ignore
, type
, structure_value_addr
)
1814 rtx structure_value_addr
;
1819 rtx old_stack_level
= 0;
1820 int reg_parm_stack_space
= 0;
1822 #ifdef REG_PARM_STACK_SPACE
1823 #ifdef MAYBE_REG_PARM_STACK_SPACE
1824 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
1826 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
1830 before_call
= get_last_insn ();
1832 timevar_push (TV_INTEGRATION
);
1834 temp
= expand_inline_function (fndecl
, actparms
, target
,
1836 structure_value_addr
);
1838 timevar_pop (TV_INTEGRATION
);
1840 /* If inlining succeeded, return. */
1841 if (temp
!= (rtx
) (size_t) - 1)
1843 if (ACCUMULATE_OUTGOING_ARGS
)
1845 /* If the outgoing argument list must be preserved, push
1846 the stack before executing the inlined function if it
1849 i
= reg_parm_stack_space
;
1850 if (i
> highest_outgoing_arg_in_use
)
1851 i
= highest_outgoing_arg_in_use
;
1852 while (--i
>= 0 && stack_usage_map
[i
] == 0)
1855 if (stack_arg_under_construction
|| i
>= 0)
1858 = before_call
? NEXT_INSN (before_call
) : get_insns ();
1859 rtx insn
= NULL_RTX
, seq
;
1861 /* Look for a call in the inline function code.
1862 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1863 nonzero then there is a call and it is not necessary
1864 to scan the insns. */
1866 if (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
== 0)
1867 for (insn
= first_insn
; insn
; insn
= NEXT_INSN (insn
))
1868 if (GET_CODE (insn
) == CALL_INSN
)
1873 /* Reserve enough stack space so that the largest
1874 argument list of any function call in the inline
1875 function does not overlap the argument list being
1876 evaluated. This is usually an overestimate because
1877 allocate_dynamic_stack_space reserves space for an
1878 outgoing argument list in addition to the requested
1879 space, but there is no way to ask for stack space such
1880 that an argument list of a certain length can be
1883 Add the stack space reserved for register arguments, if
1884 any, in the inline function. What is really needed is the
1885 largest value of reg_parm_stack_space in the inline
1886 function, but that is not available. Using the current
1887 value of reg_parm_stack_space is wrong, but gives
1888 correct results on all supported machines. */
1890 int adjust
= (DECL_SAVED_INSNS (fndecl
)->outgoing_args_size
1891 + reg_parm_stack_space
);
1894 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
1895 allocate_dynamic_stack_space (GEN_INT (adjust
),
1896 NULL_RTX
, BITS_PER_UNIT
);
1899 emit_insn_before (seq
, first_insn
);
1900 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1905 /* If the result is equivalent to TARGET, return TARGET to simplify
1906 checks in store_expr. They can be equivalent but not equal in the
1907 case of a function that returns BLKmode. */
1908 if (temp
!= target
&& rtx_equal_p (temp
, target
))
1913 /* If inlining failed, mark FNDECL as needing to be compiled
1914 separately after all. If function was declared inline,
1916 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
1917 && optimize
> 0 && !TREE_ADDRESSABLE (fndecl
))
1919 warning_with_decl (fndecl
, "inlining failed in call to `%s'");
1920 warning ("called from here");
1922 (*lang_hooks
.mark_addressable
) (fndecl
);
1923 return (rtx
) (size_t) - 1;
1926 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1927 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1928 bytes, then we would need to push some additional bytes to pad the
1929 arguments. So, we compute an adjust to the stack pointer for an
1930 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1931 bytes. Then, when the arguments are pushed the stack will be perfectly
1932 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1933 be popped after the call. Returns the adjustment. */
1936 combine_pending_stack_adjustment_and_call (unadjusted_args_size
,
1938 preferred_unit_stack_boundary
)
1939 int unadjusted_args_size
;
1940 struct args_size
*args_size
;
1941 int preferred_unit_stack_boundary
;
1943 /* The number of bytes to pop so that the stack will be
1944 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1945 HOST_WIDE_INT adjustment
;
1946 /* The alignment of the stack after the arguments are pushed, if we
1947 just pushed the arguments without adjust the stack here. */
1948 HOST_WIDE_INT unadjusted_alignment
;
1950 unadjusted_alignment
1951 = ((stack_pointer_delta
+ unadjusted_args_size
)
1952 % preferred_unit_stack_boundary
);
1954 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1955 as possible -- leaving just enough left to cancel out the
1956 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1957 PENDING_STACK_ADJUST is non-negative, and congruent to
1958 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1960 /* Begin by trying to pop all the bytes. */
1961 unadjusted_alignment
1962 = (unadjusted_alignment
1963 - (pending_stack_adjust
% preferred_unit_stack_boundary
));
1964 adjustment
= pending_stack_adjust
;
1965 /* Push enough additional bytes that the stack will be aligned
1966 after the arguments are pushed. */
1967 if (preferred_unit_stack_boundary
> 1)
1969 if (unadjusted_alignment
> 0)
1970 adjustment
-= preferred_unit_stack_boundary
- unadjusted_alignment
;
1972 adjustment
+= unadjusted_alignment
;
1975 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1976 bytes after the call. The right number is the entire
1977 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1978 by the arguments in the first place. */
1980 = pending_stack_adjust
- adjustment
+ unadjusted_args_size
;
1985 /* Scan X expression if it does not dereference any argument slots
1986 we already clobbered by tail call arguments (as noted in stored_args_map
1988 Return nonzero if X expression dereferences such argument slots,
1992 check_sibcall_argument_overlap_1 (x
)
2003 code
= GET_CODE (x
);
2007 if (XEXP (x
, 0) == current_function_internal_arg_pointer
)
2009 else if (GET_CODE (XEXP (x
, 0)) == PLUS
2010 && XEXP (XEXP (x
, 0), 0) ==
2011 current_function_internal_arg_pointer
2012 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
)
2013 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
2017 #ifdef ARGS_GROW_DOWNWARD
2018 i
= -i
- GET_MODE_SIZE (GET_MODE (x
));
2021 for (k
= 0; k
< GET_MODE_SIZE (GET_MODE (x
)); k
++)
2022 if (i
+ k
< stored_args_map
->n_bits
2023 && TEST_BIT (stored_args_map
, i
+ k
))
2029 /* Scan all subexpressions. */
2030 fmt
= GET_RTX_FORMAT (code
);
2031 for (i
= 0; i
< GET_RTX_LENGTH (code
); i
++, fmt
++)
2035 if (check_sibcall_argument_overlap_1 (XEXP (x
, i
)))
2038 else if (*fmt
== 'E')
2040 for (j
= 0; j
< XVECLEN (x
, i
); j
++)
2041 if (check_sibcall_argument_overlap_1 (XVECEXP (x
, i
, j
)))
2048 /* Scan sequence after INSN if it does not dereference any argument slots
2049 we already clobbered by tail call arguments (as noted in stored_args_map
2050 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
2051 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
2052 should be 0). Return nonzero if sequence after INSN dereferences such argument
2053 slots, zero otherwise. */
2056 check_sibcall_argument_overlap (insn
, arg
, mark_stored_args_map
)
2058 struct arg_data
*arg
;
2059 int mark_stored_args_map
;
2063 if (insn
== NULL_RTX
)
2064 insn
= get_insns ();
2066 insn
= NEXT_INSN (insn
);
2068 for (; insn
; insn
= NEXT_INSN (insn
))
2070 && check_sibcall_argument_overlap_1 (PATTERN (insn
)))
2073 if (mark_stored_args_map
)
2075 #ifdef ARGS_GROW_DOWNWARD
2076 low
= -arg
->slot_offset
.constant
- arg
->size
.constant
;
2078 low
= arg
->slot_offset
.constant
;
2081 for (high
= low
+ arg
->size
.constant
; low
< high
; low
++)
2082 SET_BIT (stored_args_map
, low
);
2084 return insn
!= NULL_RTX
;
2091 switch (unsafe_for_reeval (t
))
2096 case 1: /* Mildly unsafe. */
2097 t
= unsave_expr (t
);
2100 case 2: /* Wildly unsafe. */
2102 tree var
= build_decl (VAR_DECL
, NULL_TREE
,
2105 expand_expr (t
, NULL_RTX
, VOIDmode
, EXPAND_NORMAL
));
2116 /* Generate all the code for a function call
2117 and return an rtx for its value.
2118 Store the value in TARGET (specified as an rtx) if convenient.
2119 If the value is stored in TARGET then TARGET is returned.
2120 If IGNORE is nonzero, then we ignore the value of the function call. */
2123 expand_call (exp
, target
, ignore
)
2128 /* Nonzero if we are currently expanding a call. */
2129 static int currently_expanding_call
= 0;
2131 /* List of actual parameters. */
2132 tree actparms
= TREE_OPERAND (exp
, 1);
2133 /* RTX for the function to be called. */
2135 /* Sequence of insns to perform a tail recursive "call". */
2136 rtx tail_recursion_insns
= NULL_RTX
;
2137 /* Sequence of insns to perform a normal "call". */
2138 rtx normal_call_insns
= NULL_RTX
;
2139 /* Sequence of insns to perform a tail recursive "call". */
2140 rtx tail_call_insns
= NULL_RTX
;
2141 /* Data type of the function. */
2143 /* Declaration of the function being called,
2144 or 0 if the function is computed (not known by name). */
2147 int try_tail_call
= 1;
2148 int try_tail_recursion
= 1;
2151 /* Register in which non-BLKmode value will be returned,
2152 or 0 if no value or if value is BLKmode. */
2154 /* Address where we should return a BLKmode value;
2155 0 if value not BLKmode. */
2156 rtx structure_value_addr
= 0;
2157 /* Nonzero if that address is being passed by treating it as
2158 an extra, implicit first parameter. Otherwise,
2159 it is passed by being copied directly into struct_value_rtx. */
2160 int structure_value_addr_parm
= 0;
2161 /* Size of aggregate value wanted, or zero if none wanted
2162 or if we are using the non-reentrant PCC calling convention
2163 or expecting the value in registers. */
2164 HOST_WIDE_INT struct_value_size
= 0;
2165 /* Nonzero if called function returns an aggregate in memory PCC style,
2166 by returning the address of where to find it. */
2167 int pcc_struct_value
= 0;
2169 /* Number of actual parameters in this call, including struct value addr. */
2171 /* Number of named args. Args after this are anonymous ones
2172 and they must all go on the stack. */
2175 /* Vector of information about each argument.
2176 Arguments are numbered in the order they will be pushed,
2177 not the order they are written. */
2178 struct arg_data
*args
;
2180 /* Total size in bytes of all the stack-parms scanned so far. */
2181 struct args_size args_size
;
2182 struct args_size adjusted_args_size
;
2183 /* Size of arguments before any adjustments (such as rounding). */
2184 int unadjusted_args_size
;
2185 /* Data on reg parms scanned so far. */
2186 CUMULATIVE_ARGS args_so_far
;
2187 /* Nonzero if a reg parm has been scanned. */
2189 /* Nonzero if this is an indirect function call. */
2191 /* Nonzero if we must avoid push-insns in the args for this call.
2192 If stack space is allocated for register parameters, but not by the
2193 caller, then it is preallocated in the fixed part of the stack frame.
2194 So the entire argument block must then be preallocated (i.e., we
2195 ignore PUSH_ROUNDING in that case). */
2197 int must_preallocate
= !PUSH_ARGS
;
2199 /* Size of the stack reserved for parameter registers. */
2200 int reg_parm_stack_space
= 0;
2202 /* Address of space preallocated for stack parms
2203 (on machines that lack push insns), or 0 if space not preallocated. */
2206 /* Mask of ECF_ flags. */
2208 /* Nonzero if this is a call to an inline function. */
2209 int is_integrable
= 0;
2210 #ifdef REG_PARM_STACK_SPACE
2211 /* Define the boundary of the register parm stack space that needs to be
2213 int low_to_save
, high_to_save
;
2214 rtx save_area
= 0; /* Place that it is saved */
2217 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
2218 char *initial_stack_usage_map
= stack_usage_map
;
2219 int old_stack_arg_under_construction
= 0;
2221 rtx old_stack_level
= 0;
2222 int old_pending_adj
= 0;
2223 int old_inhibit_defer_pop
= inhibit_defer_pop
;
2224 int old_stack_allocated
;
2226 tree p
= TREE_OPERAND (exp
, 0);
2227 tree addr
= TREE_OPERAND (exp
, 0);
2229 /* The alignment of the stack, in bits. */
2230 HOST_WIDE_INT preferred_stack_boundary
;
2231 /* The alignment of the stack, in bytes. */
2232 HOST_WIDE_INT preferred_unit_stack_boundary
;
2234 /* See if this is "nothrow" function call. */
2235 if (TREE_NOTHROW (exp
))
2236 flags
|= ECF_NOTHROW
;
2238 /* See if we can find a DECL-node for the actual function.
2239 As a result, decide whether this is a call to an integrable function. */
2241 fndecl
= get_callee_fndecl (exp
);
2245 && fndecl
!= current_function_decl
2246 && DECL_INLINE (fndecl
)
2247 && DECL_SAVED_INSNS (fndecl
)
2248 && DECL_SAVED_INSNS (fndecl
)->inlinable
)
2250 else if (! TREE_ADDRESSABLE (fndecl
))
2252 /* In case this function later becomes inlinable,
2253 record that there was already a non-inline call to it.
2255 Use abstraction instead of setting TREE_ADDRESSABLE
2257 if (DECL_INLINE (fndecl
) && warn_inline
&& !flag_no_inline
2260 warning_with_decl (fndecl
, "can't inline call to `%s'");
2261 warning ("called from here");
2263 (*lang_hooks
.mark_addressable
) (fndecl
);
2266 flags
|= flags_from_decl_or_type (fndecl
);
2269 /* If we don't have specific function to call, see if we have a
2270 attributes set in the type. */
2272 flags
|= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p
)));
2274 #ifdef REG_PARM_STACK_SPACE
2275 #ifdef MAYBE_REG_PARM_STACK_SPACE
2276 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
2278 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
2282 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2283 if (reg_parm_stack_space
> 0 && PUSH_ARGS
)
2284 must_preallocate
= 1;
2287 /* Warn if this value is an aggregate type,
2288 regardless of which calling convention we are using for it. */
2289 if (warn_aggregate_return
&& AGGREGATE_TYPE_P (TREE_TYPE (exp
)))
2290 warning ("function call has aggregate value");
2292 /* Set up a place to return a structure. */
2294 /* Cater to broken compilers. */
2295 if (aggregate_value_p (exp
))
2297 /* This call returns a big structure. */
2298 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
2300 #ifdef PCC_STATIC_STRUCT_RETURN
2302 pcc_struct_value
= 1;
2303 /* Easier than making that case work right. */
2306 /* In case this is a static function, note that it has been
2308 if (! TREE_ADDRESSABLE (fndecl
))
2309 (*lang_hooks
.mark_addressable
) (fndecl
);
2313 #else /* not PCC_STATIC_STRUCT_RETURN */
2315 struct_value_size
= int_size_in_bytes (TREE_TYPE (exp
));
2317 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp
))
2319 /* The structure value address arg is already in actparms.
2320 Pull it out. It might be nice to just leave it there, but
2321 we need to set structure_value_addr. */
2322 tree return_arg
= TREE_VALUE (actparms
);
2323 actparms
= TREE_CHAIN (actparms
);
2324 structure_value_addr
= expand_expr (return_arg
, NULL_RTX
,
2325 VOIDmode
, EXPAND_NORMAL
);
2327 else if (target
&& GET_CODE (target
) == MEM
)
2328 structure_value_addr
= XEXP (target
, 0);
2331 /* For variable-sized objects, we must be called with a target
2332 specified. If we were to allocate space on the stack here,
2333 we would have no way of knowing when to free it. */
2334 rtx d
= assign_temp (TREE_TYPE (exp
), 1, 1, 1);
2336 mark_temp_addr_taken (d
);
2337 structure_value_addr
= XEXP (d
, 0);
2341 #endif /* not PCC_STATIC_STRUCT_RETURN */
2344 /* If called function is inline, try to integrate it. */
2348 rtx temp
= try_to_integrate (fndecl
, actparms
, target
,
2349 ignore
, TREE_TYPE (exp
),
2350 structure_value_addr
);
2351 if (temp
!= (rtx
) (size_t) - 1)
2355 /* Figure out the amount to which the stack should be aligned. */
2356 preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
2359 struct cgraph_rtl_info
*i
= cgraph_rtl_info (fndecl
);
2360 if (i
&& i
->preferred_incoming_stack_boundary
)
2361 preferred_stack_boundary
= i
->preferred_incoming_stack_boundary
;
2364 /* Operand 0 is a pointer-to-function; get the type of the function. */
2365 funtype
= TREE_TYPE (addr
);
2366 if (! POINTER_TYPE_P (funtype
))
2368 funtype
= TREE_TYPE (funtype
);
2370 /* See if this is a call to a function that can return more than once
2371 or a call to longjmp or malloc. */
2372 flags
|= special_function_p (fndecl
, flags
);
2374 if (flags
& ECF_MAY_BE_ALLOCA
)
2375 current_function_calls_alloca
= 1;
2377 /* If struct_value_rtx is 0, it means pass the address
2378 as if it were an extra parameter. */
2379 if (structure_value_addr
&& struct_value_rtx
== 0)
2381 /* If structure_value_addr is a REG other than
2382 virtual_outgoing_args_rtx, we can use always use it. If it
2383 is not a REG, we must always copy it into a register.
2384 If it is virtual_outgoing_args_rtx, we must copy it to another
2385 register in some cases. */
2386 rtx temp
= (GET_CODE (structure_value_addr
) != REG
2387 || (ACCUMULATE_OUTGOING_ARGS
2388 && stack_arg_under_construction
2389 && structure_value_addr
== virtual_outgoing_args_rtx
)
2390 ? copy_addr_to_reg (structure_value_addr
)
2391 : structure_value_addr
);
2394 = tree_cons (error_mark_node
,
2395 make_tree (build_pointer_type (TREE_TYPE (funtype
)),
2398 structure_value_addr_parm
= 1;
2401 /* Count the arguments and set NUM_ACTUALS. */
2402 for (p
= actparms
, num_actuals
= 0; p
; p
= TREE_CHAIN (p
))
2405 /* Compute number of named args.
2406 Normally, don't include the last named arg if anonymous args follow.
2407 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2408 (If no anonymous args follow, the result of list_length is actually
2409 one too large. This is harmless.)
2411 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2412 zero, this machine will be able to place unnamed args that were
2413 passed in registers into the stack. So treat all args as named.
2414 This allows the insns emitting for a specific argument list to be
2415 independent of the function declaration.
2417 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2418 reliable way to pass unnamed args in registers, so we must force
2419 them into memory. */
2421 if ((STRICT_ARGUMENT_NAMING
2422 || ! PRETEND_OUTGOING_VARARGS_NAMED
)
2423 && TYPE_ARG_TYPES (funtype
) != 0)
2425 = (list_length (TYPE_ARG_TYPES (funtype
))
2426 /* Don't include the last named arg. */
2427 - (STRICT_ARGUMENT_NAMING
? 0 : 1)
2428 /* Count the struct value address, if it is passed as a parm. */
2429 + structure_value_addr_parm
);
2431 /* If we know nothing, treat all args as named. */
2432 n_named_args
= num_actuals
;
2434 /* Start updating where the next arg would go.
2436 On some machines (such as the PA) indirect calls have a different
2437 calling convention than normal calls. The last argument in
2438 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2440 INIT_CUMULATIVE_ARGS (args_so_far
, funtype
, NULL_RTX
, fndecl
);
2442 /* Make a vector to hold all the information about each arg. */
2443 args
= (struct arg_data
*) alloca (num_actuals
* sizeof (struct arg_data
));
2444 memset ((char *) args
, 0, num_actuals
* sizeof (struct arg_data
));
2446 /* Build up entries in the ARGS array, compute the size of the
2447 arguments into ARGS_SIZE, etc. */
2448 initialize_argument_information (num_actuals
, args
, &args_size
,
2449 n_named_args
, actparms
, fndecl
,
2450 &args_so_far
, reg_parm_stack_space
,
2451 &old_stack_level
, &old_pending_adj
,
2452 &must_preallocate
, &flags
);
2456 /* If this function requires a variable-sized argument list, don't
2457 try to make a cse'able block for this call. We may be able to
2458 do this eventually, but it is too complicated to keep track of
2459 what insns go in the cse'able block and which don't. */
2461 flags
&= ~ECF_LIBCALL_BLOCK
;
2462 must_preallocate
= 1;
2465 /* Now make final decision about preallocating stack space. */
2466 must_preallocate
= finalize_must_preallocate (must_preallocate
,
2470 /* If the structure value address will reference the stack pointer, we
2471 must stabilize it. We don't need to do this if we know that we are
2472 not going to adjust the stack pointer in processing this call. */
2474 if (structure_value_addr
2475 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
2476 || reg_mentioned_p (virtual_outgoing_args_rtx
,
2477 structure_value_addr
))
2479 || (!ACCUMULATE_OUTGOING_ARGS
&& args_size
.constant
)))
2480 structure_value_addr
= copy_to_reg (structure_value_addr
);
2482 /* Tail calls can make things harder to debug, and we're traditionally
2483 pushed these optimizations into -O2. Don't try if we're already
2484 expanding a call, as that means we're an argument. Don't try if
2485 there's cleanups, as we know there's code to follow the call.
2487 If rtx_equal_function_value_matters is false, that means we've
2488 finished with regular parsing. Which means that some of the
2489 machinery we use to generate tail-calls is no longer in place.
2490 This is most often true of sjlj-exceptions, which we couldn't
2491 tail-call to anyway. */
2493 if (currently_expanding_call
++ != 0
2494 || !flag_optimize_sibling_calls
2495 || !rtx_equal_function_value_matters
2496 || any_pending_cleanups (1)
2498 try_tail_call
= try_tail_recursion
= 0;
2500 /* Tail recursion fails, when we are not dealing with recursive calls. */
2501 if (!try_tail_recursion
2502 || TREE_CODE (addr
) != ADDR_EXPR
2503 || TREE_OPERAND (addr
, 0) != current_function_decl
)
2504 try_tail_recursion
= 0;
2506 /* Rest of purposes for tail call optimizations to fail. */
2508 #ifdef HAVE_sibcall_epilogue
2509 !HAVE_sibcall_epilogue
2514 /* Doing sibling call optimization needs some work, since
2515 structure_value_addr can be allocated on the stack.
2516 It does not seem worth the effort since few optimizable
2517 sibling calls will return a structure. */
2518 || structure_value_addr
!= NULL_RTX
2519 /* Check whether the target is able to optimize the call
2521 || !(*targetm
.function_ok_for_sibcall
) (fndecl
, exp
)
2522 /* Functions that do not return exactly once may not be sibcall
2524 || (flags
& (ECF_RETURNS_TWICE
| ECF_LONGJMP
| ECF_NORETURN
))
2525 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr
)))
2526 /* If this function requires more stack slots than the current
2527 function, we cannot change it into a sibling call. */
2528 || args_size
.constant
> current_function_args_size
2529 /* If the callee pops its own arguments, then it must pop exactly
2530 the same number of arguments as the current function. */
2531 || RETURN_POPS_ARGS (fndecl
, funtype
, args_size
.constant
)
2532 != RETURN_POPS_ARGS (current_function_decl
,
2533 TREE_TYPE (current_function_decl
),
2534 current_function_args_size
))
2537 if (try_tail_call
|| try_tail_recursion
)
2540 actparms
= NULL_TREE
;
2541 /* Ok, we're going to give the tail call the old college try.
2542 This means we're going to evaluate the function arguments
2543 up to three times. There are two degrees of badness we can
2544 encounter, those that can be unsaved and those that can't.
2545 (See unsafe_for_reeval commentary for details.)
2547 Generate a new argument list. Pass safe arguments through
2548 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2549 For hard badness, evaluate them now and put their resulting
2550 rtx in a temporary VAR_DECL.
2552 initialize_argument_information has ordered the array for the
2553 order to be pushed, and we must remember this when reconstructing
2554 the original argument order. */
2556 if (PUSH_ARGS_REVERSED
)
2565 i
= num_actuals
- 1;
2569 for (; i
!= end
; i
+= inc
)
2571 args
[i
].tree_value
= fix_unsafe_tree (args
[i
].tree_value
);
2572 /* We need to build actparms for optimize_tail_recursion. We can
2573 safely trash away TREE_PURPOSE, since it is unused by this
2575 if (try_tail_recursion
)
2576 actparms
= tree_cons (NULL_TREE
, args
[i
].tree_value
, actparms
);
2578 /* Do the same for the function address if it is an expression. */
2580 addr
= fix_unsafe_tree (addr
);
2581 /* Expanding one of those dangerous arguments could have added
2582 cleanups, but otherwise give it a whirl. */
2583 if (any_pending_cleanups (1))
2584 try_tail_call
= try_tail_recursion
= 0;
2587 /* Generate a tail recursion sequence when calling ourselves. */
2589 if (try_tail_recursion
)
2591 /* We want to emit any pending stack adjustments before the tail
2592 recursion "call". That way we know any adjustment after the tail
2593 recursion call can be ignored if we indeed use the tail recursion
2595 int save_pending_stack_adjust
= pending_stack_adjust
;
2596 int save_stack_pointer_delta
= stack_pointer_delta
;
2598 /* Emit any queued insns now; otherwise they would end up in
2599 only one of the alternates. */
2602 /* Use a new sequence to hold any RTL we generate. We do not even
2603 know if we will use this RTL yet. The final decision can not be
2604 made until after RTL generation for the entire function is
2607 /* If expanding any of the arguments creates cleanups, we can't
2608 do a tailcall. So, we'll need to pop the pending cleanups
2609 list. If, however, all goes well, and there are no cleanups
2610 then the call to expand_start_target_temps will have no
2612 expand_start_target_temps ();
2613 if (optimize_tail_recursion (actparms
, get_last_insn ()))
2615 if (any_pending_cleanups (1))
2616 try_tail_call
= try_tail_recursion
= 0;
2618 tail_recursion_insns
= get_insns ();
2620 expand_end_target_temps ();
2623 /* Restore the original pending stack adjustment for the sibling and
2624 normal call cases below. */
2625 pending_stack_adjust
= save_pending_stack_adjust
;
2626 stack_pointer_delta
= save_stack_pointer_delta
;
2629 if (profile_arc_flag
&& (flags
& ECF_FORK_OR_EXEC
))
2631 /* A fork duplicates the profile information, and an exec discards
2632 it. We can't rely on fork/exec to be paired. So write out the
2633 profile information we have gathered so far, and clear it. */
2634 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2635 is subject to race conditions, just as with multithreaded
2638 emit_library_call (gen_rtx_SYMBOL_REF (Pmode
, "__gcov_flush"),
2643 /* Ensure current function's preferred stack boundary is at least
2644 what we need. We don't have to increase alignment for recursive
2646 if (cfun
->preferred_stack_boundary
< preferred_stack_boundary
2647 && fndecl
!= current_function_decl
)
2648 cfun
->preferred_stack_boundary
= preferred_stack_boundary
;
2649 if (fndecl
== current_function_decl
)
2650 cfun
->recursive_call_emit
= true;
2652 preferred_unit_stack_boundary
= preferred_stack_boundary
/ BITS_PER_UNIT
;
2654 function_call_count
++;
2656 /* We want to make two insn chains; one for a sibling call, the other
2657 for a normal call. We will select one of the two chains after
2658 initial RTL generation is complete. */
2659 for (pass
= try_tail_call
? 0 : 1; pass
< 2; pass
++)
2661 int sibcall_failure
= 0;
2662 /* We want to emit any pending stack adjustments before the tail
2663 recursion "call". That way we know any adjustment after the tail
2664 recursion call can be ignored if we indeed use the tail recursion
2666 int save_pending_stack_adjust
= 0;
2667 int save_stack_pointer_delta
= 0;
2669 rtx before_call
, next_arg_reg
;
2673 /* Emit any queued insns now; otherwise they would end up in
2674 only one of the alternates. */
2677 /* State variables we need to save and restore between
2679 save_pending_stack_adjust
= pending_stack_adjust
;
2680 save_stack_pointer_delta
= stack_pointer_delta
;
2683 flags
&= ~ECF_SIBCALL
;
2685 flags
|= ECF_SIBCALL
;
2687 /* Other state variables that we must reinitialize each time
2688 through the loop (that are not initialized by the loop itself). */
2692 /* Start a new sequence for the normal call case.
2694 From this point on, if the sibling call fails, we want to set
2695 sibcall_failure instead of continuing the loop. */
2700 /* We know at this point that there are not currently any
2701 pending cleanups. If, however, in the process of evaluating
2702 the arguments we were to create some, we'll need to be
2703 able to get rid of them. */
2704 expand_start_target_temps ();
2707 /* Don't let pending stack adjusts add up to too much.
2708 Also, do all pending adjustments now if there is any chance
2709 this might be a call to alloca or if we are expanding a sibling
2710 call sequence or if we are calling a function that is to return
2711 with stack pointer depressed. */
2712 if (pending_stack_adjust
>= 32
2713 || (pending_stack_adjust
> 0
2714 && (flags
& (ECF_MAY_BE_ALLOCA
| ECF_SP_DEPRESSED
)))
2716 do_pending_stack_adjust ();
2718 /* When calling a const function, we must pop the stack args right away,
2719 so that the pop is deleted or moved with the call. */
2720 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
2723 #ifdef FINAL_REG_PARM_STACK_SPACE
2724 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
2727 /* Precompute any arguments as needed. */
2729 precompute_arguments (flags
, num_actuals
, args
);
2731 /* Now we are about to start emitting insns that can be deleted
2732 if a libcall is deleted. */
2733 if (pass
&& (flags
& (ECF_LIBCALL_BLOCK
| ECF_MALLOC
)))
2736 adjusted_args_size
= args_size
;
2737 /* Compute the actual size of the argument block required. The variable
2738 and constant sizes must be combined, the size may have to be rounded,
2739 and there may be a minimum required size. When generating a sibcall
2740 pattern, do not round up, since we'll be re-using whatever space our
2742 unadjusted_args_size
2743 = compute_argument_block_size (reg_parm_stack_space
,
2744 &adjusted_args_size
,
2746 : preferred_stack_boundary
));
2748 old_stack_allocated
= stack_pointer_delta
- pending_stack_adjust
;
2750 /* The argument block when performing a sibling call is the
2751 incoming argument block. */
2754 argblock
= virtual_incoming_args_rtx
;
2756 #ifdef STACK_GROWS_DOWNWARD
2757 = plus_constant (argblock
, current_function_pretend_args_size
);
2759 = plus_constant (argblock
, -current_function_pretend_args_size
);
2761 stored_args_map
= sbitmap_alloc (args_size
.constant
);
2762 sbitmap_zero (stored_args_map
);
2765 /* If we have no actual push instructions, or shouldn't use them,
2766 make space for all args right now. */
2767 else if (adjusted_args_size
.var
!= 0)
2769 if (old_stack_level
== 0)
2771 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
2772 old_pending_adj
= pending_stack_adjust
;
2773 pending_stack_adjust
= 0;
2774 /* stack_arg_under_construction says whether a stack arg is
2775 being constructed at the old stack level. Pushing the stack
2776 gets a clean outgoing argument block. */
2777 old_stack_arg_under_construction
= stack_arg_under_construction
;
2778 stack_arg_under_construction
= 0;
2780 argblock
= push_block (ARGS_SIZE_RTX (adjusted_args_size
), 0, 0);
2784 /* Note that we must go through the motions of allocating an argument
2785 block even if the size is zero because we may be storing args
2786 in the area reserved for register arguments, which may be part of
2789 int needed
= adjusted_args_size
.constant
;
2791 /* Store the maximum argument space used. It will be pushed by
2792 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2795 if (needed
> current_function_outgoing_args_size
)
2796 current_function_outgoing_args_size
= needed
;
2798 if (must_preallocate
)
2800 if (ACCUMULATE_OUTGOING_ARGS
)
2802 /* Since the stack pointer will never be pushed, it is
2803 possible for the evaluation of a parm to clobber
2804 something we have already written to the stack.
2805 Since most function calls on RISC machines do not use
2806 the stack, this is uncommon, but must work correctly.
2808 Therefore, we save any area of the stack that was already
2809 written and that we are using. Here we set up to do this
2810 by making a new stack usage map from the old one. The
2811 actual save will be done by store_one_arg.
2813 Another approach might be to try to reorder the argument
2814 evaluations to avoid this conflicting stack usage. */
2816 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2817 /* Since we will be writing into the entire argument area,
2818 the map must be allocated for its entire size, not just
2819 the part that is the responsibility of the caller. */
2820 needed
+= reg_parm_stack_space
;
2823 #ifdef ARGS_GROW_DOWNWARD
2824 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2827 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
2831 = (char *) alloca (highest_outgoing_arg_in_use
);
2833 if (initial_highest_arg_in_use
)
2834 memcpy (stack_usage_map
, initial_stack_usage_map
,
2835 initial_highest_arg_in_use
);
2837 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
2838 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
2839 (highest_outgoing_arg_in_use
2840 - initial_highest_arg_in_use
));
2843 /* The address of the outgoing argument list must not be
2844 copied to a register here, because argblock would be left
2845 pointing to the wrong place after the call to
2846 allocate_dynamic_stack_space below. */
2848 argblock
= virtual_outgoing_args_rtx
;
2852 if (inhibit_defer_pop
== 0)
2854 /* Try to reuse some or all of the pending_stack_adjust
2855 to get this space. */
2857 = (combine_pending_stack_adjustment_and_call
2858 (unadjusted_args_size
,
2859 &adjusted_args_size
,
2860 preferred_unit_stack_boundary
));
2862 /* combine_pending_stack_adjustment_and_call computes
2863 an adjustment before the arguments are allocated.
2864 Account for them and see whether or not the stack
2865 needs to go up or down. */
2866 needed
= unadjusted_args_size
- needed
;
2870 /* We're releasing stack space. */
2871 /* ??? We can avoid any adjustment at all if we're
2872 already aligned. FIXME. */
2873 pending_stack_adjust
= -needed
;
2874 do_pending_stack_adjust ();
2878 /* We need to allocate space. We'll do that in
2879 push_block below. */
2880 pending_stack_adjust
= 0;
2883 /* Special case this because overhead of `push_block' in
2884 this case is non-trivial. */
2886 argblock
= virtual_outgoing_args_rtx
;
2888 argblock
= push_block (GEN_INT (needed
), 0, 0);
2890 /* We only really need to call `copy_to_reg' in the case
2891 where push insns are going to be used to pass ARGBLOCK
2892 to a function call in ARGS. In that case, the stack
2893 pointer changes value from the allocation point to the
2894 call point, and hence the value of
2895 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2896 as well always do it. */
2897 argblock
= copy_to_reg (argblock
);
2899 /* The save/restore code in store_one_arg handles all
2900 cases except one: a constructor call (including a C
2901 function returning a BLKmode struct) to initialize
2903 if (stack_arg_under_construction
)
2905 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2906 rtx push_size
= GEN_INT (reg_parm_stack_space
2907 + adjusted_args_size
.constant
);
2909 rtx push_size
= GEN_INT (adjusted_args_size
.constant
);
2911 if (old_stack_level
== 0)
2913 emit_stack_save (SAVE_BLOCK
, &old_stack_level
,
2915 old_pending_adj
= pending_stack_adjust
;
2916 pending_stack_adjust
= 0;
2917 /* stack_arg_under_construction says whether a stack
2918 arg is being constructed at the old stack level.
2919 Pushing the stack gets a clean outgoing argument
2921 old_stack_arg_under_construction
2922 = stack_arg_under_construction
;
2923 stack_arg_under_construction
= 0;
2924 /* Make a new map for the new argument list. */
2925 stack_usage_map
= (char *)
2926 alloca (highest_outgoing_arg_in_use
);
2927 memset (stack_usage_map
, 0, highest_outgoing_arg_in_use
);
2928 highest_outgoing_arg_in_use
= 0;
2930 allocate_dynamic_stack_space (push_size
, NULL_RTX
,
2933 /* If argument evaluation might modify the stack pointer,
2934 copy the address of the argument list to a register. */
2935 for (i
= 0; i
< num_actuals
; i
++)
2936 if (args
[i
].pass_on_stack
)
2938 argblock
= copy_addr_to_reg (argblock
);
2945 compute_argument_addresses (args
, argblock
, num_actuals
);
2947 /* If we push args individually in reverse order, perform stack alignment
2948 before the first push (the last arg). */
2949 if (PUSH_ARGS_REVERSED
&& argblock
== 0
2950 && adjusted_args_size
.constant
!= unadjusted_args_size
)
2952 /* When the stack adjustment is pending, we get better code
2953 by combining the adjustments. */
2954 if (pending_stack_adjust
2955 && ! (flags
& ECF_LIBCALL_BLOCK
)
2956 && ! inhibit_defer_pop
)
2958 pending_stack_adjust
2959 = (combine_pending_stack_adjustment_and_call
2960 (unadjusted_args_size
,
2961 &adjusted_args_size
,
2962 preferred_unit_stack_boundary
));
2963 do_pending_stack_adjust ();
2965 else if (argblock
== 0)
2966 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
2967 - unadjusted_args_size
));
2969 /* Now that the stack is properly aligned, pops can't safely
2970 be deferred during the evaluation of the arguments. */
2973 funexp
= rtx_for_function_call (fndecl
, addr
);
2975 /* Figure out the register where the value, if any, will come back. */
2977 if (TYPE_MODE (TREE_TYPE (exp
)) != VOIDmode
2978 && ! structure_value_addr
)
2980 if (pcc_struct_value
)
2981 valreg
= hard_function_value (build_pointer_type (TREE_TYPE (exp
)),
2982 fndecl
, (pass
== 0));
2984 valreg
= hard_function_value (TREE_TYPE (exp
), fndecl
, (pass
== 0));
2987 /* Precompute all register parameters. It isn't safe to compute anything
2988 once we have started filling any specific hard regs. */
2989 precompute_register_parameters (num_actuals
, args
, ®_parm_seen
);
2991 #ifdef REG_PARM_STACK_SPACE
2992 /* Save the fixed argument area if it's part of the caller's frame and
2993 is clobbered by argument setup for this call. */
2994 if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
2995 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
2996 &low_to_save
, &high_to_save
);
2999 /* Now store (and compute if necessary) all non-register parms.
3000 These come before register parms, since they can require block-moves,
3001 which could clobber the registers used for register parms.
3002 Parms which have partial registers are not stored here,
3003 but we do preallocate space here if they want that. */
3005 for (i
= 0; i
< num_actuals
; i
++)
3006 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
3008 rtx before_arg
= get_last_insn ();
3010 if (store_one_arg (&args
[i
], argblock
, flags
,
3011 adjusted_args_size
.var
!= 0,
3012 reg_parm_stack_space
)
3014 && check_sibcall_argument_overlap (before_arg
,
3016 sibcall_failure
= 1;
3019 /* If we have a parm that is passed in registers but not in memory
3020 and whose alignment does not permit a direct copy into registers,
3021 make a group of pseudos that correspond to each register that we
3023 if (STRICT_ALIGNMENT
)
3024 store_unaligned_arguments_into_pseudos (args
, num_actuals
);
3026 /* Now store any partially-in-registers parm.
3027 This is the last place a block-move can happen. */
3029 for (i
= 0; i
< num_actuals
; i
++)
3030 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
3032 rtx before_arg
= get_last_insn ();
3034 if (store_one_arg (&args
[i
], argblock
, flags
,
3035 adjusted_args_size
.var
!= 0,
3036 reg_parm_stack_space
)
3038 && check_sibcall_argument_overlap (before_arg
,
3040 sibcall_failure
= 1;
3043 /* If we pushed args in forward order, perform stack alignment
3044 after pushing the last arg. */
3045 if (!PUSH_ARGS_REVERSED
&& argblock
== 0)
3046 anti_adjust_stack (GEN_INT (adjusted_args_size
.constant
3047 - unadjusted_args_size
));
3049 /* If register arguments require space on the stack and stack space
3050 was not preallocated, allocate stack space here for arguments
3051 passed in registers. */
3052 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3053 if (!ACCUMULATE_OUTGOING_ARGS
3054 && must_preallocate
== 0 && reg_parm_stack_space
> 0)
3055 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
3058 /* Pass the function the address in which to return a
3060 if (pass
!= 0 && structure_value_addr
&& ! structure_value_addr_parm
)
3062 emit_move_insn (struct_value_rtx
,
3064 force_operand (structure_value_addr
,
3067 if (GET_CODE (struct_value_rtx
) == REG
)
3068 use_reg (&call_fusage
, struct_value_rtx
);
3071 funexp
= prepare_call_address (funexp
, fndecl
, &call_fusage
,
3072 reg_parm_seen
, pass
== 0);
3074 load_register_parameters (args
, num_actuals
, &call_fusage
, flags
,
3075 pass
== 0, &sibcall_failure
);
3077 /* Perform postincrements before actually calling the function. */
3080 /* Save a pointer to the last insn before the call, so that we can
3081 later safely search backwards to find the CALL_INSN. */
3082 before_call
= get_last_insn ();
3084 /* Set up next argument register. For sibling calls on machines
3085 with register windows this should be the incoming register. */
3086 #ifdef FUNCTION_INCOMING_ARG
3088 next_arg_reg
= FUNCTION_INCOMING_ARG (args_so_far
, VOIDmode
,
3092 next_arg_reg
= FUNCTION_ARG (args_so_far
, VOIDmode
,
3095 /* All arguments and registers used for the call must be set up by
3098 /* Stack must be properly aligned now. */
3099 if (pass
&& stack_pointer_delta
% preferred_unit_stack_boundary
)
3102 /* Generate the actual call instruction. */
3103 emit_call_1 (funexp
, fndecl
, funtype
, unadjusted_args_size
,
3104 adjusted_args_size
.constant
, struct_value_size
,
3105 next_arg_reg
, valreg
, old_inhibit_defer_pop
, call_fusage
,
3106 flags
, & args_so_far
);
3108 /* Verify that we've deallocated all the stack we used. */
3110 && old_stack_allocated
!= stack_pointer_delta
- pending_stack_adjust
)
3113 /* If call is cse'able, make appropriate pair of reg-notes around it.
3114 Test valreg so we don't crash; may safely ignore `const'
3115 if return type is void. Disable for PARALLEL return values, because
3116 we have no way to move such values into a pseudo register. */
3117 if (pass
&& (flags
& ECF_LIBCALL_BLOCK
))
3121 if (valreg
== 0 || GET_CODE (valreg
) == PARALLEL
)
3123 insns
= get_insns ();
3130 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3132 /* Mark the return value as a pointer if needed. */
3133 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3134 mark_reg_pointer (temp
,
3135 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp
))));
3137 /* Construct an "equal form" for the value which mentions all the
3138 arguments in order as well as the function name. */
3139 for (i
= 0; i
< num_actuals
; i
++)
3140 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3141 args
[i
].initial_value
, note
);
3142 note
= gen_rtx_EXPR_LIST (VOIDmode
, funexp
, note
);
3144 insns
= get_insns ();
3147 if (flags
& ECF_PURE
)
3148 note
= gen_rtx_EXPR_LIST (VOIDmode
,
3149 gen_rtx_USE (VOIDmode
,
3150 gen_rtx_MEM (BLKmode
,
3151 gen_rtx_SCRATCH (VOIDmode
))),
3154 emit_libcall_block (insns
, temp
, valreg
, note
);
3159 else if (pass
&& (flags
& ECF_MALLOC
))
3161 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
3164 /* The return value from a malloc-like function is a pointer. */
3165 if (TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
)
3166 mark_reg_pointer (temp
, BIGGEST_ALIGNMENT
);
3168 emit_move_insn (temp
, valreg
);
3170 /* The return value from a malloc-like function can not alias
3172 last
= get_last_insn ();
3174 gen_rtx_EXPR_LIST (REG_NOALIAS
, temp
, REG_NOTES (last
));
3176 /* Write out the sequence. */
3177 insns
= get_insns ();
3183 /* For calls to `setjmp', etc., inform flow.c it should complain
3184 if nonvolatile values are live. For functions that cannot return,
3185 inform flow that control does not fall through. */
3187 if ((flags
& (ECF_NORETURN
| ECF_LONGJMP
)) || pass
== 0)
3189 /* The barrier must be emitted
3190 immediately after the CALL_INSN. Some ports emit more
3191 than just a CALL_INSN above, so we must search for it here. */
3193 rtx last
= get_last_insn ();
3194 while (GET_CODE (last
) != CALL_INSN
)
3196 last
= PREV_INSN (last
);
3197 /* There was no CALL_INSN? */
3198 if (last
== before_call
)
3202 emit_barrier_after (last
);
3205 if (flags
& ECF_LONGJMP
)
3206 current_function_calls_longjmp
= 1;
3208 /* If this function is returning into a memory location marked as
3209 readonly, it means it is initializing that location. But we normally
3210 treat functions as not clobbering such locations, so we need to
3211 specify that this one does. */
3212 if (target
!= 0 && GET_CODE (target
) == MEM
3213 && structure_value_addr
!= 0 && RTX_UNCHANGING_P (target
))
3214 emit_insn (gen_rtx_CLOBBER (VOIDmode
, target
));
3216 /* If value type not void, return an rtx for the value. */
3218 /* If there are cleanups to be called, don't use a hard reg as target.
3219 We need to double check this and see if it matters anymore. */
3220 if (any_pending_cleanups (1))
3222 if (target
&& REG_P (target
)
3223 && REGNO (target
) < FIRST_PSEUDO_REGISTER
)
3225 sibcall_failure
= 1;
3228 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
3230 target
= const0_rtx
;
3231 else if (structure_value_addr
)
3233 if (target
== 0 || GET_CODE (target
) != MEM
)
3236 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3237 memory_address (TYPE_MODE (TREE_TYPE (exp
)),
3238 structure_value_addr
));
3239 set_mem_attributes (target
, exp
, 1);
3242 else if (pcc_struct_value
)
3244 /* This is the special C++ case where we need to
3245 know what the true target was. We take care to
3246 never use this value more than once in one expression. */
3247 target
= gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp
)),
3248 copy_to_reg (valreg
));
3249 set_mem_attributes (target
, exp
, 1);
3251 /* Handle calls that return values in multiple non-contiguous locations.
3252 The Irix 6 ABI has examples of this. */
3253 else if (GET_CODE (valreg
) == PARALLEL
)
3257 /* This will only be assigned once, so it can be readonly. */
3258 tree nt
= build_qualified_type (TREE_TYPE (exp
),
3259 (TYPE_QUALS (TREE_TYPE (exp
))
3260 | TYPE_QUAL_CONST
));
3262 target
= assign_temp (nt
, 0, 1, 1);
3263 preserve_temp_slots (target
);
3266 if (! rtx_equal_p (target
, valreg
))
3267 emit_group_store (target
, valreg
,
3268 int_size_in_bytes (TREE_TYPE (exp
)));
3270 /* We can not support sibling calls for this case. */
3271 sibcall_failure
= 1;
3274 && GET_MODE (target
) == TYPE_MODE (TREE_TYPE (exp
))
3275 && GET_MODE (target
) == GET_MODE (valreg
))
3277 /* TARGET and VALREG cannot be equal at this point because the
3278 latter would not have REG_FUNCTION_VALUE_P true, while the
3279 former would if it were referring to the same register.
3281 If they refer to the same register, this move will be a no-op,
3282 except when function inlining is being done. */
3283 emit_move_insn (target
, valreg
);
3285 else if (TYPE_MODE (TREE_TYPE (exp
)) == BLKmode
)
3287 target
= copy_blkmode_from_reg (target
, valreg
, TREE_TYPE (exp
));
3289 /* We can not support sibling calls for this case. */
3290 sibcall_failure
= 1;
3293 target
= copy_to_reg (valreg
);
3295 #ifdef PROMOTE_FUNCTION_RETURN
3296 /* If we promoted this return value, make the proper SUBREG. TARGET
3297 might be const0_rtx here, so be careful. */
3298 if (GET_CODE (target
) == REG
3299 && TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
3300 && GET_MODE (target
) != TYPE_MODE (TREE_TYPE (exp
)))
3302 tree type
= TREE_TYPE (exp
);
3303 int unsignedp
= TREE_UNSIGNED (type
);
3306 /* If we don't promote as expected, something is wrong. */
3307 if (GET_MODE (target
)
3308 != promote_mode (type
, TYPE_MODE (type
), &unsignedp
, 1))
3311 if ((WORDS_BIG_ENDIAN
|| BYTES_BIG_ENDIAN
)
3312 && GET_MODE_SIZE (GET_MODE (target
))
3313 > GET_MODE_SIZE (TYPE_MODE (type
)))
3315 offset
= GET_MODE_SIZE (GET_MODE (target
))
3316 - GET_MODE_SIZE (TYPE_MODE (type
));
3317 if (! BYTES_BIG_ENDIAN
)
3318 offset
= (offset
/ UNITS_PER_WORD
) * UNITS_PER_WORD
;
3319 else if (! WORDS_BIG_ENDIAN
)
3320 offset
%= UNITS_PER_WORD
;
3322 target
= gen_rtx_SUBREG (TYPE_MODE (type
), target
, offset
);
3323 SUBREG_PROMOTED_VAR_P (target
) = 1;
3324 SUBREG_PROMOTED_UNSIGNED_SET (target
, unsignedp
);
3328 /* If size of args is variable or this was a constructor call for a stack
3329 argument, restore saved stack-pointer value. */
3331 if (old_stack_level
&& ! (flags
& ECF_SP_DEPRESSED
))
3333 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
3334 pending_stack_adjust
= old_pending_adj
;
3335 stack_arg_under_construction
= old_stack_arg_under_construction
;
3336 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3337 stack_usage_map
= initial_stack_usage_map
;
3338 sibcall_failure
= 1;
3340 else if (ACCUMULATE_OUTGOING_ARGS
&& pass
)
3342 #ifdef REG_PARM_STACK_SPACE
3344 restore_fixed_argument_area (save_area
, argblock
,
3345 high_to_save
, low_to_save
);
3348 /* If we saved any argument areas, restore them. */
3349 for (i
= 0; i
< num_actuals
; i
++)
3350 if (args
[i
].save_area
)
3352 enum machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
3354 = gen_rtx_MEM (save_mode
,
3355 memory_address (save_mode
,
3356 XEXP (args
[i
].stack_slot
, 0)));
3358 if (save_mode
!= BLKmode
)
3359 emit_move_insn (stack_area
, args
[i
].save_area
);
3361 emit_block_move (stack_area
, args
[i
].save_area
,
3362 GEN_INT (args
[i
].size
.constant
),
3363 BLOCK_OP_CALL_PARM
);
3366 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
3367 stack_usage_map
= initial_stack_usage_map
;
3370 /* If this was alloca, record the new stack level for nonlocal gotos.
3371 Check for the handler slots since we might not have a save area
3372 for non-local gotos. */
3374 if ((flags
& ECF_MAY_BE_ALLOCA
) && nonlocal_goto_handler_slots
!= 0)
3375 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
3377 /* Free up storage we no longer need. */
3378 for (i
= 0; i
< num_actuals
; ++i
)
3379 if (args
[i
].aligned_regs
)
3380 free (args
[i
].aligned_regs
);
3384 /* Undo the fake expand_start_target_temps we did earlier. If
3385 there had been any cleanups created, we've already set
3387 expand_end_target_temps ();
3390 insns
= get_insns ();
3395 tail_call_insns
= insns
;
3397 /* Restore the pending stack adjustment now that we have
3398 finished generating the sibling call sequence. */
3400 pending_stack_adjust
= save_pending_stack_adjust
;
3401 stack_pointer_delta
= save_stack_pointer_delta
;
3403 /* Prepare arg structure for next iteration. */
3404 for (i
= 0; i
< num_actuals
; i
++)
3407 args
[i
].aligned_regs
= 0;
3411 sbitmap_free (stored_args_map
);
3414 normal_call_insns
= insns
;
3416 /* If something prevents making this a sibling call,
3417 zero out the sequence. */
3418 if (sibcall_failure
)
3419 tail_call_insns
= NULL_RTX
;
3422 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3423 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3424 can happen if the arguments to this function call an inline
3425 function who's expansion contains another CALL_PLACEHOLDER.
3427 If there are any C_Ps in any of these sequences, replace them
3428 with their normal call. */
3430 for (insn
= normal_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3431 if (GET_CODE (insn
) == CALL_INSN
3432 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3433 replace_call_placeholder (insn
, sibcall_use_normal
);
3435 for (insn
= tail_call_insns
; insn
; insn
= NEXT_INSN (insn
))
3436 if (GET_CODE (insn
) == CALL_INSN
3437 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3438 replace_call_placeholder (insn
, sibcall_use_normal
);
3440 for (insn
= tail_recursion_insns
; insn
; insn
= NEXT_INSN (insn
))
3441 if (GET_CODE (insn
) == CALL_INSN
3442 && GET_CODE (PATTERN (insn
)) == CALL_PLACEHOLDER
)
3443 replace_call_placeholder (insn
, sibcall_use_normal
);
3445 /* If this was a potential tail recursion site, then emit a
3446 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3447 One of them will be selected later. */
3448 if (tail_recursion_insns
|| tail_call_insns
)
3450 /* The tail recursion label must be kept around. We could expose
3451 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3452 and makes determining true tail recursion sites difficult.
3454 So we set LABEL_PRESERVE_P here, then clear it when we select
3455 one of the call sequences after rtl generation is complete. */
3456 if (tail_recursion_insns
)
3457 LABEL_PRESERVE_P (tail_recursion_label
) = 1;
3458 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode
, normal_call_insns
,
3460 tail_recursion_insns
,
3461 tail_recursion_label
));
3464 emit_insn (normal_call_insns
);
3466 currently_expanding_call
--;
3468 /* If this function returns with the stack pointer depressed, ensure
3469 this block saves and restores the stack pointer, show it was
3470 changed, and adjust for any outgoing arg space. */
3471 if (flags
& ECF_SP_DEPRESSED
)
3473 clear_pending_stack_adjust ();
3474 emit_insn (gen_rtx (CLOBBER
, VOIDmode
, stack_pointer_rtx
));
3475 emit_move_insn (virtual_stack_dynamic_rtx
, stack_pointer_rtx
);
3476 save_stack_pointer ();
3482 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3483 The RETVAL parameter specifies whether return value needs to be saved, other
3484 parameters are documented in the emit_library_call function below. */
3487 emit_library_call_value_1 (retval
, orgfun
, value
, fn_type
, outmode
, nargs
, p
)
3491 enum libcall_type fn_type
;
3492 enum machine_mode outmode
;
3496 /* Total size in bytes of all the stack-parms scanned so far. */
3497 struct args_size args_size
;
3498 /* Size of arguments before any adjustments (such as rounding). */
3499 struct args_size original_args_size
;
3504 struct args_size alignment_pad
;
3506 CUMULATIVE_ARGS args_so_far
;
3510 enum machine_mode mode
;
3513 struct args_size offset
;
3514 struct args_size size
;
3518 int old_inhibit_defer_pop
= inhibit_defer_pop
;
3519 rtx call_fusage
= 0;
3522 int pcc_struct_value
= 0;
3523 int struct_value_size
= 0;
3525 int reg_parm_stack_space
= 0;
3528 tree tfom
; /* type_for_mode (outmode, 0) */
3530 #ifdef REG_PARM_STACK_SPACE
3531 /* Define the boundary of the register parm stack space that needs to be
3533 int low_to_save
, high_to_save
;
3534 rtx save_area
= 0; /* Place that it is saved. */
3537 /* Size of the stack reserved for parameter registers. */
3538 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
3539 char *initial_stack_usage_map
= stack_usage_map
;
3541 #ifdef REG_PARM_STACK_SPACE
3542 #ifdef MAYBE_REG_PARM_STACK_SPACE
3543 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
3545 reg_parm_stack_space
= REG_PARM_STACK_SPACE ((tree
) 0);
3549 /* By default, library functions can not throw. */
3550 flags
= ECF_NOTHROW
;
3562 case LCT_CONST_MAKE_BLOCK
:
3563 flags
|= ECF_CONST
| ECF_LIBCALL_BLOCK
;
3565 case LCT_PURE_MAKE_BLOCK
:
3566 flags
|= ECF_PURE
| ECF_LIBCALL_BLOCK
;
3569 flags
|= ECF_NORETURN
;
3572 flags
= ECF_NORETURN
;
3574 case LCT_ALWAYS_RETURN
:
3575 flags
= ECF_ALWAYS_RETURN
;
3577 case LCT_RETURNS_TWICE
:
3578 flags
= ECF_RETURNS_TWICE
;
3583 /* Ensure current function's preferred stack boundary is at least
3585 if (cfun
->preferred_stack_boundary
< PREFERRED_STACK_BOUNDARY
)
3586 cfun
->preferred_stack_boundary
= PREFERRED_STACK_BOUNDARY
;
3588 /* If this kind of value comes back in memory,
3589 decide where in memory it should come back. */
3590 if (outmode
!= VOIDmode
)
3592 tfom
= (*lang_hooks
.types
.type_for_mode
) (outmode
, 0);
3593 if (aggregate_value_p (tfom
))
3595 #ifdef PCC_STATIC_STRUCT_RETURN
3597 = hard_function_value (build_pointer_type (tfom
), 0, 0);
3598 mem_value
= gen_rtx_MEM (outmode
, pointer_reg
);
3599 pcc_struct_value
= 1;
3601 value
= gen_reg_rtx (outmode
);
3602 #else /* not PCC_STATIC_STRUCT_RETURN */
3603 struct_value_size
= GET_MODE_SIZE (outmode
);
3604 if (value
!= 0 && GET_CODE (value
) == MEM
)
3607 mem_value
= assign_temp (tfom
, 0, 1, 1);
3609 /* This call returns a big structure. */
3610 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3614 tfom
= void_type_node
;
3616 /* ??? Unfinished: must pass the memory address as an argument. */
3618 /* Copy all the libcall-arguments out of the varargs data
3619 and into a vector ARGVEC.
3621 Compute how to pass each argument. We only support a very small subset
3622 of the full argument passing conventions to limit complexity here since
3623 library functions shouldn't have many args. */
3625 argvec
= (struct arg
*) alloca ((nargs
+ 1) * sizeof (struct arg
));
3626 memset ((char *) argvec
, 0, (nargs
+ 1) * sizeof (struct arg
));
3628 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3629 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far
, outmode
, fun
);
3631 INIT_CUMULATIVE_ARGS (args_so_far
, NULL_TREE
, fun
, 0);
3634 args_size
.constant
= 0;
3639 /* Now we are about to start emitting insns that can be deleted
3640 if a libcall is deleted. */
3641 if (flags
& ECF_LIBCALL_BLOCK
)
3646 /* If there's a structure value address to be passed,
3647 either pass it in the special place, or pass it as an extra argument. */
3648 if (mem_value
&& struct_value_rtx
== 0 && ! pcc_struct_value
)
3650 rtx addr
= XEXP (mem_value
, 0);
3653 /* Make sure it is a reasonable operand for a move or push insn. */
3654 if (GET_CODE (addr
) != REG
&& GET_CODE (addr
) != MEM
3655 && ! (CONSTANT_P (addr
) && LEGITIMATE_CONSTANT_P (addr
)))
3656 addr
= force_operand (addr
, NULL_RTX
);
3658 argvec
[count
].value
= addr
;
3659 argvec
[count
].mode
= Pmode
;
3660 argvec
[count
].partial
= 0;
3662 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, Pmode
, NULL_TREE
, 1);
3663 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3664 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, Pmode
, NULL_TREE
, 1))
3668 locate_and_pad_parm (Pmode
, NULL_TREE
,
3669 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3672 argvec
[count
].reg
!= 0,
3674 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3675 &argvec
[count
].size
, &alignment_pad
);
3677 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3678 || reg_parm_stack_space
> 0)
3679 args_size
.constant
+= argvec
[count
].size
.constant
;
3681 FUNCTION_ARG_ADVANCE (args_so_far
, Pmode
, (tree
) 0, 1);
3686 for (; count
< nargs
; count
++)
3688 rtx val
= va_arg (p
, rtx
);
3689 enum machine_mode mode
= va_arg (p
, enum machine_mode
);
3691 /* We cannot convert the arg value to the mode the library wants here;
3692 must do it earlier where we know the signedness of the arg. */
3694 || (GET_MODE (val
) != mode
&& GET_MODE (val
) != VOIDmode
))
3697 /* On some machines, there's no way to pass a float to a library fcn.
3698 Pass it as a double instead. */
3699 #ifdef LIBGCC_NEEDS_DOUBLE
3700 if (LIBGCC_NEEDS_DOUBLE
&& mode
== SFmode
)
3701 val
= convert_modes (DFmode
, SFmode
, val
, 0), mode
= DFmode
;
3704 /* There's no need to call protect_from_queue, because
3705 either emit_move_insn or emit_push_insn will do that. */
3707 /* Make sure it is a reasonable operand for a move or push insn. */
3708 if (GET_CODE (val
) != REG
&& GET_CODE (val
) != MEM
3709 && ! (CONSTANT_P (val
) && LEGITIMATE_CONSTANT_P (val
)))
3710 val
= force_operand (val
, NULL_RTX
);
3712 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3713 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, mode
, NULL_TREE
, 1))
3717 #ifdef FUNCTION_ARG_CALLEE_COPIES
3718 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far
, mode
,
3723 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3724 functions, so we have to pretend this isn't such a function. */
3725 if (flags
& ECF_LIBCALL_BLOCK
)
3727 rtx insns
= get_insns ();
3731 flags
&= ~(ECF_CONST
| ECF_PURE
| ECF_LIBCALL_BLOCK
);
3733 /* If this was a CONST function, it is now PURE since
3734 it now reads memory. */
3735 if (flags
& ECF_CONST
)
3737 flags
&= ~ECF_CONST
;
3741 if (GET_MODE (val
) == MEM
&& ! must_copy
)
3745 slot
= assign_temp ((*lang_hooks
.types
.type_for_mode
) (mode
, 0),
3747 emit_move_insn (slot
, val
);
3751 tree type
= (*lang_hooks
.types
.type_for_mode
) (mode
, 0);
3754 = gen_rtx_MEM (mode
,
3755 expand_expr (build1 (ADDR_EXPR
,
3756 build_pointer_type (type
),
3757 make_tree (type
, val
)),
3758 NULL_RTX
, VOIDmode
, 0));
3761 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3762 gen_rtx_USE (VOIDmode
, slot
),
3765 call_fusage
= gen_rtx_EXPR_LIST (VOIDmode
,
3766 gen_rtx_CLOBBER (VOIDmode
,
3771 val
= force_operand (XEXP (slot
, 0), NULL_RTX
);
3775 argvec
[count
].value
= val
;
3776 argvec
[count
].mode
= mode
;
3778 argvec
[count
].reg
= FUNCTION_ARG (args_so_far
, mode
, NULL_TREE
, 1);
3780 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3781 argvec
[count
].partial
3782 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, mode
, NULL_TREE
, 1);
3784 argvec
[count
].partial
= 0;
3787 locate_and_pad_parm (mode
, NULL_TREE
,
3788 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3791 argvec
[count
].reg
!= 0,
3793 NULL_TREE
, &args_size
, &argvec
[count
].offset
,
3794 &argvec
[count
].size
, &alignment_pad
);
3796 if (argvec
[count
].size
.var
)
3799 if (reg_parm_stack_space
== 0 && argvec
[count
].partial
)
3800 argvec
[count
].size
.constant
-= argvec
[count
].partial
* UNITS_PER_WORD
;
3802 if (argvec
[count
].reg
== 0 || argvec
[count
].partial
!= 0
3803 || reg_parm_stack_space
> 0)
3804 args_size
.constant
+= argvec
[count
].size
.constant
;
3806 FUNCTION_ARG_ADVANCE (args_so_far
, mode
, (tree
) 0, 1);
3809 #ifdef FINAL_REG_PARM_STACK_SPACE
3810 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
3813 /* If this machine requires an external definition for library
3814 functions, write one out. */
3815 assemble_external_libcall (fun
);
3817 original_args_size
= args_size
;
3818 args_size
.constant
= (((args_size
.constant
3819 + stack_pointer_delta
3823 - stack_pointer_delta
);
3825 args_size
.constant
= MAX (args_size
.constant
,
3826 reg_parm_stack_space
);
3828 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3829 args_size
.constant
-= reg_parm_stack_space
;
3832 if (args_size
.constant
> current_function_outgoing_args_size
)
3833 current_function_outgoing_args_size
= args_size
.constant
;
3835 if (ACCUMULATE_OUTGOING_ARGS
)
3837 /* Since the stack pointer will never be pushed, it is possible for
3838 the evaluation of a parm to clobber something we have already
3839 written to the stack. Since most function calls on RISC machines
3840 do not use the stack, this is uncommon, but must work correctly.
3842 Therefore, we save any area of the stack that was already written
3843 and that we are using. Here we set up to do this by making a new
3844 stack usage map from the old one.
3846 Another approach might be to try to reorder the argument
3847 evaluations to avoid this conflicting stack usage. */
3849 needed
= args_size
.constant
;
3851 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3852 /* Since we will be writing into the entire argument area, the
3853 map must be allocated for its entire size, not just the part that
3854 is the responsibility of the caller. */
3855 needed
+= reg_parm_stack_space
;
3858 #ifdef ARGS_GROW_DOWNWARD
3859 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3862 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
3865 stack_usage_map
= (char *) alloca (highest_outgoing_arg_in_use
);
3867 if (initial_highest_arg_in_use
)
3868 memcpy (stack_usage_map
, initial_stack_usage_map
,
3869 initial_highest_arg_in_use
);
3871 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
3872 memset (&stack_usage_map
[initial_highest_arg_in_use
], 0,
3873 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
3876 /* We must be careful to use virtual regs before they're instantiated,
3877 and real regs afterwards. Loop optimization, for example, can create
3878 new libcalls after we've instantiated the virtual regs, and if we
3879 use virtuals anyway, they won't match the rtl patterns. */
3881 if (virtuals_instantiated
)
3882 argblock
= plus_constant (stack_pointer_rtx
, STACK_POINTER_OFFSET
);
3884 argblock
= virtual_outgoing_args_rtx
;
3889 argblock
= push_block (GEN_INT (args_size
.constant
), 0, 0);
3892 /* If we push args individually in reverse order, perform stack alignment
3893 before the first push (the last arg). */
3894 if (argblock
== 0 && PUSH_ARGS_REVERSED
)
3895 anti_adjust_stack (GEN_INT (args_size
.constant
3896 - original_args_size
.constant
));
3898 if (PUSH_ARGS_REVERSED
)
3909 #ifdef REG_PARM_STACK_SPACE
3910 if (ACCUMULATE_OUTGOING_ARGS
)
3912 /* The argument list is the property of the called routine and it
3913 may clobber it. If the fixed area has been used for previous
3914 parameters, we must save and restore it. */
3915 save_area
= save_fixed_argument_area (reg_parm_stack_space
, argblock
,
3916 &low_to_save
, &high_to_save
);
3920 /* Push the args that need to be pushed. */
3922 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3923 are to be pushed. */
3924 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
3926 enum machine_mode mode
= argvec
[argnum
].mode
;
3927 rtx val
= argvec
[argnum
].value
;
3928 rtx reg
= argvec
[argnum
].reg
;
3929 int partial
= argvec
[argnum
].partial
;
3930 int lower_bound
= 0, upper_bound
= 0, i
;
3932 if (! (reg
!= 0 && partial
== 0))
3934 if (ACCUMULATE_OUTGOING_ARGS
)
3936 /* If this is being stored into a pre-allocated, fixed-size,
3937 stack area, save any previous data at that location. */
3939 #ifdef ARGS_GROW_DOWNWARD
3940 /* stack_slot is negative, but we want to index stack_usage_map
3941 with positive values. */
3942 upper_bound
= -argvec
[argnum
].offset
.constant
+ 1;
3943 lower_bound
= upper_bound
- argvec
[argnum
].size
.constant
;
3945 lower_bound
= argvec
[argnum
].offset
.constant
;
3946 upper_bound
= lower_bound
+ argvec
[argnum
].size
.constant
;
3950 /* Don't worry about things in the fixed argument area;
3951 it has already been saved. */
3952 if (i
< reg_parm_stack_space
)
3953 i
= reg_parm_stack_space
;
3954 while (i
< upper_bound
&& stack_usage_map
[i
] == 0)
3957 if (i
< upper_bound
)
3959 /* We need to make a save area. See what mode we can make
3961 enum machine_mode save_mode
3962 = mode_for_size (argvec
[argnum
].size
.constant
3970 plus_constant (argblock
,
3971 argvec
[argnum
].offset
.constant
)));
3972 argvec
[argnum
].save_area
= gen_reg_rtx (save_mode
);
3974 emit_move_insn (argvec
[argnum
].save_area
, stack_area
);
3978 emit_push_insn (val
, mode
, NULL_TREE
, NULL_RTX
, PARM_BOUNDARY
,
3979 partial
, reg
, 0, argblock
,
3980 GEN_INT (argvec
[argnum
].offset
.constant
),
3981 reg_parm_stack_space
, ARGS_SIZE_RTX (alignment_pad
));
3983 /* Now mark the segment we just used. */
3984 if (ACCUMULATE_OUTGOING_ARGS
)
3985 for (i
= lower_bound
; i
< upper_bound
; i
++)
3986 stack_usage_map
[i
] = 1;
3992 /* If we pushed args in forward order, perform stack alignment
3993 after pushing the last arg. */
3994 if (argblock
== 0 && !PUSH_ARGS_REVERSED
)
3995 anti_adjust_stack (GEN_INT (args_size
.constant
3996 - original_args_size
.constant
));
3998 if (PUSH_ARGS_REVERSED
)
4003 fun
= prepare_call_address (fun
, NULL_TREE
, &call_fusage
, 0, 0);
4005 /* Now load any reg parms into their regs. */
4007 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4008 are to be pushed. */
4009 for (count
= 0; count
< nargs
; count
++, argnum
+= inc
)
4011 rtx val
= argvec
[argnum
].value
;
4012 rtx reg
= argvec
[argnum
].reg
;
4013 int partial
= argvec
[argnum
].partial
;
4015 /* Handle calls that pass values in multiple non-contiguous
4016 locations. The PA64 has examples of this for library calls. */
4017 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
4018 emit_group_load (reg
, val
, GET_MODE_SIZE (GET_MODE (val
)));
4019 else if (reg
!= 0 && partial
== 0)
4020 emit_move_insn (reg
, val
);
4025 /* Any regs containing parms remain in use through the call. */
4026 for (count
= 0; count
< nargs
; count
++)
4028 rtx reg
= argvec
[count
].reg
;
4029 if (reg
!= 0 && GET_CODE (reg
) == PARALLEL
)
4030 use_group_regs (&call_fusage
, reg
);
4032 use_reg (&call_fusage
, reg
);
4035 /* Pass the function the address in which to return a structure value. */
4036 if (mem_value
!= 0 && struct_value_rtx
!= 0 && ! pcc_struct_value
)
4038 emit_move_insn (struct_value_rtx
,
4040 force_operand (XEXP (mem_value
, 0),
4042 if (GET_CODE (struct_value_rtx
) == REG
)
4043 use_reg (&call_fusage
, struct_value_rtx
);
4046 /* Don't allow popping to be deferred, since then
4047 cse'ing of library calls could delete a call and leave the pop. */
4049 valreg
= (mem_value
== 0 && outmode
!= VOIDmode
4050 ? hard_libcall_value (outmode
) : NULL_RTX
);
4052 /* Stack must be properly aligned now. */
4053 if (stack_pointer_delta
& (PREFERRED_STACK_BOUNDARY
/ BITS_PER_UNIT
- 1))
4056 before_call
= get_last_insn ();
4058 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4059 will set inhibit_defer_pop to that value. */
4060 /* The return type is needed to decide how many bytes the function pops.
4061 Signedness plays no role in that, so for simplicity, we pretend it's
4062 always signed. We also assume that the list of arguments passed has
4063 no impact, so we pretend it is unknown. */
4066 get_identifier (XSTR (orgfun
, 0)),
4067 build_function_type (tfom
, NULL_TREE
),
4068 original_args_size
.constant
, args_size
.constant
,
4070 FUNCTION_ARG (args_so_far
, VOIDmode
, void_type_node
, 1),
4072 old_inhibit_defer_pop
+ 1, call_fusage
, flags
, & args_so_far
);
4074 /* For calls to `setjmp', etc., inform flow.c it should complain
4075 if nonvolatile values are live. For functions that cannot return,
4076 inform flow that control does not fall through. */
4078 if (flags
& (ECF_NORETURN
| ECF_LONGJMP
))
4080 /* The barrier note must be emitted
4081 immediately after the CALL_INSN. Some ports emit more than
4082 just a CALL_INSN above, so we must search for it here. */
4084 rtx last
= get_last_insn ();
4085 while (GET_CODE (last
) != CALL_INSN
)
4087 last
= PREV_INSN (last
);
4088 /* There was no CALL_INSN? */
4089 if (last
== before_call
)
4093 emit_barrier_after (last
);
4096 /* Now restore inhibit_defer_pop to its actual original value. */
4099 /* If call is cse'able, make appropriate pair of reg-notes around it.
4100 Test valreg so we don't crash; may safely ignore `const'
4101 if return type is void. Disable for PARALLEL return values, because
4102 we have no way to move such values into a pseudo register. */
4103 if (flags
& ECF_LIBCALL_BLOCK
)
4109 insns
= get_insns ();
4119 if (GET_CODE (valreg
) == PARALLEL
)
4121 temp
= gen_reg_rtx (outmode
);
4122 emit_group_store (temp
, valreg
, outmode
);
4126 temp
= gen_reg_rtx (GET_MODE (valreg
));
4128 /* Construct an "equal form" for the value which mentions all the
4129 arguments in order as well as the function name. */
4130 for (i
= 0; i
< nargs
; i
++)
4131 note
= gen_rtx_EXPR_LIST (VOIDmode
, argvec
[i
].value
, note
);
4132 note
= gen_rtx_EXPR_LIST (VOIDmode
, fun
, note
);
4134 insns
= get_insns ();
4137 if (flags
& ECF_PURE
)
4138 note
= gen_rtx_EXPR_LIST (VOIDmode
,
4139 gen_rtx_USE (VOIDmode
,
4140 gen_rtx_MEM (BLKmode
,
4141 gen_rtx_SCRATCH (VOIDmode
))),
4144 emit_libcall_block (insns
, temp
, valreg
, note
);
4151 /* Copy the value to the right place. */
4152 if (outmode
!= VOIDmode
&& retval
)
4158 if (value
!= mem_value
)
4159 emit_move_insn (value
, mem_value
);
4161 else if (GET_CODE (valreg
) == PARALLEL
)
4164 value
= gen_reg_rtx (outmode
);
4165 emit_group_store (value
, valreg
, outmode
);
4167 else if (value
!= 0)
4168 emit_move_insn (value
, valreg
);
4173 if (ACCUMULATE_OUTGOING_ARGS
)
4175 #ifdef REG_PARM_STACK_SPACE
4177 restore_fixed_argument_area (save_area
, argblock
,
4178 high_to_save
, low_to_save
);
4181 /* If we saved any argument areas, restore them. */
4182 for (count
= 0; count
< nargs
; count
++)
4183 if (argvec
[count
].save_area
)
4185 enum machine_mode save_mode
= GET_MODE (argvec
[count
].save_area
);
4187 = gen_rtx_MEM (save_mode
,
4190 plus_constant (argblock
,
4191 argvec
[count
].offset
.constant
)));
4193 emit_move_insn (stack_area
, argvec
[count
].save_area
);
4196 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
4197 stack_usage_map
= initial_stack_usage_map
;
4204 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4205 (emitting the queue unless NO_QUEUE is nonzero),
4206 for a value of mode OUTMODE,
4207 with NARGS different arguments, passed as alternating rtx values
4208 and machine_modes to convert them to.
4209 The rtx values should have been passed through protect_from_queue already.
4211 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4212 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4213 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4214 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4215 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4216 or other LCT_ value for other types of library calls. */
4219 emit_library_call
VPARAMS((rtx orgfun
, enum libcall_type fn_type
,
4220 enum machine_mode outmode
, int nargs
, ...))
4223 VA_FIXEDARG (p
, rtx
, orgfun
);
4224 VA_FIXEDARG (p
, int, fn_type
);
4225 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4226 VA_FIXEDARG (p
, int, nargs
);
4228 emit_library_call_value_1 (0, orgfun
, NULL_RTX
, fn_type
, outmode
, nargs
, p
);
4233 /* Like emit_library_call except that an extra argument, VALUE,
4234 comes second and says where to store the result.
4235 (If VALUE is zero, this function chooses a convenient way
4236 to return the value.
4238 This function returns an rtx for where the value is to be found.
4239 If VALUE is nonzero, VALUE is returned. */
4242 emit_library_call_value
VPARAMS((rtx orgfun
, rtx value
,
4243 enum libcall_type fn_type
,
4244 enum machine_mode outmode
, int nargs
, ...))
4249 VA_FIXEDARG (p
, rtx
, orgfun
);
4250 VA_FIXEDARG (p
, rtx
, value
);
4251 VA_FIXEDARG (p
, int, fn_type
);
4252 VA_FIXEDARG (p
, enum machine_mode
, outmode
);
4253 VA_FIXEDARG (p
, int, nargs
);
4255 result
= emit_library_call_value_1 (1, orgfun
, value
, fn_type
, outmode
,
4263 /* Store a single argument for a function call
4264 into the register or memory area where it must be passed.
4265 *ARG describes the argument value and where to pass it.
4267 ARGBLOCK is the address of the stack-block for all the arguments,
4268 or 0 on a machine where arguments are pushed individually.
4270 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4271 so must be careful about how the stack is used.
4273 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4274 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4275 that we need not worry about saving and restoring the stack.
4277 FNDECL is the declaration of the function we are calling.
4279 Return nonzero if this arg should cause sibcall failure,
4283 store_one_arg (arg
, argblock
, flags
, variable_size
, reg_parm_stack_space
)
4284 struct arg_data
*arg
;
4287 int variable_size ATTRIBUTE_UNUSED
;
4288 int reg_parm_stack_space
;
4290 tree pval
= arg
->tree_value
;
4294 int i
, lower_bound
= 0, upper_bound
= 0;
4295 int sibcall_failure
= 0;
4297 if (TREE_CODE (pval
) == ERROR_MARK
)
4300 /* Push a new temporary level for any temporaries we make for
4304 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
))
4306 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4307 save any previous data at that location. */
4308 if (argblock
&& ! variable_size
&& arg
->stack
)
4310 #ifdef ARGS_GROW_DOWNWARD
4311 /* stack_slot is negative, but we want to index stack_usage_map
4312 with positive values. */
4313 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4314 upper_bound
= -INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1)) + 1;
4318 lower_bound
= upper_bound
- arg
->size
.constant
;
4320 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
4321 lower_bound
= INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1));
4325 upper_bound
= lower_bound
+ arg
->size
.constant
;
4329 /* Don't worry about things in the fixed argument area;
4330 it has already been saved. */
4331 if (i
< reg_parm_stack_space
)
4332 i
= reg_parm_stack_space
;
4333 while (i
< upper_bound
&& stack_usage_map
[i
] == 0)
4336 if (i
< upper_bound
)
4338 /* We need to make a save area. See what mode we can make it. */
4339 enum machine_mode save_mode
4340 = mode_for_size (arg
->size
.constant
* BITS_PER_UNIT
, MODE_INT
, 1);
4342 = gen_rtx_MEM (save_mode
,
4343 memory_address (save_mode
,
4344 XEXP (arg
->stack_slot
, 0)));
4346 if (save_mode
== BLKmode
)
4348 tree ot
= TREE_TYPE (arg
->tree_value
);
4349 tree nt
= build_qualified_type (ot
, (TYPE_QUALS (ot
)
4350 | TYPE_QUAL_CONST
));
4352 arg
->save_area
= assign_temp (nt
, 0, 1, 1);
4353 preserve_temp_slots (arg
->save_area
);
4354 emit_block_move (validize_mem (arg
->save_area
), stack_area
,
4355 expr_size (arg
->tree_value
),
4356 BLOCK_OP_CALL_PARM
);
4360 arg
->save_area
= gen_reg_rtx (save_mode
);
4361 emit_move_insn (arg
->save_area
, stack_area
);
4367 /* If this isn't going to be placed on both the stack and in registers,
4368 set up the register and number of words. */
4369 if (! arg
->pass_on_stack
)
4371 if (flags
& ECF_SIBCALL
)
4372 reg
= arg
->tail_call_reg
;
4375 partial
= arg
->partial
;
4378 if (reg
!= 0 && partial
== 0)
4379 /* Being passed entirely in a register. We shouldn't be called in
4383 /* If this arg needs special alignment, don't load the registers
4385 if (arg
->n_aligned_regs
!= 0)
4388 /* If this is being passed partially in a register, we can't evaluate
4389 it directly into its stack slot. Otherwise, we can. */
4390 if (arg
->value
== 0)
4392 /* stack_arg_under_construction is nonzero if a function argument is
4393 being evaluated directly into the outgoing argument list and
4394 expand_call must take special action to preserve the argument list
4395 if it is called recursively.
4397 For scalar function arguments stack_usage_map is sufficient to
4398 determine which stack slots must be saved and restored. Scalar
4399 arguments in general have pass_on_stack == 0.
4401 If this argument is initialized by a function which takes the
4402 address of the argument (a C++ constructor or a C function
4403 returning a BLKmode structure), then stack_usage_map is
4404 insufficient and expand_call must push the stack around the
4405 function call. Such arguments have pass_on_stack == 1.
4407 Note that it is always safe to set stack_arg_under_construction,
4408 but this generates suboptimal code if set when not needed. */
4410 if (arg
->pass_on_stack
)
4411 stack_arg_under_construction
++;
4413 arg
->value
= expand_expr (pval
,
4415 || TYPE_MODE (TREE_TYPE (pval
)) != arg
->mode
)
4416 ? NULL_RTX
: arg
->stack
,
4417 VOIDmode
, EXPAND_STACK_PARM
);
4419 /* If we are promoting object (or for any other reason) the mode
4420 doesn't agree, convert the mode. */
4422 if (arg
->mode
!= TYPE_MODE (TREE_TYPE (pval
)))
4423 arg
->value
= convert_modes (arg
->mode
, TYPE_MODE (TREE_TYPE (pval
)),
4424 arg
->value
, arg
->unsignedp
);
4426 if (arg
->pass_on_stack
)
4427 stack_arg_under_construction
--;
4430 /* Don't allow anything left on stack from computation
4431 of argument to alloca. */
4432 if (flags
& ECF_MAY_BE_ALLOCA
)
4433 do_pending_stack_adjust ();
4435 if (arg
->value
== arg
->stack
)
4436 /* If the value is already in the stack slot, we are done. */
4438 else if (arg
->mode
!= BLKmode
)
4442 /* Argument is a scalar, not entirely passed in registers.
4443 (If part is passed in registers, arg->partial says how much
4444 and emit_push_insn will take care of putting it there.)
4446 Push it, and if its size is less than the
4447 amount of space allocated to it,
4448 also bump stack pointer by the additional space.
4449 Note that in C the default argument promotions
4450 will prevent such mismatches. */
4452 size
= GET_MODE_SIZE (arg
->mode
);
4453 /* Compute how much space the push instruction will push.
4454 On many machines, pushing a byte will advance the stack
4455 pointer by a halfword. */
4456 #ifdef PUSH_ROUNDING
4457 size
= PUSH_ROUNDING (size
);
4461 /* Compute how much space the argument should get:
4462 round up to a multiple of the alignment for arguments. */
4463 if (none
!= FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)))
4464 used
= (((size
+ PARM_BOUNDARY
/ BITS_PER_UNIT
- 1)
4465 / (PARM_BOUNDARY
/ BITS_PER_UNIT
))
4466 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
4468 /* This isn't already where we want it on the stack, so put it there.
4469 This can either be done with push or copy insns. */
4470 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), NULL_RTX
,
4471 PARM_BOUNDARY
, partial
, reg
, used
- size
, argblock
,
4472 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4473 ARGS_SIZE_RTX (arg
->alignment_pad
));
4475 /* Unless this is a partially-in-register argument, the argument is now
4478 arg
->value
= arg
->stack
;
4482 /* BLKmode, at least partly to be pushed. */
4484 unsigned int parm_align
;
4488 /* Pushing a nonscalar.
4489 If part is passed in registers, PARTIAL says how much
4490 and emit_push_insn will take care of putting it there. */
4492 /* Round its size up to a multiple
4493 of the allocation unit for arguments. */
4495 if (arg
->size
.var
!= 0)
4498 size_rtx
= ARGS_SIZE_RTX (arg
->size
);
4502 /* PUSH_ROUNDING has no effect on us, because
4503 emit_push_insn for BLKmode is careful to avoid it. */
4504 excess
= (arg
->size
.constant
- int_size_in_bytes (TREE_TYPE (pval
))
4505 + partial
* UNITS_PER_WORD
);
4506 size_rtx
= expand_expr (size_in_bytes (TREE_TYPE (pval
)),
4507 NULL_RTX
, TYPE_MODE (sizetype
), 0);
4510 /* Some types will require stricter alignment, which will be
4511 provided for elsewhere in argument layout. */
4512 parm_align
= MAX (PARM_BOUNDARY
, TYPE_ALIGN (TREE_TYPE (pval
)));
4514 /* When an argument is padded down, the block is aligned to
4515 PARM_BOUNDARY, but the actual argument isn't. */
4516 if (FUNCTION_ARG_PADDING (arg
->mode
, TREE_TYPE (pval
)) == downward
)
4519 parm_align
= BITS_PER_UNIT
;
4522 unsigned int excess_align
= (excess
& -excess
) * BITS_PER_UNIT
;
4523 parm_align
= MIN (parm_align
, excess_align
);
4527 if ((flags
& ECF_SIBCALL
) && GET_CODE (arg
->value
) == MEM
)
4529 /* emit_push_insn might not work properly if arg->value and
4530 argblock + arg->offset areas overlap. */
4534 if (XEXP (x
, 0) == current_function_internal_arg_pointer
4535 || (GET_CODE (XEXP (x
, 0)) == PLUS
4536 && XEXP (XEXP (x
, 0), 0) ==
4537 current_function_internal_arg_pointer
4538 && GET_CODE (XEXP (XEXP (x
, 0), 1)) == CONST_INT
))
4540 if (XEXP (x
, 0) != current_function_internal_arg_pointer
)
4541 i
= INTVAL (XEXP (XEXP (x
, 0), 1));
4543 /* expand_call should ensure this */
4544 if (arg
->offset
.var
|| GET_CODE (size_rtx
) != CONST_INT
)
4547 if (arg
->offset
.constant
> i
)
4549 if (arg
->offset
.constant
< i
+ INTVAL (size_rtx
))
4550 sibcall_failure
= 1;
4552 else if (arg
->offset
.constant
< i
)
4554 if (i
< arg
->offset
.constant
+ INTVAL (size_rtx
))
4555 sibcall_failure
= 1;
4560 emit_push_insn (arg
->value
, arg
->mode
, TREE_TYPE (pval
), size_rtx
,
4561 parm_align
, partial
, reg
, excess
, argblock
,
4562 ARGS_SIZE_RTX (arg
->offset
), reg_parm_stack_space
,
4563 ARGS_SIZE_RTX (arg
->alignment_pad
));
4565 /* Unless this is a partially-in-register argument, the argument is now
4568 ??? Unlike the case above, in which we want the actual
4569 address of the data, so that we can load it directly into a
4570 register, here we want the address of the stack slot, so that
4571 it's properly aligned for word-by-word copying or something
4572 like that. It's not clear that this is always correct. */
4574 arg
->value
= arg
->stack_slot
;
4577 /* Mark all slots this store used. */
4578 if (ACCUMULATE_OUTGOING_ARGS
&& !(flags
& ECF_SIBCALL
)
4579 && argblock
&& ! variable_size
&& arg
->stack
)
4580 for (i
= lower_bound
; i
< upper_bound
; i
++)
4581 stack_usage_map
[i
] = 1;
4583 /* Once we have pushed something, pops can't safely
4584 be deferred during the rest of the arguments. */
4587 /* ANSI doesn't require a sequence point here,
4588 but PCC has one, so this will avoid some problems. */
4591 /* Free any temporary slots made in processing this argument. Show
4592 that we might have taken the address of something and pushed that
4594 preserve_temp_slots (NULL_RTX
);
4598 return sibcall_failure
;
4601 /* Nonzero if we do not know how to pass TYPE solely in registers.
4602 We cannot do so in the following cases:
4604 - if the type has variable size
4605 - if the type is marked as addressable (it is required to be constructed
4607 - if the padding and mode of the type is such that a copy into a register
4608 would put it into the wrong part of the register.
4610 Which padding can't be supported depends on the byte endianness.
4612 A value in a register is implicitly padded at the most significant end.
4613 On a big-endian machine, that is the lower end in memory.
4614 So a value padded in memory at the upper end can't go in a register.
4615 For a little-endian machine, the reverse is true. */
4618 default_must_pass_in_stack (mode
, type
)
4619 enum machine_mode mode
;
4625 /* If the type has variable size... */
4626 if (TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
4629 /* If the type is marked as addressable (it is required
4630 to be constructed into the stack)... */
4631 if (TREE_ADDRESSABLE (type
))
4634 /* If the padding and mode of the type is such that a copy into
4635 a register would put it into the wrong part of the register. */
4637 && int_size_in_bytes (type
) % (PARM_BOUNDARY
/ BITS_PER_UNIT
)
4638 && (FUNCTION_ARG_PADDING (mode
, type
)
4639 == (BYTES_BIG_ENDIAN
? upward
: downward
)))