1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
25 #include "insn-flags.h"
27 /* Decide whether a function's arguments should be processed
28 from first to last or from last to first. */
30 #ifdef STACK_GROWS_DOWNWARD
32 #define PUSH_ARGS_REVERSED /* If it's last to first */
36 /* Like STACK_BOUNDARY but in units of bytes, not bits. */
37 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
39 /* Data structure and subroutines used within expand_call. */
43 /* Tree node for this argument. */
45 /* Current RTL value for argument, or 0 if it isn't precomputed. */
47 /* Initially-compute RTL value for argument; only for const functions. */
49 /* Register to pass this argument in, 0 if passed on stack, or an
50 EXPR_LIST if the arg is to be copied into multiple different
53 /* If REG was promoted from the actual mode of the argument expression,
54 indicates whether the promotion is sign- or zero-extended. */
56 /* Number of registers to use. 0 means put the whole arg in registers.
57 Also 0 if not passed in registers. */
59 /* Non-zero if argument must be passed on stack.
60 Note that some arguments may be passed on the stack
61 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
62 pass_on_stack identifies arguments that *cannot* go in registers. */
64 /* Offset of this argument from beginning of stack-args. */
65 struct args_size offset
;
66 /* Similar, but offset to the start of the stack slot. Different from
67 OFFSET if this arg pads downward. */
68 struct args_size slot_offset
;
69 /* Size of this argument on the stack, rounded up for any padding it gets,
70 parts of the argument passed in registers do not count.
71 If REG_PARM_STACK_SPACE is defined, then register parms
72 are counted here as well. */
73 struct args_size size
;
74 /* Location on the stack at which parameter should be stored. The store
75 has already been done if STACK == VALUE. */
77 /* Location on the stack of the start of this argument slot. This can
78 differ from STACK if this arg pads downward. This location is known
79 to be aligned to FUNCTION_ARG_BOUNDARY. */
81 #ifdef ACCUMULATE_OUTGOING_ARGS
82 /* Place that this stack area has been saved, if needed. */
87 #ifdef ACCUMULATE_OUTGOING_ARGS
88 /* A vector of one char per byte of stack space. A byte if non-zero if
89 the corresponding stack location has been used.
90 This vector is used to prevent a function call within an argument from
91 clobbering any stack already set up. */
92 static char *stack_usage_map
;
94 /* Size of STACK_USAGE_MAP. */
95 static int highest_outgoing_arg_in_use
;
97 /* stack_arg_under_construction is nonzero when an argument may be
98 initialized with a constructor call (including a C function that
99 returns a BLKmode struct) and expand_call must take special action
100 to make sure the object being constructed does not overlap the
101 argument list for the constructor call. */
102 int stack_arg_under_construction
;
105 static void store_one_arg ();
106 extern enum machine_mode
mode_for_size ();
108 /* Return 1 if EXP contains a call to the built-in function `alloca'. */
115 int type
= TREE_CODE_CLASS (TREE_CODE (exp
));
116 int length
= tree_code_length
[(int) TREE_CODE (exp
)];
118 /* Only expressions and references can contain calls. */
120 if (type
!= 'e' && type
!= '<' && type
!= '1' && type
!= '2' && type
!= 'r'
124 switch (TREE_CODE (exp
))
127 if (TREE_CODE (TREE_OPERAND (exp
, 0)) == ADDR_EXPR
128 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
130 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
131 && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp
, 0), 0))
135 /* Third operand is RTL. */
140 if (SAVE_EXPR_RTL (exp
) != 0)
148 for (local
= BLOCK_VARS (exp
); local
; local
= TREE_CHAIN (local
))
149 if (DECL_INITIAL (local
) != 0 && calls_alloca (DECL_INITIAL (local
)))
153 register tree subblock
;
155 for (subblock
= BLOCK_SUBBLOCKS (exp
);
157 subblock
= TREE_CHAIN (subblock
))
158 if (calls_alloca (subblock
))
163 case METHOD_CALL_EXPR
:
167 case WITH_CLEANUP_EXPR
:
175 for (i
= 0; i
< length
; i
++)
176 if (TREE_OPERAND (exp
, i
) != 0
177 && calls_alloca (TREE_OPERAND (exp
, i
)))
183 /* Force FUNEXP into a form suitable for the address of a CALL,
184 and return that as an rtx. Also load the static chain register
185 if FNDECL is a nested function.
187 USE_INSNS points to a variable holding a chain of USE insns
188 to which a USE of the static chain
189 register should be added, if required. */
192 prepare_call_address (funexp
, fndecl
, use_insns
)
197 rtx static_chain_value
= 0;
199 funexp
= protect_from_queue (funexp
, 0);
202 /* Get possible static chain value for nested function in C. */
203 static_chain_value
= lookup_static_chain (fndecl
);
205 /* Make a valid memory address and copy constants thru pseudo-regs,
206 but not for a constant address if -fno-function-cse. */
207 if (GET_CODE (funexp
) != SYMBOL_REF
)
208 funexp
= memory_address (FUNCTION_MODE
, funexp
);
211 #ifndef NO_FUNCTION_CSE
212 if (optimize
&& ! flag_no_function_cse
)
213 #ifdef NO_RECURSIVE_FUNCTION_CSE
214 if (fndecl
!= current_function_decl
)
216 funexp
= force_reg (Pmode
, funexp
);
220 if (static_chain_value
!= 0)
222 emit_move_insn (static_chain_rtx
, static_chain_value
);
224 /* Put the USE insn in the chain we were passed. It will later be
225 output immediately in front of the CALL insn. */
226 push_to_sequence (*use_insns
);
227 emit_insn (gen_rtx (USE
, VOIDmode
, static_chain_rtx
));
228 *use_insns
= get_insns ();
235 /* Generate instructions to call function FUNEXP,
236 and optionally pop the results.
237 The CALL_INSN is the first insn generated.
239 FUNTYPE is the data type of the function, or, for a library call,
240 the identifier for the name of the call. This is given to the
241 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
243 STACK_SIZE is the number of bytes of arguments on the stack,
244 rounded up to STACK_BOUNDARY; zero if the size is variable.
245 This is both to put into the call insn and
246 to generate explicit popping code if necessary.
248 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
249 It is zero if this call doesn't want a structure value.
251 NEXT_ARG_REG is the rtx that results from executing
252 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
253 just after all the args have had their registers assigned.
254 This could be whatever you like, but normally it is the first
255 arg-register beyond those used for args in this call,
256 or 0 if all the arg-registers are used in this call.
257 It is passed on to `gen_call' so you can put this info in the call insn.
259 VALREG is a hard register in which a value is returned,
260 or 0 if the call does not return a value.
262 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
263 the args to this call were processed.
264 We restore `inhibit_defer_pop' to that value.
266 USE_INSNS is a chain of USE insns to be emitted immediately before
267 the actual CALL insn.
269 IS_CONST is true if this is a `const' call. */
272 emit_call_1 (funexp
, funtype
, stack_size
, struct_value_size
, next_arg_reg
,
273 valreg
, old_inhibit_defer_pop
, use_insns
, is_const
)
277 int struct_value_size
;
280 int old_inhibit_defer_pop
;
284 rtx stack_size_rtx
= GEN_INT (stack_size
);
285 rtx struct_value_size_rtx
= GEN_INT (struct_value_size
);
287 int already_popped
= 0;
289 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
290 and we don't want to load it into a register as an optimization,
291 because prepare_call_address already did it if it should be done. */
292 if (GET_CODE (funexp
) != SYMBOL_REF
)
293 funexp
= memory_address (FUNCTION_MODE
, funexp
);
295 #ifndef ACCUMULATE_OUTGOING_ARGS
296 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
297 if (HAVE_call_pop
&& HAVE_call_value_pop
298 && (RETURN_POPS_ARGS (funtype
, stack_size
) > 0 || stack_size
== 0))
300 rtx n_pop
= GEN_INT (RETURN_POPS_ARGS (funtype
, stack_size
));
303 /* If this subroutine pops its own args, record that in the call insn
304 if possible, for the sake of frame pointer elimination. */
306 pat
= gen_call_value_pop (valreg
,
307 gen_rtx (MEM
, FUNCTION_MODE
, funexp
),
308 stack_size_rtx
, next_arg_reg
, n_pop
);
310 pat
= gen_call_pop (gen_rtx (MEM
, FUNCTION_MODE
, funexp
),
311 stack_size_rtx
, next_arg_reg
, n_pop
);
313 emit_call_insn (pat
);
320 #if defined (HAVE_call) && defined (HAVE_call_value)
321 if (HAVE_call
&& HAVE_call_value
)
324 emit_call_insn (gen_call_value (valreg
,
325 gen_rtx (MEM
, FUNCTION_MODE
, funexp
),
326 stack_size_rtx
, next_arg_reg
));
328 emit_call_insn (gen_call (gen_rtx (MEM
, FUNCTION_MODE
, funexp
),
329 stack_size_rtx
, next_arg_reg
,
330 struct_value_size_rtx
));
336 /* Find the CALL insn we just emitted and write the USE insns before it. */
337 for (call_insn
= get_last_insn ();
338 call_insn
&& GET_CODE (call_insn
) != CALL_INSN
;
339 call_insn
= PREV_INSN (call_insn
))
345 /* Put the USE insns before the CALL. */
346 emit_insns_before (use_insns
, call_insn
);
348 /* If this is a const call, then set the insn's unchanging bit. */
350 CONST_CALL_P (call_insn
) = 1;
352 #ifndef ACCUMULATE_OUTGOING_ARGS
353 /* If returning from the subroutine does not automatically pop the args,
354 we need an instruction to pop them sooner or later.
355 Perhaps do it now; perhaps just record how much space to pop later.
357 If returning from the subroutine does pop the args, indicate that the
358 stack pointer will be changed. */
360 if (stack_size
!= 0 && RETURN_POPS_ARGS (funtype
, stack_size
) > 0)
363 emit_insn (gen_rtx (CLOBBER
, VOIDmode
, stack_pointer_rtx
));
364 stack_size
-= RETURN_POPS_ARGS (funtype
, stack_size
);
365 stack_size_rtx
= GEN_INT (stack_size
);
370 if (flag_defer_pop
&& inhibit_defer_pop
== 0)
371 pending_stack_adjust
+= stack_size
;
373 adjust_stack (stack_size_rtx
);
377 inhibit_defer_pop
= old_inhibit_defer_pop
;
380 /* Generate all the code for a function call
381 and return an rtx for its value.
382 Store the value in TARGET (specified as an rtx) if convenient.
383 If the value is stored in TARGET then TARGET is returned.
384 If IGNORE is nonzero, then we ignore the value of the function call. */
387 expand_call (exp
, target
, ignore
)
392 /* List of actual parameters. */
393 tree actparms
= TREE_OPERAND (exp
, 1);
394 /* RTX for the function to be called. */
396 /* Tree node for the function to be called (not the address!). */
398 /* Data type of the function. */
400 /* Declaration of the function being called,
401 or 0 if the function is computed (not known by name). */
405 /* Register in which non-BLKmode value will be returned,
406 or 0 if no value or if value is BLKmode. */
408 /* Address where we should return a BLKmode value;
409 0 if value not BLKmode. */
410 rtx structure_value_addr
= 0;
411 /* Nonzero if that address is being passed by treating it as
412 an extra, implicit first parameter. Otherwise,
413 it is passed by being copied directly into struct_value_rtx. */
414 int structure_value_addr_parm
= 0;
415 /* Size of aggregate value wanted, or zero if none wanted
416 or if we are using the non-reentrant PCC calling convention
417 or expecting the value in registers. */
418 int struct_value_size
= 0;
419 /* Nonzero if called function returns an aggregate in memory PCC style,
420 by returning the address of where to find it. */
421 int pcc_struct_value
= 0;
423 /* Number of actual parameters in this call, including struct value addr. */
425 /* Number of named args. Args after this are anonymous ones
426 and they must all go on the stack. */
428 /* Count arg position in order args appear. */
431 /* Vector of information about each argument.
432 Arguments are numbered in the order they will be pushed,
433 not the order they are written. */
434 struct arg_data
*args
;
436 /* Total size in bytes of all the stack-parms scanned so far. */
437 struct args_size args_size
;
438 /* Size of arguments before any adjustments (such as rounding). */
439 struct args_size original_args_size
;
440 /* Data on reg parms scanned so far. */
441 CUMULATIVE_ARGS args_so_far
;
442 /* Nonzero if a reg parm has been scanned. */
445 /* Nonzero if we must avoid push-insns in the args for this call.
446 If stack space is allocated for register parameters, but not by the
447 caller, then it is preallocated in the fixed part of the stack frame.
448 So the entire argument block must then be preallocated (i.e., we
449 ignore PUSH_ROUNDING in that case). */
451 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
452 int must_preallocate
= 1;
455 int must_preallocate
= 0;
457 int must_preallocate
= 1;
461 /* Size of the stack reserved for parameter registers. */
462 int reg_parm_stack_space
= 0;
464 /* 1 if scanning parms front to back, -1 if scanning back to front. */
466 /* Address of space preallocated for stack parms
467 (on machines that lack push insns), or 0 if space not preallocated. */
470 /* Nonzero if it is plausible that this is a call to alloca. */
472 /* Nonzero if this is a call to setjmp or a related function. */
474 /* Nonzero if this is a call to `longjmp'. */
476 /* Nonzero if this is a call to an inline function. */
477 int is_integrable
= 0;
478 /* Nonzero if this is a call to a `const' function.
479 Note that only explicitly named functions are handled as `const' here. */
481 /* Nonzero if this is a call to a `volatile' function. */
483 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
484 /* Define the boundary of the register parm stack space that needs to be
486 int low_to_save
= -1, high_to_save
;
487 rtx save_area
= 0; /* Place that it is saved */
490 #ifdef ACCUMULATE_OUTGOING_ARGS
491 int initial_highest_arg_in_use
= highest_outgoing_arg_in_use
;
492 char *initial_stack_usage_map
= stack_usage_map
;
495 rtx old_stack_level
= 0;
497 int old_stack_arg_under_construction
;
498 int old_inhibit_defer_pop
= inhibit_defer_pop
;
499 tree old_cleanups
= cleanups_this_call
;
506 /* See if we can find a DECL-node for the actual function.
507 As a result, decide whether this is a call to an integrable function. */
509 p
= TREE_OPERAND (exp
, 0);
510 if (TREE_CODE (p
) == ADDR_EXPR
)
512 fndecl
= TREE_OPERAND (p
, 0);
513 if (TREE_CODE (fndecl
) != FUNCTION_DECL
)
515 /* May still be a `const' function if it is
516 a call through a pointer-to-const.
517 But we don't handle that. */
523 && fndecl
!= current_function_decl
524 && DECL_SAVED_INSNS (fndecl
))
526 else if (! TREE_ADDRESSABLE (fndecl
))
528 /* In case this function later becomes inlinable,
529 record that there was already a non-inline call to it.
531 Use abstraction instead of setting TREE_ADDRESSABLE
533 if (DECL_INLINE (fndecl
) && extra_warnings
&& !flag_no_inline
)
534 warning_with_decl (fndecl
, "can't inline call to `%s' which was declared inline");
535 mark_addressable (fndecl
);
538 if (TREE_READONLY (fndecl
) && ! TREE_THIS_VOLATILE (fndecl
)
539 && TYPE_MODE (TREE_TYPE (exp
)) != VOIDmode
)
544 is_volatile
= TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p
)));
546 #ifdef REG_PARM_STACK_SPACE
547 #ifdef MAYBE_REG_PARM_STACK_SPACE
548 reg_parm_stack_space
= MAYBE_REG_PARM_STACK_SPACE
;
550 reg_parm_stack_space
= REG_PARM_STACK_SPACE (fndecl
);
554 /* Warn if this value is an aggregate type,
555 regardless of which calling convention we are using for it. */
556 if (warn_aggregate_return
557 && (TREE_CODE (TREE_TYPE (exp
)) == RECORD_TYPE
558 || TREE_CODE (TREE_TYPE (exp
)) == UNION_TYPE
559 || TREE_CODE (TREE_TYPE (exp
)) == ARRAY_TYPE
))
560 warning ("function call has aggregate value");
562 /* Set up a place to return a structure. */
564 /* Cater to broken compilers. */
565 if (aggregate_value_p (exp
))
567 /* This call returns a big structure. */
570 #ifdef PCC_STATIC_STRUCT_RETURN
571 if (flag_pcc_struct_return
)
573 pcc_struct_value
= 1;
574 is_integrable
= 0; /* Easier than making that case work right. */
579 struct_value_size
= int_size_in_bytes (TREE_TYPE (exp
));
581 if (struct_value_size
< 0)
584 if (target
&& GET_CODE (target
) == MEM
)
585 structure_value_addr
= XEXP (target
, 0);
588 /* Assign a temporary on the stack to hold the value. */
590 /* For variable-sized objects, we must be called with a target
591 specified. If we were to allocate space on the stack here,
592 we would have no way of knowing when to free it. */
595 = XEXP (assign_stack_temp (BLKmode
, struct_value_size
, 1), 0);
601 /* If called function is inline, try to integrate it. */
606 rtx before_call
= get_last_insn ();
608 temp
= expand_inline_function (fndecl
, actparms
, target
,
609 ignore
, TREE_TYPE (exp
),
610 structure_value_addr
);
612 /* If inlining succeeded, return. */
613 if ((HOST_WIDE_INT
) temp
!= -1)
617 /* Perform all cleanups needed for the arguments of this call
618 (i.e. destructors in C++). It is ok if these destructors
619 clobber RETURN_VALUE_REG, because the only time we care about
620 this is when TARGET is that register. But in C++, we take
621 care to never return that register directly. */
622 expand_cleanups_to (old_cleanups
);
624 #ifdef ACCUMULATE_OUTGOING_ARGS
625 /* If the outgoing argument list must be preserved, push
626 the stack before executing the inlined function if it
629 for (i
= reg_parm_stack_space
- 1; i
>= 0; i
--)
630 if (i
< highest_outgoing_arg_in_use
&& stack_usage_map
[i
] != 0)
633 if (stack_arg_under_construction
|| i
>= 0)
635 rtx insn
= NEXT_INSN (before_call
), seq
;
637 /* Look for a call in the inline function code.
638 If OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) is
639 nonzero then there is a call and it is not necessary
640 to scan the insns. */
642 if (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl
)) == 0)
643 for (; insn
; insn
= NEXT_INSN (insn
))
644 if (GET_CODE (insn
) == CALL_INSN
)
649 /* Reserve enough stack space so that the largest
650 argument list of any function call in the inline
651 function does not overlap the argument list being
652 evaluated. This is usually an overestimate because
653 allocate_dynamic_stack_space reserves space for an
654 outgoing argument list in addition to the requested
655 space, but there is no way to ask for stack space such
656 that an argument list of a certain length can be
657 safely constructed. */
659 int adjust
= OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl
));
660 #ifdef REG_PARM_STACK_SPACE
661 /* Add the stack space reserved for register arguments
662 in the inline function. What is really needed is the
663 largest value of reg_parm_stack_space in the inline
664 function, but that is not available. Using the current
665 value of reg_parm_stack_space is wrong, but gives
666 correct results on all supported machines. */
667 adjust
+= reg_parm_stack_space
;
670 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, 0);
671 allocate_dynamic_stack_space (GEN_INT (adjust
),
672 NULL_RTX
, BITS_PER_UNIT
);
675 emit_insns_before (seq
, NEXT_INSN (before_call
));
676 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
681 /* If the result is equivalent to TARGET, return TARGET to simplify
682 checks in store_expr. They can be equivalent but not equal in the
683 case of a function that returns BLKmode. */
684 if (temp
!= target
&& rtx_equal_p (temp
, target
))
689 /* If inlining failed, mark FNDECL as needing to be compiled
690 separately after all. */
691 mark_addressable (fndecl
);
694 /* When calling a const function, we must pop the stack args right away,
695 so that the pop is deleted or moved with the call. */
699 function_call_count
++;
701 if (fndecl
&& DECL_NAME (fndecl
))
702 name
= IDENTIFIER_POINTER (DECL_NAME (fndecl
));
705 /* Unless it's a call to a specific function that isn't alloca,
706 if it has one argument, we must assume it might be alloca. */
709 (!(fndecl
!= 0 && strcmp (name
, "alloca"))
711 && TREE_CHAIN (actparms
) == 0);
713 /* We assume that alloca will always be called by name. It
714 makes no sense to pass it as a pointer-to-function to
715 anything that does not understand its behavior. */
717 (name
&& ((IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 6
719 && ! strcmp (name
, "alloca"))
720 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) == 16
722 && ! strcmp (name
, "__builtin_alloca"))));
725 /* See if this is a call to a function that can return more than once
726 or a call to longjmp. */
731 if (name
!= 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl
)) <= 15)
736 tname
+= ((name
[1] == '_' && name
[2] == 'x') ? 3 : 1);
742 && (! strcmp (tname
, "setjmp")
743 || ! strcmp (tname
, "setjmp_syscall")))
745 && ! strcmp (tname
, "sigsetjmp"))
747 && ! strcmp (tname
, "savectx")));
749 && ! strcmp (tname
, "siglongjmp"))
752 else if ((tname
[0] == 'q' && tname
[1] == 's'
753 && ! strcmp (tname
, "qsetjmp"))
754 || (tname
[0] == 'v' && tname
[1] == 'f'
755 && ! strcmp (tname
, "vfork")))
758 else if (tname
[0] == 'l' && tname
[1] == 'o'
759 && ! strcmp (tname
, "longjmp"))
764 current_function_calls_alloca
= 1;
766 /* Don't let pending stack adjusts add up to too much.
767 Also, do all pending adjustments now
768 if there is any chance this might be a call to alloca. */
770 if (pending_stack_adjust
>= 32
771 || (pending_stack_adjust
> 0 && may_be_alloca
))
772 do_pending_stack_adjust ();
774 /* Operand 0 is a pointer-to-function; get the type of the function. */
775 funtype
= TREE_TYPE (TREE_OPERAND (exp
, 0));
776 if (TREE_CODE (funtype
) != POINTER_TYPE
)
778 funtype
= TREE_TYPE (funtype
);
780 /* Push the temporary stack slot level so that we can free temporaries used
781 by each of the arguments separately. */
784 /* Start updating where the next arg would go. */
785 INIT_CUMULATIVE_ARGS (args_so_far
, funtype
, NULL_RTX
);
787 /* If struct_value_rtx is 0, it means pass the address
788 as if it were an extra parameter. */
789 if (structure_value_addr
&& struct_value_rtx
== 0)
791 #ifdef ACCUMULATE_OUTGOING_ARGS
792 /* If the stack will be adjusted, make sure the structure address
793 does not refer to virtual_outgoing_args_rtx. */
794 rtx temp
= (stack_arg_under_construction
795 ? copy_addr_to_reg (structure_value_addr
)
796 : force_reg (Pmode
, structure_value_addr
));
798 rtx temp
= force_reg (Pmode
, structure_value_addr
);
802 = tree_cons (error_mark_node
,
803 make_tree (build_pointer_type (TREE_TYPE (funtype
)),
806 structure_value_addr_parm
= 1;
809 /* Count the arguments and set NUM_ACTUALS. */
810 for (p
= actparms
, i
= 0; p
; p
= TREE_CHAIN (p
)) i
++;
813 /* Compute number of named args.
814 Normally, don't include the last named arg if anonymous args follow.
815 (If no anonymous args follow, the result of list_length
816 is actually one too large.)
818 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
819 place unnamed args that were passed in registers into the stack. So
820 treat all args as named. This allows the insns emitting for a specific
821 argument list to be independent of the function declaration.
823 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
824 way to pass unnamed args in registers, so we must force them into
826 #ifndef SETUP_INCOMING_VARARGS
827 if (TYPE_ARG_TYPES (funtype
) != 0)
829 = list_length (TYPE_ARG_TYPES (funtype
)) - 1
830 /* Count the struct value address, if it is passed as a parm. */
831 + structure_value_addr_parm
;
834 /* If we know nothing, treat all args as named. */
835 n_named_args
= num_actuals
;
837 /* Make a vector to hold all the information about each arg. */
838 args
= (struct arg_data
*) alloca (num_actuals
* sizeof (struct arg_data
));
839 bzero (args
, num_actuals
* sizeof (struct arg_data
));
841 args_size
.constant
= 0;
844 /* In this loop, we consider args in the order they are written.
845 We fill up ARGS from the front of from the back if necessary
846 so that in any case the first arg to be pushed ends up at the front. */
848 #ifdef PUSH_ARGS_REVERSED
849 i
= num_actuals
- 1, inc
= -1;
850 /* In this case, must reverse order of args
851 so that we compute and push the last arg first. */
856 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
857 for (p
= actparms
, argpos
= 0; p
; p
= TREE_CHAIN (p
), i
+= inc
, argpos
++)
859 tree type
= TREE_TYPE (TREE_VALUE (p
));
860 enum machine_mode mode
;
862 args
[i
].tree_value
= TREE_VALUE (p
);
864 /* Replace erroneous argument with constant zero. */
865 if (type
== error_mark_node
|| TYPE_SIZE (type
) == 0)
866 args
[i
].tree_value
= integer_zero_node
, type
= integer_type_node
;
868 /* Decide where to pass this arg.
870 args[i].reg is nonzero if all or part is passed in registers.
872 args[i].partial is nonzero if part but not all is passed in registers,
873 and the exact value says how many words are passed in registers.
875 args[i].pass_on_stack is nonzero if the argument must at least be
876 computed on the stack. It may then be loaded back into registers
877 if args[i].reg is nonzero.
879 These decisions are driven by the FUNCTION_... macros and must agree
880 with those made by function.c. */
882 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
883 /* See if this argument should be passed by invisible reference. */
884 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far
, TYPE_MODE (type
), type
,
885 argpos
< n_named_args
))
887 /* We make a copy of the object and pass the address to the function
891 if (TYPE_SIZE (type
) == 0
892 || TREE_CODE (TYPE_SIZE (type
)) != INTEGER_CST
)
894 /* This is a variable-sized object. Make space on the stack
896 rtx size_rtx
= expand_expr (size_in_bytes (type
), NULL_RTX
,
899 if (old_stack_level
== 0)
901 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
902 old_pending_adj
= pending_stack_adjust
;
903 pending_stack_adjust
= 0;
906 copy
= gen_rtx (MEM
, BLKmode
,
907 allocate_dynamic_stack_space (size_rtx
, NULL_RTX
,
912 int size
= int_size_in_bytes (type
);
913 copy
= assign_stack_temp (TYPE_MODE (type
), size
, 1);
916 store_expr (args
[i
].tree_value
, copy
, 0);
918 args
[i
].tree_value
= build1 (ADDR_EXPR
, build_pointer_type (type
),
919 make_tree (type
, copy
));
920 type
= build_pointer_type (type
);
924 mode
= TYPE_MODE (type
);
926 #ifdef PROMOTE_FUNCTION_ARGS
927 /* Compute the mode in which the arg is actually to be extended to. */
928 if (TREE_CODE (type
) == INTEGER_TYPE
|| TREE_CODE (type
) == ENUMERAL_TYPE
929 || TREE_CODE (type
) == BOOLEAN_TYPE
|| TREE_CODE (type
) == CHAR_TYPE
930 || TREE_CODE (type
) == REAL_TYPE
|| TREE_CODE (type
) == POINTER_TYPE
931 || TREE_CODE (type
) == OFFSET_TYPE
)
933 int unsignedp
= TREE_UNSIGNED (type
);
934 PROMOTE_MODE (mode
, unsignedp
, type
);
935 args
[i
].unsignedp
= unsignedp
;
939 args
[i
].reg
= FUNCTION_ARG (args_so_far
, mode
, type
,
940 argpos
< n_named_args
);
941 #ifdef FUNCTION_ARG_PARTIAL_NREGS
944 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far
, mode
, type
,
945 argpos
< n_named_args
);
948 args
[i
].pass_on_stack
= MUST_PASS_IN_STACK (mode
, type
);
950 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
951 we are to pass this arg in the register(s) designated by FOO, but
952 also to pass it in the stack. */
953 if (args
[i
].reg
&& GET_CODE (args
[i
].reg
) == EXPR_LIST
954 && XEXP (args
[i
].reg
, 0) == 0)
955 args
[i
].pass_on_stack
= 1, args
[i
].reg
= XEXP (args
[i
].reg
, 1);
957 /* If this is an addressable type, we must preallocate the stack
958 since we must evaluate the object into its final location.
960 If this is to be passed in both registers and the stack, it is simpler
962 if (TREE_ADDRESSABLE (type
)
963 || (args
[i
].pass_on_stack
&& args
[i
].reg
!= 0))
964 must_preallocate
= 1;
966 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
967 we cannot consider this function call constant. */
968 if (TREE_ADDRESSABLE (type
))
971 /* Compute the stack-size of this argument. */
972 if (args
[i
].reg
== 0 || args
[i
].partial
!= 0
973 #ifdef REG_PARM_STACK_SPACE
974 || reg_parm_stack_space
> 0
976 || args
[i
].pass_on_stack
)
977 locate_and_pad_parm (TYPE_MODE (type
), type
,
978 #ifdef STACK_PARMS_IN_REG_PARM_AREA
983 fndecl
, &args_size
, &args
[i
].offset
,
986 #ifndef ARGS_GROW_DOWNWARD
987 args
[i
].slot_offset
= args_size
;
990 #ifndef REG_PARM_STACK_SPACE
991 /* If a part of the arg was put into registers,
992 don't include that part in the amount pushed. */
993 if (! args
[i
].pass_on_stack
)
994 args
[i
].size
.constant
-= ((args
[i
].partial
* UNITS_PER_WORD
)
995 / (PARM_BOUNDARY
/ BITS_PER_UNIT
)
996 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
999 /* Update ARGS_SIZE, the total stack space for args so far. */
1001 args_size
.constant
+= args
[i
].size
.constant
;
1002 if (args
[i
].size
.var
)
1004 ADD_PARM_SIZE (args_size
, args
[i
].size
.var
);
1007 /* Since the slot offset points to the bottom of the slot,
1008 we must record it after incrementing if the args grow down. */
1009 #ifdef ARGS_GROW_DOWNWARD
1010 args
[i
].slot_offset
= args_size
;
1012 args
[i
].slot_offset
.constant
= -args_size
.constant
;
1015 SUB_PARM_SIZE (args
[i
].slot_offset
, args_size
.var
);
1019 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1020 have been used, etc. */
1022 FUNCTION_ARG_ADVANCE (args_so_far
, TYPE_MODE (type
), type
,
1023 argpos
< n_named_args
);
1026 #ifdef FINAL_REG_PARM_STACK_SPACE
1027 reg_parm_stack_space
= FINAL_REG_PARM_STACK_SPACE (args_size
.constant
,
1031 /* Compute the actual size of the argument block required. The variable
1032 and constant sizes must be combined, the size may have to be rounded,
1033 and there may be a minimum required size. */
1035 original_args_size
= args_size
;
1038 /* If this function requires a variable-sized argument list, don't try to
1039 make a cse'able block for this call. We may be able to do this
1040 eventually, but it is too complicated to keep track of what insns go
1041 in the cse'able block and which don't. */
1044 must_preallocate
= 1;
1046 args_size
.var
= ARGS_SIZE_TREE (args_size
);
1047 args_size
.constant
= 0;
1049 #ifdef STACK_BOUNDARY
1050 if (STACK_BOUNDARY
!= BITS_PER_UNIT
)
1051 args_size
.var
= round_up (args_size
.var
, STACK_BYTES
);
1054 #ifdef REG_PARM_STACK_SPACE
1055 if (reg_parm_stack_space
> 0)
1058 = size_binop (MAX_EXPR
, args_size
.var
,
1059 size_int (REG_PARM_STACK_SPACE (fndecl
)));
1061 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1062 /* The area corresponding to register parameters is not to count in
1063 the size of the block we need. So make the adjustment. */
1065 = size_binop (MINUS_EXPR
, args_size
.var
,
1066 size_int (reg_parm_stack_space
));
1073 #ifdef STACK_BOUNDARY
1074 args_size
.constant
= (((args_size
.constant
+ (STACK_BYTES
- 1))
1075 / STACK_BYTES
) * STACK_BYTES
);
1078 #ifdef REG_PARM_STACK_SPACE
1079 args_size
.constant
= MAX (args_size
.constant
,
1080 reg_parm_stack_space
);
1081 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1082 args_size
.constant
-= reg_parm_stack_space
;
1087 /* See if we have or want to preallocate stack space.
1089 If we would have to push a partially-in-regs parm
1090 before other stack parms, preallocate stack space instead.
1092 If the size of some parm is not a multiple of the required stack
1093 alignment, we must preallocate.
1095 If the total size of arguments that would otherwise create a copy in
1096 a temporary (such as a CALL) is more than half the total argument list
1097 size, preallocation is faster.
1099 Another reason to preallocate is if we have a machine (like the m88k)
1100 where stack alignment is required to be maintained between every
1101 pair of insns, not just when the call is made. However, we assume here
1102 that such machines either do not have push insns (and hence preallocation
1103 would occur anyway) or the problem is taken care of with
1106 if (! must_preallocate
)
1108 int partial_seen
= 0;
1109 int copy_to_evaluate_size
= 0;
1111 for (i
= 0; i
< num_actuals
&& ! must_preallocate
; i
++)
1113 if (args
[i
].partial
> 0 && ! args
[i
].pass_on_stack
)
1115 else if (partial_seen
&& args
[i
].reg
== 0)
1116 must_preallocate
= 1;
1118 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1119 && (TREE_CODE (args
[i
].tree_value
) == CALL_EXPR
1120 || TREE_CODE (args
[i
].tree_value
) == TARGET_EXPR
1121 || TREE_CODE (args
[i
].tree_value
) == COND_EXPR
1122 || TREE_ADDRESSABLE (TREE_TYPE (args
[i
].tree_value
))))
1123 copy_to_evaluate_size
1124 += int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
));
1127 if (copy_to_evaluate_size
* 2 >= args_size
.constant
1128 && args_size
.constant
> 0)
1129 must_preallocate
= 1;
1132 /* If the structure value address will reference the stack pointer, we must
1133 stabilize it. We don't need to do this if we know that we are not going
1134 to adjust the stack pointer in processing this call. */
1136 if (structure_value_addr
1137 && (reg_mentioned_p (virtual_stack_dynamic_rtx
, structure_value_addr
)
1138 || reg_mentioned_p (virtual_outgoing_args_rtx
, structure_value_addr
))
1140 #ifndef ACCUMULATE_OUTGOING_ARGS
1141 || args_size
.constant
1144 structure_value_addr
= copy_to_reg (structure_value_addr
);
1146 /* If this function call is cse'able, precompute all the parameters.
1147 Note that if the parameter is constructed into a temporary, this will
1148 cause an additional copy because the parameter will be constructed
1149 into a temporary location and then copied into the outgoing arguments.
1150 If a parameter contains a call to alloca and this function uses the
1151 stack, precompute the parameter. */
1153 for (i
= 0; i
< num_actuals
; i
++)
1155 || ((args_size
.var
!= 0 || args_size
.constant
!= 0)
1156 && calls_alloca (args
[i
].tree_value
)))
1158 args
[i
].initial_value
= args
[i
].value
1159 = expand_expr (args
[i
].tree_value
, NULL_RTX
, VOIDmode
, 0);
1160 preserve_temp_slots (args
[i
].value
);
1163 /* ANSI doesn't require a sequence point here,
1164 but PCC has one, so this will avoid some problems. */
1168 /* Now we are about to start emitting insns that can be deleted
1169 if a libcall is deleted. */
1173 /* If we have no actual push instructions, or shouldn't use them,
1174 make space for all args right now. */
1176 if (args_size
.var
!= 0)
1178 if (old_stack_level
== 0)
1180 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
1181 old_pending_adj
= pending_stack_adjust
;
1182 pending_stack_adjust
= 0;
1183 #ifdef ACCUMULATE_OUTGOING_ARGS
1184 /* stack_arg_under_construction says whether a stack arg is
1185 being constructed at the old stack level. Pushing the stack
1186 gets a clean outgoing argument block. */
1187 old_stack_arg_under_construction
= stack_arg_under_construction
;
1188 stack_arg_under_construction
= 0;
1191 argblock
= push_block (ARGS_SIZE_RTX (args_size
), 0, 0);
1193 else if (must_preallocate
)
1195 /* Note that we must go through the motions of allocating an argument
1196 block even if the size is zero because we may be storing args
1197 in the area reserved for register arguments, which may be part of
1199 int needed
= args_size
.constant
;
1201 #ifdef ACCUMULATE_OUTGOING_ARGS
1202 /* Store the maximum argument space used. It will be pushed by the
1205 Since the stack pointer will never be pushed, it is possible for
1206 the evaluation of a parm to clobber something we have already
1207 written to the stack. Since most function calls on RISC machines
1208 do not use the stack, this is uncommon, but must work correctly.
1210 Therefore, we save any area of the stack that was already written
1211 and that we are using. Here we set up to do this by making a new
1212 stack usage map from the old one. The actual save will be done
1215 Another approach might be to try to reorder the argument
1216 evaluations to avoid this conflicting stack usage. */
1218 if (needed
> current_function_outgoing_args_size
)
1219 current_function_outgoing_args_size
= needed
;
1221 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1222 /* Since we will be writing into the entire argument area, the
1223 map must be allocated for its entire size, not just the part that
1224 is the responsibility of the caller. */
1225 needed
+= reg_parm_stack_space
;
1228 #ifdef ARGS_GROW_DOWNWARD
1229 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
,
1232 highest_outgoing_arg_in_use
= MAX (initial_highest_arg_in_use
, needed
);
1234 stack_usage_map
= (char *) alloca (highest_outgoing_arg_in_use
);
1236 if (initial_highest_arg_in_use
)
1237 bcopy (initial_stack_usage_map
, stack_usage_map
,
1238 initial_highest_arg_in_use
);
1240 if (initial_highest_arg_in_use
!= highest_outgoing_arg_in_use
)
1241 bzero (&stack_usage_map
[initial_highest_arg_in_use
],
1242 highest_outgoing_arg_in_use
- initial_highest_arg_in_use
);
1245 /* The address of the outgoing argument list must not be copied to a
1246 register here, because argblock would be left pointing to the
1247 wrong place after the call to allocate_dynamic_stack_space below. */
1249 argblock
= virtual_outgoing_args_rtx
;
1251 #else /* not ACCUMULATE_OUTGOING_ARGS */
1252 if (inhibit_defer_pop
== 0)
1254 /* Try to reuse some or all of the pending_stack_adjust
1255 to get this space. Maybe we can avoid any pushing. */
1256 if (needed
> pending_stack_adjust
)
1258 needed
-= pending_stack_adjust
;
1259 pending_stack_adjust
= 0;
1263 pending_stack_adjust
-= needed
;
1267 /* Special case this because overhead of `push_block' in this
1268 case is non-trivial. */
1270 argblock
= virtual_outgoing_args_rtx
;
1272 argblock
= push_block (GEN_INT (needed
), 0, 0);
1274 /* We only really need to call `copy_to_reg' in the case where push
1275 insns are going to be used to pass ARGBLOCK to a function
1276 call in ARGS. In that case, the stack pointer changes value
1277 from the allocation point to the call point, and hence
1278 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1279 But might as well always do it. */
1280 argblock
= copy_to_reg (argblock
);
1281 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1285 #ifdef ACCUMULATE_OUTGOING_ARGS
1286 /* The save/restore code in store_one_arg handles all cases except one:
1287 a constructor call (including a C function returning a BLKmode struct)
1288 to initialize an argument. */
1289 if (stack_arg_under_construction
)
1291 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1292 rtx push_size
= GEN_INT (reg_parm_stack_space
+ args_size
.constant
);
1294 rtx push_size
= GEN_INT (args_size
.constant
);
1296 if (old_stack_level
== 0)
1298 emit_stack_save (SAVE_BLOCK
, &old_stack_level
, NULL_RTX
);
1299 old_pending_adj
= pending_stack_adjust
;
1300 pending_stack_adjust
= 0;
1301 /* stack_arg_under_construction says whether a stack arg is
1302 being constructed at the old stack level. Pushing the stack
1303 gets a clean outgoing argument block. */
1304 old_stack_arg_under_construction
= stack_arg_under_construction
;
1305 stack_arg_under_construction
= 0;
1306 /* Make a new map for the new argument list. */
1307 stack_usage_map
= (char *)alloca (highest_outgoing_arg_in_use
);
1308 bzero (stack_usage_map
, highest_outgoing_arg_in_use
);
1309 highest_outgoing_arg_in_use
= 0;
1311 allocate_dynamic_stack_space (push_size
, NULL_RTX
, BITS_PER_UNIT
);
1313 /* If argument evaluation might modify the stack pointer, copy the
1314 address of the argument list to a register. */
1315 for (i
= 0; i
< num_actuals
; i
++)
1316 if (args
[i
].pass_on_stack
)
1318 argblock
= copy_addr_to_reg (argblock
);
1324 /* If we preallocated stack space, compute the address of each argument.
1325 We need not ensure it is a valid memory address here; it will be
1326 validized when it is used. */
1329 rtx arg_reg
= argblock
;
1332 if (GET_CODE (argblock
) == PLUS
)
1333 arg_reg
= XEXP (argblock
, 0), arg_offset
= INTVAL (XEXP (argblock
, 1));
1335 for (i
= 0; i
< num_actuals
; i
++)
1337 rtx offset
= ARGS_SIZE_RTX (args
[i
].offset
);
1338 rtx slot_offset
= ARGS_SIZE_RTX (args
[i
].slot_offset
);
1341 /* Skip this parm if it will not be passed on the stack. */
1342 if (! args
[i
].pass_on_stack
&& args
[i
].reg
!= 0)
1345 if (GET_CODE (offset
) == CONST_INT
)
1346 addr
= plus_constant (arg_reg
, INTVAL (offset
));
1348 addr
= gen_rtx (PLUS
, Pmode
, arg_reg
, offset
);
1350 addr
= plus_constant (addr
, arg_offset
);
1352 = gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)), addr
);
1354 if (GET_CODE (slot_offset
) == CONST_INT
)
1355 addr
= plus_constant (arg_reg
, INTVAL (slot_offset
));
1357 addr
= gen_rtx (PLUS
, Pmode
, arg_reg
, slot_offset
);
1359 addr
= plus_constant (addr
, arg_offset
);
1361 = gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)), addr
);
1365 #ifdef PUSH_ARGS_REVERSED
1366 #ifdef STACK_BOUNDARY
1367 /* If we push args individually in reverse order, perform stack alignment
1368 before the first push (the last arg). */
1370 anti_adjust_stack (GEN_INT (args_size
.constant
1371 - original_args_size
.constant
));
1375 /* Don't try to defer pops if preallocating, not even from the first arg,
1376 since ARGBLOCK probably refers to the SP. */
1380 /* Get the function to call, in the form of RTL. */
1382 /* Get a SYMBOL_REF rtx for the function address. */
1383 funexp
= XEXP (DECL_RTL (fndecl
), 0);
1385 /* Generate an rtx (probably a pseudo-register) for the address. */
1387 funexp
= expand_expr (TREE_OPERAND (exp
, 0), NULL_RTX
, VOIDmode
, 0);
1388 free_temp_slots (); /* FUNEXP can't be BLKmode */
1392 /* Figure out the register where the value, if any, will come back. */
1394 if (TYPE_MODE (TREE_TYPE (exp
)) != VOIDmode
1395 && ! structure_value_addr
)
1397 if (pcc_struct_value
)
1398 valreg
= hard_function_value (build_pointer_type (TREE_TYPE (exp
)),
1401 valreg
= hard_function_value (TREE_TYPE (exp
), fndecl
);
1404 /* Precompute all register parameters. It isn't safe to compute anything
1405 once we have started filling any specific hard regs. */
1407 for (i
= 0; i
< num_actuals
; i
++)
1408 if (args
[i
].reg
!= 0 && ! args
[i
].pass_on_stack
)
1410 enum machine_mode mode
;
1414 if (args
[i
].value
== 0)
1416 args
[i
].value
= expand_expr (args
[i
].tree_value
, NULL_RTX
,
1418 preserve_temp_slots (args
[i
].value
);
1421 /* ANSI doesn't require a sequence point here,
1422 but PCC has one, so this will avoid some problems. */
1426 /* If we are to promote the function arg to a wider mode,
1428 mode
= (GET_CODE (args
[i
].reg
) == EXPR_LIST
1429 ? GET_MODE (XEXP (args
[i
].reg
, 0)) : GET_MODE (args
[i
].reg
));
1431 if (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) != mode
)
1432 args
[i
].value
= convert_to_mode (mode
, args
[i
].value
,
1436 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1437 /* The argument list is the property of the called routine and it
1438 may clobber it. If the fixed area has been used for previous
1439 parameters, we must save and restore it.
1441 Here we compute the boundary of the that needs to be saved, if any. */
1443 #ifdef ARGS_GROW_DOWNWARD
1444 for (i
= 0; i
< reg_parm_stack_space
+ 1; i
++)
1446 for (i
= 0; i
< reg_parm_stack_space
; i
++)
1449 if (i
>= highest_outgoing_arg_in_use
1450 || stack_usage_map
[i
] == 0)
1453 if (low_to_save
== -1)
1459 if (low_to_save
>= 0)
1461 int num_to_save
= high_to_save
- low_to_save
+ 1;
1462 enum machine_mode save_mode
1463 = mode_for_size (num_to_save
* BITS_PER_UNIT
, MODE_INT
, 1);
1466 /* If we don't have the required alignment, must do this in BLKmode. */
1467 if ((low_to_save
& (MIN (GET_MODE_SIZE (save_mode
),
1468 BIGGEST_ALIGNMENT
/ UNITS_PER_WORD
) - 1)))
1469 save_mode
= BLKmode
;
1471 stack_area
= gen_rtx (MEM
, save_mode
,
1472 memory_address (save_mode
,
1474 #ifdef ARGS_GROW_DOWNWARD
1475 plus_constant (argblock
,
1478 plus_constant (argblock
,
1482 if (save_mode
== BLKmode
)
1484 save_area
= assign_stack_temp (BLKmode
, num_to_save
, 1);
1485 emit_block_move (validize_mem (save_area
), stack_area
,
1486 GEN_INT (num_to_save
),
1487 PARM_BOUNDARY
/ BITS_PER_UNIT
);
1491 save_area
= gen_reg_rtx (save_mode
);
1492 emit_move_insn (save_area
, stack_area
);
1498 /* Now store (and compute if necessary) all non-register parms.
1499 These come before register parms, since they can require block-moves,
1500 which could clobber the registers used for register parms.
1501 Parms which have partial registers are not stored here,
1502 but we do preallocate space here if they want that. */
1504 for (i
= 0; i
< num_actuals
; i
++)
1505 if (args
[i
].reg
== 0 || args
[i
].pass_on_stack
)
1506 store_one_arg (&args
[i
], argblock
, may_be_alloca
,
1507 args_size
.var
!= 0, fndecl
, reg_parm_stack_space
);
1509 /* Now store any partially-in-registers parm.
1510 This is the last place a block-move can happen. */
1512 for (i
= 0; i
< num_actuals
; i
++)
1513 if (args
[i
].partial
!= 0 && ! args
[i
].pass_on_stack
)
1514 store_one_arg (&args
[i
], argblock
, may_be_alloca
,
1515 args_size
.var
!= 0, fndecl
, reg_parm_stack_space
);
1517 #ifndef PUSH_ARGS_REVERSED
1518 #ifdef STACK_BOUNDARY
1519 /* If we pushed args in forward order, perform stack alignment
1520 after pushing the last arg. */
1522 anti_adjust_stack (GEN_INT (args_size
.constant
1523 - original_args_size
.constant
));
1527 /* If register arguments require space on the stack and stack space
1528 was not preallocated, allocate stack space here for arguments
1529 passed in registers. */
1530 #if ! defined(ALLOCATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
1531 if (must_preallocate
== 0 && reg_parm_stack_space
> 0)
1532 anti_adjust_stack (GEN_INT (reg_parm_stack_space
));
1535 /* Pass the function the address in which to return a structure value. */
1536 if (structure_value_addr
&& ! structure_value_addr_parm
)
1538 emit_move_insn (struct_value_rtx
,
1540 force_operand (structure_value_addr
,
1542 if (GET_CODE (struct_value_rtx
) == REG
)
1544 push_to_sequence (use_insns
);
1545 emit_insn (gen_rtx (USE
, VOIDmode
, struct_value_rtx
));
1546 use_insns
= get_insns ();
1551 /* Now do the register loads required for any wholly-register parms or any
1552 parms which are passed both on the stack and in a register. Their
1553 expressions were already evaluated.
1555 Mark all register-parms as living through the call, putting these USE
1556 insns in a list headed by USE_INSNS. */
1558 for (i
= 0; i
< num_actuals
; i
++)
1560 rtx list
= args
[i
].reg
;
1561 int partial
= args
[i
].partial
;
1568 /* Process each register that needs to get this arg. */
1569 if (GET_CODE (list
) == EXPR_LIST
)
1570 reg
= XEXP (list
, 0), list
= XEXP (list
, 1);
1572 reg
= list
, list
= 0;
1574 /* Set to non-zero if must move a word at a time, even if just one
1575 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1576 we just use a normal move insn. */
1577 nregs
= (partial
? partial
1578 : (TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)) == BLKmode
1579 ? ((int_size_in_bytes (TREE_TYPE (args
[i
].tree_value
))
1580 + (UNITS_PER_WORD
- 1)) / UNITS_PER_WORD
)
1583 /* If simple case, just do move. If normal partial, store_one_arg
1584 has already loaded the register for us. In all other cases,
1585 load the register(s) from memory. */
1588 emit_move_insn (reg
, args
[i
].value
);
1589 else if (args
[i
].partial
== 0 || args
[i
].pass_on_stack
)
1590 move_block_to_reg (REGNO (reg
),
1591 validize_mem (args
[i
].value
), nregs
,
1592 TYPE_MODE (TREE_TYPE (args
[i
].tree_value
)));
1594 push_to_sequence (use_insns
);
1596 emit_insn (gen_rtx (USE
, VOIDmode
, reg
));
1598 use_regs (REGNO (reg
), nregs
);
1599 use_insns
= get_insns ();
1602 /* PARTIAL referred only to the first register, so clear it for the
1608 /* Perform postincrements before actually calling the function. */
1611 /* All arguments and registers used for the call must be set up by now! */
1613 funexp
= prepare_call_address (funexp
, fndecl
, &use_insns
);
1615 /* Generate the actual call instruction. */
1616 emit_call_1 (funexp
, funtype
, args_size
.constant
, struct_value_size
,
1617 FUNCTION_ARG (args_so_far
, VOIDmode
, void_type_node
, 1),
1618 valreg
, old_inhibit_defer_pop
, use_insns
, is_const
);
1620 /* If call is cse'able, make appropriate pair of reg-notes around it.
1621 Test valreg so we don't crash; may safely ignore `const'
1622 if return type is void. */
1623 if (is_const
&& valreg
!= 0)
1626 rtx temp
= gen_reg_rtx (GET_MODE (valreg
));
1629 /* Construct an "equal form" for the value which mentions all the
1630 arguments in order as well as the function name. */
1631 #ifdef PUSH_ARGS_REVERSED
1632 for (i
= 0; i
< num_actuals
; i
++)
1633 note
= gen_rtx (EXPR_LIST
, VOIDmode
, args
[i
].initial_value
, note
);
1635 for (i
= num_actuals
- 1; i
>= 0; i
--)
1636 note
= gen_rtx (EXPR_LIST
, VOIDmode
, args
[i
].initial_value
, note
);
1638 note
= gen_rtx (EXPR_LIST
, VOIDmode
, funexp
, note
);
1640 insns
= get_insns ();
1643 emit_libcall_block (insns
, temp
, valreg
, note
);
1648 /* For calls to `setjmp', etc., inform flow.c it should complain
1649 if nonvolatile values are live. */
1653 emit_note (name
, NOTE_INSN_SETJMP
);
1654 current_function_calls_setjmp
= 1;
1658 current_function_calls_longjmp
= 1;
1660 /* Notice functions that cannot return.
1661 If optimizing, insns emitted below will be dead.
1662 If not optimizing, they will exist, which is useful
1663 if the user uses the `return' command in the debugger. */
1665 if (is_volatile
|| is_longjmp
)
1668 /* If value type not void, return an rtx for the value. */
1670 /* If there are cleanups to be called, don't use a hard reg as target. */
1671 if (cleanups_this_call
!= old_cleanups
1672 && target
&& REG_P (target
)
1673 && REGNO (target
) < FIRST_PSEUDO_REGISTER
)
1676 if (TYPE_MODE (TREE_TYPE (exp
)) == VOIDmode
1679 target
= const0_rtx
;
1681 else if (structure_value_addr
)
1683 if (target
== 0 || GET_CODE (target
) != MEM
)
1685 target
= gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (exp
)),
1686 memory_address (TYPE_MODE (TREE_TYPE (exp
)),
1687 structure_value_addr
));
1688 MEM_IN_STRUCT_P (target
)
1689 = (TREE_CODE (TREE_TYPE (exp
)) == ARRAY_TYPE
1690 || TREE_CODE (TREE_TYPE (exp
)) == RECORD_TYPE
1691 || TREE_CODE (TREE_TYPE (exp
)) == UNION_TYPE
);
1694 else if (pcc_struct_value
)
1698 target
= gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (exp
)),
1699 copy_to_reg (valreg
));
1700 MEM_IN_STRUCT_P (target
)
1701 = (TREE_CODE (TREE_TYPE (exp
)) == ARRAY_TYPE
1702 || TREE_CODE (TREE_TYPE (exp
)) == RECORD_TYPE
1703 || TREE_CODE (TREE_TYPE (exp
)) == UNION_TYPE
);
1705 else if (TYPE_MODE (TREE_TYPE (exp
)) != BLKmode
)
1706 emit_move_insn (target
, gen_rtx (MEM
, TYPE_MODE (TREE_TYPE (exp
)),
1707 copy_to_reg (valreg
)));
1709 emit_block_move (target
, gen_rtx (MEM
, BLKmode
, copy_to_reg (valreg
)),
1711 TYPE_ALIGN (TREE_TYPE (exp
)) / BITS_PER_UNIT
);
1713 else if (target
&& GET_MODE (target
) == TYPE_MODE (TREE_TYPE (exp
))
1714 && GET_MODE (target
) == GET_MODE (valreg
))
1715 /* TARGET and VALREG cannot be equal at this point because the latter
1716 would not have REG_FUNCTION_VALUE_P true, while the former would if
1717 it were referring to the same register.
1719 If they refer to the same register, this move will be a no-op, except
1720 when function inlining is being done. */
1721 emit_move_insn (target
, valreg
);
1723 target
= copy_to_reg (valreg
);
1725 #ifdef PROMOTE_FUNCTION_RETURN
1726 /* If we promoted this return value, make the proper SUBREG. */
1727 if (GET_MODE (target
) != TYPE_MODE (TREE_TYPE (exp
)))
1729 enum machine_mode mode
= GET_MODE (target
);
1730 int unsignedp
= TREE_UNSIGNED (TREE_TYPE (exp
));
1732 if (TREE_CODE (TREE_TYPE (exp
)) == INTEGER_TYPE
1733 || TREE_CODE (TREE_TYPE (exp
)) == ENUMERAL_TYPE
1734 || TREE_CODE (TREE_TYPE (exp
)) == BOOLEAN_TYPE
1735 || TREE_CODE (TREE_TYPE (exp
)) == CHAR_TYPE
1736 || TREE_CODE (TREE_TYPE (exp
)) == REAL_TYPE
1737 || TREE_CODE (TREE_TYPE (exp
)) == POINTER_TYPE
1738 || TREE_CODE (TREE_TYPE (exp
)) == OFFSET_TYPE
)
1740 PROMOTE_MODE (mode
, unsignedp
, TREE_TYPE (exp
));
1743 target
= gen_rtx (SUBREG
, TYPE_MODE (TREE_TYPE (exp
)), target
, 0);
1744 SUBREG_PROMOTED_VAR_P (target
) = 1;
1745 SUBREG_PROMOTED_UNSIGNED_P (target
) = unsignedp
;
1749 /* Perform all cleanups needed for the arguments of this call
1750 (i.e. destructors in C++). */
1751 expand_cleanups_to (old_cleanups
);
1753 /* If size of args is variable or this was a constructor call for a stack
1754 argument, restore saved stack-pointer value. */
1756 if (old_stack_level
)
1758 emit_stack_restore (SAVE_BLOCK
, old_stack_level
, NULL_RTX
);
1759 pending_stack_adjust
= old_pending_adj
;
1760 #ifdef ACCUMULATE_OUTGOING_ARGS
1761 stack_arg_under_construction
= old_stack_arg_under_construction
;
1762 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
1763 stack_usage_map
= initial_stack_usage_map
;
1766 #ifdef ACCUMULATE_OUTGOING_ARGS
1769 #ifdef REG_PARM_STACK_SPACE
1772 enum machine_mode save_mode
= GET_MODE (save_area
);
1774 = gen_rtx (MEM
, save_mode
,
1775 memory_address (save_mode
,
1776 #ifdef ARGS_GROW_DOWNWARD
1777 plus_constant (argblock
, - high_to_save
)
1779 plus_constant (argblock
, low_to_save
)
1783 if (save_mode
!= BLKmode
)
1784 emit_move_insn (stack_area
, save_area
);
1786 emit_block_move (stack_area
, validize_mem (save_area
),
1787 GEN_INT (high_to_save
- low_to_save
+ 1),
1788 PARM_BOUNDARY
/ BITS_PER_UNIT
);
1792 /* If we saved any argument areas, restore them. */
1793 for (i
= 0; i
< num_actuals
; i
++)
1794 if (args
[i
].save_area
)
1796 enum machine_mode save_mode
= GET_MODE (args
[i
].save_area
);
1798 = gen_rtx (MEM
, save_mode
,
1799 memory_address (save_mode
,
1800 XEXP (args
[i
].stack_slot
, 0)));
1802 if (save_mode
!= BLKmode
)
1803 emit_move_insn (stack_area
, args
[i
].save_area
);
1805 emit_block_move (stack_area
, validize_mem (args
[i
].save_area
),
1806 GEN_INT (args
[i
].size
.constant
),
1807 PARM_BOUNDARY
/ BITS_PER_UNIT
);
1810 highest_outgoing_arg_in_use
= initial_highest_arg_in_use
;
1811 stack_usage_map
= initial_stack_usage_map
;
1815 /* If this was alloca, record the new stack level for nonlocal gotos.
1816 Check for the handler slots since we might not have a save area
1817 for non-local gotos. */
1819 if (may_be_alloca
&& nonlocal_goto_handler_slot
!= 0)
1820 emit_stack_save (SAVE_NONLOCAL
, &nonlocal_goto_stack_level
, NULL_RTX
);
1828 /* Return an rtx which represents a suitable home on the stack
1829 given TYPE, the type of the argument looking for a home.
1830 This is called only for BLKmode arguments.
1832 SIZE is the size needed for this target.
1833 ARGS_ADDR is the address of the bottom of the argument block for this call.
1834 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1835 if this machine uses push insns. */
1838 target_for_arg (type
, size
, args_addr
, offset
)
1842 struct args_size offset
;
1845 rtx offset_rtx
= ARGS_SIZE_RTX (offset
);
1847 /* We do not call memory_address if possible,
1848 because we want to address as close to the stack
1849 as possible. For non-variable sized arguments,
1850 this will be stack-pointer relative addressing. */
1851 if (GET_CODE (offset_rtx
) == CONST_INT
)
1852 target
= plus_constant (args_addr
, INTVAL (offset_rtx
));
1855 /* I have no idea how to guarantee that this
1856 will work in the presence of register parameters. */
1857 target
= gen_rtx (PLUS
, Pmode
, args_addr
, offset_rtx
);
1858 target
= memory_address (QImode
, target
);
1861 return gen_rtx (MEM
, BLKmode
, target
);
1865 /* Store a single argument for a function call
1866 into the register or memory area where it must be passed.
1867 *ARG describes the argument value and where to pass it.
1869 ARGBLOCK is the address of the stack-block for all the arguments,
1870 or 0 on a machine where arguments are pushed individually.
1872 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1873 so must be careful about how the stack is used.
1875 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1876 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1877 that we need not worry about saving and restoring the stack.
1879 FNDECL is the declaration of the function we are calling. */
1882 store_one_arg (arg
, argblock
, may_be_alloca
, variable_size
, fndecl
,
1883 reg_parm_stack_space
)
1884 struct arg_data
*arg
;
1889 int reg_parm_stack_space
;
1891 register tree pval
= arg
->tree_value
;
1895 int i
, lower_bound
, upper_bound
;
1897 if (TREE_CODE (pval
) == ERROR_MARK
)
1900 #ifdef ACCUMULATE_OUTGOING_ARGS
1901 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1902 save any previous data at that location. */
1903 if (argblock
&& ! variable_size
&& arg
->stack
)
1905 #ifdef ARGS_GROW_DOWNWARD
1906 /* stack_slot is negative, but we want to index stack_usage_map */
1907 /* with positive values. */
1908 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
1909 upper_bound
= -INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1)) + 1;
1913 lower_bound
= upper_bound
- arg
->size
.constant
;
1915 if (GET_CODE (XEXP (arg
->stack_slot
, 0)) == PLUS
)
1916 lower_bound
= INTVAL (XEXP (XEXP (arg
->stack_slot
, 0), 1));
1920 upper_bound
= lower_bound
+ arg
->size
.constant
;
1923 for (i
= lower_bound
; i
< upper_bound
; i
++)
1924 if (stack_usage_map
[i
]
1925 #ifdef REG_PARM_STACK_SPACE
1926 /* Don't store things in the fixed argument area at this point;
1927 it has already been saved. */
1928 && i
> reg_parm_stack_space
1933 if (i
!= upper_bound
)
1935 /* We need to make a save area. See what mode we can make it. */
1936 enum machine_mode save_mode
1937 = mode_for_size (arg
->size
.constant
* BITS_PER_UNIT
, MODE_INT
, 1);
1939 = gen_rtx (MEM
, save_mode
,
1940 memory_address (save_mode
, XEXP (arg
->stack_slot
, 0)));
1942 if (save_mode
== BLKmode
)
1944 arg
->save_area
= assign_stack_temp (BLKmode
,
1945 arg
->size
.constant
, 1);
1946 emit_block_move (validize_mem (arg
->save_area
), stack_area
,
1947 GEN_INT (arg
->size
.constant
),
1948 PARM_BOUNDARY
/ BITS_PER_UNIT
);
1952 arg
->save_area
= gen_reg_rtx (save_mode
);
1953 emit_move_insn (arg
->save_area
, stack_area
);
1959 /* If this isn't going to be placed on both the stack and in registers,
1960 set up the register and number of words. */
1961 if (! arg
->pass_on_stack
)
1962 reg
= arg
->reg
, partial
= arg
->partial
;
1964 if (reg
!= 0 && partial
== 0)
1965 /* Being passed entirely in a register. We shouldn't be called in
1969 /* If this is being partially passed in a register, but multiple locations
1970 are specified, we assume that the one partially used is the one that is
1972 if (reg
&& GET_CODE (reg
) == EXPR_LIST
)
1973 reg
= XEXP (reg
, 0);
1975 /* If this is being passes partially in a register, we can't evaluate
1976 it directly into its stack slot. Otherwise, we can. */
1977 if (arg
->value
== 0)
1979 #ifdef ACCUMULATE_OUTGOING_ARGS
1980 /* stack_arg_under_construction is nonzero if a function argument is
1981 being evaluated directly into the outgoing argument list and
1982 expand_call must take special action to preserve the argument list
1983 if it is called recursively.
1985 For scalar function arguments stack_usage_map is sufficient to
1986 determine which stack slots must be saved and restored. Scalar
1987 arguments in general have pass_on_stack == 0.
1989 If this argument is initialized by a function which takes the
1990 address of the argument (a C++ constructor or a C function
1991 returning a BLKmode structure), then stack_usage_map is
1992 insufficient and expand_call must push the stack around the
1993 function call. Such arguments have pass_on_stack == 1.
1995 Note that it is always safe to set stack_arg_under_construction,
1996 but this generates suboptimal code if set when not needed. */
1998 if (arg
->pass_on_stack
)
1999 stack_arg_under_construction
++;
2001 arg
->value
= expand_expr (pval
, partial
? NULL_RTX
: arg
->stack
,
2003 #ifdef ACCUMULATE_OUTGOING_ARGS
2004 if (arg
->pass_on_stack
)
2005 stack_arg_under_construction
--;
2009 /* Don't allow anything left on stack from computation
2010 of argument to alloca. */
2012 do_pending_stack_adjust ();
2014 if (arg
->value
== arg
->stack
)
2015 /* If the value is already in the stack slot, we are done. */
2017 else if (TYPE_MODE (TREE_TYPE (pval
)) != BLKmode
)
2021 /* Argument is a scalar, not entirely passed in registers.
2022 (If part is passed in registers, arg->partial says how much
2023 and emit_push_insn will take care of putting it there.)
2025 Push it, and if its size is less than the
2026 amount of space allocated to it,
2027 also bump stack pointer by the additional space.
2028 Note that in C the default argument promotions
2029 will prevent such mismatches. */
2031 size
= GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval
)));
2032 /* Compute how much space the push instruction will push.
2033 On many machines, pushing a byte will advance the stack
2034 pointer by a halfword. */
2035 #ifdef PUSH_ROUNDING
2036 size
= PUSH_ROUNDING (size
);
2040 /* Compute how much space the argument should get:
2041 round up to a multiple of the alignment for arguments. */
2042 if (none
!= FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval
)),
2044 used
= (((size
+ PARM_BOUNDARY
/ BITS_PER_UNIT
- 1)
2045 / (PARM_BOUNDARY
/ BITS_PER_UNIT
))
2046 * (PARM_BOUNDARY
/ BITS_PER_UNIT
));
2048 /* This isn't already where we want it on the stack, so put it there.
2049 This can either be done with push or copy insns. */
2050 emit_push_insn (arg
->value
, TYPE_MODE (TREE_TYPE (pval
)),
2051 TREE_TYPE (pval
), 0, 0, partial
, reg
,
2052 used
- size
, argblock
, ARGS_SIZE_RTX (arg
->offset
));
2056 /* BLKmode, at least partly to be pushed. */
2058 register int excess
;
2061 /* Pushing a nonscalar.
2062 If part is passed in registers, PARTIAL says how much
2063 and emit_push_insn will take care of putting it there. */
2065 /* Round its size up to a multiple
2066 of the allocation unit for arguments. */
2068 if (arg
->size
.var
!= 0)
2071 size_rtx
= ARGS_SIZE_RTX (arg
->size
);
2075 register tree size
= size_in_bytes (TREE_TYPE (pval
));
2076 /* PUSH_ROUNDING has no effect on us, because
2077 emit_push_insn for BLKmode is careful to avoid it. */
2078 excess
= (arg
->size
.constant
- TREE_INT_CST_LOW (size
)
2079 + partial
* UNITS_PER_WORD
);
2080 size_rtx
= expand_expr (size
, NULL_RTX
, VOIDmode
, 0);
2083 emit_push_insn (arg
->value
, TYPE_MODE (TREE_TYPE (pval
)),
2084 TREE_TYPE (pval
), size_rtx
,
2085 TYPE_ALIGN (TREE_TYPE (pval
)) / BITS_PER_UNIT
, partial
,
2086 reg
, excess
, argblock
, ARGS_SIZE_RTX (arg
->offset
));
2090 /* Unless this is a partially-in-register argument, the argument is now
2093 ??? Note that this can change arg->value from arg->stack to
2094 arg->stack_slot and it matters when they are not the same.
2095 It isn't totally clear that this is correct in all cases. */
2097 arg
->value
= arg
->stack_slot
;
2099 /* Once we have pushed something, pops can't safely
2100 be deferred during the rest of the arguments. */
2103 /* ANSI doesn't require a sequence point here,
2104 but PCC has one, so this will avoid some problems. */
2107 /* Free any temporary slots made in processing this argument. */
2110 #ifdef ACCUMULATE_OUTGOING_ARGS
2111 /* Now mark the segment we just used. */
2112 if (argblock
&& ! variable_size
&& arg
->stack
)
2113 for (i
= lower_bound
; i
< upper_bound
; i
++)
2114 stack_usage_map
[i
] = 1;