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 word 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 inlineable,
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_PTR);
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
889 int size = int_size_in_bytes (type);
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,
911 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
913 store_expr (args[i].tree_value, copy, 0);
915 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
916 make_tree (type, copy));
917 type = build_pointer_type (type);
921 mode = TYPE_MODE (type);
923 #ifdef PROMOTE_FUNCTION_ARGS
924 /* Compute the mode in which the arg is actually to be extended to. */
925 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
926 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
927 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
928 || TREE_CODE (type) == OFFSET_TYPE)
930 int unsignedp = TREE_UNSIGNED (type);
931 PROMOTE_MODE (mode, unsignedp, type);
932 args[i].unsignedp = unsignedp;
936 args[i].reg = FUNCTION_ARG (args_so_far, mode, type,
937 argpos < n_named_args);
938 #ifdef FUNCTION_ARG_PARTIAL_NREGS
941 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, type,
942 argpos < n_named_args);
945 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
947 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
948 we are to pass this arg in the register(s) designated by FOO, but
949 also to pass it in the stack. */
950 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
951 && XEXP (args[i].reg, 0) == 0)
952 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
954 /* If this is an addressable type, we must preallocate the stack
955 since we must evaluate the object into its final location.
957 If this is to be passed in both registers and the stack, it is simpler
959 if (TREE_ADDRESSABLE (type)
960 || (args[i].pass_on_stack && args[i].reg != 0))
961 must_preallocate = 1;
963 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
964 we cannot consider this function call constant. */
965 if (TREE_ADDRESSABLE (type))
968 /* Compute the stack-size of this argument. */
969 if (args[i].reg == 0 || args[i].partial != 0
970 #ifdef REG_PARM_STACK_SPACE
971 || reg_parm_stack_space > 0
973 || args[i].pass_on_stack)
974 locate_and_pad_parm (TYPE_MODE (type), type,
975 #ifdef STACK_PARMS_IN_REG_PARM_AREA
980 fndecl, &args_size, &args[i].offset,
983 #ifndef ARGS_GROW_DOWNWARD
984 args[i].slot_offset = args_size;
987 #ifndef REG_PARM_STACK_SPACE
988 /* If a part of the arg was put into registers,
989 don't include that part in the amount pushed. */
990 if (! args[i].pass_on_stack)
991 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
992 / (PARM_BOUNDARY / BITS_PER_UNIT)
993 * (PARM_BOUNDARY / BITS_PER_UNIT));
996 /* Update ARGS_SIZE, the total stack space for args so far. */
998 args_size.constant += args[i].size.constant;
999 if (args[i].size.var)
1001 ADD_PARM_SIZE (args_size, args[i].size.var);
1004 /* Since the slot offset points to the bottom of the slot,
1005 we must record it after incrementing if the args grow down. */
1006 #ifdef ARGS_GROW_DOWNWARD
1007 args[i].slot_offset = args_size;
1009 args[i].slot_offset.constant = -args_size.constant;
1012 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
1016 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1017 have been used, etc. */
1019 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
1020 argpos < n_named_args);
1023 #ifdef FINAL_REG_PARM_STACK_SPACE
1024 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
1028 /* Compute the actual size of the argument block required. The variable
1029 and constant sizes must be combined, the size may have to be rounded,
1030 and there may be a minimum required size. */
1032 original_args_size = args_size;
1035 /* If this function requires a variable-sized argument list, don't try to
1036 make a cse'able block for this call. We may be able to do this
1037 eventually, but it is too complicated to keep track of what insns go
1038 in the cse'able block and which don't. */
1041 must_preallocate = 1;
1043 args_size.var = ARGS_SIZE_TREE (args_size);
1044 args_size.constant = 0;
1046 #ifdef STACK_BOUNDARY
1047 if (STACK_BOUNDARY != BITS_PER_UNIT)
1048 args_size.var = round_up (args_size.var, STACK_BYTES);
1051 #ifdef REG_PARM_STACK_SPACE
1052 if (reg_parm_stack_space > 0)
1055 = size_binop (MAX_EXPR, args_size.var,
1056 size_int (REG_PARM_STACK_SPACE (fndecl)));
1058 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1059 /* The area corresponding to register parameters is not to count in
1060 the size of the block we need. So make the adjustment. */
1062 = size_binop (MINUS_EXPR, args_size.var,
1063 size_int (reg_parm_stack_space));
1070 #ifdef STACK_BOUNDARY
1071 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
1072 / STACK_BYTES) * STACK_BYTES);
1075 #ifdef REG_PARM_STACK_SPACE
1076 args_size.constant = MAX (args_size.constant,
1077 reg_parm_stack_space);
1078 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1079 args_size.constant -= reg_parm_stack_space;
1084 /* See if we have or want to preallocate stack space.
1086 If we would have to push a partially-in-regs parm
1087 before other stack parms, preallocate stack space instead.
1089 If the size of some parm is not a multiple of the required stack
1090 alignment, we must preallocate.
1092 If the total size of arguments that would otherwise create a copy in
1093 a temporary (such as a CALL) is more than half the total argument list
1094 size, preallocation is faster.
1096 Another reason to preallocate is if we have a machine (like the m88k)
1097 where stack alignment is required to be maintained between every
1098 pair of insns, not just when the call is made. However, we assume here
1099 that such machines either do not have push insns (and hence preallocation
1100 would occur anyway) or the problem is taken care of with
1103 if (! must_preallocate)
1105 int partial_seen = 0;
1106 int copy_to_evaluate_size = 0;
1108 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1110 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1112 else if (partial_seen && args[i].reg == 0)
1113 must_preallocate = 1;
1115 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1116 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1117 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1118 || TREE_CODE (args[i].tree_value) == COND_EXPR
1119 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1120 copy_to_evaluate_size
1121 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1124 if (copy_to_evaluate_size * 2 >= args_size.constant
1125 && args_size.constant > 0)
1126 must_preallocate = 1;
1129 /* If the structure value address will reference the stack pointer, we must
1130 stabilize it. We don't need to do this if we know that we are not going
1131 to adjust the stack pointer in processing this call. */
1133 if (structure_value_addr
1134 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1135 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1137 #ifndef ACCUMULATE_OUTGOING_ARGS
1138 || args_size.constant
1141 structure_value_addr = copy_to_reg (structure_value_addr);
1143 /* If this function call is cse'able, precompute all the parameters.
1144 Note that if the parameter is constructed into a temporary, this will
1145 cause an additional copy because the parameter will be constructed
1146 into a temporary location and then copied into the outgoing arguments.
1147 If a parameter contains a call to alloca and this function uses the
1148 stack, precompute the parameter. */
1150 for (i = 0; i < num_actuals; i++)
1152 || ((args_size.var != 0 || args_size.constant != 0)
1153 && calls_alloca (args[i].tree_value)))
1155 args[i].initial_value = args[i].value
1156 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1157 preserve_temp_slots (args[i].value);
1160 /* ANSI doesn't require a sequence point here,
1161 but PCC has one, so this will avoid some problems. */
1165 /* Now we are about to start emitting insns that can be deleted
1166 if a libcall is deleted. */
1170 /* If we have no actual push instructions, or shouldn't use them,
1171 make space for all args right now. */
1173 if (args_size.var != 0)
1175 if (old_stack_level == 0)
1177 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1178 old_pending_adj = pending_stack_adjust;
1179 pending_stack_adjust = 0;
1180 #ifdef ACCUMULATE_OUTGOING_ARGS
1181 /* stack_arg_under_construction says whether a stack arg is
1182 being constructed at the old stack level. Pushing the stack
1183 gets a clean outgoing argument block. */
1184 old_stack_arg_under_construction = stack_arg_under_construction;
1185 stack_arg_under_construction = 0;
1188 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1190 else if (must_preallocate)
1192 /* Note that we must go through the motions of allocating an argument
1193 block even if the size is zero because we may be storing args
1194 in the area reserved for register arguments, which may be part of
1196 int needed = args_size.constant;
1198 #ifdef ACCUMULATE_OUTGOING_ARGS
1199 /* Store the maximum argument space used. It will be pushed by the
1202 Since the stack pointer will never be pushed, it is possible for
1203 the evaluation of a parm to clobber something we have already
1204 written to the stack. Since most function calls on RISC machines
1205 do not use the stack, this is uncommon, but must work correctly.
1207 Therefore, we save any area of the stack that was already written
1208 and that we are using. Here we set up to do this by making a new
1209 stack usage map from the old one. The actual save will be done
1212 Another approach might be to try to reorder the argument
1213 evaluations to avoid this conflicting stack usage. */
1215 if (needed > current_function_outgoing_args_size)
1216 current_function_outgoing_args_size = needed;
1218 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1219 /* Since we will be writing into the entire argument area, the
1220 map must be allocated for its entire size, not just the part that
1221 is the responsibility of the caller. */
1222 needed += reg_parm_stack_space;
1225 #ifdef ARGS_GROW_DOWNWARD
1226 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1229 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1231 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1233 if (initial_highest_arg_in_use)
1234 bcopy (initial_stack_usage_map, stack_usage_map,
1235 initial_highest_arg_in_use);
1237 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1238 bzero (&stack_usage_map[initial_highest_arg_in_use],
1239 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1242 /* The address of the outgoing argument list must not be copied to a
1243 register here, because argblock would be left pointing to the
1244 wrong place after the call to allocate_dynamic_stack_space below. */
1246 argblock = virtual_outgoing_args_rtx;
1248 #else /* not ACCUMULATE_OUTGOING_ARGS */
1249 if (inhibit_defer_pop == 0)
1251 /* Try to reuse some or all of the pending_stack_adjust
1252 to get this space. Maybe we can avoid any pushing. */
1253 if (needed > pending_stack_adjust)
1255 needed -= pending_stack_adjust;
1256 pending_stack_adjust = 0;
1260 pending_stack_adjust -= needed;
1264 /* Special case this because overhead of `push_block' in this
1265 case is non-trivial. */
1267 argblock = virtual_outgoing_args_rtx;
1269 argblock = push_block (GEN_INT (needed), 0, 0);
1271 /* We only really need to call `copy_to_reg' in the case where push
1272 insns are going to be used to pass ARGBLOCK to a function
1273 call in ARGS. In that case, the stack pointer changes value
1274 from the allocation point to the call point, and hence
1275 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1276 But might as well always do it. */
1277 argblock = copy_to_reg (argblock);
1278 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1282 #ifdef ACCUMULATE_OUTGOING_ARGS
1283 /* The save/restore code in store_one_arg handles all cases except one:
1284 a constructor call (including a C function returning a BLKmode struct)
1285 to initialize an argument. */
1286 if (stack_arg_under_construction)
1288 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1289 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
1291 rtx push_size = GEN_INT (args_size.constant);
1293 if (old_stack_level == 0)
1295 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1296 old_pending_adj = pending_stack_adjust;
1297 pending_stack_adjust = 0;
1298 /* stack_arg_under_construction says whether a stack arg is
1299 being constructed at the old stack level. Pushing the stack
1300 gets a clean outgoing argument block. */
1301 old_stack_arg_under_construction = stack_arg_under_construction;
1302 stack_arg_under_construction = 0;
1303 /* Make a new map for the new argument list. */
1304 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
1305 bzero (stack_usage_map, highest_outgoing_arg_in_use);
1306 highest_outgoing_arg_in_use = 0;
1308 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
1310 /* If argument evaluation might modify the stack pointer, copy the
1311 address of the argument list to a register. */
1312 for (i = 0; i < num_actuals; i++)
1313 if (args[i].pass_on_stack)
1315 argblock = copy_addr_to_reg (argblock);
1321 /* If we preallocated stack space, compute the address of each argument.
1322 We need not ensure it is a valid memory address here; it will be
1323 validized when it is used. */
1326 rtx arg_reg = argblock;
1329 if (GET_CODE (argblock) == PLUS)
1330 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1332 for (i = 0; i < num_actuals; i++)
1334 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1335 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1338 /* Skip this parm if it will not be passed on the stack. */
1339 if (! args[i].pass_on_stack && args[i].reg != 0)
1342 if (GET_CODE (offset) == CONST_INT)
1343 addr = plus_constant (arg_reg, INTVAL (offset));
1345 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1347 addr = plus_constant (addr, arg_offset);
1349 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1351 if (GET_CODE (slot_offset) == CONST_INT)
1352 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1354 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1356 addr = plus_constant (addr, arg_offset);
1358 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1362 #ifdef PUSH_ARGS_REVERSED
1363 #ifdef STACK_BOUNDARY
1364 /* If we push args individually in reverse order, perform stack alignment
1365 before the first push (the last arg). */
1367 anti_adjust_stack (GEN_INT (args_size.constant
1368 - original_args_size.constant));
1372 /* Don't try to defer pops if preallocating, not even from the first arg,
1373 since ARGBLOCK probably refers to the SP. */
1377 /* Get the function to call, in the form of RTL. */
1379 /* Get a SYMBOL_REF rtx for the function address. */
1380 funexp = XEXP (DECL_RTL (fndecl), 0);
1382 /* Generate an rtx (probably a pseudo-register) for the address. */
1384 funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1385 free_temp_slots (); /* FUNEXP can't be BLKmode */
1389 /* Figure out the register where the value, if any, will come back. */
1391 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1392 && ! structure_value_addr)
1394 if (pcc_struct_value)
1395 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1398 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1401 /* Precompute all register parameters. It isn't safe to compute anything
1402 once we have started filling any specific hard regs. */
1404 for (i = 0; i < num_actuals; i++)
1405 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1407 enum machine_mode mode;
1411 if (args[i].value == 0)
1413 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
1415 preserve_temp_slots (args[i].value);
1418 /* ANSI doesn't require a sequence point here,
1419 but PCC has one, so this will avoid some problems. */
1423 /* If we are to promote the function arg to a wider mode,
1425 mode = (GET_CODE (args[i].reg) == EXPR_LIST
1426 ? GET_MODE (XEXP (args[i].reg, 0)) : GET_MODE (args[i].reg));
1428 if (GET_MODE (args[i].value) != mode)
1429 args[i].value = convert_to_mode (mode, args[i].value,
1433 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1434 /* The argument list is the property of the called routine and it
1435 may clobber it. If the fixed area has been used for previous
1436 parameters, we must save and restore it.
1438 Here we compute the boundary of the that needs to be saved, if any. */
1440 for (i = 0; i < reg_parm_stack_space; i++)
1442 if (i >= highest_outgoing_arg_in_use
1443 || stack_usage_map[i] == 0)
1446 if (low_to_save == -1)
1452 if (low_to_save >= 0)
1454 int num_to_save = high_to_save - low_to_save + 1;
1455 enum machine_mode save_mode
1456 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1459 /* If we don't have the required alignment, must do this in BLKmode. */
1460 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1461 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1462 save_mode = BLKmode;
1464 stack_area = gen_rtx (MEM, save_mode,
1465 memory_address (save_mode,
1466 plus_constant (argblock,
1468 if (save_mode == BLKmode)
1470 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1471 emit_block_move (validize_mem (save_area), stack_area,
1472 GEN_INT (num_to_save),
1473 PARM_BOUNDARY / BITS_PER_UNIT);
1477 save_area = gen_reg_rtx (save_mode);
1478 emit_move_insn (save_area, stack_area);
1484 /* Now store (and compute if necessary) all non-register parms.
1485 These come before register parms, since they can require block-moves,
1486 which could clobber the registers used for register parms.
1487 Parms which have partial registers are not stored here,
1488 but we do preallocate space here if they want that. */
1490 for (i = 0; i < num_actuals; i++)
1491 if (args[i].reg == 0 || args[i].pass_on_stack)
1492 store_one_arg (&args[i], argblock, may_be_alloca,
1493 args_size.var != 0, fndecl, reg_parm_stack_space);
1495 /* Now store any partially-in-registers parm.
1496 This is the last place a block-move can happen. */
1498 for (i = 0; i < num_actuals; i++)
1499 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1500 store_one_arg (&args[i], argblock, may_be_alloca,
1501 args_size.var != 0, fndecl, reg_parm_stack_space);
1503 #ifndef PUSH_ARGS_REVERSED
1504 #ifdef STACK_BOUNDARY
1505 /* If we pushed args in forward order, perform stack alignment
1506 after pushing the last arg. */
1508 anti_adjust_stack (GEN_INT (args_size.constant
1509 - original_args_size.constant));
1513 /* If register arguments require space on the stack and stack space
1514 was not preallocated, allocate stack space here for arguments
1515 passed in registers. */
1516 #if ! defined(ALLOCATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
1517 if (must_preallocate == 0 && reg_parm_stack_space > 0)
1518 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
1521 /* Pass the function the address in which to return a structure value. */
1522 if (structure_value_addr && ! structure_value_addr_parm)
1524 emit_move_insn (struct_value_rtx,
1526 force_operand (structure_value_addr,
1528 if (GET_CODE (struct_value_rtx) == REG)
1530 push_to_sequence (use_insns);
1531 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1532 use_insns = get_insns ();
1537 /* Now do the register loads required for any wholly-register parms or any
1538 parms which are passed both on the stack and in a register. Their
1539 expressions were already evaluated.
1541 Mark all register-parms as living through the call, putting these USE
1542 insns in a list headed by USE_INSNS. */
1544 for (i = 0; i < num_actuals; i++)
1546 rtx list = args[i].reg;
1547 int partial = args[i].partial;
1554 /* Process each register that needs to get this arg. */
1555 if (GET_CODE (list) == EXPR_LIST)
1556 reg = XEXP (list, 0), list = XEXP (list, 1);
1558 reg = list, list = 0;
1560 /* Set to non-zero if must move a word at a time, even if just one
1561 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1562 we just use a normal move insn. */
1563 nregs = (partial ? partial
1564 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1565 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1566 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1569 /* If simple case, just do move. If normal partial, store_one_arg
1570 has already loaded the register for us. In all other cases,
1571 load the register(s) from memory. */
1574 emit_move_insn (reg, args[i].value);
1575 else if (args[i].partial == 0 || args[i].pass_on_stack)
1576 move_block_to_reg (REGNO (reg),
1577 validize_mem (args[i].value), nregs,
1578 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1580 push_to_sequence (use_insns);
1582 emit_insn (gen_rtx (USE, VOIDmode, reg));
1584 use_regs (REGNO (reg), nregs);
1585 use_insns = get_insns ();
1588 /* PARTIAL referred only to the first register, so clear it for the
1594 /* Perform postincrements before actually calling the function. */
1597 /* All arguments and registers used for the call must be set up by now! */
1599 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1601 /* Generate the actual call instruction. */
1602 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1603 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1604 valreg, old_inhibit_defer_pop, use_insns, is_const);
1606 /* If call is cse'able, make appropriate pair of reg-notes around it.
1607 Test valreg so we don't crash; may safely ignore `const'
1608 if return type is void. */
1609 if (is_const && valreg != 0)
1612 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1615 /* Construct an "equal form" for the value which mentions all the
1616 arguments in order as well as the function name. */
1617 #ifdef PUSH_ARGS_REVERSED
1618 for (i = 0; i < num_actuals; i++)
1619 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1621 for (i = num_actuals - 1; i >= 0; i--)
1622 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1624 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1626 insns = get_insns ();
1629 emit_libcall_block (insns, temp, valreg, note);
1634 /* For calls to `setjmp', etc., inform flow.c it should complain
1635 if nonvolatile values are live. */
1639 emit_note (name, NOTE_INSN_SETJMP);
1640 current_function_calls_setjmp = 1;
1644 current_function_calls_longjmp = 1;
1646 /* Notice functions that cannot return.
1647 If optimizing, insns emitted below will be dead.
1648 If not optimizing, they will exist, which is useful
1649 if the user uses the `return' command in the debugger. */
1651 if (is_volatile || is_longjmp)
1654 /* If value type not void, return an rtx for the value. */
1656 /* If there are cleanups to be called, don't use a hard reg as target. */
1657 if (cleanups_this_call != old_cleanups
1658 && target && REG_P (target)
1659 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1662 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1665 target = const0_rtx;
1667 else if (structure_value_addr)
1669 if (target == 0 || GET_CODE (target) != MEM)
1671 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1672 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1673 structure_value_addr));
1674 MEM_IN_STRUCT_P (target)
1675 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1676 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1677 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1680 else if (pcc_struct_value)
1684 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1685 copy_to_reg (valreg));
1686 MEM_IN_STRUCT_P (target)
1687 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1688 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1689 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1691 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1692 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1693 copy_to_reg (valreg)));
1695 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1697 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1699 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
1700 && GET_MODE (target) == GET_MODE (valreg))
1701 /* TARGET and VALREG cannot be equal at this point because the latter
1702 would not have REG_FUNCTION_VALUE_P true, while the former would if
1703 it were referring to the same register.
1705 If they refer to the same register, this move will be a no-op, except
1706 when function inlining is being done. */
1707 emit_move_insn (target, valreg);
1709 target = copy_to_reg (valreg);
1711 #ifdef PROMOTE_FUNCTION_RETURN
1712 /* If we promoted this return value, make the proper SUBREG. */
1713 if (GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
1715 enum machine_mode mode = GET_MODE (target);
1716 int unsignedp = TREE_UNSIGNED (TREE_TYPE (exp));
1718 if (TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE
1719 || TREE_CODE (TREE_TYPE (exp)) == ENUMERAL_TYPE
1720 || TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE
1721 || TREE_CODE (TREE_TYPE (exp)) == CHAR_TYPE
1722 || TREE_CODE (TREE_TYPE (exp)) == REAL_TYPE
1723 || TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE
1724 || TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE)
1726 PROMOTE_MODE (mode, unsignedp, TREE_TYPE (exp));
1729 target = gen_rtx (SUBREG, TYPE_MODE (TREE_TYPE (exp)), target, 0);
1730 SUBREG_PROMOTED_VAR_P (target) = 1;
1731 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
1735 /* Perform all cleanups needed for the arguments of this call
1736 (i.e. destructors in C++). */
1737 expand_cleanups_to (old_cleanups);
1739 /* If size of args is variable or this was a constructor call for a stack
1740 argument, restore saved stack-pointer value. */
1742 if (old_stack_level)
1744 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1745 pending_stack_adjust = old_pending_adj;
1746 #ifdef ACCUMULATE_OUTGOING_ARGS
1747 stack_arg_under_construction = old_stack_arg_under_construction;
1748 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1749 stack_usage_map = initial_stack_usage_map;
1752 #ifdef ACCUMULATE_OUTGOING_ARGS
1755 #ifdef REG_PARM_STACK_SPACE
1758 enum machine_mode save_mode = GET_MODE (save_area);
1760 = gen_rtx (MEM, save_mode,
1761 memory_address (save_mode,
1762 plus_constant (argblock, low_to_save)));
1764 if (save_mode != BLKmode)
1765 emit_move_insn (stack_area, save_area);
1767 emit_block_move (stack_area, validize_mem (save_area),
1768 GEN_INT (high_to_save - low_to_save + 1),
1769 PARM_BOUNDARY / BITS_PER_UNIT);
1773 /* If we saved any argument areas, restore them. */
1774 for (i = 0; i < num_actuals; i++)
1775 if (args[i].save_area)
1777 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1779 = gen_rtx (MEM, save_mode,
1780 memory_address (save_mode,
1781 XEXP (args[i].stack_slot, 0)));
1783 if (save_mode != BLKmode)
1784 emit_move_insn (stack_area, args[i].save_area);
1786 emit_block_move (stack_area, validize_mem (args[i].save_area),
1787 GEN_INT (args[i].size.constant),
1788 PARM_BOUNDARY / BITS_PER_UNIT);
1791 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1792 stack_usage_map = initial_stack_usage_map;
1796 /* If this was alloca, record the new stack level for nonlocal gotos.
1797 Check for the handler slots since we might not have a save area
1798 for non-local gotos. */
1800 if (may_be_alloca && nonlocal_goto_handler_slot != 0)
1801 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1809 /* Return an rtx which represents a suitable home on the stack
1810 given TYPE, the type of the argument looking for a home.
1811 This is called only for BLKmode arguments.
1813 SIZE is the size needed for this target.
1814 ARGS_ADDR is the address of the bottom of the argument block for this call.
1815 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1816 if this machine uses push insns. */
1819 target_for_arg (type, size, args_addr, offset)
1823 struct args_size offset;
1826 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1828 /* We do not call memory_address if possible,
1829 because we want to address as close to the stack
1830 as possible. For non-variable sized arguments,
1831 this will be stack-pointer relative addressing. */
1832 if (GET_CODE (offset_rtx) == CONST_INT)
1833 target = plus_constant (args_addr, INTVAL (offset_rtx));
1836 /* I have no idea how to guarantee that this
1837 will work in the presence of register parameters. */
1838 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1839 target = memory_address (QImode, target);
1842 return gen_rtx (MEM, BLKmode, target);
1846 /* Store a single argument for a function call
1847 into the register or memory area where it must be passed.
1848 *ARG describes the argument value and where to pass it.
1850 ARGBLOCK is the address of the stack-block for all the arguments,
1851 or 0 on a machine where arguments are pushed individually.
1853 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1854 so must be careful about how the stack is used.
1856 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1857 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1858 that we need not worry about saving and restoring the stack.
1860 FNDECL is the declaration of the function we are calling. */
1863 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl,
1864 reg_parm_stack_space)
1865 struct arg_data *arg;
1870 int reg_parm_stack_space;
1872 register tree pval = arg->tree_value;
1876 int i, lower_bound, upper_bound;
1878 if (TREE_CODE (pval) == ERROR_MARK)
1881 #ifdef ACCUMULATE_OUTGOING_ARGS
1882 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1883 save any previous data at that location. */
1884 if (argblock && ! variable_size && arg->stack)
1886 #ifdef ARGS_GROW_DOWNWARD
1887 /* stack_slot is negative, but we want to index stack_usage_map */
1888 /* with positive values. */
1889 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1890 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1894 lower_bound = upper_bound - arg->size.constant;
1896 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1897 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1901 upper_bound = lower_bound + arg->size.constant;
1904 for (i = lower_bound; i < upper_bound; i++)
1905 if (stack_usage_map[i]
1906 #ifdef REG_PARM_STACK_SPACE
1907 /* Don't store things in the fixed argument area at this point;
1908 it has already been saved. */
1909 && i > reg_parm_stack_space
1914 if (i != upper_bound)
1916 /* We need to make a save area. See what mode we can make it. */
1917 enum machine_mode save_mode
1918 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1920 = gen_rtx (MEM, save_mode,
1921 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1923 if (save_mode == BLKmode)
1925 arg->save_area = assign_stack_temp (BLKmode,
1926 arg->size.constant, 1);
1927 emit_block_move (validize_mem (arg->save_area), stack_area,
1928 GEN_INT (arg->size.constant),
1929 PARM_BOUNDARY / BITS_PER_UNIT);
1933 arg->save_area = gen_reg_rtx (save_mode);
1934 emit_move_insn (arg->save_area, stack_area);
1940 /* If this isn't going to be placed on both the stack and in registers,
1941 set up the register and number of words. */
1942 if (! arg->pass_on_stack)
1943 reg = arg->reg, partial = arg->partial;
1945 if (reg != 0 && partial == 0)
1946 /* Being passed entirely in a register. We shouldn't be called in
1950 /* If this is being partially passed in a register, but multiple locations
1951 are specified, we assume that the one partially used is the one that is
1953 if (reg && GET_CODE (reg) == EXPR_LIST)
1954 reg = XEXP (reg, 0);
1956 /* If this is being passes partially in a register, we can't evaluate
1957 it directly into its stack slot. Otherwise, we can. */
1958 if (arg->value == 0)
1960 #ifdef ACCUMULATE_OUTGOING_ARGS
1961 /* stack_arg_under_construction is nonzero if a function argument is
1962 being evaluated directly into the outgoing argument list and
1963 expand_call must take special action to preserve the argument list
1964 if it is called recursively.
1966 For scalar function arguments stack_usage_map is sufficient to
1967 determine which stack slots must be saved and restored. Scalar
1968 arguments in general have pass_on_stack == 0.
1970 If this argument is initialized by a function which takes the
1971 address of the argument (a C++ constructor or a C function
1972 returning a BLKmode structure), then stack_usage_map is
1973 insufficient and expand_call must push the stack around the
1974 function call. Such arguments have pass_on_stack == 1.
1976 Note that it is always safe to set stack_arg_under_construction,
1977 but this generates suboptimal code if set when not needed. */
1979 if (arg->pass_on_stack)
1980 stack_arg_under_construction++;
1982 arg->value = expand_expr (pval, partial ? NULL_RTX : arg->stack,
1984 #ifdef ACCUMULATE_OUTGOING_ARGS
1985 if (arg->pass_on_stack)
1986 stack_arg_under_construction--;
1990 /* Don't allow anything left on stack from computation
1991 of argument to alloca. */
1993 do_pending_stack_adjust ();
1995 if (arg->value == arg->stack)
1996 /* If the value is already in the stack slot, we are done. */
1998 else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
2002 /* Argument is a scalar, not entirely passed in registers.
2003 (If part is passed in registers, arg->partial says how much
2004 and emit_push_insn will take care of putting it there.)
2006 Push it, and if its size is less than the
2007 amount of space allocated to it,
2008 also bump stack pointer by the additional space.
2009 Note that in C the default argument promotions
2010 will prevent such mismatches. */
2012 size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
2013 /* Compute how much space the push instruction will push.
2014 On many machines, pushing a byte will advance the stack
2015 pointer by a halfword. */
2016 #ifdef PUSH_ROUNDING
2017 size = PUSH_ROUNDING (size);
2021 /* Compute how much space the argument should get:
2022 round up to a multiple of the alignment for arguments. */
2023 if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
2025 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
2026 / (PARM_BOUNDARY / BITS_PER_UNIT))
2027 * (PARM_BOUNDARY / BITS_PER_UNIT));
2029 /* This isn't already where we want it on the stack, so put it there.
2030 This can either be done with push or copy insns. */
2031 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2032 TREE_TYPE (pval), 0, 0, partial, reg,
2033 used - size, argblock, ARGS_SIZE_RTX (arg->offset));
2037 /* BLKmode, at least partly to be pushed. */
2039 register int excess;
2042 /* Pushing a nonscalar.
2043 If part is passed in registers, PARTIAL says how much
2044 and emit_push_insn will take care of putting it there. */
2046 /* Round its size up to a multiple
2047 of the allocation unit for arguments. */
2049 if (arg->size.var != 0)
2052 size_rtx = ARGS_SIZE_RTX (arg->size);
2056 register tree size = size_in_bytes (TREE_TYPE (pval));
2057 /* PUSH_ROUNDING has no effect on us, because
2058 emit_push_insn for BLKmode is careful to avoid it. */
2059 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
2060 + partial * UNITS_PER_WORD);
2061 size_rtx = expand_expr (size, NULL_RTX, VOIDmode, 0);
2064 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2065 TREE_TYPE (pval), size_rtx,
2066 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
2067 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
2071 /* Unless this is a partially-in-register argument, the argument is now
2074 ??? Note that this can change arg->value from arg->stack to
2075 arg->stack_slot and it matters when they are not the same.
2076 It isn't totally clear that this is correct in all cases. */
2078 arg->value = arg->stack_slot;
2080 /* Once we have pushed something, pops can't safely
2081 be deferred during the rest of the arguments. */
2084 /* ANSI doesn't require a sequence point here,
2085 but PCC has one, so this will avoid some problems. */
2088 /* Free any temporary slots made in processing this argument. */
2091 #ifdef ACCUMULATE_OUTGOING_ARGS
2092 /* Now mark the segment we just used. */
2093 if (argblock && ! variable_size && arg->stack)
2094 for (i = lower_bound; i < upper_bound; i++)
2095 stack_usage_map[i] = 1;