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 /* Number of registers to use. 0 means put the whole arg in registers.
54 Also 0 if not passed in registers. */
56 /* Non-zero if argument must be passed on stack. */
58 /* Offset of this argument from beginning of stack-args. */
59 struct args_size offset;
60 /* Similar, but offset to the start of the stack slot. Different from
61 OFFSET if this arg pads downward. */
62 struct args_size slot_offset;
63 /* Size of this argument on the stack, rounded up for any padding it gets,
64 parts of the argument passed in registers do not count.
65 If REG_PARM_STACK_SPACE is defined, then register parms
66 are counted here as well. */
67 struct args_size size;
68 /* Location on the stack at which parameter should be stored. The store
69 has already been done if STACK == VALUE. */
71 /* Location on the stack of the start of this argument slot. This can
72 differ from STACK if this arg pads downward. This location is known
73 to be aligned to FUNCTION_ARG_BOUNDARY. */
75 #ifdef ACCUMULATE_OUTGOING_ARGS
76 /* Place that this stack area has been saved, if needed. */
81 #ifdef ACCUMULATE_OUTGOING_ARGS
82 /* A vector of one char per word of stack space. A byte if non-zero if
83 the corresponding stack location has been used.
84 This vector is used to prevent a function call within an argument from
85 clobbering any stack already set up. */
86 static char *stack_usage_map;
88 /* Size of STACK_USAGE_MAP. */
89 static int highest_outgoing_arg_in_use;
92 static void store_one_arg ();
93 extern enum machine_mode mode_for_size ();
95 /* Return 1 if EXP contains a call to the built-in function `alloca'. */
102 int type = TREE_CODE_CLASS (TREE_CODE (exp));
103 int length = tree_code_length[(int) TREE_CODE (exp)];
105 /* Only expressions and references can contain calls. */
107 if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r')
110 switch (TREE_CODE (exp))
113 if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
114 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
116 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
117 && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
121 /* Third operand is RTL. */
126 if (SAVE_EXPR_RTL (exp) != 0)
131 /* Must not look at BLOCK_SUPERCONTEXT since it will point back to
136 case METHOD_CALL_EXPR:
140 case WITH_CLEANUP_EXPR:
148 for (i = 0; i < length; i++)
149 if (TREE_OPERAND (exp, i) != 0
150 && calls_alloca (TREE_OPERAND (exp, i)))
156 /* Force FUNEXP into a form suitable for the address of a CALL,
157 and return that as an rtx. Also load the static chain register
158 if FNDECL is a nested function.
160 USE_INSNS points to a variable holding a chain of USE insns
161 to which a USE of the static chain
162 register should be added, if required. */
165 prepare_call_address (funexp, fndecl, use_insns)
170 rtx static_chain_value = 0;
172 funexp = protect_from_queue (funexp, 0);
175 /* Get possible static chain value for nested function in C. */
176 static_chain_value = lookup_static_chain (fndecl);
178 /* Make a valid memory address and copy constants thru pseudo-regs,
179 but not for a constant address if -fno-function-cse. */
180 if (GET_CODE (funexp) != SYMBOL_REF)
181 funexp = memory_address (FUNCTION_MODE, funexp);
184 #ifndef NO_FUNCTION_CSE
185 if (optimize && ! flag_no_function_cse)
186 #ifdef NO_RECURSIVE_FUNCTION_CSE
187 if (fndecl != current_function_decl)
189 funexp = force_reg (Pmode, funexp);
193 if (static_chain_value != 0)
195 emit_move_insn (static_chain_rtx, static_chain_value);
197 /* Put the USE insn in the chain we were passed. It will later be
198 output immediately in front of the CALL insn. */
199 push_to_sequence (*use_insns);
200 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
201 *use_insns = get_insns ();
208 /* Generate instructions to call function FUNEXP,
209 and optionally pop the results.
210 The CALL_INSN is the first insn generated.
212 FUNTYPE is the data type of the function, or, for a library call,
213 the identifier for the name of the call. This is given to the
214 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
216 STACK_SIZE is the number of bytes of arguments on the stack,
217 rounded up to STACK_BOUNDARY; zero if the size is variable.
218 This is both to put into the call insn and
219 to generate explicit popping code if necessary.
221 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
222 It is zero if this call doesn't want a structure value.
224 NEXT_ARG_REG is the rtx that results from executing
225 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
226 just after all the args have had their registers assigned.
227 This could be whatever you like, but normally it is the first
228 arg-register beyond those used for args in this call,
229 or 0 if all the arg-registers are used in this call.
230 It is passed on to `gen_call' so you can put this info in the call insn.
232 VALREG is a hard register in which a value is returned,
233 or 0 if the call does not return a value.
235 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
236 the args to this call were processed.
237 We restore `inhibit_defer_pop' to that value.
239 USE_INSNS is a chain of USE insns to be emitted immediately before
240 the actual CALL insn.
242 IS_CONST is true if this is a `const' call. */
245 emit_call_1 (funexp, funtype, stack_size, struct_value_size, next_arg_reg,
246 valreg, old_inhibit_defer_pop, use_insns, is_const)
250 int struct_value_size;
253 int old_inhibit_defer_pop;
257 rtx stack_size_rtx = gen_rtx (CONST_INT, VOIDmode, stack_size);
258 rtx struct_value_size_rtx = gen_rtx (CONST_INT, VOIDmode, struct_value_size);
260 int already_popped = 0;
262 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
263 and we don't want to load it into a register as an optimization,
264 because prepare_call_address already did it if it should be done. */
265 if (GET_CODE (funexp) != SYMBOL_REF)
266 funexp = memory_address (FUNCTION_MODE, funexp);
268 #ifndef ACCUMULATE_OUTGOING_ARGS
269 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
270 if (HAVE_call_pop && HAVE_call_value_pop
271 && (RETURN_POPS_ARGS (funtype, stack_size) > 0 || stack_size == 0))
273 rtx n_pop = gen_rtx (CONST_INT, VOIDmode,
274 RETURN_POPS_ARGS (funtype, stack_size));
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
280 pat = gen_call_value_pop (valreg,
281 gen_rtx (MEM, FUNCTION_MODE, funexp),
282 stack_size_rtx, next_arg_reg, n_pop);
284 pat = gen_call_pop (gen_rtx (MEM, FUNCTION_MODE, funexp),
285 stack_size_rtx, next_arg_reg, n_pop);
287 emit_call_insn (pat);
294 #if defined (HAVE_call) && defined (HAVE_call_value)
295 if (HAVE_call && HAVE_call_value)
298 emit_call_insn (gen_call_value (valreg,
299 gen_rtx (MEM, FUNCTION_MODE, funexp),
300 stack_size_rtx, next_arg_reg));
302 emit_call_insn (gen_call (gen_rtx (MEM, FUNCTION_MODE, funexp),
303 stack_size_rtx, next_arg_reg,
304 struct_value_size_rtx));
310 /* Find the CALL insn we just emitted and write the USE insns before it. */
311 for (call_insn = get_last_insn ();
312 call_insn && GET_CODE (call_insn) != CALL_INSN;
313 call_insn = PREV_INSN (call_insn))
319 /* Put the USE insns before the CALL. */
320 emit_insns_before (use_insns, call_insn);
322 /* If this is a const call, then set the insn's unchanging bit. */
324 CONST_CALL_P (call_insn) = 1;
326 #ifndef ACCUMULATE_OUTGOING_ARGS
327 /* If returning from the subroutine does not automatically pop the args,
328 we need an instruction to pop them sooner or later.
329 Perhaps do it now; perhaps just record how much space to pop later.
331 If returning from the subroutine does pop the args, indicate that the
332 stack pointer will be changed. */
334 if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0)
337 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
338 stack_size -= RETURN_POPS_ARGS (funtype, stack_size);
339 stack_size_rtx = gen_rtx (CONST_INT, VOIDmode, stack_size);
344 if (flag_defer_pop && inhibit_defer_pop == 0)
345 pending_stack_adjust += stack_size;
347 adjust_stack (stack_size_rtx);
351 inhibit_defer_pop = old_inhibit_defer_pop;
354 /* Generate all the code for a function call
355 and return an rtx for its value.
356 Store the value in TARGET (specified as an rtx) if convenient.
357 If the value is stored in TARGET then TARGET is returned.
358 If IGNORE is nonzero, then we ignore the value of the function call. */
361 expand_call (exp, target, ignore)
366 /* List of actual parameters. */
367 tree actparms = TREE_OPERAND (exp, 1);
368 /* RTX for the function to be called. */
370 /* Tree node for the function to be called (not the address!). */
372 /* Data type of the function. */
374 /* Declaration of the function being called,
375 or 0 if the function is computed (not known by name). */
379 /* Register in which non-BLKmode value will be returned,
380 or 0 if no value or if value is BLKmode. */
382 /* Address where we should return a BLKmode value;
383 0 if value not BLKmode. */
384 rtx structure_value_addr = 0;
385 /* Nonzero if that address is being passed by treating it as
386 an extra, implicit first parameter. Otherwise,
387 it is passed by being copied directly into struct_value_rtx. */
388 int structure_value_addr_parm = 0;
389 /* Size of aggregate value wanted, or zero if none wanted
390 or if we are using the non-reentrant PCC calling convention
391 or expecting the value in registers. */
392 int struct_value_size = 0;
393 /* Nonzero if called function returns an aggregate in memory PCC style,
394 by returning the address of where to find it. */
395 int pcc_struct_value = 0;
397 /* Number of actual parameters in this call, including struct value addr. */
399 /* Number of named args. Args after this are anonymous ones
400 and they must all go on the stack. */
402 /* Count arg position in order args appear. */
405 /* Vector of information about each argument.
406 Arguments are numbered in the order they will be pushed,
407 not the order they are written. */
408 struct arg_data *args;
410 /* Total size in bytes of all the stack-parms scanned so far. */
411 struct args_size args_size;
412 /* Size of arguments before any adjustments (such as rounding). */
413 struct args_size original_args_size;
414 /* Data on reg parms scanned so far. */
415 CUMULATIVE_ARGS args_so_far;
416 /* Nonzero if a reg parm has been scanned. */
419 /* Nonzero if we must avoid push-insns in the args for this call.
420 If stack space is allocated for register parameters, but not by the
421 caller, then it is preallocated in the fixed part of the stack frame.
422 So the entire argument block must then be preallocated (i.e., we
423 ignore PUSH_ROUNDING in that case). */
425 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
426 int must_preallocate = 1;
429 int must_preallocate = 0;
431 int must_preallocate = 1;
435 /* Size of the stack reserved for paramter registers. */
436 int reg_parm_stack_space = 0;
438 /* 1 if scanning parms front to back, -1 if scanning back to front. */
440 /* Address of space preallocated for stack parms
441 (on machines that lack push insns), or 0 if space not preallocated. */
444 /* Nonzero if it is plausible that this is a call to alloca. */
446 /* Nonzero if this is a call to setjmp or a related function. */
448 /* Nonzero if this is a call to `longjmp'. */
450 /* Nonzero if this is a call to an inline function. */
451 int is_integrable = 0;
452 /* Nonzero if this is a call to a `const' function.
453 Note that only explicitly named functions are handled as `const' here. */
455 /* Nonzero if this is a call to a `volatile' function. */
457 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
458 /* Define the boundary of the register parm stack space that needs to be
460 int low_to_save = -1, high_to_save;
461 rtx save_area = 0; /* Place that it is saved */
464 #ifdef ACCUMULATE_OUTGOING_ARGS
465 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
466 char *initial_stack_usage_map = stack_usage_map;
469 rtx old_stack_level = 0;
471 int old_inhibit_defer_pop = inhibit_defer_pop;
472 tree old_cleanups = cleanups_this_call;
479 /* See if we can find a DECL-node for the actual function.
480 As a result, decide whether this is a call to an integrable function. */
482 p = TREE_OPERAND (exp, 0);
483 if (TREE_CODE (p) == ADDR_EXPR)
485 fndecl = TREE_OPERAND (p, 0);
486 if (TREE_CODE (fndecl) != FUNCTION_DECL)
488 /* May still be a `const' function if it is
489 a call through a pointer-to-const.
490 But we don't handle that. */
496 && fndecl != current_function_decl
497 && DECL_SAVED_INSNS (fndecl))
499 else if (! TREE_ADDRESSABLE (fndecl))
501 /* In case this function later becomes inlineable,
502 record that there was already a non-inline call to it.
504 Use abstraction instead of setting TREE_ADDRESSABLE
506 if (TREE_INLINE (fndecl) && extra_warnings && !flag_no_inline)
507 warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline");
508 mark_addressable (fndecl);
511 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
512 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
517 is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
519 #ifdef REG_PARM_STACK_SPACE
520 #ifdef MAYBE_REG_PARM_STACK_SPACE
521 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
523 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
527 /* Warn if this value is an aggregate type,
528 regardless of which calling convention we are using for it. */
529 if (warn_aggregate_return
530 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
531 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
532 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
533 warning ("function call has aggregate value");
535 /* Set up a place to return a structure. */
537 /* Cater to broken compilers. */
538 if (aggregate_value_p (exp))
540 /* This call returns a big structure. */
543 #ifdef PCC_STATIC_STRUCT_RETURN
544 if (flag_pcc_struct_return)
546 pcc_struct_value = 1;
547 is_integrable = 0; /* Easier than making that case work right. */
552 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
554 if (struct_value_size < 0)
557 if (target && GET_CODE (target) == MEM)
558 structure_value_addr = XEXP (target, 0);
561 /* Assign a temporary on the stack to hold the value. */
563 /* For variable-sized objects, we must be called with a target
564 specified. If we were to allocate space on the stack here,
565 we would have no way of knowing when to free it. */
568 = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
574 /* If called function is inline, try to integrate it. */
580 temp = expand_inline_function (fndecl, actparms, target,
581 ignore, TREE_TYPE (exp),
582 structure_value_addr);
584 /* If inlining succeeded, return. */
585 if ((int) temp != -1)
587 /* Perform all cleanups needed for the arguments of this call
588 (i.e. destructors in C++). It is ok if these destructors
589 clobber RETURN_VALUE_REG, because the only time we care about
590 this is when TARGET is that register. But in C++, we take
591 care to never return that register directly. */
592 expand_cleanups_to (old_cleanups);
594 /* If the result is equivalent to TARGET, return TARGET to simplify
595 checks in store_expr. They can be equivalent but not equal in the
596 case of a function that returns BLKmode. */
597 if (temp != target && rtx_equal_p (temp, target))
602 /* If inlining failed, mark FNDECL as needing to be compiled
603 separately after all. */
604 mark_addressable (fndecl);
607 /* When calling a const function, we must pop the stack args right away,
608 so that the pop is deleted or moved with the call. */
612 function_call_count++;
614 if (fndecl && DECL_NAME (fndecl))
615 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
618 /* Unless it's a call to a specific function that isn't alloca,
619 if it has one argument, we must assume it might be alloca. */
622 (!(fndecl != 0 && strcmp (name, "alloca"))
624 && TREE_CHAIN (actparms) == 0);
626 /* We assume that alloca will always be called by name. It
627 makes no sense to pass it as a pointer-to-function to
628 anything that does not understand its behavior. */
630 (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
632 && ! strcmp (name, "alloca"))
633 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
635 && ! strcmp (name, "__builtin_alloca"))));
638 /* See if this is a call to a function that can return more than once
639 or a call to longjmp. */
644 if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
649 tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
655 && (! strcmp (tname, "setjmp")
656 || ! strcmp (tname, "setjmp_syscall")))
658 && ! strcmp (tname, "sigsetjmp"))
660 && ! strcmp (tname, "savectx")));
662 && ! strcmp (tname, "siglongjmp"))
665 else if ((tname[0] == 'q' && tname[1] == 's'
666 && ! strcmp (tname, "qsetjmp"))
667 || (tname[0] == 'v' && tname[1] == 'f'
668 && ! strcmp (tname, "vfork")))
671 else if (tname[0] == 'l' && tname[1] == 'o'
672 && ! strcmp (tname, "longjmp"))
677 current_function_calls_alloca = 1;
679 /* Don't let pending stack adjusts add up to too much.
680 Also, do all pending adjustments now
681 if there is any chance this might be a call to alloca. */
683 if (pending_stack_adjust >= 32
684 || (pending_stack_adjust > 0 && may_be_alloca))
685 do_pending_stack_adjust ();
687 /* Operand 0 is a pointer-to-function; get the type of the function. */
688 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
689 if (TREE_CODE (funtype) != POINTER_TYPE)
691 funtype = TREE_TYPE (funtype);
693 /* Push the temporary stack slot level so that we can free temporaries used
694 by each of the arguments separately. */
697 /* Start updating where the next arg would go. */
698 INIT_CUMULATIVE_ARGS (args_so_far, funtype, 0);
700 /* If struct_value_rtx is 0, it means pass the address
701 as if it were an extra parameter. */
702 if (structure_value_addr && struct_value_rtx == 0)
705 = tree_cons (error_mark_node,
706 make_tree (build_pointer_type (TREE_TYPE (funtype)),
707 force_reg (Pmode, structure_value_addr)),
709 structure_value_addr_parm = 1;
712 /* Count the arguments and set NUM_ACTUALS. */
713 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
716 /* Compute number of named args.
717 Normally, don't include the last named arg if anonymous args follow.
718 (If no anonymous args follow, the result of list_length
719 is actually one too large.)
721 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
722 place unnamed args that were passed in registers into the stack. So
723 treat all args as named. This allows the insns emitting for a specific
724 argument list to be independent of the function declaration.
726 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
727 way to pass unnamed args in registers, so we must force them into
729 #ifndef SETUP_INCOMING_VARARGS
730 if (TYPE_ARG_TYPES (funtype) != 0)
732 = list_length (TYPE_ARG_TYPES (funtype)) - 1
733 /* Count the struct value address, if it is passed as a parm. */
734 + structure_value_addr_parm;
737 /* If we know nothing, treat all args as named. */
738 n_named_args = num_actuals;
740 /* Make a vector to hold all the information about each arg. */
741 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
742 bzero (args, num_actuals * sizeof (struct arg_data));
744 args_size.constant = 0;
747 /* In this loop, we consider args in the order they are written.
748 We fill up ARGS from the front of from the back if necessary
749 so that in any case the first arg to be pushed ends up at the front. */
751 #ifdef PUSH_ARGS_REVERSED
752 i = num_actuals - 1, inc = -1;
753 /* In this case, must reverse order of args
754 so that we compute and push the last arg first. */
759 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
760 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
762 tree type = TREE_TYPE (TREE_VALUE (p));
764 args[i].tree_value = TREE_VALUE (p);
766 /* Replace erroneous argument with constant zero. */
767 if (type == error_mark_node || TYPE_SIZE (type) == 0)
768 args[i].tree_value = integer_zero_node, type = integer_type_node;
770 /* Decide where to pass this arg.
772 args[i].reg is nonzero if all or part is passed in registers.
774 args[i].partial is nonzero if part but not all is passed in registers,
775 and the exact value says how many words are passed in registers.
777 args[i].pass_on_stack is nonzero if the argument must at least be
778 computed on the stack. It may then be loaded back into registers
779 if args[i].reg is nonzero.
781 These decisions are driven by the FUNCTION_... macros and must agree
782 with those made by function.c. */
784 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
785 /* See if this argument should be passed by invisible reference. */
786 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
787 argpos < n_named_args))
789 /* We make a copy of the object and pass the address to the function
791 int size = int_size_in_bytes (type);
796 /* This is a variable-sized object. Make space on the stack
798 rtx size_rtx = expand_expr (size_in_bytes (type), 0,
801 if (old_stack_level == 0)
803 emit_stack_save (SAVE_BLOCK, &old_stack_level, 0);
804 old_pending_adj = pending_stack_adjust;
805 pending_stack_adjust = 0;
808 copy = gen_rtx (MEM, BLKmode,
809 allocate_dynamic_stack_space (size_rtx, 0,
813 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
815 store_expr (args[i].tree_value, copy, 0);
817 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
818 make_tree (type, copy));
819 type = build_pointer_type (type);
823 args[i].reg = FUNCTION_ARG (args_so_far, TYPE_MODE (type), type,
824 argpos < n_named_args);
825 #ifdef FUNCTION_ARG_PARTIAL_NREGS
828 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, TYPE_MODE (type), type,
829 argpos < n_named_args);
832 args[i].pass_on_stack = MUST_PASS_IN_STACK (TYPE_MODE (type), type);
834 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
835 we are to pass this arg in the register(s) designated by FOO, but
836 also to pass it in the stack. */
837 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
838 && XEXP (args[i].reg, 0) == 0)
839 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
841 /* If this is an addressable type, we must preallocate the stack
842 since we must evaluate the object into its final location.
844 If this is to be passed in both registers and the stack, it is simpler
846 if (TREE_ADDRESSABLE (type)
847 || (args[i].pass_on_stack && args[i].reg != 0))
848 must_preallocate = 1;
850 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
851 we cannot consider this function call constant. */
852 if (TREE_ADDRESSABLE (type))
855 /* Compute the stack-size of this argument. */
856 if (args[i].reg == 0 || args[i].partial != 0
857 #ifdef REG_PARM_STACK_SPACE
858 || reg_parm_stack_space > 0
860 || args[i].pass_on_stack)
861 locate_and_pad_parm (TYPE_MODE (type), type,
862 #ifdef STACK_PARMS_IN_REG_PARM_AREA
867 fndecl, &args_size, &args[i].offset,
870 #ifndef ARGS_GROW_DOWNWARD
871 args[i].slot_offset = args_size;
874 #ifndef REG_PARM_STACK_SPACE
875 /* If a part of the arg was put into registers,
876 don't include that part in the amount pushed. */
877 if (! args[i].pass_on_stack)
878 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
879 / (PARM_BOUNDARY / BITS_PER_UNIT)
880 * (PARM_BOUNDARY / BITS_PER_UNIT));
883 /* Update ARGS_SIZE, the total stack space for args so far. */
885 args_size.constant += args[i].size.constant;
886 if (args[i].size.var)
888 ADD_PARM_SIZE (args_size, args[i].size.var);
891 /* Since the slot offset points to the bottom of the slot,
892 we must record it after incrementing if the args grow down. */
893 #ifdef ARGS_GROW_DOWNWARD
894 args[i].slot_offset = args_size;
896 args[i].slot_offset.constant = -args_size.constant;
899 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
903 /* Increment ARGS_SO_FAR, which has info about which arg-registers
904 have been used, etc. */
906 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
907 argpos < n_named_args);
910 #ifdef FINAL_REG_PARM_STACK_SPACE
911 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
915 /* Compute the actual size of the argument block required. The variable
916 and constant sizes must be combined, the size may have to be rounded,
917 and there may be a minimum required size. */
919 original_args_size = args_size;
922 /* If this function requires a variable-sized argument list, don't try to
923 make a cse'able block for this call. We may be able to do this
924 eventually, but it is too complicated to keep track of what insns go
925 in the cse'able block and which don't. */
928 must_preallocate = 1;
930 args_size.var = ARGS_SIZE_TREE (args_size);
931 args_size.constant = 0;
933 #ifdef STACK_BOUNDARY
934 if (STACK_BOUNDARY != BITS_PER_UNIT)
935 args_size.var = round_up (args_size.var, STACK_BYTES);
938 #ifdef REG_PARM_STACK_SPACE
939 if (reg_parm_stack_space > 0)
942 = size_binop (MAX_EXPR, args_size.var,
943 size_int (REG_PARM_STACK_SPACE (fndecl)));
945 #ifndef OUTGOING_REG_PARM_STACK_SPACE
946 /* The area corresponding to register parameters is not to count in
947 the size of the block we need. So make the adjustment. */
949 = size_binop (MINUS_EXPR, args_size.var,
950 size_int (reg_parm_stack_space));
957 #ifdef STACK_BOUNDARY
958 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
959 / STACK_BYTES) * STACK_BYTES);
962 #ifdef REG_PARM_STACK_SPACE
963 args_size.constant = MAX (args_size.constant,
964 reg_parm_stack_space);
965 #ifndef OUTGOING_REG_PARM_STACK_SPACE
966 args_size.constant -= reg_parm_stack_space;
971 /* See if we have or want to preallocate stack space.
973 If we would have to push a partially-in-regs parm
974 before other stack parms, preallocate stack space instead.
976 If the size of some parm is not a multiple of the required stack
977 alignment, we must preallocate.
979 If the total size of arguments that would otherwise create a copy in
980 a temporary (such as a CALL) is more than half the total argument list
981 size, preallocation is faster.
983 Another reason to preallocate is if we have a machine (like the m88k)
984 where stack alignment is required to be maintained between every
985 pair of insns, not just when the call is made. However, we assume here
986 that such machines either do not have push insns (and hence preallocation
987 would occur anyway) or the problem is taken care of with
990 if (! must_preallocate)
992 int partial_seen = 0;
993 int copy_to_evaluate_size = 0;
995 for (i = 0; i < num_actuals && ! must_preallocate; i++)
997 if (args[i].partial > 0 && ! args[i].pass_on_stack)
999 else if (partial_seen && args[i].reg == 0)
1000 must_preallocate = 1;
1002 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1003 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1004 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1005 || TREE_CODE (args[i].tree_value) == COND_EXPR
1006 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1007 copy_to_evaluate_size
1008 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1011 if (copy_to_evaluate_size * 2 >= args_size.constant
1012 && args_size.constant > 0)
1013 must_preallocate = 1;
1016 /* If the structure value address will reference the stack pointer, we must
1017 stabilize it. We don't need to do this if we know that we are not going
1018 to adjust the stack pointer in processing this call. */
1020 if (structure_value_addr
1021 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1022 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1024 #ifndef ACCUMULATE_OUTGOING_ARGS
1025 || args_size.constant
1028 structure_value_addr = copy_to_reg (structure_value_addr);
1030 /* If this function call is cse'able, precompute all the parameters.
1031 Note that if the parameter is constructed into a temporary, this will
1032 cause an additional copy because the parameter will be constructed
1033 into a temporary location and then copied into the outgoing arguments.
1034 If a parameter contains a call to alloca and this function uses the
1035 stack, precompute the parameter. */
1037 for (i = 0; i < num_actuals; i++)
1039 || ((args_size.var != 0 || args_size.constant != 0)
1040 && calls_alloca (args[i].tree_value)))
1042 args[i].initial_value = args[i].value
1043 = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1044 preserve_temp_slots (args[i].value);
1047 /* ANSI doesn't require a sequence point here,
1048 but PCC has one, so this will avoid some problems. */
1052 /* Now we are about to start emitting insns that can be deleted
1053 if a libcall is deleted. */
1057 /* If we have no actual push instructions, or shouldn't use them,
1058 make space for all args right now. */
1060 if (args_size.var != 0)
1062 if (old_stack_level == 0)
1064 emit_stack_save (SAVE_BLOCK, &old_stack_level, 0);
1065 old_pending_adj = pending_stack_adjust;
1066 pending_stack_adjust = 0;
1068 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1070 else if (must_preallocate)
1072 /* Note that we must go through the motions of allocating an argument
1073 block even if the size is zero because we may be storing args
1074 in the area reserved for register arguments, which may be part of
1076 int needed = args_size.constant;
1078 #ifdef ACCUMULATE_OUTGOING_ARGS
1079 /* Store the maximum argument space used. It will be pushed by the
1082 Since the stack pointer will never be pushed, it is possible for
1083 the evaluation of a parm to clobber something we have already
1084 written to the stack. Since most function calls on RISC machines
1085 do not use the stack, this is uncommon, but must work correctly.
1087 Therefore, we save any area of the stack that was already written
1088 and that we are using. Here we set up to do this by making a new
1089 stack usage map from the old one. The actual save will be done
1092 Another approach might be to try to reorder the argument
1093 evaluations to avoid this conflicting stack usage. */
1095 if (needed > current_function_outgoing_args_size)
1096 current_function_outgoing_args_size = needed;
1098 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1099 /* Since we will be writing into the entire argument area, the
1100 map must be allocated for its entire size, not just the part that
1101 is the responsibility of the caller. */
1102 needed += reg_parm_stack_space;
1105 #ifdef ARGS_GROW_DOWNWARD
1106 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1109 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1111 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1113 if (initial_highest_arg_in_use)
1114 bcopy (initial_stack_usage_map, stack_usage_map,
1115 initial_highest_arg_in_use);
1117 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1118 bzero (&stack_usage_map[initial_highest_arg_in_use],
1119 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1121 /* No need to copy this virtual register; the space we're
1122 using gets preallocated at the start of the function
1123 so the stack pointer won't change here. */
1124 argblock = virtual_outgoing_args_rtx;
1125 #else /* not ACCUMULATE_OUTGOING_ARGS */
1126 if (inhibit_defer_pop == 0)
1128 /* Try to reuse some or all of the pending_stack_adjust
1129 to get this space. Maybe we can avoid any pushing. */
1130 if (needed > pending_stack_adjust)
1132 needed -= pending_stack_adjust;
1133 pending_stack_adjust = 0;
1137 pending_stack_adjust -= needed;
1141 /* Special case this because overhead of `push_block' in this
1142 case is non-trivial. */
1144 argblock = virtual_outgoing_args_rtx;
1146 argblock = push_block (gen_rtx (CONST_INT, VOIDmode, needed), 0, 0);
1148 /* We only really need to call `copy_to_reg' in the case where push
1149 insns are going to be used to pass ARGBLOCK to a function
1150 call in ARGS. In that case, the stack pointer changes value
1151 from the allocation point to the call point, and hence
1152 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1153 But might as well always do it. */
1154 argblock = copy_to_reg (argblock);
1155 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1158 /* If we preallocated stack space, compute the address of each argument.
1159 We need not ensure it is a valid memory address here; it will be
1160 validized when it is used. */
1163 rtx arg_reg = argblock;
1166 if (GET_CODE (argblock) == PLUS)
1167 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1169 for (i = 0; i < num_actuals; i++)
1171 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1172 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1175 /* Skip this parm if it will not be passed on the stack. */
1176 if (! args[i].pass_on_stack && args[i].reg != 0)
1179 if (GET_CODE (offset) == CONST_INT)
1180 addr = plus_constant (arg_reg, INTVAL (offset));
1182 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1184 addr = plus_constant (addr, arg_offset);
1186 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1188 if (GET_CODE (slot_offset) == CONST_INT)
1189 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1191 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1193 addr = plus_constant (addr, arg_offset);
1195 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1199 #ifdef PUSH_ARGS_REVERSED
1200 #ifdef STACK_BOUNDARY
1201 /* If we push args individually in reverse order, perform stack alignment
1202 before the first push (the last arg). */
1204 anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1206 - original_args_size.constant)));
1210 /* Don't try to defer pops if preallocating, not even from the first arg,
1211 since ARGBLOCK probably refers to the SP. */
1215 /* Get the function to call, in the form of RTL. */
1217 /* Get a SYMBOL_REF rtx for the function address. */
1218 funexp = XEXP (DECL_RTL (fndecl), 0);
1220 /* Generate an rtx (probably a pseudo-register) for the address. */
1222 funexp = expand_expr (TREE_OPERAND (exp, 0), 0, VOIDmode, 0);
1223 free_temp_slots (); /* FUNEXP can't be BLKmode */
1227 /* Figure out the register where the value, if any, will come back. */
1229 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1230 && ! structure_value_addr)
1232 if (pcc_struct_value)
1233 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1236 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1239 /* Precompute all register parameters. It isn't safe to compute anything
1240 once we have started filling any specific hard regs. */
1242 for (i = 0; i < num_actuals; i++)
1243 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1247 if (args[i].value == 0)
1249 args[i].value = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1250 preserve_temp_slots (args[i].value);
1253 /* ANSI doesn't require a sequence point here,
1254 but PCC has one, so this will avoid some problems. */
1259 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1260 /* The argument list is the property of the called routine and it
1261 may clobber it. If the fixed area has been used for previous
1262 parameters, we must save and restore it.
1264 Here we compute the boundary of the that needs to be saved, if any. */
1266 for (i = 0; i < reg_parm_stack_space; i++)
1268 if (i >= highest_outgoing_arg_in_use
1269 || stack_usage_map[i] == 0)
1272 if (low_to_save == -1)
1278 if (low_to_save >= 0)
1280 int num_to_save = high_to_save - low_to_save + 1;
1281 enum machine_mode save_mode
1282 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1285 /* If we don't have the required alignment, must do this in BLKmode. */
1286 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1287 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1288 save_mode = BLKmode;
1290 stack_area = gen_rtx (MEM, save_mode,
1291 memory_address (save_mode,
1292 plus_constant (argblock,
1294 if (save_mode == BLKmode)
1296 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1297 emit_block_move (validize_mem (save_area), stack_area,
1298 gen_rtx (CONST_INT, VOIDmode, num_to_save),
1299 PARM_BOUNDARY / BITS_PER_UNIT);
1303 save_area = gen_reg_rtx (save_mode);
1304 emit_move_insn (save_area, stack_area);
1310 /* Now store (and compute if necessary) all non-register parms.
1311 These come before register parms, since they can require block-moves,
1312 which could clobber the registers used for register parms.
1313 Parms which have partial registers are not stored here,
1314 but we do preallocate space here if they want that. */
1316 for (i = 0; i < num_actuals; i++)
1317 if (args[i].reg == 0 || args[i].pass_on_stack)
1318 store_one_arg (&args[i], argblock, may_be_alloca,
1319 args_size.var != 0, fndecl, reg_parm_stack_space);
1321 /* Now store any partially-in-registers parm.
1322 This is the last place a block-move can happen. */
1324 for (i = 0; i < num_actuals; i++)
1325 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1326 store_one_arg (&args[i], argblock, may_be_alloca,
1327 args_size.var != 0, fndecl, reg_parm_stack_space);
1329 #ifndef PUSH_ARGS_REVERSED
1330 #ifdef STACK_BOUNDARY
1331 /* If we pushed args in forward order, perform stack alignment
1332 after pushing the last arg. */
1334 anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1336 - original_args_size.constant)));
1340 /* Pass the function the address in which to return a structure value. */
1341 if (structure_value_addr && ! structure_value_addr_parm)
1343 emit_move_insn (struct_value_rtx,
1345 force_operand (structure_value_addr, 0)));
1346 if (GET_CODE (struct_value_rtx) == REG)
1348 push_to_sequence (use_insns);
1349 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1350 use_insns = get_insns ();
1355 /* Now do the register loads required for any wholly-register parms or any
1356 parms which are passed both on the stack and in a register. Their
1357 expressions were already evaluated.
1359 Mark all register-parms as living through the call, putting these USE
1360 insns in a list headed by USE_INSNS. */
1362 for (i = 0; i < num_actuals; i++)
1364 rtx list = args[i].reg;
1365 int partial = args[i].partial;
1372 /* Process each register that needs to get this arg. */
1373 if (GET_CODE (list) == EXPR_LIST)
1374 reg = XEXP (list, 0), list = XEXP (list, 1);
1376 reg = list, list = 0;
1378 /* Set to non-zero if must move a word at a time, even if just one
1379 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1380 we just use a normal move insn. */
1381 nregs = (partial ? partial
1382 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1383 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1384 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1387 /* If simple case, just do move. If normal partial, store_one_arg
1388 has already loaded the register for us. In all other cases,
1389 load the register(s) from memory. */
1392 emit_move_insn (reg, args[i].value);
1393 else if (args[i].partial == 0 || args[i].pass_on_stack)
1394 move_block_to_reg (REGNO (reg),
1395 validize_mem (args[i].value), nregs,
1396 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1398 push_to_sequence (use_insns);
1400 emit_insn (gen_rtx (USE, VOIDmode, reg));
1402 use_regs (REGNO (reg), nregs);
1403 use_insns = get_insns ();
1406 /* PARTIAL referred only to the first register, so clear it for the
1412 /* Perform postincrements before actually calling the function. */
1415 /* All arguments and registers used for the call must be set up by now! */
1417 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1419 /* Generate the actual call instruction. */
1420 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1421 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1422 valreg, old_inhibit_defer_pop, use_insns, is_const);
1424 /* If call is cse'able, make appropriate pair of reg-notes around it.
1425 Test valreg so we don't crash; may safely ignore `const'
1426 if return type is void. */
1427 if (is_const && valreg != 0)
1430 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1433 /* Construct an "equal form" for the value which mentions all the
1434 arguments in order as well as the function name. */
1435 #ifdef PUSH_ARGS_REVERSED
1436 for (i = 0; i < num_actuals; i++)
1437 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1439 for (i = num_actuals - 1; i >= 0; i--)
1440 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1442 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1444 insns = get_insns ();
1447 emit_libcall_block (insns, temp, valreg, note);
1452 /* For calls to `setjmp', etc., inform flow.c it should complain
1453 if nonvolatile values are live. */
1457 emit_note (name, NOTE_INSN_SETJMP);
1458 current_function_calls_setjmp = 1;
1462 current_function_calls_longjmp = 1;
1464 /* Notice functions that cannot return.
1465 If optimizing, insns emitted below will be dead.
1466 If not optimizing, they will exist, which is useful
1467 if the user uses the `return' command in the debugger. */
1469 if (is_volatile || is_longjmp)
1472 /* If value type not void, return an rtx for the value. */
1474 /* If there are cleanups to be called, don't use a hard reg as target. */
1475 if (cleanups_this_call != old_cleanups
1476 && target && REG_P (target)
1477 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1480 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1483 target = const0_rtx;
1485 else if (structure_value_addr)
1487 if (target == 0 || GET_CODE (target) != MEM)
1488 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1489 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1490 structure_value_addr));
1492 else if (pcc_struct_value)
1495 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1496 copy_to_reg (valreg));
1497 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1498 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1499 copy_to_reg (valreg)));
1501 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1503 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1505 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)))
1506 /* TARGET and VALREG cannot be equal at this point because the latter
1507 would not have REG_FUNCTION_VALUE_P true, while the former would if
1508 it were referring to the same register.
1510 If they refer to the same register, this move will be a no-op, except
1511 when function inlining is being done. */
1512 emit_move_insn (target, valreg);
1514 target = copy_to_reg (valreg);
1516 /* Perform all cleanups needed for the arguments of this call
1517 (i.e. destructors in C++). */
1518 expand_cleanups_to (old_cleanups);
1520 /* If size of args is variable, restore saved stack-pointer value. */
1522 if (old_stack_level)
1524 emit_stack_restore (SAVE_BLOCK, old_stack_level, 0);
1525 pending_stack_adjust = old_pending_adj;
1528 #ifdef ACCUMULATE_OUTGOING_ARGS
1531 #ifdef REG_PARM_STACK_SPACE
1534 enum machine_mode save_mode = GET_MODE (save_area);
1536 = gen_rtx (MEM, save_mode,
1537 memory_address (save_mode,
1538 plus_constant (argblock, low_to_save)));
1540 if (save_mode != BLKmode)
1541 emit_move_insn (stack_area, save_area);
1543 emit_block_move (stack_area, validize_mem (save_area),
1544 gen_rtx (CONST_INT, VOIDmode,
1545 high_to_save - low_to_save + 1,
1546 PARM_BOUNDARY / BITS_PER_UNIT));
1550 /* If we saved any argument areas, restore them. */
1551 for (i = 0; i < num_actuals; i++)
1552 if (args[i].save_area)
1554 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1556 = gen_rtx (MEM, save_mode,
1557 memory_address (save_mode,
1558 XEXP (args[i].stack_slot, 0)));
1560 if (save_mode != BLKmode)
1561 emit_move_insn (stack_area, args[i].save_area);
1563 emit_block_move (stack_area, validize_mem (args[i].save_area),
1564 gen_rtx (CONST_INT, VOIDmode,
1565 args[i].size.constant),
1566 PARM_BOUNDARY / BITS_PER_UNIT);
1569 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1570 stack_usage_map = initial_stack_usage_map;
1574 /* If this was alloca, record the new stack level for nonlocal gotos.
1575 Check for the handler slots since we might not have a save area
1576 for non-local gotos. */
1578 if (may_be_alloca && nonlocal_goto_handler_slot != 0)
1579 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, 0);
1587 /* Return an rtx which represents a suitable home on the stack
1588 given TYPE, the type of the argument looking for a home.
1589 This is called only for BLKmode arguments.
1591 SIZE is the size needed for this target.
1592 ARGS_ADDR is the address of the bottom of the argument block for this call.
1593 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1594 if this machine uses push insns. */
1597 target_for_arg (type, size, args_addr, offset)
1601 struct args_size offset;
1604 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1606 /* We do not call memory_address if possible,
1607 because we want to address as close to the stack
1608 as possible. For non-variable sized arguments,
1609 this will be stack-pointer relative addressing. */
1610 if (GET_CODE (offset_rtx) == CONST_INT)
1611 target = plus_constant (args_addr, INTVAL (offset_rtx));
1614 /* I have no idea how to guarantee that this
1615 will work in the presence of register parameters. */
1616 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1617 target = memory_address (QImode, target);
1620 return gen_rtx (MEM, BLKmode, target);
1624 /* Store a single argument for a function call
1625 into the register or memory area where it must be passed.
1626 *ARG describes the argument value and where to pass it.
1628 ARGBLOCK is the address of the stack-block for all the arguments,
1629 or 0 on a machine where arguments are pushed individually.
1631 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1632 so must be careful about how the stack is used.
1634 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1635 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1636 that we need not worry about saving and restoring the stack.
1638 FNDECL is the declaration of the function we are calling. */
1641 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl,
1642 reg_parm_stack_space)
1643 struct arg_data *arg;
1648 int reg_parm_stack_space;
1650 register tree pval = arg->tree_value;
1654 int i, lower_bound, upper_bound;
1656 if (TREE_CODE (pval) == ERROR_MARK)
1659 #ifdef ACCUMULATE_OUTGOING_ARGS
1660 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1661 save any previous data at that location. */
1662 if (argblock && ! variable_size && arg->stack)
1664 #ifdef ARGS_GROW_DOWNWARD
1665 /* stack_slot is negative, but we want to index stack_usage_map */
1666 /* with positive values. */
1667 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1668 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1672 lower_bound = upper_bound - arg->size.constant;
1674 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1675 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1679 upper_bound = lower_bound + arg->size.constant;
1682 for (i = lower_bound; i < upper_bound; i++)
1683 if (stack_usage_map[i]
1684 #ifdef REG_PARM_STACK_SPACE
1685 /* Don't store things in the fixed argument area at this point;
1686 it has already been saved. */
1687 && i > reg_parm_stack_space
1692 if (i != upper_bound)
1694 /* We need to make a save area. See what mode we can make it. */
1695 enum machine_mode save_mode
1696 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1698 = gen_rtx (MEM, save_mode,
1699 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1701 if (save_mode == BLKmode)
1703 arg->save_area = assign_stack_temp (BLKmode,
1704 arg->size.constant, 1);
1705 emit_block_move (validize_mem (arg->save_area), stack_area,
1706 gen_rtx (CONST_INT, VOIDmode,
1707 arg->size.constant),
1708 PARM_BOUNDARY / BITS_PER_UNIT);
1712 arg->save_area = gen_reg_rtx (save_mode);
1713 emit_move_insn (arg->save_area, stack_area);
1719 /* If this isn't going to be placed on both the stack and in registers,
1720 set up the register and number of words. */
1721 if (! arg->pass_on_stack)
1722 reg = arg->reg, partial = arg->partial;
1724 if (reg != 0 && partial == 0)
1725 /* Being passed entirely in a register. We shouldn't be called in
1729 /* If this is being partially passed in a register, but multiple locations
1730 are specified, we assume that the one partially used is the one that is
1732 if (reg && GET_CODE (reg) == EXPR_LIST)
1733 reg = XEXP (reg, 0);
1735 /* If this is being passes partially in a register, we can't evaluate
1736 it directly into its stack slot. Otherwise, we can. */
1737 if (arg->value == 0)
1738 arg->value = expand_expr (pval, partial ? 0 : arg->stack, VOIDmode, 0);
1740 /* Don't allow anything left on stack from computation
1741 of argument to alloca. */
1743 do_pending_stack_adjust ();
1745 if (arg->value == arg->stack)
1746 /* If the value is already in the stack slot, we are done. */
1748 else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
1752 /* Argument is a scalar, not entirely passed in registers.
1753 (If part is passed in registers, arg->partial says how much
1754 and emit_push_insn will take care of putting it there.)
1756 Push it, and if its size is less than the
1757 amount of space allocated to it,
1758 also bump stack pointer by the additional space.
1759 Note that in C the default argument promotions
1760 will prevent such mismatches. */
1762 size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
1763 /* Compute how much space the push instruction will push.
1764 On many machines, pushing a byte will advance the stack
1765 pointer by a halfword. */
1766 #ifdef PUSH_ROUNDING
1767 size = PUSH_ROUNDING (size);
1771 /* Compute how much space the argument should get:
1772 round up to a multiple of the alignment for arguments. */
1773 if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
1775 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
1776 / (PARM_BOUNDARY / BITS_PER_UNIT))
1777 * (PARM_BOUNDARY / BITS_PER_UNIT));
1779 /* This isn't already where we want it on the stack, so put it there.
1780 This can either be done with push or copy insns. */
1781 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1782 TREE_TYPE (pval), 0, 0, partial, reg,
1783 used - size, argblock, ARGS_SIZE_RTX (arg->offset));
1787 /* BLKmode, at least partly to be pushed. */
1789 register int excess;
1792 /* Pushing a nonscalar.
1793 If part is passed in registers, PARTIAL says how much
1794 and emit_push_insn will take care of putting it there. */
1796 /* Round its size up to a multiple
1797 of the allocation unit for arguments. */
1799 if (arg->size.var != 0)
1802 size_rtx = ARGS_SIZE_RTX (arg->size);
1806 register tree size = size_in_bytes (TREE_TYPE (pval));
1807 /* PUSH_ROUNDING has no effect on us, because
1808 emit_push_insn for BLKmode is careful to avoid it. */
1809 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
1810 + partial * UNITS_PER_WORD);
1811 size_rtx = expand_expr (size, 0, VOIDmode, 0);
1814 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1815 TREE_TYPE (pval), size_rtx,
1816 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
1817 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
1821 /* Unless this is a partially-in-register argument, the argument is now
1824 ??? Note that this can change arg->value from arg->stack to
1825 arg->stack_slot and it matters when they are not the same.
1826 It isn't totally clear that this is correct in all cases. */
1828 arg->value = arg->stack_slot;
1830 /* Once we have pushed something, pops can't safely
1831 be deferred during the rest of the arguments. */
1834 /* ANSI doesn't require a sequence point here,
1835 but PCC has one, so this will avoid some problems. */
1838 /* Free any temporary slots made in processing this argument. */
1841 #ifdef ACCUMULATE_OUTGOING_ARGS
1842 /* Now mark the segment we just used. */
1843 if (argblock && ! variable_size && arg->stack)
1844 for (i = lower_bound; i < upper_bound; i++)
1845 stack_usage_map[i] = 1;