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 inhibit_defer_pop = old_inhibit_defer_pop;
328 #ifndef ACCUMULATE_OUTGOING_ARGS
329 /* If returning from the subroutine does not automatically pop the args,
330 we need an instruction to pop them sooner or later.
331 Perhaps do it now; perhaps just record how much space to pop later.
333 If returning from the subroutine does pop the args, indicate that the
334 stack pointer will be changed. */
336 if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0)
339 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
340 stack_size -= RETURN_POPS_ARGS (funtype, stack_size);
341 stack_size_rtx = gen_rtx (CONST_INT, VOIDmode, stack_size);
346 if (flag_defer_pop && inhibit_defer_pop == 0)
347 pending_stack_adjust += stack_size;
349 adjust_stack (stack_size_rtx);
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 /* 1 if scanning parms front to back, -1 if scanning back to front. */
437 /* Address of space preallocated for stack parms
438 (on machines that lack push insns), or 0 if space not preallocated. */
441 /* Nonzero if it is plausible that this is a call to alloca. */
443 /* Nonzero if this is a call to setjmp or a related function. */
445 /* Nonzero if this is a call to `longjmp'. */
447 /* Nonzero if this is a call to an inline function. */
448 int is_integrable = 0;
449 /* Nonzero if this is a call to a `const' function.
450 Note that only explicitly named functions are handled as `const' here. */
452 /* Nonzero if this is a call to a `volatile' function. */
454 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
455 /* Define the boundary of the register parm stack space that needs to be
457 int low_to_save = -1, high_to_save;
458 rtx save_area = 0; /* Place that it is saved */
461 #ifdef ACCUMULATE_OUTGOING_ARGS
462 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
463 char *initial_stack_usage_map = stack_usage_map;
466 rtx old_stack_level = 0;
468 int old_inhibit_defer_pop = inhibit_defer_pop;
469 tree old_cleanups = cleanups_this_call;
476 /* See if we can find a DECL-node for the actual function.
477 As a result, decide whether this is a call to an integrable function. */
479 p = TREE_OPERAND (exp, 0);
480 if (TREE_CODE (p) == ADDR_EXPR)
482 fndecl = TREE_OPERAND (p, 0);
483 if (TREE_CODE (fndecl) != FUNCTION_DECL)
485 /* May still be a `const' function if it is
486 a call through a pointer-to-const.
487 But we don't handle that. */
493 && fndecl != current_function_decl
494 && DECL_SAVED_INSNS (fndecl))
496 else if (! TREE_ADDRESSABLE (fndecl))
498 /* In case this function later becomes inlineable,
499 record that there was already a non-inline call to it.
501 Use abstraction instead of setting TREE_ADDRESSABLE
503 if (TREE_INLINE (fndecl) && extra_warnings && !flag_no_inline)
504 warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline");
505 mark_addressable (fndecl);
508 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
509 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
514 is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
516 /* Warn if this value is an aggregate type,
517 regardless of which calling convention we are using for it. */
518 if (warn_aggregate_return
519 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
520 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
521 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
522 warning ("function call has aggregate value");
524 /* Set up a place to return a structure. */
526 /* Cater to broken compilers. */
527 if (aggregate_value_p (exp))
529 /* This call returns a big structure. */
532 #ifdef PCC_STATIC_STRUCT_RETURN
533 if (flag_pcc_struct_return)
535 pcc_struct_value = 1;
536 is_integrable = 0; /* Easier than making that case work right. */
541 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
543 if (struct_value_size < 0)
546 if (target && GET_CODE (target) == MEM)
547 structure_value_addr = XEXP (target, 0);
550 /* Assign a temporary on the stack to hold the value. */
552 /* For variable-sized objects, we must be called with a target
553 specified. If we were to allocate space on the stack here,
554 we would have no way of knowing when to free it. */
557 = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
563 /* If called function is inline, try to integrate it. */
569 temp = expand_inline_function (fndecl, actparms, target,
570 ignore, TREE_TYPE (exp),
571 structure_value_addr);
573 /* If inlining succeeded, return. */
574 if ((int) temp != -1)
576 /* Perform all cleanups needed for the arguments of this call
577 (i.e. destructors in C++). It is ok if these destructors
578 clobber RETURN_VALUE_REG, because the only time we care about
579 this is when TARGET is that register. But in C++, we take
580 care to never return that register directly. */
581 expand_cleanups_to (old_cleanups);
583 /* If the result is equivalent to TARGET, return TARGET to simplify
584 checks in store_expr. They can be equivalent but not equal in the
585 case of a function that returns BLKmode. */
586 if (temp != target && rtx_equal_p (temp, target))
591 /* If inlining failed, mark FNDECL as needing to be compiled
592 separately after all. */
593 mark_addressable (fndecl);
596 /* When calling a const function, we must pop the stack args right away,
597 so that the pop is deleted or moved with the call. */
601 function_call_count++;
603 if (fndecl && DECL_NAME (fndecl))
604 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
607 /* Unless it's a call to a specific function that isn't alloca,
608 if it has one argument, we must assume it might be alloca. */
611 (!(fndecl != 0 && strcmp (name, "alloca"))
613 && TREE_CHAIN (actparms) == 0);
615 /* We assume that alloca will always be called by name. It
616 makes no sense to pass it as a pointer-to-function to
617 anything that does not understand its behavior. */
619 (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
621 && ! strcmp (name, "alloca"))
622 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
624 && ! strcmp (name, "__builtin_alloca"))));
627 /* See if this is a call to a function that can return more than once
628 or a call to longjmp. */
633 if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
638 tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
644 && (! strcmp (tname, "setjmp")
645 || ! strcmp (tname, "setjmp_syscall")))
647 && ! strcmp (tname, "sigsetjmp"))
649 && ! strcmp (tname, "savectx")));
651 && ! strcmp (tname, "siglongjmp"))
654 else if ((tname[0] == 'q' && tname[1] == 's'
655 && ! strcmp (tname, "qsetjmp"))
656 || (tname[0] == 'v' && tname[1] == 'f'
657 && ! strcmp (tname, "vfork")))
660 else if (tname[0] == 'l' && tname[1] == 'o'
661 && ! strcmp (tname, "longjmp"))
666 current_function_calls_alloca = 1;
668 /* Don't let pending stack adjusts add up to too much.
669 Also, do all pending adjustments now
670 if there is any chance this might be a call to alloca. */
672 if (pending_stack_adjust >= 32
673 || (pending_stack_adjust > 0 && may_be_alloca))
674 do_pending_stack_adjust ();
676 /* Operand 0 is a pointer-to-function; get the type of the function. */
677 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
678 if (TREE_CODE (funtype) != POINTER_TYPE)
680 funtype = TREE_TYPE (funtype);
682 /* Push the temporary stack slot level so that we can free temporaries used
683 by each of the arguments separately. */
686 /* Start updating where the next arg would go. */
687 INIT_CUMULATIVE_ARGS (args_so_far, funtype, 0);
689 /* If struct_value_rtx is 0, it means pass the address
690 as if it were an extra parameter. */
691 if (structure_value_addr && struct_value_rtx == 0)
694 = tree_cons (error_mark_node,
695 make_tree (build_pointer_type (TREE_TYPE (funtype)),
696 force_reg (Pmode, structure_value_addr)),
698 structure_value_addr_parm = 1;
701 /* Count the arguments and set NUM_ACTUALS. */
702 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
705 /* Compute number of named args.
706 Normally, don't include the last named arg if anonymous args follow.
707 (If no anonymous args follow, the result of list_length
708 is actually one too large.)
710 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
711 place unnamed args that were passed in registers into the stack. So
712 treat all args as named. This allows the insns emitting for a specific
713 argument list to be independent of the function declaration.
715 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
716 way to pass unnamed args in registers, so we must force them into
718 #ifndef SETUP_INCOMING_VARARGS
719 if (TYPE_ARG_TYPES (funtype) != 0)
721 = list_length (TYPE_ARG_TYPES (funtype)) - 1
722 /* Count the struct value address, if it is passed as a parm. */
723 + structure_value_addr_parm;
726 /* If we know nothing, treat all args as named. */
727 n_named_args = num_actuals;
729 /* Make a vector to hold all the information about each arg. */
730 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
731 bzero (args, num_actuals * sizeof (struct arg_data));
733 args_size.constant = 0;
736 /* In this loop, we consider args in the order they are written.
737 We fill up ARGS from the front of from the back if necessary
738 so that in any case the first arg to be pushed ends up at the front. */
740 #ifdef PUSH_ARGS_REVERSED
741 i = num_actuals - 1, inc = -1;
742 /* In this case, must reverse order of args
743 so that we compute and push the last arg first. */
748 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
749 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
751 tree type = TREE_TYPE (TREE_VALUE (p));
753 args[i].tree_value = TREE_VALUE (p);
755 /* Replace erroneous argument with constant zero. */
756 if (type == error_mark_node || TYPE_SIZE (type) == 0)
757 args[i].tree_value = integer_zero_node, type = integer_type_node;
759 /* Decide where to pass this arg.
761 args[i].reg is nonzero if all or part is passed in registers.
763 args[i].partial is nonzero if part but not all is passed in registers,
764 and the exact value says how many words are passed in registers.
766 args[i].pass_on_stack is nonzero if the argument must at least be
767 computed on the stack. It may then be loaded back into registers
768 if args[i].reg is nonzero.
770 These decisions are driven by the FUNCTION_... macros and must agree
771 with those made by function.c. */
773 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
774 /* See if this argument should be passed by invisible reference. */
775 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
776 argpos < n_named_args))
778 /* We make a copy of the object and pass the address to the function
780 int size = int_size_in_bytes (type);
785 /* This is a variable-sized object. Make space on the stack
787 rtx size_rtx = expand_expr (size_in_bytes (type), 0,
790 if (old_stack_level == 0)
792 old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx);
793 old_pending_adj = pending_stack_adjust;
794 pending_stack_adjust = 0;
797 copy = gen_rtx (MEM, BLKmode,
798 allocate_dynamic_stack_space (size_rtx, 0,
802 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
804 store_expr (args[i].tree_value, copy, 0);
806 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
807 make_tree (type, copy));
808 type = build_pointer_type (type);
812 args[i].reg = FUNCTION_ARG (args_so_far, TYPE_MODE (type), type,
813 argpos < n_named_args);
814 #ifdef FUNCTION_ARG_PARTIAL_NREGS
817 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, TYPE_MODE (type), type,
818 argpos < n_named_args);
821 args[i].pass_on_stack = MUST_PASS_IN_STACK (TYPE_MODE (type), type);
823 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
824 we are to pass this arg in the register(s) designated by FOO, but
825 also to pass it in the stack. */
826 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
827 && XEXP (args[i].reg, 0) == 0)
828 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
830 /* If this is an addressable type, we must preallocate the stack
831 since we must evaluate the object into its final location.
833 If this is to be passed in both registers and the stack, it is simpler
835 if (TREE_ADDRESSABLE (type)
836 || (args[i].pass_on_stack && args[i].reg != 0))
837 must_preallocate = 1;
839 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
840 we cannot consider this function call constant. */
841 if (TREE_ADDRESSABLE (type))
844 /* Compute the stack-size of this argument. */
845 if (args[i].reg == 0 || args[i].partial != 0
846 #ifdef REG_PARM_STACK_SPACE
847 || REG_PARM_STACK_SPACE (fndecl) > 0
849 || args[i].pass_on_stack)
850 locate_and_pad_parm (TYPE_MODE (type), type,
851 #ifdef STACK_PARMS_IN_REG_PARM_AREA
856 fndecl, &args_size, &args[i].offset,
859 #ifndef ARGS_GROW_DOWNWARD
860 args[i].slot_offset = args_size;
863 #ifndef REG_PARM_STACK_SPACE
864 /* If a part of the arg was put into registers,
865 don't include that part in the amount pushed. */
866 if (! args[i].pass_on_stack)
867 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
868 / (PARM_BOUNDARY / BITS_PER_UNIT)
869 * (PARM_BOUNDARY / BITS_PER_UNIT));
872 /* Update ARGS_SIZE, the total stack space for args so far. */
874 args_size.constant += args[i].size.constant;
875 if (args[i].size.var)
877 ADD_PARM_SIZE (args_size, args[i].size.var);
880 /* Since the slot offset points to the bottom of the slot,
881 we must record it after incrementing if the args grow down. */
882 #ifdef ARGS_GROW_DOWNWARD
883 args[i].slot_offset = args_size;
885 args[i].slot_offset.constant = -args_size.constant;
888 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
892 /* Increment ARGS_SO_FAR, which has info about which arg-registers
893 have been used, etc. */
895 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
896 argpos < n_named_args);
899 /* Compute the actual size of the argument block required. The variable
900 and constant sizes must be combined, the size may have to be rounded,
901 and there may be a minimum required size. */
903 original_args_size = args_size;
906 /* If this function requires a variable-sized argument list, don't try to
907 make a cse'able block for this call. We may be able to do this
908 eventually, but it is too complicated to keep track of what insns go
909 in the cse'able block and which don't. */
912 must_preallocate = 1;
914 args_size.var = ARGS_SIZE_TREE (args_size);
915 args_size.constant = 0;
917 #ifdef STACK_BOUNDARY
918 if (STACK_BOUNDARY != BITS_PER_UNIT)
919 args_size.var = round_up (args_size.var, STACK_BYTES);
922 #ifdef REG_PARM_STACK_SPACE
923 if (REG_PARM_STACK_SPACE (fndecl) > 0)
926 = size_binop (MAX_EXPR, args_size.var,
927 size_int (REG_PARM_STACK_SPACE (fndecl)));
929 #ifndef OUTGOING_REG_PARM_STACK_SPACE
930 /* The area corresponding to register parameters is not to count in
931 the size of the block we need. So make the adjustment. */
933 = size_binop (MINUS_EXPR, args_size.var,
934 size_int (REG_PARM_STACK_SPACE (fndecl)));
941 #ifdef STACK_BOUNDARY
942 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
943 / STACK_BYTES) * STACK_BYTES);
946 #ifdef REG_PARM_STACK_SPACE
947 args_size.constant = MAX (args_size.constant,
948 REG_PARM_STACK_SPACE (fndecl));
949 #ifndef OUTGOING_REG_PARM_STACK_SPACE
950 args_size.constant -= REG_PARM_STACK_SPACE (fndecl);
955 /* See if we have or want to preallocate stack space.
957 If we would have to push a partially-in-regs parm
958 before other stack parms, preallocate stack space instead.
960 If the size of some parm is not a multiple of the required stack
961 alignment, we must preallocate.
963 If the total size of arguments that would otherwise create a copy in
964 a temporary (such as a CALL) is more than half the total argument list
965 size, preallocation is faster.
967 Another reason to preallocate is if we have a machine (like the m88k)
968 where stack alignment is required to be maintained between every
969 pair of insns, not just when the call is made. However, we assume here
970 that such machines either do not have push insns (and hence preallocation
971 would occur anyway) or the problem is taken care of with
974 if (! must_preallocate)
976 int partial_seen = 0;
977 int copy_to_evaluate_size = 0;
979 for (i = 0; i < num_actuals && ! must_preallocate; i++)
981 if (args[i].partial > 0 && ! args[i].pass_on_stack)
983 else if (partial_seen && args[i].reg == 0)
984 must_preallocate = 1;
986 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
987 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
988 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
989 || TREE_CODE (args[i].tree_value) == COND_EXPR
990 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
991 copy_to_evaluate_size
992 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
995 if (copy_to_evaluate_size >= args_size.constant / 2)
996 must_preallocate = 1;
999 /* If the structure value address will reference the stack pointer, we must
1000 stabilize it. We don't need to do this if we know that we are not going
1001 to adjust the stack pointer in processing this call. */
1003 if (structure_value_addr
1004 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1005 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1007 #ifndef ACCUMULATE_OUTGOING_ARGS
1008 || args_size.constant
1011 structure_value_addr = copy_to_reg (structure_value_addr);
1013 /* If this function call is cse'able, precompute all the parameters.
1014 Note that if the parameter is constructed into a temporary, this will
1015 cause an additional copy because the parameter will be constructed
1016 into a temporary location and then copied into the outgoing arguments.
1017 If a parameter contains a call to alloca and this function uses the
1018 stack, precompute the parameter. */
1020 for (i = 0; i < num_actuals; i++)
1022 || ((args_size.var != 0 || args_size.constant != 0)
1023 && calls_alloca (args[i].tree_value)))
1025 args[i].initial_value = args[i].value
1026 = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1027 preserve_temp_slots (args[i].value);
1030 /* ANSI doesn't require a sequence point here,
1031 but PCC has one, so this will avoid some problems. */
1035 /* Now we are about to start emitting insns that can be deleted
1036 if a libcall is deleted. */
1040 /* If we have no actual push instructions, or shouldn't use them,
1041 make space for all args right now. */
1043 if (args_size.var != 0)
1045 if (old_stack_level == 0)
1047 old_stack_level = copy_to_mode_reg (Pmode, stack_pointer_rtx);
1048 old_pending_adj = pending_stack_adjust;
1049 pending_stack_adjust = 0;
1051 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1053 else if (must_preallocate)
1055 /* Note that we must go through the motions of allocating an argument
1056 block even if the size is zero because we may be storing args
1057 in the area reserved for register arguments, which may be part of
1059 int needed = args_size.constant;
1061 #ifdef ACCUMULATE_OUTGOING_ARGS
1062 /* Store the maximum argument space used. It will be pushed by the
1065 Since the stack pointer will never be pushed, it is possible for
1066 the evaluation of a parm to clobber something we have already
1067 written to the stack. Since most function calls on RISC machines
1068 do not use the stack, this is uncommon, but must work correctly.
1070 Therefore, we save any area of the stack that was already written
1071 and that we are using. Here we set up to do this by making a new
1072 stack usage map from the old one. The actual save will be done
1075 Another approach might be to try to reorder the argument
1076 evaluations to avoid this conflicting stack usage. */
1078 if (needed > current_function_outgoing_args_size)
1079 current_function_outgoing_args_size = needed;
1081 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1082 /* Since we will be writing into the entire argument area, the
1083 map must be allocated for its entire size, not just the part that
1084 is the responsibility of the caller. */
1085 needed += REG_PARM_STACK_SPACE (fndecl);
1088 #ifdef ARGS_GROW_DOWNWARD
1089 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1092 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1094 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1096 if (initial_highest_arg_in_use)
1097 bcopy (initial_stack_usage_map, stack_usage_map,
1098 initial_highest_arg_in_use);
1100 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1101 bzero (&stack_usage_map[initial_highest_arg_in_use],
1102 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1104 /* No need to copy this virtual register; the space we're
1105 using gets preallocated at the start of the function
1106 so the stack pointer won't change here. */
1107 argblock = virtual_outgoing_args_rtx;
1108 #else /* not ACCUMULATE_OUTGOING_ARGS */
1109 if (inhibit_defer_pop == 0)
1111 /* Try to reuse some or all of the pending_stack_adjust
1112 to get this space. Maybe we can avoid any pushing. */
1113 if (needed > pending_stack_adjust)
1115 needed -= pending_stack_adjust;
1116 pending_stack_adjust = 0;
1120 pending_stack_adjust -= needed;
1124 /* Special case this because overhead of `push_block' in this
1125 case is non-trivial. */
1127 argblock = virtual_outgoing_args_rtx;
1129 argblock = push_block (gen_rtx (CONST_INT, VOIDmode, needed), 0, 0);
1131 /* We only really need to call `copy_to_reg' in the case where push
1132 insns are going to be used to pass ARGBLOCK to a function
1133 call in ARGS. In that case, the stack pointer changes value
1134 from the allocation point to the call point, and hence
1135 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1136 But might as well always do it. */
1137 argblock = copy_to_reg (argblock);
1138 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1141 /* If we preallocated stack space, compute the address of each argument.
1142 We need not ensure it is a valid memory address here; it will be
1143 validized when it is used. */
1146 rtx arg_reg = argblock;
1149 if (GET_CODE (argblock) == PLUS)
1150 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1152 for (i = 0; i < num_actuals; i++)
1154 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1155 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1158 /* Skip this parm if it will not be passed on the stack. */
1159 if (! args[i].pass_on_stack && args[i].reg != 0)
1162 if (GET_CODE (offset) == CONST_INT)
1163 addr = plus_constant (arg_reg, INTVAL (offset));
1165 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1167 addr = plus_constant (addr, arg_offset);
1169 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1171 if (GET_CODE (slot_offset) == CONST_INT)
1172 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1174 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1176 addr = plus_constant (addr, arg_offset);
1178 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1182 #ifdef PUSH_ARGS_REVERSED
1183 #ifdef STACK_BOUNDARY
1184 /* If we push args individually in reverse order, perform stack alignment
1185 before the first push (the last arg). */
1187 anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1189 - original_args_size.constant)));
1193 /* Don't try to defer pops if preallocating, not even from the first arg,
1194 since ARGBLOCK probably refers to the SP. */
1198 /* Get the function to call, in the form of RTL. */
1200 /* Get a SYMBOL_REF rtx for the function address. */
1201 funexp = XEXP (DECL_RTL (fndecl), 0);
1203 /* Generate an rtx (probably a pseudo-register) for the address. */
1205 funexp = expand_expr (TREE_OPERAND (exp, 0), 0, VOIDmode, 0);
1206 free_temp_slots (); /* FUNEXP can't be BLKmode */
1210 /* Figure out the register where the value, if any, will come back. */
1212 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1213 && ! structure_value_addr)
1215 if (pcc_struct_value)
1216 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1219 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1222 /* Precompute all register parameters. It isn't safe to compute anything
1223 once we have started filling any specific hard regs. */
1225 for (i = 0; i < num_actuals; i++)
1226 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1230 if (args[i].value == 0)
1232 args[i].value = expand_expr (args[i].tree_value, 0, VOIDmode, 0);
1233 preserve_temp_slots (args[i].value);
1236 /* ANSI doesn't require a sequence point here,
1237 but PCC has one, so this will avoid some problems. */
1242 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1243 /* The argument list is the property of the called routine and it
1244 may clobber it. If the fixed area has been used for previous
1245 parameters, we must save and restore it.
1247 Here we compute the boundary of the that needs to be saved, if any. */
1249 for (i = 0; i < REG_PARM_STACK_SPACE (fndecl); i++)
1251 if (i >= highest_outgoing_arg_in_use
1252 || stack_usage_map[i] == 0)
1255 if (low_to_save == -1)
1261 if (low_to_save >= 0)
1263 int num_to_save = high_to_save - low_to_save + 1;
1264 enum machine_mode save_mode
1265 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1268 /* If we don't have the required alignment, must do this in BLKmode. */
1269 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1270 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1271 save_mode = BLKmode;
1273 stack_area = gen_rtx (MEM, save_mode,
1274 memory_address (save_mode,
1275 plus_constant (argblock,
1277 if (save_mode == BLKmode)
1279 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1280 emit_block_move (validize_mem (save_area), stack_area,
1281 gen_rtx (CONST_INT, VOIDmode, num_to_save),
1282 PARM_BOUNDARY / BITS_PER_UNIT);
1286 save_area = gen_reg_rtx (save_mode);
1287 emit_move_insn (save_area, stack_area);
1293 /* Now store (and compute if necessary) all non-register parms.
1294 These come before register parms, since they can require block-moves,
1295 which could clobber the registers used for register parms.
1296 Parms which have partial registers are not stored here,
1297 but we do preallocate space here if they want that. */
1299 for (i = 0; i < num_actuals; i++)
1300 if (args[i].reg == 0 || args[i].pass_on_stack)
1301 store_one_arg (&args[i], argblock, may_be_alloca,
1302 args_size.var != 0, fndecl);
1304 /* Now store any partially-in-registers parm.
1305 This is the last place a block-move can happen. */
1307 for (i = 0; i < num_actuals; i++)
1308 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1309 store_one_arg (&args[i], argblock, may_be_alloca,
1310 args_size.var != 0, fndecl);
1312 #ifndef PUSH_ARGS_REVERSED
1313 #ifdef STACK_BOUNDARY
1314 /* If we pushed args in forward order, perform stack alignment
1315 after pushing the last arg. */
1317 anti_adjust_stack (gen_rtx (CONST_INT, VOIDmode,
1319 - original_args_size.constant)));
1323 /* Pass the function the address in which to return a structure value. */
1324 if (structure_value_addr && ! structure_value_addr_parm)
1326 emit_move_insn (struct_value_rtx,
1328 force_operand (structure_value_addr, 0)));
1329 if (GET_CODE (struct_value_rtx) == REG)
1331 push_to_sequence (use_insns);
1332 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1333 use_insns = get_insns ();
1338 /* Now do the register loads required for any wholly-register parms or any
1339 parms which are passed both on the stack and in a register. Their
1340 expressions were already evaluated.
1342 Mark all register-parms as living through the call, putting these USE
1343 insns in a list headed by USE_INSNS. */
1345 for (i = 0; i < num_actuals; i++)
1347 rtx list = args[i].reg;
1348 int partial = args[i].partial;
1355 /* Process each register that needs to get this arg. */
1356 if (GET_CODE (list) == EXPR_LIST)
1357 reg = XEXP (list, 0), list = XEXP (list, 1);
1359 reg = list, list = 0;
1361 /* Set to non-zero if must move a word at a time, even if just one
1362 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1363 we just use a normal move insn. */
1364 nregs = (partial ? partial
1365 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1366 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1367 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1370 /* If simple case, just do move. If normal partial, store_one_arg
1371 has already loaded the register for us. In all other cases,
1372 load the register(s) from memory. */
1375 emit_move_insn (reg, args[i].value);
1376 else if (args[i].partial == 0 || args[i].pass_on_stack)
1377 move_block_to_reg (REGNO (reg),
1378 validize_mem (args[i].value), nregs,
1379 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1381 push_to_sequence (use_insns);
1383 emit_insn (gen_rtx (USE, VOIDmode, reg));
1385 use_regs (REGNO (reg), nregs);
1386 use_insns = get_insns ();
1389 /* PARTIAL referred only to the first register, so clear it for the
1395 /* Perform postincrements before actually calling the function. */
1398 /* All arguments and registers used for the call must be set up by now! */
1400 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1402 /* Generate the actual call instruction. */
1403 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1404 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1405 valreg, old_inhibit_defer_pop, use_insns, is_const);
1407 /* If call is cse'able, make appropriate pair of reg-notes around it.
1408 Test valreg so we don't crash; may safely ignore `const'
1409 if return type is void. */
1410 if (is_const && valreg != 0)
1413 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1416 /* Construct an "equal form" for the value which mentions all the
1417 arguments in order as well as the function name. */
1418 #ifdef PUSH_ARGS_REVERSED
1419 for (i = 0; i < num_actuals; i++)
1420 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1422 for (i = num_actuals - 1; i >= 0; i--)
1423 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1425 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1427 insns = get_insns ();
1430 emit_libcall_block (insns, temp, valreg, note);
1435 /* For calls to `setjmp', etc., inform flow.c it should complain
1436 if nonvolatile values are live. */
1440 emit_note (name, NOTE_INSN_SETJMP);
1441 current_function_calls_setjmp = 1;
1445 current_function_calls_longjmp = 1;
1447 /* Notice functions that cannot return.
1448 If optimizing, insns emitted below will be dead.
1449 If not optimizing, they will exist, which is useful
1450 if the user uses the `return' command in the debugger. */
1452 if (is_volatile || is_longjmp)
1455 /* If value type not void, return an rtx for the value. */
1457 /* If there are cleanups to be called, don't use a hard reg as target. */
1458 if (cleanups_this_call != old_cleanups
1459 && target && REG_P (target)
1460 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1463 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1466 target = const0_rtx;
1468 else if (structure_value_addr)
1470 if (target == 0 || GET_CODE (target) != MEM)
1471 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1472 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1473 structure_value_addr));
1475 else if (pcc_struct_value)
1478 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1479 copy_to_reg (valreg));
1480 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1481 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1482 copy_to_reg (valreg)));
1484 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1486 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1488 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp)))
1489 /* TARGET and VALREG cannot be equal at this point because the latter
1490 would not have REG_FUNCTION_VALUE_P true, while the former would if
1491 it were referring to the same register.
1493 If they refer to the same register, this move will be a no-op, except
1494 when function inlining is being done. */
1495 emit_move_insn (target, valreg);
1497 target = copy_to_reg (valreg);
1499 /* Perform all cleanups needed for the arguments of this call
1500 (i.e. destructors in C++). */
1501 expand_cleanups_to (old_cleanups);
1503 /* If size of args is variable, restore saved stack-pointer value. */
1505 if (old_stack_level)
1507 emit_move_insn (stack_pointer_rtx, old_stack_level);
1508 pending_stack_adjust = old_pending_adj;
1511 #ifdef ACCUMULATE_OUTGOING_ARGS
1514 #ifdef REG_PARM_STACK_SPACE
1517 enum machine_mode save_mode = GET_MODE (save_area);
1519 = gen_rtx (MEM, save_mode,
1520 memory_address (save_mode,
1521 plus_constant (argblock, low_to_save)));
1523 if (save_mode != BLKmode)
1524 emit_move_insn (stack_area, save_area);
1526 emit_block_move (stack_area, validize_mem (save_area),
1527 gen_rtx (CONST_INT, VOIDmode,
1528 high_to_save - low_to_save + 1,
1529 PARM_BOUNDARY / BITS_PER_UNIT));
1533 /* If we saved any argument areas, restore them. */
1534 for (i = 0; i < num_actuals; i++)
1535 if (args[i].save_area)
1537 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1539 = gen_rtx (MEM, save_mode,
1540 memory_address (save_mode,
1541 XEXP (args[i].stack_slot, 0)));
1543 if (save_mode != BLKmode)
1544 emit_move_insn (stack_area, args[i].save_area);
1546 emit_block_move (stack_area, validize_mem (args[i].save_area),
1547 gen_rtx (CONST_INT, VOIDmode,
1548 args[i].size.constant),
1549 PARM_BOUNDARY / BITS_PER_UNIT);
1552 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1553 stack_usage_map = initial_stack_usage_map;
1557 /* If this was alloca, record the new stack level for nonlocal gotos. */
1558 if (may_be_alloca && nonlocal_goto_stack_level != 0)
1559 emit_move_insn (nonlocal_goto_stack_level, stack_pointer_rtx);
1567 /* Return an rtx which represents a suitable home on the stack
1568 given TYPE, the type of the argument looking for a home.
1569 This is called only for BLKmode arguments.
1571 SIZE is the size needed for this target.
1572 ARGS_ADDR is the address of the bottom of the argument block for this call.
1573 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1574 if this machine uses push insns. */
1577 target_for_arg (type, size, args_addr, offset)
1581 struct args_size offset;
1584 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1586 /* We do not call memory_address if possible,
1587 because we want to address as close to the stack
1588 as possible. For non-variable sized arguments,
1589 this will be stack-pointer relative addressing. */
1590 if (GET_CODE (offset_rtx) == CONST_INT)
1591 target = plus_constant (args_addr, INTVAL (offset_rtx));
1594 /* I have no idea how to guarantee that this
1595 will work in the presence of register parameters. */
1596 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1597 target = memory_address (QImode, target);
1600 return gen_rtx (MEM, BLKmode, target);
1604 /* Store a single argument for a function call
1605 into the register or memory area where it must be passed.
1606 *ARG describes the argument value and where to pass it.
1608 ARGBLOCK is the address of the stack-block for all the arguments,
1609 or 0 on a machine where arguments are pushed individually.
1611 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1612 so must be careful about how the stack is used.
1614 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1615 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1616 that we need not worry about saving and restoring the stack.
1618 FNDECL is the declaration of the function we are calling. */
1621 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl)
1622 struct arg_data *arg;
1628 register tree pval = arg->tree_value;
1632 int i, lower_bound, upper_bound;
1634 if (TREE_CODE (pval) == ERROR_MARK)
1637 #ifdef ACCUMULATE_OUTGOING_ARGS
1638 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1639 save any previous data at that location. */
1640 if (argblock && ! variable_size && arg->stack)
1642 #ifdef ARGS_GROW_DOWNWARD
1643 /* stack_slot is negative, but we want to index stack_usage_map */
1644 /* with positive values. */
1645 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1646 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1650 lower_bound = upper_bound - arg->size.constant;
1652 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1653 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1657 upper_bound = lower_bound + arg->size.constant;
1660 for (i = lower_bound; i < upper_bound; i++)
1661 if (stack_usage_map[i]
1662 #ifdef REG_PARM_STACK_SPACE
1663 /* Don't store things in the fixed argument area at this point;
1664 it has already been saved. */
1665 && i > REG_PARM_STACK_SPACE (fndecl)
1670 if (i != upper_bound)
1672 /* We need to make a save area. See what mode we can make it. */
1673 enum machine_mode save_mode
1674 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1676 = gen_rtx (MEM, save_mode,
1677 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1679 if (save_mode == BLKmode)
1681 arg->save_area = assign_stack_temp (BLKmode,
1682 arg->size.constant, 1);
1683 emit_block_move (validize_mem (arg->save_area), stack_area,
1684 gen_rtx (CONST_INT, VOIDmode,
1685 arg->size.constant),
1686 PARM_BOUNDARY / BITS_PER_UNIT);
1690 arg->save_area = gen_reg_rtx (save_mode);
1691 emit_move_insn (arg->save_area, stack_area);
1697 /* If this isn't going to be placed on both the stack and in registers,
1698 set up the register and number of words. */
1699 if (! arg->pass_on_stack)
1700 reg = arg->reg, partial = arg->partial;
1702 if (reg != 0 && partial == 0)
1703 /* Being passed entirely in a register. We shouldn't be called in
1707 /* If this is being partially passed in a register, but multiple locations
1708 are specified, we assume that the one partially used is the one that is
1710 if (reg && GET_CODE (reg) == EXPR_LIST)
1711 reg = XEXP (reg, 0);
1713 /* If this is being passes partially in a register, we can't evaluate
1714 it directly into its stack slot. Otherwise, we can. */
1715 if (arg->value == 0)
1716 arg->value = expand_expr (pval, partial ? 0 : arg->stack, VOIDmode, 0);
1718 /* Don't allow anything left on stack from computation
1719 of argument to alloca. */
1721 do_pending_stack_adjust ();
1723 if (arg->value == arg->stack)
1724 /* If the value is already in the stack slot, we are done. */
1726 else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
1730 /* Argument is a scalar, not entirely passed in registers.
1731 (If part is passed in registers, arg->partial says how much
1732 and emit_push_insn will take care of putting it there.)
1734 Push it, and if its size is less than the
1735 amount of space allocated to it,
1736 also bump stack pointer by the additional space.
1737 Note that in C the default argument promotions
1738 will prevent such mismatches. */
1740 size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
1741 /* Compute how much space the push instruction will push.
1742 On many machines, pushing a byte will advance the stack
1743 pointer by a halfword. */
1744 #ifdef PUSH_ROUNDING
1745 size = PUSH_ROUNDING (size);
1749 /* Compute how much space the argument should get:
1750 round up to a multiple of the alignment for arguments. */
1751 if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
1753 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
1754 / (PARM_BOUNDARY / BITS_PER_UNIT))
1755 * (PARM_BOUNDARY / BITS_PER_UNIT));
1757 /* This isn't already where we want it on the stack, so put it there.
1758 This can either be done with push or copy insns. */
1759 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1760 TREE_TYPE (pval), 0, 0, partial, reg,
1761 used - size, argblock, ARGS_SIZE_RTX (arg->offset));
1765 /* BLKmode, at least partly to be pushed. */
1767 register int excess;
1770 /* Pushing a nonscalar.
1771 If part is passed in registers, PARTIAL says how much
1772 and emit_push_insn will take care of putting it there. */
1774 /* Round its size up to a multiple
1775 of the allocation unit for arguments. */
1777 if (arg->size.var != 0)
1780 size_rtx = ARGS_SIZE_RTX (arg->size);
1784 register tree size = size_in_bytes (TREE_TYPE (pval));
1785 /* PUSH_ROUNDING has no effect on us, because
1786 emit_push_insn for BLKmode is careful to avoid it. */
1787 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
1788 + partial * UNITS_PER_WORD);
1789 size_rtx = expand_expr (size, 0, VOIDmode, 0);
1792 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
1793 TREE_TYPE (pval), size_rtx,
1794 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
1795 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
1799 /* Unless this is a partially-in-register argument, the argument is now
1802 ??? Note that this can change arg->value from arg->stack to
1803 arg->stack_slot and it matters when they are not the same.
1804 It isn't totally clear that this is correct in all cases. */
1806 arg->value = arg->stack_slot;
1808 /* Once we have pushed something, pops can't safely
1809 be deferred during the rest of the arguments. */
1812 /* ANSI doesn't require a sequence point here,
1813 but PCC has one, so this will avoid some problems. */
1816 /* Free any temporary slots made in processing this argument. */
1819 #ifdef ACCUMULATE_OUTGOING_ARGS
1820 /* Now mark the segment we just used. */
1821 if (argblock && ! variable_size && arg->stack)
1822 for (i = lower_bound; i < upper_bound; i++)
1823 stack_usage_map[i] = 1;