1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992 Free Software Foundation, Inc.
4 This file is part of GNU CC.
6 GNU CC is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU CC is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU CC; see the file COPYING. If not, write to
18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
25 #include "insn-flags.h"
27 /* Decide whether a function's arguments should be processed
28 from first to last or from last to first. */
30 #ifdef STACK_GROWS_DOWNWARD
32 #define PUSH_ARGS_REVERSED /* If it's last to first */
36 /* Like STACK_BOUNDARY but in units of bytes, not bits. */
37 #define STACK_BYTES (STACK_BOUNDARY / BITS_PER_UNIT)
39 /* Data structure and subroutines used within expand_call. */
43 /* Tree node for this argument. */
45 /* Current RTL value for argument, or 0 if it isn't precomputed. */
47 /* Initially-compute RTL value for argument; only for const functions. */
49 /* Register to pass this argument in, 0 if passed on stack, or an
50 EXPR_LIST if the arg is to be copied into multiple different
53 /* If REG was promoted from the actual mode of the argument expression,
54 indicates whether the promotion is sign- or zero-extended. */
56 /* Number of registers to use. 0 means put the whole arg in registers.
57 Also 0 if not passed in registers. */
59 /* Non-zero if argument must be passed on stack.
60 Note that some arguments may be passed on the stack
61 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
62 pass_on_stack identifies arguments that *cannot* go in registers. */
64 /* Offset of this argument from beginning of stack-args. */
65 struct args_size offset;
66 /* Similar, but offset to the start of the stack slot. Different from
67 OFFSET if this arg pads downward. */
68 struct args_size slot_offset;
69 /* Size of this argument on the stack, rounded up for any padding it gets,
70 parts of the argument passed in registers do not count.
71 If REG_PARM_STACK_SPACE is defined, then register parms
72 are counted here as well. */
73 struct args_size size;
74 /* Location on the stack at which parameter should be stored. The store
75 has already been done if STACK == VALUE. */
77 /* Location on the stack of the start of this argument slot. This can
78 differ from STACK if this arg pads downward. This location is known
79 to be aligned to FUNCTION_ARG_BOUNDARY. */
81 #ifdef ACCUMULATE_OUTGOING_ARGS
82 /* Place that this stack area has been saved, if needed. */
87 #ifdef ACCUMULATE_OUTGOING_ARGS
88 /* A vector of one char per byte of stack space. A byte if non-zero if
89 the corresponding stack location has been used.
90 This vector is used to prevent a function call within an argument from
91 clobbering any stack already set up. */
92 static char *stack_usage_map;
94 /* Size of STACK_USAGE_MAP. */
95 static int highest_outgoing_arg_in_use;
97 /* stack_arg_under_construction is nonzero when an argument may be
98 initialized with a constructor call (including a C function that
99 returns a BLKmode struct) and expand_call must take special action
100 to make sure the object being constructed does not overlap the
101 argument list for the constructor call. */
102 int stack_arg_under_construction;
105 static void store_one_arg ();
106 extern enum machine_mode mode_for_size ();
108 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
111 If WHICH is 0, return 1 if EXP contains a call to any function.
112 Actually, we only need return 1 if evaluating EXP would require pushing
113 arguments on the stack, but that is too difficult to compute, so we just
114 assume any function call might require the stack. */
117 calls_function (exp, which)
122 int type = TREE_CODE_CLASS (TREE_CODE (exp));
123 int length = tree_code_length[(int) TREE_CODE (exp)];
125 /* Only expressions and references can contain calls. */
127 if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r'
131 switch (TREE_CODE (exp))
136 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
137 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
139 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
140 && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
144 /* Third operand is RTL. */
149 if (SAVE_EXPR_RTL (exp) != 0)
157 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
158 if (DECL_INITIAL (local) != 0
159 && calls_function (DECL_INITIAL (local), which))
163 register tree subblock;
165 for (subblock = BLOCK_SUBBLOCKS (exp);
167 subblock = TREE_CHAIN (subblock))
168 if (calls_function (subblock, which))
173 case METHOD_CALL_EXPR:
177 case WITH_CLEANUP_EXPR:
185 for (i = 0; i < length; i++)
186 if (TREE_OPERAND (exp, i) != 0
187 && calls_function (TREE_OPERAND (exp, i), which))
193 /* Force FUNEXP into a form suitable for the address of a CALL,
194 and return that as an rtx. Also load the static chain register
195 if FNDECL is a nested function.
197 USE_INSNS points to a variable holding a chain of USE insns
198 to which a USE of the static chain
199 register should be added, if required. */
202 prepare_call_address (funexp, fndecl, use_insns)
207 rtx static_chain_value = 0;
209 funexp = protect_from_queue (funexp, 0);
212 /* Get possible static chain value for nested function in C. */
213 static_chain_value = lookup_static_chain (fndecl);
215 /* Make a valid memory address and copy constants thru pseudo-regs,
216 but not for a constant address if -fno-function-cse. */
217 if (GET_CODE (funexp) != SYMBOL_REF)
218 funexp = memory_address (FUNCTION_MODE, funexp);
221 #ifndef NO_FUNCTION_CSE
222 if (optimize && ! flag_no_function_cse)
223 #ifdef NO_RECURSIVE_FUNCTION_CSE
224 if (fndecl != current_function_decl)
226 funexp = force_reg (Pmode, funexp);
230 if (static_chain_value != 0)
232 emit_move_insn (static_chain_rtx, static_chain_value);
234 /* Put the USE insn in the chain we were passed. It will later be
235 output immediately in front of the CALL insn. */
236 push_to_sequence (*use_insns);
237 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
238 *use_insns = get_insns ();
245 /* Generate instructions to call function FUNEXP,
246 and optionally pop the results.
247 The CALL_INSN is the first insn generated.
249 FUNTYPE is the data type of the function, or, for a library call,
250 the identifier for the name of the call. This is given to the
251 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
253 STACK_SIZE is the number of bytes of arguments on the stack,
254 rounded up to STACK_BOUNDARY; zero if the size is variable.
255 This is both to put into the call insn and
256 to generate explicit popping code if necessary.
258 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
259 It is zero if this call doesn't want a structure value.
261 NEXT_ARG_REG is the rtx that results from executing
262 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
263 just after all the args have had their registers assigned.
264 This could be whatever you like, but normally it is the first
265 arg-register beyond those used for args in this call,
266 or 0 if all the arg-registers are used in this call.
267 It is passed on to `gen_call' so you can put this info in the call insn.
269 VALREG is a hard register in which a value is returned,
270 or 0 if the call does not return a value.
272 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
273 the args to this call were processed.
274 We restore `inhibit_defer_pop' to that value.
276 USE_INSNS is a chain of USE insns to be emitted immediately before
277 the actual CALL insn.
279 IS_CONST is true if this is a `const' call. */
282 emit_call_1 (funexp, funtype, stack_size, struct_value_size, next_arg_reg,
283 valreg, old_inhibit_defer_pop, use_insns, is_const)
287 int struct_value_size;
290 int old_inhibit_defer_pop;
294 rtx stack_size_rtx = GEN_INT (stack_size);
295 rtx struct_value_size_rtx = GEN_INT (struct_value_size);
297 int already_popped = 0;
299 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
300 and we don't want to load it into a register as an optimization,
301 because prepare_call_address already did it if it should be done. */
302 if (GET_CODE (funexp) != SYMBOL_REF)
303 funexp = memory_address (FUNCTION_MODE, funexp);
305 #ifndef ACCUMULATE_OUTGOING_ARGS
306 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
307 if (HAVE_call_pop && HAVE_call_value_pop
308 && (RETURN_POPS_ARGS (funtype, stack_size) > 0 || stack_size == 0))
310 rtx n_pop = GEN_INT (RETURN_POPS_ARGS (funtype, stack_size));
313 /* If this subroutine pops its own args, record that in the call insn
314 if possible, for the sake of frame pointer elimination. */
316 pat = gen_call_value_pop (valreg,
317 gen_rtx (MEM, FUNCTION_MODE, funexp),
318 stack_size_rtx, next_arg_reg, n_pop);
320 pat = gen_call_pop (gen_rtx (MEM, FUNCTION_MODE, funexp),
321 stack_size_rtx, next_arg_reg, n_pop);
323 emit_call_insn (pat);
330 #if defined (HAVE_call) && defined (HAVE_call_value)
331 if (HAVE_call && HAVE_call_value)
334 emit_call_insn (gen_call_value (valreg,
335 gen_rtx (MEM, FUNCTION_MODE, funexp),
336 stack_size_rtx, next_arg_reg,
339 emit_call_insn (gen_call (gen_rtx (MEM, FUNCTION_MODE, funexp),
340 stack_size_rtx, next_arg_reg,
341 struct_value_size_rtx));
347 /* Find the CALL insn we just emitted and write the USE insns before it. */
348 for (call_insn = get_last_insn ();
349 call_insn && GET_CODE (call_insn) != CALL_INSN;
350 call_insn = PREV_INSN (call_insn))
356 /* Put the USE insns before the CALL. */
357 emit_insns_before (use_insns, call_insn);
359 /* If this is a const call, then set the insn's unchanging bit. */
361 CONST_CALL_P (call_insn) = 1;
363 #ifndef ACCUMULATE_OUTGOING_ARGS
364 /* If returning from the subroutine does not automatically pop the args,
365 we need an instruction to pop them sooner or later.
366 Perhaps do it now; perhaps just record how much space to pop later.
368 If returning from the subroutine does pop the args, indicate that the
369 stack pointer will be changed. */
371 if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0)
374 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
375 stack_size -= RETURN_POPS_ARGS (funtype, stack_size);
376 stack_size_rtx = GEN_INT (stack_size);
381 if (flag_defer_pop && inhibit_defer_pop == 0)
382 pending_stack_adjust += stack_size;
384 adjust_stack (stack_size_rtx);
388 inhibit_defer_pop = old_inhibit_defer_pop;
391 /* Generate all the code for a function call
392 and return an rtx for its value.
393 Store the value in TARGET (specified as an rtx) if convenient.
394 If the value is stored in TARGET then TARGET is returned.
395 If IGNORE is nonzero, then we ignore the value of the function call. */
398 expand_call (exp, target, ignore)
403 /* List of actual parameters. */
404 tree actparms = TREE_OPERAND (exp, 1);
405 /* RTX for the function to be called. */
407 /* Tree node for the function to be called (not the address!). */
409 /* Data type of the function. */
411 /* Declaration of the function being called,
412 or 0 if the function is computed (not known by name). */
416 /* Register in which non-BLKmode value will be returned,
417 or 0 if no value or if value is BLKmode. */
419 /* Address where we should return a BLKmode value;
420 0 if value not BLKmode. */
421 rtx structure_value_addr = 0;
422 /* Nonzero if that address is being passed by treating it as
423 an extra, implicit first parameter. Otherwise,
424 it is passed by being copied directly into struct_value_rtx. */
425 int structure_value_addr_parm = 0;
426 /* Size of aggregate value wanted, or zero if none wanted
427 or if we are using the non-reentrant PCC calling convention
428 or expecting the value in registers. */
429 int struct_value_size = 0;
430 /* Nonzero if called function returns an aggregate in memory PCC style,
431 by returning the address of where to find it. */
432 int pcc_struct_value = 0;
434 /* Number of actual parameters in this call, including struct value addr. */
436 /* Number of named args. Args after this are anonymous ones
437 and they must all go on the stack. */
439 /* Count arg position in order args appear. */
442 /* Vector of information about each argument.
443 Arguments are numbered in the order they will be pushed,
444 not the order they are written. */
445 struct arg_data *args;
447 /* Total size in bytes of all the stack-parms scanned so far. */
448 struct args_size args_size;
449 /* Size of arguments before any adjustments (such as rounding). */
450 struct args_size original_args_size;
451 /* Data on reg parms scanned so far. */
452 CUMULATIVE_ARGS args_so_far;
453 /* Nonzero if a reg parm has been scanned. */
456 /* Nonzero if we must avoid push-insns in the args for this call.
457 If stack space is allocated for register parameters, but not by the
458 caller, then it is preallocated in the fixed part of the stack frame.
459 So the entire argument block must then be preallocated (i.e., we
460 ignore PUSH_ROUNDING in that case). */
462 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
463 int must_preallocate = 1;
466 int must_preallocate = 0;
468 int must_preallocate = 1;
472 /* Size of the stack reserved for parameter registers. */
473 int reg_parm_stack_space = 0;
475 /* 1 if scanning parms front to back, -1 if scanning back to front. */
477 /* Address of space preallocated for stack parms
478 (on machines that lack push insns), or 0 if space not preallocated. */
481 /* Nonzero if it is plausible that this is a call to alloca. */
483 /* Nonzero if this is a call to setjmp or a related function. */
485 /* Nonzero if this is a call to `longjmp'. */
487 /* Nonzero if this is a call to an inline function. */
488 int is_integrable = 0;
489 /* Nonzero if this is a call to a `const' function.
490 Note that only explicitly named functions are handled as `const' here. */
492 /* Nonzero if this is a call to a `volatile' function. */
494 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
495 /* Define the boundary of the register parm stack space that needs to be
497 int low_to_save = -1, high_to_save;
498 rtx save_area = 0; /* Place that it is saved */
501 #ifdef ACCUMULATE_OUTGOING_ARGS
502 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
503 char *initial_stack_usage_map = stack_usage_map;
506 rtx old_stack_level = 0;
508 int old_stack_arg_under_construction;
509 int old_inhibit_defer_pop = inhibit_defer_pop;
510 tree old_cleanups = cleanups_this_call;
517 /* See if we can find a DECL-node for the actual function.
518 As a result, decide whether this is a call to an integrable function. */
520 p = TREE_OPERAND (exp, 0);
521 if (TREE_CODE (p) == ADDR_EXPR)
523 fndecl = TREE_OPERAND (p, 0);
524 if (TREE_CODE (fndecl) != FUNCTION_DECL)
526 /* May still be a `const' function if it is
527 a call through a pointer-to-const.
528 But we don't handle that. */
534 && fndecl != current_function_decl
535 && DECL_SAVED_INSNS (fndecl))
537 else if (! TREE_ADDRESSABLE (fndecl))
539 /* In case this function later becomes inlinable,
540 record that there was already a non-inline call to it.
542 Use abstraction instead of setting TREE_ADDRESSABLE
544 if (DECL_INLINE (fndecl) && extra_warnings && !flag_no_inline)
545 warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline");
546 mark_addressable (fndecl);
549 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
550 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
555 is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
557 #ifdef REG_PARM_STACK_SPACE
558 #ifdef MAYBE_REG_PARM_STACK_SPACE
559 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
561 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
565 /* Warn if this value is an aggregate type,
566 regardless of which calling convention we are using for it. */
567 if (warn_aggregate_return
568 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
569 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
570 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
571 warning ("function call has aggregate value");
573 /* Set up a place to return a structure. */
575 /* Cater to broken compilers. */
576 if (aggregate_value_p (exp))
578 /* This call returns a big structure. */
581 #ifdef PCC_STATIC_STRUCT_RETURN
582 if (flag_pcc_struct_return)
584 pcc_struct_value = 1;
585 is_integrable = 0; /* Easier than making that case work right. */
590 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
592 if (struct_value_size < 0)
595 if (target && GET_CODE (target) == MEM)
596 structure_value_addr = XEXP (target, 0);
599 /* Assign a temporary on the stack to hold the value. */
601 /* For variable-sized objects, we must be called with a target
602 specified. If we were to allocate space on the stack here,
603 we would have no way of knowing when to free it. */
606 = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
612 /* If called function is inline, try to integrate it. */
617 rtx before_call = get_last_insn ();
619 temp = expand_inline_function (fndecl, actparms, target,
620 ignore, TREE_TYPE (exp),
621 structure_value_addr);
623 /* If inlining succeeded, return. */
624 if ((HOST_WIDE_INT) temp != -1)
628 /* Perform all cleanups needed for the arguments of this call
629 (i.e. destructors in C++). It is ok if these destructors
630 clobber RETURN_VALUE_REG, because the only time we care about
631 this is when TARGET is that register. But in C++, we take
632 care to never return that register directly. */
633 expand_cleanups_to (old_cleanups);
635 #ifdef ACCUMULATE_OUTGOING_ARGS
636 /* If the outgoing argument list must be preserved, push
637 the stack before executing the inlined function if it
640 for (i = reg_parm_stack_space - 1; i >= 0; i--)
641 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
644 if (stack_arg_under_construction || i >= 0)
646 rtx insn = NEXT_INSN (before_call), seq;
648 /* Look for a call in the inline function code.
649 If OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) is
650 nonzero then there is a call and it is not necessary
651 to scan the insns. */
653 if (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) == 0)
654 for (; insn; insn = NEXT_INSN (insn))
655 if (GET_CODE (insn) == CALL_INSN)
660 /* Reserve enough stack space so that the largest
661 argument list of any function call in the inline
662 function does not overlap the argument list being
663 evaluated. This is usually an overestimate because
664 allocate_dynamic_stack_space reserves space for an
665 outgoing argument list in addition to the requested
666 space, but there is no way to ask for stack space such
667 that an argument list of a certain length can be
668 safely constructed. */
670 int adjust = OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl));
671 #ifdef REG_PARM_STACK_SPACE
672 /* Add the stack space reserved for register arguments
673 in the inline function. What is really needed is the
674 largest value of reg_parm_stack_space in the inline
675 function, but that is not available. Using the current
676 value of reg_parm_stack_space is wrong, but gives
677 correct results on all supported machines. */
678 adjust += reg_parm_stack_space;
681 emit_stack_save (SAVE_BLOCK, &old_stack_level, 0);
682 allocate_dynamic_stack_space (GEN_INT (adjust),
683 NULL_RTX, BITS_PER_UNIT);
686 emit_insns_before (seq, NEXT_INSN (before_call));
687 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
692 /* If the result is equivalent to TARGET, return TARGET to simplify
693 checks in store_expr. They can be equivalent but not equal in the
694 case of a function that returns BLKmode. */
695 if (temp != target && rtx_equal_p (temp, target))
700 /* If inlining failed, mark FNDECL as needing to be compiled
701 separately after all. */
702 mark_addressable (fndecl);
705 /* When calling a const function, we must pop the stack args right away,
706 so that the pop is deleted or moved with the call. */
710 function_call_count++;
712 if (fndecl && DECL_NAME (fndecl))
713 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
716 /* Unless it's a call to a specific function that isn't alloca,
717 if it has one argument, we must assume it might be alloca. */
720 (!(fndecl != 0 && strcmp (name, "alloca"))
722 && TREE_CHAIN (actparms) == 0);
724 /* We assume that alloca will always be called by name. It
725 makes no sense to pass it as a pointer-to-function to
726 anything that does not understand its behavior. */
728 (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
730 && ! strcmp (name, "alloca"))
731 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
733 && ! strcmp (name, "__builtin_alloca"))));
736 /* See if this is a call to a function that can return more than once
737 or a call to longjmp. */
742 if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
747 tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
753 && (! strcmp (tname, "setjmp")
754 || ! strcmp (tname, "setjmp_syscall")))
756 && ! strcmp (tname, "sigsetjmp"))
758 && ! strcmp (tname, "savectx")));
760 && ! strcmp (tname, "siglongjmp"))
763 else if ((tname[0] == 'q' && tname[1] == 's'
764 && ! strcmp (tname, "qsetjmp"))
765 || (tname[0] == 'v' && tname[1] == 'f'
766 && ! strcmp (tname, "vfork")))
769 else if (tname[0] == 'l' && tname[1] == 'o'
770 && ! strcmp (tname, "longjmp"))
775 current_function_calls_alloca = 1;
777 /* Don't let pending stack adjusts add up to too much.
778 Also, do all pending adjustments now
779 if there is any chance this might be a call to alloca. */
781 if (pending_stack_adjust >= 32
782 || (pending_stack_adjust > 0 && may_be_alloca))
783 do_pending_stack_adjust ();
785 /* Operand 0 is a pointer-to-function; get the type of the function. */
786 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
787 if (TREE_CODE (funtype) != POINTER_TYPE)
789 funtype = TREE_TYPE (funtype);
791 /* Push the temporary stack slot level so that we can free temporaries used
792 by each of the arguments separately. */
795 /* Start updating where the next arg would go. */
796 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX);
798 /* If struct_value_rtx is 0, it means pass the address
799 as if it were an extra parameter. */
800 if (structure_value_addr && struct_value_rtx == 0)
802 #ifdef ACCUMULATE_OUTGOING_ARGS
803 /* If the stack will be adjusted, make sure the structure address
804 does not refer to virtual_outgoing_args_rtx. */
805 rtx temp = (stack_arg_under_construction
806 ? copy_addr_to_reg (structure_value_addr)
807 : force_reg (Pmode, structure_value_addr));
809 rtx temp = force_reg (Pmode, structure_value_addr);
813 = tree_cons (error_mark_node,
814 make_tree (build_pointer_type (TREE_TYPE (funtype)),
817 structure_value_addr_parm = 1;
820 /* Count the arguments and set NUM_ACTUALS. */
821 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
824 /* Compute number of named args.
825 Normally, don't include the last named arg if anonymous args follow.
826 (If no anonymous args follow, the result of list_length
827 is actually one too large.)
829 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
830 place unnamed args that were passed in registers into the stack. So
831 treat all args as named. This allows the insns emitting for a specific
832 argument list to be independent of the function declaration.
834 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
835 way to pass unnamed args in registers, so we must force them into
837 #ifndef SETUP_INCOMING_VARARGS
838 if (TYPE_ARG_TYPES (funtype) != 0)
840 = list_length (TYPE_ARG_TYPES (funtype)) - 1
841 /* Count the struct value address, if it is passed as a parm. */
842 + structure_value_addr_parm;
845 /* If we know nothing, treat all args as named. */
846 n_named_args = num_actuals;
848 /* Make a vector to hold all the information about each arg. */
849 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
850 bzero (args, num_actuals * sizeof (struct arg_data));
852 args_size.constant = 0;
855 /* In this loop, we consider args in the order they are written.
856 We fill up ARGS from the front of from the back if necessary
857 so that in any case the first arg to be pushed ends up at the front. */
859 #ifdef PUSH_ARGS_REVERSED
860 i = num_actuals - 1, inc = -1;
861 /* In this case, must reverse order of args
862 so that we compute and push the last arg first. */
867 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
868 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
870 tree type = TREE_TYPE (TREE_VALUE (p));
871 enum machine_mode mode;
873 args[i].tree_value = TREE_VALUE (p);
875 /* Replace erroneous argument with constant zero. */
876 if (type == error_mark_node || TYPE_SIZE (type) == 0)
877 args[i].tree_value = integer_zero_node, type = integer_type_node;
879 /* Decide where to pass this arg.
881 args[i].reg is nonzero if all or part is passed in registers.
883 args[i].partial is nonzero if part but not all is passed in registers,
884 and the exact value says how many words are passed in registers.
886 args[i].pass_on_stack is nonzero if the argument must at least be
887 computed on the stack. It may then be loaded back into registers
888 if args[i].reg is nonzero.
890 These decisions are driven by the FUNCTION_... macros and must agree
891 with those made by function.c. */
893 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
894 /* See if this argument should be passed by invisible reference. */
895 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
896 argpos < n_named_args))
898 /* We make a copy of the object and pass the address to the function
902 if (TYPE_SIZE (type) == 0
903 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
905 /* This is a variable-sized object. Make space on the stack
907 rtx size_rtx = expand_expr (size_in_bytes (type), NULL_RTX,
910 if (old_stack_level == 0)
912 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
913 old_pending_adj = pending_stack_adjust;
914 pending_stack_adjust = 0;
917 copy = gen_rtx (MEM, BLKmode,
918 allocate_dynamic_stack_space (size_rtx, NULL_RTX,
923 int size = int_size_in_bytes (type);
924 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
927 store_expr (args[i].tree_value, copy, 0);
929 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
930 make_tree (type, copy));
931 type = build_pointer_type (type);
935 mode = TYPE_MODE (type);
937 #ifdef PROMOTE_FUNCTION_ARGS
938 /* Compute the mode in which the arg is actually to be extended to. */
939 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
940 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
941 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
942 || TREE_CODE (type) == OFFSET_TYPE)
944 int unsignedp = TREE_UNSIGNED (type);
945 PROMOTE_MODE (mode, unsignedp, type);
946 args[i].unsignedp = unsignedp;
950 args[i].reg = FUNCTION_ARG (args_so_far, mode, type,
951 argpos < n_named_args);
952 #ifdef FUNCTION_ARG_PARTIAL_NREGS
955 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, type,
956 argpos < n_named_args);
959 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
961 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
962 we are to pass this arg in the register(s) designated by FOO, but
963 also to pass it in the stack. */
964 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
965 && XEXP (args[i].reg, 0) == 0)
966 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
968 /* If this is an addressable type, we must preallocate the stack
969 since we must evaluate the object into its final location.
971 If this is to be passed in both registers and the stack, it is simpler
973 if (TREE_ADDRESSABLE (type)
974 || (args[i].pass_on_stack && args[i].reg != 0))
975 must_preallocate = 1;
977 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
978 we cannot consider this function call constant. */
979 if (TREE_ADDRESSABLE (type))
982 /* Compute the stack-size of this argument. */
983 if (args[i].reg == 0 || args[i].partial != 0
984 #ifdef REG_PARM_STACK_SPACE
985 || reg_parm_stack_space > 0
987 || args[i].pass_on_stack)
988 locate_and_pad_parm (TYPE_MODE (type), type,
989 #ifdef STACK_PARMS_IN_REG_PARM_AREA
994 fndecl, &args_size, &args[i].offset,
997 #ifndef ARGS_GROW_DOWNWARD
998 args[i].slot_offset = args_size;
1001 #ifndef REG_PARM_STACK_SPACE
1002 /* If a part of the arg was put into registers,
1003 don't include that part in the amount pushed. */
1004 if (! args[i].pass_on_stack)
1005 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1006 / (PARM_BOUNDARY / BITS_PER_UNIT)
1007 * (PARM_BOUNDARY / BITS_PER_UNIT));
1010 /* Update ARGS_SIZE, the total stack space for args so far. */
1012 args_size.constant += args[i].size.constant;
1013 if (args[i].size.var)
1015 ADD_PARM_SIZE (args_size, args[i].size.var);
1018 /* Since the slot offset points to the bottom of the slot,
1019 we must record it after incrementing if the args grow down. */
1020 #ifdef ARGS_GROW_DOWNWARD
1021 args[i].slot_offset = args_size;
1023 args[i].slot_offset.constant = -args_size.constant;
1026 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
1030 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1031 have been used, etc. */
1033 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
1034 argpos < n_named_args);
1037 #ifdef FINAL_REG_PARM_STACK_SPACE
1038 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
1042 /* Compute the actual size of the argument block required. The variable
1043 and constant sizes must be combined, the size may have to be rounded,
1044 and there may be a minimum required size. */
1046 original_args_size = args_size;
1049 /* If this function requires a variable-sized argument list, don't try to
1050 make a cse'able block for this call. We may be able to do this
1051 eventually, but it is too complicated to keep track of what insns go
1052 in the cse'able block and which don't. */
1055 must_preallocate = 1;
1057 args_size.var = ARGS_SIZE_TREE (args_size);
1058 args_size.constant = 0;
1060 #ifdef STACK_BOUNDARY
1061 if (STACK_BOUNDARY != BITS_PER_UNIT)
1062 args_size.var = round_up (args_size.var, STACK_BYTES);
1065 #ifdef REG_PARM_STACK_SPACE
1066 if (reg_parm_stack_space > 0)
1069 = size_binop (MAX_EXPR, args_size.var,
1070 size_int (REG_PARM_STACK_SPACE (fndecl)));
1072 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1073 /* The area corresponding to register parameters is not to count in
1074 the size of the block we need. So make the adjustment. */
1076 = size_binop (MINUS_EXPR, args_size.var,
1077 size_int (reg_parm_stack_space));
1084 #ifdef STACK_BOUNDARY
1085 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
1086 / STACK_BYTES) * STACK_BYTES);
1089 #ifdef REG_PARM_STACK_SPACE
1090 args_size.constant = MAX (args_size.constant,
1091 reg_parm_stack_space);
1092 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1093 args_size.constant -= reg_parm_stack_space;
1098 /* See if we have or want to preallocate stack space.
1100 If we would have to push a partially-in-regs parm
1101 before other stack parms, preallocate stack space instead.
1103 If the size of some parm is not a multiple of the required stack
1104 alignment, we must preallocate.
1106 If the total size of arguments that would otherwise create a copy in
1107 a temporary (such as a CALL) is more than half the total argument list
1108 size, preallocation is faster.
1110 Another reason to preallocate is if we have a machine (like the m88k)
1111 where stack alignment is required to be maintained between every
1112 pair of insns, not just when the call is made. However, we assume here
1113 that such machines either do not have push insns (and hence preallocation
1114 would occur anyway) or the problem is taken care of with
1117 if (! must_preallocate)
1119 int partial_seen = 0;
1120 int copy_to_evaluate_size = 0;
1122 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1124 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1126 else if (partial_seen && args[i].reg == 0)
1127 must_preallocate = 1;
1129 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1130 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1131 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1132 || TREE_CODE (args[i].tree_value) == COND_EXPR
1133 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1134 copy_to_evaluate_size
1135 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1138 if (copy_to_evaluate_size * 2 >= args_size.constant
1139 && args_size.constant > 0)
1140 must_preallocate = 1;
1143 /* If the structure value address will reference the stack pointer, we must
1144 stabilize it. We don't need to do this if we know that we are not going
1145 to adjust the stack pointer in processing this call. */
1147 if (structure_value_addr
1148 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1149 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1151 #ifndef ACCUMULATE_OUTGOING_ARGS
1152 || args_size.constant
1155 structure_value_addr = copy_to_reg (structure_value_addr);
1157 /* If this function call is cse'able, precompute all the parameters.
1158 Note that if the parameter is constructed into a temporary, this will
1159 cause an additional copy because the parameter will be constructed
1160 into a temporary location and then copied into the outgoing arguments.
1161 If a parameter contains a call to alloca and this function uses the
1162 stack, precompute the parameter. */
1164 /* If we preallocated the stack space, and some arguments must be passed
1165 on the stack, then we must precompute any parameter which contains a
1166 function call which will store arguments on the stack.
1167 Otherwise, evaluating the parameter may clobber previous parameters
1168 which have already been stored into the stack. */
1170 for (i = 0; i < num_actuals; i++)
1172 || ((args_size.var != 0 || args_size.constant != 0)
1173 && calls_function (args[i].tree_value, 1))
1174 || (must_preallocate && (args_size.var != 0 || args_size.constant != 0)
1175 && calls_function (args[i].tree_value, 0)))
1177 args[i].initial_value = args[i].value
1178 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1179 preserve_temp_slots (args[i].value);
1182 /* ANSI doesn't require a sequence point here,
1183 but PCC has one, so this will avoid some problems. */
1187 /* Now we are about to start emitting insns that can be deleted
1188 if a libcall is deleted. */
1192 /* If we have no actual push instructions, or shouldn't use them,
1193 make space for all args right now. */
1195 if (args_size.var != 0)
1197 if (old_stack_level == 0)
1199 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1200 old_pending_adj = pending_stack_adjust;
1201 pending_stack_adjust = 0;
1202 #ifdef ACCUMULATE_OUTGOING_ARGS
1203 /* stack_arg_under_construction says whether a stack arg is
1204 being constructed at the old stack level. Pushing the stack
1205 gets a clean outgoing argument block. */
1206 old_stack_arg_under_construction = stack_arg_under_construction;
1207 stack_arg_under_construction = 0;
1210 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1212 else if (must_preallocate)
1214 /* Note that we must go through the motions of allocating an argument
1215 block even if the size is zero because we may be storing args
1216 in the area reserved for register arguments, which may be part of
1218 int needed = args_size.constant;
1220 #ifdef ACCUMULATE_OUTGOING_ARGS
1221 /* Store the maximum argument space used. It will be pushed by the
1224 Since the stack pointer will never be pushed, it is possible for
1225 the evaluation of a parm to clobber something we have already
1226 written to the stack. Since most function calls on RISC machines
1227 do not use the stack, this is uncommon, but must work correctly.
1229 Therefore, we save any area of the stack that was already written
1230 and that we are using. Here we set up to do this by making a new
1231 stack usage map from the old one. The actual save will be done
1234 Another approach might be to try to reorder the argument
1235 evaluations to avoid this conflicting stack usage. */
1237 if (needed > current_function_outgoing_args_size)
1238 current_function_outgoing_args_size = needed;
1240 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1241 /* Since we will be writing into the entire argument area, the
1242 map must be allocated for its entire size, not just the part that
1243 is the responsibility of the caller. */
1244 needed += reg_parm_stack_space;
1247 #ifdef ARGS_GROW_DOWNWARD
1248 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1251 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1253 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1255 if (initial_highest_arg_in_use)
1256 bcopy (initial_stack_usage_map, stack_usage_map,
1257 initial_highest_arg_in_use);
1259 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1260 bzero (&stack_usage_map[initial_highest_arg_in_use],
1261 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1264 /* The address of the outgoing argument list must not be copied to a
1265 register here, because argblock would be left pointing to the
1266 wrong place after the call to allocate_dynamic_stack_space below. */
1268 argblock = virtual_outgoing_args_rtx;
1270 #else /* not ACCUMULATE_OUTGOING_ARGS */
1271 if (inhibit_defer_pop == 0)
1273 /* Try to reuse some or all of the pending_stack_adjust
1274 to get this space. Maybe we can avoid any pushing. */
1275 if (needed > pending_stack_adjust)
1277 needed -= pending_stack_adjust;
1278 pending_stack_adjust = 0;
1282 pending_stack_adjust -= needed;
1286 /* Special case this because overhead of `push_block' in this
1287 case is non-trivial. */
1289 argblock = virtual_outgoing_args_rtx;
1291 argblock = push_block (GEN_INT (needed), 0, 0);
1293 /* We only really need to call `copy_to_reg' in the case where push
1294 insns are going to be used to pass ARGBLOCK to a function
1295 call in ARGS. In that case, the stack pointer changes value
1296 from the allocation point to the call point, and hence
1297 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1298 But might as well always do it. */
1299 argblock = copy_to_reg (argblock);
1300 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1304 #ifdef ACCUMULATE_OUTGOING_ARGS
1305 /* The save/restore code in store_one_arg handles all cases except one:
1306 a constructor call (including a C function returning a BLKmode struct)
1307 to initialize an argument. */
1308 if (stack_arg_under_construction)
1310 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1311 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
1313 rtx push_size = GEN_INT (args_size.constant);
1315 if (old_stack_level == 0)
1317 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1318 old_pending_adj = pending_stack_adjust;
1319 pending_stack_adjust = 0;
1320 /* stack_arg_under_construction says whether a stack arg is
1321 being constructed at the old stack level. Pushing the stack
1322 gets a clean outgoing argument block. */
1323 old_stack_arg_under_construction = stack_arg_under_construction;
1324 stack_arg_under_construction = 0;
1325 /* Make a new map for the new argument list. */
1326 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
1327 bzero (stack_usage_map, highest_outgoing_arg_in_use);
1328 highest_outgoing_arg_in_use = 0;
1330 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
1332 /* If argument evaluation might modify the stack pointer, copy the
1333 address of the argument list to a register. */
1334 for (i = 0; i < num_actuals; i++)
1335 if (args[i].pass_on_stack)
1337 argblock = copy_addr_to_reg (argblock);
1343 /* If we preallocated stack space, compute the address of each argument.
1344 We need not ensure it is a valid memory address here; it will be
1345 validized when it is used. */
1348 rtx arg_reg = argblock;
1351 if (GET_CODE (argblock) == PLUS)
1352 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1354 for (i = 0; i < num_actuals; i++)
1356 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1357 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1360 /* Skip this parm if it will not be passed on the stack. */
1361 if (! args[i].pass_on_stack && args[i].reg != 0)
1364 if (GET_CODE (offset) == CONST_INT)
1365 addr = plus_constant (arg_reg, INTVAL (offset));
1367 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1369 addr = plus_constant (addr, arg_offset);
1371 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1373 if (GET_CODE (slot_offset) == CONST_INT)
1374 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1376 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1378 addr = plus_constant (addr, arg_offset);
1380 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1384 #ifdef PUSH_ARGS_REVERSED
1385 #ifdef STACK_BOUNDARY
1386 /* If we push args individually in reverse order, perform stack alignment
1387 before the first push (the last arg). */
1389 anti_adjust_stack (GEN_INT (args_size.constant
1390 - original_args_size.constant));
1394 /* Don't try to defer pops if preallocating, not even from the first arg,
1395 since ARGBLOCK probably refers to the SP. */
1399 /* Get the function to call, in the form of RTL. */
1401 /* Get a SYMBOL_REF rtx for the function address. */
1402 funexp = XEXP (DECL_RTL (fndecl), 0);
1404 /* Generate an rtx (probably a pseudo-register) for the address. */
1406 funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1407 free_temp_slots (); /* FUNEXP can't be BLKmode */
1411 /* Figure out the register where the value, if any, will come back. */
1413 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1414 && ! structure_value_addr)
1416 if (pcc_struct_value)
1417 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1420 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1423 /* Precompute all register parameters. It isn't safe to compute anything
1424 once we have started filling any specific hard regs. */
1426 for (i = 0; i < num_actuals; i++)
1427 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1429 enum machine_mode mode;
1433 if (args[i].value == 0)
1435 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
1437 preserve_temp_slots (args[i].value);
1440 /* ANSI doesn't require a sequence point here,
1441 but PCC has one, so this will avoid some problems. */
1445 /* If we are to promote the function arg to a wider mode,
1447 mode = (GET_CODE (args[i].reg) == EXPR_LIST
1448 ? GET_MODE (XEXP (args[i].reg, 0)) : GET_MODE (args[i].reg));
1450 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) != mode)
1451 args[i].value = convert_to_mode (mode, args[i].value,
1455 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1456 /* The argument list is the property of the called routine and it
1457 may clobber it. If the fixed area has been used for previous
1458 parameters, we must save and restore it.
1460 Here we compute the boundary of the that needs to be saved, if any. */
1462 #ifdef ARGS_GROW_DOWNWARD
1463 for (i = 0; i < reg_parm_stack_space + 1; i++)
1465 for (i = 0; i < reg_parm_stack_space; i++)
1468 if (i >= highest_outgoing_arg_in_use
1469 || stack_usage_map[i] == 0)
1472 if (low_to_save == -1)
1478 if (low_to_save >= 0)
1480 int num_to_save = high_to_save - low_to_save + 1;
1481 enum machine_mode save_mode
1482 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1485 /* If we don't have the required alignment, must do this in BLKmode. */
1486 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1487 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1488 save_mode = BLKmode;
1490 stack_area = gen_rtx (MEM, save_mode,
1491 memory_address (save_mode,
1493 #ifdef ARGS_GROW_DOWNWARD
1494 plus_constant (argblock,
1497 plus_constant (argblock,
1501 if (save_mode == BLKmode)
1503 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1504 emit_block_move (validize_mem (save_area), stack_area,
1505 GEN_INT (num_to_save),
1506 PARM_BOUNDARY / BITS_PER_UNIT);
1510 save_area = gen_reg_rtx (save_mode);
1511 emit_move_insn (save_area, stack_area);
1517 /* Now store (and compute if necessary) all non-register parms.
1518 These come before register parms, since they can require block-moves,
1519 which could clobber the registers used for register parms.
1520 Parms which have partial registers are not stored here,
1521 but we do preallocate space here if they want that. */
1523 for (i = 0; i < num_actuals; i++)
1524 if (args[i].reg == 0 || args[i].pass_on_stack)
1525 store_one_arg (&args[i], argblock, may_be_alloca,
1526 args_size.var != 0, fndecl, reg_parm_stack_space);
1528 /* Now store any partially-in-registers parm.
1529 This is the last place a block-move can happen. */
1531 for (i = 0; i < num_actuals; i++)
1532 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1533 store_one_arg (&args[i], argblock, may_be_alloca,
1534 args_size.var != 0, fndecl, reg_parm_stack_space);
1536 #ifndef PUSH_ARGS_REVERSED
1537 #ifdef STACK_BOUNDARY
1538 /* If we pushed args in forward order, perform stack alignment
1539 after pushing the last arg. */
1541 anti_adjust_stack (GEN_INT (args_size.constant
1542 - original_args_size.constant));
1546 /* If register arguments require space on the stack and stack space
1547 was not preallocated, allocate stack space here for arguments
1548 passed in registers. */
1549 #if ! defined(ALLOCATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
1550 if (must_preallocate == 0 && reg_parm_stack_space > 0)
1551 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
1554 /* Pass the function the address in which to return a structure value. */
1555 if (structure_value_addr && ! structure_value_addr_parm)
1557 emit_move_insn (struct_value_rtx,
1559 force_operand (structure_value_addr,
1561 if (GET_CODE (struct_value_rtx) == REG)
1563 push_to_sequence (use_insns);
1564 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1565 use_insns = get_insns ();
1570 /* Now do the register loads required for any wholly-register parms or any
1571 parms which are passed both on the stack and in a register. Their
1572 expressions were already evaluated.
1574 Mark all register-parms as living through the call, putting these USE
1575 insns in a list headed by USE_INSNS. */
1577 for (i = 0; i < num_actuals; i++)
1579 rtx list = args[i].reg;
1580 int partial = args[i].partial;
1587 /* Process each register that needs to get this arg. */
1588 if (GET_CODE (list) == EXPR_LIST)
1589 reg = XEXP (list, 0), list = XEXP (list, 1);
1591 reg = list, list = 0;
1593 /* Set to non-zero if must move a word at a time, even if just one
1594 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1595 we just use a normal move insn. */
1596 nregs = (partial ? partial
1597 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1598 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1599 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1602 /* If simple case, just do move. If normal partial, store_one_arg
1603 has already loaded the register for us. In all other cases,
1604 load the register(s) from memory. */
1607 emit_move_insn (reg, args[i].value);
1608 else if (args[i].partial == 0 || args[i].pass_on_stack)
1609 move_block_to_reg (REGNO (reg),
1610 validize_mem (args[i].value), nregs,
1611 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1613 push_to_sequence (use_insns);
1615 emit_insn (gen_rtx (USE, VOIDmode, reg));
1617 use_regs (REGNO (reg), nregs);
1618 use_insns = get_insns ();
1621 /* PARTIAL referred only to the first register, so clear it for the
1627 /* Perform postincrements before actually calling the function. */
1630 /* All arguments and registers used for the call must be set up by now! */
1632 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1634 /* Generate the actual call instruction. */
1635 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1636 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1637 valreg, old_inhibit_defer_pop, use_insns, is_const);
1639 /* If call is cse'able, make appropriate pair of reg-notes around it.
1640 Test valreg so we don't crash; may safely ignore `const'
1641 if return type is void. */
1642 if (is_const && valreg != 0)
1645 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1648 /* Construct an "equal form" for the value which mentions all the
1649 arguments in order as well as the function name. */
1650 #ifdef PUSH_ARGS_REVERSED
1651 for (i = 0; i < num_actuals; i++)
1652 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1654 for (i = num_actuals - 1; i >= 0; i--)
1655 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1657 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1659 insns = get_insns ();
1662 emit_libcall_block (insns, temp, valreg, note);
1667 /* For calls to `setjmp', etc., inform flow.c it should complain
1668 if nonvolatile values are live. */
1672 emit_note (name, NOTE_INSN_SETJMP);
1673 current_function_calls_setjmp = 1;
1677 current_function_calls_longjmp = 1;
1679 /* Notice functions that cannot return.
1680 If optimizing, insns emitted below will be dead.
1681 If not optimizing, they will exist, which is useful
1682 if the user uses the `return' command in the debugger. */
1684 if (is_volatile || is_longjmp)
1687 /* If value type not void, return an rtx for the value. */
1689 /* If there are cleanups to be called, don't use a hard reg as target. */
1690 if (cleanups_this_call != old_cleanups
1691 && target && REG_P (target)
1692 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1695 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1698 target = const0_rtx;
1700 else if (structure_value_addr)
1702 if (target == 0 || GET_CODE (target) != MEM)
1704 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1705 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1706 structure_value_addr));
1707 MEM_IN_STRUCT_P (target)
1708 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1709 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1710 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1713 else if (pcc_struct_value)
1717 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1718 copy_to_reg (valreg));
1719 MEM_IN_STRUCT_P (target)
1720 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1721 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1722 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1724 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1725 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1726 copy_to_reg (valreg)));
1728 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1730 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1732 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
1733 && GET_MODE (target) == GET_MODE (valreg))
1734 /* TARGET and VALREG cannot be equal at this point because the latter
1735 would not have REG_FUNCTION_VALUE_P true, while the former would if
1736 it were referring to the same register.
1738 If they refer to the same register, this move will be a no-op, except
1739 when function inlining is being done. */
1740 emit_move_insn (target, valreg);
1742 target = copy_to_reg (valreg);
1744 #ifdef PROMOTE_FUNCTION_RETURN
1745 /* If we promoted this return value, make the proper SUBREG. */
1746 if (GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
1748 enum machine_mode mode = GET_MODE (target);
1749 int unsignedp = TREE_UNSIGNED (TREE_TYPE (exp));
1751 if (TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE
1752 || TREE_CODE (TREE_TYPE (exp)) == ENUMERAL_TYPE
1753 || TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE
1754 || TREE_CODE (TREE_TYPE (exp)) == CHAR_TYPE
1755 || TREE_CODE (TREE_TYPE (exp)) == REAL_TYPE
1756 || TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE
1757 || TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE)
1759 PROMOTE_MODE (mode, unsignedp, TREE_TYPE (exp));
1762 target = gen_rtx (SUBREG, TYPE_MODE (TREE_TYPE (exp)), target, 0);
1763 SUBREG_PROMOTED_VAR_P (target) = 1;
1764 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
1768 /* Perform all cleanups needed for the arguments of this call
1769 (i.e. destructors in C++). */
1770 expand_cleanups_to (old_cleanups);
1772 /* If size of args is variable or this was a constructor call for a stack
1773 argument, restore saved stack-pointer value. */
1775 if (old_stack_level)
1777 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1778 pending_stack_adjust = old_pending_adj;
1779 #ifdef ACCUMULATE_OUTGOING_ARGS
1780 stack_arg_under_construction = old_stack_arg_under_construction;
1781 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1782 stack_usage_map = initial_stack_usage_map;
1785 #ifdef ACCUMULATE_OUTGOING_ARGS
1788 #ifdef REG_PARM_STACK_SPACE
1791 enum machine_mode save_mode = GET_MODE (save_area);
1793 = gen_rtx (MEM, save_mode,
1794 memory_address (save_mode,
1795 #ifdef ARGS_GROW_DOWNWARD
1796 plus_constant (argblock, - high_to_save)
1798 plus_constant (argblock, low_to_save)
1802 if (save_mode != BLKmode)
1803 emit_move_insn (stack_area, save_area);
1805 emit_block_move (stack_area, validize_mem (save_area),
1806 GEN_INT (high_to_save - low_to_save + 1),
1807 PARM_BOUNDARY / BITS_PER_UNIT);
1811 /* If we saved any argument areas, restore them. */
1812 for (i = 0; i < num_actuals; i++)
1813 if (args[i].save_area)
1815 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1817 = gen_rtx (MEM, save_mode,
1818 memory_address (save_mode,
1819 XEXP (args[i].stack_slot, 0)));
1821 if (save_mode != BLKmode)
1822 emit_move_insn (stack_area, args[i].save_area);
1824 emit_block_move (stack_area, validize_mem (args[i].save_area),
1825 GEN_INT (args[i].size.constant),
1826 PARM_BOUNDARY / BITS_PER_UNIT);
1829 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1830 stack_usage_map = initial_stack_usage_map;
1834 /* If this was alloca, record the new stack level for nonlocal gotos.
1835 Check for the handler slots since we might not have a save area
1836 for non-local gotos. */
1838 if (may_be_alloca && nonlocal_goto_handler_slot != 0)
1839 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1847 /* Return an rtx which represents a suitable home on the stack
1848 given TYPE, the type of the argument looking for a home.
1849 This is called only for BLKmode arguments.
1851 SIZE is the size needed for this target.
1852 ARGS_ADDR is the address of the bottom of the argument block for this call.
1853 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1854 if this machine uses push insns. */
1857 target_for_arg (type, size, args_addr, offset)
1861 struct args_size offset;
1864 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1866 /* We do not call memory_address if possible,
1867 because we want to address as close to the stack
1868 as possible. For non-variable sized arguments,
1869 this will be stack-pointer relative addressing. */
1870 if (GET_CODE (offset_rtx) == CONST_INT)
1871 target = plus_constant (args_addr, INTVAL (offset_rtx));
1874 /* I have no idea how to guarantee that this
1875 will work in the presence of register parameters. */
1876 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1877 target = memory_address (QImode, target);
1880 return gen_rtx (MEM, BLKmode, target);
1884 /* Store a single argument for a function call
1885 into the register or memory area where it must be passed.
1886 *ARG describes the argument value and where to pass it.
1888 ARGBLOCK is the address of the stack-block for all the arguments,
1889 or 0 on a machine where arguments are pushed individually.
1891 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1892 so must be careful about how the stack is used.
1894 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1895 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1896 that we need not worry about saving and restoring the stack.
1898 FNDECL is the declaration of the function we are calling. */
1901 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl,
1902 reg_parm_stack_space)
1903 struct arg_data *arg;
1908 int reg_parm_stack_space;
1910 register tree pval = arg->tree_value;
1914 int i, lower_bound, upper_bound;
1916 if (TREE_CODE (pval) == ERROR_MARK)
1919 #ifdef ACCUMULATE_OUTGOING_ARGS
1920 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1921 save any previous data at that location. */
1922 if (argblock && ! variable_size && arg->stack)
1924 #ifdef ARGS_GROW_DOWNWARD
1925 /* stack_slot is negative, but we want to index stack_usage_map */
1926 /* with positive values. */
1927 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1928 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1932 lower_bound = upper_bound - arg->size.constant;
1934 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1935 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1939 upper_bound = lower_bound + arg->size.constant;
1942 for (i = lower_bound; i < upper_bound; i++)
1943 if (stack_usage_map[i]
1944 #ifdef REG_PARM_STACK_SPACE
1945 /* Don't store things in the fixed argument area at this point;
1946 it has already been saved. */
1947 && i > reg_parm_stack_space
1952 if (i != upper_bound)
1954 /* We need to make a save area. See what mode we can make it. */
1955 enum machine_mode save_mode
1956 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1958 = gen_rtx (MEM, save_mode,
1959 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1961 if (save_mode == BLKmode)
1963 arg->save_area = assign_stack_temp (BLKmode,
1964 arg->size.constant, 1);
1965 emit_block_move (validize_mem (arg->save_area), stack_area,
1966 GEN_INT (arg->size.constant),
1967 PARM_BOUNDARY / BITS_PER_UNIT);
1971 arg->save_area = gen_reg_rtx (save_mode);
1972 emit_move_insn (arg->save_area, stack_area);
1978 /* If this isn't going to be placed on both the stack and in registers,
1979 set up the register and number of words. */
1980 if (! arg->pass_on_stack)
1981 reg = arg->reg, partial = arg->partial;
1983 if (reg != 0 && partial == 0)
1984 /* Being passed entirely in a register. We shouldn't be called in
1988 /* If this is being partially passed in a register, but multiple locations
1989 are specified, we assume that the one partially used is the one that is
1991 if (reg && GET_CODE (reg) == EXPR_LIST)
1992 reg = XEXP (reg, 0);
1994 /* If this is being passes partially in a register, we can't evaluate
1995 it directly into its stack slot. Otherwise, we can. */
1996 if (arg->value == 0)
1998 #ifdef ACCUMULATE_OUTGOING_ARGS
1999 /* stack_arg_under_construction is nonzero if a function argument is
2000 being evaluated directly into the outgoing argument list and
2001 expand_call must take special action to preserve the argument list
2002 if it is called recursively.
2004 For scalar function arguments stack_usage_map is sufficient to
2005 determine which stack slots must be saved and restored. Scalar
2006 arguments in general have pass_on_stack == 0.
2008 If this argument is initialized by a function which takes the
2009 address of the argument (a C++ constructor or a C function
2010 returning a BLKmode structure), then stack_usage_map is
2011 insufficient and expand_call must push the stack around the
2012 function call. Such arguments have pass_on_stack == 1.
2014 Note that it is always safe to set stack_arg_under_construction,
2015 but this generates suboptimal code if set when not needed. */
2017 if (arg->pass_on_stack)
2018 stack_arg_under_construction++;
2020 arg->value = expand_expr (pval, partial ? NULL_RTX : arg->stack,
2022 #ifdef ACCUMULATE_OUTGOING_ARGS
2023 if (arg->pass_on_stack)
2024 stack_arg_under_construction--;
2028 /* Don't allow anything left on stack from computation
2029 of argument to alloca. */
2031 do_pending_stack_adjust ();
2033 if (arg->value == arg->stack)
2034 /* If the value is already in the stack slot, we are done. */
2036 else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
2040 /* Argument is a scalar, not entirely passed in registers.
2041 (If part is passed in registers, arg->partial says how much
2042 and emit_push_insn will take care of putting it there.)
2044 Push it, and if its size is less than the
2045 amount of space allocated to it,
2046 also bump stack pointer by the additional space.
2047 Note that in C the default argument promotions
2048 will prevent such mismatches. */
2050 size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
2051 /* Compute how much space the push instruction will push.
2052 On many machines, pushing a byte will advance the stack
2053 pointer by a halfword. */
2054 #ifdef PUSH_ROUNDING
2055 size = PUSH_ROUNDING (size);
2059 /* Compute how much space the argument should get:
2060 round up to a multiple of the alignment for arguments. */
2061 if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
2063 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
2064 / (PARM_BOUNDARY / BITS_PER_UNIT))
2065 * (PARM_BOUNDARY / BITS_PER_UNIT));
2067 /* This isn't already where we want it on the stack, so put it there.
2068 This can either be done with push or copy insns. */
2069 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2070 TREE_TYPE (pval), 0, 0, partial, reg,
2071 used - size, argblock, ARGS_SIZE_RTX (arg->offset));
2075 /* BLKmode, at least partly to be pushed. */
2077 register int excess;
2080 /* Pushing a nonscalar.
2081 If part is passed in registers, PARTIAL says how much
2082 and emit_push_insn will take care of putting it there. */
2084 /* Round its size up to a multiple
2085 of the allocation unit for arguments. */
2087 if (arg->size.var != 0)
2090 size_rtx = ARGS_SIZE_RTX (arg->size);
2094 register tree size = size_in_bytes (TREE_TYPE (pval));
2095 /* PUSH_ROUNDING has no effect on us, because
2096 emit_push_insn for BLKmode is careful to avoid it. */
2097 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
2098 + partial * UNITS_PER_WORD);
2099 size_rtx = expand_expr (size, NULL_RTX, VOIDmode, 0);
2102 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2103 TREE_TYPE (pval), size_rtx,
2104 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
2105 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
2109 /* Unless this is a partially-in-register argument, the argument is now
2112 ??? Note that this can change arg->value from arg->stack to
2113 arg->stack_slot and it matters when they are not the same.
2114 It isn't totally clear that this is correct in all cases. */
2116 arg->value = arg->stack_slot;
2118 /* Once we have pushed something, pops can't safely
2119 be deferred during the rest of the arguments. */
2122 /* ANSI doesn't require a sequence point here,
2123 but PCC has one, so this will avoid some problems. */
2126 /* Free any temporary slots made in processing this argument. */
2129 #ifdef ACCUMULATE_OUTGOING_ARGS
2130 /* Now mark the segment we just used. */
2131 if (argblock && ! variable_size && arg->stack)
2132 for (i = lower_bound; i < upper_bound; i++)
2133 stack_usage_map[i] = 1;