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 /* Mode for value; TYPE_MODE unless promoted. */
46 enum machine_mode mode;
47 /* Current RTL value for argument, or 0 if it isn't precomputed. */
49 /* Initially-compute RTL value for argument; only for const functions. */
51 /* Register to pass this argument in, 0 if passed on stack, or an
52 EXPR_LIST if the arg is to be copied into multiple different
55 /* If REG was promoted from the actual mode of the argument expression,
56 indicates whether the promotion is sign- or zero-extended. */
58 /* Number of registers to use. 0 means put the whole arg in registers.
59 Also 0 if not passed in registers. */
61 /* Non-zero if argument must be passed on stack.
62 Note that some arguments may be passed on the stack
63 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
64 pass_on_stack identifies arguments that *cannot* go in registers. */
66 /* Offset of this argument from beginning of stack-args. */
67 struct args_size offset;
68 /* Similar, but offset to the start of the stack slot. Different from
69 OFFSET if this arg pads downward. */
70 struct args_size slot_offset;
71 /* Size of this argument on the stack, rounded up for any padding it gets,
72 parts of the argument passed in registers do not count.
73 If REG_PARM_STACK_SPACE is defined, then register parms
74 are counted here as well. */
75 struct args_size size;
76 /* Location on the stack at which parameter should be stored. The store
77 has already been done if STACK == VALUE. */
79 /* Location on the stack of the start of this argument slot. This can
80 differ from STACK if this arg pads downward. This location is known
81 to be aligned to FUNCTION_ARG_BOUNDARY. */
83 #ifdef ACCUMULATE_OUTGOING_ARGS
84 /* Place that this stack area has been saved, if needed. */
87 #ifdef STRICT_ALIGNMENT
88 /* If an argument's alignment does not permit direct copying into registers,
89 copy in smaller-sized pieces into pseudos. These are stored in a
90 block pointed to by this field. The next field says how many
91 word-sized pseudos we made. */
97 #ifdef ACCUMULATE_OUTGOING_ARGS
98 /* A vector of one char per byte of stack space. A byte if non-zero if
99 the corresponding stack location has been used.
100 This vector is used to prevent a function call within an argument from
101 clobbering any stack already set up. */
102 static char *stack_usage_map;
104 /* Size of STACK_USAGE_MAP. */
105 static int highest_outgoing_arg_in_use;
107 /* stack_arg_under_construction is nonzero when an argument may be
108 initialized with a constructor call (including a C function that
109 returns a BLKmode struct) and expand_call must take special action
110 to make sure the object being constructed does not overlap the
111 argument list for the constructor call. */
112 int stack_arg_under_construction;
115 static void store_one_arg ();
116 extern enum machine_mode mode_for_size ();
118 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
121 If WHICH is 0, return 1 if EXP contains a call to any function.
122 Actually, we only need return 1 if evaluating EXP would require pushing
123 arguments on the stack, but that is too difficult to compute, so we just
124 assume any function call might require the stack. */
127 calls_function (exp, which)
132 int type = TREE_CODE_CLASS (TREE_CODE (exp));
133 int length = tree_code_length[(int) TREE_CODE (exp)];
135 /* Only expressions and references can contain calls. */
137 if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r'
141 switch (TREE_CODE (exp))
146 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
147 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
149 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
150 && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
154 /* Third operand is RTL. */
159 if (SAVE_EXPR_RTL (exp) != 0)
167 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
168 if (DECL_INITIAL (local) != 0
169 && calls_function (DECL_INITIAL (local), which))
173 register tree subblock;
175 for (subblock = BLOCK_SUBBLOCKS (exp);
177 subblock = TREE_CHAIN (subblock))
178 if (calls_function (subblock, which))
183 case METHOD_CALL_EXPR:
187 case WITH_CLEANUP_EXPR:
195 for (i = 0; i < length; i++)
196 if (TREE_OPERAND (exp, i) != 0
197 && calls_function (TREE_OPERAND (exp, i), which))
203 /* Force FUNEXP into a form suitable for the address of a CALL,
204 and return that as an rtx. Also load the static chain register
205 if FNDECL is a nested function.
207 USE_INSNS points to a variable holding a chain of USE insns
208 to which a USE of the static chain
209 register should be added, if required. */
212 prepare_call_address (funexp, fndecl, use_insns)
217 rtx static_chain_value = 0;
219 funexp = protect_from_queue (funexp, 0);
222 /* Get possible static chain value for nested function in C. */
223 static_chain_value = lookup_static_chain (fndecl);
225 /* Make a valid memory address and copy constants thru pseudo-regs,
226 but not for a constant address if -fno-function-cse. */
227 if (GET_CODE (funexp) != SYMBOL_REF)
228 funexp = memory_address (FUNCTION_MODE, funexp);
231 #ifndef NO_FUNCTION_CSE
232 if (optimize && ! flag_no_function_cse)
233 #ifdef NO_RECURSIVE_FUNCTION_CSE
234 if (fndecl != current_function_decl)
236 funexp = force_reg (Pmode, funexp);
240 if (static_chain_value != 0)
242 emit_move_insn (static_chain_rtx, static_chain_value);
244 /* Put the USE insn in the chain we were passed. It will later be
245 output immediately in front of the CALL insn. */
246 push_to_sequence (*use_insns);
247 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
248 *use_insns = get_insns ();
255 /* Generate instructions to call function FUNEXP,
256 and optionally pop the results.
257 The CALL_INSN is the first insn generated.
259 FUNTYPE is the data type of the function, or, for a library call,
260 the identifier for the name of the call. This is given to the
261 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
263 STACK_SIZE is the number of bytes of arguments on the stack,
264 rounded up to STACK_BOUNDARY; zero if the size is variable.
265 This is both to put into the call insn and
266 to generate explicit popping code if necessary.
268 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
269 It is zero if this call doesn't want a structure value.
271 NEXT_ARG_REG is the rtx that results from executing
272 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
273 just after all the args have had their registers assigned.
274 This could be whatever you like, but normally it is the first
275 arg-register beyond those used for args in this call,
276 or 0 if all the arg-registers are used in this call.
277 It is passed on to `gen_call' so you can put this info in the call insn.
279 VALREG is a hard register in which a value is returned,
280 or 0 if the call does not return a value.
282 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
283 the args to this call were processed.
284 We restore `inhibit_defer_pop' to that value.
286 USE_INSNS is a chain of USE insns to be emitted immediately before
287 the actual CALL insn.
289 IS_CONST is true if this is a `const' call. */
292 emit_call_1 (funexp, funtype, stack_size, struct_value_size, next_arg_reg,
293 valreg, old_inhibit_defer_pop, use_insns, is_const)
297 int struct_value_size;
300 int old_inhibit_defer_pop;
304 rtx stack_size_rtx = GEN_INT (stack_size);
305 rtx struct_value_size_rtx = GEN_INT (struct_value_size);
307 int already_popped = 0;
309 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
310 and we don't want to load it into a register as an optimization,
311 because prepare_call_address already did it if it should be done. */
312 if (GET_CODE (funexp) != SYMBOL_REF)
313 funexp = memory_address (FUNCTION_MODE, funexp);
315 #ifndef ACCUMULATE_OUTGOING_ARGS
316 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
317 if (HAVE_call_pop && HAVE_call_value_pop
318 && (RETURN_POPS_ARGS (funtype, stack_size) > 0 || stack_size == 0))
320 rtx n_pop = GEN_INT (RETURN_POPS_ARGS (funtype, stack_size));
323 /* If this subroutine pops its own args, record that in the call insn
324 if possible, for the sake of frame pointer elimination. */
326 pat = gen_call_value_pop (valreg,
327 gen_rtx (MEM, FUNCTION_MODE, funexp),
328 stack_size_rtx, next_arg_reg, n_pop);
330 pat = gen_call_pop (gen_rtx (MEM, FUNCTION_MODE, funexp),
331 stack_size_rtx, next_arg_reg, n_pop);
333 emit_call_insn (pat);
340 #if defined (HAVE_call) && defined (HAVE_call_value)
341 if (HAVE_call && HAVE_call_value)
344 emit_call_insn (gen_call_value (valreg,
345 gen_rtx (MEM, FUNCTION_MODE, funexp),
346 stack_size_rtx, next_arg_reg,
349 emit_call_insn (gen_call (gen_rtx (MEM, FUNCTION_MODE, funexp),
350 stack_size_rtx, next_arg_reg,
351 struct_value_size_rtx));
357 /* Find the CALL insn we just emitted and write the USE insns before it. */
358 for (call_insn = get_last_insn ();
359 call_insn && GET_CODE (call_insn) != CALL_INSN;
360 call_insn = PREV_INSN (call_insn))
366 /* Put the USE insns before the CALL. */
367 emit_insns_before (use_insns, call_insn);
369 /* If this is a const call, then set the insn's unchanging bit. */
371 CONST_CALL_P (call_insn) = 1;
373 #ifndef ACCUMULATE_OUTGOING_ARGS
374 /* If returning from the subroutine does not automatically pop the args,
375 we need an instruction to pop them sooner or later.
376 Perhaps do it now; perhaps just record how much space to pop later.
378 If returning from the subroutine does pop the args, indicate that the
379 stack pointer will be changed. */
381 if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0)
384 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
385 stack_size -= RETURN_POPS_ARGS (funtype, stack_size);
386 stack_size_rtx = GEN_INT (stack_size);
391 if (flag_defer_pop && inhibit_defer_pop == 0)
392 pending_stack_adjust += stack_size;
394 adjust_stack (stack_size_rtx);
398 inhibit_defer_pop = old_inhibit_defer_pop;
401 /* Generate all the code for a function call
402 and return an rtx for its value.
403 Store the value in TARGET (specified as an rtx) if convenient.
404 If the value is stored in TARGET then TARGET is returned.
405 If IGNORE is nonzero, then we ignore the value of the function call. */
408 expand_call (exp, target, ignore)
413 /* List of actual parameters. */
414 tree actparms = TREE_OPERAND (exp, 1);
415 /* RTX for the function to be called. */
417 /* Tree node for the function to be called (not the address!). */
419 /* Data type of the function. */
421 /* Declaration of the function being called,
422 or 0 if the function is computed (not known by name). */
426 /* Register in which non-BLKmode value will be returned,
427 or 0 if no value or if value is BLKmode. */
429 /* Address where we should return a BLKmode value;
430 0 if value not BLKmode. */
431 rtx structure_value_addr = 0;
432 /* Nonzero if that address is being passed by treating it as
433 an extra, implicit first parameter. Otherwise,
434 it is passed by being copied directly into struct_value_rtx. */
435 int structure_value_addr_parm = 0;
436 /* Size of aggregate value wanted, or zero if none wanted
437 or if we are using the non-reentrant PCC calling convention
438 or expecting the value in registers. */
439 int struct_value_size = 0;
440 /* Nonzero if called function returns an aggregate in memory PCC style,
441 by returning the address of where to find it. */
442 int pcc_struct_value = 0;
444 /* Number of actual parameters in this call, including struct value addr. */
446 /* Number of named args. Args after this are anonymous ones
447 and they must all go on the stack. */
449 /* Count arg position in order args appear. */
452 /* Vector of information about each argument.
453 Arguments are numbered in the order they will be pushed,
454 not the order they are written. */
455 struct arg_data *args;
457 /* Total size in bytes of all the stack-parms scanned so far. */
458 struct args_size args_size;
459 /* Size of arguments before any adjustments (such as rounding). */
460 struct args_size original_args_size;
461 /* Data on reg parms scanned so far. */
462 CUMULATIVE_ARGS args_so_far;
463 /* Nonzero if a reg parm has been scanned. */
466 /* Nonzero if we must avoid push-insns in the args for this call.
467 If stack space is allocated for register parameters, but not by the
468 caller, then it is preallocated in the fixed part of the stack frame.
469 So the entire argument block must then be preallocated (i.e., we
470 ignore PUSH_ROUNDING in that case). */
472 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
473 int must_preallocate = 1;
476 int must_preallocate = 0;
478 int must_preallocate = 1;
482 /* Size of the stack reserved for parameter registers. */
483 int reg_parm_stack_space = 0;
485 /* 1 if scanning parms front to back, -1 if scanning back to front. */
487 /* Address of space preallocated for stack parms
488 (on machines that lack push insns), or 0 if space not preallocated. */
491 /* Nonzero if it is plausible that this is a call to alloca. */
493 /* Nonzero if this is a call to setjmp or a related function. */
495 /* Nonzero if this is a call to `longjmp'. */
497 /* Nonzero if this is a call to an inline function. */
498 int is_integrable = 0;
499 /* Nonzero if this is a call to a `const' function.
500 Note that only explicitly named functions are handled as `const' here. */
502 /* Nonzero if this is a call to a `volatile' function. */
504 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
505 /* Define the boundary of the register parm stack space that needs to be
507 int low_to_save = -1, high_to_save;
508 rtx save_area = 0; /* Place that it is saved */
511 #ifdef ACCUMULATE_OUTGOING_ARGS
512 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
513 char *initial_stack_usage_map = stack_usage_map;
516 rtx old_stack_level = 0;
518 int old_stack_arg_under_construction;
519 int old_inhibit_defer_pop = inhibit_defer_pop;
520 tree old_cleanups = cleanups_this_call;
527 /* See if we can find a DECL-node for the actual function.
528 As a result, decide whether this is a call to an integrable function. */
530 p = TREE_OPERAND (exp, 0);
531 if (TREE_CODE (p) == ADDR_EXPR)
533 fndecl = TREE_OPERAND (p, 0);
534 if (TREE_CODE (fndecl) != FUNCTION_DECL)
536 /* May still be a `const' function if it is
537 a call through a pointer-to-const.
538 But we don't handle that. */
544 && fndecl != current_function_decl
545 && DECL_SAVED_INSNS (fndecl))
547 else if (! TREE_ADDRESSABLE (fndecl))
549 /* In case this function later becomes inlinable,
550 record that there was already a non-inline call to it.
552 Use abstraction instead of setting TREE_ADDRESSABLE
554 if (DECL_INLINE (fndecl) && extra_warnings && !flag_no_inline)
555 warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline");
556 mark_addressable (fndecl);
559 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
560 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
565 is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
567 #ifdef REG_PARM_STACK_SPACE
568 #ifdef MAYBE_REG_PARM_STACK_SPACE
569 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
571 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
575 /* Warn if this value is an aggregate type,
576 regardless of which calling convention we are using for it. */
577 if (warn_aggregate_return
578 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
579 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
580 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
581 warning ("function call has aggregate value");
583 /* Set up a place to return a structure. */
585 /* Cater to broken compilers. */
586 if (aggregate_value_p (exp))
588 /* This call returns a big structure. */
591 #ifdef PCC_STATIC_STRUCT_RETURN
592 if (flag_pcc_struct_return)
594 pcc_struct_value = 1;
595 is_integrable = 0; /* Easier than making that case work right. */
600 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
602 if (struct_value_size < 0)
605 if (target && GET_CODE (target) == MEM)
606 structure_value_addr = XEXP (target, 0);
609 /* Assign a temporary on the stack to hold the value. */
611 /* For variable-sized objects, we must be called with a target
612 specified. If we were to allocate space on the stack here,
613 we would have no way of knowing when to free it. */
616 = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
622 /* If called function is inline, try to integrate it. */
627 rtx before_call = get_last_insn ();
629 temp = expand_inline_function (fndecl, actparms, target,
630 ignore, TREE_TYPE (exp),
631 structure_value_addr);
633 /* If inlining succeeded, return. */
634 if ((HOST_WIDE_INT) temp != -1)
636 /* Perform all cleanups needed for the arguments of this call
637 (i.e. destructors in C++). It is ok if these destructors
638 clobber RETURN_VALUE_REG, because the only time we care about
639 this is when TARGET is that register. But in C++, we take
640 care to never return that register directly. */
641 expand_cleanups_to (old_cleanups);
643 #ifdef ACCUMULATE_OUTGOING_ARGS
644 /* If the outgoing argument list must be preserved, push
645 the stack before executing the inlined function if it
648 for (i = reg_parm_stack_space - 1; i >= 0; i--)
649 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
652 if (stack_arg_under_construction || i >= 0)
654 rtx insn = NEXT_INSN (before_call), seq;
656 /* Look for a call in the inline function code.
657 If OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) is
658 nonzero then there is a call and it is not necessary
659 to scan the insns. */
661 if (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) == 0)
662 for (; insn; insn = NEXT_INSN (insn))
663 if (GET_CODE (insn) == CALL_INSN)
668 /* Reserve enough stack space so that the largest
669 argument list of any function call in the inline
670 function does not overlap the argument list being
671 evaluated. This is usually an overestimate because
672 allocate_dynamic_stack_space reserves space for an
673 outgoing argument list in addition to the requested
674 space, but there is no way to ask for stack space such
675 that an argument list of a certain length can be
676 safely constructed. */
678 int adjust = OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl));
679 #ifdef REG_PARM_STACK_SPACE
680 /* Add the stack space reserved for register arguments
681 in the inline function. What is really needed is the
682 largest value of reg_parm_stack_space in the inline
683 function, but that is not available. Using the current
684 value of reg_parm_stack_space is wrong, but gives
685 correct results on all supported machines. */
686 adjust += reg_parm_stack_space;
689 emit_stack_save (SAVE_BLOCK, &old_stack_level, 0);
690 allocate_dynamic_stack_space (GEN_INT (adjust),
691 NULL_RTX, BITS_PER_UNIT);
694 emit_insns_before (seq, NEXT_INSN (before_call));
695 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
700 /* If the result is equivalent to TARGET, return TARGET to simplify
701 checks in store_expr. They can be equivalent but not equal in the
702 case of a function that returns BLKmode. */
703 if (temp != target && rtx_equal_p (temp, target))
708 /* If inlining failed, mark FNDECL as needing to be compiled
709 separately after all. */
710 mark_addressable (fndecl);
713 /* When calling a const function, we must pop the stack args right away,
714 so that the pop is deleted or moved with the call. */
718 function_call_count++;
720 if (fndecl && DECL_NAME (fndecl))
721 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
724 /* Unless it's a call to a specific function that isn't alloca,
725 if it has one argument, we must assume it might be alloca. */
728 (!(fndecl != 0 && strcmp (name, "alloca"))
730 && TREE_CHAIN (actparms) == 0);
732 /* We assume that alloca will always be called by name. It
733 makes no sense to pass it as a pointer-to-function to
734 anything that does not understand its behavior. */
736 (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
738 && ! strcmp (name, "alloca"))
739 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
741 && ! strcmp (name, "__builtin_alloca"))));
744 /* See if this is a call to a function that can return more than once
745 or a call to longjmp. */
750 if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
755 tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
761 && (! strcmp (tname, "setjmp")
762 || ! strcmp (tname, "setjmp_syscall")))
764 && ! strcmp (tname, "sigsetjmp"))
766 && ! strcmp (tname, "savectx")));
768 && ! strcmp (tname, "siglongjmp"))
771 else if ((tname[0] == 'q' && tname[1] == 's'
772 && ! strcmp (tname, "qsetjmp"))
773 || (tname[0] == 'v' && tname[1] == 'f'
774 && ! strcmp (tname, "vfork")))
777 else if (tname[0] == 'l' && tname[1] == 'o'
778 && ! strcmp (tname, "longjmp"))
783 current_function_calls_alloca = 1;
785 /* Don't let pending stack adjusts add up to too much.
786 Also, do all pending adjustments now
787 if there is any chance this might be a call to alloca. */
789 if (pending_stack_adjust >= 32
790 || (pending_stack_adjust > 0 && may_be_alloca))
791 do_pending_stack_adjust ();
793 /* Operand 0 is a pointer-to-function; get the type of the function. */
794 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
795 if (TREE_CODE (funtype) != POINTER_TYPE)
797 funtype = TREE_TYPE (funtype);
799 /* Push the temporary stack slot level so that we can free temporaries used
800 by each of the arguments separately. */
803 /* Start updating where the next arg would go. */
804 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX);
806 /* If struct_value_rtx is 0, it means pass the address
807 as if it were an extra parameter. */
808 if (structure_value_addr && struct_value_rtx == 0)
810 #ifdef ACCUMULATE_OUTGOING_ARGS
811 /* If the stack will be adjusted, make sure the structure address
812 does not refer to virtual_outgoing_args_rtx. */
813 rtx temp = (stack_arg_under_construction
814 ? copy_addr_to_reg (structure_value_addr)
815 : force_reg (Pmode, structure_value_addr));
817 rtx temp = force_reg (Pmode, structure_value_addr);
821 = tree_cons (error_mark_node,
822 make_tree (build_pointer_type (TREE_TYPE (funtype)),
825 structure_value_addr_parm = 1;
828 /* Count the arguments and set NUM_ACTUALS. */
829 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
832 /* Compute number of named args.
833 Normally, don't include the last named arg if anonymous args follow.
834 (If no anonymous args follow, the result of list_length
835 is actually one too large.)
837 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
838 place unnamed args that were passed in registers into the stack. So
839 treat all args as named. This allows the insns emitting for a specific
840 argument list to be independent of the function declaration.
842 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
843 way to pass unnamed args in registers, so we must force them into
845 #ifndef SETUP_INCOMING_VARARGS
846 if (TYPE_ARG_TYPES (funtype) != 0)
848 = list_length (TYPE_ARG_TYPES (funtype)) - 1
849 /* Count the struct value address, if it is passed as a parm. */
850 + structure_value_addr_parm;
853 /* If we know nothing, treat all args as named. */
854 n_named_args = num_actuals;
856 /* Make a vector to hold all the information about each arg. */
857 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
858 bzero (args, num_actuals * sizeof (struct arg_data));
860 args_size.constant = 0;
863 /* In this loop, we consider args in the order they are written.
864 We fill up ARGS from the front of from the back if necessary
865 so that in any case the first arg to be pushed ends up at the front. */
867 #ifdef PUSH_ARGS_REVERSED
868 i = num_actuals - 1, inc = -1;
869 /* In this case, must reverse order of args
870 so that we compute and push the last arg first. */
875 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
876 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
878 tree type = TREE_TYPE (TREE_VALUE (p));
879 enum machine_mode mode;
881 args[i].tree_value = TREE_VALUE (p);
883 /* Replace erroneous argument with constant zero. */
884 if (type == error_mark_node || TYPE_SIZE (type) == 0)
885 args[i].tree_value = integer_zero_node, type = integer_type_node;
887 /* Decide where to pass this arg.
889 args[i].reg is nonzero if all or part is passed in registers.
891 args[i].partial is nonzero if part but not all is passed in registers,
892 and the exact value says how many words are passed in registers.
894 args[i].pass_on_stack is nonzero if the argument must at least be
895 computed on the stack. It may then be loaded back into registers
896 if args[i].reg is nonzero.
898 These decisions are driven by the FUNCTION_... macros and must agree
899 with those made by function.c. */
901 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
902 /* See if this argument should be passed by invisible reference. */
903 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
904 argpos < n_named_args))
906 /* We make a copy of the object and pass the address to the function
910 if (TYPE_SIZE (type) == 0
911 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
913 /* This is a variable-sized object. Make space on the stack
915 rtx size_rtx = expand_expr (size_in_bytes (type), NULL_RTX,
918 if (old_stack_level == 0)
920 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
921 old_pending_adj = pending_stack_adjust;
922 pending_stack_adjust = 0;
925 copy = gen_rtx (MEM, BLKmode,
926 allocate_dynamic_stack_space (size_rtx, NULL_RTX,
931 int size = int_size_in_bytes (type);
932 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
935 store_expr (args[i].tree_value, copy, 0);
937 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
938 make_tree (type, copy));
939 type = build_pointer_type (type);
943 mode = TYPE_MODE (type);
945 #ifdef PROMOTE_FUNCTION_ARGS
946 /* Compute the mode in which the arg is actually to be extended to. */
947 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
948 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
949 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
950 || TREE_CODE (type) == OFFSET_TYPE)
952 int unsignedp = TREE_UNSIGNED (type);
953 PROMOTE_MODE (mode, unsignedp, type);
954 args[i].unsignedp = unsignedp;
959 args[i].reg = FUNCTION_ARG (args_so_far, mode, type,
960 argpos < n_named_args);
961 #ifdef FUNCTION_ARG_PARTIAL_NREGS
964 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, type,
965 argpos < n_named_args);
968 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
970 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
971 we are to pass this arg in the register(s) designated by FOO, but
972 also to pass it in the stack. */
973 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
974 && XEXP (args[i].reg, 0) == 0)
975 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
977 /* If this is an addressable type, we must preallocate the stack
978 since we must evaluate the object into its final location.
980 If this is to be passed in both registers and the stack, it is simpler
982 if (TREE_ADDRESSABLE (type)
983 || (args[i].pass_on_stack && args[i].reg != 0))
984 must_preallocate = 1;
986 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
987 we cannot consider this function call constant. */
988 if (TREE_ADDRESSABLE (type))
991 /* Compute the stack-size of this argument. */
992 if (args[i].reg == 0 || args[i].partial != 0
993 #ifdef REG_PARM_STACK_SPACE
994 || reg_parm_stack_space > 0
996 || args[i].pass_on_stack)
997 locate_and_pad_parm (mode, type,
998 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1003 fndecl, &args_size, &args[i].offset,
1006 #ifndef ARGS_GROW_DOWNWARD
1007 args[i].slot_offset = args_size;
1010 #ifndef REG_PARM_STACK_SPACE
1011 /* If a part of the arg was put into registers,
1012 don't include that part in the amount pushed. */
1013 if (! args[i].pass_on_stack)
1014 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1015 / (PARM_BOUNDARY / BITS_PER_UNIT)
1016 * (PARM_BOUNDARY / BITS_PER_UNIT));
1019 /* Update ARGS_SIZE, the total stack space for args so far. */
1021 args_size.constant += args[i].size.constant;
1022 if (args[i].size.var)
1024 ADD_PARM_SIZE (args_size, args[i].size.var);
1027 /* Since the slot offset points to the bottom of the slot,
1028 we must record it after incrementing if the args grow down. */
1029 #ifdef ARGS_GROW_DOWNWARD
1030 args[i].slot_offset = args_size;
1032 args[i].slot_offset.constant = -args_size.constant;
1035 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
1039 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1040 have been used, etc. */
1042 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
1043 argpos < n_named_args);
1046 #ifdef FINAL_REG_PARM_STACK_SPACE
1047 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
1051 /* Compute the actual size of the argument block required. The variable
1052 and constant sizes must be combined, the size may have to be rounded,
1053 and there may be a minimum required size. */
1055 original_args_size = args_size;
1058 /* If this function requires a variable-sized argument list, don't try to
1059 make a cse'able block for this call. We may be able to do this
1060 eventually, but it is too complicated to keep track of what insns go
1061 in the cse'able block and which don't. */
1064 must_preallocate = 1;
1066 args_size.var = ARGS_SIZE_TREE (args_size);
1067 args_size.constant = 0;
1069 #ifdef STACK_BOUNDARY
1070 if (STACK_BOUNDARY != BITS_PER_UNIT)
1071 args_size.var = round_up (args_size.var, STACK_BYTES);
1074 #ifdef REG_PARM_STACK_SPACE
1075 if (reg_parm_stack_space > 0)
1078 = size_binop (MAX_EXPR, args_size.var,
1079 size_int (REG_PARM_STACK_SPACE (fndecl)));
1081 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1082 /* The area corresponding to register parameters is not to count in
1083 the size of the block we need. So make the adjustment. */
1085 = size_binop (MINUS_EXPR, args_size.var,
1086 size_int (reg_parm_stack_space));
1093 #ifdef STACK_BOUNDARY
1094 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
1095 / STACK_BYTES) * STACK_BYTES);
1098 #ifdef REG_PARM_STACK_SPACE
1099 args_size.constant = MAX (args_size.constant,
1100 reg_parm_stack_space);
1101 #ifdef MAYBE_REG_PARM_STACK_SPACE
1102 if (reg_parm_stack_space == 0)
1103 args_size.constant = 0;
1105 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1106 args_size.constant -= reg_parm_stack_space;
1111 /* See if we have or want to preallocate stack space.
1113 If we would have to push a partially-in-regs parm
1114 before other stack parms, preallocate stack space instead.
1116 If the size of some parm is not a multiple of the required stack
1117 alignment, we must preallocate.
1119 If the total size of arguments that would otherwise create a copy in
1120 a temporary (such as a CALL) is more than half the total argument list
1121 size, preallocation is faster.
1123 Another reason to preallocate is if we have a machine (like the m88k)
1124 where stack alignment is required to be maintained between every
1125 pair of insns, not just when the call is made. However, we assume here
1126 that such machines either do not have push insns (and hence preallocation
1127 would occur anyway) or the problem is taken care of with
1130 if (! must_preallocate)
1132 int partial_seen = 0;
1133 int copy_to_evaluate_size = 0;
1135 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1137 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1139 else if (partial_seen && args[i].reg == 0)
1140 must_preallocate = 1;
1142 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1143 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1144 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1145 || TREE_CODE (args[i].tree_value) == COND_EXPR
1146 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1147 copy_to_evaluate_size
1148 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1151 if (copy_to_evaluate_size * 2 >= args_size.constant
1152 && args_size.constant > 0)
1153 must_preallocate = 1;
1156 /* If the structure value address will reference the stack pointer, we must
1157 stabilize it. We don't need to do this if we know that we are not going
1158 to adjust the stack pointer in processing this call. */
1160 if (structure_value_addr
1161 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1162 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1164 #ifndef ACCUMULATE_OUTGOING_ARGS
1165 || args_size.constant
1168 structure_value_addr = copy_to_reg (structure_value_addr);
1170 /* If this function call is cse'able, precompute all the parameters.
1171 Note that if the parameter is constructed into a temporary, this will
1172 cause an additional copy because the parameter will be constructed
1173 into a temporary location and then copied into the outgoing arguments.
1174 If a parameter contains a call to alloca and this function uses the
1175 stack, precompute the parameter. */
1177 /* If we preallocated the stack space, and some arguments must be passed
1178 on the stack, then we must precompute any parameter which contains a
1179 function call which will store arguments on the stack.
1180 Otherwise, evaluating the parameter may clobber previous parameters
1181 which have already been stored into the stack. */
1183 for (i = 0; i < num_actuals; i++)
1185 || ((args_size.var != 0 || args_size.constant != 0)
1186 && calls_function (args[i].tree_value, 1))
1187 || (must_preallocate && (args_size.var != 0 || args_size.constant != 0)
1188 && calls_function (args[i].tree_value, 0)))
1190 args[i].initial_value = args[i].value
1191 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1193 if (GET_MODE (args[i].value ) != VOIDmode
1194 && GET_MODE (args[i].value) != args[i].mode)
1195 args[i].value = convert_to_mode (args[i].mode, args[i].value,
1197 preserve_temp_slots (args[i].value);
1201 /* ANSI doesn't require a sequence point here,
1202 but PCC has one, so this will avoid some problems. */
1206 /* Now we are about to start emitting insns that can be deleted
1207 if a libcall is deleted. */
1211 /* If we have no actual push instructions, or shouldn't use them,
1212 make space for all args right now. */
1214 if (args_size.var != 0)
1216 if (old_stack_level == 0)
1218 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1219 old_pending_adj = pending_stack_adjust;
1220 pending_stack_adjust = 0;
1221 #ifdef ACCUMULATE_OUTGOING_ARGS
1222 /* stack_arg_under_construction says whether a stack arg is
1223 being constructed at the old stack level. Pushing the stack
1224 gets a clean outgoing argument block. */
1225 old_stack_arg_under_construction = stack_arg_under_construction;
1226 stack_arg_under_construction = 0;
1229 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1231 else if (must_preallocate)
1233 /* Note that we must go through the motions of allocating an argument
1234 block even if the size is zero because we may be storing args
1235 in the area reserved for register arguments, which may be part of
1237 int needed = args_size.constant;
1239 #ifdef ACCUMULATE_OUTGOING_ARGS
1240 /* Store the maximum argument space used. It will be pushed by the
1243 Since the stack pointer will never be pushed, it is possible for
1244 the evaluation of a parm to clobber something we have already
1245 written to the stack. Since most function calls on RISC machines
1246 do not use the stack, this is uncommon, but must work correctly.
1248 Therefore, we save any area of the stack that was already written
1249 and that we are using. Here we set up to do this by making a new
1250 stack usage map from the old one. The actual save will be done
1253 Another approach might be to try to reorder the argument
1254 evaluations to avoid this conflicting stack usage. */
1256 if (needed > current_function_outgoing_args_size)
1257 current_function_outgoing_args_size = needed;
1259 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1260 /* Since we will be writing into the entire argument area, the
1261 map must be allocated for its entire size, not just the part that
1262 is the responsibility of the caller. */
1263 needed += reg_parm_stack_space;
1266 #ifdef ARGS_GROW_DOWNWARD
1267 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1270 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1272 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1274 if (initial_highest_arg_in_use)
1275 bcopy (initial_stack_usage_map, stack_usage_map,
1276 initial_highest_arg_in_use);
1278 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1279 bzero (&stack_usage_map[initial_highest_arg_in_use],
1280 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1283 /* The address of the outgoing argument list must not be copied to a
1284 register here, because argblock would be left pointing to the
1285 wrong place after the call to allocate_dynamic_stack_space below. */
1287 argblock = virtual_outgoing_args_rtx;
1289 #else /* not ACCUMULATE_OUTGOING_ARGS */
1290 if (inhibit_defer_pop == 0)
1292 /* Try to reuse some or all of the pending_stack_adjust
1293 to get this space. Maybe we can avoid any pushing. */
1294 if (needed > pending_stack_adjust)
1296 needed -= pending_stack_adjust;
1297 pending_stack_adjust = 0;
1301 pending_stack_adjust -= needed;
1305 /* Special case this because overhead of `push_block' in this
1306 case is non-trivial. */
1308 argblock = virtual_outgoing_args_rtx;
1310 argblock = push_block (GEN_INT (needed), 0, 0);
1312 /* We only really need to call `copy_to_reg' in the case where push
1313 insns are going to be used to pass ARGBLOCK to a function
1314 call in ARGS. In that case, the stack pointer changes value
1315 from the allocation point to the call point, and hence
1316 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1317 But might as well always do it. */
1318 argblock = copy_to_reg (argblock);
1319 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1323 #ifdef ACCUMULATE_OUTGOING_ARGS
1324 /* The save/restore code in store_one_arg handles all cases except one:
1325 a constructor call (including a C function returning a BLKmode struct)
1326 to initialize an argument. */
1327 if (stack_arg_under_construction)
1329 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1330 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
1332 rtx push_size = GEN_INT (args_size.constant);
1334 if (old_stack_level == 0)
1336 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1337 old_pending_adj = pending_stack_adjust;
1338 pending_stack_adjust = 0;
1339 /* stack_arg_under_construction says whether a stack arg is
1340 being constructed at the old stack level. Pushing the stack
1341 gets a clean outgoing argument block. */
1342 old_stack_arg_under_construction = stack_arg_under_construction;
1343 stack_arg_under_construction = 0;
1344 /* Make a new map for the new argument list. */
1345 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
1346 bzero (stack_usage_map, highest_outgoing_arg_in_use);
1347 highest_outgoing_arg_in_use = 0;
1349 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
1351 /* If argument evaluation might modify the stack pointer, copy the
1352 address of the argument list to a register. */
1353 for (i = 0; i < num_actuals; i++)
1354 if (args[i].pass_on_stack)
1356 argblock = copy_addr_to_reg (argblock);
1362 /* If we preallocated stack space, compute the address of each argument.
1363 We need not ensure it is a valid memory address here; it will be
1364 validized when it is used. */
1367 rtx arg_reg = argblock;
1370 if (GET_CODE (argblock) == PLUS)
1371 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1373 for (i = 0; i < num_actuals; i++)
1375 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1376 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1379 /* Skip this parm if it will not be passed on the stack. */
1380 if (! args[i].pass_on_stack && args[i].reg != 0)
1383 if (GET_CODE (offset) == CONST_INT)
1384 addr = plus_constant (arg_reg, INTVAL (offset));
1386 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1388 addr = plus_constant (addr, arg_offset);
1389 args[i].stack = gen_rtx (MEM, args[i].mode, addr);
1391 if (GET_CODE (slot_offset) == CONST_INT)
1392 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1394 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1396 addr = plus_constant (addr, arg_offset);
1397 args[i].stack_slot = gen_rtx (MEM, args[i].mode, addr);
1401 #ifdef PUSH_ARGS_REVERSED
1402 #ifdef STACK_BOUNDARY
1403 /* If we push args individually in reverse order, perform stack alignment
1404 before the first push (the last arg). */
1406 anti_adjust_stack (GEN_INT (args_size.constant
1407 - original_args_size.constant));
1411 /* Don't try to defer pops if preallocating, not even from the first arg,
1412 since ARGBLOCK probably refers to the SP. */
1416 /* Get the function to call, in the form of RTL. */
1418 /* Get a SYMBOL_REF rtx for the function address. */
1419 funexp = XEXP (DECL_RTL (fndecl), 0);
1421 /* Generate an rtx (probably a pseudo-register) for the address. */
1423 funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1424 free_temp_slots (); /* FUNEXP can't be BLKmode */
1428 /* Figure out the register where the value, if any, will come back. */
1430 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1431 && ! structure_value_addr)
1433 if (pcc_struct_value)
1434 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1437 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1440 /* Precompute all register parameters. It isn't safe to compute anything
1441 once we have started filling any specific hard regs. */
1443 for (i = 0; i < num_actuals; i++)
1444 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1448 if (args[i].value == 0)
1450 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
1452 preserve_temp_slots (args[i].value);
1455 /* ANSI doesn't require a sequence point here,
1456 but PCC has one, so this will avoid some problems. */
1460 /* If we are to promote the function arg to a wider mode,
1463 if (GET_MODE (args[i].value) != VOIDmode
1464 && GET_MODE (args[i].value) != args[i].mode)
1465 args[i].value = convert_to_mode (args[i].mode, args[i].value,
1469 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1470 /* The argument list is the property of the called routine and it
1471 may clobber it. If the fixed area has been used for previous
1472 parameters, we must save and restore it.
1474 Here we compute the boundary of the that needs to be saved, if any. */
1476 #ifdef ARGS_GROW_DOWNWARD
1477 for (i = 0; i < reg_parm_stack_space + 1; i++)
1479 for (i = 0; i < reg_parm_stack_space; i++)
1482 if (i >= highest_outgoing_arg_in_use
1483 || stack_usage_map[i] == 0)
1486 if (low_to_save == -1)
1492 if (low_to_save >= 0)
1494 int num_to_save = high_to_save - low_to_save + 1;
1495 enum machine_mode save_mode
1496 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1499 /* If we don't have the required alignment, must do this in BLKmode. */
1500 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1501 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1502 save_mode = BLKmode;
1504 stack_area = gen_rtx (MEM, save_mode,
1505 memory_address (save_mode,
1507 #ifdef ARGS_GROW_DOWNWARD
1508 plus_constant (argblock,
1511 plus_constant (argblock,
1515 if (save_mode == BLKmode)
1517 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1518 emit_block_move (validize_mem (save_area), stack_area,
1519 GEN_INT (num_to_save),
1520 PARM_BOUNDARY / BITS_PER_UNIT);
1524 save_area = gen_reg_rtx (save_mode);
1525 emit_move_insn (save_area, stack_area);
1531 /* Now store (and compute if necessary) all non-register parms.
1532 These come before register parms, since they can require block-moves,
1533 which could clobber the registers used for register parms.
1534 Parms which have partial registers are not stored here,
1535 but we do preallocate space here if they want that. */
1537 for (i = 0; i < num_actuals; i++)
1538 if (args[i].reg == 0 || args[i].pass_on_stack)
1539 store_one_arg (&args[i], argblock, may_be_alloca,
1540 args_size.var != 0, fndecl, reg_parm_stack_space);
1542 #ifdef STRICT_ALIGNMENT
1543 /* If we have a parm that is passed in registers but not in memory
1544 and whose alignment does not permit a direct copy into registers,
1545 make a group of pseudos that correspond to each register that we
1548 for (i = 0; i < num_actuals; i++)
1549 if (args[i].reg != 0 && ! args[i].pass_on_stack
1550 && args[i].mode == BLKmode
1551 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
1552 < MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
1554 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1556 args[i].n_aligned_regs
1557 = args[i].partial ? args[i].partial
1558 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1560 args[i].aligned_regs = (rtx *) alloca (sizeof (rtx)
1561 * args[i].n_aligned_regs);
1563 for (j = 0; j < args[i].n_aligned_regs; j++)
1565 rtx reg = gen_reg_rtx (word_mode);
1566 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1567 int bitsize = TYPE_ALIGN (TREE_TYPE (args[i].tree_value));
1570 args[i].aligned_regs[j] = reg;
1572 /* Clobber REG and move each partword into it. Ensure we don't
1573 go past the end of the structure. Note that the loop below
1574 works because we've already verified that padding
1575 and endianness are compatible. */
1577 emit_insn (gen_rtx (CLOBBER, VOIDmode, reg));
1580 bitpos < BITS_PER_WORD && bytes >= 0;
1581 bitpos += bitsize, bytes -= bitsize / BITS_PER_UNIT)
1583 int xbitpos = (BYTES_BIG_ENDIAN
1584 ? bitpos = BITS_PER_WORD - bitpos - bitsize
1587 store_bit_field (reg, bitsize, xbitpos, word_mode,
1588 extract_bit_field (word, bitsize, xbitpos, 1,
1589 NULL_RTX, word_mode,
1591 bitsize / BITS_PER_UNIT,
1593 bitsize / BITS_PER_UNIT, BITS_PER_WORD);
1599 /* Now store any partially-in-registers parm.
1600 This is the last place a block-move can happen. */
1602 for (i = 0; i < num_actuals; i++)
1603 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1604 store_one_arg (&args[i], argblock, may_be_alloca,
1605 args_size.var != 0, fndecl, reg_parm_stack_space);
1607 #ifndef PUSH_ARGS_REVERSED
1608 #ifdef STACK_BOUNDARY
1609 /* If we pushed args in forward order, perform stack alignment
1610 after pushing the last arg. */
1612 anti_adjust_stack (GEN_INT (args_size.constant
1613 - original_args_size.constant));
1617 /* If register arguments require space on the stack and stack space
1618 was not preallocated, allocate stack space here for arguments
1619 passed in registers. */
1620 #if ! defined(ALLOCATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
1621 if (must_preallocate == 0 && reg_parm_stack_space > 0)
1622 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
1625 /* Pass the function the address in which to return a structure value. */
1626 if (structure_value_addr && ! structure_value_addr_parm)
1628 emit_move_insn (struct_value_rtx,
1630 force_operand (structure_value_addr,
1632 if (GET_CODE (struct_value_rtx) == REG)
1634 push_to_sequence (use_insns);
1635 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1636 use_insns = get_insns ();
1641 /* Now do the register loads required for any wholly-register parms or any
1642 parms which are passed both on the stack and in a register. Their
1643 expressions were already evaluated.
1645 Mark all register-parms as living through the call, putting these USE
1646 insns in a list headed by USE_INSNS. */
1648 for (i = 0; i < num_actuals; i++)
1650 rtx list = args[i].reg;
1651 int partial = args[i].partial;
1658 /* Process each register that needs to get this arg. */
1659 if (GET_CODE (list) == EXPR_LIST)
1660 reg = XEXP (list, 0), list = XEXP (list, 1);
1662 reg = list, list = 0;
1664 /* Set to non-zero if must move a word at a time, even if just one
1665 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1666 we just use a normal move insn. */
1667 nregs = (partial ? partial
1668 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1669 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1670 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1673 /* If simple case, just do move. If normal partial, store_one_arg
1674 has already loaded the register for us. In all other cases,
1675 load the register(s) from memory. */
1678 emit_move_insn (reg, args[i].value);
1680 #ifdef STRICT_ALIGNMENT
1681 /* If we have pre-computed the values to put in the registers in
1682 the case of non-aligned structures, copy them in now. */
1684 else if (args[i].n_aligned_regs != 0)
1685 for (j = 0; j < args[i].n_aligned_regs; j++)
1686 emit_move_insn (gen_rtx (REG, word_mode, REGNO (reg) + j),
1687 args[i].aligned_regs[j]);
1690 else if (args[i].partial == 0 || args[i].pass_on_stack)
1691 move_block_to_reg (REGNO (reg),
1692 validize_mem (args[i].value), nregs,
1695 push_to_sequence (use_insns);
1697 emit_insn (gen_rtx (USE, VOIDmode, reg));
1699 use_regs (REGNO (reg), nregs);
1700 use_insns = get_insns ();
1703 /* PARTIAL referred only to the first register, so clear it for the
1709 /* Perform postincrements before actually calling the function. */
1712 /* All arguments and registers used for the call must be set up by now! */
1714 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1716 /* Generate the actual call instruction. */
1717 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1718 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1719 valreg, old_inhibit_defer_pop, use_insns, is_const);
1721 /* If call is cse'able, make appropriate pair of reg-notes around it.
1722 Test valreg so we don't crash; may safely ignore `const'
1723 if return type is void. */
1724 if (is_const && valreg != 0)
1727 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1730 /* Construct an "equal form" for the value which mentions all the
1731 arguments in order as well as the function name. */
1732 #ifdef PUSH_ARGS_REVERSED
1733 for (i = 0; i < num_actuals; i++)
1734 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1736 for (i = num_actuals - 1; i >= 0; i--)
1737 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1739 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1741 insns = get_insns ();
1744 emit_libcall_block (insns, temp, valreg, note);
1749 /* For calls to `setjmp', etc., inform flow.c it should complain
1750 if nonvolatile values are live. */
1754 emit_note (name, NOTE_INSN_SETJMP);
1755 current_function_calls_setjmp = 1;
1759 current_function_calls_longjmp = 1;
1761 /* Notice functions that cannot return.
1762 If optimizing, insns emitted below will be dead.
1763 If not optimizing, they will exist, which is useful
1764 if the user uses the `return' command in the debugger. */
1766 if (is_volatile || is_longjmp)
1769 /* If value type not void, return an rtx for the value. */
1771 /* If there are cleanups to be called, don't use a hard reg as target. */
1772 if (cleanups_this_call != old_cleanups
1773 && target && REG_P (target)
1774 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1777 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1780 target = const0_rtx;
1782 else if (structure_value_addr)
1784 if (target == 0 || GET_CODE (target) != MEM)
1786 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1787 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1788 structure_value_addr));
1789 MEM_IN_STRUCT_P (target)
1790 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1791 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1792 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1795 else if (pcc_struct_value)
1799 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1800 copy_to_reg (valreg));
1801 MEM_IN_STRUCT_P (target)
1802 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1803 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1804 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1806 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1807 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1808 copy_to_reg (valreg)));
1810 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1812 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1814 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
1815 && GET_MODE (target) == GET_MODE (valreg))
1816 /* TARGET and VALREG cannot be equal at this point because the latter
1817 would not have REG_FUNCTION_VALUE_P true, while the former would if
1818 it were referring to the same register.
1820 If they refer to the same register, this move will be a no-op, except
1821 when function inlining is being done. */
1822 emit_move_insn (target, valreg);
1824 target = copy_to_reg (valreg);
1826 #ifdef PROMOTE_FUNCTION_RETURN
1827 /* If we promoted this return value, make the proper SUBREG. */
1828 if (GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
1830 enum machine_mode mode = GET_MODE (target);
1831 int unsignedp = TREE_UNSIGNED (TREE_TYPE (exp));
1833 if (TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE
1834 || TREE_CODE (TREE_TYPE (exp)) == ENUMERAL_TYPE
1835 || TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE
1836 || TREE_CODE (TREE_TYPE (exp)) == CHAR_TYPE
1837 || TREE_CODE (TREE_TYPE (exp)) == REAL_TYPE
1838 || TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE
1839 || TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE)
1841 PROMOTE_MODE (mode, unsignedp, TREE_TYPE (exp));
1844 target = gen_rtx (SUBREG, TYPE_MODE (TREE_TYPE (exp)), target, 0);
1845 SUBREG_PROMOTED_VAR_P (target) = 1;
1846 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
1850 /* Perform all cleanups needed for the arguments of this call
1851 (i.e. destructors in C++). */
1852 expand_cleanups_to (old_cleanups);
1854 /* If size of args is variable or this was a constructor call for a stack
1855 argument, restore saved stack-pointer value. */
1857 if (old_stack_level)
1859 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1860 pending_stack_adjust = old_pending_adj;
1861 #ifdef ACCUMULATE_OUTGOING_ARGS
1862 stack_arg_under_construction = old_stack_arg_under_construction;
1863 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1864 stack_usage_map = initial_stack_usage_map;
1867 #ifdef ACCUMULATE_OUTGOING_ARGS
1870 #ifdef REG_PARM_STACK_SPACE
1873 enum machine_mode save_mode = GET_MODE (save_area);
1875 = gen_rtx (MEM, save_mode,
1876 memory_address (save_mode,
1877 #ifdef ARGS_GROW_DOWNWARD
1878 plus_constant (argblock, - high_to_save)
1880 plus_constant (argblock, low_to_save)
1884 if (save_mode != BLKmode)
1885 emit_move_insn (stack_area, save_area);
1887 emit_block_move (stack_area, validize_mem (save_area),
1888 GEN_INT (high_to_save - low_to_save + 1),
1889 PARM_BOUNDARY / BITS_PER_UNIT);
1893 /* If we saved any argument areas, restore them. */
1894 for (i = 0; i < num_actuals; i++)
1895 if (args[i].save_area)
1897 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1899 = gen_rtx (MEM, save_mode,
1900 memory_address (save_mode,
1901 XEXP (args[i].stack_slot, 0)));
1903 if (save_mode != BLKmode)
1904 emit_move_insn (stack_area, args[i].save_area);
1906 emit_block_move (stack_area, validize_mem (args[i].save_area),
1907 GEN_INT (args[i].size.constant),
1908 PARM_BOUNDARY / BITS_PER_UNIT);
1911 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1912 stack_usage_map = initial_stack_usage_map;
1916 /* If this was alloca, record the new stack level for nonlocal gotos.
1917 Check for the handler slots since we might not have a save area
1918 for non-local gotos. */
1920 if (may_be_alloca && nonlocal_goto_handler_slot != 0)
1921 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1929 /* Return an rtx which represents a suitable home on the stack
1930 given TYPE, the type of the argument looking for a home.
1931 This is called only for BLKmode arguments.
1933 SIZE is the size needed for this target.
1934 ARGS_ADDR is the address of the bottom of the argument block for this call.
1935 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1936 if this machine uses push insns. */
1939 target_for_arg (type, size, args_addr, offset)
1943 struct args_size offset;
1946 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1948 /* We do not call memory_address if possible,
1949 because we want to address as close to the stack
1950 as possible. For non-variable sized arguments,
1951 this will be stack-pointer relative addressing. */
1952 if (GET_CODE (offset_rtx) == CONST_INT)
1953 target = plus_constant (args_addr, INTVAL (offset_rtx));
1956 /* I have no idea how to guarantee that this
1957 will work in the presence of register parameters. */
1958 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1959 target = memory_address (QImode, target);
1962 return gen_rtx (MEM, BLKmode, target);
1966 /* Store a single argument for a function call
1967 into the register or memory area where it must be passed.
1968 *ARG describes the argument value and where to pass it.
1970 ARGBLOCK is the address of the stack-block for all the arguments,
1971 or 0 on a machine where arguments are pushed individually.
1973 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1974 so must be careful about how the stack is used.
1976 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1977 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1978 that we need not worry about saving and restoring the stack.
1980 FNDECL is the declaration of the function we are calling. */
1983 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl,
1984 reg_parm_stack_space)
1985 struct arg_data *arg;
1990 int reg_parm_stack_space;
1992 register tree pval = arg->tree_value;
1996 int i, lower_bound, upper_bound;
1998 if (TREE_CODE (pval) == ERROR_MARK)
2001 #ifdef ACCUMULATE_OUTGOING_ARGS
2002 /* If this is being stored into a pre-allocated, fixed-size, stack area,
2003 save any previous data at that location. */
2004 if (argblock && ! variable_size && arg->stack)
2006 #ifdef ARGS_GROW_DOWNWARD
2007 /* stack_slot is negative, but we want to index stack_usage_map */
2008 /* with positive values. */
2009 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
2010 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
2014 lower_bound = upper_bound - arg->size.constant;
2016 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
2017 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
2021 upper_bound = lower_bound + arg->size.constant;
2024 for (i = lower_bound; i < upper_bound; i++)
2025 if (stack_usage_map[i]
2026 #ifdef REG_PARM_STACK_SPACE
2027 /* Don't store things in the fixed argument area at this point;
2028 it has already been saved. */
2029 && i > reg_parm_stack_space
2034 if (i != upper_bound)
2036 /* We need to make a save area. See what mode we can make it. */
2037 enum machine_mode save_mode
2038 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
2040 = gen_rtx (MEM, save_mode,
2041 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
2043 if (save_mode == BLKmode)
2045 arg->save_area = assign_stack_temp (BLKmode,
2046 arg->size.constant, 1);
2047 emit_block_move (validize_mem (arg->save_area), stack_area,
2048 GEN_INT (arg->size.constant),
2049 PARM_BOUNDARY / BITS_PER_UNIT);
2053 arg->save_area = gen_reg_rtx (save_mode);
2054 emit_move_insn (arg->save_area, stack_area);
2060 /* If this isn't going to be placed on both the stack and in registers,
2061 set up the register and number of words. */
2062 if (! arg->pass_on_stack)
2063 reg = arg->reg, partial = arg->partial;
2065 if (reg != 0 && partial == 0)
2066 /* Being passed entirely in a register. We shouldn't be called in
2070 #ifdef STRICT_ALIGNMENT
2071 /* If this arg needs special alignment, don't load the registers
2073 if (arg->n_aligned_regs != 0)
2077 /* If this is being partially passed in a register, but multiple locations
2078 are specified, we assume that the one partially used is the one that is
2080 if (reg && GET_CODE (reg) == EXPR_LIST)
2081 reg = XEXP (reg, 0);
2083 /* If this is being passed partially in a register, we can't evaluate
2084 it directly into its stack slot. Otherwise, we can. */
2085 if (arg->value == 0)
2087 #ifdef ACCUMULATE_OUTGOING_ARGS
2088 /* stack_arg_under_construction is nonzero if a function argument is
2089 being evaluated directly into the outgoing argument list and
2090 expand_call must take special action to preserve the argument list
2091 if it is called recursively.
2093 For scalar function arguments stack_usage_map is sufficient to
2094 determine which stack slots must be saved and restored. Scalar
2095 arguments in general have pass_on_stack == 0.
2097 If this argument is initialized by a function which takes the
2098 address of the argument (a C++ constructor or a C function
2099 returning a BLKmode structure), then stack_usage_map is
2100 insufficient and expand_call must push the stack around the
2101 function call. Such arguments have pass_on_stack == 1.
2103 Note that it is always safe to set stack_arg_under_construction,
2104 but this generates suboptimal code if set when not needed. */
2106 if (arg->pass_on_stack)
2107 stack_arg_under_construction++;
2109 arg->value = expand_expr (pval, partial ? NULL_RTX : arg->stack,
2112 /* If we are promoting object (or for any other reason) the mode
2113 doesn't agree, convert the mode. */
2115 if (GET_MODE (arg->value) != VOIDmode
2116 && GET_MODE (arg->value) != arg->mode)
2117 arg->value = convert_to_mode (arg->mode, arg->value, arg->unsignedp);
2119 #ifdef ACCUMULATE_OUTGOING_ARGS
2120 if (arg->pass_on_stack)
2121 stack_arg_under_construction--;
2125 /* Don't allow anything left on stack from computation
2126 of argument to alloca. */
2128 do_pending_stack_adjust ();
2130 if (arg->value == arg->stack)
2131 /* If the value is already in the stack slot, we are done. */
2133 else if (arg->mode != BLKmode)
2137 /* Argument is a scalar, not entirely passed in registers.
2138 (If part is passed in registers, arg->partial says how much
2139 and emit_push_insn will take care of putting it there.)
2141 Push it, and if its size is less than the
2142 amount of space allocated to it,
2143 also bump stack pointer by the additional space.
2144 Note that in C the default argument promotions
2145 will prevent such mismatches. */
2147 size = GET_MODE_SIZE (arg->mode);
2148 /* Compute how much space the push instruction will push.
2149 On many machines, pushing a byte will advance the stack
2150 pointer by a halfword. */
2151 #ifdef PUSH_ROUNDING
2152 size = PUSH_ROUNDING (size);
2156 /* Compute how much space the argument should get:
2157 round up to a multiple of the alignment for arguments. */
2158 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
2159 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
2160 / (PARM_BOUNDARY / BITS_PER_UNIT))
2161 * (PARM_BOUNDARY / BITS_PER_UNIT));
2163 /* This isn't already where we want it on the stack, so put it there.
2164 This can either be done with push or copy insns. */
2165 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), 0, 0, partial,
2166 reg, used - size, argblock, ARGS_SIZE_RTX (arg->offset));
2170 /* BLKmode, at least partly to be pushed. */
2172 register int excess;
2175 /* Pushing a nonscalar.
2176 If part is passed in registers, PARTIAL says how much
2177 and emit_push_insn will take care of putting it there. */
2179 /* Round its size up to a multiple
2180 of the allocation unit for arguments. */
2182 if (arg->size.var != 0)
2185 size_rtx = ARGS_SIZE_RTX (arg->size);
2189 register tree size = size_in_bytes (TREE_TYPE (pval));
2190 /* PUSH_ROUNDING has no effect on us, because
2191 emit_push_insn for BLKmode is careful to avoid it. */
2192 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
2193 + partial * UNITS_PER_WORD);
2194 size_rtx = expand_expr (size, NULL_RTX, VOIDmode, 0);
2197 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
2198 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
2199 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
2203 /* Unless this is a partially-in-register argument, the argument is now
2206 ??? Note that this can change arg->value from arg->stack to
2207 arg->stack_slot and it matters when they are not the same.
2208 It isn't totally clear that this is correct in all cases. */
2210 arg->value = arg->stack_slot;
2212 /* Once we have pushed something, pops can't safely
2213 be deferred during the rest of the arguments. */
2216 /* ANSI doesn't require a sequence point here,
2217 but PCC has one, so this will avoid some problems. */
2220 /* Free any temporary slots made in processing this argument. */
2223 #ifdef ACCUMULATE_OUTGOING_ARGS
2224 /* Now mark the segment we just used. */
2225 if (argblock && ! variable_size && arg->stack)
2226 for (i = lower_bound; i < upper_bound; i++)
2227 stack_usage_map[i] = 1;