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 /* Return 1 if EXP contains a call to the built-in function `alloca'. */
115 int type = TREE_CODE_CLASS (TREE_CODE (exp));
116 int length = tree_code_length[(int) TREE_CODE (exp)];
118 /* Only expressions and references can contain calls. */
120 if (type != 'e' && type != '<' && type != '1' && type != '2' && type != 'r'
124 switch (TREE_CODE (exp))
127 if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
128 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
130 && DECL_BUILT_IN (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
131 && (DECL_FUNCTION_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
135 /* Third operand is RTL. */
140 if (SAVE_EXPR_RTL (exp) != 0)
148 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
149 if (DECL_INITIAL (local) != 0 && calls_alloca (DECL_INITIAL (local)))
153 register tree subblock;
155 for (subblock = BLOCK_SUBBLOCKS (exp);
157 subblock = TREE_CHAIN (subblock))
158 if (calls_alloca (subblock))
163 case METHOD_CALL_EXPR:
167 case WITH_CLEANUP_EXPR:
175 for (i = 0; i < length; i++)
176 if (TREE_OPERAND (exp, i) != 0
177 && calls_alloca (TREE_OPERAND (exp, i)))
183 /* Force FUNEXP into a form suitable for the address of a CALL,
184 and return that as an rtx. Also load the static chain register
185 if FNDECL is a nested function.
187 USE_INSNS points to a variable holding a chain of USE insns
188 to which a USE of the static chain
189 register should be added, if required. */
192 prepare_call_address (funexp, fndecl, use_insns)
197 rtx static_chain_value = 0;
199 funexp = protect_from_queue (funexp, 0);
202 /* Get possible static chain value for nested function in C. */
203 static_chain_value = lookup_static_chain (fndecl);
205 /* Make a valid memory address and copy constants thru pseudo-regs,
206 but not for a constant address if -fno-function-cse. */
207 if (GET_CODE (funexp) != SYMBOL_REF)
208 funexp = memory_address (FUNCTION_MODE, funexp);
211 #ifndef NO_FUNCTION_CSE
212 if (optimize && ! flag_no_function_cse)
213 #ifdef NO_RECURSIVE_FUNCTION_CSE
214 if (fndecl != current_function_decl)
216 funexp = force_reg (Pmode, funexp);
220 if (static_chain_value != 0)
222 emit_move_insn (static_chain_rtx, static_chain_value);
224 /* Put the USE insn in the chain we were passed. It will later be
225 output immediately in front of the CALL insn. */
226 push_to_sequence (*use_insns);
227 emit_insn (gen_rtx (USE, VOIDmode, static_chain_rtx));
228 *use_insns = get_insns ();
235 /* Generate instructions to call function FUNEXP,
236 and optionally pop the results.
237 The CALL_INSN is the first insn generated.
239 FUNTYPE is the data type of the function, or, for a library call,
240 the identifier for the name of the call. This is given to the
241 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
243 STACK_SIZE is the number of bytes of arguments on the stack,
244 rounded up to STACK_BOUNDARY; zero if the size is variable.
245 This is both to put into the call insn and
246 to generate explicit popping code if necessary.
248 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
249 It is zero if this call doesn't want a structure value.
251 NEXT_ARG_REG is the rtx that results from executing
252 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
253 just after all the args have had their registers assigned.
254 This could be whatever you like, but normally it is the first
255 arg-register beyond those used for args in this call,
256 or 0 if all the arg-registers are used in this call.
257 It is passed on to `gen_call' so you can put this info in the call insn.
259 VALREG is a hard register in which a value is returned,
260 or 0 if the call does not return a value.
262 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
263 the args to this call were processed.
264 We restore `inhibit_defer_pop' to that value.
266 USE_INSNS is a chain of USE insns to be emitted immediately before
267 the actual CALL insn.
269 IS_CONST is true if this is a `const' call. */
272 emit_call_1 (funexp, funtype, stack_size, struct_value_size, next_arg_reg,
273 valreg, old_inhibit_defer_pop, use_insns, is_const)
277 int struct_value_size;
280 int old_inhibit_defer_pop;
284 rtx stack_size_rtx = GEN_INT (stack_size);
285 rtx struct_value_size_rtx = GEN_INT (struct_value_size);
287 int already_popped = 0;
289 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
290 and we don't want to load it into a register as an optimization,
291 because prepare_call_address already did it if it should be done. */
292 if (GET_CODE (funexp) != SYMBOL_REF)
293 funexp = memory_address (FUNCTION_MODE, funexp);
295 #ifndef ACCUMULATE_OUTGOING_ARGS
296 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
297 if (HAVE_call_pop && HAVE_call_value_pop
298 && (RETURN_POPS_ARGS (funtype, stack_size) > 0 || stack_size == 0))
300 rtx n_pop = GEN_INT (RETURN_POPS_ARGS (funtype, stack_size));
303 /* If this subroutine pops its own args, record that in the call insn
304 if possible, for the sake of frame pointer elimination. */
306 pat = gen_call_value_pop (valreg,
307 gen_rtx (MEM, FUNCTION_MODE, funexp),
308 stack_size_rtx, next_arg_reg, n_pop);
310 pat = gen_call_pop (gen_rtx (MEM, FUNCTION_MODE, funexp),
311 stack_size_rtx, next_arg_reg, n_pop);
313 emit_call_insn (pat);
320 #if defined (HAVE_call) && defined (HAVE_call_value)
321 if (HAVE_call && HAVE_call_value)
324 emit_call_insn (gen_call_value (valreg,
325 gen_rtx (MEM, FUNCTION_MODE, funexp),
326 stack_size_rtx, next_arg_reg,
329 emit_call_insn (gen_call (gen_rtx (MEM, FUNCTION_MODE, funexp),
330 stack_size_rtx, next_arg_reg,
331 struct_value_size_rtx));
337 /* Find the CALL insn we just emitted and write the USE insns before it. */
338 for (call_insn = get_last_insn ();
339 call_insn && GET_CODE (call_insn) != CALL_INSN;
340 call_insn = PREV_INSN (call_insn))
346 /* Put the USE insns before the CALL. */
347 emit_insns_before (use_insns, call_insn);
349 /* If this is a const call, then set the insn's unchanging bit. */
351 CONST_CALL_P (call_insn) = 1;
353 #ifndef ACCUMULATE_OUTGOING_ARGS
354 /* If returning from the subroutine does not automatically pop the args,
355 we need an instruction to pop them sooner or later.
356 Perhaps do it now; perhaps just record how much space to pop later.
358 If returning from the subroutine does pop the args, indicate that the
359 stack pointer will be changed. */
361 if (stack_size != 0 && RETURN_POPS_ARGS (funtype, stack_size) > 0)
364 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
365 stack_size -= RETURN_POPS_ARGS (funtype, stack_size);
366 stack_size_rtx = GEN_INT (stack_size);
371 if (flag_defer_pop && inhibit_defer_pop == 0)
372 pending_stack_adjust += stack_size;
374 adjust_stack (stack_size_rtx);
378 inhibit_defer_pop = old_inhibit_defer_pop;
381 /* Generate all the code for a function call
382 and return an rtx for its value.
383 Store the value in TARGET (specified as an rtx) if convenient.
384 If the value is stored in TARGET then TARGET is returned.
385 If IGNORE is nonzero, then we ignore the value of the function call. */
388 expand_call (exp, target, ignore)
393 /* List of actual parameters. */
394 tree actparms = TREE_OPERAND (exp, 1);
395 /* RTX for the function to be called. */
397 /* Tree node for the function to be called (not the address!). */
399 /* Data type of the function. */
401 /* Declaration of the function being called,
402 or 0 if the function is computed (not known by name). */
406 /* Register in which non-BLKmode value will be returned,
407 or 0 if no value or if value is BLKmode. */
409 /* Address where we should return a BLKmode value;
410 0 if value not BLKmode. */
411 rtx structure_value_addr = 0;
412 /* Nonzero if that address is being passed by treating it as
413 an extra, implicit first parameter. Otherwise,
414 it is passed by being copied directly into struct_value_rtx. */
415 int structure_value_addr_parm = 0;
416 /* Size of aggregate value wanted, or zero if none wanted
417 or if we are using the non-reentrant PCC calling convention
418 or expecting the value in registers. */
419 int struct_value_size = 0;
420 /* Nonzero if called function returns an aggregate in memory PCC style,
421 by returning the address of where to find it. */
422 int pcc_struct_value = 0;
424 /* Number of actual parameters in this call, including struct value addr. */
426 /* Number of named args. Args after this are anonymous ones
427 and they must all go on the stack. */
429 /* Count arg position in order args appear. */
432 /* Vector of information about each argument.
433 Arguments are numbered in the order they will be pushed,
434 not the order they are written. */
435 struct arg_data *args;
437 /* Total size in bytes of all the stack-parms scanned so far. */
438 struct args_size args_size;
439 /* Size of arguments before any adjustments (such as rounding). */
440 struct args_size original_args_size;
441 /* Data on reg parms scanned so far. */
442 CUMULATIVE_ARGS args_so_far;
443 /* Nonzero if a reg parm has been scanned. */
446 /* Nonzero if we must avoid push-insns in the args for this call.
447 If stack space is allocated for register parameters, but not by the
448 caller, then it is preallocated in the fixed part of the stack frame.
449 So the entire argument block must then be preallocated (i.e., we
450 ignore PUSH_ROUNDING in that case). */
452 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
453 int must_preallocate = 1;
456 int must_preallocate = 0;
458 int must_preallocate = 1;
462 /* Size of the stack reserved for parameter registers. */
463 int reg_parm_stack_space = 0;
465 /* 1 if scanning parms front to back, -1 if scanning back to front. */
467 /* Address of space preallocated for stack parms
468 (on machines that lack push insns), or 0 if space not preallocated. */
471 /* Nonzero if it is plausible that this is a call to alloca. */
473 /* Nonzero if this is a call to setjmp or a related function. */
475 /* Nonzero if this is a call to `longjmp'. */
477 /* Nonzero if this is a call to an inline function. */
478 int is_integrable = 0;
479 /* Nonzero if this is a call to a `const' function.
480 Note that only explicitly named functions are handled as `const' here. */
482 /* Nonzero if this is a call to a `volatile' function. */
484 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
485 /* Define the boundary of the register parm stack space that needs to be
487 int low_to_save = -1, high_to_save;
488 rtx save_area = 0; /* Place that it is saved */
491 #ifdef ACCUMULATE_OUTGOING_ARGS
492 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
493 char *initial_stack_usage_map = stack_usage_map;
496 rtx old_stack_level = 0;
498 int old_stack_arg_under_construction;
499 int old_inhibit_defer_pop = inhibit_defer_pop;
500 tree old_cleanups = cleanups_this_call;
507 /* See if we can find a DECL-node for the actual function.
508 As a result, decide whether this is a call to an integrable function. */
510 p = TREE_OPERAND (exp, 0);
511 if (TREE_CODE (p) == ADDR_EXPR)
513 fndecl = TREE_OPERAND (p, 0);
514 if (TREE_CODE (fndecl) != FUNCTION_DECL)
516 /* May still be a `const' function if it is
517 a call through a pointer-to-const.
518 But we don't handle that. */
524 && fndecl != current_function_decl
525 && DECL_SAVED_INSNS (fndecl))
527 else if (! TREE_ADDRESSABLE (fndecl))
529 /* In case this function later becomes inlinable,
530 record that there was already a non-inline call to it.
532 Use abstraction instead of setting TREE_ADDRESSABLE
534 if (DECL_INLINE (fndecl) && extra_warnings && !flag_no_inline)
535 warning_with_decl (fndecl, "can't inline call to `%s' which was declared inline");
536 mark_addressable (fndecl);
539 if (TREE_READONLY (fndecl) && ! TREE_THIS_VOLATILE (fndecl)
540 && TYPE_MODE (TREE_TYPE (exp)) != VOIDmode)
545 is_volatile = TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (p)));
547 #ifdef REG_PARM_STACK_SPACE
548 #ifdef MAYBE_REG_PARM_STACK_SPACE
549 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
551 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
555 /* Warn if this value is an aggregate type,
556 regardless of which calling convention we are using for it. */
557 if (warn_aggregate_return
558 && (TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
559 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE
560 || TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE))
561 warning ("function call has aggregate value");
563 /* Set up a place to return a structure. */
565 /* Cater to broken compilers. */
566 if (aggregate_value_p (exp))
568 /* This call returns a big structure. */
571 #ifdef PCC_STATIC_STRUCT_RETURN
572 if (flag_pcc_struct_return)
574 pcc_struct_value = 1;
575 is_integrable = 0; /* Easier than making that case work right. */
580 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
582 if (struct_value_size < 0)
585 if (target && GET_CODE (target) == MEM)
586 structure_value_addr = XEXP (target, 0);
589 /* Assign a temporary on the stack to hold the value. */
591 /* For variable-sized objects, we must be called with a target
592 specified. If we were to allocate space on the stack here,
593 we would have no way of knowing when to free it. */
596 = XEXP (assign_stack_temp (BLKmode, struct_value_size, 1), 0);
602 /* If called function is inline, try to integrate it. */
607 rtx before_call = get_last_insn ();
609 temp = expand_inline_function (fndecl, actparms, target,
610 ignore, TREE_TYPE (exp),
611 structure_value_addr);
613 /* If inlining succeeded, return. */
614 if ((HOST_WIDE_INT) temp != -1)
618 /* Perform all cleanups needed for the arguments of this call
619 (i.e. destructors in C++). It is ok if these destructors
620 clobber RETURN_VALUE_REG, because the only time we care about
621 this is when TARGET is that register. But in C++, we take
622 care to never return that register directly. */
623 expand_cleanups_to (old_cleanups);
625 #ifdef ACCUMULATE_OUTGOING_ARGS
626 /* If the outgoing argument list must be preserved, push
627 the stack before executing the inlined function if it
630 for (i = reg_parm_stack_space - 1; i >= 0; i--)
631 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
634 if (stack_arg_under_construction || i >= 0)
636 rtx insn = NEXT_INSN (before_call), seq;
638 /* Look for a call in the inline function code.
639 If OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) is
640 nonzero then there is a call and it is not necessary
641 to scan the insns. */
643 if (OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl)) == 0)
644 for (; insn; insn = NEXT_INSN (insn))
645 if (GET_CODE (insn) == CALL_INSN)
650 /* Reserve enough stack space so that the largest
651 argument list of any function call in the inline
652 function does not overlap the argument list being
653 evaluated. This is usually an overestimate because
654 allocate_dynamic_stack_space reserves space for an
655 outgoing argument list in addition to the requested
656 space, but there is no way to ask for stack space such
657 that an argument list of a certain length can be
658 safely constructed. */
660 int adjust = OUTGOING_ARGS_SIZE (DECL_SAVED_INSNS (fndecl));
661 #ifdef REG_PARM_STACK_SPACE
662 /* Add the stack space reserved for register arguments
663 in the inline function. What is really needed is the
664 largest value of reg_parm_stack_space in the inline
665 function, but that is not available. Using the current
666 value of reg_parm_stack_space is wrong, but gives
667 correct results on all supported machines. */
668 adjust += reg_parm_stack_space;
671 emit_stack_save (SAVE_BLOCK, &old_stack_level, 0);
672 allocate_dynamic_stack_space (GEN_INT (adjust),
673 NULL_RTX, BITS_PER_UNIT);
676 emit_insns_before (seq, NEXT_INSN (before_call));
677 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
682 /* If the result is equivalent to TARGET, return TARGET to simplify
683 checks in store_expr. They can be equivalent but not equal in the
684 case of a function that returns BLKmode. */
685 if (temp != target && rtx_equal_p (temp, target))
690 /* If inlining failed, mark FNDECL as needing to be compiled
691 separately after all. */
692 mark_addressable (fndecl);
695 /* When calling a const function, we must pop the stack args right away,
696 so that the pop is deleted or moved with the call. */
700 function_call_count++;
702 if (fndecl && DECL_NAME (fndecl))
703 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
706 /* Unless it's a call to a specific function that isn't alloca,
707 if it has one argument, we must assume it might be alloca. */
710 (!(fndecl != 0 && strcmp (name, "alloca"))
712 && TREE_CHAIN (actparms) == 0);
714 /* We assume that alloca will always be called by name. It
715 makes no sense to pass it as a pointer-to-function to
716 anything that does not understand its behavior. */
718 (name && ((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
720 && ! strcmp (name, "alloca"))
721 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
723 && ! strcmp (name, "__builtin_alloca"))));
726 /* See if this is a call to a function that can return more than once
727 or a call to longjmp. */
732 if (name != 0 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 15)
737 tname += ((name[1] == '_' && name[2] == 'x') ? 3 : 1);
743 && (! strcmp (tname, "setjmp")
744 || ! strcmp (tname, "setjmp_syscall")))
746 && ! strcmp (tname, "sigsetjmp"))
748 && ! strcmp (tname, "savectx")));
750 && ! strcmp (tname, "siglongjmp"))
753 else if ((tname[0] == 'q' && tname[1] == 's'
754 && ! strcmp (tname, "qsetjmp"))
755 || (tname[0] == 'v' && tname[1] == 'f'
756 && ! strcmp (tname, "vfork")))
759 else if (tname[0] == 'l' && tname[1] == 'o'
760 && ! strcmp (tname, "longjmp"))
765 current_function_calls_alloca = 1;
767 /* Don't let pending stack adjusts add up to too much.
768 Also, do all pending adjustments now
769 if there is any chance this might be a call to alloca. */
771 if (pending_stack_adjust >= 32
772 || (pending_stack_adjust > 0 && may_be_alloca))
773 do_pending_stack_adjust ();
775 /* Operand 0 is a pointer-to-function; get the type of the function. */
776 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
777 if (TREE_CODE (funtype) != POINTER_TYPE)
779 funtype = TREE_TYPE (funtype);
781 /* Push the temporary stack slot level so that we can free temporaries used
782 by each of the arguments separately. */
785 /* Start updating where the next arg would go. */
786 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX);
788 /* If struct_value_rtx is 0, it means pass the address
789 as if it were an extra parameter. */
790 if (structure_value_addr && struct_value_rtx == 0)
792 #ifdef ACCUMULATE_OUTGOING_ARGS
793 /* If the stack will be adjusted, make sure the structure address
794 does not refer to virtual_outgoing_args_rtx. */
795 rtx temp = (stack_arg_under_construction
796 ? copy_addr_to_reg (structure_value_addr)
797 : force_reg (Pmode, structure_value_addr));
799 rtx temp = force_reg (Pmode, structure_value_addr);
803 = tree_cons (error_mark_node,
804 make_tree (build_pointer_type (TREE_TYPE (funtype)),
807 structure_value_addr_parm = 1;
810 /* Count the arguments and set NUM_ACTUALS. */
811 for (p = actparms, i = 0; p; p = TREE_CHAIN (p)) i++;
814 /* Compute number of named args.
815 Normally, don't include the last named arg if anonymous args follow.
816 (If no anonymous args follow, the result of list_length
817 is actually one too large.)
819 If SETUP_INCOMING_VARARGS is defined, this machine will be able to
820 place unnamed args that were passed in registers into the stack. So
821 treat all args as named. This allows the insns emitting for a specific
822 argument list to be independent of the function declaration.
824 If SETUP_INCOMING_VARARGS is not defined, we do not have any reliable
825 way to pass unnamed args in registers, so we must force them into
827 #ifndef SETUP_INCOMING_VARARGS
828 if (TYPE_ARG_TYPES (funtype) != 0)
830 = list_length (TYPE_ARG_TYPES (funtype)) - 1
831 /* Count the struct value address, if it is passed as a parm. */
832 + structure_value_addr_parm;
835 /* If we know nothing, treat all args as named. */
836 n_named_args = num_actuals;
838 /* Make a vector to hold all the information about each arg. */
839 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
840 bzero (args, num_actuals * sizeof (struct arg_data));
842 args_size.constant = 0;
845 /* In this loop, we consider args in the order they are written.
846 We fill up ARGS from the front of from the back if necessary
847 so that in any case the first arg to be pushed ends up at the front. */
849 #ifdef PUSH_ARGS_REVERSED
850 i = num_actuals - 1, inc = -1;
851 /* In this case, must reverse order of args
852 so that we compute and push the last arg first. */
857 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
858 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
860 tree type = TREE_TYPE (TREE_VALUE (p));
861 enum machine_mode mode;
863 args[i].tree_value = TREE_VALUE (p);
865 /* Replace erroneous argument with constant zero. */
866 if (type == error_mark_node || TYPE_SIZE (type) == 0)
867 args[i].tree_value = integer_zero_node, type = integer_type_node;
869 /* Decide where to pass this arg.
871 args[i].reg is nonzero if all or part is passed in registers.
873 args[i].partial is nonzero if part but not all is passed in registers,
874 and the exact value says how many words are passed in registers.
876 args[i].pass_on_stack is nonzero if the argument must at least be
877 computed on the stack. It may then be loaded back into registers
878 if args[i].reg is nonzero.
880 These decisions are driven by the FUNCTION_... macros and must agree
881 with those made by function.c. */
883 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
884 /* See if this argument should be passed by invisible reference. */
885 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, TYPE_MODE (type), type,
886 argpos < n_named_args))
888 /* We make a copy of the object and pass the address to the function
892 if (TYPE_SIZE (type) == 0
893 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
895 /* This is a variable-sized object. Make space on the stack
897 rtx size_rtx = expand_expr (size_in_bytes (type), NULL_RTX,
900 if (old_stack_level == 0)
902 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
903 old_pending_adj = pending_stack_adjust;
904 pending_stack_adjust = 0;
907 copy = gen_rtx (MEM, BLKmode,
908 allocate_dynamic_stack_space (size_rtx, NULL_RTX,
913 int size = int_size_in_bytes (type);
914 copy = assign_stack_temp (TYPE_MODE (type), size, 1);
917 store_expr (args[i].tree_value, copy, 0);
919 args[i].tree_value = build1 (ADDR_EXPR, build_pointer_type (type),
920 make_tree (type, copy));
921 type = build_pointer_type (type);
925 mode = TYPE_MODE (type);
927 #ifdef PROMOTE_FUNCTION_ARGS
928 /* Compute the mode in which the arg is actually to be extended to. */
929 if (TREE_CODE (type) == INTEGER_TYPE || TREE_CODE (type) == ENUMERAL_TYPE
930 || TREE_CODE (type) == BOOLEAN_TYPE || TREE_CODE (type) == CHAR_TYPE
931 || TREE_CODE (type) == REAL_TYPE || TREE_CODE (type) == POINTER_TYPE
932 || TREE_CODE (type) == OFFSET_TYPE)
934 int unsignedp = TREE_UNSIGNED (type);
935 PROMOTE_MODE (mode, unsignedp, type);
936 args[i].unsignedp = unsignedp;
940 args[i].reg = FUNCTION_ARG (args_so_far, mode, type,
941 argpos < n_named_args);
942 #ifdef FUNCTION_ARG_PARTIAL_NREGS
945 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, type,
946 argpos < n_named_args);
949 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
951 /* If FUNCTION_ARG returned an (expr_list (nil) FOO), it means that
952 we are to pass this arg in the register(s) designated by FOO, but
953 also to pass it in the stack. */
954 if (args[i].reg && GET_CODE (args[i].reg) == EXPR_LIST
955 && XEXP (args[i].reg, 0) == 0)
956 args[i].pass_on_stack = 1, args[i].reg = XEXP (args[i].reg, 1);
958 /* If this is an addressable type, we must preallocate the stack
959 since we must evaluate the object into its final location.
961 If this is to be passed in both registers and the stack, it is simpler
963 if (TREE_ADDRESSABLE (type)
964 || (args[i].pass_on_stack && args[i].reg != 0))
965 must_preallocate = 1;
967 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
968 we cannot consider this function call constant. */
969 if (TREE_ADDRESSABLE (type))
972 /* Compute the stack-size of this argument. */
973 if (args[i].reg == 0 || args[i].partial != 0
974 #ifdef REG_PARM_STACK_SPACE
975 || reg_parm_stack_space > 0
977 || args[i].pass_on_stack)
978 locate_and_pad_parm (TYPE_MODE (type), type,
979 #ifdef STACK_PARMS_IN_REG_PARM_AREA
984 fndecl, &args_size, &args[i].offset,
987 #ifndef ARGS_GROW_DOWNWARD
988 args[i].slot_offset = args_size;
991 #ifndef REG_PARM_STACK_SPACE
992 /* If a part of the arg was put into registers,
993 don't include that part in the amount pushed. */
994 if (! args[i].pass_on_stack)
995 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
996 / (PARM_BOUNDARY / BITS_PER_UNIT)
997 * (PARM_BOUNDARY / BITS_PER_UNIT));
1000 /* Update ARGS_SIZE, the total stack space for args so far. */
1002 args_size.constant += args[i].size.constant;
1003 if (args[i].size.var)
1005 ADD_PARM_SIZE (args_size, args[i].size.var);
1008 /* Since the slot offset points to the bottom of the slot,
1009 we must record it after incrementing if the args grow down. */
1010 #ifdef ARGS_GROW_DOWNWARD
1011 args[i].slot_offset = args_size;
1013 args[i].slot_offset.constant = -args_size.constant;
1016 SUB_PARM_SIZE (args[i].slot_offset, args_size.var);
1020 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1021 have been used, etc. */
1023 FUNCTION_ARG_ADVANCE (args_so_far, TYPE_MODE (type), type,
1024 argpos < n_named_args);
1027 #ifdef FINAL_REG_PARM_STACK_SPACE
1028 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
1032 /* Compute the actual size of the argument block required. The variable
1033 and constant sizes must be combined, the size may have to be rounded,
1034 and there may be a minimum required size. */
1036 original_args_size = args_size;
1039 /* If this function requires a variable-sized argument list, don't try to
1040 make a cse'able block for this call. We may be able to do this
1041 eventually, but it is too complicated to keep track of what insns go
1042 in the cse'able block and which don't. */
1045 must_preallocate = 1;
1047 args_size.var = ARGS_SIZE_TREE (args_size);
1048 args_size.constant = 0;
1050 #ifdef STACK_BOUNDARY
1051 if (STACK_BOUNDARY != BITS_PER_UNIT)
1052 args_size.var = round_up (args_size.var, STACK_BYTES);
1055 #ifdef REG_PARM_STACK_SPACE
1056 if (reg_parm_stack_space > 0)
1059 = size_binop (MAX_EXPR, args_size.var,
1060 size_int (REG_PARM_STACK_SPACE (fndecl)));
1062 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1063 /* The area corresponding to register parameters is not to count in
1064 the size of the block we need. So make the adjustment. */
1066 = size_binop (MINUS_EXPR, args_size.var,
1067 size_int (reg_parm_stack_space));
1074 #ifdef STACK_BOUNDARY
1075 args_size.constant = (((args_size.constant + (STACK_BYTES - 1))
1076 / STACK_BYTES) * STACK_BYTES);
1079 #ifdef REG_PARM_STACK_SPACE
1080 args_size.constant = MAX (args_size.constant,
1081 reg_parm_stack_space);
1082 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1083 args_size.constant -= reg_parm_stack_space;
1088 /* See if we have or want to preallocate stack space.
1090 If we would have to push a partially-in-regs parm
1091 before other stack parms, preallocate stack space instead.
1093 If the size of some parm is not a multiple of the required stack
1094 alignment, we must preallocate.
1096 If the total size of arguments that would otherwise create a copy in
1097 a temporary (such as a CALL) is more than half the total argument list
1098 size, preallocation is faster.
1100 Another reason to preallocate is if we have a machine (like the m88k)
1101 where stack alignment is required to be maintained between every
1102 pair of insns, not just when the call is made. However, we assume here
1103 that such machines either do not have push insns (and hence preallocation
1104 would occur anyway) or the problem is taken care of with
1107 if (! must_preallocate)
1109 int partial_seen = 0;
1110 int copy_to_evaluate_size = 0;
1112 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1114 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1116 else if (partial_seen && args[i].reg == 0)
1117 must_preallocate = 1;
1119 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1120 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1121 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1122 || TREE_CODE (args[i].tree_value) == COND_EXPR
1123 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1124 copy_to_evaluate_size
1125 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1128 if (copy_to_evaluate_size * 2 >= args_size.constant
1129 && args_size.constant > 0)
1130 must_preallocate = 1;
1133 /* If the structure value address will reference the stack pointer, we must
1134 stabilize it. We don't need to do this if we know that we are not going
1135 to adjust the stack pointer in processing this call. */
1137 if (structure_value_addr
1138 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
1139 || reg_mentioned_p (virtual_outgoing_args_rtx, structure_value_addr))
1141 #ifndef ACCUMULATE_OUTGOING_ARGS
1142 || args_size.constant
1145 structure_value_addr = copy_to_reg (structure_value_addr);
1147 /* If this function call is cse'able, precompute all the parameters.
1148 Note that if the parameter is constructed into a temporary, this will
1149 cause an additional copy because the parameter will be constructed
1150 into a temporary location and then copied into the outgoing arguments.
1151 If a parameter contains a call to alloca and this function uses the
1152 stack, precompute the parameter. */
1154 for (i = 0; i < num_actuals; i++)
1156 || ((args_size.var != 0 || args_size.constant != 0)
1157 && calls_alloca (args[i].tree_value)))
1159 args[i].initial_value = args[i].value
1160 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1161 preserve_temp_slots (args[i].value);
1164 /* ANSI doesn't require a sequence point here,
1165 but PCC has one, so this will avoid some problems. */
1169 /* Now we are about to start emitting insns that can be deleted
1170 if a libcall is deleted. */
1174 /* If we have no actual push instructions, or shouldn't use them,
1175 make space for all args right now. */
1177 if (args_size.var != 0)
1179 if (old_stack_level == 0)
1181 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1182 old_pending_adj = pending_stack_adjust;
1183 pending_stack_adjust = 0;
1184 #ifdef ACCUMULATE_OUTGOING_ARGS
1185 /* stack_arg_under_construction says whether a stack arg is
1186 being constructed at the old stack level. Pushing the stack
1187 gets a clean outgoing argument block. */
1188 old_stack_arg_under_construction = stack_arg_under_construction;
1189 stack_arg_under_construction = 0;
1192 argblock = push_block (ARGS_SIZE_RTX (args_size), 0, 0);
1194 else if (must_preallocate)
1196 /* Note that we must go through the motions of allocating an argument
1197 block even if the size is zero because we may be storing args
1198 in the area reserved for register arguments, which may be part of
1200 int needed = args_size.constant;
1202 #ifdef ACCUMULATE_OUTGOING_ARGS
1203 /* Store the maximum argument space used. It will be pushed by the
1206 Since the stack pointer will never be pushed, it is possible for
1207 the evaluation of a parm to clobber something we have already
1208 written to the stack. Since most function calls on RISC machines
1209 do not use the stack, this is uncommon, but must work correctly.
1211 Therefore, we save any area of the stack that was already written
1212 and that we are using. Here we set up to do this by making a new
1213 stack usage map from the old one. The actual save will be done
1216 Another approach might be to try to reorder the argument
1217 evaluations to avoid this conflicting stack usage. */
1219 if (needed > current_function_outgoing_args_size)
1220 current_function_outgoing_args_size = needed;
1222 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1223 /* Since we will be writing into the entire argument area, the
1224 map must be allocated for its entire size, not just the part that
1225 is the responsibility of the caller. */
1226 needed += reg_parm_stack_space;
1229 #ifdef ARGS_GROW_DOWNWARD
1230 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
1233 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use, needed);
1235 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
1237 if (initial_highest_arg_in_use)
1238 bcopy (initial_stack_usage_map, stack_usage_map,
1239 initial_highest_arg_in_use);
1241 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
1242 bzero (&stack_usage_map[initial_highest_arg_in_use],
1243 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
1246 /* The address of the outgoing argument list must not be copied to a
1247 register here, because argblock would be left pointing to the
1248 wrong place after the call to allocate_dynamic_stack_space below. */
1250 argblock = virtual_outgoing_args_rtx;
1252 #else /* not ACCUMULATE_OUTGOING_ARGS */
1253 if (inhibit_defer_pop == 0)
1255 /* Try to reuse some or all of the pending_stack_adjust
1256 to get this space. Maybe we can avoid any pushing. */
1257 if (needed > pending_stack_adjust)
1259 needed -= pending_stack_adjust;
1260 pending_stack_adjust = 0;
1264 pending_stack_adjust -= needed;
1268 /* Special case this because overhead of `push_block' in this
1269 case is non-trivial. */
1271 argblock = virtual_outgoing_args_rtx;
1273 argblock = push_block (GEN_INT (needed), 0, 0);
1275 /* We only really need to call `copy_to_reg' in the case where push
1276 insns are going to be used to pass ARGBLOCK to a function
1277 call in ARGS. In that case, the stack pointer changes value
1278 from the allocation point to the call point, and hence
1279 the value of VIRTUAL_OUTGOING_ARGS_RTX changes as well.
1280 But might as well always do it. */
1281 argblock = copy_to_reg (argblock);
1282 #endif /* not ACCUMULATE_OUTGOING_ARGS */
1286 #ifdef ACCUMULATE_OUTGOING_ARGS
1287 /* The save/restore code in store_one_arg handles all cases except one:
1288 a constructor call (including a C function returning a BLKmode struct)
1289 to initialize an argument. */
1290 if (stack_arg_under_construction)
1292 #if defined(REG_PARM_STACK_SPACE) && ! defined(OUTGOING_REG_PARM_STACK_SPACE)
1293 rtx push_size = GEN_INT (reg_parm_stack_space + args_size.constant);
1295 rtx push_size = GEN_INT (args_size.constant);
1297 if (old_stack_level == 0)
1299 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1300 old_pending_adj = pending_stack_adjust;
1301 pending_stack_adjust = 0;
1302 /* stack_arg_under_construction says whether a stack arg is
1303 being constructed at the old stack level. Pushing the stack
1304 gets a clean outgoing argument block. */
1305 old_stack_arg_under_construction = stack_arg_under_construction;
1306 stack_arg_under_construction = 0;
1307 /* Make a new map for the new argument list. */
1308 stack_usage_map = (char *)alloca (highest_outgoing_arg_in_use);
1309 bzero (stack_usage_map, highest_outgoing_arg_in_use);
1310 highest_outgoing_arg_in_use = 0;
1312 allocate_dynamic_stack_space (push_size, NULL_RTX, BITS_PER_UNIT);
1314 /* If argument evaluation might modify the stack pointer, copy the
1315 address of the argument list to a register. */
1316 for (i = 0; i < num_actuals; i++)
1317 if (args[i].pass_on_stack)
1319 argblock = copy_addr_to_reg (argblock);
1325 /* If we preallocated stack space, compute the address of each argument.
1326 We need not ensure it is a valid memory address here; it will be
1327 validized when it is used. */
1330 rtx arg_reg = argblock;
1333 if (GET_CODE (argblock) == PLUS)
1334 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1336 for (i = 0; i < num_actuals; i++)
1338 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1339 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1342 /* Skip this parm if it will not be passed on the stack. */
1343 if (! args[i].pass_on_stack && args[i].reg != 0)
1346 if (GET_CODE (offset) == CONST_INT)
1347 addr = plus_constant (arg_reg, INTVAL (offset));
1349 addr = gen_rtx (PLUS, Pmode, arg_reg, offset);
1351 addr = plus_constant (addr, arg_offset);
1353 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1355 if (GET_CODE (slot_offset) == CONST_INT)
1356 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1358 addr = gen_rtx (PLUS, Pmode, arg_reg, slot_offset);
1360 addr = plus_constant (addr, arg_offset);
1362 = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (args[i].tree_value)), addr);
1366 #ifdef PUSH_ARGS_REVERSED
1367 #ifdef STACK_BOUNDARY
1368 /* If we push args individually in reverse order, perform stack alignment
1369 before the first push (the last arg). */
1371 anti_adjust_stack (GEN_INT (args_size.constant
1372 - original_args_size.constant));
1376 /* Don't try to defer pops if preallocating, not even from the first arg,
1377 since ARGBLOCK probably refers to the SP. */
1381 /* Get the function to call, in the form of RTL. */
1383 /* Get a SYMBOL_REF rtx for the function address. */
1384 funexp = XEXP (DECL_RTL (fndecl), 0);
1386 /* Generate an rtx (probably a pseudo-register) for the address. */
1388 funexp = expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1389 free_temp_slots (); /* FUNEXP can't be BLKmode */
1393 /* Figure out the register where the value, if any, will come back. */
1395 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
1396 && ! structure_value_addr)
1398 if (pcc_struct_value)
1399 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
1402 valreg = hard_function_value (TREE_TYPE (exp), fndecl);
1405 /* Precompute all register parameters. It isn't safe to compute anything
1406 once we have started filling any specific hard regs. */
1408 for (i = 0; i < num_actuals; i++)
1409 if (args[i].reg != 0 && ! args[i].pass_on_stack)
1411 enum machine_mode mode;
1415 if (args[i].value == 0)
1417 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
1419 preserve_temp_slots (args[i].value);
1422 /* ANSI doesn't require a sequence point here,
1423 but PCC has one, so this will avoid some problems. */
1427 /* If we are to promote the function arg to a wider mode,
1429 mode = (GET_CODE (args[i].reg) == EXPR_LIST
1430 ? GET_MODE (XEXP (args[i].reg, 0)) : GET_MODE (args[i].reg));
1432 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) != mode)
1433 args[i].value = convert_to_mode (mode, args[i].value,
1437 #if defined(ACCUMULATE_OUTGOING_ARGS) && defined(REG_PARM_STACK_SPACE)
1438 /* The argument list is the property of the called routine and it
1439 may clobber it. If the fixed area has been used for previous
1440 parameters, we must save and restore it.
1442 Here we compute the boundary of the that needs to be saved, if any. */
1444 #ifdef ARGS_GROW_DOWNWARD
1445 for (i = 0; i < reg_parm_stack_space + 1; i++)
1447 for (i = 0; i < reg_parm_stack_space; i++)
1450 if (i >= highest_outgoing_arg_in_use
1451 || stack_usage_map[i] == 0)
1454 if (low_to_save == -1)
1460 if (low_to_save >= 0)
1462 int num_to_save = high_to_save - low_to_save + 1;
1463 enum machine_mode save_mode
1464 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
1467 /* If we don't have the required alignment, must do this in BLKmode. */
1468 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
1469 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
1470 save_mode = BLKmode;
1472 stack_area = gen_rtx (MEM, save_mode,
1473 memory_address (save_mode,
1475 #ifdef ARGS_GROW_DOWNWARD
1476 plus_constant (argblock,
1479 plus_constant (argblock,
1483 if (save_mode == BLKmode)
1485 save_area = assign_stack_temp (BLKmode, num_to_save, 1);
1486 emit_block_move (validize_mem (save_area), stack_area,
1487 GEN_INT (num_to_save),
1488 PARM_BOUNDARY / BITS_PER_UNIT);
1492 save_area = gen_reg_rtx (save_mode);
1493 emit_move_insn (save_area, stack_area);
1499 /* Now store (and compute if necessary) all non-register parms.
1500 These come before register parms, since they can require block-moves,
1501 which could clobber the registers used for register parms.
1502 Parms which have partial registers are not stored here,
1503 but we do preallocate space here if they want that. */
1505 for (i = 0; i < num_actuals; i++)
1506 if (args[i].reg == 0 || args[i].pass_on_stack)
1507 store_one_arg (&args[i], argblock, may_be_alloca,
1508 args_size.var != 0, fndecl, reg_parm_stack_space);
1510 /* Now store any partially-in-registers parm.
1511 This is the last place a block-move can happen. */
1513 for (i = 0; i < num_actuals; i++)
1514 if (args[i].partial != 0 && ! args[i].pass_on_stack)
1515 store_one_arg (&args[i], argblock, may_be_alloca,
1516 args_size.var != 0, fndecl, reg_parm_stack_space);
1518 #ifndef PUSH_ARGS_REVERSED
1519 #ifdef STACK_BOUNDARY
1520 /* If we pushed args in forward order, perform stack alignment
1521 after pushing the last arg. */
1523 anti_adjust_stack (GEN_INT (args_size.constant
1524 - original_args_size.constant));
1528 /* If register arguments require space on the stack and stack space
1529 was not preallocated, allocate stack space here for arguments
1530 passed in registers. */
1531 #if ! defined(ALLOCATE_OUTGOING_ARGS) && defined(OUTGOING_REG_PARM_STACK_SPACE)
1532 if (must_preallocate == 0 && reg_parm_stack_space > 0)
1533 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
1536 /* Pass the function the address in which to return a structure value. */
1537 if (structure_value_addr && ! structure_value_addr_parm)
1539 emit_move_insn (struct_value_rtx,
1541 force_operand (structure_value_addr,
1543 if (GET_CODE (struct_value_rtx) == REG)
1545 push_to_sequence (use_insns);
1546 emit_insn (gen_rtx (USE, VOIDmode, struct_value_rtx));
1547 use_insns = get_insns ();
1552 /* Now do the register loads required for any wholly-register parms or any
1553 parms which are passed both on the stack and in a register. Their
1554 expressions were already evaluated.
1556 Mark all register-parms as living through the call, putting these USE
1557 insns in a list headed by USE_INSNS. */
1559 for (i = 0; i < num_actuals; i++)
1561 rtx list = args[i].reg;
1562 int partial = args[i].partial;
1569 /* Process each register that needs to get this arg. */
1570 if (GET_CODE (list) == EXPR_LIST)
1571 reg = XEXP (list, 0), list = XEXP (list, 1);
1573 reg = list, list = 0;
1575 /* Set to non-zero if must move a word at a time, even if just one
1576 word (e.g, partial == 1 && mode == DFmode). Set to zero if
1577 we just use a normal move insn. */
1578 nregs = (partial ? partial
1579 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1580 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1581 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1584 /* If simple case, just do move. If normal partial, store_one_arg
1585 has already loaded the register for us. In all other cases,
1586 load the register(s) from memory. */
1589 emit_move_insn (reg, args[i].value);
1590 else if (args[i].partial == 0 || args[i].pass_on_stack)
1591 move_block_to_reg (REGNO (reg),
1592 validize_mem (args[i].value), nregs,
1593 TYPE_MODE (TREE_TYPE (args[i].tree_value)));
1595 push_to_sequence (use_insns);
1597 emit_insn (gen_rtx (USE, VOIDmode, reg));
1599 use_regs (REGNO (reg), nregs);
1600 use_insns = get_insns ();
1603 /* PARTIAL referred only to the first register, so clear it for the
1609 /* Perform postincrements before actually calling the function. */
1612 /* All arguments and registers used for the call must be set up by now! */
1614 funexp = prepare_call_address (funexp, fndecl, &use_insns);
1616 /* Generate the actual call instruction. */
1617 emit_call_1 (funexp, funtype, args_size.constant, struct_value_size,
1618 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
1619 valreg, old_inhibit_defer_pop, use_insns, is_const);
1621 /* If call is cse'able, make appropriate pair of reg-notes around it.
1622 Test valreg so we don't crash; may safely ignore `const'
1623 if return type is void. */
1624 if (is_const && valreg != 0)
1627 rtx temp = gen_reg_rtx (GET_MODE (valreg));
1630 /* Construct an "equal form" for the value which mentions all the
1631 arguments in order as well as the function name. */
1632 #ifdef PUSH_ARGS_REVERSED
1633 for (i = 0; i < num_actuals; i++)
1634 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1636 for (i = num_actuals - 1; i >= 0; i--)
1637 note = gen_rtx (EXPR_LIST, VOIDmode, args[i].initial_value, note);
1639 note = gen_rtx (EXPR_LIST, VOIDmode, funexp, note);
1641 insns = get_insns ();
1644 emit_libcall_block (insns, temp, valreg, note);
1649 /* For calls to `setjmp', etc., inform flow.c it should complain
1650 if nonvolatile values are live. */
1654 emit_note (name, NOTE_INSN_SETJMP);
1655 current_function_calls_setjmp = 1;
1659 current_function_calls_longjmp = 1;
1661 /* Notice functions that cannot return.
1662 If optimizing, insns emitted below will be dead.
1663 If not optimizing, they will exist, which is useful
1664 if the user uses the `return' command in the debugger. */
1666 if (is_volatile || is_longjmp)
1669 /* If value type not void, return an rtx for the value. */
1671 /* If there are cleanups to be called, don't use a hard reg as target. */
1672 if (cleanups_this_call != old_cleanups
1673 && target && REG_P (target)
1674 && REGNO (target) < FIRST_PSEUDO_REGISTER)
1677 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
1680 target = const0_rtx;
1682 else if (structure_value_addr)
1684 if (target == 0 || GET_CODE (target) != MEM)
1686 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1687 memory_address (TYPE_MODE (TREE_TYPE (exp)),
1688 structure_value_addr));
1689 MEM_IN_STRUCT_P (target)
1690 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1691 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1692 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1695 else if (pcc_struct_value)
1699 target = gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1700 copy_to_reg (valreg));
1701 MEM_IN_STRUCT_P (target)
1702 = (TREE_CODE (TREE_TYPE (exp)) == ARRAY_TYPE
1703 || TREE_CODE (TREE_TYPE (exp)) == RECORD_TYPE
1704 || TREE_CODE (TREE_TYPE (exp)) == UNION_TYPE);
1706 else if (TYPE_MODE (TREE_TYPE (exp)) != BLKmode)
1707 emit_move_insn (target, gen_rtx (MEM, TYPE_MODE (TREE_TYPE (exp)),
1708 copy_to_reg (valreg)));
1710 emit_block_move (target, gen_rtx (MEM, BLKmode, copy_to_reg (valreg)),
1712 TYPE_ALIGN (TREE_TYPE (exp)) / BITS_PER_UNIT);
1714 else if (target && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
1715 && GET_MODE (target) == GET_MODE (valreg))
1716 /* TARGET and VALREG cannot be equal at this point because the latter
1717 would not have REG_FUNCTION_VALUE_P true, while the former would if
1718 it were referring to the same register.
1720 If they refer to the same register, this move will be a no-op, except
1721 when function inlining is being done. */
1722 emit_move_insn (target, valreg);
1724 target = copy_to_reg (valreg);
1726 #ifdef PROMOTE_FUNCTION_RETURN
1727 /* If we promoted this return value, make the proper SUBREG. */
1728 if (GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
1730 enum machine_mode mode = GET_MODE (target);
1731 int unsignedp = TREE_UNSIGNED (TREE_TYPE (exp));
1733 if (TREE_CODE (TREE_TYPE (exp)) == INTEGER_TYPE
1734 || TREE_CODE (TREE_TYPE (exp)) == ENUMERAL_TYPE
1735 || TREE_CODE (TREE_TYPE (exp)) == BOOLEAN_TYPE
1736 || TREE_CODE (TREE_TYPE (exp)) == CHAR_TYPE
1737 || TREE_CODE (TREE_TYPE (exp)) == REAL_TYPE
1738 || TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE
1739 || TREE_CODE (TREE_TYPE (exp)) == OFFSET_TYPE)
1741 PROMOTE_MODE (mode, unsignedp, TREE_TYPE (exp));
1744 target = gen_rtx (SUBREG, TYPE_MODE (TREE_TYPE (exp)), target, 0);
1745 SUBREG_PROMOTED_VAR_P (target) = 1;
1746 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
1750 /* Perform all cleanups needed for the arguments of this call
1751 (i.e. destructors in C++). */
1752 expand_cleanups_to (old_cleanups);
1754 /* If size of args is variable or this was a constructor call for a stack
1755 argument, restore saved stack-pointer value. */
1757 if (old_stack_level)
1759 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1760 pending_stack_adjust = old_pending_adj;
1761 #ifdef ACCUMULATE_OUTGOING_ARGS
1762 stack_arg_under_construction = old_stack_arg_under_construction;
1763 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1764 stack_usage_map = initial_stack_usage_map;
1767 #ifdef ACCUMULATE_OUTGOING_ARGS
1770 #ifdef REG_PARM_STACK_SPACE
1773 enum machine_mode save_mode = GET_MODE (save_area);
1775 = gen_rtx (MEM, save_mode,
1776 memory_address (save_mode,
1777 #ifdef ARGS_GROW_DOWNWARD
1778 plus_constant (argblock, - high_to_save)
1780 plus_constant (argblock, low_to_save)
1784 if (save_mode != BLKmode)
1785 emit_move_insn (stack_area, save_area);
1787 emit_block_move (stack_area, validize_mem (save_area),
1788 GEN_INT (high_to_save - low_to_save + 1),
1789 PARM_BOUNDARY / BITS_PER_UNIT);
1793 /* If we saved any argument areas, restore them. */
1794 for (i = 0; i < num_actuals; i++)
1795 if (args[i].save_area)
1797 enum machine_mode save_mode = GET_MODE (args[i].save_area);
1799 = gen_rtx (MEM, save_mode,
1800 memory_address (save_mode,
1801 XEXP (args[i].stack_slot, 0)));
1803 if (save_mode != BLKmode)
1804 emit_move_insn (stack_area, args[i].save_area);
1806 emit_block_move (stack_area, validize_mem (args[i].save_area),
1807 GEN_INT (args[i].size.constant),
1808 PARM_BOUNDARY / BITS_PER_UNIT);
1811 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
1812 stack_usage_map = initial_stack_usage_map;
1816 /* If this was alloca, record the new stack level for nonlocal gotos.
1817 Check for the handler slots since we might not have a save area
1818 for non-local gotos. */
1820 if (may_be_alloca && nonlocal_goto_handler_slot != 0)
1821 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
1829 /* Return an rtx which represents a suitable home on the stack
1830 given TYPE, the type of the argument looking for a home.
1831 This is called only for BLKmode arguments.
1833 SIZE is the size needed for this target.
1834 ARGS_ADDR is the address of the bottom of the argument block for this call.
1835 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
1836 if this machine uses push insns. */
1839 target_for_arg (type, size, args_addr, offset)
1843 struct args_size offset;
1846 rtx offset_rtx = ARGS_SIZE_RTX (offset);
1848 /* We do not call memory_address if possible,
1849 because we want to address as close to the stack
1850 as possible. For non-variable sized arguments,
1851 this will be stack-pointer relative addressing. */
1852 if (GET_CODE (offset_rtx) == CONST_INT)
1853 target = plus_constant (args_addr, INTVAL (offset_rtx));
1856 /* I have no idea how to guarantee that this
1857 will work in the presence of register parameters. */
1858 target = gen_rtx (PLUS, Pmode, args_addr, offset_rtx);
1859 target = memory_address (QImode, target);
1862 return gen_rtx (MEM, BLKmode, target);
1866 /* Store a single argument for a function call
1867 into the register or memory area where it must be passed.
1868 *ARG describes the argument value and where to pass it.
1870 ARGBLOCK is the address of the stack-block for all the arguments,
1871 or 0 on a machine where arguments are pushed individually.
1873 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
1874 so must be careful about how the stack is used.
1876 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
1877 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
1878 that we need not worry about saving and restoring the stack.
1880 FNDECL is the declaration of the function we are calling. */
1883 store_one_arg (arg, argblock, may_be_alloca, variable_size, fndecl,
1884 reg_parm_stack_space)
1885 struct arg_data *arg;
1890 int reg_parm_stack_space;
1892 register tree pval = arg->tree_value;
1896 int i, lower_bound, upper_bound;
1898 if (TREE_CODE (pval) == ERROR_MARK)
1901 #ifdef ACCUMULATE_OUTGOING_ARGS
1902 /* If this is being stored into a pre-allocated, fixed-size, stack area,
1903 save any previous data at that location. */
1904 if (argblock && ! variable_size && arg->stack)
1906 #ifdef ARGS_GROW_DOWNWARD
1907 /* stack_slot is negative, but we want to index stack_usage_map */
1908 /* with positive values. */
1909 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1910 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
1914 lower_bound = upper_bound - arg->size.constant;
1916 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
1917 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
1921 upper_bound = lower_bound + arg->size.constant;
1924 for (i = lower_bound; i < upper_bound; i++)
1925 if (stack_usage_map[i]
1926 #ifdef REG_PARM_STACK_SPACE
1927 /* Don't store things in the fixed argument area at this point;
1928 it has already been saved. */
1929 && i > reg_parm_stack_space
1934 if (i != upper_bound)
1936 /* We need to make a save area. See what mode we can make it. */
1937 enum machine_mode save_mode
1938 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
1940 = gen_rtx (MEM, save_mode,
1941 memory_address (save_mode, XEXP (arg->stack_slot, 0)));
1943 if (save_mode == BLKmode)
1945 arg->save_area = assign_stack_temp (BLKmode,
1946 arg->size.constant, 1);
1947 emit_block_move (validize_mem (arg->save_area), stack_area,
1948 GEN_INT (arg->size.constant),
1949 PARM_BOUNDARY / BITS_PER_UNIT);
1953 arg->save_area = gen_reg_rtx (save_mode);
1954 emit_move_insn (arg->save_area, stack_area);
1960 /* If this isn't going to be placed on both the stack and in registers,
1961 set up the register and number of words. */
1962 if (! arg->pass_on_stack)
1963 reg = arg->reg, partial = arg->partial;
1965 if (reg != 0 && partial == 0)
1966 /* Being passed entirely in a register. We shouldn't be called in
1970 /* If this is being partially passed in a register, but multiple locations
1971 are specified, we assume that the one partially used is the one that is
1973 if (reg && GET_CODE (reg) == EXPR_LIST)
1974 reg = XEXP (reg, 0);
1976 /* If this is being passes partially in a register, we can't evaluate
1977 it directly into its stack slot. Otherwise, we can. */
1978 if (arg->value == 0)
1980 #ifdef ACCUMULATE_OUTGOING_ARGS
1981 /* stack_arg_under_construction is nonzero if a function argument is
1982 being evaluated directly into the outgoing argument list and
1983 expand_call must take special action to preserve the argument list
1984 if it is called recursively.
1986 For scalar function arguments stack_usage_map is sufficient to
1987 determine which stack slots must be saved and restored. Scalar
1988 arguments in general have pass_on_stack == 0.
1990 If this argument is initialized by a function which takes the
1991 address of the argument (a C++ constructor or a C function
1992 returning a BLKmode structure), then stack_usage_map is
1993 insufficient and expand_call must push the stack around the
1994 function call. Such arguments have pass_on_stack == 1.
1996 Note that it is always safe to set stack_arg_under_construction,
1997 but this generates suboptimal code if set when not needed. */
1999 if (arg->pass_on_stack)
2000 stack_arg_under_construction++;
2002 arg->value = expand_expr (pval, partial ? NULL_RTX : arg->stack,
2004 #ifdef ACCUMULATE_OUTGOING_ARGS
2005 if (arg->pass_on_stack)
2006 stack_arg_under_construction--;
2010 /* Don't allow anything left on stack from computation
2011 of argument to alloca. */
2013 do_pending_stack_adjust ();
2015 if (arg->value == arg->stack)
2016 /* If the value is already in the stack slot, we are done. */
2018 else if (TYPE_MODE (TREE_TYPE (pval)) != BLKmode)
2022 /* Argument is a scalar, not entirely passed in registers.
2023 (If part is passed in registers, arg->partial says how much
2024 and emit_push_insn will take care of putting it there.)
2026 Push it, and if its size is less than the
2027 amount of space allocated to it,
2028 also bump stack pointer by the additional space.
2029 Note that in C the default argument promotions
2030 will prevent such mismatches. */
2032 size = GET_MODE_SIZE (TYPE_MODE (TREE_TYPE (pval)));
2033 /* Compute how much space the push instruction will push.
2034 On many machines, pushing a byte will advance the stack
2035 pointer by a halfword. */
2036 #ifdef PUSH_ROUNDING
2037 size = PUSH_ROUNDING (size);
2041 /* Compute how much space the argument should get:
2042 round up to a multiple of the alignment for arguments. */
2043 if (none != FUNCTION_ARG_PADDING (TYPE_MODE (TREE_TYPE (pval)),
2045 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
2046 / (PARM_BOUNDARY / BITS_PER_UNIT))
2047 * (PARM_BOUNDARY / BITS_PER_UNIT));
2049 /* This isn't already where we want it on the stack, so put it there.
2050 This can either be done with push or copy insns. */
2051 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2052 TREE_TYPE (pval), 0, 0, partial, reg,
2053 used - size, argblock, ARGS_SIZE_RTX (arg->offset));
2057 /* BLKmode, at least partly to be pushed. */
2059 register int excess;
2062 /* Pushing a nonscalar.
2063 If part is passed in registers, PARTIAL says how much
2064 and emit_push_insn will take care of putting it there. */
2066 /* Round its size up to a multiple
2067 of the allocation unit for arguments. */
2069 if (arg->size.var != 0)
2072 size_rtx = ARGS_SIZE_RTX (arg->size);
2076 register tree size = size_in_bytes (TREE_TYPE (pval));
2077 /* PUSH_ROUNDING has no effect on us, because
2078 emit_push_insn for BLKmode is careful to avoid it. */
2079 excess = (arg->size.constant - TREE_INT_CST_LOW (size)
2080 + partial * UNITS_PER_WORD);
2081 size_rtx = expand_expr (size, NULL_RTX, VOIDmode, 0);
2084 emit_push_insn (arg->value, TYPE_MODE (TREE_TYPE (pval)),
2085 TREE_TYPE (pval), size_rtx,
2086 TYPE_ALIGN (TREE_TYPE (pval)) / BITS_PER_UNIT, partial,
2087 reg, excess, argblock, ARGS_SIZE_RTX (arg->offset));
2091 /* Unless this is a partially-in-register argument, the argument is now
2094 ??? Note that this can change arg->value from arg->stack to
2095 arg->stack_slot and it matters when they are not the same.
2096 It isn't totally clear that this is correct in all cases. */
2098 arg->value = arg->stack_slot;
2100 /* Once we have pushed something, pops can't safely
2101 be deferred during the rest of the arguments. */
2104 /* ANSI doesn't require a sequence point here,
2105 but PCC has one, so this will avoid some problems. */
2108 /* Free any temporary slots made in processing this argument. */
2111 #ifdef ACCUMULATE_OUTGOING_ARGS
2112 /* Now mark the segment we just used. */
2113 if (argblock && ! variable_size && arg->stack)
2114 for (i = lower_bound; i < upper_bound; i++)
2115 stack_usage_map[i] = 1;