1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
3 1999, 2000 Free Software Foundation, Inc.
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
30 #include "insn-flags.h"
35 #ifndef ACCUMULATE_OUTGOING_ARGS
36 #define ACCUMULATE_OUTGOING_ARGS 0
39 /* Supply a default definition for PUSH_ARGS. */
42 #define PUSH_ARGS !ACCUMULATE_OUTGOING_ARGS
48 #if !defined FUNCTION_OK_FOR_SIBCALL
49 #define FUNCTION_OK_FOR_SIBCALL(DECL) 1
52 #if !defined PREFERRED_STACK_BOUNDARY && defined STACK_BOUNDARY
53 #define PREFERRED_STACK_BOUNDARY STACK_BOUNDARY
56 /* Decide whether a function's arguments should be processed
57 from first to last or from last to first.
59 They should if the stack and args grow in opposite directions, but
60 only if we have push insns. */
64 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
65 #define PUSH_ARGS_REVERSED PUSH_ARGS
70 #ifndef PUSH_ARGS_REVERSED
71 #define PUSH_ARGS_REVERSED 0
74 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
75 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
77 /* Data structure and subroutines used within expand_call. */
81 /* Tree node for this argument. */
83 /* Mode for value; TYPE_MODE unless promoted. */
84 enum machine_mode mode;
85 /* Current RTL value for argument, or 0 if it isn't precomputed. */
87 /* Initially-compute RTL value for argument; only for const functions. */
89 /* Register to pass this argument in, 0 if passed on stack, or an
90 PARALLEL if the arg is to be copied into multiple non-contiguous
93 /* Register to pass this argument in when generating tail call sequence.
94 This is not the same register as for normal calls on machines with
97 /* If REG was promoted from the actual mode of the argument expression,
98 indicates whether the promotion is sign- or zero-extended. */
100 /* Number of registers to use. 0 means put the whole arg in registers.
101 Also 0 if not passed in registers. */
103 /* Non-zero if argument must be passed on stack.
104 Note that some arguments may be passed on the stack
105 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
106 pass_on_stack identifies arguments that *cannot* go in registers. */
108 /* Offset of this argument from beginning of stack-args. */
109 struct args_size offset;
110 /* Similar, but offset to the start of the stack slot. Different from
111 OFFSET if this arg pads downward. */
112 struct args_size slot_offset;
113 /* Size of this argument on the stack, rounded up for any padding it gets,
114 parts of the argument passed in registers do not count.
115 If REG_PARM_STACK_SPACE is defined, then register parms
116 are counted here as well. */
117 struct args_size size;
118 /* Location on the stack at which parameter should be stored. The store
119 has already been done if STACK == VALUE. */
121 /* Location on the stack of the start of this argument slot. This can
122 differ from STACK if this arg pads downward. This location is known
123 to be aligned to FUNCTION_ARG_BOUNDARY. */
125 /* Place that this stack area has been saved, if needed. */
127 /* If an argument's alignment does not permit direct copying into registers,
128 copy in smaller-sized pieces into pseudos. These are stored in a
129 block pointed to by this field. The next field says how many
130 word-sized pseudos we made. */
133 /* The amount that the stack pointer needs to be adjusted to
134 force alignment for the next argument. */
135 struct args_size alignment_pad;
138 /* A vector of one char per byte of stack space. A byte if non-zero if
139 the corresponding stack location has been used.
140 This vector is used to prevent a function call within an argument from
141 clobbering any stack already set up. */
142 static char *stack_usage_map;
144 /* Size of STACK_USAGE_MAP. */
145 static int highest_outgoing_arg_in_use;
147 /* stack_arg_under_construction is nonzero when an argument may be
148 initialized with a constructor call (including a C function that
149 returns a BLKmode struct) and expand_call must take special action
150 to make sure the object being constructed does not overlap the
151 argument list for the constructor call. */
152 int stack_arg_under_construction;
154 static int calls_function PARAMS ((tree, int));
155 static int calls_function_1 PARAMS ((tree, int));
157 /* Nonzero if this is a call to a `const' function. */
159 /* Nonzero if this is a call to a `volatile' function. */
160 #define ECF_NORETURN 2
161 /* Nonzero if this is a call to malloc or a related function. */
163 /* Nonzero if it is plausible that this is a call to alloca. */
164 #define ECF_MAY_BE_ALLOCA 8
165 /* Nonzero if this is a call to a function that won't throw an exception. */
166 #define ECF_NOTHROW 16
167 /* Nonzero if this is a call to setjmp or a related function. */
168 #define ECF_RETURNS_TWICE 32
169 /* Nonzero if this is a call to `longjmp'. */
170 #define ECF_LONGJMP 64
171 /* Nonzero if this is a syscall that makes a new process in the image of
173 #define ECF_FORK_OR_EXEC 128
174 #define ECF_SIBCALL 256
175 /* Nonzero if this is a call to "pure" function (like const function,
176 but may read memory. */
179 static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
180 HOST_WIDE_INT, HOST_WIDE_INT, rtx,
181 rtx, int, rtx, int));
182 static void precompute_register_parameters PARAMS ((int,
185 static void store_one_arg PARAMS ((struct arg_data *, rtx, int, int,
187 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
189 static int finalize_must_preallocate PARAMS ((int, int,
191 struct args_size *));
192 static void precompute_arguments PARAMS ((int, int,
194 static int compute_argument_block_size PARAMS ((int,
197 static void initialize_argument_information PARAMS ((int,
204 static void compute_argument_addresses PARAMS ((struct arg_data *,
206 static rtx rtx_for_function_call PARAMS ((tree, tree));
207 static void load_register_parameters PARAMS ((struct arg_data *,
209 static int libfunc_nothrow PARAMS ((rtx));
210 static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx, int,
213 static int special_function_p PARAMS ((tree, int));
214 static int flags_from_decl_or_type PARAMS ((tree));
215 static rtx try_to_integrate PARAMS ((tree, tree, rtx,
217 static int combine_pending_stack_adjustment_and_call
218 PARAMS ((int, struct args_size *, int));
220 #ifdef REG_PARM_STACK_SPACE
221 static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *));
222 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
225 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
228 If WHICH is 0, return 1 if EXP contains a call to any function.
229 Actually, we only need return 1 if evaluating EXP would require pushing
230 arguments on the stack, but that is too difficult to compute, so we just
231 assume any function call might require the stack. */
233 static tree calls_function_save_exprs;
236 calls_function (exp, which)
242 calls_function_save_exprs = 0;
243 val = calls_function_1 (exp, which);
244 calls_function_save_exprs = 0;
248 /* Recursive function to do the work of above function. */
251 calls_function_1 (exp, which)
256 enum tree_code code = TREE_CODE (exp);
257 int class = TREE_CODE_CLASS (code);
258 int length = first_rtl_op (code);
260 /* If this code is language-specific, we don't know what it will do. */
261 if ((int) code >= NUM_TREE_CODES)
269 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
270 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
272 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
274 & ECF_MAY_BE_ALLOCA))
280 if (SAVE_EXPR_RTL (exp) != 0)
282 if (value_member (exp, calls_function_save_exprs))
284 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
285 calls_function_save_exprs);
286 return (TREE_OPERAND (exp, 0) != 0
287 && calls_function_1 (TREE_OPERAND (exp, 0), which));
292 register tree subblock;
294 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
295 if (DECL_INITIAL (local) != 0
296 && calls_function_1 (DECL_INITIAL (local), which))
299 for (subblock = BLOCK_SUBBLOCKS (exp);
301 subblock = TREE_CHAIN (subblock))
302 if (calls_function_1 (subblock, which))
308 for (; exp != 0; exp = TREE_CHAIN (exp))
309 if (calls_function_1 (TREE_VALUE (exp), which))
317 /* Only expressions, references, and blocks can contain calls. */
318 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
321 for (i = 0; i < length; i++)
322 if (TREE_OPERAND (exp, i) != 0
323 && calls_function_1 (TREE_OPERAND (exp, i), which))
329 /* Force FUNEXP into a form suitable for the address of a CALL,
330 and return that as an rtx. Also load the static chain register
331 if FNDECL is a nested function.
333 CALL_FUSAGE points to a variable holding the prospective
334 CALL_INSN_FUNCTION_USAGE information. */
337 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen)
343 rtx static_chain_value = 0;
345 funexp = protect_from_queue (funexp, 0);
348 /* Get possible static chain value for nested function in C. */
349 static_chain_value = lookup_static_chain (fndecl);
351 /* Make a valid memory address and copy constants thru pseudo-regs,
352 but not for a constant address if -fno-function-cse. */
353 if (GET_CODE (funexp) != SYMBOL_REF)
354 /* If we are using registers for parameters, force the
355 function address into a register now. */
356 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
357 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
358 : memory_address (FUNCTION_MODE, funexp));
361 #ifndef NO_FUNCTION_CSE
362 if (optimize && ! flag_no_function_cse)
363 #ifdef NO_RECURSIVE_FUNCTION_CSE
364 if (fndecl != current_function_decl)
366 funexp = force_reg (Pmode, funexp);
370 if (static_chain_value != 0)
372 emit_move_insn (static_chain_rtx, static_chain_value);
374 if (GET_CODE (static_chain_rtx) == REG)
375 use_reg (call_fusage, static_chain_rtx);
381 /* Generate instructions to call function FUNEXP,
382 and optionally pop the results.
383 The CALL_INSN is the first insn generated.
385 FNDECL is the declaration node of the function. This is given to the
386 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
388 FUNTYPE is the data type of the function. This is given to the macro
389 RETURN_POPS_ARGS to determine whether this function pops its own args.
390 We used to allow an identifier for library functions, but that doesn't
391 work when the return type is an aggregate type and the calling convention
392 says that the pointer to this aggregate is to be popped by the callee.
394 STACK_SIZE is the number of bytes of arguments on the stack,
395 ROUNDED_STACK_SIZE is that number rounded up to
396 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
397 both to put into the call insn and to generate explicit popping
400 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
401 It is zero if this call doesn't want a structure value.
403 NEXT_ARG_REG is the rtx that results from executing
404 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
405 just after all the args have had their registers assigned.
406 This could be whatever you like, but normally it is the first
407 arg-register beyond those used for args in this call,
408 or 0 if all the arg-registers are used in this call.
409 It is passed on to `gen_call' so you can put this info in the call insn.
411 VALREG is a hard register in which a value is returned,
412 or 0 if the call does not return a value.
414 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
415 the args to this call were processed.
416 We restore `inhibit_defer_pop' to that value.
418 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
419 denote registers used by the called function. */
422 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
423 struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
424 call_fusage, ecf_flags)
426 tree fndecl ATTRIBUTE_UNUSED;
427 tree funtype ATTRIBUTE_UNUSED;
428 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
429 HOST_WIDE_INT rounded_stack_size;
430 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
433 int old_inhibit_defer_pop;
437 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
439 int already_popped = 0;
440 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
441 #if defined (HAVE_call) && defined (HAVE_call_value)
442 rtx struct_value_size_rtx;
443 struct_value_size_rtx = GEN_INT (struct_value_size);
446 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
447 and we don't want to load it into a register as an optimization,
448 because prepare_call_address already did it if it should be done. */
449 if (GET_CODE (funexp) != SYMBOL_REF)
450 funexp = memory_address (FUNCTION_MODE, funexp);
452 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
453 if ((ecf_flags & ECF_SIBCALL)
454 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
455 && (RETURN_POPS_ARGS (fndecl, funtype, stack_size) > 0
458 rtx n_pop = GEN_INT (RETURN_POPS_ARGS (fndecl, funtype, stack_size));
461 /* If this subroutine pops its own args, record that in the call insn
462 if possible, for the sake of frame pointer elimination. */
465 pat = GEN_SIBCALL_VALUE_POP (valreg,
466 gen_rtx_MEM (FUNCTION_MODE, funexp),
467 rounded_stack_size_rtx, next_arg_reg,
470 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
471 rounded_stack_size_rtx, next_arg_reg, n_pop);
473 emit_call_insn (pat);
479 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
480 /* If the target has "call" or "call_value" insns, then prefer them
481 if no arguments are actually popped. If the target does not have
482 "call" or "call_value" insns, then we must use the popping versions
483 even if the call has no arguments to pop. */
484 #if defined (HAVE_call) && defined (HAVE_call_value)
485 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
488 if (HAVE_call_pop && HAVE_call_value_pop)
491 rtx n_pop = GEN_INT (n_popped);
494 /* If this subroutine pops its own args, record that in the call insn
495 if possible, for the sake of frame pointer elimination. */
498 pat = GEN_CALL_VALUE_POP (valreg,
499 gen_rtx_MEM (FUNCTION_MODE, funexp),
500 rounded_stack_size_rtx, next_arg_reg, n_pop);
502 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
503 rounded_stack_size_rtx, next_arg_reg, n_pop);
505 emit_call_insn (pat);
511 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
512 if ((ecf_flags & ECF_SIBCALL)
513 && HAVE_sibcall && HAVE_sibcall_value)
516 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
517 gen_rtx_MEM (FUNCTION_MODE, funexp),
518 rounded_stack_size_rtx,
519 next_arg_reg, NULL_RTX));
521 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
522 rounded_stack_size_rtx, next_arg_reg,
523 struct_value_size_rtx));
528 #if defined (HAVE_call) && defined (HAVE_call_value)
529 if (HAVE_call && HAVE_call_value)
532 emit_call_insn (GEN_CALL_VALUE (valreg,
533 gen_rtx_MEM (FUNCTION_MODE, funexp),
534 rounded_stack_size_rtx, next_arg_reg,
537 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
538 rounded_stack_size_rtx, next_arg_reg,
539 struct_value_size_rtx));
545 /* Find the CALL insn we just emitted. */
546 for (call_insn = get_last_insn ();
547 call_insn && GET_CODE (call_insn) != CALL_INSN;
548 call_insn = PREV_INSN (call_insn))
554 /* Mark memory as used for "pure" function call. */
555 if (ecf_flags & ECF_PURE)
557 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
558 gen_rtx_USE (VOIDmode,
559 gen_rtx_MEM (BLKmode,
560 gen_rtx_SCRATCH (VOIDmode))), call_fusage);
563 /* Put the register usage information on the CALL. If there is already
564 some usage information, put ours at the end. */
565 if (CALL_INSN_FUNCTION_USAGE (call_insn))
569 for (link = CALL_INSN_FUNCTION_USAGE (call_insn); XEXP (link, 1) != 0;
570 link = XEXP (link, 1))
573 XEXP (link, 1) = call_fusage;
576 CALL_INSN_FUNCTION_USAGE (call_insn) = call_fusage;
578 /* If this is a const call, then set the insn's unchanging bit. */
579 if (ecf_flags & (ECF_CONST | ECF_PURE))
580 CONST_CALL_P (call_insn) = 1;
582 /* If this call can't throw, attach a REG_EH_REGION reg note to that
584 if (ecf_flags & ECF_NOTHROW)
585 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
586 REG_NOTES (call_insn));
588 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
590 /* Restore this now, so that we do defer pops for this call's args
591 if the context of the call as a whole permits. */
592 inhibit_defer_pop = old_inhibit_defer_pop;
597 CALL_INSN_FUNCTION_USAGE (call_insn)
598 = gen_rtx_EXPR_LIST (VOIDmode,
599 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
600 CALL_INSN_FUNCTION_USAGE (call_insn));
601 rounded_stack_size -= n_popped;
602 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
603 stack_pointer_delta -= n_popped;
606 if (!ACCUMULATE_OUTGOING_ARGS)
608 /* If returning from the subroutine does not automatically pop the args,
609 we need an instruction to pop them sooner or later.
610 Perhaps do it now; perhaps just record how much space to pop later.
612 If returning from the subroutine does pop the args, indicate that the
613 stack pointer will be changed. */
615 if (rounded_stack_size != 0)
617 if (flag_defer_pop && inhibit_defer_pop == 0
618 && !(ecf_flags & (ECF_CONST | ECF_PURE)))
619 pending_stack_adjust += rounded_stack_size;
621 adjust_stack (rounded_stack_size_rtx);
624 /* When we accumulate outgoing args, we must avoid any stack manipulations.
625 Restore the stack pointer to its original value now. Usually
626 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
627 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
628 popping variants of functions exist as well.
630 ??? We may optimize similar to defer_pop above, but it is
631 probably not worthwhile.
633 ??? It will be worthwhile to enable combine_stack_adjustments even for
636 anti_adjust_stack (GEN_INT (n_popped));
639 /* Determine if the function identified by NAME and FNDECL is one with
640 special properties we wish to know about.
642 For example, if the function might return more than one time (setjmp), then
643 set RETURNS_TWICE to a nonzero value.
645 Similarly set LONGJMP for if the function is in the longjmp family.
647 Set MALLOC for any of the standard memory allocation functions which
648 allocate from the heap.
650 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
651 space from the stack such as alloca. */
654 special_function_p (fndecl, flags)
658 if (! (flags & ECF_MALLOC)
659 && fndecl && DECL_NAME (fndecl)
660 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
661 /* Exclude functions not at the file scope, or not `extern',
662 since they are not the magic functions we would otherwise
664 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
666 char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
669 /* We assume that alloca will always be called by name. It
670 makes no sense to pass it as a pointer-to-function to
671 anything that does not understand its behavior. */
672 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
674 && ! strcmp (name, "alloca"))
675 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
677 && ! strcmp (name, "__builtin_alloca"))))
678 flags |= ECF_MAY_BE_ALLOCA;
680 /* Disregard prefix _, __ or __x. */
683 if (name[1] == '_' && name[2] == 'x')
685 else if (name[1] == '_')
694 && (! strcmp (tname, "setjmp")
695 || ! strcmp (tname, "setjmp_syscall")))
697 && ! strcmp (tname, "sigsetjmp"))
699 && ! strcmp (tname, "savectx")))
700 flags |= ECF_RETURNS_TWICE;
703 && ! strcmp (tname, "siglongjmp"))
704 flags |= ECF_LONGJMP;
706 else if ((tname[0] == 'q' && tname[1] == 's'
707 && ! strcmp (tname, "qsetjmp"))
708 || (tname[0] == 'v' && tname[1] == 'f'
709 && ! strcmp (tname, "vfork")))
710 flags |= ECF_RETURNS_TWICE;
712 else if (tname[0] == 'l' && tname[1] == 'o'
713 && ! strcmp (tname, "longjmp"))
714 flags |= ECF_LONGJMP;
716 else if ((tname[0] == 'f' && tname[1] == 'o'
717 && ! strcmp (tname, "fork"))
718 /* Linux specific: __clone. check NAME to insist on the
719 leading underscores, to avoid polluting the ISO / POSIX
721 || (name[0] == '_' && name[1] == '_'
722 && ! strcmp (tname, "clone"))
723 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
724 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
726 || ((tname[5] == 'p' || tname[5] == 'e')
727 && tname[6] == '\0'))))
728 flags |= ECF_FORK_OR_EXEC;
730 /* Do not add any more malloc-like functions to this list,
731 instead mark them as malloc functions using the malloc attribute.
732 Note, realloc is not suitable for attribute malloc since
733 it may return the same address across multiple calls.
734 C++ operator new is not suitable because it is not required
735 to return a unique pointer; indeed, the standard placement new
736 just returns its argument. */
737 else if (TYPE_MODE (TREE_TYPE (TREE_TYPE (fndecl))) == Pmode
738 && (! strcmp (tname, "malloc")
739 || ! strcmp (tname, "calloc")
740 || ! strcmp (tname, "strdup")))
746 /* Return nonzero when tree represent call to longjmp. */
748 setjmp_call_p (fndecl)
751 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
754 /* Detect flags (function attributes) from the function type node. */
756 flags_from_decl_or_type (exp)
760 /* ??? We can't set IS_MALLOC for function types? */
763 /* The function exp may have the `malloc' attribute. */
764 if (DECL_P (exp) && DECL_IS_MALLOC (exp))
767 /* The function exp may have the `pure' attribute. */
768 if (DECL_P (exp) && DECL_IS_PURE (exp))
771 if (TREE_NOTHROW (exp))
772 flags |= ECF_NOTHROW;
775 if (TREE_READONLY (exp) && !TREE_THIS_VOLATILE (exp))
778 if (TREE_THIS_VOLATILE (exp))
779 flags |= ECF_NORETURN;
785 /* Precompute all register parameters as described by ARGS, storing values
786 into fields within the ARGS array.
788 NUM_ACTUALS indicates the total number elements in the ARGS array.
790 Set REG_PARM_SEEN if we encounter a register parameter. */
793 precompute_register_parameters (num_actuals, args, reg_parm_seen)
795 struct arg_data *args;
802 for (i = 0; i < num_actuals; i++)
803 if (args[i].reg != 0 && ! args[i].pass_on_stack)
807 if (args[i].value == 0)
810 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
812 preserve_temp_slots (args[i].value);
815 /* ANSI doesn't require a sequence point here,
816 but PCC has one, so this will avoid some problems. */
820 /* If we are to promote the function arg to a wider mode,
823 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
825 = convert_modes (args[i].mode,
826 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
827 args[i].value, args[i].unsignedp);
829 /* If the value is expensive, and we are inside an appropriately
830 short loop, put the value into a pseudo and then put the pseudo
833 For small register classes, also do this if this call uses
834 register parameters. This is to avoid reload conflicts while
835 loading the parameters registers. */
837 if ((! (GET_CODE (args[i].value) == REG
838 || (GET_CODE (args[i].value) == SUBREG
839 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
840 && args[i].mode != BLKmode
841 && rtx_cost (args[i].value, SET) > 2
842 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
843 || preserve_subexpressions_p ()))
844 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
848 #ifdef REG_PARM_STACK_SPACE
850 /* The argument list is the property of the called routine and it
851 may clobber it. If the fixed area has been used for previous
852 parameters, we must save and restore it. */
854 save_fixed_argument_area (reg_parm_stack_space, argblock,
855 low_to_save, high_to_save)
856 int reg_parm_stack_space;
862 rtx save_area = NULL_RTX;
864 /* Compute the boundary of the that needs to be saved, if any. */
865 #ifdef ARGS_GROW_DOWNWARD
866 for (i = 0; i < reg_parm_stack_space + 1; i++)
868 for (i = 0; i < reg_parm_stack_space; i++)
871 if (i >= highest_outgoing_arg_in_use
872 || stack_usage_map[i] == 0)
875 if (*low_to_save == -1)
881 if (*low_to_save >= 0)
883 int num_to_save = *high_to_save - *low_to_save + 1;
884 enum machine_mode save_mode
885 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
888 /* If we don't have the required alignment, must do this in BLKmode. */
889 if ((*low_to_save & (MIN (GET_MODE_SIZE (save_mode),
890 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
893 #ifdef ARGS_GROW_DOWNWARD
894 stack_area = gen_rtx_MEM (save_mode,
895 memory_address (save_mode,
896 plus_constant (argblock,
899 stack_area = gen_rtx_MEM (save_mode,
900 memory_address (save_mode,
901 plus_constant (argblock,
904 if (save_mode == BLKmode)
906 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
907 /* Cannot use emit_block_move here because it can be done by a
908 library call which in turn gets into this place again and deadly
909 infinite recursion happens. */
910 move_by_pieces (validize_mem (save_area), stack_area, num_to_save,
915 save_area = gen_reg_rtx (save_mode);
916 emit_move_insn (save_area, stack_area);
923 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
929 enum machine_mode save_mode = GET_MODE (save_area);
930 #ifdef ARGS_GROW_DOWNWARD
932 = gen_rtx_MEM (save_mode,
933 memory_address (save_mode,
934 plus_constant (argblock,
938 = gen_rtx_MEM (save_mode,
939 memory_address (save_mode,
940 plus_constant (argblock,
944 if (save_mode != BLKmode)
945 emit_move_insn (stack_area, save_area);
947 /* Cannot use emit_block_move here because it can be done by a library
948 call which in turn gets into this place again and deadly infinite
949 recursion happens. */
950 move_by_pieces (stack_area, validize_mem (save_area),
951 high_to_save - low_to_save + 1, PARM_BOUNDARY);
955 /* If any elements in ARGS refer to parameters that are to be passed in
956 registers, but not in memory, and whose alignment does not permit a
957 direct copy into registers. Copy the values into a group of pseudos
958 which we will later copy into the appropriate hard registers.
960 Pseudos for each unaligned argument will be stored into the array
961 args[argnum].aligned_regs. The caller is responsible for deallocating
962 the aligned_regs array if it is nonzero. */
965 store_unaligned_arguments_into_pseudos (args, num_actuals)
966 struct arg_data *args;
971 for (i = 0; i < num_actuals; i++)
972 if (args[i].reg != 0 && ! args[i].pass_on_stack
973 && args[i].mode == BLKmode
974 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
975 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
977 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
978 int big_endian_correction = 0;
980 args[i].n_aligned_regs
981 = args[i].partial ? args[i].partial
982 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
984 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
985 * args[i].n_aligned_regs);
987 /* Structures smaller than a word are aligned to the least
988 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
989 this means we must skip the empty high order bytes when
990 calculating the bit offset. */
991 if (BYTES_BIG_ENDIAN && bytes < UNITS_PER_WORD)
992 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
994 for (j = 0; j < args[i].n_aligned_regs; j++)
996 rtx reg = gen_reg_rtx (word_mode);
997 rtx word = operand_subword_force (args[i].value, j, BLKmode);
998 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
999 int bitalign = TYPE_ALIGN (TREE_TYPE (args[i].tree_value));
1001 args[i].aligned_regs[j] = reg;
1003 /* There is no need to restrict this code to loading items
1004 in TYPE_ALIGN sized hunks. The bitfield instructions can
1005 load up entire word sized registers efficiently.
1007 ??? This may not be needed anymore.
1008 We use to emit a clobber here but that doesn't let later
1009 passes optimize the instructions we emit. By storing 0 into
1010 the register later passes know the first AND to zero out the
1011 bitfield being set in the register is unnecessary. The store
1012 of 0 will be deleted as will at least the first AND. */
1014 emit_move_insn (reg, const0_rtx);
1016 bytes -= bitsize / BITS_PER_UNIT;
1017 store_bit_field (reg, bitsize, big_endian_correction, word_mode,
1018 extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1019 word_mode, word_mode, bitalign,
1021 bitalign, BITS_PER_WORD);
1026 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1029 NUM_ACTUALS is the total number of parameters.
1031 N_NAMED_ARGS is the total number of named arguments.
1033 FNDECL is the tree code for the target of this call (if known)
1035 ARGS_SO_FAR holds state needed by the target to know where to place
1038 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1039 for arguments which are passed in registers.
1041 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1042 and may be modified by this routine.
1044 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1045 flags which may may be modified by this routine. */
1048 initialize_argument_information (num_actuals, args, args_size, n_named_args,
1049 actparms, fndecl, args_so_far,
1050 reg_parm_stack_space, old_stack_level,
1051 old_pending_adj, must_preallocate,
1053 int num_actuals ATTRIBUTE_UNUSED;
1054 struct arg_data *args;
1055 struct args_size *args_size;
1056 int n_named_args ATTRIBUTE_UNUSED;
1059 CUMULATIVE_ARGS *args_so_far;
1060 int reg_parm_stack_space;
1061 rtx *old_stack_level;
1062 int *old_pending_adj;
1063 int *must_preallocate;
1066 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1069 /* Count arg position in order args appear. */
1072 struct args_size alignment_pad;
1076 args_size->constant = 0;
1079 /* In this loop, we consider args in the order they are written.
1080 We fill up ARGS from the front or from the back if necessary
1081 so that in any case the first arg to be pushed ends up at the front. */
1083 if (PUSH_ARGS_REVERSED)
1085 i = num_actuals - 1, inc = -1;
1086 /* In this case, must reverse order of args
1087 so that we compute and push the last arg first. */
1094 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1095 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1097 tree type = TREE_TYPE (TREE_VALUE (p));
1099 enum machine_mode mode;
1101 args[i].tree_value = TREE_VALUE (p);
1103 /* Replace erroneous argument with constant zero. */
1104 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1105 args[i].tree_value = integer_zero_node, type = integer_type_node;
1107 /* If TYPE is a transparent union, pass things the way we would
1108 pass the first field of the union. We have already verified that
1109 the modes are the same. */
1110 if (TYPE_TRANSPARENT_UNION (type))
1111 type = TREE_TYPE (TYPE_FIELDS (type));
1113 /* Decide where to pass this arg.
1115 args[i].reg is nonzero if all or part is passed in registers.
1117 args[i].partial is nonzero if part but not all is passed in registers,
1118 and the exact value says how many words are passed in registers.
1120 args[i].pass_on_stack is nonzero if the argument must at least be
1121 computed on the stack. It may then be loaded back into registers
1122 if args[i].reg is nonzero.
1124 These decisions are driven by the FUNCTION_... macros and must agree
1125 with those made by function.c. */
1127 /* See if this argument should be passed by invisible reference. */
1128 if ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1129 && contains_placeholder_p (TYPE_SIZE (type)))
1130 || TREE_ADDRESSABLE (type)
1131 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1132 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1133 type, argpos < n_named_args)
1137 /* If we're compiling a thunk, pass through invisible
1138 references instead of making a copy. */
1139 if (current_function_is_thunk
1140 #ifdef FUNCTION_ARG_CALLEE_COPIES
1141 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1142 type, argpos < n_named_args)
1143 /* If it's in a register, we must make a copy of it too. */
1144 /* ??? Is this a sufficient test? Is there a better one? */
1145 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1146 && REG_P (DECL_RTL (args[i].tree_value)))
1147 && ! TREE_ADDRESSABLE (type))
1151 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1152 new object from the argument. If we are passing by
1153 invisible reference, the callee will do that for us, so we
1154 can strip off the TARGET_EXPR. This is not always safe,
1155 but it is safe in the only case where this is a useful
1156 optimization; namely, when the argument is a plain object.
1157 In that case, the frontend is just asking the backend to
1158 make a bitwise copy of the argument. */
1160 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1161 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1162 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1163 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1165 args[i].tree_value = build1 (ADDR_EXPR,
1166 build_pointer_type (type),
1167 args[i].tree_value);
1168 type = build_pointer_type (type);
1172 /* We make a copy of the object and pass the address to the
1173 function being called. */
1176 if (!COMPLETE_TYPE_P (type)
1177 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1178 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1179 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1180 STACK_CHECK_MAX_VAR_SIZE))))
1182 /* This is a variable-sized object. Make space on the stack
1184 rtx size_rtx = expr_size (TREE_VALUE (p));
1186 if (*old_stack_level == 0)
1188 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1189 *old_pending_adj = pending_stack_adjust;
1190 pending_stack_adjust = 0;
1193 copy = gen_rtx_MEM (BLKmode,
1194 allocate_dynamic_stack_space (size_rtx,
1196 TYPE_ALIGN (type)));
1200 int size = int_size_in_bytes (type);
1201 copy = assign_stack_temp (TYPE_MODE (type), size, 0);
1204 MEM_SET_IN_STRUCT_P (copy, AGGREGATE_TYPE_P (type));
1206 store_expr (args[i].tree_value, copy, 0);
1207 *ecf_flags &= ~(ECF_CONST | ECF_PURE);
1209 args[i].tree_value = build1 (ADDR_EXPR,
1210 build_pointer_type (type),
1211 make_tree (type, copy));
1212 type = build_pointer_type (type);
1216 mode = TYPE_MODE (type);
1217 unsignedp = TREE_UNSIGNED (type);
1219 #ifdef PROMOTE_FUNCTION_ARGS
1220 mode = promote_mode (type, mode, &unsignedp, 1);
1223 args[i].unsignedp = unsignedp;
1224 args[i].mode = mode;
1226 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1227 argpos < n_named_args);
1228 #ifdef FUNCTION_INCOMING_ARG
1229 /* If this is a sibling call and the machine has register windows, the
1230 register window has to be unwinded before calling the routine, so
1231 arguments have to go into the incoming registers. */
1232 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1233 argpos < n_named_args);
1235 args[i].tail_call_reg = args[i].reg;
1238 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1241 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1242 argpos < n_named_args);
1245 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1247 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1248 it means that we are to pass this arg in the register(s) designated
1249 by the PARALLEL, but also to pass it in the stack. */
1250 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1251 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1252 args[i].pass_on_stack = 1;
1254 /* If this is an addressable type, we must preallocate the stack
1255 since we must evaluate the object into its final location.
1257 If this is to be passed in both registers and the stack, it is simpler
1259 if (TREE_ADDRESSABLE (type)
1260 || (args[i].pass_on_stack && args[i].reg != 0))
1261 *must_preallocate = 1;
1263 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1264 we cannot consider this function call constant. */
1265 if (TREE_ADDRESSABLE (type))
1266 *ecf_flags &= ~(ECF_CONST | ECF_PURE);
1268 /* Compute the stack-size of this argument. */
1269 if (args[i].reg == 0 || args[i].partial != 0
1270 || reg_parm_stack_space > 0
1271 || args[i].pass_on_stack)
1272 locate_and_pad_parm (mode, type,
1273 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1278 fndecl, args_size, &args[i].offset,
1279 &args[i].size, &alignment_pad);
1281 #ifndef ARGS_GROW_DOWNWARD
1282 args[i].slot_offset = *args_size;
1285 args[i].alignment_pad = alignment_pad;
1287 /* If a part of the arg was put into registers,
1288 don't include that part in the amount pushed. */
1289 if (reg_parm_stack_space == 0 && ! args[i].pass_on_stack)
1290 args[i].size.constant -= ((args[i].partial * UNITS_PER_WORD)
1291 / (PARM_BOUNDARY / BITS_PER_UNIT)
1292 * (PARM_BOUNDARY / BITS_PER_UNIT));
1294 /* Update ARGS_SIZE, the total stack space for args so far. */
1296 args_size->constant += args[i].size.constant;
1297 if (args[i].size.var)
1299 ADD_PARM_SIZE (*args_size, args[i].size.var);
1302 /* Since the slot offset points to the bottom of the slot,
1303 we must record it after incrementing if the args grow down. */
1304 #ifdef ARGS_GROW_DOWNWARD
1305 args[i].slot_offset = *args_size;
1307 args[i].slot_offset.constant = -args_size->constant;
1309 SUB_PARM_SIZE (args[i].slot_offset, args_size->var);
1312 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1313 have been used, etc. */
1315 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1316 argpos < n_named_args);
1320 /* Update ARGS_SIZE to contain the total size for the argument block.
1321 Return the original constant component of the argument block's size.
1323 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1324 for arguments passed in registers. */
1327 compute_argument_block_size (reg_parm_stack_space, args_size,
1328 preferred_stack_boundary)
1329 int reg_parm_stack_space;
1330 struct args_size *args_size;
1331 int preferred_stack_boundary ATTRIBUTE_UNUSED;
1333 int unadjusted_args_size = args_size->constant;
1335 /* For accumulate outgoing args mode we don't need to align, since the frame
1336 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1337 backends from generating missaligned frame sizes. */
1338 #ifdef STACK_BOUNDARY
1339 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1340 preferred_stack_boundary = STACK_BOUNDARY;
1343 /* Compute the actual size of the argument block required. The variable
1344 and constant sizes must be combined, the size may have to be rounded,
1345 and there may be a minimum required size. */
1349 args_size->var = ARGS_SIZE_TREE (*args_size);
1350 args_size->constant = 0;
1352 #ifdef PREFERRED_STACK_BOUNDARY
1353 preferred_stack_boundary /= BITS_PER_UNIT;
1354 if (preferred_stack_boundary > 1)
1356 /* We don't handle this case yet. To handle it correctly we have
1357 to add the delta, round and substract the delta.
1358 Currently no machine description requires this support. */
1359 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1361 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1365 if (reg_parm_stack_space > 0)
1368 = size_binop (MAX_EXPR, args_size->var,
1369 ssize_int (reg_parm_stack_space));
1371 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1372 /* The area corresponding to register parameters is not to count in
1373 the size of the block we need. So make the adjustment. */
1375 = size_binop (MINUS_EXPR, args_size->var,
1376 ssize_int (reg_parm_stack_space));
1382 #ifdef PREFERRED_STACK_BOUNDARY
1383 preferred_stack_boundary /= BITS_PER_UNIT;
1384 if (preferred_stack_boundary < 1)
1385 preferred_stack_boundary = 1;
1386 args_size->constant = (((args_size->constant
1387 + stack_pointer_delta
1388 + preferred_stack_boundary - 1)
1389 / preferred_stack_boundary
1390 * preferred_stack_boundary)
1391 - stack_pointer_delta);
1394 args_size->constant = MAX (args_size->constant,
1395 reg_parm_stack_space);
1397 #ifdef MAYBE_REG_PARM_STACK_SPACE
1398 if (reg_parm_stack_space == 0)
1399 args_size->constant = 0;
1402 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1403 args_size->constant -= reg_parm_stack_space;
1406 return unadjusted_args_size;
1409 /* Precompute parameters as needed for a function call.
1411 FLAGS is mask of ECF_* constants.
1413 NUM_ACTUALS is the number of arguments.
1415 ARGS is an array containing information for each argument; this routine
1416 fills in the INITIAL_VALUE and VALUE fields for each precomputed argument.
1420 precompute_arguments (flags, num_actuals, args)
1423 struct arg_data *args;
1427 /* If this function call is cse'able, precompute all the parameters.
1428 Note that if the parameter is constructed into a temporary, this will
1429 cause an additional copy because the parameter will be constructed
1430 into a temporary location and then copied into the outgoing arguments.
1431 If a parameter contains a call to alloca and this function uses the
1432 stack, precompute the parameter. */
1434 /* If we preallocated the stack space, and some arguments must be passed
1435 on the stack, then we must precompute any parameter which contains a
1436 function call which will store arguments on the stack.
1437 Otherwise, evaluating the parameter may clobber previous parameters
1438 which have already been stored into the stack. (we have code to avoid
1439 such case by saving the ougoing stack arguments, but it results in
1442 for (i = 0; i < num_actuals; i++)
1443 if ((flags & (ECF_CONST | ECF_PURE))
1444 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1446 /* If this is an addressable type, we cannot pre-evaluate it. */
1447 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1453 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1455 preserve_temp_slots (args[i].value);
1458 /* ANSI doesn't require a sequence point here,
1459 but PCC has one, so this will avoid some problems. */
1462 args[i].initial_value = args[i].value
1463 = protect_from_queue (args[i].value, 0);
1465 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) != args[i].mode)
1468 = convert_modes (args[i].mode,
1469 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1470 args[i].value, args[i].unsignedp);
1471 #ifdef PROMOTE_FOR_CALL_ONLY
1472 /* CSE will replace this only if it contains args[i].value
1473 pseudo, so convert it down to the declared mode using
1475 if (GET_CODE (args[i].value) == REG
1476 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1478 args[i].initial_value
1479 = gen_rtx_SUBREG (TYPE_MODE (TREE_TYPE (args[i].tree_value)),
1481 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1482 SUBREG_PROMOTED_UNSIGNED_P (args[i].initial_value)
1483 = args[i].unsignedp;
1490 /* Given the current state of MUST_PREALLOCATE and information about
1491 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1492 compute and return the final value for MUST_PREALLOCATE. */
1495 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1496 int must_preallocate;
1498 struct arg_data *args;
1499 struct args_size *args_size;
1501 /* See if we have or want to preallocate stack space.
1503 If we would have to push a partially-in-regs parm
1504 before other stack parms, preallocate stack space instead.
1506 If the size of some parm is not a multiple of the required stack
1507 alignment, we must preallocate.
1509 If the total size of arguments that would otherwise create a copy in
1510 a temporary (such as a CALL) is more than half the total argument list
1511 size, preallocation is faster.
1513 Another reason to preallocate is if we have a machine (like the m88k)
1514 where stack alignment is required to be maintained between every
1515 pair of insns, not just when the call is made. However, we assume here
1516 that such machines either do not have push insns (and hence preallocation
1517 would occur anyway) or the problem is taken care of with
1520 if (! must_preallocate)
1522 int partial_seen = 0;
1523 int copy_to_evaluate_size = 0;
1526 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1528 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1530 else if (partial_seen && args[i].reg == 0)
1531 must_preallocate = 1;
1533 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1534 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1535 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1536 || TREE_CODE (args[i].tree_value) == COND_EXPR
1537 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1538 copy_to_evaluate_size
1539 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1542 if (copy_to_evaluate_size * 2 >= args_size->constant
1543 && args_size->constant > 0)
1544 must_preallocate = 1;
1546 return must_preallocate;
1549 /* If we preallocated stack space, compute the address of each argument
1550 and store it into the ARGS array.
1552 We need not ensure it is a valid memory address here; it will be
1553 validized when it is used.
1555 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1558 compute_argument_addresses (args, argblock, num_actuals)
1559 struct arg_data *args;
1565 rtx arg_reg = argblock;
1566 int i, arg_offset = 0;
1568 if (GET_CODE (argblock) == PLUS)
1569 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1571 for (i = 0; i < num_actuals; i++)
1573 rtx offset = ARGS_SIZE_RTX (args[i].offset);
1574 rtx slot_offset = ARGS_SIZE_RTX (args[i].slot_offset);
1577 /* Skip this parm if it will not be passed on the stack. */
1578 if (! args[i].pass_on_stack && args[i].reg != 0)
1581 if (GET_CODE (offset) == CONST_INT)
1582 addr = plus_constant (arg_reg, INTVAL (offset));
1584 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1586 addr = plus_constant (addr, arg_offset);
1587 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1590 AGGREGATE_TYPE_P (TREE_TYPE (args[i].tree_value)));
1592 if (GET_CODE (slot_offset) == CONST_INT)
1593 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1595 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1597 addr = plus_constant (addr, arg_offset);
1598 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1603 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1604 in a call instruction.
1606 FNDECL is the tree node for the target function. For an indirect call
1607 FNDECL will be NULL_TREE.
1609 EXP is the CALL_EXPR for this call. */
1612 rtx_for_function_call (fndecl, exp)
1618 /* Get the function to call, in the form of RTL. */
1621 /* If this is the first use of the function, see if we need to
1622 make an external definition for it. */
1623 if (! TREE_USED (fndecl))
1625 assemble_external (fndecl);
1626 TREE_USED (fndecl) = 1;
1629 /* Get a SYMBOL_REF rtx for the function address. */
1630 funexp = XEXP (DECL_RTL (fndecl), 0);
1633 /* Generate an rtx (probably a pseudo-register) for the address. */
1638 expand_expr (TREE_OPERAND (exp, 0), NULL_RTX, VOIDmode, 0);
1639 pop_temp_slots (); /* FUNEXP can't be BLKmode */
1641 /* Check the function is executable. */
1642 if (current_function_check_memory_usage)
1644 #ifdef POINTERS_EXTEND_UNSIGNED
1645 /* It might be OK to convert funexp in place, but there's
1646 a lot going on between here and when it happens naturally
1647 that this seems safer. */
1648 funaddr = convert_memory_address (Pmode, funexp);
1650 emit_library_call (chkr_check_exec_libfunc, 1,
1659 /* Do the register loads required for any wholly-register parms or any
1660 parms which are passed both on the stack and in a register. Their
1661 expressions were already evaluated.
1663 Mark all register-parms as living through the call, putting these USE
1664 insns in the CALL_INSN_FUNCTION_USAGE field. */
1667 load_register_parameters (args, num_actuals, call_fusage, flags)
1668 struct arg_data *args;
1675 #ifdef LOAD_ARGS_REVERSED
1676 for (i = num_actuals - 1; i >= 0; i--)
1678 for (i = 0; i < num_actuals; i++)
1681 rtx reg = ((flags & ECF_SIBCALL)
1682 ? args[i].tail_call_reg : args[i].reg);
1683 int partial = args[i].partial;
1688 /* Set to non-negative if must move a word at a time, even if just
1689 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1690 we just use a normal move insn. This value can be zero if the
1691 argument is a zero size structure with no fields. */
1692 nregs = (partial ? partial
1693 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1694 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1695 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1698 /* Handle calls that pass values in multiple non-contiguous
1699 locations. The Irix 6 ABI has examples of this. */
1701 if (GET_CODE (reg) == PARALLEL)
1702 emit_group_load (reg, args[i].value,
1703 int_size_in_bytes (TREE_TYPE (args[i].tree_value)),
1704 TYPE_ALIGN (TREE_TYPE (args[i].tree_value)));
1706 /* If simple case, just do move. If normal partial, store_one_arg
1707 has already loaded the register for us. In all other cases,
1708 load the register(s) from memory. */
1710 else if (nregs == -1)
1711 emit_move_insn (reg, args[i].value);
1713 /* If we have pre-computed the values to put in the registers in
1714 the case of non-aligned structures, copy them in now. */
1716 else if (args[i].n_aligned_regs != 0)
1717 for (j = 0; j < args[i].n_aligned_regs; j++)
1718 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1719 args[i].aligned_regs[j]);
1721 else if (partial == 0 || args[i].pass_on_stack)
1722 move_block_to_reg (REGNO (reg),
1723 validize_mem (args[i].value), nregs,
1726 /* Handle calls that pass values in multiple non-contiguous
1727 locations. The Irix 6 ABI has examples of this. */
1728 if (GET_CODE (reg) == PARALLEL)
1729 use_group_regs (call_fusage, reg);
1730 else if (nregs == -1)
1731 use_reg (call_fusage, reg);
1733 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1738 /* Try to integreate function. See expand_inline_function for documentation
1739 about the parameters. */
1742 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1748 rtx structure_value_addr;
1753 rtx old_stack_level = 0;
1754 int reg_parm_stack_space = 0;
1756 #ifdef REG_PARM_STACK_SPACE
1757 #ifdef MAYBE_REG_PARM_STACK_SPACE
1758 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1760 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1764 before_call = get_last_insn ();
1766 temp = expand_inline_function (fndecl, actparms, target,
1768 structure_value_addr);
1770 /* If inlining succeeded, return. */
1771 if (temp != (rtx) (HOST_WIDE_INT) - 1)
1773 if (ACCUMULATE_OUTGOING_ARGS)
1775 /* If the outgoing argument list must be preserved, push
1776 the stack before executing the inlined function if it
1779 for (i = reg_parm_stack_space - 1; i >= 0; i--)
1780 if (i < highest_outgoing_arg_in_use && stack_usage_map[i] != 0)
1783 if (stack_arg_under_construction || i >= 0)
1786 = before_call ? NEXT_INSN (before_call) : get_insns ();
1787 rtx insn = NULL_RTX, seq;
1789 /* Look for a call in the inline function code.
1790 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1791 nonzero then there is a call and it is not necessary
1792 to scan the insns. */
1794 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1795 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1796 if (GET_CODE (insn) == CALL_INSN)
1801 /* Reserve enough stack space so that the largest
1802 argument list of any function call in the inline
1803 function does not overlap the argument list being
1804 evaluated. This is usually an overestimate because
1805 allocate_dynamic_stack_space reserves space for an
1806 outgoing argument list in addition to the requested
1807 space, but there is no way to ask for stack space such
1808 that an argument list of a certain length can be
1811 Add the stack space reserved for register arguments, if
1812 any, in the inline function. What is really needed is the
1813 largest value of reg_parm_stack_space in the inline
1814 function, but that is not available. Using the current
1815 value of reg_parm_stack_space is wrong, but gives
1816 correct results on all supported machines. */
1818 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1819 + reg_parm_stack_space);
1822 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1823 allocate_dynamic_stack_space (GEN_INT (adjust),
1824 NULL_RTX, BITS_PER_UNIT);
1827 emit_insns_before (seq, first_insn);
1828 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1833 /* If the result is equivalent to TARGET, return TARGET to simplify
1834 checks in store_expr. They can be equivalent but not equal in the
1835 case of a function that returns BLKmode. */
1836 if (temp != target && rtx_equal_p (temp, target))
1841 /* If inlining failed, mark FNDECL as needing to be compiled
1842 separately after all. If function was declared inline,
1844 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1845 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1847 warning_with_decl (fndecl, "inlining failed in call to `%s'");
1848 warning ("called from here");
1850 mark_addressable (fndecl);
1851 return (rtx) (HOST_WIDE_INT) - 1;
1854 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1855 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1856 bytes, then we would need to push some additional bytes to pad the
1857 arguments. So, we compute an adjust to the stack pointer for an
1858 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1859 bytes. Then, when the arguments are pushed the stack will be perfectly
1860 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1861 be popped after the call. Returns the adjustment. */
1864 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1866 preferred_unit_stack_boundary)
1867 int unadjusted_args_size;
1868 struct args_size *args_size;
1869 int preferred_unit_stack_boundary;
1871 /* The number of bytes to pop so that the stack will be
1872 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1873 HOST_WIDE_INT adjustment;
1874 /* The alignment of the stack after the arguments are pushed, if we
1875 just pushed the arguments without adjust the stack here. */
1876 HOST_WIDE_INT unadjusted_alignment;
1878 unadjusted_alignment
1879 = ((stack_pointer_delta + unadjusted_args_size)
1880 % preferred_unit_stack_boundary);
1882 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1883 as possible -- leaving just enough left to cancel out the
1884 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1885 PENDING_STACK_ADJUST is non-negative, and congruent to
1886 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1888 /* Begin by trying to pop all the bytes. */
1889 unadjusted_alignment
1890 = (unadjusted_alignment
1891 - (pending_stack_adjust % preferred_unit_stack_boundary));
1892 adjustment = pending_stack_adjust;
1893 /* Push enough additional bytes that the stack will be aligned
1894 after the arguments are pushed. */
1895 if (unadjusted_alignment >= 0)
1896 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1898 adjustment += unadjusted_alignment;
1900 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1901 bytes after the call. The right number is the entire
1902 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1903 by the arguments in the first place. */
1905 = pending_stack_adjust - adjustment + unadjusted_args_size;
1910 /* Generate all the code for a function call
1911 and return an rtx for its value.
1912 Store the value in TARGET (specified as an rtx) if convenient.
1913 If the value is stored in TARGET then TARGET is returned.
1914 If IGNORE is nonzero, then we ignore the value of the function call. */
1917 expand_call (exp, target, ignore)
1922 /* Nonzero if we are currently expanding a call. */
1923 static int currently_expanding_call = 0;
1925 /* List of actual parameters. */
1926 tree actparms = TREE_OPERAND (exp, 1);
1927 /* RTX for the function to be called. */
1929 /* Sequence of insns to perform a tail recursive "call". */
1930 rtx tail_recursion_insns = NULL_RTX;
1931 /* Sequence of insns to perform a normal "call". */
1932 rtx normal_call_insns = NULL_RTX;
1933 /* Sequence of insns to perform a tail recursive "call". */
1934 rtx tail_call_insns = NULL_RTX;
1935 /* Data type of the function. */
1937 /* Declaration of the function being called,
1938 or 0 if the function is computed (not known by name). */
1942 int try_tail_call = 1;
1943 int try_tail_recursion = 1;
1946 /* Register in which non-BLKmode value will be returned,
1947 or 0 if no value or if value is BLKmode. */
1949 /* Address where we should return a BLKmode value;
1950 0 if value not BLKmode. */
1951 rtx structure_value_addr = 0;
1952 /* Nonzero if that address is being passed by treating it as
1953 an extra, implicit first parameter. Otherwise,
1954 it is passed by being copied directly into struct_value_rtx. */
1955 int structure_value_addr_parm = 0;
1956 /* Size of aggregate value wanted, or zero if none wanted
1957 or if we are using the non-reentrant PCC calling convention
1958 or expecting the value in registers. */
1959 HOST_WIDE_INT struct_value_size = 0;
1960 /* Nonzero if called function returns an aggregate in memory PCC style,
1961 by returning the address of where to find it. */
1962 int pcc_struct_value = 0;
1964 /* Number of actual parameters in this call, including struct value addr. */
1966 /* Number of named args. Args after this are anonymous ones
1967 and they must all go on the stack. */
1970 /* Vector of information about each argument.
1971 Arguments are numbered in the order they will be pushed,
1972 not the order they are written. */
1973 struct arg_data *args;
1975 /* Total size in bytes of all the stack-parms scanned so far. */
1976 struct args_size args_size;
1977 struct args_size adjusted_args_size;
1978 /* Size of arguments before any adjustments (such as rounding). */
1979 int unadjusted_args_size;
1980 /* Data on reg parms scanned so far. */
1981 CUMULATIVE_ARGS args_so_far;
1982 /* Nonzero if a reg parm has been scanned. */
1984 /* Nonzero if this is an indirect function call. */
1986 /* Nonzero if we must avoid push-insns in the args for this call.
1987 If stack space is allocated for register parameters, but not by the
1988 caller, then it is preallocated in the fixed part of the stack frame.
1989 So the entire argument block must then be preallocated (i.e., we
1990 ignore PUSH_ROUNDING in that case). */
1992 int must_preallocate = !PUSH_ARGS;
1994 /* Size of the stack reserved for parameter registers. */
1995 int reg_parm_stack_space = 0;
1997 /* Address of space preallocated for stack parms
1998 (on machines that lack push insns), or 0 if space not preallocated. */
2001 /* Mask of ECF_ flags. */
2003 /* Nonzero if this is a call to an inline function. */
2004 int is_integrable = 0;
2005 #ifdef REG_PARM_STACK_SPACE
2006 /* Define the boundary of the register parm stack space that needs to be
2008 int low_to_save = -1, high_to_save;
2009 rtx save_area = 0; /* Place that it is saved */
2012 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2013 char *initial_stack_usage_map = stack_usage_map;
2014 int old_stack_arg_under_construction = 0;
2016 rtx old_stack_level = 0;
2017 int old_pending_adj = 0;
2018 int old_inhibit_defer_pop = inhibit_defer_pop;
2019 int old_stack_allocated;
2023 /* The alignment of the stack, in bits. */
2024 HOST_WIDE_INT preferred_stack_boundary;
2025 /* The alignment of the stack, in bytes. */
2026 HOST_WIDE_INT preferred_unit_stack_boundary;
2028 /* The value of the function call can be put in a hard register. But
2029 if -fcheck-memory-usage, code which invokes functions (and thus
2030 damages some hard registers) can be inserted before using the value.
2031 So, target is always a pseudo-register in that case. */
2032 if (current_function_check_memory_usage)
2035 /* See if this is "nothrow" function call. */
2036 if (TREE_NOTHROW (exp))
2037 flags |= ECF_NOTHROW;
2039 /* See if we can find a DECL-node for the actual function.
2040 As a result, decide whether this is a call to an integrable function. */
2042 fndecl = get_callee_fndecl (exp);
2046 && fndecl != current_function_decl
2047 && DECL_INLINE (fndecl)
2048 && DECL_SAVED_INSNS (fndecl)
2049 && DECL_SAVED_INSNS (fndecl)->inlinable)
2051 else if (! TREE_ADDRESSABLE (fndecl))
2053 /* In case this function later becomes inlinable,
2054 record that there was already a non-inline call to it.
2056 Use abstraction instead of setting TREE_ADDRESSABLE
2058 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2061 warning_with_decl (fndecl, "can't inline call to `%s'");
2062 warning ("called from here");
2064 mark_addressable (fndecl);
2067 flags |= flags_from_decl_or_type (fndecl);
2070 /* If we don't have specific function to call, see if we have a
2071 attributes set in the type. */
2074 p = TREE_OPERAND (exp, 0);
2075 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2078 #ifdef REG_PARM_STACK_SPACE
2079 #ifdef MAYBE_REG_PARM_STACK_SPACE
2080 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2082 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2086 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2087 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2088 must_preallocate = 1;
2091 /* Warn if this value is an aggregate type,
2092 regardless of which calling convention we are using for it. */
2093 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2094 warning ("function call has aggregate value");
2096 /* Set up a place to return a structure. */
2098 /* Cater to broken compilers. */
2099 if (aggregate_value_p (exp))
2101 /* This call returns a big structure. */
2102 flags &= ~(ECF_CONST | ECF_PURE);
2104 #ifdef PCC_STATIC_STRUCT_RETURN
2106 pcc_struct_value = 1;
2107 /* Easier than making that case work right. */
2110 /* In case this is a static function, note that it has been
2112 if (! TREE_ADDRESSABLE (fndecl))
2113 mark_addressable (fndecl);
2117 #else /* not PCC_STATIC_STRUCT_RETURN */
2119 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2121 if (target && GET_CODE (target) == MEM)
2122 structure_value_addr = XEXP (target, 0);
2125 /* Assign a temporary to hold the value. */
2128 /* For variable-sized objects, we must be called with a target
2129 specified. If we were to allocate space on the stack here,
2130 we would have no way of knowing when to free it. */
2132 if (struct_value_size < 0)
2135 /* This DECL is just something to feed to mark_addressable;
2136 it doesn't get pushed. */
2137 d = build_decl (VAR_DECL, NULL_TREE, TREE_TYPE (exp));
2138 DECL_RTL (d) = assign_temp (TREE_TYPE (exp), 1, 0, 1);
2139 mark_addressable (d);
2140 mark_temp_addr_taken (DECL_RTL (d));
2141 structure_value_addr = XEXP (DECL_RTL (d), 0);
2146 #endif /* not PCC_STATIC_STRUCT_RETURN */
2149 /* If called function is inline, try to integrate it. */
2153 rtx temp = try_to_integrate (fndecl, actparms, target,
2154 ignore, TREE_TYPE (exp),
2155 structure_value_addr);
2156 if (temp != (rtx) (HOST_WIDE_INT) - 1)
2160 if (fndecl && DECL_NAME (fndecl))
2161 name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
2163 /* Figure out the amount to which the stack should be aligned. */
2164 #ifdef PREFERRED_STACK_BOUNDARY
2165 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2167 preferred_stack_boundary = STACK_BOUNDARY;
2170 /* Operand 0 is a pointer-to-function; get the type of the function. */
2171 funtype = TREE_TYPE (TREE_OPERAND (exp, 0));
2172 if (! POINTER_TYPE_P (funtype))
2174 funtype = TREE_TYPE (funtype);
2176 /* See if this is a call to a function that can return more than once
2177 or a call to longjmp or malloc. */
2178 flags |= special_function_p (fndecl, flags);
2180 if (flags & ECF_MAY_BE_ALLOCA)
2181 current_function_calls_alloca = 1;
2183 /* If struct_value_rtx is 0, it means pass the address
2184 as if it were an extra parameter. */
2185 if (structure_value_addr && struct_value_rtx == 0)
2187 /* If structure_value_addr is a REG other than
2188 virtual_outgoing_args_rtx, we can use always use it. If it
2189 is not a REG, we must always copy it into a register.
2190 If it is virtual_outgoing_args_rtx, we must copy it to another
2191 register in some cases. */
2192 rtx temp = (GET_CODE (structure_value_addr) != REG
2193 || (ACCUMULATE_OUTGOING_ARGS
2194 && stack_arg_under_construction
2195 && structure_value_addr == virtual_outgoing_args_rtx)
2196 ? copy_addr_to_reg (structure_value_addr)
2197 : structure_value_addr);
2200 = tree_cons (error_mark_node,
2201 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2204 structure_value_addr_parm = 1;
2207 /* Count the arguments and set NUM_ACTUALS. */
2208 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2211 /* Compute number of named args.
2212 Normally, don't include the last named arg if anonymous args follow.
2213 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2214 (If no anonymous args follow, the result of list_length is actually
2215 one too large. This is harmless.)
2217 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2218 zero, this machine will be able to place unnamed args that were
2219 passed in registers into the stack. So treat all args as named.
2220 This allows the insns emitting for a specific argument list to be
2221 independent of the function declaration.
2223 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2224 reliable way to pass unnamed args in registers, so we must force
2225 them into memory. */
2227 if ((STRICT_ARGUMENT_NAMING
2228 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2229 && TYPE_ARG_TYPES (funtype) != 0)
2231 = (list_length (TYPE_ARG_TYPES (funtype))
2232 /* Don't include the last named arg. */
2233 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2234 /* Count the struct value address, if it is passed as a parm. */
2235 + structure_value_addr_parm);
2237 /* If we know nothing, treat all args as named. */
2238 n_named_args = num_actuals;
2240 /* Start updating where the next arg would go.
2242 On some machines (such as the PA) indirect calls have a different
2243 calling convention than normal calls. The last argument in
2244 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2246 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, (fndecl == 0));
2249 /* Make a vector to hold all the information about each arg. */
2250 args = (struct arg_data *) alloca (num_actuals
2251 * sizeof (struct arg_data));
2252 bzero ((char *) args, num_actuals * sizeof (struct arg_data));
2254 /* Build up entries inthe ARGS array, compute the size of the arguments
2255 into ARGS_SIZE, etc. */
2256 initialize_argument_information (num_actuals, args, &args_size,
2257 n_named_args, actparms, fndecl,
2258 &args_so_far, reg_parm_stack_space,
2259 &old_stack_level, &old_pending_adj,
2260 &must_preallocate, &flags);
2264 /* If this function requires a variable-sized argument list, don't
2265 try to make a cse'able block for this call. We may be able to
2266 do this eventually, but it is too complicated to keep track of
2267 what insns go in the cse'able block and which don't. */
2269 flags &= ~(ECF_CONST | ECF_PURE);
2270 must_preallocate = 1;
2273 /* Now make final decision about preallocating stack space. */
2274 must_preallocate = finalize_must_preallocate (must_preallocate,
2278 /* If the structure value address will reference the stack pointer, we
2279 must stabilize it. We don't need to do this if we know that we are
2280 not going to adjust the stack pointer in processing this call. */
2282 if (structure_value_addr
2283 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2284 || reg_mentioned_p (virtual_outgoing_args_rtx,
2285 structure_value_addr))
2287 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2288 structure_value_addr = copy_to_reg (structure_value_addr);
2290 /* Tail calls can make things harder to debug, and we're traditionally
2291 pushed these optimizations into -O2. Don't try if we're already
2292 expanding a call, as that means we're an argument. Similarly, if
2293 there's pending loops or cleanups we know there's code to follow
2296 If rtx_equal_function_value_matters is false, that means we've
2297 finished with regular parsing. Which means that some of the
2298 machinery we use to generate tail-calls is no longer in place.
2299 This is most often true of sjlj-exceptions, which we couldn't
2300 tail-call to anyway. */
2302 if (currently_expanding_call++ != 0
2303 || !flag_optimize_sibling_calls
2304 || !rtx_equal_function_value_matters
2305 || !stmt_loop_nest_empty ()
2306 || any_pending_cleanups (1)
2308 try_tail_call = try_tail_recursion = 0;
2310 /* Tail recursion fails, when we are not dealing with recursive calls. */
2311 if (!try_tail_recursion
2312 || TREE_CODE (TREE_OPERAND (exp, 0)) != ADDR_EXPR
2313 || TREE_OPERAND (TREE_OPERAND (exp, 0), 0) != current_function_decl)
2314 try_tail_recursion = 0;
2316 /* Rest of purposes for tail call optimizations to fail. */
2318 #ifdef HAVE_sibcall_epilogue
2319 !HAVE_sibcall_epilogue
2324 /* Doing sibling call optimization needs some work, since
2325 structure_value_addr can be allocated on the stack.
2326 It does not seem worth the effort since few optimizable
2327 sibling calls will return a structure. */
2328 || structure_value_addr != NULL_RTX
2329 /* If the register holding the address is a callee saved
2330 register, then we lose. We have no way to prevent that,
2331 so we only allow calls to named functions. */
2332 /* ??? This could be done by having the insn constraints
2333 use a register class that is all call-clobbered. Any
2334 reload insns generated to fix things up would appear
2335 before the sibcall_epilogue. */
2336 || fndecl == NULL_TREE
2337 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP))
2338 || !FUNCTION_OK_FOR_SIBCALL (fndecl)
2339 /* If this function requires more stack slots than the current
2340 function, we cannot change it into a sibling call. */
2341 || args_size.constant > current_function_args_size
2342 /* If the callee pops its own arguments, then it must pop exactly
2343 the same number of arguments as the current function. */
2344 || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2345 != RETURN_POPS_ARGS (current_function_decl,
2346 TREE_TYPE (current_function_decl),
2347 current_function_args_size))
2350 if (try_tail_call || try_tail_recursion)
2353 actparms = NULL_TREE;
2354 /* Ok, we're going to give the tail call the old college try.
2355 This means we're going to evaluate the function arguments
2356 up to three times. There are two degrees of badness we can
2357 encounter, those that can be unsaved and those that can't.
2358 (See unsafe_for_reeval commentary for details.)
2360 Generate a new argument list. Pass safe arguments through
2361 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2362 For hard badness, evaluate them now and put their resulting
2363 rtx in a temporary VAR_DECL.
2365 initialize_argument_information has ordered the array for the
2366 order to be pushed, and we must remember this when reconstructing
2367 the original argument orde. */
2369 if (PUSH_ARGS_REVERSED)
2378 i = num_actuals - 1;
2382 for (; i != end; i += inc)
2384 switch (unsafe_for_reeval (args[i].tree_value))
2389 case 1: /* Mildly unsafe. */
2390 args[i].tree_value = unsave_expr (args[i].tree_value);
2393 case 2: /* Wildly unsafe. */
2395 tree var = build_decl (VAR_DECL, NULL_TREE,
2396 TREE_TYPE (args[i].tree_value));
2397 DECL_RTL (var) = expand_expr (args[i].tree_value, NULL_RTX,
2398 VOIDmode, EXPAND_NORMAL);
2399 args[i].tree_value = var;
2406 /* We need to build actparms for optimize_tail_recursion. We can
2407 safely trash away TREE_PURPOSE, since it is unused by this
2409 if (try_tail_recursion)
2410 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2412 /* Expanding one of those dangerous arguments could have added
2413 cleanups, but otherwise give it a whirl. */
2414 if (any_pending_cleanups (1))
2415 try_tail_call = try_tail_recursion = 0;
2418 /* Generate a tail recursion sequence when calling ourselves. */
2420 if (try_tail_recursion)
2422 /* We want to emit any pending stack adjustments before the tail
2423 recursion "call". That way we know any adjustment after the tail
2424 recursion call can be ignored if we indeed use the tail recursion
2426 int save_pending_stack_adjust = pending_stack_adjust;
2427 int save_stack_pointer_delta = stack_pointer_delta;
2429 /* Use a new sequence to hold any RTL we generate. We do not even
2430 know if we will use this RTL yet. The final decision can not be
2431 made until after RTL generation for the entire function is
2434 /* If expanding any of the arguments creates cleanups, we can't
2435 do a tailcall. So, we'll need to pop the pending cleanups
2436 list. If, however, all goes well, and there are no cleanups
2437 then the call to expand_start_target_temps will have no
2439 expand_start_target_temps ();
2440 if (optimize_tail_recursion (actparms, get_last_insn ()))
2442 if (any_pending_cleanups (1))
2443 try_tail_call = try_tail_recursion = 0;
2445 tail_recursion_insns = get_insns ();
2447 expand_end_target_temps ();
2450 /* Restore the original pending stack adjustment for the sibling and
2451 normal call cases below. */
2452 pending_stack_adjust = save_pending_stack_adjust;
2453 stack_pointer_delta = save_stack_pointer_delta;
2456 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2458 /* A fork duplicates the profile information, and an exec discards
2459 it. We can't rely on fork/exec to be paired. So write out the
2460 profile information we have gathered so far, and clear it. */
2461 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2462 is subject to race conditions, just as with multithreaded
2465 emit_library_call (gen_rtx_SYMBOL_REF (Pmode, "__bb_fork_func"), 0,
2469 /* Ensure current function's preferred stack boundary is at least
2470 what we need. We don't have to increase alignment for recursive
2472 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2473 && fndecl != current_function_decl)
2474 cfun->preferred_stack_boundary = preferred_stack_boundary;
2476 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2478 function_call_count++;
2480 /* We want to make two insn chains; one for a sibling call, the other
2481 for a normal call. We will select one of the two chains after
2482 initial RTL generation is complete. */
2483 for (pass = 0; pass < 2; pass++)
2485 int sibcall_failure = 0;
2486 /* We want to emit ay pending stack adjustments before the tail
2487 recursion "call". That way we know any adjustment after the tail
2488 recursion call can be ignored if we indeed use the tail recursion
2490 int save_pending_stack_adjust;
2491 int save_stack_pointer_delta;
2493 rtx before_call, next_arg_reg;
2497 if (! try_tail_call)
2500 /* Emit any queued insns now; otherwise they would end up in
2501 only one of the alternates. */
2504 /* State variables we need to save and restore between
2506 save_pending_stack_adjust = pending_stack_adjust;
2507 save_stack_pointer_delta = stack_pointer_delta;
2510 flags &= ~ECF_SIBCALL;
2512 flags |= ECF_SIBCALL;
2514 /* Other state variables that we must reinitialize each time
2515 through the loop (that are not initialized by the loop itself). */
2519 /* Start a new sequence for the normal call case.
2521 From this point on, if the sibling call fails, we want to set
2522 sibcall_failure instead of continuing the loop. */
2527 /* We know at this point that there are not currently any
2528 pending cleanups. If, however, in the process of evaluating
2529 the arguments we were to create some, we'll need to be
2530 able to get rid of them. */
2531 expand_start_target_temps ();
2534 /* When calling a const function, we must pop the stack args right away,
2535 so that the pop is deleted or moved with the call. */
2536 if (flags & (ECF_CONST | ECF_PURE))
2539 /* Don't let pending stack adjusts add up to too much.
2540 Also, do all pending adjustments now if there is any chance
2541 this might be a call to alloca or if we are expanding a sibling
2543 if (pending_stack_adjust >= 32
2544 || (pending_stack_adjust > 0 && (flags & ECF_MAY_BE_ALLOCA))
2546 do_pending_stack_adjust ();
2548 /* Push the temporary stack slot level so that we can free any
2549 temporaries we make. */
2553 #ifdef FINAL_REG_PARM_STACK_SPACE
2554 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2557 /* Precompute any arguments as needed. */
2559 precompute_arguments (flags, num_actuals, args);
2561 /* Now we are about to start emitting insns that can be deleted
2562 if a libcall is deleted. */
2563 if (flags & (ECF_CONST | ECF_PURE | ECF_MALLOC))
2566 adjusted_args_size = args_size;
2567 /* Compute the actual size of the argument block required. The variable
2568 and constant sizes must be combined, the size may have to be rounded,
2569 and there may be a minimum required size. When generating a sibcall
2570 pattern, do not round up, since we'll be re-using whatever space our
2572 unadjusted_args_size
2573 = compute_argument_block_size (reg_parm_stack_space, &adjusted_args_size,
2575 : preferred_stack_boundary));
2577 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2579 /* The argument block when performing a sibling call is the
2580 incoming argument block. */
2582 argblock = virtual_incoming_args_rtx;
2584 /* If we have no actual push instructions, or shouldn't use them,
2585 make space for all args right now. */
2586 else if (adjusted_args_size.var != 0)
2588 if (old_stack_level == 0)
2590 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2591 old_pending_adj = pending_stack_adjust;
2592 pending_stack_adjust = 0;
2593 /* stack_arg_under_construction says whether a stack arg is
2594 being constructed at the old stack level. Pushing the stack
2595 gets a clean outgoing argument block. */
2596 old_stack_arg_under_construction = stack_arg_under_construction;
2597 stack_arg_under_construction = 0;
2599 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2603 /* Note that we must go through the motions of allocating an argument
2604 block even if the size is zero because we may be storing args
2605 in the area reserved for register arguments, which may be part of
2608 int needed = adjusted_args_size.constant;
2610 /* Store the maximum argument space used. It will be pushed by
2611 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2614 if (needed > current_function_outgoing_args_size)
2615 current_function_outgoing_args_size = needed;
2617 if (must_preallocate)
2619 if (ACCUMULATE_OUTGOING_ARGS)
2621 /* Since the stack pointer will never be pushed, it is
2622 possible for the evaluation of a parm to clobber
2623 something we have already written to the stack.
2624 Since most function calls on RISC machines do not use
2625 the stack, this is uncommon, but must work correctly.
2627 Therefore, we save any area of the stack that was already
2628 written and that we are using. Here we set up to do this
2629 by making a new stack usage map from the old one. The
2630 actual save will be done by store_one_arg.
2632 Another approach might be to try to reorder the argument
2633 evaluations to avoid this conflicting stack usage. */
2635 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2636 /* Since we will be writing into the entire argument area,
2637 the map must be allocated for its entire size, not just
2638 the part that is the responsibility of the caller. */
2639 needed += reg_parm_stack_space;
2642 #ifdef ARGS_GROW_DOWNWARD
2643 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2646 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2650 = (char *) alloca (highest_outgoing_arg_in_use);
2652 if (initial_highest_arg_in_use)
2653 bcopy (initial_stack_usage_map, stack_usage_map,
2654 initial_highest_arg_in_use);
2656 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2657 bzero (&stack_usage_map[initial_highest_arg_in_use],
2658 (highest_outgoing_arg_in_use
2659 - initial_highest_arg_in_use));
2662 /* The address of the outgoing argument list must not be
2663 copied to a register here, because argblock would be left
2664 pointing to the wrong place after the call to
2665 allocate_dynamic_stack_space below. */
2667 argblock = virtual_outgoing_args_rtx;
2671 if (inhibit_defer_pop == 0)
2673 /* Try to reuse some or all of the pending_stack_adjust
2674 to get this space. */
2676 = (combine_pending_stack_adjustment_and_call
2677 (unadjusted_args_size,
2678 &adjusted_args_size,
2679 preferred_unit_stack_boundary));
2681 /* combine_pending_stack_adjustment_and_call computes
2682 an adjustment before the arguments are allocated.
2683 Account for them and see whether or not the stack
2684 needs to go up or down. */
2685 needed = unadjusted_args_size - needed;
2689 /* We're releasing stack space. */
2690 /* ??? We can avoid any adjustment at all if we're
2691 already aligned. FIXME. */
2692 pending_stack_adjust = -needed;
2693 do_pending_stack_adjust ();
2697 /* We need to allocate space. We'll do that in
2698 push_block below. */
2699 pending_stack_adjust = 0;
2702 /* Special case this because overhead of `push_block' in
2703 this case is non-trivial. */
2705 argblock = virtual_outgoing_args_rtx;
2707 argblock = push_block (GEN_INT (needed), 0, 0);
2709 /* We only really need to call `copy_to_reg' in the case
2710 where push insns are going to be used to pass ARGBLOCK
2711 to a function call in ARGS. In that case, the stack
2712 pointer changes value from the allocation point to the
2713 call point, and hence the value of
2714 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2715 as well always do it. */
2716 argblock = copy_to_reg (argblock);
2718 /* The save/restore code in store_one_arg handles all
2719 cases except one: a constructor call (including a C
2720 function returning a BLKmode struct) to initialize
2722 if (stack_arg_under_construction)
2724 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2725 rtx push_size = GEN_INT (reg_parm_stack_space
2726 + adjusted_args_size.constant);
2728 rtx push_size = GEN_INT (adjusted_args_size.constant);
2730 if (old_stack_level == 0)
2732 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2734 old_pending_adj = pending_stack_adjust;
2735 pending_stack_adjust = 0;
2736 /* stack_arg_under_construction says whether a stack
2737 arg is being constructed at the old stack level.
2738 Pushing the stack gets a clean outgoing argument
2740 old_stack_arg_under_construction
2741 = stack_arg_under_construction;
2742 stack_arg_under_construction = 0;
2743 /* Make a new map for the new argument list. */
2744 stack_usage_map = (char *)
2745 alloca (highest_outgoing_arg_in_use);
2746 bzero (stack_usage_map, highest_outgoing_arg_in_use);
2747 highest_outgoing_arg_in_use = 0;
2749 allocate_dynamic_stack_space (push_size, NULL_RTX,
2752 /* If argument evaluation might modify the stack pointer,
2753 copy the address of the argument list to a register. */
2754 for (i = 0; i < num_actuals; i++)
2755 if (args[i].pass_on_stack)
2757 argblock = copy_addr_to_reg (argblock);
2764 compute_argument_addresses (args, argblock, num_actuals);
2766 #ifdef PREFERRED_STACK_BOUNDARY
2767 /* If we push args individually in reverse order, perform stack alignment
2768 before the first push (the last arg). */
2769 if (PUSH_ARGS_REVERSED && argblock == 0
2770 && adjusted_args_size.constant != unadjusted_args_size)
2772 /* When the stack adjustment is pending, we get better code
2773 by combining the adjustments. */
2774 if (pending_stack_adjust
2775 && ! (flags & (ECF_CONST | ECF_PURE))
2776 && ! inhibit_defer_pop)
2778 pending_stack_adjust
2779 = (combine_pending_stack_adjustment_and_call
2780 (unadjusted_args_size,
2781 &adjusted_args_size,
2782 preferred_unit_stack_boundary));
2783 do_pending_stack_adjust ();
2785 else if (argblock == 0)
2786 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2787 - unadjusted_args_size));
2789 /* Now that the stack is properly aligned, pops can't safely
2790 be deferred during the evaluation of the arguments. */
2794 /* Don't try to defer pops if preallocating, not even from the first arg,
2795 since ARGBLOCK probably refers to the SP. */
2799 funexp = rtx_for_function_call (fndecl, exp);
2801 /* Figure out the register where the value, if any, will come back. */
2803 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2804 && ! structure_value_addr)
2806 if (pcc_struct_value)
2807 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2808 fndecl, (pass == 0));
2810 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2813 /* Precompute all register parameters. It isn't safe to compute anything
2814 once we have started filling any specific hard regs. */
2815 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2817 #ifdef REG_PARM_STACK_SPACE
2818 /* Save the fixed argument area if it's part of the caller's frame and
2819 is clobbered by argument setup for this call. */
2820 if (ACCUMULATE_OUTGOING_ARGS && pass)
2821 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2822 &low_to_save, &high_to_save);
2825 /* Now store (and compute if necessary) all non-register parms.
2826 These come before register parms, since they can require block-moves,
2827 which could clobber the registers used for register parms.
2828 Parms which have partial registers are not stored here,
2829 but we do preallocate space here if they want that. */
2831 for (i = 0; i < num_actuals; i++)
2832 if (args[i].reg == 0 || args[i].pass_on_stack)
2833 store_one_arg (&args[i], argblock, flags,
2834 adjusted_args_size.var != 0, reg_parm_stack_space);
2836 /* If we have a parm that is passed in registers but not in memory
2837 and whose alignment does not permit a direct copy into registers,
2838 make a group of pseudos that correspond to each register that we
2840 if (STRICT_ALIGNMENT)
2841 store_unaligned_arguments_into_pseudos (args, num_actuals);
2843 /* Now store any partially-in-registers parm.
2844 This is the last place a block-move can happen. */
2846 for (i = 0; i < num_actuals; i++)
2847 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2848 store_one_arg (&args[i], argblock, flags,
2849 adjusted_args_size.var != 0, reg_parm_stack_space);
2851 #ifdef PREFERRED_STACK_BOUNDARY
2852 /* If we pushed args in forward order, perform stack alignment
2853 after pushing the last arg. */
2854 if (!PUSH_ARGS_REVERSED && argblock == 0)
2855 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2856 - unadjusted_args_size));
2859 /* If register arguments require space on the stack and stack space
2860 was not preallocated, allocate stack space here for arguments
2861 passed in registers. */
2862 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2863 if (!ACCUMULATE_OUTGOING_ARGS
2864 && must_preallocate == 0 && reg_parm_stack_space > 0)
2865 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2868 /* Pass the function the address in which to return a
2870 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2872 emit_move_insn (struct_value_rtx,
2874 force_operand (structure_value_addr,
2877 /* Mark the memory for the aggregate as write-only. */
2878 if (current_function_check_memory_usage)
2879 emit_library_call (chkr_set_right_libfunc, 1,
2881 structure_value_addr, ptr_mode,
2882 GEN_INT (struct_value_size),
2883 TYPE_MODE (sizetype),
2884 GEN_INT (MEMORY_USE_WO),
2885 TYPE_MODE (integer_type_node));
2887 if (GET_CODE (struct_value_rtx) == REG)
2888 use_reg (&call_fusage, struct_value_rtx);
2891 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
2894 load_register_parameters (args, num_actuals, &call_fusage, flags);
2896 /* Perform postincrements before actually calling the function. */
2899 /* Save a pointer to the last insn before the call, so that we can
2900 later safely search backwards to find the CALL_INSN. */
2901 before_call = get_last_insn ();
2903 /* Set up next argument register. For sibling calls on machines
2904 with register windows this should be the incoming register. */
2905 #ifdef FUNCTION_INCOMING_ARG
2907 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2911 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2914 /* All arguments and registers used for the call must be set up by
2917 #ifdef PREFERRED_STACK_BOUNDARY
2918 /* Stack must be properly aligned now. */
2919 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
2923 /* Generate the actual call instruction. */
2924 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
2925 adjusted_args_size.constant, struct_value_size,
2926 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2929 /* Verify that we've deallocated all the stack we used. */
2931 && old_stack_allocated != stack_pointer_delta - pending_stack_adjust)
2934 /* If call is cse'able, make appropriate pair of reg-notes around it.
2935 Test valreg so we don't crash; may safely ignore `const'
2936 if return type is void. Disable for PARALLEL return values, because
2937 we have no way to move such values into a pseudo register. */
2939 && (flags & (ECF_CONST | ECF_PURE))
2940 && valreg != 0 && GET_CODE (valreg) != PARALLEL)
2943 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2946 /* Mark the return value as a pointer if needed. */
2947 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2948 mark_reg_pointer (temp, TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2950 /* Construct an "equal form" for the value which mentions all the
2951 arguments in order as well as the function name. */
2952 for (i = 0; i < num_actuals; i++)
2953 note = gen_rtx_EXPR_LIST (VOIDmode, args[i].initial_value, note);
2954 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2956 insns = get_insns ();
2959 if (flags & ECF_PURE)
2960 note = gen_rtx_EXPR_LIST (VOIDmode,
2961 gen_rtx_USE (VOIDmode,
2962 gen_rtx_MEM (BLKmode,
2963 gen_rtx_SCRATCH (VOIDmode))), note);
2965 emit_libcall_block (insns, temp, valreg, note);
2969 else if (flags & (ECF_CONST | ECF_PURE))
2971 /* Otherwise, just write out the sequence without a note. */
2972 rtx insns = get_insns ();
2977 else if (flags & ECF_MALLOC)
2979 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2982 /* The return value from a malloc-like function is a pointer. */
2983 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2984 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2986 emit_move_insn (temp, valreg);
2988 /* The return value from a malloc-like function can not alias
2990 last = get_last_insn ();
2992 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2994 /* Write out the sequence. */
2995 insns = get_insns ();
3001 /* For calls to `setjmp', etc., inform flow.c it should complain
3002 if nonvolatile values are live. For functions that cannot return,
3003 inform flow that control does not fall through. */
3005 if ((flags & (ECF_RETURNS_TWICE | ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3007 /* The barrier or NOTE_INSN_SETJMP note must be emitted
3008 immediately after the CALL_INSN. Some ports emit more
3009 than just a CALL_INSN above, so we must search for it here. */
3011 rtx last = get_last_insn ();
3012 while (GET_CODE (last) != CALL_INSN)
3014 last = PREV_INSN (last);
3015 /* There was no CALL_INSN? */
3016 if (last == before_call)
3020 if (flags & ECF_RETURNS_TWICE)
3022 emit_note_after (NOTE_INSN_SETJMP, last);
3023 current_function_calls_setjmp = 1;
3026 emit_barrier_after (last);
3029 if (flags & ECF_LONGJMP)
3030 current_function_calls_longjmp = 1;
3032 /* If this function is returning into a memory location marked as
3033 readonly, it means it is initializing that location. But we normally
3034 treat functions as not clobbering such locations, so we need to
3035 specify that this one does. */
3036 if (target != 0 && GET_CODE (target) == MEM
3037 && structure_value_addr != 0 && RTX_UNCHANGING_P (target))
3038 emit_insn (gen_rtx_CLOBBER (VOIDmode, target));
3040 /* If value type not void, return an rtx for the value. */
3042 /* If there are cleanups to be called, don't use a hard reg as target.
3043 We need to double check this and see if it matters anymore. */
3044 if (any_pending_cleanups (1))
3046 if (target && REG_P (target)
3047 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3049 sibcall_failure = 1;
3052 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3055 target = const0_rtx;
3057 else if (structure_value_addr)
3059 if (target == 0 || GET_CODE (target) != MEM)
3061 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3062 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3063 structure_value_addr));
3064 MEM_SET_IN_STRUCT_P (target,
3065 AGGREGATE_TYPE_P (TREE_TYPE (exp)));
3068 else if (pcc_struct_value)
3070 /* This is the special C++ case where we need to
3071 know what the true target was. We take care to
3072 never use this value more than once in one expression. */
3073 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3074 copy_to_reg (valreg));
3075 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
3077 /* Handle calls that return values in multiple non-contiguous locations.
3078 The Irix 6 ABI has examples of this. */
3079 else if (GET_CODE (valreg) == PARALLEL)
3081 int bytes = int_size_in_bytes (TREE_TYPE (exp));
3085 target = assign_stack_temp (TYPE_MODE (TREE_TYPE (exp)),
3087 MEM_SET_IN_STRUCT_P (target, AGGREGATE_TYPE_P (TREE_TYPE (exp)));
3088 preserve_temp_slots (target);
3091 if (! rtx_equal_p (target, valreg))
3092 emit_group_store (target, valreg, bytes,
3093 TYPE_ALIGN (TREE_TYPE (exp)));
3095 /* We can not support sibling calls for this case. */
3096 sibcall_failure = 1;
3099 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3100 && GET_MODE (target) == GET_MODE (valreg))
3102 /* TARGET and VALREG cannot be equal at this point because the
3103 latter would not have REG_FUNCTION_VALUE_P true, while the
3104 former would if it were referring to the same register.
3106 If they refer to the same register, this move will be a no-op,
3107 except when function inlining is being done. */
3108 emit_move_insn (target, valreg);
3110 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3111 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3113 target = copy_to_reg (valreg);
3115 #ifdef PROMOTE_FUNCTION_RETURN
3116 /* If we promoted this return value, make the proper SUBREG. TARGET
3117 might be const0_rtx here, so be careful. */
3118 if (GET_CODE (target) == REG
3119 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3120 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3122 tree type = TREE_TYPE (exp);
3123 int unsignedp = TREE_UNSIGNED (type);
3125 /* If we don't promote as expected, something is wrong. */
3126 if (GET_MODE (target)
3127 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3130 target = gen_rtx_SUBREG (TYPE_MODE (type), target, 0);
3131 SUBREG_PROMOTED_VAR_P (target) = 1;
3132 SUBREG_PROMOTED_UNSIGNED_P (target) = unsignedp;
3136 /* If size of args is variable or this was a constructor call for a stack
3137 argument, restore saved stack-pointer value. */
3139 if (old_stack_level)
3141 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3142 pending_stack_adjust = old_pending_adj;
3143 stack_arg_under_construction = old_stack_arg_under_construction;
3144 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3145 stack_usage_map = initial_stack_usage_map;
3146 sibcall_failure = 1;
3148 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3150 #ifdef REG_PARM_STACK_SPACE
3153 restore_fixed_argument_area (save_area, argblock,
3154 high_to_save, low_to_save);
3158 /* If we saved any argument areas, restore them. */
3159 for (i = 0; i < num_actuals; i++)
3160 if (args[i].save_area)
3162 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3164 = gen_rtx_MEM (save_mode,
3165 memory_address (save_mode,
3166 XEXP (args[i].stack_slot, 0)));
3168 if (save_mode != BLKmode)
3169 emit_move_insn (stack_area, args[i].save_area);
3171 emit_block_move (stack_area,
3172 validize_mem (args[i].save_area),
3173 GEN_INT (args[i].size.constant),
3177 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3178 stack_usage_map = initial_stack_usage_map;
3181 /* If this was alloca, record the new stack level for nonlocal gotos.
3182 Check for the handler slots since we might not have a save area
3183 for non-local gotos. */
3185 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3186 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3190 /* Free up storage we no longer need. */
3191 for (i = 0; i < num_actuals; ++i)
3192 if (args[i].aligned_regs)
3193 free (args[i].aligned_regs);
3197 /* Undo the fake expand_start_target_temps we did earlier. If
3198 there had been any cleanups created, we've already set
3200 expand_end_target_temps ();
3203 insns = get_insns ();
3208 tail_call_insns = insns;
3210 /* If something prevents making this a sibling call,
3211 zero out the sequence. */
3212 if (sibcall_failure)
3213 tail_call_insns = NULL_RTX;
3214 /* Restore the pending stack adjustment now that we have
3215 finished generating the sibling call sequence. */
3217 pending_stack_adjust = save_pending_stack_adjust;
3218 stack_pointer_delta = save_stack_pointer_delta;
3220 /* Prepare arg structure for next iteration. */
3221 for (i = 0 ; i < num_actuals ; i++)
3224 args[i].aligned_regs = 0;
3229 normal_call_insns = insns;
3232 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3233 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3234 can happen if the arguments to this function call an inline
3235 function who's expansion contains another CALL_PLACEHOLDER.
3237 If there are any C_Ps in any of these sequences, replace them
3238 with their normal call. */
3240 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3241 if (GET_CODE (insn) == CALL_INSN
3242 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3243 replace_call_placeholder (insn, sibcall_use_normal);
3245 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3246 if (GET_CODE (insn) == CALL_INSN
3247 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3248 replace_call_placeholder (insn, sibcall_use_normal);
3250 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3251 if (GET_CODE (insn) == CALL_INSN
3252 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3253 replace_call_placeholder (insn, sibcall_use_normal);
3255 /* If this was a potential tail recursion site, then emit a
3256 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3257 One of them will be selected later. */
3258 if (tail_recursion_insns || tail_call_insns)
3260 /* The tail recursion label must be kept around. We could expose
3261 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3262 and makes determining true tail recursion sites difficult.
3264 So we set LABEL_PRESERVE_P here, then clear it when we select
3265 one of the call sequences after rtl generation is complete. */
3266 if (tail_recursion_insns)
3267 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3268 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3270 tail_recursion_insns,
3271 tail_recursion_label));
3274 emit_insns (normal_call_insns);
3276 currently_expanding_call--;
3281 /* Returns nonzero if FUN is the symbol for a library function which can
3285 libfunc_nothrow (fun)
3288 if (fun == throw_libfunc
3289 || fun == rethrow_libfunc
3290 || fun == sjthrow_libfunc
3291 || fun == sjpopnthrow_libfunc)
3297 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3298 The RETVAL parameter specifies whether return value needs to be saved, other
3299 parameters are documented in the emit_library_call function bellow. */
3301 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3306 enum machine_mode outmode;
3310 /* Total size in bytes of all the stack-parms scanned so far. */
3311 struct args_size args_size;
3312 /* Size of arguments before any adjustments (such as rounding). */
3313 struct args_size original_args_size;
3314 register int argnum;
3318 struct args_size alignment_pad;
3320 CUMULATIVE_ARGS args_so_far;
3321 struct arg { rtx value; enum machine_mode mode; rtx reg; int partial;
3322 struct args_size offset; struct args_size size; rtx save_area; };
3324 int old_inhibit_defer_pop = inhibit_defer_pop;
3325 rtx call_fusage = 0;
3328 int pcc_struct_value = 0;
3329 int struct_value_size = 0;
3331 int reg_parm_stack_space = 0;
3334 #ifdef REG_PARM_STACK_SPACE
3335 /* Define the boundary of the register parm stack space that needs to be
3337 int low_to_save = -1, high_to_save = 0;
3338 rtx save_area = 0; /* Place that it is saved */
3341 /* Size of the stack reserved for parameter registers. */
3342 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3343 char *initial_stack_usage_map = stack_usage_map;
3345 #ifdef REG_PARM_STACK_SPACE
3346 #ifdef MAYBE_REG_PARM_STACK_SPACE
3347 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3349 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3355 else if (fn_type == 2)
3359 if (libfunc_nothrow (fun))
3360 flags |= ECF_NOTHROW;
3362 #ifdef PREFERRED_STACK_BOUNDARY
3363 /* Ensure current function's preferred stack boundary is at least
3365 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3366 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3369 /* If this kind of value comes back in memory,
3370 decide where in memory it should come back. */
3371 if (outmode != VOIDmode && aggregate_value_p (type_for_mode (outmode, 0)))
3373 #ifdef PCC_STATIC_STRUCT_RETURN
3375 = hard_function_value (build_pointer_type (type_for_mode (outmode, 0)),
3377 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3378 pcc_struct_value = 1;
3380 value = gen_reg_rtx (outmode);
3381 #else /* not PCC_STATIC_STRUCT_RETURN */
3382 struct_value_size = GET_MODE_SIZE (outmode);
3383 if (value != 0 && GET_CODE (value) == MEM)
3386 mem_value = assign_stack_temp (outmode, GET_MODE_SIZE (outmode), 0);
3389 /* This call returns a big structure. */
3390 flags &= ~(ECF_CONST | ECF_PURE);
3393 /* ??? Unfinished: must pass the memory address as an argument. */
3395 /* Copy all the libcall-arguments out of the varargs data
3396 and into a vector ARGVEC.
3398 Compute how to pass each argument. We only support a very small subset
3399 of the full argument passing conventions to limit complexity here since
3400 library functions shouldn't have many args. */
3402 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3403 bzero ((char *) argvec, (nargs + 1) * sizeof (struct arg));
3405 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3407 args_size.constant = 0;
3412 /* Now we are about to start emitting insns that can be deleted
3413 if a libcall is deleted. */
3414 if (flags & (ECF_CONST | ECF_PURE))
3419 /* If there's a structure value address to be passed,
3420 either pass it in the special place, or pass it as an extra argument. */
3421 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3423 rtx addr = XEXP (mem_value, 0);
3426 /* Make sure it is a reasonable operand for a move or push insn. */
3427 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3428 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3429 addr = force_operand (addr, NULL_RTX);
3431 argvec[count].value = addr;
3432 argvec[count].mode = Pmode;
3433 argvec[count].partial = 0;
3435 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3436 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3437 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3441 locate_and_pad_parm (Pmode, NULL_TREE,
3442 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3445 argvec[count].reg != 0,
3447 NULL_TREE, &args_size, &argvec[count].offset,
3448 &argvec[count].size, &alignment_pad);
3451 if (argvec[count].reg == 0 || argvec[count].partial != 0
3452 || reg_parm_stack_space > 0)
3453 args_size.constant += argvec[count].size.constant;
3455 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3460 for (; count < nargs; count++)
3462 rtx val = va_arg (p, rtx);
3463 enum machine_mode mode = va_arg (p, enum machine_mode);
3465 /* We cannot convert the arg value to the mode the library wants here;
3466 must do it earlier where we know the signedness of the arg. */
3468 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3471 /* On some machines, there's no way to pass a float to a library fcn.
3472 Pass it as a double instead. */
3473 #ifdef LIBGCC_NEEDS_DOUBLE
3474 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3475 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3478 /* There's no need to call protect_from_queue, because
3479 either emit_move_insn or emit_push_insn will do that. */
3481 /* Make sure it is a reasonable operand for a move or push insn. */
3482 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3483 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3484 val = force_operand (val, NULL_RTX);
3486 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3487 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3489 /* We do not support FUNCTION_ARG_CALLEE_COPIES here since it can
3490 be viewed as just an efficiency improvement. */
3491 rtx slot = assign_stack_temp (mode, GET_MODE_SIZE (mode), 0);
3492 emit_move_insn (slot, val);
3493 val = force_operand (XEXP (slot, 0), NULL_RTX);
3498 argvec[count].value = val;
3499 argvec[count].mode = mode;
3501 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3503 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3504 argvec[count].partial
3505 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3507 argvec[count].partial = 0;
3510 locate_and_pad_parm (mode, NULL_TREE,
3511 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3514 argvec[count].reg != 0,
3516 NULL_TREE, &args_size, &argvec[count].offset,
3517 &argvec[count].size, &alignment_pad);
3519 if (argvec[count].size.var)
3522 if (reg_parm_stack_space == 0 && argvec[count].partial)
3523 argvec[count].size.constant -= argvec[count].partial * UNITS_PER_WORD;
3525 if (argvec[count].reg == 0 || argvec[count].partial != 0
3526 || reg_parm_stack_space > 0)
3527 args_size.constant += argvec[count].size.constant;
3529 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3532 #ifdef FINAL_REG_PARM_STACK_SPACE
3533 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3536 /* If this machine requires an external definition for library
3537 functions, write one out. */
3538 assemble_external_libcall (fun);
3540 original_args_size = args_size;
3541 #ifdef PREFERRED_STACK_BOUNDARY
3542 args_size.constant = (((args_size.constant
3543 + stack_pointer_delta
3547 - stack_pointer_delta);
3550 args_size.constant = MAX (args_size.constant,
3551 reg_parm_stack_space);
3553 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3554 args_size.constant -= reg_parm_stack_space;
3557 if (args_size.constant > current_function_outgoing_args_size)
3558 current_function_outgoing_args_size = args_size.constant;
3560 if (ACCUMULATE_OUTGOING_ARGS)
3562 /* Since the stack pointer will never be pushed, it is possible for
3563 the evaluation of a parm to clobber something we have already
3564 written to the stack. Since most function calls on RISC machines
3565 do not use the stack, this is uncommon, but must work correctly.
3567 Therefore, we save any area of the stack that was already written
3568 and that we are using. Here we set up to do this by making a new
3569 stack usage map from the old one.
3571 Another approach might be to try to reorder the argument
3572 evaluations to avoid this conflicting stack usage. */
3574 needed = args_size.constant;
3576 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3577 /* Since we will be writing into the entire argument area, the
3578 map must be allocated for its entire size, not just the part that
3579 is the responsibility of the caller. */
3580 needed += reg_parm_stack_space;
3583 #ifdef ARGS_GROW_DOWNWARD
3584 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3587 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3590 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3592 if (initial_highest_arg_in_use)
3593 bcopy (initial_stack_usage_map, stack_usage_map,
3594 initial_highest_arg_in_use);
3596 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3597 bzero (&stack_usage_map[initial_highest_arg_in_use],
3598 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3601 /* The address of the outgoing argument list must not be copied to a
3602 register here, because argblock would be left pointing to the
3603 wrong place after the call to allocate_dynamic_stack_space below.
3606 argblock = virtual_outgoing_args_rtx;
3611 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3614 #ifdef PREFERRED_STACK_BOUNDARY
3615 /* If we push args individually in reverse order, perform stack alignment
3616 before the first push (the last arg). */
3617 if (argblock == 0 && PUSH_ARGS_REVERSED)
3618 anti_adjust_stack (GEN_INT (args_size.constant
3619 - original_args_size.constant));
3622 if (PUSH_ARGS_REVERSED)
3633 #ifdef REG_PARM_STACK_SPACE
3634 if (ACCUMULATE_OUTGOING_ARGS)
3636 /* The argument list is the property of the called routine and it
3637 may clobber it. If the fixed area has been used for previous
3638 parameters, we must save and restore it.
3640 Here we compute the boundary of the that needs to be saved, if any. */
3642 #ifdef ARGS_GROW_DOWNWARD
3643 for (count = 0; count < reg_parm_stack_space + 1; count++)
3645 for (count = 0; count < reg_parm_stack_space; count++)
3648 if (count >= highest_outgoing_arg_in_use
3649 || stack_usage_map[count] == 0)
3652 if (low_to_save == -1)
3653 low_to_save = count;
3655 high_to_save = count;
3658 if (low_to_save >= 0)
3660 int num_to_save = high_to_save - low_to_save + 1;
3661 enum machine_mode save_mode
3662 = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
3665 /* If we don't have the required alignment, must do this in BLKmode. */
3666 if ((low_to_save & (MIN (GET_MODE_SIZE (save_mode),
3667 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
3668 save_mode = BLKmode;
3670 #ifdef ARGS_GROW_DOWNWARD
3671 stack_area = gen_rtx_MEM (save_mode,
3672 memory_address (save_mode,
3673 plus_constant (argblock,
3676 stack_area = gen_rtx_MEM (save_mode,
3677 memory_address (save_mode,
3678 plus_constant (argblock,
3681 if (save_mode == BLKmode)
3683 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
3684 emit_block_move (validize_mem (save_area), stack_area,
3685 GEN_INT (num_to_save), PARM_BOUNDARY);
3689 save_area = gen_reg_rtx (save_mode);
3690 emit_move_insn (save_area, stack_area);
3696 /* Push the args that need to be pushed. */
3698 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3699 are to be pushed. */
3700 for (count = 0; count < nargs; count++, argnum += inc)
3702 register enum machine_mode mode = argvec[argnum].mode;
3703 register rtx val = argvec[argnum].value;
3704 rtx reg = argvec[argnum].reg;
3705 int partial = argvec[argnum].partial;
3706 int lower_bound = 0, upper_bound = 0, i;
3708 if (! (reg != 0 && partial == 0))
3710 if (ACCUMULATE_OUTGOING_ARGS)
3712 /* If this is being stored into a pre-allocated, fixed-size,
3713 stack area, save any previous data at that location. */
3715 #ifdef ARGS_GROW_DOWNWARD
3716 /* stack_slot is negative, but we want to index stack_usage_map
3717 with positive values. */
3718 upper_bound = -argvec[argnum].offset.constant + 1;
3719 lower_bound = upper_bound - argvec[argnum].size.constant;
3721 lower_bound = argvec[argnum].offset.constant;
3722 upper_bound = lower_bound + argvec[argnum].size.constant;
3725 for (i = lower_bound; i < upper_bound; i++)
3726 if (stack_usage_map[i]
3727 /* Don't store things in the fixed argument area at this
3728 point; it has already been saved. */
3729 && i > reg_parm_stack_space)
3732 if (i != upper_bound)
3734 /* We need to make a save area. See what mode we can make
3736 enum machine_mode save_mode
3737 = mode_for_size (argvec[argnum].size.constant
3745 plus_constant (argblock,
3746 argvec[argnum].offset.constant)));
3747 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3749 emit_move_insn (argvec[argnum].save_area, stack_area);
3753 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, 0, partial, reg, 0,
3754 argblock, GEN_INT (argvec[argnum].offset.constant),
3755 reg_parm_stack_space, ARGS_SIZE_RTX (alignment_pad));
3757 /* Now mark the segment we just used. */
3758 if (ACCUMULATE_OUTGOING_ARGS)
3759 for (i = lower_bound; i < upper_bound; i++)
3760 stack_usage_map[i] = 1;
3766 #ifdef PREFERRED_STACK_BOUNDARY
3767 /* If we pushed args in forward order, perform stack alignment
3768 after pushing the last arg. */
3769 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3770 anti_adjust_stack (GEN_INT (args_size.constant
3771 - original_args_size.constant));
3774 if (PUSH_ARGS_REVERSED)
3779 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0);
3781 /* Now load any reg parms into their regs. */
3783 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3784 are to be pushed. */
3785 for (count = 0; count < nargs; count++, argnum += inc)
3787 register rtx val = argvec[argnum].value;
3788 rtx reg = argvec[argnum].reg;
3789 int partial = argvec[argnum].partial;
3791 /* Handle calls that pass values in multiple non-contiguous
3792 locations. The PA64 has examples of this for library calls. */
3793 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3794 emit_group_load (reg, val,
3795 GET_MODE_SIZE (GET_MODE (val)),
3796 GET_MODE_ALIGNMENT (GET_MODE (val)));
3797 else if (reg != 0 && partial == 0)
3798 emit_move_insn (reg, val);
3803 /* Any regs containing parms remain in use through the call. */
3804 for (count = 0; count < nargs; count++)
3806 rtx reg = argvec[count].reg;
3807 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3808 use_group_regs (&call_fusage, reg);
3810 use_reg (&call_fusage, reg);
3813 /* Pass the function the address in which to return a structure value. */
3814 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
3816 emit_move_insn (struct_value_rtx,
3818 force_operand (XEXP (mem_value, 0),
3820 if (GET_CODE (struct_value_rtx) == REG)
3821 use_reg (&call_fusage, struct_value_rtx);
3824 /* Don't allow popping to be deferred, since then
3825 cse'ing of library calls could delete a call and leave the pop. */
3827 valreg = (mem_value == 0 && outmode != VOIDmode
3828 ? hard_libcall_value (outmode) : NULL_RTX);
3830 #ifdef PREFERRED_STACK_BOUNDARY
3831 /* Stack must be properly aligned now. */
3832 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
3836 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3837 will set inhibit_defer_pop to that value. */
3838 /* The return type is needed to decide how many bytes the function pops.
3839 Signedness plays no role in that, so for simplicity, we pretend it's
3840 always signed. We also assume that the list of arguments passed has
3841 no impact, so we pretend it is unknown. */
3844 get_identifier (XSTR (orgfun, 0)),
3845 build_function_type (outmode == VOIDmode ? void_type_node
3846 : type_for_mode (outmode, 0), NULL_TREE),
3847 original_args_size.constant, args_size.constant,
3849 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3851 old_inhibit_defer_pop + 1, call_fusage, flags);
3853 /* Now restore inhibit_defer_pop to its actual original value. */
3856 /* If call is cse'able, make appropriate pair of reg-notes around it.
3857 Test valreg so we don't crash; may safely ignore `const'
3858 if return type is void. Disable for PARALLEL return values, because
3859 we have no way to move such values into a pseudo register. */
3860 if ((flags & (ECF_CONST | ECF_PURE))
3861 && valreg != 0 && GET_CODE (valreg) != PARALLEL)
3864 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3868 /* Construct an "equal form" for the value which mentions all the
3869 arguments in order as well as the function name. */
3870 for (i = 0; i < nargs; i++)
3871 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3872 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3874 insns = get_insns ();
3877 if (flags & ECF_PURE)
3878 note = gen_rtx_EXPR_LIST (VOIDmode,
3879 gen_rtx_USE (VOIDmode,
3880 gen_rtx_MEM (BLKmode,
3881 gen_rtx_SCRATCH (VOIDmode))), note);
3883 emit_libcall_block (insns, temp, valreg, note);
3887 else if (flags & (ECF_CONST | ECF_PURE))
3889 /* Otherwise, just write out the sequence without a note. */
3890 rtx insns = get_insns ();
3897 /* Copy the value to the right place. */
3898 if (outmode != VOIDmode && retval)
3904 if (value != mem_value)
3905 emit_move_insn (value, mem_value);
3907 else if (value != 0)
3908 emit_move_insn (value, hard_libcall_value (outmode));
3910 value = hard_libcall_value (outmode);
3913 if (ACCUMULATE_OUTGOING_ARGS)
3915 #ifdef REG_PARM_STACK_SPACE
3918 enum machine_mode save_mode = GET_MODE (save_area);
3919 #ifdef ARGS_GROW_DOWNWARD
3921 = gen_rtx_MEM (save_mode,
3922 memory_address (save_mode,
3923 plus_constant (argblock,
3927 = gen_rtx_MEM (save_mode,
3928 memory_address (save_mode,
3929 plus_constant (argblock, low_to_save)));
3931 if (save_mode != BLKmode)
3932 emit_move_insn (stack_area, save_area);
3934 emit_block_move (stack_area, validize_mem (save_area),
3935 GEN_INT (high_to_save - low_to_save + 1),
3940 /* If we saved any argument areas, restore them. */
3941 for (count = 0; count < nargs; count++)
3942 if (argvec[count].save_area)
3944 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3946 = gen_rtx_MEM (save_mode,
3949 plus_constant (argblock,
3950 argvec[count].offset.constant)));
3952 emit_move_insn (stack_area, argvec[count].save_area);
3955 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3956 stack_usage_map = initial_stack_usage_map;
3963 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3964 (emitting the queue unless NO_QUEUE is nonzero),
3965 for a value of mode OUTMODE,
3966 with NARGS different arguments, passed as alternating rtx values
3967 and machine_modes to convert them to.
3968 The rtx values should have been passed through protect_from_queue already.
3970 FN_TYPE will is zero for `normal' calls, one for `const' calls, wich
3971 which will be enclosed in REG_LIBCALL/REG_RETVAL notes and two for `pure'
3972 calls, that are handled like `const' calls with extra
3973 (use (memory (scratch)). */
3976 emit_library_call VPARAMS((rtx orgfun, int fn_type, enum machine_mode outmode,
3979 #ifndef ANSI_PROTOTYPES
3982 enum machine_mode outmode;
3987 VA_START (p, nargs);
3989 #ifndef ANSI_PROTOTYPES
3990 orgfun = va_arg (p, rtx);
3991 fn_type = va_arg (p, int);
3992 outmode = va_arg (p, enum machine_mode);
3993 nargs = va_arg (p, int);
3996 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4001 /* Like emit_library_call except that an extra argument, VALUE,
4002 comes second and says where to store the result.
4003 (If VALUE is zero, this function chooses a convenient way
4004 to return the value.
4006 This function returns an rtx for where the value is to be found.
4007 If VALUE is nonzero, VALUE is returned. */
4010 emit_library_call_value VPARAMS((rtx orgfun, rtx value, int fn_type,
4011 enum machine_mode outmode, int nargs, ...))
4013 #ifndef ANSI_PROTOTYPES
4017 enum machine_mode outmode;
4022 VA_START (p, nargs);
4024 #ifndef ANSI_PROTOTYPES
4025 orgfun = va_arg (p, rtx);
4026 value = va_arg (p, rtx);
4027 fn_type = va_arg (p, int);
4028 outmode = va_arg (p, enum machine_mode);
4029 nargs = va_arg (p, int);
4032 value = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode, nargs, p);
4040 /* Return an rtx which represents a suitable home on the stack
4041 given TYPE, the type of the argument looking for a home.
4042 This is called only for BLKmode arguments.
4044 SIZE is the size needed for this target.
4045 ARGS_ADDR is the address of the bottom of the argument block for this call.
4046 OFFSET describes this parameter's offset into ARGS_ADDR. It is meaningless
4047 if this machine uses push insns. */
4050 target_for_arg (type, size, args_addr, offset)
4054 struct args_size offset;
4057 rtx offset_rtx = ARGS_SIZE_RTX (offset);
4059 /* We do not call memory_address if possible,
4060 because we want to address as close to the stack
4061 as possible. For non-variable sized arguments,
4062 this will be stack-pointer relative addressing. */
4063 if (GET_CODE (offset_rtx) == CONST_INT)
4064 target = plus_constant (args_addr, INTVAL (offset_rtx));
4067 /* I have no idea how to guarantee that this
4068 will work in the presence of register parameters. */
4069 target = gen_rtx_PLUS (Pmode, args_addr, offset_rtx);
4070 target = memory_address (QImode, target);
4073 return gen_rtx_MEM (BLKmode, target);
4077 /* Store a single argument for a function call
4078 into the register or memory area where it must be passed.
4079 *ARG describes the argument value and where to pass it.
4081 ARGBLOCK is the address of the stack-block for all the arguments,
4082 or 0 on a machine where arguments are pushed individually.
4084 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4085 so must be careful about how the stack is used.
4087 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4088 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4089 that we need not worry about saving and restoring the stack.
4091 FNDECL is the declaration of the function we are calling. */
4094 store_one_arg (arg, argblock, flags, variable_size,
4095 reg_parm_stack_space)
4096 struct arg_data *arg;
4099 int variable_size ATTRIBUTE_UNUSED;
4100 int reg_parm_stack_space;
4102 register tree pval = arg->tree_value;
4106 int i, lower_bound = 0, upper_bound = 0;
4108 if (TREE_CODE (pval) == ERROR_MARK)
4111 /* Push a new temporary level for any temporaries we make for
4115 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4117 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4118 save any previous data at that location. */
4119 if (argblock && ! variable_size && arg->stack)
4121 #ifdef ARGS_GROW_DOWNWARD
4122 /* stack_slot is negative, but we want to index stack_usage_map
4123 with positive values. */
4124 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4125 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4129 lower_bound = upper_bound - arg->size.constant;
4131 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4132 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4136 upper_bound = lower_bound + arg->size.constant;
4139 for (i = lower_bound; i < upper_bound; i++)
4140 if (stack_usage_map[i]
4141 /* Don't store things in the fixed argument area at this point;
4142 it has already been saved. */
4143 && i > reg_parm_stack_space)
4146 if (i != upper_bound)
4148 /* We need to make a save area. See what mode we can make it. */
4149 enum machine_mode save_mode
4150 = mode_for_size (arg->size.constant * BITS_PER_UNIT, MODE_INT, 1);
4152 = gen_rtx_MEM (save_mode,
4153 memory_address (save_mode,
4154 XEXP (arg->stack_slot, 0)));
4156 if (save_mode == BLKmode)
4158 arg->save_area = assign_stack_temp (BLKmode,
4159 arg->size.constant, 0);
4160 MEM_SET_IN_STRUCT_P (arg->save_area,
4161 AGGREGATE_TYPE_P (TREE_TYPE
4162 (arg->tree_value)));
4163 preserve_temp_slots (arg->save_area);
4164 emit_block_move (validize_mem (arg->save_area), stack_area,
4165 GEN_INT (arg->size.constant),
4170 arg->save_area = gen_reg_rtx (save_mode);
4171 emit_move_insn (arg->save_area, stack_area);
4175 /* Now that we have saved any slots that will be overwritten by this
4176 store, mark all slots this store will use. We must do this before
4177 we actually expand the argument since the expansion itself may
4178 trigger library calls which might need to use the same stack slot. */
4179 if (argblock && ! variable_size && arg->stack)
4180 for (i = lower_bound; i < upper_bound; i++)
4181 stack_usage_map[i] = 1;
4184 /* If this isn't going to be placed on both the stack and in registers,
4185 set up the register and number of words. */
4186 if (! arg->pass_on_stack)
4187 reg = arg->reg, partial = arg->partial;
4189 if (reg != 0 && partial == 0)
4190 /* Being passed entirely in a register. We shouldn't be called in
4194 /* If this arg needs special alignment, don't load the registers
4196 if (arg->n_aligned_regs != 0)
4199 /* If this is being passed partially in a register, we can't evaluate
4200 it directly into its stack slot. Otherwise, we can. */
4201 if (arg->value == 0)
4203 /* stack_arg_under_construction is nonzero if a function argument is
4204 being evaluated directly into the outgoing argument list and
4205 expand_call must take special action to preserve the argument list
4206 if it is called recursively.
4208 For scalar function arguments stack_usage_map is sufficient to
4209 determine which stack slots must be saved and restored. Scalar
4210 arguments in general have pass_on_stack == 0.
4212 If this argument is initialized by a function which takes the
4213 address of the argument (a C++ constructor or a C function
4214 returning a BLKmode structure), then stack_usage_map is
4215 insufficient and expand_call must push the stack around the
4216 function call. Such arguments have pass_on_stack == 1.
4218 Note that it is always safe to set stack_arg_under_construction,
4219 but this generates suboptimal code if set when not needed. */
4221 if (arg->pass_on_stack)
4222 stack_arg_under_construction++;
4224 arg->value = expand_expr (pval,
4226 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4227 ? NULL_RTX : arg->stack,
4230 /* If we are promoting object (or for any other reason) the mode
4231 doesn't agree, convert the mode. */
4233 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4234 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4235 arg->value, arg->unsignedp);
4237 if (arg->pass_on_stack)
4238 stack_arg_under_construction--;
4241 /* Don't allow anything left on stack from computation
4242 of argument to alloca. */
4243 if (flags & ECF_MAY_BE_ALLOCA)
4244 do_pending_stack_adjust ();
4246 if (arg->value == arg->stack)
4248 /* If the value is already in the stack slot, we are done. */
4249 if (current_function_check_memory_usage && GET_CODE (arg->stack) == MEM)
4251 emit_library_call (chkr_set_right_libfunc, 1, VOIDmode, 3,
4252 XEXP (arg->stack, 0), Pmode,
4253 ARGS_SIZE_RTX (arg->size),
4254 TYPE_MODE (sizetype),
4255 GEN_INT (MEMORY_USE_RW),
4256 TYPE_MODE (integer_type_node));
4259 else if (arg->mode != BLKmode)
4263 /* Argument is a scalar, not entirely passed in registers.
4264 (If part is passed in registers, arg->partial says how much
4265 and emit_push_insn will take care of putting it there.)
4267 Push it, and if its size is less than the
4268 amount of space allocated to it,
4269 also bump stack pointer by the additional space.
4270 Note that in C the default argument promotions
4271 will prevent such mismatches. */
4273 size = GET_MODE_SIZE (arg->mode);
4274 /* Compute how much space the push instruction will push.
4275 On many machines, pushing a byte will advance the stack
4276 pointer by a halfword. */
4277 #ifdef PUSH_ROUNDING
4278 size = PUSH_ROUNDING (size);
4282 /* Compute how much space the argument should get:
4283 round up to a multiple of the alignment for arguments. */
4284 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4285 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4286 / (PARM_BOUNDARY / BITS_PER_UNIT))
4287 * (PARM_BOUNDARY / BITS_PER_UNIT));
4289 /* This isn't already where we want it on the stack, so put it there.
4290 This can either be done with push or copy insns. */
4291 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX, 0,
4292 partial, reg, used - size, argblock,
4293 ARGS_SIZE_RTX (arg->offset), reg_parm_stack_space,
4294 ARGS_SIZE_RTX (arg->alignment_pad));
4298 /* BLKmode, at least partly to be pushed. */
4300 register int excess;
4303 /* Pushing a nonscalar.
4304 If part is passed in registers, PARTIAL says how much
4305 and emit_push_insn will take care of putting it there. */
4307 /* Round its size up to a multiple
4308 of the allocation unit for arguments. */
4310 if (arg->size.var != 0)
4313 size_rtx = ARGS_SIZE_RTX (arg->size);
4317 /* PUSH_ROUNDING has no effect on us, because
4318 emit_push_insn for BLKmode is careful to avoid it. */
4319 excess = (arg->size.constant - int_size_in_bytes (TREE_TYPE (pval))
4320 + partial * UNITS_PER_WORD);
4321 size_rtx = expr_size (pval);
4324 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4325 TYPE_ALIGN (TREE_TYPE (pval)), partial, reg, excess,
4326 argblock, ARGS_SIZE_RTX (arg->offset),
4327 reg_parm_stack_space,
4328 ARGS_SIZE_RTX (arg->alignment_pad));
4332 /* Unless this is a partially-in-register argument, the argument is now
4335 ??? Note that this can change arg->value from arg->stack to
4336 arg->stack_slot and it matters when they are not the same.
4337 It isn't totally clear that this is correct in all cases. */
4339 arg->value = arg->stack_slot;
4341 /* Once we have pushed something, pops can't safely
4342 be deferred during the rest of the arguments. */
4345 /* ANSI doesn't require a sequence point here,
4346 but PCC has one, so this will avoid some problems. */
4349 /* Free any temporary slots made in processing this argument. Show
4350 that we might have taken the address of something and pushed that
4352 preserve_temp_slots (NULL_RTX);
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