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, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
38 #include "langhooks.h"
43 /* Decide whether a function's arguments should be processed
44 from first to last or from last to first.
46 They should if the stack and args grow in opposite directions, but
47 only if we have push insns. */
51 #ifndef PUSH_ARGS_REVERSED
52 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
53 #define PUSH_ARGS_REVERSED PUSH_ARGS
59 #ifndef PUSH_ARGS_REVERSED
60 #define PUSH_ARGS_REVERSED 0
63 #ifndef STACK_POINTER_OFFSET
64 #define STACK_POINTER_OFFSET 0
67 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
68 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
70 /* Data structure and subroutines used within expand_call. */
74 /* Tree node for this argument. */
76 /* Mode for value; TYPE_MODE unless promoted. */
77 enum machine_mode mode;
78 /* Current RTL value for argument, or 0 if it isn't precomputed. */
80 /* Initially-compute RTL value for argument; only for const functions. */
82 /* Register to pass this argument in, 0 if passed on stack, or an
83 PARALLEL if the arg is to be copied into multiple non-contiguous
86 /* Register to pass this argument in when generating tail call sequence.
87 This is not the same register as for normal calls on machines with
90 /* If REG was promoted from the actual mode of the argument expression,
91 indicates whether the promotion is sign- or zero-extended. */
93 /* Number of registers to use. 0 means put the whole arg in registers.
94 Also 0 if not passed in registers. */
96 /* Nonzero if argument must be passed on stack.
97 Note that some arguments may be passed on the stack
98 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
99 pass_on_stack identifies arguments that *cannot* go in registers. */
101 /* Some fields packaged up for locate_and_pad_parm. */
102 struct locate_and_pad_arg_data locate;
103 /* Location on the stack at which parameter should be stored. The store
104 has already been done if STACK == VALUE. */
106 /* Location on the stack of the start of this argument slot. This can
107 differ from STACK if this arg pads downward. This location is known
108 to be aligned to FUNCTION_ARG_BOUNDARY. */
110 /* Place that this stack area has been saved, if needed. */
112 /* If an argument's alignment does not permit direct copying into registers,
113 copy in smaller-sized pieces into pseudos. These are stored in a
114 block pointed to by this field. The next field says how many
115 word-sized pseudos we made. */
120 /* A vector of one char per byte of stack space. A byte if nonzero if
121 the corresponding stack location has been used.
122 This vector is used to prevent a function call within an argument from
123 clobbering any stack already set up. */
124 static char *stack_usage_map;
126 /* Size of STACK_USAGE_MAP. */
127 static int highest_outgoing_arg_in_use;
129 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
130 stack location's tail call argument has been already stored into the stack.
131 This bitmap is used to prevent sibling call optimization if function tries
132 to use parent's incoming argument slots when they have been already
133 overwritten with tail call arguments. */
134 static sbitmap stored_args_map;
136 /* stack_arg_under_construction is nonzero when an argument may be
137 initialized with a constructor call (including a C function that
138 returns a BLKmode struct) and expand_call must take special action
139 to make sure the object being constructed does not overlap the
140 argument list for the constructor call. */
141 int stack_arg_under_construction;
143 static int calls_function PARAMS ((tree, int));
144 static int calls_function_1 PARAMS ((tree, int));
146 static void emit_call_1 PARAMS ((rtx, tree, tree, HOST_WIDE_INT,
147 HOST_WIDE_INT, HOST_WIDE_INT, rtx,
150 static void precompute_register_parameters PARAMS ((int,
153 static int store_one_arg PARAMS ((struct arg_data *, rtx, int, int,
155 static void store_unaligned_arguments_into_pseudos PARAMS ((struct arg_data *,
157 static int finalize_must_preallocate PARAMS ((int, int,
159 struct args_size *));
160 static void precompute_arguments PARAMS ((int, int,
162 static int compute_argument_block_size PARAMS ((int,
165 static void initialize_argument_information PARAMS ((int,
172 static void compute_argument_addresses PARAMS ((struct arg_data *,
174 static rtx rtx_for_function_call PARAMS ((tree, tree));
175 static void load_register_parameters PARAMS ((struct arg_data *,
178 static rtx emit_library_call_value_1 PARAMS ((int, rtx, rtx,
182 static int special_function_p PARAMS ((tree, int));
183 static rtx try_to_integrate PARAMS ((tree, tree, rtx,
185 static int check_sibcall_argument_overlap_1 PARAMS ((rtx));
186 static int check_sibcall_argument_overlap PARAMS ((rtx, struct arg_data *,
189 static int combine_pending_stack_adjustment_and_call
190 PARAMS ((int, struct args_size *, int));
191 static tree fix_unsafe_tree PARAMS ((tree));
193 #ifdef REG_PARM_STACK_SPACE
194 static rtx save_fixed_argument_area PARAMS ((int, rtx, int *, int *));
195 static void restore_fixed_argument_area PARAMS ((rtx, rtx, int, int));
198 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
201 If WHICH is 0, return 1 if EXP contains a call to any function.
202 Actually, we only need return 1 if evaluating EXP would require pushing
203 arguments on the stack, but that is too difficult to compute, so we just
204 assume any function call might require the stack. */
206 static tree calls_function_save_exprs;
209 calls_function (exp, which)
215 calls_function_save_exprs = 0;
216 val = calls_function_1 (exp, which);
217 calls_function_save_exprs = 0;
221 /* Recursive function to do the work of above function. */
224 calls_function_1 (exp, which)
229 enum tree_code code = TREE_CODE (exp);
230 int class = TREE_CODE_CLASS (code);
231 int length = first_rtl_op (code);
233 /* If this code is language-specific, we don't know what it will do. */
234 if ((int) code >= NUM_TREE_CODES)
242 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
244 && (TYPE_RETURNS_STACK_DEPRESSED
245 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
247 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
248 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
250 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
252 & ECF_MAY_BE_ALLOCA))
261 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
262 if (calls_function_1 (TREE_VALUE (tem), which))
269 if (SAVE_EXPR_RTL (exp) != 0)
271 if (value_member (exp, calls_function_save_exprs))
273 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
274 calls_function_save_exprs);
275 return (TREE_OPERAND (exp, 0) != 0
276 && calls_function_1 (TREE_OPERAND (exp, 0), which));
283 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
284 if (DECL_INITIAL (local) != 0
285 && calls_function_1 (DECL_INITIAL (local), which))
288 for (subblock = BLOCK_SUBBLOCKS (exp);
290 subblock = TREE_CHAIN (subblock))
291 if (calls_function_1 (subblock, which))
297 for (; exp != 0; exp = TREE_CHAIN (exp))
298 if (calls_function_1 (TREE_VALUE (exp), which))
306 /* Only expressions, references, and blocks can contain calls. */
307 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
310 for (i = 0; i < length; i++)
311 if (TREE_OPERAND (exp, i) != 0
312 && calls_function_1 (TREE_OPERAND (exp, i), which))
318 /* Force FUNEXP into a form suitable for the address of a CALL,
319 and return that as an rtx. Also load the static chain register
320 if FNDECL is a nested function.
322 CALL_FUSAGE points to a variable holding the prospective
323 CALL_INSN_FUNCTION_USAGE information. */
326 prepare_call_address (funexp, fndecl, call_fusage, reg_parm_seen, sibcallp)
333 rtx static_chain_value = 0;
335 funexp = protect_from_queue (funexp, 0);
338 /* Get possible static chain value for nested function in C. */
339 static_chain_value = lookup_static_chain (fndecl);
341 /* Make a valid memory address and copy constants thru pseudo-regs,
342 but not for a constant address if -fno-function-cse. */
343 if (GET_CODE (funexp) != SYMBOL_REF)
344 /* If we are using registers for parameters, force the
345 function address into a register now. */
346 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
347 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
348 : memory_address (FUNCTION_MODE, funexp));
351 #ifndef NO_FUNCTION_CSE
352 if (optimize && ! flag_no_function_cse)
353 #ifdef NO_RECURSIVE_FUNCTION_CSE
354 if (fndecl != current_function_decl)
356 funexp = force_reg (Pmode, funexp);
360 if (static_chain_value != 0)
362 emit_move_insn (static_chain_rtx, static_chain_value);
364 if (GET_CODE (static_chain_rtx) == REG)
365 use_reg (call_fusage, static_chain_rtx);
371 /* Generate instructions to call function FUNEXP,
372 and optionally pop the results.
373 The CALL_INSN is the first insn generated.
375 FNDECL is the declaration node of the function. This is given to the
376 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
378 FUNTYPE is the data type of the function. This is given to the macro
379 RETURN_POPS_ARGS to determine whether this function pops its own args.
380 We used to allow an identifier for library functions, but that doesn't
381 work when the return type is an aggregate type and the calling convention
382 says that the pointer to this aggregate is to be popped by the callee.
384 STACK_SIZE is the number of bytes of arguments on the stack,
385 ROUNDED_STACK_SIZE is that number rounded up to
386 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
387 both to put into the call insn and to generate explicit popping
390 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
391 It is zero if this call doesn't want a structure value.
393 NEXT_ARG_REG is the rtx that results from executing
394 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
395 just after all the args have had their registers assigned.
396 This could be whatever you like, but normally it is the first
397 arg-register beyond those used for args in this call,
398 or 0 if all the arg-registers are used in this call.
399 It is passed on to `gen_call' so you can put this info in the call insn.
401 VALREG is a hard register in which a value is returned,
402 or 0 if the call does not return a value.
404 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
405 the args to this call were processed.
406 We restore `inhibit_defer_pop' to that value.
408 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
409 denote registers used by the called function. */
412 emit_call_1 (funexp, fndecl, funtype, stack_size, rounded_stack_size,
413 struct_value_size, next_arg_reg, valreg, old_inhibit_defer_pop,
414 call_fusage, ecf_flags, args_so_far)
416 tree fndecl ATTRIBUTE_UNUSED;
417 tree funtype ATTRIBUTE_UNUSED;
418 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED;
419 HOST_WIDE_INT rounded_stack_size;
420 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED;
421 rtx next_arg_reg ATTRIBUTE_UNUSED;
423 int old_inhibit_defer_pop;
426 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED;
428 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
430 int already_popped = 0;
431 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
432 #if defined (HAVE_call) && defined (HAVE_call_value)
433 rtx struct_value_size_rtx;
434 struct_value_size_rtx = GEN_INT (struct_value_size);
437 #ifdef CALL_POPS_ARGS
438 n_popped += CALL_POPS_ARGS (* args_so_far);
441 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
442 and we don't want to load it into a register as an optimization,
443 because prepare_call_address already did it if it should be done. */
444 if (GET_CODE (funexp) != SYMBOL_REF)
445 funexp = memory_address (FUNCTION_MODE, funexp);
447 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
448 if ((ecf_flags & ECF_SIBCALL)
449 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
450 && (n_popped > 0 || stack_size == 0))
452 rtx n_pop = GEN_INT (n_popped);
455 /* If this subroutine pops its own args, record that in the call insn
456 if possible, for the sake of frame pointer elimination. */
459 pat = GEN_SIBCALL_VALUE_POP (valreg,
460 gen_rtx_MEM (FUNCTION_MODE, funexp),
461 rounded_stack_size_rtx, next_arg_reg,
464 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
465 rounded_stack_size_rtx, next_arg_reg, n_pop);
467 emit_call_insn (pat);
473 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
474 /* If the target has "call" or "call_value" insns, then prefer them
475 if no arguments are actually popped. If the target does not have
476 "call" or "call_value" insns, then we must use the popping versions
477 even if the call has no arguments to pop. */
478 #if defined (HAVE_call) && defined (HAVE_call_value)
479 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
480 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
482 if (HAVE_call_pop && HAVE_call_value_pop)
485 rtx n_pop = GEN_INT (n_popped);
488 /* If this subroutine pops its own args, record that in the call insn
489 if possible, for the sake of frame pointer elimination. */
492 pat = GEN_CALL_VALUE_POP (valreg,
493 gen_rtx_MEM (FUNCTION_MODE, funexp),
494 rounded_stack_size_rtx, next_arg_reg, n_pop);
496 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
497 rounded_stack_size_rtx, next_arg_reg, n_pop);
499 emit_call_insn (pat);
505 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
506 if ((ecf_flags & ECF_SIBCALL)
507 && HAVE_sibcall && HAVE_sibcall_value)
510 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
511 gen_rtx_MEM (FUNCTION_MODE, funexp),
512 rounded_stack_size_rtx,
513 next_arg_reg, NULL_RTX));
515 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
516 rounded_stack_size_rtx, next_arg_reg,
517 struct_value_size_rtx));
522 #if defined (HAVE_call) && defined (HAVE_call_value)
523 if (HAVE_call && HAVE_call_value)
526 emit_call_insn (GEN_CALL_VALUE (valreg,
527 gen_rtx_MEM (FUNCTION_MODE, funexp),
528 rounded_stack_size_rtx, next_arg_reg,
531 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
532 rounded_stack_size_rtx, next_arg_reg,
533 struct_value_size_rtx));
539 /* Find the call we just emitted. */
540 call_insn = last_call_insn ();
542 /* Mark memory as used for "pure" function call. */
543 if (ecf_flags & ECF_PURE)
547 gen_rtx_USE (VOIDmode,
548 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
551 /* Put the register usage information there. */
552 add_function_usage_to (call_insn, call_fusage);
554 /* If this is a const call, then set the insn's unchanging bit. */
555 if (ecf_flags & (ECF_CONST | ECF_PURE))
556 CONST_OR_PURE_CALL_P (call_insn) = 1;
558 /* If this call can't throw, attach a REG_EH_REGION reg note to that
560 if (ecf_flags & ECF_NOTHROW)
561 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
562 REG_NOTES (call_insn));
564 note_eh_region_may_contain_throw ();
566 if (ecf_flags & ECF_NORETURN)
567 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
568 REG_NOTES (call_insn));
569 if (ecf_flags & ECF_ALWAYS_RETURN)
570 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
571 REG_NOTES (call_insn));
573 if (ecf_flags & ECF_RETURNS_TWICE)
575 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
576 REG_NOTES (call_insn));
577 current_function_calls_setjmp = 1;
580 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
582 /* Restore this now, so that we do defer pops for this call's args
583 if the context of the call as a whole permits. */
584 inhibit_defer_pop = old_inhibit_defer_pop;
589 CALL_INSN_FUNCTION_USAGE (call_insn)
590 = gen_rtx_EXPR_LIST (VOIDmode,
591 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
592 CALL_INSN_FUNCTION_USAGE (call_insn));
593 rounded_stack_size -= n_popped;
594 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
595 stack_pointer_delta -= n_popped;
598 if (!ACCUMULATE_OUTGOING_ARGS)
600 /* If returning from the subroutine does not automatically pop the args,
601 we need an instruction to pop them sooner or later.
602 Perhaps do it now; perhaps just record how much space to pop later.
604 If returning from the subroutine does pop the args, indicate that the
605 stack pointer will be changed. */
607 if (rounded_stack_size != 0)
609 if (ecf_flags & ECF_SP_DEPRESSED)
610 /* Just pretend we did the pop. */
611 stack_pointer_delta -= rounded_stack_size;
612 else if (flag_defer_pop && inhibit_defer_pop == 0
613 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
614 pending_stack_adjust += rounded_stack_size;
616 adjust_stack (rounded_stack_size_rtx);
619 /* When we accumulate outgoing args, we must avoid any stack manipulations.
620 Restore the stack pointer to its original value now. Usually
621 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
622 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
623 popping variants of functions exist as well.
625 ??? We may optimize similar to defer_pop above, but it is
626 probably not worthwhile.
628 ??? It will be worthwhile to enable combine_stack_adjustments even for
631 anti_adjust_stack (GEN_INT (n_popped));
634 /* Determine if the function identified by NAME and FNDECL is one with
635 special properties we wish to know about.
637 For example, if the function might return more than one time (setjmp), then
638 set RETURNS_TWICE to a nonzero value.
640 Similarly set LONGJMP for if the function is in the longjmp family.
642 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
643 space from the stack such as alloca. */
646 special_function_p (fndecl, flags)
650 if (! (flags & ECF_MALLOC)
651 && fndecl && DECL_NAME (fndecl)
652 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
653 /* Exclude functions not at the file scope, or not `extern',
654 since they are not the magic functions we would otherwise
656 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
658 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
659 const char *tname = name;
661 /* We assume that alloca will always be called by name. It
662 makes no sense to pass it as a pointer-to-function to
663 anything that does not understand its behavior. */
664 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
666 && ! strcmp (name, "alloca"))
667 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
669 && ! strcmp (name, "__builtin_alloca"))))
670 flags |= ECF_MAY_BE_ALLOCA;
672 /* Disregard prefix _, __ or __x. */
675 if (name[1] == '_' && name[2] == 'x')
677 else if (name[1] == '_')
686 && (! strcmp (tname, "setjmp")
687 || ! strcmp (tname, "setjmp_syscall")))
689 && ! strcmp (tname, "sigsetjmp"))
691 && ! strcmp (tname, "savectx")))
692 flags |= ECF_RETURNS_TWICE;
695 && ! strcmp (tname, "siglongjmp"))
696 flags |= ECF_LONGJMP;
698 else if ((tname[0] == 'q' && tname[1] == 's'
699 && ! strcmp (tname, "qsetjmp"))
700 || (tname[0] == 'v' && tname[1] == 'f'
701 && ! strcmp (tname, "vfork")))
702 flags |= ECF_RETURNS_TWICE;
704 else if (tname[0] == 'l' && tname[1] == 'o'
705 && ! strcmp (tname, "longjmp"))
706 flags |= ECF_LONGJMP;
708 else if ((tname[0] == 'f' && tname[1] == 'o'
709 && ! strcmp (tname, "fork"))
710 /* Linux specific: __clone. check NAME to insist on the
711 leading underscores, to avoid polluting the ISO / POSIX
713 || (name[0] == '_' && name[1] == '_'
714 && ! strcmp (tname, "clone"))
715 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
716 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
718 || ((tname[5] == 'p' || tname[5] == 'e')
719 && tname[6] == '\0'))))
720 flags |= ECF_FORK_OR_EXEC;
725 /* Return nonzero when tree represent call to longjmp. */
728 setjmp_call_p (fndecl)
731 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
734 /* Return true when exp contains alloca call. */
739 if (TREE_CODE (exp) == CALL_EXPR
740 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
741 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
743 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
744 0) & ECF_MAY_BE_ALLOCA))
749 /* Detect flags (function attributes) from the function decl or type node. */
752 flags_from_decl_or_type (exp)
760 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
761 type = TREE_TYPE (exp);
765 if (i->pure_function)
766 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
767 if (i->const_function)
768 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
771 /* The function exp may have the `malloc' attribute. */
772 if (DECL_IS_MALLOC (exp))
775 /* The function exp may have the `pure' attribute. */
776 if (DECL_IS_PURE (exp))
777 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
779 if (TREE_NOTHROW (exp))
780 flags |= ECF_NOTHROW;
783 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
784 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
786 if (TREE_THIS_VOLATILE (exp))
787 flags |= ECF_NORETURN;
789 /* Mark if the function returns with the stack pointer depressed. We
790 cannot consider it pure or constant in that case. */
791 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
793 flags |= ECF_SP_DEPRESSED;
794 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
800 /* Precompute all register parameters as described by ARGS, storing values
801 into fields within the ARGS array.
803 NUM_ACTUALS indicates the total number elements in the ARGS array.
805 Set REG_PARM_SEEN if we encounter a register parameter. */
808 precompute_register_parameters (num_actuals, args, reg_parm_seen)
810 struct arg_data *args;
817 for (i = 0; i < num_actuals; i++)
818 if (args[i].reg != 0 && ! args[i].pass_on_stack)
822 if (args[i].value == 0)
825 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
827 preserve_temp_slots (args[i].value);
830 /* ANSI doesn't require a sequence point here,
831 but PCC has one, so this will avoid some problems. */
835 /* If the value is a non-legitimate constant, force it into a
836 pseudo now. TLS symbols sometimes need a call to resolve. */
837 if (CONSTANT_P (args[i].value)
838 && !LEGITIMATE_CONSTANT_P (args[i].value))
839 args[i].value = force_reg (args[i].mode, args[i].value);
841 /* If we are to promote the function arg to a wider mode,
844 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
846 = convert_modes (args[i].mode,
847 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
848 args[i].value, args[i].unsignedp);
850 /* If the value is expensive, and we are inside an appropriately
851 short loop, put the value into a pseudo and then put the pseudo
854 For small register classes, also do this if this call uses
855 register parameters. This is to avoid reload conflicts while
856 loading the parameters registers. */
858 if ((! (GET_CODE (args[i].value) == REG
859 || (GET_CODE (args[i].value) == SUBREG
860 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
861 && args[i].mode != BLKmode
862 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
863 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
864 || preserve_subexpressions_p ()))
865 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
869 #ifdef REG_PARM_STACK_SPACE
871 /* The argument list is the property of the called routine and it
872 may clobber it. If the fixed area has been used for previous
873 parameters, we must save and restore it. */
876 save_fixed_argument_area (reg_parm_stack_space, argblock,
877 low_to_save, high_to_save)
878 int reg_parm_stack_space;
886 /* Compute the boundary of the area that needs to be saved, if any. */
887 high = reg_parm_stack_space;
888 #ifdef ARGS_GROW_DOWNWARD
891 if (high > highest_outgoing_arg_in_use)
892 high = highest_outgoing_arg_in_use;
894 for (low = 0; low < high; low++)
895 if (stack_usage_map[low] != 0)
898 enum machine_mode save_mode;
903 while (stack_usage_map[--high] == 0)
907 *high_to_save = high;
909 num_to_save = high - low + 1;
910 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
912 /* If we don't have the required alignment, must do this
914 if ((low & (MIN (GET_MODE_SIZE (save_mode),
915 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
918 #ifdef ARGS_GROW_DOWNWARD
923 stack_area = gen_rtx_MEM (save_mode,
924 memory_address (save_mode,
925 plus_constant (argblock,
928 set_mem_align (stack_area, PARM_BOUNDARY);
929 if (save_mode == BLKmode)
931 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
932 emit_block_move (validize_mem (save_area), stack_area,
933 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
937 save_area = gen_reg_rtx (save_mode);
938 emit_move_insn (save_area, stack_area);
948 restore_fixed_argument_area (save_area, argblock, high_to_save, low_to_save)
954 enum machine_mode save_mode = GET_MODE (save_area);
958 #ifdef ARGS_GROW_DOWNWARD
959 delta = -high_to_save;
963 stack_area = gen_rtx_MEM (save_mode,
964 memory_address (save_mode,
965 plus_constant (argblock, delta)));
966 set_mem_align (stack_area, PARM_BOUNDARY);
968 if (save_mode != BLKmode)
969 emit_move_insn (stack_area, save_area);
971 emit_block_move (stack_area, validize_mem (save_area),
972 GEN_INT (high_to_save - low_to_save + 1),
975 #endif /* REG_PARM_STACK_SPACE */
977 /* If any elements in ARGS refer to parameters that are to be passed in
978 registers, but not in memory, and whose alignment does not permit a
979 direct copy into registers. Copy the values into a group of pseudos
980 which we will later copy into the appropriate hard registers.
982 Pseudos for each unaligned argument will be stored into the array
983 args[argnum].aligned_regs. The caller is responsible for deallocating
984 the aligned_regs array if it is nonzero. */
987 store_unaligned_arguments_into_pseudos (args, num_actuals)
988 struct arg_data *args;
993 for (i = 0; i < num_actuals; i++)
994 if (args[i].reg != 0 && ! args[i].pass_on_stack
995 && args[i].mode == BLKmode
996 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
997 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
999 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1000 int big_endian_correction = 0;
1002 args[i].n_aligned_regs
1003 = args[i].partial ? args[i].partial
1004 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1006 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
1007 * args[i].n_aligned_regs);
1009 /* Structures smaller than a word are aligned to the least
1010 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
1011 this means we must skip the empty high order bytes when
1012 calculating the bit offset. */
1013 if (BYTES_BIG_ENDIAN
1014 && bytes < UNITS_PER_WORD)
1015 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
1017 for (j = 0; j < args[i].n_aligned_regs; j++)
1019 rtx reg = gen_reg_rtx (word_mode);
1020 rtx word = operand_subword_force (args[i].value, j, BLKmode);
1021 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
1023 args[i].aligned_regs[j] = reg;
1025 /* There is no need to restrict this code to loading items
1026 in TYPE_ALIGN sized hunks. The bitfield instructions can
1027 load up entire word sized registers efficiently.
1029 ??? This may not be needed anymore.
1030 We use to emit a clobber here but that doesn't let later
1031 passes optimize the instructions we emit. By storing 0 into
1032 the register later passes know the first AND to zero out the
1033 bitfield being set in the register is unnecessary. The store
1034 of 0 will be deleted as will at least the first AND. */
1036 emit_move_insn (reg, const0_rtx);
1038 bytes -= bitsize / BITS_PER_UNIT;
1039 store_bit_field (reg, bitsize, big_endian_correction, word_mode,
1040 extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
1041 word_mode, word_mode,
1048 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1051 NUM_ACTUALS is the total number of parameters.
1053 N_NAMED_ARGS is the total number of named arguments.
1055 FNDECL is the tree code for the target of this call (if known)
1057 ARGS_SO_FAR holds state needed by the target to know where to place
1060 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1061 for arguments which are passed in registers.
1063 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1064 and may be modified by this routine.
1066 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1067 flags which may may be modified by this routine. */
1070 initialize_argument_information (num_actuals, args, args_size, n_named_args,
1071 actparms, fndecl, args_so_far,
1072 reg_parm_stack_space, old_stack_level,
1073 old_pending_adj, must_preallocate,
1075 int num_actuals ATTRIBUTE_UNUSED;
1076 struct arg_data *args;
1077 struct args_size *args_size;
1078 int n_named_args ATTRIBUTE_UNUSED;
1081 CUMULATIVE_ARGS *args_so_far;
1082 int reg_parm_stack_space;
1083 rtx *old_stack_level;
1084 int *old_pending_adj;
1085 int *must_preallocate;
1088 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1091 /* Count arg position in order args appear. */
1097 args_size->constant = 0;
1100 /* In this loop, we consider args in the order they are written.
1101 We fill up ARGS from the front or from the back if necessary
1102 so that in any case the first arg to be pushed ends up at the front. */
1104 if (PUSH_ARGS_REVERSED)
1106 i = num_actuals - 1, inc = -1;
1107 /* In this case, must reverse order of args
1108 so that we compute and push the last arg first. */
1115 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1116 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1118 tree type = TREE_TYPE (TREE_VALUE (p));
1120 enum machine_mode mode;
1122 args[i].tree_value = TREE_VALUE (p);
1124 /* Replace erroneous argument with constant zero. */
1125 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1126 args[i].tree_value = integer_zero_node, type = integer_type_node;
1128 /* If TYPE is a transparent union, pass things the way we would
1129 pass the first field of the union. We have already verified that
1130 the modes are the same. */
1131 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1132 type = TREE_TYPE (TYPE_FIELDS (type));
1134 /* Decide where to pass this arg.
1136 args[i].reg is nonzero if all or part is passed in registers.
1138 args[i].partial is nonzero if part but not all is passed in registers,
1139 and the exact value says how many words are passed in registers.
1141 args[i].pass_on_stack is nonzero if the argument must at least be
1142 computed on the stack. It may then be loaded back into registers
1143 if args[i].reg is nonzero.
1145 These decisions are driven by the FUNCTION_... macros and must agree
1146 with those made by function.c. */
1148 /* See if this argument should be passed by invisible reference. */
1149 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1150 || TREE_ADDRESSABLE (type)
1151 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1152 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1153 type, argpos < n_named_args)
1157 /* If we're compiling a thunk, pass through invisible
1158 references instead of making a copy. */
1159 if (current_function_is_thunk
1160 #ifdef FUNCTION_ARG_CALLEE_COPIES
1161 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1162 type, argpos < n_named_args)
1163 /* If it's in a register, we must make a copy of it too. */
1164 /* ??? Is this a sufficient test? Is there a better one? */
1165 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1166 && REG_P (DECL_RTL (args[i].tree_value)))
1167 && ! TREE_ADDRESSABLE (type))
1171 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1172 new object from the argument. If we are passing by
1173 invisible reference, the callee will do that for us, so we
1174 can strip off the TARGET_EXPR. This is not always safe,
1175 but it is safe in the only case where this is a useful
1176 optimization; namely, when the argument is a plain object.
1177 In that case, the frontend is just asking the backend to
1178 make a bitwise copy of the argument. */
1180 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1181 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1182 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1183 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1185 args[i].tree_value = build1 (ADDR_EXPR,
1186 build_pointer_type (type),
1187 args[i].tree_value);
1188 type = build_pointer_type (type);
1190 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1192 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1193 We implement this by passing the address of the temporary
1194 rather than expanding it into another allocated slot. */
1195 args[i].tree_value = build1 (ADDR_EXPR,
1196 build_pointer_type (type),
1197 args[i].tree_value);
1198 type = build_pointer_type (type);
1202 /* We make a copy of the object and pass the address to the
1203 function being called. */
1206 if (!COMPLETE_TYPE_P (type)
1207 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1208 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1209 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1210 STACK_CHECK_MAX_VAR_SIZE))))
1212 /* This is a variable-sized object. Make space on the stack
1214 rtx size_rtx = expr_size (TREE_VALUE (p));
1216 if (*old_stack_level == 0)
1218 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1219 *old_pending_adj = pending_stack_adjust;
1220 pending_stack_adjust = 0;
1223 copy = gen_rtx_MEM (BLKmode,
1224 allocate_dynamic_stack_space
1225 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1226 set_mem_attributes (copy, type, 1);
1229 copy = assign_temp (type, 0, 1, 0);
1231 store_expr (args[i].tree_value, copy, 0);
1232 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1234 args[i].tree_value = build1 (ADDR_EXPR,
1235 build_pointer_type (type),
1236 make_tree (type, copy));
1237 type = build_pointer_type (type);
1241 mode = TYPE_MODE (type);
1242 unsignedp = TREE_UNSIGNED (type);
1244 #ifdef PROMOTE_FUNCTION_ARGS
1245 mode = promote_mode (type, mode, &unsignedp, 1);
1248 args[i].unsignedp = unsignedp;
1249 args[i].mode = mode;
1251 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1252 argpos < n_named_args);
1253 #ifdef FUNCTION_INCOMING_ARG
1254 /* If this is a sibling call and the machine has register windows, the
1255 register window has to be unwinded before calling the routine, so
1256 arguments have to go into the incoming registers. */
1257 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1258 argpos < n_named_args);
1260 args[i].tail_call_reg = args[i].reg;
1263 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1266 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1267 argpos < n_named_args);
1270 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1272 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1273 it means that we are to pass this arg in the register(s) designated
1274 by the PARALLEL, but also to pass it in the stack. */
1275 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1276 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1277 args[i].pass_on_stack = 1;
1279 /* If this is an addressable type, we must preallocate the stack
1280 since we must evaluate the object into its final location.
1282 If this is to be passed in both registers and the stack, it is simpler
1284 if (TREE_ADDRESSABLE (type)
1285 || (args[i].pass_on_stack && args[i].reg != 0))
1286 *must_preallocate = 1;
1288 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1289 we cannot consider this function call constant. */
1290 if (TREE_ADDRESSABLE (type))
1291 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1293 /* Compute the stack-size of this argument. */
1294 if (args[i].reg == 0 || args[i].partial != 0
1295 || reg_parm_stack_space > 0
1296 || args[i].pass_on_stack)
1297 locate_and_pad_parm (mode, type,
1298 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1303 args[i].pass_on_stack ? 0 : args[i].partial,
1304 fndecl, args_size, &args[i].locate);
1306 /* Update ARGS_SIZE, the total stack space for args so far. */
1308 args_size->constant += args[i].locate.size.constant;
1309 if (args[i].locate.size.var)
1310 ADD_PARM_SIZE (*args_size, args[i].locate.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 misaligned frame sizes. */
1338 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1339 preferred_stack_boundary = STACK_BOUNDARY;
1341 /* Compute the actual size of the argument block required. The variable
1342 and constant sizes must be combined, the size may have to be rounded,
1343 and there may be a minimum required size. */
1347 args_size->var = ARGS_SIZE_TREE (*args_size);
1348 args_size->constant = 0;
1350 preferred_stack_boundary /= BITS_PER_UNIT;
1351 if (preferred_stack_boundary > 1)
1353 /* We don't handle this case yet. To handle it correctly we have
1354 to add the delta, round and subtract the delta.
1355 Currently no machine description requires this support. */
1356 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1358 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1361 if (reg_parm_stack_space > 0)
1364 = size_binop (MAX_EXPR, args_size->var,
1365 ssize_int (reg_parm_stack_space));
1367 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1368 /* The area corresponding to register parameters is not to count in
1369 the size of the block we need. So make the adjustment. */
1371 = size_binop (MINUS_EXPR, args_size->var,
1372 ssize_int (reg_parm_stack_space));
1378 preferred_stack_boundary /= BITS_PER_UNIT;
1379 if (preferred_stack_boundary < 1)
1380 preferred_stack_boundary = 1;
1381 args_size->constant = (((args_size->constant
1382 + stack_pointer_delta
1383 + preferred_stack_boundary - 1)
1384 / preferred_stack_boundary
1385 * preferred_stack_boundary)
1386 - stack_pointer_delta);
1388 args_size->constant = MAX (args_size->constant,
1389 reg_parm_stack_space);
1391 #ifdef MAYBE_REG_PARM_STACK_SPACE
1392 if (reg_parm_stack_space == 0)
1393 args_size->constant = 0;
1396 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1397 args_size->constant -= reg_parm_stack_space;
1400 return unadjusted_args_size;
1403 /* Precompute parameters as needed for a function call.
1405 FLAGS is mask of ECF_* constants.
1407 NUM_ACTUALS is the number of arguments.
1409 ARGS is an array containing information for each argument; this
1410 routine fills in the INITIAL_VALUE and VALUE fields for each
1411 precomputed argument. */
1414 precompute_arguments (flags, num_actuals, args)
1417 struct arg_data *args;
1421 /* If this function call is cse'able, precompute all the parameters.
1422 Note that if the parameter is constructed into a temporary, this will
1423 cause an additional copy because the parameter will be constructed
1424 into a temporary location and then copied into the outgoing arguments.
1425 If a parameter contains a call to alloca and this function uses the
1426 stack, precompute the parameter. */
1428 /* If we preallocated the stack space, and some arguments must be passed
1429 on the stack, then we must precompute any parameter which contains a
1430 function call which will store arguments on the stack.
1431 Otherwise, evaluating the parameter may clobber previous parameters
1432 which have already been stored into the stack. (we have code to avoid
1433 such case by saving the outgoing stack arguments, but it results in
1436 for (i = 0; i < num_actuals; i++)
1437 if ((flags & ECF_LIBCALL_BLOCK)
1438 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1440 enum machine_mode mode;
1442 /* If this is an addressable type, we cannot pre-evaluate it. */
1443 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1447 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1449 /* ANSI doesn't require a sequence point here,
1450 but PCC has one, so this will avoid some problems. */
1453 args[i].initial_value = args[i].value
1454 = protect_from_queue (args[i].value, 0);
1456 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1457 if (mode != args[i].mode)
1460 = convert_modes (args[i].mode, mode,
1461 args[i].value, args[i].unsignedp);
1462 #ifdef PROMOTE_FOR_CALL_ONLY
1463 /* CSE will replace this only if it contains args[i].value
1464 pseudo, so convert it down to the declared mode using
1466 if (GET_CODE (args[i].value) == REG
1467 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1469 args[i].initial_value
1470 = gen_lowpart_SUBREG (mode, args[i].value);
1471 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1472 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1480 /* Given the current state of MUST_PREALLOCATE and information about
1481 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1482 compute and return the final value for MUST_PREALLOCATE. */
1485 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1486 int must_preallocate;
1488 struct arg_data *args;
1489 struct args_size *args_size;
1491 /* See if we have or want to preallocate stack space.
1493 If we would have to push a partially-in-regs parm
1494 before other stack parms, preallocate stack space instead.
1496 If the size of some parm is not a multiple of the required stack
1497 alignment, we must preallocate.
1499 If the total size of arguments that would otherwise create a copy in
1500 a temporary (such as a CALL) is more than half the total argument list
1501 size, preallocation is faster.
1503 Another reason to preallocate is if we have a machine (like the m88k)
1504 where stack alignment is required to be maintained between every
1505 pair of insns, not just when the call is made. However, we assume here
1506 that such machines either do not have push insns (and hence preallocation
1507 would occur anyway) or the problem is taken care of with
1510 if (! must_preallocate)
1512 int partial_seen = 0;
1513 int copy_to_evaluate_size = 0;
1516 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1518 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1520 else if (partial_seen && args[i].reg == 0)
1521 must_preallocate = 1;
1523 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1524 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1525 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1526 || TREE_CODE (args[i].tree_value) == COND_EXPR
1527 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1528 copy_to_evaluate_size
1529 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1532 if (copy_to_evaluate_size * 2 >= args_size->constant
1533 && args_size->constant > 0)
1534 must_preallocate = 1;
1536 return must_preallocate;
1539 /* If we preallocated stack space, compute the address of each argument
1540 and store it into the ARGS array.
1542 We need not ensure it is a valid memory address here; it will be
1543 validized when it is used.
1545 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1548 compute_argument_addresses (args, argblock, num_actuals)
1549 struct arg_data *args;
1555 rtx arg_reg = argblock;
1556 int i, arg_offset = 0;
1558 if (GET_CODE (argblock) == PLUS)
1559 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1561 for (i = 0; i < num_actuals; i++)
1563 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1564 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1567 /* Skip this parm if it will not be passed on the stack. */
1568 if (! args[i].pass_on_stack && args[i].reg != 0)
1571 if (GET_CODE (offset) == CONST_INT)
1572 addr = plus_constant (arg_reg, INTVAL (offset));
1574 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1576 addr = plus_constant (addr, arg_offset);
1577 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1578 set_mem_align (args[i].stack, PARM_BOUNDARY);
1579 set_mem_attributes (args[i].stack,
1580 TREE_TYPE (args[i].tree_value), 1);
1582 if (GET_CODE (slot_offset) == CONST_INT)
1583 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1585 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1587 addr = plus_constant (addr, arg_offset);
1588 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1589 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1590 set_mem_attributes (args[i].stack_slot,
1591 TREE_TYPE (args[i].tree_value), 1);
1593 /* Function incoming arguments may overlap with sibling call
1594 outgoing arguments and we cannot allow reordering of reads
1595 from function arguments with stores to outgoing arguments
1596 of sibling calls. */
1597 set_mem_alias_set (args[i].stack, 0);
1598 set_mem_alias_set (args[i].stack_slot, 0);
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 ADDR is the operand 0 of CALL_EXPR for this call. */
1612 rtx_for_function_call (fndecl, addr)
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. */
1636 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1637 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1643 /* Do the register loads required for any wholly-register parms or any
1644 parms which are passed both on the stack and in a register. Their
1645 expressions were already evaluated.
1647 Mark all register-parms as living through the call, putting these USE
1648 insns in the CALL_INSN_FUNCTION_USAGE field.
1650 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1651 checking, setting *SIBCALL_FAILURE if appropriate. */
1654 load_register_parameters (args, num_actuals, call_fusage, flags,
1655 is_sibcall, sibcall_failure)
1656 struct arg_data *args;
1661 int *sibcall_failure;
1665 #ifdef LOAD_ARGS_REVERSED
1666 for (i = num_actuals - 1; i >= 0; i--)
1668 for (i = 0; i < num_actuals; i++)
1671 rtx reg = ((flags & ECF_SIBCALL)
1672 ? args[i].tail_call_reg : args[i].reg);
1673 int partial = args[i].partial;
1678 rtx before_arg = get_last_insn ();
1679 /* Set to non-negative if must move a word at a time, even if just
1680 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1681 we just use a normal move insn. This value can be zero if the
1682 argument is a zero size structure with no fields. */
1683 nregs = (partial ? partial
1684 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1685 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1686 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1689 /* Handle calls that pass values in multiple non-contiguous
1690 locations. The Irix 6 ABI has examples of this. */
1692 if (GET_CODE (reg) == PARALLEL)
1693 emit_group_load (reg, args[i].value,
1694 int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1696 /* If simple case, just do move. If normal partial, store_one_arg
1697 has already loaded the register for us. In all other cases,
1698 load the register(s) from memory. */
1700 else if (nregs == -1)
1701 emit_move_insn (reg, args[i].value);
1703 /* If we have pre-computed the values to put in the registers in
1704 the case of non-aligned structures, copy them in now. */
1706 else if (args[i].n_aligned_regs != 0)
1707 for (j = 0; j < args[i].n_aligned_regs; j++)
1708 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1709 args[i].aligned_regs[j]);
1711 else if (partial == 0 || args[i].pass_on_stack)
1712 move_block_to_reg (REGNO (reg),
1713 validize_mem (args[i].value), nregs,
1716 /* When a parameter is a block, and perhaps in other cases, it is
1717 possible that it did a load from an argument slot that was
1718 already clobbered. */
1720 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1721 *sibcall_failure = 1;
1723 /* Handle calls that pass values in multiple non-contiguous
1724 locations. The Irix 6 ABI has examples of this. */
1725 if (GET_CODE (reg) == PARALLEL)
1726 use_group_regs (call_fusage, reg);
1727 else if (nregs == -1)
1728 use_reg (call_fusage, reg);
1730 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1735 /* Try to integrate function. See expand_inline_function for documentation
1736 about the parameters. */
1739 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1745 rtx structure_value_addr;
1750 rtx old_stack_level = 0;
1751 int reg_parm_stack_space = 0;
1753 #ifdef REG_PARM_STACK_SPACE
1754 #ifdef MAYBE_REG_PARM_STACK_SPACE
1755 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1757 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1761 before_call = get_last_insn ();
1763 timevar_push (TV_INTEGRATION);
1765 temp = expand_inline_function (fndecl, actparms, target,
1767 structure_value_addr);
1769 timevar_pop (TV_INTEGRATION);
1771 /* If inlining succeeded, return. */
1772 if (temp != (rtx) (size_t) - 1)
1774 if (ACCUMULATE_OUTGOING_ARGS)
1776 /* If the outgoing argument list must be preserved, push
1777 the stack before executing the inlined function if it
1780 i = reg_parm_stack_space;
1781 if (i > highest_outgoing_arg_in_use)
1782 i = highest_outgoing_arg_in_use;
1783 while (--i >= 0 && stack_usage_map[i] == 0)
1786 if (stack_arg_under_construction || i >= 0)
1789 = before_call ? NEXT_INSN (before_call) : get_insns ();
1790 rtx insn = NULL_RTX, seq;
1792 /* Look for a call in the inline function code.
1793 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1794 nonzero then there is a call and it is not necessary
1795 to scan the insns. */
1797 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1798 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1799 if (GET_CODE (insn) == CALL_INSN)
1804 /* Reserve enough stack space so that the largest
1805 argument list of any function call in the inline
1806 function does not overlap the argument list being
1807 evaluated. This is usually an overestimate because
1808 allocate_dynamic_stack_space reserves space for an
1809 outgoing argument list in addition to the requested
1810 space, but there is no way to ask for stack space such
1811 that an argument list of a certain length can be
1814 Add the stack space reserved for register arguments, if
1815 any, in the inline function. What is really needed is the
1816 largest value of reg_parm_stack_space in the inline
1817 function, but that is not available. Using the current
1818 value of reg_parm_stack_space is wrong, but gives
1819 correct results on all supported machines. */
1821 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1822 + reg_parm_stack_space);
1825 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1826 allocate_dynamic_stack_space (GEN_INT (adjust),
1827 NULL_RTX, BITS_PER_UNIT);
1830 emit_insn_before (seq, first_insn);
1831 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1836 /* If the result is equivalent to TARGET, return TARGET to simplify
1837 checks in store_expr. They can be equivalent but not equal in the
1838 case of a function that returns BLKmode. */
1839 if (temp != target && rtx_equal_p (temp, target))
1844 /* If inlining failed, mark FNDECL as needing to be compiled
1845 separately after all. If function was declared inline,
1847 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1848 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1850 warning_with_decl (fndecl, "inlining failed in call to `%s'");
1851 warning ("called from here");
1853 (*lang_hooks.mark_addressable) (fndecl);
1854 return (rtx) (size_t) - 1;
1857 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1858 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1859 bytes, then we would need to push some additional bytes to pad the
1860 arguments. So, we compute an adjust to the stack pointer for an
1861 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1862 bytes. Then, when the arguments are pushed the stack will be perfectly
1863 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1864 be popped after the call. Returns the adjustment. */
1867 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1869 preferred_unit_stack_boundary)
1870 int unadjusted_args_size;
1871 struct args_size *args_size;
1872 int preferred_unit_stack_boundary;
1874 /* The number of bytes to pop so that the stack will be
1875 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1876 HOST_WIDE_INT adjustment;
1877 /* The alignment of the stack after the arguments are pushed, if we
1878 just pushed the arguments without adjust the stack here. */
1879 HOST_WIDE_INT unadjusted_alignment;
1881 unadjusted_alignment
1882 = ((stack_pointer_delta + unadjusted_args_size)
1883 % preferred_unit_stack_boundary);
1885 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1886 as possible -- leaving just enough left to cancel out the
1887 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1888 PENDING_STACK_ADJUST is non-negative, and congruent to
1889 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1891 /* Begin by trying to pop all the bytes. */
1892 unadjusted_alignment
1893 = (unadjusted_alignment
1894 - (pending_stack_adjust % preferred_unit_stack_boundary));
1895 adjustment = pending_stack_adjust;
1896 /* Push enough additional bytes that the stack will be aligned
1897 after the arguments are pushed. */
1898 if (preferred_unit_stack_boundary > 1)
1900 if (unadjusted_alignment > 0)
1901 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1903 adjustment += unadjusted_alignment;
1906 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1907 bytes after the call. The right number is the entire
1908 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1909 by the arguments in the first place. */
1911 = pending_stack_adjust - adjustment + unadjusted_args_size;
1916 /* Scan X expression if it does not dereference any argument slots
1917 we already clobbered by tail call arguments (as noted in stored_args_map
1919 Return nonzero if X expression dereferences such argument slots,
1923 check_sibcall_argument_overlap_1 (x)
1934 code = GET_CODE (x);
1938 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1940 else if (GET_CODE (XEXP (x, 0)) == PLUS
1941 && XEXP (XEXP (x, 0), 0) ==
1942 current_function_internal_arg_pointer
1943 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1944 i = INTVAL (XEXP (XEXP (x, 0), 1));
1948 #ifdef ARGS_GROW_DOWNWARD
1949 i = -i - GET_MODE_SIZE (GET_MODE (x));
1952 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1953 if (i + k < stored_args_map->n_bits
1954 && TEST_BIT (stored_args_map, i + k))
1960 /* Scan all subexpressions. */
1961 fmt = GET_RTX_FORMAT (code);
1962 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1966 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1969 else if (*fmt == 'E')
1971 for (j = 0; j < XVECLEN (x, i); j++)
1972 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1979 /* Scan sequence after INSN if it does not dereference any argument slots
1980 we already clobbered by tail call arguments (as noted in stored_args_map
1981 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1982 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1983 should be 0). Return nonzero if sequence after INSN dereferences such argument
1984 slots, zero otherwise. */
1987 check_sibcall_argument_overlap (insn, arg, mark_stored_args_map)
1989 struct arg_data *arg;
1990 int mark_stored_args_map;
1994 if (insn == NULL_RTX)
1995 insn = get_insns ();
1997 insn = NEXT_INSN (insn);
1999 for (; insn; insn = NEXT_INSN (insn))
2001 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2004 if (mark_stored_args_map)
2006 #ifdef ARGS_GROW_DOWNWARD
2007 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2009 low = arg->locate.slot_offset.constant;
2012 for (high = low + arg->locate.size.constant; low < high; low++)
2013 SET_BIT (stored_args_map, low);
2015 return insn != NULL_RTX;
2022 switch (unsafe_for_reeval (t))
2027 case 1: /* Mildly unsafe. */
2028 t = unsave_expr (t);
2031 case 2: /* Wildly unsafe. */
2033 tree var = build_decl (VAR_DECL, NULL_TREE,
2036 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2047 /* Generate all the code for a function call
2048 and return an rtx for its value.
2049 Store the value in TARGET (specified as an rtx) if convenient.
2050 If the value is stored in TARGET then TARGET is returned.
2051 If IGNORE is nonzero, then we ignore the value of the function call. */
2054 expand_call (exp, target, ignore)
2059 /* Nonzero if we are currently expanding a call. */
2060 static int currently_expanding_call = 0;
2062 /* List of actual parameters. */
2063 tree actparms = TREE_OPERAND (exp, 1);
2064 /* RTX for the function to be called. */
2066 /* Sequence of insns to perform a tail recursive "call". */
2067 rtx tail_recursion_insns = NULL_RTX;
2068 /* Sequence of insns to perform a normal "call". */
2069 rtx normal_call_insns = NULL_RTX;
2070 /* Sequence of insns to perform a tail recursive "call". */
2071 rtx tail_call_insns = NULL_RTX;
2072 /* Data type of the function. */
2074 tree type_arg_types;
2075 /* Declaration of the function being called,
2076 or 0 if the function is computed (not known by name). */
2079 int try_tail_call = 1;
2080 int try_tail_recursion = 1;
2083 /* Register in which non-BLKmode value will be returned,
2084 or 0 if no value or if value is BLKmode. */
2086 /* Address where we should return a BLKmode value;
2087 0 if value not BLKmode. */
2088 rtx structure_value_addr = 0;
2089 /* Nonzero if that address is being passed by treating it as
2090 an extra, implicit first parameter. Otherwise,
2091 it is passed by being copied directly into struct_value_rtx. */
2092 int structure_value_addr_parm = 0;
2093 /* Size of aggregate value wanted, or zero if none wanted
2094 or if we are using the non-reentrant PCC calling convention
2095 or expecting the value in registers. */
2096 HOST_WIDE_INT struct_value_size = 0;
2097 /* Nonzero if called function returns an aggregate in memory PCC style,
2098 by returning the address of where to find it. */
2099 int pcc_struct_value = 0;
2101 /* Number of actual parameters in this call, including struct value addr. */
2103 /* Number of named args. Args after this are anonymous ones
2104 and they must all go on the stack. */
2107 /* Vector of information about each argument.
2108 Arguments are numbered in the order they will be pushed,
2109 not the order they are written. */
2110 struct arg_data *args;
2112 /* Total size in bytes of all the stack-parms scanned so far. */
2113 struct args_size args_size;
2114 struct args_size adjusted_args_size;
2115 /* Size of arguments before any adjustments (such as rounding). */
2116 int unadjusted_args_size;
2117 /* Data on reg parms scanned so far. */
2118 CUMULATIVE_ARGS args_so_far;
2119 /* Nonzero if a reg parm has been scanned. */
2121 /* Nonzero if this is an indirect function call. */
2123 /* Nonzero if we must avoid push-insns in the args for this call.
2124 If stack space is allocated for register parameters, but not by the
2125 caller, then it is preallocated in the fixed part of the stack frame.
2126 So the entire argument block must then be preallocated (i.e., we
2127 ignore PUSH_ROUNDING in that case). */
2129 int must_preallocate = !PUSH_ARGS;
2131 /* Size of the stack reserved for parameter registers. */
2132 int reg_parm_stack_space = 0;
2134 /* Address of space preallocated for stack parms
2135 (on machines that lack push insns), or 0 if space not preallocated. */
2138 /* Mask of ECF_ flags. */
2140 /* Nonzero if this is a call to an inline function. */
2141 int is_integrable = 0;
2142 #ifdef REG_PARM_STACK_SPACE
2143 /* Define the boundary of the register parm stack space that needs to be
2145 int low_to_save, high_to_save;
2146 rtx save_area = 0; /* Place that it is saved */
2149 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2150 char *initial_stack_usage_map = stack_usage_map;
2152 int old_stack_allocated;
2154 /* State variables to track stack modifications. */
2155 rtx old_stack_level = 0;
2156 int old_stack_arg_under_construction = 0;
2157 int old_pending_adj = 0;
2158 int old_inhibit_defer_pop = inhibit_defer_pop;
2160 /* Some stack pointer alterations we make are performed via
2161 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2162 which we then also need to save/restore along the way. */
2163 int old_stack_pointer_delta = 0;
2166 tree p = TREE_OPERAND (exp, 0);
2167 tree addr = TREE_OPERAND (exp, 0);
2169 /* The alignment of the stack, in bits. */
2170 HOST_WIDE_INT preferred_stack_boundary;
2171 /* The alignment of the stack, in bytes. */
2172 HOST_WIDE_INT preferred_unit_stack_boundary;
2174 /* See if this is "nothrow" function call. */
2175 if (TREE_NOTHROW (exp))
2176 flags |= ECF_NOTHROW;
2178 /* See if we can find a DECL-node for the actual function.
2179 As a result, decide whether this is a call to an integrable function. */
2181 fndecl = get_callee_fndecl (exp);
2185 && fndecl != current_function_decl
2186 && DECL_INLINE (fndecl)
2187 && DECL_SAVED_INSNS (fndecl)
2188 && DECL_SAVED_INSNS (fndecl)->inlinable)
2190 else if (! TREE_ADDRESSABLE (fndecl))
2192 /* In case this function later becomes inlinable,
2193 record that there was already a non-inline call to it.
2195 Use abstraction instead of setting TREE_ADDRESSABLE
2197 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2200 warning_with_decl (fndecl, "can't inline call to `%s'");
2201 warning ("called from here");
2203 (*lang_hooks.mark_addressable) (fndecl);
2206 flags |= flags_from_decl_or_type (fndecl);
2209 /* If we don't have specific function to call, see if we have a
2210 attributes set in the type. */
2212 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2214 /* Warn if this value is an aggregate type,
2215 regardless of which calling convention we are using for it. */
2216 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2217 warning ("function call has aggregate value");
2219 /* If the result of a pure or const function call is ignored (or void),
2220 and none of its arguments are volatile, we can avoid expanding the
2221 call and just evaluate the arguments for side-effects. */
2222 if ((flags & (ECF_CONST | ECF_PURE))
2223 && (ignore || target == const0_rtx
2224 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2226 bool volatilep = false;
2229 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2230 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2238 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2239 expand_expr (TREE_VALUE (arg), const0_rtx,
2240 VOIDmode, EXPAND_NORMAL);
2245 #ifdef REG_PARM_STACK_SPACE
2246 #ifdef MAYBE_REG_PARM_STACK_SPACE
2247 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2249 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2253 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2254 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2255 must_preallocate = 1;
2258 /* Set up a place to return a structure. */
2260 /* Cater to broken compilers. */
2261 if (aggregate_value_p (exp))
2263 /* This call returns a big structure. */
2264 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2266 #ifdef PCC_STATIC_STRUCT_RETURN
2268 pcc_struct_value = 1;
2269 /* Easier than making that case work right. */
2272 /* In case this is a static function, note that it has been
2274 if (! TREE_ADDRESSABLE (fndecl))
2275 (*lang_hooks.mark_addressable) (fndecl);
2279 #else /* not PCC_STATIC_STRUCT_RETURN */
2281 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2283 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2285 /* The structure value address arg is already in actparms.
2286 Pull it out. It might be nice to just leave it there, but
2287 we need to set structure_value_addr. */
2288 tree return_arg = TREE_VALUE (actparms);
2289 actparms = TREE_CHAIN (actparms);
2290 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2291 VOIDmode, EXPAND_NORMAL);
2293 else if (target && GET_CODE (target) == MEM)
2294 structure_value_addr = XEXP (target, 0);
2297 /* For variable-sized objects, we must be called with a target
2298 specified. If we were to allocate space on the stack here,
2299 we would have no way of knowing when to free it. */
2300 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2302 mark_temp_addr_taken (d);
2303 structure_value_addr = XEXP (d, 0);
2307 #endif /* not PCC_STATIC_STRUCT_RETURN */
2310 /* If called function is inline, try to integrate it. */
2314 rtx temp = try_to_integrate (fndecl, actparms, target,
2315 ignore, TREE_TYPE (exp),
2316 structure_value_addr);
2317 if (temp != (rtx) (size_t) - 1)
2321 /* Figure out the amount to which the stack should be aligned. */
2322 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2325 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2326 if (i && i->preferred_incoming_stack_boundary)
2327 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2330 /* Operand 0 is a pointer-to-function; get the type of the function. */
2331 funtype = TREE_TYPE (addr);
2332 if (! POINTER_TYPE_P (funtype))
2334 funtype = TREE_TYPE (funtype);
2336 /* Munge the tree to split complex arguments into their imaginary
2338 if (SPLIT_COMPLEX_ARGS)
2340 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2341 actparms = split_complex_values (actparms);
2344 type_arg_types = TYPE_ARG_TYPES (funtype);
2346 /* See if this is a call to a function that can return more than once
2347 or a call to longjmp or malloc. */
2348 flags |= special_function_p (fndecl, flags);
2350 if (flags & ECF_MAY_BE_ALLOCA)
2351 current_function_calls_alloca = 1;
2353 /* If struct_value_rtx is 0, it means pass the address
2354 as if it were an extra parameter. */
2355 if (structure_value_addr && struct_value_rtx == 0)
2357 /* If structure_value_addr is a REG other than
2358 virtual_outgoing_args_rtx, we can use always use it. If it
2359 is not a REG, we must always copy it into a register.
2360 If it is virtual_outgoing_args_rtx, we must copy it to another
2361 register in some cases. */
2362 rtx temp = (GET_CODE (structure_value_addr) != REG
2363 || (ACCUMULATE_OUTGOING_ARGS
2364 && stack_arg_under_construction
2365 && structure_value_addr == virtual_outgoing_args_rtx)
2366 ? copy_addr_to_reg (structure_value_addr)
2367 : structure_value_addr);
2370 = tree_cons (error_mark_node,
2371 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2374 structure_value_addr_parm = 1;
2377 /* Count the arguments and set NUM_ACTUALS. */
2378 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2381 /* Compute number of named args.
2382 Normally, don't include the last named arg if anonymous args follow.
2383 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2384 (If no anonymous args follow, the result of list_length is actually
2385 one too large. This is harmless.)
2387 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2388 zero, this machine will be able to place unnamed args that were
2389 passed in registers into the stack. So treat all args as named.
2390 This allows the insns emitting for a specific argument list to be
2391 independent of the function declaration.
2393 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2394 reliable way to pass unnamed args in registers, so we must force
2395 them into memory. */
2397 if ((STRICT_ARGUMENT_NAMING
2398 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2399 && type_arg_types != 0)
2401 = (list_length (type_arg_types)
2402 /* Don't include the last named arg. */
2403 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2404 /* Count the struct value address, if it is passed as a parm. */
2405 + structure_value_addr_parm);
2407 /* If we know nothing, treat all args as named. */
2408 n_named_args = num_actuals;
2410 /* Start updating where the next arg would go.
2412 On some machines (such as the PA) indirect calls have a different
2413 calling convention than normal calls. The last argument in
2414 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2416 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2418 /* Make a vector to hold all the information about each arg. */
2419 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2420 memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2422 /* Build up entries in the ARGS array, compute the size of the
2423 arguments into ARGS_SIZE, etc. */
2424 initialize_argument_information (num_actuals, args, &args_size,
2425 n_named_args, actparms, fndecl,
2426 &args_so_far, reg_parm_stack_space,
2427 &old_stack_level, &old_pending_adj,
2428 &must_preallocate, &flags);
2432 /* If this function requires a variable-sized argument list, don't
2433 try to make a cse'able block for this call. We may be able to
2434 do this eventually, but it is too complicated to keep track of
2435 what insns go in the cse'able block and which don't. */
2437 flags &= ~ECF_LIBCALL_BLOCK;
2438 must_preallocate = 1;
2441 /* Now make final decision about preallocating stack space. */
2442 must_preallocate = finalize_must_preallocate (must_preallocate,
2446 /* If the structure value address will reference the stack pointer, we
2447 must stabilize it. We don't need to do this if we know that we are
2448 not going to adjust the stack pointer in processing this call. */
2450 if (structure_value_addr
2451 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2452 || reg_mentioned_p (virtual_outgoing_args_rtx,
2453 structure_value_addr))
2455 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2456 structure_value_addr = copy_to_reg (structure_value_addr);
2458 /* Tail calls can make things harder to debug, and we're traditionally
2459 pushed these optimizations into -O2. Don't try if we're already
2460 expanding a call, as that means we're an argument. Don't try if
2461 there's cleanups, as we know there's code to follow the call.
2463 If rtx_equal_function_value_matters is false, that means we've
2464 finished with regular parsing. Which means that some of the
2465 machinery we use to generate tail-calls is no longer in place.
2466 This is most often true of sjlj-exceptions, which we couldn't
2467 tail-call to anyway. */
2469 if (currently_expanding_call++ != 0
2470 || !flag_optimize_sibling_calls
2471 || !rtx_equal_function_value_matters
2472 || any_pending_cleanups (1)
2474 try_tail_call = try_tail_recursion = 0;
2476 /* Tail recursion fails, when we are not dealing with recursive calls. */
2477 if (!try_tail_recursion
2478 || TREE_CODE (addr) != ADDR_EXPR
2479 || TREE_OPERAND (addr, 0) != current_function_decl)
2480 try_tail_recursion = 0;
2482 /* Rest of purposes for tail call optimizations to fail. */
2484 #ifdef HAVE_sibcall_epilogue
2485 !HAVE_sibcall_epilogue
2490 /* Doing sibling call optimization needs some work, since
2491 structure_value_addr can be allocated on the stack.
2492 It does not seem worth the effort since few optimizable
2493 sibling calls will return a structure. */
2494 || structure_value_addr != NULL_RTX
2495 /* Check whether the target is able to optimize the call
2497 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2498 /* Functions that do not return exactly once may not be sibcall
2500 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2501 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2502 /* If the called function is nested in the current one, it might access
2503 some of the caller's arguments, but could clobber them beforehand if
2504 the argument areas are shared. */
2505 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2506 /* If this function requires more stack slots than the current
2507 function, we cannot change it into a sibling call. */
2508 || args_size.constant > current_function_args_size
2509 /* If the callee pops its own arguments, then it must pop exactly
2510 the same number of arguments as the current function. */
2511 || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2512 != RETURN_POPS_ARGS (current_function_decl,
2513 TREE_TYPE (current_function_decl),
2514 current_function_args_size))
2517 if (try_tail_call || try_tail_recursion)
2520 actparms = NULL_TREE;
2521 /* Ok, we're going to give the tail call the old college try.
2522 This means we're going to evaluate the function arguments
2523 up to three times. There are two degrees of badness we can
2524 encounter, those that can be unsaved and those that can't.
2525 (See unsafe_for_reeval commentary for details.)
2527 Generate a new argument list. Pass safe arguments through
2528 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2529 For hard badness, evaluate them now and put their resulting
2530 rtx in a temporary VAR_DECL.
2532 initialize_argument_information has ordered the array for the
2533 order to be pushed, and we must remember this when reconstructing
2534 the original argument order. */
2536 if (PUSH_ARGS_REVERSED)
2545 i = num_actuals - 1;
2549 for (; i != end; i += inc)
2551 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2552 /* We need to build actparms for optimize_tail_recursion. We can
2553 safely trash away TREE_PURPOSE, since it is unused by this
2555 if (try_tail_recursion)
2556 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2558 /* Do the same for the function address if it is an expression. */
2560 addr = fix_unsafe_tree (addr);
2561 /* Expanding one of those dangerous arguments could have added
2562 cleanups, but otherwise give it a whirl. */
2563 if (any_pending_cleanups (1))
2564 try_tail_call = try_tail_recursion = 0;
2567 /* Generate a tail recursion sequence when calling ourselves. */
2569 if (try_tail_recursion)
2571 /* We want to emit any pending stack adjustments before the tail
2572 recursion "call". That way we know any adjustment after the tail
2573 recursion call can be ignored if we indeed use the tail recursion
2575 int save_pending_stack_adjust = pending_stack_adjust;
2576 int save_stack_pointer_delta = stack_pointer_delta;
2578 /* Emit any queued insns now; otherwise they would end up in
2579 only one of the alternates. */
2582 /* Use a new sequence to hold any RTL we generate. We do not even
2583 know if we will use this RTL yet. The final decision can not be
2584 made until after RTL generation for the entire function is
2587 /* If expanding any of the arguments creates cleanups, we can't
2588 do a tailcall. So, we'll need to pop the pending cleanups
2589 list. If, however, all goes well, and there are no cleanups
2590 then the call to expand_start_target_temps will have no
2592 expand_start_target_temps ();
2593 if (optimize_tail_recursion (actparms, get_last_insn ()))
2595 if (any_pending_cleanups (1))
2596 try_tail_call = try_tail_recursion = 0;
2598 tail_recursion_insns = get_insns ();
2600 expand_end_target_temps ();
2603 /* Restore the original pending stack adjustment for the sibling and
2604 normal call cases below. */
2605 pending_stack_adjust = save_pending_stack_adjust;
2606 stack_pointer_delta = save_stack_pointer_delta;
2609 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2611 /* A fork duplicates the profile information, and an exec discards
2612 it. We can't rely on fork/exec to be paired. So write out the
2613 profile information we have gathered so far, and clear it. */
2614 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2615 is subject to race conditions, just as with multithreaded
2618 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2621 /* Ensure current function's preferred stack boundary is at least
2622 what we need. We don't have to increase alignment for recursive
2624 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2625 && fndecl != current_function_decl)
2626 cfun->preferred_stack_boundary = preferred_stack_boundary;
2627 if (fndecl == current_function_decl)
2628 cfun->recursive_call_emit = true;
2630 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2632 function_call_count++;
2634 /* We want to make two insn chains; one for a sibling call, the other
2635 for a normal call. We will select one of the two chains after
2636 initial RTL generation is complete. */
2637 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2639 int sibcall_failure = 0;
2640 /* We want to emit any pending stack adjustments before the tail
2641 recursion "call". That way we know any adjustment after the tail
2642 recursion call can be ignored if we indeed use the tail recursion
2644 int save_pending_stack_adjust = 0;
2645 int save_stack_pointer_delta = 0;
2647 rtx before_call, next_arg_reg;
2651 /* Emit any queued insns now; otherwise they would end up in
2652 only one of the alternates. */
2655 /* State variables we need to save and restore between
2657 save_pending_stack_adjust = pending_stack_adjust;
2658 save_stack_pointer_delta = stack_pointer_delta;
2661 flags &= ~ECF_SIBCALL;
2663 flags |= ECF_SIBCALL;
2665 /* Other state variables that we must reinitialize each time
2666 through the loop (that are not initialized by the loop itself). */
2670 /* Start a new sequence for the normal call case.
2672 From this point on, if the sibling call fails, we want to set
2673 sibcall_failure instead of continuing the loop. */
2678 /* We know at this point that there are not currently any
2679 pending cleanups. If, however, in the process of evaluating
2680 the arguments we were to create some, we'll need to be
2681 able to get rid of them. */
2682 expand_start_target_temps ();
2685 /* Don't let pending stack adjusts add up to too much.
2686 Also, do all pending adjustments now if there is any chance
2687 this might be a call to alloca or if we are expanding a sibling
2688 call sequence or if we are calling a function that is to return
2689 with stack pointer depressed. */
2690 if (pending_stack_adjust >= 32
2691 || (pending_stack_adjust > 0
2692 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2694 do_pending_stack_adjust ();
2696 /* When calling a const function, we must pop the stack args right away,
2697 so that the pop is deleted or moved with the call. */
2698 if (pass && (flags & ECF_LIBCALL_BLOCK))
2701 #ifdef FINAL_REG_PARM_STACK_SPACE
2702 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2705 /* Precompute any arguments as needed. */
2707 precompute_arguments (flags, num_actuals, args);
2709 /* Now we are about to start emitting insns that can be deleted
2710 if a libcall is deleted. */
2711 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2714 adjusted_args_size = args_size;
2715 /* Compute the actual size of the argument block required. The variable
2716 and constant sizes must be combined, the size may have to be rounded,
2717 and there may be a minimum required size. When generating a sibcall
2718 pattern, do not round up, since we'll be re-using whatever space our
2720 unadjusted_args_size
2721 = compute_argument_block_size (reg_parm_stack_space,
2722 &adjusted_args_size,
2724 : preferred_stack_boundary));
2726 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2728 /* The argument block when performing a sibling call is the
2729 incoming argument block. */
2732 argblock = virtual_incoming_args_rtx;
2734 #ifdef STACK_GROWS_DOWNWARD
2735 = plus_constant (argblock, current_function_pretend_args_size);
2737 = plus_constant (argblock, -current_function_pretend_args_size);
2739 stored_args_map = sbitmap_alloc (args_size.constant);
2740 sbitmap_zero (stored_args_map);
2743 /* If we have no actual push instructions, or shouldn't use them,
2744 make space for all args right now. */
2745 else if (adjusted_args_size.var != 0)
2747 if (old_stack_level == 0)
2749 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2750 old_stack_pointer_delta = stack_pointer_delta;
2751 old_pending_adj = pending_stack_adjust;
2752 pending_stack_adjust = 0;
2753 /* stack_arg_under_construction says whether a stack arg is
2754 being constructed at the old stack level. Pushing the stack
2755 gets a clean outgoing argument block. */
2756 old_stack_arg_under_construction = stack_arg_under_construction;
2757 stack_arg_under_construction = 0;
2759 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2763 /* Note that we must go through the motions of allocating an argument
2764 block even if the size is zero because we may be storing args
2765 in the area reserved for register arguments, which may be part of
2768 int needed = adjusted_args_size.constant;
2770 /* Store the maximum argument space used. It will be pushed by
2771 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2774 if (needed > current_function_outgoing_args_size)
2775 current_function_outgoing_args_size = needed;
2777 if (must_preallocate)
2779 if (ACCUMULATE_OUTGOING_ARGS)
2781 /* Since the stack pointer will never be pushed, it is
2782 possible for the evaluation of a parm to clobber
2783 something we have already written to the stack.
2784 Since most function calls on RISC machines do not use
2785 the stack, this is uncommon, but must work correctly.
2787 Therefore, we save any area of the stack that was already
2788 written and that we are using. Here we set up to do this
2789 by making a new stack usage map from the old one. The
2790 actual save will be done by store_one_arg.
2792 Another approach might be to try to reorder the argument
2793 evaluations to avoid this conflicting stack usage. */
2795 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2796 /* Since we will be writing into the entire argument area,
2797 the map must be allocated for its entire size, not just
2798 the part that is the responsibility of the caller. */
2799 needed += reg_parm_stack_space;
2802 #ifdef ARGS_GROW_DOWNWARD
2803 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2806 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2810 = (char *) alloca (highest_outgoing_arg_in_use);
2812 if (initial_highest_arg_in_use)
2813 memcpy (stack_usage_map, initial_stack_usage_map,
2814 initial_highest_arg_in_use);
2816 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2817 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2818 (highest_outgoing_arg_in_use
2819 - initial_highest_arg_in_use));
2822 /* The address of the outgoing argument list must not be
2823 copied to a register here, because argblock would be left
2824 pointing to the wrong place after the call to
2825 allocate_dynamic_stack_space below. */
2827 argblock = virtual_outgoing_args_rtx;
2831 if (inhibit_defer_pop == 0)
2833 /* Try to reuse some or all of the pending_stack_adjust
2834 to get this space. */
2836 = (combine_pending_stack_adjustment_and_call
2837 (unadjusted_args_size,
2838 &adjusted_args_size,
2839 preferred_unit_stack_boundary));
2841 /* combine_pending_stack_adjustment_and_call computes
2842 an adjustment before the arguments are allocated.
2843 Account for them and see whether or not the stack
2844 needs to go up or down. */
2845 needed = unadjusted_args_size - needed;
2849 /* We're releasing stack space. */
2850 /* ??? We can avoid any adjustment at all if we're
2851 already aligned. FIXME. */
2852 pending_stack_adjust = -needed;
2853 do_pending_stack_adjust ();
2857 /* We need to allocate space. We'll do that in
2858 push_block below. */
2859 pending_stack_adjust = 0;
2862 /* Special case this because overhead of `push_block' in
2863 this case is non-trivial. */
2865 argblock = virtual_outgoing_args_rtx;
2868 argblock = push_block (GEN_INT (needed), 0, 0);
2869 #ifdef ARGS_GROW_DOWNWARD
2870 argblock = plus_constant (argblock, needed);
2874 /* We only really need to call `copy_to_reg' in the case
2875 where push insns are going to be used to pass ARGBLOCK
2876 to a function call in ARGS. In that case, the stack
2877 pointer changes value from the allocation point to the
2878 call point, and hence the value of
2879 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2880 as well always do it. */
2881 argblock = copy_to_reg (argblock);
2886 if (ACCUMULATE_OUTGOING_ARGS)
2888 /* The save/restore code in store_one_arg handles all
2889 cases except one: a constructor call (including a C
2890 function returning a BLKmode struct) to initialize
2892 if (stack_arg_under_construction)
2894 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2895 rtx push_size = GEN_INT (reg_parm_stack_space
2896 + adjusted_args_size.constant);
2898 rtx push_size = GEN_INT (adjusted_args_size.constant);
2900 if (old_stack_level == 0)
2902 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2904 old_stack_pointer_delta = stack_pointer_delta;
2905 old_pending_adj = pending_stack_adjust;
2906 pending_stack_adjust = 0;
2907 /* stack_arg_under_construction says whether a stack
2908 arg is being constructed at the old stack level.
2909 Pushing the stack gets a clean outgoing argument
2911 old_stack_arg_under_construction
2912 = stack_arg_under_construction;
2913 stack_arg_under_construction = 0;
2914 /* Make a new map for the new argument list. */
2915 stack_usage_map = (char *)
2916 alloca (highest_outgoing_arg_in_use);
2917 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2918 highest_outgoing_arg_in_use = 0;
2920 allocate_dynamic_stack_space (push_size, NULL_RTX,
2924 /* If argument evaluation might modify the stack pointer,
2925 copy the address of the argument list to a register. */
2926 for (i = 0; i < num_actuals; i++)
2927 if (args[i].pass_on_stack)
2929 argblock = copy_addr_to_reg (argblock);
2934 compute_argument_addresses (args, argblock, num_actuals);
2936 /* If we push args individually in reverse order, perform stack alignment
2937 before the first push (the last arg). */
2938 if (PUSH_ARGS_REVERSED && argblock == 0
2939 && adjusted_args_size.constant != unadjusted_args_size)
2941 /* When the stack adjustment is pending, we get better code
2942 by combining the adjustments. */
2943 if (pending_stack_adjust
2944 && ! (flags & ECF_LIBCALL_BLOCK)
2945 && ! inhibit_defer_pop)
2947 pending_stack_adjust
2948 = (combine_pending_stack_adjustment_and_call
2949 (unadjusted_args_size,
2950 &adjusted_args_size,
2951 preferred_unit_stack_boundary));
2952 do_pending_stack_adjust ();
2954 else if (argblock == 0)
2955 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2956 - unadjusted_args_size));
2958 /* Now that the stack is properly aligned, pops can't safely
2959 be deferred during the evaluation of the arguments. */
2962 funexp = rtx_for_function_call (fndecl, addr);
2964 /* Figure out the register where the value, if any, will come back. */
2966 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2967 && ! structure_value_addr)
2969 if (pcc_struct_value)
2970 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2971 fndecl, (pass == 0));
2973 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2976 /* Precompute all register parameters. It isn't safe to compute anything
2977 once we have started filling any specific hard regs. */
2978 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2980 #ifdef REG_PARM_STACK_SPACE
2981 /* Save the fixed argument area if it's part of the caller's frame and
2982 is clobbered by argument setup for this call. */
2983 if (ACCUMULATE_OUTGOING_ARGS && pass)
2984 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2985 &low_to_save, &high_to_save);
2988 /* Now store (and compute if necessary) all non-register parms.
2989 These come before register parms, since they can require block-moves,
2990 which could clobber the registers used for register parms.
2991 Parms which have partial registers are not stored here,
2992 but we do preallocate space here if they want that. */
2994 for (i = 0; i < num_actuals; i++)
2995 if (args[i].reg == 0 || args[i].pass_on_stack)
2997 rtx before_arg = get_last_insn ();
2999 if (store_one_arg (&args[i], argblock, flags,
3000 adjusted_args_size.var != 0,
3001 reg_parm_stack_space)
3003 && check_sibcall_argument_overlap (before_arg,
3005 sibcall_failure = 1;
3008 /* If we have a parm that is passed in registers but not in memory
3009 and whose alignment does not permit a direct copy into registers,
3010 make a group of pseudos that correspond to each register that we
3012 if (STRICT_ALIGNMENT)
3013 store_unaligned_arguments_into_pseudos (args, num_actuals);
3015 /* Now store any partially-in-registers parm.
3016 This is the last place a block-move can happen. */
3018 for (i = 0; i < num_actuals; i++)
3019 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3021 rtx before_arg = get_last_insn ();
3023 if (store_one_arg (&args[i], argblock, flags,
3024 adjusted_args_size.var != 0,
3025 reg_parm_stack_space)
3027 && check_sibcall_argument_overlap (before_arg,
3029 sibcall_failure = 1;
3032 /* If we pushed args in forward order, perform stack alignment
3033 after pushing the last arg. */
3034 if (!PUSH_ARGS_REVERSED && argblock == 0)
3035 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3036 - unadjusted_args_size));
3038 /* If register arguments require space on the stack and stack space
3039 was not preallocated, allocate stack space here for arguments
3040 passed in registers. */
3041 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3042 if (!ACCUMULATE_OUTGOING_ARGS
3043 && must_preallocate == 0 && reg_parm_stack_space > 0)
3044 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3047 /* Pass the function the address in which to return a
3049 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3051 emit_move_insn (struct_value_rtx,
3053 force_operand (structure_value_addr,
3056 if (GET_CODE (struct_value_rtx) == REG)
3057 use_reg (&call_fusage, struct_value_rtx);
3060 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3061 reg_parm_seen, pass == 0);
3063 load_register_parameters (args, num_actuals, &call_fusage, flags,
3064 pass == 0, &sibcall_failure);
3066 /* Perform postincrements before actually calling the function. */
3069 /* Save a pointer to the last insn before the call, so that we can
3070 later safely search backwards to find the CALL_INSN. */
3071 before_call = get_last_insn ();
3073 /* Set up next argument register. For sibling calls on machines
3074 with register windows this should be the incoming register. */
3075 #ifdef FUNCTION_INCOMING_ARG
3077 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3081 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3084 /* All arguments and registers used for the call must be set up by
3087 /* Stack must be properly aligned now. */
3088 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3091 /* Generate the actual call instruction. */
3092 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3093 adjusted_args_size.constant, struct_value_size,
3094 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3095 flags, & args_so_far);
3097 /* If call is cse'able, make appropriate pair of reg-notes around it.
3098 Test valreg so we don't crash; may safely ignore `const'
3099 if return type is void. Disable for PARALLEL return values, because
3100 we have no way to move such values into a pseudo register. */
3101 if (pass && (flags & ECF_LIBCALL_BLOCK))
3105 if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3107 insns = get_insns ();
3114 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3116 /* Mark the return value as a pointer if needed. */
3117 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3118 mark_reg_pointer (temp,
3119 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3121 /* Construct an "equal form" for the value which mentions all the
3122 arguments in order as well as the function name. */
3123 for (i = 0; i < num_actuals; i++)
3124 note = gen_rtx_EXPR_LIST (VOIDmode,
3125 args[i].initial_value, note);
3126 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3128 insns = get_insns ();
3131 if (flags & ECF_PURE)
3132 note = gen_rtx_EXPR_LIST (VOIDmode,
3133 gen_rtx_USE (VOIDmode,
3134 gen_rtx_MEM (BLKmode,
3135 gen_rtx_SCRATCH (VOIDmode))),
3138 emit_libcall_block (insns, temp, valreg, note);
3143 else if (pass && (flags & ECF_MALLOC))
3145 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3148 /* The return value from a malloc-like function is a pointer. */
3149 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3150 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3152 emit_move_insn (temp, valreg);
3154 /* The return value from a malloc-like function can not alias
3156 last = get_last_insn ();
3158 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3160 /* Write out the sequence. */
3161 insns = get_insns ();
3167 /* For calls to `setjmp', etc., inform flow.c it should complain
3168 if nonvolatile values are live. For functions that cannot return,
3169 inform flow that control does not fall through. */
3171 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3173 /* The barrier must be emitted
3174 immediately after the CALL_INSN. Some ports emit more
3175 than just a CALL_INSN above, so we must search for it here. */
3177 rtx last = get_last_insn ();
3178 while (GET_CODE (last) != CALL_INSN)
3180 last = PREV_INSN (last);
3181 /* There was no CALL_INSN? */
3182 if (last == before_call)
3186 emit_barrier_after (last);
3189 if (flags & ECF_LONGJMP)
3190 current_function_calls_longjmp = 1;
3192 /* If value type not void, return an rtx for the value. */
3194 /* If there are cleanups to be called, don't use a hard reg as target.
3195 We need to double check this and see if it matters anymore. */
3196 if (any_pending_cleanups (1))
3198 if (target && REG_P (target)
3199 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3201 sibcall_failure = 1;
3204 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3206 target = const0_rtx;
3207 else if (structure_value_addr)
3209 if (target == 0 || GET_CODE (target) != MEM)
3212 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3213 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3214 structure_value_addr));
3215 set_mem_attributes (target, exp, 1);
3218 else if (pcc_struct_value)
3220 /* This is the special C++ case where we need to
3221 know what the true target was. We take care to
3222 never use this value more than once in one expression. */
3223 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3224 copy_to_reg (valreg));
3225 set_mem_attributes (target, exp, 1);
3227 /* Handle calls that return values in multiple non-contiguous locations.
3228 The Irix 6 ABI has examples of this. */
3229 else if (GET_CODE (valreg) == PARALLEL)
3233 /* This will only be assigned once, so it can be readonly. */
3234 tree nt = build_qualified_type (TREE_TYPE (exp),
3235 (TYPE_QUALS (TREE_TYPE (exp))
3236 | TYPE_QUAL_CONST));
3238 target = assign_temp (nt, 0, 1, 1);
3239 preserve_temp_slots (target);
3242 if (! rtx_equal_p (target, valreg))
3243 emit_group_store (target, valreg,
3244 int_size_in_bytes (TREE_TYPE (exp)));
3246 /* We can not support sibling calls for this case. */
3247 sibcall_failure = 1;
3250 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3251 && GET_MODE (target) == GET_MODE (valreg))
3253 /* TARGET and VALREG cannot be equal at this point because the
3254 latter would not have REG_FUNCTION_VALUE_P true, while the
3255 former would if it were referring to the same register.
3257 If they refer to the same register, this move will be a no-op,
3258 except when function inlining is being done. */
3259 emit_move_insn (target, valreg);
3261 /* If we are setting a MEM, this code must be executed. Since it is
3262 emitted after the call insn, sibcall optimization cannot be
3263 performed in that case. */
3264 if (GET_CODE (target) == MEM)
3265 sibcall_failure = 1;
3267 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3269 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3271 /* We can not support sibling calls for this case. */
3272 sibcall_failure = 1;
3275 target = copy_to_reg (valreg);
3277 #ifdef PROMOTE_FUNCTION_RETURN
3278 /* If we promoted this return value, make the proper SUBREG. TARGET
3279 might be const0_rtx here, so be careful. */
3280 if (GET_CODE (target) == REG
3281 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3282 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3284 tree type = TREE_TYPE (exp);
3285 int unsignedp = TREE_UNSIGNED (type);
3288 /* If we don't promote as expected, something is wrong. */
3289 if (GET_MODE (target)
3290 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3293 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3294 && GET_MODE_SIZE (GET_MODE (target))
3295 > GET_MODE_SIZE (TYPE_MODE (type)))
3297 offset = GET_MODE_SIZE (GET_MODE (target))
3298 - GET_MODE_SIZE (TYPE_MODE (type));
3299 if (! BYTES_BIG_ENDIAN)
3300 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3301 else if (! WORDS_BIG_ENDIAN)
3302 offset %= UNITS_PER_WORD;
3304 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3305 SUBREG_PROMOTED_VAR_P (target) = 1;
3306 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3310 /* If size of args is variable or this was a constructor call for a stack
3311 argument, restore saved stack-pointer value. */
3313 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3315 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3316 stack_pointer_delta = old_stack_pointer_delta;
3317 pending_stack_adjust = old_pending_adj;
3318 stack_arg_under_construction = old_stack_arg_under_construction;
3319 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3320 stack_usage_map = initial_stack_usage_map;
3321 sibcall_failure = 1;
3323 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3325 #ifdef REG_PARM_STACK_SPACE
3327 restore_fixed_argument_area (save_area, argblock,
3328 high_to_save, low_to_save);
3331 /* If we saved any argument areas, restore them. */
3332 for (i = 0; i < num_actuals; i++)
3333 if (args[i].save_area)
3335 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3337 = gen_rtx_MEM (save_mode,
3338 memory_address (save_mode,
3339 XEXP (args[i].stack_slot, 0)));
3341 if (save_mode != BLKmode)
3342 emit_move_insn (stack_area, args[i].save_area);
3344 emit_block_move (stack_area, args[i].save_area,
3345 GEN_INT (args[i].locate.size.constant),
3346 BLOCK_OP_CALL_PARM);
3349 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3350 stack_usage_map = initial_stack_usage_map;
3353 /* If this was alloca, record the new stack level for nonlocal gotos.
3354 Check for the handler slots since we might not have a save area
3355 for non-local gotos. */
3357 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3358 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3360 /* Free up storage we no longer need. */
3361 for (i = 0; i < num_actuals; ++i)
3362 if (args[i].aligned_regs)
3363 free (args[i].aligned_regs);
3367 /* Undo the fake expand_start_target_temps we did earlier. If
3368 there had been any cleanups created, we've already set
3370 expand_end_target_temps ();
3373 /* If this function is returning into a memory location marked as
3374 readonly, it means it is initializing that location. We normally treat
3375 functions as not clobbering such locations, so we need to specify that
3376 this one does. We do this by adding the appropriate CLOBBER to the
3377 CALL_INSN function usage list. This cannot be done by emitting a
3378 standalone CLOBBER after the call because the latter would be ignored
3379 by at least the delay slot scheduling pass. We do this now instead of
3380 adding to call_fusage before the call to emit_call_1 because TARGET
3381 may be modified in the meantime. */
3382 if (structure_value_addr != 0 && target != 0
3383 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3384 add_function_usage_to
3386 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3389 insns = get_insns ();
3394 tail_call_insns = insns;
3396 /* Restore the pending stack adjustment now that we have
3397 finished generating the sibling call sequence. */
3399 pending_stack_adjust = save_pending_stack_adjust;
3400 stack_pointer_delta = save_stack_pointer_delta;
3402 /* Prepare arg structure for next iteration. */
3403 for (i = 0; i < num_actuals; i++)
3406 args[i].aligned_regs = 0;
3410 sbitmap_free (stored_args_map);
3414 normal_call_insns = insns;
3416 /* Verify that we've deallocated all the stack we used. */
3417 if (old_stack_allocated !=
3418 stack_pointer_delta - pending_stack_adjust)
3422 /* If something prevents making this a sibling call,
3423 zero out the sequence. */
3424 if (sibcall_failure)
3425 tail_call_insns = NULL_RTX;
3428 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3429 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3430 can happen if the arguments to this function call an inline
3431 function who's expansion contains another CALL_PLACEHOLDER.
3433 If there are any C_Ps in any of these sequences, replace them
3434 with their normal call. */
3436 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3437 if (GET_CODE (insn) == CALL_INSN
3438 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3439 replace_call_placeholder (insn, sibcall_use_normal);
3441 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3442 if (GET_CODE (insn) == CALL_INSN
3443 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3444 replace_call_placeholder (insn, sibcall_use_normal);
3446 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3447 if (GET_CODE (insn) == CALL_INSN
3448 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3449 replace_call_placeholder (insn, sibcall_use_normal);
3451 /* If this was a potential tail recursion site, then emit a
3452 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3453 One of them will be selected later. */
3454 if (tail_recursion_insns || tail_call_insns)
3456 /* The tail recursion label must be kept around. We could expose
3457 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3458 and makes determining true tail recursion sites difficult.
3460 So we set LABEL_PRESERVE_P here, then clear it when we select
3461 one of the call sequences after rtl generation is complete. */
3462 if (tail_recursion_insns)
3463 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3464 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3466 tail_recursion_insns,
3467 tail_recursion_label));
3470 emit_insn (normal_call_insns);
3472 currently_expanding_call--;
3474 /* If this function returns with the stack pointer depressed, ensure
3475 this block saves and restores the stack pointer, show it was
3476 changed, and adjust for any outgoing arg space. */
3477 if (flags & ECF_SP_DEPRESSED)
3479 clear_pending_stack_adjust ();
3480 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3481 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3482 save_stack_pointer ();
3488 /* Traverse an argument list in VALUES and expand all complex
3489 arguments into their components. */
3491 split_complex_values (tree values)
3495 values = copy_list (values);
3497 for (p = values; p; p = TREE_CHAIN (p))
3499 tree complex_value = TREE_VALUE (p);
3502 complex_type = TREE_TYPE (complex_value);
3506 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3509 tree real, imag, next;
3511 subtype = TREE_TYPE (complex_type);
3512 complex_value = save_expr (complex_value);
3513 real = build1 (REALPART_EXPR, subtype, complex_value);
3514 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3516 TREE_VALUE (p) = real;
3517 next = TREE_CHAIN (p);
3518 imag = build_tree_list (NULL_TREE, imag);
3519 TREE_CHAIN (p) = imag;
3520 TREE_CHAIN (imag) = next;
3522 /* Skip the newly created node. */
3530 /* Traverse a list of TYPES and expand all complex types into their
3533 split_complex_types (tree types)
3537 types = copy_list (types);
3539 for (p = types; p; p = TREE_CHAIN (p))
3541 tree complex_type = TREE_VALUE (p);
3543 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3547 /* Rewrite complex type with component type. */
3548 TREE_VALUE (p) = TREE_TYPE (complex_type);
3549 next = TREE_CHAIN (p);
3551 /* Add another component type for the imaginary part. */
3552 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3553 TREE_CHAIN (p) = imag;
3554 TREE_CHAIN (imag) = next;
3556 /* Skip the newly created node. */
3564 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3565 The RETVAL parameter specifies whether return value needs to be saved, other
3566 parameters are documented in the emit_library_call function below. */
3569 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3573 enum libcall_type fn_type;
3574 enum machine_mode outmode;
3578 /* Total size in bytes of all the stack-parms scanned so far. */
3579 struct args_size args_size;
3580 /* Size of arguments before any adjustments (such as rounding). */
3581 struct args_size original_args_size;
3587 CUMULATIVE_ARGS args_so_far;
3591 enum machine_mode mode;
3594 struct locate_and_pad_arg_data locate;
3598 int old_inhibit_defer_pop = inhibit_defer_pop;
3599 rtx call_fusage = 0;
3602 int pcc_struct_value = 0;
3603 int struct_value_size = 0;
3605 int reg_parm_stack_space = 0;
3608 tree tfom; /* type_for_mode (outmode, 0) */
3610 #ifdef REG_PARM_STACK_SPACE
3611 /* Define the boundary of the register parm stack space that needs to be
3613 int low_to_save, high_to_save;
3614 rtx save_area = 0; /* Place that it is saved. */
3617 /* Size of the stack reserved for parameter registers. */
3618 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3619 char *initial_stack_usage_map = stack_usage_map;
3621 #ifdef REG_PARM_STACK_SPACE
3622 #ifdef MAYBE_REG_PARM_STACK_SPACE
3623 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3625 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3629 /* By default, library functions can not throw. */
3630 flags = ECF_NOTHROW;
3642 case LCT_CONST_MAKE_BLOCK:
3643 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3645 case LCT_PURE_MAKE_BLOCK:
3646 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3649 flags |= ECF_NORETURN;
3652 flags = ECF_NORETURN;
3654 case LCT_ALWAYS_RETURN:
3655 flags = ECF_ALWAYS_RETURN;
3657 case LCT_RETURNS_TWICE:
3658 flags = ECF_RETURNS_TWICE;
3663 /* Ensure current function's preferred stack boundary is at least
3665 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3666 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3668 /* If this kind of value comes back in memory,
3669 decide where in memory it should come back. */
3670 if (outmode != VOIDmode)
3672 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3673 if (aggregate_value_p (tfom))
3675 #ifdef PCC_STATIC_STRUCT_RETURN
3677 = hard_function_value (build_pointer_type (tfom), 0, 0);
3678 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3679 pcc_struct_value = 1;
3681 value = gen_reg_rtx (outmode);
3682 #else /* not PCC_STATIC_STRUCT_RETURN */
3683 struct_value_size = GET_MODE_SIZE (outmode);
3684 if (value != 0 && GET_CODE (value) == MEM)
3687 mem_value = assign_temp (tfom, 0, 1, 1);
3689 /* This call returns a big structure. */
3690 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3694 tfom = void_type_node;
3696 /* ??? Unfinished: must pass the memory address as an argument. */
3698 /* Copy all the libcall-arguments out of the varargs data
3699 and into a vector ARGVEC.
3701 Compute how to pass each argument. We only support a very small subset
3702 of the full argument passing conventions to limit complexity here since
3703 library functions shouldn't have many args. */
3705 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3706 memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3708 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3709 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3711 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3714 args_size.constant = 0;
3719 /* Now we are about to start emitting insns that can be deleted
3720 if a libcall is deleted. */
3721 if (flags & ECF_LIBCALL_BLOCK)
3726 /* If there's a structure value address to be passed,
3727 either pass it in the special place, or pass it as an extra argument. */
3728 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3730 rtx addr = XEXP (mem_value, 0);
3733 /* Make sure it is a reasonable operand for a move or push insn. */
3734 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3735 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3736 addr = force_operand (addr, NULL_RTX);
3738 argvec[count].value = addr;
3739 argvec[count].mode = Pmode;
3740 argvec[count].partial = 0;
3742 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3743 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3744 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3748 locate_and_pad_parm (Pmode, NULL_TREE,
3749 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3752 argvec[count].reg != 0,
3754 0, NULL_TREE, &args_size, &argvec[count].locate);
3756 if (argvec[count].reg == 0 || argvec[count].partial != 0
3757 || reg_parm_stack_space > 0)
3758 args_size.constant += argvec[count].locate.size.constant;
3760 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3765 for (; count < nargs; count++)
3767 rtx val = va_arg (p, rtx);
3768 enum machine_mode mode = va_arg (p, enum machine_mode);
3770 /* We cannot convert the arg value to the mode the library wants here;
3771 must do it earlier where we know the signedness of the arg. */
3773 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3776 /* On some machines, there's no way to pass a float to a library fcn.
3777 Pass it as a double instead. */
3778 #ifdef LIBGCC_NEEDS_DOUBLE
3779 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3780 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3783 /* There's no need to call protect_from_queue, because
3784 either emit_move_insn or emit_push_insn will do that. */
3786 /* Make sure it is a reasonable operand for a move or push insn. */
3787 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3788 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3789 val = force_operand (val, NULL_RTX);
3791 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3792 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3796 #ifdef FUNCTION_ARG_CALLEE_COPIES
3797 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3802 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3803 functions, so we have to pretend this isn't such a function. */
3804 if (flags & ECF_LIBCALL_BLOCK)
3806 rtx insns = get_insns ();
3810 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3812 /* If this was a CONST function, it is now PURE since
3813 it now reads memory. */
3814 if (flags & ECF_CONST)
3816 flags &= ~ECF_CONST;
3820 if (GET_MODE (val) == MEM && ! must_copy)
3824 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3826 emit_move_insn (slot, val);
3830 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3833 = gen_rtx_MEM (mode,
3834 expand_expr (build1 (ADDR_EXPR,
3835 build_pointer_type (type),
3836 make_tree (type, val)),
3837 NULL_RTX, VOIDmode, 0));
3840 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3841 gen_rtx_USE (VOIDmode, slot),
3844 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3845 gen_rtx_CLOBBER (VOIDmode,
3850 val = force_operand (XEXP (slot, 0), NULL_RTX);
3854 argvec[count].value = val;
3855 argvec[count].mode = mode;
3857 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3859 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3860 argvec[count].partial
3861 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3863 argvec[count].partial = 0;
3866 locate_and_pad_parm (mode, NULL_TREE,
3867 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3870 argvec[count].reg != 0,
3872 argvec[count].partial,
3873 NULL_TREE, &args_size, &argvec[count].locate);
3875 if (argvec[count].locate.size.var)
3878 if (argvec[count].reg == 0 || argvec[count].partial != 0
3879 || reg_parm_stack_space > 0)
3880 args_size.constant += argvec[count].locate.size.constant;
3882 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3885 #ifdef FINAL_REG_PARM_STACK_SPACE
3886 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3889 /* If this machine requires an external definition for library
3890 functions, write one out. */
3891 assemble_external_libcall (fun);
3893 original_args_size = args_size;
3894 args_size.constant = (((args_size.constant
3895 + stack_pointer_delta
3899 - stack_pointer_delta);
3901 args_size.constant = MAX (args_size.constant,
3902 reg_parm_stack_space);
3904 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3905 args_size.constant -= reg_parm_stack_space;
3908 if (args_size.constant > current_function_outgoing_args_size)
3909 current_function_outgoing_args_size = args_size.constant;
3911 if (ACCUMULATE_OUTGOING_ARGS)
3913 /* Since the stack pointer will never be pushed, it is possible for
3914 the evaluation of a parm to clobber something we have already
3915 written to the stack. Since most function calls on RISC machines
3916 do not use the stack, this is uncommon, but must work correctly.
3918 Therefore, we save any area of the stack that was already written
3919 and that we are using. Here we set up to do this by making a new
3920 stack usage map from the old one.
3922 Another approach might be to try to reorder the argument
3923 evaluations to avoid this conflicting stack usage. */
3925 needed = args_size.constant;
3927 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3928 /* Since we will be writing into the entire argument area, the
3929 map must be allocated for its entire size, not just the part that
3930 is the responsibility of the caller. */
3931 needed += reg_parm_stack_space;
3934 #ifdef ARGS_GROW_DOWNWARD
3935 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3938 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3941 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3943 if (initial_highest_arg_in_use)
3944 memcpy (stack_usage_map, initial_stack_usage_map,
3945 initial_highest_arg_in_use);
3947 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3948 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3949 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3952 /* We must be careful to use virtual regs before they're instantiated,
3953 and real regs afterwards. Loop optimization, for example, can create
3954 new libcalls after we've instantiated the virtual regs, and if we
3955 use virtuals anyway, they won't match the rtl patterns. */
3957 if (virtuals_instantiated)
3958 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3960 argblock = virtual_outgoing_args_rtx;
3965 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3968 /* If we push args individually in reverse order, perform stack alignment
3969 before the first push (the last arg). */
3970 if (argblock == 0 && PUSH_ARGS_REVERSED)
3971 anti_adjust_stack (GEN_INT (args_size.constant
3972 - original_args_size.constant));
3974 if (PUSH_ARGS_REVERSED)
3985 #ifdef REG_PARM_STACK_SPACE
3986 if (ACCUMULATE_OUTGOING_ARGS)
3988 /* The argument list is the property of the called routine and it
3989 may clobber it. If the fixed area has been used for previous
3990 parameters, we must save and restore it. */
3991 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3992 &low_to_save, &high_to_save);
3996 /* Push the args that need to be pushed. */
3998 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3999 are to be pushed. */
4000 for (count = 0; count < nargs; count++, argnum += inc)
4002 enum machine_mode mode = argvec[argnum].mode;
4003 rtx val = argvec[argnum].value;
4004 rtx reg = argvec[argnum].reg;
4005 int partial = argvec[argnum].partial;
4006 int lower_bound = 0, upper_bound = 0, i;
4008 if (! (reg != 0 && partial == 0))
4010 if (ACCUMULATE_OUTGOING_ARGS)
4012 /* If this is being stored into a pre-allocated, fixed-size,
4013 stack area, save any previous data at that location. */
4015 #ifdef ARGS_GROW_DOWNWARD
4016 /* stack_slot is negative, but we want to index stack_usage_map
4017 with positive values. */
4018 upper_bound = -argvec[argnum].locate.offset.constant + 1;
4019 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
4021 lower_bound = argvec[argnum].locate.offset.constant;
4022 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
4026 /* Don't worry about things in the fixed argument area;
4027 it has already been saved. */
4028 if (i < reg_parm_stack_space)
4029 i = reg_parm_stack_space;
4030 while (i < upper_bound && stack_usage_map[i] == 0)
4033 if (i < upper_bound)
4035 /* We need to make a save area. */
4037 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4038 enum machine_mode save_mode
4039 = mode_for_size (size, MODE_INT, 1);
4041 = plus_constant (argblock,
4042 argvec[argnum].locate.offset.constant);
4044 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4045 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4047 emit_move_insn (argvec[argnum].save_area, stack_area);
4051 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
4052 partial, reg, 0, argblock,
4053 GEN_INT (argvec[argnum].locate.offset.constant),
4054 reg_parm_stack_space,
4055 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4057 /* Now mark the segment we just used. */
4058 if (ACCUMULATE_OUTGOING_ARGS)
4059 for (i = lower_bound; i < upper_bound; i++)
4060 stack_usage_map[i] = 1;
4066 /* If we pushed args in forward order, perform stack alignment
4067 after pushing the last arg. */
4068 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4069 anti_adjust_stack (GEN_INT (args_size.constant
4070 - original_args_size.constant));
4072 if (PUSH_ARGS_REVERSED)
4077 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4079 /* Now load any reg parms into their regs. */
4081 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4082 are to be pushed. */
4083 for (count = 0; count < nargs; count++, argnum += inc)
4085 rtx val = argvec[argnum].value;
4086 rtx reg = argvec[argnum].reg;
4087 int partial = argvec[argnum].partial;
4089 /* Handle calls that pass values in multiple non-contiguous
4090 locations. The PA64 has examples of this for library calls. */
4091 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4092 emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
4093 else if (reg != 0 && partial == 0)
4094 emit_move_insn (reg, val);
4099 /* Any regs containing parms remain in use through the call. */
4100 for (count = 0; count < nargs; count++)
4102 rtx reg = argvec[count].reg;
4103 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4104 use_group_regs (&call_fusage, reg);
4106 use_reg (&call_fusage, reg);
4109 /* Pass the function the address in which to return a structure value. */
4110 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4112 emit_move_insn (struct_value_rtx,
4114 force_operand (XEXP (mem_value, 0),
4116 if (GET_CODE (struct_value_rtx) == REG)
4117 use_reg (&call_fusage, struct_value_rtx);
4120 /* Don't allow popping to be deferred, since then
4121 cse'ing of library calls could delete a call and leave the pop. */
4123 valreg = (mem_value == 0 && outmode != VOIDmode
4124 ? hard_libcall_value (outmode) : NULL_RTX);
4126 /* Stack must be properly aligned now. */
4127 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4130 before_call = get_last_insn ();
4132 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4133 will set inhibit_defer_pop to that value. */
4134 /* The return type is needed to decide how many bytes the function pops.
4135 Signedness plays no role in that, so for simplicity, we pretend it's
4136 always signed. We also assume that the list of arguments passed has
4137 no impact, so we pretend it is unknown. */
4140 get_identifier (XSTR (orgfun, 0)),
4141 build_function_type (tfom, NULL_TREE),
4142 original_args_size.constant, args_size.constant,
4144 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4146 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4148 /* For calls to `setjmp', etc., inform flow.c it should complain
4149 if nonvolatile values are live. For functions that cannot return,
4150 inform flow that control does not fall through. */
4152 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4154 /* The barrier note must be emitted
4155 immediately after the CALL_INSN. Some ports emit more than
4156 just a CALL_INSN above, so we must search for it here. */
4158 rtx last = get_last_insn ();
4159 while (GET_CODE (last) != CALL_INSN)
4161 last = PREV_INSN (last);
4162 /* There was no CALL_INSN? */
4163 if (last == before_call)
4167 emit_barrier_after (last);
4170 /* Now restore inhibit_defer_pop to its actual original value. */
4173 /* If call is cse'able, make appropriate pair of reg-notes around it.
4174 Test valreg so we don't crash; may safely ignore `const'
4175 if return type is void. Disable for PARALLEL return values, because
4176 we have no way to move such values into a pseudo register. */
4177 if (flags & ECF_LIBCALL_BLOCK)
4183 insns = get_insns ();
4193 if (GET_CODE (valreg) == PARALLEL)
4195 temp = gen_reg_rtx (outmode);
4196 emit_group_store (temp, valreg, outmode);
4200 temp = gen_reg_rtx (GET_MODE (valreg));
4202 /* Construct an "equal form" for the value which mentions all the
4203 arguments in order as well as the function name. */
4204 for (i = 0; i < nargs; i++)
4205 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4206 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4208 insns = get_insns ();
4211 if (flags & ECF_PURE)
4212 note = gen_rtx_EXPR_LIST (VOIDmode,
4213 gen_rtx_USE (VOIDmode,
4214 gen_rtx_MEM (BLKmode,
4215 gen_rtx_SCRATCH (VOIDmode))),
4218 emit_libcall_block (insns, temp, valreg, note);
4225 /* Copy the value to the right place. */
4226 if (outmode != VOIDmode && retval)
4232 if (value != mem_value)
4233 emit_move_insn (value, mem_value);
4235 else if (GET_CODE (valreg) == PARALLEL)
4238 value = gen_reg_rtx (outmode);
4239 emit_group_store (value, valreg, outmode);
4241 else if (value != 0)
4242 emit_move_insn (value, valreg);
4247 if (ACCUMULATE_OUTGOING_ARGS)
4249 #ifdef REG_PARM_STACK_SPACE
4251 restore_fixed_argument_area (save_area, argblock,
4252 high_to_save, low_to_save);
4255 /* If we saved any argument areas, restore them. */
4256 for (count = 0; count < nargs; count++)
4257 if (argvec[count].save_area)
4259 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4260 rtx adr = plus_constant (argblock,
4261 argvec[count].locate.offset.constant);
4262 rtx stack_area = gen_rtx_MEM (save_mode,
4263 memory_address (save_mode, adr));
4265 emit_move_insn (stack_area, argvec[count].save_area);
4268 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4269 stack_usage_map = initial_stack_usage_map;
4276 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4277 (emitting the queue unless NO_QUEUE is nonzero),
4278 for a value of mode OUTMODE,
4279 with NARGS different arguments, passed as alternating rtx values
4280 and machine_modes to convert them to.
4281 The rtx values should have been passed through protect_from_queue already.
4283 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4284 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4285 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4286 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4287 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4288 or other LCT_ value for other types of library calls. */
4291 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4292 enum machine_mode outmode, int nargs, ...)
4296 va_start (p, nargs);
4297 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4301 /* Like emit_library_call except that an extra argument, VALUE,
4302 comes second and says where to store the result.
4303 (If VALUE is zero, this function chooses a convenient way
4304 to return the value.
4306 This function returns an rtx for where the value is to be found.
4307 If VALUE is nonzero, VALUE is returned. */
4310 emit_library_call_value (rtx orgfun, rtx value,
4311 enum libcall_type fn_type,
4312 enum machine_mode outmode, int nargs, ...)
4317 va_start (p, nargs);
4318 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4325 /* Store a single argument for a function call
4326 into the register or memory area where it must be passed.
4327 *ARG describes the argument value and where to pass it.
4329 ARGBLOCK is the address of the stack-block for all the arguments,
4330 or 0 on a machine where arguments are pushed individually.
4332 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4333 so must be careful about how the stack is used.
4335 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4336 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4337 that we need not worry about saving and restoring the stack.
4339 FNDECL is the declaration of the function we are calling.
4341 Return nonzero if this arg should cause sibcall failure,
4345 store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
4346 struct arg_data *arg;
4349 int variable_size ATTRIBUTE_UNUSED;
4350 int reg_parm_stack_space;
4352 tree pval = arg->tree_value;
4356 int i, lower_bound = 0, upper_bound = 0;
4357 int sibcall_failure = 0;
4359 if (TREE_CODE (pval) == ERROR_MARK)
4362 /* Push a new temporary level for any temporaries we make for
4366 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4368 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4369 save any previous data at that location. */
4370 if (argblock && ! variable_size && arg->stack)
4372 #ifdef ARGS_GROW_DOWNWARD
4373 /* stack_slot is negative, but we want to index stack_usage_map
4374 with positive values. */
4375 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4376 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4380 lower_bound = upper_bound - arg->locate.size.constant;
4382 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4383 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4387 upper_bound = lower_bound + arg->locate.size.constant;
4391 /* Don't worry about things in the fixed argument area;
4392 it has already been saved. */
4393 if (i < reg_parm_stack_space)
4394 i = reg_parm_stack_space;
4395 while (i < upper_bound && stack_usage_map[i] == 0)
4398 if (i < upper_bound)
4400 /* We need to make a save area. */
4401 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4402 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4403 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4404 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4406 if (save_mode == BLKmode)
4408 tree ot = TREE_TYPE (arg->tree_value);
4409 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4410 | TYPE_QUAL_CONST));
4412 arg->save_area = assign_temp (nt, 0, 1, 1);
4413 preserve_temp_slots (arg->save_area);
4414 emit_block_move (validize_mem (arg->save_area), stack_area,
4415 expr_size (arg->tree_value),
4416 BLOCK_OP_CALL_PARM);
4420 arg->save_area = gen_reg_rtx (save_mode);
4421 emit_move_insn (arg->save_area, stack_area);
4427 /* If this isn't going to be placed on both the stack and in registers,
4428 set up the register and number of words. */
4429 if (! arg->pass_on_stack)
4431 if (flags & ECF_SIBCALL)
4432 reg = arg->tail_call_reg;
4435 partial = arg->partial;
4438 if (reg != 0 && partial == 0)
4439 /* Being passed entirely in a register. We shouldn't be called in
4443 /* If this arg needs special alignment, don't load the registers
4445 if (arg->n_aligned_regs != 0)
4448 /* If this is being passed partially in a register, we can't evaluate
4449 it directly into its stack slot. Otherwise, we can. */
4450 if (arg->value == 0)
4452 /* stack_arg_under_construction is nonzero if a function argument is
4453 being evaluated directly into the outgoing argument list and
4454 expand_call must take special action to preserve the argument list
4455 if it is called recursively.
4457 For scalar function arguments stack_usage_map is sufficient to
4458 determine which stack slots must be saved and restored. Scalar
4459 arguments in general have pass_on_stack == 0.
4461 If this argument is initialized by a function which takes the
4462 address of the argument (a C++ constructor or a C function
4463 returning a BLKmode structure), then stack_usage_map is
4464 insufficient and expand_call must push the stack around the
4465 function call. Such arguments have pass_on_stack == 1.
4467 Note that it is always safe to set stack_arg_under_construction,
4468 but this generates suboptimal code if set when not needed. */
4470 if (arg->pass_on_stack)
4471 stack_arg_under_construction++;
4473 arg->value = expand_expr (pval,
4475 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4476 ? NULL_RTX : arg->stack,
4477 VOIDmode, EXPAND_STACK_PARM);
4479 /* If we are promoting object (or for any other reason) the mode
4480 doesn't agree, convert the mode. */
4482 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4483 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4484 arg->value, arg->unsignedp);
4486 if (arg->pass_on_stack)
4487 stack_arg_under_construction--;
4490 /* Don't allow anything left on stack from computation
4491 of argument to alloca. */
4492 if (flags & ECF_MAY_BE_ALLOCA)
4493 do_pending_stack_adjust ();
4495 if (arg->value == arg->stack)
4496 /* If the value is already in the stack slot, we are done. */
4498 else if (arg->mode != BLKmode)
4502 /* Argument is a scalar, not entirely passed in registers.
4503 (If part is passed in registers, arg->partial says how much
4504 and emit_push_insn will take care of putting it there.)
4506 Push it, and if its size is less than the
4507 amount of space allocated to it,
4508 also bump stack pointer by the additional space.
4509 Note that in C the default argument promotions
4510 will prevent such mismatches. */
4512 size = GET_MODE_SIZE (arg->mode);
4513 /* Compute how much space the push instruction will push.
4514 On many machines, pushing a byte will advance the stack
4515 pointer by a halfword. */
4516 #ifdef PUSH_ROUNDING
4517 size = PUSH_ROUNDING (size);
4521 /* Compute how much space the argument should get:
4522 round up to a multiple of the alignment for arguments. */
4523 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4524 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4525 / (PARM_BOUNDARY / BITS_PER_UNIT))
4526 * (PARM_BOUNDARY / BITS_PER_UNIT));
4528 /* This isn't already where we want it on the stack, so put it there.
4529 This can either be done with push or copy insns. */
4530 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4531 PARM_BOUNDARY, partial, reg, used - size, argblock,
4532 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4533 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4535 /* Unless this is a partially-in-register argument, the argument is now
4538 arg->value = arg->stack;
4542 /* BLKmode, at least partly to be pushed. */
4544 unsigned int parm_align;
4548 /* Pushing a nonscalar.
4549 If part is passed in registers, PARTIAL says how much
4550 and emit_push_insn will take care of putting it there. */
4552 /* Round its size up to a multiple
4553 of the allocation unit for arguments. */
4555 if (arg->locate.size.var != 0)
4558 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4562 /* PUSH_ROUNDING has no effect on us, because
4563 emit_push_insn for BLKmode is careful to avoid it. */
4564 excess = (arg->locate.size.constant
4565 - int_size_in_bytes (TREE_TYPE (pval))
4566 + partial * UNITS_PER_WORD);
4567 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4568 NULL_RTX, TYPE_MODE (sizetype), 0);
4571 /* Some types will require stricter alignment, which will be
4572 provided for elsewhere in argument layout. */
4573 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4575 /* When an argument is padded down, the block is aligned to
4576 PARM_BOUNDARY, but the actual argument isn't. */
4577 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4579 if (arg->locate.size.var)
4580 parm_align = BITS_PER_UNIT;
4583 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4584 parm_align = MIN (parm_align, excess_align);
4588 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4590 /* emit_push_insn might not work properly if arg->value and
4591 argblock + arg->locate.offset areas overlap. */
4595 if (XEXP (x, 0) == current_function_internal_arg_pointer
4596 || (GET_CODE (XEXP (x, 0)) == PLUS
4597 && XEXP (XEXP (x, 0), 0) ==
4598 current_function_internal_arg_pointer
4599 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4601 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4602 i = INTVAL (XEXP (XEXP (x, 0), 1));
4604 /* expand_call should ensure this */
4605 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4608 if (arg->locate.offset.constant > i)
4610 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4611 sibcall_failure = 1;
4613 else if (arg->locate.offset.constant < i)
4615 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4616 sibcall_failure = 1;
4621 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4622 parm_align, partial, reg, excess, argblock,
4623 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4624 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4626 /* Unless this is a partially-in-register argument, the argument is now
4629 ??? Unlike the case above, in which we want the actual
4630 address of the data, so that we can load it directly into a
4631 register, here we want the address of the stack slot, so that
4632 it's properly aligned for word-by-word copying or something
4633 like that. It's not clear that this is always correct. */
4635 arg->value = arg->stack_slot;
4638 /* Mark all slots this store used. */
4639 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4640 && argblock && ! variable_size && arg->stack)
4641 for (i = lower_bound; i < upper_bound; i++)
4642 stack_usage_map[i] = 1;
4644 /* Once we have pushed something, pops can't safely
4645 be deferred during the rest of the arguments. */
4648 /* ANSI doesn't require a sequence point here,
4649 but PCC has one, so this will avoid some problems. */
4652 /* Free any temporary slots made in processing this argument. Show
4653 that we might have taken the address of something and pushed that
4655 preserve_temp_slots (NULL_RTX);
4659 return sibcall_failure;
4662 /* Nonzero if we do not know how to pass TYPE solely in registers.
4663 We cannot do so in the following cases:
4665 - if the type has variable size
4666 - if the type is marked as addressable (it is required to be constructed
4668 - if the padding and mode of the type is such that a copy into a register
4669 would put it into the wrong part of the register.
4671 Which padding can't be supported depends on the byte endianness.
4673 A value in a register is implicitly padded at the most significant end.
4674 On a big-endian machine, that is the lower end in memory.
4675 So a value padded in memory at the upper end can't go in a register.
4676 For a little-endian machine, the reverse is true. */
4679 default_must_pass_in_stack (mode, type)
4680 enum machine_mode mode;
4686 /* If the type has variable size... */
4687 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4690 /* If the type is marked as addressable (it is required
4691 to be constructed into the stack)... */
4692 if (TREE_ADDRESSABLE (type))
4695 /* If the padding and mode of the type is such that a copy into
4696 a register would put it into the wrong part of the register. */
4698 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4699 && (FUNCTION_ARG_PADDING (mode, type)
4700 == (BYTES_BIG_ENDIAN ? upward : downward)))
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