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 ((TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1150 && contains_placeholder_p (TYPE_SIZE (type)))
1151 || TREE_ADDRESSABLE (type)
1152 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1153 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1154 type, argpos < n_named_args)
1158 /* If we're compiling a thunk, pass through invisible
1159 references instead of making a copy. */
1160 if (current_function_is_thunk
1161 #ifdef FUNCTION_ARG_CALLEE_COPIES
1162 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1163 type, argpos < n_named_args)
1164 /* If it's in a register, we must make a copy of it too. */
1165 /* ??? Is this a sufficient test? Is there a better one? */
1166 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1167 && REG_P (DECL_RTL (args[i].tree_value)))
1168 && ! TREE_ADDRESSABLE (type))
1172 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1173 new object from the argument. If we are passing by
1174 invisible reference, the callee will do that for us, so we
1175 can strip off the TARGET_EXPR. This is not always safe,
1176 but it is safe in the only case where this is a useful
1177 optimization; namely, when the argument is a plain object.
1178 In that case, the frontend is just asking the backend to
1179 make a bitwise copy of the argument. */
1181 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1182 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1183 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1184 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1186 args[i].tree_value = build1 (ADDR_EXPR,
1187 build_pointer_type (type),
1188 args[i].tree_value);
1189 type = build_pointer_type (type);
1191 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1193 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1194 We implement this by passing the address of the temporary
1195 rather than expanding it into another allocated slot. */
1196 args[i].tree_value = build1 (ADDR_EXPR,
1197 build_pointer_type (type),
1198 args[i].tree_value);
1199 type = build_pointer_type (type);
1203 /* We make a copy of the object and pass the address to the
1204 function being called. */
1207 if (!COMPLETE_TYPE_P (type)
1208 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1209 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1210 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1211 STACK_CHECK_MAX_VAR_SIZE))))
1213 /* This is a variable-sized object. Make space on the stack
1215 rtx size_rtx = expr_size (TREE_VALUE (p));
1217 if (*old_stack_level == 0)
1219 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1220 *old_pending_adj = pending_stack_adjust;
1221 pending_stack_adjust = 0;
1224 copy = gen_rtx_MEM (BLKmode,
1225 allocate_dynamic_stack_space
1226 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1227 set_mem_attributes (copy, type, 1);
1230 copy = assign_temp (type, 0, 1, 0);
1232 store_expr (args[i].tree_value, copy, 0);
1233 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1235 args[i].tree_value = build1 (ADDR_EXPR,
1236 build_pointer_type (type),
1237 make_tree (type, copy));
1238 type = build_pointer_type (type);
1242 mode = TYPE_MODE (type);
1243 unsignedp = TREE_UNSIGNED (type);
1245 #ifdef PROMOTE_FUNCTION_ARGS
1246 mode = promote_mode (type, mode, &unsignedp, 1);
1249 args[i].unsignedp = unsignedp;
1250 args[i].mode = mode;
1252 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1253 argpos < n_named_args);
1254 #ifdef FUNCTION_INCOMING_ARG
1255 /* If this is a sibling call and the machine has register windows, the
1256 register window has to be unwinded before calling the routine, so
1257 arguments have to go into the incoming registers. */
1258 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1259 argpos < n_named_args);
1261 args[i].tail_call_reg = args[i].reg;
1264 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1267 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1268 argpos < n_named_args);
1271 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1273 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1274 it means that we are to pass this arg in the register(s) designated
1275 by the PARALLEL, but also to pass it in the stack. */
1276 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1277 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1278 args[i].pass_on_stack = 1;
1280 /* If this is an addressable type, we must preallocate the stack
1281 since we must evaluate the object into its final location.
1283 If this is to be passed in both registers and the stack, it is simpler
1285 if (TREE_ADDRESSABLE (type)
1286 || (args[i].pass_on_stack && args[i].reg != 0))
1287 *must_preallocate = 1;
1289 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1290 we cannot consider this function call constant. */
1291 if (TREE_ADDRESSABLE (type))
1292 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1294 /* Compute the stack-size of this argument. */
1295 if (args[i].reg == 0 || args[i].partial != 0
1296 || reg_parm_stack_space > 0
1297 || args[i].pass_on_stack)
1298 locate_and_pad_parm (mode, type,
1299 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1304 args[i].pass_on_stack ? 0 : args[i].partial,
1305 fndecl, args_size, &args[i].locate);
1307 /* Update ARGS_SIZE, the total stack space for args so far. */
1309 args_size->constant += args[i].locate.size.constant;
1310 if (args[i].locate.size.var)
1311 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1313 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1314 have been used, etc. */
1316 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1317 argpos < n_named_args);
1321 /* Update ARGS_SIZE to contain the total size for the argument block.
1322 Return the original constant component of the argument block's size.
1324 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1325 for arguments passed in registers. */
1328 compute_argument_block_size (reg_parm_stack_space, args_size,
1329 preferred_stack_boundary)
1330 int reg_parm_stack_space;
1331 struct args_size *args_size;
1332 int preferred_stack_boundary ATTRIBUTE_UNUSED;
1334 int unadjusted_args_size = args_size->constant;
1336 /* For accumulate outgoing args mode we don't need to align, since the frame
1337 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1338 backends from generating misaligned frame sizes. */
1339 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1340 preferred_stack_boundary = STACK_BOUNDARY;
1342 /* Compute the actual size of the argument block required. The variable
1343 and constant sizes must be combined, the size may have to be rounded,
1344 and there may be a minimum required size. */
1348 args_size->var = ARGS_SIZE_TREE (*args_size);
1349 args_size->constant = 0;
1351 preferred_stack_boundary /= BITS_PER_UNIT;
1352 if (preferred_stack_boundary > 1)
1354 /* We don't handle this case yet. To handle it correctly we have
1355 to add the delta, round and subtract the delta.
1356 Currently no machine description requires this support. */
1357 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1359 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1362 if (reg_parm_stack_space > 0)
1365 = size_binop (MAX_EXPR, args_size->var,
1366 ssize_int (reg_parm_stack_space));
1368 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1369 /* The area corresponding to register parameters is not to count in
1370 the size of the block we need. So make the adjustment. */
1372 = size_binop (MINUS_EXPR, args_size->var,
1373 ssize_int (reg_parm_stack_space));
1379 preferred_stack_boundary /= BITS_PER_UNIT;
1380 if (preferred_stack_boundary < 1)
1381 preferred_stack_boundary = 1;
1382 args_size->constant = (((args_size->constant
1383 + stack_pointer_delta
1384 + preferred_stack_boundary - 1)
1385 / preferred_stack_boundary
1386 * preferred_stack_boundary)
1387 - stack_pointer_delta);
1389 args_size->constant = MAX (args_size->constant,
1390 reg_parm_stack_space);
1392 #ifdef MAYBE_REG_PARM_STACK_SPACE
1393 if (reg_parm_stack_space == 0)
1394 args_size->constant = 0;
1397 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1398 args_size->constant -= reg_parm_stack_space;
1401 return unadjusted_args_size;
1404 /* Precompute parameters as needed for a function call.
1406 FLAGS is mask of ECF_* constants.
1408 NUM_ACTUALS is the number of arguments.
1410 ARGS is an array containing information for each argument; this
1411 routine fills in the INITIAL_VALUE and VALUE fields for each
1412 precomputed argument. */
1415 precompute_arguments (flags, num_actuals, args)
1418 struct arg_data *args;
1422 /* If this function call is cse'able, precompute all the parameters.
1423 Note that if the parameter is constructed into a temporary, this will
1424 cause an additional copy because the parameter will be constructed
1425 into a temporary location and then copied into the outgoing arguments.
1426 If a parameter contains a call to alloca and this function uses the
1427 stack, precompute the parameter. */
1429 /* If we preallocated the stack space, and some arguments must be passed
1430 on the stack, then we must precompute any parameter which contains a
1431 function call which will store arguments on the stack.
1432 Otherwise, evaluating the parameter may clobber previous parameters
1433 which have already been stored into the stack. (we have code to avoid
1434 such case by saving the outgoing stack arguments, but it results in
1437 for (i = 0; i < num_actuals; i++)
1438 if ((flags & ECF_LIBCALL_BLOCK)
1439 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1441 enum machine_mode mode;
1443 /* If this is an addressable type, we cannot pre-evaluate it. */
1444 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1448 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1450 /* ANSI doesn't require a sequence point here,
1451 but PCC has one, so this will avoid some problems. */
1454 args[i].initial_value = args[i].value
1455 = protect_from_queue (args[i].value, 0);
1457 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1458 if (mode != args[i].mode)
1461 = convert_modes (args[i].mode, mode,
1462 args[i].value, args[i].unsignedp);
1463 #ifdef PROMOTE_FOR_CALL_ONLY
1464 /* CSE will replace this only if it contains args[i].value
1465 pseudo, so convert it down to the declared mode using
1467 if (GET_CODE (args[i].value) == REG
1468 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1470 args[i].initial_value
1471 = gen_lowpart_SUBREG (mode, args[i].value);
1472 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1473 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1481 /* Given the current state of MUST_PREALLOCATE and information about
1482 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1483 compute and return the final value for MUST_PREALLOCATE. */
1486 finalize_must_preallocate (must_preallocate, num_actuals, args, args_size)
1487 int must_preallocate;
1489 struct arg_data *args;
1490 struct args_size *args_size;
1492 /* See if we have or want to preallocate stack space.
1494 If we would have to push a partially-in-regs parm
1495 before other stack parms, preallocate stack space instead.
1497 If the size of some parm is not a multiple of the required stack
1498 alignment, we must preallocate.
1500 If the total size of arguments that would otherwise create a copy in
1501 a temporary (such as a CALL) is more than half the total argument list
1502 size, preallocation is faster.
1504 Another reason to preallocate is if we have a machine (like the m88k)
1505 where stack alignment is required to be maintained between every
1506 pair of insns, not just when the call is made. However, we assume here
1507 that such machines either do not have push insns (and hence preallocation
1508 would occur anyway) or the problem is taken care of with
1511 if (! must_preallocate)
1513 int partial_seen = 0;
1514 int copy_to_evaluate_size = 0;
1517 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1519 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1521 else if (partial_seen && args[i].reg == 0)
1522 must_preallocate = 1;
1524 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1525 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1526 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1527 || TREE_CODE (args[i].tree_value) == COND_EXPR
1528 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1529 copy_to_evaluate_size
1530 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1533 if (copy_to_evaluate_size * 2 >= args_size->constant
1534 && args_size->constant > 0)
1535 must_preallocate = 1;
1537 return must_preallocate;
1540 /* If we preallocated stack space, compute the address of each argument
1541 and store it into the ARGS array.
1543 We need not ensure it is a valid memory address here; it will be
1544 validized when it is used.
1546 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1549 compute_argument_addresses (args, argblock, num_actuals)
1550 struct arg_data *args;
1556 rtx arg_reg = argblock;
1557 int i, arg_offset = 0;
1559 if (GET_CODE (argblock) == PLUS)
1560 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1562 for (i = 0; i < num_actuals; i++)
1564 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1565 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1568 /* Skip this parm if it will not be passed on the stack. */
1569 if (! args[i].pass_on_stack && args[i].reg != 0)
1572 if (GET_CODE (offset) == CONST_INT)
1573 addr = plus_constant (arg_reg, INTVAL (offset));
1575 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1577 addr = plus_constant (addr, arg_offset);
1578 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1579 set_mem_align (args[i].stack, PARM_BOUNDARY);
1580 set_mem_attributes (args[i].stack,
1581 TREE_TYPE (args[i].tree_value), 1);
1583 if (GET_CODE (slot_offset) == CONST_INT)
1584 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1586 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1588 addr = plus_constant (addr, arg_offset);
1589 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1590 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1591 set_mem_attributes (args[i].stack_slot,
1592 TREE_TYPE (args[i].tree_value), 1);
1594 /* Function incoming arguments may overlap with sibling call
1595 outgoing arguments and we cannot allow reordering of reads
1596 from function arguments with stores to outgoing arguments
1597 of sibling calls. */
1598 set_mem_alias_set (args[i].stack, 0);
1599 set_mem_alias_set (args[i].stack_slot, 0);
1604 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1605 in a call instruction.
1607 FNDECL is the tree node for the target function. For an indirect call
1608 FNDECL will be NULL_TREE.
1610 ADDR is the operand 0 of CALL_EXPR for this call. */
1613 rtx_for_function_call (fndecl, addr)
1619 /* Get the function to call, in the form of RTL. */
1622 /* If this is the first use of the function, see if we need to
1623 make an external definition for it. */
1624 if (! TREE_USED (fndecl))
1626 assemble_external (fndecl);
1627 TREE_USED (fndecl) = 1;
1630 /* Get a SYMBOL_REF rtx for the function address. */
1631 funexp = XEXP (DECL_RTL (fndecl), 0);
1634 /* Generate an rtx (probably a pseudo-register) for the address. */
1637 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1638 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1644 /* Do the register loads required for any wholly-register parms or any
1645 parms which are passed both on the stack and in a register. Their
1646 expressions were already evaluated.
1648 Mark all register-parms as living through the call, putting these USE
1649 insns in the CALL_INSN_FUNCTION_USAGE field.
1651 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1652 checking, setting *SIBCALL_FAILURE if appropriate. */
1655 load_register_parameters (args, num_actuals, call_fusage, flags,
1656 is_sibcall, sibcall_failure)
1657 struct arg_data *args;
1662 int *sibcall_failure;
1666 #ifdef LOAD_ARGS_REVERSED
1667 for (i = num_actuals - 1; i >= 0; i--)
1669 for (i = 0; i < num_actuals; i++)
1672 rtx reg = ((flags & ECF_SIBCALL)
1673 ? args[i].tail_call_reg : args[i].reg);
1674 int partial = args[i].partial;
1679 rtx before_arg = get_last_insn ();
1680 /* Set to non-negative if must move a word at a time, even if just
1681 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1682 we just use a normal move insn. This value can be zero if the
1683 argument is a zero size structure with no fields. */
1684 nregs = (partial ? partial
1685 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1686 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1687 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1690 /* Handle calls that pass values in multiple non-contiguous
1691 locations. The Irix 6 ABI has examples of this. */
1693 if (GET_CODE (reg) == PARALLEL)
1694 emit_group_load (reg, args[i].value,
1695 int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1697 /* If simple case, just do move. If normal partial, store_one_arg
1698 has already loaded the register for us. In all other cases,
1699 load the register(s) from memory. */
1701 else if (nregs == -1)
1702 emit_move_insn (reg, args[i].value);
1704 /* If we have pre-computed the values to put in the registers in
1705 the case of non-aligned structures, copy them in now. */
1707 else if (args[i].n_aligned_regs != 0)
1708 for (j = 0; j < args[i].n_aligned_regs; j++)
1709 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1710 args[i].aligned_regs[j]);
1712 else if (partial == 0 || args[i].pass_on_stack)
1713 move_block_to_reg (REGNO (reg),
1714 validize_mem (args[i].value), nregs,
1717 /* When a parameter is a block, and perhaps in other cases, it is
1718 possible that it did a load from an argument slot that was
1719 already clobbered. */
1721 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1722 *sibcall_failure = 1;
1724 /* Handle calls that pass values in multiple non-contiguous
1725 locations. The Irix 6 ABI has examples of this. */
1726 if (GET_CODE (reg) == PARALLEL)
1727 use_group_regs (call_fusage, reg);
1728 else if (nregs == -1)
1729 use_reg (call_fusage, reg);
1731 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1736 /* Try to integrate function. See expand_inline_function for documentation
1737 about the parameters. */
1740 try_to_integrate (fndecl, actparms, target, ignore, type, structure_value_addr)
1746 rtx structure_value_addr;
1751 rtx old_stack_level = 0;
1752 int reg_parm_stack_space = 0;
1754 #ifdef REG_PARM_STACK_SPACE
1755 #ifdef MAYBE_REG_PARM_STACK_SPACE
1756 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1758 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1762 before_call = get_last_insn ();
1764 timevar_push (TV_INTEGRATION);
1766 temp = expand_inline_function (fndecl, actparms, target,
1768 structure_value_addr);
1770 timevar_pop (TV_INTEGRATION);
1772 /* If inlining succeeded, return. */
1773 if (temp != (rtx) (size_t) - 1)
1775 if (ACCUMULATE_OUTGOING_ARGS)
1777 /* If the outgoing argument list must be preserved, push
1778 the stack before executing the inlined function if it
1781 i = reg_parm_stack_space;
1782 if (i > highest_outgoing_arg_in_use)
1783 i = highest_outgoing_arg_in_use;
1784 while (--i >= 0 && stack_usage_map[i] == 0)
1787 if (stack_arg_under_construction || i >= 0)
1790 = before_call ? NEXT_INSN (before_call) : get_insns ();
1791 rtx insn = NULL_RTX, seq;
1793 /* Look for a call in the inline function code.
1794 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1795 nonzero then there is a call and it is not necessary
1796 to scan the insns. */
1798 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1799 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1800 if (GET_CODE (insn) == CALL_INSN)
1805 /* Reserve enough stack space so that the largest
1806 argument list of any function call in the inline
1807 function does not overlap the argument list being
1808 evaluated. This is usually an overestimate because
1809 allocate_dynamic_stack_space reserves space for an
1810 outgoing argument list in addition to the requested
1811 space, but there is no way to ask for stack space such
1812 that an argument list of a certain length can be
1815 Add the stack space reserved for register arguments, if
1816 any, in the inline function. What is really needed is the
1817 largest value of reg_parm_stack_space in the inline
1818 function, but that is not available. Using the current
1819 value of reg_parm_stack_space is wrong, but gives
1820 correct results on all supported machines. */
1822 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1823 + reg_parm_stack_space);
1826 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1827 allocate_dynamic_stack_space (GEN_INT (adjust),
1828 NULL_RTX, BITS_PER_UNIT);
1831 emit_insn_before (seq, first_insn);
1832 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1837 /* If the result is equivalent to TARGET, return TARGET to simplify
1838 checks in store_expr. They can be equivalent but not equal in the
1839 case of a function that returns BLKmode. */
1840 if (temp != target && rtx_equal_p (temp, target))
1845 /* If inlining failed, mark FNDECL as needing to be compiled
1846 separately after all. If function was declared inline,
1848 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1849 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1851 warning_with_decl (fndecl, "inlining failed in call to `%s'");
1852 warning ("called from here");
1854 (*lang_hooks.mark_addressable) (fndecl);
1855 return (rtx) (size_t) - 1;
1858 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1859 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1860 bytes, then we would need to push some additional bytes to pad the
1861 arguments. So, we compute an adjust to the stack pointer for an
1862 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1863 bytes. Then, when the arguments are pushed the stack will be perfectly
1864 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1865 be popped after the call. Returns the adjustment. */
1868 combine_pending_stack_adjustment_and_call (unadjusted_args_size,
1870 preferred_unit_stack_boundary)
1871 int unadjusted_args_size;
1872 struct args_size *args_size;
1873 int preferred_unit_stack_boundary;
1875 /* The number of bytes to pop so that the stack will be
1876 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1877 HOST_WIDE_INT adjustment;
1878 /* The alignment of the stack after the arguments are pushed, if we
1879 just pushed the arguments without adjust the stack here. */
1880 HOST_WIDE_INT unadjusted_alignment;
1882 unadjusted_alignment
1883 = ((stack_pointer_delta + unadjusted_args_size)
1884 % preferred_unit_stack_boundary);
1886 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1887 as possible -- leaving just enough left to cancel out the
1888 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1889 PENDING_STACK_ADJUST is non-negative, and congruent to
1890 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1892 /* Begin by trying to pop all the bytes. */
1893 unadjusted_alignment
1894 = (unadjusted_alignment
1895 - (pending_stack_adjust % preferred_unit_stack_boundary));
1896 adjustment = pending_stack_adjust;
1897 /* Push enough additional bytes that the stack will be aligned
1898 after the arguments are pushed. */
1899 if (preferred_unit_stack_boundary > 1)
1901 if (unadjusted_alignment > 0)
1902 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1904 adjustment += unadjusted_alignment;
1907 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1908 bytes after the call. The right number is the entire
1909 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1910 by the arguments in the first place. */
1912 = pending_stack_adjust - adjustment + unadjusted_args_size;
1917 /* Scan X expression if it does not dereference any argument slots
1918 we already clobbered by tail call arguments (as noted in stored_args_map
1920 Return nonzero if X expression dereferences such argument slots,
1924 check_sibcall_argument_overlap_1 (x)
1935 code = GET_CODE (x);
1939 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1941 else if (GET_CODE (XEXP (x, 0)) == PLUS
1942 && XEXP (XEXP (x, 0), 0) ==
1943 current_function_internal_arg_pointer
1944 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1945 i = INTVAL (XEXP (XEXP (x, 0), 1));
1949 #ifdef ARGS_GROW_DOWNWARD
1950 i = -i - GET_MODE_SIZE (GET_MODE (x));
1953 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1954 if (i + k < stored_args_map->n_bits
1955 && TEST_BIT (stored_args_map, i + k))
1961 /* Scan all subexpressions. */
1962 fmt = GET_RTX_FORMAT (code);
1963 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1967 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1970 else if (*fmt == 'E')
1972 for (j = 0; j < XVECLEN (x, i); j++)
1973 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1980 /* Scan sequence after INSN if it does not dereference any argument slots
1981 we already clobbered by tail call arguments (as noted in stored_args_map
1982 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1983 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1984 should be 0). Return nonzero if sequence after INSN dereferences such argument
1985 slots, zero otherwise. */
1988 check_sibcall_argument_overlap (insn, arg, mark_stored_args_map)
1990 struct arg_data *arg;
1991 int mark_stored_args_map;
1995 if (insn == NULL_RTX)
1996 insn = get_insns ();
1998 insn = NEXT_INSN (insn);
2000 for (; insn; insn = NEXT_INSN (insn))
2002 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
2005 if (mark_stored_args_map)
2007 #ifdef ARGS_GROW_DOWNWARD
2008 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
2010 low = arg->locate.slot_offset.constant;
2013 for (high = low + arg->locate.size.constant; low < high; low++)
2014 SET_BIT (stored_args_map, low);
2016 return insn != NULL_RTX;
2023 switch (unsafe_for_reeval (t))
2028 case 1: /* Mildly unsafe. */
2029 t = unsave_expr (t);
2032 case 2: /* Wildly unsafe. */
2034 tree var = build_decl (VAR_DECL, NULL_TREE,
2037 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2048 /* Generate all the code for a function call
2049 and return an rtx for its value.
2050 Store the value in TARGET (specified as an rtx) if convenient.
2051 If the value is stored in TARGET then TARGET is returned.
2052 If IGNORE is nonzero, then we ignore the value of the function call. */
2055 expand_call (exp, target, ignore)
2060 /* Nonzero if we are currently expanding a call. */
2061 static int currently_expanding_call = 0;
2063 /* List of actual parameters. */
2064 tree actparms = TREE_OPERAND (exp, 1);
2065 /* RTX for the function to be called. */
2067 /* Sequence of insns to perform a tail recursive "call". */
2068 rtx tail_recursion_insns = NULL_RTX;
2069 /* Sequence of insns to perform a normal "call". */
2070 rtx normal_call_insns = NULL_RTX;
2071 /* Sequence of insns to perform a tail recursive "call". */
2072 rtx tail_call_insns = NULL_RTX;
2073 /* Data type of the function. */
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 #ifdef REG_PARM_STACK_SPACE
2215 #ifdef MAYBE_REG_PARM_STACK_SPACE
2216 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2218 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2222 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2223 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2224 must_preallocate = 1;
2227 /* Warn if this value is an aggregate type,
2228 regardless of which calling convention we are using for it. */
2229 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2230 warning ("function call has aggregate value");
2232 /* Set up a place to return a structure. */
2234 /* Cater to broken compilers. */
2235 if (aggregate_value_p (exp))
2237 /* This call returns a big structure. */
2238 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2240 #ifdef PCC_STATIC_STRUCT_RETURN
2242 pcc_struct_value = 1;
2243 /* Easier than making that case work right. */
2246 /* In case this is a static function, note that it has been
2248 if (! TREE_ADDRESSABLE (fndecl))
2249 (*lang_hooks.mark_addressable) (fndecl);
2253 #else /* not PCC_STATIC_STRUCT_RETURN */
2255 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2257 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2259 /* The structure value address arg is already in actparms.
2260 Pull it out. It might be nice to just leave it there, but
2261 we need to set structure_value_addr. */
2262 tree return_arg = TREE_VALUE (actparms);
2263 actparms = TREE_CHAIN (actparms);
2264 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2265 VOIDmode, EXPAND_NORMAL);
2267 else if (target && GET_CODE (target) == MEM)
2268 structure_value_addr = XEXP (target, 0);
2271 /* For variable-sized objects, we must be called with a target
2272 specified. If we were to allocate space on the stack here,
2273 we would have no way of knowing when to free it. */
2274 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2276 mark_temp_addr_taken (d);
2277 structure_value_addr = XEXP (d, 0);
2281 #endif /* not PCC_STATIC_STRUCT_RETURN */
2284 /* If called function is inline, try to integrate it. */
2288 rtx temp = try_to_integrate (fndecl, actparms, target,
2289 ignore, TREE_TYPE (exp),
2290 structure_value_addr);
2291 if (temp != (rtx) (size_t) - 1)
2295 /* Figure out the amount to which the stack should be aligned. */
2296 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2299 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2300 if (i && i->preferred_incoming_stack_boundary)
2301 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2304 /* Operand 0 is a pointer-to-function; get the type of the function. */
2305 funtype = TREE_TYPE (addr);
2306 if (! POINTER_TYPE_P (funtype))
2308 funtype = TREE_TYPE (funtype);
2310 /* See if this is a call to a function that can return more than once
2311 or a call to longjmp or malloc. */
2312 flags |= special_function_p (fndecl, flags);
2314 if (flags & ECF_MAY_BE_ALLOCA)
2315 current_function_calls_alloca = 1;
2317 /* If struct_value_rtx is 0, it means pass the address
2318 as if it were an extra parameter. */
2319 if (structure_value_addr && struct_value_rtx == 0)
2321 /* If structure_value_addr is a REG other than
2322 virtual_outgoing_args_rtx, we can use always use it. If it
2323 is not a REG, we must always copy it into a register.
2324 If it is virtual_outgoing_args_rtx, we must copy it to another
2325 register in some cases. */
2326 rtx temp = (GET_CODE (structure_value_addr) != REG
2327 || (ACCUMULATE_OUTGOING_ARGS
2328 && stack_arg_under_construction
2329 && structure_value_addr == virtual_outgoing_args_rtx)
2330 ? copy_addr_to_reg (structure_value_addr)
2331 : structure_value_addr);
2334 = tree_cons (error_mark_node,
2335 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2338 structure_value_addr_parm = 1;
2341 /* Count the arguments and set NUM_ACTUALS. */
2342 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2345 /* Compute number of named args.
2346 Normally, don't include the last named arg if anonymous args follow.
2347 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2348 (If no anonymous args follow, the result of list_length is actually
2349 one too large. This is harmless.)
2351 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2352 zero, this machine will be able to place unnamed args that were
2353 passed in registers into the stack. So treat all args as named.
2354 This allows the insns emitting for a specific argument list to be
2355 independent of the function declaration.
2357 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2358 reliable way to pass unnamed args in registers, so we must force
2359 them into memory. */
2361 if ((STRICT_ARGUMENT_NAMING
2362 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2363 && TYPE_ARG_TYPES (funtype) != 0)
2365 = (list_length (TYPE_ARG_TYPES (funtype))
2366 /* Don't include the last named arg. */
2367 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2368 /* Count the struct value address, if it is passed as a parm. */
2369 + structure_value_addr_parm);
2371 /* If we know nothing, treat all args as named. */
2372 n_named_args = num_actuals;
2374 /* Start updating where the next arg would go.
2376 On some machines (such as the PA) indirect calls have a different
2377 calling convention than normal calls. The last argument in
2378 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2380 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2382 /* Make a vector to hold all the information about each arg. */
2383 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2384 memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2386 /* Build up entries in the ARGS array, compute the size of the
2387 arguments into ARGS_SIZE, etc. */
2388 initialize_argument_information (num_actuals, args, &args_size,
2389 n_named_args, actparms, fndecl,
2390 &args_so_far, reg_parm_stack_space,
2391 &old_stack_level, &old_pending_adj,
2392 &must_preallocate, &flags);
2396 /* If this function requires a variable-sized argument list, don't
2397 try to make a cse'able block for this call. We may be able to
2398 do this eventually, but it is too complicated to keep track of
2399 what insns go in the cse'able block and which don't. */
2401 flags &= ~ECF_LIBCALL_BLOCK;
2402 must_preallocate = 1;
2405 /* Now make final decision about preallocating stack space. */
2406 must_preallocate = finalize_must_preallocate (must_preallocate,
2410 /* If the structure value address will reference the stack pointer, we
2411 must stabilize it. We don't need to do this if we know that we are
2412 not going to adjust the stack pointer in processing this call. */
2414 if (structure_value_addr
2415 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2416 || reg_mentioned_p (virtual_outgoing_args_rtx,
2417 structure_value_addr))
2419 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2420 structure_value_addr = copy_to_reg (structure_value_addr);
2422 /* Tail calls can make things harder to debug, and we're traditionally
2423 pushed these optimizations into -O2. Don't try if we're already
2424 expanding a call, as that means we're an argument. Don't try if
2425 there's cleanups, as we know there's code to follow the call.
2427 If rtx_equal_function_value_matters is false, that means we've
2428 finished with regular parsing. Which means that some of the
2429 machinery we use to generate tail-calls is no longer in place.
2430 This is most often true of sjlj-exceptions, which we couldn't
2431 tail-call to anyway. */
2433 if (currently_expanding_call++ != 0
2434 || !flag_optimize_sibling_calls
2435 || !rtx_equal_function_value_matters
2436 || any_pending_cleanups (1)
2438 try_tail_call = try_tail_recursion = 0;
2440 /* Tail recursion fails, when we are not dealing with recursive calls. */
2441 if (!try_tail_recursion
2442 || TREE_CODE (addr) != ADDR_EXPR
2443 || TREE_OPERAND (addr, 0) != current_function_decl)
2444 try_tail_recursion = 0;
2446 /* Rest of purposes for tail call optimizations to fail. */
2448 #ifdef HAVE_sibcall_epilogue
2449 !HAVE_sibcall_epilogue
2454 /* Doing sibling call optimization needs some work, since
2455 structure_value_addr can be allocated on the stack.
2456 It does not seem worth the effort since few optimizable
2457 sibling calls will return a structure. */
2458 || structure_value_addr != NULL_RTX
2459 /* Check whether the target is able to optimize the call
2461 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2462 /* Functions that do not return exactly once may not be sibcall
2464 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2465 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2466 /* If the called function is nested in the current one, it might access
2467 some of the caller's arguments, but could clobber them beforehand if
2468 the argument areas are shared. */
2469 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2470 /* If this function requires more stack slots than the current
2471 function, we cannot change it into a sibling call. */
2472 || args_size.constant > current_function_args_size
2473 /* If the callee pops its own arguments, then it must pop exactly
2474 the same number of arguments as the current function. */
2475 || RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2476 != RETURN_POPS_ARGS (current_function_decl,
2477 TREE_TYPE (current_function_decl),
2478 current_function_args_size))
2481 if (try_tail_call || try_tail_recursion)
2484 actparms = NULL_TREE;
2485 /* Ok, we're going to give the tail call the old college try.
2486 This means we're going to evaluate the function arguments
2487 up to three times. There are two degrees of badness we can
2488 encounter, those that can be unsaved and those that can't.
2489 (See unsafe_for_reeval commentary for details.)
2491 Generate a new argument list. Pass safe arguments through
2492 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2493 For hard badness, evaluate them now and put their resulting
2494 rtx in a temporary VAR_DECL.
2496 initialize_argument_information has ordered the array for the
2497 order to be pushed, and we must remember this when reconstructing
2498 the original argument order. */
2500 if (PUSH_ARGS_REVERSED)
2509 i = num_actuals - 1;
2513 for (; i != end; i += inc)
2515 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2516 /* We need to build actparms for optimize_tail_recursion. We can
2517 safely trash away TREE_PURPOSE, since it is unused by this
2519 if (try_tail_recursion)
2520 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2522 /* Do the same for the function address if it is an expression. */
2524 addr = fix_unsafe_tree (addr);
2525 /* Expanding one of those dangerous arguments could have added
2526 cleanups, but otherwise give it a whirl. */
2527 if (any_pending_cleanups (1))
2528 try_tail_call = try_tail_recursion = 0;
2531 /* Generate a tail recursion sequence when calling ourselves. */
2533 if (try_tail_recursion)
2535 /* We want to emit any pending stack adjustments before the tail
2536 recursion "call". That way we know any adjustment after the tail
2537 recursion call can be ignored if we indeed use the tail recursion
2539 int save_pending_stack_adjust = pending_stack_adjust;
2540 int save_stack_pointer_delta = stack_pointer_delta;
2542 /* Emit any queued insns now; otherwise they would end up in
2543 only one of the alternates. */
2546 /* Use a new sequence to hold any RTL we generate. We do not even
2547 know if we will use this RTL yet. The final decision can not be
2548 made until after RTL generation for the entire function is
2551 /* If expanding any of the arguments creates cleanups, we can't
2552 do a tailcall. So, we'll need to pop the pending cleanups
2553 list. If, however, all goes well, and there are no cleanups
2554 then the call to expand_start_target_temps will have no
2556 expand_start_target_temps ();
2557 if (optimize_tail_recursion (actparms, get_last_insn ()))
2559 if (any_pending_cleanups (1))
2560 try_tail_call = try_tail_recursion = 0;
2562 tail_recursion_insns = get_insns ();
2564 expand_end_target_temps ();
2567 /* Restore the original pending stack adjustment for the sibling and
2568 normal call cases below. */
2569 pending_stack_adjust = save_pending_stack_adjust;
2570 stack_pointer_delta = save_stack_pointer_delta;
2573 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2575 /* A fork duplicates the profile information, and an exec discards
2576 it. We can't rely on fork/exec to be paired. So write out the
2577 profile information we have gathered so far, and clear it. */
2578 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2579 is subject to race conditions, just as with multithreaded
2582 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2585 /* Ensure current function's preferred stack boundary is at least
2586 what we need. We don't have to increase alignment for recursive
2588 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2589 && fndecl != current_function_decl)
2590 cfun->preferred_stack_boundary = preferred_stack_boundary;
2591 if (fndecl == current_function_decl)
2592 cfun->recursive_call_emit = true;
2594 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2596 function_call_count++;
2598 /* We want to make two insn chains; one for a sibling call, the other
2599 for a normal call. We will select one of the two chains after
2600 initial RTL generation is complete. */
2601 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2603 int sibcall_failure = 0;
2604 /* We want to emit any pending stack adjustments before the tail
2605 recursion "call". That way we know any adjustment after the tail
2606 recursion call can be ignored if we indeed use the tail recursion
2608 int save_pending_stack_adjust = 0;
2609 int save_stack_pointer_delta = 0;
2611 rtx before_call, next_arg_reg;
2615 /* Emit any queued insns now; otherwise they would end up in
2616 only one of the alternates. */
2619 /* State variables we need to save and restore between
2621 save_pending_stack_adjust = pending_stack_adjust;
2622 save_stack_pointer_delta = stack_pointer_delta;
2625 flags &= ~ECF_SIBCALL;
2627 flags |= ECF_SIBCALL;
2629 /* Other state variables that we must reinitialize each time
2630 through the loop (that are not initialized by the loop itself). */
2634 /* Start a new sequence for the normal call case.
2636 From this point on, if the sibling call fails, we want to set
2637 sibcall_failure instead of continuing the loop. */
2642 /* We know at this point that there are not currently any
2643 pending cleanups. If, however, in the process of evaluating
2644 the arguments we were to create some, we'll need to be
2645 able to get rid of them. */
2646 expand_start_target_temps ();
2649 /* Don't let pending stack adjusts add up to too much.
2650 Also, do all pending adjustments now if there is any chance
2651 this might be a call to alloca or if we are expanding a sibling
2652 call sequence or if we are calling a function that is to return
2653 with stack pointer depressed. */
2654 if (pending_stack_adjust >= 32
2655 || (pending_stack_adjust > 0
2656 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2658 do_pending_stack_adjust ();
2660 /* When calling a const function, we must pop the stack args right away,
2661 so that the pop is deleted or moved with the call. */
2662 if (pass && (flags & ECF_LIBCALL_BLOCK))
2665 #ifdef FINAL_REG_PARM_STACK_SPACE
2666 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2669 /* Precompute any arguments as needed. */
2671 precompute_arguments (flags, num_actuals, args);
2673 /* Now we are about to start emitting insns that can be deleted
2674 if a libcall is deleted. */
2675 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2678 adjusted_args_size = args_size;
2679 /* Compute the actual size of the argument block required. The variable
2680 and constant sizes must be combined, the size may have to be rounded,
2681 and there may be a minimum required size. When generating a sibcall
2682 pattern, do not round up, since we'll be re-using whatever space our
2684 unadjusted_args_size
2685 = compute_argument_block_size (reg_parm_stack_space,
2686 &adjusted_args_size,
2688 : preferred_stack_boundary));
2690 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2692 /* The argument block when performing a sibling call is the
2693 incoming argument block. */
2696 argblock = virtual_incoming_args_rtx;
2698 #ifdef STACK_GROWS_DOWNWARD
2699 = plus_constant (argblock, current_function_pretend_args_size);
2701 = plus_constant (argblock, -current_function_pretend_args_size);
2703 stored_args_map = sbitmap_alloc (args_size.constant);
2704 sbitmap_zero (stored_args_map);
2707 /* If we have no actual push instructions, or shouldn't use them,
2708 make space for all args right now. */
2709 else if (adjusted_args_size.var != 0)
2711 if (old_stack_level == 0)
2713 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2714 old_stack_pointer_delta = stack_pointer_delta;
2715 old_pending_adj = pending_stack_adjust;
2716 pending_stack_adjust = 0;
2717 /* stack_arg_under_construction says whether a stack arg is
2718 being constructed at the old stack level. Pushing the stack
2719 gets a clean outgoing argument block. */
2720 old_stack_arg_under_construction = stack_arg_under_construction;
2721 stack_arg_under_construction = 0;
2723 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2727 /* Note that we must go through the motions of allocating an argument
2728 block even if the size is zero because we may be storing args
2729 in the area reserved for register arguments, which may be part of
2732 int needed = adjusted_args_size.constant;
2734 /* Store the maximum argument space used. It will be pushed by
2735 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2738 if (needed > current_function_outgoing_args_size)
2739 current_function_outgoing_args_size = needed;
2741 if (must_preallocate)
2743 if (ACCUMULATE_OUTGOING_ARGS)
2745 /* Since the stack pointer will never be pushed, it is
2746 possible for the evaluation of a parm to clobber
2747 something we have already written to the stack.
2748 Since most function calls on RISC machines do not use
2749 the stack, this is uncommon, but must work correctly.
2751 Therefore, we save any area of the stack that was already
2752 written and that we are using. Here we set up to do this
2753 by making a new stack usage map from the old one. The
2754 actual save will be done by store_one_arg.
2756 Another approach might be to try to reorder the argument
2757 evaluations to avoid this conflicting stack usage. */
2759 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2760 /* Since we will be writing into the entire argument area,
2761 the map must be allocated for its entire size, not just
2762 the part that is the responsibility of the caller. */
2763 needed += reg_parm_stack_space;
2766 #ifdef ARGS_GROW_DOWNWARD
2767 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2770 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2774 = (char *) alloca (highest_outgoing_arg_in_use);
2776 if (initial_highest_arg_in_use)
2777 memcpy (stack_usage_map, initial_stack_usage_map,
2778 initial_highest_arg_in_use);
2780 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2781 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2782 (highest_outgoing_arg_in_use
2783 - initial_highest_arg_in_use));
2786 /* The address of the outgoing argument list must not be
2787 copied to a register here, because argblock would be left
2788 pointing to the wrong place after the call to
2789 allocate_dynamic_stack_space below. */
2791 argblock = virtual_outgoing_args_rtx;
2795 if (inhibit_defer_pop == 0)
2797 /* Try to reuse some or all of the pending_stack_adjust
2798 to get this space. */
2800 = (combine_pending_stack_adjustment_and_call
2801 (unadjusted_args_size,
2802 &adjusted_args_size,
2803 preferred_unit_stack_boundary));
2805 /* combine_pending_stack_adjustment_and_call computes
2806 an adjustment before the arguments are allocated.
2807 Account for them and see whether or not the stack
2808 needs to go up or down. */
2809 needed = unadjusted_args_size - needed;
2813 /* We're releasing stack space. */
2814 /* ??? We can avoid any adjustment at all if we're
2815 already aligned. FIXME. */
2816 pending_stack_adjust = -needed;
2817 do_pending_stack_adjust ();
2821 /* We need to allocate space. We'll do that in
2822 push_block below. */
2823 pending_stack_adjust = 0;
2826 /* Special case this because overhead of `push_block' in
2827 this case is non-trivial. */
2829 argblock = virtual_outgoing_args_rtx;
2831 argblock = push_block (GEN_INT (needed), 0, 0);
2833 /* We only really need to call `copy_to_reg' in the case
2834 where push insns are going to be used to pass ARGBLOCK
2835 to a function call in ARGS. In that case, the stack
2836 pointer changes value from the allocation point to the
2837 call point, and hence the value of
2838 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2839 as well always do it. */
2840 argblock = copy_to_reg (argblock);
2845 if (ACCUMULATE_OUTGOING_ARGS)
2847 /* The save/restore code in store_one_arg handles all
2848 cases except one: a constructor call (including a C
2849 function returning a BLKmode struct) to initialize
2851 if (stack_arg_under_construction)
2853 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2854 rtx push_size = GEN_INT (reg_parm_stack_space
2855 + adjusted_args_size.constant);
2857 rtx push_size = GEN_INT (adjusted_args_size.constant);
2859 if (old_stack_level == 0)
2861 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2863 old_stack_pointer_delta = stack_pointer_delta;
2864 old_pending_adj = pending_stack_adjust;
2865 pending_stack_adjust = 0;
2866 /* stack_arg_under_construction says whether a stack
2867 arg is being constructed at the old stack level.
2868 Pushing the stack gets a clean outgoing argument
2870 old_stack_arg_under_construction
2871 = stack_arg_under_construction;
2872 stack_arg_under_construction = 0;
2873 /* Make a new map for the new argument list. */
2874 stack_usage_map = (char *)
2875 alloca (highest_outgoing_arg_in_use);
2876 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2877 highest_outgoing_arg_in_use = 0;
2879 allocate_dynamic_stack_space (push_size, NULL_RTX,
2883 /* If argument evaluation might modify the stack pointer,
2884 copy the address of the argument list to a register. */
2885 for (i = 0; i < num_actuals; i++)
2886 if (args[i].pass_on_stack)
2888 argblock = copy_addr_to_reg (argblock);
2893 compute_argument_addresses (args, argblock, num_actuals);
2895 /* If we push args individually in reverse order, perform stack alignment
2896 before the first push (the last arg). */
2897 if (PUSH_ARGS_REVERSED && argblock == 0
2898 && adjusted_args_size.constant != unadjusted_args_size)
2900 /* When the stack adjustment is pending, we get better code
2901 by combining the adjustments. */
2902 if (pending_stack_adjust
2903 && ! (flags & ECF_LIBCALL_BLOCK)
2904 && ! inhibit_defer_pop)
2906 pending_stack_adjust
2907 = (combine_pending_stack_adjustment_and_call
2908 (unadjusted_args_size,
2909 &adjusted_args_size,
2910 preferred_unit_stack_boundary));
2911 do_pending_stack_adjust ();
2913 else if (argblock == 0)
2914 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2915 - unadjusted_args_size));
2917 /* Now that the stack is properly aligned, pops can't safely
2918 be deferred during the evaluation of the arguments. */
2921 funexp = rtx_for_function_call (fndecl, addr);
2923 /* Figure out the register where the value, if any, will come back. */
2925 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2926 && ! structure_value_addr)
2928 if (pcc_struct_value)
2929 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2930 fndecl, (pass == 0));
2932 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2935 /* Precompute all register parameters. It isn't safe to compute anything
2936 once we have started filling any specific hard regs. */
2937 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2939 #ifdef REG_PARM_STACK_SPACE
2940 /* Save the fixed argument area if it's part of the caller's frame and
2941 is clobbered by argument setup for this call. */
2942 if (ACCUMULATE_OUTGOING_ARGS && pass)
2943 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2944 &low_to_save, &high_to_save);
2947 /* Now store (and compute if necessary) all non-register parms.
2948 These come before register parms, since they can require block-moves,
2949 which could clobber the registers used for register parms.
2950 Parms which have partial registers are not stored here,
2951 but we do preallocate space here if they want that. */
2953 for (i = 0; i < num_actuals; i++)
2954 if (args[i].reg == 0 || args[i].pass_on_stack)
2956 rtx before_arg = get_last_insn ();
2958 if (store_one_arg (&args[i], argblock, flags,
2959 adjusted_args_size.var != 0,
2960 reg_parm_stack_space)
2962 && check_sibcall_argument_overlap (before_arg,
2964 sibcall_failure = 1;
2967 /* If we have a parm that is passed in registers but not in memory
2968 and whose alignment does not permit a direct copy into registers,
2969 make a group of pseudos that correspond to each register that we
2971 if (STRICT_ALIGNMENT)
2972 store_unaligned_arguments_into_pseudos (args, num_actuals);
2974 /* Now store any partially-in-registers parm.
2975 This is the last place a block-move can happen. */
2977 for (i = 0; i < num_actuals; i++)
2978 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2980 rtx before_arg = get_last_insn ();
2982 if (store_one_arg (&args[i], argblock, flags,
2983 adjusted_args_size.var != 0,
2984 reg_parm_stack_space)
2986 && check_sibcall_argument_overlap (before_arg,
2988 sibcall_failure = 1;
2991 /* If we pushed args in forward order, perform stack alignment
2992 after pushing the last arg. */
2993 if (!PUSH_ARGS_REVERSED && argblock == 0)
2994 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2995 - unadjusted_args_size));
2997 /* If register arguments require space on the stack and stack space
2998 was not preallocated, allocate stack space here for arguments
2999 passed in registers. */
3000 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3001 if (!ACCUMULATE_OUTGOING_ARGS
3002 && must_preallocate == 0 && reg_parm_stack_space > 0)
3003 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3006 /* Pass the function the address in which to return a
3008 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3010 emit_move_insn (struct_value_rtx,
3012 force_operand (structure_value_addr,
3015 if (GET_CODE (struct_value_rtx) == REG)
3016 use_reg (&call_fusage, struct_value_rtx);
3019 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3020 reg_parm_seen, pass == 0);
3022 load_register_parameters (args, num_actuals, &call_fusage, flags,
3023 pass == 0, &sibcall_failure);
3025 /* Perform postincrements before actually calling the function. */
3028 /* Save a pointer to the last insn before the call, so that we can
3029 later safely search backwards to find the CALL_INSN. */
3030 before_call = get_last_insn ();
3032 /* Set up next argument register. For sibling calls on machines
3033 with register windows this should be the incoming register. */
3034 #ifdef FUNCTION_INCOMING_ARG
3036 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3040 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3043 /* All arguments and registers used for the call must be set up by
3046 /* Stack must be properly aligned now. */
3047 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3050 /* Generate the actual call instruction. */
3051 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3052 adjusted_args_size.constant, struct_value_size,
3053 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3054 flags, & args_so_far);
3056 /* If call is cse'able, make appropriate pair of reg-notes around it.
3057 Test valreg so we don't crash; may safely ignore `const'
3058 if return type is void. Disable for PARALLEL return values, because
3059 we have no way to move such values into a pseudo register. */
3060 if (pass && (flags & ECF_LIBCALL_BLOCK))
3064 if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3066 insns = get_insns ();
3073 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3075 /* Mark the return value as a pointer if needed. */
3076 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3077 mark_reg_pointer (temp,
3078 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3080 /* Construct an "equal form" for the value which mentions all the
3081 arguments in order as well as the function name. */
3082 for (i = 0; i < num_actuals; i++)
3083 note = gen_rtx_EXPR_LIST (VOIDmode,
3084 args[i].initial_value, note);
3085 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3087 insns = get_insns ();
3090 if (flags & ECF_PURE)
3091 note = gen_rtx_EXPR_LIST (VOIDmode,
3092 gen_rtx_USE (VOIDmode,
3093 gen_rtx_MEM (BLKmode,
3094 gen_rtx_SCRATCH (VOIDmode))),
3097 emit_libcall_block (insns, temp, valreg, note);
3102 else if (pass && (flags & ECF_MALLOC))
3104 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3107 /* The return value from a malloc-like function is a pointer. */
3108 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3109 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3111 emit_move_insn (temp, valreg);
3113 /* The return value from a malloc-like function can not alias
3115 last = get_last_insn ();
3117 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3119 /* Write out the sequence. */
3120 insns = get_insns ();
3126 /* For calls to `setjmp', etc., inform flow.c it should complain
3127 if nonvolatile values are live. For functions that cannot return,
3128 inform flow that control does not fall through. */
3130 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3132 /* The barrier must be emitted
3133 immediately after the CALL_INSN. Some ports emit more
3134 than just a CALL_INSN above, so we must search for it here. */
3136 rtx last = get_last_insn ();
3137 while (GET_CODE (last) != CALL_INSN)
3139 last = PREV_INSN (last);
3140 /* There was no CALL_INSN? */
3141 if (last == before_call)
3145 emit_barrier_after (last);
3148 if (flags & ECF_LONGJMP)
3149 current_function_calls_longjmp = 1;
3151 /* If value type not void, return an rtx for the value. */
3153 /* If there are cleanups to be called, don't use a hard reg as target.
3154 We need to double check this and see if it matters anymore. */
3155 if (any_pending_cleanups (1))
3157 if (target && REG_P (target)
3158 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3160 sibcall_failure = 1;
3163 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3165 target = const0_rtx;
3166 else if (structure_value_addr)
3168 if (target == 0 || GET_CODE (target) != MEM)
3171 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3172 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3173 structure_value_addr));
3174 set_mem_attributes (target, exp, 1);
3177 else if (pcc_struct_value)
3179 /* This is the special C++ case where we need to
3180 know what the true target was. We take care to
3181 never use this value more than once in one expression. */
3182 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3183 copy_to_reg (valreg));
3184 set_mem_attributes (target, exp, 1);
3186 /* Handle calls that return values in multiple non-contiguous locations.
3187 The Irix 6 ABI has examples of this. */
3188 else if (GET_CODE (valreg) == PARALLEL)
3192 /* This will only be assigned once, so it can be readonly. */
3193 tree nt = build_qualified_type (TREE_TYPE (exp),
3194 (TYPE_QUALS (TREE_TYPE (exp))
3195 | TYPE_QUAL_CONST));
3197 target = assign_temp (nt, 0, 1, 1);
3198 preserve_temp_slots (target);
3201 if (! rtx_equal_p (target, valreg))
3202 emit_group_store (target, valreg,
3203 int_size_in_bytes (TREE_TYPE (exp)));
3205 /* We can not support sibling calls for this case. */
3206 sibcall_failure = 1;
3209 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3210 && GET_MODE (target) == GET_MODE (valreg))
3212 /* TARGET and VALREG cannot be equal at this point because the
3213 latter would not have REG_FUNCTION_VALUE_P true, while the
3214 former would if it were referring to the same register.
3216 If they refer to the same register, this move will be a no-op,
3217 except when function inlining is being done. */
3218 emit_move_insn (target, valreg);
3220 /* If we are setting a MEM, this code must be executed. Since it is
3221 emitted after the call insn, sibcall optimization cannot be
3222 performed in that case. */
3223 if (GET_CODE (target) == MEM)
3224 sibcall_failure = 1;
3226 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3228 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3230 /* We can not support sibling calls for this case. */
3231 sibcall_failure = 1;
3234 target = copy_to_reg (valreg);
3236 #ifdef PROMOTE_FUNCTION_RETURN
3237 /* If we promoted this return value, make the proper SUBREG. TARGET
3238 might be const0_rtx here, so be careful. */
3239 if (GET_CODE (target) == REG
3240 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3241 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3243 tree type = TREE_TYPE (exp);
3244 int unsignedp = TREE_UNSIGNED (type);
3247 /* If we don't promote as expected, something is wrong. */
3248 if (GET_MODE (target)
3249 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3252 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3253 && GET_MODE_SIZE (GET_MODE (target))
3254 > GET_MODE_SIZE (TYPE_MODE (type)))
3256 offset = GET_MODE_SIZE (GET_MODE (target))
3257 - GET_MODE_SIZE (TYPE_MODE (type));
3258 if (! BYTES_BIG_ENDIAN)
3259 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3260 else if (! WORDS_BIG_ENDIAN)
3261 offset %= UNITS_PER_WORD;
3263 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3264 SUBREG_PROMOTED_VAR_P (target) = 1;
3265 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3269 /* If size of args is variable or this was a constructor call for a stack
3270 argument, restore saved stack-pointer value. */
3272 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3274 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3275 stack_pointer_delta = old_stack_pointer_delta;
3276 pending_stack_adjust = old_pending_adj;
3277 stack_arg_under_construction = old_stack_arg_under_construction;
3278 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3279 stack_usage_map = initial_stack_usage_map;
3280 sibcall_failure = 1;
3282 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3284 #ifdef REG_PARM_STACK_SPACE
3286 restore_fixed_argument_area (save_area, argblock,
3287 high_to_save, low_to_save);
3290 /* If we saved any argument areas, restore them. */
3291 for (i = 0; i < num_actuals; i++)
3292 if (args[i].save_area)
3294 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3296 = gen_rtx_MEM (save_mode,
3297 memory_address (save_mode,
3298 XEXP (args[i].stack_slot, 0)));
3300 if (save_mode != BLKmode)
3301 emit_move_insn (stack_area, args[i].save_area);
3303 emit_block_move (stack_area, args[i].save_area,
3304 GEN_INT (args[i].locate.size.constant),
3305 BLOCK_OP_CALL_PARM);
3308 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3309 stack_usage_map = initial_stack_usage_map;
3312 /* If this was alloca, record the new stack level for nonlocal gotos.
3313 Check for the handler slots since we might not have a save area
3314 for non-local gotos. */
3316 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3317 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3319 /* Free up storage we no longer need. */
3320 for (i = 0; i < num_actuals; ++i)
3321 if (args[i].aligned_regs)
3322 free (args[i].aligned_regs);
3326 /* Undo the fake expand_start_target_temps we did earlier. If
3327 there had been any cleanups created, we've already set
3329 expand_end_target_temps ();
3332 /* If this function is returning into a memory location marked as
3333 readonly, it means it is initializing that location. We normally treat
3334 functions as not clobbering such locations, so we need to specify that
3335 this one does. We do this by adding the appropriate CLOBBER to the
3336 CALL_INSN function usage list. This cannot be done by emitting a
3337 standalone CLOBBER after the call because the latter would be ignored
3338 by at least the delay slot scheduling pass. We do this now instead of
3339 adding to call_fusage before the call to emit_call_1 because TARGET
3340 may be modified in the meantime. */
3341 if (structure_value_addr != 0 && target != 0
3342 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3343 add_function_usage_to
3345 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3348 insns = get_insns ();
3353 tail_call_insns = insns;
3355 /* Restore the pending stack adjustment now that we have
3356 finished generating the sibling call sequence. */
3358 pending_stack_adjust = save_pending_stack_adjust;
3359 stack_pointer_delta = save_stack_pointer_delta;
3361 /* Prepare arg structure for next iteration. */
3362 for (i = 0; i < num_actuals; i++)
3365 args[i].aligned_regs = 0;
3369 sbitmap_free (stored_args_map);
3373 normal_call_insns = insns;
3375 /* Verify that we've deallocated all the stack we used. */
3376 if (old_stack_allocated !=
3377 stack_pointer_delta - pending_stack_adjust)
3381 /* If something prevents making this a sibling call,
3382 zero out the sequence. */
3383 if (sibcall_failure)
3384 tail_call_insns = NULL_RTX;
3387 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3388 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3389 can happen if the arguments to this function call an inline
3390 function who's expansion contains another CALL_PLACEHOLDER.
3392 If there are any C_Ps in any of these sequences, replace them
3393 with their normal call. */
3395 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3396 if (GET_CODE (insn) == CALL_INSN
3397 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3398 replace_call_placeholder (insn, sibcall_use_normal);
3400 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3401 if (GET_CODE (insn) == CALL_INSN
3402 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3403 replace_call_placeholder (insn, sibcall_use_normal);
3405 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3406 if (GET_CODE (insn) == CALL_INSN
3407 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3408 replace_call_placeholder (insn, sibcall_use_normal);
3410 /* If this was a potential tail recursion site, then emit a
3411 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3412 One of them will be selected later. */
3413 if (tail_recursion_insns || tail_call_insns)
3415 /* The tail recursion label must be kept around. We could expose
3416 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3417 and makes determining true tail recursion sites difficult.
3419 So we set LABEL_PRESERVE_P here, then clear it when we select
3420 one of the call sequences after rtl generation is complete. */
3421 if (tail_recursion_insns)
3422 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3423 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3425 tail_recursion_insns,
3426 tail_recursion_label));
3429 emit_insn (normal_call_insns);
3431 currently_expanding_call--;
3433 /* If this function returns with the stack pointer depressed, ensure
3434 this block saves and restores the stack pointer, show it was
3435 changed, and adjust for any outgoing arg space. */
3436 if (flags & ECF_SP_DEPRESSED)
3438 clear_pending_stack_adjust ();
3439 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3440 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3441 save_stack_pointer ();
3447 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3448 The RETVAL parameter specifies whether return value needs to be saved, other
3449 parameters are documented in the emit_library_call function below. */
3452 emit_library_call_value_1 (retval, orgfun, value, fn_type, outmode, nargs, p)
3456 enum libcall_type fn_type;
3457 enum machine_mode outmode;
3461 /* Total size in bytes of all the stack-parms scanned so far. */
3462 struct args_size args_size;
3463 /* Size of arguments before any adjustments (such as rounding). */
3464 struct args_size original_args_size;
3470 CUMULATIVE_ARGS args_so_far;
3474 enum machine_mode mode;
3477 struct locate_and_pad_arg_data locate;
3481 int old_inhibit_defer_pop = inhibit_defer_pop;
3482 rtx call_fusage = 0;
3485 int pcc_struct_value = 0;
3486 int struct_value_size = 0;
3488 int reg_parm_stack_space = 0;
3491 tree tfom; /* type_for_mode (outmode, 0) */
3493 #ifdef REG_PARM_STACK_SPACE
3494 /* Define the boundary of the register parm stack space that needs to be
3496 int low_to_save, high_to_save;
3497 rtx save_area = 0; /* Place that it is saved. */
3500 /* Size of the stack reserved for parameter registers. */
3501 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3502 char *initial_stack_usage_map = stack_usage_map;
3504 #ifdef REG_PARM_STACK_SPACE
3505 #ifdef MAYBE_REG_PARM_STACK_SPACE
3506 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3508 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3512 /* By default, library functions can not throw. */
3513 flags = ECF_NOTHROW;
3525 case LCT_CONST_MAKE_BLOCK:
3526 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3528 case LCT_PURE_MAKE_BLOCK:
3529 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3532 flags |= ECF_NORETURN;
3535 flags = ECF_NORETURN;
3537 case LCT_ALWAYS_RETURN:
3538 flags = ECF_ALWAYS_RETURN;
3540 case LCT_RETURNS_TWICE:
3541 flags = ECF_RETURNS_TWICE;
3546 /* Ensure current function's preferred stack boundary is at least
3548 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3549 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3551 /* If this kind of value comes back in memory,
3552 decide where in memory it should come back. */
3553 if (outmode != VOIDmode)
3555 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3556 if (aggregate_value_p (tfom))
3558 #ifdef PCC_STATIC_STRUCT_RETURN
3560 = hard_function_value (build_pointer_type (tfom), 0, 0);
3561 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3562 pcc_struct_value = 1;
3564 value = gen_reg_rtx (outmode);
3565 #else /* not PCC_STATIC_STRUCT_RETURN */
3566 struct_value_size = GET_MODE_SIZE (outmode);
3567 if (value != 0 && GET_CODE (value) == MEM)
3570 mem_value = assign_temp (tfom, 0, 1, 1);
3572 /* This call returns a big structure. */
3573 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3577 tfom = void_type_node;
3579 /* ??? Unfinished: must pass the memory address as an argument. */
3581 /* Copy all the libcall-arguments out of the varargs data
3582 and into a vector ARGVEC.
3584 Compute how to pass each argument. We only support a very small subset
3585 of the full argument passing conventions to limit complexity here since
3586 library functions shouldn't have many args. */
3588 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3589 memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3591 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3592 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3594 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3597 args_size.constant = 0;
3602 /* Now we are about to start emitting insns that can be deleted
3603 if a libcall is deleted. */
3604 if (flags & ECF_LIBCALL_BLOCK)
3609 /* If there's a structure value address to be passed,
3610 either pass it in the special place, or pass it as an extra argument. */
3611 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3613 rtx addr = XEXP (mem_value, 0);
3616 /* Make sure it is a reasonable operand for a move or push insn. */
3617 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3618 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3619 addr = force_operand (addr, NULL_RTX);
3621 argvec[count].value = addr;
3622 argvec[count].mode = Pmode;
3623 argvec[count].partial = 0;
3625 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3626 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3627 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3631 locate_and_pad_parm (Pmode, NULL_TREE,
3632 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3635 argvec[count].reg != 0,
3637 0, NULL_TREE, &args_size, &argvec[count].locate);
3639 if (argvec[count].reg == 0 || argvec[count].partial != 0
3640 || reg_parm_stack_space > 0)
3641 args_size.constant += argvec[count].locate.size.constant;
3643 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3648 for (; count < nargs; count++)
3650 rtx val = va_arg (p, rtx);
3651 enum machine_mode mode = va_arg (p, enum machine_mode);
3653 /* We cannot convert the arg value to the mode the library wants here;
3654 must do it earlier where we know the signedness of the arg. */
3656 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3659 /* On some machines, there's no way to pass a float to a library fcn.
3660 Pass it as a double instead. */
3661 #ifdef LIBGCC_NEEDS_DOUBLE
3662 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3663 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
3666 /* There's no need to call protect_from_queue, because
3667 either emit_move_insn or emit_push_insn will do that. */
3669 /* Make sure it is a reasonable operand for a move or push insn. */
3670 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3671 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3672 val = force_operand (val, NULL_RTX);
3674 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3675 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3679 #ifdef FUNCTION_ARG_CALLEE_COPIES
3680 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3685 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3686 functions, so we have to pretend this isn't such a function. */
3687 if (flags & ECF_LIBCALL_BLOCK)
3689 rtx insns = get_insns ();
3693 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3695 /* If this was a CONST function, it is now PURE since
3696 it now reads memory. */
3697 if (flags & ECF_CONST)
3699 flags &= ~ECF_CONST;
3703 if (GET_MODE (val) == MEM && ! must_copy)
3707 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3709 emit_move_insn (slot, val);
3713 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3716 = gen_rtx_MEM (mode,
3717 expand_expr (build1 (ADDR_EXPR,
3718 build_pointer_type (type),
3719 make_tree (type, val)),
3720 NULL_RTX, VOIDmode, 0));
3723 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3724 gen_rtx_USE (VOIDmode, slot),
3727 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3728 gen_rtx_CLOBBER (VOIDmode,
3733 val = force_operand (XEXP (slot, 0), NULL_RTX);
3737 argvec[count].value = val;
3738 argvec[count].mode = mode;
3740 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3742 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3743 argvec[count].partial
3744 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3746 argvec[count].partial = 0;
3749 locate_and_pad_parm (mode, NULL_TREE,
3750 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3753 argvec[count].reg != 0,
3755 argvec[count].partial,
3756 NULL_TREE, &args_size, &argvec[count].locate);
3758 if (argvec[count].locate.size.var)
3761 if (argvec[count].reg == 0 || argvec[count].partial != 0
3762 || reg_parm_stack_space > 0)
3763 args_size.constant += argvec[count].locate.size.constant;
3765 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3768 #ifdef FINAL_REG_PARM_STACK_SPACE
3769 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3772 /* If this machine requires an external definition for library
3773 functions, write one out. */
3774 assemble_external_libcall (fun);
3776 original_args_size = args_size;
3777 args_size.constant = (((args_size.constant
3778 + stack_pointer_delta
3782 - stack_pointer_delta);
3784 args_size.constant = MAX (args_size.constant,
3785 reg_parm_stack_space);
3787 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3788 args_size.constant -= reg_parm_stack_space;
3791 if (args_size.constant > current_function_outgoing_args_size)
3792 current_function_outgoing_args_size = args_size.constant;
3794 if (ACCUMULATE_OUTGOING_ARGS)
3796 /* Since the stack pointer will never be pushed, it is possible for
3797 the evaluation of a parm to clobber something we have already
3798 written to the stack. Since most function calls on RISC machines
3799 do not use the stack, this is uncommon, but must work correctly.
3801 Therefore, we save any area of the stack that was already written
3802 and that we are using. Here we set up to do this by making a new
3803 stack usage map from the old one.
3805 Another approach might be to try to reorder the argument
3806 evaluations to avoid this conflicting stack usage. */
3808 needed = args_size.constant;
3810 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3811 /* Since we will be writing into the entire argument area, the
3812 map must be allocated for its entire size, not just the part that
3813 is the responsibility of the caller. */
3814 needed += reg_parm_stack_space;
3817 #ifdef ARGS_GROW_DOWNWARD
3818 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3821 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3824 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3826 if (initial_highest_arg_in_use)
3827 memcpy (stack_usage_map, initial_stack_usage_map,
3828 initial_highest_arg_in_use);
3830 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3831 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3832 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3835 /* We must be careful to use virtual regs before they're instantiated,
3836 and real regs afterwards. Loop optimization, for example, can create
3837 new libcalls after we've instantiated the virtual regs, and if we
3838 use virtuals anyway, they won't match the rtl patterns. */
3840 if (virtuals_instantiated)
3841 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3843 argblock = virtual_outgoing_args_rtx;
3848 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3851 /* If we push args individually in reverse order, perform stack alignment
3852 before the first push (the last arg). */
3853 if (argblock == 0 && PUSH_ARGS_REVERSED)
3854 anti_adjust_stack (GEN_INT (args_size.constant
3855 - original_args_size.constant));
3857 if (PUSH_ARGS_REVERSED)
3868 #ifdef REG_PARM_STACK_SPACE
3869 if (ACCUMULATE_OUTGOING_ARGS)
3871 /* The argument list is the property of the called routine and it
3872 may clobber it. If the fixed area has been used for previous
3873 parameters, we must save and restore it. */
3874 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3875 &low_to_save, &high_to_save);
3879 /* Push the args that need to be pushed. */
3881 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3882 are to be pushed. */
3883 for (count = 0; count < nargs; count++, argnum += inc)
3885 enum machine_mode mode = argvec[argnum].mode;
3886 rtx val = argvec[argnum].value;
3887 rtx reg = argvec[argnum].reg;
3888 int partial = argvec[argnum].partial;
3889 int lower_bound = 0, upper_bound = 0, i;
3891 if (! (reg != 0 && partial == 0))
3893 if (ACCUMULATE_OUTGOING_ARGS)
3895 /* If this is being stored into a pre-allocated, fixed-size,
3896 stack area, save any previous data at that location. */
3898 #ifdef ARGS_GROW_DOWNWARD
3899 /* stack_slot is negative, but we want to index stack_usage_map
3900 with positive values. */
3901 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3902 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3904 lower_bound = argvec[argnum].locate.offset.constant;
3905 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3909 /* Don't worry about things in the fixed argument area;
3910 it has already been saved. */
3911 if (i < reg_parm_stack_space)
3912 i = reg_parm_stack_space;
3913 while (i < upper_bound && stack_usage_map[i] == 0)
3916 if (i < upper_bound)
3918 /* We need to make a save area. */
3920 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3921 enum machine_mode save_mode
3922 = mode_for_size (size, MODE_INT, 1);
3924 = plus_constant (argblock,
3925 argvec[argnum].locate.offset.constant);
3927 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3928 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3930 emit_move_insn (argvec[argnum].save_area, stack_area);
3934 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3935 partial, reg, 0, argblock,
3936 GEN_INT (argvec[argnum].locate.offset.constant),
3937 reg_parm_stack_space,
3938 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3940 /* Now mark the segment we just used. */
3941 if (ACCUMULATE_OUTGOING_ARGS)
3942 for (i = lower_bound; i < upper_bound; i++)
3943 stack_usage_map[i] = 1;
3949 /* If we pushed args in forward order, perform stack alignment
3950 after pushing the last arg. */
3951 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3952 anti_adjust_stack (GEN_INT (args_size.constant
3953 - original_args_size.constant));
3955 if (PUSH_ARGS_REVERSED)
3960 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
3962 /* Now load any reg parms into their regs. */
3964 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3965 are to be pushed. */
3966 for (count = 0; count < nargs; count++, argnum += inc)
3968 rtx val = argvec[argnum].value;
3969 rtx reg = argvec[argnum].reg;
3970 int partial = argvec[argnum].partial;
3972 /* Handle calls that pass values in multiple non-contiguous
3973 locations. The PA64 has examples of this for library calls. */
3974 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3975 emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
3976 else if (reg != 0 && partial == 0)
3977 emit_move_insn (reg, val);
3982 /* Any regs containing parms remain in use through the call. */
3983 for (count = 0; count < nargs; count++)
3985 rtx reg = argvec[count].reg;
3986 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3987 use_group_regs (&call_fusage, reg);
3989 use_reg (&call_fusage, reg);
3992 /* Pass the function the address in which to return a structure value. */
3993 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
3995 emit_move_insn (struct_value_rtx,
3997 force_operand (XEXP (mem_value, 0),
3999 if (GET_CODE (struct_value_rtx) == REG)
4000 use_reg (&call_fusage, struct_value_rtx);
4003 /* Don't allow popping to be deferred, since then
4004 cse'ing of library calls could delete a call and leave the pop. */
4006 valreg = (mem_value == 0 && outmode != VOIDmode
4007 ? hard_libcall_value (outmode) : NULL_RTX);
4009 /* Stack must be properly aligned now. */
4010 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4013 before_call = get_last_insn ();
4015 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4016 will set inhibit_defer_pop to that value. */
4017 /* The return type is needed to decide how many bytes the function pops.
4018 Signedness plays no role in that, so for simplicity, we pretend it's
4019 always signed. We also assume that the list of arguments passed has
4020 no impact, so we pretend it is unknown. */
4023 get_identifier (XSTR (orgfun, 0)),
4024 build_function_type (tfom, NULL_TREE),
4025 original_args_size.constant, args_size.constant,
4027 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4029 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4031 /* For calls to `setjmp', etc., inform flow.c it should complain
4032 if nonvolatile values are live. For functions that cannot return,
4033 inform flow that control does not fall through. */
4035 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4037 /* The barrier note must be emitted
4038 immediately after the CALL_INSN. Some ports emit more than
4039 just a CALL_INSN above, so we must search for it here. */
4041 rtx last = get_last_insn ();
4042 while (GET_CODE (last) != CALL_INSN)
4044 last = PREV_INSN (last);
4045 /* There was no CALL_INSN? */
4046 if (last == before_call)
4050 emit_barrier_after (last);
4053 /* Now restore inhibit_defer_pop to its actual original value. */
4056 /* If call is cse'able, make appropriate pair of reg-notes around it.
4057 Test valreg so we don't crash; may safely ignore `const'
4058 if return type is void. Disable for PARALLEL return values, because
4059 we have no way to move such values into a pseudo register. */
4060 if (flags & ECF_LIBCALL_BLOCK)
4066 insns = get_insns ();
4076 if (GET_CODE (valreg) == PARALLEL)
4078 temp = gen_reg_rtx (outmode);
4079 emit_group_store (temp, valreg, outmode);
4083 temp = gen_reg_rtx (GET_MODE (valreg));
4085 /* Construct an "equal form" for the value which mentions all the
4086 arguments in order as well as the function name. */
4087 for (i = 0; i < nargs; i++)
4088 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4089 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4091 insns = get_insns ();
4094 if (flags & ECF_PURE)
4095 note = gen_rtx_EXPR_LIST (VOIDmode,
4096 gen_rtx_USE (VOIDmode,
4097 gen_rtx_MEM (BLKmode,
4098 gen_rtx_SCRATCH (VOIDmode))),
4101 emit_libcall_block (insns, temp, valreg, note);
4108 /* Copy the value to the right place. */
4109 if (outmode != VOIDmode && retval)
4115 if (value != mem_value)
4116 emit_move_insn (value, mem_value);
4118 else if (GET_CODE (valreg) == PARALLEL)
4121 value = gen_reg_rtx (outmode);
4122 emit_group_store (value, valreg, outmode);
4124 else if (value != 0)
4125 emit_move_insn (value, valreg);
4130 if (ACCUMULATE_OUTGOING_ARGS)
4132 #ifdef REG_PARM_STACK_SPACE
4134 restore_fixed_argument_area (save_area, argblock,
4135 high_to_save, low_to_save);
4138 /* If we saved any argument areas, restore them. */
4139 for (count = 0; count < nargs; count++)
4140 if (argvec[count].save_area)
4142 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4143 rtx adr = plus_constant (argblock,
4144 argvec[count].locate.offset.constant);
4145 rtx stack_area = gen_rtx_MEM (save_mode,
4146 memory_address (save_mode, adr));
4148 emit_move_insn (stack_area, argvec[count].save_area);
4151 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4152 stack_usage_map = initial_stack_usage_map;
4159 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4160 (emitting the queue unless NO_QUEUE is nonzero),
4161 for a value of mode OUTMODE,
4162 with NARGS different arguments, passed as alternating rtx values
4163 and machine_modes to convert them to.
4164 The rtx values should have been passed through protect_from_queue already.
4166 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4167 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4168 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4169 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4170 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4171 or other LCT_ value for other types of library calls. */
4174 emit_library_call VPARAMS((rtx orgfun, enum libcall_type fn_type,
4175 enum machine_mode outmode, int nargs, ...))
4178 VA_FIXEDARG (p, rtx, orgfun);
4179 VA_FIXEDARG (p, int, fn_type);
4180 VA_FIXEDARG (p, enum machine_mode, outmode);
4181 VA_FIXEDARG (p, int, nargs);
4183 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4188 /* Like emit_library_call except that an extra argument, VALUE,
4189 comes second and says where to store the result.
4190 (If VALUE is zero, this function chooses a convenient way
4191 to return the value.
4193 This function returns an rtx for where the value is to be found.
4194 If VALUE is nonzero, VALUE is returned. */
4197 emit_library_call_value VPARAMS((rtx orgfun, rtx value,
4198 enum libcall_type fn_type,
4199 enum machine_mode outmode, int nargs, ...))
4204 VA_FIXEDARG (p, rtx, orgfun);
4205 VA_FIXEDARG (p, rtx, value);
4206 VA_FIXEDARG (p, int, fn_type);
4207 VA_FIXEDARG (p, enum machine_mode, outmode);
4208 VA_FIXEDARG (p, int, nargs);
4210 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4218 /* Store a single argument for a function call
4219 into the register or memory area where it must be passed.
4220 *ARG describes the argument value and where to pass it.
4222 ARGBLOCK is the address of the stack-block for all the arguments,
4223 or 0 on a machine where arguments are pushed individually.
4225 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4226 so must be careful about how the stack is used.
4228 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4229 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4230 that we need not worry about saving and restoring the stack.
4232 FNDECL is the declaration of the function we are calling.
4234 Return nonzero if this arg should cause sibcall failure,
4238 store_one_arg (arg, argblock, flags, variable_size, reg_parm_stack_space)
4239 struct arg_data *arg;
4242 int variable_size ATTRIBUTE_UNUSED;
4243 int reg_parm_stack_space;
4245 tree pval = arg->tree_value;
4249 int i, lower_bound = 0, upper_bound = 0;
4250 int sibcall_failure = 0;
4252 if (TREE_CODE (pval) == ERROR_MARK)
4255 /* Push a new temporary level for any temporaries we make for
4259 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4261 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4262 save any previous data at that location. */
4263 if (argblock && ! variable_size && arg->stack)
4265 #ifdef ARGS_GROW_DOWNWARD
4266 /* stack_slot is negative, but we want to index stack_usage_map
4267 with positive values. */
4268 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4269 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4273 lower_bound = upper_bound - arg->locate.size.constant;
4275 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4276 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4280 upper_bound = lower_bound + arg->locate.size.constant;
4284 /* Don't worry about things in the fixed argument area;
4285 it has already been saved. */
4286 if (i < reg_parm_stack_space)
4287 i = reg_parm_stack_space;
4288 while (i < upper_bound && stack_usage_map[i] == 0)
4291 if (i < upper_bound)
4293 /* We need to make a save area. */
4294 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4295 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4296 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4297 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4299 if (save_mode == BLKmode)
4301 tree ot = TREE_TYPE (arg->tree_value);
4302 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4303 | TYPE_QUAL_CONST));
4305 arg->save_area = assign_temp (nt, 0, 1, 1);
4306 preserve_temp_slots (arg->save_area);
4307 emit_block_move (validize_mem (arg->save_area), stack_area,
4308 expr_size (arg->tree_value),
4309 BLOCK_OP_CALL_PARM);
4313 arg->save_area = gen_reg_rtx (save_mode);
4314 emit_move_insn (arg->save_area, stack_area);
4320 /* If this isn't going to be placed on both the stack and in registers,
4321 set up the register and number of words. */
4322 if (! arg->pass_on_stack)
4324 if (flags & ECF_SIBCALL)
4325 reg = arg->tail_call_reg;
4328 partial = arg->partial;
4331 if (reg != 0 && partial == 0)
4332 /* Being passed entirely in a register. We shouldn't be called in
4336 /* If this arg needs special alignment, don't load the registers
4338 if (arg->n_aligned_regs != 0)
4341 /* If this is being passed partially in a register, we can't evaluate
4342 it directly into its stack slot. Otherwise, we can. */
4343 if (arg->value == 0)
4345 /* stack_arg_under_construction is nonzero if a function argument is
4346 being evaluated directly into the outgoing argument list and
4347 expand_call must take special action to preserve the argument list
4348 if it is called recursively.
4350 For scalar function arguments stack_usage_map is sufficient to
4351 determine which stack slots must be saved and restored. Scalar
4352 arguments in general have pass_on_stack == 0.
4354 If this argument is initialized by a function which takes the
4355 address of the argument (a C++ constructor or a C function
4356 returning a BLKmode structure), then stack_usage_map is
4357 insufficient and expand_call must push the stack around the
4358 function call. Such arguments have pass_on_stack == 1.
4360 Note that it is always safe to set stack_arg_under_construction,
4361 but this generates suboptimal code if set when not needed. */
4363 if (arg->pass_on_stack)
4364 stack_arg_under_construction++;
4366 arg->value = expand_expr (pval,
4368 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4369 ? NULL_RTX : arg->stack,
4370 VOIDmode, EXPAND_STACK_PARM);
4372 /* If we are promoting object (or for any other reason) the mode
4373 doesn't agree, convert the mode. */
4375 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4376 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4377 arg->value, arg->unsignedp);
4379 if (arg->pass_on_stack)
4380 stack_arg_under_construction--;
4383 /* Don't allow anything left on stack from computation
4384 of argument to alloca. */
4385 if (flags & ECF_MAY_BE_ALLOCA)
4386 do_pending_stack_adjust ();
4388 if (arg->value == arg->stack)
4389 /* If the value is already in the stack slot, we are done. */
4391 else if (arg->mode != BLKmode)
4395 /* Argument is a scalar, not entirely passed in registers.
4396 (If part is passed in registers, arg->partial says how much
4397 and emit_push_insn will take care of putting it there.)
4399 Push it, and if its size is less than the
4400 amount of space allocated to it,
4401 also bump stack pointer by the additional space.
4402 Note that in C the default argument promotions
4403 will prevent such mismatches. */
4405 size = GET_MODE_SIZE (arg->mode);
4406 /* Compute how much space the push instruction will push.
4407 On many machines, pushing a byte will advance the stack
4408 pointer by a halfword. */
4409 #ifdef PUSH_ROUNDING
4410 size = PUSH_ROUNDING (size);
4414 /* Compute how much space the argument should get:
4415 round up to a multiple of the alignment for arguments. */
4416 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4417 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4418 / (PARM_BOUNDARY / BITS_PER_UNIT))
4419 * (PARM_BOUNDARY / BITS_PER_UNIT));
4421 /* This isn't already where we want it on the stack, so put it there.
4422 This can either be done with push or copy insns. */
4423 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4424 PARM_BOUNDARY, partial, reg, used - size, argblock,
4425 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4426 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4428 /* Unless this is a partially-in-register argument, the argument is now
4431 arg->value = arg->stack;
4435 /* BLKmode, at least partly to be pushed. */
4437 unsigned int parm_align;
4441 /* Pushing a nonscalar.
4442 If part is passed in registers, PARTIAL says how much
4443 and emit_push_insn will take care of putting it there. */
4445 /* Round its size up to a multiple
4446 of the allocation unit for arguments. */
4448 if (arg->locate.size.var != 0)
4451 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4455 /* PUSH_ROUNDING has no effect on us, because
4456 emit_push_insn for BLKmode is careful to avoid it. */
4457 excess = (arg->locate.size.constant
4458 - int_size_in_bytes (TREE_TYPE (pval))
4459 + partial * UNITS_PER_WORD);
4460 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4461 NULL_RTX, TYPE_MODE (sizetype), 0);
4464 /* Some types will require stricter alignment, which will be
4465 provided for elsewhere in argument layout. */
4466 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4468 /* When an argument is padded down, the block is aligned to
4469 PARM_BOUNDARY, but the actual argument isn't. */
4470 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4472 if (arg->locate.size.var)
4473 parm_align = BITS_PER_UNIT;
4476 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4477 parm_align = MIN (parm_align, excess_align);
4481 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4483 /* emit_push_insn might not work properly if arg->value and
4484 argblock + arg->locate.offset areas overlap. */
4488 if (XEXP (x, 0) == current_function_internal_arg_pointer
4489 || (GET_CODE (XEXP (x, 0)) == PLUS
4490 && XEXP (XEXP (x, 0), 0) ==
4491 current_function_internal_arg_pointer
4492 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4494 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4495 i = INTVAL (XEXP (XEXP (x, 0), 1));
4497 /* expand_call should ensure this */
4498 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4501 if (arg->locate.offset.constant > i)
4503 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4504 sibcall_failure = 1;
4506 else if (arg->locate.offset.constant < i)
4508 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4509 sibcall_failure = 1;
4514 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4515 parm_align, partial, reg, excess, argblock,
4516 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4517 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4519 /* Unless this is a partially-in-register argument, the argument is now
4522 ??? Unlike the case above, in which we want the actual
4523 address of the data, so that we can load it directly into a
4524 register, here we want the address of the stack slot, so that
4525 it's properly aligned for word-by-word copying or something
4526 like that. It's not clear that this is always correct. */
4528 arg->value = arg->stack_slot;
4531 /* Mark all slots this store used. */
4532 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4533 && argblock && ! variable_size && arg->stack)
4534 for (i = lower_bound; i < upper_bound; i++)
4535 stack_usage_map[i] = 1;
4537 /* Once we have pushed something, pops can't safely
4538 be deferred during the rest of the arguments. */
4541 /* ANSI doesn't require a sequence point here,
4542 but PCC has one, so this will avoid some problems. */
4545 /* Free any temporary slots made in processing this argument. Show
4546 that we might have taken the address of something and pushed that
4548 preserve_temp_slots (NULL_RTX);
4552 return sibcall_failure;
4555 /* Nonzero if we do not know how to pass TYPE solely in registers.
4556 We cannot do so in the following cases:
4558 - if the type has variable size
4559 - if the type is marked as addressable (it is required to be constructed
4561 - if the padding and mode of the type is such that a copy into a register
4562 would put it into the wrong part of the register.
4564 Which padding can't be supported depends on the byte endianness.
4566 A value in a register is implicitly padded at the most significant end.
4567 On a big-endian machine, that is the lower end in memory.
4568 So a value padded in memory at the upper end can't go in a register.
4569 For a little-endian machine, the reverse is true. */
4572 default_must_pass_in_stack (mode, type)
4573 enum machine_mode mode;
4579 /* If the type has variable size... */
4580 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4583 /* If the type is marked as addressable (it is required
4584 to be constructed into the stack)... */
4585 if (TREE_ADDRESSABLE (type))
4588 /* If the padding and mode of the type is such that a copy into
4589 a register would put it into the wrong part of the register. */
4591 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4592 && (FUNCTION_ARG_PADDING (mode, type)
4593 == (BYTES_BIG_ENDIAN ? upward : downward)))