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"
39 #include "langhooks.h"
44 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
45 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
47 /* Data structure and subroutines used within expand_call. */
51 /* Tree node for this argument. */
53 /* Mode for value; TYPE_MODE unless promoted. */
54 enum machine_mode mode;
55 /* Current RTL value for argument, or 0 if it isn't precomputed. */
57 /* Initially-compute RTL value for argument; only for const functions. */
59 /* Register to pass this argument in, 0 if passed on stack, or an
60 PARALLEL if the arg is to be copied into multiple non-contiguous
63 /* Register to pass this argument in when generating tail call sequence.
64 This is not the same register as for normal calls on machines with
67 /* If REG was promoted from the actual mode of the argument expression,
68 indicates whether the promotion is sign- or zero-extended. */
70 /* Number of registers to use. 0 means put the whole arg in registers.
71 Also 0 if not passed in registers. */
73 /* Nonzero if argument must be passed on stack.
74 Note that some arguments may be passed on the stack
75 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
76 pass_on_stack identifies arguments that *cannot* go in registers. */
78 /* Some fields packaged up for locate_and_pad_parm. */
79 struct locate_and_pad_arg_data locate;
80 /* Location on the stack at which parameter should be stored. The store
81 has already been done if STACK == VALUE. */
83 /* Location on the stack of the start of this argument slot. This can
84 differ from STACK if this arg pads downward. This location is known
85 to be aligned to FUNCTION_ARG_BOUNDARY. */
87 /* Place that this stack area has been saved, if needed. */
89 /* If an argument's alignment does not permit direct copying into registers,
90 copy in smaller-sized pieces into pseudos. These are stored in a
91 block pointed to by this field. The next field says how many
92 word-sized pseudos we made. */
97 /* A vector of one char per byte of stack space. A byte if nonzero if
98 the corresponding stack location has been used.
99 This vector is used to prevent a function call within an argument from
100 clobbering any stack already set up. */
101 static char *stack_usage_map;
103 /* Size of STACK_USAGE_MAP. */
104 static int highest_outgoing_arg_in_use;
106 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
107 stack location's tail call argument has been already stored into the stack.
108 This bitmap is used to prevent sibling call optimization if function tries
109 to use parent's incoming argument slots when they have been already
110 overwritten with tail call arguments. */
111 static sbitmap stored_args_map;
113 /* stack_arg_under_construction is nonzero when an argument may be
114 initialized with a constructor call (including a C function that
115 returns a BLKmode struct) and expand_call must take special action
116 to make sure the object being constructed does not overlap the
117 argument list for the constructor call. */
118 int stack_arg_under_construction;
120 static int calls_function (tree, int);
121 static int calls_function_1 (tree, int);
123 static void emit_call_1 (rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
124 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
126 static void precompute_register_parameters (int, struct arg_data *, int *);
127 static int store_one_arg (struct arg_data *, rtx, int, int, int);
128 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
129 static int finalize_must_preallocate (int, int, struct arg_data *,
131 static void precompute_arguments (int, int, struct arg_data *);
132 static int compute_argument_block_size (int, struct args_size *, int);
133 static void initialize_argument_information (int, struct arg_data *,
134 struct args_size *, int, tree,
135 tree, CUMULATIVE_ARGS *, int,
136 rtx *, int *, int *, int *);
137 static void compute_argument_addresses (struct arg_data *, rtx, int);
138 static rtx rtx_for_function_call (tree, tree);
139 static void load_register_parameters (struct arg_data *, int, rtx *, int,
141 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
142 enum machine_mode, int, va_list);
143 static int special_function_p (tree, int);
144 static rtx try_to_integrate (tree, tree, rtx, int, tree, rtx);
145 static int check_sibcall_argument_overlap_1 (rtx);
146 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
148 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
150 static tree fix_unsafe_tree (tree);
151 static bool shift_returned_value (tree, rtx *);
153 #ifdef REG_PARM_STACK_SPACE
154 static rtx save_fixed_argument_area (int, rtx, int *, int *);
155 static void restore_fixed_argument_area (rtx, rtx, int, int);
158 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
161 If WHICH is 0, return 1 if EXP contains a call to any function.
162 Actually, we only need return 1 if evaluating EXP would require pushing
163 arguments on the stack, but that is too difficult to compute, so we just
164 assume any function call might require the stack. */
166 static tree calls_function_save_exprs;
169 calls_function (tree exp, int which)
173 calls_function_save_exprs = 0;
174 val = calls_function_1 (exp, which);
175 calls_function_save_exprs = 0;
179 /* Recursive function to do the work of above function. */
182 calls_function_1 (tree exp, int which)
185 enum tree_code code = TREE_CODE (exp);
186 int class = TREE_CODE_CLASS (code);
187 int length = first_rtl_op (code);
189 /* If this code is language-specific, we don't know what it will do. */
190 if ((int) code >= NUM_TREE_CODES)
198 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
200 && (TYPE_RETURNS_STACK_DEPRESSED
201 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
203 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
204 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
206 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
208 & ECF_MAY_BE_ALLOCA))
217 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
218 if (calls_function_1 (TREE_VALUE (tem), which))
225 if (SAVE_EXPR_RTL (exp) != 0)
227 if (value_member (exp, calls_function_save_exprs))
229 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
230 calls_function_save_exprs);
231 return (TREE_OPERAND (exp, 0) != 0
232 && calls_function_1 (TREE_OPERAND (exp, 0), which));
239 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
240 if (DECL_INITIAL (local) != 0
241 && calls_function_1 (DECL_INITIAL (local), which))
244 for (subblock = BLOCK_SUBBLOCKS (exp);
246 subblock = TREE_CHAIN (subblock))
247 if (calls_function_1 (subblock, which))
253 for (; exp != 0; exp = TREE_CHAIN (exp))
254 if (calls_function_1 (TREE_VALUE (exp), which))
262 /* Only expressions and blocks can contain calls. */
263 if (! IS_EXPR_CODE_CLASS (class) && class != 'b')
266 for (i = 0; i < length; i++)
267 if (TREE_OPERAND (exp, i) != 0
268 && calls_function_1 (TREE_OPERAND (exp, i), which))
274 /* Force FUNEXP into a form suitable for the address of a CALL,
275 and return that as an rtx. Also load the static chain register
276 if FNDECL is a nested function.
278 CALL_FUSAGE points to a variable holding the prospective
279 CALL_INSN_FUNCTION_USAGE information. */
282 prepare_call_address (rtx funexp, tree fndecl, rtx *call_fusage,
283 int reg_parm_seen, int sibcallp)
285 rtx static_chain_value = 0;
287 funexp = protect_from_queue (funexp, 0);
290 /* Get possible static chain value for nested function in C. */
291 static_chain_value = lookup_static_chain (fndecl);
293 /* Make a valid memory address and copy constants through pseudo-regs,
294 but not for a constant address if -fno-function-cse. */
295 if (GET_CODE (funexp) != SYMBOL_REF)
296 /* If we are using registers for parameters, force the
297 function address into a register now. */
298 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
299 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
300 : memory_address (FUNCTION_MODE, funexp));
303 #ifndef NO_FUNCTION_CSE
304 if (optimize && ! flag_no_function_cse)
305 #ifdef NO_RECURSIVE_FUNCTION_CSE
306 if (fndecl != current_function_decl)
308 funexp = force_reg (Pmode, funexp);
312 if (static_chain_value != 0)
314 emit_move_insn (static_chain_rtx, static_chain_value);
316 if (GET_CODE (static_chain_rtx) == REG)
317 use_reg (call_fusage, static_chain_rtx);
323 /* Generate instructions to call function FUNEXP,
324 and optionally pop the results.
325 The CALL_INSN is the first insn generated.
327 FNDECL is the declaration node of the function. This is given to the
328 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
330 FUNTYPE is the data type of the function. This is given to the macro
331 RETURN_POPS_ARGS to determine whether this function pops its own args.
332 We used to allow an identifier for library functions, but that doesn't
333 work when the return type is an aggregate type and the calling convention
334 says that the pointer to this aggregate is to be popped by the callee.
336 STACK_SIZE is the number of bytes of arguments on the stack,
337 ROUNDED_STACK_SIZE is that number rounded up to
338 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
339 both to put into the call insn and to generate explicit popping
342 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
343 It is zero if this call doesn't want a structure value.
345 NEXT_ARG_REG is the rtx that results from executing
346 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
347 just after all the args have had their registers assigned.
348 This could be whatever you like, but normally it is the first
349 arg-register beyond those used for args in this call,
350 or 0 if all the arg-registers are used in this call.
351 It is passed on to `gen_call' so you can put this info in the call insn.
353 VALREG is a hard register in which a value is returned,
354 or 0 if the call does not return a value.
356 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
357 the args to this call were processed.
358 We restore `inhibit_defer_pop' to that value.
360 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
361 denote registers used by the called function. */
364 emit_call_1 (rtx funexp, tree fndecl ATTRIBUTE_UNUSED, tree funtype ATTRIBUTE_UNUSED,
365 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
366 HOST_WIDE_INT rounded_stack_size,
367 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
368 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
369 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
370 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
372 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
374 int already_popped = 0;
375 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
376 #if defined (HAVE_call) && defined (HAVE_call_value)
377 rtx struct_value_size_rtx;
378 struct_value_size_rtx = GEN_INT (struct_value_size);
381 #ifdef CALL_POPS_ARGS
382 n_popped += CALL_POPS_ARGS (* args_so_far);
385 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
386 and we don't want to load it into a register as an optimization,
387 because prepare_call_address already did it if it should be done. */
388 if (GET_CODE (funexp) != SYMBOL_REF)
389 funexp = memory_address (FUNCTION_MODE, funexp);
391 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
392 if ((ecf_flags & ECF_SIBCALL)
393 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
394 && (n_popped > 0 || stack_size == 0))
396 rtx n_pop = GEN_INT (n_popped);
399 /* If this subroutine pops its own args, record that in the call insn
400 if possible, for the sake of frame pointer elimination. */
403 pat = GEN_SIBCALL_VALUE_POP (valreg,
404 gen_rtx_MEM (FUNCTION_MODE, funexp),
405 rounded_stack_size_rtx, next_arg_reg,
408 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
409 rounded_stack_size_rtx, next_arg_reg, n_pop);
411 emit_call_insn (pat);
417 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
418 /* If the target has "call" or "call_value" insns, then prefer them
419 if no arguments are actually popped. If the target does not have
420 "call" or "call_value" insns, then we must use the popping versions
421 even if the call has no arguments to pop. */
422 #if defined (HAVE_call) && defined (HAVE_call_value)
423 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
424 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
426 if (HAVE_call_pop && HAVE_call_value_pop)
429 rtx n_pop = GEN_INT (n_popped);
432 /* If this subroutine pops its own args, record that in the call insn
433 if possible, for the sake of frame pointer elimination. */
436 pat = GEN_CALL_VALUE_POP (valreg,
437 gen_rtx_MEM (FUNCTION_MODE, funexp),
438 rounded_stack_size_rtx, next_arg_reg, n_pop);
440 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
441 rounded_stack_size_rtx, next_arg_reg, n_pop);
443 emit_call_insn (pat);
449 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
450 if ((ecf_flags & ECF_SIBCALL)
451 && HAVE_sibcall && HAVE_sibcall_value)
454 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
455 gen_rtx_MEM (FUNCTION_MODE, funexp),
456 rounded_stack_size_rtx,
457 next_arg_reg, NULL_RTX));
459 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
460 rounded_stack_size_rtx, next_arg_reg,
461 struct_value_size_rtx));
466 #if defined (HAVE_call) && defined (HAVE_call_value)
467 if (HAVE_call && HAVE_call_value)
470 emit_call_insn (GEN_CALL_VALUE (valreg,
471 gen_rtx_MEM (FUNCTION_MODE, funexp),
472 rounded_stack_size_rtx, next_arg_reg,
475 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
476 rounded_stack_size_rtx, next_arg_reg,
477 struct_value_size_rtx));
483 /* Find the call we just emitted. */
484 call_insn = last_call_insn ();
486 /* Mark memory as used for "pure" function call. */
487 if (ecf_flags & ECF_PURE)
491 gen_rtx_USE (VOIDmode,
492 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
495 /* Put the register usage information there. */
496 add_function_usage_to (call_insn, call_fusage);
498 /* If this is a const call, then set the insn's unchanging bit. */
499 if (ecf_flags & (ECF_CONST | ECF_PURE))
500 CONST_OR_PURE_CALL_P (call_insn) = 1;
502 /* If this call can't throw, attach a REG_EH_REGION reg note to that
504 if (ecf_flags & ECF_NOTHROW)
505 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
506 REG_NOTES (call_insn));
508 note_eh_region_may_contain_throw ();
510 if (ecf_flags & ECF_NORETURN)
511 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
512 REG_NOTES (call_insn));
513 if (ecf_flags & ECF_ALWAYS_RETURN)
514 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
515 REG_NOTES (call_insn));
517 if (ecf_flags & ECF_RETURNS_TWICE)
519 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
520 REG_NOTES (call_insn));
521 current_function_calls_setjmp = 1;
524 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
526 /* Restore this now, so that we do defer pops for this call's args
527 if the context of the call as a whole permits. */
528 inhibit_defer_pop = old_inhibit_defer_pop;
533 CALL_INSN_FUNCTION_USAGE (call_insn)
534 = gen_rtx_EXPR_LIST (VOIDmode,
535 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
536 CALL_INSN_FUNCTION_USAGE (call_insn));
537 rounded_stack_size -= n_popped;
538 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
539 stack_pointer_delta -= n_popped;
542 if (!ACCUMULATE_OUTGOING_ARGS)
544 /* If returning from the subroutine does not automatically pop the args,
545 we need an instruction to pop them sooner or later.
546 Perhaps do it now; perhaps just record how much space to pop later.
548 If returning from the subroutine does pop the args, indicate that the
549 stack pointer will be changed. */
551 if (rounded_stack_size != 0)
553 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN | ECF_LONGJMP))
554 /* Just pretend we did the pop. */
555 stack_pointer_delta -= rounded_stack_size;
556 else if (flag_defer_pop && inhibit_defer_pop == 0
557 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
558 pending_stack_adjust += rounded_stack_size;
560 adjust_stack (rounded_stack_size_rtx);
563 /* When we accumulate outgoing args, we must avoid any stack manipulations.
564 Restore the stack pointer to its original value now. Usually
565 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
566 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
567 popping variants of functions exist as well.
569 ??? We may optimize similar to defer_pop above, but it is
570 probably not worthwhile.
572 ??? It will be worthwhile to enable combine_stack_adjustments even for
575 anti_adjust_stack (GEN_INT (n_popped));
578 /* Determine if the function identified by NAME and FNDECL is one with
579 special properties we wish to know about.
581 For example, if the function might return more than one time (setjmp), then
582 set RETURNS_TWICE to a nonzero value.
584 Similarly set LONGJMP for if the function is in the longjmp family.
586 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
587 space from the stack such as alloca. */
590 special_function_p (tree fndecl, int flags)
592 if (! (flags & ECF_MALLOC)
593 && fndecl && DECL_NAME (fndecl)
594 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
595 /* Exclude functions not at the file scope, or not `extern',
596 since they are not the magic functions we would otherwise
598 FIXME: this should be handled with attributes, not with this
599 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
600 because you can declare fork() inside a function if you
602 && (DECL_CONTEXT (fndecl) == NULL_TREE
603 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
604 && TREE_PUBLIC (fndecl))
606 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
607 const char *tname = name;
609 /* We assume that alloca will always be called by name. It
610 makes no sense to pass it as a pointer-to-function to
611 anything that does not understand its behavior. */
612 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
614 && ! strcmp (name, "alloca"))
615 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
617 && ! strcmp (name, "__builtin_alloca"))))
618 flags |= ECF_MAY_BE_ALLOCA;
620 /* Disregard prefix _, __ or __x. */
623 if (name[1] == '_' && name[2] == 'x')
625 else if (name[1] == '_')
634 && (! strcmp (tname, "setjmp")
635 || ! strcmp (tname, "setjmp_syscall")))
637 && ! strcmp (tname, "sigsetjmp"))
639 && ! strcmp (tname, "savectx")))
640 flags |= ECF_RETURNS_TWICE;
643 && ! strcmp (tname, "siglongjmp"))
644 flags |= ECF_LONGJMP;
646 else if ((tname[0] == 'q' && tname[1] == 's'
647 && ! strcmp (tname, "qsetjmp"))
648 || (tname[0] == 'v' && tname[1] == 'f'
649 && ! strcmp (tname, "vfork")))
650 flags |= ECF_RETURNS_TWICE;
652 else if (tname[0] == 'l' && tname[1] == 'o'
653 && ! strcmp (tname, "longjmp"))
654 flags |= ECF_LONGJMP;
656 else if ((tname[0] == 'f' && tname[1] == 'o'
657 && ! strcmp (tname, "fork"))
658 /* Linux specific: __clone. check NAME to insist on the
659 leading underscores, to avoid polluting the ISO / POSIX
661 || (name[0] == '_' && name[1] == '_'
662 && ! strcmp (tname, "clone"))
663 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
664 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
666 || ((tname[5] == 'p' || tname[5] == 'e')
667 && tname[6] == '\0'))))
668 flags |= ECF_FORK_OR_EXEC;
673 /* Return nonzero when tree represent call to longjmp. */
676 setjmp_call_p (tree fndecl)
678 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
681 /* Return true when exp contains alloca call. */
683 alloca_call_p (tree exp)
685 if (TREE_CODE (exp) == CALL_EXPR
686 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
687 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
689 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
690 0) & ECF_MAY_BE_ALLOCA))
695 /* Detect flags (function attributes) from the function decl or type node. */
698 flags_from_decl_or_type (tree exp)
705 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
706 type = TREE_TYPE (exp);
710 if (i->pure_function)
711 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
712 if (i->const_function)
713 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
716 /* The function exp may have the `malloc' attribute. */
717 if (DECL_IS_MALLOC (exp))
720 /* The function exp may have the `pure' attribute. */
721 if (DECL_IS_PURE (exp))
722 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
724 if (TREE_NOTHROW (exp))
725 flags |= ECF_NOTHROW;
727 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
728 flags |= ECF_LIBCALL_BLOCK;
731 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
734 if (TREE_THIS_VOLATILE (exp))
735 flags |= ECF_NORETURN;
737 /* Mark if the function returns with the stack pointer depressed. We
738 cannot consider it pure or constant in that case. */
739 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
741 flags |= ECF_SP_DEPRESSED;
742 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
748 /* Detect flags from a CALL_EXPR. */
751 call_expr_flags (tree t)
754 tree decl = get_callee_fndecl (t);
757 flags = flags_from_decl_or_type (decl);
760 t = TREE_TYPE (TREE_OPERAND (t, 0));
761 if (t && TREE_CODE (t) == POINTER_TYPE)
762 flags = flags_from_decl_or_type (TREE_TYPE (t));
770 /* Precompute all register parameters as described by ARGS, storing values
771 into fields within the ARGS array.
773 NUM_ACTUALS indicates the total number elements in the ARGS array.
775 Set REG_PARM_SEEN if we encounter a register parameter. */
778 precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
784 for (i = 0; i < num_actuals; i++)
785 if (args[i].reg != 0 && ! args[i].pass_on_stack)
789 if (args[i].value == 0)
792 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
794 preserve_temp_slots (args[i].value);
797 /* ANSI doesn't require a sequence point here,
798 but PCC has one, so this will avoid some problems. */
802 /* If the value is a non-legitimate constant, force it into a
803 pseudo now. TLS symbols sometimes need a call to resolve. */
804 if (CONSTANT_P (args[i].value)
805 && !LEGITIMATE_CONSTANT_P (args[i].value))
806 args[i].value = force_reg (args[i].mode, args[i].value);
808 /* If we are to promote the function arg to a wider mode,
811 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
813 = convert_modes (args[i].mode,
814 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
815 args[i].value, args[i].unsignedp);
817 /* If the value is expensive, and we are inside an appropriately
818 short loop, put the value into a pseudo and then put the pseudo
821 For small register classes, also do this if this call uses
822 register parameters. This is to avoid reload conflicts while
823 loading the parameters registers. */
825 if ((! (GET_CODE (args[i].value) == REG
826 || (GET_CODE (args[i].value) == SUBREG
827 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
828 && args[i].mode != BLKmode
829 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
830 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
831 || preserve_subexpressions_p ()))
832 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
836 #ifdef REG_PARM_STACK_SPACE
838 /* The argument list is the property of the called routine and it
839 may clobber it. If the fixed area has been used for previous
840 parameters, we must save and restore it. */
843 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
848 /* Compute the boundary of the area that needs to be saved, if any. */
849 high = reg_parm_stack_space;
850 #ifdef ARGS_GROW_DOWNWARD
853 if (high > highest_outgoing_arg_in_use)
854 high = highest_outgoing_arg_in_use;
856 for (low = 0; low < high; low++)
857 if (stack_usage_map[low] != 0)
860 enum machine_mode save_mode;
865 while (stack_usage_map[--high] == 0)
869 *high_to_save = high;
871 num_to_save = high - low + 1;
872 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
874 /* If we don't have the required alignment, must do this
876 if ((low & (MIN (GET_MODE_SIZE (save_mode),
877 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
880 #ifdef ARGS_GROW_DOWNWARD
885 stack_area = gen_rtx_MEM (save_mode,
886 memory_address (save_mode,
887 plus_constant (argblock,
890 set_mem_align (stack_area, PARM_BOUNDARY);
891 if (save_mode == BLKmode)
893 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
894 emit_block_move (validize_mem (save_area), stack_area,
895 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
899 save_area = gen_reg_rtx (save_mode);
900 emit_move_insn (save_area, stack_area);
910 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
912 enum machine_mode save_mode = GET_MODE (save_area);
916 #ifdef ARGS_GROW_DOWNWARD
917 delta = -high_to_save;
921 stack_area = gen_rtx_MEM (save_mode,
922 memory_address (save_mode,
923 plus_constant (argblock, delta)));
924 set_mem_align (stack_area, PARM_BOUNDARY);
926 if (save_mode != BLKmode)
927 emit_move_insn (stack_area, save_area);
929 emit_block_move (stack_area, validize_mem (save_area),
930 GEN_INT (high_to_save - low_to_save + 1),
933 #endif /* REG_PARM_STACK_SPACE */
935 /* If any elements in ARGS refer to parameters that are to be passed in
936 registers, but not in memory, and whose alignment does not permit a
937 direct copy into registers. Copy the values into a group of pseudos
938 which we will later copy into the appropriate hard registers.
940 Pseudos for each unaligned argument will be stored into the array
941 args[argnum].aligned_regs. The caller is responsible for deallocating
942 the aligned_regs array if it is nonzero. */
945 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
949 for (i = 0; i < num_actuals; i++)
950 if (args[i].reg != 0 && ! args[i].pass_on_stack
951 && args[i].mode == BLKmode
952 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
953 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
955 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
956 int nregs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
957 int endian_correction = 0;
959 args[i].n_aligned_regs = args[i].partial ? args[i].partial : nregs;
960 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
962 /* Structures smaller than a word are normally aligned to the
963 least significant byte. On a BYTES_BIG_ENDIAN machine,
964 this means we must skip the empty high order bytes when
965 calculating the bit offset. */
966 if (bytes < UNITS_PER_WORD
967 #ifdef BLOCK_REG_PADDING
968 && (BLOCK_REG_PADDING (args[i].mode,
969 TREE_TYPE (args[i].tree_value), 1)
975 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
977 for (j = 0; j < args[i].n_aligned_regs; j++)
979 rtx reg = gen_reg_rtx (word_mode);
980 rtx word = operand_subword_force (args[i].value, j, BLKmode);
981 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
983 args[i].aligned_regs[j] = reg;
984 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
985 word_mode, word_mode, BITS_PER_WORD);
987 /* There is no need to restrict this code to loading items
988 in TYPE_ALIGN sized hunks. The bitfield instructions can
989 load up entire word sized registers efficiently.
991 ??? This may not be needed anymore.
992 We use to emit a clobber here but that doesn't let later
993 passes optimize the instructions we emit. By storing 0 into
994 the register later passes know the first AND to zero out the
995 bitfield being set in the register is unnecessary. The store
996 of 0 will be deleted as will at least the first AND. */
998 emit_move_insn (reg, const0_rtx);
1000 bytes -= bitsize / BITS_PER_UNIT;
1001 store_bit_field (reg, bitsize, endian_correction, word_mode,
1002 word, BITS_PER_WORD);
1007 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
1010 NUM_ACTUALS is the total number of parameters.
1012 N_NAMED_ARGS is the total number of named arguments.
1014 FNDECL is the tree code for the target of this call (if known)
1016 ARGS_SO_FAR holds state needed by the target to know where to place
1019 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1020 for arguments which are passed in registers.
1022 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1023 and may be modified by this routine.
1025 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1026 flags which may may be modified by this routine. */
1029 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1030 struct arg_data *args,
1031 struct args_size *args_size,
1032 int n_named_args ATTRIBUTE_UNUSED,
1033 tree actparms, tree fndecl,
1034 CUMULATIVE_ARGS *args_so_far,
1035 int reg_parm_stack_space,
1036 rtx *old_stack_level, int *old_pending_adj,
1037 int *must_preallocate, int *ecf_flags)
1039 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1042 /* Count arg position in order args appear. */
1048 args_size->constant = 0;
1051 /* In this loop, we consider args in the order they are written.
1052 We fill up ARGS from the front or from the back if necessary
1053 so that in any case the first arg to be pushed ends up at the front. */
1055 if (PUSH_ARGS_REVERSED)
1057 i = num_actuals - 1, inc = -1;
1058 /* In this case, must reverse order of args
1059 so that we compute and push the last arg first. */
1066 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1067 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1069 tree type = TREE_TYPE (TREE_VALUE (p));
1071 enum machine_mode mode;
1073 args[i].tree_value = TREE_VALUE (p);
1075 /* Replace erroneous argument with constant zero. */
1076 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1077 args[i].tree_value = integer_zero_node, type = integer_type_node;
1079 /* If TYPE is a transparent union, pass things the way we would
1080 pass the first field of the union. We have already verified that
1081 the modes are the same. */
1082 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1083 type = TREE_TYPE (TYPE_FIELDS (type));
1085 /* Decide where to pass this arg.
1087 args[i].reg is nonzero if all or part is passed in registers.
1089 args[i].partial is nonzero if part but not all is passed in registers,
1090 and the exact value says how many words are passed in registers.
1092 args[i].pass_on_stack is nonzero if the argument must at least be
1093 computed on the stack. It may then be loaded back into registers
1094 if args[i].reg is nonzero.
1096 These decisions are driven by the FUNCTION_... macros and must agree
1097 with those made by function.c. */
1099 /* See if this argument should be passed by invisible reference. */
1100 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1101 || TREE_ADDRESSABLE (type)
1102 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1103 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1104 type, argpos < n_named_args)
1108 /* If we're compiling a thunk, pass through invisible
1109 references instead of making a copy. */
1110 if (current_function_is_thunk
1111 #ifdef FUNCTION_ARG_CALLEE_COPIES
1112 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1113 type, argpos < n_named_args)
1114 /* If it's in a register, we must make a copy of it too. */
1115 /* ??? Is this a sufficient test? Is there a better one? */
1116 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1117 && REG_P (DECL_RTL (args[i].tree_value)))
1118 && ! TREE_ADDRESSABLE (type))
1122 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1123 new object from the argument. If we are passing by
1124 invisible reference, the callee will do that for us, so we
1125 can strip off the TARGET_EXPR. This is not always safe,
1126 but it is safe in the only case where this is a useful
1127 optimization; namely, when the argument is a plain object.
1128 In that case, the frontend is just asking the backend to
1129 make a bitwise copy of the argument. */
1131 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1132 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1133 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1134 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1136 args[i].tree_value = build1 (ADDR_EXPR,
1137 build_pointer_type (type),
1138 args[i].tree_value);
1139 type = build_pointer_type (type);
1141 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1143 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1144 We implement this by passing the address of the temporary
1145 rather than expanding it into another allocated slot. */
1146 args[i].tree_value = build1 (ADDR_EXPR,
1147 build_pointer_type (type),
1148 args[i].tree_value);
1149 type = build_pointer_type (type);
1153 /* We make a copy of the object and pass the address to the
1154 function being called. */
1157 if (!COMPLETE_TYPE_P (type)
1158 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1159 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1160 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1161 STACK_CHECK_MAX_VAR_SIZE))))
1163 /* This is a variable-sized object. Make space on the stack
1165 rtx size_rtx = expr_size (TREE_VALUE (p));
1167 if (*old_stack_level == 0)
1169 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1170 *old_pending_adj = pending_stack_adjust;
1171 pending_stack_adjust = 0;
1174 copy = gen_rtx_MEM (BLKmode,
1175 allocate_dynamic_stack_space
1176 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1177 set_mem_attributes (copy, type, 1);
1180 copy = assign_temp (type, 0, 1, 0);
1182 store_expr (args[i].tree_value, copy, 0);
1183 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1185 args[i].tree_value = build1 (ADDR_EXPR,
1186 build_pointer_type (type),
1187 make_tree (type, copy));
1188 type = build_pointer_type (type);
1192 mode = TYPE_MODE (type);
1193 unsignedp = TREE_UNSIGNED (type);
1195 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1196 mode = promote_mode (type, mode, &unsignedp, 1);
1198 args[i].unsignedp = unsignedp;
1199 args[i].mode = mode;
1201 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1202 argpos < n_named_args);
1203 #ifdef FUNCTION_INCOMING_ARG
1204 /* If this is a sibling call and the machine has register windows, the
1205 register window has to be unwinded before calling the routine, so
1206 arguments have to go into the incoming registers. */
1207 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1208 argpos < n_named_args);
1210 args[i].tail_call_reg = args[i].reg;
1213 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1216 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1217 argpos < n_named_args);
1220 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1222 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1223 it means that we are to pass this arg in the register(s) designated
1224 by the PARALLEL, but also to pass it in the stack. */
1225 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1226 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1227 args[i].pass_on_stack = 1;
1229 /* If this is an addressable type, we must preallocate the stack
1230 since we must evaluate the object into its final location.
1232 If this is to be passed in both registers and the stack, it is simpler
1234 if (TREE_ADDRESSABLE (type)
1235 || (args[i].pass_on_stack && args[i].reg != 0))
1236 *must_preallocate = 1;
1238 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1239 we cannot consider this function call constant. */
1240 if (TREE_ADDRESSABLE (type))
1241 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1243 /* Compute the stack-size of this argument. */
1244 if (args[i].reg == 0 || args[i].partial != 0
1245 || reg_parm_stack_space > 0
1246 || args[i].pass_on_stack)
1247 locate_and_pad_parm (mode, type,
1248 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1253 args[i].pass_on_stack ? 0 : args[i].partial,
1254 fndecl, args_size, &args[i].locate);
1255 #ifdef BLOCK_REG_PADDING
1257 /* The argument is passed entirely in registers. See at which
1258 end it should be padded. */
1259 args[i].locate.where_pad =
1260 BLOCK_REG_PADDING (mode, type,
1261 int_size_in_bytes (type) <= UNITS_PER_WORD);
1264 /* Update ARGS_SIZE, the total stack space for args so far. */
1266 args_size->constant += args[i].locate.size.constant;
1267 if (args[i].locate.size.var)
1268 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1270 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1271 have been used, etc. */
1273 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1274 argpos < n_named_args);
1278 /* Update ARGS_SIZE to contain the total size for the argument block.
1279 Return the original constant component of the argument block's size.
1281 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1282 for arguments passed in registers. */
1285 compute_argument_block_size (int reg_parm_stack_space,
1286 struct args_size *args_size,
1287 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1289 int unadjusted_args_size = args_size->constant;
1291 /* For accumulate outgoing args mode we don't need to align, since the frame
1292 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1293 backends from generating misaligned frame sizes. */
1294 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1295 preferred_stack_boundary = STACK_BOUNDARY;
1297 /* Compute the actual size of the argument block required. The variable
1298 and constant sizes must be combined, the size may have to be rounded,
1299 and there may be a minimum required size. */
1303 args_size->var = ARGS_SIZE_TREE (*args_size);
1304 args_size->constant = 0;
1306 preferred_stack_boundary /= BITS_PER_UNIT;
1307 if (preferred_stack_boundary > 1)
1309 /* We don't handle this case yet. To handle it correctly we have
1310 to add the delta, round and subtract the delta.
1311 Currently no machine description requires this support. */
1312 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1314 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1317 if (reg_parm_stack_space > 0)
1320 = size_binop (MAX_EXPR, args_size->var,
1321 ssize_int (reg_parm_stack_space));
1323 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1324 /* The area corresponding to register parameters is not to count in
1325 the size of the block we need. So make the adjustment. */
1327 = size_binop (MINUS_EXPR, args_size->var,
1328 ssize_int (reg_parm_stack_space));
1334 preferred_stack_boundary /= BITS_PER_UNIT;
1335 if (preferred_stack_boundary < 1)
1336 preferred_stack_boundary = 1;
1337 args_size->constant = (((args_size->constant
1338 + stack_pointer_delta
1339 + preferred_stack_boundary - 1)
1340 / preferred_stack_boundary
1341 * preferred_stack_boundary)
1342 - stack_pointer_delta);
1344 args_size->constant = MAX (args_size->constant,
1345 reg_parm_stack_space);
1347 #ifdef MAYBE_REG_PARM_STACK_SPACE
1348 if (reg_parm_stack_space == 0)
1349 args_size->constant = 0;
1352 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1353 args_size->constant -= reg_parm_stack_space;
1356 return unadjusted_args_size;
1359 /* Precompute parameters as needed for a function call.
1361 FLAGS is mask of ECF_* constants.
1363 NUM_ACTUALS is the number of arguments.
1365 ARGS is an array containing information for each argument; this
1366 routine fills in the INITIAL_VALUE and VALUE fields for each
1367 precomputed argument. */
1370 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1374 /* If this function call is cse'able, precompute all the parameters.
1375 Note that if the parameter is constructed into a temporary, this will
1376 cause an additional copy because the parameter will be constructed
1377 into a temporary location and then copied into the outgoing arguments.
1378 If a parameter contains a call to alloca and this function uses the
1379 stack, precompute the parameter. */
1381 /* If we preallocated the stack space, and some arguments must be passed
1382 on the stack, then we must precompute any parameter which contains a
1383 function call which will store arguments on the stack.
1384 Otherwise, evaluating the parameter may clobber previous parameters
1385 which have already been stored into the stack. (we have code to avoid
1386 such case by saving the outgoing stack arguments, but it results in
1389 for (i = 0; i < num_actuals; i++)
1390 if ((flags & ECF_LIBCALL_BLOCK)
1391 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1393 enum machine_mode mode;
1395 /* If this is an addressable type, we cannot pre-evaluate it. */
1396 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1400 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1402 /* ANSI doesn't require a sequence point here,
1403 but PCC has one, so this will avoid some problems. */
1406 args[i].initial_value = args[i].value
1407 = protect_from_queue (args[i].value, 0);
1409 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1410 if (mode != args[i].mode)
1413 = convert_modes (args[i].mode, mode,
1414 args[i].value, args[i].unsignedp);
1415 #ifdef PROMOTE_FOR_CALL_ONLY
1416 /* CSE will replace this only if it contains args[i].value
1417 pseudo, so convert it down to the declared mode using
1419 if (GET_CODE (args[i].value) == REG
1420 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1422 args[i].initial_value
1423 = gen_lowpart_SUBREG (mode, args[i].value);
1424 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1425 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1433 /* Given the current state of MUST_PREALLOCATE and information about
1434 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1435 compute and return the final value for MUST_PREALLOCATE. */
1438 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1440 /* See if we have or want to preallocate stack space.
1442 If we would have to push a partially-in-regs parm
1443 before other stack parms, preallocate stack space instead.
1445 If the size of some parm is not a multiple of the required stack
1446 alignment, we must preallocate.
1448 If the total size of arguments that would otherwise create a copy in
1449 a temporary (such as a CALL) is more than half the total argument list
1450 size, preallocation is faster.
1452 Another reason to preallocate is if we have a machine (like the m88k)
1453 where stack alignment is required to be maintained between every
1454 pair of insns, not just when the call is made. However, we assume here
1455 that such machines either do not have push insns (and hence preallocation
1456 would occur anyway) or the problem is taken care of with
1459 if (! must_preallocate)
1461 int partial_seen = 0;
1462 int copy_to_evaluate_size = 0;
1465 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1467 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1469 else if (partial_seen && args[i].reg == 0)
1470 must_preallocate = 1;
1472 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1473 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1474 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1475 || TREE_CODE (args[i].tree_value) == COND_EXPR
1476 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1477 copy_to_evaluate_size
1478 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1481 if (copy_to_evaluate_size * 2 >= args_size->constant
1482 && args_size->constant > 0)
1483 must_preallocate = 1;
1485 return must_preallocate;
1488 /* If we preallocated stack space, compute the address of each argument
1489 and store it into the ARGS array.
1491 We need not ensure it is a valid memory address here; it will be
1492 validized when it is used.
1494 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1497 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1501 rtx arg_reg = argblock;
1502 int i, arg_offset = 0;
1504 if (GET_CODE (argblock) == PLUS)
1505 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1507 for (i = 0; i < num_actuals; i++)
1509 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1510 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1513 /* Skip this parm if it will not be passed on the stack. */
1514 if (! args[i].pass_on_stack && args[i].reg != 0)
1517 if (GET_CODE (offset) == CONST_INT)
1518 addr = plus_constant (arg_reg, INTVAL (offset));
1520 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1522 addr = plus_constant (addr, arg_offset);
1523 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1524 set_mem_align (args[i].stack, PARM_BOUNDARY);
1525 set_mem_attributes (args[i].stack,
1526 TREE_TYPE (args[i].tree_value), 1);
1528 if (GET_CODE (slot_offset) == CONST_INT)
1529 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1531 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1533 addr = plus_constant (addr, arg_offset);
1534 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1535 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1536 set_mem_attributes (args[i].stack_slot,
1537 TREE_TYPE (args[i].tree_value), 1);
1539 /* Function incoming arguments may overlap with sibling call
1540 outgoing arguments and we cannot allow reordering of reads
1541 from function arguments with stores to outgoing arguments
1542 of sibling calls. */
1543 set_mem_alias_set (args[i].stack, 0);
1544 set_mem_alias_set (args[i].stack_slot, 0);
1549 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1550 in a call instruction.
1552 FNDECL is the tree node for the target function. For an indirect call
1553 FNDECL will be NULL_TREE.
1555 ADDR is the operand 0 of CALL_EXPR for this call. */
1558 rtx_for_function_call (tree fndecl, tree addr)
1562 /* Get the function to call, in the form of RTL. */
1565 /* If this is the first use of the function, see if we need to
1566 make an external definition for it. */
1567 if (! TREE_USED (fndecl))
1569 assemble_external (fndecl);
1570 TREE_USED (fndecl) = 1;
1573 /* Get a SYMBOL_REF rtx for the function address. */
1574 funexp = XEXP (DECL_RTL (fndecl), 0);
1577 /* Generate an rtx (probably a pseudo-register) for the address. */
1580 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1581 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1587 /* Do the register loads required for any wholly-register parms or any
1588 parms which are passed both on the stack and in a register. Their
1589 expressions were already evaluated.
1591 Mark all register-parms as living through the call, putting these USE
1592 insns in the CALL_INSN_FUNCTION_USAGE field.
1594 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1595 checking, setting *SIBCALL_FAILURE if appropriate. */
1598 load_register_parameters (struct arg_data *args, int num_actuals,
1599 rtx *call_fusage, int flags, int is_sibcall,
1600 int *sibcall_failure)
1604 for (i = 0; i < num_actuals; i++)
1606 rtx reg = ((flags & ECF_SIBCALL)
1607 ? args[i].tail_call_reg : args[i].reg);
1610 int partial = args[i].partial;
1613 rtx before_arg = get_last_insn ();
1614 /* Set to non-negative if must move a word at a time, even if just
1615 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1616 we just use a normal move insn. This value can be zero if the
1617 argument is a zero size structure with no fields. */
1621 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1623 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1624 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1627 size = GET_MODE_SIZE (args[i].mode);
1629 /* Handle calls that pass values in multiple non-contiguous
1630 locations. The Irix 6 ABI has examples of this. */
1632 if (GET_CODE (reg) == PARALLEL)
1634 tree type = TREE_TYPE (args[i].tree_value);
1635 emit_group_load (reg, args[i].value, type,
1636 int_size_in_bytes (type));
1639 /* If simple case, just do move. If normal partial, store_one_arg
1640 has already loaded the register for us. In all other cases,
1641 load the register(s) from memory. */
1643 else if (nregs == -1)
1645 emit_move_insn (reg, args[i].value);
1646 #ifdef BLOCK_REG_PADDING
1647 /* Handle case where we have a value that needs shifting
1648 up to the msb. eg. a QImode value and we're padding
1649 upward on a BYTES_BIG_ENDIAN machine. */
1650 if (size < UNITS_PER_WORD
1651 && (args[i].locate.where_pad
1652 == (BYTES_BIG_ENDIAN ? upward : downward)))
1655 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1657 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1658 report the whole reg as used. Strictly speaking, the
1659 call only uses SIZE bytes at the msb end, but it doesn't
1660 seem worth generating rtl to say that. */
1661 reg = gen_rtx_REG (word_mode, REGNO (reg));
1662 x = expand_binop (word_mode, ashl_optab, reg,
1663 GEN_INT (shift), reg, 1, OPTAB_WIDEN);
1665 emit_move_insn (reg, x);
1670 /* If we have pre-computed the values to put in the registers in
1671 the case of non-aligned structures, copy them in now. */
1673 else if (args[i].n_aligned_regs != 0)
1674 for (j = 0; j < args[i].n_aligned_regs; j++)
1675 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1676 args[i].aligned_regs[j]);
1678 else if (partial == 0 || args[i].pass_on_stack)
1680 rtx mem = validize_mem (args[i].value);
1682 #ifdef BLOCK_REG_PADDING
1683 /* Handle a BLKmode that needs shifting. */
1684 if (nregs == 1 && size < UNITS_PER_WORD
1685 && args[i].locate.where_pad == downward)
1687 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1688 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1689 rtx x = gen_reg_rtx (word_mode);
1690 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1691 optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1693 emit_move_insn (x, tem);
1694 x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1695 ri, 1, OPTAB_WIDEN);
1697 emit_move_insn (ri, x);
1701 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1704 /* When a parameter is a block, and perhaps in other cases, it is
1705 possible that it did a load from an argument slot that was
1706 already clobbered. */
1708 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1709 *sibcall_failure = 1;
1711 /* Handle calls that pass values in multiple non-contiguous
1712 locations. The Irix 6 ABI has examples of this. */
1713 if (GET_CODE (reg) == PARALLEL)
1714 use_group_regs (call_fusage, reg);
1715 else if (nregs == -1)
1716 use_reg (call_fusage, reg);
1718 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1723 /* Try to integrate function. See expand_inline_function for documentation
1724 about the parameters. */
1727 try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1728 tree type, rtx structure_value_addr)
1733 rtx old_stack_level = 0;
1734 int reg_parm_stack_space = 0;
1736 #ifdef REG_PARM_STACK_SPACE
1737 #ifdef MAYBE_REG_PARM_STACK_SPACE
1738 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1740 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1744 before_call = get_last_insn ();
1746 timevar_push (TV_INTEGRATION);
1748 temp = expand_inline_function (fndecl, actparms, target,
1750 structure_value_addr);
1752 timevar_pop (TV_INTEGRATION);
1754 /* If inlining succeeded, return. */
1755 if (temp != (rtx) (size_t) - 1)
1757 if (ACCUMULATE_OUTGOING_ARGS)
1759 /* If the outgoing argument list must be preserved, push
1760 the stack before executing the inlined function if it
1763 i = reg_parm_stack_space;
1764 if (i > highest_outgoing_arg_in_use)
1765 i = highest_outgoing_arg_in_use;
1766 while (--i >= 0 && stack_usage_map[i] == 0)
1769 if (stack_arg_under_construction || i >= 0)
1772 = before_call ? NEXT_INSN (before_call) : get_insns ();
1773 rtx insn = NULL_RTX, seq;
1775 /* Look for a call in the inline function code.
1776 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1777 nonzero then there is a call and it is not necessary
1778 to scan the insns. */
1780 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1781 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1782 if (GET_CODE (insn) == CALL_INSN)
1787 /* Reserve enough stack space so that the largest
1788 argument list of any function call in the inline
1789 function does not overlap the argument list being
1790 evaluated. This is usually an overestimate because
1791 allocate_dynamic_stack_space reserves space for an
1792 outgoing argument list in addition to the requested
1793 space, but there is no way to ask for stack space such
1794 that an argument list of a certain length can be
1797 Add the stack space reserved for register arguments, if
1798 any, in the inline function. What is really needed is the
1799 largest value of reg_parm_stack_space in the inline
1800 function, but that is not available. Using the current
1801 value of reg_parm_stack_space is wrong, but gives
1802 correct results on all supported machines. */
1804 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1805 + reg_parm_stack_space);
1808 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1809 allocate_dynamic_stack_space (GEN_INT (adjust),
1810 NULL_RTX, BITS_PER_UNIT);
1813 emit_insn_before (seq, first_insn);
1814 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1819 /* If the result is equivalent to TARGET, return TARGET to simplify
1820 checks in store_expr. They can be equivalent but not equal in the
1821 case of a function that returns BLKmode. */
1822 if (temp != target && rtx_equal_p (temp, target))
1827 /* If inlining failed, mark FNDECL as needing to be compiled
1828 separately after all. If function was declared inline,
1830 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1831 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1833 warning ("%Jinlining failed in call to '%F'", fndecl, fndecl);
1834 warning ("called from here");
1836 (*lang_hooks.mark_addressable) (fndecl);
1837 return (rtx) (size_t) - 1;
1840 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1841 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1842 bytes, then we would need to push some additional bytes to pad the
1843 arguments. So, we compute an adjust to the stack pointer for an
1844 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1845 bytes. Then, when the arguments are pushed the stack will be perfectly
1846 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1847 be popped after the call. Returns the adjustment. */
1850 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1851 struct args_size *args_size,
1852 int preferred_unit_stack_boundary)
1854 /* The number of bytes to pop so that the stack will be
1855 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1856 HOST_WIDE_INT adjustment;
1857 /* The alignment of the stack after the arguments are pushed, if we
1858 just pushed the arguments without adjust the stack here. */
1859 HOST_WIDE_INT unadjusted_alignment;
1861 unadjusted_alignment
1862 = ((stack_pointer_delta + unadjusted_args_size)
1863 % preferred_unit_stack_boundary);
1865 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1866 as possible -- leaving just enough left to cancel out the
1867 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1868 PENDING_STACK_ADJUST is non-negative, and congruent to
1869 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1871 /* Begin by trying to pop all the bytes. */
1872 unadjusted_alignment
1873 = (unadjusted_alignment
1874 - (pending_stack_adjust % preferred_unit_stack_boundary));
1875 adjustment = pending_stack_adjust;
1876 /* Push enough additional bytes that the stack will be aligned
1877 after the arguments are pushed. */
1878 if (preferred_unit_stack_boundary > 1)
1880 if (unadjusted_alignment > 0)
1881 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1883 adjustment += unadjusted_alignment;
1886 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1887 bytes after the call. The right number is the entire
1888 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1889 by the arguments in the first place. */
1891 = pending_stack_adjust - adjustment + unadjusted_args_size;
1896 /* Scan X expression if it does not dereference any argument slots
1897 we already clobbered by tail call arguments (as noted in stored_args_map
1899 Return nonzero if X expression dereferences such argument slots,
1903 check_sibcall_argument_overlap_1 (rtx x)
1913 code = GET_CODE (x);
1917 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1919 else if (GET_CODE (XEXP (x, 0)) == PLUS
1920 && XEXP (XEXP (x, 0), 0) ==
1921 current_function_internal_arg_pointer
1922 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1923 i = INTVAL (XEXP (XEXP (x, 0), 1));
1927 #ifdef ARGS_GROW_DOWNWARD
1928 i = -i - GET_MODE_SIZE (GET_MODE (x));
1931 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1932 if (i + k < stored_args_map->n_bits
1933 && TEST_BIT (stored_args_map, i + k))
1939 /* Scan all subexpressions. */
1940 fmt = GET_RTX_FORMAT (code);
1941 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1945 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1948 else if (*fmt == 'E')
1950 for (j = 0; j < XVECLEN (x, i); j++)
1951 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1958 /* Scan sequence after INSN if it does not dereference any argument slots
1959 we already clobbered by tail call arguments (as noted in stored_args_map
1960 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1961 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1962 should be 0). Return nonzero if sequence after INSN dereferences such argument
1963 slots, zero otherwise. */
1966 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1970 if (insn == NULL_RTX)
1971 insn = get_insns ();
1973 insn = NEXT_INSN (insn);
1975 for (; insn; insn = NEXT_INSN (insn))
1977 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1980 if (mark_stored_args_map)
1982 #ifdef ARGS_GROW_DOWNWARD
1983 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1985 low = arg->locate.slot_offset.constant;
1988 for (high = low + arg->locate.size.constant; low < high; low++)
1989 SET_BIT (stored_args_map, low);
1991 return insn != NULL_RTX;
1995 fix_unsafe_tree (tree t)
1997 switch (unsafe_for_reeval (t))
2002 case 1: /* Mildly unsafe. */
2003 t = unsave_expr (t);
2006 case 2: /* Wildly unsafe. */
2008 tree var = build_decl (VAR_DECL, NULL_TREE,
2011 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2023 /* If function value *VALUE was returned at the most significant end of a
2024 register, shift it towards the least significant end and convert it to
2025 TYPE's mode. Return true and update *VALUE if some action was needed.
2027 TYPE is the type of the function's return value, which is known not
2028 to have mode BLKmode. */
2031 shift_returned_value (tree type, rtx *value)
2033 if (targetm.calls.return_in_msb (type))
2035 HOST_WIDE_INT shift;
2037 shift = (GET_MODE_BITSIZE (GET_MODE (*value))
2038 - BITS_PER_UNIT * int_size_in_bytes (type));
2041 *value = expand_binop (GET_MODE (*value), lshr_optab, *value,
2042 GEN_INT (shift), 0, 1, OPTAB_WIDEN);
2043 *value = convert_to_mode (TYPE_MODE (type), *value, 0);
2050 /* Generate all the code for a function call
2051 and return an rtx for its value.
2052 Store the value in TARGET (specified as an rtx) if convenient.
2053 If the value is stored in TARGET then TARGET is returned.
2054 If IGNORE is nonzero, then we ignore the value of the function call. */
2057 expand_call (tree exp, rtx target, int ignore)
2059 /* Nonzero if we are currently expanding a call. */
2060 static int currently_expanding_call = 0;
2062 /* List of actual parameters. */
2063 tree actparms = TREE_OPERAND (exp, 1);
2064 /* RTX for the function to be called. */
2066 /* Sequence of insns to perform a tail recursive "call". */
2067 rtx tail_recursion_insns = NULL_RTX;
2068 /* Sequence of insns to perform a normal "call". */
2069 rtx normal_call_insns = NULL_RTX;
2070 /* Sequence of insns to perform a tail recursive "call". */
2071 rtx tail_call_insns = NULL_RTX;
2072 /* Data type of the function. */
2074 tree type_arg_types;
2075 /* Declaration of the function being called,
2076 or 0 if the function is computed (not known by name). */
2079 int try_tail_call = 1;
2080 int try_tail_recursion = 1;
2083 /* Register in which non-BLKmode value will be returned,
2084 or 0 if no value or if value is BLKmode. */
2086 /* Address where we should return a BLKmode value;
2087 0 if value not BLKmode. */
2088 rtx structure_value_addr = 0;
2089 /* Nonzero if that address is being passed by treating it as
2090 an extra, implicit first parameter. Otherwise,
2091 it is passed by being copied directly into struct_value_rtx. */
2092 int structure_value_addr_parm = 0;
2093 /* Size of aggregate value wanted, or zero if none wanted
2094 or if we are using the non-reentrant PCC calling convention
2095 or expecting the value in registers. */
2096 HOST_WIDE_INT struct_value_size = 0;
2097 /* Nonzero if called function returns an aggregate in memory PCC style,
2098 by returning the address of where to find it. */
2099 int pcc_struct_value = 0;
2100 rtx struct_value = 0;
2102 /* Number of actual parameters in this call, including struct value addr. */
2104 /* Number of named args. Args after this are anonymous ones
2105 and they must all go on the stack. */
2108 /* Vector of information about each argument.
2109 Arguments are numbered in the order they will be pushed,
2110 not the order they are written. */
2111 struct arg_data *args;
2113 /* Total size in bytes of all the stack-parms scanned so far. */
2114 struct args_size args_size;
2115 struct args_size adjusted_args_size;
2116 /* Size of arguments before any adjustments (such as rounding). */
2117 int unadjusted_args_size;
2118 /* Data on reg parms scanned so far. */
2119 CUMULATIVE_ARGS args_so_far;
2120 /* Nonzero if a reg parm has been scanned. */
2122 /* Nonzero if this is an indirect function call. */
2124 /* Nonzero if we must avoid push-insns in the args for this call.
2125 If stack space is allocated for register parameters, but not by the
2126 caller, then it is preallocated in the fixed part of the stack frame.
2127 So the entire argument block must then be preallocated (i.e., we
2128 ignore PUSH_ROUNDING in that case). */
2130 int must_preallocate = !PUSH_ARGS;
2132 /* Size of the stack reserved for parameter registers. */
2133 int reg_parm_stack_space = 0;
2135 /* Address of space preallocated for stack parms
2136 (on machines that lack push insns), or 0 if space not preallocated. */
2139 /* Mask of ECF_ flags. */
2141 /* Nonzero if this is a call to an inline function. */
2142 int is_integrable = 0;
2143 #ifdef REG_PARM_STACK_SPACE
2144 /* Define the boundary of the register parm stack space that needs to be
2146 int low_to_save, high_to_save;
2147 rtx save_area = 0; /* Place that it is saved */
2150 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2151 rtx temp_target = 0;
2152 char *initial_stack_usage_map = stack_usage_map;
2154 int old_stack_allocated;
2156 /* State variables to track stack modifications. */
2157 rtx old_stack_level = 0;
2158 int old_stack_arg_under_construction = 0;
2159 int old_pending_adj = 0;
2160 int old_inhibit_defer_pop = inhibit_defer_pop;
2162 /* Some stack pointer alterations we make are performed via
2163 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2164 which we then also need to save/restore along the way. */
2165 int old_stack_pointer_delta = 0;
2168 tree p = TREE_OPERAND (exp, 0);
2169 tree addr = TREE_OPERAND (exp, 0);
2171 /* The alignment of the stack, in bits. */
2172 HOST_WIDE_INT preferred_stack_boundary;
2173 /* The alignment of the stack, in bytes. */
2174 HOST_WIDE_INT preferred_unit_stack_boundary;
2176 /* See if this is "nothrow" function call. */
2177 if (TREE_NOTHROW (exp))
2178 flags |= ECF_NOTHROW;
2180 /* See if we can find a DECL-node for the actual function.
2181 As a result, decide whether this is a call to an integrable function. */
2183 fndecl = get_callee_fndecl (exp);
2187 && fndecl != current_function_decl
2188 && DECL_INLINE (fndecl)
2189 && DECL_SAVED_INSNS (fndecl)
2190 && DECL_SAVED_INSNS (fndecl)->inlinable)
2192 else if (! TREE_ADDRESSABLE (fndecl))
2194 /* In case this function later becomes inlinable,
2195 record that there was already a non-inline call to it.
2197 Use abstraction instead of setting TREE_ADDRESSABLE
2199 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2202 warning ("%Jcan't inline call to '%F'", fndecl, fndecl);
2203 warning ("called from here");
2205 (*lang_hooks.mark_addressable) (fndecl);
2209 && lookup_attribute ("warn_unused_result",
2210 TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
2211 warning ("ignoring return value of `%D', "
2212 "declared with attribute warn_unused_result", fndecl);
2214 flags |= flags_from_decl_or_type (fndecl);
2217 /* If we don't have specific function to call, see if we have a
2218 attributes set in the type. */
2222 && lookup_attribute ("warn_unused_result",
2223 TYPE_ATTRIBUTES (TREE_TYPE (TREE_TYPE (p)))))
2224 warning ("ignoring return value of function "
2225 "declared with attribute warn_unused_result");
2226 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2229 struct_value = targetm.calls.struct_value_rtx (fndecl ? TREE_TYPE (fndecl) : 0, 0);
2231 /* Warn if this value is an aggregate type,
2232 regardless of which calling convention we are using for it. */
2233 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2234 warning ("function call has aggregate value");
2236 /* If the result of a pure or const function call is ignored (or void),
2237 and none of its arguments are volatile, we can avoid expanding the
2238 call and just evaluate the arguments for side-effects. */
2239 if ((flags & (ECF_CONST | ECF_PURE))
2240 && (ignore || target == const0_rtx
2241 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2243 bool volatilep = false;
2246 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2247 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2255 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2256 expand_expr (TREE_VALUE (arg), const0_rtx,
2257 VOIDmode, EXPAND_NORMAL);
2262 #ifdef REG_PARM_STACK_SPACE
2263 #ifdef MAYBE_REG_PARM_STACK_SPACE
2264 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2266 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2270 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2271 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2272 must_preallocate = 1;
2275 /* Set up a place to return a structure. */
2277 /* Cater to broken compilers. */
2278 if (aggregate_value_p (exp, fndecl))
2280 /* This call returns a big structure. */
2281 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2283 #ifdef PCC_STATIC_STRUCT_RETURN
2285 pcc_struct_value = 1;
2286 /* Easier than making that case work right. */
2289 /* In case this is a static function, note that it has been
2291 if (! TREE_ADDRESSABLE (fndecl))
2292 (*lang_hooks.mark_addressable) (fndecl);
2296 #else /* not PCC_STATIC_STRUCT_RETURN */
2298 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2300 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2302 /* The structure value address arg is already in actparms.
2303 Pull it out. It might be nice to just leave it there, but
2304 we need to set structure_value_addr. */
2305 tree return_arg = TREE_VALUE (actparms);
2306 actparms = TREE_CHAIN (actparms);
2307 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2308 VOIDmode, EXPAND_NORMAL);
2310 else if (target && GET_CODE (target) == MEM)
2311 structure_value_addr = XEXP (target, 0);
2314 /* For variable-sized objects, we must be called with a target
2315 specified. If we were to allocate space on the stack here,
2316 we would have no way of knowing when to free it. */
2317 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2319 mark_temp_addr_taken (d);
2320 structure_value_addr = XEXP (d, 0);
2324 #endif /* not PCC_STATIC_STRUCT_RETURN */
2327 /* If called function is inline, try to integrate it. */
2331 rtx temp = try_to_integrate (fndecl, actparms, target,
2332 ignore, TREE_TYPE (exp),
2333 structure_value_addr);
2334 if (temp != (rtx) (size_t) - 1)
2338 /* Figure out the amount to which the stack should be aligned. */
2339 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2342 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2343 if (i && i->preferred_incoming_stack_boundary)
2344 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2347 /* Operand 0 is a pointer-to-function; get the type of the function. */
2348 funtype = TREE_TYPE (addr);
2349 if (! POINTER_TYPE_P (funtype))
2351 funtype = TREE_TYPE (funtype);
2353 /* Munge the tree to split complex arguments into their imaginary
2355 if (SPLIT_COMPLEX_ARGS)
2357 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2358 actparms = split_complex_values (actparms);
2361 type_arg_types = TYPE_ARG_TYPES (funtype);
2363 /* See if this is a call to a function that can return more than once
2364 or a call to longjmp or malloc. */
2365 flags |= special_function_p (fndecl, flags);
2367 if (flags & ECF_MAY_BE_ALLOCA)
2368 current_function_calls_alloca = 1;
2370 /* If struct_value_rtx is 0, it means pass the address
2371 as if it were an extra parameter. */
2372 if (structure_value_addr && struct_value == 0)
2374 /* If structure_value_addr is a REG other than
2375 virtual_outgoing_args_rtx, we can use always use it. If it
2376 is not a REG, we must always copy it into a register.
2377 If it is virtual_outgoing_args_rtx, we must copy it to another
2378 register in some cases. */
2379 rtx temp = (GET_CODE (structure_value_addr) != REG
2380 || (ACCUMULATE_OUTGOING_ARGS
2381 && stack_arg_under_construction
2382 && structure_value_addr == virtual_outgoing_args_rtx)
2383 ? copy_addr_to_reg (structure_value_addr)
2384 : structure_value_addr);
2387 = tree_cons (error_mark_node,
2388 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2391 structure_value_addr_parm = 1;
2394 /* Count the arguments and set NUM_ACTUALS. */
2395 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2398 /* Start updating where the next arg would go.
2400 On some machines (such as the PA) indirect calls have a different
2401 calling convention than normal calls. The last argument in
2402 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2404 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2406 /* Compute number of named args.
2407 Normally, don't include the last named arg if anonymous args follow.
2408 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2409 (If no anonymous args follow, the result of list_length is actually
2410 one too large. This is harmless.)
2412 If targetm.calls.pretend_outgoing_varargs_named() returns
2413 nonzero, and STRICT_ARGUMENT_NAMING is zero, this machine will be
2414 able to place unnamed args that were passed in registers into the
2415 stack. So treat all args as named. This allows the insns
2416 emitting for a specific argument list to be independent of the
2417 function declaration.
2419 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2420 we do not have any reliable way to pass unnamed args in
2421 registers, so we must force them into memory. */
2423 if ((targetm.calls.strict_argument_naming (&args_so_far)
2424 || ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2425 && type_arg_types != 0)
2427 = (list_length (type_arg_types)
2428 /* Don't include the last named arg. */
2429 - (targetm.calls.strict_argument_naming (&args_so_far) ? 0 : 1)
2430 /* Count the struct value address, if it is passed as a parm. */
2431 + structure_value_addr_parm);
2433 /* If we know nothing, treat all args as named. */
2434 n_named_args = num_actuals;
2436 /* Make a vector to hold all the information about each arg. */
2437 args = alloca (num_actuals * sizeof (struct arg_data));
2438 memset (args, 0, num_actuals * sizeof (struct arg_data));
2440 /* Build up entries in the ARGS array, compute the size of the
2441 arguments into ARGS_SIZE, etc. */
2442 initialize_argument_information (num_actuals, args, &args_size,
2443 n_named_args, actparms, fndecl,
2444 &args_so_far, reg_parm_stack_space,
2445 &old_stack_level, &old_pending_adj,
2446 &must_preallocate, &flags);
2450 /* If this function requires a variable-sized argument list, don't
2451 try to make a cse'able block for this call. We may be able to
2452 do this eventually, but it is too complicated to keep track of
2453 what insns go in the cse'able block and which don't. */
2455 flags &= ~ECF_LIBCALL_BLOCK;
2456 must_preallocate = 1;
2459 /* Now make final decision about preallocating stack space. */
2460 must_preallocate = finalize_must_preallocate (must_preallocate,
2464 /* If the structure value address will reference the stack pointer, we
2465 must stabilize it. We don't need to do this if we know that we are
2466 not going to adjust the stack pointer in processing this call. */
2468 if (structure_value_addr
2469 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2470 || reg_mentioned_p (virtual_outgoing_args_rtx,
2471 structure_value_addr))
2473 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2474 structure_value_addr = copy_to_reg (structure_value_addr);
2476 /* Tail calls can make things harder to debug, and we're traditionally
2477 pushed these optimizations into -O2. Don't try if we're already
2478 expanding a call, as that means we're an argument. Don't try if
2479 there's cleanups, as we know there's code to follow the call.
2481 If rtx_equal_function_value_matters is false, that means we've
2482 finished with regular parsing. Which means that some of the
2483 machinery we use to generate tail-calls is no longer in place.
2484 This is most often true of sjlj-exceptions, which we couldn't
2485 tail-call to anyway.
2487 If current_nesting_level () == 0, we're being called after
2488 the function body has been expanded. This can happen when
2489 setting up trampolines in expand_function_end. */
2490 if (currently_expanding_call++ != 0
2491 || !flag_optimize_sibling_calls
2492 || !rtx_equal_function_value_matters
2493 || current_nesting_level () == 0
2494 || any_pending_cleanups ()
2496 try_tail_call = try_tail_recursion = 0;
2498 /* Tail recursion fails, when we are not dealing with recursive calls. */
2499 if (!try_tail_recursion
2500 || TREE_CODE (addr) != ADDR_EXPR
2501 || TREE_OPERAND (addr, 0) != current_function_decl)
2502 try_tail_recursion = 0;
2504 /* Rest of purposes for tail call optimizations to fail. */
2506 #ifdef HAVE_sibcall_epilogue
2507 !HAVE_sibcall_epilogue
2512 /* Doing sibling call optimization needs some work, since
2513 structure_value_addr can be allocated on the stack.
2514 It does not seem worth the effort since few optimizable
2515 sibling calls will return a structure. */
2516 || structure_value_addr != NULL_RTX
2517 /* Check whether the target is able to optimize the call
2519 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2520 /* Functions that do not return exactly once may not be sibcall
2522 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2523 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2524 /* If the called function is nested in the current one, it might access
2525 some of the caller's arguments, but could clobber them beforehand if
2526 the argument areas are shared. */
2527 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2528 /* If this function requires more stack slots than the current
2529 function, we cannot change it into a sibling call. */
2530 || args_size.constant > current_function_args_size
2531 /* If the callee pops its own arguments, then it must pop exactly
2532 the same number of arguments as the current function. */
2533 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2534 != RETURN_POPS_ARGS (current_function_decl,
2535 TREE_TYPE (current_function_decl),
2536 current_function_args_size))
2537 || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2540 if (try_tail_call || try_tail_recursion)
2543 actparms = NULL_TREE;
2544 /* Ok, we're going to give the tail call the old college try.
2545 This means we're going to evaluate the function arguments
2546 up to three times. There are two degrees of badness we can
2547 encounter, those that can be unsaved and those that can't.
2548 (See unsafe_for_reeval commentary for details.)
2550 Generate a new argument list. Pass safe arguments through
2551 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2552 For hard badness, evaluate them now and put their resulting
2553 rtx in a temporary VAR_DECL.
2555 initialize_argument_information has ordered the array for the
2556 order to be pushed, and we must remember this when reconstructing
2557 the original argument order. */
2559 if (PUSH_ARGS_REVERSED)
2568 i = num_actuals - 1;
2572 for (; i != end; i += inc)
2574 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2575 /* We need to build actparms for optimize_tail_recursion. We can
2576 safely trash away TREE_PURPOSE, since it is unused by this
2578 if (try_tail_recursion)
2579 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2581 /* Do the same for the function address if it is an expression. */
2583 addr = fix_unsafe_tree (addr);
2584 /* Expanding one of those dangerous arguments could have added
2585 cleanups, but otherwise give it a whirl. */
2586 if (any_pending_cleanups ())
2587 try_tail_call = try_tail_recursion = 0;
2590 /* Generate a tail recursion sequence when calling ourselves. */
2592 if (try_tail_recursion)
2594 /* We want to emit any pending stack adjustments before the tail
2595 recursion "call". That way we know any adjustment after the tail
2596 recursion call can be ignored if we indeed use the tail recursion
2598 int save_pending_stack_adjust = pending_stack_adjust;
2599 int save_stack_pointer_delta = stack_pointer_delta;
2601 /* Emit any queued insns now; otherwise they would end up in
2602 only one of the alternates. */
2605 /* Use a new sequence to hold any RTL we generate. We do not even
2606 know if we will use this RTL yet. The final decision can not be
2607 made until after RTL generation for the entire function is
2610 /* If expanding any of the arguments creates cleanups, we can't
2611 do a tailcall. So, we'll need to pop the pending cleanups
2612 list. If, however, all goes well, and there are no cleanups
2613 then the call to expand_start_target_temps will have no
2615 expand_start_target_temps ();
2616 if (optimize_tail_recursion (actparms, get_last_insn ()))
2618 if (any_pending_cleanups ())
2619 try_tail_call = try_tail_recursion = 0;
2621 tail_recursion_insns = get_insns ();
2623 expand_end_target_temps ();
2626 /* Restore the original pending stack adjustment for the sibling and
2627 normal call cases below. */
2628 pending_stack_adjust = save_pending_stack_adjust;
2629 stack_pointer_delta = save_stack_pointer_delta;
2632 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2634 /* A fork duplicates the profile information, and an exec discards
2635 it. We can't rely on fork/exec to be paired. So write out the
2636 profile information we have gathered so far, and clear it. */
2637 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2638 is subject to race conditions, just as with multithreaded
2641 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2644 /* Ensure current function's preferred stack boundary is at least
2645 what we need. We don't have to increase alignment for recursive
2647 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2648 && fndecl != current_function_decl)
2649 cfun->preferred_stack_boundary = preferred_stack_boundary;
2650 if (fndecl == current_function_decl)
2651 cfun->recursive_call_emit = true;
2653 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2655 function_call_count++;
2657 /* We want to make two insn chains; one for a sibling call, the other
2658 for a normal call. We will select one of the two chains after
2659 initial RTL generation is complete. */
2660 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2662 int sibcall_failure = 0;
2663 /* We want to emit any pending stack adjustments before the tail
2664 recursion "call". That way we know any adjustment after the tail
2665 recursion call can be ignored if we indeed use the tail recursion
2667 int save_pending_stack_adjust = 0;
2668 int save_stack_pointer_delta = 0;
2670 rtx before_call, next_arg_reg;
2674 /* Emit any queued insns now; otherwise they would end up in
2675 only one of the alternates. */
2678 /* State variables we need to save and restore between
2680 save_pending_stack_adjust = pending_stack_adjust;
2681 save_stack_pointer_delta = stack_pointer_delta;
2684 flags &= ~ECF_SIBCALL;
2686 flags |= ECF_SIBCALL;
2688 /* Other state variables that we must reinitialize each time
2689 through the loop (that are not initialized by the loop itself). */
2693 /* Start a new sequence for the normal call case.
2695 From this point on, if the sibling call fails, we want to set
2696 sibcall_failure instead of continuing the loop. */
2701 /* We know at this point that there are not currently any
2702 pending cleanups. If, however, in the process of evaluating
2703 the arguments we were to create some, we'll need to be
2704 able to get rid of them. */
2705 expand_start_target_temps ();
2708 /* Don't let pending stack adjusts add up to too much.
2709 Also, do all pending adjustments now if there is any chance
2710 this might be a call to alloca or if we are expanding a sibling
2711 call sequence or if we are calling a function that is to return
2712 with stack pointer depressed. */
2713 if (pending_stack_adjust >= 32
2714 || (pending_stack_adjust > 0
2715 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2717 do_pending_stack_adjust ();
2719 /* When calling a const function, we must pop the stack args right away,
2720 so that the pop is deleted or moved with the call. */
2721 if (pass && (flags & ECF_LIBCALL_BLOCK))
2724 #ifdef FINAL_REG_PARM_STACK_SPACE
2725 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2728 /* Precompute any arguments as needed. */
2730 precompute_arguments (flags, num_actuals, args);
2732 /* Now we are about to start emitting insns that can be deleted
2733 if a libcall is deleted. */
2734 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2737 adjusted_args_size = args_size;
2738 /* Compute the actual size of the argument block required. The variable
2739 and constant sizes must be combined, the size may have to be rounded,
2740 and there may be a minimum required size. When generating a sibcall
2741 pattern, do not round up, since we'll be re-using whatever space our
2743 unadjusted_args_size
2744 = compute_argument_block_size (reg_parm_stack_space,
2745 &adjusted_args_size,
2747 : preferred_stack_boundary));
2749 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2751 /* The argument block when performing a sibling call is the
2752 incoming argument block. */
2755 argblock = virtual_incoming_args_rtx;
2757 #ifdef STACK_GROWS_DOWNWARD
2758 = plus_constant (argblock, current_function_pretend_args_size);
2760 = plus_constant (argblock, -current_function_pretend_args_size);
2762 stored_args_map = sbitmap_alloc (args_size.constant);
2763 sbitmap_zero (stored_args_map);
2766 /* If we have no actual push instructions, or shouldn't use them,
2767 make space for all args right now. */
2768 else if (adjusted_args_size.var != 0)
2770 if (old_stack_level == 0)
2772 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2773 old_stack_pointer_delta = stack_pointer_delta;
2774 old_pending_adj = pending_stack_adjust;
2775 pending_stack_adjust = 0;
2776 /* stack_arg_under_construction says whether a stack arg is
2777 being constructed at the old stack level. Pushing the stack
2778 gets a clean outgoing argument block. */
2779 old_stack_arg_under_construction = stack_arg_under_construction;
2780 stack_arg_under_construction = 0;
2782 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2786 /* Note that we must go through the motions of allocating an argument
2787 block even if the size is zero because we may be storing args
2788 in the area reserved for register arguments, which may be part of
2791 int needed = adjusted_args_size.constant;
2793 /* Store the maximum argument space used. It will be pushed by
2794 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2797 if (needed > current_function_outgoing_args_size)
2798 current_function_outgoing_args_size = needed;
2800 if (must_preallocate)
2802 if (ACCUMULATE_OUTGOING_ARGS)
2804 /* Since the stack pointer will never be pushed, it is
2805 possible for the evaluation of a parm to clobber
2806 something we have already written to the stack.
2807 Since most function calls on RISC machines do not use
2808 the stack, this is uncommon, but must work correctly.
2810 Therefore, we save any area of the stack that was already
2811 written and that we are using. Here we set up to do this
2812 by making a new stack usage map from the old one. The
2813 actual save will be done by store_one_arg.
2815 Another approach might be to try to reorder the argument
2816 evaluations to avoid this conflicting stack usage. */
2818 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2819 /* Since we will be writing into the entire argument area,
2820 the map must be allocated for its entire size, not just
2821 the part that is the responsibility of the caller. */
2822 needed += reg_parm_stack_space;
2825 #ifdef ARGS_GROW_DOWNWARD
2826 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2829 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2832 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2834 if (initial_highest_arg_in_use)
2835 memcpy (stack_usage_map, initial_stack_usage_map,
2836 initial_highest_arg_in_use);
2838 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2839 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2840 (highest_outgoing_arg_in_use
2841 - initial_highest_arg_in_use));
2844 /* The address of the outgoing argument list must not be
2845 copied to a register here, because argblock would be left
2846 pointing to the wrong place after the call to
2847 allocate_dynamic_stack_space below. */
2849 argblock = virtual_outgoing_args_rtx;
2853 if (inhibit_defer_pop == 0)
2855 /* Try to reuse some or all of the pending_stack_adjust
2856 to get this space. */
2858 = (combine_pending_stack_adjustment_and_call
2859 (unadjusted_args_size,
2860 &adjusted_args_size,
2861 preferred_unit_stack_boundary));
2863 /* combine_pending_stack_adjustment_and_call computes
2864 an adjustment before the arguments are allocated.
2865 Account for them and see whether or not the stack
2866 needs to go up or down. */
2867 needed = unadjusted_args_size - needed;
2871 /* We're releasing stack space. */
2872 /* ??? We can avoid any adjustment at all if we're
2873 already aligned. FIXME. */
2874 pending_stack_adjust = -needed;
2875 do_pending_stack_adjust ();
2879 /* We need to allocate space. We'll do that in
2880 push_block below. */
2881 pending_stack_adjust = 0;
2884 /* Special case this because overhead of `push_block' in
2885 this case is non-trivial. */
2887 argblock = virtual_outgoing_args_rtx;
2890 argblock = push_block (GEN_INT (needed), 0, 0);
2891 #ifdef ARGS_GROW_DOWNWARD
2892 argblock = plus_constant (argblock, needed);
2896 /* We only really need to call `copy_to_reg' in the case
2897 where push insns are going to be used to pass ARGBLOCK
2898 to a function call in ARGS. In that case, the stack
2899 pointer changes value from the allocation point to the
2900 call point, and hence the value of
2901 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2902 as well always do it. */
2903 argblock = copy_to_reg (argblock);
2908 if (ACCUMULATE_OUTGOING_ARGS)
2910 /* The save/restore code in store_one_arg handles all
2911 cases except one: a constructor call (including a C
2912 function returning a BLKmode struct) to initialize
2914 if (stack_arg_under_construction)
2916 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2917 rtx push_size = GEN_INT (reg_parm_stack_space
2918 + adjusted_args_size.constant);
2920 rtx push_size = GEN_INT (adjusted_args_size.constant);
2922 if (old_stack_level == 0)
2924 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2926 old_stack_pointer_delta = stack_pointer_delta;
2927 old_pending_adj = pending_stack_adjust;
2928 pending_stack_adjust = 0;
2929 /* stack_arg_under_construction says whether a stack
2930 arg is being constructed at the old stack level.
2931 Pushing the stack gets a clean outgoing argument
2933 old_stack_arg_under_construction
2934 = stack_arg_under_construction;
2935 stack_arg_under_construction = 0;
2936 /* Make a new map for the new argument list. */
2937 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2938 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2939 highest_outgoing_arg_in_use = 0;
2941 allocate_dynamic_stack_space (push_size, NULL_RTX,
2945 /* If argument evaluation might modify the stack pointer,
2946 copy the address of the argument list to a register. */
2947 for (i = 0; i < num_actuals; i++)
2948 if (args[i].pass_on_stack)
2950 argblock = copy_addr_to_reg (argblock);
2955 compute_argument_addresses (args, argblock, num_actuals);
2957 /* If we push args individually in reverse order, perform stack alignment
2958 before the first push (the last arg). */
2959 if (PUSH_ARGS_REVERSED && argblock == 0
2960 && adjusted_args_size.constant != unadjusted_args_size)
2962 /* When the stack adjustment is pending, we get better code
2963 by combining the adjustments. */
2964 if (pending_stack_adjust
2965 && ! (flags & ECF_LIBCALL_BLOCK)
2966 && ! inhibit_defer_pop)
2968 pending_stack_adjust
2969 = (combine_pending_stack_adjustment_and_call
2970 (unadjusted_args_size,
2971 &adjusted_args_size,
2972 preferred_unit_stack_boundary));
2973 do_pending_stack_adjust ();
2975 else if (argblock == 0)
2976 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2977 - unadjusted_args_size));
2979 /* Now that the stack is properly aligned, pops can't safely
2980 be deferred during the evaluation of the arguments. */
2983 funexp = rtx_for_function_call (fndecl, addr);
2985 /* Figure out the register where the value, if any, will come back. */
2987 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2988 && ! structure_value_addr)
2990 if (pcc_struct_value)
2991 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2992 fndecl, (pass == 0));
2994 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2997 /* Precompute all register parameters. It isn't safe to compute anything
2998 once we have started filling any specific hard regs. */
2999 precompute_register_parameters (num_actuals, args, ®_parm_seen);
3001 #ifdef REG_PARM_STACK_SPACE
3002 /* Save the fixed argument area if it's part of the caller's frame and
3003 is clobbered by argument setup for this call. */
3004 if (ACCUMULATE_OUTGOING_ARGS && pass)
3005 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3006 &low_to_save, &high_to_save);
3009 /* Now store (and compute if necessary) all non-register parms.
3010 These come before register parms, since they can require block-moves,
3011 which could clobber the registers used for register parms.
3012 Parms which have partial registers are not stored here,
3013 but we do preallocate space here if they want that. */
3015 for (i = 0; i < num_actuals; i++)
3016 if (args[i].reg == 0 || args[i].pass_on_stack)
3018 rtx before_arg = get_last_insn ();
3020 if (store_one_arg (&args[i], argblock, flags,
3021 adjusted_args_size.var != 0,
3022 reg_parm_stack_space)
3024 && check_sibcall_argument_overlap (before_arg,
3026 sibcall_failure = 1;
3029 /* If we have a parm that is passed in registers but not in memory
3030 and whose alignment does not permit a direct copy into registers,
3031 make a group of pseudos that correspond to each register that we
3033 if (STRICT_ALIGNMENT)
3034 store_unaligned_arguments_into_pseudos (args, num_actuals);
3036 /* Now store any partially-in-registers parm.
3037 This is the last place a block-move can happen. */
3039 for (i = 0; i < num_actuals; i++)
3040 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3042 rtx before_arg = get_last_insn ();
3044 if (store_one_arg (&args[i], argblock, flags,
3045 adjusted_args_size.var != 0,
3046 reg_parm_stack_space)
3048 && check_sibcall_argument_overlap (before_arg,
3050 sibcall_failure = 1;
3053 /* If we pushed args in forward order, perform stack alignment
3054 after pushing the last arg. */
3055 if (!PUSH_ARGS_REVERSED && argblock == 0)
3056 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3057 - unadjusted_args_size));
3059 /* If register arguments require space on the stack and stack space
3060 was not preallocated, allocate stack space here for arguments
3061 passed in registers. */
3062 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3063 if (!ACCUMULATE_OUTGOING_ARGS
3064 && must_preallocate == 0 && reg_parm_stack_space > 0)
3065 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3068 /* Pass the function the address in which to return a
3070 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3072 structure_value_addr
3073 = convert_memory_address (Pmode, structure_value_addr);
3074 emit_move_insn (struct_value,
3076 force_operand (structure_value_addr,
3079 if (GET_CODE (struct_value) == REG)
3080 use_reg (&call_fusage, struct_value);
3083 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3084 reg_parm_seen, pass == 0);
3086 load_register_parameters (args, num_actuals, &call_fusage, flags,
3087 pass == 0, &sibcall_failure);
3089 /* Perform postincrements before actually calling the function. */
3092 /* Save a pointer to the last insn before the call, so that we can
3093 later safely search backwards to find the CALL_INSN. */
3094 before_call = get_last_insn ();
3096 /* Set up next argument register. For sibling calls on machines
3097 with register windows this should be the incoming register. */
3098 #ifdef FUNCTION_INCOMING_ARG
3100 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3104 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3107 /* All arguments and registers used for the call must be set up by
3110 /* Stack must be properly aligned now. */
3111 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3114 /* Generate the actual call instruction. */
3115 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3116 adjusted_args_size.constant, struct_value_size,
3117 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3118 flags, & args_so_far);
3120 /* If call is cse'able, make appropriate pair of reg-notes around it.
3121 Test valreg so we don't crash; may safely ignore `const'
3122 if return type is void. Disable for PARALLEL return values, because
3123 we have no way to move such values into a pseudo register. */
3124 if (pass && (flags & ECF_LIBCALL_BLOCK))
3128 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
3130 insns = get_insns ();
3132 /* Expansion of block moves possibly introduced a loop that may
3133 not appear inside libcall block. */
3134 for (insn = insns; insn; insn = NEXT_INSN (insn))
3135 if (GET_CODE (insn) == JUMP_INSN)
3146 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3148 /* Mark the return value as a pointer if needed. */
3149 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3150 mark_reg_pointer (temp,
3151 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3153 /* Construct an "equal form" for the value which mentions all the
3154 arguments in order as well as the function name. */
3155 for (i = 0; i < num_actuals; i++)
3156 note = gen_rtx_EXPR_LIST (VOIDmode,
3157 args[i].initial_value, note);
3158 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3162 if (flags & ECF_PURE)
3163 note = gen_rtx_EXPR_LIST (VOIDmode,
3164 gen_rtx_USE (VOIDmode,
3165 gen_rtx_MEM (BLKmode,
3166 gen_rtx_SCRATCH (VOIDmode))),
3169 emit_libcall_block (insns, temp, valreg, note);
3174 else if (pass && (flags & ECF_MALLOC))
3176 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3179 /* The return value from a malloc-like function is a pointer. */
3180 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3181 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3183 emit_move_insn (temp, valreg);
3185 /* The return value from a malloc-like function can not alias
3187 last = get_last_insn ();
3189 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3191 /* Write out the sequence. */
3192 insns = get_insns ();
3198 /* For calls to `setjmp', etc., inform flow.c it should complain
3199 if nonvolatile values are live. For functions that cannot return,
3200 inform flow that control does not fall through. */
3202 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3204 /* The barrier must be emitted
3205 immediately after the CALL_INSN. Some ports emit more
3206 than just a CALL_INSN above, so we must search for it here. */
3208 rtx last = get_last_insn ();
3209 while (GET_CODE (last) != CALL_INSN)
3211 last = PREV_INSN (last);
3212 /* There was no CALL_INSN? */
3213 if (last == before_call)
3217 emit_barrier_after (last);
3219 /* Stack adjustments after a noreturn call are dead code.
3220 However when NO_DEFER_POP is in effect, we must preserve
3221 stack_pointer_delta. */
3222 if (inhibit_defer_pop == 0)
3224 stack_pointer_delta = old_stack_allocated;
3225 pending_stack_adjust = 0;
3229 if (flags & ECF_LONGJMP)
3230 current_function_calls_longjmp = 1;
3232 /* If value type not void, return an rtx for the value. */
3234 /* If there are cleanups to be called, don't use a hard reg as target.
3235 We need to double check this and see if it matters anymore. */
3236 if (any_pending_cleanups ())
3238 if (target && REG_P (target)
3239 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3241 sibcall_failure = 1;
3244 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3246 target = const0_rtx;
3247 else if (structure_value_addr)
3249 if (target == 0 || GET_CODE (target) != MEM)
3252 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3253 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3254 structure_value_addr));
3255 set_mem_attributes (target, exp, 1);
3258 else if (pcc_struct_value)
3260 /* This is the special C++ case where we need to
3261 know what the true target was. We take care to
3262 never use this value more than once in one expression. */
3263 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3264 copy_to_reg (valreg));
3265 set_mem_attributes (target, exp, 1);
3267 /* Handle calls that return values in multiple non-contiguous locations.
3268 The Irix 6 ABI has examples of this. */
3269 else if (GET_CODE (valreg) == PARALLEL)
3271 /* Second condition is added because "target" is freed at the
3272 the end of "pass0" for -O2 when call is made to
3273 expand_end_target_temps (). Its "in_use" flag has been set
3274 to false, so allocate a new temp. */
3275 if (target == 0 || (pass == 1 && target == temp_target))
3277 /* This will only be assigned once, so it can be readonly. */
3278 tree nt = build_qualified_type (TREE_TYPE (exp),
3279 (TYPE_QUALS (TREE_TYPE (exp))
3280 | TYPE_QUAL_CONST));
3282 target = assign_temp (nt, 0, 1, 1);
3283 temp_target = target;
3284 preserve_temp_slots (target);
3287 if (! rtx_equal_p (target, valreg))
3288 emit_group_store (target, valreg, TREE_TYPE (exp),
3289 int_size_in_bytes (TREE_TYPE (exp)));
3291 /* We can not support sibling calls for this case. */
3292 sibcall_failure = 1;
3295 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3296 && GET_MODE (target) == GET_MODE (valreg))
3298 /* TARGET and VALREG cannot be equal at this point because the
3299 latter would not have REG_FUNCTION_VALUE_P true, while the
3300 former would if it were referring to the same register.
3302 If they refer to the same register, this move will be a no-op,
3303 except when function inlining is being done. */
3304 emit_move_insn (target, valreg);
3306 /* If we are setting a MEM, this code must be executed. Since it is
3307 emitted after the call insn, sibcall optimization cannot be
3308 performed in that case. */
3309 if (GET_CODE (target) == MEM)
3310 sibcall_failure = 1;
3312 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3314 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3316 /* We can not support sibling calls for this case. */
3317 sibcall_failure = 1;
3321 if (shift_returned_value (TREE_TYPE (exp), &valreg))
3322 sibcall_failure = 1;
3324 target = copy_to_reg (valreg);
3327 if (targetm.calls.promote_function_return(funtype))
3329 /* If we promoted this return value, make the proper SUBREG. TARGET
3330 might be const0_rtx here, so be careful. */
3331 if (GET_CODE (target) == REG
3332 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3333 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3335 tree type = TREE_TYPE (exp);
3336 int unsignedp = TREE_UNSIGNED (type);
3339 /* If we don't promote as expected, something is wrong. */
3340 if (GET_MODE (target)
3341 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3344 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3345 && GET_MODE_SIZE (GET_MODE (target))
3346 > GET_MODE_SIZE (TYPE_MODE (type)))
3348 offset = GET_MODE_SIZE (GET_MODE (target))
3349 - GET_MODE_SIZE (TYPE_MODE (type));
3350 if (! BYTES_BIG_ENDIAN)
3351 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3352 else if (! WORDS_BIG_ENDIAN)
3353 offset %= UNITS_PER_WORD;
3355 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3356 SUBREG_PROMOTED_VAR_P (target) = 1;
3357 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3361 /* If size of args is variable or this was a constructor call for a stack
3362 argument, restore saved stack-pointer value. */
3364 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3366 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3367 stack_pointer_delta = old_stack_pointer_delta;
3368 pending_stack_adjust = old_pending_adj;
3369 stack_arg_under_construction = old_stack_arg_under_construction;
3370 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3371 stack_usage_map = initial_stack_usage_map;
3372 sibcall_failure = 1;
3374 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3376 #ifdef REG_PARM_STACK_SPACE
3378 restore_fixed_argument_area (save_area, argblock,
3379 high_to_save, low_to_save);
3382 /* If we saved any argument areas, restore them. */
3383 for (i = 0; i < num_actuals; i++)
3384 if (args[i].save_area)
3386 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3388 = gen_rtx_MEM (save_mode,
3389 memory_address (save_mode,
3390 XEXP (args[i].stack_slot, 0)));
3392 if (save_mode != BLKmode)
3393 emit_move_insn (stack_area, args[i].save_area);
3395 emit_block_move (stack_area, args[i].save_area,
3396 GEN_INT (args[i].locate.size.constant),
3397 BLOCK_OP_CALL_PARM);
3400 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3401 stack_usage_map = initial_stack_usage_map;
3404 /* If this was alloca, record the new stack level for nonlocal gotos.
3405 Check for the handler slots since we might not have a save area
3406 for non-local gotos. */
3408 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3409 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3411 /* Free up storage we no longer need. */
3412 for (i = 0; i < num_actuals; ++i)
3413 if (args[i].aligned_regs)
3414 free (args[i].aligned_regs);
3418 /* Undo the fake expand_start_target_temps we did earlier. If
3419 there had been any cleanups created, we've already set
3421 expand_end_target_temps ();
3424 /* If this function is returning into a memory location marked as
3425 readonly, it means it is initializing that location. We normally treat
3426 functions as not clobbering such locations, so we need to specify that
3427 this one does. We do this by adding the appropriate CLOBBER to the
3428 CALL_INSN function usage list. This cannot be done by emitting a
3429 standalone CLOBBER after the call because the latter would be ignored
3430 by at least the delay slot scheduling pass. We do this now instead of
3431 adding to call_fusage before the call to emit_call_1 because TARGET
3432 may be modified in the meantime. */
3433 if (structure_value_addr != 0 && target != 0
3434 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3435 add_function_usage_to
3437 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3440 insns = get_insns ();
3445 tail_call_insns = insns;
3447 /* Restore the pending stack adjustment now that we have
3448 finished generating the sibling call sequence. */
3450 pending_stack_adjust = save_pending_stack_adjust;
3451 stack_pointer_delta = save_stack_pointer_delta;
3453 /* Prepare arg structure for next iteration. */
3454 for (i = 0; i < num_actuals; i++)
3457 args[i].aligned_regs = 0;
3461 sbitmap_free (stored_args_map);
3465 normal_call_insns = insns;
3467 /* Verify that we've deallocated all the stack we used. */
3468 if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3469 && old_stack_allocated != stack_pointer_delta
3470 - pending_stack_adjust)
3474 /* If something prevents making this a sibling call,
3475 zero out the sequence. */
3476 if (sibcall_failure)
3477 tail_call_insns = NULL_RTX;
3480 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3481 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3482 can happen if the arguments to this function call an inline
3483 function who's expansion contains another CALL_PLACEHOLDER.
3485 If there are any C_Ps in any of these sequences, replace them
3486 with their normal call. */
3488 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3489 if (GET_CODE (insn) == CALL_INSN
3490 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3491 replace_call_placeholder (insn, sibcall_use_normal);
3493 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3494 if (GET_CODE (insn) == CALL_INSN
3495 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3496 replace_call_placeholder (insn, sibcall_use_normal);
3498 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3499 if (GET_CODE (insn) == CALL_INSN
3500 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3501 replace_call_placeholder (insn, sibcall_use_normal);
3503 /* If this was a potential tail recursion site, then emit a
3504 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3505 One of them will be selected later. */
3506 if (tail_recursion_insns || tail_call_insns)
3508 /* The tail recursion label must be kept around. We could expose
3509 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3510 and makes determining true tail recursion sites difficult.
3512 So we set LABEL_PRESERVE_P here, then clear it when we select
3513 one of the call sequences after rtl generation is complete. */
3514 if (tail_recursion_insns)
3515 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3516 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3518 tail_recursion_insns,
3519 tail_recursion_label));
3522 emit_insn (normal_call_insns);
3524 currently_expanding_call--;
3526 /* If this function returns with the stack pointer depressed, ensure
3527 this block saves and restores the stack pointer, show it was
3528 changed, and adjust for any outgoing arg space. */
3529 if (flags & ECF_SP_DEPRESSED)
3531 clear_pending_stack_adjust ();
3532 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3533 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3534 save_stack_pointer ();
3540 /* Traverse an argument list in VALUES and expand all complex
3541 arguments into their components. */
3543 split_complex_values (tree values)
3547 values = copy_list (values);
3549 for (p = values; p; p = TREE_CHAIN (p))
3551 tree complex_value = TREE_VALUE (p);
3554 complex_type = TREE_TYPE (complex_value);
3558 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3561 tree real, imag, next;
3563 subtype = TREE_TYPE (complex_type);
3564 complex_value = save_expr (complex_value);
3565 real = build1 (REALPART_EXPR, subtype, complex_value);
3566 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3568 TREE_VALUE (p) = real;
3569 next = TREE_CHAIN (p);
3570 imag = build_tree_list (NULL_TREE, imag);
3571 TREE_CHAIN (p) = imag;
3572 TREE_CHAIN (imag) = next;
3574 /* Skip the newly created node. */
3582 /* Traverse a list of TYPES and expand all complex types into their
3585 split_complex_types (tree types)
3589 types = copy_list (types);
3591 for (p = types; p; p = TREE_CHAIN (p))
3593 tree complex_type = TREE_VALUE (p);
3595 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3599 /* Rewrite complex type with component type. */
3600 TREE_VALUE (p) = TREE_TYPE (complex_type);
3601 next = TREE_CHAIN (p);
3603 /* Add another component type for the imaginary part. */
3604 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3605 TREE_CHAIN (p) = imag;
3606 TREE_CHAIN (imag) = next;
3608 /* Skip the newly created node. */
3616 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3617 The RETVAL parameter specifies whether return value needs to be saved, other
3618 parameters are documented in the emit_library_call function below. */
3621 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3622 enum libcall_type fn_type,
3623 enum machine_mode outmode, int nargs, va_list p)
3625 /* Total size in bytes of all the stack-parms scanned so far. */
3626 struct args_size args_size;
3627 /* Size of arguments before any adjustments (such as rounding). */
3628 struct args_size original_args_size;
3634 CUMULATIVE_ARGS args_so_far;
3638 enum machine_mode mode;
3641 struct locate_and_pad_arg_data locate;
3645 int old_inhibit_defer_pop = inhibit_defer_pop;
3646 rtx call_fusage = 0;
3649 int pcc_struct_value = 0;
3650 int struct_value_size = 0;
3652 int reg_parm_stack_space = 0;
3655 tree tfom; /* type_for_mode (outmode, 0) */
3657 #ifdef REG_PARM_STACK_SPACE
3658 /* Define the boundary of the register parm stack space that needs to be
3660 int low_to_save, high_to_save;
3661 rtx save_area = 0; /* Place that it is saved. */
3664 /* Size of the stack reserved for parameter registers. */
3665 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3666 char *initial_stack_usage_map = stack_usage_map;
3668 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3670 #ifdef REG_PARM_STACK_SPACE
3671 #ifdef MAYBE_REG_PARM_STACK_SPACE
3672 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3674 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3678 /* By default, library functions can not throw. */
3679 flags = ECF_NOTHROW;
3691 case LCT_CONST_MAKE_BLOCK:
3692 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3694 case LCT_PURE_MAKE_BLOCK:
3695 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3698 flags |= ECF_NORETURN;
3701 flags = ECF_NORETURN;
3703 case LCT_ALWAYS_RETURN:
3704 flags = ECF_ALWAYS_RETURN;
3706 case LCT_RETURNS_TWICE:
3707 flags = ECF_RETURNS_TWICE;
3712 /* Ensure current function's preferred stack boundary is at least
3714 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3715 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3717 /* If this kind of value comes back in memory,
3718 decide where in memory it should come back. */
3719 if (outmode != VOIDmode)
3721 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3722 if (aggregate_value_p (tfom, 0))
3724 #ifdef PCC_STATIC_STRUCT_RETURN
3726 = hard_function_value (build_pointer_type (tfom), 0, 0);
3727 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3728 pcc_struct_value = 1;
3730 value = gen_reg_rtx (outmode);
3731 #else /* not PCC_STATIC_STRUCT_RETURN */
3732 struct_value_size = GET_MODE_SIZE (outmode);
3733 if (value != 0 && GET_CODE (value) == MEM)
3736 mem_value = assign_temp (tfom, 0, 1, 1);
3738 /* This call returns a big structure. */
3739 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3743 tfom = void_type_node;
3745 /* ??? Unfinished: must pass the memory address as an argument. */
3747 /* Copy all the libcall-arguments out of the varargs data
3748 and into a vector ARGVEC.
3750 Compute how to pass each argument. We only support a very small subset
3751 of the full argument passing conventions to limit complexity here since
3752 library functions shouldn't have many args. */
3754 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3755 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3757 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3758 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3760 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3763 args_size.constant = 0;
3768 /* Now we are about to start emitting insns that can be deleted
3769 if a libcall is deleted. */
3770 if (flags & ECF_LIBCALL_BLOCK)
3775 /* If there's a structure value address to be passed,
3776 either pass it in the special place, or pass it as an extra argument. */
3777 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3779 rtx addr = XEXP (mem_value, 0);
3782 /* Make sure it is a reasonable operand for a move or push insn. */
3783 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3784 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3785 addr = force_operand (addr, NULL_RTX);
3787 argvec[count].value = addr;
3788 argvec[count].mode = Pmode;
3789 argvec[count].partial = 0;
3791 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3792 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3793 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3797 locate_and_pad_parm (Pmode, NULL_TREE,
3798 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3801 argvec[count].reg != 0,
3803 0, NULL_TREE, &args_size, &argvec[count].locate);
3805 if (argvec[count].reg == 0 || argvec[count].partial != 0
3806 || reg_parm_stack_space > 0)
3807 args_size.constant += argvec[count].locate.size.constant;
3809 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3814 for (; count < nargs; count++)
3816 rtx val = va_arg (p, rtx);
3817 enum machine_mode mode = va_arg (p, enum machine_mode);
3819 /* We cannot convert the arg value to the mode the library wants here;
3820 must do it earlier where we know the signedness of the arg. */
3822 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3825 /* There's no need to call protect_from_queue, because
3826 either emit_move_insn or emit_push_insn will do that. */
3828 /* Make sure it is a reasonable operand for a move or push insn. */
3829 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3830 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3831 val = force_operand (val, NULL_RTX);
3833 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3834 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3838 #ifdef FUNCTION_ARG_CALLEE_COPIES
3839 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3844 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3845 functions, so we have to pretend this isn't such a function. */
3846 if (flags & ECF_LIBCALL_BLOCK)
3848 rtx insns = get_insns ();
3852 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3854 /* If this was a CONST function, it is now PURE since
3855 it now reads memory. */
3856 if (flags & ECF_CONST)
3858 flags &= ~ECF_CONST;
3862 if (GET_MODE (val) == MEM && ! must_copy)
3866 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3868 emit_move_insn (slot, val);
3872 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3875 = gen_rtx_MEM (mode,
3876 expand_expr (build1 (ADDR_EXPR,
3877 build_pointer_type (type),
3878 make_tree (type, val)),
3879 NULL_RTX, VOIDmode, 0));
3882 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3883 gen_rtx_USE (VOIDmode, slot),
3886 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3887 gen_rtx_CLOBBER (VOIDmode,
3892 val = force_operand (XEXP (slot, 0), NULL_RTX);
3896 argvec[count].value = val;
3897 argvec[count].mode = mode;
3899 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3901 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3902 argvec[count].partial
3903 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3905 argvec[count].partial = 0;
3908 locate_and_pad_parm (mode, NULL_TREE,
3909 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3912 argvec[count].reg != 0,
3914 argvec[count].partial,
3915 NULL_TREE, &args_size, &argvec[count].locate);
3917 if (argvec[count].locate.size.var)
3920 if (argvec[count].reg == 0 || argvec[count].partial != 0
3921 || reg_parm_stack_space > 0)
3922 args_size.constant += argvec[count].locate.size.constant;
3924 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3927 #ifdef FINAL_REG_PARM_STACK_SPACE
3928 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3931 /* If this machine requires an external definition for library
3932 functions, write one out. */
3933 assemble_external_libcall (fun);
3935 original_args_size = args_size;
3936 args_size.constant = (((args_size.constant
3937 + stack_pointer_delta
3941 - stack_pointer_delta);
3943 args_size.constant = MAX (args_size.constant,
3944 reg_parm_stack_space);
3946 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3947 args_size.constant -= reg_parm_stack_space;
3950 if (args_size.constant > current_function_outgoing_args_size)
3951 current_function_outgoing_args_size = args_size.constant;
3953 if (ACCUMULATE_OUTGOING_ARGS)
3955 /* Since the stack pointer will never be pushed, it is possible for
3956 the evaluation of a parm to clobber something we have already
3957 written to the stack. Since most function calls on RISC machines
3958 do not use the stack, this is uncommon, but must work correctly.
3960 Therefore, we save any area of the stack that was already written
3961 and that we are using. Here we set up to do this by making a new
3962 stack usage map from the old one.
3964 Another approach might be to try to reorder the argument
3965 evaluations to avoid this conflicting stack usage. */
3967 needed = args_size.constant;
3969 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3970 /* Since we will be writing into the entire argument area, the
3971 map must be allocated for its entire size, not just the part that
3972 is the responsibility of the caller. */
3973 needed += reg_parm_stack_space;
3976 #ifdef ARGS_GROW_DOWNWARD
3977 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3980 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3983 stack_usage_map = alloca (highest_outgoing_arg_in_use);
3985 if (initial_highest_arg_in_use)
3986 memcpy (stack_usage_map, initial_stack_usage_map,
3987 initial_highest_arg_in_use);
3989 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3990 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3991 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3994 /* We must be careful to use virtual regs before they're instantiated,
3995 and real regs afterwards. Loop optimization, for example, can create
3996 new libcalls after we've instantiated the virtual regs, and if we
3997 use virtuals anyway, they won't match the rtl patterns. */
3999 if (virtuals_instantiated)
4000 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
4002 argblock = virtual_outgoing_args_rtx;
4007 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
4010 /* If we push args individually in reverse order, perform stack alignment
4011 before the first push (the last arg). */
4012 if (argblock == 0 && PUSH_ARGS_REVERSED)
4013 anti_adjust_stack (GEN_INT (args_size.constant
4014 - original_args_size.constant));
4016 if (PUSH_ARGS_REVERSED)
4027 #ifdef REG_PARM_STACK_SPACE
4028 if (ACCUMULATE_OUTGOING_ARGS)
4030 /* The argument list is the property of the called routine and it
4031 may clobber it. If the fixed area has been used for previous
4032 parameters, we must save and restore it. */
4033 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4034 &low_to_save, &high_to_save);
4038 /* Push the args that need to be pushed. */
4040 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4041 are to be pushed. */
4042 for (count = 0; count < nargs; count++, argnum += inc)
4044 enum machine_mode mode = argvec[argnum].mode;
4045 rtx val = argvec[argnum].value;
4046 rtx reg = argvec[argnum].reg;
4047 int partial = argvec[argnum].partial;
4048 int lower_bound = 0, upper_bound = 0, i;
4050 if (! (reg != 0 && partial == 0))
4052 if (ACCUMULATE_OUTGOING_ARGS)
4054 /* If this is being stored into a pre-allocated, fixed-size,
4055 stack area, save any previous data at that location. */
4057 #ifdef ARGS_GROW_DOWNWARD
4058 /* stack_slot is negative, but we want to index stack_usage_map
4059 with positive values. */
4060 upper_bound = -argvec[argnum].locate.offset.constant + 1;
4061 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
4063 lower_bound = argvec[argnum].locate.offset.constant;
4064 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
4068 /* Don't worry about things in the fixed argument area;
4069 it has already been saved. */
4070 if (i < reg_parm_stack_space)
4071 i = reg_parm_stack_space;
4072 while (i < upper_bound && stack_usage_map[i] == 0)
4075 if (i < upper_bound)
4077 /* We need to make a save area. */
4079 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4080 enum machine_mode save_mode
4081 = mode_for_size (size, MODE_INT, 1);
4083 = plus_constant (argblock,
4084 argvec[argnum].locate.offset.constant);
4086 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4088 if (save_mode == BLKmode)
4090 argvec[argnum].save_area
4091 = assign_stack_temp (BLKmode,
4092 argvec[argnum].locate.size.constant,
4095 emit_block_move (validize_mem (argvec[argnum].save_area),
4097 GEN_INT (argvec[argnum].locate.size.constant),
4098 BLOCK_OP_CALL_PARM);
4102 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4104 emit_move_insn (argvec[argnum].save_area, stack_area);
4109 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
4110 partial, reg, 0, argblock,
4111 GEN_INT (argvec[argnum].locate.offset.constant),
4112 reg_parm_stack_space,
4113 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4115 /* Now mark the segment we just used. */
4116 if (ACCUMULATE_OUTGOING_ARGS)
4117 for (i = lower_bound; i < upper_bound; i++)
4118 stack_usage_map[i] = 1;
4124 /* If we pushed args in forward order, perform stack alignment
4125 after pushing the last arg. */
4126 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4127 anti_adjust_stack (GEN_INT (args_size.constant
4128 - original_args_size.constant));
4130 if (PUSH_ARGS_REVERSED)
4135 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4137 /* Now load any reg parms into their regs. */
4139 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4140 are to be pushed. */
4141 for (count = 0; count < nargs; count++, argnum += inc)
4143 rtx val = argvec[argnum].value;
4144 rtx reg = argvec[argnum].reg;
4145 int partial = argvec[argnum].partial;
4147 /* Handle calls that pass values in multiple non-contiguous
4148 locations. The PA64 has examples of this for library calls. */
4149 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4150 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (GET_MODE (val)));
4151 else if (reg != 0 && partial == 0)
4152 emit_move_insn (reg, val);
4157 /* Any regs containing parms remain in use through the call. */
4158 for (count = 0; count < nargs; count++)
4160 rtx reg = argvec[count].reg;
4161 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4162 use_group_regs (&call_fusage, reg);
4164 use_reg (&call_fusage, reg);
4167 /* Pass the function the address in which to return a structure value. */
4168 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4170 emit_move_insn (struct_value,
4172 force_operand (XEXP (mem_value, 0),
4174 if (GET_CODE (struct_value) == REG)
4175 use_reg (&call_fusage, struct_value);
4178 /* Don't allow popping to be deferred, since then
4179 cse'ing of library calls could delete a call and leave the pop. */
4181 valreg = (mem_value == 0 && outmode != VOIDmode
4182 ? hard_libcall_value (outmode) : NULL_RTX);
4184 /* Stack must be properly aligned now. */
4185 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4188 before_call = get_last_insn ();
4190 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4191 will set inhibit_defer_pop to that value. */
4192 /* The return type is needed to decide how many bytes the function pops.
4193 Signedness plays no role in that, so for simplicity, we pretend it's
4194 always signed. We also assume that the list of arguments passed has
4195 no impact, so we pretend it is unknown. */
4198 get_identifier (XSTR (orgfun, 0)),
4199 build_function_type (tfom, NULL_TREE),
4200 original_args_size.constant, args_size.constant,
4202 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4204 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4206 /* For calls to `setjmp', etc., inform flow.c it should complain
4207 if nonvolatile values are live. For functions that cannot return,
4208 inform flow that control does not fall through. */
4210 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4212 /* The barrier note must be emitted
4213 immediately after the CALL_INSN. Some ports emit more than
4214 just a CALL_INSN above, so we must search for it here. */
4216 rtx last = get_last_insn ();
4217 while (GET_CODE (last) != CALL_INSN)
4219 last = PREV_INSN (last);
4220 /* There was no CALL_INSN? */
4221 if (last == before_call)
4225 emit_barrier_after (last);
4228 /* Now restore inhibit_defer_pop to its actual original value. */
4231 /* If call is cse'able, make appropriate pair of reg-notes around it.
4232 Test valreg so we don't crash; may safely ignore `const'
4233 if return type is void. Disable for PARALLEL return values, because
4234 we have no way to move such values into a pseudo register. */
4235 if (flags & ECF_LIBCALL_BLOCK)
4241 insns = get_insns ();
4251 if (GET_CODE (valreg) == PARALLEL)
4253 temp = gen_reg_rtx (outmode);
4254 emit_group_store (temp, valreg, NULL_TREE,
4255 GET_MODE_SIZE (outmode));
4259 temp = gen_reg_rtx (GET_MODE (valreg));
4261 /* Construct an "equal form" for the value which mentions all the
4262 arguments in order as well as the function name. */
4263 for (i = 0; i < nargs; i++)
4264 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4265 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4267 insns = get_insns ();
4270 if (flags & ECF_PURE)
4271 note = gen_rtx_EXPR_LIST (VOIDmode,
4272 gen_rtx_USE (VOIDmode,
4273 gen_rtx_MEM (BLKmode,
4274 gen_rtx_SCRATCH (VOIDmode))),
4277 emit_libcall_block (insns, temp, valreg, note);
4284 /* Copy the value to the right place. */
4285 if (outmode != VOIDmode && retval)
4291 if (value != mem_value)
4292 emit_move_insn (value, mem_value);
4294 else if (GET_CODE (valreg) == PARALLEL)
4297 value = gen_reg_rtx (outmode);
4298 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4300 else if (value != 0)
4301 emit_move_insn (value, valreg);
4306 if (ACCUMULATE_OUTGOING_ARGS)
4308 #ifdef REG_PARM_STACK_SPACE
4310 restore_fixed_argument_area (save_area, argblock,
4311 high_to_save, low_to_save);
4314 /* If we saved any argument areas, restore them. */
4315 for (count = 0; count < nargs; count++)
4316 if (argvec[count].save_area)
4318 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4319 rtx adr = plus_constant (argblock,
4320 argvec[count].locate.offset.constant);
4321 rtx stack_area = gen_rtx_MEM (save_mode,
4322 memory_address (save_mode, adr));
4324 if (save_mode == BLKmode)
4325 emit_block_move (stack_area,
4326 validize_mem (argvec[count].save_area),
4327 GEN_INT (argvec[count].locate.size.constant),
4328 BLOCK_OP_CALL_PARM);
4330 emit_move_insn (stack_area, argvec[count].save_area);
4333 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4334 stack_usage_map = initial_stack_usage_map;
4341 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4342 (emitting the queue unless NO_QUEUE is nonzero),
4343 for a value of mode OUTMODE,
4344 with NARGS different arguments, passed as alternating rtx values
4345 and machine_modes to convert them to.
4346 The rtx values should have been passed through protect_from_queue already.
4348 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4349 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4350 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4351 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4352 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4353 or other LCT_ value for other types of library calls. */
4356 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4357 enum machine_mode outmode, int nargs, ...)
4361 va_start (p, nargs);
4362 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4366 /* Like emit_library_call except that an extra argument, VALUE,
4367 comes second and says where to store the result.
4368 (If VALUE is zero, this function chooses a convenient way
4369 to return the value.
4371 This function returns an rtx for where the value is to be found.
4372 If VALUE is nonzero, VALUE is returned. */
4375 emit_library_call_value (rtx orgfun, rtx value,
4376 enum libcall_type fn_type,
4377 enum machine_mode outmode, int nargs, ...)
4382 va_start (p, nargs);
4383 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4390 /* Store a single argument for a function call
4391 into the register or memory area where it must be passed.
4392 *ARG describes the argument value and where to pass it.
4394 ARGBLOCK is the address of the stack-block for all the arguments,
4395 or 0 on a machine where arguments are pushed individually.
4397 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4398 so must be careful about how the stack is used.
4400 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4401 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4402 that we need not worry about saving and restoring the stack.
4404 FNDECL is the declaration of the function we are calling.
4406 Return nonzero if this arg should cause sibcall failure,
4410 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4411 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4413 tree pval = arg->tree_value;
4417 int i, lower_bound = 0, upper_bound = 0;
4418 int sibcall_failure = 0;
4420 if (TREE_CODE (pval) == ERROR_MARK)
4423 /* Push a new temporary level for any temporaries we make for
4427 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4429 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4430 save any previous data at that location. */
4431 if (argblock && ! variable_size && arg->stack)
4433 #ifdef ARGS_GROW_DOWNWARD
4434 /* stack_slot is negative, but we want to index stack_usage_map
4435 with positive values. */
4436 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4437 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4441 lower_bound = upper_bound - arg->locate.size.constant;
4443 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4444 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4448 upper_bound = lower_bound + arg->locate.size.constant;
4452 /* Don't worry about things in the fixed argument area;
4453 it has already been saved. */
4454 if (i < reg_parm_stack_space)
4455 i = reg_parm_stack_space;
4456 while (i < upper_bound && stack_usage_map[i] == 0)
4459 if (i < upper_bound)
4461 /* We need to make a save area. */
4462 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4463 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4464 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4465 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4467 if (save_mode == BLKmode)
4469 tree ot = TREE_TYPE (arg->tree_value);
4470 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4471 | TYPE_QUAL_CONST));
4473 arg->save_area = assign_temp (nt, 0, 1, 1);
4474 preserve_temp_slots (arg->save_area);
4475 emit_block_move (validize_mem (arg->save_area), stack_area,
4476 expr_size (arg->tree_value),
4477 BLOCK_OP_CALL_PARM);
4481 arg->save_area = gen_reg_rtx (save_mode);
4482 emit_move_insn (arg->save_area, stack_area);
4488 /* If this isn't going to be placed on both the stack and in registers,
4489 set up the register and number of words. */
4490 if (! arg->pass_on_stack)
4492 if (flags & ECF_SIBCALL)
4493 reg = arg->tail_call_reg;
4496 partial = arg->partial;
4499 if (reg != 0 && partial == 0)
4500 /* Being passed entirely in a register. We shouldn't be called in
4504 /* If this arg needs special alignment, don't load the registers
4506 if (arg->n_aligned_regs != 0)
4509 /* If this is being passed partially in a register, we can't evaluate
4510 it directly into its stack slot. Otherwise, we can. */
4511 if (arg->value == 0)
4513 /* stack_arg_under_construction is nonzero if a function argument is
4514 being evaluated directly into the outgoing argument list and
4515 expand_call must take special action to preserve the argument list
4516 if it is called recursively.
4518 For scalar function arguments stack_usage_map is sufficient to
4519 determine which stack slots must be saved and restored. Scalar
4520 arguments in general have pass_on_stack == 0.
4522 If this argument is initialized by a function which takes the
4523 address of the argument (a C++ constructor or a C function
4524 returning a BLKmode structure), then stack_usage_map is
4525 insufficient and expand_call must push the stack around the
4526 function call. Such arguments have pass_on_stack == 1.
4528 Note that it is always safe to set stack_arg_under_construction,
4529 but this generates suboptimal code if set when not needed. */
4531 if (arg->pass_on_stack)
4532 stack_arg_under_construction++;
4534 arg->value = expand_expr (pval,
4536 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4537 ? NULL_RTX : arg->stack,
4538 VOIDmode, EXPAND_STACK_PARM);
4540 /* If we are promoting object (or for any other reason) the mode
4541 doesn't agree, convert the mode. */
4543 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4544 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4545 arg->value, arg->unsignedp);
4547 if (arg->pass_on_stack)
4548 stack_arg_under_construction--;
4551 /* Don't allow anything left on stack from computation
4552 of argument to alloca. */
4553 if (flags & ECF_MAY_BE_ALLOCA)
4554 do_pending_stack_adjust ();
4556 if (arg->value == arg->stack)
4557 /* If the value is already in the stack slot, we are done. */
4559 else if (arg->mode != BLKmode)
4563 /* Argument is a scalar, not entirely passed in registers.
4564 (If part is passed in registers, arg->partial says how much
4565 and emit_push_insn will take care of putting it there.)
4567 Push it, and if its size is less than the
4568 amount of space allocated to it,
4569 also bump stack pointer by the additional space.
4570 Note that in C the default argument promotions
4571 will prevent such mismatches. */
4573 size = GET_MODE_SIZE (arg->mode);
4574 /* Compute how much space the push instruction will push.
4575 On many machines, pushing a byte will advance the stack
4576 pointer by a halfword. */
4577 #ifdef PUSH_ROUNDING
4578 size = PUSH_ROUNDING (size);
4582 /* Compute how much space the argument should get:
4583 round up to a multiple of the alignment for arguments. */
4584 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4585 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4586 / (PARM_BOUNDARY / BITS_PER_UNIT))
4587 * (PARM_BOUNDARY / BITS_PER_UNIT));
4589 /* This isn't already where we want it on the stack, so put it there.
4590 This can either be done with push or copy insns. */
4591 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4592 PARM_BOUNDARY, partial, reg, used - size, argblock,
4593 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4594 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4596 /* Unless this is a partially-in-register argument, the argument is now
4599 arg->value = arg->stack;
4603 /* BLKmode, at least partly to be pushed. */
4605 unsigned int parm_align;
4609 /* Pushing a nonscalar.
4610 If part is passed in registers, PARTIAL says how much
4611 and emit_push_insn will take care of putting it there. */
4613 /* Round its size up to a multiple
4614 of the allocation unit for arguments. */
4616 if (arg->locate.size.var != 0)
4619 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4623 /* PUSH_ROUNDING has no effect on us, because
4624 emit_push_insn for BLKmode is careful to avoid it. */
4625 if (reg && GET_CODE (reg) == PARALLEL)
4627 /* Use the size of the elt to compute excess. */
4628 rtx elt = XEXP (XVECEXP (reg, 0, 0), 0);
4629 excess = (arg->locate.size.constant
4630 - int_size_in_bytes (TREE_TYPE (pval))
4631 + partial * GET_MODE_SIZE (GET_MODE (elt)));
4634 excess = (arg->locate.size.constant
4635 - int_size_in_bytes (TREE_TYPE (pval))
4636 + partial * UNITS_PER_WORD);
4637 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4638 NULL_RTX, TYPE_MODE (sizetype), 0);
4641 /* Some types will require stricter alignment, which will be
4642 provided for elsewhere in argument layout. */
4643 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4645 /* When an argument is padded down, the block is aligned to
4646 PARM_BOUNDARY, but the actual argument isn't. */
4647 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4649 if (arg->locate.size.var)
4650 parm_align = BITS_PER_UNIT;
4653 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4654 parm_align = MIN (parm_align, excess_align);
4658 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4660 /* emit_push_insn might not work properly if arg->value and
4661 argblock + arg->locate.offset areas overlap. */
4665 if (XEXP (x, 0) == current_function_internal_arg_pointer
4666 || (GET_CODE (XEXP (x, 0)) == PLUS
4667 && XEXP (XEXP (x, 0), 0) ==
4668 current_function_internal_arg_pointer
4669 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4671 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4672 i = INTVAL (XEXP (XEXP (x, 0), 1));
4674 /* expand_call should ensure this */
4675 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4678 if (arg->locate.offset.constant > i)
4680 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4681 sibcall_failure = 1;
4683 else if (arg->locate.offset.constant < i)
4685 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4686 sibcall_failure = 1;
4691 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4692 parm_align, partial, reg, excess, argblock,
4693 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4694 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4696 /* Unless this is a partially-in-register argument, the argument is now
4699 ??? Unlike the case above, in which we want the actual
4700 address of the data, so that we can load it directly into a
4701 register, here we want the address of the stack slot, so that
4702 it's properly aligned for word-by-word copying or something
4703 like that. It's not clear that this is always correct. */
4705 arg->value = arg->stack_slot;
4708 /* Mark all slots this store used. */
4709 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4710 && argblock && ! variable_size && arg->stack)
4711 for (i = lower_bound; i < upper_bound; i++)
4712 stack_usage_map[i] = 1;
4714 /* Once we have pushed something, pops can't safely
4715 be deferred during the rest of the arguments. */
4718 /* ANSI doesn't require a sequence point here,
4719 but PCC has one, so this will avoid some problems. */
4722 /* Free any temporary slots made in processing this argument. Show
4723 that we might have taken the address of something and pushed that
4725 preserve_temp_slots (NULL_RTX);
4729 return sibcall_failure;
4732 /* Nonzero if we do not know how to pass TYPE solely in registers.
4733 We cannot do so in the following cases:
4735 - if the type has variable size
4736 - if the type is marked as addressable (it is required to be constructed
4738 - if the padding and mode of the type is such that a copy into a register
4739 would put it into the wrong part of the register.
4741 Which padding can't be supported depends on the byte endianness.
4743 A value in a register is implicitly padded at the most significant end.
4744 On a big-endian machine, that is the lower end in memory.
4745 So a value padded in memory at the upper end can't go in a register.
4746 For a little-endian machine, the reverse is true. */
4749 default_must_pass_in_stack (enum machine_mode mode, tree type)
4754 /* If the type has variable size... */
4755 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4758 /* If the type is marked as addressable (it is required
4759 to be constructed into the stack)... */
4760 if (TREE_ADDRESSABLE (type))
4763 /* If the padding and mode of the type is such that a copy into
4764 a register would put it into the wrong part of the register. */
4766 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4767 && (FUNCTION_ARG_PADDING (mode, type)
4768 == (BYTES_BIG_ENDIAN ? upward : downward)))