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 #ifdef LOAD_ARGS_REVERSED
1605 for (i = num_actuals - 1; i >= 0; i--)
1607 for (i = 0; i < num_actuals; i++)
1610 rtx reg = ((flags & ECF_SIBCALL)
1611 ? args[i].tail_call_reg : args[i].reg);
1614 int partial = args[i].partial;
1617 rtx before_arg = get_last_insn ();
1618 /* Set to non-negative if must move a word at a time, even if just
1619 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1620 we just use a normal move insn. This value can be zero if the
1621 argument is a zero size structure with no fields. */
1625 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1627 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1628 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1631 size = GET_MODE_SIZE (args[i].mode);
1633 /* Handle calls that pass values in multiple non-contiguous
1634 locations. The Irix 6 ABI has examples of this. */
1636 if (GET_CODE (reg) == PARALLEL)
1638 tree type = TREE_TYPE (args[i].tree_value);
1639 emit_group_load (reg, args[i].value, type,
1640 int_size_in_bytes (type));
1643 /* If simple case, just do move. If normal partial, store_one_arg
1644 has already loaded the register for us. In all other cases,
1645 load the register(s) from memory. */
1647 else if (nregs == -1)
1649 emit_move_insn (reg, args[i].value);
1650 #ifdef BLOCK_REG_PADDING
1651 /* Handle case where we have a value that needs shifting
1652 up to the msb. eg. a QImode value and we're padding
1653 upward on a BYTES_BIG_ENDIAN machine. */
1654 if (size < UNITS_PER_WORD
1655 && (args[i].locate.where_pad
1656 == (BYTES_BIG_ENDIAN ? upward : downward)))
1659 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1661 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1662 report the whole reg as used. Strictly speaking, the
1663 call only uses SIZE bytes at the msb end, but it doesn't
1664 seem worth generating rtl to say that. */
1665 reg = gen_rtx_REG (word_mode, REGNO (reg));
1666 x = expand_binop (word_mode, ashl_optab, reg,
1667 GEN_INT (shift), reg, 1, OPTAB_WIDEN);
1669 emit_move_insn (reg, x);
1674 /* If we have pre-computed the values to put in the registers in
1675 the case of non-aligned structures, copy them in now. */
1677 else if (args[i].n_aligned_regs != 0)
1678 for (j = 0; j < args[i].n_aligned_regs; j++)
1679 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1680 args[i].aligned_regs[j]);
1682 else if (partial == 0 || args[i].pass_on_stack)
1684 rtx mem = validize_mem (args[i].value);
1686 #ifdef BLOCK_REG_PADDING
1687 /* Handle a BLKmode that needs shifting. */
1688 if (nregs == 1 && size < UNITS_PER_WORD
1689 && args[i].locate.where_pad == downward)
1691 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1692 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1693 rtx x = gen_reg_rtx (word_mode);
1694 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1695 optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1697 emit_move_insn (x, tem);
1698 x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1699 ri, 1, OPTAB_WIDEN);
1701 emit_move_insn (ri, x);
1705 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1708 /* When a parameter is a block, and perhaps in other cases, it is
1709 possible that it did a load from an argument slot that was
1710 already clobbered. */
1712 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1713 *sibcall_failure = 1;
1715 /* Handle calls that pass values in multiple non-contiguous
1716 locations. The Irix 6 ABI has examples of this. */
1717 if (GET_CODE (reg) == PARALLEL)
1718 use_group_regs (call_fusage, reg);
1719 else if (nregs == -1)
1720 use_reg (call_fusage, reg);
1722 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1727 /* Try to integrate function. See expand_inline_function for documentation
1728 about the parameters. */
1731 try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1732 tree type, rtx structure_value_addr)
1737 rtx old_stack_level = 0;
1738 int reg_parm_stack_space = 0;
1740 #ifdef REG_PARM_STACK_SPACE
1741 #ifdef MAYBE_REG_PARM_STACK_SPACE
1742 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1744 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1748 before_call = get_last_insn ();
1750 timevar_push (TV_INTEGRATION);
1752 temp = expand_inline_function (fndecl, actparms, target,
1754 structure_value_addr);
1756 timevar_pop (TV_INTEGRATION);
1758 /* If inlining succeeded, return. */
1759 if (temp != (rtx) (size_t) - 1)
1761 if (ACCUMULATE_OUTGOING_ARGS)
1763 /* If the outgoing argument list must be preserved, push
1764 the stack before executing the inlined function if it
1767 i = reg_parm_stack_space;
1768 if (i > highest_outgoing_arg_in_use)
1769 i = highest_outgoing_arg_in_use;
1770 while (--i >= 0 && stack_usage_map[i] == 0)
1773 if (stack_arg_under_construction || i >= 0)
1776 = before_call ? NEXT_INSN (before_call) : get_insns ();
1777 rtx insn = NULL_RTX, seq;
1779 /* Look for a call in the inline function code.
1780 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1781 nonzero then there is a call and it is not necessary
1782 to scan the insns. */
1784 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1785 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1786 if (GET_CODE (insn) == CALL_INSN)
1791 /* Reserve enough stack space so that the largest
1792 argument list of any function call in the inline
1793 function does not overlap the argument list being
1794 evaluated. This is usually an overestimate because
1795 allocate_dynamic_stack_space reserves space for an
1796 outgoing argument list in addition to the requested
1797 space, but there is no way to ask for stack space such
1798 that an argument list of a certain length can be
1801 Add the stack space reserved for register arguments, if
1802 any, in the inline function. What is really needed is the
1803 largest value of reg_parm_stack_space in the inline
1804 function, but that is not available. Using the current
1805 value of reg_parm_stack_space is wrong, but gives
1806 correct results on all supported machines. */
1808 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1809 + reg_parm_stack_space);
1812 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1813 allocate_dynamic_stack_space (GEN_INT (adjust),
1814 NULL_RTX, BITS_PER_UNIT);
1817 emit_insn_before (seq, first_insn);
1818 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1823 /* If the result is equivalent to TARGET, return TARGET to simplify
1824 checks in store_expr. They can be equivalent but not equal in the
1825 case of a function that returns BLKmode. */
1826 if (temp != target && rtx_equal_p (temp, target))
1831 /* If inlining failed, mark FNDECL as needing to be compiled
1832 separately after all. If function was declared inline,
1834 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1835 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1837 warning ("%Jinlining failed in call to '%F'", fndecl, fndecl);
1838 warning ("called from here");
1840 (*lang_hooks.mark_addressable) (fndecl);
1841 return (rtx) (size_t) - 1;
1844 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1845 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1846 bytes, then we would need to push some additional bytes to pad the
1847 arguments. So, we compute an adjust to the stack pointer for an
1848 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1849 bytes. Then, when the arguments are pushed the stack will be perfectly
1850 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1851 be popped after the call. Returns the adjustment. */
1854 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1855 struct args_size *args_size,
1856 int preferred_unit_stack_boundary)
1858 /* The number of bytes to pop so that the stack will be
1859 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1860 HOST_WIDE_INT adjustment;
1861 /* The alignment of the stack after the arguments are pushed, if we
1862 just pushed the arguments without adjust the stack here. */
1863 HOST_WIDE_INT unadjusted_alignment;
1865 unadjusted_alignment
1866 = ((stack_pointer_delta + unadjusted_args_size)
1867 % preferred_unit_stack_boundary);
1869 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1870 as possible -- leaving just enough left to cancel out the
1871 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1872 PENDING_STACK_ADJUST is non-negative, and congruent to
1873 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1875 /* Begin by trying to pop all the bytes. */
1876 unadjusted_alignment
1877 = (unadjusted_alignment
1878 - (pending_stack_adjust % preferred_unit_stack_boundary));
1879 adjustment = pending_stack_adjust;
1880 /* Push enough additional bytes that the stack will be aligned
1881 after the arguments are pushed. */
1882 if (preferred_unit_stack_boundary > 1)
1884 if (unadjusted_alignment > 0)
1885 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1887 adjustment += unadjusted_alignment;
1890 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1891 bytes after the call. The right number is the entire
1892 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1893 by the arguments in the first place. */
1895 = pending_stack_adjust - adjustment + unadjusted_args_size;
1900 /* Scan X expression if it does not dereference any argument slots
1901 we already clobbered by tail call arguments (as noted in stored_args_map
1903 Return nonzero if X expression dereferences such argument slots,
1907 check_sibcall_argument_overlap_1 (rtx x)
1917 code = GET_CODE (x);
1921 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1923 else if (GET_CODE (XEXP (x, 0)) == PLUS
1924 && XEXP (XEXP (x, 0), 0) ==
1925 current_function_internal_arg_pointer
1926 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1927 i = INTVAL (XEXP (XEXP (x, 0), 1));
1931 #ifdef ARGS_GROW_DOWNWARD
1932 i = -i - GET_MODE_SIZE (GET_MODE (x));
1935 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1936 if (i + k < stored_args_map->n_bits
1937 && TEST_BIT (stored_args_map, i + k))
1943 /* Scan all subexpressions. */
1944 fmt = GET_RTX_FORMAT (code);
1945 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1949 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1952 else if (*fmt == 'E')
1954 for (j = 0; j < XVECLEN (x, i); j++)
1955 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1962 /* Scan sequence after INSN if it does not dereference any argument slots
1963 we already clobbered by tail call arguments (as noted in stored_args_map
1964 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1965 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1966 should be 0). Return nonzero if sequence after INSN dereferences such argument
1967 slots, zero otherwise. */
1970 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1974 if (insn == NULL_RTX)
1975 insn = get_insns ();
1977 insn = NEXT_INSN (insn);
1979 for (; insn; insn = NEXT_INSN (insn))
1981 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1984 if (mark_stored_args_map)
1986 #ifdef ARGS_GROW_DOWNWARD
1987 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1989 low = arg->locate.slot_offset.constant;
1992 for (high = low + arg->locate.size.constant; low < high; low++)
1993 SET_BIT (stored_args_map, low);
1995 return insn != NULL_RTX;
1999 fix_unsafe_tree (tree t)
2001 switch (unsafe_for_reeval (t))
2006 case 1: /* Mildly unsafe. */
2007 t = unsave_expr (t);
2010 case 2: /* Wildly unsafe. */
2012 tree var = build_decl (VAR_DECL, NULL_TREE,
2015 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2027 /* If function value *VALUE was returned at the most significant end of a
2028 register, shift it towards the least significant end and convert it to
2029 TYPE's mode. Return true and update *VALUE if some action was needed.
2031 TYPE is the type of the function's return value, which is known not
2032 to have mode BLKmode. */
2035 shift_returned_value (tree type, rtx *value)
2037 if (targetm.calls.return_in_msb (type))
2039 HOST_WIDE_INT shift;
2041 shift = (GET_MODE_BITSIZE (GET_MODE (*value))
2042 - BITS_PER_UNIT * int_size_in_bytes (type));
2045 *value = expand_binop (GET_MODE (*value), lshr_optab, *value,
2046 GEN_INT (shift), 0, 1, OPTAB_WIDEN);
2047 *value = convert_to_mode (TYPE_MODE (type), *value, 0);
2054 /* Generate all the code for a function call
2055 and return an rtx for its value.
2056 Store the value in TARGET (specified as an rtx) if convenient.
2057 If the value is stored in TARGET then TARGET is returned.
2058 If IGNORE is nonzero, then we ignore the value of the function call. */
2061 expand_call (tree exp, rtx target, int ignore)
2063 /* Nonzero if we are currently expanding a call. */
2064 static int currently_expanding_call = 0;
2066 /* List of actual parameters. */
2067 tree actparms = TREE_OPERAND (exp, 1);
2068 /* RTX for the function to be called. */
2070 /* Sequence of insns to perform a tail recursive "call". */
2071 rtx tail_recursion_insns = NULL_RTX;
2072 /* Sequence of insns to perform a normal "call". */
2073 rtx normal_call_insns = NULL_RTX;
2074 /* Sequence of insns to perform a tail recursive "call". */
2075 rtx tail_call_insns = NULL_RTX;
2076 /* Data type of the function. */
2078 tree type_arg_types;
2079 /* Declaration of the function being called,
2080 or 0 if the function is computed (not known by name). */
2083 int try_tail_call = 1;
2084 int try_tail_recursion = 1;
2087 /* Register in which non-BLKmode value will be returned,
2088 or 0 if no value or if value is BLKmode. */
2090 /* Address where we should return a BLKmode value;
2091 0 if value not BLKmode. */
2092 rtx structure_value_addr = 0;
2093 /* Nonzero if that address is being passed by treating it as
2094 an extra, implicit first parameter. Otherwise,
2095 it is passed by being copied directly into struct_value_rtx. */
2096 int structure_value_addr_parm = 0;
2097 /* Size of aggregate value wanted, or zero if none wanted
2098 or if we are using the non-reentrant PCC calling convention
2099 or expecting the value in registers. */
2100 HOST_WIDE_INT struct_value_size = 0;
2101 /* Nonzero if called function returns an aggregate in memory PCC style,
2102 by returning the address of where to find it. */
2103 int pcc_struct_value = 0;
2104 rtx struct_value = 0;
2106 /* Number of actual parameters in this call, including struct value addr. */
2108 /* Number of named args. Args after this are anonymous ones
2109 and they must all go on the stack. */
2112 /* Vector of information about each argument.
2113 Arguments are numbered in the order they will be pushed,
2114 not the order they are written. */
2115 struct arg_data *args;
2117 /* Total size in bytes of all the stack-parms scanned so far. */
2118 struct args_size args_size;
2119 struct args_size adjusted_args_size;
2120 /* Size of arguments before any adjustments (such as rounding). */
2121 int unadjusted_args_size;
2122 /* Data on reg parms scanned so far. */
2123 CUMULATIVE_ARGS args_so_far;
2124 /* Nonzero if a reg parm has been scanned. */
2126 /* Nonzero if this is an indirect function call. */
2128 /* Nonzero if we must avoid push-insns in the args for this call.
2129 If stack space is allocated for register parameters, but not by the
2130 caller, then it is preallocated in the fixed part of the stack frame.
2131 So the entire argument block must then be preallocated (i.e., we
2132 ignore PUSH_ROUNDING in that case). */
2134 int must_preallocate = !PUSH_ARGS;
2136 /* Size of the stack reserved for parameter registers. */
2137 int reg_parm_stack_space = 0;
2139 /* Address of space preallocated for stack parms
2140 (on machines that lack push insns), or 0 if space not preallocated. */
2143 /* Mask of ECF_ flags. */
2145 /* Nonzero if this is a call to an inline function. */
2146 int is_integrable = 0;
2147 #ifdef REG_PARM_STACK_SPACE
2148 /* Define the boundary of the register parm stack space that needs to be
2150 int low_to_save, high_to_save;
2151 rtx save_area = 0; /* Place that it is saved */
2154 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2155 rtx temp_target = 0;
2156 char *initial_stack_usage_map = stack_usage_map;
2158 int old_stack_allocated;
2160 /* State variables to track stack modifications. */
2161 rtx old_stack_level = 0;
2162 int old_stack_arg_under_construction = 0;
2163 int old_pending_adj = 0;
2164 int old_inhibit_defer_pop = inhibit_defer_pop;
2166 /* Some stack pointer alterations we make are performed via
2167 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2168 which we then also need to save/restore along the way. */
2169 int old_stack_pointer_delta = 0;
2172 tree p = TREE_OPERAND (exp, 0);
2173 tree addr = TREE_OPERAND (exp, 0);
2175 /* The alignment of the stack, in bits. */
2176 HOST_WIDE_INT preferred_stack_boundary;
2177 /* The alignment of the stack, in bytes. */
2178 HOST_WIDE_INT preferred_unit_stack_boundary;
2180 /* See if this is "nothrow" function call. */
2181 if (TREE_NOTHROW (exp))
2182 flags |= ECF_NOTHROW;
2184 /* See if we can find a DECL-node for the actual function.
2185 As a result, decide whether this is a call to an integrable function. */
2187 fndecl = get_callee_fndecl (exp);
2191 && fndecl != current_function_decl
2192 && DECL_INLINE (fndecl)
2193 && DECL_SAVED_INSNS (fndecl)
2194 && DECL_SAVED_INSNS (fndecl)->inlinable)
2196 else if (! TREE_ADDRESSABLE (fndecl))
2198 /* In case this function later becomes inlinable,
2199 record that there was already a non-inline call to it.
2201 Use abstraction instead of setting TREE_ADDRESSABLE
2203 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2206 warning ("%Jcan't inline call to '%F'", fndecl, fndecl);
2207 warning ("called from here");
2209 (*lang_hooks.mark_addressable) (fndecl);
2213 && lookup_attribute ("warn_unused_result",
2214 TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
2215 warning ("ignoring return value of `%D', "
2216 "declared with attribute warn_unused_result", fndecl);
2218 flags |= flags_from_decl_or_type (fndecl);
2221 /* If we don't have specific function to call, see if we have a
2222 attributes set in the type. */
2226 && lookup_attribute ("warn_unused_result",
2227 TYPE_ATTRIBUTES (TREE_TYPE (TREE_TYPE (p)))))
2228 warning ("ignoring return value of function "
2229 "declared with attribute warn_unused_result");
2230 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2233 struct_value = targetm.calls.struct_value_rtx (fndecl ? TREE_TYPE (fndecl) : 0, 0);
2235 /* Warn if this value is an aggregate type,
2236 regardless of which calling convention we are using for it. */
2237 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2238 warning ("function call has aggregate value");
2240 /* If the result of a pure or const function call is ignored (or void),
2241 and none of its arguments are volatile, we can avoid expanding the
2242 call and just evaluate the arguments for side-effects. */
2243 if ((flags & (ECF_CONST | ECF_PURE))
2244 && (ignore || target == const0_rtx
2245 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2247 bool volatilep = false;
2250 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2251 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2259 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2260 expand_expr (TREE_VALUE (arg), const0_rtx,
2261 VOIDmode, EXPAND_NORMAL);
2266 #ifdef REG_PARM_STACK_SPACE
2267 #ifdef MAYBE_REG_PARM_STACK_SPACE
2268 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2270 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2274 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2275 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2276 must_preallocate = 1;
2279 /* Set up a place to return a structure. */
2281 /* Cater to broken compilers. */
2282 if (aggregate_value_p (exp, fndecl))
2284 /* This call returns a big structure. */
2285 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2287 #ifdef PCC_STATIC_STRUCT_RETURN
2289 pcc_struct_value = 1;
2290 /* Easier than making that case work right. */
2293 /* In case this is a static function, note that it has been
2295 if (! TREE_ADDRESSABLE (fndecl))
2296 (*lang_hooks.mark_addressable) (fndecl);
2300 #else /* not PCC_STATIC_STRUCT_RETURN */
2302 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2304 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2306 /* The structure value address arg is already in actparms.
2307 Pull it out. It might be nice to just leave it there, but
2308 we need to set structure_value_addr. */
2309 tree return_arg = TREE_VALUE (actparms);
2310 actparms = TREE_CHAIN (actparms);
2311 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2312 VOIDmode, EXPAND_NORMAL);
2314 else if (target && GET_CODE (target) == MEM)
2315 structure_value_addr = XEXP (target, 0);
2318 /* For variable-sized objects, we must be called with a target
2319 specified. If we were to allocate space on the stack here,
2320 we would have no way of knowing when to free it. */
2321 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2323 mark_temp_addr_taken (d);
2324 structure_value_addr = XEXP (d, 0);
2328 #endif /* not PCC_STATIC_STRUCT_RETURN */
2331 /* If called function is inline, try to integrate it. */
2335 rtx temp = try_to_integrate (fndecl, actparms, target,
2336 ignore, TREE_TYPE (exp),
2337 structure_value_addr);
2338 if (temp != (rtx) (size_t) - 1)
2342 /* Figure out the amount to which the stack should be aligned. */
2343 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2346 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2347 if (i && i->preferred_incoming_stack_boundary)
2348 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2351 /* Operand 0 is a pointer-to-function; get the type of the function. */
2352 funtype = TREE_TYPE (addr);
2353 if (! POINTER_TYPE_P (funtype))
2355 funtype = TREE_TYPE (funtype);
2357 /* Munge the tree to split complex arguments into their imaginary
2359 if (SPLIT_COMPLEX_ARGS)
2361 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2362 actparms = split_complex_values (actparms);
2365 type_arg_types = TYPE_ARG_TYPES (funtype);
2367 /* See if this is a call to a function that can return more than once
2368 or a call to longjmp or malloc. */
2369 flags |= special_function_p (fndecl, flags);
2371 if (flags & ECF_MAY_BE_ALLOCA)
2372 current_function_calls_alloca = 1;
2374 /* If struct_value_rtx is 0, it means pass the address
2375 as if it were an extra parameter. */
2376 if (structure_value_addr && struct_value == 0)
2378 /* If structure_value_addr is a REG other than
2379 virtual_outgoing_args_rtx, we can use always use it. If it
2380 is not a REG, we must always copy it into a register.
2381 If it is virtual_outgoing_args_rtx, we must copy it to another
2382 register in some cases. */
2383 rtx temp = (GET_CODE (structure_value_addr) != REG
2384 || (ACCUMULATE_OUTGOING_ARGS
2385 && stack_arg_under_construction
2386 && structure_value_addr == virtual_outgoing_args_rtx)
2387 ? copy_addr_to_reg (structure_value_addr)
2388 : structure_value_addr);
2391 = tree_cons (error_mark_node,
2392 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2395 structure_value_addr_parm = 1;
2398 /* Count the arguments and set NUM_ACTUALS. */
2399 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2402 /* Start updating where the next arg would go.
2404 On some machines (such as the PA) indirect calls have a different
2405 calling convention than normal calls. The last argument in
2406 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2408 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2410 /* Compute number of named args.
2411 Normally, don't include the last named arg if anonymous args follow.
2412 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2413 (If no anonymous args follow, the result of list_length is actually
2414 one too large. This is harmless.)
2416 If targetm.calls.pretend_outgoing_varargs_named() returns
2417 nonzero, and STRICT_ARGUMENT_NAMING is zero, this machine will be
2418 able to place unnamed args that were passed in registers into the
2419 stack. So treat all args as named. This allows the insns
2420 emitting for a specific argument list to be independent of the
2421 function declaration.
2423 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2424 we do not have any reliable way to pass unnamed args in
2425 registers, so we must force them into memory. */
2427 if ((targetm.calls.strict_argument_naming (&args_so_far)
2428 || ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2429 && type_arg_types != 0)
2431 = (list_length (type_arg_types)
2432 /* Don't include the last named arg. */
2433 - (targetm.calls.strict_argument_naming (&args_so_far) ? 0 : 1)
2434 /* Count the struct value address, if it is passed as a parm. */
2435 + structure_value_addr_parm);
2437 /* If we know nothing, treat all args as named. */
2438 n_named_args = num_actuals;
2440 /* Make a vector to hold all the information about each arg. */
2441 args = alloca (num_actuals * sizeof (struct arg_data));
2442 memset (args, 0, num_actuals * sizeof (struct arg_data));
2444 /* Build up entries in the ARGS array, compute the size of the
2445 arguments into ARGS_SIZE, etc. */
2446 initialize_argument_information (num_actuals, args, &args_size,
2447 n_named_args, actparms, fndecl,
2448 &args_so_far, reg_parm_stack_space,
2449 &old_stack_level, &old_pending_adj,
2450 &must_preallocate, &flags);
2454 /* If this function requires a variable-sized argument list, don't
2455 try to make a cse'able block for this call. We may be able to
2456 do this eventually, but it is too complicated to keep track of
2457 what insns go in the cse'able block and which don't. */
2459 flags &= ~ECF_LIBCALL_BLOCK;
2460 must_preallocate = 1;
2463 /* Now make final decision about preallocating stack space. */
2464 must_preallocate = finalize_must_preallocate (must_preallocate,
2468 /* If the structure value address will reference the stack pointer, we
2469 must stabilize it. We don't need to do this if we know that we are
2470 not going to adjust the stack pointer in processing this call. */
2472 if (structure_value_addr
2473 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2474 || reg_mentioned_p (virtual_outgoing_args_rtx,
2475 structure_value_addr))
2477 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2478 structure_value_addr = copy_to_reg (structure_value_addr);
2480 /* Tail calls can make things harder to debug, and we're traditionally
2481 pushed these optimizations into -O2. Don't try if we're already
2482 expanding a call, as that means we're an argument. Don't try if
2483 there's cleanups, as we know there's code to follow the call.
2485 If rtx_equal_function_value_matters is false, that means we've
2486 finished with regular parsing. Which means that some of the
2487 machinery we use to generate tail-calls is no longer in place.
2488 This is most often true of sjlj-exceptions, which we couldn't
2489 tail-call to anyway.
2491 If current_nesting_level () == 0, we're being called after
2492 the function body has been expanded. This can happen when
2493 setting up trampolines in expand_function_end. */
2494 if (currently_expanding_call++ != 0
2495 || !flag_optimize_sibling_calls
2496 || !rtx_equal_function_value_matters
2497 || current_nesting_level () == 0
2498 || any_pending_cleanups ()
2500 try_tail_call = try_tail_recursion = 0;
2502 /* Tail recursion fails, when we are not dealing with recursive calls. */
2503 if (!try_tail_recursion
2504 || TREE_CODE (addr) != ADDR_EXPR
2505 || TREE_OPERAND (addr, 0) != current_function_decl)
2506 try_tail_recursion = 0;
2508 /* Rest of purposes for tail call optimizations to fail. */
2510 #ifdef HAVE_sibcall_epilogue
2511 !HAVE_sibcall_epilogue
2516 /* Doing sibling call optimization needs some work, since
2517 structure_value_addr can be allocated on the stack.
2518 It does not seem worth the effort since few optimizable
2519 sibling calls will return a structure. */
2520 || structure_value_addr != NULL_RTX
2521 /* Check whether the target is able to optimize the call
2523 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2524 /* Functions that do not return exactly once may not be sibcall
2526 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2527 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2528 /* If the called function is nested in the current one, it might access
2529 some of the caller's arguments, but could clobber them beforehand if
2530 the argument areas are shared. */
2531 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2532 /* If this function requires more stack slots than the current
2533 function, we cannot change it into a sibling call. */
2534 || args_size.constant > current_function_args_size
2535 /* If the callee pops its own arguments, then it must pop exactly
2536 the same number of arguments as the current function. */
2537 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2538 != RETURN_POPS_ARGS (current_function_decl,
2539 TREE_TYPE (current_function_decl),
2540 current_function_args_size))
2541 || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2544 if (try_tail_call || try_tail_recursion)
2547 actparms = NULL_TREE;
2548 /* Ok, we're going to give the tail call the old college try.
2549 This means we're going to evaluate the function arguments
2550 up to three times. There are two degrees of badness we can
2551 encounter, those that can be unsaved and those that can't.
2552 (See unsafe_for_reeval commentary for details.)
2554 Generate a new argument list. Pass safe arguments through
2555 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2556 For hard badness, evaluate them now and put their resulting
2557 rtx in a temporary VAR_DECL.
2559 initialize_argument_information has ordered the array for the
2560 order to be pushed, and we must remember this when reconstructing
2561 the original argument order. */
2563 if (PUSH_ARGS_REVERSED)
2572 i = num_actuals - 1;
2576 for (; i != end; i += inc)
2578 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2579 /* We need to build actparms for optimize_tail_recursion. We can
2580 safely trash away TREE_PURPOSE, since it is unused by this
2582 if (try_tail_recursion)
2583 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2585 /* Do the same for the function address if it is an expression. */
2587 addr = fix_unsafe_tree (addr);
2588 /* Expanding one of those dangerous arguments could have added
2589 cleanups, but otherwise give it a whirl. */
2590 if (any_pending_cleanups ())
2591 try_tail_call = try_tail_recursion = 0;
2594 /* Generate a tail recursion sequence when calling ourselves. */
2596 if (try_tail_recursion)
2598 /* We want to emit any pending stack adjustments before the tail
2599 recursion "call". That way we know any adjustment after the tail
2600 recursion call can be ignored if we indeed use the tail recursion
2602 int save_pending_stack_adjust = pending_stack_adjust;
2603 int save_stack_pointer_delta = stack_pointer_delta;
2605 /* Emit any queued insns now; otherwise they would end up in
2606 only one of the alternates. */
2609 /* Use a new sequence to hold any RTL we generate. We do not even
2610 know if we will use this RTL yet. The final decision can not be
2611 made until after RTL generation for the entire function is
2614 /* If expanding any of the arguments creates cleanups, we can't
2615 do a tailcall. So, we'll need to pop the pending cleanups
2616 list. If, however, all goes well, and there are no cleanups
2617 then the call to expand_start_target_temps will have no
2619 expand_start_target_temps ();
2620 if (optimize_tail_recursion (actparms, get_last_insn ()))
2622 if (any_pending_cleanups ())
2623 try_tail_call = try_tail_recursion = 0;
2625 tail_recursion_insns = get_insns ();
2627 expand_end_target_temps ();
2630 /* Restore the original pending stack adjustment for the sibling and
2631 normal call cases below. */
2632 pending_stack_adjust = save_pending_stack_adjust;
2633 stack_pointer_delta = save_stack_pointer_delta;
2636 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2638 /* A fork duplicates the profile information, and an exec discards
2639 it. We can't rely on fork/exec to be paired. So write out the
2640 profile information we have gathered so far, and clear it. */
2641 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2642 is subject to race conditions, just as with multithreaded
2645 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2648 /* Ensure current function's preferred stack boundary is at least
2649 what we need. We don't have to increase alignment for recursive
2651 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2652 && fndecl != current_function_decl)
2653 cfun->preferred_stack_boundary = preferred_stack_boundary;
2654 if (fndecl == current_function_decl)
2655 cfun->recursive_call_emit = true;
2657 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2659 function_call_count++;
2661 /* We want to make two insn chains; one for a sibling call, the other
2662 for a normal call. We will select one of the two chains after
2663 initial RTL generation is complete. */
2664 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2666 int sibcall_failure = 0;
2667 /* We want to emit any pending stack adjustments before the tail
2668 recursion "call". That way we know any adjustment after the tail
2669 recursion call can be ignored if we indeed use the tail recursion
2671 int save_pending_stack_adjust = 0;
2672 int save_stack_pointer_delta = 0;
2674 rtx before_call, next_arg_reg;
2678 /* Emit any queued insns now; otherwise they would end up in
2679 only one of the alternates. */
2682 /* State variables we need to save and restore between
2684 save_pending_stack_adjust = pending_stack_adjust;
2685 save_stack_pointer_delta = stack_pointer_delta;
2688 flags &= ~ECF_SIBCALL;
2690 flags |= ECF_SIBCALL;
2692 /* Other state variables that we must reinitialize each time
2693 through the loop (that are not initialized by the loop itself). */
2697 /* Start a new sequence for the normal call case.
2699 From this point on, if the sibling call fails, we want to set
2700 sibcall_failure instead of continuing the loop. */
2705 /* We know at this point that there are not currently any
2706 pending cleanups. If, however, in the process of evaluating
2707 the arguments we were to create some, we'll need to be
2708 able to get rid of them. */
2709 expand_start_target_temps ();
2712 /* Don't let pending stack adjusts add up to too much.
2713 Also, do all pending adjustments now if there is any chance
2714 this might be a call to alloca or if we are expanding a sibling
2715 call sequence or if we are calling a function that is to return
2716 with stack pointer depressed. */
2717 if (pending_stack_adjust >= 32
2718 || (pending_stack_adjust > 0
2719 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2721 do_pending_stack_adjust ();
2723 /* When calling a const function, we must pop the stack args right away,
2724 so that the pop is deleted or moved with the call. */
2725 if (pass && (flags & ECF_LIBCALL_BLOCK))
2728 #ifdef FINAL_REG_PARM_STACK_SPACE
2729 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2732 /* Precompute any arguments as needed. */
2734 precompute_arguments (flags, num_actuals, args);
2736 /* Now we are about to start emitting insns that can be deleted
2737 if a libcall is deleted. */
2738 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2741 adjusted_args_size = args_size;
2742 /* Compute the actual size of the argument block required. The variable
2743 and constant sizes must be combined, the size may have to be rounded,
2744 and there may be a minimum required size. When generating a sibcall
2745 pattern, do not round up, since we'll be re-using whatever space our
2747 unadjusted_args_size
2748 = compute_argument_block_size (reg_parm_stack_space,
2749 &adjusted_args_size,
2751 : preferred_stack_boundary));
2753 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2755 /* The argument block when performing a sibling call is the
2756 incoming argument block. */
2759 argblock = virtual_incoming_args_rtx;
2761 #ifdef STACK_GROWS_DOWNWARD
2762 = plus_constant (argblock, current_function_pretend_args_size);
2764 = plus_constant (argblock, -current_function_pretend_args_size);
2766 stored_args_map = sbitmap_alloc (args_size.constant);
2767 sbitmap_zero (stored_args_map);
2770 /* If we have no actual push instructions, or shouldn't use them,
2771 make space for all args right now. */
2772 else if (adjusted_args_size.var != 0)
2774 if (old_stack_level == 0)
2776 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2777 old_stack_pointer_delta = stack_pointer_delta;
2778 old_pending_adj = pending_stack_adjust;
2779 pending_stack_adjust = 0;
2780 /* stack_arg_under_construction says whether a stack arg is
2781 being constructed at the old stack level. Pushing the stack
2782 gets a clean outgoing argument block. */
2783 old_stack_arg_under_construction = stack_arg_under_construction;
2784 stack_arg_under_construction = 0;
2786 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2790 /* Note that we must go through the motions of allocating an argument
2791 block even if the size is zero because we may be storing args
2792 in the area reserved for register arguments, which may be part of
2795 int needed = adjusted_args_size.constant;
2797 /* Store the maximum argument space used. It will be pushed by
2798 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2801 if (needed > current_function_outgoing_args_size)
2802 current_function_outgoing_args_size = needed;
2804 if (must_preallocate)
2806 if (ACCUMULATE_OUTGOING_ARGS)
2808 /* Since the stack pointer will never be pushed, it is
2809 possible for the evaluation of a parm to clobber
2810 something we have already written to the stack.
2811 Since most function calls on RISC machines do not use
2812 the stack, this is uncommon, but must work correctly.
2814 Therefore, we save any area of the stack that was already
2815 written and that we are using. Here we set up to do this
2816 by making a new stack usage map from the old one. The
2817 actual save will be done by store_one_arg.
2819 Another approach might be to try to reorder the argument
2820 evaluations to avoid this conflicting stack usage. */
2822 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2823 /* Since we will be writing into the entire argument area,
2824 the map must be allocated for its entire size, not just
2825 the part that is the responsibility of the caller. */
2826 needed += reg_parm_stack_space;
2829 #ifdef ARGS_GROW_DOWNWARD
2830 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2833 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2836 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2838 if (initial_highest_arg_in_use)
2839 memcpy (stack_usage_map, initial_stack_usage_map,
2840 initial_highest_arg_in_use);
2842 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2843 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2844 (highest_outgoing_arg_in_use
2845 - initial_highest_arg_in_use));
2848 /* The address of the outgoing argument list must not be
2849 copied to a register here, because argblock would be left
2850 pointing to the wrong place after the call to
2851 allocate_dynamic_stack_space below. */
2853 argblock = virtual_outgoing_args_rtx;
2857 if (inhibit_defer_pop == 0)
2859 /* Try to reuse some or all of the pending_stack_adjust
2860 to get this space. */
2862 = (combine_pending_stack_adjustment_and_call
2863 (unadjusted_args_size,
2864 &adjusted_args_size,
2865 preferred_unit_stack_boundary));
2867 /* combine_pending_stack_adjustment_and_call computes
2868 an adjustment before the arguments are allocated.
2869 Account for them and see whether or not the stack
2870 needs to go up or down. */
2871 needed = unadjusted_args_size - needed;
2875 /* We're releasing stack space. */
2876 /* ??? We can avoid any adjustment at all if we're
2877 already aligned. FIXME. */
2878 pending_stack_adjust = -needed;
2879 do_pending_stack_adjust ();
2883 /* We need to allocate space. We'll do that in
2884 push_block below. */
2885 pending_stack_adjust = 0;
2888 /* Special case this because overhead of `push_block' in
2889 this case is non-trivial. */
2891 argblock = virtual_outgoing_args_rtx;
2894 argblock = push_block (GEN_INT (needed), 0, 0);
2895 #ifdef ARGS_GROW_DOWNWARD
2896 argblock = plus_constant (argblock, needed);
2900 /* We only really need to call `copy_to_reg' in the case
2901 where push insns are going to be used to pass ARGBLOCK
2902 to a function call in ARGS. In that case, the stack
2903 pointer changes value from the allocation point to the
2904 call point, and hence the value of
2905 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2906 as well always do it. */
2907 argblock = copy_to_reg (argblock);
2912 if (ACCUMULATE_OUTGOING_ARGS)
2914 /* The save/restore code in store_one_arg handles all
2915 cases except one: a constructor call (including a C
2916 function returning a BLKmode struct) to initialize
2918 if (stack_arg_under_construction)
2920 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2921 rtx push_size = GEN_INT (reg_parm_stack_space
2922 + adjusted_args_size.constant);
2924 rtx push_size = GEN_INT (adjusted_args_size.constant);
2926 if (old_stack_level == 0)
2928 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2930 old_stack_pointer_delta = stack_pointer_delta;
2931 old_pending_adj = pending_stack_adjust;
2932 pending_stack_adjust = 0;
2933 /* stack_arg_under_construction says whether a stack
2934 arg is being constructed at the old stack level.
2935 Pushing the stack gets a clean outgoing argument
2937 old_stack_arg_under_construction
2938 = stack_arg_under_construction;
2939 stack_arg_under_construction = 0;
2940 /* Make a new map for the new argument list. */
2941 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2942 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2943 highest_outgoing_arg_in_use = 0;
2945 allocate_dynamic_stack_space (push_size, NULL_RTX,
2949 /* If argument evaluation might modify the stack pointer,
2950 copy the address of the argument list to a register. */
2951 for (i = 0; i < num_actuals; i++)
2952 if (args[i].pass_on_stack)
2954 argblock = copy_addr_to_reg (argblock);
2959 compute_argument_addresses (args, argblock, num_actuals);
2961 /* If we push args individually in reverse order, perform stack alignment
2962 before the first push (the last arg). */
2963 if (PUSH_ARGS_REVERSED && argblock == 0
2964 && adjusted_args_size.constant != unadjusted_args_size)
2966 /* When the stack adjustment is pending, we get better code
2967 by combining the adjustments. */
2968 if (pending_stack_adjust
2969 && ! (flags & ECF_LIBCALL_BLOCK)
2970 && ! inhibit_defer_pop)
2972 pending_stack_adjust
2973 = (combine_pending_stack_adjustment_and_call
2974 (unadjusted_args_size,
2975 &adjusted_args_size,
2976 preferred_unit_stack_boundary));
2977 do_pending_stack_adjust ();
2979 else if (argblock == 0)
2980 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2981 - unadjusted_args_size));
2983 /* Now that the stack is properly aligned, pops can't safely
2984 be deferred during the evaluation of the arguments. */
2987 funexp = rtx_for_function_call (fndecl, addr);
2989 /* Figure out the register where the value, if any, will come back. */
2991 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2992 && ! structure_value_addr)
2994 if (pcc_struct_value)
2995 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2996 fndecl, (pass == 0));
2998 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
3001 /* Precompute all register parameters. It isn't safe to compute anything
3002 once we have started filling any specific hard regs. */
3003 precompute_register_parameters (num_actuals, args, ®_parm_seen);
3005 #ifdef REG_PARM_STACK_SPACE
3006 /* Save the fixed argument area if it's part of the caller's frame and
3007 is clobbered by argument setup for this call. */
3008 if (ACCUMULATE_OUTGOING_ARGS && pass)
3009 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3010 &low_to_save, &high_to_save);
3013 /* Now store (and compute if necessary) all non-register parms.
3014 These come before register parms, since they can require block-moves,
3015 which could clobber the registers used for register parms.
3016 Parms which have partial registers are not stored here,
3017 but we do preallocate space here if they want that. */
3019 for (i = 0; i < num_actuals; i++)
3020 if (args[i].reg == 0 || args[i].pass_on_stack)
3022 rtx before_arg = get_last_insn ();
3024 if (store_one_arg (&args[i], argblock, flags,
3025 adjusted_args_size.var != 0,
3026 reg_parm_stack_space)
3028 && check_sibcall_argument_overlap (before_arg,
3030 sibcall_failure = 1;
3033 /* If we have a parm that is passed in registers but not in memory
3034 and whose alignment does not permit a direct copy into registers,
3035 make a group of pseudos that correspond to each register that we
3037 if (STRICT_ALIGNMENT)
3038 store_unaligned_arguments_into_pseudos (args, num_actuals);
3040 /* Now store any partially-in-registers parm.
3041 This is the last place a block-move can happen. */
3043 for (i = 0; i < num_actuals; i++)
3044 if (args[i].partial != 0 && ! args[i].pass_on_stack)
3046 rtx before_arg = get_last_insn ();
3048 if (store_one_arg (&args[i], argblock, flags,
3049 adjusted_args_size.var != 0,
3050 reg_parm_stack_space)
3052 && check_sibcall_argument_overlap (before_arg,
3054 sibcall_failure = 1;
3057 /* If we pushed args in forward order, perform stack alignment
3058 after pushing the last arg. */
3059 if (!PUSH_ARGS_REVERSED && argblock == 0)
3060 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3061 - unadjusted_args_size));
3063 /* If register arguments require space on the stack and stack space
3064 was not preallocated, allocate stack space here for arguments
3065 passed in registers. */
3066 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3067 if (!ACCUMULATE_OUTGOING_ARGS
3068 && must_preallocate == 0 && reg_parm_stack_space > 0)
3069 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3072 /* Pass the function the address in which to return a
3074 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3076 structure_value_addr
3077 = convert_memory_address (Pmode, structure_value_addr);
3078 emit_move_insn (struct_value,
3080 force_operand (structure_value_addr,
3083 if (GET_CODE (struct_value) == REG)
3084 use_reg (&call_fusage, struct_value);
3087 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3088 reg_parm_seen, pass == 0);
3090 load_register_parameters (args, num_actuals, &call_fusage, flags,
3091 pass == 0, &sibcall_failure);
3093 /* Perform postincrements before actually calling the function. */
3096 /* Save a pointer to the last insn before the call, so that we can
3097 later safely search backwards to find the CALL_INSN. */
3098 before_call = get_last_insn ();
3100 /* Set up next argument register. For sibling calls on machines
3101 with register windows this should be the incoming register. */
3102 #ifdef FUNCTION_INCOMING_ARG
3104 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3108 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3111 /* All arguments and registers used for the call must be set up by
3114 /* Stack must be properly aligned now. */
3115 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3118 /* Generate the actual call instruction. */
3119 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3120 adjusted_args_size.constant, struct_value_size,
3121 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3122 flags, & args_so_far);
3124 /* If call is cse'able, make appropriate pair of reg-notes around it.
3125 Test valreg so we don't crash; may safely ignore `const'
3126 if return type is void. Disable for PARALLEL return values, because
3127 we have no way to move such values into a pseudo register. */
3128 if (pass && (flags & ECF_LIBCALL_BLOCK))
3132 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
3134 insns = get_insns ();
3136 /* Expansion of block moves possibly introduced a loop that may
3137 not appear inside libcall block. */
3138 for (insn = insns; insn; insn = NEXT_INSN (insn))
3139 if (GET_CODE (insn) == JUMP_INSN)
3150 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3152 /* Mark the return value as a pointer if needed. */
3153 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3154 mark_reg_pointer (temp,
3155 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3157 /* Construct an "equal form" for the value which mentions all the
3158 arguments in order as well as the function name. */
3159 for (i = 0; i < num_actuals; i++)
3160 note = gen_rtx_EXPR_LIST (VOIDmode,
3161 args[i].initial_value, note);
3162 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3166 if (flags & ECF_PURE)
3167 note = gen_rtx_EXPR_LIST (VOIDmode,
3168 gen_rtx_USE (VOIDmode,
3169 gen_rtx_MEM (BLKmode,
3170 gen_rtx_SCRATCH (VOIDmode))),
3173 emit_libcall_block (insns, temp, valreg, note);
3178 else if (pass && (flags & ECF_MALLOC))
3180 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3183 /* The return value from a malloc-like function is a pointer. */
3184 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3185 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3187 emit_move_insn (temp, valreg);
3189 /* The return value from a malloc-like function can not alias
3191 last = get_last_insn ();
3193 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3195 /* Write out the sequence. */
3196 insns = get_insns ();
3202 /* For calls to `setjmp', etc., inform flow.c it should complain
3203 if nonvolatile values are live. For functions that cannot return,
3204 inform flow that control does not fall through. */
3206 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3208 /* The barrier must be emitted
3209 immediately after the CALL_INSN. Some ports emit more
3210 than just a CALL_INSN above, so we must search for it here. */
3212 rtx last = get_last_insn ();
3213 while (GET_CODE (last) != CALL_INSN)
3215 last = PREV_INSN (last);
3216 /* There was no CALL_INSN? */
3217 if (last == before_call)
3221 emit_barrier_after (last);
3223 /* Stack adjustments after a noreturn call are dead code.
3224 However when NO_DEFER_POP is in effect, we must preserve
3225 stack_pointer_delta. */
3226 if (inhibit_defer_pop == 0)
3228 stack_pointer_delta = old_stack_allocated;
3229 pending_stack_adjust = 0;
3233 if (flags & ECF_LONGJMP)
3234 current_function_calls_longjmp = 1;
3236 /* If value type not void, return an rtx for the value. */
3238 /* If there are cleanups to be called, don't use a hard reg as target.
3239 We need to double check this and see if it matters anymore. */
3240 if (any_pending_cleanups ())
3242 if (target && REG_P (target)
3243 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3245 sibcall_failure = 1;
3248 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3250 target = const0_rtx;
3251 else if (structure_value_addr)
3253 if (target == 0 || GET_CODE (target) != MEM)
3256 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3257 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3258 structure_value_addr));
3259 set_mem_attributes (target, exp, 1);
3262 else if (pcc_struct_value)
3264 /* This is the special C++ case where we need to
3265 know what the true target was. We take care to
3266 never use this value more than once in one expression. */
3267 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3268 copy_to_reg (valreg));
3269 set_mem_attributes (target, exp, 1);
3271 /* Handle calls that return values in multiple non-contiguous locations.
3272 The Irix 6 ABI has examples of this. */
3273 else if (GET_CODE (valreg) == PARALLEL)
3275 /* Second condition is added because "target" is freed at the
3276 the end of "pass0" for -O2 when call is made to
3277 expand_end_target_temps (). Its "in_use" flag has been set
3278 to false, so allocate a new temp. */
3279 if (target == 0 || (pass == 1 && target == temp_target))
3281 /* This will only be assigned once, so it can be readonly. */
3282 tree nt = build_qualified_type (TREE_TYPE (exp),
3283 (TYPE_QUALS (TREE_TYPE (exp))
3284 | TYPE_QUAL_CONST));
3286 target = assign_temp (nt, 0, 1, 1);
3287 temp_target = target;
3288 preserve_temp_slots (target);
3291 if (! rtx_equal_p (target, valreg))
3292 emit_group_store (target, valreg, TREE_TYPE (exp),
3293 int_size_in_bytes (TREE_TYPE (exp)));
3295 /* We can not support sibling calls for this case. */
3296 sibcall_failure = 1;
3299 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3300 && GET_MODE (target) == GET_MODE (valreg))
3302 /* TARGET and VALREG cannot be equal at this point because the
3303 latter would not have REG_FUNCTION_VALUE_P true, while the
3304 former would if it were referring to the same register.
3306 If they refer to the same register, this move will be a no-op,
3307 except when function inlining is being done. */
3308 emit_move_insn (target, valreg);
3310 /* If we are setting a MEM, this code must be executed. Since it is
3311 emitted after the call insn, sibcall optimization cannot be
3312 performed in that case. */
3313 if (GET_CODE (target) == MEM)
3314 sibcall_failure = 1;
3316 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3318 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3320 /* We can not support sibling calls for this case. */
3321 sibcall_failure = 1;
3325 if (shift_returned_value (TREE_TYPE (exp), &valreg))
3326 sibcall_failure = 1;
3328 target = copy_to_reg (valreg);
3331 if (targetm.calls.promote_function_return(funtype))
3333 /* If we promoted this return value, make the proper SUBREG. TARGET
3334 might be const0_rtx here, so be careful. */
3335 if (GET_CODE (target) == REG
3336 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3337 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3339 tree type = TREE_TYPE (exp);
3340 int unsignedp = TREE_UNSIGNED (type);
3343 /* If we don't promote as expected, something is wrong. */
3344 if (GET_MODE (target)
3345 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3348 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3349 && GET_MODE_SIZE (GET_MODE (target))
3350 > GET_MODE_SIZE (TYPE_MODE (type)))
3352 offset = GET_MODE_SIZE (GET_MODE (target))
3353 - GET_MODE_SIZE (TYPE_MODE (type));
3354 if (! BYTES_BIG_ENDIAN)
3355 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3356 else if (! WORDS_BIG_ENDIAN)
3357 offset %= UNITS_PER_WORD;
3359 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3360 SUBREG_PROMOTED_VAR_P (target) = 1;
3361 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3365 /* If size of args is variable or this was a constructor call for a stack
3366 argument, restore saved stack-pointer value. */
3368 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3370 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3371 stack_pointer_delta = old_stack_pointer_delta;
3372 pending_stack_adjust = old_pending_adj;
3373 stack_arg_under_construction = old_stack_arg_under_construction;
3374 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3375 stack_usage_map = initial_stack_usage_map;
3376 sibcall_failure = 1;
3378 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3380 #ifdef REG_PARM_STACK_SPACE
3382 restore_fixed_argument_area (save_area, argblock,
3383 high_to_save, low_to_save);
3386 /* If we saved any argument areas, restore them. */
3387 for (i = 0; i < num_actuals; i++)
3388 if (args[i].save_area)
3390 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3392 = gen_rtx_MEM (save_mode,
3393 memory_address (save_mode,
3394 XEXP (args[i].stack_slot, 0)));
3396 if (save_mode != BLKmode)
3397 emit_move_insn (stack_area, args[i].save_area);
3399 emit_block_move (stack_area, args[i].save_area,
3400 GEN_INT (args[i].locate.size.constant),
3401 BLOCK_OP_CALL_PARM);
3404 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3405 stack_usage_map = initial_stack_usage_map;
3408 /* If this was alloca, record the new stack level for nonlocal gotos.
3409 Check for the handler slots since we might not have a save area
3410 for non-local gotos. */
3412 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3413 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3415 /* Free up storage we no longer need. */
3416 for (i = 0; i < num_actuals; ++i)
3417 if (args[i].aligned_regs)
3418 free (args[i].aligned_regs);
3422 /* Undo the fake expand_start_target_temps we did earlier. If
3423 there had been any cleanups created, we've already set
3425 expand_end_target_temps ();
3428 /* If this function is returning into a memory location marked as
3429 readonly, it means it is initializing that location. We normally treat
3430 functions as not clobbering such locations, so we need to specify that
3431 this one does. We do this by adding the appropriate CLOBBER to the
3432 CALL_INSN function usage list. This cannot be done by emitting a
3433 standalone CLOBBER after the call because the latter would be ignored
3434 by at least the delay slot scheduling pass. We do this now instead of
3435 adding to call_fusage before the call to emit_call_1 because TARGET
3436 may be modified in the meantime. */
3437 if (structure_value_addr != 0 && target != 0
3438 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3439 add_function_usage_to
3441 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3444 insns = get_insns ();
3449 tail_call_insns = insns;
3451 /* Restore the pending stack adjustment now that we have
3452 finished generating the sibling call sequence. */
3454 pending_stack_adjust = save_pending_stack_adjust;
3455 stack_pointer_delta = save_stack_pointer_delta;
3457 /* Prepare arg structure for next iteration. */
3458 for (i = 0; i < num_actuals; i++)
3461 args[i].aligned_regs = 0;
3465 sbitmap_free (stored_args_map);
3469 normal_call_insns = insns;
3471 /* Verify that we've deallocated all the stack we used. */
3472 if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3473 && old_stack_allocated != stack_pointer_delta
3474 - pending_stack_adjust)
3478 /* If something prevents making this a sibling call,
3479 zero out the sequence. */
3480 if (sibcall_failure)
3481 tail_call_insns = NULL_RTX;
3484 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3485 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3486 can happen if the arguments to this function call an inline
3487 function who's expansion contains another CALL_PLACEHOLDER.
3489 If there are any C_Ps in any of these sequences, replace them
3490 with their normal call. */
3492 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3493 if (GET_CODE (insn) == CALL_INSN
3494 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3495 replace_call_placeholder (insn, sibcall_use_normal);
3497 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3498 if (GET_CODE (insn) == CALL_INSN
3499 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3500 replace_call_placeholder (insn, sibcall_use_normal);
3502 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3503 if (GET_CODE (insn) == CALL_INSN
3504 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3505 replace_call_placeholder (insn, sibcall_use_normal);
3507 /* If this was a potential tail recursion site, then emit a
3508 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3509 One of them will be selected later. */
3510 if (tail_recursion_insns || tail_call_insns)
3512 /* The tail recursion label must be kept around. We could expose
3513 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3514 and makes determining true tail recursion sites difficult.
3516 So we set LABEL_PRESERVE_P here, then clear it when we select
3517 one of the call sequences after rtl generation is complete. */
3518 if (tail_recursion_insns)
3519 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3520 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3522 tail_recursion_insns,
3523 tail_recursion_label));
3526 emit_insn (normal_call_insns);
3528 currently_expanding_call--;
3530 /* If this function returns with the stack pointer depressed, ensure
3531 this block saves and restores the stack pointer, show it was
3532 changed, and adjust for any outgoing arg space. */
3533 if (flags & ECF_SP_DEPRESSED)
3535 clear_pending_stack_adjust ();
3536 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3537 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3538 save_stack_pointer ();
3544 /* Traverse an argument list in VALUES and expand all complex
3545 arguments into their components. */
3547 split_complex_values (tree values)
3551 values = copy_list (values);
3553 for (p = values; p; p = TREE_CHAIN (p))
3555 tree complex_value = TREE_VALUE (p);
3558 complex_type = TREE_TYPE (complex_value);
3562 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3565 tree real, imag, next;
3567 subtype = TREE_TYPE (complex_type);
3568 complex_value = save_expr (complex_value);
3569 real = build1 (REALPART_EXPR, subtype, complex_value);
3570 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3572 TREE_VALUE (p) = real;
3573 next = TREE_CHAIN (p);
3574 imag = build_tree_list (NULL_TREE, imag);
3575 TREE_CHAIN (p) = imag;
3576 TREE_CHAIN (imag) = next;
3578 /* Skip the newly created node. */
3586 /* Traverse a list of TYPES and expand all complex types into their
3589 split_complex_types (tree types)
3593 types = copy_list (types);
3595 for (p = types; p; p = TREE_CHAIN (p))
3597 tree complex_type = TREE_VALUE (p);
3599 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3603 /* Rewrite complex type with component type. */
3604 TREE_VALUE (p) = TREE_TYPE (complex_type);
3605 next = TREE_CHAIN (p);
3607 /* Add another component type for the imaginary part. */
3608 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3609 TREE_CHAIN (p) = imag;
3610 TREE_CHAIN (imag) = next;
3612 /* Skip the newly created node. */
3620 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3621 The RETVAL parameter specifies whether return value needs to be saved, other
3622 parameters are documented in the emit_library_call function below. */
3625 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3626 enum libcall_type fn_type,
3627 enum machine_mode outmode, int nargs, va_list p)
3629 /* Total size in bytes of all the stack-parms scanned so far. */
3630 struct args_size args_size;
3631 /* Size of arguments before any adjustments (such as rounding). */
3632 struct args_size original_args_size;
3638 CUMULATIVE_ARGS args_so_far;
3642 enum machine_mode mode;
3645 struct locate_and_pad_arg_data locate;
3649 int old_inhibit_defer_pop = inhibit_defer_pop;
3650 rtx call_fusage = 0;
3653 int pcc_struct_value = 0;
3654 int struct_value_size = 0;
3656 int reg_parm_stack_space = 0;
3659 tree tfom; /* type_for_mode (outmode, 0) */
3661 #ifdef REG_PARM_STACK_SPACE
3662 /* Define the boundary of the register parm stack space that needs to be
3664 int low_to_save, high_to_save;
3665 rtx save_area = 0; /* Place that it is saved. */
3668 /* Size of the stack reserved for parameter registers. */
3669 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3670 char *initial_stack_usage_map = stack_usage_map;
3672 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3674 #ifdef REG_PARM_STACK_SPACE
3675 #ifdef MAYBE_REG_PARM_STACK_SPACE
3676 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3678 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3682 /* By default, library functions can not throw. */
3683 flags = ECF_NOTHROW;
3695 case LCT_CONST_MAKE_BLOCK:
3696 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3698 case LCT_PURE_MAKE_BLOCK:
3699 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3702 flags |= ECF_NORETURN;
3705 flags = ECF_NORETURN;
3707 case LCT_ALWAYS_RETURN:
3708 flags = ECF_ALWAYS_RETURN;
3710 case LCT_RETURNS_TWICE:
3711 flags = ECF_RETURNS_TWICE;
3716 /* Ensure current function's preferred stack boundary is at least
3718 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3719 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3721 /* If this kind of value comes back in memory,
3722 decide where in memory it should come back. */
3723 if (outmode != VOIDmode)
3725 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3726 if (aggregate_value_p (tfom, 0))
3728 #ifdef PCC_STATIC_STRUCT_RETURN
3730 = hard_function_value (build_pointer_type (tfom), 0, 0);
3731 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3732 pcc_struct_value = 1;
3734 value = gen_reg_rtx (outmode);
3735 #else /* not PCC_STATIC_STRUCT_RETURN */
3736 struct_value_size = GET_MODE_SIZE (outmode);
3737 if (value != 0 && GET_CODE (value) == MEM)
3740 mem_value = assign_temp (tfom, 0, 1, 1);
3742 /* This call returns a big structure. */
3743 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3747 tfom = void_type_node;
3749 /* ??? Unfinished: must pass the memory address as an argument. */
3751 /* Copy all the libcall-arguments out of the varargs data
3752 and into a vector ARGVEC.
3754 Compute how to pass each argument. We only support a very small subset
3755 of the full argument passing conventions to limit complexity here since
3756 library functions shouldn't have many args. */
3758 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3759 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3761 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3762 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3764 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3767 args_size.constant = 0;
3772 /* Now we are about to start emitting insns that can be deleted
3773 if a libcall is deleted. */
3774 if (flags & ECF_LIBCALL_BLOCK)
3779 /* If there's a structure value address to be passed,
3780 either pass it in the special place, or pass it as an extra argument. */
3781 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3783 rtx addr = XEXP (mem_value, 0);
3786 /* Make sure it is a reasonable operand for a move or push insn. */
3787 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3788 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3789 addr = force_operand (addr, NULL_RTX);
3791 argvec[count].value = addr;
3792 argvec[count].mode = Pmode;
3793 argvec[count].partial = 0;
3795 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3796 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3797 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3801 locate_and_pad_parm (Pmode, NULL_TREE,
3802 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3805 argvec[count].reg != 0,
3807 0, NULL_TREE, &args_size, &argvec[count].locate);
3809 if (argvec[count].reg == 0 || argvec[count].partial != 0
3810 || reg_parm_stack_space > 0)
3811 args_size.constant += argvec[count].locate.size.constant;
3813 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3818 for (; count < nargs; count++)
3820 rtx val = va_arg (p, rtx);
3821 enum machine_mode mode = va_arg (p, enum machine_mode);
3823 /* We cannot convert the arg value to the mode the library wants here;
3824 must do it earlier where we know the signedness of the arg. */
3826 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3829 /* There's no need to call protect_from_queue, because
3830 either emit_move_insn or emit_push_insn will do that. */
3832 /* Make sure it is a reasonable operand for a move or push insn. */
3833 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3834 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3835 val = force_operand (val, NULL_RTX);
3837 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3838 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3842 #ifdef FUNCTION_ARG_CALLEE_COPIES
3843 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3848 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3849 functions, so we have to pretend this isn't such a function. */
3850 if (flags & ECF_LIBCALL_BLOCK)
3852 rtx insns = get_insns ();
3856 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3858 /* If this was a CONST function, it is now PURE since
3859 it now reads memory. */
3860 if (flags & ECF_CONST)
3862 flags &= ~ECF_CONST;
3866 if (GET_MODE (val) == MEM && ! must_copy)
3870 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3872 emit_move_insn (slot, val);
3876 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3879 = gen_rtx_MEM (mode,
3880 expand_expr (build1 (ADDR_EXPR,
3881 build_pointer_type (type),
3882 make_tree (type, val)),
3883 NULL_RTX, VOIDmode, 0));
3886 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3887 gen_rtx_USE (VOIDmode, slot),
3890 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3891 gen_rtx_CLOBBER (VOIDmode,
3896 val = force_operand (XEXP (slot, 0), NULL_RTX);
3900 argvec[count].value = val;
3901 argvec[count].mode = mode;
3903 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3905 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3906 argvec[count].partial
3907 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3909 argvec[count].partial = 0;
3912 locate_and_pad_parm (mode, NULL_TREE,
3913 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3916 argvec[count].reg != 0,
3918 argvec[count].partial,
3919 NULL_TREE, &args_size, &argvec[count].locate);
3921 if (argvec[count].locate.size.var)
3924 if (argvec[count].reg == 0 || argvec[count].partial != 0
3925 || reg_parm_stack_space > 0)
3926 args_size.constant += argvec[count].locate.size.constant;
3928 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3931 #ifdef FINAL_REG_PARM_STACK_SPACE
3932 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3935 /* If this machine requires an external definition for library
3936 functions, write one out. */
3937 assemble_external_libcall (fun);
3939 original_args_size = args_size;
3940 args_size.constant = (((args_size.constant
3941 + stack_pointer_delta
3945 - stack_pointer_delta);
3947 args_size.constant = MAX (args_size.constant,
3948 reg_parm_stack_space);
3950 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3951 args_size.constant -= reg_parm_stack_space;
3954 if (args_size.constant > current_function_outgoing_args_size)
3955 current_function_outgoing_args_size = args_size.constant;
3957 if (ACCUMULATE_OUTGOING_ARGS)
3959 /* Since the stack pointer will never be pushed, it is possible for
3960 the evaluation of a parm to clobber something we have already
3961 written to the stack. Since most function calls on RISC machines
3962 do not use the stack, this is uncommon, but must work correctly.
3964 Therefore, we save any area of the stack that was already written
3965 and that we are using. Here we set up to do this by making a new
3966 stack usage map from the old one.
3968 Another approach might be to try to reorder the argument
3969 evaluations to avoid this conflicting stack usage. */
3971 needed = args_size.constant;
3973 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3974 /* Since we will be writing into the entire argument area, the
3975 map must be allocated for its entire size, not just the part that
3976 is the responsibility of the caller. */
3977 needed += reg_parm_stack_space;
3980 #ifdef ARGS_GROW_DOWNWARD
3981 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3984 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3987 stack_usage_map = alloca (highest_outgoing_arg_in_use);
3989 if (initial_highest_arg_in_use)
3990 memcpy (stack_usage_map, initial_stack_usage_map,
3991 initial_highest_arg_in_use);
3993 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3994 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3995 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3998 /* We must be careful to use virtual regs before they're instantiated,
3999 and real regs afterwards. Loop optimization, for example, can create
4000 new libcalls after we've instantiated the virtual regs, and if we
4001 use virtuals anyway, they won't match the rtl patterns. */
4003 if (virtuals_instantiated)
4004 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
4006 argblock = virtual_outgoing_args_rtx;
4011 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
4014 /* If we push args individually in reverse order, perform stack alignment
4015 before the first push (the last arg). */
4016 if (argblock == 0 && PUSH_ARGS_REVERSED)
4017 anti_adjust_stack (GEN_INT (args_size.constant
4018 - original_args_size.constant));
4020 if (PUSH_ARGS_REVERSED)
4031 #ifdef REG_PARM_STACK_SPACE
4032 if (ACCUMULATE_OUTGOING_ARGS)
4034 /* The argument list is the property of the called routine and it
4035 may clobber it. If the fixed area has been used for previous
4036 parameters, we must save and restore it. */
4037 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
4038 &low_to_save, &high_to_save);
4042 /* Push the args that need to be pushed. */
4044 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4045 are to be pushed. */
4046 for (count = 0; count < nargs; count++, argnum += inc)
4048 enum machine_mode mode = argvec[argnum].mode;
4049 rtx val = argvec[argnum].value;
4050 rtx reg = argvec[argnum].reg;
4051 int partial = argvec[argnum].partial;
4052 int lower_bound = 0, upper_bound = 0, i;
4054 if (! (reg != 0 && partial == 0))
4056 if (ACCUMULATE_OUTGOING_ARGS)
4058 /* If this is being stored into a pre-allocated, fixed-size,
4059 stack area, save any previous data at that location. */
4061 #ifdef ARGS_GROW_DOWNWARD
4062 /* stack_slot is negative, but we want to index stack_usage_map
4063 with positive values. */
4064 upper_bound = -argvec[argnum].locate.offset.constant + 1;
4065 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
4067 lower_bound = argvec[argnum].locate.offset.constant;
4068 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
4072 /* Don't worry about things in the fixed argument area;
4073 it has already been saved. */
4074 if (i < reg_parm_stack_space)
4075 i = reg_parm_stack_space;
4076 while (i < upper_bound && stack_usage_map[i] == 0)
4079 if (i < upper_bound)
4081 /* We need to make a save area. */
4083 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4084 enum machine_mode save_mode
4085 = mode_for_size (size, MODE_INT, 1);
4087 = plus_constant (argblock,
4088 argvec[argnum].locate.offset.constant);
4090 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4092 if (save_mode == BLKmode)
4094 argvec[argnum].save_area
4095 = assign_stack_temp (BLKmode,
4096 argvec[argnum].locate.size.constant,
4099 emit_block_move (validize_mem (argvec[argnum].save_area),
4101 GEN_INT (argvec[argnum].locate.size.constant),
4102 BLOCK_OP_CALL_PARM);
4106 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4108 emit_move_insn (argvec[argnum].save_area, stack_area);
4113 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
4114 partial, reg, 0, argblock,
4115 GEN_INT (argvec[argnum].locate.offset.constant),
4116 reg_parm_stack_space,
4117 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4119 /* Now mark the segment we just used. */
4120 if (ACCUMULATE_OUTGOING_ARGS)
4121 for (i = lower_bound; i < upper_bound; i++)
4122 stack_usage_map[i] = 1;
4128 /* If we pushed args in forward order, perform stack alignment
4129 after pushing the last arg. */
4130 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4131 anti_adjust_stack (GEN_INT (args_size.constant
4132 - original_args_size.constant));
4134 if (PUSH_ARGS_REVERSED)
4139 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4141 /* Now load any reg parms into their regs. */
4143 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4144 are to be pushed. */
4145 for (count = 0; count < nargs; count++, argnum += inc)
4147 rtx val = argvec[argnum].value;
4148 rtx reg = argvec[argnum].reg;
4149 int partial = argvec[argnum].partial;
4151 /* Handle calls that pass values in multiple non-contiguous
4152 locations. The PA64 has examples of this for library calls. */
4153 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4154 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (GET_MODE (val)));
4155 else if (reg != 0 && partial == 0)
4156 emit_move_insn (reg, val);
4161 /* Any regs containing parms remain in use through the call. */
4162 for (count = 0; count < nargs; count++)
4164 rtx reg = argvec[count].reg;
4165 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4166 use_group_regs (&call_fusage, reg);
4168 use_reg (&call_fusage, reg);
4171 /* Pass the function the address in which to return a structure value. */
4172 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4174 emit_move_insn (struct_value,
4176 force_operand (XEXP (mem_value, 0),
4178 if (GET_CODE (struct_value) == REG)
4179 use_reg (&call_fusage, struct_value);
4182 /* Don't allow popping to be deferred, since then
4183 cse'ing of library calls could delete a call and leave the pop. */
4185 valreg = (mem_value == 0 && outmode != VOIDmode
4186 ? hard_libcall_value (outmode) : NULL_RTX);
4188 /* Stack must be properly aligned now. */
4189 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4192 before_call = get_last_insn ();
4194 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4195 will set inhibit_defer_pop to that value. */
4196 /* The return type is needed to decide how many bytes the function pops.
4197 Signedness plays no role in that, so for simplicity, we pretend it's
4198 always signed. We also assume that the list of arguments passed has
4199 no impact, so we pretend it is unknown. */
4202 get_identifier (XSTR (orgfun, 0)),
4203 build_function_type (tfom, NULL_TREE),
4204 original_args_size.constant, args_size.constant,
4206 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4208 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4210 /* For calls to `setjmp', etc., inform flow.c it should complain
4211 if nonvolatile values are live. For functions that cannot return,
4212 inform flow that control does not fall through. */
4214 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4216 /* The barrier note must be emitted
4217 immediately after the CALL_INSN. Some ports emit more than
4218 just a CALL_INSN above, so we must search for it here. */
4220 rtx last = get_last_insn ();
4221 while (GET_CODE (last) != CALL_INSN)
4223 last = PREV_INSN (last);
4224 /* There was no CALL_INSN? */
4225 if (last == before_call)
4229 emit_barrier_after (last);
4232 /* Now restore inhibit_defer_pop to its actual original value. */
4235 /* If call is cse'able, make appropriate pair of reg-notes around it.
4236 Test valreg so we don't crash; may safely ignore `const'
4237 if return type is void. Disable for PARALLEL return values, because
4238 we have no way to move such values into a pseudo register. */
4239 if (flags & ECF_LIBCALL_BLOCK)
4245 insns = get_insns ();
4255 if (GET_CODE (valreg) == PARALLEL)
4257 temp = gen_reg_rtx (outmode);
4258 emit_group_store (temp, valreg, NULL_TREE,
4259 GET_MODE_SIZE (outmode));
4263 temp = gen_reg_rtx (GET_MODE (valreg));
4265 /* Construct an "equal form" for the value which mentions all the
4266 arguments in order as well as the function name. */
4267 for (i = 0; i < nargs; i++)
4268 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4269 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4271 insns = get_insns ();
4274 if (flags & ECF_PURE)
4275 note = gen_rtx_EXPR_LIST (VOIDmode,
4276 gen_rtx_USE (VOIDmode,
4277 gen_rtx_MEM (BLKmode,
4278 gen_rtx_SCRATCH (VOIDmode))),
4281 emit_libcall_block (insns, temp, valreg, note);
4288 /* Copy the value to the right place. */
4289 if (outmode != VOIDmode && retval)
4295 if (value != mem_value)
4296 emit_move_insn (value, mem_value);
4298 else if (GET_CODE (valreg) == PARALLEL)
4301 value = gen_reg_rtx (outmode);
4302 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4304 else if (value != 0)
4305 emit_move_insn (value, valreg);
4310 if (ACCUMULATE_OUTGOING_ARGS)
4312 #ifdef REG_PARM_STACK_SPACE
4314 restore_fixed_argument_area (save_area, argblock,
4315 high_to_save, low_to_save);
4318 /* If we saved any argument areas, restore them. */
4319 for (count = 0; count < nargs; count++)
4320 if (argvec[count].save_area)
4322 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4323 rtx adr = plus_constant (argblock,
4324 argvec[count].locate.offset.constant);
4325 rtx stack_area = gen_rtx_MEM (save_mode,
4326 memory_address (save_mode, adr));
4328 if (save_mode == BLKmode)
4329 emit_block_move (stack_area,
4330 validize_mem (argvec[count].save_area),
4331 GEN_INT (argvec[count].locate.size.constant),
4332 BLOCK_OP_CALL_PARM);
4334 emit_move_insn (stack_area, argvec[count].save_area);
4337 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4338 stack_usage_map = initial_stack_usage_map;
4345 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4346 (emitting the queue unless NO_QUEUE is nonzero),
4347 for a value of mode OUTMODE,
4348 with NARGS different arguments, passed as alternating rtx values
4349 and machine_modes to convert them to.
4350 The rtx values should have been passed through protect_from_queue already.
4352 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4353 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4354 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4355 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4356 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4357 or other LCT_ value for other types of library calls. */
4360 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4361 enum machine_mode outmode, int nargs, ...)
4365 va_start (p, nargs);
4366 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4370 /* Like emit_library_call except that an extra argument, VALUE,
4371 comes second and says where to store the result.
4372 (If VALUE is zero, this function chooses a convenient way
4373 to return the value.
4375 This function returns an rtx for where the value is to be found.
4376 If VALUE is nonzero, VALUE is returned. */
4379 emit_library_call_value (rtx orgfun, rtx value,
4380 enum libcall_type fn_type,
4381 enum machine_mode outmode, int nargs, ...)
4386 va_start (p, nargs);
4387 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4394 /* Store a single argument for a function call
4395 into the register or memory area where it must be passed.
4396 *ARG describes the argument value and where to pass it.
4398 ARGBLOCK is the address of the stack-block for all the arguments,
4399 or 0 on a machine where arguments are pushed individually.
4401 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4402 so must be careful about how the stack is used.
4404 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4405 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4406 that we need not worry about saving and restoring the stack.
4408 FNDECL is the declaration of the function we are calling.
4410 Return nonzero if this arg should cause sibcall failure,
4414 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4415 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4417 tree pval = arg->tree_value;
4421 int i, lower_bound = 0, upper_bound = 0;
4422 int sibcall_failure = 0;
4424 if (TREE_CODE (pval) == ERROR_MARK)
4427 /* Push a new temporary level for any temporaries we make for
4431 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4433 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4434 save any previous data at that location. */
4435 if (argblock && ! variable_size && arg->stack)
4437 #ifdef ARGS_GROW_DOWNWARD
4438 /* stack_slot is negative, but we want to index stack_usage_map
4439 with positive values. */
4440 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4441 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4445 lower_bound = upper_bound - arg->locate.size.constant;
4447 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4448 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4452 upper_bound = lower_bound + arg->locate.size.constant;
4456 /* Don't worry about things in the fixed argument area;
4457 it has already been saved. */
4458 if (i < reg_parm_stack_space)
4459 i = reg_parm_stack_space;
4460 while (i < upper_bound && stack_usage_map[i] == 0)
4463 if (i < upper_bound)
4465 /* We need to make a save area. */
4466 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4467 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4468 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4469 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4471 if (save_mode == BLKmode)
4473 tree ot = TREE_TYPE (arg->tree_value);
4474 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4475 | TYPE_QUAL_CONST));
4477 arg->save_area = assign_temp (nt, 0, 1, 1);
4478 preserve_temp_slots (arg->save_area);
4479 emit_block_move (validize_mem (arg->save_area), stack_area,
4480 expr_size (arg->tree_value),
4481 BLOCK_OP_CALL_PARM);
4485 arg->save_area = gen_reg_rtx (save_mode);
4486 emit_move_insn (arg->save_area, stack_area);
4492 /* If this isn't going to be placed on both the stack and in registers,
4493 set up the register and number of words. */
4494 if (! arg->pass_on_stack)
4496 if (flags & ECF_SIBCALL)
4497 reg = arg->tail_call_reg;
4500 partial = arg->partial;
4503 if (reg != 0 && partial == 0)
4504 /* Being passed entirely in a register. We shouldn't be called in
4508 /* If this arg needs special alignment, don't load the registers
4510 if (arg->n_aligned_regs != 0)
4513 /* If this is being passed partially in a register, we can't evaluate
4514 it directly into its stack slot. Otherwise, we can. */
4515 if (arg->value == 0)
4517 /* stack_arg_under_construction is nonzero if a function argument is
4518 being evaluated directly into the outgoing argument list and
4519 expand_call must take special action to preserve the argument list
4520 if it is called recursively.
4522 For scalar function arguments stack_usage_map is sufficient to
4523 determine which stack slots must be saved and restored. Scalar
4524 arguments in general have pass_on_stack == 0.
4526 If this argument is initialized by a function which takes the
4527 address of the argument (a C++ constructor or a C function
4528 returning a BLKmode structure), then stack_usage_map is
4529 insufficient and expand_call must push the stack around the
4530 function call. Such arguments have pass_on_stack == 1.
4532 Note that it is always safe to set stack_arg_under_construction,
4533 but this generates suboptimal code if set when not needed. */
4535 if (arg->pass_on_stack)
4536 stack_arg_under_construction++;
4538 arg->value = expand_expr (pval,
4540 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4541 ? NULL_RTX : arg->stack,
4542 VOIDmode, EXPAND_STACK_PARM);
4544 /* If we are promoting object (or for any other reason) the mode
4545 doesn't agree, convert the mode. */
4547 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4548 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4549 arg->value, arg->unsignedp);
4551 if (arg->pass_on_stack)
4552 stack_arg_under_construction--;
4555 /* Don't allow anything left on stack from computation
4556 of argument to alloca. */
4557 if (flags & ECF_MAY_BE_ALLOCA)
4558 do_pending_stack_adjust ();
4560 if (arg->value == arg->stack)
4561 /* If the value is already in the stack slot, we are done. */
4563 else if (arg->mode != BLKmode)
4567 /* Argument is a scalar, not entirely passed in registers.
4568 (If part is passed in registers, arg->partial says how much
4569 and emit_push_insn will take care of putting it there.)
4571 Push it, and if its size is less than the
4572 amount of space allocated to it,
4573 also bump stack pointer by the additional space.
4574 Note that in C the default argument promotions
4575 will prevent such mismatches. */
4577 size = GET_MODE_SIZE (arg->mode);
4578 /* Compute how much space the push instruction will push.
4579 On many machines, pushing a byte will advance the stack
4580 pointer by a halfword. */
4581 #ifdef PUSH_ROUNDING
4582 size = PUSH_ROUNDING (size);
4586 /* Compute how much space the argument should get:
4587 round up to a multiple of the alignment for arguments. */
4588 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4589 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4590 / (PARM_BOUNDARY / BITS_PER_UNIT))
4591 * (PARM_BOUNDARY / BITS_PER_UNIT));
4593 /* This isn't already where we want it on the stack, so put it there.
4594 This can either be done with push or copy insns. */
4595 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4596 PARM_BOUNDARY, partial, reg, used - size, argblock,
4597 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4598 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4600 /* Unless this is a partially-in-register argument, the argument is now
4603 arg->value = arg->stack;
4607 /* BLKmode, at least partly to be pushed. */
4609 unsigned int parm_align;
4613 /* Pushing a nonscalar.
4614 If part is passed in registers, PARTIAL says how much
4615 and emit_push_insn will take care of putting it there. */
4617 /* Round its size up to a multiple
4618 of the allocation unit for arguments. */
4620 if (arg->locate.size.var != 0)
4623 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4627 /* PUSH_ROUNDING has no effect on us, because
4628 emit_push_insn for BLKmode is careful to avoid it. */
4629 if (reg && GET_CODE (reg) == PARALLEL)
4631 /* Use the size of the elt to compute excess. */
4632 rtx elt = XEXP (XVECEXP (reg, 0, 0), 0);
4633 excess = (arg->locate.size.constant
4634 - int_size_in_bytes (TREE_TYPE (pval))
4635 + partial * GET_MODE_SIZE (GET_MODE (elt)));
4638 excess = (arg->locate.size.constant
4639 - int_size_in_bytes (TREE_TYPE (pval))
4640 + partial * UNITS_PER_WORD);
4641 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4642 NULL_RTX, TYPE_MODE (sizetype), 0);
4645 /* Some types will require stricter alignment, which will be
4646 provided for elsewhere in argument layout. */
4647 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4649 /* When an argument is padded down, the block is aligned to
4650 PARM_BOUNDARY, but the actual argument isn't. */
4651 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4653 if (arg->locate.size.var)
4654 parm_align = BITS_PER_UNIT;
4657 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4658 parm_align = MIN (parm_align, excess_align);
4662 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4664 /* emit_push_insn might not work properly if arg->value and
4665 argblock + arg->locate.offset areas overlap. */
4669 if (XEXP (x, 0) == current_function_internal_arg_pointer
4670 || (GET_CODE (XEXP (x, 0)) == PLUS
4671 && XEXP (XEXP (x, 0), 0) ==
4672 current_function_internal_arg_pointer
4673 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4675 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4676 i = INTVAL (XEXP (XEXP (x, 0), 1));
4678 /* expand_call should ensure this */
4679 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4682 if (arg->locate.offset.constant > i)
4684 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4685 sibcall_failure = 1;
4687 else if (arg->locate.offset.constant < i)
4689 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4690 sibcall_failure = 1;
4695 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4696 parm_align, partial, reg, excess, argblock,
4697 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4698 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4700 /* Unless this is a partially-in-register argument, the argument is now
4703 ??? Unlike the case above, in which we want the actual
4704 address of the data, so that we can load it directly into a
4705 register, here we want the address of the stack slot, so that
4706 it's properly aligned for word-by-word copying or something
4707 like that. It's not clear that this is always correct. */
4709 arg->value = arg->stack_slot;
4712 /* Mark all slots this store used. */
4713 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4714 && argblock && ! variable_size && arg->stack)
4715 for (i = lower_bound; i < upper_bound; i++)
4716 stack_usage_map[i] = 1;
4718 /* Once we have pushed something, pops can't safely
4719 be deferred during the rest of the arguments. */
4722 /* ANSI doesn't require a sequence point here,
4723 but PCC has one, so this will avoid some problems. */
4726 /* Free any temporary slots made in processing this argument. Show
4727 that we might have taken the address of something and pushed that
4729 preserve_temp_slots (NULL_RTX);
4733 return sibcall_failure;
4736 /* Nonzero if we do not know how to pass TYPE solely in registers.
4737 We cannot do so in the following cases:
4739 - if the type has variable size
4740 - if the type is marked as addressable (it is required to be constructed
4742 - if the padding and mode of the type is such that a copy into a register
4743 would put it into the wrong part of the register.
4745 Which padding can't be supported depends on the byte endianness.
4747 A value in a register is implicitly padded at the most significant end.
4748 On a big-endian machine, that is the lower end in memory.
4749 So a value padded in memory at the upper end can't go in a register.
4750 For a little-endian machine, the reverse is true. */
4753 default_must_pass_in_stack (enum machine_mode mode, tree type)
4758 /* If the type has variable size... */
4759 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4762 /* If the type is marked as addressable (it is required
4763 to be constructed into the stack)... */
4764 if (TREE_ADDRESSABLE (type))
4767 /* If the padding and mode of the type is such that a copy into
4768 a register would put it into the wrong part of the register. */
4770 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4771 && (FUNCTION_ARG_PADDING (mode, type)
4772 == (BYTES_BIG_ENDIAN ? upward : downward)))