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 #ifndef STACK_POINTER_OFFSET
45 #define STACK_POINTER_OFFSET 0
48 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
49 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
51 /* Data structure and subroutines used within expand_call. */
55 /* Tree node for this argument. */
57 /* Mode for value; TYPE_MODE unless promoted. */
58 enum machine_mode mode;
59 /* Current RTL value for argument, or 0 if it isn't precomputed. */
61 /* Initially-compute RTL value for argument; only for const functions. */
63 /* Register to pass this argument in, 0 if passed on stack, or an
64 PARALLEL if the arg is to be copied into multiple non-contiguous
67 /* Register to pass this argument in when generating tail call sequence.
68 This is not the same register as for normal calls on machines with
71 /* If REG was promoted from the actual mode of the argument expression,
72 indicates whether the promotion is sign- or zero-extended. */
74 /* Number of registers to use. 0 means put the whole arg in registers.
75 Also 0 if not passed in registers. */
77 /* Nonzero if argument must be passed on stack.
78 Note that some arguments may be passed on the stack
79 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
80 pass_on_stack identifies arguments that *cannot* go in registers. */
82 /* Some fields packaged up for locate_and_pad_parm. */
83 struct locate_and_pad_arg_data locate;
84 /* Location on the stack at which parameter should be stored. The store
85 has already been done if STACK == VALUE. */
87 /* Location on the stack of the start of this argument slot. This can
88 differ from STACK if this arg pads downward. This location is known
89 to be aligned to FUNCTION_ARG_BOUNDARY. */
91 /* Place that this stack area has been saved, if needed. */
93 /* If an argument's alignment does not permit direct copying into registers,
94 copy in smaller-sized pieces into pseudos. These are stored in a
95 block pointed to by this field. The next field says how many
96 word-sized pseudos we made. */
101 /* A vector of one char per byte of stack space. A byte if nonzero if
102 the corresponding stack location has been used.
103 This vector is used to prevent a function call within an argument from
104 clobbering any stack already set up. */
105 static char *stack_usage_map;
107 /* Size of STACK_USAGE_MAP. */
108 static int highest_outgoing_arg_in_use;
110 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
111 stack location's tail call argument has been already stored into the stack.
112 This bitmap is used to prevent sibling call optimization if function tries
113 to use parent's incoming argument slots when they have been already
114 overwritten with tail call arguments. */
115 static sbitmap stored_args_map;
117 /* stack_arg_under_construction is nonzero when an argument may be
118 initialized with a constructor call (including a C function that
119 returns a BLKmode struct) and expand_call must take special action
120 to make sure the object being constructed does not overlap the
121 argument list for the constructor call. */
122 int stack_arg_under_construction;
124 static int calls_function (tree, int);
125 static int calls_function_1 (tree, int);
127 static void emit_call_1 (rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
128 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
130 static void precompute_register_parameters (int, struct arg_data *, int *);
131 static int store_one_arg (struct arg_data *, rtx, int, int, int);
132 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
133 static int finalize_must_preallocate (int, int, struct arg_data *,
135 static void precompute_arguments (int, int, struct arg_data *);
136 static int compute_argument_block_size (int, struct args_size *, int);
137 static void initialize_argument_information (int, struct arg_data *,
138 struct args_size *, int, tree,
139 tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *);
141 static void compute_argument_addresses (struct arg_data *, rtx, int);
142 static rtx rtx_for_function_call (tree, tree);
143 static void load_register_parameters (struct arg_data *, int, rtx *, int,
145 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
146 enum machine_mode, int, va_list);
147 static int special_function_p (tree, int);
148 static rtx try_to_integrate (tree, tree, rtx, int, tree, rtx);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree fix_unsafe_tree (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
164 If WHICH is 0, return 1 if EXP contains a call to any function.
165 Actually, we only need return 1 if evaluating EXP would require pushing
166 arguments on the stack, but that is too difficult to compute, so we just
167 assume any function call might require the stack. */
169 static tree calls_function_save_exprs;
172 calls_function (tree exp, int which)
176 calls_function_save_exprs = 0;
177 val = calls_function_1 (exp, which);
178 calls_function_save_exprs = 0;
182 /* Recursive function to do the work of above function. */
185 calls_function_1 (tree exp, int which)
188 enum tree_code code = TREE_CODE (exp);
189 int class = TREE_CODE_CLASS (code);
190 int length = first_rtl_op (code);
192 /* If this code is language-specific, we don't know what it will do. */
193 if ((int) code >= NUM_TREE_CODES)
201 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
203 && (TYPE_RETURNS_STACK_DEPRESSED
204 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
206 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
207 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
209 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
211 & ECF_MAY_BE_ALLOCA))
220 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
221 if (calls_function_1 (TREE_VALUE (tem), which))
228 if (SAVE_EXPR_RTL (exp) != 0)
230 if (value_member (exp, calls_function_save_exprs))
232 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
233 calls_function_save_exprs);
234 return (TREE_OPERAND (exp, 0) != 0
235 && calls_function_1 (TREE_OPERAND (exp, 0), which));
242 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
243 if (DECL_INITIAL (local) != 0
244 && calls_function_1 (DECL_INITIAL (local), which))
247 for (subblock = BLOCK_SUBBLOCKS (exp);
249 subblock = TREE_CHAIN (subblock))
250 if (calls_function_1 (subblock, which))
256 for (; exp != 0; exp = TREE_CHAIN (exp))
257 if (calls_function_1 (TREE_VALUE (exp), which))
265 /* Only expressions and blocks can contain calls. */
266 if (! IS_EXPR_CODE_CLASS (class) && class != 'b')
269 for (i = 0; i < length; i++)
270 if (TREE_OPERAND (exp, i) != 0
271 && calls_function_1 (TREE_OPERAND (exp, i), which))
277 /* Force FUNEXP into a form suitable for the address of a CALL,
278 and return that as an rtx. Also load the static chain register
279 if FNDECL is a nested function.
281 CALL_FUSAGE points to a variable holding the prospective
282 CALL_INSN_FUNCTION_USAGE information. */
285 prepare_call_address (rtx funexp, tree fndecl, rtx *call_fusage,
286 int reg_parm_seen, int sibcallp)
288 rtx static_chain_value = 0;
290 funexp = protect_from_queue (funexp, 0);
293 /* Get possible static chain value for nested function in C. */
294 static_chain_value = lookup_static_chain (fndecl);
296 /* Make a valid memory address and copy constants thru pseudo-regs,
297 but not for a constant address if -fno-function-cse. */
298 if (GET_CODE (funexp) != SYMBOL_REF)
299 /* If we are using registers for parameters, force the
300 function address into a register now. */
301 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
302 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
303 : memory_address (FUNCTION_MODE, funexp));
306 #ifndef NO_FUNCTION_CSE
307 if (optimize && ! flag_no_function_cse)
308 #ifdef NO_RECURSIVE_FUNCTION_CSE
309 if (fndecl != current_function_decl)
311 funexp = force_reg (Pmode, funexp);
315 if (static_chain_value != 0)
317 emit_move_insn (static_chain_rtx, static_chain_value);
319 if (GET_CODE (static_chain_rtx) == REG)
320 use_reg (call_fusage, static_chain_rtx);
326 /* Generate instructions to call function FUNEXP,
327 and optionally pop the results.
328 The CALL_INSN is the first insn generated.
330 FNDECL is the declaration node of the function. This is given to the
331 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
333 FUNTYPE is the data type of the function. This is given to the macro
334 RETURN_POPS_ARGS to determine whether this function pops its own args.
335 We used to allow an identifier for library functions, but that doesn't
336 work when the return type is an aggregate type and the calling convention
337 says that the pointer to this aggregate is to be popped by the callee.
339 STACK_SIZE is the number of bytes of arguments on the stack,
340 ROUNDED_STACK_SIZE is that number rounded up to
341 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
342 both to put into the call insn and to generate explicit popping
345 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
346 It is zero if this call doesn't want a structure value.
348 NEXT_ARG_REG is the rtx that results from executing
349 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
350 just after all the args have had their registers assigned.
351 This could be whatever you like, but normally it is the first
352 arg-register beyond those used for args in this call,
353 or 0 if all the arg-registers are used in this call.
354 It is passed on to `gen_call' so you can put this info in the call insn.
356 VALREG is a hard register in which a value is returned,
357 or 0 if the call does not return a value.
359 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
360 the args to this call were processed.
361 We restore `inhibit_defer_pop' to that value.
363 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
364 denote registers used by the called function. */
367 emit_call_1 (rtx funexp, tree fndecl ATTRIBUTE_UNUSED, tree funtype ATTRIBUTE_UNUSED,
368 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
369 HOST_WIDE_INT rounded_stack_size,
370 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
371 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
372 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
373 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
375 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
377 int already_popped = 0;
378 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
379 #if defined (HAVE_call) && defined (HAVE_call_value)
380 rtx struct_value_size_rtx;
381 struct_value_size_rtx = GEN_INT (struct_value_size);
384 #ifdef CALL_POPS_ARGS
385 n_popped += CALL_POPS_ARGS (* args_so_far);
388 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
389 and we don't want to load it into a register as an optimization,
390 because prepare_call_address already did it if it should be done. */
391 if (GET_CODE (funexp) != SYMBOL_REF)
392 funexp = memory_address (FUNCTION_MODE, funexp);
394 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
395 if ((ecf_flags & ECF_SIBCALL)
396 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
397 && (n_popped > 0 || stack_size == 0))
399 rtx n_pop = GEN_INT (n_popped);
402 /* If this subroutine pops its own args, record that in the call insn
403 if possible, for the sake of frame pointer elimination. */
406 pat = GEN_SIBCALL_VALUE_POP (valreg,
407 gen_rtx_MEM (FUNCTION_MODE, funexp),
408 rounded_stack_size_rtx, next_arg_reg,
411 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
412 rounded_stack_size_rtx, next_arg_reg, n_pop);
414 emit_call_insn (pat);
420 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
421 /* If the target has "call" or "call_value" insns, then prefer them
422 if no arguments are actually popped. If the target does not have
423 "call" or "call_value" insns, then we must use the popping versions
424 even if the call has no arguments to pop. */
425 #if defined (HAVE_call) && defined (HAVE_call_value)
426 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
427 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
429 if (HAVE_call_pop && HAVE_call_value_pop)
432 rtx n_pop = GEN_INT (n_popped);
435 /* If this subroutine pops its own args, record that in the call insn
436 if possible, for the sake of frame pointer elimination. */
439 pat = GEN_CALL_VALUE_POP (valreg,
440 gen_rtx_MEM (FUNCTION_MODE, funexp),
441 rounded_stack_size_rtx, next_arg_reg, n_pop);
443 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
444 rounded_stack_size_rtx, next_arg_reg, n_pop);
446 emit_call_insn (pat);
452 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
453 if ((ecf_flags & ECF_SIBCALL)
454 && HAVE_sibcall && HAVE_sibcall_value)
457 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
458 gen_rtx_MEM (FUNCTION_MODE, funexp),
459 rounded_stack_size_rtx,
460 next_arg_reg, NULL_RTX));
462 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
463 rounded_stack_size_rtx, next_arg_reg,
464 struct_value_size_rtx));
469 #if defined (HAVE_call) && defined (HAVE_call_value)
470 if (HAVE_call && HAVE_call_value)
473 emit_call_insn (GEN_CALL_VALUE (valreg,
474 gen_rtx_MEM (FUNCTION_MODE, funexp),
475 rounded_stack_size_rtx, next_arg_reg,
478 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
479 rounded_stack_size_rtx, next_arg_reg,
480 struct_value_size_rtx));
486 /* Find the call we just emitted. */
487 call_insn = last_call_insn ();
489 /* Mark memory as used for "pure" function call. */
490 if (ecf_flags & ECF_PURE)
494 gen_rtx_USE (VOIDmode,
495 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
498 /* Put the register usage information there. */
499 add_function_usage_to (call_insn, call_fusage);
501 /* If this is a const call, then set the insn's unchanging bit. */
502 if (ecf_flags & (ECF_CONST | ECF_PURE))
503 CONST_OR_PURE_CALL_P (call_insn) = 1;
505 /* If this call can't throw, attach a REG_EH_REGION reg note to that
507 if (ecf_flags & ECF_NOTHROW)
508 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
509 REG_NOTES (call_insn));
511 note_eh_region_may_contain_throw ();
513 if (ecf_flags & ECF_NORETURN)
514 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
515 REG_NOTES (call_insn));
516 if (ecf_flags & ECF_ALWAYS_RETURN)
517 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
518 REG_NOTES (call_insn));
520 if (ecf_flags & ECF_RETURNS_TWICE)
522 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
523 REG_NOTES (call_insn));
524 current_function_calls_setjmp = 1;
527 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
529 /* Restore this now, so that we do defer pops for this call's args
530 if the context of the call as a whole permits. */
531 inhibit_defer_pop = old_inhibit_defer_pop;
533 /* Don't bother cleaning up after a noreturn function. */
534 if (ecf_flags & (ECF_NORETURN | ECF_LONGJMP))
540 CALL_INSN_FUNCTION_USAGE (call_insn)
541 = gen_rtx_EXPR_LIST (VOIDmode,
542 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
543 CALL_INSN_FUNCTION_USAGE (call_insn));
544 rounded_stack_size -= n_popped;
545 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
546 stack_pointer_delta -= n_popped;
549 if (!ACCUMULATE_OUTGOING_ARGS)
551 /* If returning from the subroutine does not automatically pop the args,
552 we need an instruction to pop them sooner or later.
553 Perhaps do it now; perhaps just record how much space to pop later.
555 If returning from the subroutine does pop the args, indicate that the
556 stack pointer will be changed. */
558 if (rounded_stack_size != 0)
560 if (ecf_flags & ECF_SP_DEPRESSED)
561 /* Just pretend we did the pop. */
562 stack_pointer_delta -= rounded_stack_size;
563 else if (flag_defer_pop && inhibit_defer_pop == 0
564 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
565 pending_stack_adjust += rounded_stack_size;
567 adjust_stack (rounded_stack_size_rtx);
570 /* When we accumulate outgoing args, we must avoid any stack manipulations.
571 Restore the stack pointer to its original value now. Usually
572 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
573 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
574 popping variants of functions exist as well.
576 ??? We may optimize similar to defer_pop above, but it is
577 probably not worthwhile.
579 ??? It will be worthwhile to enable combine_stack_adjustments even for
582 anti_adjust_stack (GEN_INT (n_popped));
585 /* Determine if the function identified by NAME and FNDECL is one with
586 special properties we wish to know about.
588 For example, if the function might return more than one time (setjmp), then
589 set RETURNS_TWICE to a nonzero value.
591 Similarly set LONGJMP for if the function is in the longjmp family.
593 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
594 space from the stack such as alloca. */
597 special_function_p (tree fndecl, int flags)
599 if (! (flags & ECF_MALLOC)
600 && fndecl && DECL_NAME (fndecl)
601 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
602 /* Exclude functions not at the file scope, or not `extern',
603 since they are not the magic functions we would otherwise
605 FIXME: this should be handled with attributes, not with this
606 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
607 because you can declare fork() inside a function if you
609 && (DECL_CONTEXT (fndecl) == NULL_TREE
610 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
611 && TREE_PUBLIC (fndecl))
613 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
614 const char *tname = name;
616 /* We assume that alloca will always be called by name. It
617 makes no sense to pass it as a pointer-to-function to
618 anything that does not understand its behavior. */
619 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
621 && ! strcmp (name, "alloca"))
622 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
624 && ! strcmp (name, "__builtin_alloca"))))
625 flags |= ECF_MAY_BE_ALLOCA;
627 /* Disregard prefix _, __ or __x. */
630 if (name[1] == '_' && name[2] == 'x')
632 else if (name[1] == '_')
641 && (! strcmp (tname, "setjmp")
642 || ! strcmp (tname, "setjmp_syscall")))
644 && ! strcmp (tname, "sigsetjmp"))
646 && ! strcmp (tname, "savectx")))
647 flags |= ECF_RETURNS_TWICE;
650 && ! strcmp (tname, "siglongjmp"))
651 flags |= ECF_LONGJMP;
653 else if ((tname[0] == 'q' && tname[1] == 's'
654 && ! strcmp (tname, "qsetjmp"))
655 || (tname[0] == 'v' && tname[1] == 'f'
656 && ! strcmp (tname, "vfork")))
657 flags |= ECF_RETURNS_TWICE;
659 else if (tname[0] == 'l' && tname[1] == 'o'
660 && ! strcmp (tname, "longjmp"))
661 flags |= ECF_LONGJMP;
663 else if ((tname[0] == 'f' && tname[1] == 'o'
664 && ! strcmp (tname, "fork"))
665 /* Linux specific: __clone. check NAME to insist on the
666 leading underscores, to avoid polluting the ISO / POSIX
668 || (name[0] == '_' && name[1] == '_'
669 && ! strcmp (tname, "clone"))
670 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
671 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
673 || ((tname[5] == 'p' || tname[5] == 'e')
674 && tname[6] == '\0'))))
675 flags |= ECF_FORK_OR_EXEC;
680 /* Return nonzero when tree represent call to longjmp. */
683 setjmp_call_p (tree fndecl)
685 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
688 /* Return true when exp contains alloca call. */
690 alloca_call_p (tree exp)
692 if (TREE_CODE (exp) == CALL_EXPR
693 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
694 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
696 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
697 0) & ECF_MAY_BE_ALLOCA))
702 /* Detect flags (function attributes) from the function decl or type node. */
705 flags_from_decl_or_type (tree exp)
712 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
713 type = TREE_TYPE (exp);
717 if (i->pure_function)
718 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
719 if (i->const_function)
720 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
723 /* The function exp may have the `malloc' attribute. */
724 if (DECL_IS_MALLOC (exp))
727 /* The function exp may have the `pure' attribute. */
728 if (DECL_IS_PURE (exp))
729 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
731 if (TREE_NOTHROW (exp))
732 flags |= ECF_NOTHROW;
734 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
735 flags |= ECF_LIBCALL_BLOCK;
738 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
741 if (TREE_THIS_VOLATILE (exp))
742 flags |= ECF_NORETURN;
744 /* Mark if the function returns with the stack pointer depressed. We
745 cannot consider it pure or constant in that case. */
746 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
748 flags |= ECF_SP_DEPRESSED;
749 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
755 /* Precompute all register parameters as described by ARGS, storing values
756 into fields within the ARGS array.
758 NUM_ACTUALS indicates the total number elements in the ARGS array.
760 Set REG_PARM_SEEN if we encounter a register parameter. */
763 precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
769 for (i = 0; i < num_actuals; i++)
770 if (args[i].reg != 0 && ! args[i].pass_on_stack)
774 if (args[i].value == 0)
777 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
779 preserve_temp_slots (args[i].value);
782 /* ANSI doesn't require a sequence point here,
783 but PCC has one, so this will avoid some problems. */
787 /* If the value is a non-legitimate constant, force it into a
788 pseudo now. TLS symbols sometimes need a call to resolve. */
789 if (CONSTANT_P (args[i].value)
790 && !LEGITIMATE_CONSTANT_P (args[i].value))
791 args[i].value = force_reg (args[i].mode, args[i].value);
793 /* If we are to promote the function arg to a wider mode,
796 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
798 = convert_modes (args[i].mode,
799 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
800 args[i].value, args[i].unsignedp);
802 /* If the value is expensive, and we are inside an appropriately
803 short loop, put the value into a pseudo and then put the pseudo
806 For small register classes, also do this if this call uses
807 register parameters. This is to avoid reload conflicts while
808 loading the parameters registers. */
810 if ((! (GET_CODE (args[i].value) == REG
811 || (GET_CODE (args[i].value) == SUBREG
812 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
813 && args[i].mode != BLKmode
814 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
815 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
816 || preserve_subexpressions_p ()))
817 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
821 #ifdef REG_PARM_STACK_SPACE
823 /* The argument list is the property of the called routine and it
824 may clobber it. If the fixed area has been used for previous
825 parameters, we must save and restore it. */
828 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
833 /* Compute the boundary of the area that needs to be saved, if any. */
834 high = reg_parm_stack_space;
835 #ifdef ARGS_GROW_DOWNWARD
838 if (high > highest_outgoing_arg_in_use)
839 high = highest_outgoing_arg_in_use;
841 for (low = 0; low < high; low++)
842 if (stack_usage_map[low] != 0)
845 enum machine_mode save_mode;
850 while (stack_usage_map[--high] == 0)
854 *high_to_save = high;
856 num_to_save = high - low + 1;
857 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
859 /* If we don't have the required alignment, must do this
861 if ((low & (MIN (GET_MODE_SIZE (save_mode),
862 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
865 #ifdef ARGS_GROW_DOWNWARD
870 stack_area = gen_rtx_MEM (save_mode,
871 memory_address (save_mode,
872 plus_constant (argblock,
875 set_mem_align (stack_area, PARM_BOUNDARY);
876 if (save_mode == BLKmode)
878 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
879 emit_block_move (validize_mem (save_area), stack_area,
880 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
884 save_area = gen_reg_rtx (save_mode);
885 emit_move_insn (save_area, stack_area);
895 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
897 enum machine_mode save_mode = GET_MODE (save_area);
901 #ifdef ARGS_GROW_DOWNWARD
902 delta = -high_to_save;
906 stack_area = gen_rtx_MEM (save_mode,
907 memory_address (save_mode,
908 plus_constant (argblock, delta)));
909 set_mem_align (stack_area, PARM_BOUNDARY);
911 if (save_mode != BLKmode)
912 emit_move_insn (stack_area, save_area);
914 emit_block_move (stack_area, validize_mem (save_area),
915 GEN_INT (high_to_save - low_to_save + 1),
918 #endif /* REG_PARM_STACK_SPACE */
920 /* If any elements in ARGS refer to parameters that are to be passed in
921 registers, but not in memory, and whose alignment does not permit a
922 direct copy into registers. Copy the values into a group of pseudos
923 which we will later copy into the appropriate hard registers.
925 Pseudos for each unaligned argument will be stored into the array
926 args[argnum].aligned_regs. The caller is responsible for deallocating
927 the aligned_regs array if it is nonzero. */
930 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
934 for (i = 0; i < num_actuals; i++)
935 if (args[i].reg != 0 && ! args[i].pass_on_stack
936 && args[i].mode == BLKmode
937 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
938 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
940 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
941 int nregs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
942 int endian_correction = 0;
944 args[i].n_aligned_regs = args[i].partial ? args[i].partial : nregs;
945 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
947 /* Structures smaller than a word are normally aligned to the
948 least significant byte. On a BYTES_BIG_ENDIAN machine,
949 this means we must skip the empty high order bytes when
950 calculating the bit offset. */
951 if (bytes < UNITS_PER_WORD
952 #ifdef BLOCK_REG_PADDING
953 && (BLOCK_REG_PADDING (args[i].mode,
954 TREE_TYPE (args[i].tree_value), 1)
960 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
962 for (j = 0; j < args[i].n_aligned_regs; j++)
964 rtx reg = gen_reg_rtx (word_mode);
965 rtx word = operand_subword_force (args[i].value, j, BLKmode);
966 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
968 args[i].aligned_regs[j] = reg;
969 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
970 word_mode, word_mode, BITS_PER_WORD);
972 /* There is no need to restrict this code to loading items
973 in TYPE_ALIGN sized hunks. The bitfield instructions can
974 load up entire word sized registers efficiently.
976 ??? This may not be needed anymore.
977 We use to emit a clobber here but that doesn't let later
978 passes optimize the instructions we emit. By storing 0 into
979 the register later passes know the first AND to zero out the
980 bitfield being set in the register is unnecessary. The store
981 of 0 will be deleted as will at least the first AND. */
983 emit_move_insn (reg, const0_rtx);
985 bytes -= bitsize / BITS_PER_UNIT;
986 store_bit_field (reg, bitsize, endian_correction, word_mode,
987 word, BITS_PER_WORD);
992 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
995 NUM_ACTUALS is the total number of parameters.
997 N_NAMED_ARGS is the total number of named arguments.
999 FNDECL is the tree code for the target of this call (if known)
1001 ARGS_SO_FAR holds state needed by the target to know where to place
1004 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1005 for arguments which are passed in registers.
1007 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1008 and may be modified by this routine.
1010 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1011 flags which may may be modified by this routine. */
1014 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1015 struct arg_data *args,
1016 struct args_size *args_size,
1017 int n_named_args ATTRIBUTE_UNUSED,
1018 tree actparms, tree fndecl,
1019 CUMULATIVE_ARGS *args_so_far,
1020 int reg_parm_stack_space,
1021 rtx *old_stack_level, int *old_pending_adj,
1022 int *must_preallocate, int *ecf_flags)
1024 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1027 /* Count arg position in order args appear. */
1033 args_size->constant = 0;
1036 /* In this loop, we consider args in the order they are written.
1037 We fill up ARGS from the front or from the back if necessary
1038 so that in any case the first arg to be pushed ends up at the front. */
1040 if (PUSH_ARGS_REVERSED)
1042 i = num_actuals - 1, inc = -1;
1043 /* In this case, must reverse order of args
1044 so that we compute and push the last arg first. */
1051 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1052 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1054 tree type = TREE_TYPE (TREE_VALUE (p));
1056 enum machine_mode mode;
1058 args[i].tree_value = TREE_VALUE (p);
1060 /* Replace erroneous argument with constant zero. */
1061 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1062 args[i].tree_value = integer_zero_node, type = integer_type_node;
1064 /* If TYPE is a transparent union, pass things the way we would
1065 pass the first field of the union. We have already verified that
1066 the modes are the same. */
1067 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1068 type = TREE_TYPE (TYPE_FIELDS (type));
1070 /* Decide where to pass this arg.
1072 args[i].reg is nonzero if all or part is passed in registers.
1074 args[i].partial is nonzero if part but not all is passed in registers,
1075 and the exact value says how many words are passed in registers.
1077 args[i].pass_on_stack is nonzero if the argument must at least be
1078 computed on the stack. It may then be loaded back into registers
1079 if args[i].reg is nonzero.
1081 These decisions are driven by the FUNCTION_... macros and must agree
1082 with those made by function.c. */
1084 /* See if this argument should be passed by invisible reference. */
1085 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1086 || TREE_ADDRESSABLE (type)
1087 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1088 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1089 type, argpos < n_named_args)
1093 /* If we're compiling a thunk, pass through invisible
1094 references instead of making a copy. */
1095 if (current_function_is_thunk
1096 #ifdef FUNCTION_ARG_CALLEE_COPIES
1097 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1098 type, argpos < n_named_args)
1099 /* If it's in a register, we must make a copy of it too. */
1100 /* ??? Is this a sufficient test? Is there a better one? */
1101 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1102 && REG_P (DECL_RTL (args[i].tree_value)))
1103 && ! TREE_ADDRESSABLE (type))
1107 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1108 new object from the argument. If we are passing by
1109 invisible reference, the callee will do that for us, so we
1110 can strip off the TARGET_EXPR. This is not always safe,
1111 but it is safe in the only case where this is a useful
1112 optimization; namely, when the argument is a plain object.
1113 In that case, the frontend is just asking the backend to
1114 make a bitwise copy of the argument. */
1116 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1117 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1118 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1119 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1121 args[i].tree_value = build1 (ADDR_EXPR,
1122 build_pointer_type (type),
1123 args[i].tree_value);
1124 type = build_pointer_type (type);
1126 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1128 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1129 We implement this by passing the address of the temporary
1130 rather than expanding it into another allocated slot. */
1131 args[i].tree_value = build1 (ADDR_EXPR,
1132 build_pointer_type (type),
1133 args[i].tree_value);
1134 type = build_pointer_type (type);
1138 /* We make a copy of the object and pass the address to the
1139 function being called. */
1142 if (!COMPLETE_TYPE_P (type)
1143 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1144 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1145 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1146 STACK_CHECK_MAX_VAR_SIZE))))
1148 /* This is a variable-sized object. Make space on the stack
1150 rtx size_rtx = expr_size (TREE_VALUE (p));
1152 if (*old_stack_level == 0)
1154 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1155 *old_pending_adj = pending_stack_adjust;
1156 pending_stack_adjust = 0;
1159 copy = gen_rtx_MEM (BLKmode,
1160 allocate_dynamic_stack_space
1161 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1162 set_mem_attributes (copy, type, 1);
1165 copy = assign_temp (type, 0, 1, 0);
1167 store_expr (args[i].tree_value, copy, 0);
1168 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1170 args[i].tree_value = build1 (ADDR_EXPR,
1171 build_pointer_type (type),
1172 make_tree (type, copy));
1173 type = build_pointer_type (type);
1177 mode = TYPE_MODE (type);
1178 unsignedp = TREE_UNSIGNED (type);
1180 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1181 mode = promote_mode (type, mode, &unsignedp, 1);
1183 args[i].unsignedp = unsignedp;
1184 args[i].mode = mode;
1186 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1187 argpos < n_named_args);
1188 #ifdef FUNCTION_INCOMING_ARG
1189 /* If this is a sibling call and the machine has register windows, the
1190 register window has to be unwinded before calling the routine, so
1191 arguments have to go into the incoming registers. */
1192 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1193 argpos < n_named_args);
1195 args[i].tail_call_reg = args[i].reg;
1198 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1201 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1202 argpos < n_named_args);
1205 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1207 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1208 it means that we are to pass this arg in the register(s) designated
1209 by the PARALLEL, but also to pass it in the stack. */
1210 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1211 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1212 args[i].pass_on_stack = 1;
1214 /* If this is an addressable type, we must preallocate the stack
1215 since we must evaluate the object into its final location.
1217 If this is to be passed in both registers and the stack, it is simpler
1219 if (TREE_ADDRESSABLE (type)
1220 || (args[i].pass_on_stack && args[i].reg != 0))
1221 *must_preallocate = 1;
1223 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1224 we cannot consider this function call constant. */
1225 if (TREE_ADDRESSABLE (type))
1226 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1228 /* Compute the stack-size of this argument. */
1229 if (args[i].reg == 0 || args[i].partial != 0
1230 || reg_parm_stack_space > 0
1231 || args[i].pass_on_stack)
1232 locate_and_pad_parm (mode, type,
1233 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1238 args[i].pass_on_stack ? 0 : args[i].partial,
1239 fndecl, args_size, &args[i].locate);
1240 #ifdef BLOCK_REG_PADDING
1242 /* The argument is passed entirely in registers. See at which
1243 end it should be padded. */
1244 args[i].locate.where_pad =
1245 BLOCK_REG_PADDING (mode, type,
1246 int_size_in_bytes (type) <= UNITS_PER_WORD);
1249 /* Update ARGS_SIZE, the total stack space for args so far. */
1251 args_size->constant += args[i].locate.size.constant;
1252 if (args[i].locate.size.var)
1253 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1255 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1256 have been used, etc. */
1258 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1259 argpos < n_named_args);
1263 /* Update ARGS_SIZE to contain the total size for the argument block.
1264 Return the original constant component of the argument block's size.
1266 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1267 for arguments passed in registers. */
1270 compute_argument_block_size (int reg_parm_stack_space,
1271 struct args_size *args_size,
1272 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1274 int unadjusted_args_size = args_size->constant;
1276 /* For accumulate outgoing args mode we don't need to align, since the frame
1277 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1278 backends from generating misaligned frame sizes. */
1279 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1280 preferred_stack_boundary = STACK_BOUNDARY;
1282 /* Compute the actual size of the argument block required. The variable
1283 and constant sizes must be combined, the size may have to be rounded,
1284 and there may be a minimum required size. */
1288 args_size->var = ARGS_SIZE_TREE (*args_size);
1289 args_size->constant = 0;
1291 preferred_stack_boundary /= BITS_PER_UNIT;
1292 if (preferred_stack_boundary > 1)
1294 /* We don't handle this case yet. To handle it correctly we have
1295 to add the delta, round and subtract the delta.
1296 Currently no machine description requires this support. */
1297 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1299 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1302 if (reg_parm_stack_space > 0)
1305 = size_binop (MAX_EXPR, args_size->var,
1306 ssize_int (reg_parm_stack_space));
1308 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1309 /* The area corresponding to register parameters is not to count in
1310 the size of the block we need. So make the adjustment. */
1312 = size_binop (MINUS_EXPR, args_size->var,
1313 ssize_int (reg_parm_stack_space));
1319 preferred_stack_boundary /= BITS_PER_UNIT;
1320 if (preferred_stack_boundary < 1)
1321 preferred_stack_boundary = 1;
1322 args_size->constant = (((args_size->constant
1323 + stack_pointer_delta
1324 + preferred_stack_boundary - 1)
1325 / preferred_stack_boundary
1326 * preferred_stack_boundary)
1327 - stack_pointer_delta);
1329 args_size->constant = MAX (args_size->constant,
1330 reg_parm_stack_space);
1332 #ifdef MAYBE_REG_PARM_STACK_SPACE
1333 if (reg_parm_stack_space == 0)
1334 args_size->constant = 0;
1337 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1338 args_size->constant -= reg_parm_stack_space;
1341 return unadjusted_args_size;
1344 /* Precompute parameters as needed for a function call.
1346 FLAGS is mask of ECF_* constants.
1348 NUM_ACTUALS is the number of arguments.
1350 ARGS is an array containing information for each argument; this
1351 routine fills in the INITIAL_VALUE and VALUE fields for each
1352 precomputed argument. */
1355 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1359 /* If this function call is cse'able, precompute all the parameters.
1360 Note that if the parameter is constructed into a temporary, this will
1361 cause an additional copy because the parameter will be constructed
1362 into a temporary location and then copied into the outgoing arguments.
1363 If a parameter contains a call to alloca and this function uses the
1364 stack, precompute the parameter. */
1366 /* If we preallocated the stack space, and some arguments must be passed
1367 on the stack, then we must precompute any parameter which contains a
1368 function call which will store arguments on the stack.
1369 Otherwise, evaluating the parameter may clobber previous parameters
1370 which have already been stored into the stack. (we have code to avoid
1371 such case by saving the outgoing stack arguments, but it results in
1374 for (i = 0; i < num_actuals; i++)
1375 if ((flags & ECF_LIBCALL_BLOCK)
1376 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1378 enum machine_mode mode;
1380 /* If this is an addressable type, we cannot pre-evaluate it. */
1381 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1385 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1387 /* ANSI doesn't require a sequence point here,
1388 but PCC has one, so this will avoid some problems. */
1391 args[i].initial_value = args[i].value
1392 = protect_from_queue (args[i].value, 0);
1394 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1395 if (mode != args[i].mode)
1398 = convert_modes (args[i].mode, mode,
1399 args[i].value, args[i].unsignedp);
1400 #ifdef PROMOTE_FOR_CALL_ONLY
1401 /* CSE will replace this only if it contains args[i].value
1402 pseudo, so convert it down to the declared mode using
1404 if (GET_CODE (args[i].value) == REG
1405 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1407 args[i].initial_value
1408 = gen_lowpart_SUBREG (mode, args[i].value);
1409 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1410 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1418 /* Given the current state of MUST_PREALLOCATE and information about
1419 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1420 compute and return the final value for MUST_PREALLOCATE. */
1423 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1425 /* See if we have or want to preallocate stack space.
1427 If we would have to push a partially-in-regs parm
1428 before other stack parms, preallocate stack space instead.
1430 If the size of some parm is not a multiple of the required stack
1431 alignment, we must preallocate.
1433 If the total size of arguments that would otherwise create a copy in
1434 a temporary (such as a CALL) is more than half the total argument list
1435 size, preallocation is faster.
1437 Another reason to preallocate is if we have a machine (like the m88k)
1438 where stack alignment is required to be maintained between every
1439 pair of insns, not just when the call is made. However, we assume here
1440 that such machines either do not have push insns (and hence preallocation
1441 would occur anyway) or the problem is taken care of with
1444 if (! must_preallocate)
1446 int partial_seen = 0;
1447 int copy_to_evaluate_size = 0;
1450 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1452 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1454 else if (partial_seen && args[i].reg == 0)
1455 must_preallocate = 1;
1457 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1458 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1459 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1460 || TREE_CODE (args[i].tree_value) == COND_EXPR
1461 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1462 copy_to_evaluate_size
1463 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1466 if (copy_to_evaluate_size * 2 >= args_size->constant
1467 && args_size->constant > 0)
1468 must_preallocate = 1;
1470 return must_preallocate;
1473 /* If we preallocated stack space, compute the address of each argument
1474 and store it into the ARGS array.
1476 We need not ensure it is a valid memory address here; it will be
1477 validized when it is used.
1479 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1482 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1486 rtx arg_reg = argblock;
1487 int i, arg_offset = 0;
1489 if (GET_CODE (argblock) == PLUS)
1490 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1492 for (i = 0; i < num_actuals; i++)
1494 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1495 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1498 /* Skip this parm if it will not be passed on the stack. */
1499 if (! args[i].pass_on_stack && args[i].reg != 0)
1502 if (GET_CODE (offset) == CONST_INT)
1503 addr = plus_constant (arg_reg, INTVAL (offset));
1505 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1507 addr = plus_constant (addr, arg_offset);
1508 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1509 set_mem_align (args[i].stack, PARM_BOUNDARY);
1510 set_mem_attributes (args[i].stack,
1511 TREE_TYPE (args[i].tree_value), 1);
1513 if (GET_CODE (slot_offset) == CONST_INT)
1514 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1516 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1518 addr = plus_constant (addr, arg_offset);
1519 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1520 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1521 set_mem_attributes (args[i].stack_slot,
1522 TREE_TYPE (args[i].tree_value), 1);
1524 /* Function incoming arguments may overlap with sibling call
1525 outgoing arguments and we cannot allow reordering of reads
1526 from function arguments with stores to outgoing arguments
1527 of sibling calls. */
1528 set_mem_alias_set (args[i].stack, 0);
1529 set_mem_alias_set (args[i].stack_slot, 0);
1534 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1535 in a call instruction.
1537 FNDECL is the tree node for the target function. For an indirect call
1538 FNDECL will be NULL_TREE.
1540 ADDR is the operand 0 of CALL_EXPR for this call. */
1543 rtx_for_function_call (tree fndecl, tree addr)
1547 /* Get the function to call, in the form of RTL. */
1550 /* If this is the first use of the function, see if we need to
1551 make an external definition for it. */
1552 if (! TREE_USED (fndecl))
1554 assemble_external (fndecl);
1555 TREE_USED (fndecl) = 1;
1558 /* Get a SYMBOL_REF rtx for the function address. */
1559 funexp = XEXP (DECL_RTL (fndecl), 0);
1562 /* Generate an rtx (probably a pseudo-register) for the address. */
1565 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1566 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1572 /* Do the register loads required for any wholly-register parms or any
1573 parms which are passed both on the stack and in a register. Their
1574 expressions were already evaluated.
1576 Mark all register-parms as living through the call, putting these USE
1577 insns in the CALL_INSN_FUNCTION_USAGE field.
1579 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1580 checking, setting *SIBCALL_FAILURE if appropriate. */
1583 load_register_parameters (struct arg_data *args, int num_actuals,
1584 rtx *call_fusage, int flags, int is_sibcall,
1585 int *sibcall_failure)
1589 #ifdef LOAD_ARGS_REVERSED
1590 for (i = num_actuals - 1; i >= 0; i--)
1592 for (i = 0; i < num_actuals; i++)
1595 rtx reg = ((flags & ECF_SIBCALL)
1596 ? args[i].tail_call_reg : args[i].reg);
1599 int partial = args[i].partial;
1602 rtx before_arg = get_last_insn ();
1603 /* Set to non-negative if must move a word at a time, even if just
1604 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1605 we just use a normal move insn. This value can be zero if the
1606 argument is a zero size structure with no fields. */
1610 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1612 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1613 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1616 size = GET_MODE_SIZE (args[i].mode);
1618 /* Handle calls that pass values in multiple non-contiguous
1619 locations. The Irix 6 ABI has examples of this. */
1621 if (GET_CODE (reg) == PARALLEL)
1623 tree type = TREE_TYPE (args[i].tree_value);
1624 emit_group_load (reg, args[i].value, type,
1625 int_size_in_bytes (type));
1628 /* If simple case, just do move. If normal partial, store_one_arg
1629 has already loaded the register for us. In all other cases,
1630 load the register(s) from memory. */
1632 else if (nregs == -1)
1634 emit_move_insn (reg, args[i].value);
1635 #ifdef BLOCK_REG_PADDING
1636 /* Handle case where we have a value that needs shifting
1637 up to the msb. eg. a QImode value and we're padding
1638 upward on a BYTES_BIG_ENDIAN machine. */
1639 if (size < UNITS_PER_WORD
1640 && (args[i].locate.where_pad
1641 == (BYTES_BIG_ENDIAN ? upward : downward)))
1644 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1646 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1647 report the whole reg as used. Strictly speaking, the
1648 call only uses SIZE bytes at the msb end, but it doesn't
1649 seem worth generating rtl to say that. */
1650 reg = gen_rtx_REG (word_mode, REGNO (reg));
1651 x = expand_binop (word_mode, ashl_optab, reg,
1652 GEN_INT (shift), reg, 1, OPTAB_WIDEN);
1654 emit_move_insn (reg, x);
1659 /* If we have pre-computed the values to put in the registers in
1660 the case of non-aligned structures, copy them in now. */
1662 else if (args[i].n_aligned_regs != 0)
1663 for (j = 0; j < args[i].n_aligned_regs; j++)
1664 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1665 args[i].aligned_regs[j]);
1667 else if (partial == 0 || args[i].pass_on_stack)
1669 rtx mem = validize_mem (args[i].value);
1671 #ifdef BLOCK_REG_PADDING
1672 /* Handle a BLKmode that needs shifting. */
1673 if (nregs == 1 && size < UNITS_PER_WORD
1674 && args[i].locate.where_pad == downward)
1676 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1677 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1678 rtx x = gen_reg_rtx (word_mode);
1679 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1680 optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1682 emit_move_insn (x, tem);
1683 x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1684 ri, 1, OPTAB_WIDEN);
1686 emit_move_insn (ri, x);
1690 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1693 /* When a parameter is a block, and perhaps in other cases, it is
1694 possible that it did a load from an argument slot that was
1695 already clobbered. */
1697 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1698 *sibcall_failure = 1;
1700 /* Handle calls that pass values in multiple non-contiguous
1701 locations. The Irix 6 ABI has examples of this. */
1702 if (GET_CODE (reg) == PARALLEL)
1703 use_group_regs (call_fusage, reg);
1704 else if (nregs == -1)
1705 use_reg (call_fusage, reg);
1707 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1712 /* Try to integrate function. See expand_inline_function for documentation
1713 about the parameters. */
1716 try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1717 tree type, rtx structure_value_addr)
1722 rtx old_stack_level = 0;
1723 int reg_parm_stack_space = 0;
1725 #ifdef REG_PARM_STACK_SPACE
1726 #ifdef MAYBE_REG_PARM_STACK_SPACE
1727 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1729 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1733 before_call = get_last_insn ();
1735 timevar_push (TV_INTEGRATION);
1737 temp = expand_inline_function (fndecl, actparms, target,
1739 structure_value_addr);
1741 timevar_pop (TV_INTEGRATION);
1743 /* If inlining succeeded, return. */
1744 if (temp != (rtx) (size_t) - 1)
1746 if (ACCUMULATE_OUTGOING_ARGS)
1748 /* If the outgoing argument list must be preserved, push
1749 the stack before executing the inlined function if it
1752 i = reg_parm_stack_space;
1753 if (i > highest_outgoing_arg_in_use)
1754 i = highest_outgoing_arg_in_use;
1755 while (--i >= 0 && stack_usage_map[i] == 0)
1758 if (stack_arg_under_construction || i >= 0)
1761 = before_call ? NEXT_INSN (before_call) : get_insns ();
1762 rtx insn = NULL_RTX, seq;
1764 /* Look for a call in the inline function code.
1765 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1766 nonzero then there is a call and it is not necessary
1767 to scan the insns. */
1769 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1770 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1771 if (GET_CODE (insn) == CALL_INSN)
1776 /* Reserve enough stack space so that the largest
1777 argument list of any function call in the inline
1778 function does not overlap the argument list being
1779 evaluated. This is usually an overestimate because
1780 allocate_dynamic_stack_space reserves space for an
1781 outgoing argument list in addition to the requested
1782 space, but there is no way to ask for stack space such
1783 that an argument list of a certain length can be
1786 Add the stack space reserved for register arguments, if
1787 any, in the inline function. What is really needed is the
1788 largest value of reg_parm_stack_space in the inline
1789 function, but that is not available. Using the current
1790 value of reg_parm_stack_space is wrong, but gives
1791 correct results on all supported machines. */
1793 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1794 + reg_parm_stack_space);
1797 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1798 allocate_dynamic_stack_space (GEN_INT (adjust),
1799 NULL_RTX, BITS_PER_UNIT);
1802 emit_insn_before (seq, first_insn);
1803 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1808 /* If the result is equivalent to TARGET, return TARGET to simplify
1809 checks in store_expr. They can be equivalent but not equal in the
1810 case of a function that returns BLKmode. */
1811 if (temp != target && rtx_equal_p (temp, target))
1816 /* If inlining failed, mark FNDECL as needing to be compiled
1817 separately after all. If function was declared inline,
1819 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1820 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1822 warning ("%Hinlining failed in call to '%F'",
1823 &DECL_SOURCE_LOCATION (fndecl), fndecl);
1824 warning ("called from here");
1826 (*lang_hooks.mark_addressable) (fndecl);
1827 return (rtx) (size_t) - 1;
1830 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1831 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1832 bytes, then we would need to push some additional bytes to pad the
1833 arguments. So, we compute an adjust to the stack pointer for an
1834 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1835 bytes. Then, when the arguments are pushed the stack will be perfectly
1836 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1837 be popped after the call. Returns the adjustment. */
1840 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1841 struct args_size *args_size,
1842 int preferred_unit_stack_boundary)
1844 /* The number of bytes to pop so that the stack will be
1845 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1846 HOST_WIDE_INT adjustment;
1847 /* The alignment of the stack after the arguments are pushed, if we
1848 just pushed the arguments without adjust the stack here. */
1849 HOST_WIDE_INT unadjusted_alignment;
1851 unadjusted_alignment
1852 = ((stack_pointer_delta + unadjusted_args_size)
1853 % preferred_unit_stack_boundary);
1855 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1856 as possible -- leaving just enough left to cancel out the
1857 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1858 PENDING_STACK_ADJUST is non-negative, and congruent to
1859 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1861 /* Begin by trying to pop all the bytes. */
1862 unadjusted_alignment
1863 = (unadjusted_alignment
1864 - (pending_stack_adjust % preferred_unit_stack_boundary));
1865 adjustment = pending_stack_adjust;
1866 /* Push enough additional bytes that the stack will be aligned
1867 after the arguments are pushed. */
1868 if (preferred_unit_stack_boundary > 1)
1870 if (unadjusted_alignment > 0)
1871 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1873 adjustment += unadjusted_alignment;
1876 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1877 bytes after the call. The right number is the entire
1878 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1879 by the arguments in the first place. */
1881 = pending_stack_adjust - adjustment + unadjusted_args_size;
1886 /* Scan X expression if it does not dereference any argument slots
1887 we already clobbered by tail call arguments (as noted in stored_args_map
1889 Return nonzero if X expression dereferences such argument slots,
1893 check_sibcall_argument_overlap_1 (rtx x)
1903 code = GET_CODE (x);
1907 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1909 else if (GET_CODE (XEXP (x, 0)) == PLUS
1910 && XEXP (XEXP (x, 0), 0) ==
1911 current_function_internal_arg_pointer
1912 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1913 i = INTVAL (XEXP (XEXP (x, 0), 1));
1917 #ifdef ARGS_GROW_DOWNWARD
1918 i = -i - GET_MODE_SIZE (GET_MODE (x));
1921 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1922 if (i + k < stored_args_map->n_bits
1923 && TEST_BIT (stored_args_map, i + k))
1929 /* Scan all subexpressions. */
1930 fmt = GET_RTX_FORMAT (code);
1931 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1935 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1938 else if (*fmt == 'E')
1940 for (j = 0; j < XVECLEN (x, i); j++)
1941 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1948 /* Scan sequence after INSN if it does not dereference any argument slots
1949 we already clobbered by tail call arguments (as noted in stored_args_map
1950 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1951 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1952 should be 0). Return nonzero if sequence after INSN dereferences such argument
1953 slots, zero otherwise. */
1956 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1960 if (insn == NULL_RTX)
1961 insn = get_insns ();
1963 insn = NEXT_INSN (insn);
1965 for (; insn; insn = NEXT_INSN (insn))
1967 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1970 if (mark_stored_args_map)
1972 #ifdef ARGS_GROW_DOWNWARD
1973 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1975 low = arg->locate.slot_offset.constant;
1978 for (high = low + arg->locate.size.constant; low < high; low++)
1979 SET_BIT (stored_args_map, low);
1981 return insn != NULL_RTX;
1985 fix_unsafe_tree (tree t)
1987 switch (unsafe_for_reeval (t))
1992 case 1: /* Mildly unsafe. */
1993 t = unsave_expr (t);
1996 case 2: /* Wildly unsafe. */
1998 tree var = build_decl (VAR_DECL, NULL_TREE,
2001 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
2012 /* Generate all the code for a function call
2013 and return an rtx for its value.
2014 Store the value in TARGET (specified as an rtx) if convenient.
2015 If the value is stored in TARGET then TARGET is returned.
2016 If IGNORE is nonzero, then we ignore the value of the function call. */
2019 expand_call (tree exp, rtx target, int ignore)
2021 /* Nonzero if we are currently expanding a call. */
2022 static int currently_expanding_call = 0;
2024 /* List of actual parameters. */
2025 tree actparms = TREE_OPERAND (exp, 1);
2026 /* RTX for the function to be called. */
2028 /* Sequence of insns to perform a tail recursive "call". */
2029 rtx tail_recursion_insns = NULL_RTX;
2030 /* Sequence of insns to perform a normal "call". */
2031 rtx normal_call_insns = NULL_RTX;
2032 /* Sequence of insns to perform a tail recursive "call". */
2033 rtx tail_call_insns = NULL_RTX;
2034 /* Data type of the function. */
2036 tree type_arg_types;
2037 /* Declaration of the function being called,
2038 or 0 if the function is computed (not known by name). */
2041 int try_tail_call = 1;
2042 int try_tail_recursion = 1;
2045 /* Register in which non-BLKmode value will be returned,
2046 or 0 if no value or if value is BLKmode. */
2048 /* Address where we should return a BLKmode value;
2049 0 if value not BLKmode. */
2050 rtx structure_value_addr = 0;
2051 /* Nonzero if that address is being passed by treating it as
2052 an extra, implicit first parameter. Otherwise,
2053 it is passed by being copied directly into struct_value_rtx. */
2054 int structure_value_addr_parm = 0;
2055 /* Size of aggregate value wanted, or zero if none wanted
2056 or if we are using the non-reentrant PCC calling convention
2057 or expecting the value in registers. */
2058 HOST_WIDE_INT struct_value_size = 0;
2059 /* Nonzero if called function returns an aggregate in memory PCC style,
2060 by returning the address of where to find it. */
2061 int pcc_struct_value = 0;
2062 rtx struct_value = 0;
2064 /* Number of actual parameters in this call, including struct value addr. */
2066 /* Number of named args. Args after this are anonymous ones
2067 and they must all go on the stack. */
2070 /* Vector of information about each argument.
2071 Arguments are numbered in the order they will be pushed,
2072 not the order they are written. */
2073 struct arg_data *args;
2075 /* Total size in bytes of all the stack-parms scanned so far. */
2076 struct args_size args_size;
2077 struct args_size adjusted_args_size;
2078 /* Size of arguments before any adjustments (such as rounding). */
2079 int unadjusted_args_size;
2080 /* Data on reg parms scanned so far. */
2081 CUMULATIVE_ARGS args_so_far;
2082 /* Nonzero if a reg parm has been scanned. */
2084 /* Nonzero if this is an indirect function call. */
2086 /* Nonzero if we must avoid push-insns in the args for this call.
2087 If stack space is allocated for register parameters, but not by the
2088 caller, then it is preallocated in the fixed part of the stack frame.
2089 So the entire argument block must then be preallocated (i.e., we
2090 ignore PUSH_ROUNDING in that case). */
2092 int must_preallocate = !PUSH_ARGS;
2094 /* Size of the stack reserved for parameter registers. */
2095 int reg_parm_stack_space = 0;
2097 /* Address of space preallocated for stack parms
2098 (on machines that lack push insns), or 0 if space not preallocated. */
2101 /* Mask of ECF_ flags. */
2103 /* Nonzero if this is a call to an inline function. */
2104 int is_integrable = 0;
2105 #ifdef REG_PARM_STACK_SPACE
2106 /* Define the boundary of the register parm stack space that needs to be
2108 int low_to_save, high_to_save;
2109 rtx save_area = 0; /* Place that it is saved */
2112 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2113 char *initial_stack_usage_map = stack_usage_map;
2115 int old_stack_allocated;
2117 /* State variables to track stack modifications. */
2118 rtx old_stack_level = 0;
2119 int old_stack_arg_under_construction = 0;
2120 int old_pending_adj = 0;
2121 int old_inhibit_defer_pop = inhibit_defer_pop;
2123 /* Some stack pointer alterations we make are performed via
2124 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2125 which we then also need to save/restore along the way. */
2126 int old_stack_pointer_delta = 0;
2129 tree p = TREE_OPERAND (exp, 0);
2130 tree addr = TREE_OPERAND (exp, 0);
2132 /* The alignment of the stack, in bits. */
2133 HOST_WIDE_INT preferred_stack_boundary;
2134 /* The alignment of the stack, in bytes. */
2135 HOST_WIDE_INT preferred_unit_stack_boundary;
2137 /* See if this is "nothrow" function call. */
2138 if (TREE_NOTHROW (exp))
2139 flags |= ECF_NOTHROW;
2141 /* See if we can find a DECL-node for the actual function.
2142 As a result, decide whether this is a call to an integrable function. */
2144 fndecl = get_callee_fndecl (exp);
2148 && fndecl != current_function_decl
2149 && DECL_INLINE (fndecl)
2150 && DECL_SAVED_INSNS (fndecl)
2151 && DECL_SAVED_INSNS (fndecl)->inlinable)
2153 else if (! TREE_ADDRESSABLE (fndecl))
2155 /* In case this function later becomes inlinable,
2156 record that there was already a non-inline call to it.
2158 Use abstraction instead of setting TREE_ADDRESSABLE
2160 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2163 warning ("%Hcan't inline call to '%F'",
2164 &DECL_SOURCE_LOCATION (fndecl), fndecl);
2165 warning ("called from here");
2167 (*lang_hooks.mark_addressable) (fndecl);
2171 && lookup_attribute ("warn_unused_result",
2172 TYPE_ATTRIBUTES (TREE_TYPE (fndecl))))
2173 warning ("ignoring return value of `%D', "
2174 "declared with attribute warn_unused_result", fndecl);
2176 flags |= flags_from_decl_or_type (fndecl);
2179 /* If we don't have specific function to call, see if we have a
2180 attributes set in the type. */
2184 && lookup_attribute ("warn_unused_result",
2185 TYPE_ATTRIBUTES (TREE_TYPE (TREE_TYPE (p)))))
2186 warning ("ignoring return value of function "
2187 "declared with attribute warn_unused_result");
2188 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2191 struct_value = targetm.calls.struct_value_rtx (fndecl ? TREE_TYPE (fndecl) : 0, 0);
2193 /* Warn if this value is an aggregate type,
2194 regardless of which calling convention we are using for it. */
2195 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2196 warning ("function call has aggregate value");
2198 /* If the result of a pure or const function call is ignored (or void),
2199 and none of its arguments are volatile, we can avoid expanding the
2200 call and just evaluate the arguments for side-effects. */
2201 if ((flags & (ECF_CONST | ECF_PURE))
2202 && (ignore || target == const0_rtx
2203 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2205 bool volatilep = false;
2208 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2209 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2217 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2218 expand_expr (TREE_VALUE (arg), const0_rtx,
2219 VOIDmode, EXPAND_NORMAL);
2224 #ifdef REG_PARM_STACK_SPACE
2225 #ifdef MAYBE_REG_PARM_STACK_SPACE
2226 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2228 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2232 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2233 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2234 must_preallocate = 1;
2237 /* Set up a place to return a structure. */
2239 /* Cater to broken compilers. */
2240 if (aggregate_value_p (exp, fndecl))
2242 /* This call returns a big structure. */
2243 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2245 #ifdef PCC_STATIC_STRUCT_RETURN
2247 pcc_struct_value = 1;
2248 /* Easier than making that case work right. */
2251 /* In case this is a static function, note that it has been
2253 if (! TREE_ADDRESSABLE (fndecl))
2254 (*lang_hooks.mark_addressable) (fndecl);
2258 #else /* not PCC_STATIC_STRUCT_RETURN */
2260 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2262 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2264 /* The structure value address arg is already in actparms.
2265 Pull it out. It might be nice to just leave it there, but
2266 we need to set structure_value_addr. */
2267 tree return_arg = TREE_VALUE (actparms);
2268 actparms = TREE_CHAIN (actparms);
2269 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2270 VOIDmode, EXPAND_NORMAL);
2272 else if (target && GET_CODE (target) == MEM)
2273 structure_value_addr = XEXP (target, 0);
2276 /* For variable-sized objects, we must be called with a target
2277 specified. If we were to allocate space on the stack here,
2278 we would have no way of knowing when to free it. */
2279 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2281 mark_temp_addr_taken (d);
2282 structure_value_addr = XEXP (d, 0);
2286 #endif /* not PCC_STATIC_STRUCT_RETURN */
2289 /* If called function is inline, try to integrate it. */
2293 rtx temp = try_to_integrate (fndecl, actparms, target,
2294 ignore, TREE_TYPE (exp),
2295 structure_value_addr);
2296 if (temp != (rtx) (size_t) - 1)
2300 /* Figure out the amount to which the stack should be aligned. */
2301 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2304 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2305 if (i && i->preferred_incoming_stack_boundary)
2306 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2309 /* Operand 0 is a pointer-to-function; get the type of the function. */
2310 funtype = TREE_TYPE (addr);
2311 if (! POINTER_TYPE_P (funtype))
2313 funtype = TREE_TYPE (funtype);
2315 /* Munge the tree to split complex arguments into their imaginary
2317 if (SPLIT_COMPLEX_ARGS)
2319 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2320 actparms = split_complex_values (actparms);
2323 type_arg_types = TYPE_ARG_TYPES (funtype);
2325 /* See if this is a call to a function that can return more than once
2326 or a call to longjmp or malloc. */
2327 flags |= special_function_p (fndecl, flags);
2329 if (flags & ECF_MAY_BE_ALLOCA)
2330 current_function_calls_alloca = 1;
2332 /* If struct_value_rtx is 0, it means pass the address
2333 as if it were an extra parameter. */
2334 if (structure_value_addr && struct_value == 0)
2336 /* If structure_value_addr is a REG other than
2337 virtual_outgoing_args_rtx, we can use always use it. If it
2338 is not a REG, we must always copy it into a register.
2339 If it is virtual_outgoing_args_rtx, we must copy it to another
2340 register in some cases. */
2341 rtx temp = (GET_CODE (structure_value_addr) != REG
2342 || (ACCUMULATE_OUTGOING_ARGS
2343 && stack_arg_under_construction
2344 && structure_value_addr == virtual_outgoing_args_rtx)
2345 ? copy_addr_to_reg (structure_value_addr)
2346 : structure_value_addr);
2349 = tree_cons (error_mark_node,
2350 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2353 structure_value_addr_parm = 1;
2356 /* Count the arguments and set NUM_ACTUALS. */
2357 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2360 /* Start updating where the next arg would go.
2362 On some machines (such as the PA) indirect calls have a difuferent
2363 calling convention than normal calls. The last argument in
2364 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2366 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2368 /* Compute number of named args.
2369 Normally, don't include the last named arg if anonymous args follow.
2370 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2371 (If no anonymous args follow, the result of list_length is actually
2372 one too large. This is harmless.)
2374 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2375 zero, this machine will be able to place unnamed args that were
2376 passed in registers into the stack. So treat all args as named.
2377 This allows the insns emitting for a specific argument list to be
2378 independent of the function declaration.
2380 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2381 reliable way to pass unnamed args in registers, so we must force
2382 them into memory. */
2384 if ((targetm.calls.strict_argument_naming (&args_so_far)
2385 || ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2386 && type_arg_types != 0)
2388 = (list_length (type_arg_types)
2389 /* Don't include the last named arg. */
2390 - (targetm.calls.strict_argument_naming (&args_so_far) ? 0 : 1)
2391 /* Count the struct value address, if it is passed as a parm. */
2392 + structure_value_addr_parm);
2394 /* If we know nothing, treat all args as named. */
2395 n_named_args = num_actuals;
2397 /* Make a vector to hold all the information about each arg. */
2398 args = alloca (num_actuals * sizeof (struct arg_data));
2399 memset (args, 0, num_actuals * sizeof (struct arg_data));
2401 /* Build up entries in the ARGS array, compute the size of the
2402 arguments into ARGS_SIZE, etc. */
2403 initialize_argument_information (num_actuals, args, &args_size,
2404 n_named_args, actparms, fndecl,
2405 &args_so_far, reg_parm_stack_space,
2406 &old_stack_level, &old_pending_adj,
2407 &must_preallocate, &flags);
2411 /* If this function requires a variable-sized argument list, don't
2412 try to make a cse'able block for this call. We may be able to
2413 do this eventually, but it is too complicated to keep track of
2414 what insns go in the cse'able block and which don't. */
2416 flags &= ~ECF_LIBCALL_BLOCK;
2417 must_preallocate = 1;
2420 /* Now make final decision about preallocating stack space. */
2421 must_preallocate = finalize_must_preallocate (must_preallocate,
2425 /* If the structure value address will reference the stack pointer, we
2426 must stabilize it. We don't need to do this if we know that we are
2427 not going to adjust the stack pointer in processing this call. */
2429 if (structure_value_addr
2430 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2431 || reg_mentioned_p (virtual_outgoing_args_rtx,
2432 structure_value_addr))
2434 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2435 structure_value_addr = copy_to_reg (structure_value_addr);
2437 /* Tail calls can make things harder to debug, and we're traditionally
2438 pushed these optimizations into -O2. Don't try if we're already
2439 expanding a call, as that means we're an argument. Don't try if
2440 there's cleanups, as we know there's code to follow the call.
2442 If rtx_equal_function_value_matters is false, that means we've
2443 finished with regular parsing. Which means that some of the
2444 machinery we use to generate tail-calls is no longer in place.
2445 This is most often true of sjlj-exceptions, which we couldn't
2446 tail-call to anyway. */
2448 if (currently_expanding_call++ != 0
2449 || !flag_optimize_sibling_calls
2450 || !rtx_equal_function_value_matters
2451 || any_pending_cleanups ()
2453 try_tail_call = try_tail_recursion = 0;
2455 /* Tail recursion fails, when we are not dealing with recursive calls. */
2456 if (!try_tail_recursion
2457 || TREE_CODE (addr) != ADDR_EXPR
2458 || TREE_OPERAND (addr, 0) != current_function_decl)
2459 try_tail_recursion = 0;
2461 /* Rest of purposes for tail call optimizations to fail. */
2463 #ifdef HAVE_sibcall_epilogue
2464 !HAVE_sibcall_epilogue
2469 /* Doing sibling call optimization needs some work, since
2470 structure_value_addr can be allocated on the stack.
2471 It does not seem worth the effort since few optimizable
2472 sibling calls will return a structure. */
2473 || structure_value_addr != NULL_RTX
2474 /* Check whether the target is able to optimize the call
2476 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2477 /* Functions that do not return exactly once may not be sibcall
2479 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2480 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2481 /* If the called function is nested in the current one, it might access
2482 some of the caller's arguments, but could clobber them beforehand if
2483 the argument areas are shared. */
2484 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2485 /* If this function requires more stack slots than the current
2486 function, we cannot change it into a sibling call. */
2487 || args_size.constant > current_function_args_size
2488 /* If the callee pops its own arguments, then it must pop exactly
2489 the same number of arguments as the current function. */
2490 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2491 != RETURN_POPS_ARGS (current_function_decl,
2492 TREE_TYPE (current_function_decl),
2493 current_function_args_size))
2494 || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2497 if (try_tail_call || try_tail_recursion)
2500 actparms = NULL_TREE;
2501 /* Ok, we're going to give the tail call the old college try.
2502 This means we're going to evaluate the function arguments
2503 up to three times. There are two degrees of badness we can
2504 encounter, those that can be unsaved and those that can't.
2505 (See unsafe_for_reeval commentary for details.)
2507 Generate a new argument list. Pass safe arguments through
2508 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2509 For hard badness, evaluate them now and put their resulting
2510 rtx in a temporary VAR_DECL.
2512 initialize_argument_information has ordered the array for the
2513 order to be pushed, and we must remember this when reconstructing
2514 the original argument order. */
2516 if (PUSH_ARGS_REVERSED)
2525 i = num_actuals - 1;
2529 for (; i != end; i += inc)
2531 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2532 /* We need to build actparms for optimize_tail_recursion. We can
2533 safely trash away TREE_PURPOSE, since it is unused by this
2535 if (try_tail_recursion)
2536 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2538 /* Do the same for the function address if it is an expression. */
2540 addr = fix_unsafe_tree (addr);
2541 /* Expanding one of those dangerous arguments could have added
2542 cleanups, but otherwise give it a whirl. */
2543 if (any_pending_cleanups ())
2544 try_tail_call = try_tail_recursion = 0;
2547 /* Generate a tail recursion sequence when calling ourselves. */
2549 if (try_tail_recursion)
2551 /* We want to emit any pending stack adjustments before the tail
2552 recursion "call". That way we know any adjustment after the tail
2553 recursion call can be ignored if we indeed use the tail recursion
2555 int save_pending_stack_adjust = pending_stack_adjust;
2556 int save_stack_pointer_delta = stack_pointer_delta;
2558 /* Emit any queued insns now; otherwise they would end up in
2559 only one of the alternates. */
2562 /* Use a new sequence to hold any RTL we generate. We do not even
2563 know if we will use this RTL yet. The final decision can not be
2564 made until after RTL generation for the entire function is
2567 /* If expanding any of the arguments creates cleanups, we can't
2568 do a tailcall. So, we'll need to pop the pending cleanups
2569 list. If, however, all goes well, and there are no cleanups
2570 then the call to expand_start_target_temps will have no
2572 expand_start_target_temps ();
2573 if (optimize_tail_recursion (actparms, get_last_insn ()))
2575 if (any_pending_cleanups ())
2576 try_tail_call = try_tail_recursion = 0;
2578 tail_recursion_insns = get_insns ();
2580 expand_end_target_temps ();
2583 /* Restore the original pending stack adjustment for the sibling and
2584 normal call cases below. */
2585 pending_stack_adjust = save_pending_stack_adjust;
2586 stack_pointer_delta = save_stack_pointer_delta;
2589 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2591 /* A fork duplicates the profile information, and an exec discards
2592 it. We can't rely on fork/exec to be paired. So write out the
2593 profile information we have gathered so far, and clear it. */
2594 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2595 is subject to race conditions, just as with multithreaded
2598 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2601 /* Ensure current function's preferred stack boundary is at least
2602 what we need. We don't have to increase alignment for recursive
2604 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2605 && fndecl != current_function_decl)
2606 cfun->preferred_stack_boundary = preferred_stack_boundary;
2607 if (fndecl == current_function_decl)
2608 cfun->recursive_call_emit = true;
2610 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2612 function_call_count++;
2614 /* We want to make two insn chains; one for a sibling call, the other
2615 for a normal call. We will select one of the two chains after
2616 initial RTL generation is complete. */
2617 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2619 int sibcall_failure = 0;
2620 /* We want to emit any pending stack adjustments before the tail
2621 recursion "call". That way we know any adjustment after the tail
2622 recursion call can be ignored if we indeed use the tail recursion
2624 int save_pending_stack_adjust = 0;
2625 int save_stack_pointer_delta = 0;
2627 rtx before_call, next_arg_reg;
2631 /* Emit any queued insns now; otherwise they would end up in
2632 only one of the alternates. */
2635 /* State variables we need to save and restore between
2637 save_pending_stack_adjust = pending_stack_adjust;
2638 save_stack_pointer_delta = stack_pointer_delta;
2641 flags &= ~ECF_SIBCALL;
2643 flags |= ECF_SIBCALL;
2645 /* Other state variables that we must reinitialize each time
2646 through the loop (that are not initialized by the loop itself). */
2650 /* Start a new sequence for the normal call case.
2652 From this point on, if the sibling call fails, we want to set
2653 sibcall_failure instead of continuing the loop. */
2658 /* We know at this point that there are not currently any
2659 pending cleanups. If, however, in the process of evaluating
2660 the arguments we were to create some, we'll need to be
2661 able to get rid of them. */
2662 expand_start_target_temps ();
2665 /* Don't let pending stack adjusts add up to too much.
2666 Also, do all pending adjustments now if there is any chance
2667 this might be a call to alloca or if we are expanding a sibling
2668 call sequence or if we are calling a function that is to return
2669 with stack pointer depressed. */
2670 if (pending_stack_adjust >= 32
2671 || (pending_stack_adjust > 0
2672 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2674 do_pending_stack_adjust ();
2676 /* When calling a const function, we must pop the stack args right away,
2677 so that the pop is deleted or moved with the call. */
2678 if (pass && (flags & ECF_LIBCALL_BLOCK))
2681 #ifdef FINAL_REG_PARM_STACK_SPACE
2682 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2685 /* Precompute any arguments as needed. */
2687 precompute_arguments (flags, num_actuals, args);
2689 /* Now we are about to start emitting insns that can be deleted
2690 if a libcall is deleted. */
2691 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2694 adjusted_args_size = args_size;
2695 /* Compute the actual size of the argument block required. The variable
2696 and constant sizes must be combined, the size may have to be rounded,
2697 and there may be a minimum required size. When generating a sibcall
2698 pattern, do not round up, since we'll be re-using whatever space our
2700 unadjusted_args_size
2701 = compute_argument_block_size (reg_parm_stack_space,
2702 &adjusted_args_size,
2704 : preferred_stack_boundary));
2706 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2708 /* The argument block when performing a sibling call is the
2709 incoming argument block. */
2712 argblock = virtual_incoming_args_rtx;
2714 #ifdef STACK_GROWS_DOWNWARD
2715 = plus_constant (argblock, current_function_pretend_args_size);
2717 = plus_constant (argblock, -current_function_pretend_args_size);
2719 stored_args_map = sbitmap_alloc (args_size.constant);
2720 sbitmap_zero (stored_args_map);
2723 /* If we have no actual push instructions, or shouldn't use them,
2724 make space for all args right now. */
2725 else if (adjusted_args_size.var != 0)
2727 if (old_stack_level == 0)
2729 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2730 old_stack_pointer_delta = stack_pointer_delta;
2731 old_pending_adj = pending_stack_adjust;
2732 pending_stack_adjust = 0;
2733 /* stack_arg_under_construction says whether a stack arg is
2734 being constructed at the old stack level. Pushing the stack
2735 gets a clean outgoing argument block. */
2736 old_stack_arg_under_construction = stack_arg_under_construction;
2737 stack_arg_under_construction = 0;
2739 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2743 /* Note that we must go through the motions of allocating an argument
2744 block even if the size is zero because we may be storing args
2745 in the area reserved for register arguments, which may be part of
2748 int needed = adjusted_args_size.constant;
2750 /* Store the maximum argument space used. It will be pushed by
2751 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2754 if (needed > current_function_outgoing_args_size)
2755 current_function_outgoing_args_size = needed;
2757 if (must_preallocate)
2759 if (ACCUMULATE_OUTGOING_ARGS)
2761 /* Since the stack pointer will never be pushed, it is
2762 possible for the evaluation of a parm to clobber
2763 something we have already written to the stack.
2764 Since most function calls on RISC machines do not use
2765 the stack, this is uncommon, but must work correctly.
2767 Therefore, we save any area of the stack that was already
2768 written and that we are using. Here we set up to do this
2769 by making a new stack usage map from the old one. The
2770 actual save will be done by store_one_arg.
2772 Another approach might be to try to reorder the argument
2773 evaluations to avoid this conflicting stack usage. */
2775 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2776 /* Since we will be writing into the entire argument area,
2777 the map must be allocated for its entire size, not just
2778 the part that is the responsibility of the caller. */
2779 needed += reg_parm_stack_space;
2782 #ifdef ARGS_GROW_DOWNWARD
2783 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2786 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2789 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2791 if (initial_highest_arg_in_use)
2792 memcpy (stack_usage_map, initial_stack_usage_map,
2793 initial_highest_arg_in_use);
2795 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2796 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2797 (highest_outgoing_arg_in_use
2798 - initial_highest_arg_in_use));
2801 /* The address of the outgoing argument list must not be
2802 copied to a register here, because argblock would be left
2803 pointing to the wrong place after the call to
2804 allocate_dynamic_stack_space below. */
2806 argblock = virtual_outgoing_args_rtx;
2810 if (inhibit_defer_pop == 0)
2812 /* Try to reuse some or all of the pending_stack_adjust
2813 to get this space. */
2815 = (combine_pending_stack_adjustment_and_call
2816 (unadjusted_args_size,
2817 &adjusted_args_size,
2818 preferred_unit_stack_boundary));
2820 /* combine_pending_stack_adjustment_and_call computes
2821 an adjustment before the arguments are allocated.
2822 Account for them and see whether or not the stack
2823 needs to go up or down. */
2824 needed = unadjusted_args_size - needed;
2828 /* We're releasing stack space. */
2829 /* ??? We can avoid any adjustment at all if we're
2830 already aligned. FIXME. */
2831 pending_stack_adjust = -needed;
2832 do_pending_stack_adjust ();
2836 /* We need to allocate space. We'll do that in
2837 push_block below. */
2838 pending_stack_adjust = 0;
2841 /* Special case this because overhead of `push_block' in
2842 this case is non-trivial. */
2844 argblock = virtual_outgoing_args_rtx;
2847 argblock = push_block (GEN_INT (needed), 0, 0);
2848 #ifdef ARGS_GROW_DOWNWARD
2849 argblock = plus_constant (argblock, needed);
2853 /* We only really need to call `copy_to_reg' in the case
2854 where push insns are going to be used to pass ARGBLOCK
2855 to a function call in ARGS. In that case, the stack
2856 pointer changes value from the allocation point to the
2857 call point, and hence the value of
2858 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2859 as well always do it. */
2860 argblock = copy_to_reg (argblock);
2865 if (ACCUMULATE_OUTGOING_ARGS)
2867 /* The save/restore code in store_one_arg handles all
2868 cases except one: a constructor call (including a C
2869 function returning a BLKmode struct) to initialize
2871 if (stack_arg_under_construction)
2873 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2874 rtx push_size = GEN_INT (reg_parm_stack_space
2875 + adjusted_args_size.constant);
2877 rtx push_size = GEN_INT (adjusted_args_size.constant);
2879 if (old_stack_level == 0)
2881 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2883 old_stack_pointer_delta = stack_pointer_delta;
2884 old_pending_adj = pending_stack_adjust;
2885 pending_stack_adjust = 0;
2886 /* stack_arg_under_construction says whether a stack
2887 arg is being constructed at the old stack level.
2888 Pushing the stack gets a clean outgoing argument
2890 old_stack_arg_under_construction
2891 = stack_arg_under_construction;
2892 stack_arg_under_construction = 0;
2893 /* Make a new map for the new argument list. */
2894 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2895 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2896 highest_outgoing_arg_in_use = 0;
2898 allocate_dynamic_stack_space (push_size, NULL_RTX,
2902 /* If argument evaluation might modify the stack pointer,
2903 copy the address of the argument list to a register. */
2904 for (i = 0; i < num_actuals; i++)
2905 if (args[i].pass_on_stack)
2907 argblock = copy_addr_to_reg (argblock);
2912 compute_argument_addresses (args, argblock, num_actuals);
2914 /* If we push args individually in reverse order, perform stack alignment
2915 before the first push (the last arg). */
2916 if (PUSH_ARGS_REVERSED && argblock == 0
2917 && adjusted_args_size.constant != unadjusted_args_size)
2919 /* When the stack adjustment is pending, we get better code
2920 by combining the adjustments. */
2921 if (pending_stack_adjust
2922 && ! (flags & ECF_LIBCALL_BLOCK)
2923 && ! inhibit_defer_pop)
2925 pending_stack_adjust
2926 = (combine_pending_stack_adjustment_and_call
2927 (unadjusted_args_size,
2928 &adjusted_args_size,
2929 preferred_unit_stack_boundary));
2930 do_pending_stack_adjust ();
2932 else if (argblock == 0)
2933 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2934 - unadjusted_args_size));
2936 /* Now that the stack is properly aligned, pops can't safely
2937 be deferred during the evaluation of the arguments. */
2940 funexp = rtx_for_function_call (fndecl, addr);
2942 /* Figure out the register where the value, if any, will come back. */
2944 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2945 && ! structure_value_addr)
2947 if (pcc_struct_value)
2948 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2949 fndecl, (pass == 0));
2951 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2954 /* Precompute all register parameters. It isn't safe to compute anything
2955 once we have started filling any specific hard regs. */
2956 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2958 #ifdef REG_PARM_STACK_SPACE
2959 /* Save the fixed argument area if it's part of the caller's frame and
2960 is clobbered by argument setup for this call. */
2961 if (ACCUMULATE_OUTGOING_ARGS && pass)
2962 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2963 &low_to_save, &high_to_save);
2966 /* Now store (and compute if necessary) all non-register parms.
2967 These come before register parms, since they can require block-moves,
2968 which could clobber the registers used for register parms.
2969 Parms which have partial registers are not stored here,
2970 but we do preallocate space here if they want that. */
2972 for (i = 0; i < num_actuals; i++)
2973 if (args[i].reg == 0 || args[i].pass_on_stack)
2975 rtx before_arg = get_last_insn ();
2977 if (store_one_arg (&args[i], argblock, flags,
2978 adjusted_args_size.var != 0,
2979 reg_parm_stack_space)
2981 && check_sibcall_argument_overlap (before_arg,
2983 sibcall_failure = 1;
2986 /* If we have a parm that is passed in registers but not in memory
2987 and whose alignment does not permit a direct copy into registers,
2988 make a group of pseudos that correspond to each register that we
2990 if (STRICT_ALIGNMENT)
2991 store_unaligned_arguments_into_pseudos (args, num_actuals);
2993 /* Now store any partially-in-registers parm.
2994 This is the last place a block-move can happen. */
2996 for (i = 0; i < num_actuals; i++)
2997 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2999 rtx before_arg = get_last_insn ();
3001 if (store_one_arg (&args[i], argblock, flags,
3002 adjusted_args_size.var != 0,
3003 reg_parm_stack_space)
3005 && check_sibcall_argument_overlap (before_arg,
3007 sibcall_failure = 1;
3010 /* If we pushed args in forward order, perform stack alignment
3011 after pushing the last arg. */
3012 if (!PUSH_ARGS_REVERSED && argblock == 0)
3013 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
3014 - unadjusted_args_size));
3016 /* If register arguments require space on the stack and stack space
3017 was not preallocated, allocate stack space here for arguments
3018 passed in registers. */
3019 #ifdef OUTGOING_REG_PARM_STACK_SPACE
3020 if (!ACCUMULATE_OUTGOING_ARGS
3021 && must_preallocate == 0 && reg_parm_stack_space > 0)
3022 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
3025 /* Pass the function the address in which to return a
3027 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
3029 structure_value_addr
3030 = convert_memory_address (Pmode, structure_value_addr);
3031 emit_move_insn (struct_value,
3033 force_operand (structure_value_addr,
3036 if (GET_CODE (struct_value) == REG)
3037 use_reg (&call_fusage, struct_value);
3040 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
3041 reg_parm_seen, pass == 0);
3043 load_register_parameters (args, num_actuals, &call_fusage, flags,
3044 pass == 0, &sibcall_failure);
3046 /* Perform postincrements before actually calling the function. */
3049 /* Save a pointer to the last insn before the call, so that we can
3050 later safely search backwards to find the CALL_INSN. */
3051 before_call = get_last_insn ();
3053 /* Set up next argument register. For sibling calls on machines
3054 with register windows this should be the incoming register. */
3055 #ifdef FUNCTION_INCOMING_ARG
3057 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
3061 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
3064 /* All arguments and registers used for the call must be set up by
3067 /* Stack must be properly aligned now. */
3068 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3071 /* Generate the actual call instruction. */
3072 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3073 adjusted_args_size.constant, struct_value_size,
3074 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3075 flags, & args_so_far);
3077 /* If call is cse'able, make appropriate pair of reg-notes around it.
3078 Test valreg so we don't crash; may safely ignore `const'
3079 if return type is void. Disable for PARALLEL return values, because
3080 we have no way to move such values into a pseudo register. */
3081 if (pass && (flags & ECF_LIBCALL_BLOCK))
3085 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
3087 insns = get_insns ();
3089 /* Expansion of block moves possibly introduced a loop that may
3090 not appear inside libcall block. */
3091 for (insn = insns; insn; insn = NEXT_INSN (insn))
3092 if (GET_CODE (insn) == JUMP_INSN)
3103 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3105 /* Mark the return value as a pointer if needed. */
3106 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3107 mark_reg_pointer (temp,
3108 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3110 /* Construct an "equal form" for the value which mentions all the
3111 arguments in order as well as the function name. */
3112 for (i = 0; i < num_actuals; i++)
3113 note = gen_rtx_EXPR_LIST (VOIDmode,
3114 args[i].initial_value, note);
3115 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3119 if (flags & ECF_PURE)
3120 note = gen_rtx_EXPR_LIST (VOIDmode,
3121 gen_rtx_USE (VOIDmode,
3122 gen_rtx_MEM (BLKmode,
3123 gen_rtx_SCRATCH (VOIDmode))),
3126 emit_libcall_block (insns, temp, valreg, note);
3131 else if (pass && (flags & ECF_MALLOC))
3133 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3136 /* The return value from a malloc-like function is a pointer. */
3137 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3138 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3140 emit_move_insn (temp, valreg);
3142 /* The return value from a malloc-like function can not alias
3144 last = get_last_insn ();
3146 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3148 /* Write out the sequence. */
3149 insns = get_insns ();
3155 /* For calls to `setjmp', etc., inform flow.c it should complain
3156 if nonvolatile values are live. For functions that cannot return,
3157 inform flow that control does not fall through. */
3159 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3161 /* The barrier must be emitted
3162 immediately after the CALL_INSN. Some ports emit more
3163 than just a CALL_INSN above, so we must search for it here. */
3165 rtx last = get_last_insn ();
3166 while (GET_CODE (last) != CALL_INSN)
3168 last = PREV_INSN (last);
3169 /* There was no CALL_INSN? */
3170 if (last == before_call)
3174 emit_barrier_after (last);
3176 /* Stack adjustments after a noreturn call are dead code. */
3177 stack_pointer_delta = old_stack_allocated;
3178 pending_stack_adjust = 0;
3181 if (flags & ECF_LONGJMP)
3182 current_function_calls_longjmp = 1;
3184 /* If value type not void, return an rtx for the value. */
3186 /* If there are cleanups to be called, don't use a hard reg as target.
3187 We need to double check this and see if it matters anymore. */
3188 if (any_pending_cleanups ())
3190 if (target && REG_P (target)
3191 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3193 sibcall_failure = 1;
3196 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3198 target = const0_rtx;
3199 else if (structure_value_addr)
3201 if (target == 0 || GET_CODE (target) != MEM)
3204 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3205 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3206 structure_value_addr));
3207 set_mem_attributes (target, exp, 1);
3210 else if (pcc_struct_value)
3212 /* This is the special C++ case where we need to
3213 know what the true target was. We take care to
3214 never use this value more than once in one expression. */
3215 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3216 copy_to_reg (valreg));
3217 set_mem_attributes (target, exp, 1);
3219 /* Handle calls that return values in multiple non-contiguous locations.
3220 The Irix 6 ABI has examples of this. */
3221 else if (GET_CODE (valreg) == PARALLEL)
3225 /* This will only be assigned once, so it can be readonly. */
3226 tree nt = build_qualified_type (TREE_TYPE (exp),
3227 (TYPE_QUALS (TREE_TYPE (exp))
3228 | TYPE_QUAL_CONST));
3230 target = assign_temp (nt, 0, 1, 1);
3231 preserve_temp_slots (target);
3234 if (! rtx_equal_p (target, valreg))
3235 emit_group_store (target, valreg, TREE_TYPE (exp),
3236 int_size_in_bytes (TREE_TYPE (exp)));
3238 /* We can not support sibling calls for this case. */
3239 sibcall_failure = 1;
3242 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3243 && GET_MODE (target) == GET_MODE (valreg))
3245 /* TARGET and VALREG cannot be equal at this point because the
3246 latter would not have REG_FUNCTION_VALUE_P true, while the
3247 former would if it were referring to the same register.
3249 If they refer to the same register, this move will be a no-op,
3250 except when function inlining is being done. */
3251 emit_move_insn (target, valreg);
3253 /* If we are setting a MEM, this code must be executed. Since it is
3254 emitted after the call insn, sibcall optimization cannot be
3255 performed in that case. */
3256 if (GET_CODE (target) == MEM)
3257 sibcall_failure = 1;
3259 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3261 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3263 /* We can not support sibling calls for this case. */
3264 sibcall_failure = 1;
3267 target = copy_to_reg (valreg);
3269 if (targetm.calls.promote_function_return(funtype))
3271 /* If we promoted this return value, make the proper SUBREG. TARGET
3272 might be const0_rtx here, so be careful. */
3273 if (GET_CODE (target) == REG
3274 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3275 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3277 tree type = TREE_TYPE (exp);
3278 int unsignedp = TREE_UNSIGNED (type);
3281 /* If we don't promote as expected, something is wrong. */
3282 if (GET_MODE (target)
3283 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3286 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3287 && GET_MODE_SIZE (GET_MODE (target))
3288 > GET_MODE_SIZE (TYPE_MODE (type)))
3290 offset = GET_MODE_SIZE (GET_MODE (target))
3291 - GET_MODE_SIZE (TYPE_MODE (type));
3292 if (! BYTES_BIG_ENDIAN)
3293 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3294 else if (! WORDS_BIG_ENDIAN)
3295 offset %= UNITS_PER_WORD;
3297 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3298 SUBREG_PROMOTED_VAR_P (target) = 1;
3299 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3303 /* If size of args is variable or this was a constructor call for a stack
3304 argument, restore saved stack-pointer value. */
3306 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3308 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3309 stack_pointer_delta = old_stack_pointer_delta;
3310 pending_stack_adjust = old_pending_adj;
3311 stack_arg_under_construction = old_stack_arg_under_construction;
3312 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3313 stack_usage_map = initial_stack_usage_map;
3314 sibcall_failure = 1;
3316 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3318 #ifdef REG_PARM_STACK_SPACE
3320 restore_fixed_argument_area (save_area, argblock,
3321 high_to_save, low_to_save);
3324 /* If we saved any argument areas, restore them. */
3325 for (i = 0; i < num_actuals; i++)
3326 if (args[i].save_area)
3328 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3330 = gen_rtx_MEM (save_mode,
3331 memory_address (save_mode,
3332 XEXP (args[i].stack_slot, 0)));
3334 if (save_mode != BLKmode)
3335 emit_move_insn (stack_area, args[i].save_area);
3337 emit_block_move (stack_area, args[i].save_area,
3338 GEN_INT (args[i].locate.size.constant),
3339 BLOCK_OP_CALL_PARM);
3342 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3343 stack_usage_map = initial_stack_usage_map;
3346 /* If this was alloca, record the new stack level for nonlocal gotos.
3347 Check for the handler slots since we might not have a save area
3348 for non-local gotos. */
3350 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3351 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3353 /* Free up storage we no longer need. */
3354 for (i = 0; i < num_actuals; ++i)
3355 if (args[i].aligned_regs)
3356 free (args[i].aligned_regs);
3360 /* Undo the fake expand_start_target_temps we did earlier. If
3361 there had been any cleanups created, we've already set
3363 expand_end_target_temps ();
3366 /* If this function is returning into a memory location marked as
3367 readonly, it means it is initializing that location. We normally treat
3368 functions as not clobbering such locations, so we need to specify that
3369 this one does. We do this by adding the appropriate CLOBBER to the
3370 CALL_INSN function usage list. This cannot be done by emitting a
3371 standalone CLOBBER after the call because the latter would be ignored
3372 by at least the delay slot scheduling pass. We do this now instead of
3373 adding to call_fusage before the call to emit_call_1 because TARGET
3374 may be modified in the meantime. */
3375 if (structure_value_addr != 0 && target != 0
3376 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3377 add_function_usage_to
3379 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3382 insns = get_insns ();
3387 tail_call_insns = insns;
3389 /* Restore the pending stack adjustment now that we have
3390 finished generating the sibling call sequence. */
3392 pending_stack_adjust = save_pending_stack_adjust;
3393 stack_pointer_delta = save_stack_pointer_delta;
3395 /* Prepare arg structure for next iteration. */
3396 for (i = 0; i < num_actuals; i++)
3399 args[i].aligned_regs = 0;
3403 sbitmap_free (stored_args_map);
3407 normal_call_insns = insns;
3409 /* Verify that we've deallocated all the stack we used. */
3410 if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3411 && old_stack_allocated != stack_pointer_delta
3412 - pending_stack_adjust)
3416 /* If something prevents making this a sibling call,
3417 zero out the sequence. */
3418 if (sibcall_failure)
3419 tail_call_insns = NULL_RTX;
3422 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3423 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3424 can happen if the arguments to this function call an inline
3425 function who's expansion contains another CALL_PLACEHOLDER.
3427 If there are any C_Ps in any of these sequences, replace them
3428 with their normal call. */
3430 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3431 if (GET_CODE (insn) == CALL_INSN
3432 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3433 replace_call_placeholder (insn, sibcall_use_normal);
3435 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3436 if (GET_CODE (insn) == CALL_INSN
3437 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3438 replace_call_placeholder (insn, sibcall_use_normal);
3440 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3441 if (GET_CODE (insn) == CALL_INSN
3442 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3443 replace_call_placeholder (insn, sibcall_use_normal);
3445 /* If this was a potential tail recursion site, then emit a
3446 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3447 One of them will be selected later. */
3448 if (tail_recursion_insns || tail_call_insns)
3450 /* The tail recursion label must be kept around. We could expose
3451 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3452 and makes determining true tail recursion sites difficult.
3454 So we set LABEL_PRESERVE_P here, then clear it when we select
3455 one of the call sequences after rtl generation is complete. */
3456 if (tail_recursion_insns)
3457 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3458 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3460 tail_recursion_insns,
3461 tail_recursion_label));
3464 emit_insn (normal_call_insns);
3466 currently_expanding_call--;
3468 /* If this function returns with the stack pointer depressed, ensure
3469 this block saves and restores the stack pointer, show it was
3470 changed, and adjust for any outgoing arg space. */
3471 if (flags & ECF_SP_DEPRESSED)
3473 clear_pending_stack_adjust ();
3474 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3475 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3476 save_stack_pointer ();
3482 /* Traverse an argument list in VALUES and expand all complex
3483 arguments into their components. */
3485 split_complex_values (tree values)
3489 values = copy_list (values);
3491 for (p = values; p; p = TREE_CHAIN (p))
3493 tree complex_value = TREE_VALUE (p);
3496 complex_type = TREE_TYPE (complex_value);
3500 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3503 tree real, imag, next;
3505 subtype = TREE_TYPE (complex_type);
3506 complex_value = save_expr (complex_value);
3507 real = build1 (REALPART_EXPR, subtype, complex_value);
3508 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3510 TREE_VALUE (p) = real;
3511 next = TREE_CHAIN (p);
3512 imag = build_tree_list (NULL_TREE, imag);
3513 TREE_CHAIN (p) = imag;
3514 TREE_CHAIN (imag) = next;
3516 /* Skip the newly created node. */
3524 /* Traverse a list of TYPES and expand all complex types into their
3527 split_complex_types (tree types)
3531 types = copy_list (types);
3533 for (p = types; p; p = TREE_CHAIN (p))
3535 tree complex_type = TREE_VALUE (p);
3537 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3541 /* Rewrite complex type with component type. */
3542 TREE_VALUE (p) = TREE_TYPE (complex_type);
3543 next = TREE_CHAIN (p);
3545 /* Add another component type for the imaginary part. */
3546 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3547 TREE_CHAIN (p) = imag;
3548 TREE_CHAIN (imag) = next;
3550 /* Skip the newly created node. */
3558 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3559 The RETVAL parameter specifies whether return value needs to be saved, other
3560 parameters are documented in the emit_library_call function below. */
3563 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3564 enum libcall_type fn_type,
3565 enum machine_mode outmode, int nargs, va_list p)
3567 /* Total size in bytes of all the stack-parms scanned so far. */
3568 struct args_size args_size;
3569 /* Size of arguments before any adjustments (such as rounding). */
3570 struct args_size original_args_size;
3576 CUMULATIVE_ARGS args_so_far;
3580 enum machine_mode mode;
3583 struct locate_and_pad_arg_data locate;
3587 int old_inhibit_defer_pop = inhibit_defer_pop;
3588 rtx call_fusage = 0;
3591 int pcc_struct_value = 0;
3592 int struct_value_size = 0;
3594 int reg_parm_stack_space = 0;
3597 tree tfom; /* type_for_mode (outmode, 0) */
3599 #ifdef REG_PARM_STACK_SPACE
3600 /* Define the boundary of the register parm stack space that needs to be
3602 int low_to_save, high_to_save;
3603 rtx save_area = 0; /* Place that it is saved. */
3606 /* Size of the stack reserved for parameter registers. */
3607 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3608 char *initial_stack_usage_map = stack_usage_map;
3610 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3612 #ifdef REG_PARM_STACK_SPACE
3613 #ifdef MAYBE_REG_PARM_STACK_SPACE
3614 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3616 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3620 /* By default, library functions can not throw. */
3621 flags = ECF_NOTHROW;
3633 case LCT_CONST_MAKE_BLOCK:
3634 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3636 case LCT_PURE_MAKE_BLOCK:
3637 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3640 flags |= ECF_NORETURN;
3643 flags = ECF_NORETURN;
3645 case LCT_ALWAYS_RETURN:
3646 flags = ECF_ALWAYS_RETURN;
3648 case LCT_RETURNS_TWICE:
3649 flags = ECF_RETURNS_TWICE;
3654 /* Ensure current function's preferred stack boundary is at least
3656 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3657 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3659 /* If this kind of value comes back in memory,
3660 decide where in memory it should come back. */
3661 if (outmode != VOIDmode)
3663 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3664 if (aggregate_value_p (tfom, 0))
3666 #ifdef PCC_STATIC_STRUCT_RETURN
3668 = hard_function_value (build_pointer_type (tfom), 0, 0);
3669 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3670 pcc_struct_value = 1;
3672 value = gen_reg_rtx (outmode);
3673 #else /* not PCC_STATIC_STRUCT_RETURN */
3674 struct_value_size = GET_MODE_SIZE (outmode);
3675 if (value != 0 && GET_CODE (value) == MEM)
3678 mem_value = assign_temp (tfom, 0, 1, 1);
3680 /* This call returns a big structure. */
3681 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3685 tfom = void_type_node;
3687 /* ??? Unfinished: must pass the memory address as an argument. */
3689 /* Copy all the libcall-arguments out of the varargs data
3690 and into a vector ARGVEC.
3692 Compute how to pass each argument. We only support a very small subset
3693 of the full argument passing conventions to limit complexity here since
3694 library functions shouldn't have many args. */
3696 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3697 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3699 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3700 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3702 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3705 args_size.constant = 0;
3710 /* Now we are about to start emitting insns that can be deleted
3711 if a libcall is deleted. */
3712 if (flags & ECF_LIBCALL_BLOCK)
3717 /* If there's a structure value address to be passed,
3718 either pass it in the special place, or pass it as an extra argument. */
3719 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3721 rtx addr = XEXP (mem_value, 0);
3724 /* Make sure it is a reasonable operand for a move or push insn. */
3725 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3726 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3727 addr = force_operand (addr, NULL_RTX);
3729 argvec[count].value = addr;
3730 argvec[count].mode = Pmode;
3731 argvec[count].partial = 0;
3733 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3734 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3735 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3739 locate_and_pad_parm (Pmode, NULL_TREE,
3740 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3743 argvec[count].reg != 0,
3745 0, NULL_TREE, &args_size, &argvec[count].locate);
3747 if (argvec[count].reg == 0 || argvec[count].partial != 0
3748 || reg_parm_stack_space > 0)
3749 args_size.constant += argvec[count].locate.size.constant;
3751 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3756 for (; count < nargs; count++)
3758 rtx val = va_arg (p, rtx);
3759 enum machine_mode mode = va_arg (p, enum machine_mode);
3761 /* We cannot convert the arg value to the mode the library wants here;
3762 must do it earlier where we know the signedness of the arg. */
3764 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3767 /* There's no need to call protect_from_queue, because
3768 either emit_move_insn or emit_push_insn will do that. */
3770 /* Make sure it is a reasonable operand for a move or push insn. */
3771 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3772 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3773 val = force_operand (val, NULL_RTX);
3775 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3776 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3780 #ifdef FUNCTION_ARG_CALLEE_COPIES
3781 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3786 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3787 functions, so we have to pretend this isn't such a function. */
3788 if (flags & ECF_LIBCALL_BLOCK)
3790 rtx insns = get_insns ();
3794 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3796 /* If this was a CONST function, it is now PURE since
3797 it now reads memory. */
3798 if (flags & ECF_CONST)
3800 flags &= ~ECF_CONST;
3804 if (GET_MODE (val) == MEM && ! must_copy)
3808 slot = assign_temp ((*lang_hooks.types.type_for_mode) (mode, 0),
3810 emit_move_insn (slot, val);
3814 tree type = (*lang_hooks.types.type_for_mode) (mode, 0);
3817 = gen_rtx_MEM (mode,
3818 expand_expr (build1 (ADDR_EXPR,
3819 build_pointer_type (type),
3820 make_tree (type, val)),
3821 NULL_RTX, VOIDmode, 0));
3824 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3825 gen_rtx_USE (VOIDmode, slot),
3828 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3829 gen_rtx_CLOBBER (VOIDmode,
3834 val = force_operand (XEXP (slot, 0), NULL_RTX);
3838 argvec[count].value = val;
3839 argvec[count].mode = mode;
3841 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3843 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3844 argvec[count].partial
3845 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3847 argvec[count].partial = 0;
3850 locate_and_pad_parm (mode, NULL_TREE,
3851 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3854 argvec[count].reg != 0,
3856 argvec[count].partial,
3857 NULL_TREE, &args_size, &argvec[count].locate);
3859 if (argvec[count].locate.size.var)
3862 if (argvec[count].reg == 0 || argvec[count].partial != 0
3863 || reg_parm_stack_space > 0)
3864 args_size.constant += argvec[count].locate.size.constant;
3866 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3869 #ifdef FINAL_REG_PARM_STACK_SPACE
3870 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3873 /* If this machine requires an external definition for library
3874 functions, write one out. */
3875 assemble_external_libcall (fun);
3877 original_args_size = args_size;
3878 args_size.constant = (((args_size.constant
3879 + stack_pointer_delta
3883 - stack_pointer_delta);
3885 args_size.constant = MAX (args_size.constant,
3886 reg_parm_stack_space);
3888 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3889 args_size.constant -= reg_parm_stack_space;
3892 if (args_size.constant > current_function_outgoing_args_size)
3893 current_function_outgoing_args_size = args_size.constant;
3895 if (ACCUMULATE_OUTGOING_ARGS)
3897 /* Since the stack pointer will never be pushed, it is possible for
3898 the evaluation of a parm to clobber something we have already
3899 written to the stack. Since most function calls on RISC machines
3900 do not use the stack, this is uncommon, but must work correctly.
3902 Therefore, we save any area of the stack that was already written
3903 and that we are using. Here we set up to do this by making a new
3904 stack usage map from the old one.
3906 Another approach might be to try to reorder the argument
3907 evaluations to avoid this conflicting stack usage. */
3909 needed = args_size.constant;
3911 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3912 /* Since we will be writing into the entire argument area, the
3913 map must be allocated for its entire size, not just the part that
3914 is the responsibility of the caller. */
3915 needed += reg_parm_stack_space;
3918 #ifdef ARGS_GROW_DOWNWARD
3919 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3922 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3925 stack_usage_map = alloca (highest_outgoing_arg_in_use);
3927 if (initial_highest_arg_in_use)
3928 memcpy (stack_usage_map, initial_stack_usage_map,
3929 initial_highest_arg_in_use);
3931 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3932 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3933 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3936 /* We must be careful to use virtual regs before they're instantiated,
3937 and real regs afterwards. Loop optimization, for example, can create
3938 new libcalls after we've instantiated the virtual regs, and if we
3939 use virtuals anyway, they won't match the rtl patterns. */
3941 if (virtuals_instantiated)
3942 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3944 argblock = virtual_outgoing_args_rtx;
3949 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3952 /* If we push args individually in reverse order, perform stack alignment
3953 before the first push (the last arg). */
3954 if (argblock == 0 && PUSH_ARGS_REVERSED)
3955 anti_adjust_stack (GEN_INT (args_size.constant
3956 - original_args_size.constant));
3958 if (PUSH_ARGS_REVERSED)
3969 #ifdef REG_PARM_STACK_SPACE
3970 if (ACCUMULATE_OUTGOING_ARGS)
3972 /* The argument list is the property of the called routine and it
3973 may clobber it. If the fixed area has been used for previous
3974 parameters, we must save and restore it. */
3975 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3976 &low_to_save, &high_to_save);
3980 /* Push the args that need to be pushed. */
3982 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3983 are to be pushed. */
3984 for (count = 0; count < nargs; count++, argnum += inc)
3986 enum machine_mode mode = argvec[argnum].mode;
3987 rtx val = argvec[argnum].value;
3988 rtx reg = argvec[argnum].reg;
3989 int partial = argvec[argnum].partial;
3990 int lower_bound = 0, upper_bound = 0, i;
3992 if (! (reg != 0 && partial == 0))
3994 if (ACCUMULATE_OUTGOING_ARGS)
3996 /* If this is being stored into a pre-allocated, fixed-size,
3997 stack area, save any previous data at that location. */
3999 #ifdef ARGS_GROW_DOWNWARD
4000 /* stack_slot is negative, but we want to index stack_usage_map
4001 with positive values. */
4002 upper_bound = -argvec[argnum].locate.offset.constant + 1;
4003 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
4005 lower_bound = argvec[argnum].locate.offset.constant;
4006 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
4010 /* Don't worry about things in the fixed argument area;
4011 it has already been saved. */
4012 if (i < reg_parm_stack_space)
4013 i = reg_parm_stack_space;
4014 while (i < upper_bound && stack_usage_map[i] == 0)
4017 if (i < upper_bound)
4019 /* We need to make a save area. */
4021 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
4022 enum machine_mode save_mode
4023 = mode_for_size (size, MODE_INT, 1);
4025 = plus_constant (argblock,
4026 argvec[argnum].locate.offset.constant);
4028 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
4030 if (save_mode == BLKmode)
4032 argvec[argnum].save_area
4033 = assign_stack_temp (BLKmode,
4034 argvec[argnum].locate.size.constant,
4037 emit_block_move (validize_mem (argvec[argnum].save_area),
4039 GEN_INT (argvec[argnum].locate.size.constant),
4040 BLOCK_OP_CALL_PARM);
4044 argvec[argnum].save_area = gen_reg_rtx (save_mode);
4046 emit_move_insn (argvec[argnum].save_area, stack_area);
4051 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
4052 partial, reg, 0, argblock,
4053 GEN_INT (argvec[argnum].locate.offset.constant),
4054 reg_parm_stack_space,
4055 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
4057 /* Now mark the segment we just used. */
4058 if (ACCUMULATE_OUTGOING_ARGS)
4059 for (i = lower_bound; i < upper_bound; i++)
4060 stack_usage_map[i] = 1;
4066 /* If we pushed args in forward order, perform stack alignment
4067 after pushing the last arg. */
4068 if (argblock == 0 && !PUSH_ARGS_REVERSED)
4069 anti_adjust_stack (GEN_INT (args_size.constant
4070 - original_args_size.constant));
4072 if (PUSH_ARGS_REVERSED)
4077 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
4079 /* Now load any reg parms into their regs. */
4081 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
4082 are to be pushed. */
4083 for (count = 0; count < nargs; count++, argnum += inc)
4085 rtx val = argvec[argnum].value;
4086 rtx reg = argvec[argnum].reg;
4087 int partial = argvec[argnum].partial;
4089 /* Handle calls that pass values in multiple non-contiguous
4090 locations. The PA64 has examples of this for library calls. */
4091 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4092 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (GET_MODE (val)));
4093 else if (reg != 0 && partial == 0)
4094 emit_move_insn (reg, val);
4099 /* Any regs containing parms remain in use through the call. */
4100 for (count = 0; count < nargs; count++)
4102 rtx reg = argvec[count].reg;
4103 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4104 use_group_regs (&call_fusage, reg);
4106 use_reg (&call_fusage, reg);
4109 /* Pass the function the address in which to return a structure value. */
4110 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4112 emit_move_insn (struct_value,
4114 force_operand (XEXP (mem_value, 0),
4116 if (GET_CODE (struct_value) == REG)
4117 use_reg (&call_fusage, struct_value);
4120 /* Don't allow popping to be deferred, since then
4121 cse'ing of library calls could delete a call and leave the pop. */
4123 valreg = (mem_value == 0 && outmode != VOIDmode
4124 ? hard_libcall_value (outmode) : NULL_RTX);
4126 /* Stack must be properly aligned now. */
4127 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4130 before_call = get_last_insn ();
4132 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4133 will set inhibit_defer_pop to that value. */
4134 /* The return type is needed to decide how many bytes the function pops.
4135 Signedness plays no role in that, so for simplicity, we pretend it's
4136 always signed. We also assume that the list of arguments passed has
4137 no impact, so we pretend it is unknown. */
4140 get_identifier (XSTR (orgfun, 0)),
4141 build_function_type (tfom, NULL_TREE),
4142 original_args_size.constant, args_size.constant,
4144 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4146 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4148 /* For calls to `setjmp', etc., inform flow.c it should complain
4149 if nonvolatile values are live. For functions that cannot return,
4150 inform flow that control does not fall through. */
4152 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4154 /* The barrier note must be emitted
4155 immediately after the CALL_INSN. Some ports emit more than
4156 just a CALL_INSN above, so we must search for it here. */
4158 rtx last = get_last_insn ();
4159 while (GET_CODE (last) != CALL_INSN)
4161 last = PREV_INSN (last);
4162 /* There was no CALL_INSN? */
4163 if (last == before_call)
4167 emit_barrier_after (last);
4170 /* Now restore inhibit_defer_pop to its actual original value. */
4173 /* If call is cse'able, make appropriate pair of reg-notes around it.
4174 Test valreg so we don't crash; may safely ignore `const'
4175 if return type is void. Disable for PARALLEL return values, because
4176 we have no way to move such values into a pseudo register. */
4177 if (flags & ECF_LIBCALL_BLOCK)
4183 insns = get_insns ();
4193 if (GET_CODE (valreg) == PARALLEL)
4195 temp = gen_reg_rtx (outmode);
4196 emit_group_store (temp, valreg, NULL_TREE,
4197 GET_MODE_SIZE (outmode));
4201 temp = gen_reg_rtx (GET_MODE (valreg));
4203 /* Construct an "equal form" for the value which mentions all the
4204 arguments in order as well as the function name. */
4205 for (i = 0; i < nargs; i++)
4206 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4207 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4209 insns = get_insns ();
4212 if (flags & ECF_PURE)
4213 note = gen_rtx_EXPR_LIST (VOIDmode,
4214 gen_rtx_USE (VOIDmode,
4215 gen_rtx_MEM (BLKmode,
4216 gen_rtx_SCRATCH (VOIDmode))),
4219 emit_libcall_block (insns, temp, valreg, note);
4226 /* Copy the value to the right place. */
4227 if (outmode != VOIDmode && retval)
4233 if (value != mem_value)
4234 emit_move_insn (value, mem_value);
4236 else if (GET_CODE (valreg) == PARALLEL)
4239 value = gen_reg_rtx (outmode);
4240 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4242 else if (value != 0)
4243 emit_move_insn (value, valreg);
4248 if (ACCUMULATE_OUTGOING_ARGS)
4250 #ifdef REG_PARM_STACK_SPACE
4252 restore_fixed_argument_area (save_area, argblock,
4253 high_to_save, low_to_save);
4256 /* If we saved any argument areas, restore them. */
4257 for (count = 0; count < nargs; count++)
4258 if (argvec[count].save_area)
4260 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4261 rtx adr = plus_constant (argblock,
4262 argvec[count].locate.offset.constant);
4263 rtx stack_area = gen_rtx_MEM (save_mode,
4264 memory_address (save_mode, adr));
4266 if (save_mode == BLKmode)
4267 emit_block_move (stack_area,
4268 validize_mem (argvec[count].save_area),
4269 GEN_INT (argvec[count].locate.size.constant),
4270 BLOCK_OP_CALL_PARM);
4272 emit_move_insn (stack_area, argvec[count].save_area);
4275 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4276 stack_usage_map = initial_stack_usage_map;
4283 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4284 (emitting the queue unless NO_QUEUE is nonzero),
4285 for a value of mode OUTMODE,
4286 with NARGS different arguments, passed as alternating rtx values
4287 and machine_modes to convert them to.
4288 The rtx values should have been passed through protect_from_queue already.
4290 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4291 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4292 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4293 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4294 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4295 or other LCT_ value for other types of library calls. */
4298 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4299 enum machine_mode outmode, int nargs, ...)
4303 va_start (p, nargs);
4304 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4308 /* Like emit_library_call except that an extra argument, VALUE,
4309 comes second and says where to store the result.
4310 (If VALUE is zero, this function chooses a convenient way
4311 to return the value.
4313 This function returns an rtx for where the value is to be found.
4314 If VALUE is nonzero, VALUE is returned. */
4317 emit_library_call_value (rtx orgfun, rtx value,
4318 enum libcall_type fn_type,
4319 enum machine_mode outmode, int nargs, ...)
4324 va_start (p, nargs);
4325 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4332 /* Store a single argument for a function call
4333 into the register or memory area where it must be passed.
4334 *ARG describes the argument value and where to pass it.
4336 ARGBLOCK is the address of the stack-block for all the arguments,
4337 or 0 on a machine where arguments are pushed individually.
4339 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4340 so must be careful about how the stack is used.
4342 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4343 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4344 that we need not worry about saving and restoring the stack.
4346 FNDECL is the declaration of the function we are calling.
4348 Return nonzero if this arg should cause sibcall failure,
4352 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4353 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4355 tree pval = arg->tree_value;
4359 int i, lower_bound = 0, upper_bound = 0;
4360 int sibcall_failure = 0;
4362 if (TREE_CODE (pval) == ERROR_MARK)
4365 /* Push a new temporary level for any temporaries we make for
4369 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4371 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4372 save any previous data at that location. */
4373 if (argblock && ! variable_size && arg->stack)
4375 #ifdef ARGS_GROW_DOWNWARD
4376 /* stack_slot is negative, but we want to index stack_usage_map
4377 with positive values. */
4378 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4379 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4383 lower_bound = upper_bound - arg->locate.size.constant;
4385 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4386 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4390 upper_bound = lower_bound + arg->locate.size.constant;
4394 /* Don't worry about things in the fixed argument area;
4395 it has already been saved. */
4396 if (i < reg_parm_stack_space)
4397 i = reg_parm_stack_space;
4398 while (i < upper_bound && stack_usage_map[i] == 0)
4401 if (i < upper_bound)
4403 /* We need to make a save area. */
4404 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4405 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4406 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4407 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4409 if (save_mode == BLKmode)
4411 tree ot = TREE_TYPE (arg->tree_value);
4412 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4413 | TYPE_QUAL_CONST));
4415 arg->save_area = assign_temp (nt, 0, 1, 1);
4416 preserve_temp_slots (arg->save_area);
4417 emit_block_move (validize_mem (arg->save_area), stack_area,
4418 expr_size (arg->tree_value),
4419 BLOCK_OP_CALL_PARM);
4423 arg->save_area = gen_reg_rtx (save_mode);
4424 emit_move_insn (arg->save_area, stack_area);
4430 /* If this isn't going to be placed on both the stack and in registers,
4431 set up the register and number of words. */
4432 if (! arg->pass_on_stack)
4434 if (flags & ECF_SIBCALL)
4435 reg = arg->tail_call_reg;
4438 partial = arg->partial;
4441 if (reg != 0 && partial == 0)
4442 /* Being passed entirely in a register. We shouldn't be called in
4446 /* If this arg needs special alignment, don't load the registers
4448 if (arg->n_aligned_regs != 0)
4451 /* If this is being passed partially in a register, we can't evaluate
4452 it directly into its stack slot. Otherwise, we can. */
4453 if (arg->value == 0)
4455 /* stack_arg_under_construction is nonzero if a function argument is
4456 being evaluated directly into the outgoing argument list and
4457 expand_call must take special action to preserve the argument list
4458 if it is called recursively.
4460 For scalar function arguments stack_usage_map is sufficient to
4461 determine which stack slots must be saved and restored. Scalar
4462 arguments in general have pass_on_stack == 0.
4464 If this argument is initialized by a function which takes the
4465 address of the argument (a C++ constructor or a C function
4466 returning a BLKmode structure), then stack_usage_map is
4467 insufficient and expand_call must push the stack around the
4468 function call. Such arguments have pass_on_stack == 1.
4470 Note that it is always safe to set stack_arg_under_construction,
4471 but this generates suboptimal code if set when not needed. */
4473 if (arg->pass_on_stack)
4474 stack_arg_under_construction++;
4476 arg->value = expand_expr (pval,
4478 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4479 ? NULL_RTX : arg->stack,
4480 VOIDmode, EXPAND_STACK_PARM);
4482 /* If we are promoting object (or for any other reason) the mode
4483 doesn't agree, convert the mode. */
4485 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4486 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4487 arg->value, arg->unsignedp);
4489 if (arg->pass_on_stack)
4490 stack_arg_under_construction--;
4493 /* Don't allow anything left on stack from computation
4494 of argument to alloca. */
4495 if (flags & ECF_MAY_BE_ALLOCA)
4496 do_pending_stack_adjust ();
4498 if (arg->value == arg->stack)
4499 /* If the value is already in the stack slot, we are done. */
4501 else if (arg->mode != BLKmode)
4505 /* Argument is a scalar, not entirely passed in registers.
4506 (If part is passed in registers, arg->partial says how much
4507 and emit_push_insn will take care of putting it there.)
4509 Push it, and if its size is less than the
4510 amount of space allocated to it,
4511 also bump stack pointer by the additional space.
4512 Note that in C the default argument promotions
4513 will prevent such mismatches. */
4515 size = GET_MODE_SIZE (arg->mode);
4516 /* Compute how much space the push instruction will push.
4517 On many machines, pushing a byte will advance the stack
4518 pointer by a halfword. */
4519 #ifdef PUSH_ROUNDING
4520 size = PUSH_ROUNDING (size);
4524 /* Compute how much space the argument should get:
4525 round up to a multiple of the alignment for arguments. */
4526 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4527 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4528 / (PARM_BOUNDARY / BITS_PER_UNIT))
4529 * (PARM_BOUNDARY / BITS_PER_UNIT));
4531 /* This isn't already where we want it on the stack, so put it there.
4532 This can either be done with push or copy insns. */
4533 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4534 PARM_BOUNDARY, partial, reg, used - size, argblock,
4535 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4536 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4538 /* Unless this is a partially-in-register argument, the argument is now
4541 arg->value = arg->stack;
4545 /* BLKmode, at least partly to be pushed. */
4547 unsigned int parm_align;
4551 /* Pushing a nonscalar.
4552 If part is passed in registers, PARTIAL says how much
4553 and emit_push_insn will take care of putting it there. */
4555 /* Round its size up to a multiple
4556 of the allocation unit for arguments. */
4558 if (arg->locate.size.var != 0)
4561 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4565 /* PUSH_ROUNDING has no effect on us, because
4566 emit_push_insn for BLKmode is careful to avoid it. */
4567 excess = (arg->locate.size.constant
4568 - int_size_in_bytes (TREE_TYPE (pval))
4569 + partial * UNITS_PER_WORD);
4570 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4571 NULL_RTX, TYPE_MODE (sizetype), 0);
4574 /* Some types will require stricter alignment, which will be
4575 provided for elsewhere in argument layout. */
4576 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4578 /* When an argument is padded down, the block is aligned to
4579 PARM_BOUNDARY, but the actual argument isn't. */
4580 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4582 if (arg->locate.size.var)
4583 parm_align = BITS_PER_UNIT;
4586 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4587 parm_align = MIN (parm_align, excess_align);
4591 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4593 /* emit_push_insn might not work properly if arg->value and
4594 argblock + arg->locate.offset areas overlap. */
4598 if (XEXP (x, 0) == current_function_internal_arg_pointer
4599 || (GET_CODE (XEXP (x, 0)) == PLUS
4600 && XEXP (XEXP (x, 0), 0) ==
4601 current_function_internal_arg_pointer
4602 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4604 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4605 i = INTVAL (XEXP (XEXP (x, 0), 1));
4607 /* expand_call should ensure this */
4608 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4611 if (arg->locate.offset.constant > i)
4613 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4614 sibcall_failure = 1;
4616 else if (arg->locate.offset.constant < i)
4618 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4619 sibcall_failure = 1;
4624 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4625 parm_align, partial, reg, excess, argblock,
4626 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4627 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4629 /* Unless this is a partially-in-register argument, the argument is now
4632 ??? Unlike the case above, in which we want the actual
4633 address of the data, so that we can load it directly into a
4634 register, here we want the address of the stack slot, so that
4635 it's properly aligned for word-by-word copying or something
4636 like that. It's not clear that this is always correct. */
4638 arg->value = arg->stack_slot;
4641 /* Mark all slots this store used. */
4642 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4643 && argblock && ! variable_size && arg->stack)
4644 for (i = lower_bound; i < upper_bound; i++)
4645 stack_usage_map[i] = 1;
4647 /* Once we have pushed something, pops can't safely
4648 be deferred during the rest of the arguments. */
4651 /* ANSI doesn't require a sequence point here,
4652 but PCC has one, so this will avoid some problems. */
4655 /* Free any temporary slots made in processing this argument. Show
4656 that we might have taken the address of something and pushed that
4658 preserve_temp_slots (NULL_RTX);
4662 return sibcall_failure;
4665 /* Nonzero if we do not know how to pass TYPE solely in registers.
4666 We cannot do so in the following cases:
4668 - if the type has variable size
4669 - if the type is marked as addressable (it is required to be constructed
4671 - if the padding and mode of the type is such that a copy into a register
4672 would put it into the wrong part of the register.
4674 Which padding can't be supported depends on the byte endianness.
4676 A value in a register is implicitly padded at the most significant end.
4677 On a big-endian machine, that is the lower end in memory.
4678 So a value padded in memory at the upper end can't go in a register.
4679 For a little-endian machine, the reverse is true. */
4682 default_must_pass_in_stack (enum machine_mode mode, tree type)
4687 /* If the type has variable size... */
4688 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4691 /* If the type is marked as addressable (it is required
4692 to be constructed into the stack)... */
4693 if (TREE_ADDRESSABLE (type))
4696 /* If the padding and mode of the type is such that a copy into
4697 a register would put it into the wrong part of the register. */
4699 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4700 && (FUNCTION_ARG_PADDING (mode, type)
4701 == (BYTES_BIG_ENDIAN ? upward : downward)))