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, 2004 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
39 #include "langhooks.h"
44 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
45 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
47 /* Data structure and subroutines used within expand_call. */
51 /* Tree node for this argument. */
53 /* Mode for value; TYPE_MODE unless promoted. */
54 enum machine_mode mode;
55 /* Current RTL value for argument, or 0 if it isn't precomputed. */
57 /* Initially-compute RTL value for argument; only for const functions. */
59 /* Register to pass this argument in, 0 if passed on stack, or an
60 PARALLEL if the arg is to be copied into multiple non-contiguous
63 /* Register to pass this argument in when generating tail call sequence.
64 This is not the same register as for normal calls on machines with
67 /* If REG was promoted from the actual mode of the argument expression,
68 indicates whether the promotion is sign- or zero-extended. */
70 /* Number of registers to use. 0 means put the whole arg in registers.
71 Also 0 if not passed in registers. */
73 /* Nonzero if argument must be passed on stack.
74 Note that some arguments may be passed on the stack
75 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
76 pass_on_stack identifies arguments that *cannot* go in registers. */
78 /* Some fields packaged up for locate_and_pad_parm. */
79 struct locate_and_pad_arg_data locate;
80 /* Location on the stack at which parameter should be stored. The store
81 has already been done if STACK == VALUE. */
83 /* Location on the stack of the start of this argument slot. This can
84 differ from STACK if this arg pads downward. This location is known
85 to be aligned to FUNCTION_ARG_BOUNDARY. */
87 /* Place that this stack area has been saved, if needed. */
89 /* If an argument's alignment does not permit direct copying into registers,
90 copy in smaller-sized pieces into pseudos. These are stored in a
91 block pointed to by this field. The next field says how many
92 word-sized pseudos we made. */
97 /* A vector of one char per byte of stack space. A byte if nonzero if
98 the corresponding stack location has been used.
99 This vector is used to prevent a function call within an argument from
100 clobbering any stack already set up. */
101 static char *stack_usage_map;
103 /* Size of STACK_USAGE_MAP. */
104 static int highest_outgoing_arg_in_use;
106 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
107 stack location's tail call argument has been already stored into the stack.
108 This bitmap is used to prevent sibling call optimization if function tries
109 to use parent's incoming argument slots when they have been already
110 overwritten with tail call arguments. */
111 static sbitmap stored_args_map;
113 /* stack_arg_under_construction is nonzero when an argument may be
114 initialized with a constructor call (including a C function that
115 returns a BLKmode struct) and expand_call must take special action
116 to make sure the object being constructed does not overlap the
117 argument list for the constructor call. */
118 int stack_arg_under_construction;
120 static int calls_function (tree, int);
121 static int calls_function_1 (tree, int);
123 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
124 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
126 static void precompute_register_parameters (int, struct arg_data *, int *);
127 static int store_one_arg (struct arg_data *, rtx, int, int, int);
128 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
129 static int finalize_must_preallocate (int, int, struct arg_data *,
131 static void precompute_arguments (int, int, struct arg_data *);
132 static int compute_argument_block_size (int, struct args_size *, int);
133 static void initialize_argument_information (int, struct arg_data *,
134 struct args_size *, int, tree,
135 tree, CUMULATIVE_ARGS *, int,
136 rtx *, int *, int *, int *,
138 static void compute_argument_addresses (struct arg_data *, rtx, int);
139 static rtx rtx_for_function_call (tree, tree);
140 static void load_register_parameters (struct arg_data *, int, rtx *, int,
142 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
143 enum machine_mode, int, va_list);
144 static int special_function_p (tree, int);
145 static int check_sibcall_argument_overlap_1 (rtx);
146 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
148 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
150 static tree fix_unsafe_tree (tree);
151 static bool shift_returned_value (tree, rtx *);
153 #ifdef REG_PARM_STACK_SPACE
154 static rtx save_fixed_argument_area (int, rtx, int *, int *);
155 static void restore_fixed_argument_area (rtx, rtx, int, int);
158 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
161 If WHICH is 0, return 1 if EXP contains a call to any function.
162 Actually, we only need return 1 if evaluating EXP would require pushing
163 arguments on the stack, but that is too difficult to compute, so we just
164 assume any function call might require the stack. */
166 static tree calls_function_save_exprs;
169 calls_function (tree exp, int which)
173 calls_function_save_exprs = 0;
174 val = calls_function_1 (exp, which);
175 calls_function_save_exprs = 0;
179 /* Recursive function to do the work of above function. */
182 calls_function_1 (tree exp, int which)
185 enum tree_code code = TREE_CODE (exp);
186 int class = TREE_CODE_CLASS (code);
187 int length = first_rtl_op (code);
189 /* If this code is language-specific, we don't know what it will do. */
190 if ((int) code >= NUM_TREE_CODES)
198 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
200 && (TYPE_RETURNS_STACK_DEPRESSED
201 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
203 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
204 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
206 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
208 & ECF_MAY_BE_ALLOCA))
217 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
218 if (calls_function_1 (TREE_VALUE (tem), which))
225 if (SAVE_EXPR_RTL (exp) != 0)
227 if (value_member (exp, calls_function_save_exprs))
229 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
230 calls_function_save_exprs);
231 return (TREE_OPERAND (exp, 0) != 0
232 && calls_function_1 (TREE_OPERAND (exp, 0), which));
239 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
240 if (DECL_INITIAL (local) != 0
241 && calls_function_1 (DECL_INITIAL (local), which))
244 for (subblock = BLOCK_SUBBLOCKS (exp);
246 subblock = TREE_CHAIN (subblock))
247 if (calls_function_1 (subblock, which))
253 for (; exp != 0; exp = TREE_CHAIN (exp))
254 if (calls_function_1 (TREE_VALUE (exp), which))
262 /* Only expressions and blocks can contain calls.
263 Blocks were handled above. */
264 if (! IS_EXPR_CODE_CLASS (class))
267 for (i = 0; i < length; i++)
268 if (TREE_OPERAND (exp, i) != 0
269 && calls_function_1 (TREE_OPERAND (exp, i), which))
275 /* Force FUNEXP into a form suitable for the address of a CALL,
276 and return that as an rtx. Also load the static chain register
277 if FNDECL is a nested function.
279 CALL_FUSAGE points to a variable holding the prospective
280 CALL_INSN_FUNCTION_USAGE information. */
283 prepare_call_address (rtx funexp, rtx static_chain_value,
284 rtx *call_fusage, int reg_parm_seen, int sibcallp)
286 funexp = protect_from_queue (funexp, 0);
288 /* Make a valid memory address and copy constants through pseudo-regs,
289 but not for a constant address if -fno-function-cse. */
290 if (GET_CODE (funexp) != SYMBOL_REF)
291 /* If we are using registers for parameters, force the
292 function address into a register now. */
293 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
294 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
295 : memory_address (FUNCTION_MODE, funexp));
298 #ifndef NO_FUNCTION_CSE
299 if (optimize && ! flag_no_function_cse)
300 funexp = force_reg (Pmode, funexp);
304 if (static_chain_value != 0)
306 emit_move_insn (static_chain_rtx, static_chain_value);
308 if (GET_CODE (static_chain_rtx) == REG)
309 use_reg (call_fusage, static_chain_rtx);
315 /* Generate instructions to call function FUNEXP,
316 and optionally pop the results.
317 The CALL_INSN is the first insn generated.
319 FNDECL is the declaration node of the function. This is given to the
320 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
322 FUNTYPE is the data type of the function. This is given to the macro
323 RETURN_POPS_ARGS to determine whether this function pops its own args.
324 We used to allow an identifier for library functions, but that doesn't
325 work when the return type is an aggregate type and the calling convention
326 says that the pointer to this aggregate is to be popped by the callee.
328 STACK_SIZE is the number of bytes of arguments on the stack,
329 ROUNDED_STACK_SIZE is that number rounded up to
330 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
331 both to put into the call insn and to generate explicit popping
334 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
335 It is zero if this call doesn't want a structure value.
337 NEXT_ARG_REG is the rtx that results from executing
338 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
339 just after all the args have had their registers assigned.
340 This could be whatever you like, but normally it is the first
341 arg-register beyond those used for args in this call,
342 or 0 if all the arg-registers are used in this call.
343 It is passed on to `gen_call' so you can put this info in the call insn.
345 VALREG is a hard register in which a value is returned,
346 or 0 if the call does not return a value.
348 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
349 the args to this call were processed.
350 We restore `inhibit_defer_pop' to that value.
352 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
353 denote registers used by the called function. */
356 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
357 tree funtype ATTRIBUTE_UNUSED,
358 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
359 HOST_WIDE_INT rounded_stack_size,
360 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
361 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
362 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
363 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
365 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
367 int already_popped = 0;
368 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
369 #if defined (HAVE_call) && defined (HAVE_call_value)
370 rtx struct_value_size_rtx;
371 struct_value_size_rtx = GEN_INT (struct_value_size);
374 #ifdef CALL_POPS_ARGS
375 n_popped += CALL_POPS_ARGS (* args_so_far);
378 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
379 and we don't want to load it into a register as an optimization,
380 because prepare_call_address already did it if it should be done. */
381 if (GET_CODE (funexp) != SYMBOL_REF)
382 funexp = memory_address (FUNCTION_MODE, funexp);
384 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
385 if ((ecf_flags & ECF_SIBCALL)
386 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
387 && (n_popped > 0 || stack_size == 0))
389 rtx n_pop = GEN_INT (n_popped);
392 /* If this subroutine pops its own args, record that in the call insn
393 if possible, for the sake of frame pointer elimination. */
396 pat = GEN_SIBCALL_VALUE_POP (valreg,
397 gen_rtx_MEM (FUNCTION_MODE, funexp),
398 rounded_stack_size_rtx, next_arg_reg,
401 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
402 rounded_stack_size_rtx, next_arg_reg, n_pop);
404 emit_call_insn (pat);
410 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
411 /* If the target has "call" or "call_value" insns, then prefer them
412 if no arguments are actually popped. If the target does not have
413 "call" or "call_value" insns, then we must use the popping versions
414 even if the call has no arguments to pop. */
415 #if defined (HAVE_call) && defined (HAVE_call_value)
416 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
417 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
419 if (HAVE_call_pop && HAVE_call_value_pop)
422 rtx n_pop = GEN_INT (n_popped);
425 /* If this subroutine pops its own args, record that in the call insn
426 if possible, for the sake of frame pointer elimination. */
429 pat = GEN_CALL_VALUE_POP (valreg,
430 gen_rtx_MEM (FUNCTION_MODE, funexp),
431 rounded_stack_size_rtx, next_arg_reg, n_pop);
433 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
434 rounded_stack_size_rtx, next_arg_reg, n_pop);
436 emit_call_insn (pat);
442 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
443 if ((ecf_flags & ECF_SIBCALL)
444 && HAVE_sibcall && HAVE_sibcall_value)
447 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
448 gen_rtx_MEM (FUNCTION_MODE, funexp),
449 rounded_stack_size_rtx,
450 next_arg_reg, NULL_RTX));
452 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
453 rounded_stack_size_rtx, next_arg_reg,
454 struct_value_size_rtx));
459 #if defined (HAVE_call) && defined (HAVE_call_value)
460 if (HAVE_call && HAVE_call_value)
463 emit_call_insn (GEN_CALL_VALUE (valreg,
464 gen_rtx_MEM (FUNCTION_MODE, funexp),
465 rounded_stack_size_rtx, next_arg_reg,
468 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
469 rounded_stack_size_rtx, next_arg_reg,
470 struct_value_size_rtx));
476 /* Find the call we just emitted. */
477 call_insn = last_call_insn ();
479 /* Mark memory as used for "pure" function call. */
480 if (ecf_flags & ECF_PURE)
484 gen_rtx_USE (VOIDmode,
485 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
488 /* Put the register usage information there. */
489 add_function_usage_to (call_insn, call_fusage);
491 /* If this is a const call, then set the insn's unchanging bit. */
492 if (ecf_flags & (ECF_CONST | ECF_PURE))
493 CONST_OR_PURE_CALL_P (call_insn) = 1;
495 /* If this call can't throw, attach a REG_EH_REGION reg note to that
497 if (ecf_flags & ECF_NOTHROW)
498 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
499 REG_NOTES (call_insn));
502 int rn = lookup_stmt_eh_region (fntree);
504 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
505 throw, which we already took care of. */
507 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn),
508 REG_NOTES (call_insn));
509 note_current_region_may_contain_throw ();
512 if (ecf_flags & ECF_NORETURN)
513 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
514 REG_NOTES (call_insn));
515 if (ecf_flags & ECF_ALWAYS_RETURN)
516 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
517 REG_NOTES (call_insn));
519 if (ecf_flags & ECF_RETURNS_TWICE)
521 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
522 REG_NOTES (call_insn));
523 current_function_calls_setjmp = 1;
526 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
528 /* Restore this now, so that we do defer pops for this call's args
529 if the context of the call as a whole permits. */
530 inhibit_defer_pop = old_inhibit_defer_pop;
535 CALL_INSN_FUNCTION_USAGE (call_insn)
536 = gen_rtx_EXPR_LIST (VOIDmode,
537 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
538 CALL_INSN_FUNCTION_USAGE (call_insn));
539 rounded_stack_size -= n_popped;
540 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
541 stack_pointer_delta -= n_popped;
544 if (!ACCUMULATE_OUTGOING_ARGS)
546 /* If returning from the subroutine does not automatically pop the args,
547 we need an instruction to pop them sooner or later.
548 Perhaps do it now; perhaps just record how much space to pop later.
550 If returning from the subroutine does pop the args, indicate that the
551 stack pointer will be changed. */
553 if (rounded_stack_size != 0)
555 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN | ECF_LONGJMP))
556 /* Just pretend we did the pop. */
557 stack_pointer_delta -= rounded_stack_size;
558 else if (flag_defer_pop && inhibit_defer_pop == 0
559 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
560 pending_stack_adjust += rounded_stack_size;
562 adjust_stack (rounded_stack_size_rtx);
565 /* When we accumulate outgoing args, we must avoid any stack manipulations.
566 Restore the stack pointer to its original value now. Usually
567 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
568 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
569 popping variants of functions exist as well.
571 ??? We may optimize similar to defer_pop above, but it is
572 probably not worthwhile.
574 ??? It will be worthwhile to enable combine_stack_adjustments even for
577 anti_adjust_stack (GEN_INT (n_popped));
580 /* Determine if the function identified by NAME and FNDECL is one with
581 special properties we wish to know about.
583 For example, if the function might return more than one time (setjmp), then
584 set RETURNS_TWICE to a nonzero value.
586 Similarly set LONGJMP for if the function is in the longjmp family.
588 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
589 space from the stack such as alloca. */
592 special_function_p (tree fndecl, int flags)
594 if (fndecl && DECL_NAME (fndecl)
595 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
596 /* Exclude functions not at the file scope, or not `extern',
597 since they are not the magic functions we would otherwise
599 FIXME: this should be handled with attributes, not with this
600 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
601 because you can declare fork() inside a function if you
603 && (DECL_CONTEXT (fndecl) == NULL_TREE
604 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
605 && TREE_PUBLIC (fndecl))
607 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
608 const char *tname = name;
610 /* We assume that alloca will always be called by name. It
611 makes no sense to pass it as a pointer-to-function to
612 anything that does not understand its behavior. */
613 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
615 && ! strcmp (name, "alloca"))
616 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
618 && ! strcmp (name, "__builtin_alloca"))))
619 flags |= ECF_MAY_BE_ALLOCA;
621 /* Disregard prefix _, __ or __x. */
624 if (name[1] == '_' && name[2] == 'x')
626 else if (name[1] == '_')
635 && (! strcmp (tname, "setjmp")
636 || ! strcmp (tname, "setjmp_syscall")))
638 && ! strcmp (tname, "sigsetjmp"))
640 && ! strcmp (tname, "savectx")))
641 flags |= ECF_RETURNS_TWICE;
644 && ! strcmp (tname, "siglongjmp"))
645 flags |= ECF_LONGJMP;
647 else if ((tname[0] == 'q' && tname[1] == 's'
648 && ! strcmp (tname, "qsetjmp"))
649 || (tname[0] == 'v' && tname[1] == 'f'
650 && ! strcmp (tname, "vfork")))
651 flags |= ECF_RETURNS_TWICE;
653 else if (tname[0] == 'l' && tname[1] == 'o'
654 && ! strcmp (tname, "longjmp"))
655 flags |= ECF_LONGJMP;
661 /* Return nonzero when tree represent call to longjmp. */
664 setjmp_call_p (tree fndecl)
666 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
669 /* Return true when exp contains alloca call. */
671 alloca_call_p (tree exp)
673 if (TREE_CODE (exp) == CALL_EXPR
674 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
675 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
677 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
678 0) & ECF_MAY_BE_ALLOCA))
683 /* Detect flags (function attributes) from the function decl or type node. */
686 flags_from_decl_or_type (tree exp)
693 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
694 type = TREE_TYPE (exp);
698 if (i->pure_function)
699 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
700 if (i->const_function)
701 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
704 /* The function exp may have the `malloc' attribute. */
705 if (DECL_IS_MALLOC (exp))
708 /* The function exp may have the `pure' attribute. */
709 if (DECL_IS_PURE (exp))
710 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
712 if (TREE_NOTHROW (exp))
713 flags |= ECF_NOTHROW;
715 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
716 flags |= ECF_LIBCALL_BLOCK | ECF_CONST;
718 flags = special_function_p (exp, flags);
720 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
723 if (TREE_THIS_VOLATILE (exp))
724 flags |= ECF_NORETURN;
726 /* Mark if the function returns with the stack pointer depressed. We
727 cannot consider it pure or constant in that case. */
728 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
730 flags |= ECF_SP_DEPRESSED;
731 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
737 /* Detect flags from a CALL_EXPR. */
740 call_expr_flags (tree t)
743 tree decl = get_callee_fndecl (t);
746 flags = flags_from_decl_or_type (decl);
749 t = TREE_TYPE (TREE_OPERAND (t, 0));
750 if (t && TREE_CODE (t) == POINTER_TYPE)
751 flags = flags_from_decl_or_type (TREE_TYPE (t));
759 /* Precompute all register parameters as described by ARGS, storing values
760 into fields within the ARGS array.
762 NUM_ACTUALS indicates the total number elements in the ARGS array.
764 Set REG_PARM_SEEN if we encounter a register parameter. */
767 precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
773 for (i = 0; i < num_actuals; i++)
774 if (args[i].reg != 0 && ! args[i].pass_on_stack)
778 if (args[i].value == 0)
781 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
783 preserve_temp_slots (args[i].value);
786 /* ANSI doesn't require a sequence point here,
787 but PCC has one, so this will avoid some problems. */
791 /* If the value is a non-legitimate constant, force it into a
792 pseudo now. TLS symbols sometimes need a call to resolve. */
793 if (CONSTANT_P (args[i].value)
794 && !LEGITIMATE_CONSTANT_P (args[i].value))
795 args[i].value = force_reg (args[i].mode, args[i].value);
797 /* If we are to promote the function arg to a wider mode,
800 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
802 = convert_modes (args[i].mode,
803 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
804 args[i].value, args[i].unsignedp);
806 /* If the value is expensive, and we are inside an appropriately
807 short loop, put the value into a pseudo and then put the pseudo
810 For small register classes, also do this if this call uses
811 register parameters. This is to avoid reload conflicts while
812 loading the parameters registers. */
814 if ((! (GET_CODE (args[i].value) == REG
815 || (GET_CODE (args[i].value) == SUBREG
816 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
817 && args[i].mode != BLKmode
818 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
819 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
820 || preserve_subexpressions_p ()))
821 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
825 #ifdef REG_PARM_STACK_SPACE
827 /* The argument list is the property of the called routine and it
828 may clobber it. If the fixed area has been used for previous
829 parameters, we must save and restore it. */
832 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
837 /* Compute the boundary of the area that needs to be saved, if any. */
838 high = reg_parm_stack_space;
839 #ifdef ARGS_GROW_DOWNWARD
842 if (high > highest_outgoing_arg_in_use)
843 high = highest_outgoing_arg_in_use;
845 for (low = 0; low < high; low++)
846 if (stack_usage_map[low] != 0)
849 enum machine_mode save_mode;
854 while (stack_usage_map[--high] == 0)
858 *high_to_save = high;
860 num_to_save = high - low + 1;
861 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
863 /* If we don't have the required alignment, must do this
865 if ((low & (MIN (GET_MODE_SIZE (save_mode),
866 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
869 #ifdef ARGS_GROW_DOWNWARD
874 stack_area = gen_rtx_MEM (save_mode,
875 memory_address (save_mode,
876 plus_constant (argblock,
879 set_mem_align (stack_area, PARM_BOUNDARY);
880 if (save_mode == BLKmode)
882 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
883 emit_block_move (validize_mem (save_area), stack_area,
884 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
888 save_area = gen_reg_rtx (save_mode);
889 emit_move_insn (save_area, stack_area);
899 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
901 enum machine_mode save_mode = GET_MODE (save_area);
905 #ifdef ARGS_GROW_DOWNWARD
906 delta = -high_to_save;
910 stack_area = gen_rtx_MEM (save_mode,
911 memory_address (save_mode,
912 plus_constant (argblock, delta)));
913 set_mem_align (stack_area, PARM_BOUNDARY);
915 if (save_mode != BLKmode)
916 emit_move_insn (stack_area, save_area);
918 emit_block_move (stack_area, validize_mem (save_area),
919 GEN_INT (high_to_save - low_to_save + 1),
922 #endif /* REG_PARM_STACK_SPACE */
924 /* If any elements in ARGS refer to parameters that are to be passed in
925 registers, but not in memory, and whose alignment does not permit a
926 direct copy into registers. Copy the values into a group of pseudos
927 which we will later copy into the appropriate hard registers.
929 Pseudos for each unaligned argument will be stored into the array
930 args[argnum].aligned_regs. The caller is responsible for deallocating
931 the aligned_regs array if it is nonzero. */
934 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
938 for (i = 0; i < num_actuals; i++)
939 if (args[i].reg != 0 && ! args[i].pass_on_stack
940 && args[i].mode == BLKmode
941 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
942 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
944 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
945 int nregs = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
946 int endian_correction = 0;
948 args[i].n_aligned_regs = args[i].partial ? args[i].partial : nregs;
949 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
951 /* Structures smaller than a word are normally aligned to the
952 least significant byte. On a BYTES_BIG_ENDIAN machine,
953 this means we must skip the empty high order bytes when
954 calculating the bit offset. */
955 if (bytes < UNITS_PER_WORD
956 #ifdef BLOCK_REG_PADDING
957 && (BLOCK_REG_PADDING (args[i].mode,
958 TREE_TYPE (args[i].tree_value), 1)
964 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
966 for (j = 0; j < args[i].n_aligned_regs; j++)
968 rtx reg = gen_reg_rtx (word_mode);
969 rtx word = operand_subword_force (args[i].value, j, BLKmode);
970 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
972 args[i].aligned_regs[j] = reg;
973 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
974 word_mode, word_mode, BITS_PER_WORD);
976 /* There is no need to restrict this code to loading items
977 in TYPE_ALIGN sized hunks. The bitfield instructions can
978 load up entire word sized registers efficiently.
980 ??? This may not be needed anymore.
981 We use to emit a clobber here but that doesn't let later
982 passes optimize the instructions we emit. By storing 0 into
983 the register later passes know the first AND to zero out the
984 bitfield being set in the register is unnecessary. The store
985 of 0 will be deleted as will at least the first AND. */
987 emit_move_insn (reg, const0_rtx);
989 bytes -= bitsize / BITS_PER_UNIT;
990 store_bit_field (reg, bitsize, endian_correction, word_mode,
991 word, BITS_PER_WORD);
996 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
999 NUM_ACTUALS is the total number of parameters.
1001 N_NAMED_ARGS is the total number of named arguments.
1003 FNDECL is the tree code for the target of this call (if known)
1005 ARGS_SO_FAR holds state needed by the target to know where to place
1008 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1009 for arguments which are passed in registers.
1011 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1012 and may be modified by this routine.
1014 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1015 flags which may may be modified by this routine.
1017 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
1018 that requires allocation of stack space.
1020 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
1021 the thunked-to function. */
1024 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1025 struct arg_data *args,
1026 struct args_size *args_size,
1027 int n_named_args ATTRIBUTE_UNUSED,
1028 tree actparms, tree fndecl,
1029 CUMULATIVE_ARGS *args_so_far,
1030 int reg_parm_stack_space,
1031 rtx *old_stack_level, int *old_pending_adj,
1032 int *must_preallocate, int *ecf_flags,
1033 bool *may_tailcall, bool call_from_thunk_p)
1035 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1038 /* Count arg position in order args appear. */
1044 args_size->constant = 0;
1047 /* In this loop, we consider args in the order they are written.
1048 We fill up ARGS from the front or from the back if necessary
1049 so that in any case the first arg to be pushed ends up at the front. */
1051 if (PUSH_ARGS_REVERSED)
1053 i = num_actuals - 1, inc = -1;
1054 /* In this case, must reverse order of args
1055 so that we compute and push the last arg first. */
1062 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1063 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1065 tree type = TREE_TYPE (TREE_VALUE (p));
1067 enum machine_mode mode;
1069 args[i].tree_value = TREE_VALUE (p);
1071 /* Replace erroneous argument with constant zero. */
1072 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1073 args[i].tree_value = integer_zero_node, type = integer_type_node;
1075 /* If TYPE is a transparent union, pass things the way we would
1076 pass the first field of the union. We have already verified that
1077 the modes are the same. */
1078 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1079 type = TREE_TYPE (TYPE_FIELDS (type));
1081 /* Decide where to pass this arg.
1083 args[i].reg is nonzero if all or part is passed in registers.
1085 args[i].partial is nonzero if part but not all is passed in registers,
1086 and the exact value says how many words are passed in registers.
1088 args[i].pass_on_stack is nonzero if the argument must at least be
1089 computed on the stack. It may then be loaded back into registers
1090 if args[i].reg is nonzero.
1092 These decisions are driven by the FUNCTION_... macros and must agree
1093 with those made by function.c. */
1095 /* See if this argument should be passed by invisible reference. */
1096 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1097 || TREE_ADDRESSABLE (type)
1098 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1099 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1100 type, argpos < n_named_args)
1104 /* If we're compiling a thunk, pass through invisible
1105 references instead of making a copy. */
1106 if (call_from_thunk_p
1107 #ifdef FUNCTION_ARG_CALLEE_COPIES
1108 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1109 type, argpos < n_named_args)
1110 /* If it's in a register, we must make a copy of it too. */
1111 /* ??? Is this a sufficient test? Is there a better one? */
1112 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1113 && REG_P (DECL_RTL (args[i].tree_value)))
1114 && ! TREE_ADDRESSABLE (type))
1118 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1119 new object from the argument. If we are passing by
1120 invisible reference, the callee will do that for us, so we
1121 can strip off the TARGET_EXPR. This is not always safe,
1122 but it is safe in the only case where this is a useful
1123 optimization; namely, when the argument is a plain object.
1124 In that case, the frontend is just asking the backend to
1125 make a bitwise copy of the argument. */
1127 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1128 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1129 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1130 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1132 /* We can't use sibcalls if a callee-copied argument is stored
1133 in the current function's frame. */
1134 if (!call_from_thunk_p
1135 && (!DECL_P (args[i].tree_value)
1136 || !TREE_STATIC (args[i].tree_value)))
1137 *may_tailcall = false;
1139 args[i].tree_value = build1 (ADDR_EXPR,
1140 build_pointer_type (type),
1141 args[i].tree_value);
1142 type = build_pointer_type (type);
1144 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1146 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1147 We implement this by passing the address of the temporary
1148 rather than expanding it into another allocated slot. */
1149 args[i].tree_value = build1 (ADDR_EXPR,
1150 build_pointer_type (type),
1151 args[i].tree_value);
1152 type = build_pointer_type (type);
1153 *may_tailcall = false;
1157 /* We make a copy of the object and pass the address to the
1158 function being called. */
1161 if (!COMPLETE_TYPE_P (type)
1162 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1163 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1164 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1165 STACK_CHECK_MAX_VAR_SIZE))))
1167 /* This is a variable-sized object. Make space on the stack
1169 rtx size_rtx = expr_size (TREE_VALUE (p));
1171 if (*old_stack_level == 0)
1173 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1174 *old_pending_adj = pending_stack_adjust;
1175 pending_stack_adjust = 0;
1178 copy = gen_rtx_MEM (BLKmode,
1179 allocate_dynamic_stack_space
1180 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1181 set_mem_attributes (copy, type, 1);
1184 copy = assign_temp (type, 0, 1, 0);
1186 store_expr (args[i].tree_value, copy, 0);
1187 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1189 args[i].tree_value = build1 (ADDR_EXPR,
1190 build_pointer_type (type),
1191 make_tree (type, copy));
1192 type = build_pointer_type (type);
1193 *may_tailcall = false;
1197 mode = TYPE_MODE (type);
1198 unsignedp = TYPE_UNSIGNED (type);
1200 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1201 mode = promote_mode (type, mode, &unsignedp, 1);
1203 args[i].unsignedp = unsignedp;
1204 args[i].mode = mode;
1206 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1207 argpos < n_named_args);
1208 #ifdef FUNCTION_INCOMING_ARG
1209 /* If this is a sibling call and the machine has register windows, the
1210 register window has to be unwinded before calling the routine, so
1211 arguments have to go into the incoming registers. */
1212 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1213 argpos < n_named_args);
1215 args[i].tail_call_reg = args[i].reg;
1218 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1221 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1222 argpos < n_named_args);
1225 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1227 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1228 it means that we are to pass this arg in the register(s) designated
1229 by the PARALLEL, but also to pass it in the stack. */
1230 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1231 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1232 args[i].pass_on_stack = 1;
1234 /* If this is an addressable type, we must preallocate the stack
1235 since we must evaluate the object into its final location.
1237 If this is to be passed in both registers and the stack, it is simpler
1239 if (TREE_ADDRESSABLE (type)
1240 || (args[i].pass_on_stack && args[i].reg != 0))
1241 *must_preallocate = 1;
1243 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1244 we cannot consider this function call constant. */
1245 if (TREE_ADDRESSABLE (type))
1246 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1248 /* Compute the stack-size of this argument. */
1249 if (args[i].reg == 0 || args[i].partial != 0
1250 || reg_parm_stack_space > 0
1251 || args[i].pass_on_stack)
1252 locate_and_pad_parm (mode, type,
1253 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1258 args[i].pass_on_stack ? 0 : args[i].partial,
1259 fndecl, args_size, &args[i].locate);
1260 #ifdef BLOCK_REG_PADDING
1262 /* The argument is passed entirely in registers. See at which
1263 end it should be padded. */
1264 args[i].locate.where_pad =
1265 BLOCK_REG_PADDING (mode, type,
1266 int_size_in_bytes (type) <= UNITS_PER_WORD);
1269 /* Update ARGS_SIZE, the total stack space for args so far. */
1271 args_size->constant += args[i].locate.size.constant;
1272 if (args[i].locate.size.var)
1273 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1275 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1276 have been used, etc. */
1278 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1279 argpos < n_named_args);
1283 /* Update ARGS_SIZE to contain the total size for the argument block.
1284 Return the original constant component of the argument block's size.
1286 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1287 for arguments passed in registers. */
1290 compute_argument_block_size (int reg_parm_stack_space,
1291 struct args_size *args_size,
1292 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1294 int unadjusted_args_size = args_size->constant;
1296 /* For accumulate outgoing args mode we don't need to align, since the frame
1297 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1298 backends from generating misaligned frame sizes. */
1299 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1300 preferred_stack_boundary = STACK_BOUNDARY;
1302 /* Compute the actual size of the argument block required. The variable
1303 and constant sizes must be combined, the size may have to be rounded,
1304 and there may be a minimum required size. */
1308 args_size->var = ARGS_SIZE_TREE (*args_size);
1309 args_size->constant = 0;
1311 preferred_stack_boundary /= BITS_PER_UNIT;
1312 if (preferred_stack_boundary > 1)
1314 /* We don't handle this case yet. To handle it correctly we have
1315 to add the delta, round and subtract the delta.
1316 Currently no machine description requires this support. */
1317 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1319 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1322 if (reg_parm_stack_space > 0)
1325 = size_binop (MAX_EXPR, args_size->var,
1326 ssize_int (reg_parm_stack_space));
1328 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1329 /* The area corresponding to register parameters is not to count in
1330 the size of the block we need. So make the adjustment. */
1332 = size_binop (MINUS_EXPR, args_size->var,
1333 ssize_int (reg_parm_stack_space));
1339 preferred_stack_boundary /= BITS_PER_UNIT;
1340 if (preferred_stack_boundary < 1)
1341 preferred_stack_boundary = 1;
1342 args_size->constant = (((args_size->constant
1343 + stack_pointer_delta
1344 + preferred_stack_boundary - 1)
1345 / preferred_stack_boundary
1346 * preferred_stack_boundary)
1347 - stack_pointer_delta);
1349 args_size->constant = MAX (args_size->constant,
1350 reg_parm_stack_space);
1352 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1353 args_size->constant -= reg_parm_stack_space;
1356 return unadjusted_args_size;
1359 /* Precompute parameters as needed for a function call.
1361 FLAGS is mask of ECF_* constants.
1363 NUM_ACTUALS is the number of arguments.
1365 ARGS is an array containing information for each argument; this
1366 routine fills in the INITIAL_VALUE and VALUE fields for each
1367 precomputed argument. */
1370 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1374 /* If this is a libcall, then precompute all arguments so that we do not
1375 get extraneous instructions emitted as part of the libcall sequence.
1377 If this target defines ACCUMULATE_OUTGOING_ARGS to true, then we must
1378 precompute all arguments that contain function calls. Otherwise,
1379 computing arguments for a subcall may clobber arguments for this call.
1381 If this target defines ACCUMULATE_OUTGOING_ARGS to false, then we only
1382 need to precompute arguments that change the stack pointer, such as calls
1383 to alloca, and calls that do not pop all of their arguments. */
1385 for (i = 0; i < num_actuals; i++)
1386 if ((flags & ECF_LIBCALL_BLOCK)
1387 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1389 enum machine_mode mode;
1391 /* If this is an addressable type, we cannot pre-evaluate it. */
1392 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1396 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1398 /* ANSI doesn't require a sequence point here,
1399 but PCC has one, so this will avoid some problems. */
1402 args[i].initial_value = args[i].value
1403 = protect_from_queue (args[i].value, 0);
1405 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1406 if (mode != args[i].mode)
1409 = convert_modes (args[i].mode, mode,
1410 args[i].value, args[i].unsignedp);
1411 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1412 /* CSE will replace this only if it contains args[i].value
1413 pseudo, so convert it down to the declared mode using
1415 if (GET_CODE (args[i].value) == REG
1416 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1418 args[i].initial_value
1419 = gen_lowpart_SUBREG (mode, args[i].value);
1420 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1421 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1429 /* Given the current state of MUST_PREALLOCATE and information about
1430 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1431 compute and return the final value for MUST_PREALLOCATE. */
1434 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1436 /* See if we have or want to preallocate stack space.
1438 If we would have to push a partially-in-regs parm
1439 before other stack parms, preallocate stack space instead.
1441 If the size of some parm is not a multiple of the required stack
1442 alignment, we must preallocate.
1444 If the total size of arguments that would otherwise create a copy in
1445 a temporary (such as a CALL) is more than half the total argument list
1446 size, preallocation is faster.
1448 Another reason to preallocate is if we have a machine (like the m88k)
1449 where stack alignment is required to be maintained between every
1450 pair of insns, not just when the call is made. However, we assume here
1451 that such machines either do not have push insns (and hence preallocation
1452 would occur anyway) or the problem is taken care of with
1455 if (! must_preallocate)
1457 int partial_seen = 0;
1458 int copy_to_evaluate_size = 0;
1461 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1463 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1465 else if (partial_seen && args[i].reg == 0)
1466 must_preallocate = 1;
1468 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1469 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1470 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1471 || TREE_CODE (args[i].tree_value) == COND_EXPR
1472 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1473 copy_to_evaluate_size
1474 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1477 if (copy_to_evaluate_size * 2 >= args_size->constant
1478 && args_size->constant > 0)
1479 must_preallocate = 1;
1481 return must_preallocate;
1484 /* If we preallocated stack space, compute the address of each argument
1485 and store it into the ARGS array.
1487 We need not ensure it is a valid memory address here; it will be
1488 validized when it is used.
1490 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1493 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1497 rtx arg_reg = argblock;
1498 int i, arg_offset = 0;
1500 if (GET_CODE (argblock) == PLUS)
1501 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1503 for (i = 0; i < num_actuals; i++)
1505 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1506 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1509 /* Skip this parm if it will not be passed on the stack. */
1510 if (! args[i].pass_on_stack && args[i].reg != 0)
1513 if (GET_CODE (offset) == CONST_INT)
1514 addr = plus_constant (arg_reg, INTVAL (offset));
1516 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1518 addr = plus_constant (addr, arg_offset);
1519 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1520 set_mem_align (args[i].stack, PARM_BOUNDARY);
1521 set_mem_attributes (args[i].stack,
1522 TREE_TYPE (args[i].tree_value), 1);
1524 if (GET_CODE (slot_offset) == CONST_INT)
1525 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1527 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1529 addr = plus_constant (addr, arg_offset);
1530 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1531 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1532 set_mem_attributes (args[i].stack_slot,
1533 TREE_TYPE (args[i].tree_value), 1);
1535 /* Function incoming arguments may overlap with sibling call
1536 outgoing arguments and we cannot allow reordering of reads
1537 from function arguments with stores to outgoing arguments
1538 of sibling calls. */
1539 set_mem_alias_set (args[i].stack, 0);
1540 set_mem_alias_set (args[i].stack_slot, 0);
1545 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1546 in a call instruction.
1548 FNDECL is the tree node for the target function. For an indirect call
1549 FNDECL will be NULL_TREE.
1551 ADDR is the operand 0 of CALL_EXPR for this call. */
1554 rtx_for_function_call (tree fndecl, tree addr)
1558 /* Get the function to call, in the form of RTL. */
1561 /* If this is the first use of the function, see if we need to
1562 make an external definition for it. */
1563 if (! TREE_USED (fndecl))
1565 assemble_external (fndecl);
1566 TREE_USED (fndecl) = 1;
1569 /* Get a SYMBOL_REF rtx for the function address. */
1570 funexp = XEXP (DECL_RTL (fndecl), 0);
1573 /* Generate an rtx (probably a pseudo-register) for the address. */
1576 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1577 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1583 /* Do the register loads required for any wholly-register parms or any
1584 parms which are passed both on the stack and in a register. Their
1585 expressions were already evaluated.
1587 Mark all register-parms as living through the call, putting these USE
1588 insns in the CALL_INSN_FUNCTION_USAGE field.
1590 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1591 checking, setting *SIBCALL_FAILURE if appropriate. */
1594 load_register_parameters (struct arg_data *args, int num_actuals,
1595 rtx *call_fusage, int flags, int is_sibcall,
1596 int *sibcall_failure)
1600 for (i = 0; i < num_actuals; i++)
1602 rtx reg = ((flags & ECF_SIBCALL)
1603 ? args[i].tail_call_reg : args[i].reg);
1606 int partial = args[i].partial;
1609 rtx before_arg = get_last_insn ();
1610 /* Set to non-negative if must move a word at a time, even if just
1611 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1612 we just use a normal move insn. This value can be zero if the
1613 argument is a zero size structure with no fields. */
1617 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1619 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1620 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1623 size = GET_MODE_SIZE (args[i].mode);
1625 /* Handle calls that pass values in multiple non-contiguous
1626 locations. The Irix 6 ABI has examples of this. */
1628 if (GET_CODE (reg) == PARALLEL)
1630 tree type = TREE_TYPE (args[i].tree_value);
1631 emit_group_load (reg, args[i].value, type,
1632 int_size_in_bytes (type));
1635 /* If simple case, just do move. If normal partial, store_one_arg
1636 has already loaded the register for us. In all other cases,
1637 load the register(s) from memory. */
1639 else if (nregs == -1)
1641 emit_move_insn (reg, args[i].value);
1642 #ifdef BLOCK_REG_PADDING
1643 /* Handle case where we have a value that needs shifting
1644 up to the msb. eg. a QImode value and we're padding
1645 upward on a BYTES_BIG_ENDIAN machine. */
1646 if (size < UNITS_PER_WORD
1647 && (args[i].locate.where_pad
1648 == (BYTES_BIG_ENDIAN ? upward : downward)))
1651 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1653 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1654 report the whole reg as used. Strictly speaking, the
1655 call only uses SIZE bytes at the msb end, but it doesn't
1656 seem worth generating rtl to say that. */
1657 reg = gen_rtx_REG (word_mode, REGNO (reg));
1658 x = expand_binop (word_mode, ashl_optab, reg,
1659 GEN_INT (shift), reg, 1, OPTAB_WIDEN);
1661 emit_move_insn (reg, x);
1666 /* If we have pre-computed the values to put in the registers in
1667 the case of non-aligned structures, copy them in now. */
1669 else if (args[i].n_aligned_regs != 0)
1670 for (j = 0; j < args[i].n_aligned_regs; j++)
1671 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1672 args[i].aligned_regs[j]);
1674 else if (partial == 0 || args[i].pass_on_stack)
1676 rtx mem = validize_mem (args[i].value);
1678 /* Handle a BLKmode that needs shifting. */
1679 if (nregs == 1 && size < UNITS_PER_WORD
1680 #ifdef BLOCK_REG_PADDING
1681 && args[i].locate.where_pad == downward
1687 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1688 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1689 rtx x = gen_reg_rtx (word_mode);
1690 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1691 optab dir = BYTES_BIG_ENDIAN ? lshr_optab : ashl_optab;
1693 emit_move_insn (x, tem);
1694 x = expand_binop (word_mode, dir, x, GEN_INT (shift),
1695 ri, 1, OPTAB_WIDEN);
1697 emit_move_insn (ri, x);
1700 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1703 /* When a parameter is a block, and perhaps in other cases, it is
1704 possible that it did a load from an argument slot that was
1705 already clobbered. */
1707 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1708 *sibcall_failure = 1;
1710 /* Handle calls that pass values in multiple non-contiguous
1711 locations. The Irix 6 ABI has examples of this. */
1712 if (GET_CODE (reg) == PARALLEL)
1713 use_group_regs (call_fusage, reg);
1714 else if (nregs == -1)
1715 use_reg (call_fusage, reg);
1717 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1722 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1723 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1724 bytes, then we would need to push some additional bytes to pad the
1725 arguments. So, we compute an adjust to the stack pointer for an
1726 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1727 bytes. Then, when the arguments are pushed the stack will be perfectly
1728 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1729 be popped after the call. Returns the adjustment. */
1732 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1733 struct args_size *args_size,
1734 int preferred_unit_stack_boundary)
1736 /* The number of bytes to pop so that the stack will be
1737 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1738 HOST_WIDE_INT adjustment;
1739 /* The alignment of the stack after the arguments are pushed, if we
1740 just pushed the arguments without adjust the stack here. */
1741 HOST_WIDE_INT unadjusted_alignment;
1743 unadjusted_alignment
1744 = ((stack_pointer_delta + unadjusted_args_size)
1745 % preferred_unit_stack_boundary);
1747 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1748 as possible -- leaving just enough left to cancel out the
1749 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1750 PENDING_STACK_ADJUST is non-negative, and congruent to
1751 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1753 /* Begin by trying to pop all the bytes. */
1754 unadjusted_alignment
1755 = (unadjusted_alignment
1756 - (pending_stack_adjust % preferred_unit_stack_boundary));
1757 adjustment = pending_stack_adjust;
1758 /* Push enough additional bytes that the stack will be aligned
1759 after the arguments are pushed. */
1760 if (preferred_unit_stack_boundary > 1)
1762 if (unadjusted_alignment > 0)
1763 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1765 adjustment += unadjusted_alignment;
1768 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1769 bytes after the call. The right number is the entire
1770 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1771 by the arguments in the first place. */
1773 = pending_stack_adjust - adjustment + unadjusted_args_size;
1778 /* Scan X expression if it does not dereference any argument slots
1779 we already clobbered by tail call arguments (as noted in stored_args_map
1781 Return nonzero if X expression dereferences such argument slots,
1785 check_sibcall_argument_overlap_1 (rtx x)
1795 code = GET_CODE (x);
1799 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1801 else if (GET_CODE (XEXP (x, 0)) == PLUS
1802 && XEXP (XEXP (x, 0), 0) ==
1803 current_function_internal_arg_pointer
1804 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1805 i = INTVAL (XEXP (XEXP (x, 0), 1));
1809 #ifdef ARGS_GROW_DOWNWARD
1810 i = -i - GET_MODE_SIZE (GET_MODE (x));
1813 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1814 if (i + k < stored_args_map->n_bits
1815 && TEST_BIT (stored_args_map, i + k))
1821 /* Scan all subexpressions. */
1822 fmt = GET_RTX_FORMAT (code);
1823 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1827 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1830 else if (*fmt == 'E')
1832 for (j = 0; j < XVECLEN (x, i); j++)
1833 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1840 /* Scan sequence after INSN if it does not dereference any argument slots
1841 we already clobbered by tail call arguments (as noted in stored_args_map
1842 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1843 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1844 should be 0). Return nonzero if sequence after INSN dereferences such argument
1845 slots, zero otherwise. */
1848 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1852 if (insn == NULL_RTX)
1853 insn = get_insns ();
1855 insn = NEXT_INSN (insn);
1857 for (; insn; insn = NEXT_INSN (insn))
1859 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1862 if (mark_stored_args_map)
1864 #ifdef ARGS_GROW_DOWNWARD
1865 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1867 low = arg->locate.slot_offset.constant;
1870 for (high = low + arg->locate.size.constant; low < high; low++)
1871 SET_BIT (stored_args_map, low);
1873 return insn != NULL_RTX;
1877 fix_unsafe_tree (tree t)
1879 switch (unsafe_for_reeval (t))
1884 case 1: /* Mildly unsafe. */
1885 t = unsave_expr (t);
1888 case 2: /* Wildly unsafe. */
1890 tree var = build_decl (VAR_DECL, NULL_TREE,
1893 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
1905 /* If function value *VALUE was returned at the most significant end of a
1906 register, shift it towards the least significant end and convert it to
1907 TYPE's mode. Return true and update *VALUE if some action was needed.
1909 TYPE is the type of the function's return value, which is known not
1910 to have mode BLKmode. */
1913 shift_returned_value (tree type, rtx *value)
1915 if (targetm.calls.return_in_msb (type))
1917 HOST_WIDE_INT shift;
1919 shift = (GET_MODE_BITSIZE (GET_MODE (*value))
1920 - BITS_PER_UNIT * int_size_in_bytes (type));
1923 *value = expand_binop (GET_MODE (*value), lshr_optab, *value,
1924 GEN_INT (shift), 0, 1, OPTAB_WIDEN);
1925 *value = convert_to_mode (TYPE_MODE (type), *value, 0);
1932 /* Remove all REG_EQUIV notes found in the insn chain. */
1935 purge_reg_equiv_notes (void)
1939 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
1943 rtx note = find_reg_note (insn, REG_EQUIV, 0);
1946 /* Remove the note and keep looking at the notes for
1948 remove_note (insn, note);
1956 /* Clear RTX_UNCHANGING_P flag of incoming argument MEMs. */
1959 purge_mem_unchanging_flag (rtx x)
1968 code = GET_CODE (x);
1972 if (RTX_UNCHANGING_P (x)
1973 && (XEXP (x, 0) == current_function_internal_arg_pointer
1974 || (GET_CODE (XEXP (x, 0)) == PLUS
1975 && XEXP (XEXP (x, 0), 0) ==
1976 current_function_internal_arg_pointer
1977 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)))
1978 RTX_UNCHANGING_P (x) = 0;
1982 /* Scan all subexpressions. */
1983 fmt = GET_RTX_FORMAT (code);
1984 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1987 purge_mem_unchanging_flag (XEXP (x, i));
1988 else if (*fmt == 'E')
1989 for (j = 0; j < XVECLEN (x, i); j++)
1990 purge_mem_unchanging_flag (XVECEXP (x, i, j));
1995 /* Generate all the code for a function call
1996 and return an rtx for its value.
1997 Store the value in TARGET (specified as an rtx) if convenient.
1998 If the value is stored in TARGET then TARGET is returned.
1999 If IGNORE is nonzero, then we ignore the value of the function call. */
2002 expand_call (tree exp, rtx target, int ignore)
2004 /* Nonzero if we are currently expanding a call. */
2005 static int currently_expanding_call = 0;
2007 /* List of actual parameters. */
2008 tree actparms = TREE_OPERAND (exp, 1);
2009 /* RTX for the function to be called. */
2011 /* Sequence of insns to perform a normal "call". */
2012 rtx normal_call_insns = NULL_RTX;
2013 /* Sequence of insns to perform a tail "call". */
2014 rtx tail_call_insns = NULL_RTX;
2015 /* Data type of the function. */
2017 tree type_arg_types;
2018 /* Declaration of the function being called,
2019 or 0 if the function is computed (not known by name). */
2021 /* The type of the function being called. */
2023 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
2026 /* Register in which non-BLKmode value will be returned,
2027 or 0 if no value or if value is BLKmode. */
2029 /* Address where we should return a BLKmode value;
2030 0 if value not BLKmode. */
2031 rtx structure_value_addr = 0;
2032 /* Nonzero if that address is being passed by treating it as
2033 an extra, implicit first parameter. Otherwise,
2034 it is passed by being copied directly into struct_value_rtx. */
2035 int structure_value_addr_parm = 0;
2036 /* Size of aggregate value wanted, or zero if none wanted
2037 or if we are using the non-reentrant PCC calling convention
2038 or expecting the value in registers. */
2039 HOST_WIDE_INT struct_value_size = 0;
2040 /* Nonzero if called function returns an aggregate in memory PCC style,
2041 by returning the address of where to find it. */
2042 int pcc_struct_value = 0;
2043 rtx struct_value = 0;
2045 /* Number of actual parameters in this call, including struct value addr. */
2047 /* Number of named args. Args after this are anonymous ones
2048 and they must all go on the stack. */
2051 /* Vector of information about each argument.
2052 Arguments are numbered in the order they will be pushed,
2053 not the order they are written. */
2054 struct arg_data *args;
2056 /* Total size in bytes of all the stack-parms scanned so far. */
2057 struct args_size args_size;
2058 struct args_size adjusted_args_size;
2059 /* Size of arguments before any adjustments (such as rounding). */
2060 int unadjusted_args_size;
2061 /* Data on reg parms scanned so far. */
2062 CUMULATIVE_ARGS args_so_far;
2063 /* Nonzero if a reg parm has been scanned. */
2065 /* Nonzero if this is an indirect function call. */
2067 /* Nonzero if we must avoid push-insns in the args for this call.
2068 If stack space is allocated for register parameters, but not by the
2069 caller, then it is preallocated in the fixed part of the stack frame.
2070 So the entire argument block must then be preallocated (i.e., we
2071 ignore PUSH_ROUNDING in that case). */
2073 int must_preallocate = !PUSH_ARGS;
2075 /* Size of the stack reserved for parameter registers. */
2076 int reg_parm_stack_space = 0;
2078 /* Address of space preallocated for stack parms
2079 (on machines that lack push insns), or 0 if space not preallocated. */
2082 /* Mask of ECF_ flags. */
2084 #ifdef REG_PARM_STACK_SPACE
2085 /* Define the boundary of the register parm stack space that needs to be
2087 int low_to_save, high_to_save;
2088 rtx save_area = 0; /* Place that it is saved */
2091 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2092 char *initial_stack_usage_map = stack_usage_map;
2094 int old_stack_allocated;
2096 /* State variables to track stack modifications. */
2097 rtx old_stack_level = 0;
2098 int old_stack_arg_under_construction = 0;
2099 int old_pending_adj = 0;
2100 int old_inhibit_defer_pop = inhibit_defer_pop;
2102 /* Some stack pointer alterations we make are performed via
2103 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2104 which we then also need to save/restore along the way. */
2105 int old_stack_pointer_delta = 0;
2108 tree p = TREE_OPERAND (exp, 0);
2109 tree addr = TREE_OPERAND (exp, 0);
2111 /* The alignment of the stack, in bits. */
2112 HOST_WIDE_INT preferred_stack_boundary;
2113 /* The alignment of the stack, in bytes. */
2114 HOST_WIDE_INT preferred_unit_stack_boundary;
2115 /* The static chain value to use for this call. */
2116 rtx static_chain_value;
2117 /* See if this is "nothrow" function call. */
2118 if (TREE_NOTHROW (exp))
2119 flags |= ECF_NOTHROW;
2121 /* See if we can find a DECL-node for the actual function, and get the
2122 function attributes (flags) from the function decl or type node. */
2123 fndecl = get_callee_fndecl (exp);
2126 fntype = TREE_TYPE (fndecl);
2127 flags |= flags_from_decl_or_type (fndecl);
2131 fntype = TREE_TYPE (TREE_TYPE (p));
2132 flags |= flags_from_decl_or_type (fntype);
2135 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2137 /* Warn if this value is an aggregate type,
2138 regardless of which calling convention we are using for it. */
2139 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2140 warning ("function call has aggregate value");
2142 /* If the result of a pure or const function call is ignored (or void),
2143 and none of its arguments are volatile, we can avoid expanding the
2144 call and just evaluate the arguments for side-effects. */
2145 if ((flags & (ECF_CONST | ECF_PURE))
2146 && (ignore || target == const0_rtx
2147 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2149 bool volatilep = false;
2152 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2153 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2161 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2162 expand_expr (TREE_VALUE (arg), const0_rtx,
2163 VOIDmode, EXPAND_NORMAL);
2168 #ifdef REG_PARM_STACK_SPACE
2169 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2172 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2173 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2174 must_preallocate = 1;
2177 /* Set up a place to return a structure. */
2179 /* Cater to broken compilers. */
2180 if (aggregate_value_p (exp, fndecl))
2182 /* This call returns a big structure. */
2183 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2185 #ifdef PCC_STATIC_STRUCT_RETURN
2187 pcc_struct_value = 1;
2189 #else /* not PCC_STATIC_STRUCT_RETURN */
2191 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2193 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2195 /* The structure value address arg is already in actparms.
2196 Pull it out. It might be nice to just leave it there, but
2197 we need to set structure_value_addr. */
2198 tree return_arg = TREE_VALUE (actparms);
2199 actparms = TREE_CHAIN (actparms);
2200 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2201 VOIDmode, EXPAND_NORMAL);
2203 else if (target && GET_CODE (target) == MEM)
2204 structure_value_addr = XEXP (target, 0);
2207 /* For variable-sized objects, we must be called with a target
2208 specified. If we were to allocate space on the stack here,
2209 we would have no way of knowing when to free it. */
2210 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2212 mark_temp_addr_taken (d);
2213 structure_value_addr = XEXP (d, 0);
2217 #endif /* not PCC_STATIC_STRUCT_RETURN */
2220 /* Figure out the amount to which the stack should be aligned. */
2221 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2224 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2225 if (i && i->preferred_incoming_stack_boundary)
2226 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2229 /* Operand 0 is a pointer-to-function; get the type of the function. */
2230 funtype = TREE_TYPE (addr);
2231 if (! POINTER_TYPE_P (funtype))
2233 funtype = TREE_TYPE (funtype);
2235 /* Munge the tree to split complex arguments into their imaginary
2237 if (targetm.calls.split_complex_arg)
2239 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2240 actparms = split_complex_values (actparms);
2243 type_arg_types = TYPE_ARG_TYPES (funtype);
2245 if (flags & ECF_MAY_BE_ALLOCA)
2246 current_function_calls_alloca = 1;
2248 /* If struct_value_rtx is 0, it means pass the address
2249 as if it were an extra parameter. */
2250 if (structure_value_addr && struct_value == 0)
2252 /* If structure_value_addr is a REG other than
2253 virtual_outgoing_args_rtx, we can use always use it. If it
2254 is not a REG, we must always copy it into a register.
2255 If it is virtual_outgoing_args_rtx, we must copy it to another
2256 register in some cases. */
2257 rtx temp = (GET_CODE (structure_value_addr) != REG
2258 || (ACCUMULATE_OUTGOING_ARGS
2259 && stack_arg_under_construction
2260 && structure_value_addr == virtual_outgoing_args_rtx)
2261 ? copy_addr_to_reg (convert_memory_address
2262 (Pmode, structure_value_addr))
2263 : structure_value_addr);
2266 = tree_cons (error_mark_node,
2267 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2270 structure_value_addr_parm = 1;
2273 /* Count the arguments and set NUM_ACTUALS. */
2274 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2277 /* Compute number of named args.
2278 Normally, don't include the last named arg if anonymous args follow.
2279 We do include the last named arg if
2280 targetm.calls.strict_argument_naming() returns nonzero.
2281 (If no anonymous args follow, the result of list_length is actually
2282 one too large. This is harmless.)
2284 If targetm.calls.pretend_outgoing_varargs_named() returns
2285 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2286 this machine will be able to place unnamed args that were passed
2287 in registers into the stack. So treat all args as named. This
2288 allows the insns emitting for a specific argument list to be
2289 independent of the function declaration.
2291 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2292 we do not have any reliable way to pass unnamed args in
2293 registers, so we must force them into memory. */
2295 if ((targetm.calls.strict_argument_naming (&args_so_far)
2296 || ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2297 && type_arg_types != 0)
2299 = (list_length (type_arg_types)
2300 /* Don't include the last named arg. */
2301 - (targetm.calls.strict_argument_naming (&args_so_far) ? 0 : 1)
2302 /* Count the struct value address, if it is passed as a parm. */
2303 + structure_value_addr_parm);
2305 /* If we know nothing, treat all args as named. */
2306 n_named_args = num_actuals;
2308 /* Start updating where the next arg would go.
2310 On some machines (such as the PA) indirect calls have a different
2311 calling convention than normal calls. The fourth argument in
2312 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2314 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2316 /* Make a vector to hold all the information about each arg. */
2317 args = alloca (num_actuals * sizeof (struct arg_data));
2318 memset (args, 0, num_actuals * sizeof (struct arg_data));
2320 /* Build up entries in the ARGS array, compute the size of the
2321 arguments into ARGS_SIZE, etc. */
2322 initialize_argument_information (num_actuals, args, &args_size,
2323 n_named_args, actparms, fndecl,
2324 &args_so_far, reg_parm_stack_space,
2325 &old_stack_level, &old_pending_adj,
2326 &must_preallocate, &flags,
2327 &try_tail_call, CALL_FROM_THUNK_P (exp));
2331 /* If this function requires a variable-sized argument list, don't
2332 try to make a cse'able block for this call. We may be able to
2333 do this eventually, but it is too complicated to keep track of
2334 what insns go in the cse'able block and which don't. */
2336 flags &= ~ECF_LIBCALL_BLOCK;
2337 must_preallocate = 1;
2340 /* Now make final decision about preallocating stack space. */
2341 must_preallocate = finalize_must_preallocate (must_preallocate,
2345 /* If the structure value address will reference the stack pointer, we
2346 must stabilize it. We don't need to do this if we know that we are
2347 not going to adjust the stack pointer in processing this call. */
2349 if (structure_value_addr
2350 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2351 || reg_mentioned_p (virtual_outgoing_args_rtx,
2352 structure_value_addr))
2354 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2355 structure_value_addr = copy_to_reg (structure_value_addr);
2357 /* Tail calls can make things harder to debug, and we're traditionally
2358 pushed these optimizations into -O2. Don't try if we're already
2359 expanding a call, as that means we're an argument. Don't try if
2360 there's cleanups, as we know there's code to follow the call.
2362 If rtx_equal_function_value_matters is false, that means we've
2363 finished with regular parsing. Which means that some of the
2364 machinery we use to generate tail-calls is no longer in place.
2365 This is most often true of sjlj-exceptions, which we couldn't
2366 tail-call to anyway.
2368 If current_nesting_level () == 0, we're being called after
2369 the function body has been expanded. This can happen when
2370 setting up trampolines in expand_function_end. */
2371 if (currently_expanding_call++ != 0
2372 || !flag_optimize_sibling_calls
2373 || !rtx_equal_function_value_matters
2374 || current_nesting_level () == 0
2375 || any_pending_cleanups ()
2377 || lookup_stmt_eh_region (exp) >= 0)
2380 /* Rest of purposes for tail call optimizations to fail. */
2382 #ifdef HAVE_sibcall_epilogue
2383 !HAVE_sibcall_epilogue
2388 /* Doing sibling call optimization needs some work, since
2389 structure_value_addr can be allocated on the stack.
2390 It does not seem worth the effort since few optimizable
2391 sibling calls will return a structure. */
2392 || structure_value_addr != NULL_RTX
2393 /* Check whether the target is able to optimize the call
2395 || !targetm.function_ok_for_sibcall (fndecl, exp)
2396 /* Functions that do not return exactly once may not be sibcall
2398 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2399 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2400 /* If the called function is nested in the current one, it might access
2401 some of the caller's arguments, but could clobber them beforehand if
2402 the argument areas are shared. */
2403 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2404 /* If this function requires more stack slots than the current
2405 function, we cannot change it into a sibling call. */
2406 || args_size.constant > current_function_args_size
2407 /* If the callee pops its own arguments, then it must pop exactly
2408 the same number of arguments as the current function. */
2409 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2410 != RETURN_POPS_ARGS (current_function_decl,
2411 TREE_TYPE (current_function_decl),
2412 current_function_args_size))
2413 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2419 actparms = NULL_TREE;
2420 /* Ok, we're going to give the tail call the old college try.
2421 This means we're going to evaluate the function arguments
2422 up to three times. There are two degrees of badness we can
2423 encounter, those that can be unsaved and those that can't.
2424 (See unsafe_for_reeval commentary for details.)
2426 Generate a new argument list. Pass safe arguments through
2427 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2428 For hard badness, evaluate them now and put their resulting
2429 rtx in a temporary VAR_DECL.
2431 initialize_argument_information has ordered the array for the
2432 order to be pushed, and we must remember this when reconstructing
2433 the original argument order. */
2435 if (PUSH_ARGS_REVERSED)
2444 i = num_actuals - 1;
2448 for (; i != end; i += inc)
2450 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2452 /* Do the same for the function address if it is an expression. */
2454 addr = fix_unsafe_tree (addr);
2455 /* Expanding one of those dangerous arguments could have added
2456 cleanups, but otherwise give it a whirl. */
2457 if (any_pending_cleanups ())
2462 /* Ensure current function's preferred stack boundary is at least
2463 what we need. We don't have to increase alignment for recursive
2465 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2466 && fndecl != current_function_decl)
2467 cfun->preferred_stack_boundary = preferred_stack_boundary;
2468 if (fndecl == current_function_decl)
2469 cfun->recursive_call_emit = true;
2471 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2473 function_call_count++;
2475 /* We want to make two insn chains; one for a sibling call, the other
2476 for a normal call. We will select one of the two chains after
2477 initial RTL generation is complete. */
2478 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2480 int sibcall_failure = 0;
2481 /* We want to emit any pending stack adjustments before the tail
2482 recursion "call". That way we know any adjustment after the tail
2483 recursion call can be ignored if we indeed use the tail
2485 int save_pending_stack_adjust = 0;
2486 int save_stack_pointer_delta = 0;
2488 rtx before_call, next_arg_reg;
2492 /* Emit any queued insns now; otherwise they would end up in
2493 only one of the alternates. */
2496 /* State variables we need to save and restore between
2498 save_pending_stack_adjust = pending_stack_adjust;
2499 save_stack_pointer_delta = stack_pointer_delta;
2502 flags &= ~ECF_SIBCALL;
2504 flags |= ECF_SIBCALL;
2506 /* Other state variables that we must reinitialize each time
2507 through the loop (that are not initialized by the loop itself). */
2511 /* Start a new sequence for the normal call case.
2513 From this point on, if the sibling call fails, we want to set
2514 sibcall_failure instead of continuing the loop. */
2519 /* We know at this point that there are not currently any
2520 pending cleanups. If, however, in the process of evaluating
2521 the arguments we were to create some, we'll need to be
2522 able to get rid of them. */
2523 expand_start_target_temps ();
2526 /* Don't let pending stack adjusts add up to too much.
2527 Also, do all pending adjustments now if there is any chance
2528 this might be a call to alloca or if we are expanding a sibling
2529 call sequence or if we are calling a function that is to return
2530 with stack pointer depressed. */
2531 if (pending_stack_adjust >= 32
2532 || (pending_stack_adjust > 0
2533 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2535 do_pending_stack_adjust ();
2537 /* When calling a const function, we must pop the stack args right away,
2538 so that the pop is deleted or moved with the call. */
2539 if (pass && (flags & ECF_LIBCALL_BLOCK))
2542 /* Precompute any arguments as needed. */
2544 precompute_arguments (flags, num_actuals, args);
2546 /* Now we are about to start emitting insns that can be deleted
2547 if a libcall is deleted. */
2548 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2551 adjusted_args_size = args_size;
2552 /* Compute the actual size of the argument block required. The variable
2553 and constant sizes must be combined, the size may have to be rounded,
2554 and there may be a minimum required size. When generating a sibcall
2555 pattern, do not round up, since we'll be re-using whatever space our
2557 unadjusted_args_size
2558 = compute_argument_block_size (reg_parm_stack_space,
2559 &adjusted_args_size,
2561 : preferred_stack_boundary));
2563 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2565 /* The argument block when performing a sibling call is the
2566 incoming argument block. */
2569 argblock = virtual_incoming_args_rtx;
2571 #ifdef STACK_GROWS_DOWNWARD
2572 = plus_constant (argblock, current_function_pretend_args_size);
2574 = plus_constant (argblock, -current_function_pretend_args_size);
2576 stored_args_map = sbitmap_alloc (args_size.constant);
2577 sbitmap_zero (stored_args_map);
2580 /* If we have no actual push instructions, or shouldn't use them,
2581 make space for all args right now. */
2582 else if (adjusted_args_size.var != 0)
2584 if (old_stack_level == 0)
2586 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2587 old_stack_pointer_delta = stack_pointer_delta;
2588 old_pending_adj = pending_stack_adjust;
2589 pending_stack_adjust = 0;
2590 /* stack_arg_under_construction says whether a stack arg is
2591 being constructed at the old stack level. Pushing the stack
2592 gets a clean outgoing argument block. */
2593 old_stack_arg_under_construction = stack_arg_under_construction;
2594 stack_arg_under_construction = 0;
2596 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2600 /* Note that we must go through the motions of allocating an argument
2601 block even if the size is zero because we may be storing args
2602 in the area reserved for register arguments, which may be part of
2605 int needed = adjusted_args_size.constant;
2607 /* Store the maximum argument space used. It will be pushed by
2608 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2611 if (needed > current_function_outgoing_args_size)
2612 current_function_outgoing_args_size = needed;
2614 if (must_preallocate)
2616 if (ACCUMULATE_OUTGOING_ARGS)
2618 /* Since the stack pointer will never be pushed, it is
2619 possible for the evaluation of a parm to clobber
2620 something we have already written to the stack.
2621 Since most function calls on RISC machines do not use
2622 the stack, this is uncommon, but must work correctly.
2624 Therefore, we save any area of the stack that was already
2625 written and that we are using. Here we set up to do this
2626 by making a new stack usage map from the old one. The
2627 actual save will be done by store_one_arg.
2629 Another approach might be to try to reorder the argument
2630 evaluations to avoid this conflicting stack usage. */
2632 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2633 /* Since we will be writing into the entire argument area,
2634 the map must be allocated for its entire size, not just
2635 the part that is the responsibility of the caller. */
2636 needed += reg_parm_stack_space;
2639 #ifdef ARGS_GROW_DOWNWARD
2640 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2643 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2646 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2648 if (initial_highest_arg_in_use)
2649 memcpy (stack_usage_map, initial_stack_usage_map,
2650 initial_highest_arg_in_use);
2652 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2653 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2654 (highest_outgoing_arg_in_use
2655 - initial_highest_arg_in_use));
2658 /* The address of the outgoing argument list must not be
2659 copied to a register here, because argblock would be left
2660 pointing to the wrong place after the call to
2661 allocate_dynamic_stack_space below. */
2663 argblock = virtual_outgoing_args_rtx;
2667 if (inhibit_defer_pop == 0)
2669 /* Try to reuse some or all of the pending_stack_adjust
2670 to get this space. */
2672 = (combine_pending_stack_adjustment_and_call
2673 (unadjusted_args_size,
2674 &adjusted_args_size,
2675 preferred_unit_stack_boundary));
2677 /* combine_pending_stack_adjustment_and_call computes
2678 an adjustment before the arguments are allocated.
2679 Account for them and see whether or not the stack
2680 needs to go up or down. */
2681 needed = unadjusted_args_size - needed;
2685 /* We're releasing stack space. */
2686 /* ??? We can avoid any adjustment at all if we're
2687 already aligned. FIXME. */
2688 pending_stack_adjust = -needed;
2689 do_pending_stack_adjust ();
2693 /* We need to allocate space. We'll do that in
2694 push_block below. */
2695 pending_stack_adjust = 0;
2698 /* Special case this because overhead of `push_block' in
2699 this case is non-trivial. */
2701 argblock = virtual_outgoing_args_rtx;
2704 argblock = push_block (GEN_INT (needed), 0, 0);
2705 #ifdef ARGS_GROW_DOWNWARD
2706 argblock = plus_constant (argblock, needed);
2710 /* We only really need to call `copy_to_reg' in the case
2711 where push insns are going to be used to pass ARGBLOCK
2712 to a function call in ARGS. In that case, the stack
2713 pointer changes value from the allocation point to the
2714 call point, and hence the value of
2715 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2716 as well always do it. */
2717 argblock = copy_to_reg (argblock);
2722 if (ACCUMULATE_OUTGOING_ARGS)
2724 /* The save/restore code in store_one_arg handles all
2725 cases except one: a constructor call (including a C
2726 function returning a BLKmode struct) to initialize
2728 if (stack_arg_under_construction)
2730 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2731 rtx push_size = GEN_INT (reg_parm_stack_space
2732 + adjusted_args_size.constant);
2734 rtx push_size = GEN_INT (adjusted_args_size.constant);
2736 if (old_stack_level == 0)
2738 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2740 old_stack_pointer_delta = stack_pointer_delta;
2741 old_pending_adj = pending_stack_adjust;
2742 pending_stack_adjust = 0;
2743 /* stack_arg_under_construction says whether a stack
2744 arg is being constructed at the old stack level.
2745 Pushing the stack gets a clean outgoing argument
2747 old_stack_arg_under_construction
2748 = stack_arg_under_construction;
2749 stack_arg_under_construction = 0;
2750 /* Make a new map for the new argument list. */
2751 stack_usage_map = alloca (highest_outgoing_arg_in_use);
2752 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2753 highest_outgoing_arg_in_use = 0;
2755 allocate_dynamic_stack_space (push_size, NULL_RTX,
2759 /* If argument evaluation might modify the stack pointer,
2760 copy the address of the argument list to a register. */
2761 for (i = 0; i < num_actuals; i++)
2762 if (args[i].pass_on_stack)
2764 argblock = copy_addr_to_reg (argblock);
2769 compute_argument_addresses (args, argblock, num_actuals);
2771 /* If we push args individually in reverse order, perform stack alignment
2772 before the first push (the last arg). */
2773 if (PUSH_ARGS_REVERSED && argblock == 0
2774 && adjusted_args_size.constant != unadjusted_args_size)
2776 /* When the stack adjustment is pending, we get better code
2777 by combining the adjustments. */
2778 if (pending_stack_adjust
2779 && ! (flags & ECF_LIBCALL_BLOCK)
2780 && ! inhibit_defer_pop)
2782 pending_stack_adjust
2783 = (combine_pending_stack_adjustment_and_call
2784 (unadjusted_args_size,
2785 &adjusted_args_size,
2786 preferred_unit_stack_boundary));
2787 do_pending_stack_adjust ();
2789 else if (argblock == 0)
2790 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2791 - unadjusted_args_size));
2793 /* Now that the stack is properly aligned, pops can't safely
2794 be deferred during the evaluation of the arguments. */
2797 funexp = rtx_for_function_call (fndecl, addr);
2799 /* Figure out the register where the value, if any, will come back. */
2801 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2802 && ! structure_value_addr)
2804 if (pcc_struct_value)
2805 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2806 fndecl, (pass == 0));
2808 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2811 /* Precompute all register parameters. It isn't safe to compute anything
2812 once we have started filling any specific hard regs. */
2813 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2815 if (TREE_OPERAND (exp, 2))
2816 static_chain_value = expand_expr (TREE_OPERAND (exp, 2),
2817 NULL_RTX, VOIDmode, 0);
2819 static_chain_value = 0;
2821 #ifdef REG_PARM_STACK_SPACE
2822 /* Save the fixed argument area if it's part of the caller's frame and
2823 is clobbered by argument setup for this call. */
2824 if (ACCUMULATE_OUTGOING_ARGS && pass)
2825 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2826 &low_to_save, &high_to_save);
2829 /* Now store (and compute if necessary) all non-register parms.
2830 These come before register parms, since they can require block-moves,
2831 which could clobber the registers used for register parms.
2832 Parms which have partial registers are not stored here,
2833 but we do preallocate space here if they want that. */
2835 for (i = 0; i < num_actuals; i++)
2836 if (args[i].reg == 0 || args[i].pass_on_stack)
2838 rtx before_arg = get_last_insn ();
2840 if (store_one_arg (&args[i], argblock, flags,
2841 adjusted_args_size.var != 0,
2842 reg_parm_stack_space)
2844 && check_sibcall_argument_overlap (before_arg,
2846 sibcall_failure = 1;
2848 if (flags & ECF_CONST
2850 && args[i].value == args[i].stack)
2851 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2852 gen_rtx_USE (VOIDmode,
2857 /* If we have a parm that is passed in registers but not in memory
2858 and whose alignment does not permit a direct copy into registers,
2859 make a group of pseudos that correspond to each register that we
2861 if (STRICT_ALIGNMENT)
2862 store_unaligned_arguments_into_pseudos (args, num_actuals);
2864 /* Now store any partially-in-registers parm.
2865 This is the last place a block-move can happen. */
2867 for (i = 0; i < num_actuals; i++)
2868 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2870 rtx before_arg = get_last_insn ();
2872 if (store_one_arg (&args[i], argblock, flags,
2873 adjusted_args_size.var != 0,
2874 reg_parm_stack_space)
2876 && check_sibcall_argument_overlap (before_arg,
2878 sibcall_failure = 1;
2881 /* If we pushed args in forward order, perform stack alignment
2882 after pushing the last arg. */
2883 if (!PUSH_ARGS_REVERSED && argblock == 0)
2884 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2885 - unadjusted_args_size));
2887 /* If register arguments require space on the stack and stack space
2888 was not preallocated, allocate stack space here for arguments
2889 passed in registers. */
2890 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2891 if (!ACCUMULATE_OUTGOING_ARGS
2892 && must_preallocate == 0 && reg_parm_stack_space > 0)
2893 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2896 /* Pass the function the address in which to return a
2898 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2900 structure_value_addr
2901 = convert_memory_address (Pmode, structure_value_addr);
2902 emit_move_insn (struct_value,
2904 force_operand (structure_value_addr,
2907 if (GET_CODE (struct_value) == REG)
2908 use_reg (&call_fusage, struct_value);
2911 funexp = prepare_call_address (funexp, static_chain_value,
2912 &call_fusage, reg_parm_seen, pass == 0);
2914 load_register_parameters (args, num_actuals, &call_fusage, flags,
2915 pass == 0, &sibcall_failure);
2917 /* Perform postincrements before actually calling the function. */
2920 /* Save a pointer to the last insn before the call, so that we can
2921 later safely search backwards to find the CALL_INSN. */
2922 before_call = get_last_insn ();
2924 /* Set up next argument register. For sibling calls on machines
2925 with register windows this should be the incoming register. */
2926 #ifdef FUNCTION_INCOMING_ARG
2928 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2932 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2935 /* All arguments and registers used for the call must be set up by
2938 /* Stack must be properly aligned now. */
2939 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
2942 /* Generate the actual call instruction. */
2943 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2944 adjusted_args_size.constant, struct_value_size,
2945 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2946 flags, & args_so_far);
2948 /* If call is cse'able, make appropriate pair of reg-notes around it.
2949 Test valreg so we don't crash; may safely ignore `const'
2950 if return type is void. Disable for PARALLEL return values, because
2951 we have no way to move such values into a pseudo register. */
2952 if (pass && (flags & ECF_LIBCALL_BLOCK))
2956 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2958 insns = get_insns ();
2960 /* Expansion of block moves possibly introduced a loop that may
2961 not appear inside libcall block. */
2962 for (insn = insns; insn; insn = NEXT_INSN (insn))
2963 if (GET_CODE (insn) == JUMP_INSN)
2974 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2976 /* Mark the return value as a pointer if needed. */
2977 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2978 mark_reg_pointer (temp,
2979 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2982 if (flag_unsafe_math_optimizations
2984 && DECL_BUILT_IN (fndecl)
2985 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2986 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2987 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2988 note = gen_rtx_fmt_e (SQRT,
2990 args[0].initial_value);
2993 /* Construct an "equal form" for the value which
2994 mentions all the arguments in order as well as
2995 the function name. */
2996 for (i = 0; i < num_actuals; i++)
2997 note = gen_rtx_EXPR_LIST (VOIDmode,
2998 args[i].initial_value, note);
2999 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3001 if (flags & ECF_PURE)
3002 note = gen_rtx_EXPR_LIST (VOIDmode,
3003 gen_rtx_USE (VOIDmode,
3004 gen_rtx_MEM (BLKmode,
3005 gen_rtx_SCRATCH (VOIDmode))),
3008 emit_libcall_block (insns, temp, valreg, note);
3013 else if (pass && (flags & ECF_MALLOC))
3015 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3018 /* The return value from a malloc-like function is a pointer. */
3019 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3020 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3022 emit_move_insn (temp, valreg);
3024 /* The return value from a malloc-like function can not alias
3026 last = get_last_insn ();
3028 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3030 /* Write out the sequence. */
3031 insns = get_insns ();
3037 /* For calls to `setjmp', etc., inform flow.c it should complain
3038 if nonvolatile values are live. For functions that cannot return,
3039 inform flow that control does not fall through. */
3041 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3043 /* The barrier must be emitted
3044 immediately after the CALL_INSN. Some ports emit more
3045 than just a CALL_INSN above, so we must search for it here. */
3047 rtx last = get_last_insn ();
3048 while (GET_CODE (last) != CALL_INSN)
3050 last = PREV_INSN (last);
3051 /* There was no CALL_INSN? */
3052 if (last == before_call)
3056 emit_barrier_after (last);
3058 /* Stack adjustments after a noreturn call are dead code.
3059 However when NO_DEFER_POP is in effect, we must preserve
3060 stack_pointer_delta. */
3061 if (inhibit_defer_pop == 0)
3063 stack_pointer_delta = old_stack_allocated;
3064 pending_stack_adjust = 0;
3068 if (flags & ECF_LONGJMP)
3069 current_function_calls_longjmp = 1;
3071 /* If value type not void, return an rtx for the value. */
3073 /* If there are cleanups to be called, don't use a hard reg as target.
3074 We need to double check this and see if it matters anymore. */
3075 if (any_pending_cleanups ())
3077 if (target && REG_P (target)
3078 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3080 sibcall_failure = 1;
3083 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3085 target = const0_rtx;
3086 else if (structure_value_addr)
3088 if (target == 0 || GET_CODE (target) != MEM)
3091 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3092 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3093 structure_value_addr));
3094 set_mem_attributes (target, exp, 1);
3097 else if (pcc_struct_value)
3099 /* This is the special C++ case where we need to
3100 know what the true target was. We take care to
3101 never use this value more than once in one expression. */
3102 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3103 copy_to_reg (valreg));
3104 set_mem_attributes (target, exp, 1);
3106 /* Handle calls that return values in multiple non-contiguous locations.
3107 The Irix 6 ABI has examples of this. */
3108 else if (GET_CODE (valreg) == PARALLEL)
3112 /* This will only be assigned once, so it can be readonly. */
3113 tree nt = build_qualified_type (TREE_TYPE (exp),
3114 (TYPE_QUALS (TREE_TYPE (exp))
3115 | TYPE_QUAL_CONST));
3117 target = assign_temp (nt, 0, 1, 1);
3118 preserve_temp_slots (target);
3121 if (! rtx_equal_p (target, valreg))
3122 emit_group_store (target, valreg, TREE_TYPE (exp),
3123 int_size_in_bytes (TREE_TYPE (exp)));
3125 /* We can not support sibling calls for this case. */
3126 sibcall_failure = 1;
3129 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3130 && GET_MODE (target) == GET_MODE (valreg))
3132 /* TARGET and VALREG cannot be equal at this point because the
3133 latter would not have REG_FUNCTION_VALUE_P true, while the
3134 former would if it were referring to the same register.
3136 If they refer to the same register, this move will be a no-op,
3137 except when function inlining is being done. */
3138 emit_move_insn (target, valreg);
3140 /* If we are setting a MEM, this code must be executed. Since it is
3141 emitted after the call insn, sibcall optimization cannot be
3142 performed in that case. */
3143 if (GET_CODE (target) == MEM)
3144 sibcall_failure = 1;
3146 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3148 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3150 /* We can not support sibling calls for this case. */
3151 sibcall_failure = 1;
3155 if (shift_returned_value (TREE_TYPE (exp), &valreg))
3156 sibcall_failure = 1;
3158 target = copy_to_reg (valreg);
3161 if (targetm.calls.promote_function_return(funtype))
3163 /* If we promoted this return value, make the proper SUBREG. TARGET
3164 might be const0_rtx here, so be careful. */
3165 if (GET_CODE (target) == REG
3166 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3167 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3169 tree type = TREE_TYPE (exp);
3170 int unsignedp = TYPE_UNSIGNED (type);
3173 /* If we don't promote as expected, something is wrong. */
3174 if (GET_MODE (target)
3175 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3178 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3179 && GET_MODE_SIZE (GET_MODE (target))
3180 > GET_MODE_SIZE (TYPE_MODE (type)))
3182 offset = GET_MODE_SIZE (GET_MODE (target))
3183 - GET_MODE_SIZE (TYPE_MODE (type));
3184 if (! BYTES_BIG_ENDIAN)
3185 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3186 else if (! WORDS_BIG_ENDIAN)
3187 offset %= UNITS_PER_WORD;
3189 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3190 SUBREG_PROMOTED_VAR_P (target) = 1;
3191 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3195 /* If size of args is variable or this was a constructor call for a stack
3196 argument, restore saved stack-pointer value. */
3198 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3200 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3201 stack_pointer_delta = old_stack_pointer_delta;
3202 pending_stack_adjust = old_pending_adj;
3203 stack_arg_under_construction = old_stack_arg_under_construction;
3204 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3205 stack_usage_map = initial_stack_usage_map;
3206 sibcall_failure = 1;
3208 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3210 #ifdef REG_PARM_STACK_SPACE
3212 restore_fixed_argument_area (save_area, argblock,
3213 high_to_save, low_to_save);
3216 /* If we saved any argument areas, restore them. */
3217 for (i = 0; i < num_actuals; i++)
3218 if (args[i].save_area)
3220 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3222 = gen_rtx_MEM (save_mode,
3223 memory_address (save_mode,
3224 XEXP (args[i].stack_slot, 0)));
3226 if (save_mode != BLKmode)
3227 emit_move_insn (stack_area, args[i].save_area);
3229 emit_block_move (stack_area, args[i].save_area,
3230 GEN_INT (args[i].locate.size.constant),
3231 BLOCK_OP_CALL_PARM);
3234 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3235 stack_usage_map = initial_stack_usage_map;
3238 /* If this was alloca, record the new stack level for nonlocal gotos.
3239 Check for the handler slots since we might not have a save area
3240 for non-local gotos. */
3242 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3243 update_nonlocal_goto_save_area ();
3245 /* Free up storage we no longer need. */
3246 for (i = 0; i < num_actuals; ++i)
3247 if (args[i].aligned_regs)
3248 free (args[i].aligned_regs);
3252 /* Undo the fake expand_start_target_temps we did earlier. If
3253 there had been any cleanups created, we've already set
3255 expand_end_target_temps ();
3258 /* If this function is returning into a memory location marked as
3259 readonly, it means it is initializing that location. We normally treat
3260 functions as not clobbering such locations, so we need to specify that
3261 this one does. We do this by adding the appropriate CLOBBER to the
3262 CALL_INSN function usage list. This cannot be done by emitting a
3263 standalone CLOBBER after the call because the latter would be ignored
3264 by at least the delay slot scheduling pass. We do this now instead of
3265 adding to call_fusage before the call to emit_call_1 because TARGET
3266 may be modified in the meantime. */
3267 if (structure_value_addr != 0 && target != 0
3268 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3269 add_function_usage_to
3271 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3274 insns = get_insns ();
3279 tail_call_insns = insns;
3281 /* Restore the pending stack adjustment now that we have
3282 finished generating the sibling call sequence. */
3284 pending_stack_adjust = save_pending_stack_adjust;
3285 stack_pointer_delta = save_stack_pointer_delta;
3287 /* Prepare arg structure for next iteration. */
3288 for (i = 0; i < num_actuals; i++)
3291 args[i].aligned_regs = 0;
3295 sbitmap_free (stored_args_map);
3299 normal_call_insns = insns;
3301 /* Verify that we've deallocated all the stack we used. */
3302 if (! (flags & (ECF_NORETURN | ECF_LONGJMP))
3303 && old_stack_allocated != stack_pointer_delta
3304 - pending_stack_adjust)
3308 /* If something prevents making this a sibling call,
3309 zero out the sequence. */
3310 if (sibcall_failure)
3311 tail_call_insns = NULL_RTX;
3316 /* If tail call production suceeded, we need to remove REG_EQUIV notes on
3317 arguments too, as argument area is now clobbered by the call. */
3318 if (tail_call_insns)
3320 emit_insn (tail_call_insns);
3321 cfun->tail_call_emit = true;
3324 emit_insn (normal_call_insns);
3326 currently_expanding_call--;
3328 /* If this function returns with the stack pointer depressed, ensure
3329 this block saves and restores the stack pointer, show it was
3330 changed, and adjust for any outgoing arg space. */
3331 if (flags & ECF_SP_DEPRESSED)
3333 clear_pending_stack_adjust ();
3334 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3335 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3336 save_stack_pointer ();
3342 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3343 this function's incoming arguments.
3345 At the start of RTL generation we know the only REG_EQUIV notes
3346 in the rtl chain are those for incoming arguments, so we can safely
3347 flush any REG_EQUIV note.
3349 This is (slight) overkill. We could keep track of the highest
3350 argument we clobber and be more selective in removing notes, but it
3351 does not seem to be worth the effort. */
3353 fixup_tail_calls (void)
3358 purge_reg_equiv_notes ();
3360 /* A sibling call sequence also may invalidate RTX_UNCHANGING_P
3361 flag of some incoming arguments MEM RTLs, because it can write into
3362 those slots. We clear all those bits now.
3364 This is (slight) overkill, we could keep track of which arguments
3365 we actually write into. */
3366 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3369 purge_mem_unchanging_flag (PATTERN (insn));
3372 /* Similarly, invalidate RTX_UNCHANGING_P for any incoming
3373 arguments passed in registers. */
3374 for (arg = DECL_ARGUMENTS (current_function_decl);
3376 arg = TREE_CHAIN (arg))
3378 if (REG_P (DECL_RTL (arg)))
3379 RTX_UNCHANGING_P (DECL_RTL (arg)) = false;
3383 /* Traverse an argument list in VALUES and expand all complex
3384 arguments into their components. */
3386 split_complex_values (tree values)
3390 /* Before allocating memory, check for the common case of no complex. */
3391 for (p = values; p; p = TREE_CHAIN (p))
3393 tree type = TREE_TYPE (TREE_VALUE (p));
3394 if (type && TREE_CODE (type) == COMPLEX_TYPE
3395 && targetm.calls.split_complex_arg (type))
3401 values = copy_list (values);
3403 for (p = values; p; p = TREE_CHAIN (p))
3405 tree complex_value = TREE_VALUE (p);
3408 complex_type = TREE_TYPE (complex_value);
3412 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3413 && targetm.calls.split_complex_arg (complex_type))
3416 tree real, imag, next;
3418 subtype = TREE_TYPE (complex_type);
3419 complex_value = save_expr (complex_value);
3420 real = build1 (REALPART_EXPR, subtype, complex_value);
3421 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3423 TREE_VALUE (p) = real;
3424 next = TREE_CHAIN (p);
3425 imag = build_tree_list (NULL_TREE, imag);
3426 TREE_CHAIN (p) = imag;
3427 TREE_CHAIN (imag) = next;
3429 /* Skip the newly created node. */
3437 /* Traverse a list of TYPES and expand all complex types into their
3440 split_complex_types (tree types)
3444 /* Before allocating memory, check for the common case of no complex. */
3445 for (p = types; p; p = TREE_CHAIN (p))
3447 tree type = TREE_VALUE (p);
3448 if (TREE_CODE (type) == COMPLEX_TYPE
3449 && targetm.calls.split_complex_arg (type))
3455 types = copy_list (types);
3457 for (p = types; p; p = TREE_CHAIN (p))
3459 tree complex_type = TREE_VALUE (p);
3461 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3462 && targetm.calls.split_complex_arg (complex_type))
3466 /* Rewrite complex type with component type. */
3467 TREE_VALUE (p) = TREE_TYPE (complex_type);
3468 next = TREE_CHAIN (p);
3470 /* Add another component type for the imaginary part. */
3471 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3472 TREE_CHAIN (p) = imag;
3473 TREE_CHAIN (imag) = next;
3475 /* Skip the newly created node. */
3483 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3484 The RETVAL parameter specifies whether return value needs to be saved, other
3485 parameters are documented in the emit_library_call function below. */
3488 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3489 enum libcall_type fn_type,
3490 enum machine_mode outmode, int nargs, va_list p)
3492 /* Total size in bytes of all the stack-parms scanned so far. */
3493 struct args_size args_size;
3494 /* Size of arguments before any adjustments (such as rounding). */
3495 struct args_size original_args_size;
3501 CUMULATIVE_ARGS args_so_far;
3505 enum machine_mode mode;
3508 struct locate_and_pad_arg_data locate;
3512 int old_inhibit_defer_pop = inhibit_defer_pop;
3513 rtx call_fusage = 0;
3516 int pcc_struct_value = 0;
3517 int struct_value_size = 0;
3519 int reg_parm_stack_space = 0;
3522 tree tfom; /* type_for_mode (outmode, 0) */
3524 #ifdef REG_PARM_STACK_SPACE
3525 /* Define the boundary of the register parm stack space that needs to be
3527 int low_to_save, high_to_save;
3528 rtx save_area = 0; /* Place that it is saved. */
3531 /* Size of the stack reserved for parameter registers. */
3532 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3533 char *initial_stack_usage_map = stack_usage_map;
3535 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3537 #ifdef REG_PARM_STACK_SPACE
3538 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3541 /* By default, library functions can not throw. */
3542 flags = ECF_NOTHROW;
3554 case LCT_CONST_MAKE_BLOCK:
3555 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3557 case LCT_PURE_MAKE_BLOCK:
3558 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3561 flags |= ECF_NORETURN;
3564 flags = ECF_NORETURN;
3566 case LCT_ALWAYS_RETURN:
3567 flags = ECF_ALWAYS_RETURN;
3569 case LCT_RETURNS_TWICE:
3570 flags = ECF_RETURNS_TWICE;
3575 /* Ensure current function's preferred stack boundary is at least
3577 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3578 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3580 /* If this kind of value comes back in memory,
3581 decide where in memory it should come back. */
3582 if (outmode != VOIDmode)
3584 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3585 if (aggregate_value_p (tfom, 0))
3587 #ifdef PCC_STATIC_STRUCT_RETURN
3589 = hard_function_value (build_pointer_type (tfom), 0, 0);
3590 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3591 pcc_struct_value = 1;
3593 value = gen_reg_rtx (outmode);
3594 #else /* not PCC_STATIC_STRUCT_RETURN */
3595 struct_value_size = GET_MODE_SIZE (outmode);
3596 if (value != 0 && GET_CODE (value) == MEM)
3599 mem_value = assign_temp (tfom, 0, 1, 1);
3601 /* This call returns a big structure. */
3602 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3606 tfom = void_type_node;
3608 /* ??? Unfinished: must pass the memory address as an argument. */
3610 /* Copy all the libcall-arguments out of the varargs data
3611 and into a vector ARGVEC.
3613 Compute how to pass each argument. We only support a very small subset
3614 of the full argument passing conventions to limit complexity here since
3615 library functions shouldn't have many args. */
3617 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3618 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3620 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3621 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3623 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3626 args_size.constant = 0;
3631 /* Now we are about to start emitting insns that can be deleted
3632 if a libcall is deleted. */
3633 if (flags & ECF_LIBCALL_BLOCK)
3638 /* If there's a structure value address to be passed,
3639 either pass it in the special place, or pass it as an extra argument. */
3640 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3642 rtx addr = XEXP (mem_value, 0);
3645 /* Make sure it is a reasonable operand for a move or push insn. */
3646 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3647 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3648 addr = force_operand (addr, NULL_RTX);
3650 argvec[count].value = addr;
3651 argvec[count].mode = Pmode;
3652 argvec[count].partial = 0;
3654 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3655 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3656 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3660 locate_and_pad_parm (Pmode, NULL_TREE,
3661 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3664 argvec[count].reg != 0,
3666 0, NULL_TREE, &args_size, &argvec[count].locate);
3668 if (argvec[count].reg == 0 || argvec[count].partial != 0
3669 || reg_parm_stack_space > 0)
3670 args_size.constant += argvec[count].locate.size.constant;
3672 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3677 for (; count < nargs; count++)
3679 rtx val = va_arg (p, rtx);
3680 enum machine_mode mode = va_arg (p, enum machine_mode);
3682 /* We cannot convert the arg value to the mode the library wants here;
3683 must do it earlier where we know the signedness of the arg. */
3685 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3688 /* There's no need to call protect_from_queue, because
3689 either emit_move_insn or emit_push_insn will do that. */
3691 /* Make sure it is a reasonable operand for a move or push insn. */
3692 if (GET_CODE (val) != REG && GET_CODE (val) != MEM
3693 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3694 val = force_operand (val, NULL_RTX);
3696 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
3697 if (FUNCTION_ARG_PASS_BY_REFERENCE (args_so_far, mode, NULL_TREE, 1))
3701 #ifdef FUNCTION_ARG_CALLEE_COPIES
3702 && ! FUNCTION_ARG_CALLEE_COPIES (args_so_far, mode,
3707 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3708 functions, so we have to pretend this isn't such a function. */
3709 if (flags & ECF_LIBCALL_BLOCK)
3711 rtx insns = get_insns ();
3715 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3717 /* If this was a CONST function, it is now PURE since
3718 it now reads memory. */
3719 if (flags & ECF_CONST)
3721 flags &= ~ECF_CONST;
3725 if (GET_MODE (val) == MEM && ! must_copy)
3729 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3731 emit_move_insn (slot, val);
3735 tree type = lang_hooks.types.type_for_mode (mode, 0);
3738 = gen_rtx_MEM (mode,
3739 expand_expr (build1 (ADDR_EXPR,
3740 build_pointer_type (type),
3741 make_tree (type, val)),
3742 NULL_RTX, VOIDmode, 0));
3745 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3746 gen_rtx_USE (VOIDmode, slot),
3749 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3750 gen_rtx_CLOBBER (VOIDmode,
3755 val = force_operand (XEXP (slot, 0), NULL_RTX);
3759 argvec[count].value = val;
3760 argvec[count].mode = mode;
3762 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3764 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3765 argvec[count].partial
3766 = FUNCTION_ARG_PARTIAL_NREGS (args_so_far, mode, NULL_TREE, 1);
3768 argvec[count].partial = 0;
3771 locate_and_pad_parm (mode, NULL_TREE,
3772 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3775 argvec[count].reg != 0,
3777 argvec[count].partial,
3778 NULL_TREE, &args_size, &argvec[count].locate);
3780 if (argvec[count].locate.size.var)
3783 if (argvec[count].reg == 0 || argvec[count].partial != 0
3784 || reg_parm_stack_space > 0)
3785 args_size.constant += argvec[count].locate.size.constant;
3787 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3790 /* If this machine requires an external definition for library
3791 functions, write one out. */
3792 assemble_external_libcall (fun);
3794 original_args_size = args_size;
3795 args_size.constant = (((args_size.constant
3796 + stack_pointer_delta
3800 - stack_pointer_delta);
3802 args_size.constant = MAX (args_size.constant,
3803 reg_parm_stack_space);
3805 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3806 args_size.constant -= reg_parm_stack_space;
3809 if (args_size.constant > current_function_outgoing_args_size)
3810 current_function_outgoing_args_size = args_size.constant;
3812 if (ACCUMULATE_OUTGOING_ARGS)
3814 /* Since the stack pointer will never be pushed, it is possible for
3815 the evaluation of a parm to clobber something we have already
3816 written to the stack. Since most function calls on RISC machines
3817 do not use the stack, this is uncommon, but must work correctly.
3819 Therefore, we save any area of the stack that was already written
3820 and that we are using. Here we set up to do this by making a new
3821 stack usage map from the old one.
3823 Another approach might be to try to reorder the argument
3824 evaluations to avoid this conflicting stack usage. */
3826 needed = args_size.constant;
3828 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3829 /* Since we will be writing into the entire argument area, the
3830 map must be allocated for its entire size, not just the part that
3831 is the responsibility of the caller. */
3832 needed += reg_parm_stack_space;
3835 #ifdef ARGS_GROW_DOWNWARD
3836 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3839 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3842 stack_usage_map = alloca (highest_outgoing_arg_in_use);
3844 if (initial_highest_arg_in_use)
3845 memcpy (stack_usage_map, initial_stack_usage_map,
3846 initial_highest_arg_in_use);
3848 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3849 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3850 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3853 /* We must be careful to use virtual regs before they're instantiated,
3854 and real regs afterwards. Loop optimization, for example, can create
3855 new libcalls after we've instantiated the virtual regs, and if we
3856 use virtuals anyway, they won't match the rtl patterns. */
3858 if (virtuals_instantiated)
3859 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3861 argblock = virtual_outgoing_args_rtx;
3866 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3869 /* If we push args individually in reverse order, perform stack alignment
3870 before the first push (the last arg). */
3871 if (argblock == 0 && PUSH_ARGS_REVERSED)
3872 anti_adjust_stack (GEN_INT (args_size.constant
3873 - original_args_size.constant));
3875 if (PUSH_ARGS_REVERSED)
3886 #ifdef REG_PARM_STACK_SPACE
3887 if (ACCUMULATE_OUTGOING_ARGS)
3889 /* The argument list is the property of the called routine and it
3890 may clobber it. If the fixed area has been used for previous
3891 parameters, we must save and restore it. */
3892 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3893 &low_to_save, &high_to_save);
3897 /* Push the args that need to be pushed. */
3899 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3900 are to be pushed. */
3901 for (count = 0; count < nargs; count++, argnum += inc)
3903 enum machine_mode mode = argvec[argnum].mode;
3904 rtx val = argvec[argnum].value;
3905 rtx reg = argvec[argnum].reg;
3906 int partial = argvec[argnum].partial;
3907 int lower_bound = 0, upper_bound = 0, i;
3909 if (! (reg != 0 && partial == 0))
3911 if (ACCUMULATE_OUTGOING_ARGS)
3913 /* If this is being stored into a pre-allocated, fixed-size,
3914 stack area, save any previous data at that location. */
3916 #ifdef ARGS_GROW_DOWNWARD
3917 /* stack_slot is negative, but we want to index stack_usage_map
3918 with positive values. */
3919 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3920 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3922 lower_bound = argvec[argnum].locate.offset.constant;
3923 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3927 /* Don't worry about things in the fixed argument area;
3928 it has already been saved. */
3929 if (i < reg_parm_stack_space)
3930 i = reg_parm_stack_space;
3931 while (i < upper_bound && stack_usage_map[i] == 0)
3934 if (i < upper_bound)
3936 /* We need to make a save area. */
3938 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3939 enum machine_mode save_mode
3940 = mode_for_size (size, MODE_INT, 1);
3942 = plus_constant (argblock,
3943 argvec[argnum].locate.offset.constant);
3945 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3947 if (save_mode == BLKmode)
3949 argvec[argnum].save_area
3950 = assign_stack_temp (BLKmode,
3951 argvec[argnum].locate.size.constant,
3954 emit_block_move (validize_mem (argvec[argnum].save_area),
3956 GEN_INT (argvec[argnum].locate.size.constant),
3957 BLOCK_OP_CALL_PARM);
3961 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3963 emit_move_insn (argvec[argnum].save_area, stack_area);
3968 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3969 partial, reg, 0, argblock,
3970 GEN_INT (argvec[argnum].locate.offset.constant),
3971 reg_parm_stack_space,
3972 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3974 /* Now mark the segment we just used. */
3975 if (ACCUMULATE_OUTGOING_ARGS)
3976 for (i = lower_bound; i < upper_bound; i++)
3977 stack_usage_map[i] = 1;
3983 /* If we pushed args in forward order, perform stack alignment
3984 after pushing the last arg. */
3985 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3986 anti_adjust_stack (GEN_INT (args_size.constant
3987 - original_args_size.constant));
3989 if (PUSH_ARGS_REVERSED)
3994 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3996 /* Now load any reg parms into their regs. */
3998 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3999 are to be pushed. */
4000 for (count = 0; count < nargs; count++, argnum += inc)
4002 rtx val = argvec[argnum].value;
4003 rtx reg = argvec[argnum].reg;
4004 int partial = argvec[argnum].partial;
4006 /* Handle calls that pass values in multiple non-contiguous
4007 locations. The PA64 has examples of this for library calls. */
4008 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4009 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (GET_MODE (val)));
4010 else if (reg != 0 && partial == 0)
4011 emit_move_insn (reg, val);
4016 /* Any regs containing parms remain in use through the call. */
4017 for (count = 0; count < nargs; count++)
4019 rtx reg = argvec[count].reg;
4020 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4021 use_group_regs (&call_fusage, reg);
4023 use_reg (&call_fusage, reg);
4026 /* Pass the function the address in which to return a structure value. */
4027 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
4029 emit_move_insn (struct_value,
4031 force_operand (XEXP (mem_value, 0),
4033 if (GET_CODE (struct_value) == REG)
4034 use_reg (&call_fusage, struct_value);
4037 /* Don't allow popping to be deferred, since then
4038 cse'ing of library calls could delete a call and leave the pop. */
4040 valreg = (mem_value == 0 && outmode != VOIDmode
4041 ? hard_libcall_value (outmode) : NULL_RTX);
4043 /* Stack must be properly aligned now. */
4044 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4047 before_call = get_last_insn ();
4049 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4050 will set inhibit_defer_pop to that value. */
4051 /* The return type is needed to decide how many bytes the function pops.
4052 Signedness plays no role in that, so for simplicity, we pretend it's
4053 always signed. We also assume that the list of arguments passed has
4054 no impact, so we pretend it is unknown. */
4056 emit_call_1 (fun, NULL,
4057 get_identifier (XSTR (orgfun, 0)),
4058 build_function_type (tfom, NULL_TREE),
4059 original_args_size.constant, args_size.constant,
4061 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4063 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4065 /* For calls to `setjmp', etc., inform flow.c it should complain
4066 if nonvolatile values are live. For functions that cannot return,
4067 inform flow that control does not fall through. */
4069 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4071 /* The barrier note must be emitted
4072 immediately after the CALL_INSN. Some ports emit more than
4073 just a CALL_INSN above, so we must search for it here. */
4075 rtx last = get_last_insn ();
4076 while (GET_CODE (last) != CALL_INSN)
4078 last = PREV_INSN (last);
4079 /* There was no CALL_INSN? */
4080 if (last == before_call)
4084 emit_barrier_after (last);
4087 /* Now restore inhibit_defer_pop to its actual original value. */
4090 /* If call is cse'able, make appropriate pair of reg-notes around it.
4091 Test valreg so we don't crash; may safely ignore `const'
4092 if return type is void. Disable for PARALLEL return values, because
4093 we have no way to move such values into a pseudo register. */
4094 if (flags & ECF_LIBCALL_BLOCK)
4100 insns = get_insns ();
4110 if (GET_CODE (valreg) == PARALLEL)
4112 temp = gen_reg_rtx (outmode);
4113 emit_group_store (temp, valreg, NULL_TREE,
4114 GET_MODE_SIZE (outmode));
4118 temp = gen_reg_rtx (GET_MODE (valreg));
4120 /* Construct an "equal form" for the value which mentions all the
4121 arguments in order as well as the function name. */
4122 for (i = 0; i < nargs; i++)
4123 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4124 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4126 insns = get_insns ();
4129 if (flags & ECF_PURE)
4130 note = gen_rtx_EXPR_LIST (VOIDmode,
4131 gen_rtx_USE (VOIDmode,
4132 gen_rtx_MEM (BLKmode,
4133 gen_rtx_SCRATCH (VOIDmode))),
4136 emit_libcall_block (insns, temp, valreg, note);
4143 /* Copy the value to the right place. */
4144 if (outmode != VOIDmode && retval)
4150 if (value != mem_value)
4151 emit_move_insn (value, mem_value);
4153 else if (GET_CODE (valreg) == PARALLEL)
4156 value = gen_reg_rtx (outmode);
4157 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
4159 else if (value != 0)
4160 emit_move_insn (value, valreg);
4165 if (ACCUMULATE_OUTGOING_ARGS)
4167 #ifdef REG_PARM_STACK_SPACE
4169 restore_fixed_argument_area (save_area, argblock,
4170 high_to_save, low_to_save);
4173 /* If we saved any argument areas, restore them. */
4174 for (count = 0; count < nargs; count++)
4175 if (argvec[count].save_area)
4177 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4178 rtx adr = plus_constant (argblock,
4179 argvec[count].locate.offset.constant);
4180 rtx stack_area = gen_rtx_MEM (save_mode,
4181 memory_address (save_mode, adr));
4183 if (save_mode == BLKmode)
4184 emit_block_move (stack_area,
4185 validize_mem (argvec[count].save_area),
4186 GEN_INT (argvec[count].locate.size.constant),
4187 BLOCK_OP_CALL_PARM);
4189 emit_move_insn (stack_area, argvec[count].save_area);
4192 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4193 stack_usage_map = initial_stack_usage_map;
4200 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4201 (emitting the queue unless NO_QUEUE is nonzero),
4202 for a value of mode OUTMODE,
4203 with NARGS different arguments, passed as alternating rtx values
4204 and machine_modes to convert them to.
4205 The rtx values should have been passed through protect_from_queue already.
4207 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4208 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4209 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4210 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4211 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4212 or other LCT_ value for other types of library calls. */
4215 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4216 enum machine_mode outmode, int nargs, ...)
4220 va_start (p, nargs);
4221 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4225 /* Like emit_library_call except that an extra argument, VALUE,
4226 comes second and says where to store the result.
4227 (If VALUE is zero, this function chooses a convenient way
4228 to return the value.
4230 This function returns an rtx for where the value is to be found.
4231 If VALUE is nonzero, VALUE is returned. */
4234 emit_library_call_value (rtx orgfun, rtx value,
4235 enum libcall_type fn_type,
4236 enum machine_mode outmode, int nargs, ...)
4241 va_start (p, nargs);
4242 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4249 /* Store a single argument for a function call
4250 into the register or memory area where it must be passed.
4251 *ARG describes the argument value and where to pass it.
4253 ARGBLOCK is the address of the stack-block for all the arguments,
4254 or 0 on a machine where arguments are pushed individually.
4256 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4257 so must be careful about how the stack is used.
4259 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4260 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4261 that we need not worry about saving and restoring the stack.
4263 FNDECL is the declaration of the function we are calling.
4265 Return nonzero if this arg should cause sibcall failure,
4269 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4270 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4272 tree pval = arg->tree_value;
4276 int i, lower_bound = 0, upper_bound = 0;
4277 int sibcall_failure = 0;
4279 if (TREE_CODE (pval) == ERROR_MARK)
4282 /* Push a new temporary level for any temporaries we make for
4286 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4288 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4289 save any previous data at that location. */
4290 if (argblock && ! variable_size && arg->stack)
4292 #ifdef ARGS_GROW_DOWNWARD
4293 /* stack_slot is negative, but we want to index stack_usage_map
4294 with positive values. */
4295 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4296 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4300 lower_bound = upper_bound - arg->locate.size.constant;
4302 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4303 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4307 upper_bound = lower_bound + arg->locate.size.constant;
4311 /* Don't worry about things in the fixed argument area;
4312 it has already been saved. */
4313 if (i < reg_parm_stack_space)
4314 i = reg_parm_stack_space;
4315 while (i < upper_bound && stack_usage_map[i] == 0)
4318 if (i < upper_bound)
4320 /* We need to make a save area. */
4321 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4322 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4323 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4324 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4326 if (save_mode == BLKmode)
4328 tree ot = TREE_TYPE (arg->tree_value);
4329 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4330 | TYPE_QUAL_CONST));
4332 arg->save_area = assign_temp (nt, 0, 1, 1);
4333 preserve_temp_slots (arg->save_area);
4334 emit_block_move (validize_mem (arg->save_area), stack_area,
4335 expr_size (arg->tree_value),
4336 BLOCK_OP_CALL_PARM);
4340 arg->save_area = gen_reg_rtx (save_mode);
4341 emit_move_insn (arg->save_area, stack_area);
4347 /* If this isn't going to be placed on both the stack and in registers,
4348 set up the register and number of words. */
4349 if (! arg->pass_on_stack)
4351 if (flags & ECF_SIBCALL)
4352 reg = arg->tail_call_reg;
4355 partial = arg->partial;
4358 if (reg != 0 && partial == 0)
4359 /* Being passed entirely in a register. We shouldn't be called in
4363 /* If this arg needs special alignment, don't load the registers
4365 if (arg->n_aligned_regs != 0)
4368 /* If this is being passed partially in a register, we can't evaluate
4369 it directly into its stack slot. Otherwise, we can. */
4370 if (arg->value == 0)
4372 /* stack_arg_under_construction is nonzero if a function argument is
4373 being evaluated directly into the outgoing argument list and
4374 expand_call must take special action to preserve the argument list
4375 if it is called recursively.
4377 For scalar function arguments stack_usage_map is sufficient to
4378 determine which stack slots must be saved and restored. Scalar
4379 arguments in general have pass_on_stack == 0.
4381 If this argument is initialized by a function which takes the
4382 address of the argument (a C++ constructor or a C function
4383 returning a BLKmode structure), then stack_usage_map is
4384 insufficient and expand_call must push the stack around the
4385 function call. Such arguments have pass_on_stack == 1.
4387 Note that it is always safe to set stack_arg_under_construction,
4388 but this generates suboptimal code if set when not needed. */
4390 if (arg->pass_on_stack)
4391 stack_arg_under_construction++;
4393 arg->value = expand_expr (pval,
4395 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4396 ? NULL_RTX : arg->stack,
4397 VOIDmode, EXPAND_STACK_PARM);
4399 /* If we are promoting object (or for any other reason) the mode
4400 doesn't agree, convert the mode. */
4402 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4403 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4404 arg->value, arg->unsignedp);
4406 if (arg->pass_on_stack)
4407 stack_arg_under_construction--;
4410 /* Don't allow anything left on stack from computation
4411 of argument to alloca. */
4412 if (flags & ECF_MAY_BE_ALLOCA)
4413 do_pending_stack_adjust ();
4415 if (arg->value == arg->stack)
4416 /* If the value is already in the stack slot, we are done. */
4418 else if (arg->mode != BLKmode)
4422 /* Argument is a scalar, not entirely passed in registers.
4423 (If part is passed in registers, arg->partial says how much
4424 and emit_push_insn will take care of putting it there.)
4426 Push it, and if its size is less than the
4427 amount of space allocated to it,
4428 also bump stack pointer by the additional space.
4429 Note that in C the default argument promotions
4430 will prevent such mismatches. */
4432 size = GET_MODE_SIZE (arg->mode);
4433 /* Compute how much space the push instruction will push.
4434 On many machines, pushing a byte will advance the stack
4435 pointer by a halfword. */
4436 #ifdef PUSH_ROUNDING
4437 size = PUSH_ROUNDING (size);
4441 /* Compute how much space the argument should get:
4442 round up to a multiple of the alignment for arguments. */
4443 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4444 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4445 / (PARM_BOUNDARY / BITS_PER_UNIT))
4446 * (PARM_BOUNDARY / BITS_PER_UNIT));
4448 /* This isn't already where we want it on the stack, so put it there.
4449 This can either be done with push or copy insns. */
4450 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4451 PARM_BOUNDARY, partial, reg, used - size, argblock,
4452 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4453 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4455 /* Unless this is a partially-in-register argument, the argument is now
4458 arg->value = arg->stack;
4462 /* BLKmode, at least partly to be pushed. */
4464 unsigned int parm_align;
4468 /* Pushing a nonscalar.
4469 If part is passed in registers, PARTIAL says how much
4470 and emit_push_insn will take care of putting it there. */
4472 /* Round its size up to a multiple
4473 of the allocation unit for arguments. */
4475 if (arg->locate.size.var != 0)
4478 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4482 /* PUSH_ROUNDING has no effect on us, because
4483 emit_push_insn for BLKmode is careful to avoid it. */
4484 if (reg && GET_CODE (reg) == PARALLEL)
4486 /* Use the size of the elt to compute excess. */
4487 rtx elt = XEXP (XVECEXP (reg, 0, 0), 0);
4488 excess = (arg->locate.size.constant
4489 - int_size_in_bytes (TREE_TYPE (pval))
4490 + partial * GET_MODE_SIZE (GET_MODE (elt)));
4493 excess = (arg->locate.size.constant
4494 - int_size_in_bytes (TREE_TYPE (pval))
4495 + partial * UNITS_PER_WORD);
4496 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4497 NULL_RTX, TYPE_MODE (sizetype), 0);
4500 /* Some types will require stricter alignment, which will be
4501 provided for elsewhere in argument layout. */
4502 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4504 /* When an argument is padded down, the block is aligned to
4505 PARM_BOUNDARY, but the actual argument isn't. */
4506 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4508 if (arg->locate.size.var)
4509 parm_align = BITS_PER_UNIT;
4512 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4513 parm_align = MIN (parm_align, excess_align);
4517 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4519 /* emit_push_insn might not work properly if arg->value and
4520 argblock + arg->locate.offset areas overlap. */
4524 if (XEXP (x, 0) == current_function_internal_arg_pointer
4525 || (GET_CODE (XEXP (x, 0)) == PLUS
4526 && XEXP (XEXP (x, 0), 0) ==
4527 current_function_internal_arg_pointer
4528 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4530 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4531 i = INTVAL (XEXP (XEXP (x, 0), 1));
4533 /* expand_call should ensure this. */
4534 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4537 if (arg->locate.offset.constant > i)
4539 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4540 sibcall_failure = 1;
4542 else if (arg->locate.offset.constant < i)
4544 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4545 sibcall_failure = 1;
4550 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4551 parm_align, partial, reg, excess, argblock,
4552 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4553 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4555 /* Unless this is a partially-in-register argument, the argument is now
4558 ??? Unlike the case above, in which we want the actual
4559 address of the data, so that we can load it directly into a
4560 register, here we want the address of the stack slot, so that
4561 it's properly aligned for word-by-word copying or something
4562 like that. It's not clear that this is always correct. */
4564 arg->value = arg->stack_slot;
4567 /* Mark all slots this store used. */
4568 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4569 && argblock && ! variable_size && arg->stack)
4570 for (i = lower_bound; i < upper_bound; i++)
4571 stack_usage_map[i] = 1;
4573 /* Once we have pushed something, pops can't safely
4574 be deferred during the rest of the arguments. */
4577 /* ANSI doesn't require a sequence point here,
4578 but PCC has one, so this will avoid some problems. */
4581 /* Free any temporary slots made in processing this argument. Show
4582 that we might have taken the address of something and pushed that
4584 preserve_temp_slots (NULL_RTX);
4588 return sibcall_failure;
4591 /* Nonzero if we do not know how to pass TYPE solely in registers.
4592 We cannot do so in the following cases:
4594 - if the type has variable size
4595 - if the type is marked as addressable (it is required to be constructed
4597 - if the padding and mode of the type is such that a copy into a register
4598 would put it into the wrong part of the register.
4600 Which padding can't be supported depends on the byte endianness.
4602 A value in a register is implicitly padded at the most significant end.
4603 On a big-endian machine, that is the lower end in memory.
4604 So a value padded in memory at the upper end can't go in a register.
4605 For a little-endian machine, the reverse is true. */
4608 default_must_pass_in_stack (enum machine_mode mode, tree type)
4613 /* If the type has variable size... */
4614 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4617 /* If the type is marked as addressable (it is required
4618 to be constructed into the stack)... */
4619 if (TREE_ADDRESSABLE (type))
4622 /* If the padding and mode of the type is such that a copy into
4623 a register would put it into the wrong part of the register. */
4625 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4626 && (FUNCTION_ARG_PADDING (mode, type)
4627 == (BYTES_BIG_ENDIAN ? upward : downward)))
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