1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
3 1999, 2000, 2001, 2002, 2003 Free Software Foundation, Inc.
5 This file is part of GCC.
7 GCC is free software; you can redistribute it and/or modify it under
8 the terms of the GNU General Public License as published by the Free
9 Software Foundation; either version 2, or (at your option) any later
12 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or
14 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
17 You should have received a copy of the GNU General Public License
18 along with GCC; see the file COPYING. If not, write to the Free
19 Software Foundation, 59 Temple Place - Suite 330, Boston, MA
24 #include "coretypes.h"
38 #include "langhooks.h"
43 /* Decide whether a function's arguments should be processed
44 from first to last or from last to first.
46 They should if the stack and args grow in opposite directions, but
47 only if we have push insns. */
51 #ifndef PUSH_ARGS_REVERSED
52 #if defined (STACK_GROWS_DOWNWARD) != defined (ARGS_GROW_DOWNWARD)
53 #define PUSH_ARGS_REVERSED PUSH_ARGS
59 #ifndef PUSH_ARGS_REVERSED
60 #define PUSH_ARGS_REVERSED 0
63 #ifndef STACK_POINTER_OFFSET
64 #define STACK_POINTER_OFFSET 0
67 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
68 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
70 /* Data structure and subroutines used within expand_call. */
74 /* Tree node for this argument. */
76 /* Mode for value; TYPE_MODE unless promoted. */
77 enum machine_mode mode;
78 /* Current RTL value for argument, or 0 if it isn't precomputed. */
80 /* Initially-compute RTL value for argument; only for const functions. */
82 /* Register to pass this argument in, 0 if passed on stack, or an
83 PARALLEL if the arg is to be copied into multiple non-contiguous
86 /* Register to pass this argument in when generating tail call sequence.
87 This is not the same register as for normal calls on machines with
90 /* If REG was promoted from the actual mode of the argument expression,
91 indicates whether the promotion is sign- or zero-extended. */
93 /* Number of registers to use. 0 means put the whole arg in registers.
94 Also 0 if not passed in registers. */
96 /* Nonzero if argument must be passed on stack.
97 Note that some arguments may be passed on the stack
98 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
99 pass_on_stack identifies arguments that *cannot* go in registers. */
101 /* Some fields packaged up for locate_and_pad_parm. */
102 struct locate_and_pad_arg_data locate;
103 /* Location on the stack at which parameter should be stored. The store
104 has already been done if STACK == VALUE. */
106 /* Location on the stack of the start of this argument slot. This can
107 differ from STACK if this arg pads downward. This location is known
108 to be aligned to FUNCTION_ARG_BOUNDARY. */
110 /* Place that this stack area has been saved, if needed. */
112 /* If an argument's alignment does not permit direct copying into registers,
113 copy in smaller-sized pieces into pseudos. These are stored in a
114 block pointed to by this field. The next field says how many
115 word-sized pseudos we made. */
120 /* A vector of one char per byte of stack space. A byte if nonzero if
121 the corresponding stack location has been used.
122 This vector is used to prevent a function call within an argument from
123 clobbering any stack already set up. */
124 static char *stack_usage_map;
126 /* Size of STACK_USAGE_MAP. */
127 static int highest_outgoing_arg_in_use;
129 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
130 stack location's tail call argument has been already stored into the stack.
131 This bitmap is used to prevent sibling call optimization if function tries
132 to use parent's incoming argument slots when they have been already
133 overwritten with tail call arguments. */
134 static sbitmap stored_args_map;
136 /* stack_arg_under_construction is nonzero when an argument may be
137 initialized with a constructor call (including a C function that
138 returns a BLKmode struct) and expand_call must take special action
139 to make sure the object being constructed does not overlap the
140 argument list for the constructor call. */
141 int stack_arg_under_construction;
143 static int calls_function (tree, int);
144 static int calls_function_1 (tree, int);
146 static void emit_call_1 (rtx, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
147 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
149 static void precompute_register_parameters (int, struct arg_data *, int *);
150 static int store_one_arg (struct arg_data *, rtx, int, int, int);
151 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
152 static int finalize_must_preallocate (int, int, struct arg_data *,
154 static void precompute_arguments (int, int, struct arg_data *);
155 static int compute_argument_block_size (int, struct args_size *, int);
156 static void initialize_argument_information (int, struct arg_data *,
157 struct args_size *, int, tree,
158 tree, CUMULATIVE_ARGS *, int,
159 rtx *, int *, int *, int *);
160 static void compute_argument_addresses (struct arg_data *, rtx, int);
161 static rtx rtx_for_function_call (tree, tree);
162 static void load_register_parameters (struct arg_data *, int, rtx *, int,
164 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
165 enum machine_mode, int, va_list);
166 static int special_function_p (tree, int);
167 static rtx try_to_integrate (tree, tree, rtx, int, tree, rtx);
168 static int check_sibcall_argument_overlap_1 (rtx);
169 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
171 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
173 static tree fix_unsafe_tree (tree);
175 #ifdef REG_PARM_STACK_SPACE
176 static rtx save_fixed_argument_area (int, rtx, int *, int *);
177 static void restore_fixed_argument_area (rtx, rtx, int, int);
180 /* If WHICH is 1, return 1 if EXP contains a call to the built-in function
183 If WHICH is 0, return 1 if EXP contains a call to any function.
184 Actually, we only need return 1 if evaluating EXP would require pushing
185 arguments on the stack, but that is too difficult to compute, so we just
186 assume any function call might require the stack. */
188 static tree calls_function_save_exprs;
191 calls_function (tree exp, int which)
195 calls_function_save_exprs = 0;
196 val = calls_function_1 (exp, which);
197 calls_function_save_exprs = 0;
201 /* Recursive function to do the work of above function. */
204 calls_function_1 (tree exp, int which)
207 enum tree_code code = TREE_CODE (exp);
208 int class = TREE_CODE_CLASS (code);
209 int length = first_rtl_op (code);
211 /* If this code is language-specific, we don't know what it will do. */
212 if ((int) code >= NUM_TREE_CODES)
220 else if ((TREE_CODE (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))
222 && (TYPE_RETURNS_STACK_DEPRESSED
223 (TREE_TYPE (TREE_TYPE (TREE_OPERAND (exp, 0))))))
225 else if (TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
226 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
228 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
230 & ECF_MAY_BE_ALLOCA))
239 for (tem = CONSTRUCTOR_ELTS (exp); tem != 0; tem = TREE_CHAIN (tem))
240 if (calls_function_1 (TREE_VALUE (tem), which))
247 if (SAVE_EXPR_RTL (exp) != 0)
249 if (value_member (exp, calls_function_save_exprs))
251 calls_function_save_exprs = tree_cons (NULL_TREE, exp,
252 calls_function_save_exprs);
253 return (TREE_OPERAND (exp, 0) != 0
254 && calls_function_1 (TREE_OPERAND (exp, 0), which));
261 for (local = BLOCK_VARS (exp); local; local = TREE_CHAIN (local))
262 if (DECL_INITIAL (local) != 0
263 && calls_function_1 (DECL_INITIAL (local), which))
266 for (subblock = BLOCK_SUBBLOCKS (exp);
268 subblock = TREE_CHAIN (subblock))
269 if (calls_function_1 (subblock, which))
275 for (; exp != 0; exp = TREE_CHAIN (exp))
276 if (calls_function_1 (TREE_VALUE (exp), which))
284 /* Only expressions, references, and blocks can contain calls. */
285 if (! IS_EXPR_CODE_CLASS (class) && class != 'r' && class != 'b')
288 for (i = 0; i < length; i++)
289 if (TREE_OPERAND (exp, i) != 0
290 && calls_function_1 (TREE_OPERAND (exp, i), which))
296 /* Force FUNEXP into a form suitable for the address of a CALL,
297 and return that as an rtx. Also load the static chain register
298 if FNDECL is a nested function.
300 CALL_FUSAGE points to a variable holding the prospective
301 CALL_INSN_FUNCTION_USAGE information. */
304 prepare_call_address (rtx funexp, tree fndecl, rtx *call_fusage,
305 int reg_parm_seen, int sibcallp)
307 rtx static_chain_value = 0;
309 funexp = protect_from_queue (funexp, 0);
312 /* Get possible static chain value for nested function in C. */
313 static_chain_value = lookup_static_chain (fndecl);
315 /* Make a valid memory address and copy constants thru pseudo-regs,
316 but not for a constant address if -fno-function-cse. */
317 if (GET_CODE (funexp) != SYMBOL_REF)
318 /* If we are using registers for parameters, force the
319 function address into a register now. */
320 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
321 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
322 : memory_address (FUNCTION_MODE, funexp));
325 #ifndef NO_FUNCTION_CSE
326 if (optimize && ! flag_no_function_cse)
327 #ifdef NO_RECURSIVE_FUNCTION_CSE
328 if (fndecl != current_function_decl)
330 funexp = force_reg (Pmode, funexp);
334 if (static_chain_value != 0)
336 emit_move_insn (static_chain_rtx, static_chain_value);
338 if (GET_CODE (static_chain_rtx) == REG)
339 use_reg (call_fusage, static_chain_rtx);
345 /* Generate instructions to call function FUNEXP,
346 and optionally pop the results.
347 The CALL_INSN is the first insn generated.
349 FNDECL is the declaration node of the function. This is given to the
350 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
352 FUNTYPE is the data type of the function. This is given to the macro
353 RETURN_POPS_ARGS to determine whether this function pops its own args.
354 We used to allow an identifier for library functions, but that doesn't
355 work when the return type is an aggregate type and the calling convention
356 says that the pointer to this aggregate is to be popped by the callee.
358 STACK_SIZE is the number of bytes of arguments on the stack,
359 ROUNDED_STACK_SIZE is that number rounded up to
360 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
361 both to put into the call insn and to generate explicit popping
364 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
365 It is zero if this call doesn't want a structure value.
367 NEXT_ARG_REG is the rtx that results from executing
368 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
369 just after all the args have had their registers assigned.
370 This could be whatever you like, but normally it is the first
371 arg-register beyond those used for args in this call,
372 or 0 if all the arg-registers are used in this call.
373 It is passed on to `gen_call' so you can put this info in the call insn.
375 VALREG is a hard register in which a value is returned,
376 or 0 if the call does not return a value.
378 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
379 the args to this call were processed.
380 We restore `inhibit_defer_pop' to that value.
382 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
383 denote registers used by the called function. */
386 emit_call_1 (rtx funexp, tree fndecl, tree funtype,
387 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
388 HOST_WIDE_INT rounded_stack_size,
389 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
390 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
391 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
392 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
394 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
396 int already_popped = 0;
397 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
398 #if defined (HAVE_call) && defined (HAVE_call_value)
399 rtx struct_value_size_rtx;
400 struct_value_size_rtx = GEN_INT (struct_value_size);
403 #ifdef CALL_POPS_ARGS
404 n_popped += CALL_POPS_ARGS (* args_so_far);
407 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
408 and we don't want to load it into a register as an optimization,
409 because prepare_call_address already did it if it should be done. */
410 if (GET_CODE (funexp) != SYMBOL_REF)
411 funexp = memory_address (FUNCTION_MODE, funexp);
413 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
414 if ((ecf_flags & ECF_SIBCALL)
415 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
416 && (n_popped > 0 || stack_size == 0))
418 rtx n_pop = GEN_INT (n_popped);
421 /* If this subroutine pops its own args, record that in the call insn
422 if possible, for the sake of frame pointer elimination. */
425 pat = GEN_SIBCALL_VALUE_POP (valreg,
426 gen_rtx_MEM (FUNCTION_MODE, funexp),
427 rounded_stack_size_rtx, next_arg_reg,
430 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
431 rounded_stack_size_rtx, next_arg_reg, n_pop);
433 emit_call_insn (pat);
439 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
440 /* If the target has "call" or "call_value" insns, then prefer them
441 if no arguments are actually popped. If the target does not have
442 "call" or "call_value" insns, then we must use the popping versions
443 even if the call has no arguments to pop. */
444 #if defined (HAVE_call) && defined (HAVE_call_value)
445 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
446 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
448 if (HAVE_call_pop && HAVE_call_value_pop)
451 rtx n_pop = GEN_INT (n_popped);
454 /* If this subroutine pops its own args, record that in the call insn
455 if possible, for the sake of frame pointer elimination. */
458 pat = GEN_CALL_VALUE_POP (valreg,
459 gen_rtx_MEM (FUNCTION_MODE, funexp),
460 rounded_stack_size_rtx, next_arg_reg, n_pop);
462 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
463 rounded_stack_size_rtx, next_arg_reg, n_pop);
465 emit_call_insn (pat);
471 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
472 if ((ecf_flags & ECF_SIBCALL)
473 && HAVE_sibcall && HAVE_sibcall_value)
476 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
477 gen_rtx_MEM (FUNCTION_MODE, funexp),
478 rounded_stack_size_rtx,
479 next_arg_reg, NULL_RTX));
481 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
482 rounded_stack_size_rtx, next_arg_reg,
483 struct_value_size_rtx));
488 #if defined (HAVE_call) && defined (HAVE_call_value)
489 if (HAVE_call && HAVE_call_value)
492 emit_call_insn (GEN_CALL_VALUE (valreg,
493 gen_rtx_MEM (FUNCTION_MODE, funexp),
494 rounded_stack_size_rtx, next_arg_reg,
497 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
498 rounded_stack_size_rtx, next_arg_reg,
499 struct_value_size_rtx));
505 /* Find the call we just emitted. */
506 call_insn = last_call_insn ();
508 /* Mark memory as used for "pure" function call. */
509 if (ecf_flags & ECF_PURE)
513 gen_rtx_USE (VOIDmode,
514 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
517 /* Put the register usage information there. */
518 add_function_usage_to (call_insn, call_fusage);
520 /* If this is a const call, then set the insn's unchanging bit. */
521 if (ecf_flags & (ECF_CONST | ECF_PURE))
522 CONST_OR_PURE_CALL_P (call_insn) = 1;
524 /* If this call can't throw, attach a REG_EH_REGION reg note to that
526 if (ecf_flags & ECF_NOTHROW)
527 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
528 REG_NOTES (call_insn));
530 note_eh_region_may_contain_throw ();
532 if (ecf_flags & ECF_NORETURN)
533 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
534 REG_NOTES (call_insn));
535 if (ecf_flags & ECF_ALWAYS_RETURN)
536 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_ALWAYS_RETURN, const0_rtx,
537 REG_NOTES (call_insn));
539 if (ecf_flags & ECF_RETURNS_TWICE)
541 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
542 REG_NOTES (call_insn));
543 current_function_calls_setjmp = 1;
546 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
548 /* Restore this now, so that we do defer pops for this call's args
549 if the context of the call as a whole permits. */
550 inhibit_defer_pop = old_inhibit_defer_pop;
555 CALL_INSN_FUNCTION_USAGE (call_insn)
556 = gen_rtx_EXPR_LIST (VOIDmode,
557 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
558 CALL_INSN_FUNCTION_USAGE (call_insn));
559 rounded_stack_size -= n_popped;
560 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
561 stack_pointer_delta -= n_popped;
564 if (!ACCUMULATE_OUTGOING_ARGS)
566 /* If returning from the subroutine does not automatically pop the args,
567 we need an instruction to pop them sooner or later.
568 Perhaps do it now; perhaps just record how much space to pop later.
570 If returning from the subroutine does pop the args, indicate that the
571 stack pointer will be changed. */
573 if (rounded_stack_size != 0)
575 if (ecf_flags & ECF_SP_DEPRESSED)
576 /* Just pretend we did the pop. */
577 stack_pointer_delta -= rounded_stack_size;
578 else if (flag_defer_pop && inhibit_defer_pop == 0
579 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
580 pending_stack_adjust += rounded_stack_size;
582 adjust_stack (rounded_stack_size_rtx);
585 /* When we accumulate outgoing args, we must avoid any stack manipulations.
586 Restore the stack pointer to its original value now. Usually
587 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
588 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
589 popping variants of functions exist as well.
591 ??? We may optimize similar to defer_pop above, but it is
592 probably not worthwhile.
594 ??? It will be worthwhile to enable combine_stack_adjustments even for
597 anti_adjust_stack (GEN_INT (n_popped));
600 /* Determine if the function identified by NAME and FNDECL is one with
601 special properties we wish to know about.
603 For example, if the function might return more than one time (setjmp), then
604 set RETURNS_TWICE to a nonzero value.
606 Similarly set LONGJMP for if the function is in the longjmp family.
608 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
609 space from the stack such as alloca. */
612 special_function_p (tree fndecl, int flags)
614 if (! (flags & ECF_MALLOC)
615 && fndecl && DECL_NAME (fndecl)
616 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
617 /* Exclude functions not at the file scope, or not `extern',
618 since they are not the magic functions we would otherwise
620 && DECL_CONTEXT (fndecl) == NULL_TREE && TREE_PUBLIC (fndecl))
622 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
623 const char *tname = name;
625 /* We assume that alloca will always be called by name. It
626 makes no sense to pass it as a pointer-to-function to
627 anything that does not understand its behavior. */
628 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
630 && ! strcmp (name, "alloca"))
631 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
633 && ! strcmp (name, "__builtin_alloca"))))
634 flags |= ECF_MAY_BE_ALLOCA;
636 /* Disregard prefix _, __ or __x. */
639 if (name[1] == '_' && name[2] == 'x')
641 else if (name[1] == '_')
650 && (! strcmp (tname, "setjmp")
651 || ! strcmp (tname, "setjmp_syscall")))
653 && ! strcmp (tname, "sigsetjmp"))
655 && ! strcmp (tname, "savectx")))
656 flags |= ECF_RETURNS_TWICE;
659 && ! strcmp (tname, "siglongjmp"))
660 flags |= ECF_LONGJMP;
662 else if ((tname[0] == 'q' && tname[1] == 's'
663 && ! strcmp (tname, "qsetjmp"))
664 || (tname[0] == 'v' && tname[1] == 'f'
665 && ! strcmp (tname, "vfork")))
666 flags |= ECF_RETURNS_TWICE;
668 else if (tname[0] == 'l' && tname[1] == 'o'
669 && ! strcmp (tname, "longjmp"))
670 flags |= ECF_LONGJMP;
672 else if ((tname[0] == 'f' && tname[1] == 'o'
673 && ! strcmp (tname, "fork"))
674 /* Linux specific: __clone. check NAME to insist on the
675 leading underscores, to avoid polluting the ISO / POSIX
677 || (name[0] == '_' && name[1] == '_'
678 && ! strcmp (tname, "clone"))
679 || (tname[0] == 'e' && tname[1] == 'x' && tname[2] == 'e'
680 && tname[3] == 'c' && (tname[4] == 'l' || tname[4] == 'v')
682 || ((tname[5] == 'p' || tname[5] == 'e')
683 && tname[6] == '\0'))))
684 flags |= ECF_FORK_OR_EXEC;
689 /* Return nonzero when tree represent call to longjmp. */
692 setjmp_call_p (tree fndecl)
694 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
697 /* Return true when exp contains alloca call. */
699 alloca_call_p (tree exp)
701 if (TREE_CODE (exp) == CALL_EXPR
702 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
703 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
705 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
706 0) & ECF_MAY_BE_ALLOCA))
711 /* Detect flags (function attributes) from the function decl or type node. */
714 flags_from_decl_or_type (tree exp)
721 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
722 type = TREE_TYPE (exp);
726 if (i->pure_function)
727 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
728 if (i->const_function)
729 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
732 /* The function exp may have the `malloc' attribute. */
733 if (DECL_IS_MALLOC (exp))
736 /* The function exp may have the `pure' attribute. */
737 if (DECL_IS_PURE (exp))
738 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
740 if (TREE_NOTHROW (exp))
741 flags |= ECF_NOTHROW;
744 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
745 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
747 if (TREE_THIS_VOLATILE (exp))
748 flags |= ECF_NORETURN;
750 /* Mark if the function returns with the stack pointer depressed. We
751 cannot consider it pure or constant in that case. */
752 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
754 flags |= ECF_SP_DEPRESSED;
755 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
761 /* Precompute all register parameters as described by ARGS, storing values
762 into fields within the ARGS array.
764 NUM_ACTUALS indicates the total number elements in the ARGS array.
766 Set REG_PARM_SEEN if we encounter a register parameter. */
769 precompute_register_parameters (int num_actuals, struct arg_data *args, int *reg_parm_seen)
775 for (i = 0; i < num_actuals; i++)
776 if (args[i].reg != 0 && ! args[i].pass_on_stack)
780 if (args[i].value == 0)
783 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
785 preserve_temp_slots (args[i].value);
788 /* ANSI doesn't require a sequence point here,
789 but PCC has one, so this will avoid some problems. */
793 /* If the value is a non-legitimate constant, force it into a
794 pseudo now. TLS symbols sometimes need a call to resolve. */
795 if (CONSTANT_P (args[i].value)
796 && !LEGITIMATE_CONSTANT_P (args[i].value))
797 args[i].value = force_reg (args[i].mode, args[i].value);
799 /* If we are to promote the function arg to a wider mode,
802 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
804 = convert_modes (args[i].mode,
805 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
806 args[i].value, args[i].unsignedp);
808 /* If the value is expensive, and we are inside an appropriately
809 short loop, put the value into a pseudo and then put the pseudo
812 For small register classes, also do this if this call uses
813 register parameters. This is to avoid reload conflicts while
814 loading the parameters registers. */
816 if ((! (GET_CODE (args[i].value) == REG
817 || (GET_CODE (args[i].value) == SUBREG
818 && GET_CODE (SUBREG_REG (args[i].value)) == REG)))
819 && args[i].mode != BLKmode
820 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
821 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
822 || preserve_subexpressions_p ()))
823 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
827 #ifdef REG_PARM_STACK_SPACE
829 /* The argument list is the property of the called routine and it
830 may clobber it. If the fixed area has been used for previous
831 parameters, we must save and restore it. */
834 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
839 /* Compute the boundary of the area that needs to be saved, if any. */
840 high = reg_parm_stack_space;
841 #ifdef ARGS_GROW_DOWNWARD
844 if (high > highest_outgoing_arg_in_use)
845 high = highest_outgoing_arg_in_use;
847 for (low = 0; low < high; low++)
848 if (stack_usage_map[low] != 0)
851 enum machine_mode save_mode;
856 while (stack_usage_map[--high] == 0)
860 *high_to_save = high;
862 num_to_save = high - low + 1;
863 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
865 /* If we don't have the required alignment, must do this
867 if ((low & (MIN (GET_MODE_SIZE (save_mode),
868 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
871 #ifdef ARGS_GROW_DOWNWARD
876 stack_area = gen_rtx_MEM (save_mode,
877 memory_address (save_mode,
878 plus_constant (argblock,
881 set_mem_align (stack_area, PARM_BOUNDARY);
882 if (save_mode == BLKmode)
884 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
885 emit_block_move (validize_mem (save_area), stack_area,
886 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
890 save_area = gen_reg_rtx (save_mode);
891 emit_move_insn (save_area, stack_area);
901 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
903 enum machine_mode save_mode = GET_MODE (save_area);
907 #ifdef ARGS_GROW_DOWNWARD
908 delta = -high_to_save;
912 stack_area = gen_rtx_MEM (save_mode,
913 memory_address (save_mode,
914 plus_constant (argblock, delta)));
915 set_mem_align (stack_area, PARM_BOUNDARY);
917 if (save_mode != BLKmode)
918 emit_move_insn (stack_area, save_area);
920 emit_block_move (stack_area, validize_mem (save_area),
921 GEN_INT (high_to_save - low_to_save + 1),
924 #endif /* REG_PARM_STACK_SPACE */
926 /* If any elements in ARGS refer to parameters that are to be passed in
927 registers, but not in memory, and whose alignment does not permit a
928 direct copy into registers. Copy the values into a group of pseudos
929 which we will later copy into the appropriate hard registers.
931 Pseudos for each unaligned argument will be stored into the array
932 args[argnum].aligned_regs. The caller is responsible for deallocating
933 the aligned_regs array if it is nonzero. */
936 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
940 for (i = 0; i < num_actuals; i++)
941 if (args[i].reg != 0 && ! args[i].pass_on_stack
942 && args[i].mode == BLKmode
943 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
944 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
946 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
947 int big_endian_correction = 0;
949 args[i].n_aligned_regs
950 = args[i].partial ? args[i].partial
951 : (bytes + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
953 args[i].aligned_regs = (rtx *) xmalloc (sizeof (rtx)
954 * args[i].n_aligned_regs);
956 /* Structures smaller than a word are aligned to the least
957 significant byte (to the right). On a BYTES_BIG_ENDIAN machine,
958 this means we must skip the empty high order bytes when
959 calculating the bit offset. */
961 && bytes < UNITS_PER_WORD)
962 big_endian_correction = (BITS_PER_WORD - (bytes * BITS_PER_UNIT));
964 for (j = 0; j < args[i].n_aligned_regs; j++)
966 rtx reg = gen_reg_rtx (word_mode);
967 rtx word = operand_subword_force (args[i].value, j, BLKmode);
968 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
970 args[i].aligned_regs[j] = reg;
972 /* There is no need to restrict this code to loading items
973 in TYPE_ALIGN sized hunks. The bitfield instructions can
974 load up entire word sized registers efficiently.
976 ??? This may not be needed anymore.
977 We use to emit a clobber here but that doesn't let later
978 passes optimize the instructions we emit. By storing 0 into
979 the register later passes know the first AND to zero out the
980 bitfield being set in the register is unnecessary. The store
981 of 0 will be deleted as will at least the first AND. */
983 emit_move_insn (reg, const0_rtx);
985 bytes -= bitsize / BITS_PER_UNIT;
986 store_bit_field (reg, bitsize, big_endian_correction, word_mode,
987 extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
988 word_mode, word_mode,
995 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
998 NUM_ACTUALS is the total number of parameters.
1000 N_NAMED_ARGS is the total number of named arguments.
1002 FNDECL is the tree code for the target of this call (if known)
1004 ARGS_SO_FAR holds state needed by the target to know where to place
1007 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
1008 for arguments which are passed in registers.
1010 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
1011 and may be modified by this routine.
1013 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
1014 flags which may may be modified by this routine. */
1017 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
1018 struct arg_data *args,
1019 struct args_size *args_size,
1020 int n_named_args ATTRIBUTE_UNUSED,
1021 tree actparms, tree fndecl,
1022 CUMULATIVE_ARGS *args_so_far,
1023 int reg_parm_stack_space,
1024 rtx *old_stack_level, int *old_pending_adj,
1025 int *must_preallocate, int *ecf_flags)
1027 /* 1 if scanning parms front to back, -1 if scanning back to front. */
1030 /* Count arg position in order args appear. */
1036 args_size->constant = 0;
1039 /* In this loop, we consider args in the order they are written.
1040 We fill up ARGS from the front or from the back if necessary
1041 so that in any case the first arg to be pushed ends up at the front. */
1043 if (PUSH_ARGS_REVERSED)
1045 i = num_actuals - 1, inc = -1;
1046 /* In this case, must reverse order of args
1047 so that we compute and push the last arg first. */
1054 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1055 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
1057 tree type = TREE_TYPE (TREE_VALUE (p));
1059 enum machine_mode mode;
1061 args[i].tree_value = TREE_VALUE (p);
1063 /* Replace erroneous argument with constant zero. */
1064 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1065 args[i].tree_value = integer_zero_node, type = integer_type_node;
1067 /* If TYPE is a transparent union, pass things the way we would
1068 pass the first field of the union. We have already verified that
1069 the modes are the same. */
1070 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1071 type = TREE_TYPE (TYPE_FIELDS (type));
1073 /* Decide where to pass this arg.
1075 args[i].reg is nonzero if all or part is passed in registers.
1077 args[i].partial is nonzero if part but not all is passed in registers,
1078 and the exact value says how many words are passed in registers.
1080 args[i].pass_on_stack is nonzero if the argument must at least be
1081 computed on the stack. It may then be loaded back into registers
1082 if args[i].reg is nonzero.
1084 These decisions are driven by the FUNCTION_... macros and must agree
1085 with those made by function.c. */
1087 /* See if this argument should be passed by invisible reference. */
1088 if (CONTAINS_PLACEHOLDER_P (TYPE_SIZE (type))
1089 || TREE_ADDRESSABLE (type)
1090 #ifdef FUNCTION_ARG_PASS_BY_REFERENCE
1091 || FUNCTION_ARG_PASS_BY_REFERENCE (*args_so_far, TYPE_MODE (type),
1092 type, argpos < n_named_args)
1096 /* If we're compiling a thunk, pass through invisible
1097 references instead of making a copy. */
1098 if (current_function_is_thunk
1099 #ifdef FUNCTION_ARG_CALLEE_COPIES
1100 || (FUNCTION_ARG_CALLEE_COPIES (*args_so_far, TYPE_MODE (type),
1101 type, argpos < n_named_args)
1102 /* If it's in a register, we must make a copy of it too. */
1103 /* ??? Is this a sufficient test? Is there a better one? */
1104 && !(TREE_CODE (args[i].tree_value) == VAR_DECL
1105 && REG_P (DECL_RTL (args[i].tree_value)))
1106 && ! TREE_ADDRESSABLE (type))
1110 /* C++ uses a TARGET_EXPR to indicate that we want to make a
1111 new object from the argument. If we are passing by
1112 invisible reference, the callee will do that for us, so we
1113 can strip off the TARGET_EXPR. This is not always safe,
1114 but it is safe in the only case where this is a useful
1115 optimization; namely, when the argument is a plain object.
1116 In that case, the frontend is just asking the backend to
1117 make a bitwise copy of the argument. */
1119 if (TREE_CODE (args[i].tree_value) == TARGET_EXPR
1120 && (DECL_P (TREE_OPERAND (args[i].tree_value, 1)))
1121 && ! REG_P (DECL_RTL (TREE_OPERAND (args[i].tree_value, 1))))
1122 args[i].tree_value = TREE_OPERAND (args[i].tree_value, 1);
1124 args[i].tree_value = build1 (ADDR_EXPR,
1125 build_pointer_type (type),
1126 args[i].tree_value);
1127 type = build_pointer_type (type);
1129 else if (TREE_CODE (args[i].tree_value) == TARGET_EXPR)
1131 /* In the V3 C++ ABI, parameters are destroyed in the caller.
1132 We implement this by passing the address of the temporary
1133 rather than expanding it into another allocated slot. */
1134 args[i].tree_value = build1 (ADDR_EXPR,
1135 build_pointer_type (type),
1136 args[i].tree_value);
1137 type = build_pointer_type (type);
1141 /* We make a copy of the object and pass the address to the
1142 function being called. */
1145 if (!COMPLETE_TYPE_P (type)
1146 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1147 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1148 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1149 STACK_CHECK_MAX_VAR_SIZE))))
1151 /* This is a variable-sized object. Make space on the stack
1153 rtx size_rtx = expr_size (TREE_VALUE (p));
1155 if (*old_stack_level == 0)
1157 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1158 *old_pending_adj = pending_stack_adjust;
1159 pending_stack_adjust = 0;
1162 copy = gen_rtx_MEM (BLKmode,
1163 allocate_dynamic_stack_space
1164 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1165 set_mem_attributes (copy, type, 1);
1168 copy = assign_temp (type, 0, 1, 0);
1170 store_expr (args[i].tree_value, copy, 0);
1171 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1173 args[i].tree_value = build1 (ADDR_EXPR,
1174 build_pointer_type (type),
1175 make_tree (type, copy));
1176 type = build_pointer_type (type);
1180 mode = TYPE_MODE (type);
1181 unsignedp = TREE_UNSIGNED (type);
1183 #ifdef PROMOTE_FUNCTION_ARGS
1184 mode = promote_mode (type, mode, &unsignedp, 1);
1187 args[i].unsignedp = unsignedp;
1188 args[i].mode = mode;
1190 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1191 argpos < n_named_args);
1192 #ifdef FUNCTION_INCOMING_ARG
1193 /* If this is a sibling call and the machine has register windows, the
1194 register window has to be unwinded before calling the routine, so
1195 arguments have to go into the incoming registers. */
1196 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1197 argpos < n_named_args);
1199 args[i].tail_call_reg = args[i].reg;
1202 #ifdef FUNCTION_ARG_PARTIAL_NREGS
1205 = FUNCTION_ARG_PARTIAL_NREGS (*args_so_far, mode, type,
1206 argpos < n_named_args);
1209 args[i].pass_on_stack = MUST_PASS_IN_STACK (mode, type);
1211 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1212 it means that we are to pass this arg in the register(s) designated
1213 by the PARALLEL, but also to pass it in the stack. */
1214 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1215 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1216 args[i].pass_on_stack = 1;
1218 /* If this is an addressable type, we must preallocate the stack
1219 since we must evaluate the object into its final location.
1221 If this is to be passed in both registers and the stack, it is simpler
1223 if (TREE_ADDRESSABLE (type)
1224 || (args[i].pass_on_stack && args[i].reg != 0))
1225 *must_preallocate = 1;
1227 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1228 we cannot consider this function call constant. */
1229 if (TREE_ADDRESSABLE (type))
1230 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1232 /* Compute the stack-size of this argument. */
1233 if (args[i].reg == 0 || args[i].partial != 0
1234 || reg_parm_stack_space > 0
1235 || args[i].pass_on_stack)
1236 locate_and_pad_parm (mode, type,
1237 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1242 args[i].pass_on_stack ? 0 : args[i].partial,
1243 fndecl, args_size, &args[i].locate);
1245 /* Update ARGS_SIZE, the total stack space for args so far. */
1247 args_size->constant += args[i].locate.size.constant;
1248 if (args[i].locate.size.var)
1249 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1251 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1252 have been used, etc. */
1254 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1255 argpos < n_named_args);
1259 /* Update ARGS_SIZE to contain the total size for the argument block.
1260 Return the original constant component of the argument block's size.
1262 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1263 for arguments passed in registers. */
1266 compute_argument_block_size (int reg_parm_stack_space,
1267 struct args_size *args_size,
1268 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1270 int unadjusted_args_size = args_size->constant;
1272 /* For accumulate outgoing args mode we don't need to align, since the frame
1273 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1274 backends from generating misaligned frame sizes. */
1275 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1276 preferred_stack_boundary = STACK_BOUNDARY;
1278 /* Compute the actual size of the argument block required. The variable
1279 and constant sizes must be combined, the size may have to be rounded,
1280 and there may be a minimum required size. */
1284 args_size->var = ARGS_SIZE_TREE (*args_size);
1285 args_size->constant = 0;
1287 preferred_stack_boundary /= BITS_PER_UNIT;
1288 if (preferred_stack_boundary > 1)
1290 /* We don't handle this case yet. To handle it correctly we have
1291 to add the delta, round and subtract the delta.
1292 Currently no machine description requires this support. */
1293 if (stack_pointer_delta & (preferred_stack_boundary - 1))
1295 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1298 if (reg_parm_stack_space > 0)
1301 = size_binop (MAX_EXPR, args_size->var,
1302 ssize_int (reg_parm_stack_space));
1304 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1305 /* The area corresponding to register parameters is not to count in
1306 the size of the block we need. So make the adjustment. */
1308 = size_binop (MINUS_EXPR, args_size->var,
1309 ssize_int (reg_parm_stack_space));
1315 preferred_stack_boundary /= BITS_PER_UNIT;
1316 if (preferred_stack_boundary < 1)
1317 preferred_stack_boundary = 1;
1318 args_size->constant = (((args_size->constant
1319 + stack_pointer_delta
1320 + preferred_stack_boundary - 1)
1321 / preferred_stack_boundary
1322 * preferred_stack_boundary)
1323 - stack_pointer_delta);
1325 args_size->constant = MAX (args_size->constant,
1326 reg_parm_stack_space);
1328 #ifdef MAYBE_REG_PARM_STACK_SPACE
1329 if (reg_parm_stack_space == 0)
1330 args_size->constant = 0;
1333 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1334 args_size->constant -= reg_parm_stack_space;
1337 return unadjusted_args_size;
1340 /* Precompute parameters as needed for a function call.
1342 FLAGS is mask of ECF_* constants.
1344 NUM_ACTUALS is the number of arguments.
1346 ARGS is an array containing information for each argument; this
1347 routine fills in the INITIAL_VALUE and VALUE fields for each
1348 precomputed argument. */
1351 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1355 /* If this function call is cse'able, precompute all the parameters.
1356 Note that if the parameter is constructed into a temporary, this will
1357 cause an additional copy because the parameter will be constructed
1358 into a temporary location and then copied into the outgoing arguments.
1359 If a parameter contains a call to alloca and this function uses the
1360 stack, precompute the parameter. */
1362 /* If we preallocated the stack space, and some arguments must be passed
1363 on the stack, then we must precompute any parameter which contains a
1364 function call which will store arguments on the stack.
1365 Otherwise, evaluating the parameter may clobber previous parameters
1366 which have already been stored into the stack. (we have code to avoid
1367 such case by saving the outgoing stack arguments, but it results in
1370 for (i = 0; i < num_actuals; i++)
1371 if ((flags & ECF_LIBCALL_BLOCK)
1372 || calls_function (args[i].tree_value, !ACCUMULATE_OUTGOING_ARGS))
1374 enum machine_mode mode;
1376 /* If this is an addressable type, we cannot pre-evaluate it. */
1377 if (TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)))
1381 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1383 /* ANSI doesn't require a sequence point here,
1384 but PCC has one, so this will avoid some problems. */
1387 args[i].initial_value = args[i].value
1388 = protect_from_queue (args[i].value, 0);
1390 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1391 if (mode != args[i].mode)
1394 = convert_modes (args[i].mode, mode,
1395 args[i].value, args[i].unsignedp);
1396 #ifdef PROMOTE_FOR_CALL_ONLY
1397 /* CSE will replace this only if it contains args[i].value
1398 pseudo, so convert it down to the declared mode using
1400 if (GET_CODE (args[i].value) == REG
1401 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1403 args[i].initial_value
1404 = gen_lowpart_SUBREG (mode, args[i].value);
1405 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1406 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1414 /* Given the current state of MUST_PREALLOCATE and information about
1415 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1416 compute and return the final value for MUST_PREALLOCATE. */
1419 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1421 /* See if we have or want to preallocate stack space.
1423 If we would have to push a partially-in-regs parm
1424 before other stack parms, preallocate stack space instead.
1426 If the size of some parm is not a multiple of the required stack
1427 alignment, we must preallocate.
1429 If the total size of arguments that would otherwise create a copy in
1430 a temporary (such as a CALL) is more than half the total argument list
1431 size, preallocation is faster.
1433 Another reason to preallocate is if we have a machine (like the m88k)
1434 where stack alignment is required to be maintained between every
1435 pair of insns, not just when the call is made. However, we assume here
1436 that such machines either do not have push insns (and hence preallocation
1437 would occur anyway) or the problem is taken care of with
1440 if (! must_preallocate)
1442 int partial_seen = 0;
1443 int copy_to_evaluate_size = 0;
1446 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1448 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1450 else if (partial_seen && args[i].reg == 0)
1451 must_preallocate = 1;
1453 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1454 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1455 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1456 || TREE_CODE (args[i].tree_value) == COND_EXPR
1457 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1458 copy_to_evaluate_size
1459 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1462 if (copy_to_evaluate_size * 2 >= args_size->constant
1463 && args_size->constant > 0)
1464 must_preallocate = 1;
1466 return must_preallocate;
1469 /* If we preallocated stack space, compute the address of each argument
1470 and store it into the ARGS array.
1472 We need not ensure it is a valid memory address here; it will be
1473 validized when it is used.
1475 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1478 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1482 rtx arg_reg = argblock;
1483 int i, arg_offset = 0;
1485 if (GET_CODE (argblock) == PLUS)
1486 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1488 for (i = 0; i < num_actuals; i++)
1490 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1491 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1494 /* Skip this parm if it will not be passed on the stack. */
1495 if (! args[i].pass_on_stack && args[i].reg != 0)
1498 if (GET_CODE (offset) == CONST_INT)
1499 addr = plus_constant (arg_reg, INTVAL (offset));
1501 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1503 addr = plus_constant (addr, arg_offset);
1504 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1505 set_mem_align (args[i].stack, PARM_BOUNDARY);
1506 set_mem_attributes (args[i].stack,
1507 TREE_TYPE (args[i].tree_value), 1);
1509 if (GET_CODE (slot_offset) == CONST_INT)
1510 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1512 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1514 addr = plus_constant (addr, arg_offset);
1515 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1516 set_mem_align (args[i].stack_slot, PARM_BOUNDARY);
1517 set_mem_attributes (args[i].stack_slot,
1518 TREE_TYPE (args[i].tree_value), 1);
1520 /* Function incoming arguments may overlap with sibling call
1521 outgoing arguments and we cannot allow reordering of reads
1522 from function arguments with stores to outgoing arguments
1523 of sibling calls. */
1524 set_mem_alias_set (args[i].stack, 0);
1525 set_mem_alias_set (args[i].stack_slot, 0);
1530 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1531 in a call instruction.
1533 FNDECL is the tree node for the target function. For an indirect call
1534 FNDECL will be NULL_TREE.
1536 ADDR is the operand 0 of CALL_EXPR for this call. */
1539 rtx_for_function_call (tree fndecl, tree addr)
1543 /* Get the function to call, in the form of RTL. */
1546 /* If this is the first use of the function, see if we need to
1547 make an external definition for it. */
1548 if (! TREE_USED (fndecl))
1550 assemble_external (fndecl);
1551 TREE_USED (fndecl) = 1;
1554 /* Get a SYMBOL_REF rtx for the function address. */
1555 funexp = XEXP (DECL_RTL (fndecl), 0);
1558 /* Generate an rtx (probably a pseudo-register) for the address. */
1561 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1562 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1568 /* Do the register loads required for any wholly-register parms or any
1569 parms which are passed both on the stack and in a register. Their
1570 expressions were already evaluated.
1572 Mark all register-parms as living through the call, putting these USE
1573 insns in the CALL_INSN_FUNCTION_USAGE field.
1575 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1576 checking, setting *SIBCALL_FAILURE if appropriate. */
1579 load_register_parameters (struct arg_data *args, int num_actuals,
1580 rtx *call_fusage, int flags, int is_sibcall,
1581 int *sibcall_failure)
1585 #ifdef LOAD_ARGS_REVERSED
1586 for (i = num_actuals - 1; i >= 0; i--)
1588 for (i = 0; i < num_actuals; i++)
1591 rtx reg = ((flags & ECF_SIBCALL)
1592 ? args[i].tail_call_reg : args[i].reg);
1593 int partial = args[i].partial;
1598 rtx before_arg = get_last_insn ();
1599 /* Set to non-negative if must move a word at a time, even if just
1600 one word (e.g, partial == 1 && mode == DFmode). Set to -1 if
1601 we just use a normal move insn. This value can be zero if the
1602 argument is a zero size structure with no fields. */
1603 nregs = (partial ? partial
1604 : (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1605 ? ((int_size_in_bytes (TREE_TYPE (args[i].tree_value))
1606 + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD)
1609 /* Handle calls that pass values in multiple non-contiguous
1610 locations. The Irix 6 ABI has examples of this. */
1612 if (GET_CODE (reg) == PARALLEL)
1613 emit_group_load (reg, args[i].value,
1614 int_size_in_bytes (TREE_TYPE (args[i].tree_value)));
1616 /* If simple case, just do move. If normal partial, store_one_arg
1617 has already loaded the register for us. In all other cases,
1618 load the register(s) from memory. */
1620 else if (nregs == -1)
1621 emit_move_insn (reg, args[i].value);
1623 /* If we have pre-computed the values to put in the registers in
1624 the case of non-aligned structures, copy them in now. */
1626 else if (args[i].n_aligned_regs != 0)
1627 for (j = 0; j < args[i].n_aligned_regs; j++)
1628 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1629 args[i].aligned_regs[j]);
1631 else if (partial == 0 || args[i].pass_on_stack)
1632 move_block_to_reg (REGNO (reg),
1633 validize_mem (args[i].value), nregs,
1636 /* When a parameter is a block, and perhaps in other cases, it is
1637 possible that it did a load from an argument slot that was
1638 already clobbered. */
1640 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1641 *sibcall_failure = 1;
1643 /* Handle calls that pass values in multiple non-contiguous
1644 locations. The Irix 6 ABI has examples of this. */
1645 if (GET_CODE (reg) == PARALLEL)
1646 use_group_regs (call_fusage, reg);
1647 else if (nregs == -1)
1648 use_reg (call_fusage, reg);
1650 use_regs (call_fusage, REGNO (reg), nregs == 0 ? 1 : nregs);
1655 /* Try to integrate function. See expand_inline_function for documentation
1656 about the parameters. */
1659 try_to_integrate (tree fndecl, tree actparms, rtx target, int ignore,
1660 tree type, rtx structure_value_addr)
1665 rtx old_stack_level = 0;
1666 int reg_parm_stack_space = 0;
1668 #ifdef REG_PARM_STACK_SPACE
1669 #ifdef MAYBE_REG_PARM_STACK_SPACE
1670 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
1672 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1676 before_call = get_last_insn ();
1678 timevar_push (TV_INTEGRATION);
1680 temp = expand_inline_function (fndecl, actparms, target,
1682 structure_value_addr);
1684 timevar_pop (TV_INTEGRATION);
1686 /* If inlining succeeded, return. */
1687 if (temp != (rtx) (size_t) - 1)
1689 if (ACCUMULATE_OUTGOING_ARGS)
1691 /* If the outgoing argument list must be preserved, push
1692 the stack before executing the inlined function if it
1695 i = reg_parm_stack_space;
1696 if (i > highest_outgoing_arg_in_use)
1697 i = highest_outgoing_arg_in_use;
1698 while (--i >= 0 && stack_usage_map[i] == 0)
1701 if (stack_arg_under_construction || i >= 0)
1704 = before_call ? NEXT_INSN (before_call) : get_insns ();
1705 rtx insn = NULL_RTX, seq;
1707 /* Look for a call in the inline function code.
1708 If DECL_SAVED_INSNS (fndecl)->outgoing_args_size is
1709 nonzero then there is a call and it is not necessary
1710 to scan the insns. */
1712 if (DECL_SAVED_INSNS (fndecl)->outgoing_args_size == 0)
1713 for (insn = first_insn; insn; insn = NEXT_INSN (insn))
1714 if (GET_CODE (insn) == CALL_INSN)
1719 /* Reserve enough stack space so that the largest
1720 argument list of any function call in the inline
1721 function does not overlap the argument list being
1722 evaluated. This is usually an overestimate because
1723 allocate_dynamic_stack_space reserves space for an
1724 outgoing argument list in addition to the requested
1725 space, but there is no way to ask for stack space such
1726 that an argument list of a certain length can be
1729 Add the stack space reserved for register arguments, if
1730 any, in the inline function. What is really needed is the
1731 largest value of reg_parm_stack_space in the inline
1732 function, but that is not available. Using the current
1733 value of reg_parm_stack_space is wrong, but gives
1734 correct results on all supported machines. */
1736 int adjust = (DECL_SAVED_INSNS (fndecl)->outgoing_args_size
1737 + reg_parm_stack_space);
1740 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
1741 allocate_dynamic_stack_space (GEN_INT (adjust),
1742 NULL_RTX, BITS_PER_UNIT);
1745 emit_insn_before (seq, first_insn);
1746 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
1751 /* If the result is equivalent to TARGET, return TARGET to simplify
1752 checks in store_expr. They can be equivalent but not equal in the
1753 case of a function that returns BLKmode. */
1754 if (temp != target && rtx_equal_p (temp, target))
1759 /* If inlining failed, mark FNDECL as needing to be compiled
1760 separately after all. If function was declared inline,
1762 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
1763 && optimize > 0 && !TREE_ADDRESSABLE (fndecl))
1765 warning_with_decl (fndecl, "inlining failed in call to `%s'");
1766 warning ("called from here");
1768 (*lang_hooks.mark_addressable) (fndecl);
1769 return (rtx) (size_t) - 1;
1772 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1773 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1774 bytes, then we would need to push some additional bytes to pad the
1775 arguments. So, we compute an adjust to the stack pointer for an
1776 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1777 bytes. Then, when the arguments are pushed the stack will be perfectly
1778 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1779 be popped after the call. Returns the adjustment. */
1782 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1783 struct args_size *args_size,
1784 int preferred_unit_stack_boundary)
1786 /* The number of bytes to pop so that the stack will be
1787 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1788 HOST_WIDE_INT adjustment;
1789 /* The alignment of the stack after the arguments are pushed, if we
1790 just pushed the arguments without adjust the stack here. */
1791 HOST_WIDE_INT unadjusted_alignment;
1793 unadjusted_alignment
1794 = ((stack_pointer_delta + unadjusted_args_size)
1795 % preferred_unit_stack_boundary);
1797 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1798 as possible -- leaving just enough left to cancel out the
1799 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1800 PENDING_STACK_ADJUST is non-negative, and congruent to
1801 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1803 /* Begin by trying to pop all the bytes. */
1804 unadjusted_alignment
1805 = (unadjusted_alignment
1806 - (pending_stack_adjust % preferred_unit_stack_boundary));
1807 adjustment = pending_stack_adjust;
1808 /* Push enough additional bytes that the stack will be aligned
1809 after the arguments are pushed. */
1810 if (preferred_unit_stack_boundary > 1)
1812 if (unadjusted_alignment > 0)
1813 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1815 adjustment += unadjusted_alignment;
1818 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1819 bytes after the call. The right number is the entire
1820 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1821 by the arguments in the first place. */
1823 = pending_stack_adjust - adjustment + unadjusted_args_size;
1828 /* Scan X expression if it does not dereference any argument slots
1829 we already clobbered by tail call arguments (as noted in stored_args_map
1831 Return nonzero if X expression dereferences such argument slots,
1835 check_sibcall_argument_overlap_1 (rtx x)
1845 code = GET_CODE (x);
1849 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1851 else if (GET_CODE (XEXP (x, 0)) == PLUS
1852 && XEXP (XEXP (x, 0), 0) ==
1853 current_function_internal_arg_pointer
1854 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1855 i = INTVAL (XEXP (XEXP (x, 0), 1));
1859 #ifdef ARGS_GROW_DOWNWARD
1860 i = -i - GET_MODE_SIZE (GET_MODE (x));
1863 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1864 if (i + k < stored_args_map->n_bits
1865 && TEST_BIT (stored_args_map, i + k))
1871 /* Scan all subexpressions. */
1872 fmt = GET_RTX_FORMAT (code);
1873 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1877 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1880 else if (*fmt == 'E')
1882 for (j = 0; j < XVECLEN (x, i); j++)
1883 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1890 /* Scan sequence after INSN if it does not dereference any argument slots
1891 we already clobbered by tail call arguments (as noted in stored_args_map
1892 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1893 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1894 should be 0). Return nonzero if sequence after INSN dereferences such argument
1895 slots, zero otherwise. */
1898 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1902 if (insn == NULL_RTX)
1903 insn = get_insns ();
1905 insn = NEXT_INSN (insn);
1907 for (; insn; insn = NEXT_INSN (insn))
1909 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1912 if (mark_stored_args_map)
1914 #ifdef ARGS_GROW_DOWNWARD
1915 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1917 low = arg->locate.slot_offset.constant;
1920 for (high = low + arg->locate.size.constant; low < high; low++)
1921 SET_BIT (stored_args_map, low);
1923 return insn != NULL_RTX;
1927 fix_unsafe_tree (tree t)
1929 switch (unsafe_for_reeval (t))
1934 case 1: /* Mildly unsafe. */
1935 t = unsave_expr (t);
1938 case 2: /* Wildly unsafe. */
1940 tree var = build_decl (VAR_DECL, NULL_TREE,
1943 expand_expr (t, NULL_RTX, VOIDmode, EXPAND_NORMAL));
1954 /* Generate all the code for a function call
1955 and return an rtx for its value.
1956 Store the value in TARGET (specified as an rtx) if convenient.
1957 If the value is stored in TARGET then TARGET is returned.
1958 If IGNORE is nonzero, then we ignore the value of the function call. */
1961 expand_call (tree exp, rtx target, int ignore)
1963 /* Nonzero if we are currently expanding a call. */
1964 static int currently_expanding_call = 0;
1966 /* List of actual parameters. */
1967 tree actparms = TREE_OPERAND (exp, 1);
1968 /* RTX for the function to be called. */
1970 /* Sequence of insns to perform a tail recursive "call". */
1971 rtx tail_recursion_insns = NULL_RTX;
1972 /* Sequence of insns to perform a normal "call". */
1973 rtx normal_call_insns = NULL_RTX;
1974 /* Sequence of insns to perform a tail recursive "call". */
1975 rtx tail_call_insns = NULL_RTX;
1976 /* Data type of the function. */
1978 tree type_arg_types;
1979 /* Declaration of the function being called,
1980 or 0 if the function is computed (not known by name). */
1983 int try_tail_call = 1;
1984 int try_tail_recursion = 1;
1987 /* Register in which non-BLKmode value will be returned,
1988 or 0 if no value or if value is BLKmode. */
1990 /* Address where we should return a BLKmode value;
1991 0 if value not BLKmode. */
1992 rtx structure_value_addr = 0;
1993 /* Nonzero if that address is being passed by treating it as
1994 an extra, implicit first parameter. Otherwise,
1995 it is passed by being copied directly into struct_value_rtx. */
1996 int structure_value_addr_parm = 0;
1997 /* Size of aggregate value wanted, or zero if none wanted
1998 or if we are using the non-reentrant PCC calling convention
1999 or expecting the value in registers. */
2000 HOST_WIDE_INT struct_value_size = 0;
2001 /* Nonzero if called function returns an aggregate in memory PCC style,
2002 by returning the address of where to find it. */
2003 int pcc_struct_value = 0;
2005 /* Number of actual parameters in this call, including struct value addr. */
2007 /* Number of named args. Args after this are anonymous ones
2008 and they must all go on the stack. */
2011 /* Vector of information about each argument.
2012 Arguments are numbered in the order they will be pushed,
2013 not the order they are written. */
2014 struct arg_data *args;
2016 /* Total size in bytes of all the stack-parms scanned so far. */
2017 struct args_size args_size;
2018 struct args_size adjusted_args_size;
2019 /* Size of arguments before any adjustments (such as rounding). */
2020 int unadjusted_args_size;
2021 /* Data on reg parms scanned so far. */
2022 CUMULATIVE_ARGS args_so_far;
2023 /* Nonzero if a reg parm has been scanned. */
2025 /* Nonzero if this is an indirect function call. */
2027 /* Nonzero if we must avoid push-insns in the args for this call.
2028 If stack space is allocated for register parameters, but not by the
2029 caller, then it is preallocated in the fixed part of the stack frame.
2030 So the entire argument block must then be preallocated (i.e., we
2031 ignore PUSH_ROUNDING in that case). */
2033 int must_preallocate = !PUSH_ARGS;
2035 /* Size of the stack reserved for parameter registers. */
2036 int reg_parm_stack_space = 0;
2038 /* Address of space preallocated for stack parms
2039 (on machines that lack push insns), or 0 if space not preallocated. */
2042 /* Mask of ECF_ flags. */
2044 /* Nonzero if this is a call to an inline function. */
2045 int is_integrable = 0;
2046 #ifdef REG_PARM_STACK_SPACE
2047 /* Define the boundary of the register parm stack space that needs to be
2049 int low_to_save, high_to_save;
2050 rtx save_area = 0; /* Place that it is saved */
2053 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2054 char *initial_stack_usage_map = stack_usage_map;
2056 int old_stack_allocated;
2058 /* State variables to track stack modifications. */
2059 rtx old_stack_level = 0;
2060 int old_stack_arg_under_construction = 0;
2061 int old_pending_adj = 0;
2062 int old_inhibit_defer_pop = inhibit_defer_pop;
2064 /* Some stack pointer alterations we make are performed via
2065 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2066 which we then also need to save/restore along the way. */
2067 int old_stack_pointer_delta = 0;
2070 tree p = TREE_OPERAND (exp, 0);
2071 tree addr = TREE_OPERAND (exp, 0);
2073 /* The alignment of the stack, in bits. */
2074 HOST_WIDE_INT preferred_stack_boundary;
2075 /* The alignment of the stack, in bytes. */
2076 HOST_WIDE_INT preferred_unit_stack_boundary;
2078 /* See if this is "nothrow" function call. */
2079 if (TREE_NOTHROW (exp))
2080 flags |= ECF_NOTHROW;
2082 /* See if we can find a DECL-node for the actual function.
2083 As a result, decide whether this is a call to an integrable function. */
2085 fndecl = get_callee_fndecl (exp);
2089 && fndecl != current_function_decl
2090 && DECL_INLINE (fndecl)
2091 && DECL_SAVED_INSNS (fndecl)
2092 && DECL_SAVED_INSNS (fndecl)->inlinable)
2094 else if (! TREE_ADDRESSABLE (fndecl))
2096 /* In case this function later becomes inlinable,
2097 record that there was already a non-inline call to it.
2099 Use abstraction instead of setting TREE_ADDRESSABLE
2101 if (DECL_INLINE (fndecl) && warn_inline && !flag_no_inline
2104 warning_with_decl (fndecl, "can't inline call to `%s'");
2105 warning ("called from here");
2107 (*lang_hooks.mark_addressable) (fndecl);
2110 flags |= flags_from_decl_or_type (fndecl);
2113 /* If we don't have specific function to call, see if we have a
2114 attributes set in the type. */
2116 flags |= flags_from_decl_or_type (TREE_TYPE (TREE_TYPE (p)));
2118 /* Warn if this value is an aggregate type,
2119 regardless of which calling convention we are using for it. */
2120 if (warn_aggregate_return && AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2121 warning ("function call has aggregate value");
2123 /* If the result of a pure or const function call is ignored (or void),
2124 and none of its arguments are volatile, we can avoid expanding the
2125 call and just evaluate the arguments for side-effects. */
2126 if ((flags & (ECF_CONST | ECF_PURE))
2127 && (ignore || target == const0_rtx
2128 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2130 bool volatilep = false;
2133 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2134 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
2142 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
2143 expand_expr (TREE_VALUE (arg), const0_rtx,
2144 VOIDmode, EXPAND_NORMAL);
2149 #ifdef REG_PARM_STACK_SPACE
2150 #ifdef MAYBE_REG_PARM_STACK_SPACE
2151 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
2153 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2157 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2158 if (reg_parm_stack_space > 0 && PUSH_ARGS)
2159 must_preallocate = 1;
2162 /* Set up a place to return a structure. */
2164 /* Cater to broken compilers. */
2165 if (aggregate_value_p (exp))
2167 /* This call returns a big structure. */
2168 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2170 #ifdef PCC_STATIC_STRUCT_RETURN
2172 pcc_struct_value = 1;
2173 /* Easier than making that case work right. */
2176 /* In case this is a static function, note that it has been
2178 if (! TREE_ADDRESSABLE (fndecl))
2179 (*lang_hooks.mark_addressable) (fndecl);
2183 #else /* not PCC_STATIC_STRUCT_RETURN */
2185 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2187 if (CALL_EXPR_HAS_RETURN_SLOT_ADDR (exp))
2189 /* The structure value address arg is already in actparms.
2190 Pull it out. It might be nice to just leave it there, but
2191 we need to set structure_value_addr. */
2192 tree return_arg = TREE_VALUE (actparms);
2193 actparms = TREE_CHAIN (actparms);
2194 structure_value_addr = expand_expr (return_arg, NULL_RTX,
2195 VOIDmode, EXPAND_NORMAL);
2197 else if (target && GET_CODE (target) == MEM)
2198 structure_value_addr = XEXP (target, 0);
2201 /* For variable-sized objects, we must be called with a target
2202 specified. If we were to allocate space on the stack here,
2203 we would have no way of knowing when to free it. */
2204 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
2206 mark_temp_addr_taken (d);
2207 structure_value_addr = XEXP (d, 0);
2211 #endif /* not PCC_STATIC_STRUCT_RETURN */
2214 /* If called function is inline, try to integrate it. */
2218 rtx temp = try_to_integrate (fndecl, actparms, target,
2219 ignore, TREE_TYPE (exp),
2220 structure_value_addr);
2221 if (temp != (rtx) (size_t) - 1)
2225 /* Figure out the amount to which the stack should be aligned. */
2226 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2229 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2230 if (i && i->preferred_incoming_stack_boundary)
2231 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2234 /* Operand 0 is a pointer-to-function; get the type of the function. */
2235 funtype = TREE_TYPE (addr);
2236 if (! POINTER_TYPE_P (funtype))
2238 funtype = TREE_TYPE (funtype);
2240 /* Munge the tree to split complex arguments into their imaginary
2242 if (SPLIT_COMPLEX_ARGS)
2244 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2245 actparms = split_complex_values (actparms);
2248 type_arg_types = TYPE_ARG_TYPES (funtype);
2250 /* See if this is a call to a function that can return more than once
2251 or a call to longjmp or malloc. */
2252 flags |= special_function_p (fndecl, flags);
2254 if (flags & ECF_MAY_BE_ALLOCA)
2255 current_function_calls_alloca = 1;
2257 /* If struct_value_rtx is 0, it means pass the address
2258 as if it were an extra parameter. */
2259 if (structure_value_addr && struct_value_rtx == 0)
2261 /* If structure_value_addr is a REG other than
2262 virtual_outgoing_args_rtx, we can use always use it. If it
2263 is not a REG, we must always copy it into a register.
2264 If it is virtual_outgoing_args_rtx, we must copy it to another
2265 register in some cases. */
2266 rtx temp = (GET_CODE (structure_value_addr) != REG
2267 || (ACCUMULATE_OUTGOING_ARGS
2268 && stack_arg_under_construction
2269 && structure_value_addr == virtual_outgoing_args_rtx)
2270 ? copy_addr_to_reg (structure_value_addr)
2271 : structure_value_addr);
2274 = tree_cons (error_mark_node,
2275 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2278 structure_value_addr_parm = 1;
2281 /* Count the arguments and set NUM_ACTUALS. */
2282 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2285 /* Compute number of named args.
2286 Normally, don't include the last named arg if anonymous args follow.
2287 We do include the last named arg if STRICT_ARGUMENT_NAMING is nonzero.
2288 (If no anonymous args follow, the result of list_length is actually
2289 one too large. This is harmless.)
2291 If PRETEND_OUTGOING_VARARGS_NAMED is set and STRICT_ARGUMENT_NAMING is
2292 zero, this machine will be able to place unnamed args that were
2293 passed in registers into the stack. So treat all args as named.
2294 This allows the insns emitting for a specific argument list to be
2295 independent of the function declaration.
2297 If PRETEND_OUTGOING_VARARGS_NAMED is not set, we do not have any
2298 reliable way to pass unnamed args in registers, so we must force
2299 them into memory. */
2301 if ((STRICT_ARGUMENT_NAMING
2302 || ! PRETEND_OUTGOING_VARARGS_NAMED)
2303 && type_arg_types != 0)
2305 = (list_length (type_arg_types)
2306 /* Don't include the last named arg. */
2307 - (STRICT_ARGUMENT_NAMING ? 0 : 1)
2308 /* Count the struct value address, if it is passed as a parm. */
2309 + structure_value_addr_parm);
2311 /* If we know nothing, treat all args as named. */
2312 n_named_args = num_actuals;
2314 /* Start updating where the next arg would go.
2316 On some machines (such as the PA) indirect calls have a different
2317 calling convention than normal calls. The last argument in
2318 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2320 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl);
2322 /* Make a vector to hold all the information about each arg. */
2323 args = (struct arg_data *) alloca (num_actuals * sizeof (struct arg_data));
2324 memset ((char *) args, 0, num_actuals * sizeof (struct arg_data));
2326 /* Build up entries in the ARGS array, compute the size of the
2327 arguments into ARGS_SIZE, etc. */
2328 initialize_argument_information (num_actuals, args, &args_size,
2329 n_named_args, actparms, fndecl,
2330 &args_so_far, reg_parm_stack_space,
2331 &old_stack_level, &old_pending_adj,
2332 &must_preallocate, &flags);
2336 /* If this function requires a variable-sized argument list, don't
2337 try to make a cse'able block for this call. We may be able to
2338 do this eventually, but it is too complicated to keep track of
2339 what insns go in the cse'able block and which don't. */
2341 flags &= ~ECF_LIBCALL_BLOCK;
2342 must_preallocate = 1;
2345 /* Now make final decision about preallocating stack space. */
2346 must_preallocate = finalize_must_preallocate (must_preallocate,
2350 /* If the structure value address will reference the stack pointer, we
2351 must stabilize it. We don't need to do this if we know that we are
2352 not going to adjust the stack pointer in processing this call. */
2354 if (structure_value_addr
2355 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2356 || reg_mentioned_p (virtual_outgoing_args_rtx,
2357 structure_value_addr))
2359 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2360 structure_value_addr = copy_to_reg (structure_value_addr);
2362 /* Tail calls can make things harder to debug, and we're traditionally
2363 pushed these optimizations into -O2. Don't try if we're already
2364 expanding a call, as that means we're an argument. Don't try if
2365 there's cleanups, as we know there's code to follow the call.
2367 If rtx_equal_function_value_matters is false, that means we've
2368 finished with regular parsing. Which means that some of the
2369 machinery we use to generate tail-calls is no longer in place.
2370 This is most often true of sjlj-exceptions, which we couldn't
2371 tail-call to anyway. */
2373 if (currently_expanding_call++ != 0
2374 || !flag_optimize_sibling_calls
2375 || !rtx_equal_function_value_matters
2376 || any_pending_cleanups (1)
2378 try_tail_call = try_tail_recursion = 0;
2380 /* Tail recursion fails, when we are not dealing with recursive calls. */
2381 if (!try_tail_recursion
2382 || TREE_CODE (addr) != ADDR_EXPR
2383 || TREE_OPERAND (addr, 0) != current_function_decl)
2384 try_tail_recursion = 0;
2386 /* Rest of purposes for tail call optimizations to fail. */
2388 #ifdef HAVE_sibcall_epilogue
2389 !HAVE_sibcall_epilogue
2394 /* Doing sibling call optimization needs some work, since
2395 structure_value_addr can be allocated on the stack.
2396 It does not seem worth the effort since few optimizable
2397 sibling calls will return a structure. */
2398 || structure_value_addr != NULL_RTX
2399 /* Check whether the target is able to optimize the call
2401 || !(*targetm.function_ok_for_sibcall) (fndecl, exp)
2402 /* Functions that do not return exactly once may not be sibcall
2404 || (flags & (ECF_RETURNS_TWICE | ECF_LONGJMP | ECF_NORETURN))
2405 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2406 /* If the called function is nested in the current one, it might access
2407 some of the caller's arguments, but could clobber them beforehand if
2408 the argument areas are shared. */
2409 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2410 /* If this function requires more stack slots than the current
2411 function, we cannot change it into a sibling call. */
2412 || args_size.constant > current_function_args_size
2413 /* If the callee pops its own arguments, then it must pop exactly
2414 the same number of arguments as the current function. */
2415 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2416 != RETURN_POPS_ARGS (current_function_decl,
2417 TREE_TYPE (current_function_decl),
2418 current_function_args_size))
2419 || !(*lang_hooks.decls.ok_for_sibcall) (fndecl))
2422 if (try_tail_call || try_tail_recursion)
2425 actparms = NULL_TREE;
2426 /* Ok, we're going to give the tail call the old college try.
2427 This means we're going to evaluate the function arguments
2428 up to three times. There are two degrees of badness we can
2429 encounter, those that can be unsaved and those that can't.
2430 (See unsafe_for_reeval commentary for details.)
2432 Generate a new argument list. Pass safe arguments through
2433 unchanged. For the easy badness wrap them in UNSAVE_EXPRs.
2434 For hard badness, evaluate them now and put their resulting
2435 rtx in a temporary VAR_DECL.
2437 initialize_argument_information has ordered the array for the
2438 order to be pushed, and we must remember this when reconstructing
2439 the original argument order. */
2441 if (PUSH_ARGS_REVERSED)
2450 i = num_actuals - 1;
2454 for (; i != end; i += inc)
2456 args[i].tree_value = fix_unsafe_tree (args[i].tree_value);
2457 /* We need to build actparms for optimize_tail_recursion. We can
2458 safely trash away TREE_PURPOSE, since it is unused by this
2460 if (try_tail_recursion)
2461 actparms = tree_cons (NULL_TREE, args[i].tree_value, actparms);
2463 /* Do the same for the function address if it is an expression. */
2465 addr = fix_unsafe_tree (addr);
2466 /* Expanding one of those dangerous arguments could have added
2467 cleanups, but otherwise give it a whirl. */
2468 if (any_pending_cleanups (1))
2469 try_tail_call = try_tail_recursion = 0;
2472 /* Generate a tail recursion sequence when calling ourselves. */
2474 if (try_tail_recursion)
2476 /* We want to emit any pending stack adjustments before the tail
2477 recursion "call". That way we know any adjustment after the tail
2478 recursion call can be ignored if we indeed use the tail recursion
2480 int save_pending_stack_adjust = pending_stack_adjust;
2481 int save_stack_pointer_delta = stack_pointer_delta;
2483 /* Emit any queued insns now; otherwise they would end up in
2484 only one of the alternates. */
2487 /* Use a new sequence to hold any RTL we generate. We do not even
2488 know if we will use this RTL yet. The final decision can not be
2489 made until after RTL generation for the entire function is
2492 /* If expanding any of the arguments creates cleanups, we can't
2493 do a tailcall. So, we'll need to pop the pending cleanups
2494 list. If, however, all goes well, and there are no cleanups
2495 then the call to expand_start_target_temps will have no
2497 expand_start_target_temps ();
2498 if (optimize_tail_recursion (actparms, get_last_insn ()))
2500 if (any_pending_cleanups (1))
2501 try_tail_call = try_tail_recursion = 0;
2503 tail_recursion_insns = get_insns ();
2505 expand_end_target_temps ();
2508 /* Restore the original pending stack adjustment for the sibling and
2509 normal call cases below. */
2510 pending_stack_adjust = save_pending_stack_adjust;
2511 stack_pointer_delta = save_stack_pointer_delta;
2514 if (profile_arc_flag && (flags & ECF_FORK_OR_EXEC))
2516 /* A fork duplicates the profile information, and an exec discards
2517 it. We can't rely on fork/exec to be paired. So write out the
2518 profile information we have gathered so far, and clear it. */
2519 /* ??? When Linux's __clone is called with CLONE_VM set, profiling
2520 is subject to race conditions, just as with multithreaded
2523 emit_library_call (gcov_flush_libfunc, LCT_ALWAYS_RETURN, VOIDmode, 0);
2526 /* Ensure current function's preferred stack boundary is at least
2527 what we need. We don't have to increase alignment for recursive
2529 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2530 && fndecl != current_function_decl)
2531 cfun->preferred_stack_boundary = preferred_stack_boundary;
2532 if (fndecl == current_function_decl)
2533 cfun->recursive_call_emit = true;
2535 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2537 function_call_count++;
2539 /* We want to make two insn chains; one for a sibling call, the other
2540 for a normal call. We will select one of the two chains after
2541 initial RTL generation is complete. */
2542 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2544 int sibcall_failure = 0;
2545 /* We want to emit any pending stack adjustments before the tail
2546 recursion "call". That way we know any adjustment after the tail
2547 recursion call can be ignored if we indeed use the tail recursion
2549 int save_pending_stack_adjust = 0;
2550 int save_stack_pointer_delta = 0;
2552 rtx before_call, next_arg_reg;
2556 /* Emit any queued insns now; otherwise they would end up in
2557 only one of the alternates. */
2560 /* State variables we need to save and restore between
2562 save_pending_stack_adjust = pending_stack_adjust;
2563 save_stack_pointer_delta = stack_pointer_delta;
2566 flags &= ~ECF_SIBCALL;
2568 flags |= ECF_SIBCALL;
2570 /* Other state variables that we must reinitialize each time
2571 through the loop (that are not initialized by the loop itself). */
2575 /* Start a new sequence for the normal call case.
2577 From this point on, if the sibling call fails, we want to set
2578 sibcall_failure instead of continuing the loop. */
2583 /* We know at this point that there are not currently any
2584 pending cleanups. If, however, in the process of evaluating
2585 the arguments we were to create some, we'll need to be
2586 able to get rid of them. */
2587 expand_start_target_temps ();
2590 /* Don't let pending stack adjusts add up to too much.
2591 Also, do all pending adjustments now if there is any chance
2592 this might be a call to alloca or if we are expanding a sibling
2593 call sequence or if we are calling a function that is to return
2594 with stack pointer depressed. */
2595 if (pending_stack_adjust >= 32
2596 || (pending_stack_adjust > 0
2597 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2599 do_pending_stack_adjust ();
2601 /* When calling a const function, we must pop the stack args right away,
2602 so that the pop is deleted or moved with the call. */
2603 if (pass && (flags & ECF_LIBCALL_BLOCK))
2606 #ifdef FINAL_REG_PARM_STACK_SPACE
2607 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
2610 /* Precompute any arguments as needed. */
2612 precompute_arguments (flags, num_actuals, args);
2614 /* Now we are about to start emitting insns that can be deleted
2615 if a libcall is deleted. */
2616 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2619 adjusted_args_size = args_size;
2620 /* Compute the actual size of the argument block required. The variable
2621 and constant sizes must be combined, the size may have to be rounded,
2622 and there may be a minimum required size. When generating a sibcall
2623 pattern, do not round up, since we'll be re-using whatever space our
2625 unadjusted_args_size
2626 = compute_argument_block_size (reg_parm_stack_space,
2627 &adjusted_args_size,
2629 : preferred_stack_boundary));
2631 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2633 /* The argument block when performing a sibling call is the
2634 incoming argument block. */
2637 argblock = virtual_incoming_args_rtx;
2639 #ifdef STACK_GROWS_DOWNWARD
2640 = plus_constant (argblock, current_function_pretend_args_size);
2642 = plus_constant (argblock, -current_function_pretend_args_size);
2644 stored_args_map = sbitmap_alloc (args_size.constant);
2645 sbitmap_zero (stored_args_map);
2648 /* If we have no actual push instructions, or shouldn't use them,
2649 make space for all args right now. */
2650 else if (adjusted_args_size.var != 0)
2652 if (old_stack_level == 0)
2654 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2655 old_stack_pointer_delta = stack_pointer_delta;
2656 old_pending_adj = pending_stack_adjust;
2657 pending_stack_adjust = 0;
2658 /* stack_arg_under_construction says whether a stack arg is
2659 being constructed at the old stack level. Pushing the stack
2660 gets a clean outgoing argument block. */
2661 old_stack_arg_under_construction = stack_arg_under_construction;
2662 stack_arg_under_construction = 0;
2664 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2668 /* Note that we must go through the motions of allocating an argument
2669 block even if the size is zero because we may be storing args
2670 in the area reserved for register arguments, which may be part of
2673 int needed = adjusted_args_size.constant;
2675 /* Store the maximum argument space used. It will be pushed by
2676 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2679 if (needed > current_function_outgoing_args_size)
2680 current_function_outgoing_args_size = needed;
2682 if (must_preallocate)
2684 if (ACCUMULATE_OUTGOING_ARGS)
2686 /* Since the stack pointer will never be pushed, it is
2687 possible for the evaluation of a parm to clobber
2688 something we have already written to the stack.
2689 Since most function calls on RISC machines do not use
2690 the stack, this is uncommon, but must work correctly.
2692 Therefore, we save any area of the stack that was already
2693 written and that we are using. Here we set up to do this
2694 by making a new stack usage map from the old one. The
2695 actual save will be done by store_one_arg.
2697 Another approach might be to try to reorder the argument
2698 evaluations to avoid this conflicting stack usage. */
2700 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2701 /* Since we will be writing into the entire argument area,
2702 the map must be allocated for its entire size, not just
2703 the part that is the responsibility of the caller. */
2704 needed += reg_parm_stack_space;
2707 #ifdef ARGS_GROW_DOWNWARD
2708 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2711 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2715 = (char *) alloca (highest_outgoing_arg_in_use);
2717 if (initial_highest_arg_in_use)
2718 memcpy (stack_usage_map, initial_stack_usage_map,
2719 initial_highest_arg_in_use);
2721 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2722 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2723 (highest_outgoing_arg_in_use
2724 - initial_highest_arg_in_use));
2727 /* The address of the outgoing argument list must not be
2728 copied to a register here, because argblock would be left
2729 pointing to the wrong place after the call to
2730 allocate_dynamic_stack_space below. */
2732 argblock = virtual_outgoing_args_rtx;
2736 if (inhibit_defer_pop == 0)
2738 /* Try to reuse some or all of the pending_stack_adjust
2739 to get this space. */
2741 = (combine_pending_stack_adjustment_and_call
2742 (unadjusted_args_size,
2743 &adjusted_args_size,
2744 preferred_unit_stack_boundary));
2746 /* combine_pending_stack_adjustment_and_call computes
2747 an adjustment before the arguments are allocated.
2748 Account for them and see whether or not the stack
2749 needs to go up or down. */
2750 needed = unadjusted_args_size - needed;
2754 /* We're releasing stack space. */
2755 /* ??? We can avoid any adjustment at all if we're
2756 already aligned. FIXME. */
2757 pending_stack_adjust = -needed;
2758 do_pending_stack_adjust ();
2762 /* We need to allocate space. We'll do that in
2763 push_block below. */
2764 pending_stack_adjust = 0;
2767 /* Special case this because overhead of `push_block' in
2768 this case is non-trivial. */
2770 argblock = virtual_outgoing_args_rtx;
2773 argblock = push_block (GEN_INT (needed), 0, 0);
2774 #ifdef ARGS_GROW_DOWNWARD
2775 argblock = plus_constant (argblock, needed);
2779 /* We only really need to call `copy_to_reg' in the case
2780 where push insns are going to be used to pass ARGBLOCK
2781 to a function call in ARGS. In that case, the stack
2782 pointer changes value from the allocation point to the
2783 call point, and hence the value of
2784 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2785 as well always do it. */
2786 argblock = copy_to_reg (argblock);
2791 if (ACCUMULATE_OUTGOING_ARGS)
2793 /* The save/restore code in store_one_arg handles all
2794 cases except one: a constructor call (including a C
2795 function returning a BLKmode struct) to initialize
2797 if (stack_arg_under_construction)
2799 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2800 rtx push_size = GEN_INT (reg_parm_stack_space
2801 + adjusted_args_size.constant);
2803 rtx push_size = GEN_INT (adjusted_args_size.constant);
2805 if (old_stack_level == 0)
2807 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2809 old_stack_pointer_delta = stack_pointer_delta;
2810 old_pending_adj = pending_stack_adjust;
2811 pending_stack_adjust = 0;
2812 /* stack_arg_under_construction says whether a stack
2813 arg is being constructed at the old stack level.
2814 Pushing the stack gets a clean outgoing argument
2816 old_stack_arg_under_construction
2817 = stack_arg_under_construction;
2818 stack_arg_under_construction = 0;
2819 /* Make a new map for the new argument list. */
2820 stack_usage_map = (char *)
2821 alloca (highest_outgoing_arg_in_use);
2822 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2823 highest_outgoing_arg_in_use = 0;
2825 allocate_dynamic_stack_space (push_size, NULL_RTX,
2829 /* If argument evaluation might modify the stack pointer,
2830 copy the address of the argument list to a register. */
2831 for (i = 0; i < num_actuals; i++)
2832 if (args[i].pass_on_stack)
2834 argblock = copy_addr_to_reg (argblock);
2839 compute_argument_addresses (args, argblock, num_actuals);
2841 /* If we push args individually in reverse order, perform stack alignment
2842 before the first push (the last arg). */
2843 if (PUSH_ARGS_REVERSED && argblock == 0
2844 && adjusted_args_size.constant != unadjusted_args_size)
2846 /* When the stack adjustment is pending, we get better code
2847 by combining the adjustments. */
2848 if (pending_stack_adjust
2849 && ! (flags & ECF_LIBCALL_BLOCK)
2850 && ! inhibit_defer_pop)
2852 pending_stack_adjust
2853 = (combine_pending_stack_adjustment_and_call
2854 (unadjusted_args_size,
2855 &adjusted_args_size,
2856 preferred_unit_stack_boundary));
2857 do_pending_stack_adjust ();
2859 else if (argblock == 0)
2860 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2861 - unadjusted_args_size));
2863 /* Now that the stack is properly aligned, pops can't safely
2864 be deferred during the evaluation of the arguments. */
2867 funexp = rtx_for_function_call (fndecl, addr);
2869 /* Figure out the register where the value, if any, will come back. */
2871 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2872 && ! structure_value_addr)
2874 if (pcc_struct_value)
2875 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2876 fndecl, (pass == 0));
2878 valreg = hard_function_value (TREE_TYPE (exp), fndecl, (pass == 0));
2881 /* Precompute all register parameters. It isn't safe to compute anything
2882 once we have started filling any specific hard regs. */
2883 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2885 #ifdef REG_PARM_STACK_SPACE
2886 /* Save the fixed argument area if it's part of the caller's frame and
2887 is clobbered by argument setup for this call. */
2888 if (ACCUMULATE_OUTGOING_ARGS && pass)
2889 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2890 &low_to_save, &high_to_save);
2893 /* Now store (and compute if necessary) all non-register parms.
2894 These come before register parms, since they can require block-moves,
2895 which could clobber the registers used for register parms.
2896 Parms which have partial registers are not stored here,
2897 but we do preallocate space here if they want that. */
2899 for (i = 0; i < num_actuals; i++)
2900 if (args[i].reg == 0 || args[i].pass_on_stack)
2902 rtx before_arg = get_last_insn ();
2904 if (store_one_arg (&args[i], argblock, flags,
2905 adjusted_args_size.var != 0,
2906 reg_parm_stack_space)
2908 && check_sibcall_argument_overlap (before_arg,
2910 sibcall_failure = 1;
2913 /* If we have a parm that is passed in registers but not in memory
2914 and whose alignment does not permit a direct copy into registers,
2915 make a group of pseudos that correspond to each register that we
2917 if (STRICT_ALIGNMENT)
2918 store_unaligned_arguments_into_pseudos (args, num_actuals);
2920 /* Now store any partially-in-registers parm.
2921 This is the last place a block-move can happen. */
2923 for (i = 0; i < num_actuals; i++)
2924 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2926 rtx before_arg = get_last_insn ();
2928 if (store_one_arg (&args[i], argblock, flags,
2929 adjusted_args_size.var != 0,
2930 reg_parm_stack_space)
2932 && check_sibcall_argument_overlap (before_arg,
2934 sibcall_failure = 1;
2937 /* If we pushed args in forward order, perform stack alignment
2938 after pushing the last arg. */
2939 if (!PUSH_ARGS_REVERSED && argblock == 0)
2940 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2941 - unadjusted_args_size));
2943 /* If register arguments require space on the stack and stack space
2944 was not preallocated, allocate stack space here for arguments
2945 passed in registers. */
2946 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2947 if (!ACCUMULATE_OUTGOING_ARGS
2948 && must_preallocate == 0 && reg_parm_stack_space > 0)
2949 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2952 /* Pass the function the address in which to return a
2954 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2956 #ifdef POINTERS_EXTEND_UNSIGNED
2957 if (GET_MODE (structure_value_addr) != Pmode)
2958 structure_value_addr = convert_memory_address
2959 (Pmode, structure_value_addr);
2961 emit_move_insn (struct_value_rtx,
2963 force_operand (structure_value_addr,
2966 if (GET_CODE (struct_value_rtx) == REG)
2967 use_reg (&call_fusage, struct_value_rtx);
2970 funexp = prepare_call_address (funexp, fndecl, &call_fusage,
2971 reg_parm_seen, pass == 0);
2973 load_register_parameters (args, num_actuals, &call_fusage, flags,
2974 pass == 0, &sibcall_failure);
2976 /* Perform postincrements before actually calling the function. */
2979 /* Save a pointer to the last insn before the call, so that we can
2980 later safely search backwards to find the CALL_INSN. */
2981 before_call = get_last_insn ();
2983 /* Set up next argument register. For sibling calls on machines
2984 with register windows this should be the incoming register. */
2985 #ifdef FUNCTION_INCOMING_ARG
2987 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2991 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2994 /* All arguments and registers used for the call must be set up by
2997 /* Stack must be properly aligned now. */
2998 if (pass && stack_pointer_delta % preferred_unit_stack_boundary)
3001 /* Generate the actual call instruction. */
3002 emit_call_1 (funexp, fndecl, funtype, unadjusted_args_size,
3003 adjusted_args_size.constant, struct_value_size,
3004 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
3005 flags, & args_so_far);
3007 /* If call is cse'able, make appropriate pair of reg-notes around it.
3008 Test valreg so we don't crash; may safely ignore `const'
3009 if return type is void. Disable for PARALLEL return values, because
3010 we have no way to move such values into a pseudo register. */
3011 if (pass && (flags & ECF_LIBCALL_BLOCK))
3015 if (valreg == 0 || GET_CODE (valreg) == PARALLEL)
3017 insns = get_insns ();
3024 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3026 /* Mark the return value as a pointer if needed. */
3027 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3028 mark_reg_pointer (temp,
3029 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
3031 /* Construct an "equal form" for the value which mentions all the
3032 arguments in order as well as the function name. */
3033 for (i = 0; i < num_actuals; i++)
3034 note = gen_rtx_EXPR_LIST (VOIDmode,
3035 args[i].initial_value, note);
3036 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
3038 insns = get_insns ();
3041 if (flags & ECF_PURE)
3042 note = gen_rtx_EXPR_LIST (VOIDmode,
3043 gen_rtx_USE (VOIDmode,
3044 gen_rtx_MEM (BLKmode,
3045 gen_rtx_SCRATCH (VOIDmode))),
3048 emit_libcall_block (insns, temp, valreg, note);
3053 else if (pass && (flags & ECF_MALLOC))
3055 rtx temp = gen_reg_rtx (GET_MODE (valreg));
3058 /* The return value from a malloc-like function is a pointer. */
3059 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
3060 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
3062 emit_move_insn (temp, valreg);
3064 /* The return value from a malloc-like function can not alias
3066 last = get_last_insn ();
3068 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
3070 /* Write out the sequence. */
3071 insns = get_insns ();
3077 /* For calls to `setjmp', etc., inform flow.c it should complain
3078 if nonvolatile values are live. For functions that cannot return,
3079 inform flow that control does not fall through. */
3081 if ((flags & (ECF_NORETURN | ECF_LONGJMP)) || pass == 0)
3083 /* The barrier must be emitted
3084 immediately after the CALL_INSN. Some ports emit more
3085 than just a CALL_INSN above, so we must search for it here. */
3087 rtx last = get_last_insn ();
3088 while (GET_CODE (last) != CALL_INSN)
3090 last = PREV_INSN (last);
3091 /* There was no CALL_INSN? */
3092 if (last == before_call)
3096 emit_barrier_after (last);
3099 if (flags & ECF_LONGJMP)
3100 current_function_calls_longjmp = 1;
3102 /* If value type not void, return an rtx for the value. */
3104 /* If there are cleanups to be called, don't use a hard reg as target.
3105 We need to double check this and see if it matters anymore. */
3106 if (any_pending_cleanups (1))
3108 if (target && REG_P (target)
3109 && REGNO (target) < FIRST_PSEUDO_REGISTER)
3111 sibcall_failure = 1;
3114 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
3116 target = const0_rtx;
3117 else if (structure_value_addr)
3119 if (target == 0 || GET_CODE (target) != MEM)
3122 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3123 memory_address (TYPE_MODE (TREE_TYPE (exp)),
3124 structure_value_addr));
3125 set_mem_attributes (target, exp, 1);
3128 else if (pcc_struct_value)
3130 /* This is the special C++ case where we need to
3131 know what the true target was. We take care to
3132 never use this value more than once in one expression. */
3133 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
3134 copy_to_reg (valreg));
3135 set_mem_attributes (target, exp, 1);
3137 /* Handle calls that return values in multiple non-contiguous locations.
3138 The Irix 6 ABI has examples of this. */
3139 else if (GET_CODE (valreg) == PARALLEL)
3143 /* This will only be assigned once, so it can be readonly. */
3144 tree nt = build_qualified_type (TREE_TYPE (exp),
3145 (TYPE_QUALS (TREE_TYPE (exp))
3146 | TYPE_QUAL_CONST));
3148 target = assign_temp (nt, 0, 1, 1);
3149 preserve_temp_slots (target);
3152 if (! rtx_equal_p (target, valreg))
3153 emit_group_store (target, valreg,
3154 int_size_in_bytes (TREE_TYPE (exp)));
3156 /* We can not support sibling calls for this case. */
3157 sibcall_failure = 1;
3160 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
3161 && GET_MODE (target) == GET_MODE (valreg))
3163 /* TARGET and VALREG cannot be equal at this point because the
3164 latter would not have REG_FUNCTION_VALUE_P true, while the
3165 former would if it were referring to the same register.
3167 If they refer to the same register, this move will be a no-op,
3168 except when function inlining is being done. */
3169 emit_move_insn (target, valreg);
3171 /* If we are setting a MEM, this code must be executed. Since it is
3172 emitted after the call insn, sibcall optimization cannot be
3173 performed in that case. */
3174 if (GET_CODE (target) == MEM)
3175 sibcall_failure = 1;
3177 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
3179 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
3181 /* We can not support sibling calls for this case. */
3182 sibcall_failure = 1;
3185 target = copy_to_reg (valreg);
3187 #ifdef PROMOTE_FUNCTION_RETURN
3188 /* If we promoted this return value, make the proper SUBREG. TARGET
3189 might be const0_rtx here, so be careful. */
3190 if (GET_CODE (target) == REG
3191 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
3192 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
3194 tree type = TREE_TYPE (exp);
3195 int unsignedp = TREE_UNSIGNED (type);
3198 /* If we don't promote as expected, something is wrong. */
3199 if (GET_MODE (target)
3200 != promote_mode (type, TYPE_MODE (type), &unsignedp, 1))
3203 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3204 && GET_MODE_SIZE (GET_MODE (target))
3205 > GET_MODE_SIZE (TYPE_MODE (type)))
3207 offset = GET_MODE_SIZE (GET_MODE (target))
3208 - GET_MODE_SIZE (TYPE_MODE (type));
3209 if (! BYTES_BIG_ENDIAN)
3210 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3211 else if (! WORDS_BIG_ENDIAN)
3212 offset %= UNITS_PER_WORD;
3214 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3215 SUBREG_PROMOTED_VAR_P (target) = 1;
3216 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3220 /* If size of args is variable or this was a constructor call for a stack
3221 argument, restore saved stack-pointer value. */
3223 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
3225 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3226 stack_pointer_delta = old_stack_pointer_delta;
3227 pending_stack_adjust = old_pending_adj;
3228 stack_arg_under_construction = old_stack_arg_under_construction;
3229 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3230 stack_usage_map = initial_stack_usage_map;
3231 sibcall_failure = 1;
3233 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3235 #ifdef REG_PARM_STACK_SPACE
3237 restore_fixed_argument_area (save_area, argblock,
3238 high_to_save, low_to_save);
3241 /* If we saved any argument areas, restore them. */
3242 for (i = 0; i < num_actuals; i++)
3243 if (args[i].save_area)
3245 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3247 = gen_rtx_MEM (save_mode,
3248 memory_address (save_mode,
3249 XEXP (args[i].stack_slot, 0)));
3251 if (save_mode != BLKmode)
3252 emit_move_insn (stack_area, args[i].save_area);
3254 emit_block_move (stack_area, args[i].save_area,
3255 GEN_INT (args[i].locate.size.constant),
3256 BLOCK_OP_CALL_PARM);
3259 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3260 stack_usage_map = initial_stack_usage_map;
3263 /* If this was alloca, record the new stack level for nonlocal gotos.
3264 Check for the handler slots since we might not have a save area
3265 for non-local gotos. */
3267 if ((flags & ECF_MAY_BE_ALLOCA) && nonlocal_goto_handler_slots != 0)
3268 emit_stack_save (SAVE_NONLOCAL, &nonlocal_goto_stack_level, NULL_RTX);
3270 /* Free up storage we no longer need. */
3271 for (i = 0; i < num_actuals; ++i)
3272 if (args[i].aligned_regs)
3273 free (args[i].aligned_regs);
3277 /* Undo the fake expand_start_target_temps we did earlier. If
3278 there had been any cleanups created, we've already set
3280 expand_end_target_temps ();
3283 /* If this function is returning into a memory location marked as
3284 readonly, it means it is initializing that location. We normally treat
3285 functions as not clobbering such locations, so we need to specify that
3286 this one does. We do this by adding the appropriate CLOBBER to the
3287 CALL_INSN function usage list. This cannot be done by emitting a
3288 standalone CLOBBER after the call because the latter would be ignored
3289 by at least the delay slot scheduling pass. We do this now instead of
3290 adding to call_fusage before the call to emit_call_1 because TARGET
3291 may be modified in the meantime. */
3292 if (structure_value_addr != 0 && target != 0
3293 && GET_CODE (target) == MEM && RTX_UNCHANGING_P (target))
3294 add_function_usage_to
3296 gen_rtx_EXPR_LIST (VOIDmode, gen_rtx_CLOBBER (VOIDmode, target),
3299 insns = get_insns ();
3304 tail_call_insns = insns;
3306 /* Restore the pending stack adjustment now that we have
3307 finished generating the sibling call sequence. */
3309 pending_stack_adjust = save_pending_stack_adjust;
3310 stack_pointer_delta = save_stack_pointer_delta;
3312 /* Prepare arg structure for next iteration. */
3313 for (i = 0; i < num_actuals; i++)
3316 args[i].aligned_regs = 0;
3320 sbitmap_free (stored_args_map);
3324 normal_call_insns = insns;
3326 /* Verify that we've deallocated all the stack we used. */
3327 if (old_stack_allocated !=
3328 stack_pointer_delta - pending_stack_adjust)
3332 /* If something prevents making this a sibling call,
3333 zero out the sequence. */
3334 if (sibcall_failure)
3335 tail_call_insns = NULL_RTX;
3338 /* The function optimize_sibling_and_tail_recursive_calls doesn't
3339 handle CALL_PLACEHOLDERs inside other CALL_PLACEHOLDERs. This
3340 can happen if the arguments to this function call an inline
3341 function who's expansion contains another CALL_PLACEHOLDER.
3343 If there are any C_Ps in any of these sequences, replace them
3344 with their normal call. */
3346 for (insn = normal_call_insns; insn; insn = NEXT_INSN (insn))
3347 if (GET_CODE (insn) == CALL_INSN
3348 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3349 replace_call_placeholder (insn, sibcall_use_normal);
3351 for (insn = tail_call_insns; insn; insn = NEXT_INSN (insn))
3352 if (GET_CODE (insn) == CALL_INSN
3353 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3354 replace_call_placeholder (insn, sibcall_use_normal);
3356 for (insn = tail_recursion_insns; insn; insn = NEXT_INSN (insn))
3357 if (GET_CODE (insn) == CALL_INSN
3358 && GET_CODE (PATTERN (insn)) == CALL_PLACEHOLDER)
3359 replace_call_placeholder (insn, sibcall_use_normal);
3361 /* If this was a potential tail recursion site, then emit a
3362 CALL_PLACEHOLDER with the normal and the tail recursion streams.
3363 One of them will be selected later. */
3364 if (tail_recursion_insns || tail_call_insns)
3366 /* The tail recursion label must be kept around. We could expose
3367 its use in the CALL_PLACEHOLDER, but that creates unwanted edges
3368 and makes determining true tail recursion sites difficult.
3370 So we set LABEL_PRESERVE_P here, then clear it when we select
3371 one of the call sequences after rtl generation is complete. */
3372 if (tail_recursion_insns)
3373 LABEL_PRESERVE_P (tail_recursion_label) = 1;
3374 emit_call_insn (gen_rtx_CALL_PLACEHOLDER (VOIDmode, normal_call_insns,
3376 tail_recursion_insns,
3377 tail_recursion_label));
3380 emit_insn (normal_call_insns);
3382 currently_expanding_call--;
3384 /* If this function returns with the stack pointer depressed, ensure
3385 this block saves and restores the stack pointer, show it was
3386 changed, and adjust for any outgoing arg space. */
3387 if (flags & ECF_SP_DEPRESSED)
3389 clear_pending_stack_adjust ();
3390 emit_insn (gen_rtx (CLOBBER, VOIDmode, stack_pointer_rtx));
3391 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3392 save_stack_pointer ();
3398 /* Traverse an argument list in VALUES and expand all complex
3399 arguments into their components. */
3401 split_complex_values (tree values)
3405 values = copy_list (values);
3407 for (p = values; p; p = TREE_CHAIN (p))
3409 tree complex_value = TREE_VALUE (p);
3412 complex_type = TREE_TYPE (complex_value);
3416 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3419 tree real, imag, next;
3421 subtype = TREE_TYPE (complex_type);
3422 complex_value = save_expr (complex_value);
3423 real = build1 (REALPART_EXPR, subtype, complex_value);
3424 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3426 TREE_VALUE (p) = real;
3427 next = TREE_CHAIN (p);
3428 imag = build_tree_list (NULL_TREE, imag);
3429 TREE_CHAIN (p) = imag;
3430 TREE_CHAIN (imag) = next;
3432 /* Skip the newly created node. */
3440 /* Traverse a list of TYPES and expand all complex types into their
3443 split_complex_types (tree types)
3447 types = copy_list (types);
3449 for (p = types; p; p = TREE_CHAIN (p))
3451 tree complex_type = TREE_VALUE (p);
3453 if (TREE_CODE (complex_type) == COMPLEX_TYPE)
3457 /* Rewrite complex type with component type. */
3458 TREE_VALUE (p) = TREE_TYPE (complex_type);
3459 next = TREE_CHAIN (p);
3461 /* Add another component type for the imaginary part. */
3462 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3463 TREE_CHAIN (p) = imag;
3464 TREE_CHAIN (imag) = next;
3466 /* Skip the newly created node. */
3474 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3475 The RETVAL parameter specifies whether return value needs to be saved, other
3476 parameters are documented in the emit_library_call function below. */
3479 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3480 enum libcall_type fn_type,
3481 enum machine_mode outmode, int nargs, va_list p)
3483 /* Total size in bytes of all the stack-parms scanned so far. */
3484 struct args_size args_size;
3485 /* Size of arguments before any adjustments (such as rounding). */
3486 struct args_size original_args_size;
3492 CUMULATIVE_ARGS args_so_far;
3496 enum machine_mode mode;
3499 struct locate_and_pad_arg_data locate;
3503 int old_inhibit_defer_pop = inhibit_defer_pop;
3504 rtx call_fusage = 0;
3507 int pcc_struct_value = 0;
3508 int struct_value_size = 0;
3510 int reg_parm_stack_space = 0;
3513 tree tfom; /* type_for_mode (outmode, 0) */
3515 #ifdef REG_PARM_STACK_SPACE
3516 /* Define the boundary of the register parm stack space that needs to be
3518 int low_to_save, high_to_save;
3519 rtx save_area = 0; /* Place that it is saved. */
3522 /* Size of the stack reserved for parameter registers. */
3523 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3524 char *initial_stack_usage_map = stack_usage_map;
3526 #ifdef REG_PARM_STACK_SPACE
3527 #ifdef MAYBE_REG_PARM_STACK_SPACE
3528 reg_parm_stack_space = MAYBE_REG_PARM_STACK_SPACE;
3530 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3534 /* By default, library functions can not throw. */
3535 flags = ECF_NOTHROW;
3547 case LCT_CONST_MAKE_BLOCK:
3548 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3550 case LCT_PURE_MAKE_BLOCK:
3551 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3554 flags |= ECF_NORETURN;
3557 flags = ECF_NORETURN;
3559 case LCT_ALWAYS_RETURN:
3560 flags = ECF_ALWAYS_RETURN;
3562 case LCT_RETURNS_TWICE:
3563 flags = ECF_RETURNS_TWICE;
3568 /* Ensure current function's preferred stack boundary is at least
3570 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3571 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3573 /* If this kind of value comes back in memory,
3574 decide where in memory it should come back. */
3575 if (outmode != VOIDmode)
3577 tfom = (*lang_hooks.types.type_for_mode) (outmode, 0);
3578 if (aggregate_value_p (tfom))
3580 #ifdef PCC_STATIC_STRUCT_RETURN
3582 = hard_function_value (build_pointer_type (tfom), 0, 0);
3583 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3584 pcc_struct_value = 1;
3586 value = gen_reg_rtx (outmode);
3587 #else /* not PCC_STATIC_STRUCT_RETURN */
3588 struct_value_size = GET_MODE_SIZE (outmode);
3589 if (value != 0 && GET_CODE (value) == MEM)
3592 mem_value = assign_temp (tfom, 0, 1, 1);
3594 /* This call returns a big structure. */
3595 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3599 tfom = void_type_node;
3601 /* ??? Unfinished: must pass the memory address as an argument. */
3603 /* Copy all the libcall-arguments out of the varargs data
3604 and into a vector ARGVEC.
3606 Compute how to pass each argument. We only support a very small subset
3607 of the full argument passing conventions to limit complexity here since
3608 library functions shouldn't have many args. */
3610 argvec = (struct arg *) alloca ((nargs + 1) * sizeof (struct arg));
3611 memset ((char *) argvec, 0, (nargs + 1) * sizeof (struct arg));
3613 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3614 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3616 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0);
3619 args_size.constant = 0;
3624 /* Now we are about to start emitting insns that can be deleted
3625 if a libcall is deleted. */
3626 if (flags & ECF_LIBCALL_BLOCK)
3631 /* If there's a structure value address to be passed,
3632 either pass it in the special place, or pass it as an extra argument. */
3633 if (mem_value && struct_value_rtx == 0 && ! pcc_struct_value)
3635 rtx addr = XEXP (mem_value, 0);
3638 /* Make sure it is a reasonable operand for a move or push insn. */
3639 if (GET_CODE (addr) != REG && GET_CODE (addr) != MEM
3640 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3641 addr = force_operand (addr, NULL_RTX);
3643 argvec[count].value = addr;
3644 argvec[count].mode = Pmode;
3645 argvec[count].partial = 0;
3647 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3648 #ifdef FUNCTION_ARG_PARTIAL_NREGS
3649 if (FUNCTION_ARG_PARTIAL_NREGS (args_so_far, Pmode, NULL_TREE, 1))
3653 locate_and_pad_parm (Pmode, NULL_TREE,
3654 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3657 argvec[count].reg != 0,
3659 0, NULL_TREE, &args_size, &argvec[count].locate);
3661 if (argvec[count].reg == 0 || argvec[count].partial != 0
3662 || reg_parm_stack_space > 0)
3663 args_size.constant += argvec[count].locate.size.constant;
3665 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3670 for (; count < nargs; count++)
3672 rtx val = va_arg (p, rtx);
3673 enum machine_mode mode = va_arg (p, enum machine_mode);
3675 /* We cannot convert the arg value to the mode the library wants here;
3676 must do it earlier where we know the signedness of the arg. */
3678 || (GET_MODE (val) != mode && GET_MODE (val) != VOIDmode))
3681 /* On some machines, there's no way to pass a float to a library fcn.
3682 Pass it as a double instead. */
3683 #ifdef LIBGCC_NEEDS_DOUBLE
3684 if (LIBGCC_NEEDS_DOUBLE && mode == SFmode)
3685 val = convert_modes (DFmode, SFmode, val, 0), mode = DFmode;
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 #ifdef FINAL_REG_PARM_STACK_SPACE
3791 reg_parm_stack_space = FINAL_REG_PARM_STACK_SPACE (args_size.constant,
3794 /* If this machine requires an external definition for library
3795 functions, write one out. */
3796 assemble_external_libcall (fun);
3798 original_args_size = args_size;
3799 args_size.constant = (((args_size.constant
3800 + stack_pointer_delta
3804 - stack_pointer_delta);
3806 args_size.constant = MAX (args_size.constant,
3807 reg_parm_stack_space);
3809 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3810 args_size.constant -= reg_parm_stack_space;
3813 if (args_size.constant > current_function_outgoing_args_size)
3814 current_function_outgoing_args_size = args_size.constant;
3816 if (ACCUMULATE_OUTGOING_ARGS)
3818 /* Since the stack pointer will never be pushed, it is possible for
3819 the evaluation of a parm to clobber something we have already
3820 written to the stack. Since most function calls on RISC machines
3821 do not use the stack, this is uncommon, but must work correctly.
3823 Therefore, we save any area of the stack that was already written
3824 and that we are using. Here we set up to do this by making a new
3825 stack usage map from the old one.
3827 Another approach might be to try to reorder the argument
3828 evaluations to avoid this conflicting stack usage. */
3830 needed = args_size.constant;
3832 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3833 /* Since we will be writing into the entire argument area, the
3834 map must be allocated for its entire size, not just the part that
3835 is the responsibility of the caller. */
3836 needed += reg_parm_stack_space;
3839 #ifdef ARGS_GROW_DOWNWARD
3840 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3843 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3846 stack_usage_map = (char *) alloca (highest_outgoing_arg_in_use);
3848 if (initial_highest_arg_in_use)
3849 memcpy (stack_usage_map, initial_stack_usage_map,
3850 initial_highest_arg_in_use);
3852 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3853 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3854 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3857 /* We must be careful to use virtual regs before they're instantiated,
3858 and real regs afterwards. Loop optimization, for example, can create
3859 new libcalls after we've instantiated the virtual regs, and if we
3860 use virtuals anyway, they won't match the rtl patterns. */
3862 if (virtuals_instantiated)
3863 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3865 argblock = virtual_outgoing_args_rtx;
3870 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3873 /* If we push args individually in reverse order, perform stack alignment
3874 before the first push (the last arg). */
3875 if (argblock == 0 && PUSH_ARGS_REVERSED)
3876 anti_adjust_stack (GEN_INT (args_size.constant
3877 - original_args_size.constant));
3879 if (PUSH_ARGS_REVERSED)
3890 #ifdef REG_PARM_STACK_SPACE
3891 if (ACCUMULATE_OUTGOING_ARGS)
3893 /* The argument list is the property of the called routine and it
3894 may clobber it. If the fixed area has been used for previous
3895 parameters, we must save and restore it. */
3896 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3897 &low_to_save, &high_to_save);
3901 /* Push the args that need to be pushed. */
3903 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3904 are to be pushed. */
3905 for (count = 0; count < nargs; count++, argnum += inc)
3907 enum machine_mode mode = argvec[argnum].mode;
3908 rtx val = argvec[argnum].value;
3909 rtx reg = argvec[argnum].reg;
3910 int partial = argvec[argnum].partial;
3911 int lower_bound = 0, upper_bound = 0, i;
3913 if (! (reg != 0 && partial == 0))
3915 if (ACCUMULATE_OUTGOING_ARGS)
3917 /* If this is being stored into a pre-allocated, fixed-size,
3918 stack area, save any previous data at that location. */
3920 #ifdef ARGS_GROW_DOWNWARD
3921 /* stack_slot is negative, but we want to index stack_usage_map
3922 with positive values. */
3923 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3924 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3926 lower_bound = argvec[argnum].locate.offset.constant;
3927 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3931 /* Don't worry about things in the fixed argument area;
3932 it has already been saved. */
3933 if (i < reg_parm_stack_space)
3934 i = reg_parm_stack_space;
3935 while (i < upper_bound && stack_usage_map[i] == 0)
3938 if (i < upper_bound)
3940 /* We need to make a save area. */
3942 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3943 enum machine_mode save_mode
3944 = mode_for_size (size, MODE_INT, 1);
3946 = plus_constant (argblock,
3947 argvec[argnum].locate.offset.constant);
3949 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3950 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3952 emit_move_insn (argvec[argnum].save_area, stack_area);
3956 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3957 partial, reg, 0, argblock,
3958 GEN_INT (argvec[argnum].locate.offset.constant),
3959 reg_parm_stack_space,
3960 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3962 /* Now mark the segment we just used. */
3963 if (ACCUMULATE_OUTGOING_ARGS)
3964 for (i = lower_bound; i < upper_bound; i++)
3965 stack_usage_map[i] = 1;
3971 /* If we pushed args in forward order, perform stack alignment
3972 after pushing the last arg. */
3973 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3974 anti_adjust_stack (GEN_INT (args_size.constant
3975 - original_args_size.constant));
3977 if (PUSH_ARGS_REVERSED)
3982 fun = prepare_call_address (fun, NULL_TREE, &call_fusage, 0, 0);
3984 /* Now load any reg parms into their regs. */
3986 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3987 are to be pushed. */
3988 for (count = 0; count < nargs; count++, argnum += inc)
3990 rtx val = argvec[argnum].value;
3991 rtx reg = argvec[argnum].reg;
3992 int partial = argvec[argnum].partial;
3994 /* Handle calls that pass values in multiple non-contiguous
3995 locations. The PA64 has examples of this for library calls. */
3996 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3997 emit_group_load (reg, val, GET_MODE_SIZE (GET_MODE (val)));
3998 else if (reg != 0 && partial == 0)
3999 emit_move_insn (reg, val);
4004 /* Any regs containing parms remain in use through the call. */
4005 for (count = 0; count < nargs; count++)
4007 rtx reg = argvec[count].reg;
4008 if (reg != 0 && GET_CODE (reg) == PARALLEL)
4009 use_group_regs (&call_fusage, reg);
4011 use_reg (&call_fusage, reg);
4014 /* Pass the function the address in which to return a structure value. */
4015 if (mem_value != 0 && struct_value_rtx != 0 && ! pcc_struct_value)
4017 emit_move_insn (struct_value_rtx,
4019 force_operand (XEXP (mem_value, 0),
4021 if (GET_CODE (struct_value_rtx) == REG)
4022 use_reg (&call_fusage, struct_value_rtx);
4025 /* Don't allow popping to be deferred, since then
4026 cse'ing of library calls could delete a call and leave the pop. */
4028 valreg = (mem_value == 0 && outmode != VOIDmode
4029 ? hard_libcall_value (outmode) : NULL_RTX);
4031 /* Stack must be properly aligned now. */
4032 if (stack_pointer_delta & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1))
4035 before_call = get_last_insn ();
4037 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
4038 will set inhibit_defer_pop to that value. */
4039 /* The return type is needed to decide how many bytes the function pops.
4040 Signedness plays no role in that, so for simplicity, we pretend it's
4041 always signed. We also assume that the list of arguments passed has
4042 no impact, so we pretend it is unknown. */
4045 get_identifier (XSTR (orgfun, 0)),
4046 build_function_type (tfom, NULL_TREE),
4047 original_args_size.constant, args_size.constant,
4049 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
4051 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
4053 /* For calls to `setjmp', etc., inform flow.c it should complain
4054 if nonvolatile values are live. For functions that cannot return,
4055 inform flow that control does not fall through. */
4057 if (flags & (ECF_NORETURN | ECF_LONGJMP))
4059 /* The barrier note must be emitted
4060 immediately after the CALL_INSN. Some ports emit more than
4061 just a CALL_INSN above, so we must search for it here. */
4063 rtx last = get_last_insn ();
4064 while (GET_CODE (last) != CALL_INSN)
4066 last = PREV_INSN (last);
4067 /* There was no CALL_INSN? */
4068 if (last == before_call)
4072 emit_barrier_after (last);
4075 /* Now restore inhibit_defer_pop to its actual original value. */
4078 /* If call is cse'able, make appropriate pair of reg-notes around it.
4079 Test valreg so we don't crash; may safely ignore `const'
4080 if return type is void. Disable for PARALLEL return values, because
4081 we have no way to move such values into a pseudo register. */
4082 if (flags & ECF_LIBCALL_BLOCK)
4088 insns = get_insns ();
4098 if (GET_CODE (valreg) == PARALLEL)
4100 temp = gen_reg_rtx (outmode);
4101 emit_group_store (temp, valreg, outmode);
4105 temp = gen_reg_rtx (GET_MODE (valreg));
4107 /* Construct an "equal form" for the value which mentions all the
4108 arguments in order as well as the function name. */
4109 for (i = 0; i < nargs; i++)
4110 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
4111 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
4113 insns = get_insns ();
4116 if (flags & ECF_PURE)
4117 note = gen_rtx_EXPR_LIST (VOIDmode,
4118 gen_rtx_USE (VOIDmode,
4119 gen_rtx_MEM (BLKmode,
4120 gen_rtx_SCRATCH (VOIDmode))),
4123 emit_libcall_block (insns, temp, valreg, note);
4130 /* Copy the value to the right place. */
4131 if (outmode != VOIDmode && retval)
4137 if (value != mem_value)
4138 emit_move_insn (value, mem_value);
4140 else if (GET_CODE (valreg) == PARALLEL)
4143 value = gen_reg_rtx (outmode);
4144 emit_group_store (value, valreg, outmode);
4146 else if (value != 0)
4147 emit_move_insn (value, valreg);
4152 if (ACCUMULATE_OUTGOING_ARGS)
4154 #ifdef REG_PARM_STACK_SPACE
4156 restore_fixed_argument_area (save_area, argblock,
4157 high_to_save, low_to_save);
4160 /* If we saved any argument areas, restore them. */
4161 for (count = 0; count < nargs; count++)
4162 if (argvec[count].save_area)
4164 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
4165 rtx adr = plus_constant (argblock,
4166 argvec[count].locate.offset.constant);
4167 rtx stack_area = gen_rtx_MEM (save_mode,
4168 memory_address (save_mode, adr));
4170 emit_move_insn (stack_area, argvec[count].save_area);
4173 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
4174 stack_usage_map = initial_stack_usage_map;
4181 /* Output a library call to function FUN (a SYMBOL_REF rtx)
4182 (emitting the queue unless NO_QUEUE is nonzero),
4183 for a value of mode OUTMODE,
4184 with NARGS different arguments, passed as alternating rtx values
4185 and machine_modes to convert them to.
4186 The rtx values should have been passed through protect_from_queue already.
4188 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
4189 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
4190 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
4191 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
4192 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
4193 or other LCT_ value for other types of library calls. */
4196 emit_library_call (rtx orgfun, enum libcall_type fn_type,
4197 enum machine_mode outmode, int nargs, ...)
4201 va_start (p, nargs);
4202 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
4206 /* Like emit_library_call except that an extra argument, VALUE,
4207 comes second and says where to store the result.
4208 (If VALUE is zero, this function chooses a convenient way
4209 to return the value.
4211 This function returns an rtx for where the value is to be found.
4212 If VALUE is nonzero, VALUE is returned. */
4215 emit_library_call_value (rtx orgfun, rtx value,
4216 enum libcall_type fn_type,
4217 enum machine_mode outmode, int nargs, ...)
4222 va_start (p, nargs);
4223 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4230 /* Store a single argument for a function call
4231 into the register or memory area where it must be passed.
4232 *ARG describes the argument value and where to pass it.
4234 ARGBLOCK is the address of the stack-block for all the arguments,
4235 or 0 on a machine where arguments are pushed individually.
4237 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4238 so must be careful about how the stack is used.
4240 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4241 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4242 that we need not worry about saving and restoring the stack.
4244 FNDECL is the declaration of the function we are calling.
4246 Return nonzero if this arg should cause sibcall failure,
4250 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4251 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4253 tree pval = arg->tree_value;
4257 int i, lower_bound = 0, upper_bound = 0;
4258 int sibcall_failure = 0;
4260 if (TREE_CODE (pval) == ERROR_MARK)
4263 /* Push a new temporary level for any temporaries we make for
4267 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4269 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4270 save any previous data at that location. */
4271 if (argblock && ! variable_size && arg->stack)
4273 #ifdef ARGS_GROW_DOWNWARD
4274 /* stack_slot is negative, but we want to index stack_usage_map
4275 with positive values. */
4276 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4277 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4281 lower_bound = upper_bound - arg->locate.size.constant;
4283 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4284 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4288 upper_bound = lower_bound + arg->locate.size.constant;
4292 /* Don't worry about things in the fixed argument area;
4293 it has already been saved. */
4294 if (i < reg_parm_stack_space)
4295 i = reg_parm_stack_space;
4296 while (i < upper_bound && stack_usage_map[i] == 0)
4299 if (i < upper_bound)
4301 /* We need to make a save area. */
4302 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4303 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4304 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4305 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4307 if (save_mode == BLKmode)
4309 tree ot = TREE_TYPE (arg->tree_value);
4310 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4311 | TYPE_QUAL_CONST));
4313 arg->save_area = assign_temp (nt, 0, 1, 1);
4314 preserve_temp_slots (arg->save_area);
4315 emit_block_move (validize_mem (arg->save_area), stack_area,
4316 expr_size (arg->tree_value),
4317 BLOCK_OP_CALL_PARM);
4321 arg->save_area = gen_reg_rtx (save_mode);
4322 emit_move_insn (arg->save_area, stack_area);
4328 /* If this isn't going to be placed on both the stack and in registers,
4329 set up the register and number of words. */
4330 if (! arg->pass_on_stack)
4332 if (flags & ECF_SIBCALL)
4333 reg = arg->tail_call_reg;
4336 partial = arg->partial;
4339 if (reg != 0 && partial == 0)
4340 /* Being passed entirely in a register. We shouldn't be called in
4344 /* If this arg needs special alignment, don't load the registers
4346 if (arg->n_aligned_regs != 0)
4349 /* If this is being passed partially in a register, we can't evaluate
4350 it directly into its stack slot. Otherwise, we can. */
4351 if (arg->value == 0)
4353 /* stack_arg_under_construction is nonzero if a function argument is
4354 being evaluated directly into the outgoing argument list and
4355 expand_call must take special action to preserve the argument list
4356 if it is called recursively.
4358 For scalar function arguments stack_usage_map is sufficient to
4359 determine which stack slots must be saved and restored. Scalar
4360 arguments in general have pass_on_stack == 0.
4362 If this argument is initialized by a function which takes the
4363 address of the argument (a C++ constructor or a C function
4364 returning a BLKmode structure), then stack_usage_map is
4365 insufficient and expand_call must push the stack around the
4366 function call. Such arguments have pass_on_stack == 1.
4368 Note that it is always safe to set stack_arg_under_construction,
4369 but this generates suboptimal code if set when not needed. */
4371 if (arg->pass_on_stack)
4372 stack_arg_under_construction++;
4374 arg->value = expand_expr (pval,
4376 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4377 ? NULL_RTX : arg->stack,
4378 VOIDmode, EXPAND_STACK_PARM);
4380 /* If we are promoting object (or for any other reason) the mode
4381 doesn't agree, convert the mode. */
4383 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4384 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4385 arg->value, arg->unsignedp);
4387 if (arg->pass_on_stack)
4388 stack_arg_under_construction--;
4391 /* Don't allow anything left on stack from computation
4392 of argument to alloca. */
4393 if (flags & ECF_MAY_BE_ALLOCA)
4394 do_pending_stack_adjust ();
4396 if (arg->value == arg->stack)
4397 /* If the value is already in the stack slot, we are done. */
4399 else if (arg->mode != BLKmode)
4403 /* Argument is a scalar, not entirely passed in registers.
4404 (If part is passed in registers, arg->partial says how much
4405 and emit_push_insn will take care of putting it there.)
4407 Push it, and if its size is less than the
4408 amount of space allocated to it,
4409 also bump stack pointer by the additional space.
4410 Note that in C the default argument promotions
4411 will prevent such mismatches. */
4413 size = GET_MODE_SIZE (arg->mode);
4414 /* Compute how much space the push instruction will push.
4415 On many machines, pushing a byte will advance the stack
4416 pointer by a halfword. */
4417 #ifdef PUSH_ROUNDING
4418 size = PUSH_ROUNDING (size);
4422 /* Compute how much space the argument should get:
4423 round up to a multiple of the alignment for arguments. */
4424 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4425 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4426 / (PARM_BOUNDARY / BITS_PER_UNIT))
4427 * (PARM_BOUNDARY / BITS_PER_UNIT));
4429 /* This isn't already where we want it on the stack, so put it there.
4430 This can either be done with push or copy insns. */
4431 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4432 PARM_BOUNDARY, partial, reg, used - size, argblock,
4433 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4434 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4436 /* Unless this is a partially-in-register argument, the argument is now
4439 arg->value = arg->stack;
4443 /* BLKmode, at least partly to be pushed. */
4445 unsigned int parm_align;
4449 /* Pushing a nonscalar.
4450 If part is passed in registers, PARTIAL says how much
4451 and emit_push_insn will take care of putting it there. */
4453 /* Round its size up to a multiple
4454 of the allocation unit for arguments. */
4456 if (arg->locate.size.var != 0)
4459 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4463 /* PUSH_ROUNDING has no effect on us, because
4464 emit_push_insn for BLKmode is careful to avoid it. */
4465 excess = (arg->locate.size.constant
4466 - int_size_in_bytes (TREE_TYPE (pval))
4467 + partial * UNITS_PER_WORD);
4468 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4469 NULL_RTX, TYPE_MODE (sizetype), 0);
4472 /* Some types will require stricter alignment, which will be
4473 provided for elsewhere in argument layout. */
4474 parm_align = MAX (PARM_BOUNDARY, TYPE_ALIGN (TREE_TYPE (pval)));
4476 /* When an argument is padded down, the block is aligned to
4477 PARM_BOUNDARY, but the actual argument isn't. */
4478 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4480 if (arg->locate.size.var)
4481 parm_align = BITS_PER_UNIT;
4484 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4485 parm_align = MIN (parm_align, excess_align);
4489 if ((flags & ECF_SIBCALL) && GET_CODE (arg->value) == MEM)
4491 /* emit_push_insn might not work properly if arg->value and
4492 argblock + arg->locate.offset areas overlap. */
4496 if (XEXP (x, 0) == current_function_internal_arg_pointer
4497 || (GET_CODE (XEXP (x, 0)) == PLUS
4498 && XEXP (XEXP (x, 0), 0) ==
4499 current_function_internal_arg_pointer
4500 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4502 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4503 i = INTVAL (XEXP (XEXP (x, 0), 1));
4505 /* expand_call should ensure this */
4506 if (arg->locate.offset.var || GET_CODE (size_rtx) != CONST_INT)
4509 if (arg->locate.offset.constant > i)
4511 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4512 sibcall_failure = 1;
4514 else if (arg->locate.offset.constant < i)
4516 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4517 sibcall_failure = 1;
4522 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4523 parm_align, partial, reg, excess, argblock,
4524 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4525 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4527 /* Unless this is a partially-in-register argument, the argument is now
4530 ??? Unlike the case above, in which we want the actual
4531 address of the data, so that we can load it directly into a
4532 register, here we want the address of the stack slot, so that
4533 it's properly aligned for word-by-word copying or something
4534 like that. It's not clear that this is always correct. */
4536 arg->value = arg->stack_slot;
4539 /* Mark all slots this store used. */
4540 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4541 && argblock && ! variable_size && arg->stack)
4542 for (i = lower_bound; i < upper_bound; i++)
4543 stack_usage_map[i] = 1;
4545 /* Once we have pushed something, pops can't safely
4546 be deferred during the rest of the arguments. */
4549 /* ANSI doesn't require a sequence point here,
4550 but PCC has one, so this will avoid some problems. */
4553 /* Free any temporary slots made in processing this argument. Show
4554 that we might have taken the address of something and pushed that
4556 preserve_temp_slots (NULL_RTX);
4560 return sibcall_failure;
4563 /* Nonzero if we do not know how to pass TYPE solely in registers.
4564 We cannot do so in the following cases:
4566 - if the type has variable size
4567 - if the type is marked as addressable (it is required to be constructed
4569 - if the padding and mode of the type is such that a copy into a register
4570 would put it into the wrong part of the register.
4572 Which padding can't be supported depends on the byte endianness.
4574 A value in a register is implicitly padded at the most significant end.
4575 On a big-endian machine, that is the lower end in memory.
4576 So a value padded in memory at the upper end can't go in a register.
4577 For a little-endian machine, the reverse is true. */
4580 default_must_pass_in_stack (enum machine_mode mode, tree type)
4585 /* If the type has variable size... */
4586 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4589 /* If the type is marked as addressable (it is required
4590 to be constructed into the stack)... */
4591 if (TREE_ADDRESSABLE (type))
4594 /* If the padding and mode of the type is such that a copy into
4595 a register would put it into the wrong part of the register. */
4597 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4598 && (FUNCTION_ARG_PADDING (mode, type)
4599 == (BYTES_BIG_ENDIAN ? upward : downward)))