1 /* Convert function calls to rtl insns, for GNU C compiler.
2 Copyright (C) 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998,
3 1999, 2000, 2001, 2002, 2003, 2004, 2005
4 Free Software Foundation, Inc.
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify it under
9 the terms of the GNU General Public License as published by the Free
10 Software Foundation; either version 2, or (at your option) any later
13 GCC is distributed in the hope that it will be useful, but WITHOUT ANY
14 WARRANTY; without even the implied warranty of MERCHANTABILITY or
15 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING. If not, write to the Free
20 Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
25 #include "coretypes.h"
40 #include "langhooks.h"
45 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
46 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
48 /* Data structure and subroutines used within expand_call. */
52 /* Tree node for this argument. */
54 /* Mode for value; TYPE_MODE unless promoted. */
55 enum machine_mode mode;
56 /* Current RTL value for argument, or 0 if it isn't precomputed. */
58 /* Initially-compute RTL value for argument; only for const functions. */
60 /* Register to pass this argument in, 0 if passed on stack, or an
61 PARALLEL if the arg is to be copied into multiple non-contiguous
64 /* Register to pass this argument in when generating tail call sequence.
65 This is not the same register as for normal calls on machines with
68 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
69 form for emit_group_move. */
71 /* If REG was promoted from the actual mode of the argument expression,
72 indicates whether the promotion is sign- or zero-extended. */
74 /* Number of bytes to put in registers. 0 means put the whole arg
75 in registers. Also 0 if not passed in registers. */
77 /* Nonzero if argument must be passed on stack.
78 Note that some arguments may be passed on the stack
79 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
80 pass_on_stack identifies arguments that *cannot* go in registers. */
82 /* Some fields packaged up for locate_and_pad_parm. */
83 struct locate_and_pad_arg_data locate;
84 /* Location on the stack at which parameter should be stored. The store
85 has already been done if STACK == VALUE. */
87 /* Location on the stack of the start of this argument slot. This can
88 differ from STACK if this arg pads downward. This location is known
89 to be aligned to FUNCTION_ARG_BOUNDARY. */
91 /* Place that this stack area has been saved, if needed. */
93 /* If an argument's alignment does not permit direct copying into registers,
94 copy in smaller-sized pieces into pseudos. These are stored in a
95 block pointed to by this field. The next field says how many
96 word-sized pseudos we made. */
101 /* A vector of one char per byte of stack space. A byte if nonzero if
102 the corresponding stack location has been used.
103 This vector is used to prevent a function call within an argument from
104 clobbering any stack already set up. */
105 static char *stack_usage_map;
107 /* Size of STACK_USAGE_MAP. */
108 static int highest_outgoing_arg_in_use;
110 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
111 stack location's tail call argument has been already stored into the stack.
112 This bitmap is used to prevent sibling call optimization if function tries
113 to use parent's incoming argument slots when they have been already
114 overwritten with tail call arguments. */
115 static sbitmap stored_args_map;
117 /* stack_arg_under_construction is nonzero when an argument may be
118 initialized with a constructor call (including a C function that
119 returns a BLKmode struct) and expand_call must take special action
120 to make sure the object being constructed does not overlap the
121 argument list for the constructor call. */
122 static int stack_arg_under_construction;
124 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
125 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
127 static void precompute_register_parameters (int, struct arg_data *, int *);
128 static int store_one_arg (struct arg_data *, rtx, int, int, int);
129 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
130 static int finalize_must_preallocate (int, int, struct arg_data *,
132 static void precompute_arguments (int, int, struct arg_data *);
133 static int compute_argument_block_size (int, struct args_size *, int);
134 static void initialize_argument_information (int, struct arg_data *,
135 struct args_size *, int, tree,
136 tree, CUMULATIVE_ARGS *, int,
137 rtx *, int *, int *, int *,
139 static void compute_argument_addresses (struct arg_data *, rtx, int);
140 static rtx rtx_for_function_call (tree, tree);
141 static void load_register_parameters (struct arg_data *, int, rtx *, int,
143 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
144 enum machine_mode, int, va_list);
145 static int special_function_p (tree, int);
146 static int check_sibcall_argument_overlap_1 (rtx);
147 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
149 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
151 static tree split_complex_values (tree);
152 static tree split_complex_types (tree);
154 #ifdef REG_PARM_STACK_SPACE
155 static rtx save_fixed_argument_area (int, rtx, int *, int *);
156 static void restore_fixed_argument_area (rtx, rtx, int, int);
159 /* Force FUNEXP into a form suitable for the address of a CALL,
160 and return that as an rtx. Also load the static chain register
161 if FNDECL is a nested function.
163 CALL_FUSAGE points to a variable holding the prospective
164 CALL_INSN_FUNCTION_USAGE information. */
167 prepare_call_address (rtx funexp, rtx static_chain_value,
168 rtx *call_fusage, int reg_parm_seen, int sibcallp)
170 /* Make a valid memory address and copy constants through pseudo-regs,
171 but not for a constant address if -fno-function-cse. */
172 if (GET_CODE (funexp) != SYMBOL_REF)
173 /* If we are using registers for parameters, force the
174 function address into a register now. */
175 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
176 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
177 : memory_address (FUNCTION_MODE, funexp));
180 #ifndef NO_FUNCTION_CSE
181 if (optimize && ! flag_no_function_cse)
182 funexp = force_reg (Pmode, funexp);
186 if (static_chain_value != 0)
188 static_chain_value = convert_memory_address (Pmode, static_chain_value);
189 emit_move_insn (static_chain_rtx, static_chain_value);
191 if (REG_P (static_chain_rtx))
192 use_reg (call_fusage, static_chain_rtx);
198 /* Generate instructions to call function FUNEXP,
199 and optionally pop the results.
200 The CALL_INSN is the first insn generated.
202 FNDECL is the declaration node of the function. This is given to the
203 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
205 FUNTYPE is the data type of the function. This is given to the macro
206 RETURN_POPS_ARGS to determine whether this function pops its own args.
207 We used to allow an identifier for library functions, but that doesn't
208 work when the return type is an aggregate type and the calling convention
209 says that the pointer to this aggregate is to be popped by the callee.
211 STACK_SIZE is the number of bytes of arguments on the stack,
212 ROUNDED_STACK_SIZE is that number rounded up to
213 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
214 both to put into the call insn and to generate explicit popping
217 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
218 It is zero if this call doesn't want a structure value.
220 NEXT_ARG_REG is the rtx that results from executing
221 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
222 just after all the args have had their registers assigned.
223 This could be whatever you like, but normally it is the first
224 arg-register beyond those used for args in this call,
225 or 0 if all the arg-registers are used in this call.
226 It is passed on to `gen_call' so you can put this info in the call insn.
228 VALREG is a hard register in which a value is returned,
229 or 0 if the call does not return a value.
231 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
232 the args to this call were processed.
233 We restore `inhibit_defer_pop' to that value.
235 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
236 denote registers used by the called function. */
239 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
240 tree funtype ATTRIBUTE_UNUSED,
241 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
242 HOST_WIDE_INT rounded_stack_size,
243 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
244 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
245 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
246 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
248 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
250 int already_popped = 0;
251 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
252 #if defined (HAVE_call) && defined (HAVE_call_value)
253 rtx struct_value_size_rtx;
254 struct_value_size_rtx = GEN_INT (struct_value_size);
257 #ifdef CALL_POPS_ARGS
258 n_popped += CALL_POPS_ARGS (* args_so_far);
261 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
262 and we don't want to load it into a register as an optimization,
263 because prepare_call_address already did it if it should be done. */
264 if (GET_CODE (funexp) != SYMBOL_REF)
265 funexp = memory_address (FUNCTION_MODE, funexp);
267 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
268 if ((ecf_flags & ECF_SIBCALL)
269 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
270 && (n_popped > 0 || stack_size == 0))
272 rtx n_pop = GEN_INT (n_popped);
275 /* If this subroutine pops its own args, record that in the call insn
276 if possible, for the sake of frame pointer elimination. */
279 pat = GEN_SIBCALL_VALUE_POP (valreg,
280 gen_rtx_MEM (FUNCTION_MODE, funexp),
281 rounded_stack_size_rtx, next_arg_reg,
284 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
285 rounded_stack_size_rtx, next_arg_reg, n_pop);
287 emit_call_insn (pat);
293 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
294 /* If the target has "call" or "call_value" insns, then prefer them
295 if no arguments are actually popped. If the target does not have
296 "call" or "call_value" insns, then we must use the popping versions
297 even if the call has no arguments to pop. */
298 #if defined (HAVE_call) && defined (HAVE_call_value)
299 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
300 && n_popped > 0 && ! (ecf_flags & ECF_SP_DEPRESSED))
302 if (HAVE_call_pop && HAVE_call_value_pop)
305 rtx n_pop = GEN_INT (n_popped);
308 /* If this subroutine pops its own args, record that in the call insn
309 if possible, for the sake of frame pointer elimination. */
312 pat = GEN_CALL_VALUE_POP (valreg,
313 gen_rtx_MEM (FUNCTION_MODE, funexp),
314 rounded_stack_size_rtx, next_arg_reg, n_pop);
316 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
317 rounded_stack_size_rtx, next_arg_reg, n_pop);
319 emit_call_insn (pat);
325 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
326 if ((ecf_flags & ECF_SIBCALL)
327 && HAVE_sibcall && HAVE_sibcall_value)
330 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
331 gen_rtx_MEM (FUNCTION_MODE, funexp),
332 rounded_stack_size_rtx,
333 next_arg_reg, NULL_RTX));
335 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
336 rounded_stack_size_rtx, next_arg_reg,
337 struct_value_size_rtx));
342 #if defined (HAVE_call) && defined (HAVE_call_value)
343 if (HAVE_call && HAVE_call_value)
346 emit_call_insn (GEN_CALL_VALUE (valreg,
347 gen_rtx_MEM (FUNCTION_MODE, funexp),
348 rounded_stack_size_rtx, next_arg_reg,
351 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
352 rounded_stack_size_rtx, next_arg_reg,
353 struct_value_size_rtx));
359 /* Find the call we just emitted. */
360 call_insn = last_call_insn ();
362 /* Mark memory as used for "pure" function call. */
363 if (ecf_flags & ECF_PURE)
367 gen_rtx_USE (VOIDmode,
368 gen_rtx_MEM (BLKmode, gen_rtx_SCRATCH (VOIDmode))),
371 /* Put the register usage information there. */
372 add_function_usage_to (call_insn, call_fusage);
374 /* If this is a const call, then set the insn's unchanging bit. */
375 if (ecf_flags & (ECF_CONST | ECF_PURE))
376 CONST_OR_PURE_CALL_P (call_insn) = 1;
378 /* If this call can't throw, attach a REG_EH_REGION reg note to that
380 if (ecf_flags & ECF_NOTHROW)
381 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, const0_rtx,
382 REG_NOTES (call_insn));
385 int rn = lookup_stmt_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
390 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_EH_REGION, GEN_INT (rn),
391 REG_NOTES (call_insn));
392 note_current_region_may_contain_throw ();
395 if (ecf_flags & ECF_NORETURN)
396 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_NORETURN, const0_rtx,
397 REG_NOTES (call_insn));
399 if (ecf_flags & ECF_RETURNS_TWICE)
401 REG_NOTES (call_insn) = gen_rtx_EXPR_LIST (REG_SETJMP, const0_rtx,
402 REG_NOTES (call_insn));
403 current_function_calls_setjmp = 1;
406 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
408 /* Restore this now, so that we do defer pops for this call's args
409 if the context of the call as a whole permits. */
410 inhibit_defer_pop = old_inhibit_defer_pop;
415 CALL_INSN_FUNCTION_USAGE (call_insn)
416 = gen_rtx_EXPR_LIST (VOIDmode,
417 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
418 CALL_INSN_FUNCTION_USAGE (call_insn));
419 rounded_stack_size -= n_popped;
420 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
421 stack_pointer_delta -= n_popped;
424 if (!ACCUMULATE_OUTGOING_ARGS)
426 /* If returning from the subroutine does not automatically pop the args,
427 we need an instruction to pop them sooner or later.
428 Perhaps do it now; perhaps just record how much space to pop later.
430 If returning from the subroutine does pop the args, indicate that the
431 stack pointer will be changed. */
433 if (rounded_stack_size != 0)
435 if (ecf_flags & (ECF_SP_DEPRESSED | ECF_NORETURN))
436 /* Just pretend we did the pop. */
437 stack_pointer_delta -= rounded_stack_size;
438 else if (flag_defer_pop && inhibit_defer_pop == 0
439 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
440 pending_stack_adjust += rounded_stack_size;
442 adjust_stack (rounded_stack_size_rtx);
445 /* When we accumulate outgoing args, we must avoid any stack manipulations.
446 Restore the stack pointer to its original value now. Usually
447 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
448 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
449 popping variants of functions exist as well.
451 ??? We may optimize similar to defer_pop above, but it is
452 probably not worthwhile.
454 ??? It will be worthwhile to enable combine_stack_adjustments even for
457 anti_adjust_stack (GEN_INT (n_popped));
460 /* Determine if the function identified by NAME and FNDECL is one with
461 special properties we wish to know about.
463 For example, if the function might return more than one time (setjmp), then
464 set RETURNS_TWICE to a nonzero value.
466 Similarly set NORETURN if the function is in the longjmp family.
468 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
469 space from the stack such as alloca. */
472 special_function_p (tree fndecl, int flags)
474 if (fndecl && DECL_NAME (fndecl)
475 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
476 /* Exclude functions not at the file scope, or not `extern',
477 since they are not the magic functions we would otherwise
479 FIXME: this should be handled with attributes, not with this
480 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
481 because you can declare fork() inside a function if you
483 && (DECL_CONTEXT (fndecl) == NULL_TREE
484 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
485 && TREE_PUBLIC (fndecl))
487 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
488 const char *tname = name;
490 /* We assume that alloca will always be called by name. It
491 makes no sense to pass it as a pointer-to-function to
492 anything that does not understand its behavior. */
493 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
495 && ! strcmp (name, "alloca"))
496 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
498 && ! strcmp (name, "__builtin_alloca"))))
499 flags |= ECF_MAY_BE_ALLOCA;
501 /* Disregard prefix _, __ or __x. */
504 if (name[1] == '_' && name[2] == 'x')
506 else if (name[1] == '_')
515 && (! strcmp (tname, "setjmp")
516 || ! strcmp (tname, "setjmp_syscall")))
518 && ! strcmp (tname, "sigsetjmp"))
520 && ! strcmp (tname, "savectx")))
521 flags |= ECF_RETURNS_TWICE;
524 && ! strcmp (tname, "siglongjmp"))
525 flags |= ECF_NORETURN;
527 else if ((tname[0] == 'q' && tname[1] == 's'
528 && ! strcmp (tname, "qsetjmp"))
529 || (tname[0] == 'v' && tname[1] == 'f'
530 && ! strcmp (tname, "vfork"))
531 || (tname[0] == 'g' && tname[1] == 'e'
532 && !strcmp (tname, "getcontext")))
533 flags |= ECF_RETURNS_TWICE;
535 else if (tname[0] == 'l' && tname[1] == 'o'
536 && ! strcmp (tname, "longjmp"))
537 flags |= ECF_NORETURN;
543 /* Return nonzero when FNDECL represents a call to setjmp. */
546 setjmp_call_p (tree fndecl)
548 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
551 /* Return true when exp contains alloca call. */
553 alloca_call_p (tree exp)
555 if (TREE_CODE (exp) == CALL_EXPR
556 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
557 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
559 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
560 0) & ECF_MAY_BE_ALLOCA))
565 /* Detect flags (function attributes) from the function decl or type node. */
568 flags_from_decl_or_type (tree exp)
575 type = TREE_TYPE (exp);
577 /* The function exp may have the `malloc' attribute. */
578 if (DECL_IS_MALLOC (exp))
581 /* The function exp may have the `returns_twice' attribute. */
582 if (DECL_IS_RETURNS_TWICE (exp))
583 flags |= ECF_RETURNS_TWICE;
585 /* The function exp may have the `pure' attribute. */
586 if (DECL_IS_PURE (exp))
589 if (DECL_IS_NOVOPS (exp))
592 if (TREE_NOTHROW (exp))
593 flags |= ECF_NOTHROW;
595 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
598 flags = special_function_p (exp, flags);
600 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
603 if (TREE_THIS_VOLATILE (exp))
604 flags |= ECF_NORETURN;
606 /* Mark if the function returns with the stack pointer depressed. We
607 cannot consider it pure or constant in that case. */
608 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
610 flags |= ECF_SP_DEPRESSED;
611 flags &= ~(ECF_PURE | ECF_CONST);
617 /* Detect flags from a CALL_EXPR. */
620 call_expr_flags (tree t)
623 tree decl = get_callee_fndecl (t);
626 flags = flags_from_decl_or_type (decl);
629 t = TREE_TYPE (TREE_OPERAND (t, 0));
630 if (t && TREE_CODE (t) == POINTER_TYPE)
631 flags = flags_from_decl_or_type (TREE_TYPE (t));
639 /* Precompute all register parameters as described by ARGS, storing values
640 into fields within the ARGS array.
642 NUM_ACTUALS indicates the total number elements in the ARGS array.
644 Set REG_PARM_SEEN if we encounter a register parameter. */
647 precompute_register_parameters (int num_actuals, struct arg_data *args,
654 for (i = 0; i < num_actuals; i++)
655 if (args[i].reg != 0 && ! args[i].pass_on_stack)
659 if (args[i].value == 0)
662 args[i].value = expand_normal (args[i].tree_value);
663 preserve_temp_slots (args[i].value);
667 /* If the value is a non-legitimate constant, force it into a
668 pseudo now. TLS symbols sometimes need a call to resolve. */
669 if (CONSTANT_P (args[i].value)
670 && !LEGITIMATE_CONSTANT_P (args[i].value))
671 args[i].value = force_reg (args[i].mode, args[i].value);
673 /* If we are to promote the function arg to a wider mode,
676 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
678 = convert_modes (args[i].mode,
679 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
680 args[i].value, args[i].unsignedp);
682 /* If we're going to have to load the value by parts, pull the
683 parts into pseudos. The part extraction process can involve
684 non-trivial computation. */
685 if (GET_CODE (args[i].reg) == PARALLEL)
687 tree type = TREE_TYPE (args[i].tree_value);
688 args[i].parallel_value
689 = emit_group_load_into_temps (args[i].reg, args[i].value,
690 type, int_size_in_bytes (type));
693 /* If the value is expensive, and we are inside an appropriately
694 short loop, put the value into a pseudo and then put the pseudo
697 For small register classes, also do this if this call uses
698 register parameters. This is to avoid reload conflicts while
699 loading the parameters registers. */
701 else if ((! (REG_P (args[i].value)
702 || (GET_CODE (args[i].value) == SUBREG
703 && REG_P (SUBREG_REG (args[i].value)))))
704 && args[i].mode != BLKmode
705 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
706 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
708 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
712 #ifdef REG_PARM_STACK_SPACE
714 /* The argument list is the property of the called routine and it
715 may clobber it. If the fixed area has been used for previous
716 parameters, we must save and restore it. */
719 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
724 /* Compute the boundary of the area that needs to be saved, if any. */
725 high = reg_parm_stack_space;
726 #ifdef ARGS_GROW_DOWNWARD
729 if (high > highest_outgoing_arg_in_use)
730 high = highest_outgoing_arg_in_use;
732 for (low = 0; low < high; low++)
733 if (stack_usage_map[low] != 0)
736 enum machine_mode save_mode;
741 while (stack_usage_map[--high] == 0)
745 *high_to_save = high;
747 num_to_save = high - low + 1;
748 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
750 /* If we don't have the required alignment, must do this
752 if ((low & (MIN (GET_MODE_SIZE (save_mode),
753 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
756 #ifdef ARGS_GROW_DOWNWARD
761 stack_area = gen_rtx_MEM (save_mode,
762 memory_address (save_mode,
763 plus_constant (argblock,
766 set_mem_align (stack_area, PARM_BOUNDARY);
767 if (save_mode == BLKmode)
769 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
770 emit_block_move (validize_mem (save_area), stack_area,
771 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
775 save_area = gen_reg_rtx (save_mode);
776 emit_move_insn (save_area, stack_area);
786 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
788 enum machine_mode save_mode = GET_MODE (save_area);
792 #ifdef ARGS_GROW_DOWNWARD
793 delta = -high_to_save;
797 stack_area = gen_rtx_MEM (save_mode,
798 memory_address (save_mode,
799 plus_constant (argblock, delta)));
800 set_mem_align (stack_area, PARM_BOUNDARY);
802 if (save_mode != BLKmode)
803 emit_move_insn (stack_area, save_area);
805 emit_block_move (stack_area, validize_mem (save_area),
806 GEN_INT (high_to_save - low_to_save + 1),
809 #endif /* REG_PARM_STACK_SPACE */
811 /* If any elements in ARGS refer to parameters that are to be passed in
812 registers, but not in memory, and whose alignment does not permit a
813 direct copy into registers. Copy the values into a group of pseudos
814 which we will later copy into the appropriate hard registers.
816 Pseudos for each unaligned argument will be stored into the array
817 args[argnum].aligned_regs. The caller is responsible for deallocating
818 the aligned_regs array if it is nonzero. */
821 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
825 for (i = 0; i < num_actuals; i++)
826 if (args[i].reg != 0 && ! args[i].pass_on_stack
827 && args[i].mode == BLKmode
828 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
829 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
831 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
832 int endian_correction = 0;
836 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
837 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
841 args[i].n_aligned_regs
842 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
845 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
847 /* Structures smaller than a word are normally aligned to the
848 least significant byte. On a BYTES_BIG_ENDIAN machine,
849 this means we must skip the empty high order bytes when
850 calculating the bit offset. */
851 if (bytes < UNITS_PER_WORD
852 #ifdef BLOCK_REG_PADDING
853 && (BLOCK_REG_PADDING (args[i].mode,
854 TREE_TYPE (args[i].tree_value), 1)
860 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
862 for (j = 0; j < args[i].n_aligned_regs; j++)
864 rtx reg = gen_reg_rtx (word_mode);
865 rtx word = operand_subword_force (args[i].value, j, BLKmode);
866 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
868 args[i].aligned_regs[j] = reg;
869 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
870 word_mode, word_mode);
872 /* There is no need to restrict this code to loading items
873 in TYPE_ALIGN sized hunks. The bitfield instructions can
874 load up entire word sized registers efficiently.
876 ??? This may not be needed anymore.
877 We use to emit a clobber here but that doesn't let later
878 passes optimize the instructions we emit. By storing 0 into
879 the register later passes know the first AND to zero out the
880 bitfield being set in the register is unnecessary. The store
881 of 0 will be deleted as will at least the first AND. */
883 emit_move_insn (reg, const0_rtx);
885 bytes -= bitsize / BITS_PER_UNIT;
886 store_bit_field (reg, bitsize, endian_correction, word_mode,
892 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
895 NUM_ACTUALS is the total number of parameters.
897 N_NAMED_ARGS is the total number of named arguments.
899 FNDECL is the tree code for the target of this call (if known)
901 ARGS_SO_FAR holds state needed by the target to know where to place
904 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
905 for arguments which are passed in registers.
907 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
908 and may be modified by this routine.
910 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
911 flags which may may be modified by this routine.
913 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
914 that requires allocation of stack space.
916 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
917 the thunked-to function. */
920 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
921 struct arg_data *args,
922 struct args_size *args_size,
923 int n_named_args ATTRIBUTE_UNUSED,
924 tree actparms, tree fndecl,
925 CUMULATIVE_ARGS *args_so_far,
926 int reg_parm_stack_space,
927 rtx *old_stack_level, int *old_pending_adj,
928 int *must_preallocate, int *ecf_flags,
929 bool *may_tailcall, bool call_from_thunk_p)
931 /* 1 if scanning parms front to back, -1 if scanning back to front. */
934 /* Count arg position in order args appear. */
940 args_size->constant = 0;
943 /* In this loop, we consider args in the order they are written.
944 We fill up ARGS from the front or from the back if necessary
945 so that in any case the first arg to be pushed ends up at the front. */
947 if (PUSH_ARGS_REVERSED)
949 i = num_actuals - 1, inc = -1;
950 /* In this case, must reverse order of args
951 so that we compute and push the last arg first. */
958 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
959 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
961 tree type = TREE_TYPE (TREE_VALUE (p));
963 enum machine_mode mode;
965 args[i].tree_value = TREE_VALUE (p);
967 /* Replace erroneous argument with constant zero. */
968 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
969 args[i].tree_value = integer_zero_node, type = integer_type_node;
971 /* If TYPE is a transparent union, pass things the way we would
972 pass the first field of the union. We have already verified that
973 the modes are the same. */
974 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
975 type = TREE_TYPE (TYPE_FIELDS (type));
977 /* Decide where to pass this arg.
979 args[i].reg is nonzero if all or part is passed in registers.
981 args[i].partial is nonzero if part but not all is passed in registers,
982 and the exact value says how many bytes are passed in registers.
984 args[i].pass_on_stack is nonzero if the argument must at least be
985 computed on the stack. It may then be loaded back into registers
986 if args[i].reg is nonzero.
988 These decisions are driven by the FUNCTION_... macros and must agree
989 with those made by function.c. */
991 /* See if this argument should be passed by invisible reference. */
992 if (pass_by_reference (args_so_far, TYPE_MODE (type),
993 type, argpos < n_named_args))
999 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1000 type, argpos < n_named_args);
1002 /* If we're compiling a thunk, pass through invisible references
1003 instead of making a copy. */
1004 if (call_from_thunk_p
1006 && !TREE_ADDRESSABLE (type)
1007 && (base = get_base_address (args[i].tree_value))
1008 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1010 /* We can't use sibcalls if a callee-copied argument is
1011 stored in the current function's frame. */
1012 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1013 *may_tailcall = false;
1015 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1016 type = TREE_TYPE (args[i].tree_value);
1018 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1022 /* We make a copy of the object and pass the address to the
1023 function being called. */
1026 if (!COMPLETE_TYPE_P (type)
1027 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1028 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1029 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1030 STACK_CHECK_MAX_VAR_SIZE))))
1032 /* This is a variable-sized object. Make space on the stack
1034 rtx size_rtx = expr_size (TREE_VALUE (p));
1036 if (*old_stack_level == 0)
1038 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1039 *old_pending_adj = pending_stack_adjust;
1040 pending_stack_adjust = 0;
1043 copy = gen_rtx_MEM (BLKmode,
1044 allocate_dynamic_stack_space
1045 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1046 set_mem_attributes (copy, type, 1);
1049 copy = assign_temp (type, 0, 1, 0);
1051 store_expr (args[i].tree_value, copy, 0);
1054 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1056 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1059 = build_fold_addr_expr (make_tree (type, copy));
1060 type = TREE_TYPE (args[i].tree_value);
1061 *may_tailcall = false;
1065 mode = TYPE_MODE (type);
1066 unsignedp = TYPE_UNSIGNED (type);
1068 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1069 mode = promote_mode (type, mode, &unsignedp, 1);
1071 args[i].unsignedp = unsignedp;
1072 args[i].mode = mode;
1074 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1075 argpos < n_named_args);
1076 #ifdef FUNCTION_INCOMING_ARG
1077 /* If this is a sibling call and the machine has register windows, the
1078 register window has to be unwinded before calling the routine, so
1079 arguments have to go into the incoming registers. */
1080 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1081 argpos < n_named_args);
1083 args[i].tail_call_reg = args[i].reg;
1088 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1089 argpos < n_named_args);
1091 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1093 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1094 it means that we are to pass this arg in the register(s) designated
1095 by the PARALLEL, but also to pass it in the stack. */
1096 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1097 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1098 args[i].pass_on_stack = 1;
1100 /* If this is an addressable type, we must preallocate the stack
1101 since we must evaluate the object into its final location.
1103 If this is to be passed in both registers and the stack, it is simpler
1105 if (TREE_ADDRESSABLE (type)
1106 || (args[i].pass_on_stack && args[i].reg != 0))
1107 *must_preallocate = 1;
1109 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1110 we cannot consider this function call constant. */
1111 if (TREE_ADDRESSABLE (type))
1112 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1114 /* Compute the stack-size of this argument. */
1115 if (args[i].reg == 0 || args[i].partial != 0
1116 || reg_parm_stack_space > 0
1117 || args[i].pass_on_stack)
1118 locate_and_pad_parm (mode, type,
1119 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1124 args[i].pass_on_stack ? 0 : args[i].partial,
1125 fndecl, args_size, &args[i].locate);
1126 #ifdef BLOCK_REG_PADDING
1128 /* The argument is passed entirely in registers. See at which
1129 end it should be padded. */
1130 args[i].locate.where_pad =
1131 BLOCK_REG_PADDING (mode, type,
1132 int_size_in_bytes (type) <= UNITS_PER_WORD);
1135 /* Update ARGS_SIZE, the total stack space for args so far. */
1137 args_size->constant += args[i].locate.size.constant;
1138 if (args[i].locate.size.var)
1139 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1141 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1142 have been used, etc. */
1144 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1145 argpos < n_named_args);
1149 /* Update ARGS_SIZE to contain the total size for the argument block.
1150 Return the original constant component of the argument block's size.
1152 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1153 for arguments passed in registers. */
1156 compute_argument_block_size (int reg_parm_stack_space,
1157 struct args_size *args_size,
1158 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1160 int unadjusted_args_size = args_size->constant;
1162 /* For accumulate outgoing args mode we don't need to align, since the frame
1163 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1164 backends from generating misaligned frame sizes. */
1165 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1166 preferred_stack_boundary = STACK_BOUNDARY;
1168 /* Compute the actual size of the argument block required. The variable
1169 and constant sizes must be combined, the size may have to be rounded,
1170 and there may be a minimum required size. */
1174 args_size->var = ARGS_SIZE_TREE (*args_size);
1175 args_size->constant = 0;
1177 preferred_stack_boundary /= BITS_PER_UNIT;
1178 if (preferred_stack_boundary > 1)
1180 /* We don't handle this case yet. To handle it correctly we have
1181 to add the delta, round and subtract the delta.
1182 Currently no machine description requires this support. */
1183 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1184 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1187 if (reg_parm_stack_space > 0)
1190 = size_binop (MAX_EXPR, args_size->var,
1191 ssize_int (reg_parm_stack_space));
1193 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1194 /* The area corresponding to register parameters is not to count in
1195 the size of the block we need. So make the adjustment. */
1197 = size_binop (MINUS_EXPR, args_size->var,
1198 ssize_int (reg_parm_stack_space));
1204 preferred_stack_boundary /= BITS_PER_UNIT;
1205 if (preferred_stack_boundary < 1)
1206 preferred_stack_boundary = 1;
1207 args_size->constant = (((args_size->constant
1208 + stack_pointer_delta
1209 + preferred_stack_boundary - 1)
1210 / preferred_stack_boundary
1211 * preferred_stack_boundary)
1212 - stack_pointer_delta);
1214 args_size->constant = MAX (args_size->constant,
1215 reg_parm_stack_space);
1217 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1218 args_size->constant -= reg_parm_stack_space;
1221 return unadjusted_args_size;
1224 /* Precompute parameters as needed for a function call.
1226 FLAGS is mask of ECF_* constants.
1228 NUM_ACTUALS is the number of arguments.
1230 ARGS is an array containing information for each argument; this
1231 routine fills in the INITIAL_VALUE and VALUE fields for each
1232 precomputed argument. */
1235 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1239 /* If this is a libcall, then precompute all arguments so that we do not
1240 get extraneous instructions emitted as part of the libcall sequence. */
1241 if ((flags & ECF_LIBCALL_BLOCK) == 0)
1244 for (i = 0; i < num_actuals; i++)
1246 enum machine_mode mode;
1248 /* If this is an addressable type, we cannot pre-evaluate it. */
1249 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1251 args[i].initial_value = args[i].value
1252 = expand_normal (args[i].tree_value);
1254 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1255 if (mode != args[i].mode)
1258 = convert_modes (args[i].mode, mode,
1259 args[i].value, args[i].unsignedp);
1260 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1261 /* CSE will replace this only if it contains args[i].value
1262 pseudo, so convert it down to the declared mode using
1264 if (REG_P (args[i].value)
1265 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1267 args[i].initial_value
1268 = gen_lowpart_SUBREG (mode, args[i].value);
1269 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1270 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1278 /* Given the current state of MUST_PREALLOCATE and information about
1279 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1280 compute and return the final value for MUST_PREALLOCATE. */
1283 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1285 /* See if we have or want to preallocate stack space.
1287 If we would have to push a partially-in-regs parm
1288 before other stack parms, preallocate stack space instead.
1290 If the size of some parm is not a multiple of the required stack
1291 alignment, we must preallocate.
1293 If the total size of arguments that would otherwise create a copy in
1294 a temporary (such as a CALL) is more than half the total argument list
1295 size, preallocation is faster.
1297 Another reason to preallocate is if we have a machine (like the m88k)
1298 where stack alignment is required to be maintained between every
1299 pair of insns, not just when the call is made. However, we assume here
1300 that such machines either do not have push insns (and hence preallocation
1301 would occur anyway) or the problem is taken care of with
1304 if (! must_preallocate)
1306 int partial_seen = 0;
1307 int copy_to_evaluate_size = 0;
1310 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1312 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1314 else if (partial_seen && args[i].reg == 0)
1315 must_preallocate = 1;
1317 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1318 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1319 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1320 || TREE_CODE (args[i].tree_value) == COND_EXPR
1321 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1322 copy_to_evaluate_size
1323 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1326 if (copy_to_evaluate_size * 2 >= args_size->constant
1327 && args_size->constant > 0)
1328 must_preallocate = 1;
1330 return must_preallocate;
1333 /* If we preallocated stack space, compute the address of each argument
1334 and store it into the ARGS array.
1336 We need not ensure it is a valid memory address here; it will be
1337 validized when it is used.
1339 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1342 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1346 rtx arg_reg = argblock;
1347 int i, arg_offset = 0;
1349 if (GET_CODE (argblock) == PLUS)
1350 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1352 for (i = 0; i < num_actuals; i++)
1354 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1355 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1357 unsigned int align, boundary;
1358 unsigned int units_on_stack = 0;
1359 enum machine_mode partial_mode = VOIDmode;
1361 /* Skip this parm if it will not be passed on the stack. */
1362 if (! args[i].pass_on_stack
1364 && args[i].partial == 0)
1367 if (GET_CODE (offset) == CONST_INT)
1368 addr = plus_constant (arg_reg, INTVAL (offset));
1370 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1372 addr = plus_constant (addr, arg_offset);
1374 if (args[i].partial != 0)
1376 /* Only part of the parameter is being passed on the stack.
1377 Generate a simple memory reference of the correct size. */
1378 units_on_stack = args[i].locate.size.constant;
1379 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1381 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1382 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1386 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1387 set_mem_attributes (args[i].stack,
1388 TREE_TYPE (args[i].tree_value), 1);
1390 align = BITS_PER_UNIT;
1391 boundary = args[i].locate.boundary;
1392 if (args[i].locate.where_pad != downward)
1394 else if (GET_CODE (offset) == CONST_INT)
1396 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1397 align = align & -align;
1399 set_mem_align (args[i].stack, align);
1401 if (GET_CODE (slot_offset) == CONST_INT)
1402 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1404 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1406 addr = plus_constant (addr, arg_offset);
1408 if (args[i].partial != 0)
1410 /* Only part of the parameter is being passed on the stack.
1411 Generate a simple memory reference of the correct size. */
1412 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1413 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1417 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1418 set_mem_attributes (args[i].stack_slot,
1419 TREE_TYPE (args[i].tree_value), 1);
1421 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1423 /* Function incoming arguments may overlap with sibling call
1424 outgoing arguments and we cannot allow reordering of reads
1425 from function arguments with stores to outgoing arguments
1426 of sibling calls. */
1427 set_mem_alias_set (args[i].stack, 0);
1428 set_mem_alias_set (args[i].stack_slot, 0);
1433 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1434 in a call instruction.
1436 FNDECL is the tree node for the target function. For an indirect call
1437 FNDECL will be NULL_TREE.
1439 ADDR is the operand 0 of CALL_EXPR for this call. */
1442 rtx_for_function_call (tree fndecl, tree addr)
1446 /* Get the function to call, in the form of RTL. */
1449 /* If this is the first use of the function, see if we need to
1450 make an external definition for it. */
1451 if (! TREE_USED (fndecl))
1453 assemble_external (fndecl);
1454 TREE_USED (fndecl) = 1;
1457 /* Get a SYMBOL_REF rtx for the function address. */
1458 funexp = XEXP (DECL_RTL (fndecl), 0);
1461 /* Generate an rtx (probably a pseudo-register) for the address. */
1464 funexp = expand_normal (addr);
1465 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1470 /* Return true if and only if SIZE storage units (usually bytes)
1471 starting from address ADDR overlap with already clobbered argument
1472 area. This function is used to determine if we should give up a
1476 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1480 if (addr == current_function_internal_arg_pointer)
1482 else if (GET_CODE (addr) == PLUS
1483 && XEXP (addr, 0) == current_function_internal_arg_pointer
1484 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1485 i = INTVAL (XEXP (addr, 1));
1486 /* Return true for arg pointer based indexed addressing. */
1487 else if (GET_CODE (addr) == PLUS
1488 && (XEXP (addr, 0) == current_function_internal_arg_pointer
1489 || XEXP (addr, 1) == current_function_internal_arg_pointer))
1494 #ifdef ARGS_GROW_DOWNWARD
1499 unsigned HOST_WIDE_INT k;
1501 for (k = 0; k < size; k++)
1502 if (i + k < stored_args_map->n_bits
1503 && TEST_BIT (stored_args_map, i + k))
1510 /* Do the register loads required for any wholly-register parms or any
1511 parms which are passed both on the stack and in a register. Their
1512 expressions were already evaluated.
1514 Mark all register-parms as living through the call, putting these USE
1515 insns in the CALL_INSN_FUNCTION_USAGE field.
1517 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1518 checking, setting *SIBCALL_FAILURE if appropriate. */
1521 load_register_parameters (struct arg_data *args, int num_actuals,
1522 rtx *call_fusage, int flags, int is_sibcall,
1523 int *sibcall_failure)
1527 for (i = 0; i < num_actuals; i++)
1529 rtx reg = ((flags & ECF_SIBCALL)
1530 ? args[i].tail_call_reg : args[i].reg);
1533 int partial = args[i].partial;
1536 rtx before_arg = get_last_insn ();
1537 /* Set non-negative if we must move a word at a time, even if
1538 just one word (e.g, partial == 4 && mode == DFmode). Set
1539 to -1 if we just use a normal move insn. This value can be
1540 zero if the argument is a zero size structure. */
1542 if (GET_CODE (reg) == PARALLEL)
1546 gcc_assert (partial % UNITS_PER_WORD == 0);
1547 nregs = partial / UNITS_PER_WORD;
1549 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1551 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1552 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1555 size = GET_MODE_SIZE (args[i].mode);
1557 /* Handle calls that pass values in multiple non-contiguous
1558 locations. The Irix 6 ABI has examples of this. */
1560 if (GET_CODE (reg) == PARALLEL)
1561 emit_group_move (reg, args[i].parallel_value);
1563 /* If simple case, just do move. If normal partial, store_one_arg
1564 has already loaded the register for us. In all other cases,
1565 load the register(s) from memory. */
1567 else if (nregs == -1)
1569 emit_move_insn (reg, args[i].value);
1570 #ifdef BLOCK_REG_PADDING
1571 /* Handle case where we have a value that needs shifting
1572 up to the msb. eg. a QImode value and we're padding
1573 upward on a BYTES_BIG_ENDIAN machine. */
1574 if (size < UNITS_PER_WORD
1575 && (args[i].locate.where_pad
1576 == (BYTES_BIG_ENDIAN ? upward : downward)))
1579 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1581 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1582 report the whole reg as used. Strictly speaking, the
1583 call only uses SIZE bytes at the msb end, but it doesn't
1584 seem worth generating rtl to say that. */
1585 reg = gen_rtx_REG (word_mode, REGNO (reg));
1586 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1587 build_int_cst (NULL_TREE, shift),
1590 emit_move_insn (reg, x);
1595 /* If we have pre-computed the values to put in the registers in
1596 the case of non-aligned structures, copy them in now. */
1598 else if (args[i].n_aligned_regs != 0)
1599 for (j = 0; j < args[i].n_aligned_regs; j++)
1600 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1601 args[i].aligned_regs[j]);
1603 else if (partial == 0 || args[i].pass_on_stack)
1605 rtx mem = validize_mem (args[i].value);
1607 /* Check for overlap with already clobbered argument area. */
1609 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1611 *sibcall_failure = 1;
1613 /* Handle a BLKmode that needs shifting. */
1614 if (nregs == 1 && size < UNITS_PER_WORD
1615 #ifdef BLOCK_REG_PADDING
1616 && args[i].locate.where_pad == downward
1622 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1623 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1624 rtx x = gen_reg_rtx (word_mode);
1625 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1626 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1629 emit_move_insn (x, tem);
1630 x = expand_shift (dir, word_mode, x,
1631 build_int_cst (NULL_TREE, shift),
1634 emit_move_insn (ri, x);
1637 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1640 /* When a parameter is a block, and perhaps in other cases, it is
1641 possible that it did a load from an argument slot that was
1642 already clobbered. */
1644 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1645 *sibcall_failure = 1;
1647 /* Handle calls that pass values in multiple non-contiguous
1648 locations. The Irix 6 ABI has examples of this. */
1649 if (GET_CODE (reg) == PARALLEL)
1650 use_group_regs (call_fusage, reg);
1651 else if (nregs == -1)
1652 use_reg (call_fusage, reg);
1654 use_regs (call_fusage, REGNO (reg), nregs);
1659 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1660 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1661 bytes, then we would need to push some additional bytes to pad the
1662 arguments. So, we compute an adjust to the stack pointer for an
1663 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1664 bytes. Then, when the arguments are pushed the stack will be perfectly
1665 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1666 be popped after the call. Returns the adjustment. */
1669 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1670 struct args_size *args_size,
1671 unsigned int preferred_unit_stack_boundary)
1673 /* The number of bytes to pop so that the stack will be
1674 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1675 HOST_WIDE_INT adjustment;
1676 /* The alignment of the stack after the arguments are pushed, if we
1677 just pushed the arguments without adjust the stack here. */
1678 unsigned HOST_WIDE_INT unadjusted_alignment;
1680 unadjusted_alignment
1681 = ((stack_pointer_delta + unadjusted_args_size)
1682 % preferred_unit_stack_boundary);
1684 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1685 as possible -- leaving just enough left to cancel out the
1686 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1687 PENDING_STACK_ADJUST is non-negative, and congruent to
1688 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1690 /* Begin by trying to pop all the bytes. */
1691 unadjusted_alignment
1692 = (unadjusted_alignment
1693 - (pending_stack_adjust % preferred_unit_stack_boundary));
1694 adjustment = pending_stack_adjust;
1695 /* Push enough additional bytes that the stack will be aligned
1696 after the arguments are pushed. */
1697 if (preferred_unit_stack_boundary > 1)
1699 if (unadjusted_alignment > 0)
1700 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1702 adjustment += unadjusted_alignment;
1705 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1706 bytes after the call. The right number is the entire
1707 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1708 by the arguments in the first place. */
1710 = pending_stack_adjust - adjustment + unadjusted_args_size;
1715 /* Scan X expression if it does not dereference any argument slots
1716 we already clobbered by tail call arguments (as noted in stored_args_map
1718 Return nonzero if X expression dereferences such argument slots,
1722 check_sibcall_argument_overlap_1 (rtx x)
1731 code = GET_CODE (x);
1734 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1735 GET_MODE_SIZE (GET_MODE (x)));
1737 /* Scan all subexpressions. */
1738 fmt = GET_RTX_FORMAT (code);
1739 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1743 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1746 else if (*fmt == 'E')
1748 for (j = 0; j < XVECLEN (x, i); j++)
1749 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1756 /* Scan sequence after INSN if it does not dereference any argument slots
1757 we already clobbered by tail call arguments (as noted in stored_args_map
1758 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1759 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1760 should be 0). Return nonzero if sequence after INSN dereferences such argument
1761 slots, zero otherwise. */
1764 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1768 if (insn == NULL_RTX)
1769 insn = get_insns ();
1771 insn = NEXT_INSN (insn);
1773 for (; insn; insn = NEXT_INSN (insn))
1775 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1778 if (mark_stored_args_map)
1780 #ifdef ARGS_GROW_DOWNWARD
1781 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1783 low = arg->locate.slot_offset.constant;
1786 for (high = low + arg->locate.size.constant; low < high; low++)
1787 SET_BIT (stored_args_map, low);
1789 return insn != NULL_RTX;
1792 /* Given that a function returns a value of mode MODE at the most
1793 significant end of hard register VALUE, shift VALUE left or right
1794 as specified by LEFT_P. Return true if some action was needed. */
1797 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1799 HOST_WIDE_INT shift;
1801 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1802 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1806 /* Use ashr rather than lshr for right shifts. This is for the benefit
1807 of the MIPS port, which requires SImode values to be sign-extended
1808 when stored in 64-bit registers. */
1809 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1810 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1815 /* Generate all the code for a function call
1816 and return an rtx for its value.
1817 Store the value in TARGET (specified as an rtx) if convenient.
1818 If the value is stored in TARGET then TARGET is returned.
1819 If IGNORE is nonzero, then we ignore the value of the function call. */
1822 expand_call (tree exp, rtx target, int ignore)
1824 /* Nonzero if we are currently expanding a call. */
1825 static int currently_expanding_call = 0;
1827 /* List of actual parameters. */
1828 tree actparms = TREE_OPERAND (exp, 1);
1829 /* RTX for the function to be called. */
1831 /* Sequence of insns to perform a normal "call". */
1832 rtx normal_call_insns = NULL_RTX;
1833 /* Sequence of insns to perform a tail "call". */
1834 rtx tail_call_insns = NULL_RTX;
1835 /* Data type of the function. */
1837 tree type_arg_types;
1838 /* Declaration of the function being called,
1839 or 0 if the function is computed (not known by name). */
1841 /* The type of the function being called. */
1843 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1846 /* Register in which non-BLKmode value will be returned,
1847 or 0 if no value or if value is BLKmode. */
1849 /* Address where we should return a BLKmode value;
1850 0 if value not BLKmode. */
1851 rtx structure_value_addr = 0;
1852 /* Nonzero if that address is being passed by treating it as
1853 an extra, implicit first parameter. Otherwise,
1854 it is passed by being copied directly into struct_value_rtx. */
1855 int structure_value_addr_parm = 0;
1856 /* Size of aggregate value wanted, or zero if none wanted
1857 or if we are using the non-reentrant PCC calling convention
1858 or expecting the value in registers. */
1859 HOST_WIDE_INT struct_value_size = 0;
1860 /* Nonzero if called function returns an aggregate in memory PCC style,
1861 by returning the address of where to find it. */
1862 int pcc_struct_value = 0;
1863 rtx struct_value = 0;
1865 /* Number of actual parameters in this call, including struct value addr. */
1867 /* Number of named args. Args after this are anonymous ones
1868 and they must all go on the stack. */
1871 /* Vector of information about each argument.
1872 Arguments are numbered in the order they will be pushed,
1873 not the order they are written. */
1874 struct arg_data *args;
1876 /* Total size in bytes of all the stack-parms scanned so far. */
1877 struct args_size args_size;
1878 struct args_size adjusted_args_size;
1879 /* Size of arguments before any adjustments (such as rounding). */
1880 int unadjusted_args_size;
1881 /* Data on reg parms scanned so far. */
1882 CUMULATIVE_ARGS args_so_far;
1883 /* Nonzero if a reg parm has been scanned. */
1885 /* Nonzero if this is an indirect function call. */
1887 /* Nonzero if we must avoid push-insns in the args for this call.
1888 If stack space is allocated for register parameters, but not by the
1889 caller, then it is preallocated in the fixed part of the stack frame.
1890 So the entire argument block must then be preallocated (i.e., we
1891 ignore PUSH_ROUNDING in that case). */
1893 int must_preallocate = !PUSH_ARGS;
1895 /* Size of the stack reserved for parameter registers. */
1896 int reg_parm_stack_space = 0;
1898 /* Address of space preallocated for stack parms
1899 (on machines that lack push insns), or 0 if space not preallocated. */
1902 /* Mask of ECF_ flags. */
1904 #ifdef REG_PARM_STACK_SPACE
1905 /* Define the boundary of the register parm stack space that needs to be
1907 int low_to_save, high_to_save;
1908 rtx save_area = 0; /* Place that it is saved */
1911 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1912 char *initial_stack_usage_map = stack_usage_map;
1913 char *stack_usage_map_buf = NULL;
1915 int old_stack_allocated;
1917 /* State variables to track stack modifications. */
1918 rtx old_stack_level = 0;
1919 int old_stack_arg_under_construction = 0;
1920 int old_pending_adj = 0;
1921 int old_inhibit_defer_pop = inhibit_defer_pop;
1923 /* Some stack pointer alterations we make are performed via
1924 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1925 which we then also need to save/restore along the way. */
1926 int old_stack_pointer_delta = 0;
1929 tree p = TREE_OPERAND (exp, 0);
1930 tree addr = TREE_OPERAND (exp, 0);
1932 /* The alignment of the stack, in bits. */
1933 unsigned HOST_WIDE_INT preferred_stack_boundary;
1934 /* The alignment of the stack, in bytes. */
1935 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
1936 /* The static chain value to use for this call. */
1937 rtx static_chain_value;
1938 /* See if this is "nothrow" function call. */
1939 if (TREE_NOTHROW (exp))
1940 flags |= ECF_NOTHROW;
1942 /* See if we can find a DECL-node for the actual function, and get the
1943 function attributes (flags) from the function decl or type node. */
1944 fndecl = get_callee_fndecl (exp);
1947 fntype = TREE_TYPE (fndecl);
1948 flags |= flags_from_decl_or_type (fndecl);
1952 fntype = TREE_TYPE (TREE_TYPE (p));
1953 flags |= flags_from_decl_or_type (fntype);
1956 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
1958 /* Warn if this value is an aggregate type,
1959 regardless of which calling convention we are using for it. */
1960 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
1961 warning (OPT_Waggregate_return, "function call has aggregate value");
1963 /* If the result of a pure or const function call is ignored (or void),
1964 and none of its arguments are volatile, we can avoid expanding the
1965 call and just evaluate the arguments for side-effects. */
1966 if ((flags & (ECF_CONST | ECF_PURE))
1967 && (ignore || target == const0_rtx
1968 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
1970 bool volatilep = false;
1973 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1974 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
1982 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1983 expand_expr (TREE_VALUE (arg), const0_rtx,
1984 VOIDmode, EXPAND_NORMAL);
1989 #ifdef REG_PARM_STACK_SPACE
1990 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1993 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1994 if (reg_parm_stack_space > 0 && PUSH_ARGS)
1995 must_preallocate = 1;
1998 /* Set up a place to return a structure. */
2000 /* Cater to broken compilers. */
2001 if (aggregate_value_p (exp, fndecl))
2003 /* This call returns a big structure. */
2004 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
2006 #ifdef PCC_STATIC_STRUCT_RETURN
2008 pcc_struct_value = 1;
2010 #else /* not PCC_STATIC_STRUCT_RETURN */
2012 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2014 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2015 structure_value_addr = XEXP (target, 0);
2018 /* For variable-sized objects, we must be called with a target
2019 specified. If we were to allocate space on the stack here,
2020 we would have no way of knowing when to free it. */
2021 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2023 mark_temp_addr_taken (d);
2024 structure_value_addr = XEXP (d, 0);
2028 #endif /* not PCC_STATIC_STRUCT_RETURN */
2031 /* Figure out the amount to which the stack should be aligned. */
2032 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2035 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2036 if (i && i->preferred_incoming_stack_boundary)
2037 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2040 /* Operand 0 is a pointer-to-function; get the type of the function. */
2041 funtype = TREE_TYPE (addr);
2042 gcc_assert (POINTER_TYPE_P (funtype));
2043 funtype = TREE_TYPE (funtype);
2045 /* Munge the tree to split complex arguments into their imaginary
2047 if (targetm.calls.split_complex_arg)
2049 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2050 actparms = split_complex_values (actparms);
2053 type_arg_types = TYPE_ARG_TYPES (funtype);
2055 if (flags & ECF_MAY_BE_ALLOCA)
2056 current_function_calls_alloca = 1;
2058 /* If struct_value_rtx is 0, it means pass the address
2059 as if it were an extra parameter. */
2060 if (structure_value_addr && struct_value == 0)
2062 /* If structure_value_addr is a REG other than
2063 virtual_outgoing_args_rtx, we can use always use it. If it
2064 is not a REG, we must always copy it into a register.
2065 If it is virtual_outgoing_args_rtx, we must copy it to another
2066 register in some cases. */
2067 rtx temp = (!REG_P (structure_value_addr)
2068 || (ACCUMULATE_OUTGOING_ARGS
2069 && stack_arg_under_construction
2070 && structure_value_addr == virtual_outgoing_args_rtx)
2071 ? copy_addr_to_reg (convert_memory_address
2072 (Pmode, structure_value_addr))
2073 : structure_value_addr);
2076 = tree_cons (error_mark_node,
2077 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2080 structure_value_addr_parm = 1;
2083 /* Count the arguments and set NUM_ACTUALS. */
2084 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2087 /* Compute number of named args.
2088 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2090 if (type_arg_types != 0)
2092 = (list_length (type_arg_types)
2093 /* Count the struct value address, if it is passed as a parm. */
2094 + structure_value_addr_parm);
2096 /* If we know nothing, treat all args as named. */
2097 n_named_args = num_actuals;
2099 /* Start updating where the next arg would go.
2101 On some machines (such as the PA) indirect calls have a different
2102 calling convention than normal calls. The fourth argument in
2103 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2105 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2107 /* Now possibly adjust the number of named args.
2108 Normally, don't include the last named arg if anonymous args follow.
2109 We do include the last named arg if
2110 targetm.calls.strict_argument_naming() returns nonzero.
2111 (If no anonymous args follow, the result of list_length is actually
2112 one too large. This is harmless.)
2114 If targetm.calls.pretend_outgoing_varargs_named() returns
2115 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2116 this machine will be able to place unnamed args that were passed
2117 in registers into the stack. So treat all args as named. This
2118 allows the insns emitting for a specific argument list to be
2119 independent of the function declaration.
2121 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2122 we do not have any reliable way to pass unnamed args in
2123 registers, so we must force them into memory. */
2125 if (type_arg_types != 0
2126 && targetm.calls.strict_argument_naming (&args_so_far))
2128 else if (type_arg_types != 0
2129 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2130 /* Don't include the last named arg. */
2133 /* Treat all args as named. */
2134 n_named_args = num_actuals;
2136 /* Make a vector to hold all the information about each arg. */
2137 args = alloca (num_actuals * sizeof (struct arg_data));
2138 memset (args, 0, num_actuals * sizeof (struct arg_data));
2140 /* Build up entries in the ARGS array, compute the size of the
2141 arguments into ARGS_SIZE, etc. */
2142 initialize_argument_information (num_actuals, args, &args_size,
2143 n_named_args, actparms, fndecl,
2144 &args_so_far, reg_parm_stack_space,
2145 &old_stack_level, &old_pending_adj,
2146 &must_preallocate, &flags,
2147 &try_tail_call, CALL_FROM_THUNK_P (exp));
2151 /* If this function requires a variable-sized argument list, don't
2152 try to make a cse'able block for this call. We may be able to
2153 do this eventually, but it is too complicated to keep track of
2154 what insns go in the cse'able block and which don't. */
2156 flags &= ~ECF_LIBCALL_BLOCK;
2157 must_preallocate = 1;
2160 /* Now make final decision about preallocating stack space. */
2161 must_preallocate = finalize_must_preallocate (must_preallocate,
2165 /* If the structure value address will reference the stack pointer, we
2166 must stabilize it. We don't need to do this if we know that we are
2167 not going to adjust the stack pointer in processing this call. */
2169 if (structure_value_addr
2170 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2171 || reg_mentioned_p (virtual_outgoing_args_rtx,
2172 structure_value_addr))
2174 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2175 structure_value_addr = copy_to_reg (structure_value_addr);
2177 /* Tail calls can make things harder to debug, and we've traditionally
2178 pushed these optimizations into -O2. Don't try if we're already
2179 expanding a call, as that means we're an argument. Don't try if
2180 there's cleanups, as we know there's code to follow the call. */
2182 if (currently_expanding_call++ != 0
2183 || !flag_optimize_sibling_calls
2185 || lookup_stmt_eh_region (exp) >= 0)
2188 /* Rest of purposes for tail call optimizations to fail. */
2190 #ifdef HAVE_sibcall_epilogue
2191 !HAVE_sibcall_epilogue
2196 /* Doing sibling call optimization needs some work, since
2197 structure_value_addr can be allocated on the stack.
2198 It does not seem worth the effort since few optimizable
2199 sibling calls will return a structure. */
2200 || structure_value_addr != NULL_RTX
2201 /* Check whether the target is able to optimize the call
2203 || !targetm.function_ok_for_sibcall (fndecl, exp)
2204 /* Functions that do not return exactly once may not be sibcall
2206 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2207 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2208 /* If the called function is nested in the current one, it might access
2209 some of the caller's arguments, but could clobber them beforehand if
2210 the argument areas are shared. */
2211 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2212 /* If this function requires more stack slots than the current
2213 function, we cannot change it into a sibling call.
2214 current_function_pretend_args_size is not part of the
2215 stack allocated by our caller. */
2216 || args_size.constant > (current_function_args_size
2217 - current_function_pretend_args_size)
2218 /* If the callee pops its own arguments, then it must pop exactly
2219 the same number of arguments as the current function. */
2220 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2221 != RETURN_POPS_ARGS (current_function_decl,
2222 TREE_TYPE (current_function_decl),
2223 current_function_args_size))
2224 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2227 /* Ensure current function's preferred stack boundary is at least
2228 what we need. We don't have to increase alignment for recursive
2230 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2231 && fndecl != current_function_decl)
2232 cfun->preferred_stack_boundary = preferred_stack_boundary;
2233 if (fndecl == current_function_decl)
2234 cfun->recursive_call_emit = true;
2236 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2238 /* We want to make two insn chains; one for a sibling call, the other
2239 for a normal call. We will select one of the two chains after
2240 initial RTL generation is complete. */
2241 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2243 int sibcall_failure = 0;
2244 /* We want to emit any pending stack adjustments before the tail
2245 recursion "call". That way we know any adjustment after the tail
2246 recursion call can be ignored if we indeed use the tail
2248 int save_pending_stack_adjust = 0;
2249 int save_stack_pointer_delta = 0;
2251 rtx before_call, next_arg_reg;
2255 /* State variables we need to save and restore between
2257 save_pending_stack_adjust = pending_stack_adjust;
2258 save_stack_pointer_delta = stack_pointer_delta;
2261 flags &= ~ECF_SIBCALL;
2263 flags |= ECF_SIBCALL;
2265 /* Other state variables that we must reinitialize each time
2266 through the loop (that are not initialized by the loop itself). */
2270 /* Start a new sequence for the normal call case.
2272 From this point on, if the sibling call fails, we want to set
2273 sibcall_failure instead of continuing the loop. */
2276 /* Don't let pending stack adjusts add up to too much.
2277 Also, do all pending adjustments now if there is any chance
2278 this might be a call to alloca or if we are expanding a sibling
2279 call sequence or if we are calling a function that is to return
2280 with stack pointer depressed.
2281 Also do the adjustments before a throwing call, otherwise
2282 exception handling can fail; PR 19225. */
2283 if (pending_stack_adjust >= 32
2284 || (pending_stack_adjust > 0
2285 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2286 || (pending_stack_adjust > 0
2287 && flag_exceptions && !(flags & ECF_NOTHROW))
2289 do_pending_stack_adjust ();
2291 /* When calling a const function, we must pop the stack args right away,
2292 so that the pop is deleted or moved with the call. */
2293 if (pass && (flags & ECF_LIBCALL_BLOCK))
2296 /* Precompute any arguments as needed. */
2298 precompute_arguments (flags, num_actuals, args);
2300 /* Now we are about to start emitting insns that can be deleted
2301 if a libcall is deleted. */
2302 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2305 if (pass == 0 && cfun->stack_protect_guard)
2306 stack_protect_epilogue ();
2308 adjusted_args_size = args_size;
2309 /* Compute the actual size of the argument block required. The variable
2310 and constant sizes must be combined, the size may have to be rounded,
2311 and there may be a minimum required size. When generating a sibcall
2312 pattern, do not round up, since we'll be re-using whatever space our
2314 unadjusted_args_size
2315 = compute_argument_block_size (reg_parm_stack_space,
2316 &adjusted_args_size,
2318 : preferred_stack_boundary));
2320 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2322 /* The argument block when performing a sibling call is the
2323 incoming argument block. */
2326 argblock = virtual_incoming_args_rtx;
2328 #ifdef STACK_GROWS_DOWNWARD
2329 = plus_constant (argblock, current_function_pretend_args_size);
2331 = plus_constant (argblock, -current_function_pretend_args_size);
2333 stored_args_map = sbitmap_alloc (args_size.constant);
2334 sbitmap_zero (stored_args_map);
2337 /* If we have no actual push instructions, or shouldn't use them,
2338 make space for all args right now. */
2339 else if (adjusted_args_size.var != 0)
2341 if (old_stack_level == 0)
2343 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2344 old_stack_pointer_delta = stack_pointer_delta;
2345 old_pending_adj = pending_stack_adjust;
2346 pending_stack_adjust = 0;
2347 /* stack_arg_under_construction says whether a stack arg is
2348 being constructed at the old stack level. Pushing the stack
2349 gets a clean outgoing argument block. */
2350 old_stack_arg_under_construction = stack_arg_under_construction;
2351 stack_arg_under_construction = 0;
2353 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2357 /* Note that we must go through the motions of allocating an argument
2358 block even if the size is zero because we may be storing args
2359 in the area reserved for register arguments, which may be part of
2362 int needed = adjusted_args_size.constant;
2364 /* Store the maximum argument space used. It will be pushed by
2365 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2368 if (needed > current_function_outgoing_args_size)
2369 current_function_outgoing_args_size = needed;
2371 if (must_preallocate)
2373 if (ACCUMULATE_OUTGOING_ARGS)
2375 /* Since the stack pointer will never be pushed, it is
2376 possible for the evaluation of a parm to clobber
2377 something we have already written to the stack.
2378 Since most function calls on RISC machines do not use
2379 the stack, this is uncommon, but must work correctly.
2381 Therefore, we save any area of the stack that was already
2382 written and that we are using. Here we set up to do this
2383 by making a new stack usage map from the old one. The
2384 actual save will be done by store_one_arg.
2386 Another approach might be to try to reorder the argument
2387 evaluations to avoid this conflicting stack usage. */
2389 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2390 /* Since we will be writing into the entire argument area,
2391 the map must be allocated for its entire size, not just
2392 the part that is the responsibility of the caller. */
2393 needed += reg_parm_stack_space;
2396 #ifdef ARGS_GROW_DOWNWARD
2397 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2400 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2403 if (stack_usage_map_buf)
2404 free (stack_usage_map_buf);
2405 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2406 stack_usage_map = stack_usage_map_buf;
2408 if (initial_highest_arg_in_use)
2409 memcpy (stack_usage_map, initial_stack_usage_map,
2410 initial_highest_arg_in_use);
2412 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2413 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2414 (highest_outgoing_arg_in_use
2415 - initial_highest_arg_in_use));
2418 /* The address of the outgoing argument list must not be
2419 copied to a register here, because argblock would be left
2420 pointing to the wrong place after the call to
2421 allocate_dynamic_stack_space below. */
2423 argblock = virtual_outgoing_args_rtx;
2427 if (inhibit_defer_pop == 0)
2429 /* Try to reuse some or all of the pending_stack_adjust
2430 to get this space. */
2432 = (combine_pending_stack_adjustment_and_call
2433 (unadjusted_args_size,
2434 &adjusted_args_size,
2435 preferred_unit_stack_boundary));
2437 /* combine_pending_stack_adjustment_and_call computes
2438 an adjustment before the arguments are allocated.
2439 Account for them and see whether or not the stack
2440 needs to go up or down. */
2441 needed = unadjusted_args_size - needed;
2445 /* We're releasing stack space. */
2446 /* ??? We can avoid any adjustment at all if we're
2447 already aligned. FIXME. */
2448 pending_stack_adjust = -needed;
2449 do_pending_stack_adjust ();
2453 /* We need to allocate space. We'll do that in
2454 push_block below. */
2455 pending_stack_adjust = 0;
2458 /* Special case this because overhead of `push_block' in
2459 this case is non-trivial. */
2461 argblock = virtual_outgoing_args_rtx;
2464 argblock = push_block (GEN_INT (needed), 0, 0);
2465 #ifdef ARGS_GROW_DOWNWARD
2466 argblock = plus_constant (argblock, needed);
2470 /* We only really need to call `copy_to_reg' in the case
2471 where push insns are going to be used to pass ARGBLOCK
2472 to a function call in ARGS. In that case, the stack
2473 pointer changes value from the allocation point to the
2474 call point, and hence the value of
2475 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2476 as well always do it. */
2477 argblock = copy_to_reg (argblock);
2482 if (ACCUMULATE_OUTGOING_ARGS)
2484 /* The save/restore code in store_one_arg handles all
2485 cases except one: a constructor call (including a C
2486 function returning a BLKmode struct) to initialize
2488 if (stack_arg_under_construction)
2490 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2491 rtx push_size = GEN_INT (reg_parm_stack_space
2492 + adjusted_args_size.constant);
2494 rtx push_size = GEN_INT (adjusted_args_size.constant);
2496 if (old_stack_level == 0)
2498 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2500 old_stack_pointer_delta = stack_pointer_delta;
2501 old_pending_adj = pending_stack_adjust;
2502 pending_stack_adjust = 0;
2503 /* stack_arg_under_construction says whether a stack
2504 arg is being constructed at the old stack level.
2505 Pushing the stack gets a clean outgoing argument
2507 old_stack_arg_under_construction
2508 = stack_arg_under_construction;
2509 stack_arg_under_construction = 0;
2510 /* Make a new map for the new argument list. */
2511 if (stack_usage_map_buf)
2512 free (stack_usage_map_buf);
2513 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2514 stack_usage_map = stack_usage_map_buf;
2515 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2516 highest_outgoing_arg_in_use = 0;
2518 allocate_dynamic_stack_space (push_size, NULL_RTX,
2522 /* If argument evaluation might modify the stack pointer,
2523 copy the address of the argument list to a register. */
2524 for (i = 0; i < num_actuals; i++)
2525 if (args[i].pass_on_stack)
2527 argblock = copy_addr_to_reg (argblock);
2532 compute_argument_addresses (args, argblock, num_actuals);
2534 /* If we push args individually in reverse order, perform stack alignment
2535 before the first push (the last arg). */
2536 if (PUSH_ARGS_REVERSED && argblock == 0
2537 && adjusted_args_size.constant != unadjusted_args_size)
2539 /* When the stack adjustment is pending, we get better code
2540 by combining the adjustments. */
2541 if (pending_stack_adjust
2542 && ! (flags & ECF_LIBCALL_BLOCK)
2543 && ! inhibit_defer_pop)
2545 pending_stack_adjust
2546 = (combine_pending_stack_adjustment_and_call
2547 (unadjusted_args_size,
2548 &adjusted_args_size,
2549 preferred_unit_stack_boundary));
2550 do_pending_stack_adjust ();
2552 else if (argblock == 0)
2553 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2554 - unadjusted_args_size));
2556 /* Now that the stack is properly aligned, pops can't safely
2557 be deferred during the evaluation of the arguments. */
2560 funexp = rtx_for_function_call (fndecl, addr);
2562 /* Figure out the register where the value, if any, will come back. */
2564 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2565 && ! structure_value_addr)
2567 if (pcc_struct_value)
2568 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2569 fndecl, NULL, (pass == 0));
2571 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2575 /* Precompute all register parameters. It isn't safe to compute anything
2576 once we have started filling any specific hard regs. */
2577 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2579 if (TREE_OPERAND (exp, 2))
2580 static_chain_value = expand_normal (TREE_OPERAND (exp, 2));
2582 static_chain_value = 0;
2584 #ifdef REG_PARM_STACK_SPACE
2585 /* Save the fixed argument area if it's part of the caller's frame and
2586 is clobbered by argument setup for this call. */
2587 if (ACCUMULATE_OUTGOING_ARGS && pass)
2588 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2589 &low_to_save, &high_to_save);
2592 /* Now store (and compute if necessary) all non-register parms.
2593 These come before register parms, since they can require block-moves,
2594 which could clobber the registers used for register parms.
2595 Parms which have partial registers are not stored here,
2596 but we do preallocate space here if they want that. */
2598 for (i = 0; i < num_actuals; i++)
2599 if (args[i].reg == 0 || args[i].pass_on_stack)
2601 rtx before_arg = get_last_insn ();
2603 if (store_one_arg (&args[i], argblock, flags,
2604 adjusted_args_size.var != 0,
2605 reg_parm_stack_space)
2607 && check_sibcall_argument_overlap (before_arg,
2609 sibcall_failure = 1;
2611 if (flags & ECF_CONST
2613 && args[i].value == args[i].stack)
2614 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2615 gen_rtx_USE (VOIDmode,
2620 /* If we have a parm that is passed in registers but not in memory
2621 and whose alignment does not permit a direct copy into registers,
2622 make a group of pseudos that correspond to each register that we
2624 if (STRICT_ALIGNMENT)
2625 store_unaligned_arguments_into_pseudos (args, num_actuals);
2627 /* Now store any partially-in-registers parm.
2628 This is the last place a block-move can happen. */
2630 for (i = 0; i < num_actuals; i++)
2631 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2633 rtx before_arg = get_last_insn ();
2635 if (store_one_arg (&args[i], argblock, flags,
2636 adjusted_args_size.var != 0,
2637 reg_parm_stack_space)
2639 && check_sibcall_argument_overlap (before_arg,
2641 sibcall_failure = 1;
2644 /* If we pushed args in forward order, perform stack alignment
2645 after pushing the last arg. */
2646 if (!PUSH_ARGS_REVERSED && argblock == 0)
2647 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2648 - unadjusted_args_size));
2650 /* If register arguments require space on the stack and stack space
2651 was not preallocated, allocate stack space here for arguments
2652 passed in registers. */
2653 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2654 if (!ACCUMULATE_OUTGOING_ARGS
2655 && must_preallocate == 0 && reg_parm_stack_space > 0)
2656 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2659 /* Pass the function the address in which to return a
2661 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2663 structure_value_addr
2664 = convert_memory_address (Pmode, structure_value_addr);
2665 emit_move_insn (struct_value,
2667 force_operand (structure_value_addr,
2670 if (REG_P (struct_value))
2671 use_reg (&call_fusage, struct_value);
2674 funexp = prepare_call_address (funexp, static_chain_value,
2675 &call_fusage, reg_parm_seen, pass == 0);
2677 load_register_parameters (args, num_actuals, &call_fusage, flags,
2678 pass == 0, &sibcall_failure);
2680 /* Save a pointer to the last insn before the call, so that we can
2681 later safely search backwards to find the CALL_INSN. */
2682 before_call = get_last_insn ();
2684 /* Set up next argument register. For sibling calls on machines
2685 with register windows this should be the incoming register. */
2686 #ifdef FUNCTION_INCOMING_ARG
2688 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2692 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2695 /* All arguments and registers used for the call must be set up by
2698 /* Stack must be properly aligned now. */
2700 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2702 /* Generate the actual call instruction. */
2703 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2704 adjusted_args_size.constant, struct_value_size,
2705 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2706 flags, & args_so_far);
2708 /* If a non-BLKmode value is returned at the most significant end
2709 of a register, shift the register right by the appropriate amount
2710 and update VALREG accordingly. BLKmode values are handled by the
2711 group load/store machinery below. */
2712 if (!structure_value_addr
2713 && !pcc_struct_value
2714 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2715 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2717 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2718 sibcall_failure = 1;
2719 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2722 /* If call is cse'able, make appropriate pair of reg-notes around it.
2723 Test valreg so we don't crash; may safely ignore `const'
2724 if return type is void. Disable for PARALLEL return values, because
2725 we have no way to move such values into a pseudo register. */
2726 if (pass && (flags & ECF_LIBCALL_BLOCK))
2730 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2732 insns = get_insns ();
2734 /* Expansion of block moves possibly introduced a loop that may
2735 not appear inside libcall block. */
2736 for (insn = insns; insn; insn = NEXT_INSN (insn))
2748 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2750 /* Mark the return value as a pointer if needed. */
2751 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2752 mark_reg_pointer (temp,
2753 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2756 if (flag_unsafe_math_optimizations
2758 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2759 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2760 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2761 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2762 note = gen_rtx_fmt_e (SQRT,
2764 args[0].initial_value);
2767 /* Construct an "equal form" for the value which
2768 mentions all the arguments in order as well as
2769 the function name. */
2770 for (i = 0; i < num_actuals; i++)
2771 note = gen_rtx_EXPR_LIST (VOIDmode,
2772 args[i].initial_value, note);
2773 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2775 if (flags & ECF_PURE)
2776 note = gen_rtx_EXPR_LIST (VOIDmode,
2777 gen_rtx_USE (VOIDmode,
2778 gen_rtx_MEM (BLKmode,
2779 gen_rtx_SCRATCH (VOIDmode))),
2782 emit_libcall_block (insns, temp, valreg, note);
2787 else if (pass && (flags & ECF_MALLOC))
2789 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2792 /* The return value from a malloc-like function is a pointer. */
2793 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2794 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2796 emit_move_insn (temp, valreg);
2798 /* The return value from a malloc-like function can not alias
2800 last = get_last_insn ();
2802 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2804 /* Write out the sequence. */
2805 insns = get_insns ();
2811 /* For calls to `setjmp', etc., inform flow.c it should complain
2812 if nonvolatile values are live. For functions that cannot return,
2813 inform flow that control does not fall through. */
2815 if ((flags & ECF_NORETURN) || pass == 0)
2817 /* The barrier must be emitted
2818 immediately after the CALL_INSN. Some ports emit more
2819 than just a CALL_INSN above, so we must search for it here. */
2821 rtx last = get_last_insn ();
2822 while (!CALL_P (last))
2824 last = PREV_INSN (last);
2825 /* There was no CALL_INSN? */
2826 gcc_assert (last != before_call);
2829 emit_barrier_after (last);
2831 /* Stack adjustments after a noreturn call are dead code.
2832 However when NO_DEFER_POP is in effect, we must preserve
2833 stack_pointer_delta. */
2834 if (inhibit_defer_pop == 0)
2836 stack_pointer_delta = old_stack_allocated;
2837 pending_stack_adjust = 0;
2841 /* If value type not void, return an rtx for the value. */
2843 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2845 target = const0_rtx;
2846 else if (structure_value_addr)
2848 if (target == 0 || !MEM_P (target))
2851 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2852 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2853 structure_value_addr));
2854 set_mem_attributes (target, exp, 1);
2857 else if (pcc_struct_value)
2859 /* This is the special C++ case where we need to
2860 know what the true target was. We take care to
2861 never use this value more than once in one expression. */
2862 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2863 copy_to_reg (valreg));
2864 set_mem_attributes (target, exp, 1);
2866 /* Handle calls that return values in multiple non-contiguous locations.
2867 The Irix 6 ABI has examples of this. */
2868 else if (GET_CODE (valreg) == PARALLEL)
2872 /* This will only be assigned once, so it can be readonly. */
2873 tree nt = build_qualified_type (TREE_TYPE (exp),
2874 (TYPE_QUALS (TREE_TYPE (exp))
2875 | TYPE_QUAL_CONST));
2877 target = assign_temp (nt, 0, 1, 1);
2880 if (! rtx_equal_p (target, valreg))
2881 emit_group_store (target, valreg, TREE_TYPE (exp),
2882 int_size_in_bytes (TREE_TYPE (exp)));
2884 /* We can not support sibling calls for this case. */
2885 sibcall_failure = 1;
2888 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2889 && GET_MODE (target) == GET_MODE (valreg))
2891 bool may_overlap = false;
2893 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2894 reg to a plain register. */
2896 && HARD_REGISTER_P (valreg)
2897 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (valreg)))
2898 && !(REG_P (target) && !HARD_REGISTER_P (target)))
2899 valreg = copy_to_reg (valreg);
2901 /* If TARGET is a MEM in the argument area, and we have
2902 saved part of the argument area, then we can't store
2903 directly into TARGET as it may get overwritten when we
2904 restore the argument save area below. Don't work too
2905 hard though and simply force TARGET to a register if it
2906 is a MEM; the optimizer is quite likely to sort it out. */
2907 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2908 for (i = 0; i < num_actuals; i++)
2909 if (args[i].save_area)
2916 target = copy_to_reg (valreg);
2919 /* TARGET and VALREG cannot be equal at this point
2920 because the latter would not have
2921 REG_FUNCTION_VALUE_P true, while the former would if
2922 it were referring to the same register.
2924 If they refer to the same register, this move will be
2925 a no-op, except when function inlining is being
2927 emit_move_insn (target, valreg);
2929 /* If we are setting a MEM, this code must be executed.
2930 Since it is emitted after the call insn, sibcall
2931 optimization cannot be performed in that case. */
2933 sibcall_failure = 1;
2936 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2938 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2940 /* We can not support sibling calls for this case. */
2941 sibcall_failure = 1;
2944 target = copy_to_reg (valreg);
2946 if (targetm.calls.promote_function_return(funtype))
2948 /* If we promoted this return value, make the proper SUBREG.
2949 TARGET might be const0_rtx here, so be careful. */
2951 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2952 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2954 tree type = TREE_TYPE (exp);
2955 int unsignedp = TYPE_UNSIGNED (type);
2957 enum machine_mode pmode;
2959 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2960 /* If we don't promote as expected, something is wrong. */
2961 gcc_assert (GET_MODE (target) == pmode);
2963 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2964 && (GET_MODE_SIZE (GET_MODE (target))
2965 > GET_MODE_SIZE (TYPE_MODE (type))))
2967 offset = GET_MODE_SIZE (GET_MODE (target))
2968 - GET_MODE_SIZE (TYPE_MODE (type));
2969 if (! BYTES_BIG_ENDIAN)
2970 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
2971 else if (! WORDS_BIG_ENDIAN)
2972 offset %= UNITS_PER_WORD;
2974 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
2975 SUBREG_PROMOTED_VAR_P (target) = 1;
2976 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
2980 /* If size of args is variable or this was a constructor call for a stack
2981 argument, restore saved stack-pointer value. */
2983 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
2985 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2986 stack_pointer_delta = old_stack_pointer_delta;
2987 pending_stack_adjust = old_pending_adj;
2988 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2989 stack_arg_under_construction = old_stack_arg_under_construction;
2990 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2991 stack_usage_map = initial_stack_usage_map;
2992 sibcall_failure = 1;
2994 else if (ACCUMULATE_OUTGOING_ARGS && pass)
2996 #ifdef REG_PARM_STACK_SPACE
2998 restore_fixed_argument_area (save_area, argblock,
2999 high_to_save, low_to_save);
3002 /* If we saved any argument areas, restore them. */
3003 for (i = 0; i < num_actuals; i++)
3004 if (args[i].save_area)
3006 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3008 = gen_rtx_MEM (save_mode,
3009 memory_address (save_mode,
3010 XEXP (args[i].stack_slot, 0)));
3012 if (save_mode != BLKmode)
3013 emit_move_insn (stack_area, args[i].save_area);
3015 emit_block_move (stack_area, args[i].save_area,
3016 GEN_INT (args[i].locate.size.constant),
3017 BLOCK_OP_CALL_PARM);
3020 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3021 stack_usage_map = initial_stack_usage_map;
3024 /* If this was alloca, record the new stack level for nonlocal gotos.
3025 Check for the handler slots since we might not have a save area
3026 for non-local gotos. */
3028 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3029 update_nonlocal_goto_save_area ();
3031 /* Free up storage we no longer need. */
3032 for (i = 0; i < num_actuals; ++i)
3033 if (args[i].aligned_regs)
3034 free (args[i].aligned_regs);
3036 insns = get_insns ();
3041 tail_call_insns = insns;
3043 /* Restore the pending stack adjustment now that we have
3044 finished generating the sibling call sequence. */
3046 pending_stack_adjust = save_pending_stack_adjust;
3047 stack_pointer_delta = save_stack_pointer_delta;
3049 /* Prepare arg structure for next iteration. */
3050 for (i = 0; i < num_actuals; i++)
3053 args[i].aligned_regs = 0;
3057 sbitmap_free (stored_args_map);
3061 normal_call_insns = insns;
3063 /* Verify that we've deallocated all the stack we used. */
3064 gcc_assert ((flags & ECF_NORETURN)
3065 || (old_stack_allocated
3066 == stack_pointer_delta - pending_stack_adjust));
3069 /* If something prevents making this a sibling call,
3070 zero out the sequence. */
3071 if (sibcall_failure)
3072 tail_call_insns = NULL_RTX;
3077 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3078 arguments too, as argument area is now clobbered by the call. */
3079 if (tail_call_insns)
3081 emit_insn (tail_call_insns);
3082 cfun->tail_call_emit = true;
3085 emit_insn (normal_call_insns);
3087 currently_expanding_call--;
3089 /* If this function returns with the stack pointer depressed, ensure
3090 this block saves and restores the stack pointer, show it was
3091 changed, and adjust for any outgoing arg space. */
3092 if (flags & ECF_SP_DEPRESSED)
3094 clear_pending_stack_adjust ();
3095 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3096 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3099 if (stack_usage_map_buf)
3100 free (stack_usage_map_buf);
3105 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3106 this function's incoming arguments.
3108 At the start of RTL generation we know the only REG_EQUIV notes
3109 in the rtl chain are those for incoming arguments, so we can look
3110 for REG_EQUIV notes between the start of the function and the
3111 NOTE_INSN_FUNCTION_BEG.
3113 This is (slight) overkill. We could keep track of the highest
3114 argument we clobber and be more selective in removing notes, but it
3115 does not seem to be worth the effort. */
3118 fixup_tail_calls (void)
3122 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3124 /* There are never REG_EQUIV notes for the incoming arguments
3125 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3127 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
3132 rtx note = find_reg_note (insn, REG_EQUIV, 0);
3135 /* Remove the note and keep looking at the notes for
3137 remove_note (insn, note);
3145 /* Traverse an argument list in VALUES and expand all complex
3146 arguments into their components. */
3148 split_complex_values (tree values)
3152 /* Before allocating memory, check for the common case of no complex. */
3153 for (p = values; p; p = TREE_CHAIN (p))
3155 tree type = TREE_TYPE (TREE_VALUE (p));
3156 if (type && TREE_CODE (type) == COMPLEX_TYPE
3157 && targetm.calls.split_complex_arg (type))
3163 values = copy_list (values);
3165 for (p = values; p; p = TREE_CHAIN (p))
3167 tree complex_value = TREE_VALUE (p);
3170 complex_type = TREE_TYPE (complex_value);
3174 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3175 && targetm.calls.split_complex_arg (complex_type))
3178 tree real, imag, next;
3180 subtype = TREE_TYPE (complex_type);
3181 complex_value = save_expr (complex_value);
3182 real = build1 (REALPART_EXPR, subtype, complex_value);
3183 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3185 TREE_VALUE (p) = real;
3186 next = TREE_CHAIN (p);
3187 imag = build_tree_list (NULL_TREE, imag);
3188 TREE_CHAIN (p) = imag;
3189 TREE_CHAIN (imag) = next;
3191 /* Skip the newly created node. */
3199 /* Traverse a list of TYPES and expand all complex types into their
3202 split_complex_types (tree types)
3206 /* Before allocating memory, check for the common case of no complex. */
3207 for (p = types; p; p = TREE_CHAIN (p))
3209 tree type = TREE_VALUE (p);
3210 if (TREE_CODE (type) == COMPLEX_TYPE
3211 && targetm.calls.split_complex_arg (type))
3217 types = copy_list (types);
3219 for (p = types; p; p = TREE_CHAIN (p))
3221 tree complex_type = TREE_VALUE (p);
3223 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3224 && targetm.calls.split_complex_arg (complex_type))
3228 /* Rewrite complex type with component type. */
3229 TREE_VALUE (p) = TREE_TYPE (complex_type);
3230 next = TREE_CHAIN (p);
3232 /* Add another component type for the imaginary part. */
3233 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3234 TREE_CHAIN (p) = imag;
3235 TREE_CHAIN (imag) = next;
3237 /* Skip the newly created node. */
3245 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3246 The RETVAL parameter specifies whether return value needs to be saved, other
3247 parameters are documented in the emit_library_call function below. */
3250 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3251 enum libcall_type fn_type,
3252 enum machine_mode outmode, int nargs, va_list p)
3254 /* Total size in bytes of all the stack-parms scanned so far. */
3255 struct args_size args_size;
3256 /* Size of arguments before any adjustments (such as rounding). */
3257 struct args_size original_args_size;
3263 CUMULATIVE_ARGS args_so_far;
3267 enum machine_mode mode;
3270 struct locate_and_pad_arg_data locate;
3274 int old_inhibit_defer_pop = inhibit_defer_pop;
3275 rtx call_fusage = 0;
3278 int pcc_struct_value = 0;
3279 int struct_value_size = 0;
3281 int reg_parm_stack_space = 0;
3284 tree tfom; /* type_for_mode (outmode, 0) */
3286 #ifdef REG_PARM_STACK_SPACE
3287 /* Define the boundary of the register parm stack space that needs to be
3289 int low_to_save, high_to_save;
3290 rtx save_area = 0; /* Place that it is saved. */
3293 /* Size of the stack reserved for parameter registers. */
3294 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3295 char *initial_stack_usage_map = stack_usage_map;
3296 char *stack_usage_map_buf = NULL;
3298 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3300 #ifdef REG_PARM_STACK_SPACE
3301 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3304 /* By default, library functions can not throw. */
3305 flags = ECF_NOTHROW;
3317 case LCT_CONST_MAKE_BLOCK:
3318 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3320 case LCT_PURE_MAKE_BLOCK:
3321 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3324 flags |= ECF_NORETURN;
3327 flags = ECF_NORETURN;
3329 case LCT_RETURNS_TWICE:
3330 flags = ECF_RETURNS_TWICE;
3335 /* Ensure current function's preferred stack boundary is at least
3337 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3338 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3340 /* If this kind of value comes back in memory,
3341 decide where in memory it should come back. */
3342 if (outmode != VOIDmode)
3344 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3345 if (aggregate_value_p (tfom, 0))
3347 #ifdef PCC_STATIC_STRUCT_RETURN
3349 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3350 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3351 pcc_struct_value = 1;
3353 value = gen_reg_rtx (outmode);
3354 #else /* not PCC_STATIC_STRUCT_RETURN */
3355 struct_value_size = GET_MODE_SIZE (outmode);
3356 if (value != 0 && MEM_P (value))
3359 mem_value = assign_temp (tfom, 0, 1, 1);
3361 /* This call returns a big structure. */
3362 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3366 tfom = void_type_node;
3368 /* ??? Unfinished: must pass the memory address as an argument. */
3370 /* Copy all the libcall-arguments out of the varargs data
3371 and into a vector ARGVEC.
3373 Compute how to pass each argument. We only support a very small subset
3374 of the full argument passing conventions to limit complexity here since
3375 library functions shouldn't have many args. */
3377 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3378 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3380 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3381 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3383 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3386 args_size.constant = 0;
3391 /* Now we are about to start emitting insns that can be deleted
3392 if a libcall is deleted. */
3393 if (flags & ECF_LIBCALL_BLOCK)
3398 /* If there's a structure value address to be passed,
3399 either pass it in the special place, or pass it as an extra argument. */
3400 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3402 rtx addr = XEXP (mem_value, 0);
3406 /* Make sure it is a reasonable operand for a move or push insn. */
3407 if (!REG_P (addr) && !MEM_P (addr)
3408 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3409 addr = force_operand (addr, NULL_RTX);
3411 argvec[count].value = addr;
3412 argvec[count].mode = Pmode;
3413 argvec[count].partial = 0;
3415 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3416 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3417 NULL_TREE, 1) == 0);
3419 locate_and_pad_parm (Pmode, NULL_TREE,
3420 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3423 argvec[count].reg != 0,
3425 0, NULL_TREE, &args_size, &argvec[count].locate);
3427 if (argvec[count].reg == 0 || argvec[count].partial != 0
3428 || reg_parm_stack_space > 0)
3429 args_size.constant += argvec[count].locate.size.constant;
3431 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3436 for (; count < nargs; count++)
3438 rtx val = va_arg (p, rtx);
3439 enum machine_mode mode = va_arg (p, enum machine_mode);
3441 /* We cannot convert the arg value to the mode the library wants here;
3442 must do it earlier where we know the signedness of the arg. */
3443 gcc_assert (mode != BLKmode
3444 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3446 /* Make sure it is a reasonable operand for a move or push insn. */
3447 if (!REG_P (val) && !MEM_P (val)
3448 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3449 val = force_operand (val, NULL_RTX);
3451 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3455 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3457 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3458 functions, so we have to pretend this isn't such a function. */
3459 if (flags & ECF_LIBCALL_BLOCK)
3461 rtx insns = get_insns ();
3465 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3467 /* If this was a CONST function, it is now PURE since
3468 it now reads memory. */
3469 if (flags & ECF_CONST)
3471 flags &= ~ECF_CONST;
3475 if (GET_MODE (val) == MEM && !must_copy)
3479 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3481 emit_move_insn (slot, val);
3484 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3485 gen_rtx_USE (VOIDmode, slot),
3488 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3489 gen_rtx_CLOBBER (VOIDmode,
3494 val = force_operand (XEXP (slot, 0), NULL_RTX);
3497 argvec[count].value = val;
3498 argvec[count].mode = mode;
3500 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3502 argvec[count].partial
3503 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3505 locate_and_pad_parm (mode, NULL_TREE,
3506 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3509 argvec[count].reg != 0,
3511 argvec[count].partial,
3512 NULL_TREE, &args_size, &argvec[count].locate);
3514 gcc_assert (!argvec[count].locate.size.var);
3516 if (argvec[count].reg == 0 || argvec[count].partial != 0
3517 || reg_parm_stack_space > 0)
3518 args_size.constant += argvec[count].locate.size.constant;
3520 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3523 /* If this machine requires an external definition for library
3524 functions, write one out. */
3525 assemble_external_libcall (fun);
3527 original_args_size = args_size;
3528 args_size.constant = (((args_size.constant
3529 + stack_pointer_delta
3533 - stack_pointer_delta);
3535 args_size.constant = MAX (args_size.constant,
3536 reg_parm_stack_space);
3538 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3539 args_size.constant -= reg_parm_stack_space;
3542 if (args_size.constant > current_function_outgoing_args_size)
3543 current_function_outgoing_args_size = args_size.constant;
3545 if (ACCUMULATE_OUTGOING_ARGS)
3547 /* Since the stack pointer will never be pushed, it is possible for
3548 the evaluation of a parm to clobber something we have already
3549 written to the stack. Since most function calls on RISC machines
3550 do not use the stack, this is uncommon, but must work correctly.
3552 Therefore, we save any area of the stack that was already written
3553 and that we are using. Here we set up to do this by making a new
3554 stack usage map from the old one.
3556 Another approach might be to try to reorder the argument
3557 evaluations to avoid this conflicting stack usage. */
3559 needed = args_size.constant;
3561 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3562 /* Since we will be writing into the entire argument area, the
3563 map must be allocated for its entire size, not just the part that
3564 is the responsibility of the caller. */
3565 needed += reg_parm_stack_space;
3568 #ifdef ARGS_GROW_DOWNWARD
3569 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3572 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3575 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3576 stack_usage_map = stack_usage_map_buf;
3578 if (initial_highest_arg_in_use)
3579 memcpy (stack_usage_map, initial_stack_usage_map,
3580 initial_highest_arg_in_use);
3582 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3583 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3584 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3587 /* We must be careful to use virtual regs before they're instantiated,
3588 and real regs afterwards. Loop optimization, for example, can create
3589 new libcalls after we've instantiated the virtual regs, and if we
3590 use virtuals anyway, they won't match the rtl patterns. */
3592 if (virtuals_instantiated)
3593 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3595 argblock = virtual_outgoing_args_rtx;
3600 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3603 /* If we push args individually in reverse order, perform stack alignment
3604 before the first push (the last arg). */
3605 if (argblock == 0 && PUSH_ARGS_REVERSED)
3606 anti_adjust_stack (GEN_INT (args_size.constant
3607 - original_args_size.constant));
3609 if (PUSH_ARGS_REVERSED)
3620 #ifdef REG_PARM_STACK_SPACE
3621 if (ACCUMULATE_OUTGOING_ARGS)
3623 /* The argument list is the property of the called routine and it
3624 may clobber it. If the fixed area has been used for previous
3625 parameters, we must save and restore it. */
3626 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3627 &low_to_save, &high_to_save);
3631 /* Push the args that need to be pushed. */
3633 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3634 are to be pushed. */
3635 for (count = 0; count < nargs; count++, argnum += inc)
3637 enum machine_mode mode = argvec[argnum].mode;
3638 rtx val = argvec[argnum].value;
3639 rtx reg = argvec[argnum].reg;
3640 int partial = argvec[argnum].partial;
3641 int lower_bound = 0, upper_bound = 0, i;
3643 if (! (reg != 0 && partial == 0))
3645 if (ACCUMULATE_OUTGOING_ARGS)
3647 /* If this is being stored into a pre-allocated, fixed-size,
3648 stack area, save any previous data at that location. */
3650 #ifdef ARGS_GROW_DOWNWARD
3651 /* stack_slot is negative, but we want to index stack_usage_map
3652 with positive values. */
3653 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3654 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3656 lower_bound = argvec[argnum].locate.offset.constant;
3657 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3661 /* Don't worry about things in the fixed argument area;
3662 it has already been saved. */
3663 if (i < reg_parm_stack_space)
3664 i = reg_parm_stack_space;
3665 while (i < upper_bound && stack_usage_map[i] == 0)
3668 if (i < upper_bound)
3670 /* We need to make a save area. */
3672 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3673 enum machine_mode save_mode
3674 = mode_for_size (size, MODE_INT, 1);
3676 = plus_constant (argblock,
3677 argvec[argnum].locate.offset.constant);
3679 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3681 if (save_mode == BLKmode)
3683 argvec[argnum].save_area
3684 = assign_stack_temp (BLKmode,
3685 argvec[argnum].locate.size.constant,
3688 emit_block_move (validize_mem (argvec[argnum].save_area),
3690 GEN_INT (argvec[argnum].locate.size.constant),
3691 BLOCK_OP_CALL_PARM);
3695 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3697 emit_move_insn (argvec[argnum].save_area, stack_area);
3702 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3703 partial, reg, 0, argblock,
3704 GEN_INT (argvec[argnum].locate.offset.constant),
3705 reg_parm_stack_space,
3706 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3708 /* Now mark the segment we just used. */
3709 if (ACCUMULATE_OUTGOING_ARGS)
3710 for (i = lower_bound; i < upper_bound; i++)
3711 stack_usage_map[i] = 1;
3715 if (flags & ECF_CONST)
3719 /* Indicate argument access so that alias.c knows that these
3722 use = plus_constant (argblock,
3723 argvec[argnum].locate.offset.constant);
3725 /* When arguments are pushed, trying to tell alias.c where
3726 exactly this argument is won't work, because the
3727 auto-increment causes confusion. So we merely indicate
3728 that we access something with a known mode somewhere on
3730 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3731 gen_rtx_SCRATCH (Pmode));
3732 use = gen_rtx_MEM (argvec[argnum].mode, use);
3733 use = gen_rtx_USE (VOIDmode, use);
3734 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3739 /* If we pushed args in forward order, perform stack alignment
3740 after pushing the last arg. */
3741 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3742 anti_adjust_stack (GEN_INT (args_size.constant
3743 - original_args_size.constant));
3745 if (PUSH_ARGS_REVERSED)
3750 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3752 /* Now load any reg parms into their regs. */
3754 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3755 are to be pushed. */
3756 for (count = 0; count < nargs; count++, argnum += inc)
3758 enum machine_mode mode = argvec[argnum].mode;
3759 rtx val = argvec[argnum].value;
3760 rtx reg = argvec[argnum].reg;
3761 int partial = argvec[argnum].partial;
3763 /* Handle calls that pass values in multiple non-contiguous
3764 locations. The PA64 has examples of this for library calls. */
3765 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3766 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3767 else if (reg != 0 && partial == 0)
3768 emit_move_insn (reg, val);
3773 /* Any regs containing parms remain in use through the call. */
3774 for (count = 0; count < nargs; count++)
3776 rtx reg = argvec[count].reg;
3777 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3778 use_group_regs (&call_fusage, reg);
3780 use_reg (&call_fusage, reg);
3783 /* Pass the function the address in which to return a structure value. */
3784 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3786 emit_move_insn (struct_value,
3788 force_operand (XEXP (mem_value, 0),
3790 if (REG_P (struct_value))
3791 use_reg (&call_fusage, struct_value);
3794 /* Don't allow popping to be deferred, since then
3795 cse'ing of library calls could delete a call and leave the pop. */
3797 valreg = (mem_value == 0 && outmode != VOIDmode
3798 ? hard_libcall_value (outmode) : NULL_RTX);
3800 /* Stack must be properly aligned now. */
3801 gcc_assert (!(stack_pointer_delta
3802 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3804 before_call = get_last_insn ();
3806 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3807 will set inhibit_defer_pop to that value. */
3808 /* The return type is needed to decide how many bytes the function pops.
3809 Signedness plays no role in that, so for simplicity, we pretend it's
3810 always signed. We also assume that the list of arguments passed has
3811 no impact, so we pretend it is unknown. */
3813 emit_call_1 (fun, NULL,
3814 get_identifier (XSTR (orgfun, 0)),
3815 build_function_type (tfom, NULL_TREE),
3816 original_args_size.constant, args_size.constant,
3818 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3820 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3822 /* For calls to `setjmp', etc., inform flow.c it should complain
3823 if nonvolatile values are live. For functions that cannot return,
3824 inform flow that control does not fall through. */
3826 if (flags & ECF_NORETURN)
3828 /* The barrier note must be emitted
3829 immediately after the CALL_INSN. Some ports emit more than
3830 just a CALL_INSN above, so we must search for it here. */
3832 rtx last = get_last_insn ();
3833 while (!CALL_P (last))
3835 last = PREV_INSN (last);
3836 /* There was no CALL_INSN? */
3837 gcc_assert (last != before_call);
3840 emit_barrier_after (last);
3843 /* Now restore inhibit_defer_pop to its actual original value. */
3846 /* If call is cse'able, make appropriate pair of reg-notes around it.
3847 Test valreg so we don't crash; may safely ignore `const'
3848 if return type is void. Disable for PARALLEL return values, because
3849 we have no way to move such values into a pseudo register. */
3850 if (flags & ECF_LIBCALL_BLOCK)
3856 insns = get_insns ();
3866 if (GET_CODE (valreg) == PARALLEL)
3868 temp = gen_reg_rtx (outmode);
3869 emit_group_store (temp, valreg, NULL_TREE,
3870 GET_MODE_SIZE (outmode));
3874 temp = gen_reg_rtx (GET_MODE (valreg));
3876 /* Construct an "equal form" for the value which mentions all the
3877 arguments in order as well as the function name. */
3878 for (i = 0; i < nargs; i++)
3879 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3880 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3882 insns = get_insns ();
3885 if (flags & ECF_PURE)
3886 note = gen_rtx_EXPR_LIST (VOIDmode,
3887 gen_rtx_USE (VOIDmode,
3888 gen_rtx_MEM (BLKmode,
3889 gen_rtx_SCRATCH (VOIDmode))),
3892 emit_libcall_block (insns, temp, valreg, note);
3899 /* Copy the value to the right place. */
3900 if (outmode != VOIDmode && retval)
3906 if (value != mem_value)
3907 emit_move_insn (value, mem_value);
3909 else if (GET_CODE (valreg) == PARALLEL)
3912 value = gen_reg_rtx (outmode);
3913 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3915 else if (value != 0)
3916 emit_move_insn (value, valreg);
3921 if (ACCUMULATE_OUTGOING_ARGS)
3923 #ifdef REG_PARM_STACK_SPACE
3925 restore_fixed_argument_area (save_area, argblock,
3926 high_to_save, low_to_save);
3929 /* If we saved any argument areas, restore them. */
3930 for (count = 0; count < nargs; count++)
3931 if (argvec[count].save_area)
3933 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3934 rtx adr = plus_constant (argblock,
3935 argvec[count].locate.offset.constant);
3936 rtx stack_area = gen_rtx_MEM (save_mode,
3937 memory_address (save_mode, adr));
3939 if (save_mode == BLKmode)
3940 emit_block_move (stack_area,
3941 validize_mem (argvec[count].save_area),
3942 GEN_INT (argvec[count].locate.size.constant),
3943 BLOCK_OP_CALL_PARM);
3945 emit_move_insn (stack_area, argvec[count].save_area);
3948 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3949 stack_usage_map = initial_stack_usage_map;
3952 if (stack_usage_map_buf)
3953 free (stack_usage_map_buf);
3959 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3960 (emitting the queue unless NO_QUEUE is nonzero),
3961 for a value of mode OUTMODE,
3962 with NARGS different arguments, passed as alternating rtx values
3963 and machine_modes to convert them to.
3965 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
3966 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
3967 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
3968 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
3969 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
3970 or other LCT_ value for other types of library calls. */
3973 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3974 enum machine_mode outmode, int nargs, ...)
3978 va_start (p, nargs);
3979 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3983 /* Like emit_library_call except that an extra argument, VALUE,
3984 comes second and says where to store the result.
3985 (If VALUE is zero, this function chooses a convenient way
3986 to return the value.
3988 This function returns an rtx for where the value is to be found.
3989 If VALUE is nonzero, VALUE is returned. */
3992 emit_library_call_value (rtx orgfun, rtx value,
3993 enum libcall_type fn_type,
3994 enum machine_mode outmode, int nargs, ...)
3999 va_start (p, nargs);
4000 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
4007 /* Store a single argument for a function call
4008 into the register or memory area where it must be passed.
4009 *ARG describes the argument value and where to pass it.
4011 ARGBLOCK is the address of the stack-block for all the arguments,
4012 or 0 on a machine where arguments are pushed individually.
4014 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
4015 so must be careful about how the stack is used.
4017 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
4018 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
4019 that we need not worry about saving and restoring the stack.
4021 FNDECL is the declaration of the function we are calling.
4023 Return nonzero if this arg should cause sibcall failure,
4027 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
4028 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
4030 tree pval = arg->tree_value;
4034 int i, lower_bound = 0, upper_bound = 0;
4035 int sibcall_failure = 0;
4037 if (TREE_CODE (pval) == ERROR_MARK)
4040 /* Push a new temporary level for any temporaries we make for
4044 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4046 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4047 save any previous data at that location. */
4048 if (argblock && ! variable_size && arg->stack)
4050 #ifdef ARGS_GROW_DOWNWARD
4051 /* stack_slot is negative, but we want to index stack_usage_map
4052 with positive values. */
4053 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4054 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4058 lower_bound = upper_bound - arg->locate.size.constant;
4060 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4061 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4065 upper_bound = lower_bound + arg->locate.size.constant;
4069 /* Don't worry about things in the fixed argument area;
4070 it has already been saved. */
4071 if (i < reg_parm_stack_space)
4072 i = reg_parm_stack_space;
4073 while (i < upper_bound && stack_usage_map[i] == 0)
4076 if (i < upper_bound)
4078 /* We need to make a save area. */
4079 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4080 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4081 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4082 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4084 if (save_mode == BLKmode)
4086 tree ot = TREE_TYPE (arg->tree_value);
4087 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4088 | TYPE_QUAL_CONST));
4090 arg->save_area = assign_temp (nt, 0, 1, 1);
4091 preserve_temp_slots (arg->save_area);
4092 emit_block_move (validize_mem (arg->save_area), stack_area,
4093 GEN_INT (arg->locate.size.constant),
4094 BLOCK_OP_CALL_PARM);
4098 arg->save_area = gen_reg_rtx (save_mode);
4099 emit_move_insn (arg->save_area, stack_area);
4105 /* If this isn't going to be placed on both the stack and in registers,
4106 set up the register and number of words. */
4107 if (! arg->pass_on_stack)
4109 if (flags & ECF_SIBCALL)
4110 reg = arg->tail_call_reg;
4113 partial = arg->partial;
4116 /* Being passed entirely in a register. We shouldn't be called in
4118 gcc_assert (reg == 0 || partial != 0);
4120 /* If this arg needs special alignment, don't load the registers
4122 if (arg->n_aligned_regs != 0)
4125 /* If this is being passed partially in a register, we can't evaluate
4126 it directly into its stack slot. Otherwise, we can. */
4127 if (arg->value == 0)
4129 /* stack_arg_under_construction is nonzero if a function argument is
4130 being evaluated directly into the outgoing argument list and
4131 expand_call must take special action to preserve the argument list
4132 if it is called recursively.
4134 For scalar function arguments stack_usage_map is sufficient to
4135 determine which stack slots must be saved and restored. Scalar
4136 arguments in general have pass_on_stack == 0.
4138 If this argument is initialized by a function which takes the
4139 address of the argument (a C++ constructor or a C function
4140 returning a BLKmode structure), then stack_usage_map is
4141 insufficient and expand_call must push the stack around the
4142 function call. Such arguments have pass_on_stack == 1.
4144 Note that it is always safe to set stack_arg_under_construction,
4145 but this generates suboptimal code if set when not needed. */
4147 if (arg->pass_on_stack)
4148 stack_arg_under_construction++;
4150 arg->value = expand_expr (pval,
4152 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4153 ? NULL_RTX : arg->stack,
4154 VOIDmode, EXPAND_STACK_PARM);
4156 /* If we are promoting object (or for any other reason) the mode
4157 doesn't agree, convert the mode. */
4159 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4160 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4161 arg->value, arg->unsignedp);
4163 if (arg->pass_on_stack)
4164 stack_arg_under_construction--;
4167 /* Check for overlap with already clobbered argument area. */
4168 if ((flags & ECF_SIBCALL)
4169 && MEM_P (arg->value)
4170 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4171 arg->locate.size.constant))
4172 sibcall_failure = 1;
4174 /* Don't allow anything left on stack from computation
4175 of argument to alloca. */
4176 if (flags & ECF_MAY_BE_ALLOCA)
4177 do_pending_stack_adjust ();
4179 if (arg->value == arg->stack)
4180 /* If the value is already in the stack slot, we are done. */
4182 else if (arg->mode != BLKmode)
4186 /* Argument is a scalar, not entirely passed in registers.
4187 (If part is passed in registers, arg->partial says how much
4188 and emit_push_insn will take care of putting it there.)
4190 Push it, and if its size is less than the
4191 amount of space allocated to it,
4192 also bump stack pointer by the additional space.
4193 Note that in C the default argument promotions
4194 will prevent such mismatches. */
4196 size = GET_MODE_SIZE (arg->mode);
4197 /* Compute how much space the push instruction will push.
4198 On many machines, pushing a byte will advance the stack
4199 pointer by a halfword. */
4200 #ifdef PUSH_ROUNDING
4201 size = PUSH_ROUNDING (size);
4205 /* Compute how much space the argument should get:
4206 round up to a multiple of the alignment for arguments. */
4207 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4208 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4209 / (PARM_BOUNDARY / BITS_PER_UNIT))
4210 * (PARM_BOUNDARY / BITS_PER_UNIT));
4212 /* This isn't already where we want it on the stack, so put it there.
4213 This can either be done with push or copy insns. */
4214 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4215 PARM_BOUNDARY, partial, reg, used - size, argblock,
4216 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4217 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4219 /* Unless this is a partially-in-register argument, the argument is now
4222 arg->value = arg->stack;
4226 /* BLKmode, at least partly to be pushed. */
4228 unsigned int parm_align;
4232 /* Pushing a nonscalar.
4233 If part is passed in registers, PARTIAL says how much
4234 and emit_push_insn will take care of putting it there. */
4236 /* Round its size up to a multiple
4237 of the allocation unit for arguments. */
4239 if (arg->locate.size.var != 0)
4242 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4246 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4247 for BLKmode is careful to avoid it. */
4248 excess = (arg->locate.size.constant
4249 - int_size_in_bytes (TREE_TYPE (pval))
4251 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4252 NULL_RTX, TYPE_MODE (sizetype), 0);
4255 parm_align = arg->locate.boundary;
4257 /* When an argument is padded down, the block is aligned to
4258 PARM_BOUNDARY, but the actual argument isn't. */
4259 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4261 if (arg->locate.size.var)
4262 parm_align = BITS_PER_UNIT;
4265 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4266 parm_align = MIN (parm_align, excess_align);
4270 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4272 /* emit_push_insn might not work properly if arg->value and
4273 argblock + arg->locate.offset areas overlap. */
4277 if (XEXP (x, 0) == current_function_internal_arg_pointer
4278 || (GET_CODE (XEXP (x, 0)) == PLUS
4279 && XEXP (XEXP (x, 0), 0) ==
4280 current_function_internal_arg_pointer
4281 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4283 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4284 i = INTVAL (XEXP (XEXP (x, 0), 1));
4286 /* expand_call should ensure this. */
4287 gcc_assert (!arg->locate.offset.var
4288 && GET_CODE (size_rtx) == CONST_INT);
4290 if (arg->locate.offset.constant > i)
4292 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4293 sibcall_failure = 1;
4295 else if (arg->locate.offset.constant < i)
4297 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4298 sibcall_failure = 1;
4303 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4304 parm_align, partial, reg, excess, argblock,
4305 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4306 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4308 /* Unless this is a partially-in-register argument, the argument is now
4311 ??? Unlike the case above, in which we want the actual
4312 address of the data, so that we can load it directly into a
4313 register, here we want the address of the stack slot, so that
4314 it's properly aligned for word-by-word copying or something
4315 like that. It's not clear that this is always correct. */
4317 arg->value = arg->stack_slot;
4320 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4322 tree type = TREE_TYPE (arg->tree_value);
4324 = emit_group_load_into_temps (arg->reg, arg->value, type,
4325 int_size_in_bytes (type));
4328 /* Mark all slots this store used. */
4329 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4330 && argblock && ! variable_size && arg->stack)
4331 for (i = lower_bound; i < upper_bound; i++)
4332 stack_usage_map[i] = 1;
4334 /* Once we have pushed something, pops can't safely
4335 be deferred during the rest of the arguments. */
4338 /* Free any temporary slots made in processing this argument. Show
4339 that we might have taken the address of something and pushed that
4341 preserve_temp_slots (NULL_RTX);
4345 return sibcall_failure;
4348 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4351 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4357 /* If the type has variable size... */
4358 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4361 /* If the type is marked as addressable (it is required
4362 to be constructed into the stack)... */
4363 if (TREE_ADDRESSABLE (type))
4369 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4370 takes trailing padding of a structure into account. */
4371 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4374 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type)
4379 /* If the type has variable size... */
4380 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4383 /* If the type is marked as addressable (it is required
4384 to be constructed into the stack)... */
4385 if (TREE_ADDRESSABLE (type))
4388 /* If the padding and mode of the type is such that a copy into
4389 a register would put it into the wrong part of the register. */
4391 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4392 && (FUNCTION_ARG_PADDING (mode, type)
4393 == (BYTES_BIG_ENDIAN ? upward : downward)))