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 flags |= ECF_RETURNS_TWICE;
533 else if (tname[0] == 'l' && tname[1] == 'o'
534 && ! strcmp (tname, "longjmp"))
535 flags |= ECF_NORETURN;
541 /* Return nonzero when FNDECL represents a call to setjmp. */
544 setjmp_call_p (tree fndecl)
546 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
549 /* Return true when exp contains alloca call. */
551 alloca_call_p (tree exp)
553 if (TREE_CODE (exp) == CALL_EXPR
554 && TREE_CODE (TREE_OPERAND (exp, 0)) == ADDR_EXPR
555 && (TREE_CODE (TREE_OPERAND (TREE_OPERAND (exp, 0), 0))
557 && (special_function_p (TREE_OPERAND (TREE_OPERAND (exp, 0), 0),
558 0) & ECF_MAY_BE_ALLOCA))
563 /* Detect flags (function attributes) from the function decl or type node. */
566 flags_from_decl_or_type (tree exp)
573 struct cgraph_rtl_info *i = cgraph_rtl_info (exp);
574 type = TREE_TYPE (exp);
578 if (i->pure_function)
579 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
580 if (i->const_function)
581 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
584 /* The function exp may have the `malloc' attribute. */
585 if (DECL_IS_MALLOC (exp))
588 /* The function exp may have the `returns_twice' attribute. */
589 if (DECL_IS_RETURNS_TWICE (exp))
590 flags |= ECF_RETURNS_TWICE;
592 /* The function exp may have the `pure' attribute. */
593 if (DECL_IS_PURE (exp))
594 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
596 if (DECL_IS_NOVOPS (exp))
599 if (TREE_NOTHROW (exp))
600 flags |= ECF_NOTHROW;
602 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
603 flags |= ECF_LIBCALL_BLOCK | ECF_CONST;
605 flags = special_function_p (exp, flags);
607 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
610 if (TREE_THIS_VOLATILE (exp))
611 flags |= ECF_NORETURN;
613 /* Mark if the function returns with the stack pointer depressed. We
614 cannot consider it pure or constant in that case. */
615 if (TREE_CODE (type) == FUNCTION_TYPE && TYPE_RETURNS_STACK_DEPRESSED (type))
617 flags |= ECF_SP_DEPRESSED;
618 flags &= ~(ECF_PURE | ECF_CONST | ECF_LIBCALL_BLOCK);
624 /* Detect flags from a CALL_EXPR. */
627 call_expr_flags (tree t)
630 tree decl = get_callee_fndecl (t);
633 flags = flags_from_decl_or_type (decl);
636 t = TREE_TYPE (TREE_OPERAND (t, 0));
637 if (t && TREE_CODE (t) == POINTER_TYPE)
638 flags = flags_from_decl_or_type (TREE_TYPE (t));
646 /* Precompute all register parameters as described by ARGS, storing values
647 into fields within the ARGS array.
649 NUM_ACTUALS indicates the total number elements in the ARGS array.
651 Set REG_PARM_SEEN if we encounter a register parameter. */
654 precompute_register_parameters (int num_actuals, struct arg_data *args,
661 for (i = 0; i < num_actuals; i++)
662 if (args[i].reg != 0 && ! args[i].pass_on_stack)
666 if (args[i].value == 0)
669 args[i].value = expand_expr (args[i].tree_value, NULL_RTX,
671 preserve_temp_slots (args[i].value);
675 /* If the value is a non-legitimate constant, force it into a
676 pseudo now. TLS symbols sometimes need a call to resolve. */
677 if (CONSTANT_P (args[i].value)
678 && !LEGITIMATE_CONSTANT_P (args[i].value))
679 args[i].value = force_reg (args[i].mode, args[i].value);
681 /* If we are to promote the function arg to a wider mode,
684 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
686 = convert_modes (args[i].mode,
687 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
688 args[i].value, args[i].unsignedp);
690 /* If we're going to have to load the value by parts, pull the
691 parts into pseudos. The part extraction process can involve
692 non-trivial computation. */
693 if (GET_CODE (args[i].reg) == PARALLEL)
695 tree type = TREE_TYPE (args[i].tree_value);
696 args[i].parallel_value
697 = emit_group_load_into_temps (args[i].reg, args[i].value,
698 type, int_size_in_bytes (type));
701 /* If the value is expensive, and we are inside an appropriately
702 short loop, put the value into a pseudo and then put the pseudo
705 For small register classes, also do this if this call uses
706 register parameters. This is to avoid reload conflicts while
707 loading the parameters registers. */
709 else if ((! (REG_P (args[i].value)
710 || (GET_CODE (args[i].value) == SUBREG
711 && REG_P (SUBREG_REG (args[i].value)))))
712 && args[i].mode != BLKmode
713 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
714 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
716 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
720 #ifdef REG_PARM_STACK_SPACE
722 /* The argument list is the property of the called routine and it
723 may clobber it. If the fixed area has been used for previous
724 parameters, we must save and restore it. */
727 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
732 /* Compute the boundary of the area that needs to be saved, if any. */
733 high = reg_parm_stack_space;
734 #ifdef ARGS_GROW_DOWNWARD
737 if (high > highest_outgoing_arg_in_use)
738 high = highest_outgoing_arg_in_use;
740 for (low = 0; low < high; low++)
741 if (stack_usage_map[low] != 0)
744 enum machine_mode save_mode;
749 while (stack_usage_map[--high] == 0)
753 *high_to_save = high;
755 num_to_save = high - low + 1;
756 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
758 /* If we don't have the required alignment, must do this
760 if ((low & (MIN (GET_MODE_SIZE (save_mode),
761 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
764 #ifdef ARGS_GROW_DOWNWARD
769 stack_area = gen_rtx_MEM (save_mode,
770 memory_address (save_mode,
771 plus_constant (argblock,
774 set_mem_align (stack_area, PARM_BOUNDARY);
775 if (save_mode == BLKmode)
777 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
778 emit_block_move (validize_mem (save_area), stack_area,
779 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
783 save_area = gen_reg_rtx (save_mode);
784 emit_move_insn (save_area, stack_area);
794 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
796 enum machine_mode save_mode = GET_MODE (save_area);
800 #ifdef ARGS_GROW_DOWNWARD
801 delta = -high_to_save;
805 stack_area = gen_rtx_MEM (save_mode,
806 memory_address (save_mode,
807 plus_constant (argblock, delta)));
808 set_mem_align (stack_area, PARM_BOUNDARY);
810 if (save_mode != BLKmode)
811 emit_move_insn (stack_area, save_area);
813 emit_block_move (stack_area, validize_mem (save_area),
814 GEN_INT (high_to_save - low_to_save + 1),
817 #endif /* REG_PARM_STACK_SPACE */
819 /* If any elements in ARGS refer to parameters that are to be passed in
820 registers, but not in memory, and whose alignment does not permit a
821 direct copy into registers. Copy the values into a group of pseudos
822 which we will later copy into the appropriate hard registers.
824 Pseudos for each unaligned argument will be stored into the array
825 args[argnum].aligned_regs. The caller is responsible for deallocating
826 the aligned_regs array if it is nonzero. */
829 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
833 for (i = 0; i < num_actuals; i++)
834 if (args[i].reg != 0 && ! args[i].pass_on_stack
835 && args[i].mode == BLKmode
836 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
837 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
839 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
840 int endian_correction = 0;
844 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
845 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
849 args[i].n_aligned_regs
850 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
853 args[i].aligned_regs = xmalloc (sizeof (rtx) * args[i].n_aligned_regs);
855 /* Structures smaller than a word are normally aligned to the
856 least significant byte. On a BYTES_BIG_ENDIAN machine,
857 this means we must skip the empty high order bytes when
858 calculating the bit offset. */
859 if (bytes < UNITS_PER_WORD
860 #ifdef BLOCK_REG_PADDING
861 && (BLOCK_REG_PADDING (args[i].mode,
862 TREE_TYPE (args[i].tree_value), 1)
868 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
870 for (j = 0; j < args[i].n_aligned_regs; j++)
872 rtx reg = gen_reg_rtx (word_mode);
873 rtx word = operand_subword_force (args[i].value, j, BLKmode);
874 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
876 args[i].aligned_regs[j] = reg;
877 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
878 word_mode, word_mode);
880 /* There is no need to restrict this code to loading items
881 in TYPE_ALIGN sized hunks. The bitfield instructions can
882 load up entire word sized registers efficiently.
884 ??? This may not be needed anymore.
885 We use to emit a clobber here but that doesn't let later
886 passes optimize the instructions we emit. By storing 0 into
887 the register later passes know the first AND to zero out the
888 bitfield being set in the register is unnecessary. The store
889 of 0 will be deleted as will at least the first AND. */
891 emit_move_insn (reg, const0_rtx);
893 bytes -= bitsize / BITS_PER_UNIT;
894 store_bit_field (reg, bitsize, endian_correction, word_mode,
900 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
903 NUM_ACTUALS is the total number of parameters.
905 N_NAMED_ARGS is the total number of named arguments.
907 FNDECL is the tree code for the target of this call (if known)
909 ARGS_SO_FAR holds state needed by the target to know where to place
912 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
913 for arguments which are passed in registers.
915 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
916 and may be modified by this routine.
918 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
919 flags which may may be modified by this routine.
921 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
922 that requires allocation of stack space.
924 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
925 the thunked-to function. */
928 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
929 struct arg_data *args,
930 struct args_size *args_size,
931 int n_named_args ATTRIBUTE_UNUSED,
932 tree actparms, tree fndecl,
933 CUMULATIVE_ARGS *args_so_far,
934 int reg_parm_stack_space,
935 rtx *old_stack_level, int *old_pending_adj,
936 int *must_preallocate, int *ecf_flags,
937 bool *may_tailcall, bool call_from_thunk_p)
939 /* 1 if scanning parms front to back, -1 if scanning back to front. */
942 /* Count arg position in order args appear. */
948 args_size->constant = 0;
951 /* In this loop, we consider args in the order they are written.
952 We fill up ARGS from the front or from the back if necessary
953 so that in any case the first arg to be pushed ends up at the front. */
955 if (PUSH_ARGS_REVERSED)
957 i = num_actuals - 1, inc = -1;
958 /* In this case, must reverse order of args
959 so that we compute and push the last arg first. */
966 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
967 for (p = actparms, argpos = 0; p; p = TREE_CHAIN (p), i += inc, argpos++)
969 tree type = TREE_TYPE (TREE_VALUE (p));
971 enum machine_mode mode;
973 args[i].tree_value = TREE_VALUE (p);
975 /* Replace erroneous argument with constant zero. */
976 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
977 args[i].tree_value = integer_zero_node, type = integer_type_node;
979 /* If TYPE is a transparent union, pass things the way we would
980 pass the first field of the union. We have already verified that
981 the modes are the same. */
982 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
983 type = TREE_TYPE (TYPE_FIELDS (type));
985 /* Decide where to pass this arg.
987 args[i].reg is nonzero if all or part is passed in registers.
989 args[i].partial is nonzero if part but not all is passed in registers,
990 and the exact value says how many bytes are passed in registers.
992 args[i].pass_on_stack is nonzero if the argument must at least be
993 computed on the stack. It may then be loaded back into registers
994 if args[i].reg is nonzero.
996 These decisions are driven by the FUNCTION_... macros and must agree
997 with those made by function.c. */
999 /* See if this argument should be passed by invisible reference. */
1000 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1001 type, argpos < n_named_args))
1007 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1008 type, argpos < n_named_args);
1010 /* If we're compiling a thunk, pass through invisible references
1011 instead of making a copy. */
1012 if (call_from_thunk_p
1014 && !TREE_ADDRESSABLE (type)
1015 && (base = get_base_address (args[i].tree_value))
1016 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1018 /* We can't use sibcalls if a callee-copied argument is
1019 stored in the current function's frame. */
1020 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1021 *may_tailcall = false;
1023 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1024 type = TREE_TYPE (args[i].tree_value);
1026 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1030 /* We make a copy of the object and pass the address to the
1031 function being called. */
1034 if (!COMPLETE_TYPE_P (type)
1035 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1036 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1037 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1038 STACK_CHECK_MAX_VAR_SIZE))))
1040 /* This is a variable-sized object. Make space on the stack
1042 rtx size_rtx = expr_size (TREE_VALUE (p));
1044 if (*old_stack_level == 0)
1046 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1047 *old_pending_adj = pending_stack_adjust;
1048 pending_stack_adjust = 0;
1051 copy = gen_rtx_MEM (BLKmode,
1052 allocate_dynamic_stack_space
1053 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1054 set_mem_attributes (copy, type, 1);
1057 copy = assign_temp (type, 0, 1, 0);
1059 store_expr (args[i].tree_value, copy, 0);
1062 *ecf_flags &= ~(ECF_CONST | ECF_LIBCALL_BLOCK);
1064 *ecf_flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1067 = build_fold_addr_expr (make_tree (type, copy));
1068 type = TREE_TYPE (args[i].tree_value);
1069 *may_tailcall = false;
1073 mode = TYPE_MODE (type);
1074 unsignedp = TYPE_UNSIGNED (type);
1076 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1077 mode = promote_mode (type, mode, &unsignedp, 1);
1079 args[i].unsignedp = unsignedp;
1080 args[i].mode = mode;
1082 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1083 argpos < n_named_args);
1084 #ifdef FUNCTION_INCOMING_ARG
1085 /* If this is a sibling call and the machine has register windows, the
1086 register window has to be unwinded before calling the routine, so
1087 arguments have to go into the incoming registers. */
1088 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1089 argpos < n_named_args);
1091 args[i].tail_call_reg = args[i].reg;
1096 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1097 argpos < n_named_args);
1099 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1101 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1102 it means that we are to pass this arg in the register(s) designated
1103 by the PARALLEL, but also to pass it in the stack. */
1104 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1105 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1106 args[i].pass_on_stack = 1;
1108 /* If this is an addressable type, we must preallocate the stack
1109 since we must evaluate the object into its final location.
1111 If this is to be passed in both registers and the stack, it is simpler
1113 if (TREE_ADDRESSABLE (type)
1114 || (args[i].pass_on_stack && args[i].reg != 0))
1115 *must_preallocate = 1;
1117 /* If this is an addressable type, we cannot pre-evaluate it. Thus,
1118 we cannot consider this function call constant. */
1119 if (TREE_ADDRESSABLE (type))
1120 *ecf_flags &= ~ECF_LIBCALL_BLOCK;
1122 /* Compute the stack-size of this argument. */
1123 if (args[i].reg == 0 || args[i].partial != 0
1124 || reg_parm_stack_space > 0
1125 || args[i].pass_on_stack)
1126 locate_and_pad_parm (mode, type,
1127 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1132 args[i].pass_on_stack ? 0 : args[i].partial,
1133 fndecl, args_size, &args[i].locate);
1134 #ifdef BLOCK_REG_PADDING
1136 /* The argument is passed entirely in registers. See at which
1137 end it should be padded. */
1138 args[i].locate.where_pad =
1139 BLOCK_REG_PADDING (mode, type,
1140 int_size_in_bytes (type) <= UNITS_PER_WORD);
1143 /* Update ARGS_SIZE, the total stack space for args so far. */
1145 args_size->constant += args[i].locate.size.constant;
1146 if (args[i].locate.size.var)
1147 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1149 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1150 have been used, etc. */
1152 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1153 argpos < n_named_args);
1157 /* Update ARGS_SIZE to contain the total size for the argument block.
1158 Return the original constant component of the argument block's size.
1160 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1161 for arguments passed in registers. */
1164 compute_argument_block_size (int reg_parm_stack_space,
1165 struct args_size *args_size,
1166 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1168 int unadjusted_args_size = args_size->constant;
1170 /* For accumulate outgoing args mode we don't need to align, since the frame
1171 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1172 backends from generating misaligned frame sizes. */
1173 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1174 preferred_stack_boundary = STACK_BOUNDARY;
1176 /* Compute the actual size of the argument block required. The variable
1177 and constant sizes must be combined, the size may have to be rounded,
1178 and there may be a minimum required size. */
1182 args_size->var = ARGS_SIZE_TREE (*args_size);
1183 args_size->constant = 0;
1185 preferred_stack_boundary /= BITS_PER_UNIT;
1186 if (preferred_stack_boundary > 1)
1188 /* We don't handle this case yet. To handle it correctly we have
1189 to add the delta, round and subtract the delta.
1190 Currently no machine description requires this support. */
1191 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1192 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1195 if (reg_parm_stack_space > 0)
1198 = size_binop (MAX_EXPR, args_size->var,
1199 ssize_int (reg_parm_stack_space));
1201 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1202 /* The area corresponding to register parameters is not to count in
1203 the size of the block we need. So make the adjustment. */
1205 = size_binop (MINUS_EXPR, args_size->var,
1206 ssize_int (reg_parm_stack_space));
1212 preferred_stack_boundary /= BITS_PER_UNIT;
1213 if (preferred_stack_boundary < 1)
1214 preferred_stack_boundary = 1;
1215 args_size->constant = (((args_size->constant
1216 + stack_pointer_delta
1217 + preferred_stack_boundary - 1)
1218 / preferred_stack_boundary
1219 * preferred_stack_boundary)
1220 - stack_pointer_delta);
1222 args_size->constant = MAX (args_size->constant,
1223 reg_parm_stack_space);
1225 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1226 args_size->constant -= reg_parm_stack_space;
1229 return unadjusted_args_size;
1232 /* Precompute parameters as needed for a function call.
1234 FLAGS is mask of ECF_* constants.
1236 NUM_ACTUALS is the number of arguments.
1238 ARGS is an array containing information for each argument; this
1239 routine fills in the INITIAL_VALUE and VALUE fields for each
1240 precomputed argument. */
1243 precompute_arguments (int flags, int num_actuals, struct arg_data *args)
1247 /* If this is a libcall, then precompute all arguments so that we do not
1248 get extraneous instructions emitted as part of the libcall sequence. */
1249 if ((flags & ECF_LIBCALL_BLOCK) == 0)
1252 for (i = 0; i < num_actuals; i++)
1254 enum machine_mode mode;
1256 /* If this is an addressable type, we cannot pre-evaluate it. */
1257 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1259 args[i].initial_value = args[i].value
1260 = expand_expr (args[i].tree_value, NULL_RTX, VOIDmode, 0);
1262 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1263 if (mode != args[i].mode)
1266 = convert_modes (args[i].mode, mode,
1267 args[i].value, args[i].unsignedp);
1268 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1269 /* CSE will replace this only if it contains args[i].value
1270 pseudo, so convert it down to the declared mode using
1272 if (REG_P (args[i].value)
1273 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1275 args[i].initial_value
1276 = gen_lowpart_SUBREG (mode, args[i].value);
1277 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1278 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1286 /* Given the current state of MUST_PREALLOCATE and information about
1287 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1288 compute and return the final value for MUST_PREALLOCATE. */
1291 finalize_must_preallocate (int must_preallocate, int num_actuals, struct arg_data *args, struct args_size *args_size)
1293 /* See if we have or want to preallocate stack space.
1295 If we would have to push a partially-in-regs parm
1296 before other stack parms, preallocate stack space instead.
1298 If the size of some parm is not a multiple of the required stack
1299 alignment, we must preallocate.
1301 If the total size of arguments that would otherwise create a copy in
1302 a temporary (such as a CALL) is more than half the total argument list
1303 size, preallocation is faster.
1305 Another reason to preallocate is if we have a machine (like the m88k)
1306 where stack alignment is required to be maintained between every
1307 pair of insns, not just when the call is made. However, we assume here
1308 that such machines either do not have push insns (and hence preallocation
1309 would occur anyway) or the problem is taken care of with
1312 if (! must_preallocate)
1314 int partial_seen = 0;
1315 int copy_to_evaluate_size = 0;
1318 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1320 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1322 else if (partial_seen && args[i].reg == 0)
1323 must_preallocate = 1;
1325 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1326 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1327 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1328 || TREE_CODE (args[i].tree_value) == COND_EXPR
1329 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1330 copy_to_evaluate_size
1331 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1334 if (copy_to_evaluate_size * 2 >= args_size->constant
1335 && args_size->constant > 0)
1336 must_preallocate = 1;
1338 return must_preallocate;
1341 /* If we preallocated stack space, compute the address of each argument
1342 and store it into the ARGS array.
1344 We need not ensure it is a valid memory address here; it will be
1345 validized when it is used.
1347 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1350 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1354 rtx arg_reg = argblock;
1355 int i, arg_offset = 0;
1357 if (GET_CODE (argblock) == PLUS)
1358 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1360 for (i = 0; i < num_actuals; i++)
1362 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1363 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1365 unsigned int align, boundary;
1367 /* Skip this parm if it will not be passed on the stack. */
1368 if (! args[i].pass_on_stack && args[i].reg != 0)
1371 if (GET_CODE (offset) == CONST_INT)
1372 addr = plus_constant (arg_reg, INTVAL (offset));
1374 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1376 addr = plus_constant (addr, arg_offset);
1377 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1378 set_mem_attributes (args[i].stack,
1379 TREE_TYPE (args[i].tree_value), 1);
1380 align = BITS_PER_UNIT;
1381 boundary = args[i].locate.boundary;
1382 if (args[i].locate.where_pad != downward)
1384 else if (GET_CODE (offset) == CONST_INT)
1386 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1387 align = align & -align;
1389 set_mem_align (args[i].stack, align);
1391 if (GET_CODE (slot_offset) == CONST_INT)
1392 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1394 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1396 addr = plus_constant (addr, arg_offset);
1397 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1398 set_mem_attributes (args[i].stack_slot,
1399 TREE_TYPE (args[i].tree_value), 1);
1400 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1402 /* Function incoming arguments may overlap with sibling call
1403 outgoing arguments and we cannot allow reordering of reads
1404 from function arguments with stores to outgoing arguments
1405 of sibling calls. */
1406 set_mem_alias_set (args[i].stack, 0);
1407 set_mem_alias_set (args[i].stack_slot, 0);
1412 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1413 in a call instruction.
1415 FNDECL is the tree node for the target function. For an indirect call
1416 FNDECL will be NULL_TREE.
1418 ADDR is the operand 0 of CALL_EXPR for this call. */
1421 rtx_for_function_call (tree fndecl, tree addr)
1425 /* Get the function to call, in the form of RTL. */
1428 /* If this is the first use of the function, see if we need to
1429 make an external definition for it. */
1430 if (! TREE_USED (fndecl))
1432 assemble_external (fndecl);
1433 TREE_USED (fndecl) = 1;
1436 /* Get a SYMBOL_REF rtx for the function address. */
1437 funexp = XEXP (DECL_RTL (fndecl), 0);
1440 /* Generate an rtx (probably a pseudo-register) for the address. */
1443 funexp = expand_expr (addr, NULL_RTX, VOIDmode, 0);
1444 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1449 /* Do the register loads required for any wholly-register parms or any
1450 parms which are passed both on the stack and in a register. Their
1451 expressions were already evaluated.
1453 Mark all register-parms as living through the call, putting these USE
1454 insns in the CALL_INSN_FUNCTION_USAGE field.
1456 When IS_SIBCALL, perform the check_sibcall_overlap_argument_overlap
1457 checking, setting *SIBCALL_FAILURE if appropriate. */
1460 load_register_parameters (struct arg_data *args, int num_actuals,
1461 rtx *call_fusage, int flags, int is_sibcall,
1462 int *sibcall_failure)
1466 for (i = 0; i < num_actuals; i++)
1468 rtx reg = ((flags & ECF_SIBCALL)
1469 ? args[i].tail_call_reg : args[i].reg);
1472 int partial = args[i].partial;
1475 rtx before_arg = get_last_insn ();
1476 /* Set non-negative if we must move a word at a time, even if
1477 just one word (e.g, partial == 4 && mode == DFmode). Set
1478 to -1 if we just use a normal move insn. This value can be
1479 zero if the argument is a zero size structure. */
1481 if (GET_CODE (reg) == PARALLEL)
1485 gcc_assert (partial % UNITS_PER_WORD == 0);
1486 nregs = partial / UNITS_PER_WORD;
1488 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1490 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1491 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1494 size = GET_MODE_SIZE (args[i].mode);
1496 /* Handle calls that pass values in multiple non-contiguous
1497 locations. The Irix 6 ABI has examples of this. */
1499 if (GET_CODE (reg) == PARALLEL)
1500 emit_group_move (reg, args[i].parallel_value);
1502 /* If simple case, just do move. If normal partial, store_one_arg
1503 has already loaded the register for us. In all other cases,
1504 load the register(s) from memory. */
1506 else if (nregs == -1)
1508 emit_move_insn (reg, args[i].value);
1509 #ifdef BLOCK_REG_PADDING
1510 /* Handle case where we have a value that needs shifting
1511 up to the msb. eg. a QImode value and we're padding
1512 upward on a BYTES_BIG_ENDIAN machine. */
1513 if (size < UNITS_PER_WORD
1514 && (args[i].locate.where_pad
1515 == (BYTES_BIG_ENDIAN ? upward : downward)))
1518 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1520 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1521 report the whole reg as used. Strictly speaking, the
1522 call only uses SIZE bytes at the msb end, but it doesn't
1523 seem worth generating rtl to say that. */
1524 reg = gen_rtx_REG (word_mode, REGNO (reg));
1525 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1526 build_int_cst (NULL_TREE, shift),
1529 emit_move_insn (reg, x);
1534 /* If we have pre-computed the values to put in the registers in
1535 the case of non-aligned structures, copy them in now. */
1537 else if (args[i].n_aligned_regs != 0)
1538 for (j = 0; j < args[i].n_aligned_regs; j++)
1539 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1540 args[i].aligned_regs[j]);
1542 else if (partial == 0 || args[i].pass_on_stack)
1544 rtx mem = validize_mem (args[i].value);
1546 /* Handle a BLKmode that needs shifting. */
1547 if (nregs == 1 && size < UNITS_PER_WORD
1548 #ifdef BLOCK_REG_PADDING
1549 && args[i].locate.where_pad == downward
1555 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1556 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1557 rtx x = gen_reg_rtx (word_mode);
1558 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1559 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1562 emit_move_insn (x, tem);
1563 x = expand_shift (dir, word_mode, x,
1564 build_int_cst (NULL_TREE, shift),
1567 emit_move_insn (ri, x);
1570 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1573 /* When a parameter is a block, and perhaps in other cases, it is
1574 possible that it did a load from an argument slot that was
1575 already clobbered. */
1577 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1578 *sibcall_failure = 1;
1580 /* Handle calls that pass values in multiple non-contiguous
1581 locations. The Irix 6 ABI has examples of this. */
1582 if (GET_CODE (reg) == PARALLEL)
1583 use_group_regs (call_fusage, reg);
1584 else if (nregs == -1)
1585 use_reg (call_fusage, reg);
1587 use_regs (call_fusage, REGNO (reg), nregs);
1592 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1593 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1594 bytes, then we would need to push some additional bytes to pad the
1595 arguments. So, we compute an adjust to the stack pointer for an
1596 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1597 bytes. Then, when the arguments are pushed the stack will be perfectly
1598 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1599 be popped after the call. Returns the adjustment. */
1602 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1603 struct args_size *args_size,
1604 unsigned int preferred_unit_stack_boundary)
1606 /* The number of bytes to pop so that the stack will be
1607 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1608 HOST_WIDE_INT adjustment;
1609 /* The alignment of the stack after the arguments are pushed, if we
1610 just pushed the arguments without adjust the stack here. */
1611 unsigned HOST_WIDE_INT unadjusted_alignment;
1613 unadjusted_alignment
1614 = ((stack_pointer_delta + unadjusted_args_size)
1615 % preferred_unit_stack_boundary);
1617 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1618 as possible -- leaving just enough left to cancel out the
1619 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1620 PENDING_STACK_ADJUST is non-negative, and congruent to
1621 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1623 /* Begin by trying to pop all the bytes. */
1624 unadjusted_alignment
1625 = (unadjusted_alignment
1626 - (pending_stack_adjust % preferred_unit_stack_boundary));
1627 adjustment = pending_stack_adjust;
1628 /* Push enough additional bytes that the stack will be aligned
1629 after the arguments are pushed. */
1630 if (preferred_unit_stack_boundary > 1)
1632 if (unadjusted_alignment > 0)
1633 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1635 adjustment += unadjusted_alignment;
1638 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1639 bytes after the call. The right number is the entire
1640 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1641 by the arguments in the first place. */
1643 = pending_stack_adjust - adjustment + unadjusted_args_size;
1648 /* Scan X expression if it does not dereference any argument slots
1649 we already clobbered by tail call arguments (as noted in stored_args_map
1651 Return nonzero if X expression dereferences such argument slots,
1655 check_sibcall_argument_overlap_1 (rtx x)
1665 code = GET_CODE (x);
1669 if (XEXP (x, 0) == current_function_internal_arg_pointer)
1671 else if (GET_CODE (XEXP (x, 0)) == PLUS
1672 && XEXP (XEXP (x, 0), 0) ==
1673 current_function_internal_arg_pointer
1674 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT)
1675 i = INTVAL (XEXP (XEXP (x, 0), 1));
1679 #ifdef ARGS_GROW_DOWNWARD
1680 i = -i - GET_MODE_SIZE (GET_MODE (x));
1683 for (k = 0; k < GET_MODE_SIZE (GET_MODE (x)); k++)
1684 if (i + k < stored_args_map->n_bits
1685 && TEST_BIT (stored_args_map, i + k))
1691 /* Scan all subexpressions. */
1692 fmt = GET_RTX_FORMAT (code);
1693 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1697 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1700 else if (*fmt == 'E')
1702 for (j = 0; j < XVECLEN (x, i); j++)
1703 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1710 /* Scan sequence after INSN if it does not dereference any argument slots
1711 we already clobbered by tail call arguments (as noted in stored_args_map
1712 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1713 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1714 should be 0). Return nonzero if sequence after INSN dereferences such argument
1715 slots, zero otherwise. */
1718 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1722 if (insn == NULL_RTX)
1723 insn = get_insns ();
1725 insn = NEXT_INSN (insn);
1727 for (; insn; insn = NEXT_INSN (insn))
1729 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1732 if (mark_stored_args_map)
1734 #ifdef ARGS_GROW_DOWNWARD
1735 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1737 low = arg->locate.slot_offset.constant;
1740 for (high = low + arg->locate.size.constant; low < high; low++)
1741 SET_BIT (stored_args_map, low);
1743 return insn != NULL_RTX;
1746 /* Given that a function returns a value of mode MODE at the most
1747 significant end of hard register VALUE, shift VALUE left or right
1748 as specified by LEFT_P. Return true if some action was needed. */
1751 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1753 HOST_WIDE_INT shift;
1755 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1756 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1760 /* Use ashr rather than lshr for right shifts. This is for the benefit
1761 of the MIPS port, which requires SImode values to be sign-extended
1762 when stored in 64-bit registers. */
1763 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1764 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1769 /* Generate all the code for a function call
1770 and return an rtx for its value.
1771 Store the value in TARGET (specified as an rtx) if convenient.
1772 If the value is stored in TARGET then TARGET is returned.
1773 If IGNORE is nonzero, then we ignore the value of the function call. */
1776 expand_call (tree exp, rtx target, int ignore)
1778 /* Nonzero if we are currently expanding a call. */
1779 static int currently_expanding_call = 0;
1781 /* List of actual parameters. */
1782 tree actparms = TREE_OPERAND (exp, 1);
1783 /* RTX for the function to be called. */
1785 /* Sequence of insns to perform a normal "call". */
1786 rtx normal_call_insns = NULL_RTX;
1787 /* Sequence of insns to perform a tail "call". */
1788 rtx tail_call_insns = NULL_RTX;
1789 /* Data type of the function. */
1791 tree type_arg_types;
1792 /* Declaration of the function being called,
1793 or 0 if the function is computed (not known by name). */
1795 /* The type of the function being called. */
1797 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1800 /* Register in which non-BLKmode value will be returned,
1801 or 0 if no value or if value is BLKmode. */
1803 /* Address where we should return a BLKmode value;
1804 0 if value not BLKmode. */
1805 rtx structure_value_addr = 0;
1806 /* Nonzero if that address is being passed by treating it as
1807 an extra, implicit first parameter. Otherwise,
1808 it is passed by being copied directly into struct_value_rtx. */
1809 int structure_value_addr_parm = 0;
1810 /* Size of aggregate value wanted, or zero if none wanted
1811 or if we are using the non-reentrant PCC calling convention
1812 or expecting the value in registers. */
1813 HOST_WIDE_INT struct_value_size = 0;
1814 /* Nonzero if called function returns an aggregate in memory PCC style,
1815 by returning the address of where to find it. */
1816 int pcc_struct_value = 0;
1817 rtx struct_value = 0;
1819 /* Number of actual parameters in this call, including struct value addr. */
1821 /* Number of named args. Args after this are anonymous ones
1822 and they must all go on the stack. */
1825 /* Vector of information about each argument.
1826 Arguments are numbered in the order they will be pushed,
1827 not the order they are written. */
1828 struct arg_data *args;
1830 /* Total size in bytes of all the stack-parms scanned so far. */
1831 struct args_size args_size;
1832 struct args_size adjusted_args_size;
1833 /* Size of arguments before any adjustments (such as rounding). */
1834 int unadjusted_args_size;
1835 /* Data on reg parms scanned so far. */
1836 CUMULATIVE_ARGS args_so_far;
1837 /* Nonzero if a reg parm has been scanned. */
1839 /* Nonzero if this is an indirect function call. */
1841 /* Nonzero if we must avoid push-insns in the args for this call.
1842 If stack space is allocated for register parameters, but not by the
1843 caller, then it is preallocated in the fixed part of the stack frame.
1844 So the entire argument block must then be preallocated (i.e., we
1845 ignore PUSH_ROUNDING in that case). */
1847 int must_preallocate = !PUSH_ARGS;
1849 /* Size of the stack reserved for parameter registers. */
1850 int reg_parm_stack_space = 0;
1852 /* Address of space preallocated for stack parms
1853 (on machines that lack push insns), or 0 if space not preallocated. */
1856 /* Mask of ECF_ flags. */
1858 #ifdef REG_PARM_STACK_SPACE
1859 /* Define the boundary of the register parm stack space that needs to be
1861 int low_to_save, high_to_save;
1862 rtx save_area = 0; /* Place that it is saved */
1865 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1866 char *initial_stack_usage_map = stack_usage_map;
1867 char *stack_usage_map_buf = NULL;
1869 int old_stack_allocated;
1871 /* State variables to track stack modifications. */
1872 rtx old_stack_level = 0;
1873 int old_stack_arg_under_construction = 0;
1874 int old_pending_adj = 0;
1875 int old_inhibit_defer_pop = inhibit_defer_pop;
1877 /* Some stack pointer alterations we make are performed via
1878 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1879 which we then also need to save/restore along the way. */
1880 int old_stack_pointer_delta = 0;
1883 tree p = TREE_OPERAND (exp, 0);
1884 tree addr = TREE_OPERAND (exp, 0);
1886 /* The alignment of the stack, in bits. */
1887 unsigned HOST_WIDE_INT preferred_stack_boundary;
1888 /* The alignment of the stack, in bytes. */
1889 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
1890 /* The static chain value to use for this call. */
1891 rtx static_chain_value;
1892 /* See if this is "nothrow" function call. */
1893 if (TREE_NOTHROW (exp))
1894 flags |= ECF_NOTHROW;
1896 /* See if we can find a DECL-node for the actual function, and get the
1897 function attributes (flags) from the function decl or type node. */
1898 fndecl = get_callee_fndecl (exp);
1901 fntype = TREE_TYPE (fndecl);
1902 flags |= flags_from_decl_or_type (fndecl);
1906 fntype = TREE_TYPE (TREE_TYPE (p));
1907 flags |= flags_from_decl_or_type (fntype);
1910 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
1912 /* Warn if this value is an aggregate type,
1913 regardless of which calling convention we are using for it. */
1914 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
1915 warning (OPT_Waggregate_return, "function call has aggregate value");
1917 /* If the result of a pure or const function call is ignored (or void),
1918 and none of its arguments are volatile, we can avoid expanding the
1919 call and just evaluate the arguments for side-effects. */
1920 if ((flags & (ECF_CONST | ECF_PURE))
1921 && (ignore || target == const0_rtx
1922 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
1924 bool volatilep = false;
1927 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1928 if (TREE_THIS_VOLATILE (TREE_VALUE (arg)))
1936 for (arg = actparms; arg; arg = TREE_CHAIN (arg))
1937 expand_expr (TREE_VALUE (arg), const0_rtx,
1938 VOIDmode, EXPAND_NORMAL);
1943 #ifdef REG_PARM_STACK_SPACE
1944 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
1947 #ifndef OUTGOING_REG_PARM_STACK_SPACE
1948 if (reg_parm_stack_space > 0 && PUSH_ARGS)
1949 must_preallocate = 1;
1952 /* Set up a place to return a structure. */
1954 /* Cater to broken compilers. */
1955 if (aggregate_value_p (exp, fndecl))
1957 /* This call returns a big structure. */
1958 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
1960 #ifdef PCC_STATIC_STRUCT_RETURN
1962 pcc_struct_value = 1;
1964 #else /* not PCC_STATIC_STRUCT_RETURN */
1966 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
1968 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
1969 structure_value_addr = XEXP (target, 0);
1972 /* For variable-sized objects, we must be called with a target
1973 specified. If we were to allocate space on the stack here,
1974 we would have no way of knowing when to free it. */
1975 rtx d = assign_temp (TREE_TYPE (exp), 1, 1, 1);
1977 mark_temp_addr_taken (d);
1978 structure_value_addr = XEXP (d, 0);
1982 #endif /* not PCC_STATIC_STRUCT_RETURN */
1985 /* Figure out the amount to which the stack should be aligned. */
1986 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
1989 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
1990 if (i && i->preferred_incoming_stack_boundary)
1991 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
1994 /* Operand 0 is a pointer-to-function; get the type of the function. */
1995 funtype = TREE_TYPE (addr);
1996 gcc_assert (POINTER_TYPE_P (funtype));
1997 funtype = TREE_TYPE (funtype);
1999 /* Munge the tree to split complex arguments into their imaginary
2001 if (targetm.calls.split_complex_arg)
2003 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2004 actparms = split_complex_values (actparms);
2007 type_arg_types = TYPE_ARG_TYPES (funtype);
2009 if (flags & ECF_MAY_BE_ALLOCA)
2010 current_function_calls_alloca = 1;
2012 /* If struct_value_rtx is 0, it means pass the address
2013 as if it were an extra parameter. */
2014 if (structure_value_addr && struct_value == 0)
2016 /* If structure_value_addr is a REG other than
2017 virtual_outgoing_args_rtx, we can use always use it. If it
2018 is not a REG, we must always copy it into a register.
2019 If it is virtual_outgoing_args_rtx, we must copy it to another
2020 register in some cases. */
2021 rtx temp = (!REG_P (structure_value_addr)
2022 || (ACCUMULATE_OUTGOING_ARGS
2023 && stack_arg_under_construction
2024 && structure_value_addr == virtual_outgoing_args_rtx)
2025 ? copy_addr_to_reg (convert_memory_address
2026 (Pmode, structure_value_addr))
2027 : structure_value_addr);
2030 = tree_cons (error_mark_node,
2031 make_tree (build_pointer_type (TREE_TYPE (funtype)),
2034 structure_value_addr_parm = 1;
2037 /* Count the arguments and set NUM_ACTUALS. */
2038 for (p = actparms, num_actuals = 0; p; p = TREE_CHAIN (p))
2041 /* Compute number of named args.
2042 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2044 if (type_arg_types != 0)
2046 = (list_length (type_arg_types)
2047 /* Count the struct value address, if it is passed as a parm. */
2048 + structure_value_addr_parm);
2050 /* If we know nothing, treat all args as named. */
2051 n_named_args = num_actuals;
2053 /* Start updating where the next arg would go.
2055 On some machines (such as the PA) indirect calls have a different
2056 calling convention than normal calls. The fourth argument in
2057 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2059 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2061 /* Now possibly adjust the number of named args.
2062 Normally, don't include the last named arg if anonymous args follow.
2063 We do include the last named arg if
2064 targetm.calls.strict_argument_naming() returns nonzero.
2065 (If no anonymous args follow, the result of list_length is actually
2066 one too large. This is harmless.)
2068 If targetm.calls.pretend_outgoing_varargs_named() returns
2069 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2070 this machine will be able to place unnamed args that were passed
2071 in registers into the stack. So treat all args as named. This
2072 allows the insns emitting for a specific argument list to be
2073 independent of the function declaration.
2075 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2076 we do not have any reliable way to pass unnamed args in
2077 registers, so we must force them into memory. */
2079 if (type_arg_types != 0
2080 && targetm.calls.strict_argument_naming (&args_so_far))
2082 else if (type_arg_types != 0
2083 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2084 /* Don't include the last named arg. */
2087 /* Treat all args as named. */
2088 n_named_args = num_actuals;
2090 /* Make a vector to hold all the information about each arg. */
2091 args = alloca (num_actuals * sizeof (struct arg_data));
2092 memset (args, 0, num_actuals * sizeof (struct arg_data));
2094 /* Build up entries in the ARGS array, compute the size of the
2095 arguments into ARGS_SIZE, etc. */
2096 initialize_argument_information (num_actuals, args, &args_size,
2097 n_named_args, actparms, fndecl,
2098 &args_so_far, reg_parm_stack_space,
2099 &old_stack_level, &old_pending_adj,
2100 &must_preallocate, &flags,
2101 &try_tail_call, CALL_FROM_THUNK_P (exp));
2105 /* If this function requires a variable-sized argument list, don't
2106 try to make a cse'able block for this call. We may be able to
2107 do this eventually, but it is too complicated to keep track of
2108 what insns go in the cse'able block and which don't. */
2110 flags &= ~ECF_LIBCALL_BLOCK;
2111 must_preallocate = 1;
2114 /* Now make final decision about preallocating stack space. */
2115 must_preallocate = finalize_must_preallocate (must_preallocate,
2119 /* If the structure value address will reference the stack pointer, we
2120 must stabilize it. We don't need to do this if we know that we are
2121 not going to adjust the stack pointer in processing this call. */
2123 if (structure_value_addr
2124 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2125 || reg_mentioned_p (virtual_outgoing_args_rtx,
2126 structure_value_addr))
2128 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2129 structure_value_addr = copy_to_reg (structure_value_addr);
2131 /* Tail calls can make things harder to debug, and we've traditionally
2132 pushed these optimizations into -O2. Don't try if we're already
2133 expanding a call, as that means we're an argument. Don't try if
2134 there's cleanups, as we know there's code to follow the call. */
2136 if (currently_expanding_call++ != 0
2137 || !flag_optimize_sibling_calls
2139 || lookup_stmt_eh_region (exp) >= 0)
2142 /* Rest of purposes for tail call optimizations to fail. */
2144 #ifdef HAVE_sibcall_epilogue
2145 !HAVE_sibcall_epilogue
2150 /* Doing sibling call optimization needs some work, since
2151 structure_value_addr can be allocated on the stack.
2152 It does not seem worth the effort since few optimizable
2153 sibling calls will return a structure. */
2154 || structure_value_addr != NULL_RTX
2155 /* Check whether the target is able to optimize the call
2157 || !targetm.function_ok_for_sibcall (fndecl, exp)
2158 /* Functions that do not return exactly once may not be sibcall
2160 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2161 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2162 /* If the called function is nested in the current one, it might access
2163 some of the caller's arguments, but could clobber them beforehand if
2164 the argument areas are shared. */
2165 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2166 /* If this function requires more stack slots than the current
2167 function, we cannot change it into a sibling call.
2168 current_function_pretend_args_size is not part of the
2169 stack allocated by our caller. */
2170 || args_size.constant > (current_function_args_size
2171 - current_function_pretend_args_size)
2172 /* If the callee pops its own arguments, then it must pop exactly
2173 the same number of arguments as the current function. */
2174 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2175 != RETURN_POPS_ARGS (current_function_decl,
2176 TREE_TYPE (current_function_decl),
2177 current_function_args_size))
2178 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2181 /* Ensure current function's preferred stack boundary is at least
2182 what we need. We don't have to increase alignment for recursive
2184 if (cfun->preferred_stack_boundary < preferred_stack_boundary
2185 && fndecl != current_function_decl)
2186 cfun->preferred_stack_boundary = preferred_stack_boundary;
2187 if (fndecl == current_function_decl)
2188 cfun->recursive_call_emit = true;
2190 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2192 /* We want to make two insn chains; one for a sibling call, the other
2193 for a normal call. We will select one of the two chains after
2194 initial RTL generation is complete. */
2195 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2197 int sibcall_failure = 0;
2198 /* We want to emit any pending stack adjustments before the tail
2199 recursion "call". That way we know any adjustment after the tail
2200 recursion call can be ignored if we indeed use the tail
2202 int save_pending_stack_adjust = 0;
2203 int save_stack_pointer_delta = 0;
2205 rtx before_call, next_arg_reg;
2209 /* State variables we need to save and restore between
2211 save_pending_stack_adjust = pending_stack_adjust;
2212 save_stack_pointer_delta = stack_pointer_delta;
2215 flags &= ~ECF_SIBCALL;
2217 flags |= ECF_SIBCALL;
2219 /* Other state variables that we must reinitialize each time
2220 through the loop (that are not initialized by the loop itself). */
2224 /* Start a new sequence for the normal call case.
2226 From this point on, if the sibling call fails, we want to set
2227 sibcall_failure instead of continuing the loop. */
2230 /* Don't let pending stack adjusts add up to too much.
2231 Also, do all pending adjustments now if there is any chance
2232 this might be a call to alloca or if we are expanding a sibling
2233 call sequence or if we are calling a function that is to return
2234 with stack pointer depressed.
2235 Also do the adjustments before a throwing call, otherwise
2236 exception handling can fail; PR 19225. */
2237 if (pending_stack_adjust >= 32
2238 || (pending_stack_adjust > 0
2239 && (flags & (ECF_MAY_BE_ALLOCA | ECF_SP_DEPRESSED)))
2240 || (pending_stack_adjust > 0
2241 && flag_exceptions && !(flags & ECF_NOTHROW))
2243 do_pending_stack_adjust ();
2245 /* When calling a const function, we must pop the stack args right away,
2246 so that the pop is deleted or moved with the call. */
2247 if (pass && (flags & ECF_LIBCALL_BLOCK))
2250 /* Precompute any arguments as needed. */
2252 precompute_arguments (flags, num_actuals, args);
2254 /* Now we are about to start emitting insns that can be deleted
2255 if a libcall is deleted. */
2256 if (pass && (flags & (ECF_LIBCALL_BLOCK | ECF_MALLOC)))
2259 adjusted_args_size = args_size;
2260 /* Compute the actual size of the argument block required. The variable
2261 and constant sizes must be combined, the size may have to be rounded,
2262 and there may be a minimum required size. When generating a sibcall
2263 pattern, do not round up, since we'll be re-using whatever space our
2265 unadjusted_args_size
2266 = compute_argument_block_size (reg_parm_stack_space,
2267 &adjusted_args_size,
2269 : preferred_stack_boundary));
2271 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2273 /* The argument block when performing a sibling call is the
2274 incoming argument block. */
2277 argblock = virtual_incoming_args_rtx;
2279 #ifdef STACK_GROWS_DOWNWARD
2280 = plus_constant (argblock, current_function_pretend_args_size);
2282 = plus_constant (argblock, -current_function_pretend_args_size);
2284 stored_args_map = sbitmap_alloc (args_size.constant);
2285 sbitmap_zero (stored_args_map);
2288 /* If we have no actual push instructions, or shouldn't use them,
2289 make space for all args right now. */
2290 else if (adjusted_args_size.var != 0)
2292 if (old_stack_level == 0)
2294 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2295 old_stack_pointer_delta = stack_pointer_delta;
2296 old_pending_adj = pending_stack_adjust;
2297 pending_stack_adjust = 0;
2298 /* stack_arg_under_construction says whether a stack arg is
2299 being constructed at the old stack level. Pushing the stack
2300 gets a clean outgoing argument block. */
2301 old_stack_arg_under_construction = stack_arg_under_construction;
2302 stack_arg_under_construction = 0;
2304 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2308 /* Note that we must go through the motions of allocating an argument
2309 block even if the size is zero because we may be storing args
2310 in the area reserved for register arguments, which may be part of
2313 int needed = adjusted_args_size.constant;
2315 /* Store the maximum argument space used. It will be pushed by
2316 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2319 if (needed > current_function_outgoing_args_size)
2320 current_function_outgoing_args_size = needed;
2322 if (must_preallocate)
2324 if (ACCUMULATE_OUTGOING_ARGS)
2326 /* Since the stack pointer will never be pushed, it is
2327 possible for the evaluation of a parm to clobber
2328 something we have already written to the stack.
2329 Since most function calls on RISC machines do not use
2330 the stack, this is uncommon, but must work correctly.
2332 Therefore, we save any area of the stack that was already
2333 written and that we are using. Here we set up to do this
2334 by making a new stack usage map from the old one. The
2335 actual save will be done by store_one_arg.
2337 Another approach might be to try to reorder the argument
2338 evaluations to avoid this conflicting stack usage. */
2340 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2341 /* Since we will be writing into the entire argument area,
2342 the map must be allocated for its entire size, not just
2343 the part that is the responsibility of the caller. */
2344 needed += reg_parm_stack_space;
2347 #ifdef ARGS_GROW_DOWNWARD
2348 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2351 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2354 if (stack_usage_map_buf)
2355 free (stack_usage_map_buf);
2356 stack_usage_map_buf = xmalloc (highest_outgoing_arg_in_use);
2357 stack_usage_map = stack_usage_map_buf;
2359 if (initial_highest_arg_in_use)
2360 memcpy (stack_usage_map, initial_stack_usage_map,
2361 initial_highest_arg_in_use);
2363 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2364 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2365 (highest_outgoing_arg_in_use
2366 - initial_highest_arg_in_use));
2369 /* The address of the outgoing argument list must not be
2370 copied to a register here, because argblock would be left
2371 pointing to the wrong place after the call to
2372 allocate_dynamic_stack_space below. */
2374 argblock = virtual_outgoing_args_rtx;
2378 if (inhibit_defer_pop == 0)
2380 /* Try to reuse some or all of the pending_stack_adjust
2381 to get this space. */
2383 = (combine_pending_stack_adjustment_and_call
2384 (unadjusted_args_size,
2385 &adjusted_args_size,
2386 preferred_unit_stack_boundary));
2388 /* combine_pending_stack_adjustment_and_call computes
2389 an adjustment before the arguments are allocated.
2390 Account for them and see whether or not the stack
2391 needs to go up or down. */
2392 needed = unadjusted_args_size - needed;
2396 /* We're releasing stack space. */
2397 /* ??? We can avoid any adjustment at all if we're
2398 already aligned. FIXME. */
2399 pending_stack_adjust = -needed;
2400 do_pending_stack_adjust ();
2404 /* We need to allocate space. We'll do that in
2405 push_block below. */
2406 pending_stack_adjust = 0;
2409 /* Special case this because overhead of `push_block' in
2410 this case is non-trivial. */
2412 argblock = virtual_outgoing_args_rtx;
2415 argblock = push_block (GEN_INT (needed), 0, 0);
2416 #ifdef ARGS_GROW_DOWNWARD
2417 argblock = plus_constant (argblock, needed);
2421 /* We only really need to call `copy_to_reg' in the case
2422 where push insns are going to be used to pass ARGBLOCK
2423 to a function call in ARGS. In that case, the stack
2424 pointer changes value from the allocation point to the
2425 call point, and hence the value of
2426 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2427 as well always do it. */
2428 argblock = copy_to_reg (argblock);
2433 if (ACCUMULATE_OUTGOING_ARGS)
2435 /* The save/restore code in store_one_arg handles all
2436 cases except one: a constructor call (including a C
2437 function returning a BLKmode struct) to initialize
2439 if (stack_arg_under_construction)
2441 #ifndef OUTGOING_REG_PARM_STACK_SPACE
2442 rtx push_size = GEN_INT (reg_parm_stack_space
2443 + adjusted_args_size.constant);
2445 rtx push_size = GEN_INT (adjusted_args_size.constant);
2447 if (old_stack_level == 0)
2449 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2451 old_stack_pointer_delta = stack_pointer_delta;
2452 old_pending_adj = pending_stack_adjust;
2453 pending_stack_adjust = 0;
2454 /* stack_arg_under_construction says whether a stack
2455 arg is being constructed at the old stack level.
2456 Pushing the stack gets a clean outgoing argument
2458 old_stack_arg_under_construction
2459 = stack_arg_under_construction;
2460 stack_arg_under_construction = 0;
2461 /* Make a new map for the new argument list. */
2462 if (stack_usage_map_buf)
2463 free (stack_usage_map_buf);
2464 stack_usage_map_buf = xmalloc (highest_outgoing_arg_in_use);
2465 stack_usage_map = stack_usage_map_buf;
2466 memset (stack_usage_map, 0, highest_outgoing_arg_in_use);
2467 highest_outgoing_arg_in_use = 0;
2469 allocate_dynamic_stack_space (push_size, NULL_RTX,
2473 /* If argument evaluation might modify the stack pointer,
2474 copy the address of the argument list to a register. */
2475 for (i = 0; i < num_actuals; i++)
2476 if (args[i].pass_on_stack)
2478 argblock = copy_addr_to_reg (argblock);
2483 compute_argument_addresses (args, argblock, num_actuals);
2485 /* If we push args individually in reverse order, perform stack alignment
2486 before the first push (the last arg). */
2487 if (PUSH_ARGS_REVERSED && argblock == 0
2488 && adjusted_args_size.constant != unadjusted_args_size)
2490 /* When the stack adjustment is pending, we get better code
2491 by combining the adjustments. */
2492 if (pending_stack_adjust
2493 && ! (flags & ECF_LIBCALL_BLOCK)
2494 && ! inhibit_defer_pop)
2496 pending_stack_adjust
2497 = (combine_pending_stack_adjustment_and_call
2498 (unadjusted_args_size,
2499 &adjusted_args_size,
2500 preferred_unit_stack_boundary));
2501 do_pending_stack_adjust ();
2503 else if (argblock == 0)
2504 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2505 - unadjusted_args_size));
2507 /* Now that the stack is properly aligned, pops can't safely
2508 be deferred during the evaluation of the arguments. */
2511 funexp = rtx_for_function_call (fndecl, addr);
2513 /* Figure out the register where the value, if any, will come back. */
2515 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2516 && ! structure_value_addr)
2518 if (pcc_struct_value)
2519 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2520 fndecl, NULL, (pass == 0));
2522 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2526 /* Precompute all register parameters. It isn't safe to compute anything
2527 once we have started filling any specific hard regs. */
2528 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2530 if (TREE_OPERAND (exp, 2))
2531 static_chain_value = expand_expr (TREE_OPERAND (exp, 2),
2532 NULL_RTX, VOIDmode, 0);
2534 static_chain_value = 0;
2536 #ifdef REG_PARM_STACK_SPACE
2537 /* Save the fixed argument area if it's part of the caller's frame and
2538 is clobbered by argument setup for this call. */
2539 if (ACCUMULATE_OUTGOING_ARGS && pass)
2540 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2541 &low_to_save, &high_to_save);
2544 /* Now store (and compute if necessary) all non-register parms.
2545 These come before register parms, since they can require block-moves,
2546 which could clobber the registers used for register parms.
2547 Parms which have partial registers are not stored here,
2548 but we do preallocate space here if they want that. */
2550 for (i = 0; i < num_actuals; i++)
2551 if (args[i].reg == 0 || args[i].pass_on_stack)
2553 rtx before_arg = get_last_insn ();
2555 if (store_one_arg (&args[i], argblock, flags,
2556 adjusted_args_size.var != 0,
2557 reg_parm_stack_space)
2559 && check_sibcall_argument_overlap (before_arg,
2561 sibcall_failure = 1;
2563 if (flags & ECF_CONST
2565 && args[i].value == args[i].stack)
2566 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2567 gen_rtx_USE (VOIDmode,
2572 /* If we have a parm that is passed in registers but not in memory
2573 and whose alignment does not permit a direct copy into registers,
2574 make a group of pseudos that correspond to each register that we
2576 if (STRICT_ALIGNMENT)
2577 store_unaligned_arguments_into_pseudos (args, num_actuals);
2579 /* Now store any partially-in-registers parm.
2580 This is the last place a block-move can happen. */
2582 for (i = 0; i < num_actuals; i++)
2583 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2585 rtx before_arg = get_last_insn ();
2587 if (store_one_arg (&args[i], argblock, flags,
2588 adjusted_args_size.var != 0,
2589 reg_parm_stack_space)
2591 && check_sibcall_argument_overlap (before_arg,
2593 sibcall_failure = 1;
2596 /* If we pushed args in forward order, perform stack alignment
2597 after pushing the last arg. */
2598 if (!PUSH_ARGS_REVERSED && argblock == 0)
2599 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2600 - unadjusted_args_size));
2602 /* If register arguments require space on the stack and stack space
2603 was not preallocated, allocate stack space here for arguments
2604 passed in registers. */
2605 #ifdef OUTGOING_REG_PARM_STACK_SPACE
2606 if (!ACCUMULATE_OUTGOING_ARGS
2607 && must_preallocate == 0 && reg_parm_stack_space > 0)
2608 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2611 /* Pass the function the address in which to return a
2613 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2615 structure_value_addr
2616 = convert_memory_address (Pmode, structure_value_addr);
2617 emit_move_insn (struct_value,
2619 force_operand (structure_value_addr,
2622 if (REG_P (struct_value))
2623 use_reg (&call_fusage, struct_value);
2626 funexp = prepare_call_address (funexp, static_chain_value,
2627 &call_fusage, reg_parm_seen, pass == 0);
2629 load_register_parameters (args, num_actuals, &call_fusage, flags,
2630 pass == 0, &sibcall_failure);
2632 /* Save a pointer to the last insn before the call, so that we can
2633 later safely search backwards to find the CALL_INSN. */
2634 before_call = get_last_insn ();
2636 /* Set up next argument register. For sibling calls on machines
2637 with register windows this should be the incoming register. */
2638 #ifdef FUNCTION_INCOMING_ARG
2640 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2644 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2647 /* All arguments and registers used for the call must be set up by
2650 /* Stack must be properly aligned now. */
2652 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2654 /* Generate the actual call instruction. */
2655 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2656 adjusted_args_size.constant, struct_value_size,
2657 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2658 flags, & args_so_far);
2660 /* If a non-BLKmode value is returned at the most significant end
2661 of a register, shift the register right by the appropriate amount
2662 and update VALREG accordingly. BLKmode values are handled by the
2663 group load/store machinery below. */
2664 if (!structure_value_addr
2665 && !pcc_struct_value
2666 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2667 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2669 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2670 sibcall_failure = 1;
2671 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2674 /* If call is cse'able, make appropriate pair of reg-notes around it.
2675 Test valreg so we don't crash; may safely ignore `const'
2676 if return type is void. Disable for PARALLEL return values, because
2677 we have no way to move such values into a pseudo register. */
2678 if (pass && (flags & ECF_LIBCALL_BLOCK))
2682 bool failed = valreg == 0 || GET_CODE (valreg) == PARALLEL;
2684 insns = get_insns ();
2686 /* Expansion of block moves possibly introduced a loop that may
2687 not appear inside libcall block. */
2688 for (insn = insns; insn; insn = NEXT_INSN (insn))
2700 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2702 /* Mark the return value as a pointer if needed. */
2703 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2704 mark_reg_pointer (temp,
2705 TYPE_ALIGN (TREE_TYPE (TREE_TYPE (exp))));
2708 if (flag_unsafe_math_optimizations
2710 && DECL_BUILT_IN_CLASS (fndecl) == BUILT_IN_NORMAL
2711 && (DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRT
2712 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTF
2713 || DECL_FUNCTION_CODE (fndecl) == BUILT_IN_SQRTL))
2714 note = gen_rtx_fmt_e (SQRT,
2716 args[0].initial_value);
2719 /* Construct an "equal form" for the value which
2720 mentions all the arguments in order as well as
2721 the function name. */
2722 for (i = 0; i < num_actuals; i++)
2723 note = gen_rtx_EXPR_LIST (VOIDmode,
2724 args[i].initial_value, note);
2725 note = gen_rtx_EXPR_LIST (VOIDmode, funexp, note);
2727 if (flags & ECF_PURE)
2728 note = gen_rtx_EXPR_LIST (VOIDmode,
2729 gen_rtx_USE (VOIDmode,
2730 gen_rtx_MEM (BLKmode,
2731 gen_rtx_SCRATCH (VOIDmode))),
2734 emit_libcall_block (insns, temp, valreg, note);
2739 else if (pass && (flags & ECF_MALLOC))
2741 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2744 /* The return value from a malloc-like function is a pointer. */
2745 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2746 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2748 emit_move_insn (temp, valreg);
2750 /* The return value from a malloc-like function can not alias
2752 last = get_last_insn ();
2754 gen_rtx_EXPR_LIST (REG_NOALIAS, temp, REG_NOTES (last));
2756 /* Write out the sequence. */
2757 insns = get_insns ();
2763 /* For calls to `setjmp', etc., inform flow.c it should complain
2764 if nonvolatile values are live. For functions that cannot return,
2765 inform flow that control does not fall through. */
2767 if ((flags & ECF_NORETURN) || pass == 0)
2769 /* The barrier must be emitted
2770 immediately after the CALL_INSN. Some ports emit more
2771 than just a CALL_INSN above, so we must search for it here. */
2773 rtx last = get_last_insn ();
2774 while (!CALL_P (last))
2776 last = PREV_INSN (last);
2777 /* There was no CALL_INSN? */
2778 gcc_assert (last != before_call);
2781 emit_barrier_after (last);
2783 /* Stack adjustments after a noreturn call are dead code.
2784 However when NO_DEFER_POP is in effect, we must preserve
2785 stack_pointer_delta. */
2786 if (inhibit_defer_pop == 0)
2788 stack_pointer_delta = old_stack_allocated;
2789 pending_stack_adjust = 0;
2793 /* If value type not void, return an rtx for the value. */
2795 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2797 target = const0_rtx;
2798 else if (structure_value_addr)
2800 if (target == 0 || !MEM_P (target))
2803 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2804 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2805 structure_value_addr));
2806 set_mem_attributes (target, exp, 1);
2809 else if (pcc_struct_value)
2811 /* This is the special C++ case where we need to
2812 know what the true target was. We take care to
2813 never use this value more than once in one expression. */
2814 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2815 copy_to_reg (valreg));
2816 set_mem_attributes (target, exp, 1);
2818 /* Handle calls that return values in multiple non-contiguous locations.
2819 The Irix 6 ABI has examples of this. */
2820 else if (GET_CODE (valreg) == PARALLEL)
2824 /* This will only be assigned once, so it can be readonly. */
2825 tree nt = build_qualified_type (TREE_TYPE (exp),
2826 (TYPE_QUALS (TREE_TYPE (exp))
2827 | TYPE_QUAL_CONST));
2829 target = assign_temp (nt, 0, 1, 1);
2832 if (! rtx_equal_p (target, valreg))
2833 emit_group_store (target, valreg, TREE_TYPE (exp),
2834 int_size_in_bytes (TREE_TYPE (exp)));
2836 /* We can not support sibling calls for this case. */
2837 sibcall_failure = 1;
2840 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2841 && GET_MODE (target) == GET_MODE (valreg))
2843 /* TARGET and VALREG cannot be equal at this point because the
2844 latter would not have REG_FUNCTION_VALUE_P true, while the
2845 former would if it were referring to the same register.
2847 If they refer to the same register, this move will be a no-op,
2848 except when function inlining is being done. */
2849 emit_move_insn (target, valreg);
2851 /* If we are setting a MEM, this code must be executed. Since it is
2852 emitted after the call insn, sibcall optimization cannot be
2853 performed in that case. */
2855 sibcall_failure = 1;
2857 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2859 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2861 /* We can not support sibling calls for this case. */
2862 sibcall_failure = 1;
2865 target = copy_to_reg (valreg);
2867 if (targetm.calls.promote_function_return(funtype))
2869 /* If we promoted this return value, make the proper SUBREG.
2870 TARGET might be const0_rtx here, so be careful. */
2872 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2873 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2875 tree type = TREE_TYPE (exp);
2876 int unsignedp = TYPE_UNSIGNED (type);
2878 enum machine_mode pmode;
2880 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2881 /* If we don't promote as expected, something is wrong. */
2882 gcc_assert (GET_MODE (target) == pmode);
2884 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2885 && (GET_MODE_SIZE (GET_MODE (target))
2886 > GET_MODE_SIZE (TYPE_MODE (type))))
2888 offset = GET_MODE_SIZE (GET_MODE (target))
2889 - GET_MODE_SIZE (TYPE_MODE (type));
2890 if (! BYTES_BIG_ENDIAN)
2891 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
2892 else if (! WORDS_BIG_ENDIAN)
2893 offset %= UNITS_PER_WORD;
2895 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
2896 SUBREG_PROMOTED_VAR_P (target) = 1;
2897 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
2901 /* If size of args is variable or this was a constructor call for a stack
2902 argument, restore saved stack-pointer value. */
2904 if (old_stack_level && ! (flags & ECF_SP_DEPRESSED))
2906 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2907 stack_pointer_delta = old_stack_pointer_delta;
2908 pending_stack_adjust = old_pending_adj;
2909 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2910 stack_arg_under_construction = old_stack_arg_under_construction;
2911 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2912 stack_usage_map = initial_stack_usage_map;
2913 sibcall_failure = 1;
2915 else if (ACCUMULATE_OUTGOING_ARGS && pass)
2917 #ifdef REG_PARM_STACK_SPACE
2919 restore_fixed_argument_area (save_area, argblock,
2920 high_to_save, low_to_save);
2923 /* If we saved any argument areas, restore them. */
2924 for (i = 0; i < num_actuals; i++)
2925 if (args[i].save_area)
2927 enum machine_mode save_mode = GET_MODE (args[i].save_area);
2929 = gen_rtx_MEM (save_mode,
2930 memory_address (save_mode,
2931 XEXP (args[i].stack_slot, 0)));
2933 if (save_mode != BLKmode)
2934 emit_move_insn (stack_area, args[i].save_area);
2936 emit_block_move (stack_area, args[i].save_area,
2937 GEN_INT (args[i].locate.size.constant),
2938 BLOCK_OP_CALL_PARM);
2941 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
2942 stack_usage_map = initial_stack_usage_map;
2945 /* If this was alloca, record the new stack level for nonlocal gotos.
2946 Check for the handler slots since we might not have a save area
2947 for non-local gotos. */
2949 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
2950 update_nonlocal_goto_save_area ();
2952 /* Free up storage we no longer need. */
2953 for (i = 0; i < num_actuals; ++i)
2954 if (args[i].aligned_regs)
2955 free (args[i].aligned_regs);
2957 insns = get_insns ();
2962 tail_call_insns = insns;
2964 /* Restore the pending stack adjustment now that we have
2965 finished generating the sibling call sequence. */
2967 pending_stack_adjust = save_pending_stack_adjust;
2968 stack_pointer_delta = save_stack_pointer_delta;
2970 /* Prepare arg structure for next iteration. */
2971 for (i = 0; i < num_actuals; i++)
2974 args[i].aligned_regs = 0;
2978 sbitmap_free (stored_args_map);
2982 normal_call_insns = insns;
2984 /* Verify that we've deallocated all the stack we used. */
2985 gcc_assert ((flags & ECF_NORETURN)
2986 || (old_stack_allocated
2987 == stack_pointer_delta - pending_stack_adjust));
2990 /* If something prevents making this a sibling call,
2991 zero out the sequence. */
2992 if (sibcall_failure)
2993 tail_call_insns = NULL_RTX;
2998 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
2999 arguments too, as argument area is now clobbered by the call. */
3000 if (tail_call_insns)
3002 emit_insn (tail_call_insns);
3003 cfun->tail_call_emit = true;
3006 emit_insn (normal_call_insns);
3008 currently_expanding_call--;
3010 /* If this function returns with the stack pointer depressed, ensure
3011 this block saves and restores the stack pointer, show it was
3012 changed, and adjust for any outgoing arg space. */
3013 if (flags & ECF_SP_DEPRESSED)
3015 clear_pending_stack_adjust ();
3016 emit_insn (gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx));
3017 emit_move_insn (virtual_stack_dynamic_rtx, stack_pointer_rtx);
3020 if (stack_usage_map_buf)
3021 free (stack_usage_map_buf);
3026 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3027 this function's incoming arguments.
3029 At the start of RTL generation we know the only REG_EQUIV notes
3030 in the rtl chain are those for incoming arguments, so we can look
3031 for REG_EQUIV notes between the start of the function and the
3032 NOTE_INSN_FUNCTION_BEG.
3034 This is (slight) overkill. We could keep track of the highest
3035 argument we clobber and be more selective in removing notes, but it
3036 does not seem to be worth the effort. */
3039 fixup_tail_calls (void)
3043 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3045 /* There are never REG_EQUIV notes for the incoming arguments
3046 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3048 && NOTE_LINE_NUMBER (insn) == NOTE_INSN_FUNCTION_BEG)
3053 rtx note = find_reg_note (insn, REG_EQUIV, 0);
3056 /* Remove the note and keep looking at the notes for
3058 remove_note (insn, note);
3066 /* Traverse an argument list in VALUES and expand all complex
3067 arguments into their components. */
3069 split_complex_values (tree values)
3073 /* Before allocating memory, check for the common case of no complex. */
3074 for (p = values; p; p = TREE_CHAIN (p))
3076 tree type = TREE_TYPE (TREE_VALUE (p));
3077 if (type && TREE_CODE (type) == COMPLEX_TYPE
3078 && targetm.calls.split_complex_arg (type))
3084 values = copy_list (values);
3086 for (p = values; p; p = TREE_CHAIN (p))
3088 tree complex_value = TREE_VALUE (p);
3091 complex_type = TREE_TYPE (complex_value);
3095 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3096 && targetm.calls.split_complex_arg (complex_type))
3099 tree real, imag, next;
3101 subtype = TREE_TYPE (complex_type);
3102 complex_value = save_expr (complex_value);
3103 real = build1 (REALPART_EXPR, subtype, complex_value);
3104 imag = build1 (IMAGPART_EXPR, subtype, complex_value);
3106 TREE_VALUE (p) = real;
3107 next = TREE_CHAIN (p);
3108 imag = build_tree_list (NULL_TREE, imag);
3109 TREE_CHAIN (p) = imag;
3110 TREE_CHAIN (imag) = next;
3112 /* Skip the newly created node. */
3120 /* Traverse a list of TYPES and expand all complex types into their
3123 split_complex_types (tree types)
3127 /* Before allocating memory, check for the common case of no complex. */
3128 for (p = types; p; p = TREE_CHAIN (p))
3130 tree type = TREE_VALUE (p);
3131 if (TREE_CODE (type) == COMPLEX_TYPE
3132 && targetm.calls.split_complex_arg (type))
3138 types = copy_list (types);
3140 for (p = types; p; p = TREE_CHAIN (p))
3142 tree complex_type = TREE_VALUE (p);
3144 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3145 && targetm.calls.split_complex_arg (complex_type))
3149 /* Rewrite complex type with component type. */
3150 TREE_VALUE (p) = TREE_TYPE (complex_type);
3151 next = TREE_CHAIN (p);
3153 /* Add another component type for the imaginary part. */
3154 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3155 TREE_CHAIN (p) = imag;
3156 TREE_CHAIN (imag) = next;
3158 /* Skip the newly created node. */
3166 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3167 The RETVAL parameter specifies whether return value needs to be saved, other
3168 parameters are documented in the emit_library_call function below. */
3171 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3172 enum libcall_type fn_type,
3173 enum machine_mode outmode, int nargs, va_list p)
3175 /* Total size in bytes of all the stack-parms scanned so far. */
3176 struct args_size args_size;
3177 /* Size of arguments before any adjustments (such as rounding). */
3178 struct args_size original_args_size;
3184 CUMULATIVE_ARGS args_so_far;
3188 enum machine_mode mode;
3191 struct locate_and_pad_arg_data locate;
3195 int old_inhibit_defer_pop = inhibit_defer_pop;
3196 rtx call_fusage = 0;
3199 int pcc_struct_value = 0;
3200 int struct_value_size = 0;
3202 int reg_parm_stack_space = 0;
3205 tree tfom; /* type_for_mode (outmode, 0) */
3207 #ifdef REG_PARM_STACK_SPACE
3208 /* Define the boundary of the register parm stack space that needs to be
3210 int low_to_save, high_to_save;
3211 rtx save_area = 0; /* Place that it is saved. */
3214 /* Size of the stack reserved for parameter registers. */
3215 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3216 char *initial_stack_usage_map = stack_usage_map;
3217 char *stack_usage_map_buf = NULL;
3219 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3221 #ifdef REG_PARM_STACK_SPACE
3222 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3225 /* By default, library functions can not throw. */
3226 flags = ECF_NOTHROW;
3238 case LCT_CONST_MAKE_BLOCK:
3239 flags |= ECF_CONST | ECF_LIBCALL_BLOCK;
3241 case LCT_PURE_MAKE_BLOCK:
3242 flags |= ECF_PURE | ECF_LIBCALL_BLOCK;
3245 flags |= ECF_NORETURN;
3248 flags = ECF_NORETURN;
3250 case LCT_RETURNS_TWICE:
3251 flags = ECF_RETURNS_TWICE;
3256 /* Ensure current function's preferred stack boundary is at least
3258 if (cfun->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3259 cfun->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3261 /* If this kind of value comes back in memory,
3262 decide where in memory it should come back. */
3263 if (outmode != VOIDmode)
3265 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3266 if (aggregate_value_p (tfom, 0))
3268 #ifdef PCC_STATIC_STRUCT_RETURN
3270 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3271 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3272 pcc_struct_value = 1;
3274 value = gen_reg_rtx (outmode);
3275 #else /* not PCC_STATIC_STRUCT_RETURN */
3276 struct_value_size = GET_MODE_SIZE (outmode);
3277 if (value != 0 && MEM_P (value))
3280 mem_value = assign_temp (tfom, 0, 1, 1);
3282 /* This call returns a big structure. */
3283 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3287 tfom = void_type_node;
3289 /* ??? Unfinished: must pass the memory address as an argument. */
3291 /* Copy all the libcall-arguments out of the varargs data
3292 and into a vector ARGVEC.
3294 Compute how to pass each argument. We only support a very small subset
3295 of the full argument passing conventions to limit complexity here since
3296 library functions shouldn't have many args. */
3298 argvec = alloca ((nargs + 1) * sizeof (struct arg));
3299 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3301 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3302 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3304 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3307 args_size.constant = 0;
3312 /* Now we are about to start emitting insns that can be deleted
3313 if a libcall is deleted. */
3314 if (flags & ECF_LIBCALL_BLOCK)
3319 /* If there's a structure value address to be passed,
3320 either pass it in the special place, or pass it as an extra argument. */
3321 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3323 rtx addr = XEXP (mem_value, 0);
3327 /* Make sure it is a reasonable operand for a move or push insn. */
3328 if (!REG_P (addr) && !MEM_P (addr)
3329 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3330 addr = force_operand (addr, NULL_RTX);
3332 argvec[count].value = addr;
3333 argvec[count].mode = Pmode;
3334 argvec[count].partial = 0;
3336 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3337 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3338 NULL_TREE, 1) == 0);
3340 locate_and_pad_parm (Pmode, NULL_TREE,
3341 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3344 argvec[count].reg != 0,
3346 0, NULL_TREE, &args_size, &argvec[count].locate);
3348 if (argvec[count].reg == 0 || argvec[count].partial != 0
3349 || reg_parm_stack_space > 0)
3350 args_size.constant += argvec[count].locate.size.constant;
3352 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3357 for (; count < nargs; count++)
3359 rtx val = va_arg (p, rtx);
3360 enum machine_mode mode = va_arg (p, enum machine_mode);
3362 /* We cannot convert the arg value to the mode the library wants here;
3363 must do it earlier where we know the signedness of the arg. */
3364 gcc_assert (mode != BLKmode
3365 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3367 /* Make sure it is a reasonable operand for a move or push insn. */
3368 if (!REG_P (val) && !MEM_P (val)
3369 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3370 val = force_operand (val, NULL_RTX);
3372 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3376 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3378 /* loop.c won't look at CALL_INSN_FUNCTION_USAGE of const/pure
3379 functions, so we have to pretend this isn't such a function. */
3380 if (flags & ECF_LIBCALL_BLOCK)
3382 rtx insns = get_insns ();
3386 flags &= ~(ECF_CONST | ECF_PURE | ECF_LIBCALL_BLOCK);
3388 /* If this was a CONST function, it is now PURE since
3389 it now reads memory. */
3390 if (flags & ECF_CONST)
3392 flags &= ~ECF_CONST;
3396 if (GET_MODE (val) == MEM && !must_copy)
3400 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3402 emit_move_insn (slot, val);
3405 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3406 gen_rtx_USE (VOIDmode, slot),
3409 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3410 gen_rtx_CLOBBER (VOIDmode,
3415 val = force_operand (XEXP (slot, 0), NULL_RTX);
3418 argvec[count].value = val;
3419 argvec[count].mode = mode;
3421 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3423 argvec[count].partial
3424 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3426 locate_and_pad_parm (mode, NULL_TREE,
3427 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3430 argvec[count].reg != 0,
3432 argvec[count].partial,
3433 NULL_TREE, &args_size, &argvec[count].locate);
3435 gcc_assert (!argvec[count].locate.size.var);
3437 if (argvec[count].reg == 0 || argvec[count].partial != 0
3438 || reg_parm_stack_space > 0)
3439 args_size.constant += argvec[count].locate.size.constant;
3441 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3444 /* If this machine requires an external definition for library
3445 functions, write one out. */
3446 assemble_external_libcall (fun);
3448 original_args_size = args_size;
3449 args_size.constant = (((args_size.constant
3450 + stack_pointer_delta
3454 - stack_pointer_delta);
3456 args_size.constant = MAX (args_size.constant,
3457 reg_parm_stack_space);
3459 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3460 args_size.constant -= reg_parm_stack_space;
3463 if (args_size.constant > current_function_outgoing_args_size)
3464 current_function_outgoing_args_size = args_size.constant;
3466 if (ACCUMULATE_OUTGOING_ARGS)
3468 /* Since the stack pointer will never be pushed, it is possible for
3469 the evaluation of a parm to clobber something we have already
3470 written to the stack. Since most function calls on RISC machines
3471 do not use the stack, this is uncommon, but must work correctly.
3473 Therefore, we save any area of the stack that was already written
3474 and that we are using. Here we set up to do this by making a new
3475 stack usage map from the old one.
3477 Another approach might be to try to reorder the argument
3478 evaluations to avoid this conflicting stack usage. */
3480 needed = args_size.constant;
3482 #ifndef OUTGOING_REG_PARM_STACK_SPACE
3483 /* Since we will be writing into the entire argument area, the
3484 map must be allocated for its entire size, not just the part that
3485 is the responsibility of the caller. */
3486 needed += reg_parm_stack_space;
3489 #ifdef ARGS_GROW_DOWNWARD
3490 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3493 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3496 stack_usage_map_buf = xmalloc (highest_outgoing_arg_in_use);
3497 stack_usage_map = stack_usage_map_buf;
3499 if (initial_highest_arg_in_use)
3500 memcpy (stack_usage_map, initial_stack_usage_map,
3501 initial_highest_arg_in_use);
3503 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3504 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3505 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3508 /* We must be careful to use virtual regs before they're instantiated,
3509 and real regs afterwards. Loop optimization, for example, can create
3510 new libcalls after we've instantiated the virtual regs, and if we
3511 use virtuals anyway, they won't match the rtl patterns. */
3513 if (virtuals_instantiated)
3514 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3516 argblock = virtual_outgoing_args_rtx;
3521 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3524 /* If we push args individually in reverse order, perform stack alignment
3525 before the first push (the last arg). */
3526 if (argblock == 0 && PUSH_ARGS_REVERSED)
3527 anti_adjust_stack (GEN_INT (args_size.constant
3528 - original_args_size.constant));
3530 if (PUSH_ARGS_REVERSED)
3541 #ifdef REG_PARM_STACK_SPACE
3542 if (ACCUMULATE_OUTGOING_ARGS)
3544 /* The argument list is the property of the called routine and it
3545 may clobber it. If the fixed area has been used for previous
3546 parameters, we must save and restore it. */
3547 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3548 &low_to_save, &high_to_save);
3552 /* Push the args that need to be pushed. */
3554 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3555 are to be pushed. */
3556 for (count = 0; count < nargs; count++, argnum += inc)
3558 enum machine_mode mode = argvec[argnum].mode;
3559 rtx val = argvec[argnum].value;
3560 rtx reg = argvec[argnum].reg;
3561 int partial = argvec[argnum].partial;
3562 int lower_bound = 0, upper_bound = 0, i;
3564 if (! (reg != 0 && partial == 0))
3566 if (ACCUMULATE_OUTGOING_ARGS)
3568 /* If this is being stored into a pre-allocated, fixed-size,
3569 stack area, save any previous data at that location. */
3571 #ifdef ARGS_GROW_DOWNWARD
3572 /* stack_slot is negative, but we want to index stack_usage_map
3573 with positive values. */
3574 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3575 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3577 lower_bound = argvec[argnum].locate.offset.constant;
3578 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3582 /* Don't worry about things in the fixed argument area;
3583 it has already been saved. */
3584 if (i < reg_parm_stack_space)
3585 i = reg_parm_stack_space;
3586 while (i < upper_bound && stack_usage_map[i] == 0)
3589 if (i < upper_bound)
3591 /* We need to make a save area. */
3593 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3594 enum machine_mode save_mode
3595 = mode_for_size (size, MODE_INT, 1);
3597 = plus_constant (argblock,
3598 argvec[argnum].locate.offset.constant);
3600 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3602 if (save_mode == BLKmode)
3604 argvec[argnum].save_area
3605 = assign_stack_temp (BLKmode,
3606 argvec[argnum].locate.size.constant,
3609 emit_block_move (validize_mem (argvec[argnum].save_area),
3611 GEN_INT (argvec[argnum].locate.size.constant),
3612 BLOCK_OP_CALL_PARM);
3616 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3618 emit_move_insn (argvec[argnum].save_area, stack_area);
3623 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3624 partial, reg, 0, argblock,
3625 GEN_INT (argvec[argnum].locate.offset.constant),
3626 reg_parm_stack_space,
3627 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3629 /* Now mark the segment we just used. */
3630 if (ACCUMULATE_OUTGOING_ARGS)
3631 for (i = lower_bound; i < upper_bound; i++)
3632 stack_usage_map[i] = 1;
3638 /* If we pushed args in forward order, perform stack alignment
3639 after pushing the last arg. */
3640 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3641 anti_adjust_stack (GEN_INT (args_size.constant
3642 - original_args_size.constant));
3644 if (PUSH_ARGS_REVERSED)
3649 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3651 /* Now load any reg parms into their regs. */
3653 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3654 are to be pushed. */
3655 for (count = 0; count < nargs; count++, argnum += inc)
3657 enum machine_mode mode = argvec[argnum].mode;
3658 rtx val = argvec[argnum].value;
3659 rtx reg = argvec[argnum].reg;
3660 int partial = argvec[argnum].partial;
3662 /* Handle calls that pass values in multiple non-contiguous
3663 locations. The PA64 has examples of this for library calls. */
3664 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3665 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3666 else if (reg != 0 && partial == 0)
3667 emit_move_insn (reg, val);
3672 /* Any regs containing parms remain in use through the call. */
3673 for (count = 0; count < nargs; count++)
3675 rtx reg = argvec[count].reg;
3676 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3677 use_group_regs (&call_fusage, reg);
3679 use_reg (&call_fusage, reg);
3682 /* Pass the function the address in which to return a structure value. */
3683 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3685 emit_move_insn (struct_value,
3687 force_operand (XEXP (mem_value, 0),
3689 if (REG_P (struct_value))
3690 use_reg (&call_fusage, struct_value);
3693 /* Don't allow popping to be deferred, since then
3694 cse'ing of library calls could delete a call and leave the pop. */
3696 valreg = (mem_value == 0 && outmode != VOIDmode
3697 ? hard_libcall_value (outmode) : NULL_RTX);
3699 /* Stack must be properly aligned now. */
3700 gcc_assert (!(stack_pointer_delta
3701 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3703 before_call = get_last_insn ();
3705 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3706 will set inhibit_defer_pop to that value. */
3707 /* The return type is needed to decide how many bytes the function pops.
3708 Signedness plays no role in that, so for simplicity, we pretend it's
3709 always signed. We also assume that the list of arguments passed has
3710 no impact, so we pretend it is unknown. */
3712 emit_call_1 (fun, NULL,
3713 get_identifier (XSTR (orgfun, 0)),
3714 build_function_type (tfom, NULL_TREE),
3715 original_args_size.constant, args_size.constant,
3717 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3719 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3721 /* For calls to `setjmp', etc., inform flow.c it should complain
3722 if nonvolatile values are live. For functions that cannot return,
3723 inform flow that control does not fall through. */
3725 if (flags & ECF_NORETURN)
3727 /* The barrier note must be emitted
3728 immediately after the CALL_INSN. Some ports emit more than
3729 just a CALL_INSN above, so we must search for it here. */
3731 rtx last = get_last_insn ();
3732 while (!CALL_P (last))
3734 last = PREV_INSN (last);
3735 /* There was no CALL_INSN? */
3736 gcc_assert (last != before_call);
3739 emit_barrier_after (last);
3742 /* Now restore inhibit_defer_pop to its actual original value. */
3745 /* If call is cse'able, make appropriate pair of reg-notes around it.
3746 Test valreg so we don't crash; may safely ignore `const'
3747 if return type is void. Disable for PARALLEL return values, because
3748 we have no way to move such values into a pseudo register. */
3749 if (flags & ECF_LIBCALL_BLOCK)
3755 insns = get_insns ();
3765 if (GET_CODE (valreg) == PARALLEL)
3767 temp = gen_reg_rtx (outmode);
3768 emit_group_store (temp, valreg, NULL_TREE,
3769 GET_MODE_SIZE (outmode));
3773 temp = gen_reg_rtx (GET_MODE (valreg));
3775 /* Construct an "equal form" for the value which mentions all the
3776 arguments in order as well as the function name. */
3777 for (i = 0; i < nargs; i++)
3778 note = gen_rtx_EXPR_LIST (VOIDmode, argvec[i].value, note);
3779 note = gen_rtx_EXPR_LIST (VOIDmode, fun, note);
3781 insns = get_insns ();
3784 if (flags & ECF_PURE)
3785 note = gen_rtx_EXPR_LIST (VOIDmode,
3786 gen_rtx_USE (VOIDmode,
3787 gen_rtx_MEM (BLKmode,
3788 gen_rtx_SCRATCH (VOIDmode))),
3791 emit_libcall_block (insns, temp, valreg, note);
3798 /* Copy the value to the right place. */
3799 if (outmode != VOIDmode && retval)
3805 if (value != mem_value)
3806 emit_move_insn (value, mem_value);
3808 else if (GET_CODE (valreg) == PARALLEL)
3811 value = gen_reg_rtx (outmode);
3812 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3814 else if (value != 0)
3815 emit_move_insn (value, valreg);
3820 if (ACCUMULATE_OUTGOING_ARGS)
3822 #ifdef REG_PARM_STACK_SPACE
3824 restore_fixed_argument_area (save_area, argblock,
3825 high_to_save, low_to_save);
3828 /* If we saved any argument areas, restore them. */
3829 for (count = 0; count < nargs; count++)
3830 if (argvec[count].save_area)
3832 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3833 rtx adr = plus_constant (argblock,
3834 argvec[count].locate.offset.constant);
3835 rtx stack_area = gen_rtx_MEM (save_mode,
3836 memory_address (save_mode, adr));
3838 if (save_mode == BLKmode)
3839 emit_block_move (stack_area,
3840 validize_mem (argvec[count].save_area),
3841 GEN_INT (argvec[count].locate.size.constant),
3842 BLOCK_OP_CALL_PARM);
3844 emit_move_insn (stack_area, argvec[count].save_area);
3847 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3848 stack_usage_map = initial_stack_usage_map;
3851 if (stack_usage_map_buf)
3852 free (stack_usage_map_buf);
3858 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3859 (emitting the queue unless NO_QUEUE is nonzero),
3860 for a value of mode OUTMODE,
3861 with NARGS different arguments, passed as alternating rtx values
3862 and machine_modes to convert them to.
3864 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for `const'
3865 calls, LCT_PURE for `pure' calls, LCT_CONST_MAKE_BLOCK for `const' calls
3866 which should be enclosed in REG_LIBCALL/REG_RETVAL notes,
3867 LCT_PURE_MAKE_BLOCK for `purep' calls which should be enclosed in
3868 REG_LIBCALL/REG_RETVAL notes with extra (use (memory (scratch)),
3869 or other LCT_ value for other types of library calls. */
3872 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3873 enum machine_mode outmode, int nargs, ...)
3877 va_start (p, nargs);
3878 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3882 /* Like emit_library_call except that an extra argument, VALUE,
3883 comes second and says where to store the result.
3884 (If VALUE is zero, this function chooses a convenient way
3885 to return the value.
3887 This function returns an rtx for where the value is to be found.
3888 If VALUE is nonzero, VALUE is returned. */
3891 emit_library_call_value (rtx orgfun, rtx value,
3892 enum libcall_type fn_type,
3893 enum machine_mode outmode, int nargs, ...)
3898 va_start (p, nargs);
3899 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3906 /* Store a single argument for a function call
3907 into the register or memory area where it must be passed.
3908 *ARG describes the argument value and where to pass it.
3910 ARGBLOCK is the address of the stack-block for all the arguments,
3911 or 0 on a machine where arguments are pushed individually.
3913 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3914 so must be careful about how the stack is used.
3916 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3917 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3918 that we need not worry about saving and restoring the stack.
3920 FNDECL is the declaration of the function we are calling.
3922 Return nonzero if this arg should cause sibcall failure,
3926 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3927 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3929 tree pval = arg->tree_value;
3933 int i, lower_bound = 0, upper_bound = 0;
3934 int sibcall_failure = 0;
3936 if (TREE_CODE (pval) == ERROR_MARK)
3939 /* Push a new temporary level for any temporaries we make for
3943 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3945 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3946 save any previous data at that location. */
3947 if (argblock && ! variable_size && arg->stack)
3949 #ifdef ARGS_GROW_DOWNWARD
3950 /* stack_slot is negative, but we want to index stack_usage_map
3951 with positive values. */
3952 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3953 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3957 lower_bound = upper_bound - arg->locate.size.constant;
3959 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3960 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3964 upper_bound = lower_bound + arg->locate.size.constant;
3968 /* Don't worry about things in the fixed argument area;
3969 it has already been saved. */
3970 if (i < reg_parm_stack_space)
3971 i = reg_parm_stack_space;
3972 while (i < upper_bound && stack_usage_map[i] == 0)
3975 if (i < upper_bound)
3977 /* We need to make a save area. */
3978 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
3979 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
3980 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
3981 rtx stack_area = gen_rtx_MEM (save_mode, adr);
3983 if (save_mode == BLKmode)
3985 tree ot = TREE_TYPE (arg->tree_value);
3986 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
3987 | TYPE_QUAL_CONST));
3989 arg->save_area = assign_temp (nt, 0, 1, 1);
3990 preserve_temp_slots (arg->save_area);
3991 emit_block_move (validize_mem (arg->save_area), stack_area,
3992 expr_size (arg->tree_value),
3993 BLOCK_OP_CALL_PARM);
3997 arg->save_area = gen_reg_rtx (save_mode);
3998 emit_move_insn (arg->save_area, stack_area);
4004 /* If this isn't going to be placed on both the stack and in registers,
4005 set up the register and number of words. */
4006 if (! arg->pass_on_stack)
4008 if (flags & ECF_SIBCALL)
4009 reg = arg->tail_call_reg;
4012 partial = arg->partial;
4015 /* Being passed entirely in a register. We shouldn't be called in
4017 gcc_assert (reg == 0 || partial != 0);
4019 /* If this arg needs special alignment, don't load the registers
4021 if (arg->n_aligned_regs != 0)
4024 /* If this is being passed partially in a register, we can't evaluate
4025 it directly into its stack slot. Otherwise, we can. */
4026 if (arg->value == 0)
4028 /* stack_arg_under_construction is nonzero if a function argument is
4029 being evaluated directly into the outgoing argument list and
4030 expand_call must take special action to preserve the argument list
4031 if it is called recursively.
4033 For scalar function arguments stack_usage_map is sufficient to
4034 determine which stack slots must be saved and restored. Scalar
4035 arguments in general have pass_on_stack == 0.
4037 If this argument is initialized by a function which takes the
4038 address of the argument (a C++ constructor or a C function
4039 returning a BLKmode structure), then stack_usage_map is
4040 insufficient and expand_call must push the stack around the
4041 function call. Such arguments have pass_on_stack == 1.
4043 Note that it is always safe to set stack_arg_under_construction,
4044 but this generates suboptimal code if set when not needed. */
4046 if (arg->pass_on_stack)
4047 stack_arg_under_construction++;
4049 arg->value = expand_expr (pval,
4051 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4052 ? NULL_RTX : arg->stack,
4053 VOIDmode, EXPAND_STACK_PARM);
4055 /* If we are promoting object (or for any other reason) the mode
4056 doesn't agree, convert the mode. */
4058 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4059 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4060 arg->value, arg->unsignedp);
4062 if (arg->pass_on_stack)
4063 stack_arg_under_construction--;
4066 /* Don't allow anything left on stack from computation
4067 of argument to alloca. */
4068 if (flags & ECF_MAY_BE_ALLOCA)
4069 do_pending_stack_adjust ();
4071 if (arg->value == arg->stack)
4072 /* If the value is already in the stack slot, we are done. */
4074 else if (arg->mode != BLKmode)
4078 /* Argument is a scalar, not entirely passed in registers.
4079 (If part is passed in registers, arg->partial says how much
4080 and emit_push_insn will take care of putting it there.)
4082 Push it, and if its size is less than the
4083 amount of space allocated to it,
4084 also bump stack pointer by the additional space.
4085 Note that in C the default argument promotions
4086 will prevent such mismatches. */
4088 size = GET_MODE_SIZE (arg->mode);
4089 /* Compute how much space the push instruction will push.
4090 On many machines, pushing a byte will advance the stack
4091 pointer by a halfword. */
4092 #ifdef PUSH_ROUNDING
4093 size = PUSH_ROUNDING (size);
4097 /* Compute how much space the argument should get:
4098 round up to a multiple of the alignment for arguments. */
4099 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4100 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4101 / (PARM_BOUNDARY / BITS_PER_UNIT))
4102 * (PARM_BOUNDARY / BITS_PER_UNIT));
4104 /* This isn't already where we want it on the stack, so put it there.
4105 This can either be done with push or copy insns. */
4106 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4107 PARM_BOUNDARY, partial, reg, used - size, argblock,
4108 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4109 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4111 /* Unless this is a partially-in-register argument, the argument is now
4114 arg->value = arg->stack;
4118 /* BLKmode, at least partly to be pushed. */
4120 unsigned int parm_align;
4124 /* Pushing a nonscalar.
4125 If part is passed in registers, PARTIAL says how much
4126 and emit_push_insn will take care of putting it there. */
4128 /* Round its size up to a multiple
4129 of the allocation unit for arguments. */
4131 if (arg->locate.size.var != 0)
4134 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4138 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4139 for BLKmode is careful to avoid it. */
4140 excess = (arg->locate.size.constant
4141 - int_size_in_bytes (TREE_TYPE (pval))
4143 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4144 NULL_RTX, TYPE_MODE (sizetype), 0);
4147 parm_align = arg->locate.boundary;
4149 /* When an argument is padded down, the block is aligned to
4150 PARM_BOUNDARY, but the actual argument isn't. */
4151 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4153 if (arg->locate.size.var)
4154 parm_align = BITS_PER_UNIT;
4157 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4158 parm_align = MIN (parm_align, excess_align);
4162 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4164 /* emit_push_insn might not work properly if arg->value and
4165 argblock + arg->locate.offset areas overlap. */
4169 if (XEXP (x, 0) == current_function_internal_arg_pointer
4170 || (GET_CODE (XEXP (x, 0)) == PLUS
4171 && XEXP (XEXP (x, 0), 0) ==
4172 current_function_internal_arg_pointer
4173 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4175 if (XEXP (x, 0) != current_function_internal_arg_pointer)
4176 i = INTVAL (XEXP (XEXP (x, 0), 1));
4178 /* expand_call should ensure this. */
4179 gcc_assert (!arg->locate.offset.var
4180 && GET_CODE (size_rtx) == CONST_INT);
4182 if (arg->locate.offset.constant > i)
4184 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4185 sibcall_failure = 1;
4187 else if (arg->locate.offset.constant < i)
4189 if (i < arg->locate.offset.constant + INTVAL (size_rtx))
4190 sibcall_failure = 1;
4195 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4196 parm_align, partial, reg, excess, argblock,
4197 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4198 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4200 /* Unless this is a partially-in-register argument, the argument is now
4203 ??? Unlike the case above, in which we want the actual
4204 address of the data, so that we can load it directly into a
4205 register, here we want the address of the stack slot, so that
4206 it's properly aligned for word-by-word copying or something
4207 like that. It's not clear that this is always correct. */
4209 arg->value = arg->stack_slot;
4212 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4214 tree type = TREE_TYPE (arg->tree_value);
4216 = emit_group_load_into_temps (arg->reg, arg->value, type,
4217 int_size_in_bytes (type));
4220 /* Mark all slots this store used. */
4221 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4222 && argblock && ! variable_size && arg->stack)
4223 for (i = lower_bound; i < upper_bound; i++)
4224 stack_usage_map[i] = 1;
4226 /* Once we have pushed something, pops can't safely
4227 be deferred during the rest of the arguments. */
4230 /* Free any temporary slots made in processing this argument. Show
4231 that we might have taken the address of something and pushed that
4233 preserve_temp_slots (NULL_RTX);
4237 return sibcall_failure;
4240 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4243 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4249 /* If the type has variable size... */
4250 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4253 /* If the type is marked as addressable (it is required
4254 to be constructed into the stack)... */
4255 if (TREE_ADDRESSABLE (type))
4261 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4262 takes trailing padding of a structure into account. */
4263 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4266 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, tree type)
4271 /* If the type has variable size... */
4272 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4275 /* If the type is marked as addressable (it is required
4276 to be constructed into the stack)... */
4277 if (TREE_ADDRESSABLE (type))
4280 /* If the padding and mode of the type is such that a copy into
4281 a register would put it into the wrong part of the register. */
4283 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4284 && (FUNCTION_ARG_PADDING (mode, type)
4285 == (BYTES_BIG_ENDIAN ? upward : downward)))