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, 2006, 2007
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 3, 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 COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
24 #include "coretypes.h"
39 #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, struct arg_data *);
133 static int compute_argument_block_size (int, struct args_size *, tree, int);
134 static void initialize_argument_information (int, struct arg_data *,
135 struct args_size *, int,
137 tree, CUMULATIVE_ARGS *, int,
138 rtx *, int *, int *, int *,
140 static void compute_argument_addresses (struct arg_data *, rtx, int);
141 static rtx rtx_for_function_call (tree, tree);
142 static void load_register_parameters (struct arg_data *, int, rtx *, int,
144 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
145 enum machine_mode, int, va_list);
146 static int special_function_p (const_tree, int);
147 static int check_sibcall_argument_overlap_1 (rtx);
148 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
150 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
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
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 /* Put the register usage information there. */
363 add_function_usage_to (call_insn, call_fusage);
365 /* If this is a const call, then set the insn's unchanging bit. */
366 if (ecf_flags & ECF_CONST)
367 RTL_CONST_CALL_P (call_insn) = 1;
369 /* If this is a pure call, then set the insn's unchanging bit. */
370 if (ecf_flags & ECF_PURE)
371 RTL_PURE_CALL_P (call_insn) = 1;
373 /* If this is a const call, then set the insn's unchanging bit. */
374 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
375 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
377 /* If this call can't throw, attach a REG_EH_REGION reg note to that
379 if (ecf_flags & ECF_NOTHROW)
380 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
383 int rn = lookup_stmt_eh_region (fntree);
385 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
386 throw, which we already took care of. */
388 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
391 if (ecf_flags & ECF_NORETURN)
392 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
394 if (ecf_flags & ECF_RETURNS_TWICE)
396 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
397 cfun->calls_setjmp = 1;
400 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
402 /* Restore this now, so that we do defer pops for this call's args
403 if the context of the call as a whole permits. */
404 inhibit_defer_pop = old_inhibit_defer_pop;
409 CALL_INSN_FUNCTION_USAGE (call_insn)
410 = gen_rtx_EXPR_LIST (VOIDmode,
411 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
412 CALL_INSN_FUNCTION_USAGE (call_insn));
413 rounded_stack_size -= n_popped;
414 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
415 stack_pointer_delta -= n_popped;
418 if (!ACCUMULATE_OUTGOING_ARGS)
420 /* If returning from the subroutine does not automatically pop the args,
421 we need an instruction to pop them sooner or later.
422 Perhaps do it now; perhaps just record how much space to pop later.
424 If returning from the subroutine does pop the args, indicate that the
425 stack pointer will be changed. */
427 if (rounded_stack_size != 0)
429 if (ecf_flags & ECF_NORETURN)
430 /* Just pretend we did the pop. */
431 stack_pointer_delta -= rounded_stack_size;
432 else if (flag_defer_pop && inhibit_defer_pop == 0
433 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
434 pending_stack_adjust += rounded_stack_size;
436 adjust_stack (rounded_stack_size_rtx);
439 /* When we accumulate outgoing args, we must avoid any stack manipulations.
440 Restore the stack pointer to its original value now. Usually
441 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
442 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
443 popping variants of functions exist as well.
445 ??? We may optimize similar to defer_pop above, but it is
446 probably not worthwhile.
448 ??? It will be worthwhile to enable combine_stack_adjustments even for
451 anti_adjust_stack (GEN_INT (n_popped));
454 /* Determine if the function identified by NAME and FNDECL is one with
455 special properties we wish to know about.
457 For example, if the function might return more than one time (setjmp), then
458 set RETURNS_TWICE to a nonzero value.
460 Similarly set NORETURN if the function is in the longjmp family.
462 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
463 space from the stack such as alloca. */
466 special_function_p (const_tree fndecl, int flags)
468 if (fndecl && DECL_NAME (fndecl)
469 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
470 /* Exclude functions not at the file scope, or not `extern',
471 since they are not the magic functions we would otherwise
473 FIXME: this should be handled with attributes, not with this
474 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
475 because you can declare fork() inside a function if you
477 && (DECL_CONTEXT (fndecl) == NULL_TREE
478 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
479 && TREE_PUBLIC (fndecl))
481 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
482 const char *tname = name;
484 /* We assume that alloca will always be called by name. It
485 makes no sense to pass it as a pointer-to-function to
486 anything that does not understand its behavior. */
487 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
489 && ! strcmp (name, "alloca"))
490 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
492 && ! strcmp (name, "__builtin_alloca"))))
493 flags |= ECF_MAY_BE_ALLOCA;
495 /* Disregard prefix _, __ or __x. */
498 if (name[1] == '_' && name[2] == 'x')
500 else if (name[1] == '_')
509 && (! strcmp (tname, "setjmp")
510 || ! strcmp (tname, "setjmp_syscall")))
512 && ! strcmp (tname, "sigsetjmp"))
514 && ! strcmp (tname, "savectx")))
515 flags |= ECF_RETURNS_TWICE;
518 && ! strcmp (tname, "siglongjmp"))
519 flags |= ECF_NORETURN;
521 else if ((tname[0] == 'q' && tname[1] == 's'
522 && ! strcmp (tname, "qsetjmp"))
523 || (tname[0] == 'v' && tname[1] == 'f'
524 && ! strcmp (tname, "vfork"))
525 || (tname[0] == 'g' && tname[1] == 'e'
526 && !strcmp (tname, "getcontext")))
527 flags |= ECF_RETURNS_TWICE;
529 else if (tname[0] == 'l' && tname[1] == 'o'
530 && ! strcmp (tname, "longjmp"))
531 flags |= ECF_NORETURN;
537 /* Return nonzero when FNDECL represents a call to setjmp. */
540 setjmp_call_p (const_tree fndecl)
542 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
545 /* Return true when exp contains alloca call. */
547 alloca_call_p (const_tree exp)
549 if (TREE_CODE (exp) == CALL_EXPR
550 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
551 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
552 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
553 & ECF_MAY_BE_ALLOCA))
558 /* Detect flags (function attributes) from the function decl or type node. */
561 flags_from_decl_or_type (const_tree exp)
564 const_tree type = exp;
568 type = TREE_TYPE (exp);
570 /* The function exp may have the `malloc' attribute. */
571 if (DECL_IS_MALLOC (exp))
574 /* The function exp may have the `returns_twice' attribute. */
575 if (DECL_IS_RETURNS_TWICE (exp))
576 flags |= ECF_RETURNS_TWICE;
578 /* Process the pure and const attributes. */
579 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
581 if (DECL_PURE_P (exp))
583 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
584 flags |= ECF_LOOPING_CONST_OR_PURE;
586 if (DECL_IS_NOVOPS (exp))
589 if (TREE_NOTHROW (exp))
590 flags |= ECF_NOTHROW;
592 flags = special_function_p (exp, flags);
594 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
597 if (TREE_THIS_VOLATILE (exp))
598 flags |= ECF_NORETURN;
603 /* Detect flags from a CALL_EXPR. */
606 call_expr_flags (const_tree t)
609 tree decl = get_callee_fndecl (t);
612 flags = flags_from_decl_or_type (decl);
615 t = TREE_TYPE (CALL_EXPR_FN (t));
616 if (t && TREE_CODE (t) == POINTER_TYPE)
617 flags = flags_from_decl_or_type (TREE_TYPE (t));
625 /* Precompute all register parameters as described by ARGS, storing values
626 into fields within the ARGS array.
628 NUM_ACTUALS indicates the total number elements in the ARGS array.
630 Set REG_PARM_SEEN if we encounter a register parameter. */
633 precompute_register_parameters (int num_actuals, struct arg_data *args,
640 for (i = 0; i < num_actuals; i++)
641 if (args[i].reg != 0 && ! args[i].pass_on_stack)
645 if (args[i].value == 0)
648 args[i].value = expand_normal (args[i].tree_value);
649 preserve_temp_slots (args[i].value);
653 /* If the value is a non-legitimate constant, force it into a
654 pseudo now. TLS symbols sometimes need a call to resolve. */
655 if (CONSTANT_P (args[i].value)
656 && !LEGITIMATE_CONSTANT_P (args[i].value))
657 args[i].value = force_reg (args[i].mode, args[i].value);
659 /* If we are to promote the function arg to a wider mode,
662 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
664 = convert_modes (args[i].mode,
665 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
666 args[i].value, args[i].unsignedp);
668 /* If we're going to have to load the value by parts, pull the
669 parts into pseudos. The part extraction process can involve
670 non-trivial computation. */
671 if (GET_CODE (args[i].reg) == PARALLEL)
673 tree type = TREE_TYPE (args[i].tree_value);
674 args[i].parallel_value
675 = emit_group_load_into_temps (args[i].reg, args[i].value,
676 type, int_size_in_bytes (type));
679 /* If the value is expensive, and we are inside an appropriately
680 short loop, put the value into a pseudo and then put the pseudo
683 For small register classes, also do this if this call uses
684 register parameters. This is to avoid reload conflicts while
685 loading the parameters registers. */
687 else if ((! (REG_P (args[i].value)
688 || (GET_CODE (args[i].value) == SUBREG
689 && REG_P (SUBREG_REG (args[i].value)))))
690 && args[i].mode != BLKmode
691 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
692 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
694 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
698 #ifdef REG_PARM_STACK_SPACE
700 /* The argument list is the property of the called routine and it
701 may clobber it. If the fixed area has been used for previous
702 parameters, we must save and restore it. */
705 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
710 /* Compute the boundary of the area that needs to be saved, if any. */
711 high = reg_parm_stack_space;
712 #ifdef ARGS_GROW_DOWNWARD
715 if (high > highest_outgoing_arg_in_use)
716 high = highest_outgoing_arg_in_use;
718 for (low = 0; low < high; low++)
719 if (stack_usage_map[low] != 0)
722 enum machine_mode save_mode;
727 while (stack_usage_map[--high] == 0)
731 *high_to_save = high;
733 num_to_save = high - low + 1;
734 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
736 /* If we don't have the required alignment, must do this
738 if ((low & (MIN (GET_MODE_SIZE (save_mode),
739 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
742 #ifdef ARGS_GROW_DOWNWARD
747 stack_area = gen_rtx_MEM (save_mode,
748 memory_address (save_mode,
749 plus_constant (argblock,
752 set_mem_align (stack_area, PARM_BOUNDARY);
753 if (save_mode == BLKmode)
755 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
756 emit_block_move (validize_mem (save_area), stack_area,
757 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
761 save_area = gen_reg_rtx (save_mode);
762 emit_move_insn (save_area, stack_area);
772 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
774 enum machine_mode save_mode = GET_MODE (save_area);
778 #ifdef ARGS_GROW_DOWNWARD
779 delta = -high_to_save;
783 stack_area = gen_rtx_MEM (save_mode,
784 memory_address (save_mode,
785 plus_constant (argblock, delta)));
786 set_mem_align (stack_area, PARM_BOUNDARY);
788 if (save_mode != BLKmode)
789 emit_move_insn (stack_area, save_area);
791 emit_block_move (stack_area, validize_mem (save_area),
792 GEN_INT (high_to_save - low_to_save + 1),
795 #endif /* REG_PARM_STACK_SPACE */
797 /* If any elements in ARGS refer to parameters that are to be passed in
798 registers, but not in memory, and whose alignment does not permit a
799 direct copy into registers. Copy the values into a group of pseudos
800 which we will later copy into the appropriate hard registers.
802 Pseudos for each unaligned argument will be stored into the array
803 args[argnum].aligned_regs. The caller is responsible for deallocating
804 the aligned_regs array if it is nonzero. */
807 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
811 for (i = 0; i < num_actuals; i++)
812 if (args[i].reg != 0 && ! args[i].pass_on_stack
813 && args[i].mode == BLKmode
814 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
815 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
817 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
818 int endian_correction = 0;
822 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
823 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
827 args[i].n_aligned_regs
828 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
831 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
833 /* Structures smaller than a word are normally aligned to the
834 least significant byte. On a BYTES_BIG_ENDIAN machine,
835 this means we must skip the empty high order bytes when
836 calculating the bit offset. */
837 if (bytes < UNITS_PER_WORD
838 #ifdef BLOCK_REG_PADDING
839 && (BLOCK_REG_PADDING (args[i].mode,
840 TREE_TYPE (args[i].tree_value), 1)
846 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
848 for (j = 0; j < args[i].n_aligned_regs; j++)
850 rtx reg = gen_reg_rtx (word_mode);
851 rtx word = operand_subword_force (args[i].value, j, BLKmode);
852 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
854 args[i].aligned_regs[j] = reg;
855 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
856 word_mode, word_mode);
858 /* There is no need to restrict this code to loading items
859 in TYPE_ALIGN sized hunks. The bitfield instructions can
860 load up entire word sized registers efficiently.
862 ??? This may not be needed anymore.
863 We use to emit a clobber here but that doesn't let later
864 passes optimize the instructions we emit. By storing 0 into
865 the register later passes know the first AND to zero out the
866 bitfield being set in the register is unnecessary. The store
867 of 0 will be deleted as will at least the first AND. */
869 emit_move_insn (reg, const0_rtx);
871 bytes -= bitsize / BITS_PER_UNIT;
872 store_bit_field (reg, bitsize, endian_correction, word_mode,
878 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
881 NUM_ACTUALS is the total number of parameters.
883 N_NAMED_ARGS is the total number of named arguments.
885 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
888 FNDECL is the tree code for the target of this call (if known)
890 ARGS_SO_FAR holds state needed by the target to know where to place
893 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
894 for arguments which are passed in registers.
896 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
897 and may be modified by this routine.
899 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
900 flags which may may be modified by this routine.
902 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
903 that requires allocation of stack space.
905 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
906 the thunked-to function. */
909 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
910 struct arg_data *args,
911 struct args_size *args_size,
912 int n_named_args ATTRIBUTE_UNUSED,
913 tree exp, tree struct_value_addr_value,
915 CUMULATIVE_ARGS *args_so_far,
916 int reg_parm_stack_space,
917 rtx *old_stack_level, int *old_pending_adj,
918 int *must_preallocate, int *ecf_flags,
919 bool *may_tailcall, bool call_from_thunk_p)
921 /* 1 if scanning parms front to back, -1 if scanning back to front. */
924 /* Count arg position in order args appear. */
929 args_size->constant = 0;
932 /* In this loop, we consider args in the order they are written.
933 We fill up ARGS from the front or from the back if necessary
934 so that in any case the first arg to be pushed ends up at the front. */
936 if (PUSH_ARGS_REVERSED)
938 i = num_actuals - 1, inc = -1;
939 /* In this case, must reverse order of args
940 so that we compute and push the last arg first. */
947 /* First fill in the actual arguments in the ARGS array, splitting
948 complex arguments if necessary. */
951 call_expr_arg_iterator iter;
954 if (struct_value_addr_value)
956 args[j].tree_value = struct_value_addr_value;
959 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
961 tree argtype = TREE_TYPE (arg);
962 if (targetm.calls.split_complex_arg
964 && TREE_CODE (argtype) == COMPLEX_TYPE
965 && targetm.calls.split_complex_arg (argtype))
967 tree subtype = TREE_TYPE (argtype);
968 arg = save_expr (arg);
969 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
971 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
974 args[j].tree_value = arg;
979 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
980 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
982 tree type = TREE_TYPE (args[i].tree_value);
984 enum machine_mode mode;
986 /* Replace erroneous argument with constant zero. */
987 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
988 args[i].tree_value = integer_zero_node, type = integer_type_node;
990 /* If TYPE is a transparent union, pass things the way we would
991 pass the first field of the union. We have already verified that
992 the modes are the same. */
993 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
994 type = TREE_TYPE (TYPE_FIELDS (type));
996 /* Decide where to pass this arg.
998 args[i].reg is nonzero if all or part is passed in registers.
1000 args[i].partial is nonzero if part but not all is passed in registers,
1001 and the exact value says how many bytes are passed in registers.
1003 args[i].pass_on_stack is nonzero if the argument must at least be
1004 computed on the stack. It may then be loaded back into registers
1005 if args[i].reg is nonzero.
1007 These decisions are driven by the FUNCTION_... macros and must agree
1008 with those made by function.c. */
1010 /* See if this argument should be passed by invisible reference. */
1011 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1012 type, argpos < n_named_args))
1018 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1019 type, argpos < n_named_args);
1021 /* If we're compiling a thunk, pass through invisible references
1022 instead of making a copy. */
1023 if (call_from_thunk_p
1025 && !TREE_ADDRESSABLE (type)
1026 && (base = get_base_address (args[i].tree_value))
1027 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1029 /* We can't use sibcalls if a callee-copied argument is
1030 stored in the current function's frame. */
1031 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1032 *may_tailcall = false;
1034 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1035 type = TREE_TYPE (args[i].tree_value);
1037 if (*ecf_flags & ECF_CONST)
1038 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1042 /* We make a copy of the object and pass the address to the
1043 function being called. */
1046 if (!COMPLETE_TYPE_P (type)
1047 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1048 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1049 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1050 STACK_CHECK_MAX_VAR_SIZE))))
1052 /* This is a variable-sized object. Make space on the stack
1054 rtx size_rtx = expr_size (args[i].tree_value);
1056 if (*old_stack_level == 0)
1058 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1059 *old_pending_adj = pending_stack_adjust;
1060 pending_stack_adjust = 0;
1063 copy = gen_rtx_MEM (BLKmode,
1064 allocate_dynamic_stack_space
1065 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1066 set_mem_attributes (copy, type, 1);
1069 copy = assign_temp (type, 0, 1, 0);
1071 store_expr (args[i].tree_value, copy, 0, false);
1073 /* Just change the const function to pure and then let
1074 the next test clear the pure based on
1076 if (*ecf_flags & ECF_CONST)
1078 *ecf_flags &= ~ECF_CONST;
1079 *ecf_flags |= ECF_PURE;
1082 if (!callee_copies && *ecf_flags & ECF_PURE)
1083 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1086 = build_fold_addr_expr (make_tree (type, copy));
1087 type = TREE_TYPE (args[i].tree_value);
1088 *may_tailcall = false;
1092 mode = TYPE_MODE (type);
1093 unsignedp = TYPE_UNSIGNED (type);
1095 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1096 mode = promote_mode (type, mode, &unsignedp, 1);
1098 args[i].unsignedp = unsignedp;
1099 args[i].mode = mode;
1101 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1102 argpos < n_named_args);
1103 #ifdef FUNCTION_INCOMING_ARG
1104 /* If this is a sibling call and the machine has register windows, the
1105 register window has to be unwinded before calling the routine, so
1106 arguments have to go into the incoming registers. */
1107 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1108 argpos < n_named_args);
1110 args[i].tail_call_reg = args[i].reg;
1115 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1116 argpos < n_named_args);
1118 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1120 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1121 it means that we are to pass this arg in the register(s) designated
1122 by the PARALLEL, but also to pass it in the stack. */
1123 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1124 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1125 args[i].pass_on_stack = 1;
1127 /* If this is an addressable type, we must preallocate the stack
1128 since we must evaluate the object into its final location.
1130 If this is to be passed in both registers and the stack, it is simpler
1132 if (TREE_ADDRESSABLE (type)
1133 || (args[i].pass_on_stack && args[i].reg != 0))
1134 *must_preallocate = 1;
1136 /* Compute the stack-size of this argument. */
1137 if (args[i].reg == 0 || args[i].partial != 0
1138 || reg_parm_stack_space > 0
1139 || args[i].pass_on_stack)
1140 locate_and_pad_parm (mode, type,
1141 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1146 args[i].pass_on_stack ? 0 : args[i].partial,
1147 fndecl, args_size, &args[i].locate);
1148 #ifdef BLOCK_REG_PADDING
1150 /* The argument is passed entirely in registers. See at which
1151 end it should be padded. */
1152 args[i].locate.where_pad =
1153 BLOCK_REG_PADDING (mode, type,
1154 int_size_in_bytes (type) <= UNITS_PER_WORD);
1157 /* Update ARGS_SIZE, the total stack space for args so far. */
1159 args_size->constant += args[i].locate.size.constant;
1160 if (args[i].locate.size.var)
1161 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1163 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1164 have been used, etc. */
1166 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1167 argpos < n_named_args);
1171 /* Update ARGS_SIZE to contain the total size for the argument block.
1172 Return the original constant component of the argument block's size.
1174 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1175 for arguments passed in registers. */
1178 compute_argument_block_size (int reg_parm_stack_space,
1179 struct args_size *args_size,
1180 tree fndecl ATTRIBUTE_UNUSED,
1181 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1183 int unadjusted_args_size = args_size->constant;
1185 /* For accumulate outgoing args mode we don't need to align, since the frame
1186 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1187 backends from generating misaligned frame sizes. */
1188 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1189 preferred_stack_boundary = STACK_BOUNDARY;
1191 /* Compute the actual size of the argument block required. The variable
1192 and constant sizes must be combined, the size may have to be rounded,
1193 and there may be a minimum required size. */
1197 args_size->var = ARGS_SIZE_TREE (*args_size);
1198 args_size->constant = 0;
1200 preferred_stack_boundary /= BITS_PER_UNIT;
1201 if (preferred_stack_boundary > 1)
1203 /* We don't handle this case yet. To handle it correctly we have
1204 to add the delta, round and subtract the delta.
1205 Currently no machine description requires this support. */
1206 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1207 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1210 if (reg_parm_stack_space > 0)
1213 = size_binop (MAX_EXPR, args_size->var,
1214 ssize_int (reg_parm_stack_space));
1216 /* The area corresponding to register parameters is not to count in
1217 the size of the block we need. So make the adjustment. */
1218 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1220 = size_binop (MINUS_EXPR, args_size->var,
1221 ssize_int (reg_parm_stack_space));
1226 preferred_stack_boundary /= BITS_PER_UNIT;
1227 if (preferred_stack_boundary < 1)
1228 preferred_stack_boundary = 1;
1229 args_size->constant = (((args_size->constant
1230 + stack_pointer_delta
1231 + preferred_stack_boundary - 1)
1232 / preferred_stack_boundary
1233 * preferred_stack_boundary)
1234 - stack_pointer_delta);
1236 args_size->constant = MAX (args_size->constant,
1237 reg_parm_stack_space);
1239 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1240 args_size->constant -= reg_parm_stack_space;
1242 return unadjusted_args_size;
1245 /* Precompute parameters as needed for a function call.
1247 FLAGS is mask of ECF_* constants.
1249 NUM_ACTUALS is the number of arguments.
1251 ARGS is an array containing information for each argument; this
1252 routine fills in the INITIAL_VALUE and VALUE fields for each
1253 precomputed argument. */
1256 precompute_arguments (int num_actuals, struct arg_data *args)
1260 /* If this is a libcall, then precompute all arguments so that we do not
1261 get extraneous instructions emitted as part of the libcall sequence. */
1263 /* If we preallocated the stack space, and some arguments must be passed
1264 on the stack, then we must precompute any parameter which contains a
1265 function call which will store arguments on the stack.
1266 Otherwise, evaluating the parameter may clobber previous parameters
1267 which have already been stored into the stack. (we have code to avoid
1268 such case by saving the outgoing stack arguments, but it results in
1270 if (!ACCUMULATE_OUTGOING_ARGS)
1273 for (i = 0; i < num_actuals; i++)
1275 enum machine_mode mode;
1277 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1280 /* If this is an addressable type, we cannot pre-evaluate it. */
1281 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1283 args[i].initial_value = args[i].value
1284 = expand_normal (args[i].tree_value);
1286 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1287 if (mode != args[i].mode)
1290 = convert_modes (args[i].mode, mode,
1291 args[i].value, args[i].unsignedp);
1292 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1293 /* CSE will replace this only if it contains args[i].value
1294 pseudo, so convert it down to the declared mode using
1296 if (REG_P (args[i].value)
1297 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1299 args[i].initial_value
1300 = gen_lowpart_SUBREG (mode, args[i].value);
1301 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1302 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1310 /* Given the current state of MUST_PREALLOCATE and information about
1311 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1312 compute and return the final value for MUST_PREALLOCATE. */
1315 finalize_must_preallocate (int must_preallocate, int num_actuals,
1316 struct arg_data *args, struct args_size *args_size)
1318 /* See if we have or want to preallocate stack space.
1320 If we would have to push a partially-in-regs parm
1321 before other stack parms, preallocate stack space instead.
1323 If the size of some parm is not a multiple of the required stack
1324 alignment, we must preallocate.
1326 If the total size of arguments that would otherwise create a copy in
1327 a temporary (such as a CALL) is more than half the total argument list
1328 size, preallocation is faster.
1330 Another reason to preallocate is if we have a machine (like the m88k)
1331 where stack alignment is required to be maintained between every
1332 pair of insns, not just when the call is made. However, we assume here
1333 that such machines either do not have push insns (and hence preallocation
1334 would occur anyway) or the problem is taken care of with
1337 if (! must_preallocate)
1339 int partial_seen = 0;
1340 int copy_to_evaluate_size = 0;
1343 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1345 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1347 else if (partial_seen && args[i].reg == 0)
1348 must_preallocate = 1;
1350 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1351 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1352 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1353 || TREE_CODE (args[i].tree_value) == COND_EXPR
1354 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1355 copy_to_evaluate_size
1356 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1359 if (copy_to_evaluate_size * 2 >= args_size->constant
1360 && args_size->constant > 0)
1361 must_preallocate = 1;
1363 return must_preallocate;
1366 /* If we preallocated stack space, compute the address of each argument
1367 and store it into the ARGS array.
1369 We need not ensure it is a valid memory address here; it will be
1370 validized when it is used.
1372 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1375 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1379 rtx arg_reg = argblock;
1380 int i, arg_offset = 0;
1382 if (GET_CODE (argblock) == PLUS)
1383 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1385 for (i = 0; i < num_actuals; i++)
1387 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1388 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1390 unsigned int align, boundary;
1391 unsigned int units_on_stack = 0;
1392 enum machine_mode partial_mode = VOIDmode;
1394 /* Skip this parm if it will not be passed on the stack. */
1395 if (! args[i].pass_on_stack
1397 && args[i].partial == 0)
1400 if (GET_CODE (offset) == CONST_INT)
1401 addr = plus_constant (arg_reg, INTVAL (offset));
1403 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1405 addr = plus_constant (addr, arg_offset);
1407 if (args[i].partial != 0)
1409 /* Only part of the parameter is being passed on the stack.
1410 Generate a simple memory reference of the correct size. */
1411 units_on_stack = args[i].locate.size.constant;
1412 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1414 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1415 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1419 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1420 set_mem_attributes (args[i].stack,
1421 TREE_TYPE (args[i].tree_value), 1);
1423 align = BITS_PER_UNIT;
1424 boundary = args[i].locate.boundary;
1425 if (args[i].locate.where_pad != downward)
1427 else if (GET_CODE (offset) == CONST_INT)
1429 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1430 align = align & -align;
1432 set_mem_align (args[i].stack, align);
1434 if (GET_CODE (slot_offset) == CONST_INT)
1435 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1437 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1439 addr = plus_constant (addr, arg_offset);
1441 if (args[i].partial != 0)
1443 /* Only part of the parameter is being passed on the stack.
1444 Generate a simple memory reference of the correct size.
1446 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1447 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1451 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1452 set_mem_attributes (args[i].stack_slot,
1453 TREE_TYPE (args[i].tree_value), 1);
1455 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1457 /* Function incoming arguments may overlap with sibling call
1458 outgoing arguments and we cannot allow reordering of reads
1459 from function arguments with stores to outgoing arguments
1460 of sibling calls. */
1461 set_mem_alias_set (args[i].stack, 0);
1462 set_mem_alias_set (args[i].stack_slot, 0);
1467 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1468 in a call instruction.
1470 FNDECL is the tree node for the target function. For an indirect call
1471 FNDECL will be NULL_TREE.
1473 ADDR is the operand 0 of CALL_EXPR for this call. */
1476 rtx_for_function_call (tree fndecl, tree addr)
1480 /* Get the function to call, in the form of RTL. */
1483 /* If this is the first use of the function, see if we need to
1484 make an external definition for it. */
1485 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1487 assemble_external (fndecl);
1488 TREE_USED (fndecl) = 1;
1491 /* Get a SYMBOL_REF rtx for the function address. */
1492 funexp = XEXP (DECL_RTL (fndecl), 0);
1495 /* Generate an rtx (probably a pseudo-register) for the address. */
1498 funexp = expand_normal (addr);
1499 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1504 /* Return true if and only if SIZE storage units (usually bytes)
1505 starting from address ADDR overlap with already clobbered argument
1506 area. This function is used to determine if we should give up a
1510 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1514 if (addr == crtl->args.internal_arg_pointer)
1516 else if (GET_CODE (addr) == PLUS
1517 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1518 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1519 i = INTVAL (XEXP (addr, 1));
1520 /* Return true for arg pointer based indexed addressing. */
1521 else if (GET_CODE (addr) == PLUS
1522 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1523 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1528 #ifdef ARGS_GROW_DOWNWARD
1533 unsigned HOST_WIDE_INT k;
1535 for (k = 0; k < size; k++)
1536 if (i + k < stored_args_map->n_bits
1537 && TEST_BIT (stored_args_map, i + k))
1544 /* Do the register loads required for any wholly-register parms or any
1545 parms which are passed both on the stack and in a register. Their
1546 expressions were already evaluated.
1548 Mark all register-parms as living through the call, putting these USE
1549 insns in the CALL_INSN_FUNCTION_USAGE field.
1551 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1552 checking, setting *SIBCALL_FAILURE if appropriate. */
1555 load_register_parameters (struct arg_data *args, int num_actuals,
1556 rtx *call_fusage, int flags, int is_sibcall,
1557 int *sibcall_failure)
1561 for (i = 0; i < num_actuals; i++)
1563 rtx reg = ((flags & ECF_SIBCALL)
1564 ? args[i].tail_call_reg : args[i].reg);
1567 int partial = args[i].partial;
1570 rtx before_arg = get_last_insn ();
1571 /* Set non-negative if we must move a word at a time, even if
1572 just one word (e.g, partial == 4 && mode == DFmode). Set
1573 to -1 if we just use a normal move insn. This value can be
1574 zero if the argument is a zero size structure. */
1576 if (GET_CODE (reg) == PARALLEL)
1580 gcc_assert (partial % UNITS_PER_WORD == 0);
1581 nregs = partial / UNITS_PER_WORD;
1583 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1585 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1586 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1589 size = GET_MODE_SIZE (args[i].mode);
1591 /* Handle calls that pass values in multiple non-contiguous
1592 locations. The Irix 6 ABI has examples of this. */
1594 if (GET_CODE (reg) == PARALLEL)
1595 emit_group_move (reg, args[i].parallel_value);
1597 /* If simple case, just do move. If normal partial, store_one_arg
1598 has already loaded the register for us. In all other cases,
1599 load the register(s) from memory. */
1601 else if (nregs == -1)
1603 emit_move_insn (reg, args[i].value);
1604 #ifdef BLOCK_REG_PADDING
1605 /* Handle case where we have a value that needs shifting
1606 up to the msb. eg. a QImode value and we're padding
1607 upward on a BYTES_BIG_ENDIAN machine. */
1608 if (size < UNITS_PER_WORD
1609 && (args[i].locate.where_pad
1610 == (BYTES_BIG_ENDIAN ? upward : downward)))
1613 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1615 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1616 report the whole reg as used. Strictly speaking, the
1617 call only uses SIZE bytes at the msb end, but it doesn't
1618 seem worth generating rtl to say that. */
1619 reg = gen_rtx_REG (word_mode, REGNO (reg));
1620 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1621 build_int_cst (NULL_TREE, shift),
1624 emit_move_insn (reg, x);
1629 /* If we have pre-computed the values to put in the registers in
1630 the case of non-aligned structures, copy them in now. */
1632 else if (args[i].n_aligned_regs != 0)
1633 for (j = 0; j < args[i].n_aligned_regs; j++)
1634 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1635 args[i].aligned_regs[j]);
1637 else if (partial == 0 || args[i].pass_on_stack)
1639 rtx mem = validize_mem (args[i].value);
1641 /* Check for overlap with already clobbered argument area. */
1643 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1645 *sibcall_failure = 1;
1647 /* Handle a BLKmode that needs shifting. */
1648 if (nregs == 1 && size < UNITS_PER_WORD
1649 #ifdef BLOCK_REG_PADDING
1650 && args[i].locate.where_pad == downward
1656 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1657 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1658 rtx x = gen_reg_rtx (word_mode);
1659 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1660 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1663 emit_move_insn (x, tem);
1664 x = expand_shift (dir, word_mode, x,
1665 build_int_cst (NULL_TREE, shift),
1668 emit_move_insn (ri, x);
1671 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1674 /* When a parameter is a block, and perhaps in other cases, it is
1675 possible that it did a load from an argument slot that was
1676 already clobbered. */
1678 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1679 *sibcall_failure = 1;
1681 /* Handle calls that pass values in multiple non-contiguous
1682 locations. The Irix 6 ABI has examples of this. */
1683 if (GET_CODE (reg) == PARALLEL)
1684 use_group_regs (call_fusage, reg);
1685 else if (nregs == -1)
1686 use_reg (call_fusage, reg);
1688 use_regs (call_fusage, REGNO (reg), nregs);
1693 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1694 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1695 bytes, then we would need to push some additional bytes to pad the
1696 arguments. So, we compute an adjust to the stack pointer for an
1697 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1698 bytes. Then, when the arguments are pushed the stack will be perfectly
1699 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1700 be popped after the call. Returns the adjustment. */
1703 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1704 struct args_size *args_size,
1705 unsigned int preferred_unit_stack_boundary)
1707 /* The number of bytes to pop so that the stack will be
1708 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1709 HOST_WIDE_INT adjustment;
1710 /* The alignment of the stack after the arguments are pushed, if we
1711 just pushed the arguments without adjust the stack here. */
1712 unsigned HOST_WIDE_INT unadjusted_alignment;
1714 unadjusted_alignment
1715 = ((stack_pointer_delta + unadjusted_args_size)
1716 % preferred_unit_stack_boundary);
1718 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1719 as possible -- leaving just enough left to cancel out the
1720 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1721 PENDING_STACK_ADJUST is non-negative, and congruent to
1722 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1724 /* Begin by trying to pop all the bytes. */
1725 unadjusted_alignment
1726 = (unadjusted_alignment
1727 - (pending_stack_adjust % preferred_unit_stack_boundary));
1728 adjustment = pending_stack_adjust;
1729 /* Push enough additional bytes that the stack will be aligned
1730 after the arguments are pushed. */
1731 if (preferred_unit_stack_boundary > 1)
1733 if (unadjusted_alignment > 0)
1734 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1736 adjustment += unadjusted_alignment;
1739 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1740 bytes after the call. The right number is the entire
1741 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1742 by the arguments in the first place. */
1744 = pending_stack_adjust - adjustment + unadjusted_args_size;
1749 /* Scan X expression if it does not dereference any argument slots
1750 we already clobbered by tail call arguments (as noted in stored_args_map
1752 Return nonzero if X expression dereferences such argument slots,
1756 check_sibcall_argument_overlap_1 (rtx x)
1765 code = GET_CODE (x);
1768 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1769 GET_MODE_SIZE (GET_MODE (x)));
1771 /* Scan all subexpressions. */
1772 fmt = GET_RTX_FORMAT (code);
1773 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1777 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1780 else if (*fmt == 'E')
1782 for (j = 0; j < XVECLEN (x, i); j++)
1783 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1790 /* Scan sequence after INSN if it does not dereference any argument slots
1791 we already clobbered by tail call arguments (as noted in stored_args_map
1792 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1793 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1794 should be 0). Return nonzero if sequence after INSN dereferences such argument
1795 slots, zero otherwise. */
1798 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1802 if (insn == NULL_RTX)
1803 insn = get_insns ();
1805 insn = NEXT_INSN (insn);
1807 for (; insn; insn = NEXT_INSN (insn))
1809 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1812 if (mark_stored_args_map)
1814 #ifdef ARGS_GROW_DOWNWARD
1815 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1817 low = arg->locate.slot_offset.constant;
1820 for (high = low + arg->locate.size.constant; low < high; low++)
1821 SET_BIT (stored_args_map, low);
1823 return insn != NULL_RTX;
1826 /* Given that a function returns a value of mode MODE at the most
1827 significant end of hard register VALUE, shift VALUE left or right
1828 as specified by LEFT_P. Return true if some action was needed. */
1831 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1833 HOST_WIDE_INT shift;
1835 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1836 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1840 /* Use ashr rather than lshr for right shifts. This is for the benefit
1841 of the MIPS port, which requires SImode values to be sign-extended
1842 when stored in 64-bit registers. */
1843 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1844 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1849 /* If X is a likely-spilled register value, copy it to a pseudo
1850 register and return that register. Return X otherwise. */
1853 avoid_likely_spilled_reg (rtx x)
1858 && HARD_REGISTER_P (x)
1859 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1861 /* Make sure that we generate a REG rather than a CONCAT.
1862 Moves into CONCATs can need nontrivial instructions,
1863 and the whole point of this function is to avoid
1864 using the hard register directly in such a situation. */
1865 generating_concat_p = 0;
1866 new = gen_reg_rtx (GET_MODE (x));
1867 generating_concat_p = 1;
1868 emit_move_insn (new, x);
1874 /* Generate all the code for a CALL_EXPR exp
1875 and return an rtx for its value.
1876 Store the value in TARGET (specified as an rtx) if convenient.
1877 If the value is stored in TARGET then TARGET is returned.
1878 If IGNORE is nonzero, then we ignore the value of the function call. */
1881 expand_call (tree exp, rtx target, int ignore)
1883 /* Nonzero if we are currently expanding a call. */
1884 static int currently_expanding_call = 0;
1886 /* RTX for the function to be called. */
1888 /* Sequence of insns to perform a normal "call". */
1889 rtx normal_call_insns = NULL_RTX;
1890 /* Sequence of insns to perform a tail "call". */
1891 rtx tail_call_insns = NULL_RTX;
1892 /* Data type of the function. */
1894 tree type_arg_types;
1895 /* Declaration of the function being called,
1896 or 0 if the function is computed (not known by name). */
1898 /* The type of the function being called. */
1900 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1903 /* Register in which non-BLKmode value will be returned,
1904 or 0 if no value or if value is BLKmode. */
1906 /* Address where we should return a BLKmode value;
1907 0 if value not BLKmode. */
1908 rtx structure_value_addr = 0;
1909 /* Nonzero if that address is being passed by treating it as
1910 an extra, implicit first parameter. Otherwise,
1911 it is passed by being copied directly into struct_value_rtx. */
1912 int structure_value_addr_parm = 0;
1913 /* Holds the value of implicit argument for the struct value. */
1914 tree structure_value_addr_value = NULL_TREE;
1915 /* Size of aggregate value wanted, or zero if none wanted
1916 or if we are using the non-reentrant PCC calling convention
1917 or expecting the value in registers. */
1918 HOST_WIDE_INT struct_value_size = 0;
1919 /* Nonzero if called function returns an aggregate in memory PCC style,
1920 by returning the address of where to find it. */
1921 int pcc_struct_value = 0;
1922 rtx struct_value = 0;
1924 /* Number of actual parameters in this call, including struct value addr. */
1926 /* Number of named args. Args after this are anonymous ones
1927 and they must all go on the stack. */
1929 /* Number of complex actual arguments that need to be split. */
1930 int num_complex_actuals = 0;
1932 /* Vector of information about each argument.
1933 Arguments are numbered in the order they will be pushed,
1934 not the order they are written. */
1935 struct arg_data *args;
1937 /* Total size in bytes of all the stack-parms scanned so far. */
1938 struct args_size args_size;
1939 struct args_size adjusted_args_size;
1940 /* Size of arguments before any adjustments (such as rounding). */
1941 int unadjusted_args_size;
1942 /* Data on reg parms scanned so far. */
1943 CUMULATIVE_ARGS args_so_far;
1944 /* Nonzero if a reg parm has been scanned. */
1946 /* Nonzero if this is an indirect function call. */
1948 /* Nonzero if we must avoid push-insns in the args for this call.
1949 If stack space is allocated for register parameters, but not by the
1950 caller, then it is preallocated in the fixed part of the stack frame.
1951 So the entire argument block must then be preallocated (i.e., we
1952 ignore PUSH_ROUNDING in that case). */
1954 int must_preallocate = !PUSH_ARGS;
1956 /* Size of the stack reserved for parameter registers. */
1957 int reg_parm_stack_space = 0;
1959 /* Address of space preallocated for stack parms
1960 (on machines that lack push insns), or 0 if space not preallocated. */
1963 /* Mask of ECF_ flags. */
1965 #ifdef REG_PARM_STACK_SPACE
1966 /* Define the boundary of the register parm stack space that needs to be
1968 int low_to_save, high_to_save;
1969 rtx save_area = 0; /* Place that it is saved */
1972 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1973 char *initial_stack_usage_map = stack_usage_map;
1974 char *stack_usage_map_buf = NULL;
1976 int old_stack_allocated;
1978 /* State variables to track stack modifications. */
1979 rtx old_stack_level = 0;
1980 int old_stack_arg_under_construction = 0;
1981 int old_pending_adj = 0;
1982 int old_inhibit_defer_pop = inhibit_defer_pop;
1984 /* Some stack pointer alterations we make are performed via
1985 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
1986 which we then also need to save/restore along the way. */
1987 int old_stack_pointer_delta = 0;
1990 tree p = CALL_EXPR_FN (exp);
1991 tree addr = CALL_EXPR_FN (exp);
1993 /* The alignment of the stack, in bits. */
1994 unsigned HOST_WIDE_INT preferred_stack_boundary;
1995 /* The alignment of the stack, in bytes. */
1996 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
1997 /* The static chain value to use for this call. */
1998 rtx static_chain_value;
1999 /* See if this is "nothrow" function call. */
2000 if (TREE_NOTHROW (exp))
2001 flags |= ECF_NOTHROW;
2003 /* See if we can find a DECL-node for the actual function, and get the
2004 function attributes (flags) from the function decl or type node. */
2005 fndecl = get_callee_fndecl (exp);
2008 fntype = TREE_TYPE (fndecl);
2009 flags |= flags_from_decl_or_type (fndecl);
2013 fntype = TREE_TYPE (TREE_TYPE (p));
2014 flags |= flags_from_decl_or_type (fntype);
2017 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2019 /* Warn if this value is an aggregate type,
2020 regardless of which calling convention we are using for it. */
2021 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2022 warning (OPT_Waggregate_return, "function call has aggregate value");
2024 /* If the result of a non looping pure or const function call is
2025 ignored (or void), and none of its arguments are volatile, we can
2026 avoid expanding the call and just evaluate the arguments for
2028 if ((flags & (ECF_CONST | ECF_PURE))
2029 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2030 && (ignore || target == const0_rtx
2031 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2033 bool volatilep = false;
2035 call_expr_arg_iterator iter;
2037 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2038 if (TREE_THIS_VOLATILE (arg))
2046 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2047 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2052 #ifdef REG_PARM_STACK_SPACE
2053 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2056 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2057 && reg_parm_stack_space > 0 && PUSH_ARGS)
2058 must_preallocate = 1;
2060 /* Set up a place to return a structure. */
2062 /* Cater to broken compilers. */
2063 if (aggregate_value_p (exp, fndecl))
2065 /* This call returns a big structure. */
2066 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2068 #ifdef PCC_STATIC_STRUCT_RETURN
2070 pcc_struct_value = 1;
2072 #else /* not PCC_STATIC_STRUCT_RETURN */
2074 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2076 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2077 structure_value_addr = XEXP (target, 0);
2080 /* For variable-sized objects, we must be called with a target
2081 specified. If we were to allocate space on the stack here,
2082 we would have no way of knowing when to free it. */
2083 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2085 mark_temp_addr_taken (d);
2086 structure_value_addr = XEXP (d, 0);
2090 #endif /* not PCC_STATIC_STRUCT_RETURN */
2093 /* Figure out the amount to which the stack should be aligned. */
2094 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2097 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2098 /* Without automatic stack alignment, we can't increase preferred
2099 stack boundary. With automatic stack alignment, it is
2100 unnecessary since unless we can guarantee that all callers will
2101 align the outgoing stack properly, callee has to align its
2104 && i->preferred_incoming_stack_boundary
2105 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2106 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2109 /* Operand 0 is a pointer-to-function; get the type of the function. */
2110 funtype = TREE_TYPE (addr);
2111 gcc_assert (POINTER_TYPE_P (funtype));
2112 funtype = TREE_TYPE (funtype);
2114 /* Count whether there are actual complex arguments that need to be split
2115 into their real and imaginary parts. Munge the type_arg_types
2116 appropriately here as well. */
2117 if (targetm.calls.split_complex_arg)
2119 call_expr_arg_iterator iter;
2121 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2123 tree type = TREE_TYPE (arg);
2124 if (type && TREE_CODE (type) == COMPLEX_TYPE
2125 && targetm.calls.split_complex_arg (type))
2126 num_complex_actuals++;
2128 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2131 type_arg_types = TYPE_ARG_TYPES (funtype);
2133 if (flags & ECF_MAY_BE_ALLOCA)
2134 cfun->calls_alloca = 1;
2136 /* If struct_value_rtx is 0, it means pass the address
2137 as if it were an extra parameter. Put the argument expression
2138 in structure_value_addr_value. */
2139 if (structure_value_addr && struct_value == 0)
2141 /* If structure_value_addr is a REG other than
2142 virtual_outgoing_args_rtx, we can use always use it. If it
2143 is not a REG, we must always copy it into a register.
2144 If it is virtual_outgoing_args_rtx, we must copy it to another
2145 register in some cases. */
2146 rtx temp = (!REG_P (structure_value_addr)
2147 || (ACCUMULATE_OUTGOING_ARGS
2148 && stack_arg_under_construction
2149 && structure_value_addr == virtual_outgoing_args_rtx)
2150 ? copy_addr_to_reg (convert_memory_address
2151 (Pmode, structure_value_addr))
2152 : structure_value_addr);
2154 structure_value_addr_value =
2155 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2156 structure_value_addr_parm = 1;
2159 /* Count the arguments and set NUM_ACTUALS. */
2161 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2163 /* Compute number of named args.
2164 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2166 if (type_arg_types != 0)
2168 = (list_length (type_arg_types)
2169 /* Count the struct value address, if it is passed as a parm. */
2170 + structure_value_addr_parm);
2172 /* If we know nothing, treat all args as named. */
2173 n_named_args = num_actuals;
2175 /* Start updating where the next arg would go.
2177 On some machines (such as the PA) indirect calls have a different
2178 calling convention than normal calls. The fourth argument in
2179 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2181 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2183 /* Now possibly adjust the number of named args.
2184 Normally, don't include the last named arg if anonymous args follow.
2185 We do include the last named arg if
2186 targetm.calls.strict_argument_naming() returns nonzero.
2187 (If no anonymous args follow, the result of list_length is actually
2188 one too large. This is harmless.)
2190 If targetm.calls.pretend_outgoing_varargs_named() returns
2191 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2192 this machine will be able to place unnamed args that were passed
2193 in registers into the stack. So treat all args as named. This
2194 allows the insns emitting for a specific argument list to be
2195 independent of the function declaration.
2197 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2198 we do not have any reliable way to pass unnamed args in
2199 registers, so we must force them into memory. */
2201 if (type_arg_types != 0
2202 && targetm.calls.strict_argument_naming (&args_so_far))
2204 else if (type_arg_types != 0
2205 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2206 /* Don't include the last named arg. */
2209 /* Treat all args as named. */
2210 n_named_args = num_actuals;
2212 /* Make a vector to hold all the information about each arg. */
2213 args = XALLOCAVEC (struct arg_data, num_actuals);
2214 memset (args, 0, num_actuals * sizeof (struct arg_data));
2216 /* Build up entries in the ARGS array, compute the size of the
2217 arguments into ARGS_SIZE, etc. */
2218 initialize_argument_information (num_actuals, args, &args_size,
2220 structure_value_addr_value, fndecl,
2221 &args_so_far, reg_parm_stack_space,
2222 &old_stack_level, &old_pending_adj,
2223 &must_preallocate, &flags,
2224 &try_tail_call, CALL_FROM_THUNK_P (exp));
2227 must_preallocate = 1;
2229 /* Now make final decision about preallocating stack space. */
2230 must_preallocate = finalize_must_preallocate (must_preallocate,
2234 /* If the structure value address will reference the stack pointer, we
2235 must stabilize it. We don't need to do this if we know that we are
2236 not going to adjust the stack pointer in processing this call. */
2238 if (structure_value_addr
2239 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2240 || reg_mentioned_p (virtual_outgoing_args_rtx,
2241 structure_value_addr))
2243 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2244 structure_value_addr = copy_to_reg (structure_value_addr);
2246 /* Tail calls can make things harder to debug, and we've traditionally
2247 pushed these optimizations into -O2. Don't try if we're already
2248 expanding a call, as that means we're an argument. Don't try if
2249 there's cleanups, as we know there's code to follow the call. */
2251 if (currently_expanding_call++ != 0
2252 || !flag_optimize_sibling_calls
2254 || lookup_stmt_eh_region (exp) >= 0
2255 || dbg_cnt (tail_call) == false)
2258 /* Rest of purposes for tail call optimizations to fail. */
2260 #ifdef HAVE_sibcall_epilogue
2261 !HAVE_sibcall_epilogue
2266 /* Doing sibling call optimization needs some work, since
2267 structure_value_addr can be allocated on the stack.
2268 It does not seem worth the effort since few optimizable
2269 sibling calls will return a structure. */
2270 || structure_value_addr != NULL_RTX
2271 /* Check whether the target is able to optimize the call
2273 || !targetm.function_ok_for_sibcall (fndecl, exp)
2274 /* Functions that do not return exactly once may not be sibcall
2276 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2277 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2278 /* If the called function is nested in the current one, it might access
2279 some of the caller's arguments, but could clobber them beforehand if
2280 the argument areas are shared. */
2281 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2282 /* If this function requires more stack slots than the current
2283 function, we cannot change it into a sibling call.
2284 crtl->args.pretend_args_size is not part of the
2285 stack allocated by our caller. */
2286 || args_size.constant > (crtl->args.size
2287 - crtl->args.pretend_args_size)
2288 /* If the callee pops its own arguments, then it must pop exactly
2289 the same number of arguments as the current function. */
2290 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2291 != RETURN_POPS_ARGS (current_function_decl,
2292 TREE_TYPE (current_function_decl),
2294 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2297 /* Ensure current function's preferred stack
2298 boundary is at least what we need. */
2299 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2300 crtl->preferred_stack_boundary = preferred_stack_boundary;
2302 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2304 /* We want to make two insn chains; one for a sibling call, the other
2305 for a normal call. We will select one of the two chains after
2306 initial RTL generation is complete. */
2307 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2309 int sibcall_failure = 0;
2310 /* We want to emit any pending stack adjustments before the tail
2311 recursion "call". That way we know any adjustment after the tail
2312 recursion call can be ignored if we indeed use the tail
2314 int save_pending_stack_adjust = 0;
2315 int save_stack_pointer_delta = 0;
2317 rtx before_call, next_arg_reg, after_args;
2321 /* State variables we need to save and restore between
2323 save_pending_stack_adjust = pending_stack_adjust;
2324 save_stack_pointer_delta = stack_pointer_delta;
2327 flags &= ~ECF_SIBCALL;
2329 flags |= ECF_SIBCALL;
2331 /* Other state variables that we must reinitialize each time
2332 through the loop (that are not initialized by the loop itself). */
2336 /* Start a new sequence for the normal call case.
2338 From this point on, if the sibling call fails, we want to set
2339 sibcall_failure instead of continuing the loop. */
2342 /* Don't let pending stack adjusts add up to too much.
2343 Also, do all pending adjustments now if there is any chance
2344 this might be a call to alloca or if we are expanding a sibling
2346 Also do the adjustments before a throwing call, otherwise
2347 exception handling can fail; PR 19225. */
2348 if (pending_stack_adjust >= 32
2349 || (pending_stack_adjust > 0
2350 && (flags & ECF_MAY_BE_ALLOCA))
2351 || (pending_stack_adjust > 0
2352 && flag_exceptions && !(flags & ECF_NOTHROW))
2354 do_pending_stack_adjust ();
2356 /* Precompute any arguments as needed. */
2358 precompute_arguments (num_actuals, args);
2360 /* Now we are about to start emitting insns that can be deleted
2361 if a libcall is deleted. */
2362 if (pass && (flags & ECF_MALLOC))
2365 if (pass == 0 && crtl->stack_protect_guard)
2366 stack_protect_epilogue ();
2368 adjusted_args_size = args_size;
2369 /* Compute the actual size of the argument block required. The variable
2370 and constant sizes must be combined, the size may have to be rounded,
2371 and there may be a minimum required size. When generating a sibcall
2372 pattern, do not round up, since we'll be re-using whatever space our
2374 unadjusted_args_size
2375 = compute_argument_block_size (reg_parm_stack_space,
2376 &adjusted_args_size,
2379 : preferred_stack_boundary));
2381 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2383 /* The argument block when performing a sibling call is the
2384 incoming argument block. */
2387 argblock = virtual_incoming_args_rtx;
2389 #ifdef STACK_GROWS_DOWNWARD
2390 = plus_constant (argblock, crtl->args.pretend_args_size);
2392 = plus_constant (argblock, -crtl->args.pretend_args_size);
2394 stored_args_map = sbitmap_alloc (args_size.constant);
2395 sbitmap_zero (stored_args_map);
2398 /* If we have no actual push instructions, or shouldn't use them,
2399 make space for all args right now. */
2400 else if (adjusted_args_size.var != 0)
2402 if (old_stack_level == 0)
2404 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2405 old_stack_pointer_delta = stack_pointer_delta;
2406 old_pending_adj = pending_stack_adjust;
2407 pending_stack_adjust = 0;
2408 /* stack_arg_under_construction says whether a stack arg is
2409 being constructed at the old stack level. Pushing the stack
2410 gets a clean outgoing argument block. */
2411 old_stack_arg_under_construction = stack_arg_under_construction;
2412 stack_arg_under_construction = 0;
2414 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2418 /* Note that we must go through the motions of allocating an argument
2419 block even if the size is zero because we may be storing args
2420 in the area reserved for register arguments, which may be part of
2423 int needed = adjusted_args_size.constant;
2425 /* Store the maximum argument space used. It will be pushed by
2426 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2429 if (needed > crtl->outgoing_args_size)
2430 crtl->outgoing_args_size = needed;
2432 if (must_preallocate)
2434 if (ACCUMULATE_OUTGOING_ARGS)
2436 /* Since the stack pointer will never be pushed, it is
2437 possible for the evaluation of a parm to clobber
2438 something we have already written to the stack.
2439 Since most function calls on RISC machines do not use
2440 the stack, this is uncommon, but must work correctly.
2442 Therefore, we save any area of the stack that was already
2443 written and that we are using. Here we set up to do this
2444 by making a new stack usage map from the old one. The
2445 actual save will be done by store_one_arg.
2447 Another approach might be to try to reorder the argument
2448 evaluations to avoid this conflicting stack usage. */
2450 /* Since we will be writing into the entire argument area,
2451 the map must be allocated for its entire size, not just
2452 the part that is the responsibility of the caller. */
2453 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
2454 needed += reg_parm_stack_space;
2456 #ifdef ARGS_GROW_DOWNWARD
2457 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2460 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2463 if (stack_usage_map_buf)
2464 free (stack_usage_map_buf);
2465 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2466 stack_usage_map = stack_usage_map_buf;
2468 if (initial_highest_arg_in_use)
2469 memcpy (stack_usage_map, initial_stack_usage_map,
2470 initial_highest_arg_in_use);
2472 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2473 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2474 (highest_outgoing_arg_in_use
2475 - initial_highest_arg_in_use));
2478 /* The address of the outgoing argument list must not be
2479 copied to a register here, because argblock would be left
2480 pointing to the wrong place after the call to
2481 allocate_dynamic_stack_space below. */
2483 argblock = virtual_outgoing_args_rtx;
2487 if (inhibit_defer_pop == 0)
2489 /* Try to reuse some or all of the pending_stack_adjust
2490 to get this space. */
2492 = (combine_pending_stack_adjustment_and_call
2493 (unadjusted_args_size,
2494 &adjusted_args_size,
2495 preferred_unit_stack_boundary));
2497 /* combine_pending_stack_adjustment_and_call computes
2498 an adjustment before the arguments are allocated.
2499 Account for them and see whether or not the stack
2500 needs to go up or down. */
2501 needed = unadjusted_args_size - needed;
2505 /* We're releasing stack space. */
2506 /* ??? We can avoid any adjustment at all if we're
2507 already aligned. FIXME. */
2508 pending_stack_adjust = -needed;
2509 do_pending_stack_adjust ();
2513 /* We need to allocate space. We'll do that in
2514 push_block below. */
2515 pending_stack_adjust = 0;
2518 /* Special case this because overhead of `push_block' in
2519 this case is non-trivial. */
2521 argblock = virtual_outgoing_args_rtx;
2524 argblock = push_block (GEN_INT (needed), 0, 0);
2525 #ifdef ARGS_GROW_DOWNWARD
2526 argblock = plus_constant (argblock, needed);
2530 /* We only really need to call `copy_to_reg' in the case
2531 where push insns are going to be used to pass ARGBLOCK
2532 to a function call in ARGS. In that case, the stack
2533 pointer changes value from the allocation point to the
2534 call point, and hence the value of
2535 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2536 as well always do it. */
2537 argblock = copy_to_reg (argblock);
2542 if (ACCUMULATE_OUTGOING_ARGS)
2544 /* The save/restore code in store_one_arg handles all
2545 cases except one: a constructor call (including a C
2546 function returning a BLKmode struct) to initialize
2548 if (stack_arg_under_construction)
2551 = GEN_INT (adjusted_args_size.constant
2552 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL
2553 : TREE_TYPE (fndecl))) ? 0
2554 : reg_parm_stack_space));
2555 if (old_stack_level == 0)
2557 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2559 old_stack_pointer_delta = stack_pointer_delta;
2560 old_pending_adj = pending_stack_adjust;
2561 pending_stack_adjust = 0;
2562 /* stack_arg_under_construction says whether a stack
2563 arg is being constructed at the old stack level.
2564 Pushing the stack gets a clean outgoing argument
2566 old_stack_arg_under_construction
2567 = stack_arg_under_construction;
2568 stack_arg_under_construction = 0;
2569 /* Make a new map for the new argument list. */
2570 if (stack_usage_map_buf)
2571 free (stack_usage_map_buf);
2572 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2573 stack_usage_map = stack_usage_map_buf;
2574 highest_outgoing_arg_in_use = 0;
2576 allocate_dynamic_stack_space (push_size, NULL_RTX,
2580 /* If argument evaluation might modify the stack pointer,
2581 copy the address of the argument list to a register. */
2582 for (i = 0; i < num_actuals; i++)
2583 if (args[i].pass_on_stack)
2585 argblock = copy_addr_to_reg (argblock);
2590 compute_argument_addresses (args, argblock, num_actuals);
2592 /* If we push args individually in reverse order, perform stack alignment
2593 before the first push (the last arg). */
2594 if (PUSH_ARGS_REVERSED && argblock == 0
2595 && adjusted_args_size.constant != unadjusted_args_size)
2597 /* When the stack adjustment is pending, we get better code
2598 by combining the adjustments. */
2599 if (pending_stack_adjust
2600 && ! inhibit_defer_pop)
2602 pending_stack_adjust
2603 = (combine_pending_stack_adjustment_and_call
2604 (unadjusted_args_size,
2605 &adjusted_args_size,
2606 preferred_unit_stack_boundary));
2607 do_pending_stack_adjust ();
2609 else if (argblock == 0)
2610 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2611 - unadjusted_args_size));
2613 /* Now that the stack is properly aligned, pops can't safely
2614 be deferred during the evaluation of the arguments. */
2617 funexp = rtx_for_function_call (fndecl, addr);
2619 /* Figure out the register where the value, if any, will come back. */
2621 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2622 && ! structure_value_addr)
2624 if (pcc_struct_value)
2625 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2626 fndecl, NULL, (pass == 0));
2628 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2631 /* If VALREG is a PARALLEL whose first member has a zero
2632 offset, use that. This is for targets such as m68k that
2633 return the same value in multiple places. */
2634 if (GET_CODE (valreg) == PARALLEL)
2636 rtx elem = XVECEXP (valreg, 0, 0);
2637 rtx where = XEXP (elem, 0);
2638 rtx offset = XEXP (elem, 1);
2639 if (offset == const0_rtx
2640 && GET_MODE (where) == GET_MODE (valreg))
2645 /* Precompute all register parameters. It isn't safe to compute anything
2646 once we have started filling any specific hard regs. */
2647 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2649 if (CALL_EXPR_STATIC_CHAIN (exp))
2650 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2652 static_chain_value = 0;
2654 #ifdef REG_PARM_STACK_SPACE
2655 /* Save the fixed argument area if it's part of the caller's frame and
2656 is clobbered by argument setup for this call. */
2657 if (ACCUMULATE_OUTGOING_ARGS && pass)
2658 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2659 &low_to_save, &high_to_save);
2662 /* Now store (and compute if necessary) all non-register parms.
2663 These come before register parms, since they can require block-moves,
2664 which could clobber the registers used for register parms.
2665 Parms which have partial registers are not stored here,
2666 but we do preallocate space here if they want that. */
2668 for (i = 0; i < num_actuals; i++)
2669 if (args[i].reg == 0 || args[i].pass_on_stack)
2671 rtx before_arg = get_last_insn ();
2673 if (store_one_arg (&args[i], argblock, flags,
2674 adjusted_args_size.var != 0,
2675 reg_parm_stack_space)
2677 && check_sibcall_argument_overlap (before_arg,
2679 sibcall_failure = 1;
2681 if (flags & ECF_CONST
2683 && args[i].value == args[i].stack)
2684 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2685 gen_rtx_USE (VOIDmode,
2690 /* If we have a parm that is passed in registers but not in memory
2691 and whose alignment does not permit a direct copy into registers,
2692 make a group of pseudos that correspond to each register that we
2694 if (STRICT_ALIGNMENT)
2695 store_unaligned_arguments_into_pseudos (args, num_actuals);
2697 /* Now store any partially-in-registers parm.
2698 This is the last place a block-move can happen. */
2700 for (i = 0; i < num_actuals; i++)
2701 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2703 rtx before_arg = get_last_insn ();
2705 if (store_one_arg (&args[i], argblock, flags,
2706 adjusted_args_size.var != 0,
2707 reg_parm_stack_space)
2709 && check_sibcall_argument_overlap (before_arg,
2711 sibcall_failure = 1;
2714 /* If we pushed args in forward order, perform stack alignment
2715 after pushing the last arg. */
2716 if (!PUSH_ARGS_REVERSED && argblock == 0)
2717 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2718 - unadjusted_args_size));
2720 /* If register arguments require space on the stack and stack space
2721 was not preallocated, allocate stack space here for arguments
2722 passed in registers. */
2723 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2724 && !ACCUMULATE_OUTGOING_ARGS
2725 && must_preallocate == 0 && reg_parm_stack_space > 0)
2726 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2728 /* Pass the function the address in which to return a
2730 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2732 structure_value_addr
2733 = convert_memory_address (Pmode, structure_value_addr);
2734 emit_move_insn (struct_value,
2736 force_operand (structure_value_addr,
2739 if (REG_P (struct_value))
2740 use_reg (&call_fusage, struct_value);
2743 after_args = get_last_insn ();
2744 funexp = prepare_call_address (funexp, static_chain_value,
2745 &call_fusage, reg_parm_seen, pass == 0);
2747 load_register_parameters (args, num_actuals, &call_fusage, flags,
2748 pass == 0, &sibcall_failure);
2750 /* Save a pointer to the last insn before the call, so that we can
2751 later safely search backwards to find the CALL_INSN. */
2752 before_call = get_last_insn ();
2754 /* Set up next argument register. For sibling calls on machines
2755 with register windows this should be the incoming register. */
2756 #ifdef FUNCTION_INCOMING_ARG
2758 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2762 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2765 /* All arguments and registers used for the call must be set up by
2768 /* Stack must be properly aligned now. */
2770 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2772 /* Generate the actual call instruction. */
2773 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2774 adjusted_args_size.constant, struct_value_size,
2775 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2776 flags, & args_so_far);
2778 /* If the call setup or the call itself overlaps with anything
2779 of the argument setup we probably clobbered our call address.
2780 In that case we can't do sibcalls. */
2782 && check_sibcall_argument_overlap (after_args, 0, 0))
2783 sibcall_failure = 1;
2785 /* If a non-BLKmode value is returned at the most significant end
2786 of a register, shift the register right by the appropriate amount
2787 and update VALREG accordingly. BLKmode values are handled by the
2788 group load/store machinery below. */
2789 if (!structure_value_addr
2790 && !pcc_struct_value
2791 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2792 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2794 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2795 sibcall_failure = 1;
2796 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2799 if (pass && (flags & ECF_MALLOC))
2801 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2804 /* The return value from a malloc-like function is a pointer. */
2805 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2806 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2808 emit_move_insn (temp, valreg);
2810 /* The return value from a malloc-like function can not alias
2812 last = get_last_insn ();
2813 add_reg_note (last, REG_NOALIAS, temp);
2815 /* Write out the sequence. */
2816 insns = get_insns ();
2822 /* For calls to `setjmp', etc., inform
2823 function.c:setjmp_warnings that it should complain if
2824 nonvolatile values are live. For functions that cannot
2825 return, inform flow that control does not fall through. */
2827 if ((flags & ECF_NORETURN) || pass == 0)
2829 /* The barrier must be emitted
2830 immediately after the CALL_INSN. Some ports emit more
2831 than just a CALL_INSN above, so we must search for it here. */
2833 rtx last = get_last_insn ();
2834 while (!CALL_P (last))
2836 last = PREV_INSN (last);
2837 /* There was no CALL_INSN? */
2838 gcc_assert (last != before_call);
2841 emit_barrier_after (last);
2843 /* Stack adjustments after a noreturn call are dead code.
2844 However when NO_DEFER_POP is in effect, we must preserve
2845 stack_pointer_delta. */
2846 if (inhibit_defer_pop == 0)
2848 stack_pointer_delta = old_stack_allocated;
2849 pending_stack_adjust = 0;
2853 /* If value type not void, return an rtx for the value. */
2855 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2857 target = const0_rtx;
2858 else if (structure_value_addr)
2860 if (target == 0 || !MEM_P (target))
2863 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2864 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2865 structure_value_addr));
2866 set_mem_attributes (target, exp, 1);
2869 else if (pcc_struct_value)
2871 /* This is the special C++ case where we need to
2872 know what the true target was. We take care to
2873 never use this value more than once in one expression. */
2874 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2875 copy_to_reg (valreg));
2876 set_mem_attributes (target, exp, 1);
2878 /* Handle calls that return values in multiple non-contiguous locations.
2879 The Irix 6 ABI has examples of this. */
2880 else if (GET_CODE (valreg) == PARALLEL)
2884 /* This will only be assigned once, so it can be readonly. */
2885 tree nt = build_qualified_type (TREE_TYPE (exp),
2886 (TYPE_QUALS (TREE_TYPE (exp))
2887 | TYPE_QUAL_CONST));
2889 target = assign_temp (nt, 0, 1, 1);
2892 if (! rtx_equal_p (target, valreg))
2893 emit_group_store (target, valreg, TREE_TYPE (exp),
2894 int_size_in_bytes (TREE_TYPE (exp)));
2896 /* We can not support sibling calls for this case. */
2897 sibcall_failure = 1;
2900 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2901 && GET_MODE (target) == GET_MODE (valreg))
2903 bool may_overlap = false;
2905 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2906 reg to a plain register. */
2907 if (!REG_P (target) || HARD_REGISTER_P (target))
2908 valreg = avoid_likely_spilled_reg (valreg);
2910 /* If TARGET is a MEM in the argument area, and we have
2911 saved part of the argument area, then we can't store
2912 directly into TARGET as it may get overwritten when we
2913 restore the argument save area below. Don't work too
2914 hard though and simply force TARGET to a register if it
2915 is a MEM; the optimizer is quite likely to sort it out. */
2916 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2917 for (i = 0; i < num_actuals; i++)
2918 if (args[i].save_area)
2925 target = copy_to_reg (valreg);
2928 /* TARGET and VALREG cannot be equal at this point
2929 because the latter would not have
2930 REG_FUNCTION_VALUE_P true, while the former would if
2931 it were referring to the same register.
2933 If they refer to the same register, this move will be
2934 a no-op, except when function inlining is being
2936 emit_move_insn (target, valreg);
2938 /* If we are setting a MEM, this code must be executed.
2939 Since it is emitted after the call insn, sibcall
2940 optimization cannot be performed in that case. */
2942 sibcall_failure = 1;
2945 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2947 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2949 /* We can not support sibling calls for this case. */
2950 sibcall_failure = 1;
2953 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2955 if (targetm.calls.promote_function_return(funtype))
2957 /* If we promoted this return value, make the proper SUBREG.
2958 TARGET might be const0_rtx here, so be careful. */
2960 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2961 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2963 tree type = TREE_TYPE (exp);
2964 int unsignedp = TYPE_UNSIGNED (type);
2966 enum machine_mode pmode;
2968 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2969 /* If we don't promote as expected, something is wrong. */
2970 gcc_assert (GET_MODE (target) == pmode);
2972 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2973 && (GET_MODE_SIZE (GET_MODE (target))
2974 > GET_MODE_SIZE (TYPE_MODE (type))))
2976 offset = GET_MODE_SIZE (GET_MODE (target))
2977 - GET_MODE_SIZE (TYPE_MODE (type));
2978 if (! BYTES_BIG_ENDIAN)
2979 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
2980 else if (! WORDS_BIG_ENDIAN)
2981 offset %= UNITS_PER_WORD;
2983 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
2984 SUBREG_PROMOTED_VAR_P (target) = 1;
2985 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
2989 /* If size of args is variable or this was a constructor call for a stack
2990 argument, restore saved stack-pointer value. */
2992 if (old_stack_level)
2994 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
2995 stack_pointer_delta = old_stack_pointer_delta;
2996 pending_stack_adjust = old_pending_adj;
2997 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2998 stack_arg_under_construction = old_stack_arg_under_construction;
2999 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3000 stack_usage_map = initial_stack_usage_map;
3001 sibcall_failure = 1;
3003 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3005 #ifdef REG_PARM_STACK_SPACE
3007 restore_fixed_argument_area (save_area, argblock,
3008 high_to_save, low_to_save);
3011 /* If we saved any argument areas, restore them. */
3012 for (i = 0; i < num_actuals; i++)
3013 if (args[i].save_area)
3015 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3017 = gen_rtx_MEM (save_mode,
3018 memory_address (save_mode,
3019 XEXP (args[i].stack_slot, 0)));
3021 if (save_mode != BLKmode)
3022 emit_move_insn (stack_area, args[i].save_area);
3024 emit_block_move (stack_area, args[i].save_area,
3025 GEN_INT (args[i].locate.size.constant),
3026 BLOCK_OP_CALL_PARM);
3029 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3030 stack_usage_map = initial_stack_usage_map;
3033 /* If this was alloca, record the new stack level for nonlocal gotos.
3034 Check for the handler slots since we might not have a save area
3035 for non-local gotos. */
3037 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3038 update_nonlocal_goto_save_area ();
3040 /* Free up storage we no longer need. */
3041 for (i = 0; i < num_actuals; ++i)
3042 if (args[i].aligned_regs)
3043 free (args[i].aligned_regs);
3045 insns = get_insns ();
3050 tail_call_insns = insns;
3052 /* Restore the pending stack adjustment now that we have
3053 finished generating the sibling call sequence. */
3055 pending_stack_adjust = save_pending_stack_adjust;
3056 stack_pointer_delta = save_stack_pointer_delta;
3058 /* Prepare arg structure for next iteration. */
3059 for (i = 0; i < num_actuals; i++)
3062 args[i].aligned_regs = 0;
3066 sbitmap_free (stored_args_map);
3070 normal_call_insns = insns;
3072 /* Verify that we've deallocated all the stack we used. */
3073 gcc_assert ((flags & ECF_NORETURN)
3074 || (old_stack_allocated
3075 == stack_pointer_delta - pending_stack_adjust));
3078 /* If something prevents making this a sibling call,
3079 zero out the sequence. */
3080 if (sibcall_failure)
3081 tail_call_insns = NULL_RTX;
3086 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3087 arguments too, as argument area is now clobbered by the call. */
3088 if (tail_call_insns)
3090 emit_insn (tail_call_insns);
3091 crtl->tail_call_emit = true;
3094 emit_insn (normal_call_insns);
3096 currently_expanding_call--;
3098 if (stack_usage_map_buf)
3099 free (stack_usage_map_buf);
3104 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3105 this function's incoming arguments.
3107 At the start of RTL generation we know the only REG_EQUIV notes
3108 in the rtl chain are those for incoming arguments, so we can look
3109 for REG_EQUIV notes between the start of the function and the
3110 NOTE_INSN_FUNCTION_BEG.
3112 This is (slight) overkill. We could keep track of the highest
3113 argument we clobber and be more selective in removing notes, but it
3114 does not seem to be worth the effort. */
3117 fixup_tail_calls (void)
3121 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3125 /* There are never REG_EQUIV notes for the incoming arguments
3126 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3128 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3131 note = find_reg_note (insn, REG_EQUIV, 0);
3133 remove_note (insn, note);
3134 note = find_reg_note (insn, REG_EQUIV, 0);
3139 /* Traverse a list of TYPES and expand all complex types into their
3142 split_complex_types (tree types)
3146 /* Before allocating memory, check for the common case of no complex. */
3147 for (p = types; p; p = TREE_CHAIN (p))
3149 tree type = TREE_VALUE (p);
3150 if (TREE_CODE (type) == COMPLEX_TYPE
3151 && targetm.calls.split_complex_arg (type))
3157 types = copy_list (types);
3159 for (p = types; p; p = TREE_CHAIN (p))
3161 tree complex_type = TREE_VALUE (p);
3163 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3164 && targetm.calls.split_complex_arg (complex_type))
3168 /* Rewrite complex type with component type. */
3169 TREE_VALUE (p) = TREE_TYPE (complex_type);
3170 next = TREE_CHAIN (p);
3172 /* Add another component type for the imaginary part. */
3173 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3174 TREE_CHAIN (p) = imag;
3175 TREE_CHAIN (imag) = next;
3177 /* Skip the newly created node. */
3185 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3186 The RETVAL parameter specifies whether return value needs to be saved, other
3187 parameters are documented in the emit_library_call function below. */
3190 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3191 enum libcall_type fn_type,
3192 enum machine_mode outmode, int nargs, va_list p)
3194 /* Total size in bytes of all the stack-parms scanned so far. */
3195 struct args_size args_size;
3196 /* Size of arguments before any adjustments (such as rounding). */
3197 struct args_size original_args_size;
3200 /* Todo, choose the correct decl type of orgfun. Sadly this information
3201 isn't present here, so we default to native calling abi here. */
3202 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3206 CUMULATIVE_ARGS args_so_far;
3210 enum machine_mode mode;
3213 struct locate_and_pad_arg_data locate;
3217 int old_inhibit_defer_pop = inhibit_defer_pop;
3218 rtx call_fusage = 0;
3221 int pcc_struct_value = 0;
3222 int struct_value_size = 0;
3224 int reg_parm_stack_space = 0;
3227 tree tfom; /* type_for_mode (outmode, 0) */
3229 #ifdef REG_PARM_STACK_SPACE
3230 /* Define the boundary of the register parm stack space that needs to be
3232 int low_to_save, high_to_save;
3233 rtx save_area = 0; /* Place that it is saved. */
3236 /* Size of the stack reserved for parameter registers. */
3237 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3238 char *initial_stack_usage_map = stack_usage_map;
3239 char *stack_usage_map_buf = NULL;
3241 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3243 #ifdef REG_PARM_STACK_SPACE
3244 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3247 /* By default, library functions can not throw. */
3248 flags = ECF_NOTHROW;
3261 flags |= ECF_NORETURN;
3264 flags = ECF_NORETURN;
3266 case LCT_RETURNS_TWICE:
3267 flags = ECF_RETURNS_TWICE;
3272 /* Ensure current function's preferred stack boundary is at least
3274 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3275 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3277 /* If this kind of value comes back in memory,
3278 decide where in memory it should come back. */
3279 if (outmode != VOIDmode)
3281 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3282 if (aggregate_value_p (tfom, 0))
3284 #ifdef PCC_STATIC_STRUCT_RETURN
3286 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3287 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3288 pcc_struct_value = 1;
3290 value = gen_reg_rtx (outmode);
3291 #else /* not PCC_STATIC_STRUCT_RETURN */
3292 struct_value_size = GET_MODE_SIZE (outmode);
3293 if (value != 0 && MEM_P (value))
3296 mem_value = assign_temp (tfom, 0, 1, 1);
3298 /* This call returns a big structure. */
3299 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3303 tfom = void_type_node;
3305 /* ??? Unfinished: must pass the memory address as an argument. */
3307 /* Copy all the libcall-arguments out of the varargs data
3308 and into a vector ARGVEC.
3310 Compute how to pass each argument. We only support a very small subset
3311 of the full argument passing conventions to limit complexity here since
3312 library functions shouldn't have many args. */
3314 argvec = XALLOCAVEC (struct arg, nargs + 1);
3315 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3317 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3318 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3320 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3323 args_size.constant = 0;
3330 /* If there's a structure value address to be passed,
3331 either pass it in the special place, or pass it as an extra argument. */
3332 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3334 rtx addr = XEXP (mem_value, 0);
3338 /* Make sure it is a reasonable operand for a move or push insn. */
3339 if (!REG_P (addr) && !MEM_P (addr)
3340 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3341 addr = force_operand (addr, NULL_RTX);
3343 argvec[count].value = addr;
3344 argvec[count].mode = Pmode;
3345 argvec[count].partial = 0;
3347 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3348 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3349 NULL_TREE, 1) == 0);
3351 locate_and_pad_parm (Pmode, NULL_TREE,
3352 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3355 argvec[count].reg != 0,
3357 0, NULL_TREE, &args_size, &argvec[count].locate);
3359 if (argvec[count].reg == 0 || argvec[count].partial != 0
3360 || reg_parm_stack_space > 0)
3361 args_size.constant += argvec[count].locate.size.constant;
3363 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3368 for (; count < nargs; count++)
3370 rtx val = va_arg (p, rtx);
3371 enum machine_mode mode = va_arg (p, enum machine_mode);
3373 /* We cannot convert the arg value to the mode the library wants here;
3374 must do it earlier where we know the signedness of the arg. */
3375 gcc_assert (mode != BLKmode
3376 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3378 /* Make sure it is a reasonable operand for a move or push insn. */
3379 if (!REG_P (val) && !MEM_P (val)
3380 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3381 val = force_operand (val, NULL_RTX);
3383 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3387 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3389 /* If this was a CONST function, it is now PURE since it now
3391 if (flags & ECF_CONST)
3393 flags &= ~ECF_CONST;
3397 if (GET_MODE (val) == MEM && !must_copy)
3401 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3403 emit_move_insn (slot, val);
3406 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3407 gen_rtx_USE (VOIDmode, slot),
3410 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3411 gen_rtx_CLOBBER (VOIDmode,
3416 val = force_operand (XEXP (slot, 0), NULL_RTX);
3419 argvec[count].value = val;
3420 argvec[count].mode = mode;
3422 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3424 argvec[count].partial
3425 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3427 locate_and_pad_parm (mode, NULL_TREE,
3428 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3431 argvec[count].reg != 0,
3433 argvec[count].partial,
3434 NULL_TREE, &args_size, &argvec[count].locate);
3436 gcc_assert (!argvec[count].locate.size.var);
3438 if (argvec[count].reg == 0 || argvec[count].partial != 0
3439 || reg_parm_stack_space > 0)
3440 args_size.constant += argvec[count].locate.size.constant;
3442 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3445 /* If this machine requires an external definition for library
3446 functions, write one out. */
3447 assemble_external_libcall (fun);
3449 original_args_size = args_size;
3450 args_size.constant = (((args_size.constant
3451 + stack_pointer_delta
3455 - stack_pointer_delta);
3457 args_size.constant = MAX (args_size.constant,
3458 reg_parm_stack_space);
3460 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3461 args_size.constant -= reg_parm_stack_space;
3463 if (args_size.constant > crtl->outgoing_args_size)
3464 crtl->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 /* Since we will be writing into the entire argument area, the
3483 map must be allocated for its entire size, not just the part that
3484 is the responsibility of the caller. */
3485 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3486 needed += reg_parm_stack_space;
3488 #ifdef ARGS_GROW_DOWNWARD
3489 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3492 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3495 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3496 stack_usage_map = stack_usage_map_buf;
3498 if (initial_highest_arg_in_use)
3499 memcpy (stack_usage_map, initial_stack_usage_map,
3500 initial_highest_arg_in_use);
3502 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3503 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3504 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3507 /* We must be careful to use virtual regs before they're instantiated,
3508 and real regs afterwards. Loop optimization, for example, can create
3509 new libcalls after we've instantiated the virtual regs, and if we
3510 use virtuals anyway, they won't match the rtl patterns. */
3512 if (virtuals_instantiated)
3513 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3515 argblock = virtual_outgoing_args_rtx;
3520 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3523 /* If we push args individually in reverse order, perform stack alignment
3524 before the first push (the last arg). */
3525 if (argblock == 0 && PUSH_ARGS_REVERSED)
3526 anti_adjust_stack (GEN_INT (args_size.constant
3527 - original_args_size.constant));
3529 if (PUSH_ARGS_REVERSED)
3540 #ifdef REG_PARM_STACK_SPACE
3541 if (ACCUMULATE_OUTGOING_ARGS)
3543 /* The argument list is the property of the called routine and it
3544 may clobber it. If the fixed area has been used for previous
3545 parameters, we must save and restore it. */
3546 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3547 &low_to_save, &high_to_save);
3551 /* Push the args that need to be pushed. */
3553 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3554 are to be pushed. */
3555 for (count = 0; count < nargs; count++, argnum += inc)
3557 enum machine_mode mode = argvec[argnum].mode;
3558 rtx val = argvec[argnum].value;
3559 rtx reg = argvec[argnum].reg;
3560 int partial = argvec[argnum].partial;
3561 int lower_bound = 0, upper_bound = 0, i;
3563 if (! (reg != 0 && partial == 0))
3565 if (ACCUMULATE_OUTGOING_ARGS)
3567 /* If this is being stored into a pre-allocated, fixed-size,
3568 stack area, save any previous data at that location. */
3570 #ifdef ARGS_GROW_DOWNWARD
3571 /* stack_slot is negative, but we want to index stack_usage_map
3572 with positive values. */
3573 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3574 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3576 lower_bound = argvec[argnum].locate.offset.constant;
3577 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3581 /* Don't worry about things in the fixed argument area;
3582 it has already been saved. */
3583 if (i < reg_parm_stack_space)
3584 i = reg_parm_stack_space;
3585 while (i < upper_bound && stack_usage_map[i] == 0)
3588 if (i < upper_bound)
3590 /* We need to make a save area. */
3592 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3593 enum machine_mode save_mode
3594 = mode_for_size (size, MODE_INT, 1);
3596 = plus_constant (argblock,
3597 argvec[argnum].locate.offset.constant);
3599 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3601 if (save_mode == BLKmode)
3603 argvec[argnum].save_area
3604 = assign_stack_temp (BLKmode,
3605 argvec[argnum].locate.size.constant,
3608 emit_block_move (validize_mem (argvec[argnum].save_area),
3610 GEN_INT (argvec[argnum].locate.size.constant),
3611 BLOCK_OP_CALL_PARM);
3615 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3617 emit_move_insn (argvec[argnum].save_area, stack_area);
3622 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3623 partial, reg, 0, argblock,
3624 GEN_INT (argvec[argnum].locate.offset.constant),
3625 reg_parm_stack_space,
3626 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3628 /* Now mark the segment we just used. */
3629 if (ACCUMULATE_OUTGOING_ARGS)
3630 for (i = lower_bound; i < upper_bound; i++)
3631 stack_usage_map[i] = 1;
3635 if (flags & ECF_CONST)
3639 /* Indicate argument access so that alias.c knows that these
3642 use = plus_constant (argblock,
3643 argvec[argnum].locate.offset.constant);
3645 /* When arguments are pushed, trying to tell alias.c where
3646 exactly this argument is won't work, because the
3647 auto-increment causes confusion. So we merely indicate
3648 that we access something with a known mode somewhere on
3650 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3651 gen_rtx_SCRATCH (Pmode));
3652 use = gen_rtx_MEM (argvec[argnum].mode, use);
3653 use = gen_rtx_USE (VOIDmode, use);
3654 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3659 /* If we pushed args in forward order, perform stack alignment
3660 after pushing the last arg. */
3661 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3662 anti_adjust_stack (GEN_INT (args_size.constant
3663 - original_args_size.constant));
3665 if (PUSH_ARGS_REVERSED)
3670 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3672 /* Now load any reg parms into their regs. */
3674 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3675 are to be pushed. */
3676 for (count = 0; count < nargs; count++, argnum += inc)
3678 enum machine_mode mode = argvec[argnum].mode;
3679 rtx val = argvec[argnum].value;
3680 rtx reg = argvec[argnum].reg;
3681 int partial = argvec[argnum].partial;
3683 /* Handle calls that pass values in multiple non-contiguous
3684 locations. The PA64 has examples of this for library calls. */
3685 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3686 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3687 else if (reg != 0 && partial == 0)
3688 emit_move_insn (reg, val);
3693 /* Any regs containing parms remain in use through the call. */
3694 for (count = 0; count < nargs; count++)
3696 rtx reg = argvec[count].reg;
3697 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3698 use_group_regs (&call_fusage, reg);
3701 int partial = argvec[count].partial;
3705 gcc_assert (partial % UNITS_PER_WORD == 0);
3706 nregs = partial / UNITS_PER_WORD;
3707 use_regs (&call_fusage, REGNO (reg), nregs);
3710 use_reg (&call_fusage, reg);
3714 /* Pass the function the address in which to return a structure value. */
3715 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3717 emit_move_insn (struct_value,
3719 force_operand (XEXP (mem_value, 0),
3721 if (REG_P (struct_value))
3722 use_reg (&call_fusage, struct_value);
3725 /* Don't allow popping to be deferred, since then
3726 cse'ing of library calls could delete a call and leave the pop. */
3728 valreg = (mem_value == 0 && outmode != VOIDmode
3729 ? hard_libcall_value (outmode) : NULL_RTX);
3731 /* Stack must be properly aligned now. */
3732 gcc_assert (!(stack_pointer_delta
3733 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3735 before_call = get_last_insn ();
3737 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3738 will set inhibit_defer_pop to that value. */
3739 /* The return type is needed to decide how many bytes the function pops.
3740 Signedness plays no role in that, so for simplicity, we pretend it's
3741 always signed. We also assume that the list of arguments passed has
3742 no impact, so we pretend it is unknown. */
3744 emit_call_1 (fun, NULL,
3745 get_identifier (XSTR (orgfun, 0)),
3746 build_function_type (tfom, NULL_TREE),
3747 original_args_size.constant, args_size.constant,
3749 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3751 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3753 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3754 that it should complain if nonvolatile values are live. For
3755 functions that cannot return, inform flow that control does not
3758 if (flags & ECF_NORETURN)
3760 /* The barrier note must be emitted
3761 immediately after the CALL_INSN. Some ports emit more than
3762 just a CALL_INSN above, so we must search for it here. */
3764 rtx last = get_last_insn ();
3765 while (!CALL_P (last))
3767 last = PREV_INSN (last);
3768 /* There was no CALL_INSN? */
3769 gcc_assert (last != before_call);
3772 emit_barrier_after (last);
3775 /* Now restore inhibit_defer_pop to its actual original value. */
3780 /* Copy the value to the right place. */
3781 if (outmode != VOIDmode && retval)
3787 if (value != mem_value)
3788 emit_move_insn (value, mem_value);
3790 else if (GET_CODE (valreg) == PARALLEL)
3793 value = gen_reg_rtx (outmode);
3794 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3798 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3799 if (GET_MODE (valreg) != outmode)
3801 int unsignedp = TYPE_UNSIGNED (tfom);
3803 gcc_assert (targetm.calls.promote_function_return (tfom));
3804 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3805 == GET_MODE (valreg));
3807 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3811 emit_move_insn (value, valreg);
3817 if (ACCUMULATE_OUTGOING_ARGS)
3819 #ifdef REG_PARM_STACK_SPACE
3821 restore_fixed_argument_area (save_area, argblock,
3822 high_to_save, low_to_save);
3825 /* If we saved any argument areas, restore them. */
3826 for (count = 0; count < nargs; count++)
3827 if (argvec[count].save_area)
3829 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3830 rtx adr = plus_constant (argblock,
3831 argvec[count].locate.offset.constant);
3832 rtx stack_area = gen_rtx_MEM (save_mode,
3833 memory_address (save_mode, adr));
3835 if (save_mode == BLKmode)
3836 emit_block_move (stack_area,
3837 validize_mem (argvec[count].save_area),
3838 GEN_INT (argvec[count].locate.size.constant),
3839 BLOCK_OP_CALL_PARM);
3841 emit_move_insn (stack_area, argvec[count].save_area);
3844 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3845 stack_usage_map = initial_stack_usage_map;
3848 if (stack_usage_map_buf)
3849 free (stack_usage_map_buf);
3855 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3856 (emitting the queue unless NO_QUEUE is nonzero),
3857 for a value of mode OUTMODE,
3858 with NARGS different arguments, passed as alternating rtx values
3859 and machine_modes to convert them to.
3861 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3862 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3863 other types of library calls. */
3866 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3867 enum machine_mode outmode, int nargs, ...)
3871 va_start (p, nargs);
3872 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3876 /* Like emit_library_call except that an extra argument, VALUE,
3877 comes second and says where to store the result.
3878 (If VALUE is zero, this function chooses a convenient way
3879 to return the value.
3881 This function returns an rtx for where the value is to be found.
3882 If VALUE is nonzero, VALUE is returned. */
3885 emit_library_call_value (rtx orgfun, rtx value,
3886 enum libcall_type fn_type,
3887 enum machine_mode outmode, int nargs, ...)
3892 va_start (p, nargs);
3893 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3900 /* Store a single argument for a function call
3901 into the register or memory area where it must be passed.
3902 *ARG describes the argument value and where to pass it.
3904 ARGBLOCK is the address of the stack-block for all the arguments,
3905 or 0 on a machine where arguments are pushed individually.
3907 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3908 so must be careful about how the stack is used.
3910 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3911 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3912 that we need not worry about saving and restoring the stack.
3914 FNDECL is the declaration of the function we are calling.
3916 Return nonzero if this arg should cause sibcall failure,
3920 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3921 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3923 tree pval = arg->tree_value;
3927 int i, lower_bound = 0, upper_bound = 0;
3928 int sibcall_failure = 0;
3930 if (TREE_CODE (pval) == ERROR_MARK)
3933 /* Push a new temporary level for any temporaries we make for
3937 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3939 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3940 save any previous data at that location. */
3941 if (argblock && ! variable_size && arg->stack)
3943 #ifdef ARGS_GROW_DOWNWARD
3944 /* stack_slot is negative, but we want to index stack_usage_map
3945 with positive values. */
3946 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3947 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3951 lower_bound = upper_bound - arg->locate.size.constant;
3953 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3954 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3958 upper_bound = lower_bound + arg->locate.size.constant;
3962 /* Don't worry about things in the fixed argument area;
3963 it has already been saved. */
3964 if (i < reg_parm_stack_space)
3965 i = reg_parm_stack_space;
3966 while (i < upper_bound && stack_usage_map[i] == 0)
3969 if (i < upper_bound)
3971 /* We need to make a save area. */
3972 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
3973 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
3974 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
3975 rtx stack_area = gen_rtx_MEM (save_mode, adr);
3977 if (save_mode == BLKmode)
3979 tree ot = TREE_TYPE (arg->tree_value);
3980 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
3981 | TYPE_QUAL_CONST));
3983 arg->save_area = assign_temp (nt, 0, 1, 1);
3984 preserve_temp_slots (arg->save_area);
3985 emit_block_move (validize_mem (arg->save_area), stack_area,
3986 GEN_INT (arg->locate.size.constant),
3987 BLOCK_OP_CALL_PARM);
3991 arg->save_area = gen_reg_rtx (save_mode);
3992 emit_move_insn (arg->save_area, stack_area);
3998 /* If this isn't going to be placed on both the stack and in registers,
3999 set up the register and number of words. */
4000 if (! arg->pass_on_stack)
4002 if (flags & ECF_SIBCALL)
4003 reg = arg->tail_call_reg;
4006 partial = arg->partial;
4009 /* Being passed entirely in a register. We shouldn't be called in
4011 gcc_assert (reg == 0 || partial != 0);
4013 /* If this arg needs special alignment, don't load the registers
4015 if (arg->n_aligned_regs != 0)
4018 /* If this is being passed partially in a register, we can't evaluate
4019 it directly into its stack slot. Otherwise, we can. */
4020 if (arg->value == 0)
4022 /* stack_arg_under_construction is nonzero if a function argument is
4023 being evaluated directly into the outgoing argument list and
4024 expand_call must take special action to preserve the argument list
4025 if it is called recursively.
4027 For scalar function arguments stack_usage_map is sufficient to
4028 determine which stack slots must be saved and restored. Scalar
4029 arguments in general have pass_on_stack == 0.
4031 If this argument is initialized by a function which takes the
4032 address of the argument (a C++ constructor or a C function
4033 returning a BLKmode structure), then stack_usage_map is
4034 insufficient and expand_call must push the stack around the
4035 function call. Such arguments have pass_on_stack == 1.
4037 Note that it is always safe to set stack_arg_under_construction,
4038 but this generates suboptimal code if set when not needed. */
4040 if (arg->pass_on_stack)
4041 stack_arg_under_construction++;
4043 arg->value = expand_expr (pval,
4045 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4046 ? NULL_RTX : arg->stack,
4047 VOIDmode, EXPAND_STACK_PARM);
4049 /* If we are promoting object (or for any other reason) the mode
4050 doesn't agree, convert the mode. */
4052 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4053 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4054 arg->value, arg->unsignedp);
4056 if (arg->pass_on_stack)
4057 stack_arg_under_construction--;
4060 /* Check for overlap with already clobbered argument area. */
4061 if ((flags & ECF_SIBCALL)
4062 && MEM_P (arg->value)
4063 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4064 arg->locate.size.constant))
4065 sibcall_failure = 1;
4067 /* Don't allow anything left on stack from computation
4068 of argument to alloca. */
4069 if (flags & ECF_MAY_BE_ALLOCA)
4070 do_pending_stack_adjust ();
4072 if (arg->value == arg->stack)
4073 /* If the value is already in the stack slot, we are done. */
4075 else if (arg->mode != BLKmode)
4078 unsigned int parm_align;
4080 /* Argument is a scalar, not entirely passed in registers.
4081 (If part is passed in registers, arg->partial says how much
4082 and emit_push_insn will take care of putting it there.)
4084 Push it, and if its size is less than the
4085 amount of space allocated to it,
4086 also bump stack pointer by the additional space.
4087 Note that in C the default argument promotions
4088 will prevent such mismatches. */
4090 size = GET_MODE_SIZE (arg->mode);
4091 /* Compute how much space the push instruction will push.
4092 On many machines, pushing a byte will advance the stack
4093 pointer by a halfword. */
4094 #ifdef PUSH_ROUNDING
4095 size = PUSH_ROUNDING (size);
4099 /* Compute how much space the argument should get:
4100 round up to a multiple of the alignment for arguments. */
4101 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4102 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4103 / (PARM_BOUNDARY / BITS_PER_UNIT))
4104 * (PARM_BOUNDARY / BITS_PER_UNIT));
4106 /* Compute the alignment of the pushed argument. */
4107 parm_align = arg->locate.boundary;
4108 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4110 int pad = used - size;
4113 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4114 parm_align = MIN (parm_align, pad_align);
4118 /* This isn't already where we want it on the stack, so put it there.
4119 This can either be done with push or copy insns. */
4120 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4121 parm_align, partial, reg, used - size, argblock,
4122 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4123 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4125 /* Unless this is a partially-in-register argument, the argument is now
4128 arg->value = arg->stack;
4132 /* BLKmode, at least partly to be pushed. */
4134 unsigned int parm_align;
4138 /* Pushing a nonscalar.
4139 If part is passed in registers, PARTIAL says how much
4140 and emit_push_insn will take care of putting it there. */
4142 /* Round its size up to a multiple
4143 of the allocation unit for arguments. */
4145 if (arg->locate.size.var != 0)
4148 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4152 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4153 for BLKmode is careful to avoid it. */
4154 excess = (arg->locate.size.constant
4155 - int_size_in_bytes (TREE_TYPE (pval))
4157 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4158 NULL_RTX, TYPE_MODE (sizetype), 0);
4161 parm_align = arg->locate.boundary;
4163 /* When an argument is padded down, the block is aligned to
4164 PARM_BOUNDARY, but the actual argument isn't. */
4165 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4167 if (arg->locate.size.var)
4168 parm_align = BITS_PER_UNIT;
4171 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4172 parm_align = MIN (parm_align, excess_align);
4176 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4178 /* emit_push_insn might not work properly if arg->value and
4179 argblock + arg->locate.offset areas overlap. */
4183 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4184 || (GET_CODE (XEXP (x, 0)) == PLUS
4185 && XEXP (XEXP (x, 0), 0) ==
4186 crtl->args.internal_arg_pointer
4187 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4189 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4190 i = INTVAL (XEXP (XEXP (x, 0), 1));
4192 /* expand_call should ensure this. */
4193 gcc_assert (!arg->locate.offset.var
4194 && arg->locate.size.var == 0
4195 && GET_CODE (size_rtx) == CONST_INT);
4197 if (arg->locate.offset.constant > i)
4199 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4200 sibcall_failure = 1;
4202 else if (arg->locate.offset.constant < i)
4204 /* Use arg->locate.size.constant instead of size_rtx
4205 because we only care about the part of the argument
4207 if (i < (arg->locate.offset.constant
4208 + arg->locate.size.constant))
4209 sibcall_failure = 1;
4213 /* Even though they appear to be at the same location,
4214 if part of the outgoing argument is in registers,
4215 they aren't really at the same location. Check for
4216 this by making sure that the incoming size is the
4217 same as the outgoing size. */
4218 if (arg->locate.size.constant != INTVAL (size_rtx))
4219 sibcall_failure = 1;
4224 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4225 parm_align, partial, reg, excess, argblock,
4226 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4227 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4229 /* Unless this is a partially-in-register argument, the argument is now
4232 ??? Unlike the case above, in which we want the actual
4233 address of the data, so that we can load it directly into a
4234 register, here we want the address of the stack slot, so that
4235 it's properly aligned for word-by-word copying or something
4236 like that. It's not clear that this is always correct. */
4238 arg->value = arg->stack_slot;
4241 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4243 tree type = TREE_TYPE (arg->tree_value);
4245 = emit_group_load_into_temps (arg->reg, arg->value, type,
4246 int_size_in_bytes (type));
4249 /* Mark all slots this store used. */
4250 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4251 && argblock && ! variable_size && arg->stack)
4252 for (i = lower_bound; i < upper_bound; i++)
4253 stack_usage_map[i] = 1;
4255 /* Once we have pushed something, pops can't safely
4256 be deferred during the rest of the arguments. */
4259 /* Free any temporary slots made in processing this argument. Show
4260 that we might have taken the address of something and pushed that
4262 preserve_temp_slots (NULL_RTX);
4266 return sibcall_failure;
4269 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4272 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4278 /* If the type has variable size... */
4279 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4282 /* If the type is marked as addressable (it is required
4283 to be constructed into the stack)... */
4284 if (TREE_ADDRESSABLE (type))
4290 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4291 takes trailing padding of a structure into account. */
4292 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4295 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4300 /* If the type has variable size... */
4301 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4304 /* If the type is marked as addressable (it is required
4305 to be constructed into the stack)... */
4306 if (TREE_ADDRESSABLE (type))
4309 /* If the padding and mode of the type is such that a copy into
4310 a register would put it into the wrong part of the register. */
4312 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4313 && (FUNCTION_ARG_PADDING (mode, type)
4314 == (BYTES_BIG_ENDIAN ? upward : downward)))