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"
40 #include "langhooks.h"
45 #include "tree-flow.h"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
54 /* Tree node for this argument. */
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
60 /* Initially-compute RTL value for argument; only for const functions. */
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
93 /* Place that this stack area has been saved, if needed. */
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
139 tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree split_complex_types (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
188 if (static_chain_value != 0)
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
241 emit_call_1 (rtx funexp, tree fntree, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
274 rtx n_pop = GEN_INT (n_popped);
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
289 emit_call_insn (pat);
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
304 if (HAVE_call_pop && HAVE_call_value_pop)
307 rtx n_pop = GEN_INT (n_popped);
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
321 emit_call_insn (pat);
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
379 /* If this call can't throw, attach a REG_EH_REGION reg note to that
381 if (ecf_flags & ECF_NOTHROW)
382 add_reg_note (call_insn, REG_EH_REGION, const0_rtx);
385 int rn = lookup_expr_eh_region (fntree);
387 /* If rn < 0, then either (1) tree-ssa not used or (2) doesn't
388 throw, which we already took care of. */
390 add_reg_note (call_insn, REG_EH_REGION, GEN_INT (rn));
393 if (ecf_flags & ECF_NORETURN)
394 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
396 if (ecf_flags & ECF_RETURNS_TWICE)
398 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
399 cfun->calls_setjmp = 1;
402 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
404 /* Restore this now, so that we do defer pops for this call's args
405 if the context of the call as a whole permits. */
406 inhibit_defer_pop = old_inhibit_defer_pop;
411 CALL_INSN_FUNCTION_USAGE (call_insn)
412 = gen_rtx_EXPR_LIST (VOIDmode,
413 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
414 CALL_INSN_FUNCTION_USAGE (call_insn));
415 rounded_stack_size -= n_popped;
416 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
417 stack_pointer_delta -= n_popped;
420 if (!ACCUMULATE_OUTGOING_ARGS)
422 /* If returning from the subroutine does not automatically pop the args,
423 we need an instruction to pop them sooner or later.
424 Perhaps do it now; perhaps just record how much space to pop later.
426 If returning from the subroutine does pop the args, indicate that the
427 stack pointer will be changed. */
429 if (rounded_stack_size != 0)
431 if (ecf_flags & ECF_NORETURN)
432 /* Just pretend we did the pop. */
433 stack_pointer_delta -= rounded_stack_size;
434 else if (flag_defer_pop && inhibit_defer_pop == 0
435 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
436 pending_stack_adjust += rounded_stack_size;
438 adjust_stack (rounded_stack_size_rtx);
441 /* When we accumulate outgoing args, we must avoid any stack manipulations.
442 Restore the stack pointer to its original value now. Usually
443 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
444 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
445 popping variants of functions exist as well.
447 ??? We may optimize similar to defer_pop above, but it is
448 probably not worthwhile.
450 ??? It will be worthwhile to enable combine_stack_adjustments even for
453 anti_adjust_stack (GEN_INT (n_popped));
456 /* Determine if the function identified by NAME and FNDECL is one with
457 special properties we wish to know about.
459 For example, if the function might return more than one time (setjmp), then
460 set RETURNS_TWICE to a nonzero value.
462 Similarly set NORETURN if the function is in the longjmp family.
464 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
465 space from the stack such as alloca. */
468 special_function_p (const_tree fndecl, int flags)
470 if (fndecl && DECL_NAME (fndecl)
471 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
472 /* Exclude functions not at the file scope, or not `extern',
473 since they are not the magic functions we would otherwise
475 FIXME: this should be handled with attributes, not with this
476 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
477 because you can declare fork() inside a function if you
479 && (DECL_CONTEXT (fndecl) == NULL_TREE
480 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
481 && TREE_PUBLIC (fndecl))
483 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
484 const char *tname = name;
486 /* We assume that alloca will always be called by name. It
487 makes no sense to pass it as a pointer-to-function to
488 anything that does not understand its behavior. */
489 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
491 && ! strcmp (name, "alloca"))
492 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
494 && ! strcmp (name, "__builtin_alloca"))))
495 flags |= ECF_MAY_BE_ALLOCA;
497 /* Disregard prefix _, __ or __x. */
500 if (name[1] == '_' && name[2] == 'x')
502 else if (name[1] == '_')
511 && (! strcmp (tname, "setjmp")
512 || ! strcmp (tname, "setjmp_syscall")))
514 && ! strcmp (tname, "sigsetjmp"))
516 && ! strcmp (tname, "savectx")))
517 flags |= ECF_RETURNS_TWICE;
520 && ! strcmp (tname, "siglongjmp"))
521 flags |= ECF_NORETURN;
523 else if ((tname[0] == 'q' && tname[1] == 's'
524 && ! strcmp (tname, "qsetjmp"))
525 || (tname[0] == 'v' && tname[1] == 'f'
526 && ! strcmp (tname, "vfork"))
527 || (tname[0] == 'g' && tname[1] == 'e'
528 && !strcmp (tname, "getcontext")))
529 flags |= ECF_RETURNS_TWICE;
531 else if (tname[0] == 'l' && tname[1] == 'o'
532 && ! strcmp (tname, "longjmp"))
533 flags |= ECF_NORETURN;
539 /* Return nonzero when FNDECL represents a call to setjmp. */
542 setjmp_call_p (const_tree fndecl)
544 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
548 /* Return true if STMT is an alloca call. */
551 gimple_alloca_call_p (const_gimple stmt)
555 if (!is_gimple_call (stmt))
558 fndecl = gimple_call_fndecl (stmt);
559 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
565 /* Return true when exp contains alloca call. */
568 alloca_call_p (const_tree exp)
570 if (TREE_CODE (exp) == CALL_EXPR
571 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
572 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
573 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
574 & ECF_MAY_BE_ALLOCA))
579 /* Detect flags (function attributes) from the function decl or type node. */
582 flags_from_decl_or_type (const_tree exp)
585 const_tree type = exp;
589 type = TREE_TYPE (exp);
591 /* The function exp may have the `malloc' attribute. */
592 if (DECL_IS_MALLOC (exp))
595 /* The function exp may have the `returns_twice' attribute. */
596 if (DECL_IS_RETURNS_TWICE (exp))
597 flags |= ECF_RETURNS_TWICE;
599 /* Process the pure and const attributes. */
600 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
602 if (DECL_PURE_P (exp))
604 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
605 flags |= ECF_LOOPING_CONST_OR_PURE;
607 if (DECL_IS_NOVOPS (exp))
610 if (TREE_NOTHROW (exp))
611 flags |= ECF_NOTHROW;
613 flags = special_function_p (exp, flags);
615 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
618 if (TREE_THIS_VOLATILE (exp))
619 flags |= ECF_NORETURN;
624 /* Detect flags from a CALL_EXPR. */
627 call_expr_flags (const_tree t)
630 tree decl = get_callee_fndecl (t);
633 flags = flags_from_decl_or_type (decl);
636 t = TREE_TYPE (CALL_EXPR_FN (t));
637 if (t && TREE_CODE (t) == POINTER_TYPE)
638 flags = flags_from_decl_or_type (TREE_TYPE (t));
646 /* Precompute all register parameters as described by ARGS, storing values
647 into fields within the ARGS array.
649 NUM_ACTUALS indicates the total number elements in the ARGS array.
651 Set REG_PARM_SEEN if we encounter a register parameter. */
654 precompute_register_parameters (int num_actuals, struct arg_data *args,
661 for (i = 0; i < num_actuals; i++)
662 if (args[i].reg != 0 && ! args[i].pass_on_stack)
666 if (args[i].value == 0)
669 args[i].value = expand_normal (args[i].tree_value);
670 preserve_temp_slots (args[i].value);
674 /* If the value is a non-legitimate constant, force it into a
675 pseudo now. TLS symbols sometimes need a call to resolve. */
676 if (CONSTANT_P (args[i].value)
677 && !LEGITIMATE_CONSTANT_P (args[i].value))
678 args[i].value = force_reg (args[i].mode, args[i].value);
680 /* If we are to promote the function arg to a wider mode,
683 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
685 = convert_modes (args[i].mode,
686 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
687 args[i].value, args[i].unsignedp);
689 /* If we're going to have to load the value by parts, pull the
690 parts into pseudos. The part extraction process can involve
691 non-trivial computation. */
692 if (GET_CODE (args[i].reg) == PARALLEL)
694 tree type = TREE_TYPE (args[i].tree_value);
695 args[i].parallel_value
696 = emit_group_load_into_temps (args[i].reg, args[i].value,
697 type, int_size_in_bytes (type));
700 /* If the value is expensive, and we are inside an appropriately
701 short loop, put the value into a pseudo and then put the pseudo
704 For small register classes, also do this if this call uses
705 register parameters. This is to avoid reload conflicts while
706 loading the parameters registers. */
708 else if ((! (REG_P (args[i].value)
709 || (GET_CODE (args[i].value) == SUBREG
710 && REG_P (SUBREG_REG (args[i].value)))))
711 && args[i].mode != BLKmode
712 && rtx_cost (args[i].value, SET) > COSTS_N_INSNS (1)
713 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
715 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
719 #ifdef REG_PARM_STACK_SPACE
721 /* The argument list is the property of the called routine and it
722 may clobber it. If the fixed area has been used for previous
723 parameters, we must save and restore it. */
726 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
731 /* Compute the boundary of the area that needs to be saved, if any. */
732 high = reg_parm_stack_space;
733 #ifdef ARGS_GROW_DOWNWARD
736 if (high > highest_outgoing_arg_in_use)
737 high = highest_outgoing_arg_in_use;
739 for (low = 0; low < high; low++)
740 if (stack_usage_map[low] != 0)
743 enum machine_mode save_mode;
748 while (stack_usage_map[--high] == 0)
752 *high_to_save = high;
754 num_to_save = high - low + 1;
755 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
757 /* If we don't have the required alignment, must do this
759 if ((low & (MIN (GET_MODE_SIZE (save_mode),
760 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
763 #ifdef ARGS_GROW_DOWNWARD
768 stack_area = gen_rtx_MEM (save_mode,
769 memory_address (save_mode,
770 plus_constant (argblock,
773 set_mem_align (stack_area, PARM_BOUNDARY);
774 if (save_mode == BLKmode)
776 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
777 emit_block_move (validize_mem (save_area), stack_area,
778 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
782 save_area = gen_reg_rtx (save_mode);
783 emit_move_insn (save_area, stack_area);
793 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
795 enum machine_mode save_mode = GET_MODE (save_area);
799 #ifdef ARGS_GROW_DOWNWARD
800 delta = -high_to_save;
804 stack_area = gen_rtx_MEM (save_mode,
805 memory_address (save_mode,
806 plus_constant (argblock, delta)));
807 set_mem_align (stack_area, PARM_BOUNDARY);
809 if (save_mode != BLKmode)
810 emit_move_insn (stack_area, save_area);
812 emit_block_move (stack_area, validize_mem (save_area),
813 GEN_INT (high_to_save - low_to_save + 1),
816 #endif /* REG_PARM_STACK_SPACE */
818 /* If any elements in ARGS refer to parameters that are to be passed in
819 registers, but not in memory, and whose alignment does not permit a
820 direct copy into registers. Copy the values into a group of pseudos
821 which we will later copy into the appropriate hard registers.
823 Pseudos for each unaligned argument will be stored into the array
824 args[argnum].aligned_regs. The caller is responsible for deallocating
825 the aligned_regs array if it is nonzero. */
828 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
832 for (i = 0; i < num_actuals; i++)
833 if (args[i].reg != 0 && ! args[i].pass_on_stack
834 && args[i].mode == BLKmode
835 && (TYPE_ALIGN (TREE_TYPE (args[i].tree_value))
836 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
838 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
839 int endian_correction = 0;
843 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
844 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
848 args[i].n_aligned_regs
849 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
852 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
854 /* Structures smaller than a word are normally aligned to the
855 least significant byte. On a BYTES_BIG_ENDIAN machine,
856 this means we must skip the empty high order bytes when
857 calculating the bit offset. */
858 if (bytes < UNITS_PER_WORD
859 #ifdef BLOCK_REG_PADDING
860 && (BLOCK_REG_PADDING (args[i].mode,
861 TREE_TYPE (args[i].tree_value), 1)
867 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
869 for (j = 0; j < args[i].n_aligned_regs; j++)
871 rtx reg = gen_reg_rtx (word_mode);
872 rtx word = operand_subword_force (args[i].value, j, BLKmode);
873 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
875 args[i].aligned_regs[j] = reg;
876 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
877 word_mode, word_mode);
879 /* There is no need to restrict this code to loading items
880 in TYPE_ALIGN sized hunks. The bitfield instructions can
881 load up entire word sized registers efficiently.
883 ??? This may not be needed anymore.
884 We use to emit a clobber here but that doesn't let later
885 passes optimize the instructions we emit. By storing 0 into
886 the register later passes know the first AND to zero out the
887 bitfield being set in the register is unnecessary. The store
888 of 0 will be deleted as will at least the first AND. */
890 emit_move_insn (reg, const0_rtx);
892 bytes -= bitsize / BITS_PER_UNIT;
893 store_bit_field (reg, bitsize, endian_correction, word_mode,
899 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
902 NUM_ACTUALS is the total number of parameters.
904 N_NAMED_ARGS is the total number of named arguments.
906 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
909 FNDECL is the tree code for the target of this call (if known)
911 ARGS_SO_FAR holds state needed by the target to know where to place
914 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
915 for arguments which are passed in registers.
917 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
918 and may be modified by this routine.
920 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
921 flags which may may be modified by this routine.
923 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
924 that requires allocation of stack space.
926 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
927 the thunked-to function. */
930 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
931 struct arg_data *args,
932 struct args_size *args_size,
933 int n_named_args ATTRIBUTE_UNUSED,
934 tree exp, tree struct_value_addr_value,
936 CUMULATIVE_ARGS *args_so_far,
937 int reg_parm_stack_space,
938 rtx *old_stack_level, int *old_pending_adj,
939 int *must_preallocate, int *ecf_flags,
940 bool *may_tailcall, bool call_from_thunk_p)
942 /* 1 if scanning parms front to back, -1 if scanning back to front. */
945 /* Count arg position in order args appear. */
950 args_size->constant = 0;
953 /* In this loop, we consider args in the order they are written.
954 We fill up ARGS from the front or from the back if necessary
955 so that in any case the first arg to be pushed ends up at the front. */
957 if (PUSH_ARGS_REVERSED)
959 i = num_actuals - 1, inc = -1;
960 /* In this case, must reverse order of args
961 so that we compute and push the last arg first. */
968 /* First fill in the actual arguments in the ARGS array, splitting
969 complex arguments if necessary. */
972 call_expr_arg_iterator iter;
975 if (struct_value_addr_value)
977 args[j].tree_value = struct_value_addr_value;
980 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
982 tree argtype = TREE_TYPE (arg);
983 if (targetm.calls.split_complex_arg
985 && TREE_CODE (argtype) == COMPLEX_TYPE
986 && targetm.calls.split_complex_arg (argtype))
988 tree subtype = TREE_TYPE (argtype);
989 arg = save_expr (arg);
990 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
992 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
995 args[j].tree_value = arg;
1000 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1001 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1003 tree type = TREE_TYPE (args[i].tree_value);
1005 enum machine_mode mode;
1007 /* Replace erroneous argument with constant zero. */
1008 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1009 args[i].tree_value = integer_zero_node, type = integer_type_node;
1011 /* If TYPE is a transparent union, pass things the way we would
1012 pass the first field of the union. We have already verified that
1013 the modes are the same. */
1014 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1015 type = TREE_TYPE (TYPE_FIELDS (type));
1017 /* Decide where to pass this arg.
1019 args[i].reg is nonzero if all or part is passed in registers.
1021 args[i].partial is nonzero if part but not all is passed in registers,
1022 and the exact value says how many bytes are passed in registers.
1024 args[i].pass_on_stack is nonzero if the argument must at least be
1025 computed on the stack. It may then be loaded back into registers
1026 if args[i].reg is nonzero.
1028 These decisions are driven by the FUNCTION_... macros and must agree
1029 with those made by function.c. */
1031 /* See if this argument should be passed by invisible reference. */
1032 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1033 type, argpos < n_named_args))
1039 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1040 type, argpos < n_named_args);
1042 /* If we're compiling a thunk, pass through invisible references
1043 instead of making a copy. */
1044 if (call_from_thunk_p
1046 && !TREE_ADDRESSABLE (type)
1047 && (base = get_base_address (args[i].tree_value))
1048 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1050 /* We can't use sibcalls if a callee-copied argument is
1051 stored in the current function's frame. */
1052 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1053 *may_tailcall = false;
1055 args[i].tree_value = build_fold_addr_expr (args[i].tree_value);
1056 type = TREE_TYPE (args[i].tree_value);
1058 if (*ecf_flags & ECF_CONST)
1059 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1063 /* We make a copy of the object and pass the address to the
1064 function being called. */
1067 if (!COMPLETE_TYPE_P (type)
1068 || TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST
1069 || (flag_stack_check && ! STACK_CHECK_BUILTIN
1070 && (0 < compare_tree_int (TYPE_SIZE_UNIT (type),
1071 STACK_CHECK_MAX_VAR_SIZE))))
1073 /* This is a variable-sized object. Make space on the stack
1075 rtx size_rtx = expr_size (args[i].tree_value);
1077 if (*old_stack_level == 0)
1079 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1080 *old_pending_adj = pending_stack_adjust;
1081 pending_stack_adjust = 0;
1084 copy = gen_rtx_MEM (BLKmode,
1085 allocate_dynamic_stack_space
1086 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1087 set_mem_attributes (copy, type, 1);
1090 copy = assign_temp (type, 0, 1, 0);
1092 store_expr (args[i].tree_value, copy, 0, false);
1094 /* Just change the const function to pure and then let
1095 the next test clear the pure based on
1097 if (*ecf_flags & ECF_CONST)
1099 *ecf_flags &= ~ECF_CONST;
1100 *ecf_flags |= ECF_PURE;
1103 if (!callee_copies && *ecf_flags & ECF_PURE)
1104 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1107 = build_fold_addr_expr (make_tree (type, copy));
1108 type = TREE_TYPE (args[i].tree_value);
1109 *may_tailcall = false;
1113 mode = TYPE_MODE (type);
1114 unsignedp = TYPE_UNSIGNED (type);
1116 if (targetm.calls.promote_function_args (fndecl ? TREE_TYPE (fndecl) : 0))
1117 mode = promote_mode (type, mode, &unsignedp, 1);
1119 args[i].unsignedp = unsignedp;
1120 args[i].mode = mode;
1122 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1123 argpos < n_named_args);
1124 #ifdef FUNCTION_INCOMING_ARG
1125 /* If this is a sibling call and the machine has register windows, the
1126 register window has to be unwinded before calling the routine, so
1127 arguments have to go into the incoming registers. */
1128 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1129 argpos < n_named_args);
1131 args[i].tail_call_reg = args[i].reg;
1136 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1137 argpos < n_named_args);
1139 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1141 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1142 it means that we are to pass this arg in the register(s) designated
1143 by the PARALLEL, but also to pass it in the stack. */
1144 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1145 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1146 args[i].pass_on_stack = 1;
1148 /* If this is an addressable type, we must preallocate the stack
1149 since we must evaluate the object into its final location.
1151 If this is to be passed in both registers and the stack, it is simpler
1153 if (TREE_ADDRESSABLE (type)
1154 || (args[i].pass_on_stack && args[i].reg != 0))
1155 *must_preallocate = 1;
1157 /* Compute the stack-size of this argument. */
1158 if (args[i].reg == 0 || args[i].partial != 0
1159 || reg_parm_stack_space > 0
1160 || args[i].pass_on_stack)
1161 locate_and_pad_parm (mode, type,
1162 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1167 args[i].pass_on_stack ? 0 : args[i].partial,
1168 fndecl, args_size, &args[i].locate);
1169 #ifdef BLOCK_REG_PADDING
1171 /* The argument is passed entirely in registers. See at which
1172 end it should be padded. */
1173 args[i].locate.where_pad =
1174 BLOCK_REG_PADDING (mode, type,
1175 int_size_in_bytes (type) <= UNITS_PER_WORD);
1178 /* Update ARGS_SIZE, the total stack space for args so far. */
1180 args_size->constant += args[i].locate.size.constant;
1181 if (args[i].locate.size.var)
1182 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1184 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1185 have been used, etc. */
1187 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1188 argpos < n_named_args);
1192 /* Update ARGS_SIZE to contain the total size for the argument block.
1193 Return the original constant component of the argument block's size.
1195 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1196 for arguments passed in registers. */
1199 compute_argument_block_size (int reg_parm_stack_space,
1200 struct args_size *args_size,
1201 tree fndecl ATTRIBUTE_UNUSED,
1202 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1204 int unadjusted_args_size = args_size->constant;
1206 /* For accumulate outgoing args mode we don't need to align, since the frame
1207 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1208 backends from generating misaligned frame sizes. */
1209 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1210 preferred_stack_boundary = STACK_BOUNDARY;
1212 /* Compute the actual size of the argument block required. The variable
1213 and constant sizes must be combined, the size may have to be rounded,
1214 and there may be a minimum required size. */
1218 args_size->var = ARGS_SIZE_TREE (*args_size);
1219 args_size->constant = 0;
1221 preferred_stack_boundary /= BITS_PER_UNIT;
1222 if (preferred_stack_boundary > 1)
1224 /* We don't handle this case yet. To handle it correctly we have
1225 to add the delta, round and subtract the delta.
1226 Currently no machine description requires this support. */
1227 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1228 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1231 if (reg_parm_stack_space > 0)
1234 = size_binop (MAX_EXPR, args_size->var,
1235 ssize_int (reg_parm_stack_space));
1237 /* The area corresponding to register parameters is not to count in
1238 the size of the block we need. So make the adjustment. */
1239 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1241 = size_binop (MINUS_EXPR, args_size->var,
1242 ssize_int (reg_parm_stack_space));
1247 preferred_stack_boundary /= BITS_PER_UNIT;
1248 if (preferred_stack_boundary < 1)
1249 preferred_stack_boundary = 1;
1250 args_size->constant = (((args_size->constant
1251 + stack_pointer_delta
1252 + preferred_stack_boundary - 1)
1253 / preferred_stack_boundary
1254 * preferred_stack_boundary)
1255 - stack_pointer_delta);
1257 args_size->constant = MAX (args_size->constant,
1258 reg_parm_stack_space);
1260 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
1261 args_size->constant -= reg_parm_stack_space;
1263 return unadjusted_args_size;
1266 /* Precompute parameters as needed for a function call.
1268 FLAGS is mask of ECF_* constants.
1270 NUM_ACTUALS is the number of arguments.
1272 ARGS is an array containing information for each argument; this
1273 routine fills in the INITIAL_VALUE and VALUE fields for each
1274 precomputed argument. */
1277 precompute_arguments (int num_actuals, struct arg_data *args)
1281 /* If this is a libcall, then precompute all arguments so that we do not
1282 get extraneous instructions emitted as part of the libcall sequence. */
1284 /* If we preallocated the stack space, and some arguments must be passed
1285 on the stack, then we must precompute any parameter which contains a
1286 function call which will store arguments on the stack.
1287 Otherwise, evaluating the parameter may clobber previous parameters
1288 which have already been stored into the stack. (we have code to avoid
1289 such case by saving the outgoing stack arguments, but it results in
1291 if (!ACCUMULATE_OUTGOING_ARGS)
1294 for (i = 0; i < num_actuals; i++)
1296 enum machine_mode mode;
1298 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1301 /* If this is an addressable type, we cannot pre-evaluate it. */
1302 gcc_assert (!TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value)));
1304 args[i].initial_value = args[i].value
1305 = expand_normal (args[i].tree_value);
1307 mode = TYPE_MODE (TREE_TYPE (args[i].tree_value));
1308 if (mode != args[i].mode)
1311 = convert_modes (args[i].mode, mode,
1312 args[i].value, args[i].unsignedp);
1313 #if defined(PROMOTE_FUNCTION_MODE) && !defined(PROMOTE_MODE)
1314 /* CSE will replace this only if it contains args[i].value
1315 pseudo, so convert it down to the declared mode using
1317 if (REG_P (args[i].value)
1318 && GET_MODE_CLASS (args[i].mode) == MODE_INT)
1320 args[i].initial_value
1321 = gen_lowpart_SUBREG (mode, args[i].value);
1322 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1323 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1331 /* Given the current state of MUST_PREALLOCATE and information about
1332 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1333 compute and return the final value for MUST_PREALLOCATE. */
1336 finalize_must_preallocate (int must_preallocate, int num_actuals,
1337 struct arg_data *args, struct args_size *args_size)
1339 /* See if we have or want to preallocate stack space.
1341 If we would have to push a partially-in-regs parm
1342 before other stack parms, preallocate stack space instead.
1344 If the size of some parm is not a multiple of the required stack
1345 alignment, we must preallocate.
1347 If the total size of arguments that would otherwise create a copy in
1348 a temporary (such as a CALL) is more than half the total argument list
1349 size, preallocation is faster.
1351 Another reason to preallocate is if we have a machine (like the m88k)
1352 where stack alignment is required to be maintained between every
1353 pair of insns, not just when the call is made. However, we assume here
1354 that such machines either do not have push insns (and hence preallocation
1355 would occur anyway) or the problem is taken care of with
1358 if (! must_preallocate)
1360 int partial_seen = 0;
1361 int copy_to_evaluate_size = 0;
1364 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1366 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1368 else if (partial_seen && args[i].reg == 0)
1369 must_preallocate = 1;
1371 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1372 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1373 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1374 || TREE_CODE (args[i].tree_value) == COND_EXPR
1375 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1376 copy_to_evaluate_size
1377 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1380 if (copy_to_evaluate_size * 2 >= args_size->constant
1381 && args_size->constant > 0)
1382 must_preallocate = 1;
1384 return must_preallocate;
1387 /* If we preallocated stack space, compute the address of each argument
1388 and store it into the ARGS array.
1390 We need not ensure it is a valid memory address here; it will be
1391 validized when it is used.
1393 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1396 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1400 rtx arg_reg = argblock;
1401 int i, arg_offset = 0;
1403 if (GET_CODE (argblock) == PLUS)
1404 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1406 for (i = 0; i < num_actuals; i++)
1408 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1409 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1411 unsigned int align, boundary;
1412 unsigned int units_on_stack = 0;
1413 enum machine_mode partial_mode = VOIDmode;
1415 /* Skip this parm if it will not be passed on the stack. */
1416 if (! args[i].pass_on_stack
1418 && args[i].partial == 0)
1421 if (GET_CODE (offset) == CONST_INT)
1422 addr = plus_constant (arg_reg, INTVAL (offset));
1424 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1426 addr = plus_constant (addr, arg_offset);
1428 if (args[i].partial != 0)
1430 /* Only part of the parameter is being passed on the stack.
1431 Generate a simple memory reference of the correct size. */
1432 units_on_stack = args[i].locate.size.constant;
1433 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1435 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1436 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1440 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1441 set_mem_attributes (args[i].stack,
1442 TREE_TYPE (args[i].tree_value), 1);
1444 align = BITS_PER_UNIT;
1445 boundary = args[i].locate.boundary;
1446 if (args[i].locate.where_pad != downward)
1448 else if (GET_CODE (offset) == CONST_INT)
1450 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1451 align = align & -align;
1453 set_mem_align (args[i].stack, align);
1455 if (GET_CODE (slot_offset) == CONST_INT)
1456 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1458 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1460 addr = plus_constant (addr, arg_offset);
1462 if (args[i].partial != 0)
1464 /* Only part of the parameter is being passed on the stack.
1465 Generate a simple memory reference of the correct size.
1467 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1468 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1472 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1473 set_mem_attributes (args[i].stack_slot,
1474 TREE_TYPE (args[i].tree_value), 1);
1476 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1478 /* Function incoming arguments may overlap with sibling call
1479 outgoing arguments and we cannot allow reordering of reads
1480 from function arguments with stores to outgoing arguments
1481 of sibling calls. */
1482 set_mem_alias_set (args[i].stack, 0);
1483 set_mem_alias_set (args[i].stack_slot, 0);
1488 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1489 in a call instruction.
1491 FNDECL is the tree node for the target function. For an indirect call
1492 FNDECL will be NULL_TREE.
1494 ADDR is the operand 0 of CALL_EXPR for this call. */
1497 rtx_for_function_call (tree fndecl, tree addr)
1501 /* Get the function to call, in the form of RTL. */
1504 /* If this is the first use of the function, see if we need to
1505 make an external definition for it. */
1506 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1508 assemble_external (fndecl);
1509 TREE_USED (fndecl) = 1;
1512 /* Get a SYMBOL_REF rtx for the function address. */
1513 funexp = XEXP (DECL_RTL (fndecl), 0);
1516 /* Generate an rtx (probably a pseudo-register) for the address. */
1519 funexp = expand_normal (addr);
1520 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1525 /* Return true if and only if SIZE storage units (usually bytes)
1526 starting from address ADDR overlap with already clobbered argument
1527 area. This function is used to determine if we should give up a
1531 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1535 if (addr == crtl->args.internal_arg_pointer)
1537 else if (GET_CODE (addr) == PLUS
1538 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1539 && GET_CODE (XEXP (addr, 1)) == CONST_INT)
1540 i = INTVAL (XEXP (addr, 1));
1541 /* Return true for arg pointer based indexed addressing. */
1542 else if (GET_CODE (addr) == PLUS
1543 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1544 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1549 #ifdef ARGS_GROW_DOWNWARD
1554 unsigned HOST_WIDE_INT k;
1556 for (k = 0; k < size; k++)
1557 if (i + k < stored_args_map->n_bits
1558 && TEST_BIT (stored_args_map, i + k))
1565 /* Do the register loads required for any wholly-register parms or any
1566 parms which are passed both on the stack and in a register. Their
1567 expressions were already evaluated.
1569 Mark all register-parms as living through the call, putting these USE
1570 insns in the CALL_INSN_FUNCTION_USAGE field.
1572 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1573 checking, setting *SIBCALL_FAILURE if appropriate. */
1576 load_register_parameters (struct arg_data *args, int num_actuals,
1577 rtx *call_fusage, int flags, int is_sibcall,
1578 int *sibcall_failure)
1582 for (i = 0; i < num_actuals; i++)
1584 rtx reg = ((flags & ECF_SIBCALL)
1585 ? args[i].tail_call_reg : args[i].reg);
1588 int partial = args[i].partial;
1591 rtx before_arg = get_last_insn ();
1592 /* Set non-negative if we must move a word at a time, even if
1593 just one word (e.g, partial == 4 && mode == DFmode). Set
1594 to -1 if we just use a normal move insn. This value can be
1595 zero if the argument is a zero size structure. */
1597 if (GET_CODE (reg) == PARALLEL)
1601 gcc_assert (partial % UNITS_PER_WORD == 0);
1602 nregs = partial / UNITS_PER_WORD;
1604 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1606 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1607 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1610 size = GET_MODE_SIZE (args[i].mode);
1612 /* Handle calls that pass values in multiple non-contiguous
1613 locations. The Irix 6 ABI has examples of this. */
1615 if (GET_CODE (reg) == PARALLEL)
1616 emit_group_move (reg, args[i].parallel_value);
1618 /* If simple case, just do move. If normal partial, store_one_arg
1619 has already loaded the register for us. In all other cases,
1620 load the register(s) from memory. */
1622 else if (nregs == -1)
1624 emit_move_insn (reg, args[i].value);
1625 #ifdef BLOCK_REG_PADDING
1626 /* Handle case where we have a value that needs shifting
1627 up to the msb. eg. a QImode value and we're padding
1628 upward on a BYTES_BIG_ENDIAN machine. */
1629 if (size < UNITS_PER_WORD
1630 && (args[i].locate.where_pad
1631 == (BYTES_BIG_ENDIAN ? upward : downward)))
1634 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1636 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1637 report the whole reg as used. Strictly speaking, the
1638 call only uses SIZE bytes at the msb end, but it doesn't
1639 seem worth generating rtl to say that. */
1640 reg = gen_rtx_REG (word_mode, REGNO (reg));
1641 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1642 build_int_cst (NULL_TREE, shift),
1645 emit_move_insn (reg, x);
1650 /* If we have pre-computed the values to put in the registers in
1651 the case of non-aligned structures, copy them in now. */
1653 else if (args[i].n_aligned_regs != 0)
1654 for (j = 0; j < args[i].n_aligned_regs; j++)
1655 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1656 args[i].aligned_regs[j]);
1658 else if (partial == 0 || args[i].pass_on_stack)
1660 rtx mem = validize_mem (args[i].value);
1662 /* Check for overlap with already clobbered argument area. */
1664 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1666 *sibcall_failure = 1;
1668 /* Handle a BLKmode that needs shifting. */
1669 if (nregs == 1 && size < UNITS_PER_WORD
1670 #ifdef BLOCK_REG_PADDING
1671 && args[i].locate.where_pad == downward
1677 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1678 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1679 rtx x = gen_reg_rtx (word_mode);
1680 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1681 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1684 emit_move_insn (x, tem);
1685 x = expand_shift (dir, word_mode, x,
1686 build_int_cst (NULL_TREE, shift),
1689 emit_move_insn (ri, x);
1692 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1695 /* When a parameter is a block, and perhaps in other cases, it is
1696 possible that it did a load from an argument slot that was
1697 already clobbered. */
1699 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1700 *sibcall_failure = 1;
1702 /* Handle calls that pass values in multiple non-contiguous
1703 locations. The Irix 6 ABI has examples of this. */
1704 if (GET_CODE (reg) == PARALLEL)
1705 use_group_regs (call_fusage, reg);
1706 else if (nregs == -1)
1707 use_reg (call_fusage, reg);
1709 use_regs (call_fusage, REGNO (reg), nregs);
1714 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1715 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1716 bytes, then we would need to push some additional bytes to pad the
1717 arguments. So, we compute an adjust to the stack pointer for an
1718 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1719 bytes. Then, when the arguments are pushed the stack will be perfectly
1720 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1721 be popped after the call. Returns the adjustment. */
1724 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1725 struct args_size *args_size,
1726 unsigned int preferred_unit_stack_boundary)
1728 /* The number of bytes to pop so that the stack will be
1729 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1730 HOST_WIDE_INT adjustment;
1731 /* The alignment of the stack after the arguments are pushed, if we
1732 just pushed the arguments without adjust the stack here. */
1733 unsigned HOST_WIDE_INT unadjusted_alignment;
1735 unadjusted_alignment
1736 = ((stack_pointer_delta + unadjusted_args_size)
1737 % preferred_unit_stack_boundary);
1739 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1740 as possible -- leaving just enough left to cancel out the
1741 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1742 PENDING_STACK_ADJUST is non-negative, and congruent to
1743 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1745 /* Begin by trying to pop all the bytes. */
1746 unadjusted_alignment
1747 = (unadjusted_alignment
1748 - (pending_stack_adjust % preferred_unit_stack_boundary));
1749 adjustment = pending_stack_adjust;
1750 /* Push enough additional bytes that the stack will be aligned
1751 after the arguments are pushed. */
1752 if (preferred_unit_stack_boundary > 1)
1754 if (unadjusted_alignment > 0)
1755 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1757 adjustment += unadjusted_alignment;
1760 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1761 bytes after the call. The right number is the entire
1762 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1763 by the arguments in the first place. */
1765 = pending_stack_adjust - adjustment + unadjusted_args_size;
1770 /* Scan X expression if it does not dereference any argument slots
1771 we already clobbered by tail call arguments (as noted in stored_args_map
1773 Return nonzero if X expression dereferences such argument slots,
1777 check_sibcall_argument_overlap_1 (rtx x)
1786 code = GET_CODE (x);
1789 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1790 GET_MODE_SIZE (GET_MODE (x)));
1792 /* Scan all subexpressions. */
1793 fmt = GET_RTX_FORMAT (code);
1794 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1798 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1801 else if (*fmt == 'E')
1803 for (j = 0; j < XVECLEN (x, i); j++)
1804 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1811 /* Scan sequence after INSN if it does not dereference any argument slots
1812 we already clobbered by tail call arguments (as noted in stored_args_map
1813 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1814 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1815 should be 0). Return nonzero if sequence after INSN dereferences such argument
1816 slots, zero otherwise. */
1819 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1823 if (insn == NULL_RTX)
1824 insn = get_insns ();
1826 insn = NEXT_INSN (insn);
1828 for (; insn; insn = NEXT_INSN (insn))
1830 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1833 if (mark_stored_args_map)
1835 #ifdef ARGS_GROW_DOWNWARD
1836 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1838 low = arg->locate.slot_offset.constant;
1841 for (high = low + arg->locate.size.constant; low < high; low++)
1842 SET_BIT (stored_args_map, low);
1844 return insn != NULL_RTX;
1847 /* Given that a function returns a value of mode MODE at the most
1848 significant end of hard register VALUE, shift VALUE left or right
1849 as specified by LEFT_P. Return true if some action was needed. */
1852 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1854 HOST_WIDE_INT shift;
1856 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1857 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1861 /* Use ashr rather than lshr for right shifts. This is for the benefit
1862 of the MIPS port, which requires SImode values to be sign-extended
1863 when stored in 64-bit registers. */
1864 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1865 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1870 /* If X is a likely-spilled register value, copy it to a pseudo
1871 register and return that register. Return X otherwise. */
1874 avoid_likely_spilled_reg (rtx x)
1879 && HARD_REGISTER_P (x)
1880 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1882 /* Make sure that we generate a REG rather than a CONCAT.
1883 Moves into CONCATs can need nontrivial instructions,
1884 and the whole point of this function is to avoid
1885 using the hard register directly in such a situation. */
1886 generating_concat_p = 0;
1887 new = gen_reg_rtx (GET_MODE (x));
1888 generating_concat_p = 1;
1889 emit_move_insn (new, x);
1895 /* Generate all the code for a CALL_EXPR exp
1896 and return an rtx for its value.
1897 Store the value in TARGET (specified as an rtx) if convenient.
1898 If the value is stored in TARGET then TARGET is returned.
1899 If IGNORE is nonzero, then we ignore the value of the function call. */
1902 expand_call (tree exp, rtx target, int ignore)
1904 /* Nonzero if we are currently expanding a call. */
1905 static int currently_expanding_call = 0;
1907 /* RTX for the function to be called. */
1909 /* Sequence of insns to perform a normal "call". */
1910 rtx normal_call_insns = NULL_RTX;
1911 /* Sequence of insns to perform a tail "call". */
1912 rtx tail_call_insns = NULL_RTX;
1913 /* Data type of the function. */
1915 tree type_arg_types;
1916 /* Declaration of the function being called,
1917 or 0 if the function is computed (not known by name). */
1919 /* The type of the function being called. */
1921 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1924 /* Register in which non-BLKmode value will be returned,
1925 or 0 if no value or if value is BLKmode. */
1927 /* Address where we should return a BLKmode value;
1928 0 if value not BLKmode. */
1929 rtx structure_value_addr = 0;
1930 /* Nonzero if that address is being passed by treating it as
1931 an extra, implicit first parameter. Otherwise,
1932 it is passed by being copied directly into struct_value_rtx. */
1933 int structure_value_addr_parm = 0;
1934 /* Holds the value of implicit argument for the struct value. */
1935 tree structure_value_addr_value = NULL_TREE;
1936 /* Size of aggregate value wanted, or zero if none wanted
1937 or if we are using the non-reentrant PCC calling convention
1938 or expecting the value in registers. */
1939 HOST_WIDE_INT struct_value_size = 0;
1940 /* Nonzero if called function returns an aggregate in memory PCC style,
1941 by returning the address of where to find it. */
1942 int pcc_struct_value = 0;
1943 rtx struct_value = 0;
1945 /* Number of actual parameters in this call, including struct value addr. */
1947 /* Number of named args. Args after this are anonymous ones
1948 and they must all go on the stack. */
1950 /* Number of complex actual arguments that need to be split. */
1951 int num_complex_actuals = 0;
1953 /* Vector of information about each argument.
1954 Arguments are numbered in the order they will be pushed,
1955 not the order they are written. */
1956 struct arg_data *args;
1958 /* Total size in bytes of all the stack-parms scanned so far. */
1959 struct args_size args_size;
1960 struct args_size adjusted_args_size;
1961 /* Size of arguments before any adjustments (such as rounding). */
1962 int unadjusted_args_size;
1963 /* Data on reg parms scanned so far. */
1964 CUMULATIVE_ARGS args_so_far;
1965 /* Nonzero if a reg parm has been scanned. */
1967 /* Nonzero if this is an indirect function call. */
1969 /* Nonzero if we must avoid push-insns in the args for this call.
1970 If stack space is allocated for register parameters, but not by the
1971 caller, then it is preallocated in the fixed part of the stack frame.
1972 So the entire argument block must then be preallocated (i.e., we
1973 ignore PUSH_ROUNDING in that case). */
1975 int must_preallocate = !PUSH_ARGS;
1977 /* Size of the stack reserved for parameter registers. */
1978 int reg_parm_stack_space = 0;
1980 /* Address of space preallocated for stack parms
1981 (on machines that lack push insns), or 0 if space not preallocated. */
1984 /* Mask of ECF_ flags. */
1986 #ifdef REG_PARM_STACK_SPACE
1987 /* Define the boundary of the register parm stack space that needs to be
1989 int low_to_save, high_to_save;
1990 rtx save_area = 0; /* Place that it is saved */
1993 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1994 char *initial_stack_usage_map = stack_usage_map;
1995 char *stack_usage_map_buf = NULL;
1997 int old_stack_allocated;
1999 /* State variables to track stack modifications. */
2000 rtx old_stack_level = 0;
2001 int old_stack_arg_under_construction = 0;
2002 int old_pending_adj = 0;
2003 int old_inhibit_defer_pop = inhibit_defer_pop;
2005 /* Some stack pointer alterations we make are performed via
2006 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2007 which we then also need to save/restore along the way. */
2008 int old_stack_pointer_delta = 0;
2011 tree p = CALL_EXPR_FN (exp);
2012 tree addr = CALL_EXPR_FN (exp);
2014 /* The alignment of the stack, in bits. */
2015 unsigned HOST_WIDE_INT preferred_stack_boundary;
2016 /* The alignment of the stack, in bytes. */
2017 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2018 /* The static chain value to use for this call. */
2019 rtx static_chain_value;
2020 /* See if this is "nothrow" function call. */
2021 if (TREE_NOTHROW (exp))
2022 flags |= ECF_NOTHROW;
2024 /* See if we can find a DECL-node for the actual function, and get the
2025 function attributes (flags) from the function decl or type node. */
2026 fndecl = get_callee_fndecl (exp);
2029 fntype = TREE_TYPE (fndecl);
2030 flags |= flags_from_decl_or_type (fndecl);
2034 fntype = TREE_TYPE (TREE_TYPE (p));
2035 flags |= flags_from_decl_or_type (fntype);
2038 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2040 /* Warn if this value is an aggregate type,
2041 regardless of which calling convention we are using for it. */
2042 if (AGGREGATE_TYPE_P (TREE_TYPE (exp)))
2043 warning (OPT_Waggregate_return, "function call has aggregate value");
2045 /* If the result of a non looping pure or const function call is
2046 ignored (or void), and none of its arguments are volatile, we can
2047 avoid expanding the call and just evaluate the arguments for
2049 if ((flags & (ECF_CONST | ECF_PURE))
2050 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2051 && (ignore || target == const0_rtx
2052 || TYPE_MODE (TREE_TYPE (exp)) == VOIDmode))
2054 bool volatilep = false;
2056 call_expr_arg_iterator iter;
2058 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2059 if (TREE_THIS_VOLATILE (arg))
2067 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2068 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2073 #ifdef REG_PARM_STACK_SPACE
2074 reg_parm_stack_space = REG_PARM_STACK_SPACE (fndecl);
2077 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2078 && reg_parm_stack_space > 0 && PUSH_ARGS)
2079 must_preallocate = 1;
2081 /* Set up a place to return a structure. */
2083 /* Cater to broken compilers. */
2084 if (aggregate_value_p (exp, fndecl))
2086 /* This call returns a big structure. */
2087 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2089 #ifdef PCC_STATIC_STRUCT_RETURN
2091 pcc_struct_value = 1;
2093 #else /* not PCC_STATIC_STRUCT_RETURN */
2095 struct_value_size = int_size_in_bytes (TREE_TYPE (exp));
2097 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2098 structure_value_addr = XEXP (target, 0);
2101 /* For variable-sized objects, we must be called with a target
2102 specified. If we were to allocate space on the stack here,
2103 we would have no way of knowing when to free it. */
2104 rtx d = assign_temp (TREE_TYPE (exp), 0, 1, 1);
2106 mark_temp_addr_taken (d);
2107 structure_value_addr = XEXP (d, 0);
2111 #endif /* not PCC_STATIC_STRUCT_RETURN */
2114 /* Figure out the amount to which the stack should be aligned. */
2115 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2118 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2119 /* Without automatic stack alignment, we can't increase preferred
2120 stack boundary. With automatic stack alignment, it is
2121 unnecessary since unless we can guarantee that all callers will
2122 align the outgoing stack properly, callee has to align its
2125 && i->preferred_incoming_stack_boundary
2126 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2127 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2130 /* Operand 0 is a pointer-to-function; get the type of the function. */
2131 funtype = TREE_TYPE (addr);
2132 gcc_assert (POINTER_TYPE_P (funtype));
2133 funtype = TREE_TYPE (funtype);
2135 /* Count whether there are actual complex arguments that need to be split
2136 into their real and imaginary parts. Munge the type_arg_types
2137 appropriately here as well. */
2138 if (targetm.calls.split_complex_arg)
2140 call_expr_arg_iterator iter;
2142 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2144 tree type = TREE_TYPE (arg);
2145 if (type && TREE_CODE (type) == COMPLEX_TYPE
2146 && targetm.calls.split_complex_arg (type))
2147 num_complex_actuals++;
2149 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2152 type_arg_types = TYPE_ARG_TYPES (funtype);
2154 if (flags & ECF_MAY_BE_ALLOCA)
2155 cfun->calls_alloca = 1;
2157 /* If struct_value_rtx is 0, it means pass the address
2158 as if it were an extra parameter. Put the argument expression
2159 in structure_value_addr_value. */
2160 if (structure_value_addr && struct_value == 0)
2162 /* If structure_value_addr is a REG other than
2163 virtual_outgoing_args_rtx, we can use always use it. If it
2164 is not a REG, we must always copy it into a register.
2165 If it is virtual_outgoing_args_rtx, we must copy it to another
2166 register in some cases. */
2167 rtx temp = (!REG_P (structure_value_addr)
2168 || (ACCUMULATE_OUTGOING_ARGS
2169 && stack_arg_under_construction
2170 && structure_value_addr == virtual_outgoing_args_rtx)
2171 ? copy_addr_to_reg (convert_memory_address
2172 (Pmode, structure_value_addr))
2173 : structure_value_addr);
2175 structure_value_addr_value =
2176 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2177 structure_value_addr_parm = 1;
2180 /* Count the arguments and set NUM_ACTUALS. */
2182 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2184 /* Compute number of named args.
2185 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2187 if (type_arg_types != 0)
2189 = (list_length (type_arg_types)
2190 /* Count the struct value address, if it is passed as a parm. */
2191 + structure_value_addr_parm);
2193 /* If we know nothing, treat all args as named. */
2194 n_named_args = num_actuals;
2196 /* Start updating where the next arg would go.
2198 On some machines (such as the PA) indirect calls have a different
2199 calling convention than normal calls. The fourth argument in
2200 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2202 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2204 /* Now possibly adjust the number of named args.
2205 Normally, don't include the last named arg if anonymous args follow.
2206 We do include the last named arg if
2207 targetm.calls.strict_argument_naming() returns nonzero.
2208 (If no anonymous args follow, the result of list_length is actually
2209 one too large. This is harmless.)
2211 If targetm.calls.pretend_outgoing_varargs_named() returns
2212 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2213 this machine will be able to place unnamed args that were passed
2214 in registers into the stack. So treat all args as named. This
2215 allows the insns emitting for a specific argument list to be
2216 independent of the function declaration.
2218 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2219 we do not have any reliable way to pass unnamed args in
2220 registers, so we must force them into memory. */
2222 if (type_arg_types != 0
2223 && targetm.calls.strict_argument_naming (&args_so_far))
2225 else if (type_arg_types != 0
2226 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2227 /* Don't include the last named arg. */
2230 /* Treat all args as named. */
2231 n_named_args = num_actuals;
2233 /* Make a vector to hold all the information about each arg. */
2234 args = XALLOCAVEC (struct arg_data, num_actuals);
2235 memset (args, 0, num_actuals * sizeof (struct arg_data));
2237 /* Build up entries in the ARGS array, compute the size of the
2238 arguments into ARGS_SIZE, etc. */
2239 initialize_argument_information (num_actuals, args, &args_size,
2241 structure_value_addr_value, fndecl,
2242 &args_so_far, reg_parm_stack_space,
2243 &old_stack_level, &old_pending_adj,
2244 &must_preallocate, &flags,
2245 &try_tail_call, CALL_FROM_THUNK_P (exp));
2248 must_preallocate = 1;
2250 /* Now make final decision about preallocating stack space. */
2251 must_preallocate = finalize_must_preallocate (must_preallocate,
2255 /* If the structure value address will reference the stack pointer, we
2256 must stabilize it. We don't need to do this if we know that we are
2257 not going to adjust the stack pointer in processing this call. */
2259 if (structure_value_addr
2260 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2261 || reg_mentioned_p (virtual_outgoing_args_rtx,
2262 structure_value_addr))
2264 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2265 structure_value_addr = copy_to_reg (structure_value_addr);
2267 /* Tail calls can make things harder to debug, and we've traditionally
2268 pushed these optimizations into -O2. Don't try if we're already
2269 expanding a call, as that means we're an argument. Don't try if
2270 there's cleanups, as we know there's code to follow the call. */
2272 if (currently_expanding_call++ != 0
2273 || !flag_optimize_sibling_calls
2275 || lookup_expr_eh_region (exp) >= 0
2276 || dbg_cnt (tail_call) == false)
2279 /* Rest of purposes for tail call optimizations to fail. */
2281 #ifdef HAVE_sibcall_epilogue
2282 !HAVE_sibcall_epilogue
2287 /* Doing sibling call optimization needs some work, since
2288 structure_value_addr can be allocated on the stack.
2289 It does not seem worth the effort since few optimizable
2290 sibling calls will return a structure. */
2291 || structure_value_addr != NULL_RTX
2292 /* Check whether the target is able to optimize the call
2294 || !targetm.function_ok_for_sibcall (fndecl, exp)
2295 /* Functions that do not return exactly once may not be sibcall
2297 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2298 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2299 /* If the called function is nested in the current one, it might access
2300 some of the caller's arguments, but could clobber them beforehand if
2301 the argument areas are shared. */
2302 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2303 /* If this function requires more stack slots than the current
2304 function, we cannot change it into a sibling call.
2305 crtl->args.pretend_args_size is not part of the
2306 stack allocated by our caller. */
2307 || args_size.constant > (crtl->args.size
2308 - crtl->args.pretend_args_size)
2309 /* If the callee pops its own arguments, then it must pop exactly
2310 the same number of arguments as the current function. */
2311 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2312 != RETURN_POPS_ARGS (current_function_decl,
2313 TREE_TYPE (current_function_decl),
2315 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2318 /* Ensure current function's preferred stack
2319 boundary is at least what we need. */
2320 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2321 crtl->preferred_stack_boundary = preferred_stack_boundary;
2323 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2325 /* We want to make two insn chains; one for a sibling call, the other
2326 for a normal call. We will select one of the two chains after
2327 initial RTL generation is complete. */
2328 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2330 int sibcall_failure = 0;
2331 /* We want to emit any pending stack adjustments before the tail
2332 recursion "call". That way we know any adjustment after the tail
2333 recursion call can be ignored if we indeed use the tail
2335 int save_pending_stack_adjust = 0;
2336 int save_stack_pointer_delta = 0;
2338 rtx before_call, next_arg_reg, after_args;
2342 /* State variables we need to save and restore between
2344 save_pending_stack_adjust = pending_stack_adjust;
2345 save_stack_pointer_delta = stack_pointer_delta;
2348 flags &= ~ECF_SIBCALL;
2350 flags |= ECF_SIBCALL;
2352 /* Other state variables that we must reinitialize each time
2353 through the loop (that are not initialized by the loop itself). */
2357 /* Start a new sequence for the normal call case.
2359 From this point on, if the sibling call fails, we want to set
2360 sibcall_failure instead of continuing the loop. */
2363 /* Don't let pending stack adjusts add up to too much.
2364 Also, do all pending adjustments now if there is any chance
2365 this might be a call to alloca or if we are expanding a sibling
2367 Also do the adjustments before a throwing call, otherwise
2368 exception handling can fail; PR 19225. */
2369 if (pending_stack_adjust >= 32
2370 || (pending_stack_adjust > 0
2371 && (flags & ECF_MAY_BE_ALLOCA))
2372 || (pending_stack_adjust > 0
2373 && flag_exceptions && !(flags & ECF_NOTHROW))
2375 do_pending_stack_adjust ();
2377 /* Precompute any arguments as needed. */
2379 precompute_arguments (num_actuals, args);
2381 /* Now we are about to start emitting insns that can be deleted
2382 if a libcall is deleted. */
2383 if (pass && (flags & ECF_MALLOC))
2386 if (pass == 0 && crtl->stack_protect_guard)
2387 stack_protect_epilogue ();
2389 adjusted_args_size = args_size;
2390 /* Compute the actual size of the argument block required. The variable
2391 and constant sizes must be combined, the size may have to be rounded,
2392 and there may be a minimum required size. When generating a sibcall
2393 pattern, do not round up, since we'll be re-using whatever space our
2395 unadjusted_args_size
2396 = compute_argument_block_size (reg_parm_stack_space,
2397 &adjusted_args_size,
2400 : preferred_stack_boundary));
2402 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2404 /* The argument block when performing a sibling call is the
2405 incoming argument block. */
2408 argblock = virtual_incoming_args_rtx;
2410 #ifdef STACK_GROWS_DOWNWARD
2411 = plus_constant (argblock, crtl->args.pretend_args_size);
2413 = plus_constant (argblock, -crtl->args.pretend_args_size);
2415 stored_args_map = sbitmap_alloc (args_size.constant);
2416 sbitmap_zero (stored_args_map);
2419 /* If we have no actual push instructions, or shouldn't use them,
2420 make space for all args right now. */
2421 else if (adjusted_args_size.var != 0)
2423 if (old_stack_level == 0)
2425 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2426 old_stack_pointer_delta = stack_pointer_delta;
2427 old_pending_adj = pending_stack_adjust;
2428 pending_stack_adjust = 0;
2429 /* stack_arg_under_construction says whether a stack arg is
2430 being constructed at the old stack level. Pushing the stack
2431 gets a clean outgoing argument block. */
2432 old_stack_arg_under_construction = stack_arg_under_construction;
2433 stack_arg_under_construction = 0;
2435 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2439 /* Note that we must go through the motions of allocating an argument
2440 block even if the size is zero because we may be storing args
2441 in the area reserved for register arguments, which may be part of
2444 int needed = adjusted_args_size.constant;
2446 /* Store the maximum argument space used. It will be pushed by
2447 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2450 if (needed > crtl->outgoing_args_size)
2451 crtl->outgoing_args_size = needed;
2453 if (must_preallocate)
2455 if (ACCUMULATE_OUTGOING_ARGS)
2457 /* Since the stack pointer will never be pushed, it is
2458 possible for the evaluation of a parm to clobber
2459 something we have already written to the stack.
2460 Since most function calls on RISC machines do not use
2461 the stack, this is uncommon, but must work correctly.
2463 Therefore, we save any area of the stack that was already
2464 written and that we are using. Here we set up to do this
2465 by making a new stack usage map from the old one. The
2466 actual save will be done by store_one_arg.
2468 Another approach might be to try to reorder the argument
2469 evaluations to avoid this conflicting stack usage. */
2471 /* Since we will be writing into the entire argument area,
2472 the map must be allocated for its entire size, not just
2473 the part that is the responsibility of the caller. */
2474 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
2475 needed += reg_parm_stack_space;
2477 #ifdef ARGS_GROW_DOWNWARD
2478 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2481 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2484 if (stack_usage_map_buf)
2485 free (stack_usage_map_buf);
2486 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2487 stack_usage_map = stack_usage_map_buf;
2489 if (initial_highest_arg_in_use)
2490 memcpy (stack_usage_map, initial_stack_usage_map,
2491 initial_highest_arg_in_use);
2493 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2494 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2495 (highest_outgoing_arg_in_use
2496 - initial_highest_arg_in_use));
2499 /* The address of the outgoing argument list must not be
2500 copied to a register here, because argblock would be left
2501 pointing to the wrong place after the call to
2502 allocate_dynamic_stack_space below. */
2504 argblock = virtual_outgoing_args_rtx;
2508 if (inhibit_defer_pop == 0)
2510 /* Try to reuse some or all of the pending_stack_adjust
2511 to get this space. */
2513 = (combine_pending_stack_adjustment_and_call
2514 (unadjusted_args_size,
2515 &adjusted_args_size,
2516 preferred_unit_stack_boundary));
2518 /* combine_pending_stack_adjustment_and_call computes
2519 an adjustment before the arguments are allocated.
2520 Account for them and see whether or not the stack
2521 needs to go up or down. */
2522 needed = unadjusted_args_size - needed;
2526 /* We're releasing stack space. */
2527 /* ??? We can avoid any adjustment at all if we're
2528 already aligned. FIXME. */
2529 pending_stack_adjust = -needed;
2530 do_pending_stack_adjust ();
2534 /* We need to allocate space. We'll do that in
2535 push_block below. */
2536 pending_stack_adjust = 0;
2539 /* Special case this because overhead of `push_block' in
2540 this case is non-trivial. */
2542 argblock = virtual_outgoing_args_rtx;
2545 argblock = push_block (GEN_INT (needed), 0, 0);
2546 #ifdef ARGS_GROW_DOWNWARD
2547 argblock = plus_constant (argblock, needed);
2551 /* We only really need to call `copy_to_reg' in the case
2552 where push insns are going to be used to pass ARGBLOCK
2553 to a function call in ARGS. In that case, the stack
2554 pointer changes value from the allocation point to the
2555 call point, and hence the value of
2556 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2557 as well always do it. */
2558 argblock = copy_to_reg (argblock);
2563 if (ACCUMULATE_OUTGOING_ARGS)
2565 /* The save/restore code in store_one_arg handles all
2566 cases except one: a constructor call (including a C
2567 function returning a BLKmode struct) to initialize
2569 if (stack_arg_under_construction)
2572 = GEN_INT (adjusted_args_size.constant
2573 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL
2574 : TREE_TYPE (fndecl))) ? 0
2575 : reg_parm_stack_space));
2576 if (old_stack_level == 0)
2578 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2580 old_stack_pointer_delta = stack_pointer_delta;
2581 old_pending_adj = pending_stack_adjust;
2582 pending_stack_adjust = 0;
2583 /* stack_arg_under_construction says whether a stack
2584 arg is being constructed at the old stack level.
2585 Pushing the stack gets a clean outgoing argument
2587 old_stack_arg_under_construction
2588 = stack_arg_under_construction;
2589 stack_arg_under_construction = 0;
2590 /* Make a new map for the new argument list. */
2591 if (stack_usage_map_buf)
2592 free (stack_usage_map_buf);
2593 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2594 stack_usage_map = stack_usage_map_buf;
2595 highest_outgoing_arg_in_use = 0;
2597 allocate_dynamic_stack_space (push_size, NULL_RTX,
2601 /* If argument evaluation might modify the stack pointer,
2602 copy the address of the argument list to a register. */
2603 for (i = 0; i < num_actuals; i++)
2604 if (args[i].pass_on_stack)
2606 argblock = copy_addr_to_reg (argblock);
2611 compute_argument_addresses (args, argblock, num_actuals);
2613 /* If we push args individually in reverse order, perform stack alignment
2614 before the first push (the last arg). */
2615 if (PUSH_ARGS_REVERSED && argblock == 0
2616 && adjusted_args_size.constant != unadjusted_args_size)
2618 /* When the stack adjustment is pending, we get better code
2619 by combining the adjustments. */
2620 if (pending_stack_adjust
2621 && ! inhibit_defer_pop)
2623 pending_stack_adjust
2624 = (combine_pending_stack_adjustment_and_call
2625 (unadjusted_args_size,
2626 &adjusted_args_size,
2627 preferred_unit_stack_boundary));
2628 do_pending_stack_adjust ();
2630 else if (argblock == 0)
2631 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2632 - unadjusted_args_size));
2634 /* Now that the stack is properly aligned, pops can't safely
2635 be deferred during the evaluation of the arguments. */
2638 funexp = rtx_for_function_call (fndecl, addr);
2640 /* Figure out the register where the value, if any, will come back. */
2642 if (TYPE_MODE (TREE_TYPE (exp)) != VOIDmode
2643 && ! structure_value_addr)
2645 if (pcc_struct_value)
2646 valreg = hard_function_value (build_pointer_type (TREE_TYPE (exp)),
2647 fndecl, NULL, (pass == 0));
2649 valreg = hard_function_value (TREE_TYPE (exp), fndecl, fntype,
2652 /* If VALREG is a PARALLEL whose first member has a zero
2653 offset, use that. This is for targets such as m68k that
2654 return the same value in multiple places. */
2655 if (GET_CODE (valreg) == PARALLEL)
2657 rtx elem = XVECEXP (valreg, 0, 0);
2658 rtx where = XEXP (elem, 0);
2659 rtx offset = XEXP (elem, 1);
2660 if (offset == const0_rtx
2661 && GET_MODE (where) == GET_MODE (valreg))
2666 /* Precompute all register parameters. It isn't safe to compute anything
2667 once we have started filling any specific hard regs. */
2668 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2670 if (CALL_EXPR_STATIC_CHAIN (exp))
2671 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2673 static_chain_value = 0;
2675 #ifdef REG_PARM_STACK_SPACE
2676 /* Save the fixed argument area if it's part of the caller's frame and
2677 is clobbered by argument setup for this call. */
2678 if (ACCUMULATE_OUTGOING_ARGS && pass)
2679 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2680 &low_to_save, &high_to_save);
2683 /* Now store (and compute if necessary) all non-register parms.
2684 These come before register parms, since they can require block-moves,
2685 which could clobber the registers used for register parms.
2686 Parms which have partial registers are not stored here,
2687 but we do preallocate space here if they want that. */
2689 for (i = 0; i < num_actuals; i++)
2690 if (args[i].reg == 0 || args[i].pass_on_stack)
2692 rtx before_arg = get_last_insn ();
2694 if (store_one_arg (&args[i], argblock, flags,
2695 adjusted_args_size.var != 0,
2696 reg_parm_stack_space)
2698 && check_sibcall_argument_overlap (before_arg,
2700 sibcall_failure = 1;
2702 if (flags & ECF_CONST
2704 && args[i].value == args[i].stack)
2705 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2706 gen_rtx_USE (VOIDmode,
2711 /* If we have a parm that is passed in registers but not in memory
2712 and whose alignment does not permit a direct copy into registers,
2713 make a group of pseudos that correspond to each register that we
2715 if (STRICT_ALIGNMENT)
2716 store_unaligned_arguments_into_pseudos (args, num_actuals);
2718 /* Now store any partially-in-registers parm.
2719 This is the last place a block-move can happen. */
2721 for (i = 0; i < num_actuals; i++)
2722 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2724 rtx before_arg = get_last_insn ();
2726 if (store_one_arg (&args[i], argblock, flags,
2727 adjusted_args_size.var != 0,
2728 reg_parm_stack_space)
2730 && check_sibcall_argument_overlap (before_arg,
2732 sibcall_failure = 1;
2735 /* If we pushed args in forward order, perform stack alignment
2736 after pushing the last arg. */
2737 if (!PUSH_ARGS_REVERSED && argblock == 0)
2738 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2739 - unadjusted_args_size));
2741 /* If register arguments require space on the stack and stack space
2742 was not preallocated, allocate stack space here for arguments
2743 passed in registers. */
2744 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl)))
2745 && !ACCUMULATE_OUTGOING_ARGS
2746 && must_preallocate == 0 && reg_parm_stack_space > 0)
2747 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2749 /* Pass the function the address in which to return a
2751 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2753 structure_value_addr
2754 = convert_memory_address (Pmode, structure_value_addr);
2755 emit_move_insn (struct_value,
2757 force_operand (structure_value_addr,
2760 if (REG_P (struct_value))
2761 use_reg (&call_fusage, struct_value);
2764 after_args = get_last_insn ();
2765 funexp = prepare_call_address (funexp, static_chain_value,
2766 &call_fusage, reg_parm_seen, pass == 0);
2768 load_register_parameters (args, num_actuals, &call_fusage, flags,
2769 pass == 0, &sibcall_failure);
2771 /* Save a pointer to the last insn before the call, so that we can
2772 later safely search backwards to find the CALL_INSN. */
2773 before_call = get_last_insn ();
2775 /* Set up next argument register. For sibling calls on machines
2776 with register windows this should be the incoming register. */
2777 #ifdef FUNCTION_INCOMING_ARG
2779 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2783 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2786 /* All arguments and registers used for the call must be set up by
2789 /* Stack must be properly aligned now. */
2791 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2793 /* Generate the actual call instruction. */
2794 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2795 adjusted_args_size.constant, struct_value_size,
2796 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2797 flags, & args_so_far);
2799 /* If the call setup or the call itself overlaps with anything
2800 of the argument setup we probably clobbered our call address.
2801 In that case we can't do sibcalls. */
2803 && check_sibcall_argument_overlap (after_args, 0, 0))
2804 sibcall_failure = 1;
2806 /* If a non-BLKmode value is returned at the most significant end
2807 of a register, shift the register right by the appropriate amount
2808 and update VALREG accordingly. BLKmode values are handled by the
2809 group load/store machinery below. */
2810 if (!structure_value_addr
2811 && !pcc_struct_value
2812 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2813 && targetm.calls.return_in_msb (TREE_TYPE (exp)))
2815 if (shift_return_value (TYPE_MODE (TREE_TYPE (exp)), false, valreg))
2816 sibcall_failure = 1;
2817 valreg = gen_rtx_REG (TYPE_MODE (TREE_TYPE (exp)), REGNO (valreg));
2820 if (pass && (flags & ECF_MALLOC))
2822 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2825 /* The return value from a malloc-like function is a pointer. */
2826 if (TREE_CODE (TREE_TYPE (exp)) == POINTER_TYPE)
2827 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2829 emit_move_insn (temp, valreg);
2831 /* The return value from a malloc-like function can not alias
2833 last = get_last_insn ();
2834 add_reg_note (last, REG_NOALIAS, temp);
2836 /* Write out the sequence. */
2837 insns = get_insns ();
2843 /* For calls to `setjmp', etc., inform
2844 function.c:setjmp_warnings that it should complain if
2845 nonvolatile values are live. For functions that cannot
2846 return, inform flow that control does not fall through. */
2848 if ((flags & ECF_NORETURN) || pass == 0)
2850 /* The barrier must be emitted
2851 immediately after the CALL_INSN. Some ports emit more
2852 than just a CALL_INSN above, so we must search for it here. */
2854 rtx last = get_last_insn ();
2855 while (!CALL_P (last))
2857 last = PREV_INSN (last);
2858 /* There was no CALL_INSN? */
2859 gcc_assert (last != before_call);
2862 emit_barrier_after (last);
2864 /* Stack adjustments after a noreturn call are dead code.
2865 However when NO_DEFER_POP is in effect, we must preserve
2866 stack_pointer_delta. */
2867 if (inhibit_defer_pop == 0)
2869 stack_pointer_delta = old_stack_allocated;
2870 pending_stack_adjust = 0;
2874 /* If value type not void, return an rtx for the value. */
2876 if (TYPE_MODE (TREE_TYPE (exp)) == VOIDmode
2878 target = const0_rtx;
2879 else if (structure_value_addr)
2881 if (target == 0 || !MEM_P (target))
2884 = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2885 memory_address (TYPE_MODE (TREE_TYPE (exp)),
2886 structure_value_addr));
2887 set_mem_attributes (target, exp, 1);
2890 else if (pcc_struct_value)
2892 /* This is the special C++ case where we need to
2893 know what the true target was. We take care to
2894 never use this value more than once in one expression. */
2895 target = gen_rtx_MEM (TYPE_MODE (TREE_TYPE (exp)),
2896 copy_to_reg (valreg));
2897 set_mem_attributes (target, exp, 1);
2899 /* Handle calls that return values in multiple non-contiguous locations.
2900 The Irix 6 ABI has examples of this. */
2901 else if (GET_CODE (valreg) == PARALLEL)
2905 /* This will only be assigned once, so it can be readonly. */
2906 tree nt = build_qualified_type (TREE_TYPE (exp),
2907 (TYPE_QUALS (TREE_TYPE (exp))
2908 | TYPE_QUAL_CONST));
2910 target = assign_temp (nt, 0, 1, 1);
2913 if (! rtx_equal_p (target, valreg))
2914 emit_group_store (target, valreg, TREE_TYPE (exp),
2915 int_size_in_bytes (TREE_TYPE (exp)));
2917 /* We can not support sibling calls for this case. */
2918 sibcall_failure = 1;
2921 && GET_MODE (target) == TYPE_MODE (TREE_TYPE (exp))
2922 && GET_MODE (target) == GET_MODE (valreg))
2924 bool may_overlap = false;
2926 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2927 reg to a plain register. */
2928 if (!REG_P (target) || HARD_REGISTER_P (target))
2929 valreg = avoid_likely_spilled_reg (valreg);
2931 /* If TARGET is a MEM in the argument area, and we have
2932 saved part of the argument area, then we can't store
2933 directly into TARGET as it may get overwritten when we
2934 restore the argument save area below. Don't work too
2935 hard though and simply force TARGET to a register if it
2936 is a MEM; the optimizer is quite likely to sort it out. */
2937 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2938 for (i = 0; i < num_actuals; i++)
2939 if (args[i].save_area)
2946 target = copy_to_reg (valreg);
2949 /* TARGET and VALREG cannot be equal at this point
2950 because the latter would not have
2951 REG_FUNCTION_VALUE_P true, while the former would if
2952 it were referring to the same register.
2954 If they refer to the same register, this move will be
2955 a no-op, except when function inlining is being
2957 emit_move_insn (target, valreg);
2959 /* If we are setting a MEM, this code must be executed.
2960 Since it is emitted after the call insn, sibcall
2961 optimization cannot be performed in that case. */
2963 sibcall_failure = 1;
2966 else if (TYPE_MODE (TREE_TYPE (exp)) == BLKmode)
2968 target = copy_blkmode_from_reg (target, valreg, TREE_TYPE (exp));
2970 /* We can not support sibling calls for this case. */
2971 sibcall_failure = 1;
2974 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
2976 if (targetm.calls.promote_function_return(funtype))
2978 /* If we promoted this return value, make the proper SUBREG.
2979 TARGET might be const0_rtx here, so be careful. */
2981 && TYPE_MODE (TREE_TYPE (exp)) != BLKmode
2982 && GET_MODE (target) != TYPE_MODE (TREE_TYPE (exp)))
2984 tree type = TREE_TYPE (exp);
2985 int unsignedp = TYPE_UNSIGNED (type);
2987 enum machine_mode pmode;
2989 pmode = promote_mode (type, TYPE_MODE (type), &unsignedp, 1);
2990 /* If we don't promote as expected, something is wrong. */
2991 gcc_assert (GET_MODE (target) == pmode);
2993 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
2994 && (GET_MODE_SIZE (GET_MODE (target))
2995 > GET_MODE_SIZE (TYPE_MODE (type))))
2997 offset = GET_MODE_SIZE (GET_MODE (target))
2998 - GET_MODE_SIZE (TYPE_MODE (type));
2999 if (! BYTES_BIG_ENDIAN)
3000 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3001 else if (! WORDS_BIG_ENDIAN)
3002 offset %= UNITS_PER_WORD;
3004 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3005 SUBREG_PROMOTED_VAR_P (target) = 1;
3006 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3010 /* If size of args is variable or this was a constructor call for a stack
3011 argument, restore saved stack-pointer value. */
3013 if (old_stack_level)
3015 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3016 stack_pointer_delta = old_stack_pointer_delta;
3017 pending_stack_adjust = old_pending_adj;
3018 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3019 stack_arg_under_construction = old_stack_arg_under_construction;
3020 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3021 stack_usage_map = initial_stack_usage_map;
3022 sibcall_failure = 1;
3024 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3026 #ifdef REG_PARM_STACK_SPACE
3028 restore_fixed_argument_area (save_area, argblock,
3029 high_to_save, low_to_save);
3032 /* If we saved any argument areas, restore them. */
3033 for (i = 0; i < num_actuals; i++)
3034 if (args[i].save_area)
3036 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3038 = gen_rtx_MEM (save_mode,
3039 memory_address (save_mode,
3040 XEXP (args[i].stack_slot, 0)));
3042 if (save_mode != BLKmode)
3043 emit_move_insn (stack_area, args[i].save_area);
3045 emit_block_move (stack_area, args[i].save_area,
3046 GEN_INT (args[i].locate.size.constant),
3047 BLOCK_OP_CALL_PARM);
3050 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3051 stack_usage_map = initial_stack_usage_map;
3054 /* If this was alloca, record the new stack level for nonlocal gotos.
3055 Check for the handler slots since we might not have a save area
3056 for non-local gotos. */
3058 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3059 update_nonlocal_goto_save_area ();
3061 /* Free up storage we no longer need. */
3062 for (i = 0; i < num_actuals; ++i)
3063 if (args[i].aligned_regs)
3064 free (args[i].aligned_regs);
3066 insns = get_insns ();
3071 tail_call_insns = insns;
3073 /* Restore the pending stack adjustment now that we have
3074 finished generating the sibling call sequence. */
3076 pending_stack_adjust = save_pending_stack_adjust;
3077 stack_pointer_delta = save_stack_pointer_delta;
3079 /* Prepare arg structure for next iteration. */
3080 for (i = 0; i < num_actuals; i++)
3083 args[i].aligned_regs = 0;
3087 sbitmap_free (stored_args_map);
3091 normal_call_insns = insns;
3093 /* Verify that we've deallocated all the stack we used. */
3094 gcc_assert ((flags & ECF_NORETURN)
3095 || (old_stack_allocated
3096 == stack_pointer_delta - pending_stack_adjust));
3099 /* If something prevents making this a sibling call,
3100 zero out the sequence. */
3101 if (sibcall_failure)
3102 tail_call_insns = NULL_RTX;
3107 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3108 arguments too, as argument area is now clobbered by the call. */
3109 if (tail_call_insns)
3111 emit_insn (tail_call_insns);
3112 crtl->tail_call_emit = true;
3115 emit_insn (normal_call_insns);
3117 currently_expanding_call--;
3119 if (stack_usage_map_buf)
3120 free (stack_usage_map_buf);
3125 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3126 this function's incoming arguments.
3128 At the start of RTL generation we know the only REG_EQUIV notes
3129 in the rtl chain are those for incoming arguments, so we can look
3130 for REG_EQUIV notes between the start of the function and the
3131 NOTE_INSN_FUNCTION_BEG.
3133 This is (slight) overkill. We could keep track of the highest
3134 argument we clobber and be more selective in removing notes, but it
3135 does not seem to be worth the effort. */
3138 fixup_tail_calls (void)
3142 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3146 /* There are never REG_EQUIV notes for the incoming arguments
3147 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3149 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3152 note = find_reg_note (insn, REG_EQUIV, 0);
3154 remove_note (insn, note);
3155 note = find_reg_note (insn, REG_EQUIV, 0);
3160 /* Traverse a list of TYPES and expand all complex types into their
3163 split_complex_types (tree types)
3167 /* Before allocating memory, check for the common case of no complex. */
3168 for (p = types; p; p = TREE_CHAIN (p))
3170 tree type = TREE_VALUE (p);
3171 if (TREE_CODE (type) == COMPLEX_TYPE
3172 && targetm.calls.split_complex_arg (type))
3178 types = copy_list (types);
3180 for (p = types; p; p = TREE_CHAIN (p))
3182 tree complex_type = TREE_VALUE (p);
3184 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3185 && targetm.calls.split_complex_arg (complex_type))
3189 /* Rewrite complex type with component type. */
3190 TREE_VALUE (p) = TREE_TYPE (complex_type);
3191 next = TREE_CHAIN (p);
3193 /* Add another component type for the imaginary part. */
3194 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3195 TREE_CHAIN (p) = imag;
3196 TREE_CHAIN (imag) = next;
3198 /* Skip the newly created node. */
3206 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3207 The RETVAL parameter specifies whether return value needs to be saved, other
3208 parameters are documented in the emit_library_call function below. */
3211 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3212 enum libcall_type fn_type,
3213 enum machine_mode outmode, int nargs, va_list p)
3215 /* Total size in bytes of all the stack-parms scanned so far. */
3216 struct args_size args_size;
3217 /* Size of arguments before any adjustments (such as rounding). */
3218 struct args_size original_args_size;
3221 /* Todo, choose the correct decl type of orgfun. Sadly this information
3222 isn't present here, so we default to native calling abi here. */
3223 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3227 CUMULATIVE_ARGS args_so_far;
3231 enum machine_mode mode;
3234 struct locate_and_pad_arg_data locate;
3238 int old_inhibit_defer_pop = inhibit_defer_pop;
3239 rtx call_fusage = 0;
3242 int pcc_struct_value = 0;
3243 int struct_value_size = 0;
3245 int reg_parm_stack_space = 0;
3248 tree tfom; /* type_for_mode (outmode, 0) */
3250 #ifdef REG_PARM_STACK_SPACE
3251 /* Define the boundary of the register parm stack space that needs to be
3253 int low_to_save = 0, high_to_save = 0;
3254 rtx save_area = 0; /* Place that it is saved. */
3257 /* Size of the stack reserved for parameter registers. */
3258 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3259 char *initial_stack_usage_map = stack_usage_map;
3260 char *stack_usage_map_buf = NULL;
3262 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3264 #ifdef REG_PARM_STACK_SPACE
3265 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3268 /* By default, library functions can not throw. */
3269 flags = ECF_NOTHROW;
3282 flags |= ECF_NORETURN;
3285 flags = ECF_NORETURN;
3287 case LCT_RETURNS_TWICE:
3288 flags = ECF_RETURNS_TWICE;
3293 /* Ensure current function's preferred stack boundary is at least
3295 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3296 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3298 /* If this kind of value comes back in memory,
3299 decide where in memory it should come back. */
3300 if (outmode != VOIDmode)
3302 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3303 if (aggregate_value_p (tfom, 0))
3305 #ifdef PCC_STATIC_STRUCT_RETURN
3307 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3308 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3309 pcc_struct_value = 1;
3311 value = gen_reg_rtx (outmode);
3312 #else /* not PCC_STATIC_STRUCT_RETURN */
3313 struct_value_size = GET_MODE_SIZE (outmode);
3314 if (value != 0 && MEM_P (value))
3317 mem_value = assign_temp (tfom, 0, 1, 1);
3319 /* This call returns a big structure. */
3320 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3324 tfom = void_type_node;
3326 /* ??? Unfinished: must pass the memory address as an argument. */
3328 /* Copy all the libcall-arguments out of the varargs data
3329 and into a vector ARGVEC.
3331 Compute how to pass each argument. We only support a very small subset
3332 of the full argument passing conventions to limit complexity here since
3333 library functions shouldn't have many args. */
3335 argvec = XALLOCAVEC (struct arg, nargs + 1);
3336 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3338 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3339 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3341 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3344 args_size.constant = 0;
3351 /* If there's a structure value address to be passed,
3352 either pass it in the special place, or pass it as an extra argument. */
3353 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3355 rtx addr = XEXP (mem_value, 0);
3359 /* Make sure it is a reasonable operand for a move or push insn. */
3360 if (!REG_P (addr) && !MEM_P (addr)
3361 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3362 addr = force_operand (addr, NULL_RTX);
3364 argvec[count].value = addr;
3365 argvec[count].mode = Pmode;
3366 argvec[count].partial = 0;
3368 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3369 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3370 NULL_TREE, 1) == 0);
3372 locate_and_pad_parm (Pmode, NULL_TREE,
3373 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3376 argvec[count].reg != 0,
3378 0, NULL_TREE, &args_size, &argvec[count].locate);
3380 if (argvec[count].reg == 0 || argvec[count].partial != 0
3381 || reg_parm_stack_space > 0)
3382 args_size.constant += argvec[count].locate.size.constant;
3384 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3389 for (; count < nargs; count++)
3391 rtx val = va_arg (p, rtx);
3392 enum machine_mode mode = va_arg (p, enum machine_mode);
3394 /* We cannot convert the arg value to the mode the library wants here;
3395 must do it earlier where we know the signedness of the arg. */
3396 gcc_assert (mode != BLKmode
3397 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3399 /* Make sure it is a reasonable operand for a move or push insn. */
3400 if (!REG_P (val) && !MEM_P (val)
3401 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3402 val = force_operand (val, NULL_RTX);
3404 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3408 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3410 /* If this was a CONST function, it is now PURE since it now
3412 if (flags & ECF_CONST)
3414 flags &= ~ECF_CONST;
3418 if (GET_MODE (val) == MEM && !must_copy)
3422 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3424 emit_move_insn (slot, val);
3427 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3428 gen_rtx_USE (VOIDmode, slot),
3431 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3432 gen_rtx_CLOBBER (VOIDmode,
3437 val = force_operand (XEXP (slot, 0), NULL_RTX);
3440 argvec[count].value = val;
3441 argvec[count].mode = mode;
3443 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3445 argvec[count].partial
3446 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3448 locate_and_pad_parm (mode, NULL_TREE,
3449 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3452 argvec[count].reg != 0,
3454 argvec[count].partial,
3455 NULL_TREE, &args_size, &argvec[count].locate);
3457 gcc_assert (!argvec[count].locate.size.var);
3459 if (argvec[count].reg == 0 || argvec[count].partial != 0
3460 || reg_parm_stack_space > 0)
3461 args_size.constant += argvec[count].locate.size.constant;
3463 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3466 /* If this machine requires an external definition for library
3467 functions, write one out. */
3468 assemble_external_libcall (fun);
3470 original_args_size = args_size;
3471 args_size.constant = (((args_size.constant
3472 + stack_pointer_delta
3476 - stack_pointer_delta);
3478 args_size.constant = MAX (args_size.constant,
3479 reg_parm_stack_space);
3481 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3482 args_size.constant -= reg_parm_stack_space;
3484 if (args_size.constant > crtl->outgoing_args_size)
3485 crtl->outgoing_args_size = args_size.constant;
3487 if (ACCUMULATE_OUTGOING_ARGS)
3489 /* Since the stack pointer will never be pushed, it is possible for
3490 the evaluation of a parm to clobber something we have already
3491 written to the stack. Since most function calls on RISC machines
3492 do not use the stack, this is uncommon, but must work correctly.
3494 Therefore, we save any area of the stack that was already written
3495 and that we are using. Here we set up to do this by making a new
3496 stack usage map from the old one.
3498 Another approach might be to try to reorder the argument
3499 evaluations to avoid this conflicting stack usage. */
3501 needed = args_size.constant;
3503 /* Since we will be writing into the entire argument area, the
3504 map must be allocated for its entire size, not just the part that
3505 is the responsibility of the caller. */
3506 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? NULL_TREE : TREE_TYPE (fndecl))))
3507 needed += reg_parm_stack_space;
3509 #ifdef ARGS_GROW_DOWNWARD
3510 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3513 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3516 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3517 stack_usage_map = stack_usage_map_buf;
3519 if (initial_highest_arg_in_use)
3520 memcpy (stack_usage_map, initial_stack_usage_map,
3521 initial_highest_arg_in_use);
3523 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3524 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3525 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3528 /* We must be careful to use virtual regs before they're instantiated,
3529 and real regs afterwards. Loop optimization, for example, can create
3530 new libcalls after we've instantiated the virtual regs, and if we
3531 use virtuals anyway, they won't match the rtl patterns. */
3533 if (virtuals_instantiated)
3534 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3536 argblock = virtual_outgoing_args_rtx;
3541 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3544 /* If we push args individually in reverse order, perform stack alignment
3545 before the first push (the last arg). */
3546 if (argblock == 0 && PUSH_ARGS_REVERSED)
3547 anti_adjust_stack (GEN_INT (args_size.constant
3548 - original_args_size.constant));
3550 if (PUSH_ARGS_REVERSED)
3561 #ifdef REG_PARM_STACK_SPACE
3562 if (ACCUMULATE_OUTGOING_ARGS)
3564 /* The argument list is the property of the called routine and it
3565 may clobber it. If the fixed area has been used for previous
3566 parameters, we must save and restore it. */
3567 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3568 &low_to_save, &high_to_save);
3572 /* Push the args that need to be pushed. */
3574 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3575 are to be pushed. */
3576 for (count = 0; count < nargs; count++, argnum += inc)
3578 enum machine_mode mode = argvec[argnum].mode;
3579 rtx val = argvec[argnum].value;
3580 rtx reg = argvec[argnum].reg;
3581 int partial = argvec[argnum].partial;
3582 int lower_bound = 0, upper_bound = 0, i;
3584 if (! (reg != 0 && partial == 0))
3586 if (ACCUMULATE_OUTGOING_ARGS)
3588 /* If this is being stored into a pre-allocated, fixed-size,
3589 stack area, save any previous data at that location. */
3591 #ifdef ARGS_GROW_DOWNWARD
3592 /* stack_slot is negative, but we want to index stack_usage_map
3593 with positive values. */
3594 upper_bound = -argvec[argnum].locate.offset.constant + 1;
3595 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3597 lower_bound = argvec[argnum].locate.offset.constant;
3598 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3602 /* Don't worry about things in the fixed argument area;
3603 it has already been saved. */
3604 if (i < reg_parm_stack_space)
3605 i = reg_parm_stack_space;
3606 while (i < upper_bound && stack_usage_map[i] == 0)
3609 if (i < upper_bound)
3611 /* We need to make a save area. */
3613 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3614 enum machine_mode save_mode
3615 = mode_for_size (size, MODE_INT, 1);
3617 = plus_constant (argblock,
3618 argvec[argnum].locate.offset.constant);
3620 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3622 if (save_mode == BLKmode)
3624 argvec[argnum].save_area
3625 = assign_stack_temp (BLKmode,
3626 argvec[argnum].locate.size.constant,
3629 emit_block_move (validize_mem (argvec[argnum].save_area),
3631 GEN_INT (argvec[argnum].locate.size.constant),
3632 BLOCK_OP_CALL_PARM);
3636 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3638 emit_move_insn (argvec[argnum].save_area, stack_area);
3643 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, PARM_BOUNDARY,
3644 partial, reg, 0, argblock,
3645 GEN_INT (argvec[argnum].locate.offset.constant),
3646 reg_parm_stack_space,
3647 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3649 /* Now mark the segment we just used. */
3650 if (ACCUMULATE_OUTGOING_ARGS)
3651 for (i = lower_bound; i < upper_bound; i++)
3652 stack_usage_map[i] = 1;
3656 if (flags & ECF_CONST)
3660 /* Indicate argument access so that alias.c knows that these
3663 use = plus_constant (argblock,
3664 argvec[argnum].locate.offset.constant);
3666 /* When arguments are pushed, trying to tell alias.c where
3667 exactly this argument is won't work, because the
3668 auto-increment causes confusion. So we merely indicate
3669 that we access something with a known mode somewhere on
3671 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3672 gen_rtx_SCRATCH (Pmode));
3673 use = gen_rtx_MEM (argvec[argnum].mode, use);
3674 use = gen_rtx_USE (VOIDmode, use);
3675 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3680 /* If we pushed args in forward order, perform stack alignment
3681 after pushing the last arg. */
3682 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3683 anti_adjust_stack (GEN_INT (args_size.constant
3684 - original_args_size.constant));
3686 if (PUSH_ARGS_REVERSED)
3691 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3693 /* Now load any reg parms into their regs. */
3695 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3696 are to be pushed. */
3697 for (count = 0; count < nargs; count++, argnum += inc)
3699 enum machine_mode mode = argvec[argnum].mode;
3700 rtx val = argvec[argnum].value;
3701 rtx reg = argvec[argnum].reg;
3702 int partial = argvec[argnum].partial;
3704 /* Handle calls that pass values in multiple non-contiguous
3705 locations. The PA64 has examples of this for library calls. */
3706 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3707 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3708 else if (reg != 0 && partial == 0)
3709 emit_move_insn (reg, val);
3714 /* Any regs containing parms remain in use through the call. */
3715 for (count = 0; count < nargs; count++)
3717 rtx reg = argvec[count].reg;
3718 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3719 use_group_regs (&call_fusage, reg);
3722 int partial = argvec[count].partial;
3726 gcc_assert (partial % UNITS_PER_WORD == 0);
3727 nregs = partial / UNITS_PER_WORD;
3728 use_regs (&call_fusage, REGNO (reg), nregs);
3731 use_reg (&call_fusage, reg);
3735 /* Pass the function the address in which to return a structure value. */
3736 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3738 emit_move_insn (struct_value,
3740 force_operand (XEXP (mem_value, 0),
3742 if (REG_P (struct_value))
3743 use_reg (&call_fusage, struct_value);
3746 /* Don't allow popping to be deferred, since then
3747 cse'ing of library calls could delete a call and leave the pop. */
3749 valreg = (mem_value == 0 && outmode != VOIDmode
3750 ? hard_libcall_value (outmode) : NULL_RTX);
3752 /* Stack must be properly aligned now. */
3753 gcc_assert (!(stack_pointer_delta
3754 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3756 before_call = get_last_insn ();
3758 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3759 will set inhibit_defer_pop to that value. */
3760 /* The return type is needed to decide how many bytes the function pops.
3761 Signedness plays no role in that, so for simplicity, we pretend it's
3762 always signed. We also assume that the list of arguments passed has
3763 no impact, so we pretend it is unknown. */
3765 emit_call_1 (fun, NULL,
3766 get_identifier (XSTR (orgfun, 0)),
3767 build_function_type (tfom, NULL_TREE),
3768 original_args_size.constant, args_size.constant,
3770 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3772 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3774 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3775 that it should complain if nonvolatile values are live. For
3776 functions that cannot return, inform flow that control does not
3779 if (flags & ECF_NORETURN)
3781 /* The barrier note must be emitted
3782 immediately after the CALL_INSN. Some ports emit more than
3783 just a CALL_INSN above, so we must search for it here. */
3785 rtx last = get_last_insn ();
3786 while (!CALL_P (last))
3788 last = PREV_INSN (last);
3789 /* There was no CALL_INSN? */
3790 gcc_assert (last != before_call);
3793 emit_barrier_after (last);
3796 /* Now restore inhibit_defer_pop to its actual original value. */
3801 /* Copy the value to the right place. */
3802 if (outmode != VOIDmode && retval)
3808 if (value != mem_value)
3809 emit_move_insn (value, mem_value);
3811 else if (GET_CODE (valreg) == PARALLEL)
3814 value = gen_reg_rtx (outmode);
3815 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3819 /* Convert to the proper mode if PROMOTE_MODE has been active. */
3820 if (GET_MODE (valreg) != outmode)
3822 int unsignedp = TYPE_UNSIGNED (tfom);
3824 gcc_assert (targetm.calls.promote_function_return (tfom));
3825 gcc_assert (promote_mode (tfom, outmode, &unsignedp, 0)
3826 == GET_MODE (valreg));
3828 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3832 emit_move_insn (value, valreg);
3838 if (ACCUMULATE_OUTGOING_ARGS)
3840 #ifdef REG_PARM_STACK_SPACE
3842 restore_fixed_argument_area (save_area, argblock,
3843 high_to_save, low_to_save);
3846 /* If we saved any argument areas, restore them. */
3847 for (count = 0; count < nargs; count++)
3848 if (argvec[count].save_area)
3850 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3851 rtx adr = plus_constant (argblock,
3852 argvec[count].locate.offset.constant);
3853 rtx stack_area = gen_rtx_MEM (save_mode,
3854 memory_address (save_mode, adr));
3856 if (save_mode == BLKmode)
3857 emit_block_move (stack_area,
3858 validize_mem (argvec[count].save_area),
3859 GEN_INT (argvec[count].locate.size.constant),
3860 BLOCK_OP_CALL_PARM);
3862 emit_move_insn (stack_area, argvec[count].save_area);
3865 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3866 stack_usage_map = initial_stack_usage_map;
3869 if (stack_usage_map_buf)
3870 free (stack_usage_map_buf);
3876 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3877 (emitting the queue unless NO_QUEUE is nonzero),
3878 for a value of mode OUTMODE,
3879 with NARGS different arguments, passed as alternating rtx values
3880 and machine_modes to convert them to.
3882 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3883 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3884 other types of library calls. */
3887 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3888 enum machine_mode outmode, int nargs, ...)
3892 va_start (p, nargs);
3893 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3897 /* Like emit_library_call except that an extra argument, VALUE,
3898 comes second and says where to store the result.
3899 (If VALUE is zero, this function chooses a convenient way
3900 to return the value.
3902 This function returns an rtx for where the value is to be found.
3903 If VALUE is nonzero, VALUE is returned. */
3906 emit_library_call_value (rtx orgfun, rtx value,
3907 enum libcall_type fn_type,
3908 enum machine_mode outmode, int nargs, ...)
3913 va_start (p, nargs);
3914 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3921 /* Store a single argument for a function call
3922 into the register or memory area where it must be passed.
3923 *ARG describes the argument value and where to pass it.
3925 ARGBLOCK is the address of the stack-block for all the arguments,
3926 or 0 on a machine where arguments are pushed individually.
3928 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3929 so must be careful about how the stack is used.
3931 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3932 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3933 that we need not worry about saving and restoring the stack.
3935 FNDECL is the declaration of the function we are calling.
3937 Return nonzero if this arg should cause sibcall failure,
3941 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3942 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3944 tree pval = arg->tree_value;
3948 int i, lower_bound = 0, upper_bound = 0;
3949 int sibcall_failure = 0;
3951 if (TREE_CODE (pval) == ERROR_MARK)
3954 /* Push a new temporary level for any temporaries we make for
3958 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
3960 /* If this is being stored into a pre-allocated, fixed-size, stack area,
3961 save any previous data at that location. */
3962 if (argblock && ! variable_size && arg->stack)
3964 #ifdef ARGS_GROW_DOWNWARD
3965 /* stack_slot is negative, but we want to index stack_usage_map
3966 with positive values. */
3967 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3968 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
3972 lower_bound = upper_bound - arg->locate.size.constant;
3974 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
3975 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
3979 upper_bound = lower_bound + arg->locate.size.constant;
3983 /* Don't worry about things in the fixed argument area;
3984 it has already been saved. */
3985 if (i < reg_parm_stack_space)
3986 i = reg_parm_stack_space;
3987 while (i < upper_bound && stack_usage_map[i] == 0)
3990 if (i < upper_bound)
3992 /* We need to make a save area. */
3993 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
3994 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
3995 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
3996 rtx stack_area = gen_rtx_MEM (save_mode, adr);
3998 if (save_mode == BLKmode)
4000 tree ot = TREE_TYPE (arg->tree_value);
4001 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4002 | TYPE_QUAL_CONST));
4004 arg->save_area = assign_temp (nt, 0, 1, 1);
4005 preserve_temp_slots (arg->save_area);
4006 emit_block_move (validize_mem (arg->save_area), stack_area,
4007 GEN_INT (arg->locate.size.constant),
4008 BLOCK_OP_CALL_PARM);
4012 arg->save_area = gen_reg_rtx (save_mode);
4013 emit_move_insn (arg->save_area, stack_area);
4019 /* If this isn't going to be placed on both the stack and in registers,
4020 set up the register and number of words. */
4021 if (! arg->pass_on_stack)
4023 if (flags & ECF_SIBCALL)
4024 reg = arg->tail_call_reg;
4027 partial = arg->partial;
4030 /* Being passed entirely in a register. We shouldn't be called in
4032 gcc_assert (reg == 0 || partial != 0);
4034 /* If this arg needs special alignment, don't load the registers
4036 if (arg->n_aligned_regs != 0)
4039 /* If this is being passed partially in a register, we can't evaluate
4040 it directly into its stack slot. Otherwise, we can. */
4041 if (arg->value == 0)
4043 /* stack_arg_under_construction is nonzero if a function argument is
4044 being evaluated directly into the outgoing argument list and
4045 expand_call must take special action to preserve the argument list
4046 if it is called recursively.
4048 For scalar function arguments stack_usage_map is sufficient to
4049 determine which stack slots must be saved and restored. Scalar
4050 arguments in general have pass_on_stack == 0.
4052 If this argument is initialized by a function which takes the
4053 address of the argument (a C++ constructor or a C function
4054 returning a BLKmode structure), then stack_usage_map is
4055 insufficient and expand_call must push the stack around the
4056 function call. Such arguments have pass_on_stack == 1.
4058 Note that it is always safe to set stack_arg_under_construction,
4059 but this generates suboptimal code if set when not needed. */
4061 if (arg->pass_on_stack)
4062 stack_arg_under_construction++;
4064 arg->value = expand_expr (pval,
4066 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4067 ? NULL_RTX : arg->stack,
4068 VOIDmode, EXPAND_STACK_PARM);
4070 /* If we are promoting object (or for any other reason) the mode
4071 doesn't agree, convert the mode. */
4073 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4074 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4075 arg->value, arg->unsignedp);
4077 if (arg->pass_on_stack)
4078 stack_arg_under_construction--;
4081 /* Check for overlap with already clobbered argument area. */
4082 if ((flags & ECF_SIBCALL)
4083 && MEM_P (arg->value)
4084 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4085 arg->locate.size.constant))
4086 sibcall_failure = 1;
4088 /* Don't allow anything left on stack from computation
4089 of argument to alloca. */
4090 if (flags & ECF_MAY_BE_ALLOCA)
4091 do_pending_stack_adjust ();
4093 if (arg->value == arg->stack)
4094 /* If the value is already in the stack slot, we are done. */
4096 else if (arg->mode != BLKmode)
4099 unsigned int parm_align;
4101 /* Argument is a scalar, not entirely passed in registers.
4102 (If part is passed in registers, arg->partial says how much
4103 and emit_push_insn will take care of putting it there.)
4105 Push it, and if its size is less than the
4106 amount of space allocated to it,
4107 also bump stack pointer by the additional space.
4108 Note that in C the default argument promotions
4109 will prevent such mismatches. */
4111 size = GET_MODE_SIZE (arg->mode);
4112 /* Compute how much space the push instruction will push.
4113 On many machines, pushing a byte will advance the stack
4114 pointer by a halfword. */
4115 #ifdef PUSH_ROUNDING
4116 size = PUSH_ROUNDING (size);
4120 /* Compute how much space the argument should get:
4121 round up to a multiple of the alignment for arguments. */
4122 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4123 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4124 / (PARM_BOUNDARY / BITS_PER_UNIT))
4125 * (PARM_BOUNDARY / BITS_PER_UNIT));
4127 /* Compute the alignment of the pushed argument. */
4128 parm_align = arg->locate.boundary;
4129 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4131 int pad = used - size;
4134 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4135 parm_align = MIN (parm_align, pad_align);
4139 /* This isn't already where we want it on the stack, so put it there.
4140 This can either be done with push or copy insns. */
4141 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4142 parm_align, partial, reg, used - size, argblock,
4143 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4144 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4146 /* Unless this is a partially-in-register argument, the argument is now
4149 arg->value = arg->stack;
4153 /* BLKmode, at least partly to be pushed. */
4155 unsigned int parm_align;
4159 /* Pushing a nonscalar.
4160 If part is passed in registers, PARTIAL says how much
4161 and emit_push_insn will take care of putting it there. */
4163 /* Round its size up to a multiple
4164 of the allocation unit for arguments. */
4166 if (arg->locate.size.var != 0)
4169 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4173 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4174 for BLKmode is careful to avoid it. */
4175 excess = (arg->locate.size.constant
4176 - int_size_in_bytes (TREE_TYPE (pval))
4178 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4179 NULL_RTX, TYPE_MODE (sizetype), 0);
4182 parm_align = arg->locate.boundary;
4184 /* When an argument is padded down, the block is aligned to
4185 PARM_BOUNDARY, but the actual argument isn't. */
4186 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4188 if (arg->locate.size.var)
4189 parm_align = BITS_PER_UNIT;
4192 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4193 parm_align = MIN (parm_align, excess_align);
4197 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4199 /* emit_push_insn might not work properly if arg->value and
4200 argblock + arg->locate.offset areas overlap. */
4204 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4205 || (GET_CODE (XEXP (x, 0)) == PLUS
4206 && XEXP (XEXP (x, 0), 0) ==
4207 crtl->args.internal_arg_pointer
4208 && GET_CODE (XEXP (XEXP (x, 0), 1)) == CONST_INT))
4210 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4211 i = INTVAL (XEXP (XEXP (x, 0), 1));
4213 /* expand_call should ensure this. */
4214 gcc_assert (!arg->locate.offset.var
4215 && arg->locate.size.var == 0
4216 && GET_CODE (size_rtx) == CONST_INT);
4218 if (arg->locate.offset.constant > i)
4220 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4221 sibcall_failure = 1;
4223 else if (arg->locate.offset.constant < i)
4225 /* Use arg->locate.size.constant instead of size_rtx
4226 because we only care about the part of the argument
4228 if (i < (arg->locate.offset.constant
4229 + arg->locate.size.constant))
4230 sibcall_failure = 1;
4234 /* Even though they appear to be at the same location,
4235 if part of the outgoing argument is in registers,
4236 they aren't really at the same location. Check for
4237 this by making sure that the incoming size is the
4238 same as the outgoing size. */
4239 if (arg->locate.size.constant != INTVAL (size_rtx))
4240 sibcall_failure = 1;
4245 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4246 parm_align, partial, reg, excess, argblock,
4247 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4248 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4250 /* Unless this is a partially-in-register argument, the argument is now
4253 ??? Unlike the case above, in which we want the actual
4254 address of the data, so that we can load it directly into a
4255 register, here we want the address of the stack slot, so that
4256 it's properly aligned for word-by-word copying or something
4257 like that. It's not clear that this is always correct. */
4259 arg->value = arg->stack_slot;
4262 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4264 tree type = TREE_TYPE (arg->tree_value);
4266 = emit_group_load_into_temps (arg->reg, arg->value, type,
4267 int_size_in_bytes (type));
4270 /* Mark all slots this store used. */
4271 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4272 && argblock && ! variable_size && arg->stack)
4273 for (i = lower_bound; i < upper_bound; i++)
4274 stack_usage_map[i] = 1;
4276 /* Once we have pushed something, pops can't safely
4277 be deferred during the rest of the arguments. */
4280 /* Free any temporary slots made in processing this argument. Show
4281 that we might have taken the address of something and pushed that
4283 preserve_temp_slots (NULL_RTX);
4287 return sibcall_failure;
4290 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4293 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4299 /* If the type has variable size... */
4300 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4303 /* If the type is marked as addressable (it is required
4304 to be constructed into the stack)... */
4305 if (TREE_ADDRESSABLE (type))
4311 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4312 takes trailing padding of a structure into account. */
4313 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4316 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4321 /* If the type has variable size... */
4322 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4325 /* If the type is marked as addressable (it is required
4326 to be constructed into the stack)... */
4327 if (TREE_ADDRESSABLE (type))
4330 /* If the padding and mode of the type is such that a copy into
4331 a register would put it into the wrong part of the register. */
4333 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4334 && (FUNCTION_ARG_PADDING (mode, type)
4335 == (BYTES_BIG_ENDIAN ? upward : downward)))