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, 2008, 2009
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"
46 #include "tree-flow.h"
48 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
49 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
51 /* Data structure and subroutines used within expand_call. */
55 /* Tree node for this argument. */
57 /* Mode for value; TYPE_MODE unless promoted. */
58 enum machine_mode mode;
59 /* Current RTL value for argument, or 0 if it isn't precomputed. */
61 /* Initially-compute RTL value for argument; only for const functions. */
63 /* Register to pass this argument in, 0 if passed on stack, or an
64 PARALLEL if the arg is to be copied into multiple non-contiguous
67 /* Register to pass this argument in when generating tail call sequence.
68 This is not the same register as for normal calls on machines with
71 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
72 form for emit_group_move. */
74 /* If REG was promoted from the actual mode of the argument expression,
75 indicates whether the promotion is sign- or zero-extended. */
77 /* Number of bytes to put in registers. 0 means put the whole arg
78 in registers. Also 0 if not passed in registers. */
80 /* Nonzero if argument must be passed on stack.
81 Note that some arguments may be passed on the stack
82 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
83 pass_on_stack identifies arguments that *cannot* go in registers. */
85 /* Some fields packaged up for locate_and_pad_parm. */
86 struct locate_and_pad_arg_data locate;
87 /* Location on the stack at which parameter should be stored. The store
88 has already been done if STACK == VALUE. */
90 /* Location on the stack of the start of this argument slot. This can
91 differ from STACK if this arg pads downward. This location is known
92 to be aligned to FUNCTION_ARG_BOUNDARY. */
94 /* Place that this stack area has been saved, if needed. */
96 /* If an argument's alignment does not permit direct copying into registers,
97 copy in smaller-sized pieces into pseudos. These are stored in a
98 block pointed to by this field. The next field says how many
99 word-sized pseudos we made. */
104 /* A vector of one char per byte of stack space. A byte if nonzero if
105 the corresponding stack location has been used.
106 This vector is used to prevent a function call within an argument from
107 clobbering any stack already set up. */
108 static char *stack_usage_map;
110 /* Size of STACK_USAGE_MAP. */
111 static int highest_outgoing_arg_in_use;
113 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
114 stack location's tail call argument has been already stored into the stack.
115 This bitmap is used to prevent sibling call optimization if function tries
116 to use parent's incoming argument slots when they have been already
117 overwritten with tail call arguments. */
118 static sbitmap stored_args_map;
120 /* stack_arg_under_construction is nonzero when an argument may be
121 initialized with a constructor call (including a C function that
122 returns a BLKmode struct) and expand_call must take special action
123 to make sure the object being constructed does not overlap the
124 argument list for the constructor call. */
125 static int stack_arg_under_construction;
127 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
128 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
130 static void precompute_register_parameters (int, struct arg_data *, int *);
131 static int store_one_arg (struct arg_data *, rtx, int, int, int);
132 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
133 static int finalize_must_preallocate (int, int, struct arg_data *,
135 static void precompute_arguments (int, struct arg_data *);
136 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
137 static void initialize_argument_information (int, struct arg_data *,
138 struct args_size *, int,
140 tree, tree, CUMULATIVE_ARGS *, int,
141 rtx *, int *, int *, int *,
143 static void compute_argument_addresses (struct arg_data *, rtx, int);
144 static rtx rtx_for_function_call (tree, tree);
145 static void load_register_parameters (struct arg_data *, int, rtx *, int,
147 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
148 enum machine_mode, int, va_list);
149 static int special_function_p (const_tree, int);
150 static int check_sibcall_argument_overlap_1 (rtx);
151 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
153 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
155 static tree split_complex_types (tree);
157 #ifdef REG_PARM_STACK_SPACE
158 static rtx save_fixed_argument_area (int, rtx, int *, int *);
159 static void restore_fixed_argument_area (rtx, rtx, int, int);
162 /* Force FUNEXP into a form suitable for the address of a CALL,
163 and return that as an rtx. Also load the static chain register
164 if FNDECL is a nested function.
166 CALL_FUSAGE points to a variable holding the prospective
167 CALL_INSN_FUNCTION_USAGE information. */
170 prepare_call_address (tree fndecl, rtx funexp, rtx static_chain_value,
171 rtx *call_fusage, int reg_parm_seen, int sibcallp)
173 /* Make a valid memory address and copy constants through pseudo-regs,
174 but not for a constant address if -fno-function-cse. */
175 if (GET_CODE (funexp) != SYMBOL_REF)
176 /* If we are using registers for parameters, force the
177 function address into a register now. */
178 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
179 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
180 : memory_address (FUNCTION_MODE, funexp));
183 #ifndef NO_FUNCTION_CSE
184 if (optimize && ! flag_no_function_cse)
185 funexp = force_reg (Pmode, funexp);
189 if (static_chain_value != 0)
194 chain = targetm.calls.static_chain (fndecl, false);
195 static_chain_value = convert_memory_address (Pmode, static_chain_value);
197 emit_move_insn (chain, static_chain_value);
199 use_reg (call_fusage, chain);
205 /* Generate instructions to call function FUNEXP,
206 and optionally pop the results.
207 The CALL_INSN is the first insn generated.
209 FNDECL is the declaration node of the function. This is given to the
210 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
212 FUNTYPE is the data type of the function. This is given to the macro
213 RETURN_POPS_ARGS to determine whether this function pops its own args.
214 We used to allow an identifier for library functions, but that doesn't
215 work when the return type is an aggregate type and the calling convention
216 says that the pointer to this aggregate is to be popped by the callee.
218 STACK_SIZE is the number of bytes of arguments on the stack,
219 ROUNDED_STACK_SIZE is that number rounded up to
220 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
221 both to put into the call insn and to generate explicit popping
224 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
225 It is zero if this call doesn't want a structure value.
227 NEXT_ARG_REG is the rtx that results from executing
228 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
229 just after all the args have had their registers assigned.
230 This could be whatever you like, but normally it is the first
231 arg-register beyond those used for args in this call,
232 or 0 if all the arg-registers are used in this call.
233 It is passed on to `gen_call' so you can put this info in the call insn.
235 VALREG is a hard register in which a value is returned,
236 or 0 if the call does not return a value.
238 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
239 the args to this call were processed.
240 We restore `inhibit_defer_pop' to that value.
242 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
243 denote registers used by the called function. */
246 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
247 tree funtype ATTRIBUTE_UNUSED,
248 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
249 HOST_WIDE_INT rounded_stack_size,
250 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
251 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
252 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
253 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
255 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
257 int already_popped = 0;
258 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
260 #ifdef CALL_POPS_ARGS
261 n_popped += CALL_POPS_ARGS (* args_so_far);
264 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
265 and we don't want to load it into a register as an optimization,
266 because prepare_call_address already did it if it should be done. */
267 if (GET_CODE (funexp) != SYMBOL_REF)
268 funexp = memory_address (FUNCTION_MODE, funexp);
270 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
271 if ((ecf_flags & ECF_SIBCALL)
272 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
273 && (n_popped > 0 || stack_size == 0))
275 rtx n_pop = GEN_INT (n_popped);
278 /* If this subroutine pops its own args, record that in the call insn
279 if possible, for the sake of frame pointer elimination. */
282 pat = GEN_SIBCALL_VALUE_POP (valreg,
283 gen_rtx_MEM (FUNCTION_MODE, funexp),
284 rounded_stack_size_rtx, next_arg_reg,
287 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
288 rounded_stack_size_rtx, next_arg_reg, n_pop);
290 emit_call_insn (pat);
296 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
297 /* If the target has "call" or "call_value" insns, then prefer them
298 if no arguments are actually popped. If the target does not have
299 "call" or "call_value" insns, then we must use the popping versions
300 even if the call has no arguments to pop. */
301 #if defined (HAVE_call) && defined (HAVE_call_value)
302 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
305 if (HAVE_call_pop && HAVE_call_value_pop)
308 rtx n_pop = GEN_INT (n_popped);
311 /* If this subroutine pops its own args, record that in the call insn
312 if possible, for the sake of frame pointer elimination. */
315 pat = GEN_CALL_VALUE_POP (valreg,
316 gen_rtx_MEM (FUNCTION_MODE, funexp),
317 rounded_stack_size_rtx, next_arg_reg, n_pop);
319 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
320 rounded_stack_size_rtx, next_arg_reg, n_pop);
322 emit_call_insn (pat);
328 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
329 if ((ecf_flags & ECF_SIBCALL)
330 && HAVE_sibcall && HAVE_sibcall_value)
333 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
334 gen_rtx_MEM (FUNCTION_MODE, funexp),
335 rounded_stack_size_rtx,
336 next_arg_reg, NULL_RTX));
338 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
339 rounded_stack_size_rtx, next_arg_reg,
340 GEN_INT (struct_value_size)));
345 #if defined (HAVE_call) && defined (HAVE_call_value)
346 if (HAVE_call && HAVE_call_value)
349 emit_call_insn (GEN_CALL_VALUE (valreg,
350 gen_rtx_MEM (FUNCTION_MODE, funexp),
351 rounded_stack_size_rtx, next_arg_reg,
354 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
355 rounded_stack_size_rtx, next_arg_reg,
356 GEN_INT (struct_value_size)));
362 /* Find the call we just emitted. */
363 call_insn = last_call_insn ();
365 /* Put the register usage information there. */
366 add_function_usage_to (call_insn, call_fusage);
368 /* If this is a const call, then set the insn's unchanging bit. */
369 if (ecf_flags & ECF_CONST)
370 RTL_CONST_CALL_P (call_insn) = 1;
372 /* If this is a pure call, then set the insn's unchanging bit. */
373 if (ecf_flags & ECF_PURE)
374 RTL_PURE_CALL_P (call_insn) = 1;
376 /* If this is a const call, then set the insn's unchanging bit. */
377 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
378 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
380 /* Create a nothrow REG_EH_REGION note, if needed. */
381 make_reg_eh_region_note (call_insn, ecf_flags, 0);
383 if (ecf_flags & ECF_NORETURN)
384 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
386 if (ecf_flags & ECF_RETURNS_TWICE)
388 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
389 cfun->calls_setjmp = 1;
392 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
394 /* Record debug information for virtual calls. */
395 if (flag_enable_icf_debug && fndecl == NULL)
396 (*debug_hooks->virtual_call_token) (CALL_EXPR_FN (fntree),
397 INSN_UID (call_insn));
399 /* Restore this now, so that we do defer pops for this call's args
400 if the context of the call as a whole permits. */
401 inhibit_defer_pop = old_inhibit_defer_pop;
406 CALL_INSN_FUNCTION_USAGE (call_insn)
407 = gen_rtx_EXPR_LIST (VOIDmode,
408 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
409 CALL_INSN_FUNCTION_USAGE (call_insn));
410 rounded_stack_size -= n_popped;
411 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
412 stack_pointer_delta -= n_popped;
414 /* If popup is needed, stack realign must use DRAP */
415 if (SUPPORTS_STACK_ALIGNMENT)
416 crtl->need_drap = true;
419 if (!ACCUMULATE_OUTGOING_ARGS)
421 /* If returning from the subroutine does not automatically pop the args,
422 we need an instruction to pop them sooner or later.
423 Perhaps do it now; perhaps just record how much space to pop later.
425 If returning from the subroutine does pop the args, indicate that the
426 stack pointer will be changed. */
428 if (rounded_stack_size != 0)
430 if (ecf_flags & ECF_NORETURN)
431 /* Just pretend we did the pop. */
432 stack_pointer_delta -= rounded_stack_size;
433 else if (flag_defer_pop && inhibit_defer_pop == 0
434 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
435 pending_stack_adjust += rounded_stack_size;
437 adjust_stack (rounded_stack_size_rtx);
440 /* When we accumulate outgoing args, we must avoid any stack manipulations.
441 Restore the stack pointer to its original value now. Usually
442 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
443 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
444 popping variants of functions exist as well.
446 ??? We may optimize similar to defer_pop above, but it is
447 probably not worthwhile.
449 ??? It will be worthwhile to enable combine_stack_adjustments even for
452 anti_adjust_stack (GEN_INT (n_popped));
455 /* Determine if the function identified by NAME and FNDECL is one with
456 special properties we wish to know about.
458 For example, if the function might return more than one time (setjmp), then
459 set RETURNS_TWICE to a nonzero value.
461 Similarly set NORETURN if the function is in the longjmp family.
463 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
464 space from the stack such as alloca. */
467 special_function_p (const_tree fndecl, int flags)
469 if (fndecl && DECL_NAME (fndecl)
470 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
471 /* Exclude functions not at the file scope, or not `extern',
472 since they are not the magic functions we would otherwise
474 FIXME: this should be handled with attributes, not with this
475 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
476 because you can declare fork() inside a function if you
478 && (DECL_CONTEXT (fndecl) == NULL_TREE
479 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
480 && TREE_PUBLIC (fndecl))
482 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
483 const char *tname = name;
485 /* We assume that alloca will always be called by name. It
486 makes no sense to pass it as a pointer-to-function to
487 anything that does not understand its behavior. */
488 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
490 && ! strcmp (name, "alloca"))
491 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
493 && ! strcmp (name, "__builtin_alloca"))))
494 flags |= ECF_MAY_BE_ALLOCA;
496 /* Disregard prefix _, __, __x or __builtin_. */
501 && !strncmp (name + 3, "uiltin_", 7))
503 else if (name[1] == '_' && name[2] == 'x')
505 else if (name[1] == '_')
514 && (! strcmp (tname, "setjmp")
515 || ! strcmp (tname, "setjmp_syscall")))
517 && ! strcmp (tname, "sigsetjmp"))
519 && ! strcmp (tname, "savectx")))
520 flags |= ECF_RETURNS_TWICE;
523 && ! strcmp (tname, "siglongjmp"))
524 flags |= ECF_NORETURN;
526 else if ((tname[0] == 'q' && tname[1] == 's'
527 && ! strcmp (tname, "qsetjmp"))
528 || (tname[0] == 'v' && tname[1] == 'f'
529 && ! strcmp (tname, "vfork"))
530 || (tname[0] == 'g' && tname[1] == 'e'
531 && !strcmp (tname, "getcontext")))
532 flags |= ECF_RETURNS_TWICE;
534 else if (tname[0] == 'l' && tname[1] == 'o'
535 && ! strcmp (tname, "longjmp"))
536 flags |= ECF_NORETURN;
542 /* Return nonzero when FNDECL represents a call to setjmp. */
545 setjmp_call_p (const_tree fndecl)
547 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
551 /* Return true if STMT is an alloca call. */
554 gimple_alloca_call_p (const_gimple stmt)
558 if (!is_gimple_call (stmt))
561 fndecl = gimple_call_fndecl (stmt);
562 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
568 /* Return true when exp contains alloca call. */
571 alloca_call_p (const_tree exp)
573 if (TREE_CODE (exp) == CALL_EXPR
574 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
575 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
576 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
577 & ECF_MAY_BE_ALLOCA))
582 /* Detect flags (function attributes) from the function decl or type node. */
585 flags_from_decl_or_type (const_tree 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, optimize_insn_for_speed_p ())
714 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
716 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
720 #ifdef REG_PARM_STACK_SPACE
722 /* The argument list is the property of the called routine and it
723 may clobber it. If the fixed area has been used for previous
724 parameters, we must save and restore it. */
727 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
732 /* Compute the boundary of the area that needs to be saved, if any. */
733 high = reg_parm_stack_space;
734 #ifdef ARGS_GROW_DOWNWARD
737 if (high > highest_outgoing_arg_in_use)
738 high = highest_outgoing_arg_in_use;
740 for (low = 0; low < high; low++)
741 if (stack_usage_map[low] != 0)
744 enum machine_mode save_mode;
749 while (stack_usage_map[--high] == 0)
753 *high_to_save = high;
755 num_to_save = high - low + 1;
756 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
758 /* If we don't have the required alignment, must do this
760 if ((low & (MIN (GET_MODE_SIZE (save_mode),
761 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
764 #ifdef ARGS_GROW_DOWNWARD
769 stack_area = gen_rtx_MEM (save_mode,
770 memory_address (save_mode,
771 plus_constant (argblock,
774 set_mem_align (stack_area, PARM_BOUNDARY);
775 if (save_mode == BLKmode)
777 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
778 emit_block_move (validize_mem (save_area), stack_area,
779 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
783 save_area = gen_reg_rtx (save_mode);
784 emit_move_insn (save_area, stack_area);
794 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
796 enum machine_mode save_mode = GET_MODE (save_area);
800 #ifdef ARGS_GROW_DOWNWARD
801 delta = -high_to_save;
805 stack_area = gen_rtx_MEM (save_mode,
806 memory_address (save_mode,
807 plus_constant (argblock, delta)));
808 set_mem_align (stack_area, PARM_BOUNDARY);
810 if (save_mode != BLKmode)
811 emit_move_insn (stack_area, save_area);
813 emit_block_move (stack_area, validize_mem (save_area),
814 GEN_INT (high_to_save - low_to_save + 1),
817 #endif /* REG_PARM_STACK_SPACE */
819 /* If any elements in ARGS refer to parameters that are to be passed in
820 registers, but not in memory, and whose alignment does not permit a
821 direct copy into registers. Copy the values into a group of pseudos
822 which we will later copy into the appropriate hard registers.
824 Pseudos for each unaligned argument will be stored into the array
825 args[argnum].aligned_regs. The caller is responsible for deallocating
826 the aligned_regs array if it is nonzero. */
829 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
833 for (i = 0; i < num_actuals; i++)
834 if (args[i].reg != 0 && ! args[i].pass_on_stack
835 && args[i].mode == BLKmode
836 && MEM_P (args[i].value)
837 && (MEM_ALIGN (args[i].value)
838 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
840 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
841 int endian_correction = 0;
845 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
846 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
850 args[i].n_aligned_regs
851 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
854 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
856 /* Structures smaller than a word are normally aligned to the
857 least significant byte. On a BYTES_BIG_ENDIAN machine,
858 this means we must skip the empty high order bytes when
859 calculating the bit offset. */
860 if (bytes < UNITS_PER_WORD
861 #ifdef BLOCK_REG_PADDING
862 && (BLOCK_REG_PADDING (args[i].mode,
863 TREE_TYPE (args[i].tree_value), 1)
869 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
871 for (j = 0; j < args[i].n_aligned_regs; j++)
873 rtx reg = gen_reg_rtx (word_mode);
874 rtx word = operand_subword_force (args[i].value, j, BLKmode);
875 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
877 args[i].aligned_regs[j] = reg;
878 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
879 word_mode, word_mode);
881 /* There is no need to restrict this code to loading items
882 in TYPE_ALIGN sized hunks. The bitfield instructions can
883 load up entire word sized registers efficiently.
885 ??? This may not be needed anymore.
886 We use to emit a clobber here but that doesn't let later
887 passes optimize the instructions we emit. By storing 0 into
888 the register later passes know the first AND to zero out the
889 bitfield being set in the register is unnecessary. The store
890 of 0 will be deleted as will at least the first AND. */
892 emit_move_insn (reg, const0_rtx);
894 bytes -= bitsize / BITS_PER_UNIT;
895 store_bit_field (reg, bitsize, endian_correction, word_mode,
901 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
904 NUM_ACTUALS is the total number of parameters.
906 N_NAMED_ARGS is the total number of named arguments.
908 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
911 FNDECL is the tree code for the target of this call (if known)
913 ARGS_SO_FAR holds state needed by the target to know where to place
916 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
917 for arguments which are passed in registers.
919 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
920 and may be modified by this routine.
922 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
923 flags which may may be modified by this routine.
925 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
926 that requires allocation of stack space.
928 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
929 the thunked-to function. */
932 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
933 struct arg_data *args,
934 struct args_size *args_size,
935 int n_named_args ATTRIBUTE_UNUSED,
936 tree exp, tree struct_value_addr_value,
937 tree fndecl, tree fntype,
938 CUMULATIVE_ARGS *args_so_far,
939 int reg_parm_stack_space,
940 rtx *old_stack_level, int *old_pending_adj,
941 int *must_preallocate, int *ecf_flags,
942 bool *may_tailcall, bool call_from_thunk_p)
944 location_t loc = EXPR_LOCATION (exp);
945 /* 1 if scanning parms front to back, -1 if scanning back to front. */
948 /* Count arg position in order args appear. */
953 args_size->constant = 0;
956 /* In this loop, we consider args in the order they are written.
957 We fill up ARGS from the front or from the back if necessary
958 so that in any case the first arg to be pushed ends up at the front. */
960 if (PUSH_ARGS_REVERSED)
962 i = num_actuals - 1, inc = -1;
963 /* In this case, must reverse order of args
964 so that we compute and push the last arg first. */
971 /* First fill in the actual arguments in the ARGS array, splitting
972 complex arguments if necessary. */
975 call_expr_arg_iterator iter;
978 if (struct_value_addr_value)
980 args[j].tree_value = struct_value_addr_value;
983 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
985 tree argtype = TREE_TYPE (arg);
986 if (targetm.calls.split_complex_arg
988 && TREE_CODE (argtype) == COMPLEX_TYPE
989 && targetm.calls.split_complex_arg (argtype))
991 tree subtype = TREE_TYPE (argtype);
992 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
994 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
997 args[j].tree_value = arg;
1002 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1003 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1005 tree type = TREE_TYPE (args[i].tree_value);
1007 enum machine_mode mode;
1009 /* Replace erroneous argument with constant zero. */
1010 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1011 args[i].tree_value = integer_zero_node, type = integer_type_node;
1013 /* If TYPE is a transparent union, pass things the way we would
1014 pass the first field of the union. We have already verified that
1015 the modes are the same. */
1016 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1017 type = TREE_TYPE (TYPE_FIELDS (type));
1019 /* Decide where to pass this arg.
1021 args[i].reg is nonzero if all or part is passed in registers.
1023 args[i].partial is nonzero if part but not all is passed in registers,
1024 and the exact value says how many bytes are passed in registers.
1026 args[i].pass_on_stack is nonzero if the argument must at least be
1027 computed on the stack. It may then be loaded back into registers
1028 if args[i].reg is nonzero.
1030 These decisions are driven by the FUNCTION_... macros and must agree
1031 with those made by function.c. */
1033 /* See if this argument should be passed by invisible reference. */
1034 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1035 type, argpos < n_named_args))
1041 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1042 type, argpos < n_named_args);
1044 /* If we're compiling a thunk, pass through invisible references
1045 instead of making a copy. */
1046 if (call_from_thunk_p
1048 && !TREE_ADDRESSABLE (type)
1049 && (base = get_base_address (args[i].tree_value))
1050 && TREE_CODE (base) != SSA_NAME
1051 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1053 /* We can't use sibcalls if a callee-copied argument is
1054 stored in the current function's frame. */
1055 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1056 *may_tailcall = false;
1058 args[i].tree_value = build_fold_addr_expr_loc (loc,
1059 args[i].tree_value);
1060 type = TREE_TYPE (args[i].tree_value);
1062 if (*ecf_flags & ECF_CONST)
1063 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1067 /* We make a copy of the object and pass the address to the
1068 function being called. */
1071 if (!COMPLETE_TYPE_P (type)
1072 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1073 || (flag_stack_check == GENERIC_STACK_CHECK
1074 && compare_tree_int (TYPE_SIZE_UNIT (type),
1075 STACK_CHECK_MAX_VAR_SIZE) > 0))
1077 /* This is a variable-sized object. Make space on the stack
1079 rtx size_rtx = expr_size (args[i].tree_value);
1081 if (*old_stack_level == 0)
1083 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1084 *old_pending_adj = pending_stack_adjust;
1085 pending_stack_adjust = 0;
1088 copy = gen_rtx_MEM (BLKmode,
1089 allocate_dynamic_stack_space
1090 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1091 set_mem_attributes (copy, type, 1);
1094 copy = assign_temp (type, 0, 1, 0);
1096 store_expr (args[i].tree_value, copy, 0, false);
1098 /* Just change the const function to pure and then let
1099 the next test clear the pure based on
1101 if (*ecf_flags & ECF_CONST)
1103 *ecf_flags &= ~ECF_CONST;
1104 *ecf_flags |= ECF_PURE;
1107 if (!callee_copies && *ecf_flags & ECF_PURE)
1108 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1111 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1112 type = TREE_TYPE (args[i].tree_value);
1113 *may_tailcall = false;
1117 unsignedp = TYPE_UNSIGNED (type);
1118 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1119 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1121 args[i].unsignedp = unsignedp;
1122 args[i].mode = mode;
1124 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1125 argpos < n_named_args);
1126 #ifdef FUNCTION_INCOMING_ARG
1127 /* If this is a sibling call and the machine has register windows, the
1128 register window has to be unwinded before calling the routine, so
1129 arguments have to go into the incoming registers. */
1130 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1131 argpos < n_named_args);
1133 args[i].tail_call_reg = args[i].reg;
1138 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1139 argpos < n_named_args);
1141 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1143 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1144 it means that we are to pass this arg in the register(s) designated
1145 by the PARALLEL, but also to pass it in the stack. */
1146 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1147 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1148 args[i].pass_on_stack = 1;
1150 /* If this is an addressable type, we must preallocate the stack
1151 since we must evaluate the object into its final location.
1153 If this is to be passed in both registers and the stack, it is simpler
1155 if (TREE_ADDRESSABLE (type)
1156 || (args[i].pass_on_stack && args[i].reg != 0))
1157 *must_preallocate = 1;
1159 /* Compute the stack-size of this argument. */
1160 if (args[i].reg == 0 || args[i].partial != 0
1161 || reg_parm_stack_space > 0
1162 || args[i].pass_on_stack)
1163 locate_and_pad_parm (mode, type,
1164 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1169 args[i].pass_on_stack ? 0 : args[i].partial,
1170 fndecl, args_size, &args[i].locate);
1171 #ifdef BLOCK_REG_PADDING
1173 /* The argument is passed entirely in registers. See at which
1174 end it should be padded. */
1175 args[i].locate.where_pad =
1176 BLOCK_REG_PADDING (mode, type,
1177 int_size_in_bytes (type) <= UNITS_PER_WORD);
1180 /* Update ARGS_SIZE, the total stack space for args so far. */
1182 args_size->constant += args[i].locate.size.constant;
1183 if (args[i].locate.size.var)
1184 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1186 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1187 have been used, etc. */
1189 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1190 argpos < n_named_args);
1194 /* Update ARGS_SIZE to contain the total size for the argument block.
1195 Return the original constant component of the argument block's size.
1197 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1198 for arguments passed in registers. */
1201 compute_argument_block_size (int reg_parm_stack_space,
1202 struct args_size *args_size,
1203 tree fndecl ATTRIBUTE_UNUSED,
1204 tree fntype ATTRIBUTE_UNUSED,
1205 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1207 int unadjusted_args_size = args_size->constant;
1209 /* For accumulate outgoing args mode we don't need to align, since the frame
1210 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1211 backends from generating misaligned frame sizes. */
1212 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1213 preferred_stack_boundary = STACK_BOUNDARY;
1215 /* Compute the actual size of the argument block required. The variable
1216 and constant sizes must be combined, the size may have to be rounded,
1217 and there may be a minimum required size. */
1221 args_size->var = ARGS_SIZE_TREE (*args_size);
1222 args_size->constant = 0;
1224 preferred_stack_boundary /= BITS_PER_UNIT;
1225 if (preferred_stack_boundary > 1)
1227 /* We don't handle this case yet. To handle it correctly we have
1228 to add the delta, round and subtract the delta.
1229 Currently no machine description requires this support. */
1230 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1231 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1234 if (reg_parm_stack_space > 0)
1237 = size_binop (MAX_EXPR, args_size->var,
1238 ssize_int (reg_parm_stack_space));
1240 /* The area corresponding to register parameters is not to count in
1241 the size of the block we need. So make the adjustment. */
1242 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1244 = size_binop (MINUS_EXPR, args_size->var,
1245 ssize_int (reg_parm_stack_space));
1250 preferred_stack_boundary /= BITS_PER_UNIT;
1251 if (preferred_stack_boundary < 1)
1252 preferred_stack_boundary = 1;
1253 args_size->constant = (((args_size->constant
1254 + stack_pointer_delta
1255 + preferred_stack_boundary - 1)
1256 / preferred_stack_boundary
1257 * preferred_stack_boundary)
1258 - stack_pointer_delta);
1260 args_size->constant = MAX (args_size->constant,
1261 reg_parm_stack_space);
1263 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1264 args_size->constant -= reg_parm_stack_space;
1266 return unadjusted_args_size;
1269 /* Precompute parameters as needed for a function call.
1271 FLAGS is mask of ECF_* constants.
1273 NUM_ACTUALS is the number of arguments.
1275 ARGS is an array containing information for each argument; this
1276 routine fills in the INITIAL_VALUE and VALUE fields for each
1277 precomputed argument. */
1280 precompute_arguments (int num_actuals, struct arg_data *args)
1284 /* If this is a libcall, then precompute all arguments so that we do not
1285 get extraneous instructions emitted as part of the libcall sequence. */
1287 /* If we preallocated the stack space, and some arguments must be passed
1288 on the stack, then we must precompute any parameter which contains a
1289 function call which will store arguments on the stack.
1290 Otherwise, evaluating the parameter may clobber previous parameters
1291 which have already been stored into the stack. (we have code to avoid
1292 such case by saving the outgoing stack arguments, but it results in
1294 if (!ACCUMULATE_OUTGOING_ARGS)
1297 for (i = 0; i < num_actuals; i++)
1300 enum machine_mode mode;
1302 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1305 /* If this is an addressable type, we cannot pre-evaluate it. */
1306 type = TREE_TYPE (args[i].tree_value);
1307 gcc_assert (!TREE_ADDRESSABLE (type));
1309 args[i].initial_value = args[i].value
1310 = expand_normal (args[i].tree_value);
1312 mode = TYPE_MODE (type);
1313 if (mode != args[i].mode)
1315 int unsignedp = args[i].unsignedp;
1317 = convert_modes (args[i].mode, mode,
1318 args[i].value, args[i].unsignedp);
1320 /* CSE will replace this only if it contains args[i].value
1321 pseudo, so convert it down to the declared mode using
1323 if (REG_P (args[i].value)
1324 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1325 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1327 args[i].initial_value
1328 = gen_lowpart_SUBREG (mode, args[i].value);
1329 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1330 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1337 /* Given the current state of MUST_PREALLOCATE and information about
1338 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1339 compute and return the final value for MUST_PREALLOCATE. */
1342 finalize_must_preallocate (int must_preallocate, int num_actuals,
1343 struct arg_data *args, struct args_size *args_size)
1345 /* See if we have or want to preallocate stack space.
1347 If we would have to push a partially-in-regs parm
1348 before other stack parms, preallocate stack space instead.
1350 If the size of some parm is not a multiple of the required stack
1351 alignment, we must preallocate.
1353 If the total size of arguments that would otherwise create a copy in
1354 a temporary (such as a CALL) is more than half the total argument list
1355 size, preallocation is faster.
1357 Another reason to preallocate is if we have a machine (like the m88k)
1358 where stack alignment is required to be maintained between every
1359 pair of insns, not just when the call is made. However, we assume here
1360 that such machines either do not have push insns (and hence preallocation
1361 would occur anyway) or the problem is taken care of with
1364 if (! must_preallocate)
1366 int partial_seen = 0;
1367 int copy_to_evaluate_size = 0;
1370 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1372 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1374 else if (partial_seen && args[i].reg == 0)
1375 must_preallocate = 1;
1377 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1378 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1379 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1380 || TREE_CODE (args[i].tree_value) == COND_EXPR
1381 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1382 copy_to_evaluate_size
1383 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1386 if (copy_to_evaluate_size * 2 >= args_size->constant
1387 && args_size->constant > 0)
1388 must_preallocate = 1;
1390 return must_preallocate;
1393 /* If we preallocated stack space, compute the address of each argument
1394 and store it into the ARGS array.
1396 We need not ensure it is a valid memory address here; it will be
1397 validized when it is used.
1399 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1402 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1406 rtx arg_reg = argblock;
1407 int i, arg_offset = 0;
1409 if (GET_CODE (argblock) == PLUS)
1410 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1412 for (i = 0; i < num_actuals; i++)
1414 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1415 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1417 unsigned int align, boundary;
1418 unsigned int units_on_stack = 0;
1419 enum machine_mode partial_mode = VOIDmode;
1421 /* Skip this parm if it will not be passed on the stack. */
1422 if (! args[i].pass_on_stack
1424 && args[i].partial == 0)
1427 if (CONST_INT_P (offset))
1428 addr = plus_constant (arg_reg, INTVAL (offset));
1430 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1432 addr = plus_constant (addr, arg_offset);
1434 if (args[i].partial != 0)
1436 /* Only part of the parameter is being passed on the stack.
1437 Generate a simple memory reference of the correct size. */
1438 units_on_stack = args[i].locate.size.constant;
1439 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1441 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1442 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1446 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1447 set_mem_attributes (args[i].stack,
1448 TREE_TYPE (args[i].tree_value), 1);
1450 align = BITS_PER_UNIT;
1451 boundary = args[i].locate.boundary;
1452 if (args[i].locate.where_pad != downward)
1454 else if (CONST_INT_P (offset))
1456 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1457 align = align & -align;
1459 set_mem_align (args[i].stack, align);
1461 if (CONST_INT_P (slot_offset))
1462 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1464 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1466 addr = plus_constant (addr, arg_offset);
1468 if (args[i].partial != 0)
1470 /* Only part of the parameter is being passed on the stack.
1471 Generate a simple memory reference of the correct size.
1473 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1474 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1478 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1479 set_mem_attributes (args[i].stack_slot,
1480 TREE_TYPE (args[i].tree_value), 1);
1482 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1484 /* Function incoming arguments may overlap with sibling call
1485 outgoing arguments and we cannot allow reordering of reads
1486 from function arguments with stores to outgoing arguments
1487 of sibling calls. */
1488 set_mem_alias_set (args[i].stack, 0);
1489 set_mem_alias_set (args[i].stack_slot, 0);
1494 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1495 in a call instruction.
1497 FNDECL is the tree node for the target function. For an indirect call
1498 FNDECL will be NULL_TREE.
1500 ADDR is the operand 0 of CALL_EXPR for this call. */
1503 rtx_for_function_call (tree fndecl, tree addr)
1507 /* Get the function to call, in the form of RTL. */
1510 /* If this is the first use of the function, see if we need to
1511 make an external definition for it. */
1512 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1514 assemble_external (fndecl);
1515 TREE_USED (fndecl) = 1;
1518 /* Get a SYMBOL_REF rtx for the function address. */
1519 funexp = XEXP (DECL_RTL (fndecl), 0);
1522 /* Generate an rtx (probably a pseudo-register) for the address. */
1525 funexp = expand_normal (addr);
1526 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1531 /* Return true if and only if SIZE storage units (usually bytes)
1532 starting from address ADDR overlap with already clobbered argument
1533 area. This function is used to determine if we should give up a
1537 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1541 if (addr == crtl->args.internal_arg_pointer)
1543 else if (GET_CODE (addr) == PLUS
1544 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1545 && CONST_INT_P (XEXP (addr, 1)))
1546 i = INTVAL (XEXP (addr, 1));
1547 /* Return true for arg pointer based indexed addressing. */
1548 else if (GET_CODE (addr) == PLUS
1549 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1550 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1555 #ifdef ARGS_GROW_DOWNWARD
1560 unsigned HOST_WIDE_INT k;
1562 for (k = 0; k < size; k++)
1563 if (i + k < stored_args_map->n_bits
1564 && TEST_BIT (stored_args_map, i + k))
1571 /* Do the register loads required for any wholly-register parms or any
1572 parms which are passed both on the stack and in a register. Their
1573 expressions were already evaluated.
1575 Mark all register-parms as living through the call, putting these USE
1576 insns in the CALL_INSN_FUNCTION_USAGE field.
1578 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1579 checking, setting *SIBCALL_FAILURE if appropriate. */
1582 load_register_parameters (struct arg_data *args, int num_actuals,
1583 rtx *call_fusage, int flags, int is_sibcall,
1584 int *sibcall_failure)
1588 for (i = 0; i < num_actuals; i++)
1590 rtx reg = ((flags & ECF_SIBCALL)
1591 ? args[i].tail_call_reg : args[i].reg);
1594 int partial = args[i].partial;
1597 rtx before_arg = get_last_insn ();
1598 /* Set non-negative if we must move a word at a time, even if
1599 just one word (e.g, partial == 4 && mode == DFmode). Set
1600 to -1 if we just use a normal move insn. This value can be
1601 zero if the argument is a zero size structure. */
1603 if (GET_CODE (reg) == PARALLEL)
1607 gcc_assert (partial % UNITS_PER_WORD == 0);
1608 nregs = partial / UNITS_PER_WORD;
1610 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1612 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1613 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1616 size = GET_MODE_SIZE (args[i].mode);
1618 /* Handle calls that pass values in multiple non-contiguous
1619 locations. The Irix 6 ABI has examples of this. */
1621 if (GET_CODE (reg) == PARALLEL)
1622 emit_group_move (reg, args[i].parallel_value);
1624 /* If simple case, just do move. If normal partial, store_one_arg
1625 has already loaded the register for us. In all other cases,
1626 load the register(s) from memory. */
1628 else if (nregs == -1)
1630 emit_move_insn (reg, args[i].value);
1631 #ifdef BLOCK_REG_PADDING
1632 /* Handle case where we have a value that needs shifting
1633 up to the msb. eg. a QImode value and we're padding
1634 upward on a BYTES_BIG_ENDIAN machine. */
1635 if (size < UNITS_PER_WORD
1636 && (args[i].locate.where_pad
1637 == (BYTES_BIG_ENDIAN ? upward : downward)))
1640 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1642 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1643 report the whole reg as used. Strictly speaking, the
1644 call only uses SIZE bytes at the msb end, but it doesn't
1645 seem worth generating rtl to say that. */
1646 reg = gen_rtx_REG (word_mode, REGNO (reg));
1647 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1648 build_int_cst (NULL_TREE, shift),
1651 emit_move_insn (reg, x);
1656 /* If we have pre-computed the values to put in the registers in
1657 the case of non-aligned structures, copy them in now. */
1659 else if (args[i].n_aligned_regs != 0)
1660 for (j = 0; j < args[i].n_aligned_regs; j++)
1661 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1662 args[i].aligned_regs[j]);
1664 else if (partial == 0 || args[i].pass_on_stack)
1666 rtx mem = validize_mem (args[i].value);
1668 /* Check for overlap with already clobbered argument area. */
1670 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1672 *sibcall_failure = 1;
1674 /* Handle a BLKmode that needs shifting. */
1675 if (nregs == 1 && size < UNITS_PER_WORD
1676 #ifdef BLOCK_REG_PADDING
1677 && args[i].locate.where_pad == downward
1683 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1684 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1685 rtx x = gen_reg_rtx (word_mode);
1686 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1687 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1690 emit_move_insn (x, tem);
1691 x = expand_shift (dir, word_mode, x,
1692 build_int_cst (NULL_TREE, shift),
1695 emit_move_insn (ri, x);
1698 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1701 /* When a parameter is a block, and perhaps in other cases, it is
1702 possible that it did a load from an argument slot that was
1703 already clobbered. */
1705 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1706 *sibcall_failure = 1;
1708 /* Handle calls that pass values in multiple non-contiguous
1709 locations. The Irix 6 ABI has examples of this. */
1710 if (GET_CODE (reg) == PARALLEL)
1711 use_group_regs (call_fusage, reg);
1712 else if (nregs == -1)
1713 use_reg (call_fusage, reg);
1715 use_regs (call_fusage, REGNO (reg), nregs);
1720 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1721 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1722 bytes, then we would need to push some additional bytes to pad the
1723 arguments. So, we compute an adjust to the stack pointer for an
1724 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1725 bytes. Then, when the arguments are pushed the stack will be perfectly
1726 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1727 be popped after the call. Returns the adjustment. */
1730 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1731 struct args_size *args_size,
1732 unsigned int preferred_unit_stack_boundary)
1734 /* The number of bytes to pop so that the stack will be
1735 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1736 HOST_WIDE_INT adjustment;
1737 /* The alignment of the stack after the arguments are pushed, if we
1738 just pushed the arguments without adjust the stack here. */
1739 unsigned HOST_WIDE_INT unadjusted_alignment;
1741 unadjusted_alignment
1742 = ((stack_pointer_delta + unadjusted_args_size)
1743 % preferred_unit_stack_boundary);
1745 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1746 as possible -- leaving just enough left to cancel out the
1747 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1748 PENDING_STACK_ADJUST is non-negative, and congruent to
1749 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1751 /* Begin by trying to pop all the bytes. */
1752 unadjusted_alignment
1753 = (unadjusted_alignment
1754 - (pending_stack_adjust % preferred_unit_stack_boundary));
1755 adjustment = pending_stack_adjust;
1756 /* Push enough additional bytes that the stack will be aligned
1757 after the arguments are pushed. */
1758 if (preferred_unit_stack_boundary > 1)
1760 if (unadjusted_alignment > 0)
1761 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1763 adjustment += unadjusted_alignment;
1766 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1767 bytes after the call. The right number is the entire
1768 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1769 by the arguments in the first place. */
1771 = pending_stack_adjust - adjustment + unadjusted_args_size;
1776 /* Scan X expression if it does not dereference any argument slots
1777 we already clobbered by tail call arguments (as noted in stored_args_map
1779 Return nonzero if X expression dereferences such argument slots,
1783 check_sibcall_argument_overlap_1 (rtx x)
1792 code = GET_CODE (x);
1795 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1796 GET_MODE_SIZE (GET_MODE (x)));
1798 /* Scan all subexpressions. */
1799 fmt = GET_RTX_FORMAT (code);
1800 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1804 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1807 else if (*fmt == 'E')
1809 for (j = 0; j < XVECLEN (x, i); j++)
1810 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1817 /* Scan sequence after INSN if it does not dereference any argument slots
1818 we already clobbered by tail call arguments (as noted in stored_args_map
1819 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1820 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1821 should be 0). Return nonzero if sequence after INSN dereferences such argument
1822 slots, zero otherwise. */
1825 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1829 if (insn == NULL_RTX)
1830 insn = get_insns ();
1832 insn = NEXT_INSN (insn);
1834 for (; insn; insn = NEXT_INSN (insn))
1836 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1839 if (mark_stored_args_map)
1841 #ifdef ARGS_GROW_DOWNWARD
1842 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1844 low = arg->locate.slot_offset.constant;
1847 for (high = low + arg->locate.size.constant; low < high; low++)
1848 SET_BIT (stored_args_map, low);
1850 return insn != NULL_RTX;
1853 /* Given that a function returns a value of mode MODE at the most
1854 significant end of hard register VALUE, shift VALUE left or right
1855 as specified by LEFT_P. Return true if some action was needed. */
1858 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1860 HOST_WIDE_INT shift;
1862 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1863 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1867 /* Use ashr rather than lshr for right shifts. This is for the benefit
1868 of the MIPS port, which requires SImode values to be sign-extended
1869 when stored in 64-bit registers. */
1870 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1871 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1876 /* If X is a likely-spilled register value, copy it to a pseudo
1877 register and return that register. Return X otherwise. */
1880 avoid_likely_spilled_reg (rtx x)
1885 && HARD_REGISTER_P (x)
1886 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1888 /* Make sure that we generate a REG rather than a CONCAT.
1889 Moves into CONCATs can need nontrivial instructions,
1890 and the whole point of this function is to avoid
1891 using the hard register directly in such a situation. */
1892 generating_concat_p = 0;
1893 new_rtx = gen_reg_rtx (GET_MODE (x));
1894 generating_concat_p = 1;
1895 emit_move_insn (new_rtx, x);
1901 /* Generate all the code for a CALL_EXPR exp
1902 and return an rtx for its value.
1903 Store the value in TARGET (specified as an rtx) if convenient.
1904 If the value is stored in TARGET then TARGET is returned.
1905 If IGNORE is nonzero, then we ignore the value of the function call. */
1908 expand_call (tree exp, rtx target, int ignore)
1910 /* Nonzero if we are currently expanding a call. */
1911 static int currently_expanding_call = 0;
1913 /* RTX for the function to be called. */
1915 /* Sequence of insns to perform a normal "call". */
1916 rtx normal_call_insns = NULL_RTX;
1917 /* Sequence of insns to perform a tail "call". */
1918 rtx tail_call_insns = NULL_RTX;
1919 /* Data type of the function. */
1921 tree type_arg_types;
1923 /* Declaration of the function being called,
1924 or 0 if the function is computed (not known by name). */
1926 /* The type of the function being called. */
1928 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1931 /* Register in which non-BLKmode value will be returned,
1932 or 0 if no value or if value is BLKmode. */
1934 /* Address where we should return a BLKmode value;
1935 0 if value not BLKmode. */
1936 rtx structure_value_addr = 0;
1937 /* Nonzero if that address is being passed by treating it as
1938 an extra, implicit first parameter. Otherwise,
1939 it is passed by being copied directly into struct_value_rtx. */
1940 int structure_value_addr_parm = 0;
1941 /* Holds the value of implicit argument for the struct value. */
1942 tree structure_value_addr_value = NULL_TREE;
1943 /* Size of aggregate value wanted, or zero if none wanted
1944 or if we are using the non-reentrant PCC calling convention
1945 or expecting the value in registers. */
1946 HOST_WIDE_INT struct_value_size = 0;
1947 /* Nonzero if called function returns an aggregate in memory PCC style,
1948 by returning the address of where to find it. */
1949 int pcc_struct_value = 0;
1950 rtx struct_value = 0;
1952 /* Number of actual parameters in this call, including struct value addr. */
1954 /* Number of named args. Args after this are anonymous ones
1955 and they must all go on the stack. */
1957 /* Number of complex actual arguments that need to be split. */
1958 int num_complex_actuals = 0;
1960 /* Vector of information about each argument.
1961 Arguments are numbered in the order they will be pushed,
1962 not the order they are written. */
1963 struct arg_data *args;
1965 /* Total size in bytes of all the stack-parms scanned so far. */
1966 struct args_size args_size;
1967 struct args_size adjusted_args_size;
1968 /* Size of arguments before any adjustments (such as rounding). */
1969 int unadjusted_args_size;
1970 /* Data on reg parms scanned so far. */
1971 CUMULATIVE_ARGS args_so_far;
1972 /* Nonzero if a reg parm has been scanned. */
1974 /* Nonzero if this is an indirect function call. */
1976 /* Nonzero if we must avoid push-insns in the args for this call.
1977 If stack space is allocated for register parameters, but not by the
1978 caller, then it is preallocated in the fixed part of the stack frame.
1979 So the entire argument block must then be preallocated (i.e., we
1980 ignore PUSH_ROUNDING in that case). */
1982 int must_preallocate = !PUSH_ARGS;
1984 /* Size of the stack reserved for parameter registers. */
1985 int reg_parm_stack_space = 0;
1987 /* Address of space preallocated for stack parms
1988 (on machines that lack push insns), or 0 if space not preallocated. */
1991 /* Mask of ECF_ flags. */
1993 #ifdef REG_PARM_STACK_SPACE
1994 /* Define the boundary of the register parm stack space that needs to be
1996 int low_to_save, high_to_save;
1997 rtx save_area = 0; /* Place that it is saved */
2000 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
2001 char *initial_stack_usage_map = stack_usage_map;
2002 char *stack_usage_map_buf = NULL;
2004 int old_stack_allocated;
2006 /* State variables to track stack modifications. */
2007 rtx old_stack_level = 0;
2008 int old_stack_arg_under_construction = 0;
2009 int old_pending_adj = 0;
2010 int old_inhibit_defer_pop = inhibit_defer_pop;
2012 /* Some stack pointer alterations we make are performed via
2013 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2014 which we then also need to save/restore along the way. */
2015 int old_stack_pointer_delta = 0;
2018 tree addr = CALL_EXPR_FN (exp);
2020 /* The alignment of the stack, in bits. */
2021 unsigned HOST_WIDE_INT preferred_stack_boundary;
2022 /* The alignment of the stack, in bytes. */
2023 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2024 /* The static chain value to use for this call. */
2025 rtx static_chain_value;
2026 /* See if this is "nothrow" function call. */
2027 if (TREE_NOTHROW (exp))
2028 flags |= ECF_NOTHROW;
2030 /* See if we can find a DECL-node for the actual function, and get the
2031 function attributes (flags) from the function decl or type node. */
2032 fndecl = get_callee_fndecl (exp);
2035 fntype = TREE_TYPE (fndecl);
2036 flags |= flags_from_decl_or_type (fndecl);
2040 fntype = TREE_TYPE (TREE_TYPE (addr));
2041 flags |= flags_from_decl_or_type (fntype);
2043 rettype = TREE_TYPE (exp);
2045 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2047 /* Warn if this value is an aggregate type,
2048 regardless of which calling convention we are using for it. */
2049 if (AGGREGATE_TYPE_P (rettype))
2050 warning (OPT_Waggregate_return, "function call has aggregate value");
2052 /* If the result of a non looping pure or const function call is
2053 ignored (or void), and none of its arguments are volatile, we can
2054 avoid expanding the call and just evaluate the arguments for
2056 if ((flags & (ECF_CONST | ECF_PURE))
2057 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2058 && (ignore || target == const0_rtx
2059 || TYPE_MODE (rettype) == VOIDmode))
2061 bool volatilep = false;
2063 call_expr_arg_iterator iter;
2065 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2066 if (TREE_THIS_VOLATILE (arg))
2074 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2075 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2080 #ifdef REG_PARM_STACK_SPACE
2081 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2084 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2085 && reg_parm_stack_space > 0 && PUSH_ARGS)
2086 must_preallocate = 1;
2088 /* Set up a place to return a structure. */
2090 /* Cater to broken compilers. */
2091 if (aggregate_value_p (exp, (!fndecl ? fntype : fndecl)))
2093 /* This call returns a big structure. */
2094 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2096 #ifdef PCC_STATIC_STRUCT_RETURN
2098 pcc_struct_value = 1;
2100 #else /* not PCC_STATIC_STRUCT_RETURN */
2102 struct_value_size = int_size_in_bytes (rettype);
2104 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2105 structure_value_addr = XEXP (target, 0);
2108 /* For variable-sized objects, we must be called with a target
2109 specified. If we were to allocate space on the stack here,
2110 we would have no way of knowing when to free it. */
2111 rtx d = assign_temp (rettype, 0, 1, 1);
2113 mark_temp_addr_taken (d);
2114 structure_value_addr = XEXP (d, 0);
2118 #endif /* not PCC_STATIC_STRUCT_RETURN */
2121 /* Figure out the amount to which the stack should be aligned. */
2122 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2125 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2126 /* Without automatic stack alignment, we can't increase preferred
2127 stack boundary. With automatic stack alignment, it is
2128 unnecessary since unless we can guarantee that all callers will
2129 align the outgoing stack properly, callee has to align its
2132 && i->preferred_incoming_stack_boundary
2133 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2134 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2137 /* Operand 0 is a pointer-to-function; get the type of the function. */
2138 funtype = TREE_TYPE (addr);
2139 gcc_assert (POINTER_TYPE_P (funtype));
2140 funtype = TREE_TYPE (funtype);
2142 /* Count whether there are actual complex arguments that need to be split
2143 into their real and imaginary parts. Munge the type_arg_types
2144 appropriately here as well. */
2145 if (targetm.calls.split_complex_arg)
2147 call_expr_arg_iterator iter;
2149 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2151 tree type = TREE_TYPE (arg);
2152 if (type && TREE_CODE (type) == COMPLEX_TYPE
2153 && targetm.calls.split_complex_arg (type))
2154 num_complex_actuals++;
2156 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2159 type_arg_types = TYPE_ARG_TYPES (funtype);
2161 if (flags & ECF_MAY_BE_ALLOCA)
2162 cfun->calls_alloca = 1;
2164 /* If struct_value_rtx is 0, it means pass the address
2165 as if it were an extra parameter. Put the argument expression
2166 in structure_value_addr_value. */
2167 if (structure_value_addr && struct_value == 0)
2169 /* If structure_value_addr is a REG other than
2170 virtual_outgoing_args_rtx, we can use always use it. If it
2171 is not a REG, we must always copy it into a register.
2172 If it is virtual_outgoing_args_rtx, we must copy it to another
2173 register in some cases. */
2174 rtx temp = (!REG_P (structure_value_addr)
2175 || (ACCUMULATE_OUTGOING_ARGS
2176 && stack_arg_under_construction
2177 && structure_value_addr == virtual_outgoing_args_rtx)
2178 ? copy_addr_to_reg (convert_memory_address
2179 (Pmode, structure_value_addr))
2180 : structure_value_addr);
2182 structure_value_addr_value =
2183 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2184 structure_value_addr_parm = 1;
2187 /* Count the arguments and set NUM_ACTUALS. */
2189 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2191 /* Compute number of named args.
2192 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2194 if (type_arg_types != 0)
2196 = (list_length (type_arg_types)
2197 /* Count the struct value address, if it is passed as a parm. */
2198 + structure_value_addr_parm);
2200 /* If we know nothing, treat all args as named. */
2201 n_named_args = num_actuals;
2203 /* Start updating where the next arg would go.
2205 On some machines (such as the PA) indirect calls have a different
2206 calling convention than normal calls. The fourth argument in
2207 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2209 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2211 /* Now possibly adjust the number of named args.
2212 Normally, don't include the last named arg if anonymous args follow.
2213 We do include the last named arg if
2214 targetm.calls.strict_argument_naming() returns nonzero.
2215 (If no anonymous args follow, the result of list_length is actually
2216 one too large. This is harmless.)
2218 If targetm.calls.pretend_outgoing_varargs_named() returns
2219 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2220 this machine will be able to place unnamed args that were passed
2221 in registers into the stack. So treat all args as named. This
2222 allows the insns emitting for a specific argument list to be
2223 independent of the function declaration.
2225 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2226 we do not have any reliable way to pass unnamed args in
2227 registers, so we must force them into memory. */
2229 if (type_arg_types != 0
2230 && targetm.calls.strict_argument_naming (&args_so_far))
2232 else if (type_arg_types != 0
2233 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2234 /* Don't include the last named arg. */
2237 /* Treat all args as named. */
2238 n_named_args = num_actuals;
2240 /* Make a vector to hold all the information about each arg. */
2241 args = XALLOCAVEC (struct arg_data, num_actuals);
2242 memset (args, 0, num_actuals * sizeof (struct arg_data));
2244 /* Build up entries in the ARGS array, compute the size of the
2245 arguments into ARGS_SIZE, etc. */
2246 initialize_argument_information (num_actuals, args, &args_size,
2248 structure_value_addr_value, fndecl, fntype,
2249 &args_so_far, reg_parm_stack_space,
2250 &old_stack_level, &old_pending_adj,
2251 &must_preallocate, &flags,
2252 &try_tail_call, CALL_FROM_THUNK_P (exp));
2255 must_preallocate = 1;
2257 /* Now make final decision about preallocating stack space. */
2258 must_preallocate = finalize_must_preallocate (must_preallocate,
2262 /* If the structure value address will reference the stack pointer, we
2263 must stabilize it. We don't need to do this if we know that we are
2264 not going to adjust the stack pointer in processing this call. */
2266 if (structure_value_addr
2267 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2268 || reg_mentioned_p (virtual_outgoing_args_rtx,
2269 structure_value_addr))
2271 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2272 structure_value_addr = copy_to_reg (structure_value_addr);
2274 /* Tail calls can make things harder to debug, and we've traditionally
2275 pushed these optimizations into -O2. Don't try if we're already
2276 expanding a call, as that means we're an argument. Don't try if
2277 there's cleanups, as we know there's code to follow the call. */
2279 if (currently_expanding_call++ != 0
2280 || !flag_optimize_sibling_calls
2282 || dbg_cnt (tail_call) == false)
2285 /* Rest of purposes for tail call optimizations to fail. */
2287 #ifdef HAVE_sibcall_epilogue
2288 !HAVE_sibcall_epilogue
2293 /* Doing sibling call optimization needs some work, since
2294 structure_value_addr can be allocated on the stack.
2295 It does not seem worth the effort since few optimizable
2296 sibling calls will return a structure. */
2297 || structure_value_addr != NULL_RTX
2298 #ifdef REG_PARM_STACK_SPACE
2299 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2300 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2301 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2302 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2304 /* Check whether the target is able to optimize the call
2306 || !targetm.function_ok_for_sibcall (fndecl, exp)
2307 /* Functions that do not return exactly once may not be sibcall
2309 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2310 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2311 /* If the called function is nested in the current one, it might access
2312 some of the caller's arguments, but could clobber them beforehand if
2313 the argument areas are shared. */
2314 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2315 /* If this function requires more stack slots than the current
2316 function, we cannot change it into a sibling call.
2317 crtl->args.pretend_args_size is not part of the
2318 stack allocated by our caller. */
2319 || args_size.constant > (crtl->args.size
2320 - crtl->args.pretend_args_size)
2321 /* If the callee pops its own arguments, then it must pop exactly
2322 the same number of arguments as the current function. */
2323 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2324 != RETURN_POPS_ARGS (current_function_decl,
2325 TREE_TYPE (current_function_decl),
2327 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2330 /* Check if caller and callee disagree in promotion of function
2334 enum machine_mode caller_mode, caller_promoted_mode;
2335 enum machine_mode callee_mode, callee_promoted_mode;
2336 int caller_unsignedp, callee_unsignedp;
2337 tree caller_res = DECL_RESULT (current_function_decl);
2339 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2340 caller_mode = DECL_MODE (caller_res);
2341 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2342 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2343 caller_promoted_mode
2344 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2346 TREE_TYPE (current_function_decl), 1);
2347 callee_promoted_mode
2348 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2351 if (caller_mode != VOIDmode
2352 && (caller_promoted_mode != callee_promoted_mode
2353 || ((caller_mode != caller_promoted_mode
2354 || callee_mode != callee_promoted_mode)
2355 && (caller_unsignedp != callee_unsignedp
2356 || GET_MODE_BITSIZE (caller_mode)
2357 < GET_MODE_BITSIZE (callee_mode)))))
2361 /* Ensure current function's preferred stack boundary is at least
2362 what we need. Stack alignment may also increase preferred stack
2364 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2365 crtl->preferred_stack_boundary = preferred_stack_boundary;
2367 preferred_stack_boundary = crtl->preferred_stack_boundary;
2369 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2371 /* We want to make two insn chains; one for a sibling call, the other
2372 for a normal call. We will select one of the two chains after
2373 initial RTL generation is complete. */
2374 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2376 int sibcall_failure = 0;
2377 /* We want to emit any pending stack adjustments before the tail
2378 recursion "call". That way we know any adjustment after the tail
2379 recursion call can be ignored if we indeed use the tail
2381 int save_pending_stack_adjust = 0;
2382 int save_stack_pointer_delta = 0;
2384 rtx before_call, next_arg_reg, after_args;
2388 /* State variables we need to save and restore between
2390 save_pending_stack_adjust = pending_stack_adjust;
2391 save_stack_pointer_delta = stack_pointer_delta;
2394 flags &= ~ECF_SIBCALL;
2396 flags |= ECF_SIBCALL;
2398 /* Other state variables that we must reinitialize each time
2399 through the loop (that are not initialized by the loop itself). */
2403 /* Start a new sequence for the normal call case.
2405 From this point on, if the sibling call fails, we want to set
2406 sibcall_failure instead of continuing the loop. */
2409 /* Don't let pending stack adjusts add up to too much.
2410 Also, do all pending adjustments now if there is any chance
2411 this might be a call to alloca or if we are expanding a sibling
2413 Also do the adjustments before a throwing call, otherwise
2414 exception handling can fail; PR 19225. */
2415 if (pending_stack_adjust >= 32
2416 || (pending_stack_adjust > 0
2417 && (flags & ECF_MAY_BE_ALLOCA))
2418 || (pending_stack_adjust > 0
2419 && flag_exceptions && !(flags & ECF_NOTHROW))
2421 do_pending_stack_adjust ();
2423 /* Precompute any arguments as needed. */
2425 precompute_arguments (num_actuals, args);
2427 /* Now we are about to start emitting insns that can be deleted
2428 if a libcall is deleted. */
2429 if (pass && (flags & ECF_MALLOC))
2432 if (pass == 0 && crtl->stack_protect_guard)
2433 stack_protect_epilogue ();
2435 adjusted_args_size = args_size;
2436 /* Compute the actual size of the argument block required. The variable
2437 and constant sizes must be combined, the size may have to be rounded,
2438 and there may be a minimum required size. When generating a sibcall
2439 pattern, do not round up, since we'll be re-using whatever space our
2441 unadjusted_args_size
2442 = compute_argument_block_size (reg_parm_stack_space,
2443 &adjusted_args_size,
2446 : preferred_stack_boundary));
2448 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2450 /* The argument block when performing a sibling call is the
2451 incoming argument block. */
2454 argblock = crtl->args.internal_arg_pointer;
2456 #ifdef STACK_GROWS_DOWNWARD
2457 = plus_constant (argblock, crtl->args.pretend_args_size);
2459 = plus_constant (argblock, -crtl->args.pretend_args_size);
2461 stored_args_map = sbitmap_alloc (args_size.constant);
2462 sbitmap_zero (stored_args_map);
2465 /* If we have no actual push instructions, or shouldn't use them,
2466 make space for all args right now. */
2467 else if (adjusted_args_size.var != 0)
2469 if (old_stack_level == 0)
2471 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2472 old_stack_pointer_delta = stack_pointer_delta;
2473 old_pending_adj = pending_stack_adjust;
2474 pending_stack_adjust = 0;
2475 /* stack_arg_under_construction says whether a stack arg is
2476 being constructed at the old stack level. Pushing the stack
2477 gets a clean outgoing argument block. */
2478 old_stack_arg_under_construction = stack_arg_under_construction;
2479 stack_arg_under_construction = 0;
2481 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2485 /* Note that we must go through the motions of allocating an argument
2486 block even if the size is zero because we may be storing args
2487 in the area reserved for register arguments, which may be part of
2490 int needed = adjusted_args_size.constant;
2492 /* Store the maximum argument space used. It will be pushed by
2493 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2496 if (needed > crtl->outgoing_args_size)
2497 crtl->outgoing_args_size = needed;
2499 if (must_preallocate)
2501 if (ACCUMULATE_OUTGOING_ARGS)
2503 /* Since the stack pointer will never be pushed, it is
2504 possible for the evaluation of a parm to clobber
2505 something we have already written to the stack.
2506 Since most function calls on RISC machines do not use
2507 the stack, this is uncommon, but must work correctly.
2509 Therefore, we save any area of the stack that was already
2510 written and that we are using. Here we set up to do this
2511 by making a new stack usage map from the old one. The
2512 actual save will be done by store_one_arg.
2514 Another approach might be to try to reorder the argument
2515 evaluations to avoid this conflicting stack usage. */
2517 /* Since we will be writing into the entire argument area,
2518 the map must be allocated for its entire size, not just
2519 the part that is the responsibility of the caller. */
2520 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2521 needed += reg_parm_stack_space;
2523 #ifdef ARGS_GROW_DOWNWARD
2524 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2527 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2530 if (stack_usage_map_buf)
2531 free (stack_usage_map_buf);
2532 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2533 stack_usage_map = stack_usage_map_buf;
2535 if (initial_highest_arg_in_use)
2536 memcpy (stack_usage_map, initial_stack_usage_map,
2537 initial_highest_arg_in_use);
2539 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2540 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2541 (highest_outgoing_arg_in_use
2542 - initial_highest_arg_in_use));
2545 /* The address of the outgoing argument list must not be
2546 copied to a register here, because argblock would be left
2547 pointing to the wrong place after the call to
2548 allocate_dynamic_stack_space below. */
2550 argblock = virtual_outgoing_args_rtx;
2554 if (inhibit_defer_pop == 0)
2556 /* Try to reuse some or all of the pending_stack_adjust
2557 to get this space. */
2559 = (combine_pending_stack_adjustment_and_call
2560 (unadjusted_args_size,
2561 &adjusted_args_size,
2562 preferred_unit_stack_boundary));
2564 /* combine_pending_stack_adjustment_and_call computes
2565 an adjustment before the arguments are allocated.
2566 Account for them and see whether or not the stack
2567 needs to go up or down. */
2568 needed = unadjusted_args_size - needed;
2572 /* We're releasing stack space. */
2573 /* ??? We can avoid any adjustment at all if we're
2574 already aligned. FIXME. */
2575 pending_stack_adjust = -needed;
2576 do_pending_stack_adjust ();
2580 /* We need to allocate space. We'll do that in
2581 push_block below. */
2582 pending_stack_adjust = 0;
2585 /* Special case this because overhead of `push_block' in
2586 this case is non-trivial. */
2588 argblock = virtual_outgoing_args_rtx;
2591 argblock = push_block (GEN_INT (needed), 0, 0);
2592 #ifdef ARGS_GROW_DOWNWARD
2593 argblock = plus_constant (argblock, needed);
2597 /* We only really need to call `copy_to_reg' in the case
2598 where push insns are going to be used to pass ARGBLOCK
2599 to a function call in ARGS. In that case, the stack
2600 pointer changes value from the allocation point to the
2601 call point, and hence the value of
2602 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2603 as well always do it. */
2604 argblock = copy_to_reg (argblock);
2609 if (ACCUMULATE_OUTGOING_ARGS)
2611 /* The save/restore code in store_one_arg handles all
2612 cases except one: a constructor call (including a C
2613 function returning a BLKmode struct) to initialize
2615 if (stack_arg_under_construction)
2618 = GEN_INT (adjusted_args_size.constant
2619 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2620 : TREE_TYPE (fndecl))) ? 0
2621 : reg_parm_stack_space));
2622 if (old_stack_level == 0)
2624 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2626 old_stack_pointer_delta = stack_pointer_delta;
2627 old_pending_adj = pending_stack_adjust;
2628 pending_stack_adjust = 0;
2629 /* stack_arg_under_construction says whether a stack
2630 arg is being constructed at the old stack level.
2631 Pushing the stack gets a clean outgoing argument
2633 old_stack_arg_under_construction
2634 = stack_arg_under_construction;
2635 stack_arg_under_construction = 0;
2636 /* Make a new map for the new argument list. */
2637 if (stack_usage_map_buf)
2638 free (stack_usage_map_buf);
2639 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2640 stack_usage_map = stack_usage_map_buf;
2641 highest_outgoing_arg_in_use = 0;
2643 allocate_dynamic_stack_space (push_size, NULL_RTX,
2647 /* If argument evaluation might modify the stack pointer,
2648 copy the address of the argument list to a register. */
2649 for (i = 0; i < num_actuals; i++)
2650 if (args[i].pass_on_stack)
2652 argblock = copy_addr_to_reg (argblock);
2657 compute_argument_addresses (args, argblock, num_actuals);
2659 /* If we push args individually in reverse order, perform stack alignment
2660 before the first push (the last arg). */
2661 if (PUSH_ARGS_REVERSED && argblock == 0
2662 && adjusted_args_size.constant != unadjusted_args_size)
2664 /* When the stack adjustment is pending, we get better code
2665 by combining the adjustments. */
2666 if (pending_stack_adjust
2667 && ! inhibit_defer_pop)
2669 pending_stack_adjust
2670 = (combine_pending_stack_adjustment_and_call
2671 (unadjusted_args_size,
2672 &adjusted_args_size,
2673 preferred_unit_stack_boundary));
2674 do_pending_stack_adjust ();
2676 else if (argblock == 0)
2677 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2678 - unadjusted_args_size));
2680 /* Now that the stack is properly aligned, pops can't safely
2681 be deferred during the evaluation of the arguments. */
2684 funexp = rtx_for_function_call (fndecl, addr);
2686 /* Figure out the register where the value, if any, will come back. */
2688 if (TYPE_MODE (rettype) != VOIDmode
2689 && ! structure_value_addr)
2691 if (pcc_struct_value)
2692 valreg = hard_function_value (build_pointer_type (rettype),
2693 fndecl, NULL, (pass == 0));
2695 valreg = hard_function_value (rettype, fndecl, fntype,
2698 /* If VALREG is a PARALLEL whose first member has a zero
2699 offset, use that. This is for targets such as m68k that
2700 return the same value in multiple places. */
2701 if (GET_CODE (valreg) == PARALLEL)
2703 rtx elem = XVECEXP (valreg, 0, 0);
2704 rtx where = XEXP (elem, 0);
2705 rtx offset = XEXP (elem, 1);
2706 if (offset == const0_rtx
2707 && GET_MODE (where) == GET_MODE (valreg))
2712 /* Precompute all register parameters. It isn't safe to compute anything
2713 once we have started filling any specific hard regs. */
2714 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2716 if (CALL_EXPR_STATIC_CHAIN (exp))
2717 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2719 static_chain_value = 0;
2721 #ifdef REG_PARM_STACK_SPACE
2722 /* Save the fixed argument area if it's part of the caller's frame and
2723 is clobbered by argument setup for this call. */
2724 if (ACCUMULATE_OUTGOING_ARGS && pass)
2725 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2726 &low_to_save, &high_to_save);
2729 /* Now store (and compute if necessary) all non-register parms.
2730 These come before register parms, since they can require block-moves,
2731 which could clobber the registers used for register parms.
2732 Parms which have partial registers are not stored here,
2733 but we do preallocate space here if they want that. */
2735 for (i = 0; i < num_actuals; i++)
2737 if (args[i].reg == 0 || args[i].pass_on_stack)
2739 rtx before_arg = get_last_insn ();
2741 if (store_one_arg (&args[i], argblock, flags,
2742 adjusted_args_size.var != 0,
2743 reg_parm_stack_space)
2745 && check_sibcall_argument_overlap (before_arg,
2747 sibcall_failure = 1;
2750 if (((flags & ECF_CONST)
2751 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
2753 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2754 gen_rtx_USE (VOIDmode,
2759 /* If we have a parm that is passed in registers but not in memory
2760 and whose alignment does not permit a direct copy into registers,
2761 make a group of pseudos that correspond to each register that we
2763 if (STRICT_ALIGNMENT)
2764 store_unaligned_arguments_into_pseudos (args, num_actuals);
2766 /* Now store any partially-in-registers parm.
2767 This is the last place a block-move can happen. */
2769 for (i = 0; i < num_actuals; i++)
2770 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2772 rtx before_arg = get_last_insn ();
2774 if (store_one_arg (&args[i], argblock, flags,
2775 adjusted_args_size.var != 0,
2776 reg_parm_stack_space)
2778 && check_sibcall_argument_overlap (before_arg,
2780 sibcall_failure = 1;
2783 /* If we pushed args in forward order, perform stack alignment
2784 after pushing the last arg. */
2785 if (!PUSH_ARGS_REVERSED && argblock == 0)
2786 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2787 - unadjusted_args_size));
2789 /* If register arguments require space on the stack and stack space
2790 was not preallocated, allocate stack space here for arguments
2791 passed in registers. */
2792 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2793 && !ACCUMULATE_OUTGOING_ARGS
2794 && must_preallocate == 0 && reg_parm_stack_space > 0)
2795 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2797 /* Pass the function the address in which to return a
2799 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2801 structure_value_addr
2802 = convert_memory_address (Pmode, structure_value_addr);
2803 emit_move_insn (struct_value,
2805 force_operand (structure_value_addr,
2808 if (REG_P (struct_value))
2809 use_reg (&call_fusage, struct_value);
2812 after_args = get_last_insn ();
2813 funexp = prepare_call_address (fndecl, funexp, static_chain_value,
2814 &call_fusage, reg_parm_seen, pass == 0);
2816 load_register_parameters (args, num_actuals, &call_fusage, flags,
2817 pass == 0, &sibcall_failure);
2819 /* Save a pointer to the last insn before the call, so that we can
2820 later safely search backwards to find the CALL_INSN. */
2821 before_call = get_last_insn ();
2823 /* Set up next argument register. For sibling calls on machines
2824 with register windows this should be the incoming register. */
2825 #ifdef FUNCTION_INCOMING_ARG
2827 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2831 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2834 /* All arguments and registers used for the call must be set up by
2837 /* Stack must be properly aligned now. */
2839 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2841 /* Generate the actual call instruction. */
2842 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2843 adjusted_args_size.constant, struct_value_size,
2844 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2845 flags, & args_so_far);
2847 /* If the call setup or the call itself overlaps with anything
2848 of the argument setup we probably clobbered our call address.
2849 In that case we can't do sibcalls. */
2851 && check_sibcall_argument_overlap (after_args, 0, 0))
2852 sibcall_failure = 1;
2854 /* If a non-BLKmode value is returned at the most significant end
2855 of a register, shift the register right by the appropriate amount
2856 and update VALREG accordingly. BLKmode values are handled by the
2857 group load/store machinery below. */
2858 if (!structure_value_addr
2859 && !pcc_struct_value
2860 && TYPE_MODE (rettype) != BLKmode
2861 && targetm.calls.return_in_msb (rettype))
2863 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
2864 sibcall_failure = 1;
2865 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
2868 if (pass && (flags & ECF_MALLOC))
2870 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2873 /* The return value from a malloc-like function is a pointer. */
2874 if (TREE_CODE (rettype) == POINTER_TYPE)
2875 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2877 emit_move_insn (temp, valreg);
2879 /* The return value from a malloc-like function can not alias
2881 last = get_last_insn ();
2882 add_reg_note (last, REG_NOALIAS, temp);
2884 /* Write out the sequence. */
2885 insns = get_insns ();
2891 /* For calls to `setjmp', etc., inform
2892 function.c:setjmp_warnings that it should complain if
2893 nonvolatile values are live. For functions that cannot
2894 return, inform flow that control does not fall through. */
2896 if ((flags & ECF_NORETURN) || pass == 0)
2898 /* The barrier must be emitted
2899 immediately after the CALL_INSN. Some ports emit more
2900 than just a CALL_INSN above, so we must search for it here. */
2902 rtx last = get_last_insn ();
2903 while (!CALL_P (last))
2905 last = PREV_INSN (last);
2906 /* There was no CALL_INSN? */
2907 gcc_assert (last != before_call);
2910 emit_barrier_after (last);
2912 /* Stack adjustments after a noreturn call are dead code.
2913 However when NO_DEFER_POP is in effect, we must preserve
2914 stack_pointer_delta. */
2915 if (inhibit_defer_pop == 0)
2917 stack_pointer_delta = old_stack_allocated;
2918 pending_stack_adjust = 0;
2922 /* If value type not void, return an rtx for the value. */
2924 if (TYPE_MODE (rettype) == VOIDmode
2926 target = const0_rtx;
2927 else if (structure_value_addr)
2929 if (target == 0 || !MEM_P (target))
2932 = gen_rtx_MEM (TYPE_MODE (rettype),
2933 memory_address (TYPE_MODE (rettype),
2934 structure_value_addr));
2935 set_mem_attributes (target, rettype, 1);
2938 else if (pcc_struct_value)
2940 /* This is the special C++ case where we need to
2941 know what the true target was. We take care to
2942 never use this value more than once in one expression. */
2943 target = gen_rtx_MEM (TYPE_MODE (rettype),
2944 copy_to_reg (valreg));
2945 set_mem_attributes (target, rettype, 1);
2947 /* Handle calls that return values in multiple non-contiguous locations.
2948 The Irix 6 ABI has examples of this. */
2949 else if (GET_CODE (valreg) == PARALLEL)
2953 /* This will only be assigned once, so it can be readonly. */
2954 tree nt = build_qualified_type (rettype,
2955 (TYPE_QUALS (rettype)
2956 | TYPE_QUAL_CONST));
2958 target = assign_temp (nt, 0, 1, 1);
2961 if (! rtx_equal_p (target, valreg))
2962 emit_group_store (target, valreg, rettype,
2963 int_size_in_bytes (rettype));
2965 /* We can not support sibling calls for this case. */
2966 sibcall_failure = 1;
2969 && GET_MODE (target) == TYPE_MODE (rettype)
2970 && GET_MODE (target) == GET_MODE (valreg))
2972 bool may_overlap = false;
2974 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2975 reg to a plain register. */
2976 if (!REG_P (target) || HARD_REGISTER_P (target))
2977 valreg = avoid_likely_spilled_reg (valreg);
2979 /* If TARGET is a MEM in the argument area, and we have
2980 saved part of the argument area, then we can't store
2981 directly into TARGET as it may get overwritten when we
2982 restore the argument save area below. Don't work too
2983 hard though and simply force TARGET to a register if it
2984 is a MEM; the optimizer is quite likely to sort it out. */
2985 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2986 for (i = 0; i < num_actuals; i++)
2987 if (args[i].save_area)
2994 target = copy_to_reg (valreg);
2997 /* TARGET and VALREG cannot be equal at this point
2998 because the latter would not have
2999 REG_FUNCTION_VALUE_P true, while the former would if
3000 it were referring to the same register.
3002 If they refer to the same register, this move will be
3003 a no-op, except when function inlining is being
3005 emit_move_insn (target, valreg);
3007 /* If we are setting a MEM, this code must be executed.
3008 Since it is emitted after the call insn, sibcall
3009 optimization cannot be performed in that case. */
3011 sibcall_failure = 1;
3014 else if (TYPE_MODE (rettype) == BLKmode)
3017 if (GET_MODE (val) != BLKmode)
3018 val = avoid_likely_spilled_reg (val);
3019 target = copy_blkmode_from_reg (target, val, rettype);
3021 /* We can not support sibling calls for this case. */
3022 sibcall_failure = 1;
3025 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3027 /* If we promoted this return value, make the proper SUBREG.
3028 TARGET might be const0_rtx here, so be careful. */
3030 && TYPE_MODE (rettype) != BLKmode
3031 && GET_MODE (target) != TYPE_MODE (rettype))
3033 tree type = rettype;
3034 int unsignedp = TYPE_UNSIGNED (type);
3036 enum machine_mode pmode;
3038 /* Ensure we promote as expected, and get the new unsignedness. */
3039 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3041 gcc_assert (GET_MODE (target) == pmode);
3043 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3044 && (GET_MODE_SIZE (GET_MODE (target))
3045 > GET_MODE_SIZE (TYPE_MODE (type))))
3047 offset = GET_MODE_SIZE (GET_MODE (target))
3048 - GET_MODE_SIZE (TYPE_MODE (type));
3049 if (! BYTES_BIG_ENDIAN)
3050 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3051 else if (! WORDS_BIG_ENDIAN)
3052 offset %= UNITS_PER_WORD;
3055 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3056 SUBREG_PROMOTED_VAR_P (target) = 1;
3057 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3060 /* If size of args is variable or this was a constructor call for a stack
3061 argument, restore saved stack-pointer value. */
3063 if (old_stack_level)
3065 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3066 stack_pointer_delta = old_stack_pointer_delta;
3067 pending_stack_adjust = old_pending_adj;
3068 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3069 stack_arg_under_construction = old_stack_arg_under_construction;
3070 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3071 stack_usage_map = initial_stack_usage_map;
3072 sibcall_failure = 1;
3074 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3076 #ifdef REG_PARM_STACK_SPACE
3078 restore_fixed_argument_area (save_area, argblock,
3079 high_to_save, low_to_save);
3082 /* If we saved any argument areas, restore them. */
3083 for (i = 0; i < num_actuals; i++)
3084 if (args[i].save_area)
3086 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3088 = gen_rtx_MEM (save_mode,
3089 memory_address (save_mode,
3090 XEXP (args[i].stack_slot, 0)));
3092 if (save_mode != BLKmode)
3093 emit_move_insn (stack_area, args[i].save_area);
3095 emit_block_move (stack_area, args[i].save_area,
3096 GEN_INT (args[i].locate.size.constant),
3097 BLOCK_OP_CALL_PARM);
3100 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3101 stack_usage_map = initial_stack_usage_map;
3104 /* If this was alloca, record the new stack level for nonlocal gotos.
3105 Check for the handler slots since we might not have a save area
3106 for non-local gotos. */
3108 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3109 update_nonlocal_goto_save_area ();
3111 /* Free up storage we no longer need. */
3112 for (i = 0; i < num_actuals; ++i)
3113 if (args[i].aligned_regs)
3114 free (args[i].aligned_regs);
3116 insns = get_insns ();
3121 tail_call_insns = insns;
3123 /* Restore the pending stack adjustment now that we have
3124 finished generating the sibling call sequence. */
3126 pending_stack_adjust = save_pending_stack_adjust;
3127 stack_pointer_delta = save_stack_pointer_delta;
3129 /* Prepare arg structure for next iteration. */
3130 for (i = 0; i < num_actuals; i++)
3133 args[i].aligned_regs = 0;
3137 sbitmap_free (stored_args_map);
3141 normal_call_insns = insns;
3143 /* Verify that we've deallocated all the stack we used. */
3144 gcc_assert ((flags & ECF_NORETURN)
3145 || (old_stack_allocated
3146 == stack_pointer_delta - pending_stack_adjust));
3149 /* If something prevents making this a sibling call,
3150 zero out the sequence. */
3151 if (sibcall_failure)
3152 tail_call_insns = NULL_RTX;
3157 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3158 arguments too, as argument area is now clobbered by the call. */
3159 if (tail_call_insns)
3161 emit_insn (tail_call_insns);
3162 crtl->tail_call_emit = true;
3165 emit_insn (normal_call_insns);
3167 currently_expanding_call--;
3169 if (stack_usage_map_buf)
3170 free (stack_usage_map_buf);
3175 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3176 this function's incoming arguments.
3178 At the start of RTL generation we know the only REG_EQUIV notes
3179 in the rtl chain are those for incoming arguments, so we can look
3180 for REG_EQUIV notes between the start of the function and the
3181 NOTE_INSN_FUNCTION_BEG.
3183 This is (slight) overkill. We could keep track of the highest
3184 argument we clobber and be more selective in removing notes, but it
3185 does not seem to be worth the effort. */
3188 fixup_tail_calls (void)
3192 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3196 /* There are never REG_EQUIV notes for the incoming arguments
3197 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3199 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3202 note = find_reg_note (insn, REG_EQUIV, 0);
3204 remove_note (insn, note);
3205 note = find_reg_note (insn, REG_EQUIV, 0);
3210 /* Traverse a list of TYPES and expand all complex types into their
3213 split_complex_types (tree types)
3217 /* Before allocating memory, check for the common case of no complex. */
3218 for (p = types; p; p = TREE_CHAIN (p))
3220 tree type = TREE_VALUE (p);
3221 if (TREE_CODE (type) == COMPLEX_TYPE
3222 && targetm.calls.split_complex_arg (type))
3228 types = copy_list (types);
3230 for (p = types; p; p = TREE_CHAIN (p))
3232 tree complex_type = TREE_VALUE (p);
3234 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3235 && targetm.calls.split_complex_arg (complex_type))
3239 /* Rewrite complex type with component type. */
3240 TREE_VALUE (p) = TREE_TYPE (complex_type);
3241 next = TREE_CHAIN (p);
3243 /* Add another component type for the imaginary part. */
3244 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3245 TREE_CHAIN (p) = imag;
3246 TREE_CHAIN (imag) = next;
3248 /* Skip the newly created node. */
3256 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3257 The RETVAL parameter specifies whether return value needs to be saved, other
3258 parameters are documented in the emit_library_call function below. */
3261 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3262 enum libcall_type fn_type,
3263 enum machine_mode outmode, int nargs, va_list p)
3265 /* Total size in bytes of all the stack-parms scanned so far. */
3266 struct args_size args_size;
3267 /* Size of arguments before any adjustments (such as rounding). */
3268 struct args_size original_args_size;
3271 /* Todo, choose the correct decl type of orgfun. Sadly this information
3272 isn't present here, so we default to native calling abi here. */
3273 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3274 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3278 CUMULATIVE_ARGS args_so_far;
3282 enum machine_mode mode;
3285 struct locate_and_pad_arg_data locate;
3289 int old_inhibit_defer_pop = inhibit_defer_pop;
3290 rtx call_fusage = 0;
3293 int pcc_struct_value = 0;
3294 int struct_value_size = 0;
3296 int reg_parm_stack_space = 0;
3299 tree tfom; /* type_for_mode (outmode, 0) */
3301 #ifdef REG_PARM_STACK_SPACE
3302 /* Define the boundary of the register parm stack space that needs to be
3304 int low_to_save = 0, high_to_save = 0;
3305 rtx save_area = 0; /* Place that it is saved. */
3308 /* Size of the stack reserved for parameter registers. */
3309 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3310 char *initial_stack_usage_map = stack_usage_map;
3311 char *stack_usage_map_buf = NULL;
3313 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3315 #ifdef REG_PARM_STACK_SPACE
3316 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3319 /* By default, library functions can not throw. */
3320 flags = ECF_NOTHROW;
3333 flags |= ECF_NORETURN;
3336 flags = ECF_NORETURN;
3338 case LCT_RETURNS_TWICE:
3339 flags = ECF_RETURNS_TWICE;
3344 /* Ensure current function's preferred stack boundary is at least
3346 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3347 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3349 /* If this kind of value comes back in memory,
3350 decide where in memory it should come back. */
3351 if (outmode != VOIDmode)
3353 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3354 if (aggregate_value_p (tfom, 0))
3356 #ifdef PCC_STATIC_STRUCT_RETURN
3358 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3359 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3360 pcc_struct_value = 1;
3362 value = gen_reg_rtx (outmode);
3363 #else /* not PCC_STATIC_STRUCT_RETURN */
3364 struct_value_size = GET_MODE_SIZE (outmode);
3365 if (value != 0 && MEM_P (value))
3368 mem_value = assign_temp (tfom, 0, 1, 1);
3370 /* This call returns a big structure. */
3371 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3375 tfom = void_type_node;
3377 /* ??? Unfinished: must pass the memory address as an argument. */
3379 /* Copy all the libcall-arguments out of the varargs data
3380 and into a vector ARGVEC.
3382 Compute how to pass each argument. We only support a very small subset
3383 of the full argument passing conventions to limit complexity here since
3384 library functions shouldn't have many args. */
3386 argvec = XALLOCAVEC (struct arg, nargs + 1);
3387 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3389 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3390 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3392 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3395 args_size.constant = 0;
3402 /* If there's a structure value address to be passed,
3403 either pass it in the special place, or pass it as an extra argument. */
3404 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3406 rtx addr = XEXP (mem_value, 0);
3410 /* Make sure it is a reasonable operand for a move or push insn. */
3411 if (!REG_P (addr) && !MEM_P (addr)
3412 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3413 addr = force_operand (addr, NULL_RTX);
3415 argvec[count].value = addr;
3416 argvec[count].mode = Pmode;
3417 argvec[count].partial = 0;
3419 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3420 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3421 NULL_TREE, 1) == 0);
3423 locate_and_pad_parm (Pmode, NULL_TREE,
3424 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3427 argvec[count].reg != 0,
3429 0, NULL_TREE, &args_size, &argvec[count].locate);
3431 if (argvec[count].reg == 0 || argvec[count].partial != 0
3432 || reg_parm_stack_space > 0)
3433 args_size.constant += argvec[count].locate.size.constant;
3435 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3440 for (; count < nargs; count++)
3442 rtx val = va_arg (p, rtx);
3443 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3445 /* We cannot convert the arg value to the mode the library wants here;
3446 must do it earlier where we know the signedness of the arg. */
3447 gcc_assert (mode != BLKmode
3448 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3450 /* Make sure it is a reasonable operand for a move or push insn. */
3451 if (!REG_P (val) && !MEM_P (val)
3452 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3453 val = force_operand (val, NULL_RTX);
3455 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3459 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3461 /* If this was a CONST function, it is now PURE since it now
3463 if (flags & ECF_CONST)
3465 flags &= ~ECF_CONST;
3469 if (MEM_P (val) && !must_copy)
3473 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3475 emit_move_insn (slot, val);
3478 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3479 gen_rtx_USE (VOIDmode, slot),
3482 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3483 gen_rtx_CLOBBER (VOIDmode,
3488 val = force_operand (XEXP (slot, 0), NULL_RTX);
3491 argvec[count].value = val;
3492 argvec[count].mode = mode;
3494 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3496 argvec[count].partial
3497 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3499 locate_and_pad_parm (mode, NULL_TREE,
3500 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3503 argvec[count].reg != 0,
3505 argvec[count].partial,
3506 NULL_TREE, &args_size, &argvec[count].locate);
3508 gcc_assert (!argvec[count].locate.size.var);
3510 if (argvec[count].reg == 0 || argvec[count].partial != 0
3511 || reg_parm_stack_space > 0)
3512 args_size.constant += argvec[count].locate.size.constant;
3514 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3517 /* If this machine requires an external definition for library
3518 functions, write one out. */
3519 assemble_external_libcall (fun);
3521 original_args_size = args_size;
3522 args_size.constant = (((args_size.constant
3523 + stack_pointer_delta
3527 - stack_pointer_delta);
3529 args_size.constant = MAX (args_size.constant,
3530 reg_parm_stack_space);
3532 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3533 args_size.constant -= reg_parm_stack_space;
3535 if (args_size.constant > crtl->outgoing_args_size)
3536 crtl->outgoing_args_size = args_size.constant;
3538 if (ACCUMULATE_OUTGOING_ARGS)
3540 /* Since the stack pointer will never be pushed, it is possible for
3541 the evaluation of a parm to clobber something we have already
3542 written to the stack. Since most function calls on RISC machines
3543 do not use the stack, this is uncommon, but must work correctly.
3545 Therefore, we save any area of the stack that was already written
3546 and that we are using. Here we set up to do this by making a new
3547 stack usage map from the old one.
3549 Another approach might be to try to reorder the argument
3550 evaluations to avoid this conflicting stack usage. */
3552 needed = args_size.constant;
3554 /* Since we will be writing into the entire argument area, the
3555 map must be allocated for its entire size, not just the part that
3556 is the responsibility of the caller. */
3557 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3558 needed += reg_parm_stack_space;
3560 #ifdef ARGS_GROW_DOWNWARD
3561 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3564 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3567 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3568 stack_usage_map = stack_usage_map_buf;
3570 if (initial_highest_arg_in_use)
3571 memcpy (stack_usage_map, initial_stack_usage_map,
3572 initial_highest_arg_in_use);
3574 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3575 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3576 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3579 /* We must be careful to use virtual regs before they're instantiated,
3580 and real regs afterwards. Loop optimization, for example, can create
3581 new libcalls after we've instantiated the virtual regs, and if we
3582 use virtuals anyway, they won't match the rtl patterns. */
3584 if (virtuals_instantiated)
3585 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3587 argblock = virtual_outgoing_args_rtx;
3592 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3595 /* If we push args individually in reverse order, perform stack alignment
3596 before the first push (the last arg). */
3597 if (argblock == 0 && PUSH_ARGS_REVERSED)
3598 anti_adjust_stack (GEN_INT (args_size.constant
3599 - original_args_size.constant));
3601 if (PUSH_ARGS_REVERSED)
3612 #ifdef REG_PARM_STACK_SPACE
3613 if (ACCUMULATE_OUTGOING_ARGS)
3615 /* The argument list is the property of the called routine and it
3616 may clobber it. If the fixed area has been used for previous
3617 parameters, we must save and restore it. */
3618 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3619 &low_to_save, &high_to_save);
3623 /* Push the args that need to be pushed. */
3625 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3626 are to be pushed. */
3627 for (count = 0; count < nargs; count++, argnum += inc)
3629 enum machine_mode mode = argvec[argnum].mode;
3630 rtx val = argvec[argnum].value;
3631 rtx reg = argvec[argnum].reg;
3632 int partial = argvec[argnum].partial;
3633 unsigned int parm_align = argvec[argnum].locate.boundary;
3634 int lower_bound = 0, upper_bound = 0, i;
3636 if (! (reg != 0 && partial == 0))
3638 if (ACCUMULATE_OUTGOING_ARGS)
3640 /* If this is being stored into a pre-allocated, fixed-size,
3641 stack area, save any previous data at that location. */
3643 #ifdef ARGS_GROW_DOWNWARD
3644 /* stack_slot is negative, but we want to index stack_usage_map
3645 with positive values. */
3646 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3647 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3649 lower_bound = argvec[argnum].locate.slot_offset.constant;
3650 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3654 /* Don't worry about things in the fixed argument area;
3655 it has already been saved. */
3656 if (i < reg_parm_stack_space)
3657 i = reg_parm_stack_space;
3658 while (i < upper_bound && stack_usage_map[i] == 0)
3661 if (i < upper_bound)
3663 /* We need to make a save area. */
3665 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3666 enum machine_mode save_mode
3667 = mode_for_size (size, MODE_INT, 1);
3669 = plus_constant (argblock,
3670 argvec[argnum].locate.offset.constant);
3672 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3674 if (save_mode == BLKmode)
3676 argvec[argnum].save_area
3677 = assign_stack_temp (BLKmode,
3678 argvec[argnum].locate.size.constant,
3681 emit_block_move (validize_mem (argvec[argnum].save_area),
3683 GEN_INT (argvec[argnum].locate.size.constant),
3684 BLOCK_OP_CALL_PARM);
3688 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3690 emit_move_insn (argvec[argnum].save_area, stack_area);
3695 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
3696 partial, reg, 0, argblock,
3697 GEN_INT (argvec[argnum].locate.offset.constant),
3698 reg_parm_stack_space,
3699 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3701 /* Now mark the segment we just used. */
3702 if (ACCUMULATE_OUTGOING_ARGS)
3703 for (i = lower_bound; i < upper_bound; i++)
3704 stack_usage_map[i] = 1;
3708 if ((flags & ECF_CONST)
3709 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
3713 /* Indicate argument access so that alias.c knows that these
3716 use = plus_constant (argblock,
3717 argvec[argnum].locate.offset.constant);
3719 /* When arguments are pushed, trying to tell alias.c where
3720 exactly this argument is won't work, because the
3721 auto-increment causes confusion. So we merely indicate
3722 that we access something with a known mode somewhere on
3724 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3725 gen_rtx_SCRATCH (Pmode));
3726 use = gen_rtx_MEM (argvec[argnum].mode, use);
3727 use = gen_rtx_USE (VOIDmode, use);
3728 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3733 /* If we pushed args in forward order, perform stack alignment
3734 after pushing the last arg. */
3735 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3736 anti_adjust_stack (GEN_INT (args_size.constant
3737 - original_args_size.constant));
3739 if (PUSH_ARGS_REVERSED)
3744 fun = prepare_call_address (NULL, fun, NULL, &call_fusage, 0, 0);
3746 /* Now load any reg parms into their regs. */
3748 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3749 are to be pushed. */
3750 for (count = 0; count < nargs; count++, argnum += inc)
3752 enum machine_mode mode = argvec[argnum].mode;
3753 rtx val = argvec[argnum].value;
3754 rtx reg = argvec[argnum].reg;
3755 int partial = argvec[argnum].partial;
3757 /* Handle calls that pass values in multiple non-contiguous
3758 locations. The PA64 has examples of this for library calls. */
3759 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3760 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3761 else if (reg != 0 && partial == 0)
3762 emit_move_insn (reg, val);
3767 /* Any regs containing parms remain in use through the call. */
3768 for (count = 0; count < nargs; count++)
3770 rtx reg = argvec[count].reg;
3771 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3772 use_group_regs (&call_fusage, reg);
3775 int partial = argvec[count].partial;
3779 gcc_assert (partial % UNITS_PER_WORD == 0);
3780 nregs = partial / UNITS_PER_WORD;
3781 use_regs (&call_fusage, REGNO (reg), nregs);
3784 use_reg (&call_fusage, reg);
3788 /* Pass the function the address in which to return a structure value. */
3789 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3791 emit_move_insn (struct_value,
3793 force_operand (XEXP (mem_value, 0),
3795 if (REG_P (struct_value))
3796 use_reg (&call_fusage, struct_value);
3799 /* Don't allow popping to be deferred, since then
3800 cse'ing of library calls could delete a call and leave the pop. */
3802 valreg = (mem_value == 0 && outmode != VOIDmode
3803 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
3805 /* Stack must be properly aligned now. */
3806 gcc_assert (!(stack_pointer_delta
3807 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3809 before_call = get_last_insn ();
3811 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3812 will set inhibit_defer_pop to that value. */
3813 /* The return type is needed to decide how many bytes the function pops.
3814 Signedness plays no role in that, so for simplicity, we pretend it's
3815 always signed. We also assume that the list of arguments passed has
3816 no impact, so we pretend it is unknown. */
3818 emit_call_1 (fun, NULL,
3819 get_identifier (XSTR (orgfun, 0)),
3820 build_function_type (tfom, NULL_TREE),
3821 original_args_size.constant, args_size.constant,
3823 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3825 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3827 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3828 that it should complain if nonvolatile values are live. For
3829 functions that cannot return, inform flow that control does not
3832 if (flags & ECF_NORETURN)
3834 /* The barrier note must be emitted
3835 immediately after the CALL_INSN. Some ports emit more than
3836 just a CALL_INSN above, so we must search for it here. */
3838 rtx last = get_last_insn ();
3839 while (!CALL_P (last))
3841 last = PREV_INSN (last);
3842 /* There was no CALL_INSN? */
3843 gcc_assert (last != before_call);
3846 emit_barrier_after (last);
3849 /* Now restore inhibit_defer_pop to its actual original value. */
3854 /* Copy the value to the right place. */
3855 if (outmode != VOIDmode && retval)
3861 if (value != mem_value)
3862 emit_move_insn (value, mem_value);
3864 else if (GET_CODE (valreg) == PARALLEL)
3867 value = gen_reg_rtx (outmode);
3868 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3872 /* Convert to the proper mode if a promotion has been active. */
3873 if (GET_MODE (valreg) != outmode)
3875 int unsignedp = TYPE_UNSIGNED (tfom);
3877 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
3878 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
3879 == GET_MODE (valreg));
3880 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3884 emit_move_insn (value, valreg);
3890 if (ACCUMULATE_OUTGOING_ARGS)
3892 #ifdef REG_PARM_STACK_SPACE
3894 restore_fixed_argument_area (save_area, argblock,
3895 high_to_save, low_to_save);
3898 /* If we saved any argument areas, restore them. */
3899 for (count = 0; count < nargs; count++)
3900 if (argvec[count].save_area)
3902 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3903 rtx adr = plus_constant (argblock,
3904 argvec[count].locate.offset.constant);
3905 rtx stack_area = gen_rtx_MEM (save_mode,
3906 memory_address (save_mode, adr));
3908 if (save_mode == BLKmode)
3909 emit_block_move (stack_area,
3910 validize_mem (argvec[count].save_area),
3911 GEN_INT (argvec[count].locate.size.constant),
3912 BLOCK_OP_CALL_PARM);
3914 emit_move_insn (stack_area, argvec[count].save_area);
3917 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3918 stack_usage_map = initial_stack_usage_map;
3921 if (stack_usage_map_buf)
3922 free (stack_usage_map_buf);
3928 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3929 (emitting the queue unless NO_QUEUE is nonzero),
3930 for a value of mode OUTMODE,
3931 with NARGS different arguments, passed as alternating rtx values
3932 and machine_modes to convert them to.
3934 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3935 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3936 other types of library calls. */
3939 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3940 enum machine_mode outmode, int nargs, ...)
3944 va_start (p, nargs);
3945 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3949 /* Like emit_library_call except that an extra argument, VALUE,
3950 comes second and says where to store the result.
3951 (If VALUE is zero, this function chooses a convenient way
3952 to return the value.
3954 This function returns an rtx for where the value is to be found.
3955 If VALUE is nonzero, VALUE is returned. */
3958 emit_library_call_value (rtx orgfun, rtx value,
3959 enum libcall_type fn_type,
3960 enum machine_mode outmode, int nargs, ...)
3965 va_start (p, nargs);
3966 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3973 /* Store a single argument for a function call
3974 into the register or memory area where it must be passed.
3975 *ARG describes the argument value and where to pass it.
3977 ARGBLOCK is the address of the stack-block for all the arguments,
3978 or 0 on a machine where arguments are pushed individually.
3980 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3981 so must be careful about how the stack is used.
3983 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3984 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3985 that we need not worry about saving and restoring the stack.
3987 FNDECL is the declaration of the function we are calling.
3989 Return nonzero if this arg should cause sibcall failure,
3993 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3994 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3996 tree pval = arg->tree_value;
4000 int i, lower_bound = 0, upper_bound = 0;
4001 int sibcall_failure = 0;
4003 if (TREE_CODE (pval) == ERROR_MARK)
4006 /* Push a new temporary level for any temporaries we make for
4010 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4012 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4013 save any previous data at that location. */
4014 if (argblock && ! variable_size && arg->stack)
4016 #ifdef ARGS_GROW_DOWNWARD
4017 /* stack_slot is negative, but we want to index stack_usage_map
4018 with positive values. */
4019 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4020 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4024 lower_bound = upper_bound - arg->locate.size.constant;
4026 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4027 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4031 upper_bound = lower_bound + arg->locate.size.constant;
4035 /* Don't worry about things in the fixed argument area;
4036 it has already been saved. */
4037 if (i < reg_parm_stack_space)
4038 i = reg_parm_stack_space;
4039 while (i < upper_bound && stack_usage_map[i] == 0)
4042 if (i < upper_bound)
4044 /* We need to make a save area. */
4045 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4046 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4047 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4048 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4050 if (save_mode == BLKmode)
4052 tree ot = TREE_TYPE (arg->tree_value);
4053 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4054 | TYPE_QUAL_CONST));
4056 arg->save_area = assign_temp (nt, 0, 1, 1);
4057 preserve_temp_slots (arg->save_area);
4058 emit_block_move (validize_mem (arg->save_area), stack_area,
4059 GEN_INT (arg->locate.size.constant),
4060 BLOCK_OP_CALL_PARM);
4064 arg->save_area = gen_reg_rtx (save_mode);
4065 emit_move_insn (arg->save_area, stack_area);
4071 /* If this isn't going to be placed on both the stack and in registers,
4072 set up the register and number of words. */
4073 if (! arg->pass_on_stack)
4075 if (flags & ECF_SIBCALL)
4076 reg = arg->tail_call_reg;
4079 partial = arg->partial;
4082 /* Being passed entirely in a register. We shouldn't be called in
4084 gcc_assert (reg == 0 || partial != 0);
4086 /* If this arg needs special alignment, don't load the registers
4088 if (arg->n_aligned_regs != 0)
4091 /* If this is being passed partially in a register, we can't evaluate
4092 it directly into its stack slot. Otherwise, we can. */
4093 if (arg->value == 0)
4095 /* stack_arg_under_construction is nonzero if a function argument is
4096 being evaluated directly into the outgoing argument list and
4097 expand_call must take special action to preserve the argument list
4098 if it is called recursively.
4100 For scalar function arguments stack_usage_map is sufficient to
4101 determine which stack slots must be saved and restored. Scalar
4102 arguments in general have pass_on_stack == 0.
4104 If this argument is initialized by a function which takes the
4105 address of the argument (a C++ constructor or a C function
4106 returning a BLKmode structure), then stack_usage_map is
4107 insufficient and expand_call must push the stack around the
4108 function call. Such arguments have pass_on_stack == 1.
4110 Note that it is always safe to set stack_arg_under_construction,
4111 but this generates suboptimal code if set when not needed. */
4113 if (arg->pass_on_stack)
4114 stack_arg_under_construction++;
4116 arg->value = expand_expr (pval,
4118 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4119 ? NULL_RTX : arg->stack,
4120 VOIDmode, EXPAND_STACK_PARM);
4122 /* If we are promoting object (or for any other reason) the mode
4123 doesn't agree, convert the mode. */
4125 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4126 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4127 arg->value, arg->unsignedp);
4129 if (arg->pass_on_stack)
4130 stack_arg_under_construction--;
4133 /* Check for overlap with already clobbered argument area. */
4134 if ((flags & ECF_SIBCALL)
4135 && MEM_P (arg->value)
4136 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4137 arg->locate.size.constant))
4138 sibcall_failure = 1;
4140 /* Don't allow anything left on stack from computation
4141 of argument to alloca. */
4142 if (flags & ECF_MAY_BE_ALLOCA)
4143 do_pending_stack_adjust ();
4145 if (arg->value == arg->stack)
4146 /* If the value is already in the stack slot, we are done. */
4148 else if (arg->mode != BLKmode)
4151 unsigned int parm_align;
4153 /* Argument is a scalar, not entirely passed in registers.
4154 (If part is passed in registers, arg->partial says how much
4155 and emit_push_insn will take care of putting it there.)
4157 Push it, and if its size is less than the
4158 amount of space allocated to it,
4159 also bump stack pointer by the additional space.
4160 Note that in C the default argument promotions
4161 will prevent such mismatches. */
4163 size = GET_MODE_SIZE (arg->mode);
4164 /* Compute how much space the push instruction will push.
4165 On many machines, pushing a byte will advance the stack
4166 pointer by a halfword. */
4167 #ifdef PUSH_ROUNDING
4168 size = PUSH_ROUNDING (size);
4172 /* Compute how much space the argument should get:
4173 round up to a multiple of the alignment for arguments. */
4174 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4175 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4176 / (PARM_BOUNDARY / BITS_PER_UNIT))
4177 * (PARM_BOUNDARY / BITS_PER_UNIT));
4179 /* Compute the alignment of the pushed argument. */
4180 parm_align = arg->locate.boundary;
4181 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4183 int pad = used - size;
4186 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4187 parm_align = MIN (parm_align, pad_align);
4191 /* This isn't already where we want it on the stack, so put it there.
4192 This can either be done with push or copy insns. */
4193 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4194 parm_align, partial, reg, used - size, argblock,
4195 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4196 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4198 /* Unless this is a partially-in-register argument, the argument is now
4201 arg->value = arg->stack;
4205 /* BLKmode, at least partly to be pushed. */
4207 unsigned int parm_align;
4211 /* Pushing a nonscalar.
4212 If part is passed in registers, PARTIAL says how much
4213 and emit_push_insn will take care of putting it there. */
4215 /* Round its size up to a multiple
4216 of the allocation unit for arguments. */
4218 if (arg->locate.size.var != 0)
4221 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4225 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4226 for BLKmode is careful to avoid it. */
4227 excess = (arg->locate.size.constant
4228 - int_size_in_bytes (TREE_TYPE (pval))
4230 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4231 NULL_RTX, TYPE_MODE (sizetype),
4235 parm_align = arg->locate.boundary;
4237 /* When an argument is padded down, the block is aligned to
4238 PARM_BOUNDARY, but the actual argument isn't. */
4239 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4241 if (arg->locate.size.var)
4242 parm_align = BITS_PER_UNIT;
4245 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4246 parm_align = MIN (parm_align, excess_align);
4250 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4252 /* emit_push_insn might not work properly if arg->value and
4253 argblock + arg->locate.offset areas overlap. */
4257 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4258 || (GET_CODE (XEXP (x, 0)) == PLUS
4259 && XEXP (XEXP (x, 0), 0) ==
4260 crtl->args.internal_arg_pointer
4261 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4263 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4264 i = INTVAL (XEXP (XEXP (x, 0), 1));
4266 /* expand_call should ensure this. */
4267 gcc_assert (!arg->locate.offset.var
4268 && arg->locate.size.var == 0
4269 && CONST_INT_P (size_rtx));
4271 if (arg->locate.offset.constant > i)
4273 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4274 sibcall_failure = 1;
4276 else if (arg->locate.offset.constant < i)
4278 /* Use arg->locate.size.constant instead of size_rtx
4279 because we only care about the part of the argument
4281 if (i < (arg->locate.offset.constant
4282 + arg->locate.size.constant))
4283 sibcall_failure = 1;
4287 /* Even though they appear to be at the same location,
4288 if part of the outgoing argument is in registers,
4289 they aren't really at the same location. Check for
4290 this by making sure that the incoming size is the
4291 same as the outgoing size. */
4292 if (arg->locate.size.constant != INTVAL (size_rtx))
4293 sibcall_failure = 1;
4298 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4299 parm_align, partial, reg, excess, argblock,
4300 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4301 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4303 /* Unless this is a partially-in-register argument, the argument is now
4306 ??? Unlike the case above, in which we want the actual
4307 address of the data, so that we can load it directly into a
4308 register, here we want the address of the stack slot, so that
4309 it's properly aligned for word-by-word copying or something
4310 like that. It's not clear that this is always correct. */
4312 arg->value = arg->stack_slot;
4315 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4317 tree type = TREE_TYPE (arg->tree_value);
4319 = emit_group_load_into_temps (arg->reg, arg->value, type,
4320 int_size_in_bytes (type));
4323 /* Mark all slots this store used. */
4324 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4325 && argblock && ! variable_size && arg->stack)
4326 for (i = lower_bound; i < upper_bound; i++)
4327 stack_usage_map[i] = 1;
4329 /* Once we have pushed something, pops can't safely
4330 be deferred during the rest of the arguments. */
4333 /* Free any temporary slots made in processing this argument. Show
4334 that we might have taken the address of something and pushed that
4336 preserve_temp_slots (NULL_RTX);
4340 return sibcall_failure;
4343 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4346 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4352 /* If the type has variable size... */
4353 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4356 /* If the type is marked as addressable (it is required
4357 to be constructed into the stack)... */
4358 if (TREE_ADDRESSABLE (type))
4364 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4365 takes trailing padding of a structure into account. */
4366 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4369 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4374 /* If the type has variable size... */
4375 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4378 /* If the type is marked as addressable (it is required
4379 to be constructed into the stack)... */
4380 if (TREE_ADDRESSABLE (type))
4383 /* If the padding and mode of the type is such that a copy into
4384 a register would put it into the wrong part of the register. */
4386 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4387 && (FUNCTION_ARG_PADDING (mode, type)
4388 == (BYTES_BIG_ENDIAN ? upward : downward)))