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"
45 #include "tree-flow.h"
47 /* Like PREFERRED_STACK_BOUNDARY but in units of bytes, not bits. */
48 #define STACK_BYTES (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT)
50 /* Data structure and subroutines used within expand_call. */
54 /* Tree node for this argument. */
56 /* Mode for value; TYPE_MODE unless promoted. */
57 enum machine_mode mode;
58 /* Current RTL value for argument, or 0 if it isn't precomputed. */
60 /* Initially-compute RTL value for argument; only for const functions. */
62 /* Register to pass this argument in, 0 if passed on stack, or an
63 PARALLEL if the arg is to be copied into multiple non-contiguous
66 /* Register to pass this argument in when generating tail call sequence.
67 This is not the same register as for normal calls on machines with
70 /* If REG is a PARALLEL, this is a copy of VALUE pulled into the correct
71 form for emit_group_move. */
73 /* If REG was promoted from the actual mode of the argument expression,
74 indicates whether the promotion is sign- or zero-extended. */
76 /* Number of bytes to put in registers. 0 means put the whole arg
77 in registers. Also 0 if not passed in registers. */
79 /* Nonzero if argument must be passed on stack.
80 Note that some arguments may be passed on the stack
81 even though pass_on_stack is zero, just because FUNCTION_ARG says so.
82 pass_on_stack identifies arguments that *cannot* go in registers. */
84 /* Some fields packaged up for locate_and_pad_parm. */
85 struct locate_and_pad_arg_data locate;
86 /* Location on the stack at which parameter should be stored. The store
87 has already been done if STACK == VALUE. */
89 /* Location on the stack of the start of this argument slot. This can
90 differ from STACK if this arg pads downward. This location is known
91 to be aligned to FUNCTION_ARG_BOUNDARY. */
93 /* Place that this stack area has been saved, if needed. */
95 /* If an argument's alignment does not permit direct copying into registers,
96 copy in smaller-sized pieces into pseudos. These are stored in a
97 block pointed to by this field. The next field says how many
98 word-sized pseudos we made. */
103 /* A vector of one char per byte of stack space. A byte if nonzero if
104 the corresponding stack location has been used.
105 This vector is used to prevent a function call within an argument from
106 clobbering any stack already set up. */
107 static char *stack_usage_map;
109 /* Size of STACK_USAGE_MAP. */
110 static int highest_outgoing_arg_in_use;
112 /* A bitmap of virtual-incoming stack space. Bit is set if the corresponding
113 stack location's tail call argument has been already stored into the stack.
114 This bitmap is used to prevent sibling call optimization if function tries
115 to use parent's incoming argument slots when they have been already
116 overwritten with tail call arguments. */
117 static sbitmap stored_args_map;
119 /* stack_arg_under_construction is nonzero when an argument may be
120 initialized with a constructor call (including a C function that
121 returns a BLKmode struct) and expand_call must take special action
122 to make sure the object being constructed does not overlap the
123 argument list for the constructor call. */
124 static int stack_arg_under_construction;
126 static void emit_call_1 (rtx, tree, tree, tree, HOST_WIDE_INT, HOST_WIDE_INT,
127 HOST_WIDE_INT, rtx, rtx, int, rtx, int,
129 static void precompute_register_parameters (int, struct arg_data *, int *);
130 static int store_one_arg (struct arg_data *, rtx, int, int, int);
131 static void store_unaligned_arguments_into_pseudos (struct arg_data *, int);
132 static int finalize_must_preallocate (int, int, struct arg_data *,
134 static void precompute_arguments (int, struct arg_data *);
135 static int compute_argument_block_size (int, struct args_size *, tree, tree, int);
136 static void initialize_argument_information (int, struct arg_data *,
137 struct args_size *, int,
139 tree, tree, CUMULATIVE_ARGS *, int,
140 rtx *, int *, int *, int *,
142 static void compute_argument_addresses (struct arg_data *, rtx, int);
143 static rtx rtx_for_function_call (tree, tree);
144 static void load_register_parameters (struct arg_data *, int, rtx *, int,
146 static rtx emit_library_call_value_1 (int, rtx, rtx, enum libcall_type,
147 enum machine_mode, int, va_list);
148 static int special_function_p (const_tree, int);
149 static int check_sibcall_argument_overlap_1 (rtx);
150 static int check_sibcall_argument_overlap (rtx, struct arg_data *, int);
152 static int combine_pending_stack_adjustment_and_call (int, struct args_size *,
154 static tree split_complex_types (tree);
156 #ifdef REG_PARM_STACK_SPACE
157 static rtx save_fixed_argument_area (int, rtx, int *, int *);
158 static void restore_fixed_argument_area (rtx, rtx, int, int);
161 /* Force FUNEXP into a form suitable for the address of a CALL,
162 and return that as an rtx. Also load the static chain register
163 if FNDECL is a nested function.
165 CALL_FUSAGE points to a variable holding the prospective
166 CALL_INSN_FUNCTION_USAGE information. */
169 prepare_call_address (rtx funexp, rtx static_chain_value,
170 rtx *call_fusage, int reg_parm_seen, int sibcallp)
172 /* Make a valid memory address and copy constants through pseudo-regs,
173 but not for a constant address if -fno-function-cse. */
174 if (GET_CODE (funexp) != SYMBOL_REF)
175 /* If we are using registers for parameters, force the
176 function address into a register now. */
177 funexp = ((SMALL_REGISTER_CLASSES && reg_parm_seen)
178 ? force_not_mem (memory_address (FUNCTION_MODE, funexp))
179 : memory_address (FUNCTION_MODE, funexp));
182 #ifndef NO_FUNCTION_CSE
183 if (optimize && ! flag_no_function_cse)
184 funexp = force_reg (Pmode, funexp);
188 if (static_chain_value != 0)
190 static_chain_value = convert_memory_address (Pmode, static_chain_value);
191 emit_move_insn (static_chain_rtx, static_chain_value);
193 if (REG_P (static_chain_rtx))
194 use_reg (call_fusage, static_chain_rtx);
200 /* Generate instructions to call function FUNEXP,
201 and optionally pop the results.
202 The CALL_INSN is the first insn generated.
204 FNDECL is the declaration node of the function. This is given to the
205 macro RETURN_POPS_ARGS to determine whether this function pops its own args.
207 FUNTYPE is the data type of the function. This is given to the macro
208 RETURN_POPS_ARGS to determine whether this function pops its own args.
209 We used to allow an identifier for library functions, but that doesn't
210 work when the return type is an aggregate type and the calling convention
211 says that the pointer to this aggregate is to be popped by the callee.
213 STACK_SIZE is the number of bytes of arguments on the stack,
214 ROUNDED_STACK_SIZE is that number rounded up to
215 PREFERRED_STACK_BOUNDARY; zero if the size is variable. This is
216 both to put into the call insn and to generate explicit popping
219 STRUCT_VALUE_SIZE is the number of bytes wanted in a structure value.
220 It is zero if this call doesn't want a structure value.
222 NEXT_ARG_REG is the rtx that results from executing
223 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1)
224 just after all the args have had their registers assigned.
225 This could be whatever you like, but normally it is the first
226 arg-register beyond those used for args in this call,
227 or 0 if all the arg-registers are used in this call.
228 It is passed on to `gen_call' so you can put this info in the call insn.
230 VALREG is a hard register in which a value is returned,
231 or 0 if the call does not return a value.
233 OLD_INHIBIT_DEFER_POP is the value that `inhibit_defer_pop' had before
234 the args to this call were processed.
235 We restore `inhibit_defer_pop' to that value.
237 CALL_FUSAGE is either empty or an EXPR_LIST of USE expressions that
238 denote registers used by the called function. */
241 emit_call_1 (rtx funexp, tree fntree ATTRIBUTE_UNUSED, tree fndecl ATTRIBUTE_UNUSED,
242 tree funtype ATTRIBUTE_UNUSED,
243 HOST_WIDE_INT stack_size ATTRIBUTE_UNUSED,
244 HOST_WIDE_INT rounded_stack_size,
245 HOST_WIDE_INT struct_value_size ATTRIBUTE_UNUSED,
246 rtx next_arg_reg ATTRIBUTE_UNUSED, rtx valreg,
247 int old_inhibit_defer_pop, rtx call_fusage, int ecf_flags,
248 CUMULATIVE_ARGS *args_so_far ATTRIBUTE_UNUSED)
250 rtx rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
252 int already_popped = 0;
253 HOST_WIDE_INT n_popped = RETURN_POPS_ARGS (fndecl, funtype, stack_size);
254 #if defined (HAVE_call) && defined (HAVE_call_value)
255 rtx struct_value_size_rtx;
256 struct_value_size_rtx = GEN_INT (struct_value_size);
259 #ifdef CALL_POPS_ARGS
260 n_popped += CALL_POPS_ARGS (* args_so_far);
263 /* Ensure address is valid. SYMBOL_REF is already valid, so no need,
264 and we don't want to load it into a register as an optimization,
265 because prepare_call_address already did it if it should be done. */
266 if (GET_CODE (funexp) != SYMBOL_REF)
267 funexp = memory_address (FUNCTION_MODE, funexp);
269 #if defined (HAVE_sibcall_pop) && defined (HAVE_sibcall_value_pop)
270 if ((ecf_flags & ECF_SIBCALL)
271 && HAVE_sibcall_pop && HAVE_sibcall_value_pop
272 && (n_popped > 0 || stack_size == 0))
274 rtx n_pop = GEN_INT (n_popped);
277 /* If this subroutine pops its own args, record that in the call insn
278 if possible, for the sake of frame pointer elimination. */
281 pat = GEN_SIBCALL_VALUE_POP (valreg,
282 gen_rtx_MEM (FUNCTION_MODE, funexp),
283 rounded_stack_size_rtx, next_arg_reg,
286 pat = GEN_SIBCALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
287 rounded_stack_size_rtx, next_arg_reg, n_pop);
289 emit_call_insn (pat);
295 #if defined (HAVE_call_pop) && defined (HAVE_call_value_pop)
296 /* If the target has "call" or "call_value" insns, then prefer them
297 if no arguments are actually popped. If the target does not have
298 "call" or "call_value" insns, then we must use the popping versions
299 even if the call has no arguments to pop. */
300 #if defined (HAVE_call) && defined (HAVE_call_value)
301 if (HAVE_call && HAVE_call_value && HAVE_call_pop && HAVE_call_value_pop
304 if (HAVE_call_pop && HAVE_call_value_pop)
307 rtx n_pop = GEN_INT (n_popped);
310 /* If this subroutine pops its own args, record that in the call insn
311 if possible, for the sake of frame pointer elimination. */
314 pat = GEN_CALL_VALUE_POP (valreg,
315 gen_rtx_MEM (FUNCTION_MODE, funexp),
316 rounded_stack_size_rtx, next_arg_reg, n_pop);
318 pat = GEN_CALL_POP (gen_rtx_MEM (FUNCTION_MODE, funexp),
319 rounded_stack_size_rtx, next_arg_reg, n_pop);
321 emit_call_insn (pat);
327 #if defined (HAVE_sibcall) && defined (HAVE_sibcall_value)
328 if ((ecf_flags & ECF_SIBCALL)
329 && HAVE_sibcall && HAVE_sibcall_value)
332 emit_call_insn (GEN_SIBCALL_VALUE (valreg,
333 gen_rtx_MEM (FUNCTION_MODE, funexp),
334 rounded_stack_size_rtx,
335 next_arg_reg, NULL_RTX));
337 emit_call_insn (GEN_SIBCALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
338 rounded_stack_size_rtx, next_arg_reg,
339 struct_value_size_rtx));
344 #if defined (HAVE_call) && defined (HAVE_call_value)
345 if (HAVE_call && HAVE_call_value)
348 emit_call_insn (GEN_CALL_VALUE (valreg,
349 gen_rtx_MEM (FUNCTION_MODE, funexp),
350 rounded_stack_size_rtx, next_arg_reg,
353 emit_call_insn (GEN_CALL (gen_rtx_MEM (FUNCTION_MODE, funexp),
354 rounded_stack_size_rtx, next_arg_reg,
355 struct_value_size_rtx));
361 /* Find the call we just emitted. */
362 call_insn = last_call_insn ();
364 /* Put the register usage information there. */
365 add_function_usage_to (call_insn, call_fusage);
367 /* If this is a const call, then set the insn's unchanging bit. */
368 if (ecf_flags & ECF_CONST)
369 RTL_CONST_CALL_P (call_insn) = 1;
371 /* If this is a pure call, then set the insn's unchanging bit. */
372 if (ecf_flags & ECF_PURE)
373 RTL_PURE_CALL_P (call_insn) = 1;
375 /* If this is a const call, then set the insn's unchanging bit. */
376 if (ecf_flags & ECF_LOOPING_CONST_OR_PURE)
377 RTL_LOOPING_CONST_OR_PURE_CALL_P (call_insn) = 1;
379 /* Create a nothrow REG_EH_REGION note, if needed. */
380 make_reg_eh_region_note (call_insn, ecf_flags, 0);
382 if (ecf_flags & ECF_NORETURN)
383 add_reg_note (call_insn, REG_NORETURN, const0_rtx);
385 if (ecf_flags & ECF_RETURNS_TWICE)
387 add_reg_note (call_insn, REG_SETJMP, const0_rtx);
388 cfun->calls_setjmp = 1;
391 SIBLING_CALL_P (call_insn) = ((ecf_flags & ECF_SIBCALL) != 0);
393 /* Restore this now, so that we do defer pops for this call's args
394 if the context of the call as a whole permits. */
395 inhibit_defer_pop = old_inhibit_defer_pop;
400 CALL_INSN_FUNCTION_USAGE (call_insn)
401 = gen_rtx_EXPR_LIST (VOIDmode,
402 gen_rtx_CLOBBER (VOIDmode, stack_pointer_rtx),
403 CALL_INSN_FUNCTION_USAGE (call_insn));
404 rounded_stack_size -= n_popped;
405 rounded_stack_size_rtx = GEN_INT (rounded_stack_size);
406 stack_pointer_delta -= n_popped;
408 /* If popup is needed, stack realign must use DRAP */
409 if (SUPPORTS_STACK_ALIGNMENT)
410 crtl->need_drap = true;
413 if (!ACCUMULATE_OUTGOING_ARGS)
415 /* If returning from the subroutine does not automatically pop the args,
416 we need an instruction to pop them sooner or later.
417 Perhaps do it now; perhaps just record how much space to pop later.
419 If returning from the subroutine does pop the args, indicate that the
420 stack pointer will be changed. */
422 if (rounded_stack_size != 0)
424 if (ecf_flags & ECF_NORETURN)
425 /* Just pretend we did the pop. */
426 stack_pointer_delta -= rounded_stack_size;
427 else if (flag_defer_pop && inhibit_defer_pop == 0
428 && ! (ecf_flags & (ECF_CONST | ECF_PURE)))
429 pending_stack_adjust += rounded_stack_size;
431 adjust_stack (rounded_stack_size_rtx);
434 /* When we accumulate outgoing args, we must avoid any stack manipulations.
435 Restore the stack pointer to its original value now. Usually
436 ACCUMULATE_OUTGOING_ARGS targets don't get here, but there are exceptions.
437 On i386 ACCUMULATE_OUTGOING_ARGS can be enabled on demand, and
438 popping variants of functions exist as well.
440 ??? We may optimize similar to defer_pop above, but it is
441 probably not worthwhile.
443 ??? It will be worthwhile to enable combine_stack_adjustments even for
446 anti_adjust_stack (GEN_INT (n_popped));
449 /* Determine if the function identified by NAME and FNDECL is one with
450 special properties we wish to know about.
452 For example, if the function might return more than one time (setjmp), then
453 set RETURNS_TWICE to a nonzero value.
455 Similarly set NORETURN if the function is in the longjmp family.
457 Set MAY_BE_ALLOCA for any memory allocation function that might allocate
458 space from the stack such as alloca. */
461 special_function_p (const_tree fndecl, int flags)
463 if (fndecl && DECL_NAME (fndecl)
464 && IDENTIFIER_LENGTH (DECL_NAME (fndecl)) <= 17
465 /* Exclude functions not at the file scope, or not `extern',
466 since they are not the magic functions we would otherwise
468 FIXME: this should be handled with attributes, not with this
469 hacky imitation of DECL_ASSEMBLER_NAME. It's (also) wrong
470 because you can declare fork() inside a function if you
472 && (DECL_CONTEXT (fndecl) == NULL_TREE
473 || TREE_CODE (DECL_CONTEXT (fndecl)) == TRANSLATION_UNIT_DECL)
474 && TREE_PUBLIC (fndecl))
476 const char *name = IDENTIFIER_POINTER (DECL_NAME (fndecl));
477 const char *tname = name;
479 /* We assume that alloca will always be called by name. It
480 makes no sense to pass it as a pointer-to-function to
481 anything that does not understand its behavior. */
482 if (((IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 6
484 && ! strcmp (name, "alloca"))
485 || (IDENTIFIER_LENGTH (DECL_NAME (fndecl)) == 16
487 && ! strcmp (name, "__builtin_alloca"))))
488 flags |= ECF_MAY_BE_ALLOCA;
490 /* Disregard prefix _, __, __x or __builtin_. */
495 && !strncmp (name + 3, "uiltin_", 7))
497 else if (name[1] == '_' && name[2] == 'x')
499 else if (name[1] == '_')
508 && (! strcmp (tname, "setjmp")
509 || ! strcmp (tname, "setjmp_syscall")))
511 && ! strcmp (tname, "sigsetjmp"))
513 && ! strcmp (tname, "savectx")))
514 flags |= ECF_RETURNS_TWICE;
517 && ! strcmp (tname, "siglongjmp"))
518 flags |= ECF_NORETURN;
520 else if ((tname[0] == 'q' && tname[1] == 's'
521 && ! strcmp (tname, "qsetjmp"))
522 || (tname[0] == 'v' && tname[1] == 'f'
523 && ! strcmp (tname, "vfork"))
524 || (tname[0] == 'g' && tname[1] == 'e'
525 && !strcmp (tname, "getcontext")))
526 flags |= ECF_RETURNS_TWICE;
528 else if (tname[0] == 'l' && tname[1] == 'o'
529 && ! strcmp (tname, "longjmp"))
530 flags |= ECF_NORETURN;
536 /* Return nonzero when FNDECL represents a call to setjmp. */
539 setjmp_call_p (const_tree fndecl)
541 return special_function_p (fndecl, 0) & ECF_RETURNS_TWICE;
545 /* Return true if STMT is an alloca call. */
548 gimple_alloca_call_p (const_gimple stmt)
552 if (!is_gimple_call (stmt))
555 fndecl = gimple_call_fndecl (stmt);
556 if (fndecl && (special_function_p (fndecl, 0) & ECF_MAY_BE_ALLOCA))
562 /* Return true when exp contains alloca call. */
565 alloca_call_p (const_tree exp)
567 if (TREE_CODE (exp) == CALL_EXPR
568 && TREE_CODE (CALL_EXPR_FN (exp)) == ADDR_EXPR
569 && (TREE_CODE (TREE_OPERAND (CALL_EXPR_FN (exp), 0)) == FUNCTION_DECL)
570 && (special_function_p (TREE_OPERAND (CALL_EXPR_FN (exp), 0), 0)
571 & ECF_MAY_BE_ALLOCA))
576 /* Detect flags (function attributes) from the function decl or type node. */
579 flags_from_decl_or_type (const_tree exp)
582 const_tree type = exp;
586 type = TREE_TYPE (exp);
588 /* The function exp may have the `malloc' attribute. */
589 if (DECL_IS_MALLOC (exp))
592 /* The function exp may have the `returns_twice' attribute. */
593 if (DECL_IS_RETURNS_TWICE (exp))
594 flags |= ECF_RETURNS_TWICE;
596 /* Process the pure and const attributes. */
597 if (TREE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
599 if (DECL_PURE_P (exp))
601 if (DECL_LOOPING_CONST_OR_PURE_P (exp))
602 flags |= ECF_LOOPING_CONST_OR_PURE;
604 if (DECL_IS_NOVOPS (exp))
607 if (TREE_NOTHROW (exp))
608 flags |= ECF_NOTHROW;
610 flags = special_function_p (exp, flags);
612 else if (TYPE_P (exp) && TYPE_READONLY (exp) && ! TREE_THIS_VOLATILE (exp))
615 if (TREE_THIS_VOLATILE (exp))
616 flags |= ECF_NORETURN;
621 /* Detect flags from a CALL_EXPR. */
624 call_expr_flags (const_tree t)
627 tree decl = get_callee_fndecl (t);
630 flags = flags_from_decl_or_type (decl);
633 t = TREE_TYPE (CALL_EXPR_FN (t));
634 if (t && TREE_CODE (t) == POINTER_TYPE)
635 flags = flags_from_decl_or_type (TREE_TYPE (t));
643 /* Precompute all register parameters as described by ARGS, storing values
644 into fields within the ARGS array.
646 NUM_ACTUALS indicates the total number elements in the ARGS array.
648 Set REG_PARM_SEEN if we encounter a register parameter. */
651 precompute_register_parameters (int num_actuals, struct arg_data *args,
658 for (i = 0; i < num_actuals; i++)
659 if (args[i].reg != 0 && ! args[i].pass_on_stack)
663 if (args[i].value == 0)
666 args[i].value = expand_normal (args[i].tree_value);
667 preserve_temp_slots (args[i].value);
671 /* If the value is a non-legitimate constant, force it into a
672 pseudo now. TLS symbols sometimes need a call to resolve. */
673 if (CONSTANT_P (args[i].value)
674 && !LEGITIMATE_CONSTANT_P (args[i].value))
675 args[i].value = force_reg (args[i].mode, args[i].value);
677 /* If we are to promote the function arg to a wider mode,
680 if (args[i].mode != TYPE_MODE (TREE_TYPE (args[i].tree_value)))
682 = convert_modes (args[i].mode,
683 TYPE_MODE (TREE_TYPE (args[i].tree_value)),
684 args[i].value, args[i].unsignedp);
686 /* If we're going to have to load the value by parts, pull the
687 parts into pseudos. The part extraction process can involve
688 non-trivial computation. */
689 if (GET_CODE (args[i].reg) == PARALLEL)
691 tree type = TREE_TYPE (args[i].tree_value);
692 args[i].parallel_value
693 = emit_group_load_into_temps (args[i].reg, args[i].value,
694 type, int_size_in_bytes (type));
697 /* If the value is expensive, and we are inside an appropriately
698 short loop, put the value into a pseudo and then put the pseudo
701 For small register classes, also do this if this call uses
702 register parameters. This is to avoid reload conflicts while
703 loading the parameters registers. */
705 else if ((! (REG_P (args[i].value)
706 || (GET_CODE (args[i].value) == SUBREG
707 && REG_P (SUBREG_REG (args[i].value)))))
708 && args[i].mode != BLKmode
709 && rtx_cost (args[i].value, SET, optimize_insn_for_speed_p ())
711 && ((SMALL_REGISTER_CLASSES && *reg_parm_seen)
713 args[i].value = copy_to_mode_reg (args[i].mode, args[i].value);
717 #ifdef REG_PARM_STACK_SPACE
719 /* The argument list is the property of the called routine and it
720 may clobber it. If the fixed area has been used for previous
721 parameters, we must save and restore it. */
724 save_fixed_argument_area (int reg_parm_stack_space, rtx argblock, int *low_to_save, int *high_to_save)
729 /* Compute the boundary of the area that needs to be saved, if any. */
730 high = reg_parm_stack_space;
731 #ifdef ARGS_GROW_DOWNWARD
734 if (high > highest_outgoing_arg_in_use)
735 high = highest_outgoing_arg_in_use;
737 for (low = 0; low < high; low++)
738 if (stack_usage_map[low] != 0)
741 enum machine_mode save_mode;
746 while (stack_usage_map[--high] == 0)
750 *high_to_save = high;
752 num_to_save = high - low + 1;
753 save_mode = mode_for_size (num_to_save * BITS_PER_UNIT, MODE_INT, 1);
755 /* If we don't have the required alignment, must do this
757 if ((low & (MIN (GET_MODE_SIZE (save_mode),
758 BIGGEST_ALIGNMENT / UNITS_PER_WORD) - 1)))
761 #ifdef ARGS_GROW_DOWNWARD
766 stack_area = gen_rtx_MEM (save_mode,
767 memory_address (save_mode,
768 plus_constant (argblock,
771 set_mem_align (stack_area, PARM_BOUNDARY);
772 if (save_mode == BLKmode)
774 save_area = assign_stack_temp (BLKmode, num_to_save, 0);
775 emit_block_move (validize_mem (save_area), stack_area,
776 GEN_INT (num_to_save), BLOCK_OP_CALL_PARM);
780 save_area = gen_reg_rtx (save_mode);
781 emit_move_insn (save_area, stack_area);
791 restore_fixed_argument_area (rtx save_area, rtx argblock, int high_to_save, int low_to_save)
793 enum machine_mode save_mode = GET_MODE (save_area);
797 #ifdef ARGS_GROW_DOWNWARD
798 delta = -high_to_save;
802 stack_area = gen_rtx_MEM (save_mode,
803 memory_address (save_mode,
804 plus_constant (argblock, delta)));
805 set_mem_align (stack_area, PARM_BOUNDARY);
807 if (save_mode != BLKmode)
808 emit_move_insn (stack_area, save_area);
810 emit_block_move (stack_area, validize_mem (save_area),
811 GEN_INT (high_to_save - low_to_save + 1),
814 #endif /* REG_PARM_STACK_SPACE */
816 /* If any elements in ARGS refer to parameters that are to be passed in
817 registers, but not in memory, and whose alignment does not permit a
818 direct copy into registers. Copy the values into a group of pseudos
819 which we will later copy into the appropriate hard registers.
821 Pseudos for each unaligned argument will be stored into the array
822 args[argnum].aligned_regs. The caller is responsible for deallocating
823 the aligned_regs array if it is nonzero. */
826 store_unaligned_arguments_into_pseudos (struct arg_data *args, int num_actuals)
830 for (i = 0; i < num_actuals; i++)
831 if (args[i].reg != 0 && ! args[i].pass_on_stack
832 && args[i].mode == BLKmode
833 && MEM_P (args[i].value)
834 && (MEM_ALIGN (args[i].value)
835 < (unsigned int) MIN (BIGGEST_ALIGNMENT, BITS_PER_WORD)))
837 int bytes = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
838 int endian_correction = 0;
842 gcc_assert (args[i].partial % UNITS_PER_WORD == 0);
843 args[i].n_aligned_regs = args[i].partial / UNITS_PER_WORD;
847 args[i].n_aligned_regs
848 = (bytes + UNITS_PER_WORD - 1) / UNITS_PER_WORD;
851 args[i].aligned_regs = XNEWVEC (rtx, args[i].n_aligned_regs);
853 /* Structures smaller than a word are normally aligned to the
854 least significant byte. On a BYTES_BIG_ENDIAN machine,
855 this means we must skip the empty high order bytes when
856 calculating the bit offset. */
857 if (bytes < UNITS_PER_WORD
858 #ifdef BLOCK_REG_PADDING
859 && (BLOCK_REG_PADDING (args[i].mode,
860 TREE_TYPE (args[i].tree_value), 1)
866 endian_correction = BITS_PER_WORD - bytes * BITS_PER_UNIT;
868 for (j = 0; j < args[i].n_aligned_regs; j++)
870 rtx reg = gen_reg_rtx (word_mode);
871 rtx word = operand_subword_force (args[i].value, j, BLKmode);
872 int bitsize = MIN (bytes * BITS_PER_UNIT, BITS_PER_WORD);
874 args[i].aligned_regs[j] = reg;
875 word = extract_bit_field (word, bitsize, 0, 1, NULL_RTX,
876 word_mode, word_mode);
878 /* There is no need to restrict this code to loading items
879 in TYPE_ALIGN sized hunks. The bitfield instructions can
880 load up entire word sized registers efficiently.
882 ??? This may not be needed anymore.
883 We use to emit a clobber here but that doesn't let later
884 passes optimize the instructions we emit. By storing 0 into
885 the register later passes know the first AND to zero out the
886 bitfield being set in the register is unnecessary. The store
887 of 0 will be deleted as will at least the first AND. */
889 emit_move_insn (reg, const0_rtx);
891 bytes -= bitsize / BITS_PER_UNIT;
892 store_bit_field (reg, bitsize, endian_correction, word_mode,
898 /* Fill in ARGS_SIZE and ARGS array based on the parameters found in
901 NUM_ACTUALS is the total number of parameters.
903 N_NAMED_ARGS is the total number of named arguments.
905 STRUCT_VALUE_ADDR_VALUE is the implicit argument for a struct return
908 FNDECL is the tree code for the target of this call (if known)
910 ARGS_SO_FAR holds state needed by the target to know where to place
913 REG_PARM_STACK_SPACE is the number of bytes of stack space reserved
914 for arguments which are passed in registers.
916 OLD_STACK_LEVEL is a pointer to an rtx which olds the old stack level
917 and may be modified by this routine.
919 OLD_PENDING_ADJ, MUST_PREALLOCATE and FLAGS are pointers to integer
920 flags which may may be modified by this routine.
922 MAY_TAILCALL is cleared if we encounter an invisible pass-by-reference
923 that requires allocation of stack space.
925 CALL_FROM_THUNK_P is true if this call is the jump from a thunk to
926 the thunked-to function. */
929 initialize_argument_information (int num_actuals ATTRIBUTE_UNUSED,
930 struct arg_data *args,
931 struct args_size *args_size,
932 int n_named_args ATTRIBUTE_UNUSED,
933 tree exp, tree struct_value_addr_value,
934 tree fndecl, tree fntype,
935 CUMULATIVE_ARGS *args_so_far,
936 int reg_parm_stack_space,
937 rtx *old_stack_level, int *old_pending_adj,
938 int *must_preallocate, int *ecf_flags,
939 bool *may_tailcall, bool call_from_thunk_p)
941 location_t loc = EXPR_LOCATION (exp);
942 /* 1 if scanning parms front to back, -1 if scanning back to front. */
945 /* Count arg position in order args appear. */
950 args_size->constant = 0;
953 /* In this loop, we consider args in the order they are written.
954 We fill up ARGS from the front or from the back if necessary
955 so that in any case the first arg to be pushed ends up at the front. */
957 if (PUSH_ARGS_REVERSED)
959 i = num_actuals - 1, inc = -1;
960 /* In this case, must reverse order of args
961 so that we compute and push the last arg first. */
968 /* First fill in the actual arguments in the ARGS array, splitting
969 complex arguments if necessary. */
972 call_expr_arg_iterator iter;
975 if (struct_value_addr_value)
977 args[j].tree_value = struct_value_addr_value;
980 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
982 tree argtype = TREE_TYPE (arg);
983 if (targetm.calls.split_complex_arg
985 && TREE_CODE (argtype) == COMPLEX_TYPE
986 && targetm.calls.split_complex_arg (argtype))
988 tree subtype = TREE_TYPE (argtype);
989 args[j].tree_value = build1 (REALPART_EXPR, subtype, arg);
991 args[j].tree_value = build1 (IMAGPART_EXPR, subtype, arg);
994 args[j].tree_value = arg;
999 /* I counts args in order (to be) pushed; ARGPOS counts in order written. */
1000 for (argpos = 0; argpos < num_actuals; i += inc, argpos++)
1002 tree type = TREE_TYPE (args[i].tree_value);
1004 enum machine_mode mode;
1006 /* Replace erroneous argument with constant zero. */
1007 if (type == error_mark_node || !COMPLETE_TYPE_P (type))
1008 args[i].tree_value = integer_zero_node, type = integer_type_node;
1010 /* If TYPE is a transparent union, pass things the way we would
1011 pass the first field of the union. We have already verified that
1012 the modes are the same. */
1013 if (TREE_CODE (type) == UNION_TYPE && TYPE_TRANSPARENT_UNION (type))
1014 type = TREE_TYPE (TYPE_FIELDS (type));
1016 /* Decide where to pass this arg.
1018 args[i].reg is nonzero if all or part is passed in registers.
1020 args[i].partial is nonzero if part but not all is passed in registers,
1021 and the exact value says how many bytes are passed in registers.
1023 args[i].pass_on_stack is nonzero if the argument must at least be
1024 computed on the stack. It may then be loaded back into registers
1025 if args[i].reg is nonzero.
1027 These decisions are driven by the FUNCTION_... macros and must agree
1028 with those made by function.c. */
1030 /* See if this argument should be passed by invisible reference. */
1031 if (pass_by_reference (args_so_far, TYPE_MODE (type),
1032 type, argpos < n_named_args))
1038 = reference_callee_copied (args_so_far, TYPE_MODE (type),
1039 type, argpos < n_named_args);
1041 /* If we're compiling a thunk, pass through invisible references
1042 instead of making a copy. */
1043 if (call_from_thunk_p
1045 && !TREE_ADDRESSABLE (type)
1046 && (base = get_base_address (args[i].tree_value))
1047 && TREE_CODE (base) != SSA_NAME
1048 && (!DECL_P (base) || MEM_P (DECL_RTL (base)))))
1050 /* We can't use sibcalls if a callee-copied argument is
1051 stored in the current function's frame. */
1052 if (!call_from_thunk_p && DECL_P (base) && !TREE_STATIC (base))
1053 *may_tailcall = false;
1055 args[i].tree_value = build_fold_addr_expr_loc (loc,
1056 args[i].tree_value);
1057 type = TREE_TYPE (args[i].tree_value);
1059 if (*ecf_flags & ECF_CONST)
1060 *ecf_flags &= ~(ECF_CONST | ECF_LOOPING_CONST_OR_PURE);
1064 /* We make a copy of the object and pass the address to the
1065 function being called. */
1068 if (!COMPLETE_TYPE_P (type)
1069 || TREE_CODE (TYPE_SIZE_UNIT (type)) != INTEGER_CST
1070 || (flag_stack_check == GENERIC_STACK_CHECK
1071 && compare_tree_int (TYPE_SIZE_UNIT (type),
1072 STACK_CHECK_MAX_VAR_SIZE) > 0))
1074 /* This is a variable-sized object. Make space on the stack
1076 rtx size_rtx = expr_size (args[i].tree_value);
1078 if (*old_stack_level == 0)
1080 emit_stack_save (SAVE_BLOCK, old_stack_level, NULL_RTX);
1081 *old_pending_adj = pending_stack_adjust;
1082 pending_stack_adjust = 0;
1085 copy = gen_rtx_MEM (BLKmode,
1086 allocate_dynamic_stack_space
1087 (size_rtx, NULL_RTX, TYPE_ALIGN (type)));
1088 set_mem_attributes (copy, type, 1);
1091 copy = assign_temp (type, 0, 1, 0);
1093 store_expr (args[i].tree_value, copy, 0, false);
1095 /* Just change the const function to pure and then let
1096 the next test clear the pure based on
1098 if (*ecf_flags & ECF_CONST)
1100 *ecf_flags &= ~ECF_CONST;
1101 *ecf_flags |= ECF_PURE;
1104 if (!callee_copies && *ecf_flags & ECF_PURE)
1105 *ecf_flags &= ~(ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
1108 = build_fold_addr_expr_loc (loc, make_tree (type, copy));
1109 type = TREE_TYPE (args[i].tree_value);
1110 *may_tailcall = false;
1114 unsignedp = TYPE_UNSIGNED (type);
1115 mode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
1116 fndecl ? TREE_TYPE (fndecl) : fntype, 0);
1118 args[i].unsignedp = unsignedp;
1119 args[i].mode = mode;
1121 args[i].reg = FUNCTION_ARG (*args_so_far, mode, type,
1122 argpos < n_named_args);
1123 #ifdef FUNCTION_INCOMING_ARG
1124 /* If this is a sibling call and the machine has register windows, the
1125 register window has to be unwinded before calling the routine, so
1126 arguments have to go into the incoming registers. */
1127 args[i].tail_call_reg = FUNCTION_INCOMING_ARG (*args_so_far, mode, type,
1128 argpos < n_named_args);
1130 args[i].tail_call_reg = args[i].reg;
1135 = targetm.calls.arg_partial_bytes (args_so_far, mode, type,
1136 argpos < n_named_args);
1138 args[i].pass_on_stack = targetm.calls.must_pass_in_stack (mode, type);
1140 /* If FUNCTION_ARG returned a (parallel [(expr_list (nil) ...) ...]),
1141 it means that we are to pass this arg in the register(s) designated
1142 by the PARALLEL, but also to pass it in the stack. */
1143 if (args[i].reg && GET_CODE (args[i].reg) == PARALLEL
1144 && XEXP (XVECEXP (args[i].reg, 0, 0), 0) == 0)
1145 args[i].pass_on_stack = 1;
1147 /* If this is an addressable type, we must preallocate the stack
1148 since we must evaluate the object into its final location.
1150 If this is to be passed in both registers and the stack, it is simpler
1152 if (TREE_ADDRESSABLE (type)
1153 || (args[i].pass_on_stack && args[i].reg != 0))
1154 *must_preallocate = 1;
1156 /* Compute the stack-size of this argument. */
1157 if (args[i].reg == 0 || args[i].partial != 0
1158 || reg_parm_stack_space > 0
1159 || args[i].pass_on_stack)
1160 locate_and_pad_parm (mode, type,
1161 #ifdef STACK_PARMS_IN_REG_PARM_AREA
1166 args[i].pass_on_stack ? 0 : args[i].partial,
1167 fndecl, args_size, &args[i].locate);
1168 #ifdef BLOCK_REG_PADDING
1170 /* The argument is passed entirely in registers. See at which
1171 end it should be padded. */
1172 args[i].locate.where_pad =
1173 BLOCK_REG_PADDING (mode, type,
1174 int_size_in_bytes (type) <= UNITS_PER_WORD);
1177 /* Update ARGS_SIZE, the total stack space for args so far. */
1179 args_size->constant += args[i].locate.size.constant;
1180 if (args[i].locate.size.var)
1181 ADD_PARM_SIZE (*args_size, args[i].locate.size.var);
1183 /* Increment ARGS_SO_FAR, which has info about which arg-registers
1184 have been used, etc. */
1186 FUNCTION_ARG_ADVANCE (*args_so_far, TYPE_MODE (type), type,
1187 argpos < n_named_args);
1191 /* Update ARGS_SIZE to contain the total size for the argument block.
1192 Return the original constant component of the argument block's size.
1194 REG_PARM_STACK_SPACE holds the number of bytes of stack space reserved
1195 for arguments passed in registers. */
1198 compute_argument_block_size (int reg_parm_stack_space,
1199 struct args_size *args_size,
1200 tree fndecl ATTRIBUTE_UNUSED,
1201 tree fntype ATTRIBUTE_UNUSED,
1202 int preferred_stack_boundary ATTRIBUTE_UNUSED)
1204 int unadjusted_args_size = args_size->constant;
1206 /* For accumulate outgoing args mode we don't need to align, since the frame
1207 will be already aligned. Align to STACK_BOUNDARY in order to prevent
1208 backends from generating misaligned frame sizes. */
1209 if (ACCUMULATE_OUTGOING_ARGS && preferred_stack_boundary > STACK_BOUNDARY)
1210 preferred_stack_boundary = STACK_BOUNDARY;
1212 /* Compute the actual size of the argument block required. The variable
1213 and constant sizes must be combined, the size may have to be rounded,
1214 and there may be a minimum required size. */
1218 args_size->var = ARGS_SIZE_TREE (*args_size);
1219 args_size->constant = 0;
1221 preferred_stack_boundary /= BITS_PER_UNIT;
1222 if (preferred_stack_boundary > 1)
1224 /* We don't handle this case yet. To handle it correctly we have
1225 to add the delta, round and subtract the delta.
1226 Currently no machine description requires this support. */
1227 gcc_assert (!(stack_pointer_delta & (preferred_stack_boundary - 1)));
1228 args_size->var = round_up (args_size->var, preferred_stack_boundary);
1231 if (reg_parm_stack_space > 0)
1234 = size_binop (MAX_EXPR, args_size->var,
1235 ssize_int (reg_parm_stack_space));
1237 /* The area corresponding to register parameters is not to count in
1238 the size of the block we need. So make the adjustment. */
1239 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1241 = size_binop (MINUS_EXPR, args_size->var,
1242 ssize_int (reg_parm_stack_space));
1247 preferred_stack_boundary /= BITS_PER_UNIT;
1248 if (preferred_stack_boundary < 1)
1249 preferred_stack_boundary = 1;
1250 args_size->constant = (((args_size->constant
1251 + stack_pointer_delta
1252 + preferred_stack_boundary - 1)
1253 / preferred_stack_boundary
1254 * preferred_stack_boundary)
1255 - stack_pointer_delta);
1257 args_size->constant = MAX (args_size->constant,
1258 reg_parm_stack_space);
1260 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
1261 args_size->constant -= reg_parm_stack_space;
1263 return unadjusted_args_size;
1266 /* Precompute parameters as needed for a function call.
1268 FLAGS is mask of ECF_* constants.
1270 NUM_ACTUALS is the number of arguments.
1272 ARGS is an array containing information for each argument; this
1273 routine fills in the INITIAL_VALUE and VALUE fields for each
1274 precomputed argument. */
1277 precompute_arguments (int num_actuals, struct arg_data *args)
1281 /* If this is a libcall, then precompute all arguments so that we do not
1282 get extraneous instructions emitted as part of the libcall sequence. */
1284 /* If we preallocated the stack space, and some arguments must be passed
1285 on the stack, then we must precompute any parameter which contains a
1286 function call which will store arguments on the stack.
1287 Otherwise, evaluating the parameter may clobber previous parameters
1288 which have already been stored into the stack. (we have code to avoid
1289 such case by saving the outgoing stack arguments, but it results in
1291 if (!ACCUMULATE_OUTGOING_ARGS)
1294 for (i = 0; i < num_actuals; i++)
1297 enum machine_mode mode;
1299 if (TREE_CODE (args[i].tree_value) != CALL_EXPR)
1302 /* If this is an addressable type, we cannot pre-evaluate it. */
1303 type = TREE_TYPE (args[i].tree_value);
1304 gcc_assert (!TREE_ADDRESSABLE (type));
1306 args[i].initial_value = args[i].value
1307 = expand_normal (args[i].tree_value);
1309 mode = TYPE_MODE (type);
1310 if (mode != args[i].mode)
1312 int unsignedp = args[i].unsignedp;
1314 = convert_modes (args[i].mode, mode,
1315 args[i].value, args[i].unsignedp);
1317 /* CSE will replace this only if it contains args[i].value
1318 pseudo, so convert it down to the declared mode using
1320 if (REG_P (args[i].value)
1321 && GET_MODE_CLASS (args[i].mode) == MODE_INT
1322 && promote_mode (type, mode, &unsignedp) != args[i].mode)
1324 args[i].initial_value
1325 = gen_lowpart_SUBREG (mode, args[i].value);
1326 SUBREG_PROMOTED_VAR_P (args[i].initial_value) = 1;
1327 SUBREG_PROMOTED_UNSIGNED_SET (args[i].initial_value,
1334 /* Given the current state of MUST_PREALLOCATE and information about
1335 arguments to a function call in NUM_ACTUALS, ARGS and ARGS_SIZE,
1336 compute and return the final value for MUST_PREALLOCATE. */
1339 finalize_must_preallocate (int must_preallocate, int num_actuals,
1340 struct arg_data *args, struct args_size *args_size)
1342 /* See if we have or want to preallocate stack space.
1344 If we would have to push a partially-in-regs parm
1345 before other stack parms, preallocate stack space instead.
1347 If the size of some parm is not a multiple of the required stack
1348 alignment, we must preallocate.
1350 If the total size of arguments that would otherwise create a copy in
1351 a temporary (such as a CALL) is more than half the total argument list
1352 size, preallocation is faster.
1354 Another reason to preallocate is if we have a machine (like the m88k)
1355 where stack alignment is required to be maintained between every
1356 pair of insns, not just when the call is made. However, we assume here
1357 that such machines either do not have push insns (and hence preallocation
1358 would occur anyway) or the problem is taken care of with
1361 if (! must_preallocate)
1363 int partial_seen = 0;
1364 int copy_to_evaluate_size = 0;
1367 for (i = 0; i < num_actuals && ! must_preallocate; i++)
1369 if (args[i].partial > 0 && ! args[i].pass_on_stack)
1371 else if (partial_seen && args[i].reg == 0)
1372 must_preallocate = 1;
1374 if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode
1375 && (TREE_CODE (args[i].tree_value) == CALL_EXPR
1376 || TREE_CODE (args[i].tree_value) == TARGET_EXPR
1377 || TREE_CODE (args[i].tree_value) == COND_EXPR
1378 || TREE_ADDRESSABLE (TREE_TYPE (args[i].tree_value))))
1379 copy_to_evaluate_size
1380 += int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1383 if (copy_to_evaluate_size * 2 >= args_size->constant
1384 && args_size->constant > 0)
1385 must_preallocate = 1;
1387 return must_preallocate;
1390 /* If we preallocated stack space, compute the address of each argument
1391 and store it into the ARGS array.
1393 We need not ensure it is a valid memory address here; it will be
1394 validized when it is used.
1396 ARGBLOCK is an rtx for the address of the outgoing arguments. */
1399 compute_argument_addresses (struct arg_data *args, rtx argblock, int num_actuals)
1403 rtx arg_reg = argblock;
1404 int i, arg_offset = 0;
1406 if (GET_CODE (argblock) == PLUS)
1407 arg_reg = XEXP (argblock, 0), arg_offset = INTVAL (XEXP (argblock, 1));
1409 for (i = 0; i < num_actuals; i++)
1411 rtx offset = ARGS_SIZE_RTX (args[i].locate.offset);
1412 rtx slot_offset = ARGS_SIZE_RTX (args[i].locate.slot_offset);
1414 unsigned int align, boundary;
1415 unsigned int units_on_stack = 0;
1416 enum machine_mode partial_mode = VOIDmode;
1418 /* Skip this parm if it will not be passed on the stack. */
1419 if (! args[i].pass_on_stack
1421 && args[i].partial == 0)
1424 if (CONST_INT_P (offset))
1425 addr = plus_constant (arg_reg, INTVAL (offset));
1427 addr = gen_rtx_PLUS (Pmode, arg_reg, offset);
1429 addr = plus_constant (addr, arg_offset);
1431 if (args[i].partial != 0)
1433 /* Only part of the parameter is being passed on the stack.
1434 Generate a simple memory reference of the correct size. */
1435 units_on_stack = args[i].locate.size.constant;
1436 partial_mode = mode_for_size (units_on_stack * BITS_PER_UNIT,
1438 args[i].stack = gen_rtx_MEM (partial_mode, addr);
1439 set_mem_size (args[i].stack, GEN_INT (units_on_stack));
1443 args[i].stack = gen_rtx_MEM (args[i].mode, addr);
1444 set_mem_attributes (args[i].stack,
1445 TREE_TYPE (args[i].tree_value), 1);
1447 align = BITS_PER_UNIT;
1448 boundary = args[i].locate.boundary;
1449 if (args[i].locate.where_pad != downward)
1451 else if (CONST_INT_P (offset))
1453 align = INTVAL (offset) * BITS_PER_UNIT | boundary;
1454 align = align & -align;
1456 set_mem_align (args[i].stack, align);
1458 if (CONST_INT_P (slot_offset))
1459 addr = plus_constant (arg_reg, INTVAL (slot_offset));
1461 addr = gen_rtx_PLUS (Pmode, arg_reg, slot_offset);
1463 addr = plus_constant (addr, arg_offset);
1465 if (args[i].partial != 0)
1467 /* Only part of the parameter is being passed on the stack.
1468 Generate a simple memory reference of the correct size.
1470 args[i].stack_slot = gen_rtx_MEM (partial_mode, addr);
1471 set_mem_size (args[i].stack_slot, GEN_INT (units_on_stack));
1475 args[i].stack_slot = gen_rtx_MEM (args[i].mode, addr);
1476 set_mem_attributes (args[i].stack_slot,
1477 TREE_TYPE (args[i].tree_value), 1);
1479 set_mem_align (args[i].stack_slot, args[i].locate.boundary);
1481 /* Function incoming arguments may overlap with sibling call
1482 outgoing arguments and we cannot allow reordering of reads
1483 from function arguments with stores to outgoing arguments
1484 of sibling calls. */
1485 set_mem_alias_set (args[i].stack, 0);
1486 set_mem_alias_set (args[i].stack_slot, 0);
1491 /* Given a FNDECL and EXP, return an rtx suitable for use as a target address
1492 in a call instruction.
1494 FNDECL is the tree node for the target function. For an indirect call
1495 FNDECL will be NULL_TREE.
1497 ADDR is the operand 0 of CALL_EXPR for this call. */
1500 rtx_for_function_call (tree fndecl, tree addr)
1504 /* Get the function to call, in the form of RTL. */
1507 /* If this is the first use of the function, see if we need to
1508 make an external definition for it. */
1509 if (!TREE_USED (fndecl) && fndecl != current_function_decl)
1511 assemble_external (fndecl);
1512 TREE_USED (fndecl) = 1;
1515 /* Get a SYMBOL_REF rtx for the function address. */
1516 funexp = XEXP (DECL_RTL (fndecl), 0);
1519 /* Generate an rtx (probably a pseudo-register) for the address. */
1522 funexp = expand_normal (addr);
1523 pop_temp_slots (); /* FUNEXP can't be BLKmode. */
1528 /* Return true if and only if SIZE storage units (usually bytes)
1529 starting from address ADDR overlap with already clobbered argument
1530 area. This function is used to determine if we should give up a
1534 mem_overlaps_already_clobbered_arg_p (rtx addr, unsigned HOST_WIDE_INT size)
1538 if (addr == crtl->args.internal_arg_pointer)
1540 else if (GET_CODE (addr) == PLUS
1541 && XEXP (addr, 0) == crtl->args.internal_arg_pointer
1542 && CONST_INT_P (XEXP (addr, 1)))
1543 i = INTVAL (XEXP (addr, 1));
1544 /* Return true for arg pointer based indexed addressing. */
1545 else if (GET_CODE (addr) == PLUS
1546 && (XEXP (addr, 0) == crtl->args.internal_arg_pointer
1547 || XEXP (addr, 1) == crtl->args.internal_arg_pointer))
1552 #ifdef ARGS_GROW_DOWNWARD
1557 unsigned HOST_WIDE_INT k;
1559 for (k = 0; k < size; k++)
1560 if (i + k < stored_args_map->n_bits
1561 && TEST_BIT (stored_args_map, i + k))
1568 /* Do the register loads required for any wholly-register parms or any
1569 parms which are passed both on the stack and in a register. Their
1570 expressions were already evaluated.
1572 Mark all register-parms as living through the call, putting these USE
1573 insns in the CALL_INSN_FUNCTION_USAGE field.
1575 When IS_SIBCALL, perform the check_sibcall_argument_overlap
1576 checking, setting *SIBCALL_FAILURE if appropriate. */
1579 load_register_parameters (struct arg_data *args, int num_actuals,
1580 rtx *call_fusage, int flags, int is_sibcall,
1581 int *sibcall_failure)
1585 for (i = 0; i < num_actuals; i++)
1587 rtx reg = ((flags & ECF_SIBCALL)
1588 ? args[i].tail_call_reg : args[i].reg);
1591 int partial = args[i].partial;
1594 rtx before_arg = get_last_insn ();
1595 /* Set non-negative if we must move a word at a time, even if
1596 just one word (e.g, partial == 4 && mode == DFmode). Set
1597 to -1 if we just use a normal move insn. This value can be
1598 zero if the argument is a zero size structure. */
1600 if (GET_CODE (reg) == PARALLEL)
1604 gcc_assert (partial % UNITS_PER_WORD == 0);
1605 nregs = partial / UNITS_PER_WORD;
1607 else if (TYPE_MODE (TREE_TYPE (args[i].tree_value)) == BLKmode)
1609 size = int_size_in_bytes (TREE_TYPE (args[i].tree_value));
1610 nregs = (size + (UNITS_PER_WORD - 1)) / UNITS_PER_WORD;
1613 size = GET_MODE_SIZE (args[i].mode);
1615 /* Handle calls that pass values in multiple non-contiguous
1616 locations. The Irix 6 ABI has examples of this. */
1618 if (GET_CODE (reg) == PARALLEL)
1619 emit_group_move (reg, args[i].parallel_value);
1621 /* If simple case, just do move. If normal partial, store_one_arg
1622 has already loaded the register for us. In all other cases,
1623 load the register(s) from memory. */
1625 else if (nregs == -1)
1627 emit_move_insn (reg, args[i].value);
1628 #ifdef BLOCK_REG_PADDING
1629 /* Handle case where we have a value that needs shifting
1630 up to the msb. eg. a QImode value and we're padding
1631 upward on a BYTES_BIG_ENDIAN machine. */
1632 if (size < UNITS_PER_WORD
1633 && (args[i].locate.where_pad
1634 == (BYTES_BIG_ENDIAN ? upward : downward)))
1637 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1639 /* Assigning REG here rather than a temp makes CALL_FUSAGE
1640 report the whole reg as used. Strictly speaking, the
1641 call only uses SIZE bytes at the msb end, but it doesn't
1642 seem worth generating rtl to say that. */
1643 reg = gen_rtx_REG (word_mode, REGNO (reg));
1644 x = expand_shift (LSHIFT_EXPR, word_mode, reg,
1645 build_int_cst (NULL_TREE, shift),
1648 emit_move_insn (reg, x);
1653 /* If we have pre-computed the values to put in the registers in
1654 the case of non-aligned structures, copy them in now. */
1656 else if (args[i].n_aligned_regs != 0)
1657 for (j = 0; j < args[i].n_aligned_regs; j++)
1658 emit_move_insn (gen_rtx_REG (word_mode, REGNO (reg) + j),
1659 args[i].aligned_regs[j]);
1661 else if (partial == 0 || args[i].pass_on_stack)
1663 rtx mem = validize_mem (args[i].value);
1665 /* Check for overlap with already clobbered argument area. */
1667 && mem_overlaps_already_clobbered_arg_p (XEXP (args[i].value, 0),
1669 *sibcall_failure = 1;
1671 /* Handle a BLKmode that needs shifting. */
1672 if (nregs == 1 && size < UNITS_PER_WORD
1673 #ifdef BLOCK_REG_PADDING
1674 && args[i].locate.where_pad == downward
1680 rtx tem = operand_subword_force (mem, 0, args[i].mode);
1681 rtx ri = gen_rtx_REG (word_mode, REGNO (reg));
1682 rtx x = gen_reg_rtx (word_mode);
1683 int shift = (UNITS_PER_WORD - size) * BITS_PER_UNIT;
1684 enum tree_code dir = BYTES_BIG_ENDIAN ? RSHIFT_EXPR
1687 emit_move_insn (x, tem);
1688 x = expand_shift (dir, word_mode, x,
1689 build_int_cst (NULL_TREE, shift),
1692 emit_move_insn (ri, x);
1695 move_block_to_reg (REGNO (reg), mem, nregs, args[i].mode);
1698 /* When a parameter is a block, and perhaps in other cases, it is
1699 possible that it did a load from an argument slot that was
1700 already clobbered. */
1702 && check_sibcall_argument_overlap (before_arg, &args[i], 0))
1703 *sibcall_failure = 1;
1705 /* Handle calls that pass values in multiple non-contiguous
1706 locations. The Irix 6 ABI has examples of this. */
1707 if (GET_CODE (reg) == PARALLEL)
1708 use_group_regs (call_fusage, reg);
1709 else if (nregs == -1)
1710 use_reg (call_fusage, reg);
1712 use_regs (call_fusage, REGNO (reg), nregs);
1717 /* We need to pop PENDING_STACK_ADJUST bytes. But, if the arguments
1718 wouldn't fill up an even multiple of PREFERRED_UNIT_STACK_BOUNDARY
1719 bytes, then we would need to push some additional bytes to pad the
1720 arguments. So, we compute an adjust to the stack pointer for an
1721 amount that will leave the stack under-aligned by UNADJUSTED_ARGS_SIZE
1722 bytes. Then, when the arguments are pushed the stack will be perfectly
1723 aligned. ARGS_SIZE->CONSTANT is set to the number of bytes that should
1724 be popped after the call. Returns the adjustment. */
1727 combine_pending_stack_adjustment_and_call (int unadjusted_args_size,
1728 struct args_size *args_size,
1729 unsigned int preferred_unit_stack_boundary)
1731 /* The number of bytes to pop so that the stack will be
1732 under-aligned by UNADJUSTED_ARGS_SIZE bytes. */
1733 HOST_WIDE_INT adjustment;
1734 /* The alignment of the stack after the arguments are pushed, if we
1735 just pushed the arguments without adjust the stack here. */
1736 unsigned HOST_WIDE_INT unadjusted_alignment;
1738 unadjusted_alignment
1739 = ((stack_pointer_delta + unadjusted_args_size)
1740 % preferred_unit_stack_boundary);
1742 /* We want to get rid of as many of the PENDING_STACK_ADJUST bytes
1743 as possible -- leaving just enough left to cancel out the
1744 UNADJUSTED_ALIGNMENT. In other words, we want to ensure that the
1745 PENDING_STACK_ADJUST is non-negative, and congruent to
1746 -UNADJUSTED_ALIGNMENT modulo the PREFERRED_UNIT_STACK_BOUNDARY. */
1748 /* Begin by trying to pop all the bytes. */
1749 unadjusted_alignment
1750 = (unadjusted_alignment
1751 - (pending_stack_adjust % preferred_unit_stack_boundary));
1752 adjustment = pending_stack_adjust;
1753 /* Push enough additional bytes that the stack will be aligned
1754 after the arguments are pushed. */
1755 if (preferred_unit_stack_boundary > 1)
1757 if (unadjusted_alignment > 0)
1758 adjustment -= preferred_unit_stack_boundary - unadjusted_alignment;
1760 adjustment += unadjusted_alignment;
1763 /* Now, sets ARGS_SIZE->CONSTANT so that we pop the right number of
1764 bytes after the call. The right number is the entire
1765 PENDING_STACK_ADJUST less our ADJUSTMENT plus the amount required
1766 by the arguments in the first place. */
1768 = pending_stack_adjust - adjustment + unadjusted_args_size;
1773 /* Scan X expression if it does not dereference any argument slots
1774 we already clobbered by tail call arguments (as noted in stored_args_map
1776 Return nonzero if X expression dereferences such argument slots,
1780 check_sibcall_argument_overlap_1 (rtx x)
1789 code = GET_CODE (x);
1792 return mem_overlaps_already_clobbered_arg_p (XEXP (x, 0),
1793 GET_MODE_SIZE (GET_MODE (x)));
1795 /* Scan all subexpressions. */
1796 fmt = GET_RTX_FORMAT (code);
1797 for (i = 0; i < GET_RTX_LENGTH (code); i++, fmt++)
1801 if (check_sibcall_argument_overlap_1 (XEXP (x, i)))
1804 else if (*fmt == 'E')
1806 for (j = 0; j < XVECLEN (x, i); j++)
1807 if (check_sibcall_argument_overlap_1 (XVECEXP (x, i, j)))
1814 /* Scan sequence after INSN if it does not dereference any argument slots
1815 we already clobbered by tail call arguments (as noted in stored_args_map
1816 bitmap). If MARK_STORED_ARGS_MAP, add stack slots for ARG to
1817 stored_args_map bitmap afterwards (when ARG is a register MARK_STORED_ARGS_MAP
1818 should be 0). Return nonzero if sequence after INSN dereferences such argument
1819 slots, zero otherwise. */
1822 check_sibcall_argument_overlap (rtx insn, struct arg_data *arg, int mark_stored_args_map)
1826 if (insn == NULL_RTX)
1827 insn = get_insns ();
1829 insn = NEXT_INSN (insn);
1831 for (; insn; insn = NEXT_INSN (insn))
1833 && check_sibcall_argument_overlap_1 (PATTERN (insn)))
1836 if (mark_stored_args_map)
1838 #ifdef ARGS_GROW_DOWNWARD
1839 low = -arg->locate.slot_offset.constant - arg->locate.size.constant;
1841 low = arg->locate.slot_offset.constant;
1844 for (high = low + arg->locate.size.constant; low < high; low++)
1845 SET_BIT (stored_args_map, low);
1847 return insn != NULL_RTX;
1850 /* Given that a function returns a value of mode MODE at the most
1851 significant end of hard register VALUE, shift VALUE left or right
1852 as specified by LEFT_P. Return true if some action was needed. */
1855 shift_return_value (enum machine_mode mode, bool left_p, rtx value)
1857 HOST_WIDE_INT shift;
1859 gcc_assert (REG_P (value) && HARD_REGISTER_P (value));
1860 shift = GET_MODE_BITSIZE (GET_MODE (value)) - GET_MODE_BITSIZE (mode);
1864 /* Use ashr rather than lshr for right shifts. This is for the benefit
1865 of the MIPS port, which requires SImode values to be sign-extended
1866 when stored in 64-bit registers. */
1867 if (!force_expand_binop (GET_MODE (value), left_p ? ashl_optab : ashr_optab,
1868 value, GEN_INT (shift), value, 1, OPTAB_WIDEN))
1873 /* If X is a likely-spilled register value, copy it to a pseudo
1874 register and return that register. Return X otherwise. */
1877 avoid_likely_spilled_reg (rtx x)
1882 && HARD_REGISTER_P (x)
1883 && CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (REGNO (x))))
1885 /* Make sure that we generate a REG rather than a CONCAT.
1886 Moves into CONCATs can need nontrivial instructions,
1887 and the whole point of this function is to avoid
1888 using the hard register directly in such a situation. */
1889 generating_concat_p = 0;
1890 new_rtx = gen_reg_rtx (GET_MODE (x));
1891 generating_concat_p = 1;
1892 emit_move_insn (new_rtx, x);
1898 /* Generate all the code for a CALL_EXPR exp
1899 and return an rtx for its value.
1900 Store the value in TARGET (specified as an rtx) if convenient.
1901 If the value is stored in TARGET then TARGET is returned.
1902 If IGNORE is nonzero, then we ignore the value of the function call. */
1905 expand_call (tree exp, rtx target, int ignore)
1907 /* Nonzero if we are currently expanding a call. */
1908 static int currently_expanding_call = 0;
1910 /* RTX for the function to be called. */
1912 /* Sequence of insns to perform a normal "call". */
1913 rtx normal_call_insns = NULL_RTX;
1914 /* Sequence of insns to perform a tail "call". */
1915 rtx tail_call_insns = NULL_RTX;
1916 /* Data type of the function. */
1918 tree type_arg_types;
1920 /* Declaration of the function being called,
1921 or 0 if the function is computed (not known by name). */
1923 /* The type of the function being called. */
1925 bool try_tail_call = CALL_EXPR_TAILCALL (exp);
1928 /* Register in which non-BLKmode value will be returned,
1929 or 0 if no value or if value is BLKmode. */
1931 /* Address where we should return a BLKmode value;
1932 0 if value not BLKmode. */
1933 rtx structure_value_addr = 0;
1934 /* Nonzero if that address is being passed by treating it as
1935 an extra, implicit first parameter. Otherwise,
1936 it is passed by being copied directly into struct_value_rtx. */
1937 int structure_value_addr_parm = 0;
1938 /* Holds the value of implicit argument for the struct value. */
1939 tree structure_value_addr_value = NULL_TREE;
1940 /* Size of aggregate value wanted, or zero if none wanted
1941 or if we are using the non-reentrant PCC calling convention
1942 or expecting the value in registers. */
1943 HOST_WIDE_INT struct_value_size = 0;
1944 /* Nonzero if called function returns an aggregate in memory PCC style,
1945 by returning the address of where to find it. */
1946 int pcc_struct_value = 0;
1947 rtx struct_value = 0;
1949 /* Number of actual parameters in this call, including struct value addr. */
1951 /* Number of named args. Args after this are anonymous ones
1952 and they must all go on the stack. */
1954 /* Number of complex actual arguments that need to be split. */
1955 int num_complex_actuals = 0;
1957 /* Vector of information about each argument.
1958 Arguments are numbered in the order they will be pushed,
1959 not the order they are written. */
1960 struct arg_data *args;
1962 /* Total size in bytes of all the stack-parms scanned so far. */
1963 struct args_size args_size;
1964 struct args_size adjusted_args_size;
1965 /* Size of arguments before any adjustments (such as rounding). */
1966 int unadjusted_args_size;
1967 /* Data on reg parms scanned so far. */
1968 CUMULATIVE_ARGS args_so_far;
1969 /* Nonzero if a reg parm has been scanned. */
1971 /* Nonzero if this is an indirect function call. */
1973 /* Nonzero if we must avoid push-insns in the args for this call.
1974 If stack space is allocated for register parameters, but not by the
1975 caller, then it is preallocated in the fixed part of the stack frame.
1976 So the entire argument block must then be preallocated (i.e., we
1977 ignore PUSH_ROUNDING in that case). */
1979 int must_preallocate = !PUSH_ARGS;
1981 /* Size of the stack reserved for parameter registers. */
1982 int reg_parm_stack_space = 0;
1984 /* Address of space preallocated for stack parms
1985 (on machines that lack push insns), or 0 if space not preallocated. */
1988 /* Mask of ECF_ flags. */
1990 #ifdef REG_PARM_STACK_SPACE
1991 /* Define the boundary of the register parm stack space that needs to be
1993 int low_to_save, high_to_save;
1994 rtx save_area = 0; /* Place that it is saved */
1997 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
1998 char *initial_stack_usage_map = stack_usage_map;
1999 char *stack_usage_map_buf = NULL;
2001 int old_stack_allocated;
2003 /* State variables to track stack modifications. */
2004 rtx old_stack_level = 0;
2005 int old_stack_arg_under_construction = 0;
2006 int old_pending_adj = 0;
2007 int old_inhibit_defer_pop = inhibit_defer_pop;
2009 /* Some stack pointer alterations we make are performed via
2010 allocate_dynamic_stack_space. This modifies the stack_pointer_delta,
2011 which we then also need to save/restore along the way. */
2012 int old_stack_pointer_delta = 0;
2015 tree addr = CALL_EXPR_FN (exp);
2017 /* The alignment of the stack, in bits. */
2018 unsigned HOST_WIDE_INT preferred_stack_boundary;
2019 /* The alignment of the stack, in bytes. */
2020 unsigned HOST_WIDE_INT preferred_unit_stack_boundary;
2021 /* The static chain value to use for this call. */
2022 rtx static_chain_value;
2023 /* See if this is "nothrow" function call. */
2024 if (TREE_NOTHROW (exp))
2025 flags |= ECF_NOTHROW;
2027 /* See if we can find a DECL-node for the actual function, and get the
2028 function attributes (flags) from the function decl or type node. */
2029 fndecl = get_callee_fndecl (exp);
2032 fntype = TREE_TYPE (fndecl);
2033 flags |= flags_from_decl_or_type (fndecl);
2037 fntype = TREE_TYPE (TREE_TYPE (addr));
2038 flags |= flags_from_decl_or_type (fntype);
2040 rettype = TREE_TYPE (exp);
2042 struct_value = targetm.calls.struct_value_rtx (fntype, 0);
2044 /* Warn if this value is an aggregate type,
2045 regardless of which calling convention we are using for it. */
2046 if (AGGREGATE_TYPE_P (rettype))
2047 warning (OPT_Waggregate_return, "function call has aggregate value");
2049 /* If the result of a non looping pure or const function call is
2050 ignored (or void), and none of its arguments are volatile, we can
2051 avoid expanding the call and just evaluate the arguments for
2053 if ((flags & (ECF_CONST | ECF_PURE))
2054 && (!(flags & ECF_LOOPING_CONST_OR_PURE))
2055 && (ignore || target == const0_rtx
2056 || TYPE_MODE (rettype) == VOIDmode))
2058 bool volatilep = false;
2060 call_expr_arg_iterator iter;
2062 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2063 if (TREE_THIS_VOLATILE (arg))
2071 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2072 expand_expr (arg, const0_rtx, VOIDmode, EXPAND_NORMAL);
2077 #ifdef REG_PARM_STACK_SPACE
2078 reg_parm_stack_space = REG_PARM_STACK_SPACE (!fndecl ? fntype : fndecl);
2081 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2082 && reg_parm_stack_space > 0 && PUSH_ARGS)
2083 must_preallocate = 1;
2085 /* Set up a place to return a structure. */
2087 /* Cater to broken compilers. */
2088 if (aggregate_value_p (exp, (!fndecl ? fntype : fndecl)))
2090 /* This call returns a big structure. */
2091 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
2093 #ifdef PCC_STATIC_STRUCT_RETURN
2095 pcc_struct_value = 1;
2097 #else /* not PCC_STATIC_STRUCT_RETURN */
2099 struct_value_size = int_size_in_bytes (rettype);
2101 if (target && MEM_P (target) && CALL_EXPR_RETURN_SLOT_OPT (exp))
2102 structure_value_addr = XEXP (target, 0);
2105 /* For variable-sized objects, we must be called with a target
2106 specified. If we were to allocate space on the stack here,
2107 we would have no way of knowing when to free it. */
2108 rtx d = assign_temp (rettype, 0, 1, 1);
2110 mark_temp_addr_taken (d);
2111 structure_value_addr = XEXP (d, 0);
2115 #endif /* not PCC_STATIC_STRUCT_RETURN */
2118 /* Figure out the amount to which the stack should be aligned. */
2119 preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
2122 struct cgraph_rtl_info *i = cgraph_rtl_info (fndecl);
2123 /* Without automatic stack alignment, we can't increase preferred
2124 stack boundary. With automatic stack alignment, it is
2125 unnecessary since unless we can guarantee that all callers will
2126 align the outgoing stack properly, callee has to align its
2129 && i->preferred_incoming_stack_boundary
2130 && i->preferred_incoming_stack_boundary < preferred_stack_boundary)
2131 preferred_stack_boundary = i->preferred_incoming_stack_boundary;
2134 /* Operand 0 is a pointer-to-function; get the type of the function. */
2135 funtype = TREE_TYPE (addr);
2136 gcc_assert (POINTER_TYPE_P (funtype));
2137 funtype = TREE_TYPE (funtype);
2139 /* Count whether there are actual complex arguments that need to be split
2140 into their real and imaginary parts. Munge the type_arg_types
2141 appropriately here as well. */
2142 if (targetm.calls.split_complex_arg)
2144 call_expr_arg_iterator iter;
2146 FOR_EACH_CALL_EXPR_ARG (arg, iter, exp)
2148 tree type = TREE_TYPE (arg);
2149 if (type && TREE_CODE (type) == COMPLEX_TYPE
2150 && targetm.calls.split_complex_arg (type))
2151 num_complex_actuals++;
2153 type_arg_types = split_complex_types (TYPE_ARG_TYPES (funtype));
2156 type_arg_types = TYPE_ARG_TYPES (funtype);
2158 if (flags & ECF_MAY_BE_ALLOCA)
2159 cfun->calls_alloca = 1;
2161 /* If struct_value_rtx is 0, it means pass the address
2162 as if it were an extra parameter. Put the argument expression
2163 in structure_value_addr_value. */
2164 if (structure_value_addr && struct_value == 0)
2166 /* If structure_value_addr is a REG other than
2167 virtual_outgoing_args_rtx, we can use always use it. If it
2168 is not a REG, we must always copy it into a register.
2169 If it is virtual_outgoing_args_rtx, we must copy it to another
2170 register in some cases. */
2171 rtx temp = (!REG_P (structure_value_addr)
2172 || (ACCUMULATE_OUTGOING_ARGS
2173 && stack_arg_under_construction
2174 && structure_value_addr == virtual_outgoing_args_rtx)
2175 ? copy_addr_to_reg (convert_memory_address
2176 (Pmode, structure_value_addr))
2177 : structure_value_addr);
2179 structure_value_addr_value =
2180 make_tree (build_pointer_type (TREE_TYPE (funtype)), temp);
2181 structure_value_addr_parm = 1;
2184 /* Count the arguments and set NUM_ACTUALS. */
2186 call_expr_nargs (exp) + num_complex_actuals + structure_value_addr_parm;
2188 /* Compute number of named args.
2189 First, do a raw count of the args for INIT_CUMULATIVE_ARGS. */
2191 if (type_arg_types != 0)
2193 = (list_length (type_arg_types)
2194 /* Count the struct value address, if it is passed as a parm. */
2195 + structure_value_addr_parm);
2197 /* If we know nothing, treat all args as named. */
2198 n_named_args = num_actuals;
2200 /* Start updating where the next arg would go.
2202 On some machines (such as the PA) indirect calls have a different
2203 calling convention than normal calls. The fourth argument in
2204 INIT_CUMULATIVE_ARGS tells the backend if this is an indirect call
2206 INIT_CUMULATIVE_ARGS (args_so_far, funtype, NULL_RTX, fndecl, n_named_args);
2208 /* Now possibly adjust the number of named args.
2209 Normally, don't include the last named arg if anonymous args follow.
2210 We do include the last named arg if
2211 targetm.calls.strict_argument_naming() returns nonzero.
2212 (If no anonymous args follow, the result of list_length is actually
2213 one too large. This is harmless.)
2215 If targetm.calls.pretend_outgoing_varargs_named() returns
2216 nonzero, and targetm.calls.strict_argument_naming() returns zero,
2217 this machine will be able to place unnamed args that were passed
2218 in registers into the stack. So treat all args as named. This
2219 allows the insns emitting for a specific argument list to be
2220 independent of the function declaration.
2222 If targetm.calls.pretend_outgoing_varargs_named() returns zero,
2223 we do not have any reliable way to pass unnamed args in
2224 registers, so we must force them into memory. */
2226 if (type_arg_types != 0
2227 && targetm.calls.strict_argument_naming (&args_so_far))
2229 else if (type_arg_types != 0
2230 && ! targetm.calls.pretend_outgoing_varargs_named (&args_so_far))
2231 /* Don't include the last named arg. */
2234 /* Treat all args as named. */
2235 n_named_args = num_actuals;
2237 /* Make a vector to hold all the information about each arg. */
2238 args = XALLOCAVEC (struct arg_data, num_actuals);
2239 memset (args, 0, num_actuals * sizeof (struct arg_data));
2241 /* Build up entries in the ARGS array, compute the size of the
2242 arguments into ARGS_SIZE, etc. */
2243 initialize_argument_information (num_actuals, args, &args_size,
2245 structure_value_addr_value, fndecl, fntype,
2246 &args_so_far, reg_parm_stack_space,
2247 &old_stack_level, &old_pending_adj,
2248 &must_preallocate, &flags,
2249 &try_tail_call, CALL_FROM_THUNK_P (exp));
2252 must_preallocate = 1;
2254 /* Now make final decision about preallocating stack space. */
2255 must_preallocate = finalize_must_preallocate (must_preallocate,
2259 /* If the structure value address will reference the stack pointer, we
2260 must stabilize it. We don't need to do this if we know that we are
2261 not going to adjust the stack pointer in processing this call. */
2263 if (structure_value_addr
2264 && (reg_mentioned_p (virtual_stack_dynamic_rtx, structure_value_addr)
2265 || reg_mentioned_p (virtual_outgoing_args_rtx,
2266 structure_value_addr))
2268 || (!ACCUMULATE_OUTGOING_ARGS && args_size.constant)))
2269 structure_value_addr = copy_to_reg (structure_value_addr);
2271 /* Tail calls can make things harder to debug, and we've traditionally
2272 pushed these optimizations into -O2. Don't try if we're already
2273 expanding a call, as that means we're an argument. Don't try if
2274 there's cleanups, as we know there's code to follow the call. */
2276 if (currently_expanding_call++ != 0
2277 || !flag_optimize_sibling_calls
2279 || dbg_cnt (tail_call) == false)
2282 /* Rest of purposes for tail call optimizations to fail. */
2284 #ifdef HAVE_sibcall_epilogue
2285 !HAVE_sibcall_epilogue
2290 /* Doing sibling call optimization needs some work, since
2291 structure_value_addr can be allocated on the stack.
2292 It does not seem worth the effort since few optimizable
2293 sibling calls will return a structure. */
2294 || structure_value_addr != NULL_RTX
2295 #ifdef REG_PARM_STACK_SPACE
2296 /* If outgoing reg parm stack space changes, we can not do sibcall. */
2297 || (OUTGOING_REG_PARM_STACK_SPACE (funtype)
2298 != OUTGOING_REG_PARM_STACK_SPACE (TREE_TYPE (current_function_decl)))
2299 || (reg_parm_stack_space != REG_PARM_STACK_SPACE (fndecl))
2301 /* Check whether the target is able to optimize the call
2303 || !targetm.function_ok_for_sibcall (fndecl, exp)
2304 /* Functions that do not return exactly once may not be sibcall
2306 || (flags & (ECF_RETURNS_TWICE | ECF_NORETURN))
2307 || TYPE_VOLATILE (TREE_TYPE (TREE_TYPE (addr)))
2308 /* If the called function is nested in the current one, it might access
2309 some of the caller's arguments, but could clobber them beforehand if
2310 the argument areas are shared. */
2311 || (fndecl && decl_function_context (fndecl) == current_function_decl)
2312 /* If this function requires more stack slots than the current
2313 function, we cannot change it into a sibling call.
2314 crtl->args.pretend_args_size is not part of the
2315 stack allocated by our caller. */
2316 || args_size.constant > (crtl->args.size
2317 - crtl->args.pretend_args_size)
2318 /* If the callee pops its own arguments, then it must pop exactly
2319 the same number of arguments as the current function. */
2320 || (RETURN_POPS_ARGS (fndecl, funtype, args_size.constant)
2321 != RETURN_POPS_ARGS (current_function_decl,
2322 TREE_TYPE (current_function_decl),
2324 || !lang_hooks.decls.ok_for_sibcall (fndecl))
2327 /* Check if caller and callee disagree in promotion of function
2331 enum machine_mode caller_mode, caller_promoted_mode;
2332 enum machine_mode callee_mode, callee_promoted_mode;
2333 int caller_unsignedp, callee_unsignedp;
2334 tree caller_res = DECL_RESULT (current_function_decl);
2336 caller_unsignedp = TYPE_UNSIGNED (TREE_TYPE (caller_res));
2337 caller_mode = DECL_MODE (caller_res);
2338 callee_unsignedp = TYPE_UNSIGNED (TREE_TYPE (funtype));
2339 callee_mode = TYPE_MODE (TREE_TYPE (funtype));
2340 caller_promoted_mode
2341 = promote_function_mode (TREE_TYPE (caller_res), caller_mode,
2343 TREE_TYPE (current_function_decl), 1);
2344 callee_promoted_mode
2345 = promote_function_mode (TREE_TYPE (funtype), callee_mode,
2348 if (caller_mode != VOIDmode
2349 && (caller_promoted_mode != callee_promoted_mode
2350 || ((caller_mode != caller_promoted_mode
2351 || callee_mode != callee_promoted_mode)
2352 && (caller_unsignedp != callee_unsignedp
2353 || GET_MODE_BITSIZE (caller_mode)
2354 < GET_MODE_BITSIZE (callee_mode)))))
2358 /* Ensure current function's preferred stack boundary is at least
2359 what we need. Stack alignment may also increase preferred stack
2361 if (crtl->preferred_stack_boundary < preferred_stack_boundary)
2362 crtl->preferred_stack_boundary = preferred_stack_boundary;
2364 preferred_stack_boundary = crtl->preferred_stack_boundary;
2366 preferred_unit_stack_boundary = preferred_stack_boundary / BITS_PER_UNIT;
2368 /* We want to make two insn chains; one for a sibling call, the other
2369 for a normal call. We will select one of the two chains after
2370 initial RTL generation is complete. */
2371 for (pass = try_tail_call ? 0 : 1; pass < 2; pass++)
2373 int sibcall_failure = 0;
2374 /* We want to emit any pending stack adjustments before the tail
2375 recursion "call". That way we know any adjustment after the tail
2376 recursion call can be ignored if we indeed use the tail
2378 int save_pending_stack_adjust = 0;
2379 int save_stack_pointer_delta = 0;
2381 rtx before_call, next_arg_reg, after_args;
2385 /* State variables we need to save and restore between
2387 save_pending_stack_adjust = pending_stack_adjust;
2388 save_stack_pointer_delta = stack_pointer_delta;
2391 flags &= ~ECF_SIBCALL;
2393 flags |= ECF_SIBCALL;
2395 /* Other state variables that we must reinitialize each time
2396 through the loop (that are not initialized by the loop itself). */
2400 /* Start a new sequence for the normal call case.
2402 From this point on, if the sibling call fails, we want to set
2403 sibcall_failure instead of continuing the loop. */
2406 /* Don't let pending stack adjusts add up to too much.
2407 Also, do all pending adjustments now if there is any chance
2408 this might be a call to alloca or if we are expanding a sibling
2410 Also do the adjustments before a throwing call, otherwise
2411 exception handling can fail; PR 19225. */
2412 if (pending_stack_adjust >= 32
2413 || (pending_stack_adjust > 0
2414 && (flags & ECF_MAY_BE_ALLOCA))
2415 || (pending_stack_adjust > 0
2416 && flag_exceptions && !(flags & ECF_NOTHROW))
2418 do_pending_stack_adjust ();
2420 /* Precompute any arguments as needed. */
2422 precompute_arguments (num_actuals, args);
2424 /* Now we are about to start emitting insns that can be deleted
2425 if a libcall is deleted. */
2426 if (pass && (flags & ECF_MALLOC))
2429 if (pass == 0 && crtl->stack_protect_guard)
2430 stack_protect_epilogue ();
2432 adjusted_args_size = args_size;
2433 /* Compute the actual size of the argument block required. The variable
2434 and constant sizes must be combined, the size may have to be rounded,
2435 and there may be a minimum required size. When generating a sibcall
2436 pattern, do not round up, since we'll be re-using whatever space our
2438 unadjusted_args_size
2439 = compute_argument_block_size (reg_parm_stack_space,
2440 &adjusted_args_size,
2443 : preferred_stack_boundary));
2445 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
2447 /* The argument block when performing a sibling call is the
2448 incoming argument block. */
2451 argblock = crtl->args.internal_arg_pointer;
2453 #ifdef STACK_GROWS_DOWNWARD
2454 = plus_constant (argblock, crtl->args.pretend_args_size);
2456 = plus_constant (argblock, -crtl->args.pretend_args_size);
2458 stored_args_map = sbitmap_alloc (args_size.constant);
2459 sbitmap_zero (stored_args_map);
2462 /* If we have no actual push instructions, or shouldn't use them,
2463 make space for all args right now. */
2464 else if (adjusted_args_size.var != 0)
2466 if (old_stack_level == 0)
2468 emit_stack_save (SAVE_BLOCK, &old_stack_level, NULL_RTX);
2469 old_stack_pointer_delta = stack_pointer_delta;
2470 old_pending_adj = pending_stack_adjust;
2471 pending_stack_adjust = 0;
2472 /* stack_arg_under_construction says whether a stack arg is
2473 being constructed at the old stack level. Pushing the stack
2474 gets a clean outgoing argument block. */
2475 old_stack_arg_under_construction = stack_arg_under_construction;
2476 stack_arg_under_construction = 0;
2478 argblock = push_block (ARGS_SIZE_RTX (adjusted_args_size), 0, 0);
2482 /* Note that we must go through the motions of allocating an argument
2483 block even if the size is zero because we may be storing args
2484 in the area reserved for register arguments, which may be part of
2487 int needed = adjusted_args_size.constant;
2489 /* Store the maximum argument space used. It will be pushed by
2490 the prologue (if ACCUMULATE_OUTGOING_ARGS, or stack overflow
2493 if (needed > crtl->outgoing_args_size)
2494 crtl->outgoing_args_size = needed;
2496 if (must_preallocate)
2498 if (ACCUMULATE_OUTGOING_ARGS)
2500 /* Since the stack pointer will never be pushed, it is
2501 possible for the evaluation of a parm to clobber
2502 something we have already written to the stack.
2503 Since most function calls on RISC machines do not use
2504 the stack, this is uncommon, but must work correctly.
2506 Therefore, we save any area of the stack that was already
2507 written and that we are using. Here we set up to do this
2508 by making a new stack usage map from the old one. The
2509 actual save will be done by store_one_arg.
2511 Another approach might be to try to reorder the argument
2512 evaluations to avoid this conflicting stack usage. */
2514 /* Since we will be writing into the entire argument area,
2515 the map must be allocated for its entire size, not just
2516 the part that is the responsibility of the caller. */
2517 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
2518 needed += reg_parm_stack_space;
2520 #ifdef ARGS_GROW_DOWNWARD
2521 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2524 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
2527 if (stack_usage_map_buf)
2528 free (stack_usage_map_buf);
2529 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
2530 stack_usage_map = stack_usage_map_buf;
2532 if (initial_highest_arg_in_use)
2533 memcpy (stack_usage_map, initial_stack_usage_map,
2534 initial_highest_arg_in_use);
2536 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
2537 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
2538 (highest_outgoing_arg_in_use
2539 - initial_highest_arg_in_use));
2542 /* The address of the outgoing argument list must not be
2543 copied to a register here, because argblock would be left
2544 pointing to the wrong place after the call to
2545 allocate_dynamic_stack_space below. */
2547 argblock = virtual_outgoing_args_rtx;
2551 if (inhibit_defer_pop == 0)
2553 /* Try to reuse some or all of the pending_stack_adjust
2554 to get this space. */
2556 = (combine_pending_stack_adjustment_and_call
2557 (unadjusted_args_size,
2558 &adjusted_args_size,
2559 preferred_unit_stack_boundary));
2561 /* combine_pending_stack_adjustment_and_call computes
2562 an adjustment before the arguments are allocated.
2563 Account for them and see whether or not the stack
2564 needs to go up or down. */
2565 needed = unadjusted_args_size - needed;
2569 /* We're releasing stack space. */
2570 /* ??? We can avoid any adjustment at all if we're
2571 already aligned. FIXME. */
2572 pending_stack_adjust = -needed;
2573 do_pending_stack_adjust ();
2577 /* We need to allocate space. We'll do that in
2578 push_block below. */
2579 pending_stack_adjust = 0;
2582 /* Special case this because overhead of `push_block' in
2583 this case is non-trivial. */
2585 argblock = virtual_outgoing_args_rtx;
2588 argblock = push_block (GEN_INT (needed), 0, 0);
2589 #ifdef ARGS_GROW_DOWNWARD
2590 argblock = plus_constant (argblock, needed);
2594 /* We only really need to call `copy_to_reg' in the case
2595 where push insns are going to be used to pass ARGBLOCK
2596 to a function call in ARGS. In that case, the stack
2597 pointer changes value from the allocation point to the
2598 call point, and hence the value of
2599 VIRTUAL_OUTGOING_ARGS_RTX changes as well. But might
2600 as well always do it. */
2601 argblock = copy_to_reg (argblock);
2606 if (ACCUMULATE_OUTGOING_ARGS)
2608 /* The save/restore code in store_one_arg handles all
2609 cases except one: a constructor call (including a C
2610 function returning a BLKmode struct) to initialize
2612 if (stack_arg_under_construction)
2615 = GEN_INT (adjusted_args_size.constant
2616 + (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype
2617 : TREE_TYPE (fndecl))) ? 0
2618 : reg_parm_stack_space));
2619 if (old_stack_level == 0)
2621 emit_stack_save (SAVE_BLOCK, &old_stack_level,
2623 old_stack_pointer_delta = stack_pointer_delta;
2624 old_pending_adj = pending_stack_adjust;
2625 pending_stack_adjust = 0;
2626 /* stack_arg_under_construction says whether a stack
2627 arg is being constructed at the old stack level.
2628 Pushing the stack gets a clean outgoing argument
2630 old_stack_arg_under_construction
2631 = stack_arg_under_construction;
2632 stack_arg_under_construction = 0;
2633 /* Make a new map for the new argument list. */
2634 if (stack_usage_map_buf)
2635 free (stack_usage_map_buf);
2636 stack_usage_map_buf = XCNEWVEC (char, highest_outgoing_arg_in_use);
2637 stack_usage_map = stack_usage_map_buf;
2638 highest_outgoing_arg_in_use = 0;
2640 allocate_dynamic_stack_space (push_size, NULL_RTX,
2644 /* If argument evaluation might modify the stack pointer,
2645 copy the address of the argument list to a register. */
2646 for (i = 0; i < num_actuals; i++)
2647 if (args[i].pass_on_stack)
2649 argblock = copy_addr_to_reg (argblock);
2654 compute_argument_addresses (args, argblock, num_actuals);
2656 /* If we push args individually in reverse order, perform stack alignment
2657 before the first push (the last arg). */
2658 if (PUSH_ARGS_REVERSED && argblock == 0
2659 && adjusted_args_size.constant != unadjusted_args_size)
2661 /* When the stack adjustment is pending, we get better code
2662 by combining the adjustments. */
2663 if (pending_stack_adjust
2664 && ! inhibit_defer_pop)
2666 pending_stack_adjust
2667 = (combine_pending_stack_adjustment_and_call
2668 (unadjusted_args_size,
2669 &adjusted_args_size,
2670 preferred_unit_stack_boundary));
2671 do_pending_stack_adjust ();
2673 else if (argblock == 0)
2674 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2675 - unadjusted_args_size));
2677 /* Now that the stack is properly aligned, pops can't safely
2678 be deferred during the evaluation of the arguments. */
2681 funexp = rtx_for_function_call (fndecl, addr);
2683 /* Figure out the register where the value, if any, will come back. */
2685 if (TYPE_MODE (rettype) != VOIDmode
2686 && ! structure_value_addr)
2688 if (pcc_struct_value)
2689 valreg = hard_function_value (build_pointer_type (rettype),
2690 fndecl, NULL, (pass == 0));
2692 valreg = hard_function_value (rettype, fndecl, fntype,
2695 /* If VALREG is a PARALLEL whose first member has a zero
2696 offset, use that. This is for targets such as m68k that
2697 return the same value in multiple places. */
2698 if (GET_CODE (valreg) == PARALLEL)
2700 rtx elem = XVECEXP (valreg, 0, 0);
2701 rtx where = XEXP (elem, 0);
2702 rtx offset = XEXP (elem, 1);
2703 if (offset == const0_rtx
2704 && GET_MODE (where) == GET_MODE (valreg))
2709 /* Precompute all register parameters. It isn't safe to compute anything
2710 once we have started filling any specific hard regs. */
2711 precompute_register_parameters (num_actuals, args, ®_parm_seen);
2713 if (CALL_EXPR_STATIC_CHAIN (exp))
2714 static_chain_value = expand_normal (CALL_EXPR_STATIC_CHAIN (exp));
2716 static_chain_value = 0;
2718 #ifdef REG_PARM_STACK_SPACE
2719 /* Save the fixed argument area if it's part of the caller's frame and
2720 is clobbered by argument setup for this call. */
2721 if (ACCUMULATE_OUTGOING_ARGS && pass)
2722 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
2723 &low_to_save, &high_to_save);
2726 /* Now store (and compute if necessary) all non-register parms.
2727 These come before register parms, since they can require block-moves,
2728 which could clobber the registers used for register parms.
2729 Parms which have partial registers are not stored here,
2730 but we do preallocate space here if they want that. */
2732 for (i = 0; i < num_actuals; i++)
2734 if (args[i].reg == 0 || args[i].pass_on_stack)
2736 rtx before_arg = get_last_insn ();
2738 if (store_one_arg (&args[i], argblock, flags,
2739 adjusted_args_size.var != 0,
2740 reg_parm_stack_space)
2742 && check_sibcall_argument_overlap (before_arg,
2744 sibcall_failure = 1;
2747 if (((flags & ECF_CONST)
2748 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
2750 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
2751 gen_rtx_USE (VOIDmode,
2756 /* If we have a parm that is passed in registers but not in memory
2757 and whose alignment does not permit a direct copy into registers,
2758 make a group of pseudos that correspond to each register that we
2760 if (STRICT_ALIGNMENT)
2761 store_unaligned_arguments_into_pseudos (args, num_actuals);
2763 /* Now store any partially-in-registers parm.
2764 This is the last place a block-move can happen. */
2766 for (i = 0; i < num_actuals; i++)
2767 if (args[i].partial != 0 && ! args[i].pass_on_stack)
2769 rtx before_arg = get_last_insn ();
2771 if (store_one_arg (&args[i], argblock, flags,
2772 adjusted_args_size.var != 0,
2773 reg_parm_stack_space)
2775 && check_sibcall_argument_overlap (before_arg,
2777 sibcall_failure = 1;
2780 /* If we pushed args in forward order, perform stack alignment
2781 after pushing the last arg. */
2782 if (!PUSH_ARGS_REVERSED && argblock == 0)
2783 anti_adjust_stack (GEN_INT (adjusted_args_size.constant
2784 - unadjusted_args_size));
2786 /* If register arguments require space on the stack and stack space
2787 was not preallocated, allocate stack space here for arguments
2788 passed in registers. */
2789 if (OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl)))
2790 && !ACCUMULATE_OUTGOING_ARGS
2791 && must_preallocate == 0 && reg_parm_stack_space > 0)
2792 anti_adjust_stack (GEN_INT (reg_parm_stack_space));
2794 /* Pass the function the address in which to return a
2796 if (pass != 0 && structure_value_addr && ! structure_value_addr_parm)
2798 structure_value_addr
2799 = convert_memory_address (Pmode, structure_value_addr);
2800 emit_move_insn (struct_value,
2802 force_operand (structure_value_addr,
2805 if (REG_P (struct_value))
2806 use_reg (&call_fusage, struct_value);
2809 after_args = get_last_insn ();
2810 funexp = prepare_call_address (funexp, static_chain_value,
2811 &call_fusage, reg_parm_seen, pass == 0);
2813 load_register_parameters (args, num_actuals, &call_fusage, flags,
2814 pass == 0, &sibcall_failure);
2816 /* Save a pointer to the last insn before the call, so that we can
2817 later safely search backwards to find the CALL_INSN. */
2818 before_call = get_last_insn ();
2820 /* Set up next argument register. For sibling calls on machines
2821 with register windows this should be the incoming register. */
2822 #ifdef FUNCTION_INCOMING_ARG
2824 next_arg_reg = FUNCTION_INCOMING_ARG (args_so_far, VOIDmode,
2828 next_arg_reg = FUNCTION_ARG (args_so_far, VOIDmode,
2831 /* All arguments and registers used for the call must be set up by
2834 /* Stack must be properly aligned now. */
2836 || !(stack_pointer_delta % preferred_unit_stack_boundary));
2838 /* Generate the actual call instruction. */
2839 emit_call_1 (funexp, exp, fndecl, funtype, unadjusted_args_size,
2840 adjusted_args_size.constant, struct_value_size,
2841 next_arg_reg, valreg, old_inhibit_defer_pop, call_fusage,
2842 flags, & args_so_far);
2844 /* If the call setup or the call itself overlaps with anything
2845 of the argument setup we probably clobbered our call address.
2846 In that case we can't do sibcalls. */
2848 && check_sibcall_argument_overlap (after_args, 0, 0))
2849 sibcall_failure = 1;
2851 /* If a non-BLKmode value is returned at the most significant end
2852 of a register, shift the register right by the appropriate amount
2853 and update VALREG accordingly. BLKmode values are handled by the
2854 group load/store machinery below. */
2855 if (!structure_value_addr
2856 && !pcc_struct_value
2857 && TYPE_MODE (rettype) != BLKmode
2858 && targetm.calls.return_in_msb (rettype))
2860 if (shift_return_value (TYPE_MODE (rettype), false, valreg))
2861 sibcall_failure = 1;
2862 valreg = gen_rtx_REG (TYPE_MODE (rettype), REGNO (valreg));
2865 if (pass && (flags & ECF_MALLOC))
2867 rtx temp = gen_reg_rtx (GET_MODE (valreg));
2870 /* The return value from a malloc-like function is a pointer. */
2871 if (TREE_CODE (rettype) == POINTER_TYPE)
2872 mark_reg_pointer (temp, BIGGEST_ALIGNMENT);
2874 emit_move_insn (temp, valreg);
2876 /* The return value from a malloc-like function can not alias
2878 last = get_last_insn ();
2879 add_reg_note (last, REG_NOALIAS, temp);
2881 /* Write out the sequence. */
2882 insns = get_insns ();
2888 /* For calls to `setjmp', etc., inform
2889 function.c:setjmp_warnings that it should complain if
2890 nonvolatile values are live. For functions that cannot
2891 return, inform flow that control does not fall through. */
2893 if ((flags & ECF_NORETURN) || pass == 0)
2895 /* The barrier must be emitted
2896 immediately after the CALL_INSN. Some ports emit more
2897 than just a CALL_INSN above, so we must search for it here. */
2899 rtx last = get_last_insn ();
2900 while (!CALL_P (last))
2902 last = PREV_INSN (last);
2903 /* There was no CALL_INSN? */
2904 gcc_assert (last != before_call);
2907 emit_barrier_after (last);
2909 /* Stack adjustments after a noreturn call are dead code.
2910 However when NO_DEFER_POP is in effect, we must preserve
2911 stack_pointer_delta. */
2912 if (inhibit_defer_pop == 0)
2914 stack_pointer_delta = old_stack_allocated;
2915 pending_stack_adjust = 0;
2919 /* If value type not void, return an rtx for the value. */
2921 if (TYPE_MODE (rettype) == VOIDmode
2923 target = const0_rtx;
2924 else if (structure_value_addr)
2926 if (target == 0 || !MEM_P (target))
2929 = gen_rtx_MEM (TYPE_MODE (rettype),
2930 memory_address (TYPE_MODE (rettype),
2931 structure_value_addr));
2932 set_mem_attributes (target, rettype, 1);
2935 else if (pcc_struct_value)
2937 /* This is the special C++ case where we need to
2938 know what the true target was. We take care to
2939 never use this value more than once in one expression. */
2940 target = gen_rtx_MEM (TYPE_MODE (rettype),
2941 copy_to_reg (valreg));
2942 set_mem_attributes (target, rettype, 1);
2944 /* Handle calls that return values in multiple non-contiguous locations.
2945 The Irix 6 ABI has examples of this. */
2946 else if (GET_CODE (valreg) == PARALLEL)
2950 /* This will only be assigned once, so it can be readonly. */
2951 tree nt = build_qualified_type (rettype,
2952 (TYPE_QUALS (rettype)
2953 | TYPE_QUAL_CONST));
2955 target = assign_temp (nt, 0, 1, 1);
2958 if (! rtx_equal_p (target, valreg))
2959 emit_group_store (target, valreg, rettype,
2960 int_size_in_bytes (rettype));
2962 /* We can not support sibling calls for this case. */
2963 sibcall_failure = 1;
2966 && GET_MODE (target) == TYPE_MODE (rettype)
2967 && GET_MODE (target) == GET_MODE (valreg))
2969 bool may_overlap = false;
2971 /* We have to copy a return value in a CLASS_LIKELY_SPILLED hard
2972 reg to a plain register. */
2973 if (!REG_P (target) || HARD_REGISTER_P (target))
2974 valreg = avoid_likely_spilled_reg (valreg);
2976 /* If TARGET is a MEM in the argument area, and we have
2977 saved part of the argument area, then we can't store
2978 directly into TARGET as it may get overwritten when we
2979 restore the argument save area below. Don't work too
2980 hard though and simply force TARGET to a register if it
2981 is a MEM; the optimizer is quite likely to sort it out. */
2982 if (ACCUMULATE_OUTGOING_ARGS && pass && MEM_P (target))
2983 for (i = 0; i < num_actuals; i++)
2984 if (args[i].save_area)
2991 target = copy_to_reg (valreg);
2994 /* TARGET and VALREG cannot be equal at this point
2995 because the latter would not have
2996 REG_FUNCTION_VALUE_P true, while the former would if
2997 it were referring to the same register.
2999 If they refer to the same register, this move will be
3000 a no-op, except when function inlining is being
3002 emit_move_insn (target, valreg);
3004 /* If we are setting a MEM, this code must be executed.
3005 Since it is emitted after the call insn, sibcall
3006 optimization cannot be performed in that case. */
3008 sibcall_failure = 1;
3011 else if (TYPE_MODE (rettype) == BLKmode)
3013 target = copy_blkmode_from_reg (target, valreg, rettype);
3015 /* We can not support sibling calls for this case. */
3016 sibcall_failure = 1;
3019 target = copy_to_reg (avoid_likely_spilled_reg (valreg));
3021 /* If we promoted this return value, make the proper SUBREG.
3022 TARGET might be const0_rtx here, so be careful. */
3024 && TYPE_MODE (rettype) != BLKmode
3025 && GET_MODE (target) != TYPE_MODE (rettype))
3027 tree type = rettype;
3028 int unsignedp = TYPE_UNSIGNED (type);
3030 enum machine_mode pmode;
3032 /* Ensure we promote as expected, and get the new unsignedness. */
3033 pmode = promote_function_mode (type, TYPE_MODE (type), &unsignedp,
3035 gcc_assert (GET_MODE (target) == pmode);
3037 if ((WORDS_BIG_ENDIAN || BYTES_BIG_ENDIAN)
3038 && (GET_MODE_SIZE (GET_MODE (target))
3039 > GET_MODE_SIZE (TYPE_MODE (type))))
3041 offset = GET_MODE_SIZE (GET_MODE (target))
3042 - GET_MODE_SIZE (TYPE_MODE (type));
3043 if (! BYTES_BIG_ENDIAN)
3044 offset = (offset / UNITS_PER_WORD) * UNITS_PER_WORD;
3045 else if (! WORDS_BIG_ENDIAN)
3046 offset %= UNITS_PER_WORD;
3049 target = gen_rtx_SUBREG (TYPE_MODE (type), target, offset);
3050 SUBREG_PROMOTED_VAR_P (target) = 1;
3051 SUBREG_PROMOTED_UNSIGNED_SET (target, unsignedp);
3054 /* If size of args is variable or this was a constructor call for a stack
3055 argument, restore saved stack-pointer value. */
3057 if (old_stack_level)
3059 emit_stack_restore (SAVE_BLOCK, old_stack_level, NULL_RTX);
3060 stack_pointer_delta = old_stack_pointer_delta;
3061 pending_stack_adjust = old_pending_adj;
3062 old_stack_allocated = stack_pointer_delta - pending_stack_adjust;
3063 stack_arg_under_construction = old_stack_arg_under_construction;
3064 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3065 stack_usage_map = initial_stack_usage_map;
3066 sibcall_failure = 1;
3068 else if (ACCUMULATE_OUTGOING_ARGS && pass)
3070 #ifdef REG_PARM_STACK_SPACE
3072 restore_fixed_argument_area (save_area, argblock,
3073 high_to_save, low_to_save);
3076 /* If we saved any argument areas, restore them. */
3077 for (i = 0; i < num_actuals; i++)
3078 if (args[i].save_area)
3080 enum machine_mode save_mode = GET_MODE (args[i].save_area);
3082 = gen_rtx_MEM (save_mode,
3083 memory_address (save_mode,
3084 XEXP (args[i].stack_slot, 0)));
3086 if (save_mode != BLKmode)
3087 emit_move_insn (stack_area, args[i].save_area);
3089 emit_block_move (stack_area, args[i].save_area,
3090 GEN_INT (args[i].locate.size.constant),
3091 BLOCK_OP_CALL_PARM);
3094 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3095 stack_usage_map = initial_stack_usage_map;
3098 /* If this was alloca, record the new stack level for nonlocal gotos.
3099 Check for the handler slots since we might not have a save area
3100 for non-local gotos. */
3102 if ((flags & ECF_MAY_BE_ALLOCA) && cfun->nonlocal_goto_save_area != 0)
3103 update_nonlocal_goto_save_area ();
3105 /* Free up storage we no longer need. */
3106 for (i = 0; i < num_actuals; ++i)
3107 if (args[i].aligned_regs)
3108 free (args[i].aligned_regs);
3110 insns = get_insns ();
3115 tail_call_insns = insns;
3117 /* Restore the pending stack adjustment now that we have
3118 finished generating the sibling call sequence. */
3120 pending_stack_adjust = save_pending_stack_adjust;
3121 stack_pointer_delta = save_stack_pointer_delta;
3123 /* Prepare arg structure for next iteration. */
3124 for (i = 0; i < num_actuals; i++)
3127 args[i].aligned_regs = 0;
3131 sbitmap_free (stored_args_map);
3135 normal_call_insns = insns;
3137 /* Verify that we've deallocated all the stack we used. */
3138 gcc_assert ((flags & ECF_NORETURN)
3139 || (old_stack_allocated
3140 == stack_pointer_delta - pending_stack_adjust));
3143 /* If something prevents making this a sibling call,
3144 zero out the sequence. */
3145 if (sibcall_failure)
3146 tail_call_insns = NULL_RTX;
3151 /* If tail call production succeeded, we need to remove REG_EQUIV notes on
3152 arguments too, as argument area is now clobbered by the call. */
3153 if (tail_call_insns)
3155 emit_insn (tail_call_insns);
3156 crtl->tail_call_emit = true;
3159 emit_insn (normal_call_insns);
3161 currently_expanding_call--;
3163 if (stack_usage_map_buf)
3164 free (stack_usage_map_buf);
3169 /* A sibling call sequence invalidates any REG_EQUIV notes made for
3170 this function's incoming arguments.
3172 At the start of RTL generation we know the only REG_EQUIV notes
3173 in the rtl chain are those for incoming arguments, so we can look
3174 for REG_EQUIV notes between the start of the function and the
3175 NOTE_INSN_FUNCTION_BEG.
3177 This is (slight) overkill. We could keep track of the highest
3178 argument we clobber and be more selective in removing notes, but it
3179 does not seem to be worth the effort. */
3182 fixup_tail_calls (void)
3186 for (insn = get_insns (); insn; insn = NEXT_INSN (insn))
3190 /* There are never REG_EQUIV notes for the incoming arguments
3191 after the NOTE_INSN_FUNCTION_BEG note, so stop if we see it. */
3193 && NOTE_KIND (insn) == NOTE_INSN_FUNCTION_BEG)
3196 note = find_reg_note (insn, REG_EQUIV, 0);
3198 remove_note (insn, note);
3199 note = find_reg_note (insn, REG_EQUIV, 0);
3204 /* Traverse a list of TYPES and expand all complex types into their
3207 split_complex_types (tree types)
3211 /* Before allocating memory, check for the common case of no complex. */
3212 for (p = types; p; p = TREE_CHAIN (p))
3214 tree type = TREE_VALUE (p);
3215 if (TREE_CODE (type) == COMPLEX_TYPE
3216 && targetm.calls.split_complex_arg (type))
3222 types = copy_list (types);
3224 for (p = types; p; p = TREE_CHAIN (p))
3226 tree complex_type = TREE_VALUE (p);
3228 if (TREE_CODE (complex_type) == COMPLEX_TYPE
3229 && targetm.calls.split_complex_arg (complex_type))
3233 /* Rewrite complex type with component type. */
3234 TREE_VALUE (p) = TREE_TYPE (complex_type);
3235 next = TREE_CHAIN (p);
3237 /* Add another component type for the imaginary part. */
3238 imag = build_tree_list (NULL_TREE, TREE_VALUE (p));
3239 TREE_CHAIN (p) = imag;
3240 TREE_CHAIN (imag) = next;
3242 /* Skip the newly created node. */
3250 /* Output a library call to function FUN (a SYMBOL_REF rtx).
3251 The RETVAL parameter specifies whether return value needs to be saved, other
3252 parameters are documented in the emit_library_call function below. */
3255 emit_library_call_value_1 (int retval, rtx orgfun, rtx value,
3256 enum libcall_type fn_type,
3257 enum machine_mode outmode, int nargs, va_list p)
3259 /* Total size in bytes of all the stack-parms scanned so far. */
3260 struct args_size args_size;
3261 /* Size of arguments before any adjustments (such as rounding). */
3262 struct args_size original_args_size;
3265 /* Todo, choose the correct decl type of orgfun. Sadly this information
3266 isn't present here, so we default to native calling abi here. */
3267 tree fndecl ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3268 tree fntype ATTRIBUTE_UNUSED = NULL_TREE; /* library calls default to host calling abi ? */
3272 CUMULATIVE_ARGS args_so_far;
3276 enum machine_mode mode;
3279 struct locate_and_pad_arg_data locate;
3283 int old_inhibit_defer_pop = inhibit_defer_pop;
3284 rtx call_fusage = 0;
3287 int pcc_struct_value = 0;
3288 int struct_value_size = 0;
3290 int reg_parm_stack_space = 0;
3293 tree tfom; /* type_for_mode (outmode, 0) */
3295 #ifdef REG_PARM_STACK_SPACE
3296 /* Define the boundary of the register parm stack space that needs to be
3298 int low_to_save = 0, high_to_save = 0;
3299 rtx save_area = 0; /* Place that it is saved. */
3302 /* Size of the stack reserved for parameter registers. */
3303 int initial_highest_arg_in_use = highest_outgoing_arg_in_use;
3304 char *initial_stack_usage_map = stack_usage_map;
3305 char *stack_usage_map_buf = NULL;
3307 rtx struct_value = targetm.calls.struct_value_rtx (0, 0);
3309 #ifdef REG_PARM_STACK_SPACE
3310 reg_parm_stack_space = REG_PARM_STACK_SPACE ((tree) 0);
3313 /* By default, library functions can not throw. */
3314 flags = ECF_NOTHROW;
3327 flags |= ECF_NORETURN;
3330 flags = ECF_NORETURN;
3332 case LCT_RETURNS_TWICE:
3333 flags = ECF_RETURNS_TWICE;
3338 /* Ensure current function's preferred stack boundary is at least
3340 if (crtl->preferred_stack_boundary < PREFERRED_STACK_BOUNDARY)
3341 crtl->preferred_stack_boundary = PREFERRED_STACK_BOUNDARY;
3343 /* If this kind of value comes back in memory,
3344 decide where in memory it should come back. */
3345 if (outmode != VOIDmode)
3347 tfom = lang_hooks.types.type_for_mode (outmode, 0);
3348 if (aggregate_value_p (tfom, 0))
3350 #ifdef PCC_STATIC_STRUCT_RETURN
3352 = hard_function_value (build_pointer_type (tfom), 0, 0, 0);
3353 mem_value = gen_rtx_MEM (outmode, pointer_reg);
3354 pcc_struct_value = 1;
3356 value = gen_reg_rtx (outmode);
3357 #else /* not PCC_STATIC_STRUCT_RETURN */
3358 struct_value_size = GET_MODE_SIZE (outmode);
3359 if (value != 0 && MEM_P (value))
3362 mem_value = assign_temp (tfom, 0, 1, 1);
3364 /* This call returns a big structure. */
3365 flags &= ~(ECF_CONST | ECF_PURE | ECF_LOOPING_CONST_OR_PURE);
3369 tfom = void_type_node;
3371 /* ??? Unfinished: must pass the memory address as an argument. */
3373 /* Copy all the libcall-arguments out of the varargs data
3374 and into a vector ARGVEC.
3376 Compute how to pass each argument. We only support a very small subset
3377 of the full argument passing conventions to limit complexity here since
3378 library functions shouldn't have many args. */
3380 argvec = XALLOCAVEC (struct arg, nargs + 1);
3381 memset (argvec, 0, (nargs + 1) * sizeof (struct arg));
3383 #ifdef INIT_CUMULATIVE_LIBCALL_ARGS
3384 INIT_CUMULATIVE_LIBCALL_ARGS (args_so_far, outmode, fun);
3386 INIT_CUMULATIVE_ARGS (args_so_far, NULL_TREE, fun, 0, nargs);
3389 args_size.constant = 0;
3396 /* If there's a structure value address to be passed,
3397 either pass it in the special place, or pass it as an extra argument. */
3398 if (mem_value && struct_value == 0 && ! pcc_struct_value)
3400 rtx addr = XEXP (mem_value, 0);
3404 /* Make sure it is a reasonable operand for a move or push insn. */
3405 if (!REG_P (addr) && !MEM_P (addr)
3406 && ! (CONSTANT_P (addr) && LEGITIMATE_CONSTANT_P (addr)))
3407 addr = force_operand (addr, NULL_RTX);
3409 argvec[count].value = addr;
3410 argvec[count].mode = Pmode;
3411 argvec[count].partial = 0;
3413 argvec[count].reg = FUNCTION_ARG (args_so_far, Pmode, NULL_TREE, 1);
3414 gcc_assert (targetm.calls.arg_partial_bytes (&args_so_far, Pmode,
3415 NULL_TREE, 1) == 0);
3417 locate_and_pad_parm (Pmode, NULL_TREE,
3418 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3421 argvec[count].reg != 0,
3423 0, NULL_TREE, &args_size, &argvec[count].locate);
3425 if (argvec[count].reg == 0 || argvec[count].partial != 0
3426 || reg_parm_stack_space > 0)
3427 args_size.constant += argvec[count].locate.size.constant;
3429 FUNCTION_ARG_ADVANCE (args_so_far, Pmode, (tree) 0, 1);
3434 for (; count < nargs; count++)
3436 rtx val = va_arg (p, rtx);
3437 enum machine_mode mode = (enum machine_mode) va_arg (p, int);
3439 /* We cannot convert the arg value to the mode the library wants here;
3440 must do it earlier where we know the signedness of the arg. */
3441 gcc_assert (mode != BLKmode
3442 && (GET_MODE (val) == mode || GET_MODE (val) == VOIDmode));
3444 /* Make sure it is a reasonable operand for a move or push insn. */
3445 if (!REG_P (val) && !MEM_P (val)
3446 && ! (CONSTANT_P (val) && LEGITIMATE_CONSTANT_P (val)))
3447 val = force_operand (val, NULL_RTX);
3449 if (pass_by_reference (&args_so_far, mode, NULL_TREE, 1))
3453 = !reference_callee_copied (&args_so_far, mode, NULL_TREE, 1);
3455 /* If this was a CONST function, it is now PURE since it now
3457 if (flags & ECF_CONST)
3459 flags &= ~ECF_CONST;
3463 if (MEM_P (val) && !must_copy)
3467 slot = assign_temp (lang_hooks.types.type_for_mode (mode, 0),
3469 emit_move_insn (slot, val);
3472 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3473 gen_rtx_USE (VOIDmode, slot),
3476 call_fusage = gen_rtx_EXPR_LIST (VOIDmode,
3477 gen_rtx_CLOBBER (VOIDmode,
3482 val = force_operand (XEXP (slot, 0), NULL_RTX);
3485 argvec[count].value = val;
3486 argvec[count].mode = mode;
3488 argvec[count].reg = FUNCTION_ARG (args_so_far, mode, NULL_TREE, 1);
3490 argvec[count].partial
3491 = targetm.calls.arg_partial_bytes (&args_so_far, mode, NULL_TREE, 1);
3493 locate_and_pad_parm (mode, NULL_TREE,
3494 #ifdef STACK_PARMS_IN_REG_PARM_AREA
3497 argvec[count].reg != 0,
3499 argvec[count].partial,
3500 NULL_TREE, &args_size, &argvec[count].locate);
3502 gcc_assert (!argvec[count].locate.size.var);
3504 if (argvec[count].reg == 0 || argvec[count].partial != 0
3505 || reg_parm_stack_space > 0)
3506 args_size.constant += argvec[count].locate.size.constant;
3508 FUNCTION_ARG_ADVANCE (args_so_far, mode, (tree) 0, 1);
3511 /* If this machine requires an external definition for library
3512 functions, write one out. */
3513 assemble_external_libcall (fun);
3515 original_args_size = args_size;
3516 args_size.constant = (((args_size.constant
3517 + stack_pointer_delta
3521 - stack_pointer_delta);
3523 args_size.constant = MAX (args_size.constant,
3524 reg_parm_stack_space);
3526 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3527 args_size.constant -= reg_parm_stack_space;
3529 if (args_size.constant > crtl->outgoing_args_size)
3530 crtl->outgoing_args_size = args_size.constant;
3532 if (ACCUMULATE_OUTGOING_ARGS)
3534 /* Since the stack pointer will never be pushed, it is possible for
3535 the evaluation of a parm to clobber something we have already
3536 written to the stack. Since most function calls on RISC machines
3537 do not use the stack, this is uncommon, but must work correctly.
3539 Therefore, we save any area of the stack that was already written
3540 and that we are using. Here we set up to do this by making a new
3541 stack usage map from the old one.
3543 Another approach might be to try to reorder the argument
3544 evaluations to avoid this conflicting stack usage. */
3546 needed = args_size.constant;
3548 /* Since we will be writing into the entire argument area, the
3549 map must be allocated for its entire size, not just the part that
3550 is the responsibility of the caller. */
3551 if (! OUTGOING_REG_PARM_STACK_SPACE ((!fndecl ? fntype : TREE_TYPE (fndecl))))
3552 needed += reg_parm_stack_space;
3554 #ifdef ARGS_GROW_DOWNWARD
3555 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3558 highest_outgoing_arg_in_use = MAX (initial_highest_arg_in_use,
3561 stack_usage_map_buf = XNEWVEC (char, highest_outgoing_arg_in_use);
3562 stack_usage_map = stack_usage_map_buf;
3564 if (initial_highest_arg_in_use)
3565 memcpy (stack_usage_map, initial_stack_usage_map,
3566 initial_highest_arg_in_use);
3568 if (initial_highest_arg_in_use != highest_outgoing_arg_in_use)
3569 memset (&stack_usage_map[initial_highest_arg_in_use], 0,
3570 highest_outgoing_arg_in_use - initial_highest_arg_in_use);
3573 /* We must be careful to use virtual regs before they're instantiated,
3574 and real regs afterwards. Loop optimization, for example, can create
3575 new libcalls after we've instantiated the virtual regs, and if we
3576 use virtuals anyway, they won't match the rtl patterns. */
3578 if (virtuals_instantiated)
3579 argblock = plus_constant (stack_pointer_rtx, STACK_POINTER_OFFSET);
3581 argblock = virtual_outgoing_args_rtx;
3586 argblock = push_block (GEN_INT (args_size.constant), 0, 0);
3589 /* If we push args individually in reverse order, perform stack alignment
3590 before the first push (the last arg). */
3591 if (argblock == 0 && PUSH_ARGS_REVERSED)
3592 anti_adjust_stack (GEN_INT (args_size.constant
3593 - original_args_size.constant));
3595 if (PUSH_ARGS_REVERSED)
3606 #ifdef REG_PARM_STACK_SPACE
3607 if (ACCUMULATE_OUTGOING_ARGS)
3609 /* The argument list is the property of the called routine and it
3610 may clobber it. If the fixed area has been used for previous
3611 parameters, we must save and restore it. */
3612 save_area = save_fixed_argument_area (reg_parm_stack_space, argblock,
3613 &low_to_save, &high_to_save);
3617 /* Push the args that need to be pushed. */
3619 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3620 are to be pushed. */
3621 for (count = 0; count < nargs; count++, argnum += inc)
3623 enum machine_mode mode = argvec[argnum].mode;
3624 rtx val = argvec[argnum].value;
3625 rtx reg = argvec[argnum].reg;
3626 int partial = argvec[argnum].partial;
3627 unsigned int parm_align = argvec[argnum].locate.boundary;
3628 int lower_bound = 0, upper_bound = 0, i;
3630 if (! (reg != 0 && partial == 0))
3632 if (ACCUMULATE_OUTGOING_ARGS)
3634 /* If this is being stored into a pre-allocated, fixed-size,
3635 stack area, save any previous data at that location. */
3637 #ifdef ARGS_GROW_DOWNWARD
3638 /* stack_slot is negative, but we want to index stack_usage_map
3639 with positive values. */
3640 upper_bound = -argvec[argnum].locate.slot_offset.constant + 1;
3641 lower_bound = upper_bound - argvec[argnum].locate.size.constant;
3643 lower_bound = argvec[argnum].locate.slot_offset.constant;
3644 upper_bound = lower_bound + argvec[argnum].locate.size.constant;
3648 /* Don't worry about things in the fixed argument area;
3649 it has already been saved. */
3650 if (i < reg_parm_stack_space)
3651 i = reg_parm_stack_space;
3652 while (i < upper_bound && stack_usage_map[i] == 0)
3655 if (i < upper_bound)
3657 /* We need to make a save area. */
3659 = argvec[argnum].locate.size.constant * BITS_PER_UNIT;
3660 enum machine_mode save_mode
3661 = mode_for_size (size, MODE_INT, 1);
3663 = plus_constant (argblock,
3664 argvec[argnum].locate.offset.constant);
3666 = gen_rtx_MEM (save_mode, memory_address (save_mode, adr));
3668 if (save_mode == BLKmode)
3670 argvec[argnum].save_area
3671 = assign_stack_temp (BLKmode,
3672 argvec[argnum].locate.size.constant,
3675 emit_block_move (validize_mem (argvec[argnum].save_area),
3677 GEN_INT (argvec[argnum].locate.size.constant),
3678 BLOCK_OP_CALL_PARM);
3682 argvec[argnum].save_area = gen_reg_rtx (save_mode);
3684 emit_move_insn (argvec[argnum].save_area, stack_area);
3689 emit_push_insn (val, mode, NULL_TREE, NULL_RTX, parm_align,
3690 partial, reg, 0, argblock,
3691 GEN_INT (argvec[argnum].locate.offset.constant),
3692 reg_parm_stack_space,
3693 ARGS_SIZE_RTX (argvec[argnum].locate.alignment_pad));
3695 /* Now mark the segment we just used. */
3696 if (ACCUMULATE_OUTGOING_ARGS)
3697 for (i = lower_bound; i < upper_bound; i++)
3698 stack_usage_map[i] = 1;
3702 if ((flags & ECF_CONST)
3703 || ((flags & ECF_PURE) && ACCUMULATE_OUTGOING_ARGS))
3707 /* Indicate argument access so that alias.c knows that these
3710 use = plus_constant (argblock,
3711 argvec[argnum].locate.offset.constant);
3713 /* When arguments are pushed, trying to tell alias.c where
3714 exactly this argument is won't work, because the
3715 auto-increment causes confusion. So we merely indicate
3716 that we access something with a known mode somewhere on
3718 use = gen_rtx_PLUS (Pmode, virtual_outgoing_args_rtx,
3719 gen_rtx_SCRATCH (Pmode));
3720 use = gen_rtx_MEM (argvec[argnum].mode, use);
3721 use = gen_rtx_USE (VOIDmode, use);
3722 call_fusage = gen_rtx_EXPR_LIST (VOIDmode, use, call_fusage);
3727 /* If we pushed args in forward order, perform stack alignment
3728 after pushing the last arg. */
3729 if (argblock == 0 && !PUSH_ARGS_REVERSED)
3730 anti_adjust_stack (GEN_INT (args_size.constant
3731 - original_args_size.constant));
3733 if (PUSH_ARGS_REVERSED)
3738 fun = prepare_call_address (fun, NULL, &call_fusage, 0, 0);
3740 /* Now load any reg parms into their regs. */
3742 /* ARGNUM indexes the ARGVEC array in the order in which the arguments
3743 are to be pushed. */
3744 for (count = 0; count < nargs; count++, argnum += inc)
3746 enum machine_mode mode = argvec[argnum].mode;
3747 rtx val = argvec[argnum].value;
3748 rtx reg = argvec[argnum].reg;
3749 int partial = argvec[argnum].partial;
3751 /* Handle calls that pass values in multiple non-contiguous
3752 locations. The PA64 has examples of this for library calls. */
3753 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3754 emit_group_load (reg, val, NULL_TREE, GET_MODE_SIZE (mode));
3755 else if (reg != 0 && partial == 0)
3756 emit_move_insn (reg, val);
3761 /* Any regs containing parms remain in use through the call. */
3762 for (count = 0; count < nargs; count++)
3764 rtx reg = argvec[count].reg;
3765 if (reg != 0 && GET_CODE (reg) == PARALLEL)
3766 use_group_regs (&call_fusage, reg);
3769 int partial = argvec[count].partial;
3773 gcc_assert (partial % UNITS_PER_WORD == 0);
3774 nregs = partial / UNITS_PER_WORD;
3775 use_regs (&call_fusage, REGNO (reg), nregs);
3778 use_reg (&call_fusage, reg);
3782 /* Pass the function the address in which to return a structure value. */
3783 if (mem_value != 0 && struct_value != 0 && ! pcc_struct_value)
3785 emit_move_insn (struct_value,
3787 force_operand (XEXP (mem_value, 0),
3789 if (REG_P (struct_value))
3790 use_reg (&call_fusage, struct_value);
3793 /* Don't allow popping to be deferred, since then
3794 cse'ing of library calls could delete a call and leave the pop. */
3796 valreg = (mem_value == 0 && outmode != VOIDmode
3797 ? hard_libcall_value (outmode, orgfun) : NULL_RTX);
3799 /* Stack must be properly aligned now. */
3800 gcc_assert (!(stack_pointer_delta
3801 & (PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT - 1)));
3803 before_call = get_last_insn ();
3805 /* We pass the old value of inhibit_defer_pop + 1 to emit_call_1, which
3806 will set inhibit_defer_pop to that value. */
3807 /* The return type is needed to decide how many bytes the function pops.
3808 Signedness plays no role in that, so for simplicity, we pretend it's
3809 always signed. We also assume that the list of arguments passed has
3810 no impact, so we pretend it is unknown. */
3812 emit_call_1 (fun, NULL,
3813 get_identifier (XSTR (orgfun, 0)),
3814 build_function_type (tfom, NULL_TREE),
3815 original_args_size.constant, args_size.constant,
3817 FUNCTION_ARG (args_so_far, VOIDmode, void_type_node, 1),
3819 old_inhibit_defer_pop + 1, call_fusage, flags, & args_so_far);
3821 /* For calls to `setjmp', etc., inform function.c:setjmp_warnings
3822 that it should complain if nonvolatile values are live. For
3823 functions that cannot return, inform flow that control does not
3826 if (flags & ECF_NORETURN)
3828 /* The barrier note must be emitted
3829 immediately after the CALL_INSN. Some ports emit more than
3830 just a CALL_INSN above, so we must search for it here. */
3832 rtx last = get_last_insn ();
3833 while (!CALL_P (last))
3835 last = PREV_INSN (last);
3836 /* There was no CALL_INSN? */
3837 gcc_assert (last != before_call);
3840 emit_barrier_after (last);
3843 /* Now restore inhibit_defer_pop to its actual original value. */
3848 /* Copy the value to the right place. */
3849 if (outmode != VOIDmode && retval)
3855 if (value != mem_value)
3856 emit_move_insn (value, mem_value);
3858 else if (GET_CODE (valreg) == PARALLEL)
3861 value = gen_reg_rtx (outmode);
3862 emit_group_store (value, valreg, NULL_TREE, GET_MODE_SIZE (outmode));
3866 /* Convert to the proper mode if a promotion has been active. */
3867 if (GET_MODE (valreg) != outmode)
3869 int unsignedp = TYPE_UNSIGNED (tfom);
3871 gcc_assert (promote_function_mode (tfom, outmode, &unsignedp,
3872 fndecl ? TREE_TYPE (fndecl) : fntype, 1)
3873 == GET_MODE (valreg));
3874 valreg = convert_modes (outmode, GET_MODE (valreg), valreg, 0);
3878 emit_move_insn (value, valreg);
3884 if (ACCUMULATE_OUTGOING_ARGS)
3886 #ifdef REG_PARM_STACK_SPACE
3888 restore_fixed_argument_area (save_area, argblock,
3889 high_to_save, low_to_save);
3892 /* If we saved any argument areas, restore them. */
3893 for (count = 0; count < nargs; count++)
3894 if (argvec[count].save_area)
3896 enum machine_mode save_mode = GET_MODE (argvec[count].save_area);
3897 rtx adr = plus_constant (argblock,
3898 argvec[count].locate.offset.constant);
3899 rtx stack_area = gen_rtx_MEM (save_mode,
3900 memory_address (save_mode, adr));
3902 if (save_mode == BLKmode)
3903 emit_block_move (stack_area,
3904 validize_mem (argvec[count].save_area),
3905 GEN_INT (argvec[count].locate.size.constant),
3906 BLOCK_OP_CALL_PARM);
3908 emit_move_insn (stack_area, argvec[count].save_area);
3911 highest_outgoing_arg_in_use = initial_highest_arg_in_use;
3912 stack_usage_map = initial_stack_usage_map;
3915 if (stack_usage_map_buf)
3916 free (stack_usage_map_buf);
3922 /* Output a library call to function FUN (a SYMBOL_REF rtx)
3923 (emitting the queue unless NO_QUEUE is nonzero),
3924 for a value of mode OUTMODE,
3925 with NARGS different arguments, passed as alternating rtx values
3926 and machine_modes to convert them to.
3928 FN_TYPE should be LCT_NORMAL for `normal' calls, LCT_CONST for
3929 `const' calls, LCT_PURE for `pure' calls, or other LCT_ value for
3930 other types of library calls. */
3933 emit_library_call (rtx orgfun, enum libcall_type fn_type,
3934 enum machine_mode outmode, int nargs, ...)
3938 va_start (p, nargs);
3939 emit_library_call_value_1 (0, orgfun, NULL_RTX, fn_type, outmode, nargs, p);
3943 /* Like emit_library_call except that an extra argument, VALUE,
3944 comes second and says where to store the result.
3945 (If VALUE is zero, this function chooses a convenient way
3946 to return the value.
3948 This function returns an rtx for where the value is to be found.
3949 If VALUE is nonzero, VALUE is returned. */
3952 emit_library_call_value (rtx orgfun, rtx value,
3953 enum libcall_type fn_type,
3954 enum machine_mode outmode, int nargs, ...)
3959 va_start (p, nargs);
3960 result = emit_library_call_value_1 (1, orgfun, value, fn_type, outmode,
3967 /* Store a single argument for a function call
3968 into the register or memory area where it must be passed.
3969 *ARG describes the argument value and where to pass it.
3971 ARGBLOCK is the address of the stack-block for all the arguments,
3972 or 0 on a machine where arguments are pushed individually.
3974 MAY_BE_ALLOCA nonzero says this could be a call to `alloca'
3975 so must be careful about how the stack is used.
3977 VARIABLE_SIZE nonzero says that this was a variable-sized outgoing
3978 argument stack. This is used if ACCUMULATE_OUTGOING_ARGS to indicate
3979 that we need not worry about saving and restoring the stack.
3981 FNDECL is the declaration of the function we are calling.
3983 Return nonzero if this arg should cause sibcall failure,
3987 store_one_arg (struct arg_data *arg, rtx argblock, int flags,
3988 int variable_size ATTRIBUTE_UNUSED, int reg_parm_stack_space)
3990 tree pval = arg->tree_value;
3994 int i, lower_bound = 0, upper_bound = 0;
3995 int sibcall_failure = 0;
3997 if (TREE_CODE (pval) == ERROR_MARK)
4000 /* Push a new temporary level for any temporaries we make for
4004 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL))
4006 /* If this is being stored into a pre-allocated, fixed-size, stack area,
4007 save any previous data at that location. */
4008 if (argblock && ! variable_size && arg->stack)
4010 #ifdef ARGS_GROW_DOWNWARD
4011 /* stack_slot is negative, but we want to index stack_usage_map
4012 with positive values. */
4013 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4014 upper_bound = -INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1)) + 1;
4018 lower_bound = upper_bound - arg->locate.size.constant;
4020 if (GET_CODE (XEXP (arg->stack_slot, 0)) == PLUS)
4021 lower_bound = INTVAL (XEXP (XEXP (arg->stack_slot, 0), 1));
4025 upper_bound = lower_bound + arg->locate.size.constant;
4029 /* Don't worry about things in the fixed argument area;
4030 it has already been saved. */
4031 if (i < reg_parm_stack_space)
4032 i = reg_parm_stack_space;
4033 while (i < upper_bound && stack_usage_map[i] == 0)
4036 if (i < upper_bound)
4038 /* We need to make a save area. */
4039 unsigned int size = arg->locate.size.constant * BITS_PER_UNIT;
4040 enum machine_mode save_mode = mode_for_size (size, MODE_INT, 1);
4041 rtx adr = memory_address (save_mode, XEXP (arg->stack_slot, 0));
4042 rtx stack_area = gen_rtx_MEM (save_mode, adr);
4044 if (save_mode == BLKmode)
4046 tree ot = TREE_TYPE (arg->tree_value);
4047 tree nt = build_qualified_type (ot, (TYPE_QUALS (ot)
4048 | TYPE_QUAL_CONST));
4050 arg->save_area = assign_temp (nt, 0, 1, 1);
4051 preserve_temp_slots (arg->save_area);
4052 emit_block_move (validize_mem (arg->save_area), stack_area,
4053 GEN_INT (arg->locate.size.constant),
4054 BLOCK_OP_CALL_PARM);
4058 arg->save_area = gen_reg_rtx (save_mode);
4059 emit_move_insn (arg->save_area, stack_area);
4065 /* If this isn't going to be placed on both the stack and in registers,
4066 set up the register and number of words. */
4067 if (! arg->pass_on_stack)
4069 if (flags & ECF_SIBCALL)
4070 reg = arg->tail_call_reg;
4073 partial = arg->partial;
4076 /* Being passed entirely in a register. We shouldn't be called in
4078 gcc_assert (reg == 0 || partial != 0);
4080 /* If this arg needs special alignment, don't load the registers
4082 if (arg->n_aligned_regs != 0)
4085 /* If this is being passed partially in a register, we can't evaluate
4086 it directly into its stack slot. Otherwise, we can. */
4087 if (arg->value == 0)
4089 /* stack_arg_under_construction is nonzero if a function argument is
4090 being evaluated directly into the outgoing argument list and
4091 expand_call must take special action to preserve the argument list
4092 if it is called recursively.
4094 For scalar function arguments stack_usage_map is sufficient to
4095 determine which stack slots must be saved and restored. Scalar
4096 arguments in general have pass_on_stack == 0.
4098 If this argument is initialized by a function which takes the
4099 address of the argument (a C++ constructor or a C function
4100 returning a BLKmode structure), then stack_usage_map is
4101 insufficient and expand_call must push the stack around the
4102 function call. Such arguments have pass_on_stack == 1.
4104 Note that it is always safe to set stack_arg_under_construction,
4105 but this generates suboptimal code if set when not needed. */
4107 if (arg->pass_on_stack)
4108 stack_arg_under_construction++;
4110 arg->value = expand_expr (pval,
4112 || TYPE_MODE (TREE_TYPE (pval)) != arg->mode)
4113 ? NULL_RTX : arg->stack,
4114 VOIDmode, EXPAND_STACK_PARM);
4116 /* If we are promoting object (or for any other reason) the mode
4117 doesn't agree, convert the mode. */
4119 if (arg->mode != TYPE_MODE (TREE_TYPE (pval)))
4120 arg->value = convert_modes (arg->mode, TYPE_MODE (TREE_TYPE (pval)),
4121 arg->value, arg->unsignedp);
4123 if (arg->pass_on_stack)
4124 stack_arg_under_construction--;
4127 /* Check for overlap with already clobbered argument area. */
4128 if ((flags & ECF_SIBCALL)
4129 && MEM_P (arg->value)
4130 && mem_overlaps_already_clobbered_arg_p (XEXP (arg->value, 0),
4131 arg->locate.size.constant))
4132 sibcall_failure = 1;
4134 /* Don't allow anything left on stack from computation
4135 of argument to alloca. */
4136 if (flags & ECF_MAY_BE_ALLOCA)
4137 do_pending_stack_adjust ();
4139 if (arg->value == arg->stack)
4140 /* If the value is already in the stack slot, we are done. */
4142 else if (arg->mode != BLKmode)
4145 unsigned int parm_align;
4147 /* Argument is a scalar, not entirely passed in registers.
4148 (If part is passed in registers, arg->partial says how much
4149 and emit_push_insn will take care of putting it there.)
4151 Push it, and if its size is less than the
4152 amount of space allocated to it,
4153 also bump stack pointer by the additional space.
4154 Note that in C the default argument promotions
4155 will prevent such mismatches. */
4157 size = GET_MODE_SIZE (arg->mode);
4158 /* Compute how much space the push instruction will push.
4159 On many machines, pushing a byte will advance the stack
4160 pointer by a halfword. */
4161 #ifdef PUSH_ROUNDING
4162 size = PUSH_ROUNDING (size);
4166 /* Compute how much space the argument should get:
4167 round up to a multiple of the alignment for arguments. */
4168 if (none != FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)))
4169 used = (((size + PARM_BOUNDARY / BITS_PER_UNIT - 1)
4170 / (PARM_BOUNDARY / BITS_PER_UNIT))
4171 * (PARM_BOUNDARY / BITS_PER_UNIT));
4173 /* Compute the alignment of the pushed argument. */
4174 parm_align = arg->locate.boundary;
4175 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4177 int pad = used - size;
4180 unsigned int pad_align = (pad & -pad) * BITS_PER_UNIT;
4181 parm_align = MIN (parm_align, pad_align);
4185 /* This isn't already where we want it on the stack, so put it there.
4186 This can either be done with push or copy insns. */
4187 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), NULL_RTX,
4188 parm_align, partial, reg, used - size, argblock,
4189 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4190 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4192 /* Unless this is a partially-in-register argument, the argument is now
4195 arg->value = arg->stack;
4199 /* BLKmode, at least partly to be pushed. */
4201 unsigned int parm_align;
4205 /* Pushing a nonscalar.
4206 If part is passed in registers, PARTIAL says how much
4207 and emit_push_insn will take care of putting it there. */
4209 /* Round its size up to a multiple
4210 of the allocation unit for arguments. */
4212 if (arg->locate.size.var != 0)
4215 size_rtx = ARGS_SIZE_RTX (arg->locate.size);
4219 /* PUSH_ROUNDING has no effect on us, because emit_push_insn
4220 for BLKmode is careful to avoid it. */
4221 excess = (arg->locate.size.constant
4222 - int_size_in_bytes (TREE_TYPE (pval))
4224 size_rtx = expand_expr (size_in_bytes (TREE_TYPE (pval)),
4225 NULL_RTX, TYPE_MODE (sizetype),
4229 parm_align = arg->locate.boundary;
4231 /* When an argument is padded down, the block is aligned to
4232 PARM_BOUNDARY, but the actual argument isn't. */
4233 if (FUNCTION_ARG_PADDING (arg->mode, TREE_TYPE (pval)) == downward)
4235 if (arg->locate.size.var)
4236 parm_align = BITS_PER_UNIT;
4239 unsigned int excess_align = (excess & -excess) * BITS_PER_UNIT;
4240 parm_align = MIN (parm_align, excess_align);
4244 if ((flags & ECF_SIBCALL) && MEM_P (arg->value))
4246 /* emit_push_insn might not work properly if arg->value and
4247 argblock + arg->locate.offset areas overlap. */
4251 if (XEXP (x, 0) == crtl->args.internal_arg_pointer
4252 || (GET_CODE (XEXP (x, 0)) == PLUS
4253 && XEXP (XEXP (x, 0), 0) ==
4254 crtl->args.internal_arg_pointer
4255 && CONST_INT_P (XEXP (XEXP (x, 0), 1))))
4257 if (XEXP (x, 0) != crtl->args.internal_arg_pointer)
4258 i = INTVAL (XEXP (XEXP (x, 0), 1));
4260 /* expand_call should ensure this. */
4261 gcc_assert (!arg->locate.offset.var
4262 && arg->locate.size.var == 0
4263 && CONST_INT_P (size_rtx));
4265 if (arg->locate.offset.constant > i)
4267 if (arg->locate.offset.constant < i + INTVAL (size_rtx))
4268 sibcall_failure = 1;
4270 else if (arg->locate.offset.constant < i)
4272 /* Use arg->locate.size.constant instead of size_rtx
4273 because we only care about the part of the argument
4275 if (i < (arg->locate.offset.constant
4276 + arg->locate.size.constant))
4277 sibcall_failure = 1;
4281 /* Even though they appear to be at the same location,
4282 if part of the outgoing argument is in registers,
4283 they aren't really at the same location. Check for
4284 this by making sure that the incoming size is the
4285 same as the outgoing size. */
4286 if (arg->locate.size.constant != INTVAL (size_rtx))
4287 sibcall_failure = 1;
4292 emit_push_insn (arg->value, arg->mode, TREE_TYPE (pval), size_rtx,
4293 parm_align, partial, reg, excess, argblock,
4294 ARGS_SIZE_RTX (arg->locate.offset), reg_parm_stack_space,
4295 ARGS_SIZE_RTX (arg->locate.alignment_pad));
4297 /* Unless this is a partially-in-register argument, the argument is now
4300 ??? Unlike the case above, in which we want the actual
4301 address of the data, so that we can load it directly into a
4302 register, here we want the address of the stack slot, so that
4303 it's properly aligned for word-by-word copying or something
4304 like that. It's not clear that this is always correct. */
4306 arg->value = arg->stack_slot;
4309 if (arg->reg && GET_CODE (arg->reg) == PARALLEL)
4311 tree type = TREE_TYPE (arg->tree_value);
4313 = emit_group_load_into_temps (arg->reg, arg->value, type,
4314 int_size_in_bytes (type));
4317 /* Mark all slots this store used. */
4318 if (ACCUMULATE_OUTGOING_ARGS && !(flags & ECF_SIBCALL)
4319 && argblock && ! variable_size && arg->stack)
4320 for (i = lower_bound; i < upper_bound; i++)
4321 stack_usage_map[i] = 1;
4323 /* Once we have pushed something, pops can't safely
4324 be deferred during the rest of the arguments. */
4327 /* Free any temporary slots made in processing this argument. Show
4328 that we might have taken the address of something and pushed that
4330 preserve_temp_slots (NULL_RTX);
4334 return sibcall_failure;
4337 /* Nonzero if we do not know how to pass TYPE solely in registers. */
4340 must_pass_in_stack_var_size (enum machine_mode mode ATTRIBUTE_UNUSED,
4346 /* If the type has variable size... */
4347 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4350 /* If the type is marked as addressable (it is required
4351 to be constructed into the stack)... */
4352 if (TREE_ADDRESSABLE (type))
4358 /* Another version of the TARGET_MUST_PASS_IN_STACK hook. This one
4359 takes trailing padding of a structure into account. */
4360 /* ??? Should be able to merge these two by examining BLOCK_REG_PADDING. */
4363 must_pass_in_stack_var_size_or_pad (enum machine_mode mode, const_tree type)
4368 /* If the type has variable size... */
4369 if (TREE_CODE (TYPE_SIZE (type)) != INTEGER_CST)
4372 /* If the type is marked as addressable (it is required
4373 to be constructed into the stack)... */
4374 if (TREE_ADDRESSABLE (type))
4377 /* If the padding and mode of the type is such that a copy into
4378 a register would put it into the wrong part of the register. */
4380 && int_size_in_bytes (type) % (PARM_BOUNDARY / BITS_PER_UNIT)
4381 && (FUNCTION_ARG_PADDING (mode, type)
4382 == (BYTES_BIG_ENDIAN ? upward : downward)))